No less important than the brand of fuel for the engine. Knowledge of the composition and types will help drivers choose a high-quality and, most importantly, suitable coolant for a car. What are the types, what is the difference between the composition of antifreeze and antifreeze - readers will learn all this after studying this material.
The composition of antifreeze for a car and its types
Organic and inorganic antifreezes
Today, coolant can be divided into two types - silicate and carboxylate antifreeze. As for silicate, “Tosol” refers to it. The composition of such a coolant includes inorganic acids, borates, silicates, phosphates, nitrates and nitrites. Silicates are the main additive in inorganic coolant. Such antifreeze is not suitable for modern cars, as it has many disadvantages. Made from ethylene glycol.
Additives settle on the inner surface of pipelines, their main task is to provide corrosion protection and normal conductivity. Antifreeze copes with the first task perfectly, and with the second - exactly the opposite. Due to the low thermal conductivity, heat transfer is very sluggish, which results in frequent overheating of the motor. That is why it is not recommended to use antifreeze on foreign cars, since engine wear occurs too quickly. There is another serious drawback - you need to change the silicate antifreeze every 30 thousand kilometers, otherwise, in addition to overheating, corrosion will also appear inside the cooling system.
As for carboxylate antifreezes, they use only organic acids. That is why this type has significantly fewer drawbacks than the silicate version. Organic additives cover only those areas where corrosion occurs, so heat transfer is practically not lost. This is the main advantage over silicate antifreeze. Carboxylate antifreeze is made based on ethylene glycol or propylene glycol.
It was the carboxylate liquid that began to be called antifreeze after it began to be supplied to the CIS. But many today call it antifreeze. The task of the motorist is to choose the appropriate type for his car. If this is an old domestic car, then antifreeze will not get worse, and it costs much less than organic antifreeze. In other cases, you need to purchase carboxylate coolant. As for the replacement of antifreeze, it is required only after 200 thousand kilometers. It was also possible to achieve such a long period by adding organic additives.
Antifreeze classification
To date, there are three classes of antifreeze:
- Class G11. Has a green or blue color. This class includes the cheapest fluids that are on the automotive market. The composition of antifreeze G11 is as follows: ethylene glycol, silicate additives. It is to this lower class that domestic antifreeze belongs. Silicate additives give antifreeze lubricating, anti-corrosion and anti-foam properties. As mentioned above, the service life of such antifreeze is quite low - about 30 thousand kilometers.
- Class G12. Most often it is red or pink antifreeze. Higher level of quality. Such a liquid serves much longer, has more useful properties, but the price of G12 is higher than that of G11. G12 antifreeze contains organic additives and ethylene glycol.
- Class G13(formerly G12+). Has an orange or yellow color. This class includes environmentally friendly coolants. They decompose quickly and do not harm the environment. This result became available after propylene glycol was added to G12 antifreeze, while carboxylase remained as additives. Any antifreeze based on ethylene glycol will be more toxic than the equivalent based on propylene glycol. The only disadvantage of the G13 is the high cost. Most environmentally friendly G13 is common in European countries.
Popular brands of antifreeze
We figured out the classification, now you can go through the well-known brands that drivers prefer throughout the CIS. These include:
- Felix.
- Alaska.
- nord.
- Syntec.
These are the best options in terms of price / quality ratio. So, let's start with "Felix" - this antifreeze is designed for all trucks and cars. Able to function normally in severe climatic conditions. Felix antifreeze contains special patented additives that extend the life of the cooling system pipelines, protect the engine from freezing and overheating. The composition of Felix antifreeze contains anti-foam, anti-corrosion and lubricating additives, the liquid belongs to the optimal class G12.
Composition and properties of Felix antifreeze
If we talk about high-quality liquids that belong to Tosol (G11 based on inorganic additives), then this is Alaska. The emphasis in this product is on fighting the cold. For example, a certain composition of Alaska antifreeze can withstand temperatures down to -65 ° C. There are options for warm regions, where in winter the thermometer needle does not fall below 25 ° C. Of course, the types of antifreeze marked G11 have their drawbacks.
Composition and properties of antifreeze Alaska
Another good option is NORD antifreeze. The company supplies all types of coolant to the automotive market - from G11 to G13, so it makes no sense to describe the composition of NORD antifreeze.
