The working processes of an automobile engine take place at high temperatures, therefore, to ensure its operability for a long time, it is necessary to remove excess heat. This function is provided by the cooling system (CO). In the cold season, this heat is used to heat the passenger compartment.

On vehicles with turbocharging, the function of the cooling system is to lower the temperature of the air supplied to the combustion chamber. Additionally, in one of the circles with the cooling system of some car models equipped automatic transmission gears (automatic transmission), oil cooling in the automatic transmission turns on.

Two main types of CO are installed in cars: water and air. The principle of operation of a water-cooled engine cooling system is to heat the liquid from power plant or other components and the transfer of such heat to the atmosphere through the radiator. The air system uses air as the working cooler. Both options have their merits and demerits.

However, a cooling system with liquid circulation has become more widespread.

Air CO

Air cooling

The main advantages of this layout include the simplicity of the system design and maintenance. This CO practically does not increase the mass power unit, and also not capricious to changes in ambient temperature. The negative is the significant take-off of motor power by the fan drive, elevated level noise during operation, poorly balanced heat dissipation from individual nodes, the impossibility of using the engine block system, the impossibility of accumulating the removed heat for further use, for example, heating the passenger compartment.

Liquid CO

Liquid cooling

The system with the use of heat removal using a special fluid, due to its design, can effectively remove excess heat from mechanisms and individual structural parts. Unlike air, the device of the engine cooling system with liquid contributes to a faster set of operating temperature at startup. Also, motors with antifreeze are much quieter and are subject to less knocking.

Cooling system elements

Let's take a closer look at how the engine cooling system works on modern cars. Significant differences between gasoline and diesel engines in this regard, no.

The structural cavities of the cylinder block act as a "jacket" for cooling the engine. They are located around areas from which heat needs to be removed. For faster drainage, a radiator is installed, consisting of curved copper or aluminum tubes. A large number of additional ribs accelerate the heat transfer process. Such ribs increase the cooling plane.

A fan blowing air is placed in front of the radiator. The inflow of colder flows begins after the closure of the electromagnetic clutch. It turns on when the fixed temperature values \u200b\u200bare reached.

Thermostat operation

Continuous circulation of the coolant is ensured by the operation of a centrifugal pump. The belt or gear transmission for it receives rotation from the power plant.

The thermostat controls the flow directions.

If the temperature of the coolant is not high, then the circulation takes place in a small circle, without the inclusion of a radiator in it. If the permissible thermal mode is exceeded, then the thermostat starts the flow along a large circle involving a radiator.

For closed hydraulic systems, expansion tanks are common. Such a tank is also provided in the vehicle CO.

Coolant circulation

The interior is warmed up using a heater radiator. In this case, warm air does not escape into the atmosphere, but is launched inside the car, creating comfort for the driver and passengers in the cold season. For greater efficiency, such an element is installed practically at the fluid outlet from the cylinder block.

The driver receives information about the state of the cooling system using a temperature sensor. Signals are also sent to the control unit. He can independently connect or disconnect executive devices to maintain a balance in the system.

System operation

Antifreezes with many additives, including anti-corrosion ones, are used as coolants. They help to increase the durability of units and parts used in CO. Such a liquid is forcibly pumped through the system by a centrifugal pump. Movement begins from the cylinder block, the hottest point.

First, there is a movement in a small circle with a closed thermostat without entering the radiator, because even the operating temperature for the motor has not yet been reached. After entering the operating mode, the circulation takes place in a large circle, where the radiator can be cooled with a counter flow or using a plug-in fan. After that, the fluid returns to the "jacket" around the cylinder block.

There are cars using two cooling circuits.

The first lowers the temperature of the engine, and the second takes care of the charge air, cooling it to form a fuel mixture.

• radiator
• expansion tank
• coolant pump
• fan
• thermostat
• supply lines

Engine cooling system makes it possible to quickly warm up the engine and protect it from overheating, maintaining the optimum temperature. The radiator is connected by a tube to the expansion tank. The radiator neck is closed by a plug equipped with a safety valve that discharges excess heated fluid from the radiator into expansion tank, as well as inlet valve, which makes it possible to return fluid to the radiator in the event of a decrease in engine temperature.

When the plug is in the closed position, the protrusions must be in contact with the reservoir. The fluid level is checked on the expansion tank. If the liquid level drops below the “LOW” mark, it is necessary to add it so that the level rises to the “FULL” mark.

The coolant pump, located at the front of the engine housing, is driven by the timing belt.

Figure: Components of the cooling system in the car (radiator, expansion tank, fan): 1 - radiator, 2 - radiator plug, 3,4,5 - fasteners, 6 - fan casing, 7 - fan impeller, 8 - fan motor, 9 - expansion tank, 10 - a tube connecting the radiator with an expansion tank

Figure: Components of the cooling system (fluid supply lines): 1 - thermostat cover, 2 - cover gasket, 3 - thermostat, 4 - radiator supply hose, 5 - radiator outlet hose, 6 - engine supply hose, 7 - engine inlet pipe, 8 - gasket, 9 - heating device radiator inlet hose, 10 - heating device radiator outlet inlet hose.

