Today, there is a wide variety of coolants on the market for automotive products. Ethylene glycol based antifreeze is a widely used type of coolant. They are presented in a wide range of colors and meet the requirements indicated in the technical specifications for various car brands. In the article, we will consider what ethylene glycol is, its advantages and disadvantages.
Ethylene glycol: composition and properties
ethylene glycol- This is a liquid that has no color, but is very toxic. It has a good ability to mix with various other components. For example, in combination with water, ethylene glycol in antifreeze protects metal parts very well from corrosion, external forces, and prevents water from freezing.
This substance is used in the composition of coolants. By itself, glycol freezes already at a temperature of -12 ° C, but if you mix it with water in a certain proportion, then the freezing point rises to -50 o C.
But, do not forget that ethylene glycol-based coolant should be used with caution, avoid contact with exposed skin, and keep away from children, because it is too poisonous.
And yet, try to keep the ratio of water and glycol in solutions under control, since water tends to evaporate faster and an insufficient amount of it in the mixture can lead to spontaneous combustion of the chemical.
Antifreeze
Antifreezes are designed for the correct operation of the engine cooling system. There are several types of antifreeze, which differ in composition and properties, respectively. Antifreeze is an alcohol-based antifreeze, therefore it has low protective properties, primarily against corrosion. When using this type, it forms a film on the internal parts of the car, which does not have a very favorable effect on the operation of the mechanisms. Also, after a short time, a precipitate appears, which clogs small passages in the tubes and thereby provokes a malfunction of the entire system.
Ethylene glycol-based antifreeze contains additives called additives that improve the quality of the coolant. But, it is worth maintaining the proportions of the ratio of additives and ethylene glycol, since the lack of the former will lead to the onset of an aggressive effect of glycol on metal engine parts.
For aluminum radiators, ethylene glycol antifreeze is best not to use., since ethylene glycol is an aggressive substance, and aluminum is a very thin metal, and the effect of such a cooler adversely affects the latter. The cooler class G13 is best suited, which includes propylene glycol - a less aggressive and environmentally friendly substance.
Benefits of Ethylene Glycol Antifreeze
The main and, perhaps, the most important characteristic of antifreeze is that it has a low freezing point threshold and at the same time a high boiling point.
When adding ethylene glycol to the composition of the coolant, the period of operation of the car engine is significantly increased.
There are several main advantages when using this type of cooler:
harmful additives and additives are completely excluded from the composition, which is important for the preservation of the environment;
it is possible to independently select the concentration of the coolant in order to ensure better operation of all engine systems;
does not change its properties after a long time of use;
can be used with engine parts made of aluminum and plastic;
no large amount of foam is formed when the liquid is overheated.
these antifreezes have anti-corrosion properties, which is important, since most of the parts inside the motor are made of metal.
What can be mixed
Do not think that all coolants contain ethylene glycol, and before mixing one type with another, carefully study the instructions.
The composition of coolants may also include propylene glycol - the substance is not so toxic and toxic, environmentally friendly and safe. When these two substances are mixed, nothing critically terrible will happen, no precipitate is formed. But, due to the fact that the latter, under the influence of a more aggressive substance, will lose most of its useful qualities, the use of propylene glycol will become pointless.
Due to the fact that the composition of coolants includes various additives and additives that may not be compatible with each other, mixing two different classes of coolants can lead to disastrous consequences. But when mixing propylene glycol and ethylene glycol in its pure form, nothing supernatural and terrible will happen.
Antifreeze based on ethylene glycol is an inexpensive and practical solution for your car.
The Tekhnologiya Teplo company offers for sale high-quality coolants for cars. You can buy from us at a reasonable price ethylene glycol antifreeze yellow color.
Modern manufacturers offer two main types of process fluids for car cooling systems - based on salts and acids. To make their differences clearer when buying, it is customary to paint antifreezes based on monoethylene glycol in green, in which salt additives are used, and in red with acid additives. When choosing a specific type and brand of products, you should first of all be guided by the recommendations of car manufacturers, as well as those materials that are used in the engine cooling system.
Most modern manufacturers, both in Russia and abroad, offer ethylene glycol antifreeze. Since they have certain advantages that make it possible to make high-quality cooling compositions on this basis.
An example of such products is the ethylene glycol antifreeze Glizanthin, which contains inhibitors based on silicates and salts of organic acids. This product does not contain phosphates, nitrites and amines, it is most often used in large cars - buses and trucks, in the design of which there are both iron and aluminum parts that come into direct contact with the refrigerant.
Features of ethylene glycol antifreeze.
Modern coolants for cars are most often aqueous solutions of polyhydric alcohols - propylene glycol and ethylene glycol antifreezes, which do not freeze at sufficiently low temperatures. Pure ethylene glycol is a viscous, oily, colorless liquid with a characteristic low odor. Its boiling point is +197, and its freezing point is -13 degrees Celsius, the density at a temperature of +20 degrees is 1114 kg/m3. In order to provide process fluids with a lower freezing point, ethylene glycol antifreeze concentrate is diluted with water and 30%-70% solutions are obtained, which are used in car cooling systems after adding the necessary inhibitors to them.
With a ratio of water and refrigerant of 1:1, the freezing point is -70 degrees Celsius. For the manufacture of coolants, not only ethylene glycol is used, but also propylene glycol, antifreezes based on which also have fairly good performance characteristics, while being characterized by lower toxicity. But such compositions have a higher level of viscosity and a higher freezing point even after diluting with water to the required proportions.
Why this particular type of antifreeze?
When choosing a coolant, both propylene glycol and monoethylene glycol antifreeze can be the right solution, because the main differences still relate to the additives used. Therefore, often the specialists of the Heat Technology company recommend the composition of G11 G12 antifreeze on ethylene glycol.
It is the additives that determine the anti-corrosion properties. Inhibitors also affect the boiling and freezing temperatures. But as for the lubricating qualities, they do not depend on additives and are provided by the composition of the main refrigerant used. Such a property as the foaming of the coolant in Russia is regulated by GOST 28084-89. A standard of 30 cm3 is considered normal for Russian manufacturers, and 150 cm3 for foreign manufacturers in accordance with ASTM D3306/4340/4656 and ASTM D4985/5345.
If you are interested in such issues as the purchase of high-quality coolant, the correct period of its operation, the procedure for topping up and changing, temperatures and other characteristics, then contact the specialists of the Heat Technology company. Detailed explanations and recommendations will help you navigate the variety of products offered and choose the right process fluid that is best suited for your car.
Today, the market for antifreeze for car radiators is filled with products based on ethylene glycol. This substance has a number of positive qualities in operation. The durability of the cooling system, as well as the operation of the engine, depend on the correct choice of means for the cooling system.
Ethylene glycol based antifreeze has a low freezing point, which depends on the concentration of the substance. The liquid inside the cooling system begins to crystallize in the range from 0 to -70ºС. When choosing high-quality antifreeze, it is necessary to take into account the operating conditions of the machine. In the summer, it should cool the engine as efficiently as possible. In winter, the liquid should not freeze even in severe frosts.
Types of antifreeze
Today there are two main types of antifreeze - carbosilicate and silicate substances. The second type is used in old-style cars. The most famous representative of this class of funds is antifreeze. Silicate antifreezes have a number of disadvantages, so they are not used for foreign cars.
Silica-free antifreeze based on ethylene glycol is preferable for foreign new cars. The additives that make up the product, during the operation of the car, settle exclusively in areas where corrosion forms. This was made possible by the inclusion of organic components in the composition of the product. In this case, the engine cooling is complete.
Silicate varieties based on ethylene glycol cover the entire inner surface of the tubes with inorganic components. They effectively prevent the formation of corrosion, but at the same time reduce the cooling capacity of the system.
Composition of antifreeze
Ethylene glycol-based antifreezes have a specific composition. Their main characteristics depend on this. In its pure form, ethylene glycol looks like an oily substance. Its freezing point is -13ºС, and its boiling point is +197ºС. This material is quite dense. Ethylene glycol is a strong food poison. This substance is toxic, especially after the exhaustion of its resource. Ethylene glycol-based antifreeze waste, the composition of which has been contaminated with heavy metals during operation, must be properly disposed of.
When mixed, it can significantly decrease (up to -70ºС at a ratio of water and ethylene glycol 1:2). Organic and inorganic components can be used as additives. The first option is preferable. today there are 4 types: carboxylate, traditional, organic and hybrid. Due to the difference in the components that make up the antifreeze, different brands of these products cannot be mixed. Otherwise, they will conflict with each other, reducing the effectiveness of the substance.
Antifreeze color
Initially, ethylene glycol-based antifreeze, the color of which can be seen in production, looks like a transparent substance. It has only a specific smell. Regardless of the brand, antifreeze has no color. Dyes are added to identify its quality. Among drivers and auto mechanics, there is a classification of the quality of the product adopted by them, depending on its color. There are 3 groups of antifreezes.
- Class G11 includes blue and green facilities. These are the cheapest consumables. They include ethylene glycol and silicate additives. The service life of such antifreezes is about 30 thousand km.
- The class G12 includes red and pink types of substances. They are of higher quality. They include ethylene glycol and organic additives. The service life of such funds can reach 150-200 thousand km. However, their cost is much higher.
- There is also a third class - G13. In addition to the components listed in the previous section, it contains propylene glycol. The color of such funds is most often characterized by orange and yellow hues.
Labeling system
Each ethylene glycol-based antifreeze for aluminum radiators, as well as loaded cooling systems, contains dyes. They do not affect the technical characteristics of the substance in any way. The choice of one or another color depends on the whim of the manufacturer. There is no generally accepted labeling standard, as well as the addition of dyes.
The markings presented above, which are most often taken into account by drivers and auto mechanics, were used earlier in the production of German-made VW coolant antifreezes. These funds are very popular. However, even he himself has already changed his specifications. Today, this well-known manufacturer makes 3 main classes of organic-based antifreeze. Their marking has the prefix G12++, G12+++ and G13. Therefore, before buying a product for a cooling system, it is more correct to pay attention to the recommendations of the vehicle manufacturer, as well as the composition of the consumable itself. There is no single marking for all antifreezes.
The main properties of antifreeze
In the course of their operation, antifreezes exhibit a whole range of qualities. They are regulated by the norms and approvals of car manufacturers. It should be noted that ethylene glycol is a toxic substance. With the development of its resource, this indicator increases. There are rules on how to dispose of waste antifreeze based on ethylene glycol. They are credited with various negative properties. Therefore, if necessary, contact a special organization that will properly dispose of it.
It is also important to take into account the foaming properties of antifreeze. For domestically produced products, this figure is 30 cm³, and for imported products - 150 cm³. The wettability of antifreeze is 2 times greater than that of water. Therefore, they are able to seep even into very thin cracks. This explains their ability to flow out even in the presence of microcracks.
Overview of popular brands
In our country, various brands of antifreeze based on ethylene glycol are used. The most popular include Felix, Alaska, Sintek, Long Life, Nord. They are characterized by an optimal ratio of price and quality.
