The properties of the radiator directly depend on what material it is made of. Consider the most popular types of materials used in the manufacture of radiators and heaters.
Aluminum
A metal from the light group, the third most abundant chemical element in the world. Aluminum lends itself well to various types machining and casting. Specifications metal:
- high thermal and electrical conductivity;
- the metal is not magnetized and does not burn;
- excellent anti-corrosion properties.
Corrosion resistance is created due to the formation of an oxide film that protects the aluminum surface from negative external influences.
Due to its high ductility, the metal is used in various industries, second only to iron in terms of application. Takes any form long term services. It is one of the lightest metals in the world (almost 3 times lighter than iron), while aluminum is very strong.
It has a high ability to combine with different elements, which makes it possible to obtain a wide range of alloys. Even if a small amount of another chemical element is added to the composition, this will seriously change the characteristics of the metal and expand the possibilities of its application.
Aluminum does not occur in its pure form in nature. The bulk of the world's aluminum is produced from bauxite - the reserves of this mineral are concentrated in different parts of the world. In Russia, for the production of metal, nepheline ore is used, mined in a quarry.
Aluminum radiators are corrosion resistant and have excellent thermal conductivity. Due to the high ductility of the metal, radiators are not recommended to be installed in places where equipment can be subjected to mechanical damage. To increase the resistance of the metal to external mechanical influences its surface can be additionally treated with a special powder paint.
Steel
For the production of heating radiators, low-carbon steel is usually used, which has high corrosion resistance. Pre-steel panels undergo a degreasing process, they are coated with powder enamel and subjected to heat treatment.
Advantageous characteristics of low carbon steels:
- plasticity (this allows the material to be subjected to deformation without the risk of cracking);
- excellent welding and processing ability, poor hardening.
The main area of application of low-carbon steels is the manufacture of various products by cold stamping. To give the material additional properties are added to it special items, changing the composition and characteristics of steel: increasing corrosion resistance, improving strength characteristics, etc. Carbon steel with additional additives is called alloy steel.
There are several technologies for the production of steel, mainly cast iron and scrap metal are used to obtain it. The most common smelting technology is the oxygen-converter method. TO latest methods smelting can be attributed to electrolysis.
The disadvantages of low-carbon steel compared to low-alloy types are lower strength characteristics and lower impact strength.
Cast iron
Cast iron is made up of carbon and iron. Percentage carbon can be up to 6% or more. The properties of the material are affected by the presence of impurities in the composition: manganese, sulfur, silicon, etc. Depending on the amount of impurities, there are three main types of cast iron:
- white - mainly used for steel production;
- gray - a viscous metal that can be easily processed, is used in mechanical engineering and the production of various structures operating in conditions of increased intensity;
- alloyed - this is the name of cast iron, to which elements are added to improve its main characteristics: strength, wear resistance, etc.
Cast iron is used for the production of cast structures and parts operated under conditions of low dynamic load. The material is well processed and cheaper than steel (this explains affordable price heating radiators).
The first radiator was cast from cast iron in the middle of the 18th century. Later, the equipment became widespread in Europe and Russia and is still in demand, despite the development of technologies for the production of radiators from other materials.
One of the advantages of cast iron, which has made it a popular material for the production of radiators, is its high resistance to corrosion. After installation, the surface of the radiator is covered with dry rust, which inhibits further penetration of corrosion.
The walls of cast iron radiators are very thick, which increases the weight and strength of the product, and also significantly extends its service life. Another plus is unpretentiousness to the coolant. The presence of impurities in the water does not harm the battery from the inside, the material is difficult to damage, therefore cast iron radiators provide stable work heating system for a long time without requiring replacement (up to 50 years).
The high mass of radiators provides excellent heat capacity and inertia, smoothing out changes in the temperature regime in the room. With long-term operation (more than 40 years), the destruction of cast-iron nipples may occur. Due to the porosity and roughness of cast iron, plaque forms on the inner walls of radiators over time, which leads to loss of heat transfer.
Brass
Brass is an alloy based on zinc and copper. The composition of zinc in the alloy can reach 45%, it affects the improvement of the technological and mechanical properties of brass, and also reduces the cost of the material (because it has a lower price than copper).
Various products are obtained from brass, including radiator tubes, which are distinguished by increased strength, long term service life, corrosion resistance and weldability.
The material is easy to process and has high mechanical properties. Compared to bronze, brass has higher strength and corrosion resistance. The main disadvantages of brass include poor resistance in the open air and in salt water.