The main elements of the liquid cooling system and their purpose

In liquid cooling systems for piston engines, it circulates in a closed circuit, and heat is dissipated into the environment using an air-cooled radiator.

The main parts of the liquid cooling system:

• Cooling jacket (1) is a cavity around the engine parts that require cooling. The liquid circulating through the cooling jacket removes heat from them and transfers it to the radiator.
• Coolant pump, or pump (5) - provides fluid circulation along the cooling circuit. Some engines, such as mini-tractors, may use a thermosyphon cooling system - that is, a system with natural circulation of coolant, in which this pump is absent. It can be driven either via a belt drive from the motor shaft or from a separate electric motor.
• Thermostat (2) - designed to maintain working temperature engine. The thermostat redirects the coolant in a small circle - bypassing the radiator if the temperature has not reached the operating temperature.
• Radiator cooling system (3) usually has a lamellar structure that is blown from the outside by a stream of air. Usually, aluminum is used for the manufacture of a radiator, but other materials that conduct heat well can also be used. For example, copper is often used to make oil radiators.
• Fan (4) is necessary for pumping additional air for blowing the radiator, including during stops and when driving at low speed. In older car models, the fan was driven from the engine shaft using a belt drive, but in modern cars, with the exception of large trucks, it is driven by an electric motor.
• Expansion tank contains a supply of coolant. The expansion tank communicates with the atmosphere through a valve that maintains an overpressure of the coolant during operation, which allows the engine to operate at a higher temperature, preventing the coolant from boiling. In older car models, expansion tanks were often absent and the coolant supply was in the upper radiator tank. With the proliferation of ethylene glycol-based antifreezes, the use of an expansion tank has become mandatory because when heated, a special liquid tends to expand.

During movement, many of the motor mechanisms are in constant motion. Their friction is so strong that the temperature begins to rise very quickly. But the main culprit of the high temperature is the combustible mixture, as a result of the combustion of which the temperature rises to 2000-2500 ° C. In this case, the engine can quickly fail, because for his normal work the most optimal temperature is 80-90 ° С. In order to keep the engine running, it must be cooled. For this, there is a cooling system in the motor.

The most in a simple way cooling the engine, is the counter air flow. Such a system is practically not used for cars, but it is widely used for cooling motorcycle engines. Sometimes the oncoming air also cools the engine of the cars. Among the brands we know, this system has been used on.

The principle of operation of an air cooling system is based on the fact that air is supplied to the engine by a fan. And the cooling is automatically controlled by a thermostat, with which you can maintain the desired temperature regime, avoiding neither cooling nor overheating. For most car engines a liquid cooling system is used. The principle of operation of this system is much simpler than air cooling. It is based on the fact that the heat emanating from the cylinders is absorbed by the cooling medium. As a temperature regulator, i.e. cooling medium, a special liquid is used. Heated from the cylinder walls, it enters the radiator, cools there and again passes to the cylinder walls, absorbing heat. Thus, the coolant is constantly circulating, the pump drives this system. Antifreeze is used for cooling - a mixture of ethylene glycol and alcohol. Ordinary water can also be used as a cooling medium, but in cold weather its use is unacceptable, since, if it freezes, it will damage the engine. Antifreeze does not freeze down to minus 40 ° C.

And now we will talk about how the cooling system works. This device includes a cylinder cooling jacket, radiator, pump, thermostat, fan and fan belt, louvers, connecting pipes and hoses with clamps, and a water temperature indicator. All of the listed parts are very important and if one of them breaks down, the entire cooling system may fail.

If the engine is the heart of the machine, then the water pump can be called the heart of the cooling system. Its main function - to ensure the circulation of the liquid. The fan creates a stream of air that cools the liquid. The higher the speed of the machine, the more the fan works.

You already know what a cooling jacket is: its double cylinder walls form, and coolant enters the space between them. The radiator consists of an upper and a lower reservoir, between which pipes are located. There is a hot liquid in the upper tank, which needs to be cooled. Immediately a large number of water cools very slowly. But when the car is on the way, you have no time to wait, so the designers invented such a device so that the water in it is cooled in small portions.

For example, if the tea in the cup is very hot, you can put it in a teaspoon and blow it.The radiator is based on the same principle. From the upper tank, hot liquid flows in thin streams that are well blown into the lower tank. There, the liquid is collected already cooled.

The radiator filler cap is firmly closed. But the liquid is so hot that it can even boil. For these cases, valves are provided on the plug. If excessive pressure occurs, steam is released through one valve (outlet). Through another valve (intake), air enters the radiator when the pressure in the mechanism is below atmospheric. If the engine has not yet cooled down after a long period of operation, then it is very dangerous to open the radiator cap. you can get burned by hot steam or water.