The presented antifreezes are designed for the harsh conditions of our climate. Also, the developed line of products allows the driver to choose the required product for the engine of his car. The presented means effectively resist the formation of corrosion, and also provide good cooling properties of the radiator.
Products popular today in our country effectively protect engine systems from the formation of deposits, especially in the water pump, engine compartment and supply channels.
Water is most often used as a heat carrier in heating, but sometimes antifreeze is also used. Why is it necessary to use it and how to choose antifreeze for heating systems, we will consider below.
For a long time only water was considered a universal heat carrier for heating systems. This was facilitated by its physico-chemical properties, including the specific heat capacity equal to 4.169 kJ / kg.
There are several factors that limit the use of water as a universal heat transfer medium:
- The transition temperature of a substance from a liquid to a solid state, which is quite high for water (0 ° C);
- During freezing, the volume of water increases by an average of 10%, which leads to damage to networks in which water is located during freezing.
Therefore, to solve certain problems, it is necessary to use coolants with more flexible properties. Optimal and efficient operation can be ensured by using antifreeze instead of water as a heat transfer medium for
Here we are not talking about such liquids as automobile antifreeze, ethyl alcohol or transformer oil. Antifreeze is best suited for heating networks.
In this case, the main requirement for the coolant is safety in terms of flammability or combustibility. There are also certain limitations in terms of residential regulations or reactivity when reacting with metals.
Types of antifreeze for heating
Antifreeze for heating is based on aqueous solutions of ethylene glycol and propylene glycol. These compounds in their pure form are quite aggressive media for heating systems. However, there are special additives to protect against corrosion, the appearance of foam, scale, damage to individual elements of the network and fittings.
These additives significantly increase the thermal stability, which is provided in the temperature range from -70 to + 110 °C. There is a lack of thermal degradation even at a temperature of + 165 - + 175 °C.
Antifreeze in the heating system reacts normally to materials that are used in heating networks:
- rubber;
- elastomers;
- plastic.
Ethylene glycol antifreeze
Domestic antifreezes for heating systems, which are widely represented on the market, are based on ethylene glycol.
They are manufactured in the following versions:
- freezing point in - 30 ° С;
- freezing point at - 65 ° С.
Filling the heating system with antifreeze begins with the preparation of the solution. To do this, it must be diluted with water with your own hands. The price of ethylene glycol is low, so antifreeze based on it is usually not very expensive.
A significant disadvantage of ethylene glycol is its high toxicity both when it comes into contact with the body and when inhaled fumes. The lethal dose of this substance for humans is 250 ml.
This drawback limits the use of ethylene glycol based antifreezes in double-circuit heating networks, in which the coolant can enter the hot water circuit. Therefore, the use of such antifreezes is limited only to single-circuit heating systems.
Important! For safety reasons, ethylene glycol antifreeze is dyed red. This makes it easier to spot a leak.
propylene glycol antifreeze
At the end of the last century, non-toxic antifreezes, which were made on the basis of propylene glycol, entered the markets of Western countries. The advantage of these antifreezes is complete harmlessness. This quality is the most important for double-circuit heat supply systems. These antifreezes also appeared on our market. The instruction allows them to be used at temperatures up to -35 °C.
Important! To identify propylene glycol antifreeze, it is dyed green.
Propylene glycol is an E1520 approved food additive that is often found in confectionery as an agent that aids in softening, moisture retention and dispersion.
Triethylene glycol antifreeze
At high operating temperatures (up to 180 °C), antifreezes based on triethylene glycol are used. This substance has high temperature stability. However, such coolants are not products for wide use. Typically, triethylene glycol antifreezes are used in special heating systems in which antifreeze heating radiators are also designed for high temperatures.
The composition and properties of antifreeze
Before pumping antifreeze into the heating system, it is necessary to familiarize yourself with the information on the thermal properties of ethylene glycol antifreeze solutions.
The main components of such solutions are ethylene glycol and water (about 95%). The remaining elements of these liquids are various additives.
The ratio of ethylene glycol and water to each other is determined by the physicochemical characteristics of antifreeze:
- freezing point;
- boiling point;
- viscosity;
- thermal conductivity;
- heat capacity;
- volume expansion.
The individual characteristics of each specific type of antifreeze are determined by the additive package.
It is these components that depend on such characteristics as:
- anti-corrosion;
- anti-cavitation;
- Term of the work;
- price.
The main task of additives when using antifreezes is to protect metals from corrosion. Studies have shown that additives significantly reduce the corrosion of internal walls (up to 100 times).
The layer of rust on the inner walls of pipelines and heating devices has poor thermal conductivity (50 times less than steel), thus becoming a heat insulator. TO
In addition, due to corrosion, the internal lumen of pipelines narrows. Because of this, the hydrodynamic resistance increases, and the speed of the coolant through the pipelines decreases. This increases energy costs.
Rust particles in the coolant lead to depressurization of the bearings of circulation pumps, clog heat exchange channels, elements of heating boilers, cause leaks and damage to entire elements of heating systems.
Important! The use of additives protects the metals of heating networks from corrosion damage and increases the service life of these elements by 10-15 years.
The use of antifreeze solutions based on ethylene glycol or propylene glycol without additives leads to greater losses in economic terms than the cost of an additive package.
Such substances are sold either in a ready-to-use form or in a concentrated form. The antifreeze concentrate contains only the main component of the coolant - ethylene glycol or propylene glycol. The usual proportion of diluting concentrates for our climate is two volume parts of water per one volume part of the concentrate.
- Ready-to-use antifreezes already contain water and are 45% solutions of the concentrated base stock. They are designed for use at temperatures up to -30°C;
- Before filling the heating system with antifreeze, it is best to dilute the concentrate with distilled or filtered and settled water;
- Safe concentration of ethylene glycol in water is up to 1 g/l. At this concentration, it does not harm the environment;
- Along with this, it is necessary to pay attention to the fact that antifreeze is characterized by a much lower coefficient of surface tension (compared to water). This leads to the fact that the coolant based on it has a greater fluidity and more easily penetrates into pores and cracks;
- Rubber swells more slowly in ethylene glycol than in water. Therefore, when replacing the coolant from water to antifreeze, leaks may appear in old networks.
Important! In heating systems in which antifreeze is poured, galvanized elements cannot be used. At temperatures above +75 ° C, the zinc coating layer peels off from the metal. After that, it will settle inside the heating boiler, while the anti-corrosion characteristics of antifreeze are significantly reduced. Therefore, heating radiators for antifreeze should not be galvanized.
Lifetime
The service life of a coolant based on antifreeze depends on the operating mode. It is not advised to use such solutions at a temperature close to boiling (105 - 120 ° C).
When locally heated to temperatures above + 175 ° C, thermal decomposition of the antifreeze components (primarily ethylene glycol) occurs. As a result, carbon deposits will form on the heating elements, gaseous decomposition products will be released and anti-corrosion additives will be destroyed.
Before filling the heating system with antifreeze, it is necessary to ensure proper circulation of the coolant. In addition, it is necessary to observe the correct placement of the heating elementsso that the coolant does not overheat and, as a result, does not burn.
In practice, in networks it is necessary to carry out calculations of heat exchange processes in order to determine the efficiency for a particular coolant, as well as to perform the required circulation of heat flows.
Such calculations are made on the basis of tabular data for the coefficients that are included in the similarity equation:
- Reynolds number;
- Prandtl number.
An important criterion for the effectiveness of the use of antifreeze as a coolant is compliance with the tightness of the heating system. The main component of such solutions is ethylene glycol, which oxidizes in air. As the temperature rises, this process is accelerated by about a factor of two for every 10°C rise in temperature.
When ethylene glycol is oxidized, glycolates are formed. These compounds destroy the chemical structure of the additives and lead to the oxidation of the walls of pipeline networks and to corrosion. For this reason, it is necessary to use hermetic closed expansion tanks in heating networks.
Freezing point
When operating antifreeze, it is necessary to determine the optimal ratio of the dilution concentration of the main component.
If the concentration of ethylene glycol is high, then this leads to the following consequences:
- the price goes up;
- the dynamic viscosity of the liquid increases;
- the efficiency of heat transfer decreases;
Therefore, it is important to determine how the water-ethylene glycol solution freezes. This process takes place in several stages. For water, this process takes place in one stage (liquid - ice).
Antifreeze does not freeze right away. First, crystals form in it, which move freely inside the liquid. With decreasing temperature, the content of crystals increases and, eventually, this mixture completely solidifies. Moreover, when freezing, the solution expands slightly.
The video talks about how to choose antifreeze:
conclusions
It makes sense to use antifreeze for a heating system when there is really a possibility that the water inside the network may freeze. In this case, it is necessary to determine the optimal concentration of the solution for the efficient operation of the entire heating system and take into account the safety requirements.
Coolants
In the process of fuel combustion, a large amount of heat is released, part of which is not converted into mechanical energy. This excess impairs the filling of cylinders with a combustible mixture, increases mechanical losses, increases the likelihood of glow ignition and detonation from engine parts. In this regard, a cooling system is provided in the engine design, and the coolant circulating through it transfers the heat absorbed in the engine cylinder jacket to a heat exchanger (radiator), where thermal energy is dissipated or it is used to warm up the body interior at low temperatures.
The efficiency and reliability of the engine cooling system largely depend on the quality of the coolant used. Thus, coolants must meet the following requirements:
Possess high heat capacity, thermal conductivity and a certain viscosity;
Have a high boiling point and a low freezing point;
Do not form deposits on the washed walls and do not pollute the cooling system;
Do not cause corrosion of metal parts and do not destroy rubber parts;
Have good chemical and physical stability during operation and storage;
Do not cause damage to parts of the cooling system during solidification, it is possible to change the volume less when heated and not foam when oil products enter;
Non-toxic and non-flammable;
To be cheap and not scarce.
To the greatest extent, these requirements are met by water and aqueous solutions of certain substances. Water has a number of positive properties: availability, high heat capacity (4.19 kJ / (kg ºС)), fire safety, non-toxicity, good pumpability at positive temperatures (kinematic viscosity ν 20ºС = 1 mm 2 / s). Negative properties of water: it freezes at negative temperatures (increasing in volume by about 10%, which leads to a pressure of 200-250 MPa, as a result of which cracks can form on the walls of the engine cooling jacket, the radiator, heating system, etc. can fail), and boils at temperatures above 100 ºС; with sufficiently hard water, scale forms; has corrosive activity. Organic impurities, including oil products, getting into the cooling system with water, form sludge, which pollute the channels and impair heat removal. These shortcomings limit the use of water as a coolant.
In this regard, water is used in the spring-autumn period of operation on trucks, and in those climatic zones where there are no low temperatures or cars are operated only in the summer, water can be used in cooling systems and cars. In this case, it is important to know its properties in order to avoid undesirable consequences from the operation of engines on water.