High humidity can provoke the development of brass corrosion, therefore, at the production stage, the material is processed and subjected to low-temperature firing. Brass retains its ductility even when the temperature drops, without becoming brittle.
Brass smelting is carried out in furnaces of various types, the most common technology is smelting in induction furnaces. According to technology, the alloy is not recommended to be heated to too high temperatures, as this can lead to the ignition of some components.
Copper
Mankind began to use copper as early as the 4th millennium BC, this is due to the fact that this metal can be found in nature.
The melting point of copper is 1083 ° C. It is a soft and malleable metal, good conductor electricity and has excellent thermal conductivity. At a negative temperature, the metal increases its strength characteristics and ductility.
Copper is resistant to corrosion; when used in conditions of high humidity and an atmosphere with a high content of carbon dioxide, the metal surface is covered with a special protective coating that has a greenish tint. This coating called patina.
Almost 80% of all copper on the planet is smelted from sulfide ores. The process includes several procedures: annealing, smelting, refining, etc. Due to its high heat-conducting properties, the metal is used to make heating radiators. The flexibility of the metal simplifies installation work.
There are various copper alloys: bronze, brass, etc., which increase quality characteristics metal. To obtain alloys, zinc, lead, manganese, etc. are added to the composition of copper. The content of copper itself in alloys exceeds 30%.
Copper radiators can be operated at high atmospheric pressure, and the maximum temperature limit that batteries can withstand is + 150 °. The resistance of copper to many chemical active substances allows it to be used in radiators different types coolants, including ordinary household antifreeze.
The disadvantages of the metal include its high cost, which increases the price of radiators and limits their wide distribution.
Not a single engine internal combustion not without a cooling system. It does not allow the engine to overheat during vehicle operation. On most widespread received a liquid cooling system. Among its advantages are efficient and uniform cooling of the engine, reducing the noise of operation.
car radiator
One of essential elements this design is a radiator. Its task is a liquid, while removing heat to environment. Some semblance of a modern radiator was installed even on the most early cars with ICE.
The engine cooling radiator, as a rule, consists of the upper and lower tanks, the core, where the liquid is directly cooled, and fastening parts. The liquid entering the radiator from the engine water jacket is cooled in it to the required temperature, after which it returns to the engine again. The body of the tanks and the core of the radiator are made of light metals such as brass or aluminium. Their good thermal conductivity ensures efficient cooling liquids.
The core of the radiator is made up of flat metal plates that vertically pierce hollow tubes connecting the upper and lower tanks. Thus, the liquid passes through the core in many flows, resulting in an increase in the area and intensity of cooling.
Radiator diagram
Radiator pipes connect the tanks to the engine water jacket. In the lower tank there is a faucet that is designed to drain the liquid. The same faucet is installed on the engine. Liquid is poured into the cooling system through the neck located on the upper tank of the radiator.
The cooling systems that modern cars have take into account many parameters, such as engine temperature, oil temperature, ambient temperature, etc.
Action fluid system cooling is as follows. The pump constantly and continuously circulates the fluid. Thanks to this, the cylinder walls and block heads are washed, heat is removed from them. The heated liquid is directed through the nozzles to the radiator, where heat is removed to the environment. After that, the cooled liquid returns to the engine cooling jacket and the cycle repeats.
To increase the efficiency of the entire cooling system, an additional fan is installed in front of the engine, which pumps air onto the surface of the radiator. As a result, the heat transfer process is greatly accelerated.
The vast majority of vehicles are equipped with an electrically driven radiator fan that starts automatically thanks to a control sensor when the coolant temperature becomes too high. The fan together with the cooling radiator are installed in front of the engine.
Consequences of engine overheating
- Weak overheating– the engine runs for 5-10 minutes at elevated temperature. This can happen due to a breakdown of the fan or water pump, but the driver notices overheating in a timely manner and stops the engine. The consequences of such overheating are minimal - pistons can melt slightly, and many modern engines will not even notice this at all.
- Medium superheat– engine operation at elevated temperature for more than 20 minutes. The reason for this overheating can be one of the above or any other. Most often, with an average degree of overheating, the cylinder head begins to “lead” (the seating surfaces are bent, cracks form), the head gasket breaks, the seals begin to leak oil, and the pistons can collapse.
- Severe overheating- an extreme degree of overheating, fraught with the most serious consequences, up to jamming and destruction of the engine. With severe overheating, pistons begin to melt, aluminum sticks to the cylinder walls, and the engine begins to wedge. The head of the block begins to deform, valve seats fly out, a loud knock appears in the upper part of the engine. Engine oil at such temperatures it loses its properties, the lubrication of rubbing surfaces actually stops, connecting rod bearings rotate and cause the engine to seize.