And the last option we'll look at is automotive antifreeze Sintec. The company is mainly engaged in the production of class G12 liquids. Antifreeze is great for all modern engines. Many professional repairmen recommend using this company's antifreeze for those drivers who drive cars with an aluminum engine. The composition of Sintec antifreeze includes the company's patented additives, they perfectly protect the system from the formation of deposits in the water pump, various channels, engine compartment and radiator. Sintec also reliably protects the cooling system from corrosion.
The composition and properties of antifreeze sintek
Antifreeze - a coolant based on ethylene or propylene glycol, translated "Antifreeze", from international English, as "non-freezing". Class G12 antifreeze is intended for use on cars from 96 to 2001, modern cars usually use 12+, 12 plus plus or g13 antifreezes.
“The key to stable operation of the cooling system is high-quality antifreeze”
What is the feature of G12 antifreeze
Antifreeze with class G12, as a rule, is painted in red or pink colors, and also, compared to antifreeze or G11 antifreeze, has a longer service life - from 4 to 5 years. G12 does not contain silicates in its composition, it is based on: ethylene glycol and carboxylate compounds. Thanks to the additive package, on the surface inside the block or radiator, localization of corrosion occurs only where it is needed, forming a resistant micro film. Often this type of antifreeze is poured into the cooling system of high-speed engines. Mix antifreeze g12 and coolant of another class - unacceptable.
But he has one big minus - G12 antifreeze begins to act only when a center of corrosion has already appeared. Although this action eliminates the appearance of a protective layer and its rapid shedding as a result of vibrations and temperature changes, which makes it possible to improve heat transfer and longer use.
Main technical characteristics of class G12
Represents homogeneous transparent liquid without mechanical impurity of red or pink color. G12 antifreeze is ethylene glycol with the addition of 2 or more carboxylic acids, does not form a protective film, but affects already formed corrosion centers. The density is 1.065 - 1.085 g/cm3 (at 20°C). The freezing point is within 50 degrees below zero, and the boiling point is about +118°C. Temperature characteristics depend on the concentration of polyhydric alcohols (ethylene glycol or propylene glycol). Often, the percentage of such alcohol in antifreeze is 50-60%, which allows you to achieve optimal performance. Pure, without any impurities, ethylene glycol is a viscous and colorless oily liquid with a density of 1114 kg / m3 and a boiling point of 197 ° C, and freezes at 13 ° C minutes. Therefore, a dye is added to the antifreeze to give individuality and greater visibility of the liquid level in the tank. Ethylene glycol is the strongest food poison, the effect of which can be neutralized with ordinary alcohol.
Remember that coolant is deadly to the body. For a fatal outcome, 100-200 g of ethylene glycol will be enough. Therefore, antifreeze should be hidden from children as far as possible, because a bright color that looks like a sweet drink is of great interest to them.
What does G12 antifreeze consist of
The composition of the antifreeze class G12 concentrate includes:
- dihydric alcohol ethylene glycol about 90% of the total volume that is needed to prevent freezing;
- distilled water, about five percent;
- dye(color often identifies the class of coolant, but there may be exceptions);
- additive package at least 5 percent, since ethylene glycol is aggressive to non-ferrous metals, several types of phosphate or carboxylate additives based on organic acids are added to it, acting as an inhibitor, allowing them to neutralize the negative impact. Antifreezes with a different set of additives perform their function in different ways, and their main difference is in the methods of combating corrosion.
In addition to corrosion inhibitors, the set of additives in the G12 coolant includes additives with other necessary properties. For example, the coolant must have anti-foaming, lubricants and compositions that prevent the appearance of scale.
What is the difference between G12 and G11, G12+ and G13
The main types of antifreezes, such as G11, G12 and G13, differ in the type of additives used: organic and inorganic.
General information about antifreezes, what is the difference between them and how to choose the right coolant
Cooling class G11 liquid of inorganic origin with a small set of additives, the presence of phosphates and nitrates. Such antifreeze was created using silicate technology. Silicate additives cover the internal surface of the system with a continuous protective layer, regardless of the presence of corrosion areas. Although such a layer protects already existing centers of corrosion from destruction. Such antifreeze has low stability, poor heat transfer and a short service life, after which it precipitates, forming an abrasive and thereby damaging.
Due to the fact that G11 antifreeze creates a layer similar to scale in a kettle, it is not suitable for cooling modern cars with radiators with thin channels. In addition, the boiling point of such a cooler is 105 ° C, and the service life is no more than 2 years or 50-80 thousand km. run.
Often G11 antifreeze turns green or blue colors. This coolant is used for vehicles manufactured before 1996 years and machines with a large volume of the cooling system.