First of all, this refers to scale - hard and durable deposits on the hot walls of cooling systems, formed as a result of sedimentation on the walls of calcium and magnesium bicarbonates, sulfates and chlorides contained in water (the thermal conductivity of scale is approximately 100 times less than the thermal conductivity of steel). As a result, a violation of the thermal regime of the engine, an increase in fuel and oil consumption (with a scale thickness of 1.5–2 mm, fuel consumption increases by 8–10%).
The concentration of these salts and their qualitative characteristics are described by the indicator ""general hardness"" of water (table 3.1).
Table 3.1 – Water classification and maintenance mode of the engine cooling system
| Water class | Origin of water | Stiffness group | General hardness, mg-eq/l | Influence on scale formation |
| atmospheric | rain, snow | Very soft | Up to 1.5 | Scale does not form |
| Superficial | River, lake-naya, northern reservoirs Central and southern regions | Very soft Soft Soft Medium | Up to 1.5 1.5–3 1.5–3 3–6 | Forms almost no scale Forms scale. It is necessary to descale at least 2 times a year |
| Ground | Spring, well, artesian | Tough and very tough | 6–12 or more | Significant scale is quickly deposited. It is not recommended to use water without preliminary softening. |
The total hardness of water is the sum of carbonate (temporary) and non-carbonate (mainly sulphate) hardness. The unit of hardness is 1 mg-eq / l of salts, which corresponds to 20.04 mg of calcium ion or 12.16 mg of magnesium ion in 1 liter of water. Water hardness can be approximately determined without special equipment for foaming when soaping hands with soap: in soft water, the foam is stable, and in hard water, the foam quickly goes out and a greasy residue remains on the hands.
To prevent the formation of scale, anti-scale agents are introduced into the cooling system or water is softened before filling (table 3.2). If the scale is still formed, it should be removed with the following compositions:
Solution of 0.6 kg of commercial lactic acid in 10 l/water;
A solution of a mixture of phosphoric acid (1 kg) and chromic anhydride (0.5 kg in 10 liters of water).
Processing time 0.5–1 hour.
Before processing, it is necessary to remove the thermostat, pour the composition into the cooling system. After the recommended period, start the engine and let it run for 15-20 minutes, then remove the composition and rinse the system two or three times with water. It is better to do the last flush with a hot solution of chromium peak (0.5-1%) to create an anti-corrosion protective film on the surface of the cooling system.
Table 3.2 – Ways to prevent scale formation
| Operation | Reagents and their action | Application procedure |
| Introduction of antina-kipins | Chrompeak K 2 Cr 2 O 7 or ammonium nitrate NH 4 NO 3 converts scale salts into a soluble state | Concentrate is prepared: 100 g of reagent per 1 liter of water. For 1 liter of medium hard water take 30-50 ml of concentrate, for hard 100-130 ml. When the water in the cooling system becomes cloudy, the water is changed |
| Water softening | Hexamet (NaPO 3) 6 keeps scale salts in suspension | Add 0.2 to medium hard water, and 0.3 g / l to hard water. Periodically remove sediment through faucets |
| Distillation | All soluble salts remain in the still | Get water without hardness salts (distilled) |
| Boiling | Salts of carbonate and partially sulfate hardness precipitate | Water is boiled for 20–30 minutes, settled and filtered from sediment. |
| Treatment with chemical reagents | Soda ash Na 2 CO 3 - 53 mg / l per unit of hardness | Warm water is mixed with a reagent for 20-30 minutes, settled and filtered from sediment |
Under certain vehicle operating conditions - high ambient temperatures, trailer towing, off-road driving in low gears, etc. - the coolant can reach boiling point. In this case, the cooling efficiency drops sharply, the engine overheats, and its failure is possible. To eliminate this, it is necessary to use a coolant with a high boiling point and seal the cooling system.
The cooling systems of modern engines are sealed, and the liquid in them is under low pressure, usually about 0.05 MPa, which is maintained by a valve in the radiator cap. In new car models, the pressure in the cooling system is even higher (0.12 MPa) and is maintained by a valve in the expansion tank. At a pressure of 0.05 MPa, water boils at 112 ºС, and at 0.12 MPa, at 124 ºС.
All these shortcomings necessitate the introduction of appropriate additives into the water to ensure stable operation of the cooling system.
Currently, low-freezing coolants are widely used in cooling systems - antifreeze, which are a mixture of ethylene glycol (dihydric technical alcohol, boiling at 197 ºС and crystallizing at a temperature of -11.5 ºС) with distilled water. This mixture, depending on the mutual concentration of the components, has a freezing point from 0 to -75 ºС.
Unlike water, when freezing, antifreeze does not expand and does not form a solid continuous mass. A loose mass of water crystals is formed in the ethylene glycol medium. Usually such a mass does not lead to defrosting of the block and does not prevent the engine from starting. After starting the engine, antifreeze quickly turns into a liquid state. However, heating the interior heater is difficult, so it is necessary to maintain such a concentration of antifreeze so that it does not freeze to a temperature of about -40 ºС.
Antifreezes also have some disadvantages. Thus, their thermal conductivity and heat capacity are lower than those of water, which somewhat reduces the efficiency of cooling systems. When heated, antifreezes increase their volume, which is why an expansion tank is installed in the cooling system, and in order to prevent the release of the mixture, it is not added to the cooling system by 6–8% of the total volume. Ethylene glycol is corrosive to metals, so antifreeze additives are added during manufacture: dextrin, a starch-type carbohydrate (1 g per liter), which protects lead-tin solder, aluminum and copper, and disodium phosphate (2.5–3 .5 g per liter), protecting ferrous metals, copper and brass. Sometimes molybdenum sodium (7.5–8 g per liter) is added to simple antifreezes, which prevents corrosion of zinc and chromium coatings on parts of the cooling system. At the same time, the letter M is present in the designation of antifreeze. Special anti-foam additives are also added to extinguish the foam. The total content of additives is 3–5%.
The boiling point of antifreeze is quite high and ranges from 120–132 ºС (table 3.3). Therefore, in a sealed cooling system of a modern car under normal operating conditions (without engine overheating), antifreeze losses occur mainly due to leaks (micro-slots in the radiator, loose hose clamps, and other malfunctions). It is undesirable to replenish the level of antifreeze in the cooling system with water, i.e., it is undesirable to change the concentration of ethylene glycol in the mixture, since this, in addition to lowering the freezing point, can lead to the destruction of parts and assemblies of the engine and cooling system.
Table 3.3 – Characteristics of water-ethylene glycol coolant
Table 3.4 shows the main characteristics of antifreezes produced in our country. Old antifreezes according to GOST 159-52 did not fully meet the requirements of modern cars (in terms of anti-corrosion properties, aggressiveness to rubber, etc.), and this required the creation of a new generation of antifreezes, which are known as "Tosol" and "Lena" ". All liquids are regulated by GOST 28084–89 and technical conditions.
Antifreeze Tosol A-40 is most widely used on cars (since 1985 - Tosol A-40M). Since passenger cars are rarely operated at temperatures below -40 ºС, Antifreeze A-65 is used little.
Concentrates are not used as working fluids and are intended for obtaining commercial fluids of grades 65 and 40 by diluting them with water.
It has been established that the service life of Tosol A-40 is two years, and the service life of Tosol A-40M can be increased to three years. As a rule, up to three years of operation of cars, or 60 thousand kilometers, there are no centers of corrosion in the cooling system. With longer periods of operation, corrosion centers begin to appear on some parts of the cooling system, primarily on the impeller of the water pump, i.e., on cast iron.
Aluminum parts, solder in the radiator, brass radiator tubes and the thermostat housing also corrode, and this is due to the fact that the antifreeze changes its characteristics during operation: the alkalinity decreases, the tendency to foaming increases, the aggressiveness to rubber increases and the ability to cause corrosion of metals increases. . The intensity of the change in the characteristics of antifreeze depends on the average operating temperature in the engine. In southern regions, where these temperatures are usually higher, antifreeze ages more intensively. In the northern regions of the country, antifreeze can last more than 3 years.
A three-year service life of Antifreeze A-40M is guaranteed only if the required antifreeze density is maintained during this time - at least 1075 kg / m 3. If the density is lower, Tosol AM concentrates are added in accordance with Table 3.5. Adding more than 1 liter of fresh concentrate increases the life of the antifreeze by about a year.
The Lena-40 coolant is close in its properties to Tosol A-40M, but it corrodes cast iron and aluminum parts less.
Since antifreezes differ in formulation, different brands should not be mixed with each other.
It is also necessary to ensure that gasoline and other petroleum products do not get into ethylene glycol fluids, as this causes foaming and the release of fluid through the radiator cap.
Ethylene glycol is a strong food poison, so after contact with it, you must thoroughly wash your hands with soap and water (the liquid that has got inside causes severe damage to the kidneys and nervous system).
Table 3.4 – The main indicators of antifreeze
| Index | Antifreezes (TU 6-02-751-86) | Lena (TU 113-07-02–88) | ||||
| AM | A-40M | A-65M | OZH-K | OZH-40 | OZH-65 | |
| Appearance | blue liquid | red liquid | yellow-green liquid | |||
| 1120–1140 | 1075–1085 | 1085– | 1120–1150 | 1075–1085 | 1085– | |
| –35 * | –40 | –65 | –35 * | –40 | –65 | |
| Foaming capacity: foam volume, cm3, no more | ||||||
| Foam resistance, s, no more | ||||||
| Alkalinity reserve, cm 3, not higher | ||||||
| Corrosion loss of metals when tested on a plate, mg/cm 2 , not more than: copper solder aluminum cast iron | ||||||
| – – – | 1,9 4,3 56,5 | 2,5 6,2 96,3 | – – – | 1,9 4,3 | 2,5 6,2 | |
| 6–7 | 3–3,5 | 3,5–4 | 3–3,5 | 3,5–4 | ||
| * The crystallization temperature is indicated for a concentrate diluted with distilled water in a ratio of 1:1. |
Continuation of table 3.4
| Index | OZH-25 PG (TU 6-01-17-30–85) | Antifreezes (GOST 159–52) | ||
| Concentrate | ||||
| Appearance | yellow-green liquid | Light yellow, slightly turbid liquid | Orange slightly cloudy liquid | |
| Density at 20 ºС, kg/m3, no more | 1040–1055 | 1110–1116 | 1067–1072 | 1085–1090 |
| Freezing temperature, ºС, not higher | –25 | –11,5 | –40 | –65 |
| Boiling point, ºС, not lower | – | |||
| Viscosity kinematic, mm 2 / s, at temperature: 50 ºС 20 ºС -30 ºС | 1,6 4,2 | – – – | 1,9 4,4 | 2,2 5,2 |
| Composition, %: ethylene glycol water additives (over 100%) | 6–8 | 3,5–4,5 | 4–4,5 |
Table 3.5- WITH ways to restore the optimal density of antifreeze
| Density at 20 ºС, g/cm 3 | Mass fraction of antifreeze, % | Density at 20 ºС, g/cm 3 | Mass fraction of antifreeze, % | The amount of added concentrate, l | |
| 1,054 | 3,3 | 1,067 | 2,15 | ||
| 1,055 | 3,12 | 1,068 | |||
| 1,057 | 1,071 | 1,7 | |||
| 1,059 | 2,9 | 1,074 | 1,4 | ||
| 1,06 | 2,79 | 1,076 | |||
| 1,061 | 2,66 | 1,078 | 0,64 | ||
| 1,062 | 2,54 | 1,081 | 0,25 | ||
| 1,064 | 2,41 | 1,082 | |||
| 1,065 | 2,28 | ||||
| Note - Before adding concentrate to the cooling system, the same amount of old antifreeze should be drained from it. |
Foreign manufacturers (“Addinol Froostox”, “Antifreeze”, “Afrostin”) produce low-freezing liquids similar in composition to Tosol and Lena, but more durable (up to three years). This is achieved due to the fact that for the preparation of antifreezes, aqueous solutions of alcohols, glycols, glycerin and some inorganic salts are used with the introduction of a complex of additives:
Corrosion inhibitors - silicates, nitrates, nitrites, molybdenum compounds, benzothiazole derivatives;
Buffers - borates;
Anti-foam additives - silicones.