One of the consequences of engine overheating is piston burnout.
To prevent overheating of the engine, it is necessary to monitor the readings of the temperature gauge, as well as to keep the cooling system clean and in good condition.
Something else useful for you:
Cooling radiator, dismantling, removal from the car ...
Cleaning and flushing the car radiator
To flush the radiator, the coolant must be completely drained. After that, the cooling system is filled clean water(preferably distilled). When flushing the radiator, water should be poured into the radiator filler neck.
What to wash? Very often added to the water during washing caustic soda for more effective cleaning internal surfaces. The proportion in which it is necessary to prepare the mixture is 50 grams of soda per 1 liter of clean water.
Now you need to start the engine, let it run for Idling about 10-15 minutes.
Radiator cleaner
There are also special chemicals for cleaning radiators, for example, the well-known "Hi-Gear". They are also added to the water used to flush the radiator. Due to their high concentration, they can significantly speed up the whole process. With their help, the radiator is washed in only about 7 minutes, however, when using such chemicals, you must strictly follow the instructions, otherwise the internal surfaces of the cooling system may be damaged.
In order to drain water from the system, there are special taps on the lower tank of the radiator and the cylinder block. Keep the filler neck open when draining fluid. After the liquid is drained, a new portion is poured, and the flushing process continues until clean water drains from the radiator.
After flushing, all water is drained, and the system is flushed with ordinary clean water 4-5 times.
Often the cause of overheating of a car engine is contamination of the outer surface of the radiator. It can be dust, dirt, fluff, the remains of various insects, etc.
To clean the radiator from the outside, it is blown or washed. Cleaning the radiator with compressed air can be carried out directly on the car, but this method is ineffective. The radiator is washed from the outside most often with pressurized water using conventional mini-sinks, for example, the well-known Karcher. However, be careful with pressure here - too much pressure can damage the soft radiator cells.
Water treatments for a radiator never hurt
After flushing the radiator, the cooling system is filled with fresh liquid. In order to get rid of airing the system, you should open the radiator cap, start the engine and let it run for several minutes. Excess air will come out, and you just have to top up required amount coolant.
The purpose of an automotive cooling radiator is to provide heat exchange between the hot coolant of a car engine and the surrounding air. Everything seems to be simple, but the efficiency of the radiator depends on two main factors - the material used (materials differ in thermal conductivity) and the design of the cooling core. With a radiator with good heat dissipation, the cooling fan may often not turn on; this saves fuel by saving electricity and correct engine heat balance
- Text PETER NECHIPORENKO
Material used in the production of radiators
The main material in the production of the cores of modern radiators is aluminum. It has about half the thermal conductivity of copper, which has practically fallen into disuse due to its high cost. An "obsolete" material is considered to be steel, which was used before copper; its thermal conductivity is about four times less than that of aluminum. But the use of a material with a high thermal conductivity does not in itself guarantee a high heat transfer of the radiator - more an important factor act design features radiator.
Design of car radiators
The heat dissipation of a radiator depends on its capacity. The more cooling tubes in the radiator and the wider they are, the better. Therefore, the capacitance of the radiator depends on two moments - the pitch of the cooling tubes (inversely proportional) and the thickness of the core (directly proportional). Given these points, in modern radiators there is a tendency to reduce the distance between the cooling tubes (tube pitch) and increase the thickness of the tubes. Thanks to this, we get the opportunity to use aluminum instead of copper in the production of radiators - the lack of thermal conductivity is easily compensated by an increase in the capacity of the radiator.
And in this regard, we can recall another advantage of aluminum - greater rigidity. Thanks to this, it is possible to manufacture a tube of increased width (2-3 times wider than a copper tube), which makes it possible to make the radiator single-row and thereby avoid air gap between the rows of tubes. A "copper" radiator with the same total core thickness will have to be made in two rows - and in this case the air gap between the rows of tubes will "take away" about 10% of the capacity.
Finally, the heat transfer of the radiator will depend on the "metal content". You can increase the heat transfer of the radiator by increasing the amount of metal in the core - the larger this value, the greater the heat transfer. As a rule, in the design of a radiator, the thickness of the tube is not changed, but the number of "fins" - cooling tapes or cooling plates - is increased. This changes the "pitch" of the cooling tapes (that is, the angle at which they are folded) or the number of cooling plates (their "density").