G11 is not well suited to aluminum heatsinks and blocks as its additives cannot adequately protect this metal at high temperatures.
In Europe, the authoritative specification of antifreeze classes belongs to the Volkswagen concern; therefore, the corresponding VW TL 774-C marking provides for the use of inorganic additives in antifreeze and is designated G 11. The VW TL 774-D specification provides for the presence of organic-based carboxylic acid additives and is labeled as G 12. The VW TL 774-F and VW TL 774-G standards mark the G12 + and G12 ++ classes, and the most complex and expensive G13 antifreeze is regulated by the VW TL 774-J standard. Although other manufacturers such as Ford or Toyota have their own quality standards. By the way, there is no difference between antifreeze and antifreeze. Tosol is one of the brands of Russian mineral antifreeze, which is not designed to work in engines with an aluminum block.
It is absolutely impossible to mix organic and inorganic antifreezes, since a coagulation process will occur and as a result a precipitate will appear in the form of flakes!
A liquid grades G12, G12+ and G13 varieties of organic antifreeze Long Life. Used in cooling systems of modern cars manufactured since 1996 G12 and G12+ based on ethylene glycol but only G12 plus involves the use of hybrid technology production in which silicate technology was combined with carboxylate technology. In 2008, the G12 ++ class also appeared, in such a liquid, an organic base is combined with a small amount of mineral additives (called lobrid Lobrid or SOAT coolants). In hybrid antifreezes, organic additives are mixed with inorganic additives (silicates, nitrites and phosphates can be used). Such a combination of technologies made it possible to eliminate the main drawback of G12 antifreeze - not only to eliminate corrosion when it has already appeared, but also to perform a preventive action.
G12+, unlike G12 or G13, can be mixed with a G11 or G12 class liquid, but still such a “mix” is not recommended.
Cooling class G13 fluid has been produced since 2012 and is designed for automobile engines operating in extreme conditions. From a technological point of view, it has no differences from the G12, the only difference is that made with propylene glycol, which is less toxic, decomposes faster, which means causes less harm to the environment when it is disposed of and its price is much higher than the G12 antifreeze. Invented based on the requirements to improve environmental standards. G13 antifreeze is usually purple or pink, although it can actually be dyed in any color, since it is just a dye on which its characteristics do not depend, different manufacturers can produce coolants with different colors and shades.
The difference in the action of carboxylate and silicate antifreeze
G12 antifreeze compatibility
Is it possible to mix antifreezes of different classes and different colors of interest to quite a few inexperienced car owners who have purchased a used car and do not know which brand of coolant was filled in the expansion tank.
Today I nevertheless decided to write an article about the composition of antifreezes that are used in the automotive industry. There are many myths and legends about the components, but personally I have not found normal sane information that can be read by an ordinary person, without a chemical education, and understand what kind of miracle this solution is. As usual, I will try to convey to you in ordinary "human" words ...
First, a little definition
Antifreeze (Antifreeze - non-freezing) - a liquid for a car that is used in the engine cooling system. It does not allow the motor to boil at high temperatures, and also does not freeze at negative rates. If you properly dilute this liquid, then it can hold up to - 60, - 70 degrees Celsius.
If you dig into history, earlier on many cars they used ordinary water for cooling, but it was extremely inconvenient - the water boiled already at 100 degrees Celsius and evaporated, it also froze at zero degrees, which entailed serious breakdowns.
General composition of antifreeze
Like it or not, but all antifreezes, be it, consist of 80% of almost the same thing:
- Ethylene glycol (monoethylene glycol, ethanediol, etc.) - this is a simple dihydric alcohol, oily consistency, practically odorless, slightly viscous, if you measure the density, then it is - 1.112-1.113 g / cm3 (if measured at 20 degrees Celsius). The boiling point is 196 ° C, but it freezes already at - 12, - 13 ° C (therefore, it must be diluted with water). When heated, it expands greatly, therefore, about 10% less is poured into the system in a cold state.
- Water . It is MANDATORY needed, otherwise pure "glycols" will freeze already at -13 ° C. Always use distilled water - so as not to cause scale on the walls of pipes and radiators.
- Additives . Basically, these are anti-corrosion - they are divided into four types: - lobrid, carbonoxylate, hybrid and traditional.
This is the main composition of antifreeze, if everything is clear with the first and second points, then the third point (additives) needs additional explanation.