The composition of coolants can be determined by density using a hydrometer or hydrometer, which has a dual scale showing the percentage of ethylene glycol and the crystallization temperature.
The influence of the concentration of ethylene glycol in a liquid on its density and freezing point is shown in Table 3.6.
Table 3.6 – Characteristics of antifreeze coolants
| Density of the mixture, g / cm 3 | Freezing point, ºС | Ethylene glycol concentration, % | Density of the mixture, g / cm 3 | Freezing point, ºС | |
| 26,4 | 1,034 | –10 | 65,3 | 1,0855 | –65 |
| 27,2 | 1,0376 | –12 | 65,6 | 1,086 | –66 |
| 29,6 | 1,041 | –14 | 1,0863 | –67 | |
| 1,0443 | –16 | 66,3 | 1,0866 | –68 | |
| 34,2 | 1,048 | –18 | 68,5 | 1,0888 | –66 |
| 36,4 | 1,0506 | –20 | 69,6 | 1,09 | –64 |
| 38,4 | 1,0553 | –22 | 70,8 | 1,091 | –62 |
| 40,4 | 1,056 | –24 | 72,1 | 1,0923 | –60 |
| 42,2 | 1,0586 | –26 | 73,3 | 1,0937 | –58 |
| 1,0606 | –28 | 74,5 | 1,0947 | –56 | |
| 45,6 | 1,0627 | –30 | 75,8 | 1,096 | –54 |
| 1,0643 | –32 | 1,0973 | –52 | ||
| 48,2 | 1,0663 | –34 | 78,4 | 1,0983 | –50 |
| 49,6 | 1,068 | –36 | 79,6 | 1,0997 | –48 |
| 1,0696 | –38 | 81,2 | 1,1007 | –46 | |
| 52,6 | 1,0713 | –40 | 82,5 | 1,1023 | –44 |
| 53,6 | 1,0726 | –42 | 83,9 | 1,1033 | –42 |
| 54,6 | 1,074 | –44 | 85,4 | 1,1043 | –40 |
| 55,6 | 1,0753 | –46 | 86,9 | 1,1054 | –38 |
| 56,8 | 1,0766 | –48 | 88,4 | 1,1066 | –36 |
| 1,078 | –50 | 1,1077 | –35 | ||
| 59,1 | 1,079 | –52 | 91,5 | 1,1087 | –34 |
| 60,2 | 1,0803 | –54 | 1,1096 | –33 | |
| 61,2 | 1,0813 | –56 | 94,4 | 1,1103 | –32 |
| 62,2 | 1,0823 | –58 | 1,1105 | –28 | |
| 63,1 | 1,0833 | –60 | 95,5 | 1,1107 | –27 |
| 1,0843 | –62 | 96,5 | 1,111 | –24 | |
| 64,8 | 1,085 | –64 | 1,1116 | –22 |
All values in this table are given to 20 ºС, so if there is a deviation from this temperature, then the measured density is brought to +20 ºС using the formula
ρ 20 = ρ t + γ( t – 20),
where ρ 20 is the density of antifreeze, reduced to +20 ºС, g / cm 3;
ρ t is the density of antifreeze at the measurement temperature, g/cm3;
γ is the temperature correction for the density of ethylene glycol, g/cm 3 ºС;
γ \u003d 0.000525 g / cm 3 ºС;
t- temperature of antifreeze at the time of measurement, ºС.
The density of the liquid during the operation of the car fluctuates both up and down, so the liquid must be adjusted by adding ethylene glycol (Xe) or distilled water (Xc), using the formulas:
X e \u003d (V pr - V n) V/ V n;
X in \u003d (E pr - E n) V/ En,
where Vpr is the water content in the tested antifreeze,%;
V- the volume of the mixture being tested, l.
brake fluids
Brake fluids are used to transfer energy to the actuators in the hydraulic brake system of vehicles.
The working pressure in the hydraulic drive of the brakes reaches 10 MPa or more. The developed pressure is transferred to the pistons of the brake cylinders, causing corrosion of metal parts. But the greatest danger to brake performance is temperature: when the brake fluid reaches its boiling point, vapor locks can form in it. In this case, the brake actuator becomes pliable (the pedal fails) and the efficiency of the brakes is sharply reduced, which is of particular importance for disc brakes and high-speed cars.
The main disadvantage of currently used brake fluids is hygroscopicity. It has been established that during the year the fluid in the brake system absorbs 2–3% of water, as a result of which the boiling point decreases by 30–50 °C. Therefore, car companies recommend changing the brake fluid every two years.
Reliable operation of the brake system is a necessary condition for the safe operation of a car, and brake fluid as its functional element must meet a number of technical requirements. The most important of them are discussed below.
Basic properties
Boiling temperature. This is the most important indicator characterizing the maximum permissible operating temperature of the hydraulic brake drive. The boiling point during operation decreases due to the high hygroscopicity, therefore, along with the boiling point of the "dry" brake fluid, the boiling point of the "wet" fluid containing 3.5% water is determined.
The boiling point of a "moistened" liquid indirectly characterizes the temperature at which the liquid will "boil" after 1.5–2 years of its operation in the hydraulic drive of the car's brakes. For reliable operation of the brakes, it is necessary that it be above the operating temperature of the fluid in the brake system.
From operating experience it follows that the temperature of the fluid in the hydraulic drive of the brakes of trucks usually does not exceed 100 ºС. Under conditions of intensive braking, the temperature can reach 120 ºС or more.
In passenger cars with disc brakes, the fluid temperature during movement:
On main highways - up to 60–70 ºС;
In urban conditions - up to 80–100 ºС;
At high speeds, air temperatures and heavy braking - up to 150 ºС;
In some cases (special vehicles, sports cars, etc.) the liquid temperature may exceed the indicated values.
It should be noted that the beginning of the formation of the vapor phase of brake fluids during heating, and, consequently, of vapor locks in the hydraulic brake drive, occurs at a temperature 20–25 ºС below the boiling point of the liquid. This circumstance is taken into account when establishing indicators of the quality of brake fluids.
According to the requirements of international standards, the boiling point of "dry" and "moistened" brake fluid must be at least 205 and 140 ºС, respectively, for vehicles under normal operating conditions and at least 230 and 155 ºС for vehicles operating in modes with high speeds or with frequent and intense braking. It should be borne in mind that on a car that has stopped after heavy braking, the fluid temperature may rise for some time due to the heat of the brake pads due to the termination of their cooling by the oncoming air flow.
Viscosity-temperature properties and stability. The braking process usually lasts a few seconds, and in emergency conditions - fractions of a second. Therefore, it is necessary that the force applied by the driver to the brake pedal is quickly transferred to the wheel brakes with the help of a working fluid. This condition is ensured by the fluidity of the liquid and is determined by the maximum allowable viscosity at a temperature of -40 ºС: not more than 1500 mm 2 /s for general purpose liquids and not more than 1800 mm 2 /s for high-temperature liquids. Liquids for the north should have a viscosity of no more than 1500 mm 2 /s at -55 ºС.
The most sensitive to fluid viscosity changes are brakes equipped with an anti-lock braking system (ABS) and brakes on vehicles with automatic transmission.
Thus, brake fluids in the operating temperature range from -50 to 150 ºС must maintain their original performance, i.e. resist oxidation and separation during storage and use, the formation of sediments and deposits on the parts of the brake hydraulic drive.
anti-corrosion properties. In the hydraulic brake drive, parts made of various metals are interconnected, which creates conditions for the occurrence of electrochemical corrosion. To prevent corrosion, fluids must contain inhibitors that protect steel, cast iron, tinplate, aluminum, brass, copper from corrosion.
The effectiveness of corrosion inhibitors is assessed by the change in the mass and surface condition of plates made of these metals after they have been kept in a brake fluid containing 3.5% water for 120 hours at 100 ºС.
Compatibility with rubber materials. To ensure the tightness of the hydraulic system, rubber sealing cuffs are placed on the pistons and cylinders. The necessary sealing is ensured when the cuffs swell slightly under the influence of the brake fluid and their sealing edges fit snugly against the cylinder walls. In this case, both too much swelling of the cuffs is unacceptable, since they can be destroyed when the pistons move, and shrinkage of the cuffs in order to prevent leakage of fluid from the system. The rubber swelling test is carried out by keeping cuffs or rubber samples in liquid at 70 and 120 ºС. Then the change in volume, hardness and diameter of the cuffs is determined.
Lubricating properties. The influence of the liquid on the wear of the working surfaces of brake pistons, cylinders, lip seals is determined by its lubricating properties, which are checked during bench tests that simulate the operation of a hydraulic brake drive under severe operating conditions.
ANTIFREEZES based on ethylene and propylene glycols and WATER. freezing temperatures. Viscosity. Density. Heat capacities.
Antifreezes are liquids used to cool internal combustion engines, electronic equipment, industrial heat exchangers and other installations operating at temperatures below 0 ° C. Basic requirements for antifreezes: low freezing point, high heat capacity and thermal conductivity, low viscosity at low temperatures, low foaming, high boiling and ignition points. In addition, antifreezes should not cause destruction of structural materials from which parts of cooling systems are made.
The most common antifreezes are based on aqueous solutions of ethylene glycol and propylene glycol (see below). However, such solutions cause significant corrosion of metals, so corrosion inhibitors are added to them - Na 2 HPO 4, Na 2 MoO 4, Na 2 B 4 O 7, KNO 3, dextrin, K benzoate, mercaptobenzothiazole and others. In some cases, aqueous solutions of salts are used as antifreezes; the most widely distributed CaCl2 solution. The disadvantages of such antifreezes are extremely high corrosiveness and crystallization of salts during the evaporation of water.