Do not forget about the shape of the cooling tube - the advantage is aerodynamically "correct", that is, the flat-oval shape of the tube. A round tube, unlike a flat oval one, will have an "aerodynamic shadow" - a "dead zone" behind the tube, where cold air practically does not fit.
Aluminum tubular-tape non-assembled (brazed). Most common in modern automotive industry(became widely used since the late 80s of the XX century). They have a cooling core made of flat-oval tubes and tapes folded in the form of "accordions" located between the tubes.
Copper-brass tubular-tape non-assembled (soldered). Today they are used extremely rarely and only for trucks and special equipment. Just like type 1, they have a core of flat oval tubes and bands between them. The difference from type 1 is that copper is used, not aluminum.
Aluminum tubular-lamellar prefabricated. Considered an obsolete design; emerged in the late 1980s. The cooling core consists of round tubes strung on cooling plates made of steel.
Copper-steel tubular-lamellar non-assembled (brazed). The most outdated design, currently not used due to low heat transfer and poor vibration resistance. The cooling core consists of flat-oval tubes strung on cooling plates - “lamellas” made of steel.
During the operation of the car engine, each cylinder constantly raises its temperature due to the detonation of the supplied fuel. If the temperature is not lowered, constant micro-explosions will bring the motor to a critical temperature, exceeding which will destroy the power unit.
To prevent this, a car engine cooling system is installed. In this article, we will consider all the basic information about this node.
Cooling system: what is
Many motorists are wondering - cooling system: what is it?
The cooling system is designed to cool engine parts that are heated as a result of its operation. On modern cars The cooling system, in addition to the main function, performs a number of other functions, including:
- air heating in the heating, ventilation and air conditioning system;
- oil cooling in the lubrication system;
- exhaust gas cooling in the exhaust gas recirculation system;
- air cooling in the turbocharging system;
- cooling of the working fluid in an automatic transmission.
Depending on the method of cooling, the following types of cooling systems are distinguished: liquid ( closed type), air ( open type) and combined. In a liquid-cooled system, heat is removed from the heated parts of the engine by the fluid flow. Air system uses airflow for cooling. The combined system combines liquid and air systems.
Purpose and varieties
Heat removal is far from the only purpose of the engine cooling system. It is additionally responsible for a number of other tasks:
- heating the air mass for heating the interior of the vehicle;
- reducing the waiting time required to bring the motor to operating temperature;
- decrease in the temperature of lubricants used for internal combustion engines;
- if recirculation is used, the temperature decreases exhaust gases from an internal combustion engine;
- if present automatic transmission- the lubricant located inside is cooled.
The scheme of the engine cooling system directly depends on what its mode of operation and principle of operation is. Accordingly, it is customary to classify the node into several categories:
- liquid - heat is removed due to the constant circulation of technical fluid;
- air - when using the considered scheme of engine cooling systems, heat will be removed by circulated air;
- combined - includes the use of the 1st and 2nd option at the same time.
Practice shows that the combined version is the most effective, ensuring stable operation of the motor as a whole.
Device
Considering the design on which the internal combustion engine cooling system was created, one can notice that there is practically no tank in which the liquid is stored. IN this case such a structural element is not needed, because the liquid is constantly in the channels / cavities of the internal combustion engine and the radiator.
Although the tank is still present - it is called an expansion tank. The main task of this part is a comfortable filling of the working fluid into the system, as well as the possibility of filling in an additional amount of liquid if its tightness is broken for one reason or another.
In the picture below you can see the device of the engine cooling system.
Let's start with the water pump, popularly referred to as the "pump". This is a kind of mill in which the liquid circulates through the channels of the internal combustion engine under pressure. The ultimate goal of this design is the passage of water through the cavities located in the motor block. The latter, based on the layout of the car engine, may be different.
It is in the cylinders that the highest temperature is present, which is transmitted to other parts. When the thermal energy is removed, the cylinder block is cooled, but the antifreeze itself is heated. Accordingly, the operation of the engine cooling system ensures the implementation of simple physical processes that make it possible to equalize the temperature. Further working fluid flows through other components of the motor and penetrates the radiator.
From a constructive point of view, it is a lattice formed from a large number small vertical channels, on the surface of which there are transverse plates. The device of the engine cooling radiator can be different, based on how large the engine is and how often it has to gain momentum.
Naturally, in sports engines, the engine radiator has an enlarged size. The airflow area also increases. What does the engine cooling radiator consist of? A large number of honeycombs, mounting fasteners, as well as a tank into which antifreeze is poured. It gradually flows down, resulting in cooling. The design provides for a container at the bottom, which again transfers the antifreeze to the water pump.