Antifreeze additives
As I have already indicated their 4 main types, I will try to talk about each separately:
Traditional - have been used as a corrosion deterrent for a very long time, literally from the moment of foundation, they have silicates, phosphates, borates, nitrites, amines, etc. in their compositions, it should be noted that all substances are of inorganic origin. Such antifreezes are now a thing of the past, because they have two big drawbacks:
- this is a short service life (about 2 years) after this period, the silicates that are in the composition settle on the walls of pipes and radiators - worsening cooling,
- inability to withstand large positive temperatures, already at 110 ° C, they boil.
To traditional, it is possible to carry our TOSOL, blue color.
Carbonoxylate - used in red antifreeze, made on the basis of organic compounds, namely carboxylic acids. It does not form protective films on pipes and radiators, but it fights against corrosion centers, forming a thin film (about 0.1 microns) on them, which does not interfere with cooling in any way.
He currently has the longest service life, it is 5 years.
hybrid - such additives are found in green antifreeze. It consists of both organic and non-organic compounds - that is, a "hybrid". The service life is not as long as that of carbon additives, only 3 years.
Lobrid - used in purple antifreeze. The most perfect at the moment, their composition is mineral protective substances + organic compounds. The principle of their operation can be described as follows - mineral substances form a very thin protective film that does not interfere with cooling, and organic compounds are consumed only when corrosion occurs. As the creators assure, antifreezes with such additives have a very long service life, sometimes equal to the entire life of the car.
As you can see, there are big differences in additives, each is sharpened for its own. But wait, tell me - why do we need additives at all, because it seems like alcohols do not cause corrosion, or is water to blame for everything?
About corrosion
Again, many of us “step on our own rake”, thinking that if ethylene glycol is alcohol, then it will not oxidize and react with the walls of pipes and radiators. But it's not! When mixed with water, it is a highly corrosive compound! If it is not “isolated” with additives, then it will corrode the walls of metal pipes and radiators, rust will begin to appear, and so quickly that leaks are possible after a few months.
To prevent such a process, additives are needed, this is MANDATORY! That is, they seem to pacify the mixture of ethylene glycol and water.
Temperature regime of antifreeze and composition
Antifreeze should handle high and low temperatures equally well. Let's just say that if pure ethylene glycol is poured in, it keeps positive temperatures of 196 ° C, that is, almost any engine will cool perfectly, because the operating range is often below 95 ° C (of course, there are high-temperature engines, but they are not so common).
But pure ethylene glycol will keep a disgustingly low temperature, already at -13 degrees it will simply freeze inside the engine (which will cause serious damage).
A few words about cavitation
The composition of the coolant must take into account - "cavitation" inside the cooling system. The thing is that when the fuel is detonated, high-frequency vibrations pass to the walls of the block head, which is why the antifreeze “boils”. Small bubbles are constantly formed that burst - this is cavitation. Such bubbles adversely affect the composition of the liquid, namely, they reduce the protection of additives, so a corrosion center can often occur. Therefore, it is necessary to choose the right antifreezes, for example, based on carboxylic acid and lobrid ones, they resist cavitation many times better than "traditional" and hybrid liquids.
Foam formation
It is worth noting that when developing coolants, such compositions were selected so that foam did not occur at all - after all, foam is “almost” “airing” of the cooling system pipes, which can lead to disastrous results - trite overheating. Therefore, almost none of the compositions (with various additives) does not foam. Which is already good! It is also worth noting that - “borscht” with water when diluted, it just foams beautifully.
Protection of rubber and plastic joints
There is not metal everywhere in the system, there are many rubber and plastic hoses and connections. Antifreeze should not corrode them, if it practically does not react to plastic, then rubber - it should protect against cracking and premature “drying out”. The red carbon version does a great job with this. And the rest to keep at quite a high level.
About color
This is an ambiguous question, there are many disputes and legends about it, that supposedly all reasoning is deceptive. For example, you can pour red antifreeze into green and nothing will happen! And the color is just a marketing ploy! As I wrote above, antifreezes are specially tinted so that you know what kind of additive is present in it, carboxylic acid, hybrid, conventional traditional or some other.
Also, many do not want to delve into such information - not all cars have a similar cooling system, I mean the metal from which it is made, some have brass or copper in the structure, others aluminum. For example, carboxylic acid additives (red color) perfectly protect copper and brass, but corrode aluminum. But hybrid additives (green color) perfectly protect aluminum, but copper and brass are not so good.
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.
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.