PROPERTIES OF ANTIFREEZES BASED ON AQUEOUS SOLUTIONS OF SALT(reference table for interest, such antifreezes are practically out of use)
ETHYLENE GLYCOL(1,2-ethanediol) HOCH2CH2OH, colorless viscous odorless hygroscopic liquid, sweetish taste; melting point -12.7 °C, boiling point 197.6 °C. When ethylene glycol is dissolved in water, heat is released and volume decreases. Aqueous solutions freeze at low temperatures. Ethylene glycol is toxic if ingested, affecting the central nervous system and kidneys; lethal dose 1.4 g/kg. MPC in the air of the working area is 5 mg/m 3 .
PROPYLENE GLYCOLS(propanediols) C3H6 (OH)2 Two isomers are known: 1,2-P. CH3CHOHCH2OH (1,2-propanediol) and 1,3-P. CH2OHCH2CH2OH. Propylene glycols are colorless viscous hygroscopic liquids of a sweetish taste, odorless. For 1,2-P. melting point -60 °C, boiling point 189 °C. For 1,3-P. melting point -32°C, boiling point 213.5°C. 1,2-P. soluble in water, diethyl ether, monohydric alcohols, carboxylic acids, aldehydes, amines, acetone, ethylene glycol, sparingly soluble in benzene. When mixed with water or amines, the freezing point of solutions sharply decreases. Toxicity 1,2-P. (LD50 34.6 mg/kg, rats) is lower than that of ethylene glycol.
The safety levels for the average shelf life (biochemical activity) of products when 0.2% of the mass amount of the coolant is added to them are given below.
The indicator is evaluated on a five-point scale. Five does not mean that the product cannot be poisoned in principle.
Freezing point of aqueous solutions of ethylene glycol and propylene glycol
Physical properties of an aqueous solution of ethylene glycol.
Antifreeze additives can change the parameters somewhat, make sure.
| Volume fraction in a mixture % |
Minimum working temperature t, °C |
Temperature solution t, °C |
Density kg / m 3 |
Heat capacity KJ/kg*K |
Thermal conductivity W/m*K |
Dynamic viscosity spoise \u003d mPa * s \u003d 10 -3 * N * s / m 2 |
Kinematic viscosity cSt \u003d mm 2 / s \u003d 10 -6 m 2 / s |
| 20 | -10 | -10 | 1038 | 3,85 | 0,498 | 5,19 | 5,0 |
| 0 | 1036 | 3,87 | 0,500 | 3,11 | 3,0 | ||
| 20 | 1030 | 3,90 | 0,512 | 1,65 | 1,6 | ||
| 40 | 1022 | 3,93 | 0,521 | 1,02 | 1,0 | ||
| 60 | 1014 | 3,96 | 0,531 | 0,71 | 0,7 | ||
| 80 | 1006 | 3,99 | 0,540 | 0,523 | 0,52 | ||
| 100 | 997 | 4,02 | 0,550 | 0,409 | 0,41 | ||
| 34 | -20 | -20 | 1069 | 3,51 | 0,462 | 11,76 | 11,0 |
| 0 | 1063 | 3,56 | 0,466 | 4,89 | 4,6 | ||
| 20 | 1055 | 3,62 | 0,470 | 2,32 | 2,2 | ||
| 40 | 1044 | 3,68 | 0,473 | 1,57 | 1,5 | ||
| 60 | 1033 | 3,73 | 0,475 | 1,01 | 0,98 | ||
| 80 | 1022 | 3,78 | 0,478 | 0,695 | 0,68 | ||
| 100 | 1010 | 3,84 | 0,480 | 0,515 | 0,51 | ||
| 52 | -40 | -40 | 1108 | 3,04 | 0,416 | 110,8 | 100 |
| -20 | 1100 | 3,11 | 0,409 | 27,50 | 25 | ||
| 0 | 1092 | 3,19 | 0,405 | 10,37 | 9,5 | ||
| 20 | 1082 | 3,26 | 0,402 | 4,87 | 4,5 | ||
| 40 | 1069 | 3,34 | 0,398 | 2,57 | 2,4 | ||
| 60 | 1057 | 3,41 | 0,394 | 1,59 | 1,5 | ||
| 80 | 1045 | 3,49 | 0,390 | 1,05 | 1,0 | ||
| 100 | 1032 | 3,56 | 0,385 | 0,722 | 0,7 |
Physical properties of an aqueous solution of propylene glycol (1,2-Propylene glycol C3H6(OH)2)
Antifreeze additives can change the parameters somewhat, make sure.
| Volume fraction in a mixture % |
Minimum working temperature t, °C |
Temperature solution t, °C |
Density kg / m 3 |
Heat capacity KJ/kg*K |
Thermal conductivity W/m*K |
Dynamic viscosity spoise \u003d mPa * s \u003d 10 -3 * N * s / m 2 |
Kinematic viscosity cSt \u003d mm 2 / s \u003d 10 -6 m 2 / s |
| 25 | -10 | -10 | 1032 | 3,93 | 0,466 | 10,22 | 9,9 |
| 0 | 1030 | 3,95 | 0,470 | 6,18 | 6,0 | ||
| 20 | 1024 | 3,98 | 0,478 | 2,86 | 2,8 | ||
| 40 | 1016 | 4,00 | 0,491 | 1,42 | 1,4 | ||
| 60 | 1003 | 4,03 | 0,505 | 0,903 | 0,9 | ||
| 80 | 986 | 4,05 | 0,519 | 0,671 | 0,68 | ||
| 100 | 979 | 4,08 | 0,533 | 0,509 | 0,52 | ||
| 38 | -20 | -20 | 1050 | 3,68 | 0,420 | 47,25 | 45 |
| 0 | 1045 | 3,72 | 0,425 | 12,54 | 12 | ||
| 20 | 1036 | 3,77 | 0,429 | 4,56 | 4,4 | ||
| 40 | 1025 | 3,82 | 0,433 | 2,26 | 2,2 | ||
| 60 | 1012 | 3,88 | 0,437 | 1,32 | 1,3 | ||
| 80 | 997 | 3,94 | 0,441 | 0,897 | 0,9 | ||
| 100 | 982 | 4,00 | 0,445 | 0,687 | 0,7 | ||
| 47 | -30 | -30 | 1066 | 3,45 | 0,397 | 160 | 150 |
| -20 | 1062 | 3,49 | 0,396 | 74,3 | 70 | ||
| -10 | 1058 | 3,52 | 0,395 | 31,74 | 30 | ||
| 0 | 1054 | 3,56 | 0,395 | 18,97 | 18 | ||
| 20 | 1044 | 3,62 | 0,394 | 6,264 | 6 | ||
| 40 | 1030 | 3,69 | 0,393 | 2,978 | 2,9 | ||
| 60 | 1015 | 3,76 | 0,392 | 1,624 | 1,6 | ||
| 80 | 999 | 3,82 | 0,391 | 1,10 | 1,1 | ||
| 100 | 984 | 3,89 | 0,390 | 0,807 | 0,82 |
Physical properties of water.
Water treatment additives (and sanitary) can change the parameters somewhat, make sure.
| Temperature t,(°C) |
Pressure saturated vapors 10 3 *Pa |
Density kg / m 3 |
Specific volume (m3/kg)x10 - 5 |
Heat capacity KJ/kg*K |
Entropy KJ/kg*K |
Dynamic viscosity spoise \u003d mPa * s \u003d 10 -3 * N * s / m 2 |
Kinematic viscosity cSt \u003d mm 2 / s \u003d 10 -6 m 2 / s |
Coefficient volume expansion K -1 *10 -3 |
Enthalpy KJ/kg*K |
Prandtl number |
| 0 | 0,6 | 1000 | 100 | 4,217 | 0 | 1,78 | 1,792 | -0,07 | 0 | 13,67 |
| 5 | 0,9 | 1000 | 100 | 4,204 | 0,075 | 1,52 | 21,0 | |||
| 10 | 1,2 | 1000 | 100 | 4,193 | 0,150 | 1,31 | 1,304 | 0,088 | 41,9 | 9,47 |
| 15 | 1,7 | 999 | 100 | 4,186 | 0,223 | 1,14 | 62,9 | |||
| 20 | 2,3 | 998 | 100 | 4,182 | 0,296 | 1,00 | 1,004 | 0,207 | 83,8 | 7,01 |
| 25 | 3,2 | 997 | 100 | 4,181 | 0,367 | 0,890 | 104,8 | |||
| 30 | 4,3 | 996 | 100 | 4,179 | 0,438 | 0,798 | 0,801 | 0,303 | 125,7 | 5,43 |
| 35 | 5,6 | 994 | 101 | 4,178 | 0,505 | 0,719 | 146,7 | |||
| 40 | 7,7 | 991 | 101 | 4,179 | 0,581 | 0,653 | 0,658 | 0,385 | 167,6 | 4,34 |
| 45 | 9,6 | 990 | 101 | 4,181 | 0,637 | 0,596 | 188,6 | |||
| 50 | 12,5 | 988 | 101 | 4,182 | 0,707 | 0,547 | 0,553 | 0,457 | 209,6 | 3,56 |
| 55 | 15,7 | 986 | 101 | 4,183 | 0,767 | 0,504 | 230,5 | |||
| 60 | 20,0 | 980 | 102 | 4,185 | 0,832 | 0,467 | 0,474 | 0,523 | 251,5 | 2,99 |
| 65 | 25,0 | 979 | 102 | 4,188 | 0,893 | 0,434 | 272,4 | |||
| 70 | 31,3 | 978 | 102 | 4,190 | 0,966 | 0,404 | 0,413 | 0,585 | 293,4 | 2,56 |
| 75 | 38,6 | 975 | 103 | 4,194 | 1,016 | 0,378 | 314,3 | |||
| 80 | 47,5 | 971 | 103 | 4,197 | 1,076 | 0,355 | 0,365 | 0,643 | 335,3 | 2,23 |
| 85 | 57,8 | 969 | 103 | 4,203 | 1,134 | 0,334 | 356,2 | |||
| 90 | 70,0 | 962 | 104 | 4,205 | 1,192 | 0,314 | 0,326 | 0,698 | 377,2 | 1,96 |
| 95 | 84,5 | 962 | 104 | 4,213 | 1,250 | 0,297 | 398,1 | |||
| 100 | 101,33 | 962 | 104 | 4,216 | 1,307 | 0,281 | 0,295 | 0,752 | 419,1 | 1,75 |
| 105 | 121 | 955 | 105 | 4,226 | 1,382 | 0,267 | 440,2 | |||
| 110 | 143 | 951 | 105 | 4,233 | 1,418 | 0,253 | 461,3 | |||
| 115 | 169 | 947 | 106 | 4,240 | 1,473 | 0,241 | 482,5 | |||
| 120 | 199 | 943 | 106 | 4,240 | 1,527 | 0,230 | 0,249 | 0,860 | 503,7 | 1,45 |
| 125 | 228 | 939 | 106 | 4,254 | 1,565 | 0,221 | 524,3 | |||
| 130 | 270 | 935 | 107 | 4,270 | 1,635 | 0,212 | 546,3 | |||
| 135 | 313 | 931 | 107 | 4,280 | 1,687 | 0,204 | 567,7 | |||
| 140 | 361 | 926 | 108 | 4,290 | 1,739 | 0,196 | 0,215 | 0,975 | 588,7 | 1,25 |
| 145 | 416 | 922 | 108 | 4,300 | 1,790 | 0,190 | 610,0 | |||
| 150 | 477 | 918 | 109 | 4,310 | 1,842 | 0,185 | 631,8 | |||
| 155 | 543 | 912 | 110 | 4,335 | 1,892 | 0,180 | 653,8 | |||
| 160 | 618 | 907 | 110 | 4,350 | 1,942 | 0,174 | 0,189 | 1,098 | 674,5 | 1,09 |
| 165 | 701 | 902 | 111 | 4,364 | 1,992 | 0,169 | 697,3 | |||
| 170 | 792 | 897 | 111 | 4,380 | 2,041 | 0,163 | 718,1 | |||
| 175 | 890 | 893 | 112 | 4,389 | 2,090 | 0,158 | 739,8 | |||
| 180 | 1000 | 887 | 113 | 4,420 | 2,138 | 0,153 | 0,170 | 1,233 | 763,1 | 0,98 |
| 185 | 1120 | 882 | 113 | 4,444 | 2,187 | 0,149 | 785,3 | |||
| 190 | 1260 | 876 | 114 | 4,460 | 2,236 | 0,145 | 807,5 | |||
| 195 | 1400 | 870 | 115 | 4,404 | 2,282 | 0,141 | 829,9 | |||
| 200 | 1550 | 863 | 116 | 4,497 | 2,329 | 0,138 | 0,158 | 1,392 | 851,7 | 0,92 |
| 220 | 0,149 | 1,597 | 0,88 | |||||||
| 225 | 2550 | 834 | 120 | 4,648 | 2,569 | 0,121 | 966,8 | |||
| 240 | 0,142 | 1,862 | 0,87 | |||||||
| 250 | 3990 | 800 | 125 | 4,867 | 2,797 | 0,110 | 1087 | |||
| 260 | 0,137 | 2,21 | 0,87 | |||||||
| 275 | 5950 | 756 | 132 | 5,202 | 3,022 | 0,0972 | 1211 | |||
| 300 | 8600 | 714 | 140 | 5,769 | 3,256 | 0,0897 | 1345 | |||
| 325 | 12130 | 654 | 153 | 6,861 | 3,501 | 0,0790 | 1494 | |||
| 350 | 16540 | 575 | 174 | 10,10 | 3,781 | 0,0648 | 1672 | |||
| 360 | 18680 | 526 | 190 | 14,60 | 3,921 | 0,0582 | 1764 |
To improve the thermophysical properties of an aqueous solution of ethylene glycol (coolant, antifreeze, antifreeze liquid), the additive package used contains about a dozen substances designed to reduce the corrosion and oxidizing properties of the solution, its foaming, prevent the formation of scale and remove existing scale, as well as to stabilize the thermophysical characteristics coolant (The characteristics of the quality of ethylene glycol solutions must comply with the requirements GOST 28084-89 "Non-freezing coolants" and specifications developed on its basis). Most concentrated heat transfer fluids are a solution consisting of 60%-65% ethylene glycol, 30%-35% water and 3%-4% active additives.