The radiator of the engine cooling system effectively copes with its task due to the large number of channels. Ensuring a high-quality result of its work is also guaranteed due to the constant blowing of the case air flow. That is why the part is almost always mounted on the "muzzle" of the car.
But even this may sometimes not be enough, especially when the vehicle is stationary. Therefore, in order to cool the diesel engine (as well as gasoline, in general), a special fan is used. It is fixed between the motor and the radiator assembly, helping to increase the circulation of the air mass.
To guarantee reliable performance system, you need to make sure that the radiator is in good condition. Many people ask the question - how to check the engine cooling radiator? It is quite simple to do this - you need to be sure that there are no damage to the channels, and there should be no traces of a leak on the asphalt due to depressurization.
It is necessary to check the engine cooling radiator before each trip. Failure to comply with this requirement may result in engine detonation, making it impossible to restore its performance.
Above, we figured out what the engine cooling system of most vehicles consists of. But there is also another function that the system performs - this is the heating of the power unit. Despite its contradictory name, when operating a car in winter time low temperature makes it very difficult to start the engine.
Engine cooling is slightly worse due to frost and high humidity, the fuel is sprayed more problematic, and technical fluids suffer from an increase in viscosity. To guarantee the normal operation of the engine cooling system, you will have to warm it up faster. A working thermostat allows you to achieve the desired effect. It blocks the entry of antifreeze into the radiator cells.
Bypassing this node, it flows back into the water pump, heating the cylinders. The thermostat independently supplies antifreeze when the temperature reaches 70-80 degrees Celsius (based on the settings of the control unit and the layout of the power unit). The branch pipe opened during the heating process is immediately closed.
The last device thanks to which the engine cooling circuit works is temperature sensor. It is usually installed in the interior of the vehicle. The driver constantly receives up-to-date information about the temperature of the engine in real time. If the indicators deviate from the norm, the car owner will be able to quickly take measures to localize and repair the breakdown.
Practice shows that the diesel engine cooling system most often fails due to leakage. In such a situation, the temperature immediately rises, because there is less antifreeze in the system, and the available volume is not enough for full-fledged work.
Principle of operation
The principle of operation of the engine cooling system is constantly monitored by the standard control unit power unit. In current vehicle models, cooling details are checked by a special mathematical algorithm that allows taking into account a variety of operating parameters not only of the motor, but also of related systems.
Based on how the engine cooling system works in normal mode at serviceable parts, the system tends to keep them on normal level. Therefore, electronics turns on or off certain elements for a while.
To learn more about how the engine cooling system works, we recommend that you look at the diagram below.
Since antifreeze is forced to flow through the system, it is responsible for centrifugal pump. Thanks to him, the technical fluid is pumped through the "shirt". When performing this work, the use of cooling systems allows you to achieve cooling of the motor and heating of antifreeze. Based on the type of motor and its circuit, the liquid flows:
- lengthwise;
- transversely.
The scheme of the engine cooling system provides for two circulation circles - "small" and "large". For example, when the ignition is turned on, when all the parts are not heated, the thermostat is closed, the liquid flows in a small circle. It does not reach the engine cooling radiator.
When temperature regime is brought to the required level, the thermostat opens - antifreeze penetrates into the radiator, where the temperature will decrease due to airflow. This is a big cycle that repeats many times.
This is what it consists general principle operation of the engine cooling radiator, regardless of the make and model of the vehicle.
In a car with a turbine, engine cooling occurs in a slightly different way. There are two circuits here, where the first is installed in order to reduce the temperature of the antifreeze, and the second cools the air. In this case, the first circuit is also divided into 2 parts - for servicing the block head and the cylinder block as a whole.
This is done because the engine cooling system operation scheme provides for a temperature difference between the head and the block by 15-20 degrees. Thus, the degree of probability of detonation is significantly reduced, and the combustion chambers are more efficiently filled with fuel. One feature has been added to the device of the cooling system - in a motor with a turbine, all working circuits have their own thermostat.
conclusions
The engine cooling system is present on each vehicle. The main purpose of the cooling system is to maintain the optimum temperature of the car's engine.
The basic parts of the engine cooling system are as follows - a radiator, a thermostat, a temperature sensor and a fan. The system consists of several circuits responsible for the correct functioning of the entire system.
The radiator device is quite complicated, since the design consists of a large number of small channels through which heated liquid flows. Timely verification ensures normal work power plant generally.