Such percentages of ethylene glycol, water and inhibitors make it possible to obtain the best thermophysical characteristics of an aqueous solution as an effective heat carrier with a maximum minus temperature of the onset of crystallization of -70°C.
Aqueous solutions of ethylene glycol with a lower freezing point are produced using a lower concentration of ethylene glycol and the mass fraction of additives (inhibitors) remains practically unchanged. The dependence of the freezing point on the concentration of ethylene glycol is given below, in table No. 1.
For various climatic modes of operation and operating conditions of heating systems, a series of high-quality with the required crystallization temperature and stable thermophysical characteristics:
Aqueous solution of ethylene glycol - heat transfer fluid and antifreeze liquid for heating and cooling systems (a package of anti-corrosion, anti-foam, anti-scale and stabilizing additives)
| Packing, weight in kg | Concentration, % | Temperature of the beginning of crystallization (freezing), t°C | Sale / Price in rubles / kg with VAT, when ordering from 1 ton | Sale / Price in rubles/kg with VAT, when ordering more than 2 tons |
| Canister 20 kg, can 50 kg | 65% | minus -65°C | 80.00 RUB/kg | |
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| Barrel 225 kg | 30% | minus -15°C | 49.00 RUB/kg | depending on batch size |
| Barrel 225 kg | 36% | minus -20°C | 55.00 RUB/kg | depending on batch size |
| Barrel 225 kg | 40% | minus -25°C | 57.00 RUB/kg | depending on batch size |
| Barrel 225 kg | 45% | minus -30°C | 60.00 RUB/kg | depending on batch size |
| Barrel 230 kg | 50% | minus -35°C | RUB 68.00/kg | depending on batch size |
| Barrel 230 kg | 54% | minus -40°C | 73.00 RUB/kg | depending on batch size |
| Barrel 230 kg | 65% | minus -65°C | RUB 77.00/kg | depending on batch size |
Properties, characteristics and application features
In autonomous heating and industrial air conditioning systems as coolant an aqueous solution of ethylene glycol with additives for various purposes is widely used. The density of pure ethylene glycol is 1.112 g/cm3 at 20°C, the freezing point is -13°C. Aqueous solutions with an ethylene glycol concentration of 30% to 70% have a lower freezing point. The maximum freezing point of -70 °C is reached at an ethylene glycol concentration of 70%. Upon freezing, the ethylene glycol solution becomes amorphous, forming a viscous mass with an increase in volume slightly larger than the increase in the volume of water when it freezes.
Concentrated solutions with 95% ethylene glycol content are also produced, they are diluted with water before pouring into the system. The percentage of ethylene glycol is recommended to be selected based on the minimum temperature at which the coolant will be operated. Ready-made concentrated heat transfer fluids with the required freezing point are diluted with water before filling the system. For dilution, it is desirable to use distilled water, in its absence - tap water with a hardness of up to 6 units. But it must be borne in mind that the use of unpurified water is undesirable due to possible incompatibility with the additive package.
Dilution of concentrated ethylene glycol by more than 50% leads to a noticeable deterioration in the consumer properties of the coolant.
Obtaining a high-quality aqueous solution of ethylene glycol with the desired crystallization temperature and stable thermophysical characteristics is possible only under production conditions. Operating instructions for the equipment of most heating and industrial air conditioning systems place high demands on the thermophysical properties of solutions, and therefore it is recommended to use only ready-made aqueous solutions designed for the appropriate crystallization (freezing) temperature. Therefore the company HIMTERMO produces a whole series of high qualityaqueous solutions of ethylene glycol.
The consumer needs to take into account that due to a number of significant differences in the thermophysical properties of water and heat carriers based on ethylene glycol, when using the latter, a number of technical features arise that require special attention.
The viscosity of an ethylene glycol solution is 1.5–2.5 times greater than that of water, and, accordingly, the hydrodynamic resistance to the movement of a liquid (aqueous solution) in the pipes will be higher, which will require a more powerful circulation pump (approximately 8% in terms of productivity and 50% in terms of pressure).
An aqueous solution of ethylene glycol has a higher coefficient of thermal expansion than water, so it is necessary to use a large expansion tank.
coolant based on distilled aqueous solution ethylene glycol toxic and poisonous to the human body (belongs to the third hazard class of moderately hazardous substances) and is recommended for use only in closed heating systems (with a closed expansion tank).
The heat capacity of the ethylene glycol solution is about 15% less than that of water, which worsens the heat exchange conditions and requires the installation of more powerful radiators.
An aqueous solution of ethylene glycol is undesirable to bring to a boil, as this will lead to an irreversible change in the chemical composition and properties of the aqueous solution.
Tab. No. 1. Freezing temperature dependence aqueous solution of ethylene glycol from his concentration
| Freezing point, °С | Ethylene glycol concentration, % | Freezing point, °С | |
| 5% | -2°С | 54% | -40°С |
| 11% | -4°С | 60% | -50°С |
| 15% | -6°С | 65% | -65°С |
| 21% | -9°С | 70% | -70°C |
| 25% | -11°C | 75% | -55°C |
| 30% | -15°C | 80% | -48°C |
| 36% | -20°C | 85% | -40°С |
| 40% | -25°C | 90% | -30°C |
| 45% | -30°C | 95% | -20°C |
| 50% | -35°C | 98% | -14°C |
It is no secret that the cooling system is the most important element of the internal combustion engine, on which the performance of the power unit directly depends. The main function of the system is to remove excess heat generated during the combustion of fuel. Incorrect temperature regime of the internal combustion engine can lead to a reduction in its service life, and severe overheating can lead to complete failure. The cooling system absorbs about 30% of all the energy generated by the engine (the rest is spent on efficient operation or removed through the exhaust system).
What is antifreeze
It is important to monitor the normal functioning of the cooling system for the reason that up to 40% of the malfunctions that occur in the internal combustion engine are somehow connected with a violation of its operation. Efficient heat removal from engine parts is provided by a number of mechanisms working in conjunction. But still, one of the key roles is assigned to the coolant - the liquid circulating in the cooling circuit and in direct contact with the heated surfaces.
The substance poured into the cooling system is called antifreeze. Actually, this term is applicable to liquids used in a wide variety of devices and industries. In this article, we will pay attention to automotive antifreezes designed for use in vehicle power plants.
Requirements for antifreeze
Due to the fact that a very important function is assigned to automobile antifreeze, and its working conditions are quite difficult, strict requirements are imposed on it. The fundamental ones are:
- High heat capacity and thermal conductivity;
- Low freezing point (antifreeze must retain its liquid state even at very low temperatures);
- Low viscosity over a wide temperature range (the fluid must circulate freely through the engine cooling jacket and at the same time provide good heat transfer);
- High boiling point (normal operation at normal engine temperatures);
- Low foaming;
- Good anti-corrosion properties (antifreeze should not contribute to the destruction of engine parts);
- Neutrality to elastomers (compatibility with rubber products);
- Harmless to the environment.
Composition and production technology of automotive antifreeze
The first antifreezes appeared in the 20s of the last century, and, surprisingly, their composition has changed little over the past decades. The vast majority of automotive antifreeze is based on just two components - ethylene glycol (or propylene glycol) and water. They account for 96-97% of the volume of the coolant, and the rest is occupied by additives.
Ethylene glycol, widely used in engineering, is nothing more than a dihydric alcohol, which is a colorless liquid with a density of 1.113 g / cu. see It has a sweetish taste and oily texture. The freezing point of ethylene glycol is -12.9 °С, the boiling point is about 197 °С. This is a toxic substance that, if ingested in a certain amount, can be fatal. Ethylene glycol is aggressive to metals used in a car engine, so it must be used together with anti-corrosion additives.
The main thermophysical properties of water are well known to us. It crystallizes at 0°C and begins to boil at 100°C. Freezing, water increases in volume, and even before reaching the boiling point, it begins to evaporate intensively. Another feature of ordinary water is the tendency to form deposits and scale, which is explained by the presence of salts and minerals in it. All of the above properties plus high corrosiveness do not allow the use of water in its pure form as a coolant. However, it is indispensable as one of the components, especially since soft or medium hard water with a low content of salts prone to precipitation is usually taken to prepare antifreeze.
An interesting point is that when mixing the two main components of antifreeze, a solution is formed with a significantly lower freezing point than that which the original liquids have separately. The exact crystallization temperature depends on the proportion of parts to be joined. As a rule, the proportion of ethylene glycol in antifreeze is 50-60%, which ensures the beginning of the freezing process when the thermometer reads -35 ... -49 ° С.
Another mandatory ingredient in all antifreezes are additives. Despite the fact that their share is quite small (usually about 2.5-3%), it is the composition and quality of additives that largely determine the resulting properties of the coolant, i.e. the efficiency of her work. In other words, superior technology in the production of these important components of antifreeze allows one manufacturer to make a more advanced product than others. The additives themselves are divided into the following groups:
- Additives based on inorganic compounds - silicates, nitrites, nitrates, phosphates, amines, borates and their derivatives.
- Additives based on salts of organic acids (carboxylates);
- Hybrid additives - are made on the basis of carboxylates with the addition of silicates.
Coolants with different types of additives perform their function in different ways, and, first of all, differ in the method of fighting corrosion. The very first antifreezes appeared with additives in the form of inorganic compounds. The corrosion protection mechanism of such compositions is reduced to the fact that the additive package creates a continuous protective layer on the cooled surface, which prevents direct contact with the water-glycol mixture. The layer is formed over the entire area, regardless of the presence of areas of corrosion, thereby interfering with the normal removal of heat. The active components involved in the formation of the layer are quickly consumed due to the large coverage area. As a result, the efficiency of antifreeze is low, and its service life is limited to 2-3 years.
Carboxylate additives have a slightly different mechanism of operation. They affect only the centers of corrosion, while the protective layer created is much thinner than in the case of the first type of additives. Such a selective effect saves active components, which leads to a significant increase in the service life of antifreeze (up to 5-7 years). Another advantage of the local protection mechanism is the high efficiency of heat removal due to the absence of barriers in the "healthy" areas of the metal.
In addition to the so-called corrosion inhibitors, the additive package includes additives with other useful properties. For example, anti-foaming agents, lubricants, anti-scale agents, anti-cavitation components.
Antifreezes based on carboxylates have recently become more widespread. In addition to the advantages already mentioned, they are less prone to deposit formation, provide better seal retention and have a more pronounced anti-cavitation effect.
The manufacturing technology of antifreeze is quite simple and does not require any expensive equipment. At the first stage, the concentrate is prepared, which includes ethylene glycol, additives and a small amount of water (approximate proportions are 92:5:3). The resulting mixture is subjected to multi-stage purification. After this stage, the concentrate is essentially ready to be dispensed into containers and sold. The procedure for diluting it with water is already carried out by the buyer himself. If we are talking about ready-to-use automotive antifreeze, then the enterprise itself undertakes to mix the concentrate and purified water. To obtain strictly defined parameters of the coolant, it is necessary to carefully control the dosage of the initial components.
Antifreeze or antifreeze: the history of the issue
A lot of coolants for engines called "Tosol" are sold on the market. Such a name may mislead some car owners, forcing them to believe that this is some kind of special substance that is different in composition from antifreeze. In fact, the well-known "TOSOL" is a trademark formed by a combination of the abbreviation of the department that developed the liquid ("Organic Synthesis Technology") and the ending "OL", denoting belonging to alcohols in chemistry. The long use of the word "Tosol" has led to the fact that it has become a household name and applicable to the entire category of automotive coolants.
Thus, the words antifreeze and antifreeze denote the same concept, being synonyms. Therefore, it makes no practical sense to pay attention to which of these two names this or that product received. More important are the composition of the additives, the scope and service life. The main criterion for choosing a coolant for a particular car model is the recommendations of the manufacturer of this very car, which are usually based on their own quality standards. We will talk about them below.
Classification systems and quality standards for antifreeze
As with motor oils, international standards such as ASTM or SAE have been developed for automotive antifreeze. However, at present, the specifications issued by the manufacturer of cars and engines are taking precedence. Almost all leading manufacturers not only develop their own quality standards, but also produce antifreezes under their own brand.
In the European market, one of the most authoritative are the specifications of the Volkswagen concern, in accordance with which the widespread division of antifreezes into classes G11, G12, etc. arose. Such markings correspond to well-defined regulations that determine the qualitative and quantitative composition of the additive package. So, the designation G 11 refers to the VW TL 774-C standard, which provides for the use of inorganic additives in antifreezes. Marking G 12 is applicable to coolants with carboxylate additives, defined by the VW TL 774-D specification. There are also classes G12 + and G12 ++, regulated by the VW TL 774-F and VW TL 774-G standards, respectively. And, finally, antifreezes with the most complex and expensive manufacturing technology received the G13 index.
Any of the above Volkswagen specifications excludes the presence of borates, phosphates, amines and nitrites in their respective antifreezes. The concentration of silicates is strictly regulated, and the G12+ class assumes their complete absence.
Examples of standards from leading car manufacturers:
- Ford: WSS-V97B44-D;
- Mercedes-Benz: DBL 7700.30;
- Opel/General Motors: B 040 0240;
- BMW: N 600 69.0;
- Volvo: 128 6083/002;
- Renault-Nissan: 10120 NDS00;
- Toyota: TSK2601G.
Is it possible to mix antifreezes and what does color affect?
The question of antifreeze compatibility usually arises from car owners who have purchased a used car and are not able to determine the brand of liquid poured into the cooling system. Moreover, motorists who are not versed in technical subtleties in the course of solving this problem, first of all, take into account the color of the composition splashing in the expansion tank. And, indeed, manufacturers use dyes with a variety of shades to color coolants. The most popular colors: red, green, blue, yellow, purple, orange. Some standards even regulate the use of certain shades. However, in fact, color is perhaps the last criterion that should be considered when mixing different brands of antifreeze. Dyes introduced into antifreeze are used only to make it clear that the liquid is technical, and, therefore, can threaten human health. In addition, due to the acquired shade, the visibility of antifreeze (initially colorless liquid) in the same reservoir of the cooling system improves. There is no direct connection between the color and the properties of the coolant.
What considerations should be followed when mixing antifreezes? Here are at least a couple of tips:
- Without problems, you can combine antifreezes that have the same base and meet generally recognized quality standards. True, the composition of the liquid is often not published by the manufacturer, so it remains only to follow the recommendations indicated on the label.
- Different types of antifreezes (with inorganic and organic additives) may be mixed only if the manufacturer explicitly indicates this possibility.
The incompatibility of antifreezes lies in the likelihood of a reaction between their constituent additives. This is fraught with sedimentation or deterioration of performance, which may affect the operation of the engine.
To begin with, the function of the coolant in internal combustion engines is performed by special compounds known among motorists under the name. The use of distilled water in cooling systems has long been abandoned, since water freezes at low temperatures, causes increased corrosion of channels in and, causes scale formation, etc.
Today, various TOSOLs or antifreezes can be available in two versions:
- in the form of a concentrate, which must be further diluted with distilled water in specified proportions;
- a ready-to-use product that can be immediately poured into the cooling system without additional manipulations;
In any case, the engine coolant not only protects the engine from and does not freeze in winter (unlike water), but also prevents active corrosion processes from starting in the liquid cooling system of the internal combustion engine, keeps the channels clean, and extends the life of individual elements (, etc.). e.)
It is important to take into account that antifreezes are different in composition, and also lose and change their properties during operation. This means that they cannot be mixed freely. Also, the liquid has a strictly limited service life, that is, it is necessary to periodically replace antifreeze or antifreeze, as well as regularly monitor the condition of the coolant.
Read in this article
Car engine coolant: general information
It is well known that an internal combustion engine is a heat engine that converts the energy of burning fuel into mechanical work. Naturally, such an installation must be cooled in order to maintain the required thermal regime.
In other words, for the normal operation of all components and parts under loads, the heating of the motor must remain within strictly specified limits. The operating temperature of the engine should neither fall below the specified threshold nor exceed the calculated value.
To solve the problem on cars, it is used, which is a combination of air and liquid cooling of the internal combustion engine. The fluid system involves forced circulation of the working fluid.
On a running engine, coolant heating can reach up to 100 degrees Celsius and even higher, while after stopping the engine, the liquid cools down to outside temperature during a long idle period.
As you can see, the working fluid is in rather difficult conditions. At the same time, special requirements are put forward for it. The fact is that the properties of the liquid should, first of all, ensure maximum efficiency of the engine cooling system. It directly depends on this. The coolant must have high thermal conductivity and heat capacity, have a high boiling temperature threshold, and sufficient fluidity.
Moreover, after cooling, such a liquid should not greatly expand in volume and crystallize (turn into ice). In parallel with this, the liquid should also not foam during operation, and also not be aggressive, that is, cause corrosion of various metal elements, affect rubber pipes, seals, etc.
Unfortunately, although distilled or purified water is cheap to produce and has a number of necessary properties (it has a high ability for efficient cooling, has a high heat capacity, non-combustible, etc.), it is still problematic to use it in an engine.
First of all, it has a low boiling point, evaporates quickly, and various impurities in its composition (salts, etc.) cause active scale formation. Also when the outside temperature drops to zero degrees and then ice forms.
In this case, a significant increase in the volume of frozen water occurs, which causes ruptures of channels and pipes, that is, damage occurs, cracks appear in metal parts, etc. For this reason, water cannot be used year-round in regions where average daily temperatures drop to zero or below in winter.
It is quite obvious that it is very difficult to constantly drain the water from the cooling system before parking the car on the street or in an unheated room. To solve the problem, special coolants have been developed that have acquired the property not to freeze at low temperatures.
In fact, the name "antifreeze" itself comes from the English "antifreeze", that is, non-freezing. These compositions quickly displaced water from liquid cooling systems, thereby greatly simplifying the features of vehicle operation.
As for TOSOL, this development is an analogue of Western antifreeze, only it was developed on the territory of the former USSR. The specified type of coolant was originally created for VAZ cars, while the trademark was not registered.
Today, many manufacturers of coolants in the CIS use the well-known name TOSOL for their products, however, the performance properties of liquids may differ due to the presence of various additives and additional components.
Features of antifreeze and practical operation
Note that in the engines of modern cars, antifreeze fluids are most often used, which are based on a glycol base. Simply put, such an antifreeze liquid is a mixture of water and ethylene glycol. There are also coolants that use propylene glycol, while mixing ethylene glycol coolants with propylene glycol is not recommended.
In practice, ethylene glycol or monoethylene glycol is a yellowish oily liquid. The liquid is odorless, has a slight viscosity, has an average density and a boiling point of about 200 degrees Celsius. At the same time, the crystallization (freezing) temperature is slightly less than -12 degrees.
If ethylene glycol or a solution of ethylene glycol with water is heated, a significant expansion occurs. To prevent the system from “breaking” from excess pressure, it was added to the device, which has the marks “min” and “max”. According to them, the required coolant level is determined.
It is also important to consider that ethylene glycol and its solutions are very aggressive, capable of causing severe corrosion of parts made of steel, aluminum, cast iron, copper or brass. In parallel with this, there is an increased toxicity of ethylene glycol and its extremely negative impact on living organisms. In other words, it is a strong and dangerous poison!
As for propylene glycols, they have similar properties to ethylene glycols, but are not as toxic. However, propylene glycol is much more expensive to produce, resulting in a much higher end cost. Also, at low temperatures, propylene glycol becomes more viscous, its fluidity is worse.
For the above reasons, the composition of the coolant necessarily uses a whole package of active additional additives that provide anti-corrosion, protective and detergent properties, prevent foaming, stabilize the liquid, tint the solution, give a characteristic recognizable smell, etc. Also, additives somewhat reduce toxicity.
Let's get back to using antifreeze. The need to mix ethylene glycol or propylene glycol with distilled water is dictated by the fact that the freezing point of such a solution directly depends on the proportions of these two components.
In simple words, water freezes at zero, ethylene glycol at -12, but mixing them in different proportions allows you to create solutions whose freezing threshold is from 0 to -70 degrees and even higher. The ratio of glycol to water also affects the boiling point of the solution.
Without going into details, in practice, the lowest freezing point can be achieved if the composition contains just under 67% ethylene glycol, which is diluted with 33% water. In this case, the same or very close freezing point can be obtained at different ratios of water and concentrate.
As for practical operation, as a rule, motorists often use a simple scheme when replacing coolant in many regions, diluting the antifreeze concentrate with water in proportions of 60/40. Please note that this is a general guide, before preparing the solution, read the individual recommendations of a particular antifreeze manufacturer on the package.
To check the ratio of ethylene glycol and water in the solution, the density is additionally measured. For this, a hydrometer is most often used. Based on the data obtained, we can conclude what is the content of ethylene glycol and determine the crystallization temperature.
Mixing antifreeze and antifreeze
It should be noted that the compatibility of various coolants depends on the technical conditions of their manufacture. In simple terms, fluids may be completely incompatible or only partially compatible.
The fact is that each manufacturer uses different additives that can react, thereby the mixture loses the necessary properties, precipitation occurs and a number of other undesirable consequences occur.
Taking into account the fact that during operation it periodically becomes necessary to raise the coolant level in the expansion tank (the water in the composition boils away over time), it is more correct to add distilled water or use only the brand and type of antifreeze that was previously used.
If an emergency malfunction occurred, then it is optimal or completely to drain the existing residues, flush the system and fill in fresh coolant in full, or add antifreeze that is suitable in color and properties.
As for norms and standards, as a rule, domestic TOSOLs must comply with the requirements of GOST, while they are not separately certified. Imported antifreezes are standardized according to SAE and ASTM.
Foreign standards define various properties of liquids based on ethylene or propylene glycol, determining the purpose, adjusted for operating conditions. Liquids are divided into compositions for passenger cars, small trucks, heavy vehicles, special equipment, etc. Note that antifreezes according to ASTM type D 3306 are allowed for use on domestic passenger cars.
You should also take into account the individual specifications of the automakers themselves, who often put forward a number of their own requirements. In the list of various regulations of large concerns, it should be noted that the use of antifreezes is prohibited or highly discouraged, in which the presence of various corrosion inhibitors, including nitrites, phosphates, etc., is noted.
At the same time, the maximum content of silicates, chlorides and other components in the coolant is also determined. Following these guidelines allows you to extend the life of the seals, avoid active scale formation, and increase the level of protection against corrosion.
When and why you need to replace antifreeze
As already mentioned, antifreezes can have a negative effect on the parts of the cooling system and the engine itself. To reduce the degree of this effect, various additives are used. However, during operation, these additives “wear out”, that is, the content of additives and their efficiency is reduced.
Simply put, over time, corrosion processes become more active, the coolant begins to foam more strongly, the heat dissipation deteriorates, and the temperature regime is disturbed during the operation of the internal combustion engine. For this reason, antifreezes are recommended to be changed after 2 years, or every 50-60 thousand km. mileage (whichever comes first).
As for modern developments such as G12 and G12 + antifreezes, the service life of these fluids has been extended to 3-4 years, but their higher cost can be considered a minus.
Also, the engine coolant needs to be replaced in cases where exhaust gases from the cylinders have entered the cooling system or traces of engine oil are visible in the antifreeze / antifreeze. As a rule, the cause of such malfunctions is a broken cylinder head gasket, cracks in the BC or cylinder head. In any case, the coolant under such conditions will quickly lose its useful properties.
The following signs indicate the need to replace the coolant:
- appearance in the expansion tank;
- change in the color of the coolant, the appearance of a burnt smell;
- with a slight decrease in the outside temperature, a precipitate is visible in the tank, the antifreeze becomes jelly-like, etc.
- , the cooling system fan is constantly running, the motor is on the verge of overheating;
- antifreeze has acquired a brownish-brown color, has become cloudy. This indicates that the liquid has exhausted its resource, the additives do not perform their function, and active corrosion of elements and parts occurs inside the cooling system.
We also note that in the event of an emergency, it is often necessary to add to the antifreeze either coolant from another manufacturer, distilled water of dubious quality, or ordinary running water. In such cases, it is necessary to get to the place of repair, carry out all the work, and then without fail flush the cooling system and only then completely replace the antifreeze.
- As for the process itself, you only need to change the coolant on a cold engine. After the engine has cooled down, you need to unscrew the cap of the expansion tank or the radiator cap.
- Next, you need to open the valve of the radiator of the interior heater (stove radiator). This is necessary in order to remove possible fluid residues in the radiator and pipes to it.
- Then you should unscrew the drain plugs in the radiator of the car's cooling system, as well as the plug in the cylinder block.
- After that, the coolant is drained into a pre-prepared container, after which the plugs can be tightened.
Please note that when working with coolants, it is important to understand that ethylene glycol is a strong poison, and can also enter the body even through the skin. A small dose of ethylene glycol when taken orally is enough for severe poisoning and death!
Also, ethylene glycol has a sweetish aftertaste, it must be kept out of the reach of children. It is forbidden to spill ethylene glycol or propylene glycol, as the liquid is dangerous for animals. It is forbidden to pour antifreeze into water bodies, pour it onto the ground or down the drain!
- The final step is to fill the expansion tank with fresh fluid. Fill the coolant slowly and carefully to avoid the formation of air pockets in the system.
- At the end of the procedure, the tank and / or radiator cap is screwed on, then the engine can be started. After starting, the unit warms up at XX to operating temperature (on many cars until the fan turns on).
- Now the engine must be stopped and allowed to cool, after which the reservoir cap is opened again and the coolant is added according to the level (in case of a decrease).
If we talk about flushing the cooling system and radiator, during scheduled regular replacements of antifreeze of the same brand / type, then it will be enough to flush the entire system with ordinary distilled water. In extreme cases, you can boil running water in advance, and then use it for washing.
In cases where a transition is made from TOSOL to antifreeze, from water to TOSOL, from antifreeze of one color to another type of coolant, or the dirty antifreeze, etc., simply changes, then the system needs to be cleaned more thoroughly. This means that it will be necessary to separately remove possible or obvious deposits, scale, rust, decomposition products of additives in old antifreeze, etc.
As a rule, special ready-made cleaners of the engine cooling system are used for cleaning. Such compositions are complex, have corrosion inhibitors, well remove scale and deposits. Also, motorists use various water-acid solutions of self-preparation for flushing, however, the use of such solutions is not recommended on modern internal combustion engines.
The general procedure for flushing the cooling system is as follows:
- after draining the coolant from the system, the flushing liquid is filled. Then the engine is started, after which the unit runs for a certain amount of time (usually 20-40 minutes).
- Next, the washing is drained, assessing the degree of contamination of the drained liquid. The procedure is repeated until the outflowing flush is clean.
- At the end, distilled water is poured into the system, the engine warms up again to operating temperatures, then the water is drained. This is necessary to remove wash residues. Then you can fill in fresh antifreeze without the risk of losing its properties as a result of contact with flush residues.
- We also note that although it is possible to wash the remains of the cleaner in the cooling system at one time, experienced drivers recommend flushing the system at least twice with distilled water.
During operation, the level of antifreeze in the expansion tank decreases even when the system is tight. The problem is that water is evaporating. Distilled water should be added to the tank (in extreme cases, ordinary and well-boiled water for at least 30-40 minutes).
If there is an antifreeze leak, then it is no longer possible to compensate for the loss with water alone. In other words, it is necessary to add coolant, and taking into account the fact that many coolants do not mix with each other.
It is optimal to have a concentrate and distilled water in stock for topping up, mixing the liquids in the proportion specified by the manufacturer. As for ready-made antifreezes, try to avoid purchasing such compounds in car markets or from individuals who sell similar products along highways.
There have been frequent cases when, instead of coolant, tinted running water, antifreeze treatment, etc. were sold. For this reason, the right decision would be to buy coolant in specialized car dealerships.
We also note that it is forbidden to use pure concentrate undiluted with water in the engine cooling system. As already mentioned, ethylene glycol with a package of additives freezes at negative temperatures of about -12 degrees.
It turns out that the concentrate will simply freeze in the system, since without dilution with water it cannot be considered a ready-to-use product. As for the proportions, you need to study the label on the package with the concentrate. Usually, manufacturers themselves indicate separately what to pour into the radiator or tank on different cars, how much concentrate and water is needed, and how to mix them in order to get the desired freezing temperature of the coolant.
In parallel, we note that cases of fake antifreezes of well-known brands have become more frequent in the CIS. For this reason, carefully inspect the canister. The container must be of high quality, all stickers and labels must have a clear font and be placed evenly on the canister.
The canister should indicate the batch number, manufacturer, as well as recommendations on how to properly dilute the antifreeze (in the case of a concentrate) or use a ready-made product. The boiling point, freezing point, date of manufacture, expiration date and other important information are also indicated.
Cork deserves special attention. Typically, manufacturers use caps with a disposable seal. Additionally, for better protection against counterfeiting, a hologram sticker, etc. may be present.
It is necessary to verify the integrity of the seal, the toothed ring should fit snugly against the neck, not scroll. The lid itself should not be glued to the neck. Also, the canister must be airtight, no liquid leaks or air can escape from under the lid when turned over or pressed.
Finally, we note that many manufacturers use containers made of transparent or translucent plastic, allowing you to assess the color and condition of the liquid in the canister. When shaking the coolant canister, foam should form, which settles in a couple of seconds in a canister with liquid ready for use, and also after 4-5 seconds. in the case of undiluted concentrate.
If during the inspection it is noticed that the liquid has become cloudy, the foaming is high, the sediment at the bottom is visible, or the general color of the antifreeze is suspicious, then it is better to refrain from such a purchase.