The thermostat regulates the operation of the cooling system. When the liquid heats up, the alcohol in the corrugated cylinder of the thermostat will begin to evaporate, the pressure inside the cylinder with alcohol will rise, and the cylinder, stretching in height, will open the thermostat valve. This happens at a temperature of at least 80 ° C. As soon as the temperature rises to 90 ° C, the valve will open completely and water can circulate freely in the system. The valve will close only when the temperature drops, this happens when the motorist reduces the speed of the car or stops.

On the road, even if it is very good and smooth, the car will still shake a little. Therefore, the position of the engine in relation to the radiator is constantly changing, and it cannot be placed on a solid support. Only rubber mount is allowed. For the same reason, no rigid connection is made between the engine and the radiator. But the rubberized hoses and pipes are just right. They are light and flexible, so they are not afraid of ravines and hummocks.

Jalousie are necessary to regulate the amount of air that passes through the radiator. They consist of a series of vertically installed plates that can be turned using a handle located in the passenger compartment. When the handle is in the initial position, the shutters are open and the air, without delay, flows freely to the radiator. If you pull the handle towards you, the shutters will close, and air access to the radiator will stop. Having extended the handle only halfway, the air, although not strong, will flow to the radiator. Blinds are used by drivers infrequently and mainly during the cold season to protect the radiator from hypothermia. When starting the engine in winter time the blinds must be closed so that it warms up faster and does not allow the water in the radiator to freeze.

Of course, the operation of the cooling system must be monitored. For this, there is an electric water temperature indicator on the dashboard. It is wired to a sensor placed in the cooling jacket. On the road, the driver needs to monitor the readings of this device. The engine should not overheat, because this leads to rapid wear of the mechanism. Most often, overheating occurs due to an insufficient amount of coolant or as a result of a malfunction of the cooling system. Hypothermia most often occurs in winter due to faulty blinds or lack of an insulating cover.

Overheating and cooling significantly reduce engine power, so it is necessary to regularly check the coolant level in the radiator to see if it leaks.

The cooling system needs regular inspectionduring which it is necessary to lubricate the bearings of the fan and tighten its belt and hose clamps, if necessary. In the event that you use water for cooling, then in cold weather, especially at temperatures below 0 ° C, you must ensure that the water in the radiator does not freeze, otherwise the radiator itself and the cylinder will be damaged. To protect the engine from frost, an insulating cover is put on the radiator lining.

If you want to visually familiarize yourself with the engine cooling system, then be sure to watch this video.

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Computer cooling systems are different types and different efficiency. Regardless, they all have the same goal: to cool the devices inside system unitthan to prevent them from burning and increase the efficiency of work. Different systems are designed to cool different devices and they do it in different ways. This, of course, is not the most exciting topic, but it does not become less important from this. Today we will take a closer look at what kind of cooling systems our computer needs, and how to maximize their efficiency.

To begin with, I propose to quickly go over the cooling systems in general, so that we approach the study of their computer varieties as prepared as possible. Hope it will save our time and make it easier to understand. So. Cooling systems are ...

Air cooling systems

This is the most common type of cooling system today. Its principle of operation is very simple. The heat from the heating component is transferred to the radiator with the help of heat-conducting materials (it can be an air layer or a special heat-conducting paste). The radiator receives heat and transfers it to the surrounding space, which is either simply dissipated (passive radiator) or blown away by a fan (active radiator or cooler). Such cooling systems are installed directly into the system unit and on almost all heated computer components. The cooling efficiency depends on the size of the effective area of \u200b\u200bthe radiator, the metal from which it is made (copper, aluminum), the speed of the passing air flow (on the power and size of the fan) and its temperature. Passive radiators are installed on those components of the computer system that do not get very hot during operation, and near which natural air flows constantly circulate. Active systems coolers or coolers are designed mainly for the processor, video adapter and other constantly and intensely working internal components. Sometimes passive radiators can also be installed for them, but always with more efficient heat removal than usual at low air flow rates. This is more expensive and is used in special silent computers.

Liquid cooling systems

A miracle-miracle invention of the last decade, is used mainly for servers, but due to the rapid development of technology, over time it has every chance of moving into home systems. Expensive and a little scary if you imagine, but quite effective, since water conducts heat 30 (or so) times faster than air. With this system, several internal components can be cooled simultaneously with virtually no noise. A special metal plate (heat sink) is placed above the processor, which collects heat from the processor. Distilled water is periodically pumped over the heat sink. Collecting heat from it, water enters the radiator cooled by air, cools down and begins its second circle from the metal plate above the processor. At the same time, the radiator dissipates the collected heat into the environment, cools down and waits for a new portion of the heated liquid. The water in such systems can be special, for example, with a bactericidal or antigalvanic effect. Instead of such water, antifreeze, oils, liquid metals or some other liquid with high thermal conductivity and high specific heat capacity can be used in order to ensure maximum cooling efficiency at the lowest fluid circulation rate. Of course, such systems are more expensive and complex. They consist of a pump, a heat sink (water block or cooling head) attached to the processor, a radiator (can be either active or passive), usually attached to the back of the computer case, a reservoir for working fluid, hoses and flow sensors, a variety of meters, filters, drain valves, etc. (the listed components, starting from sensors, are optional). By the way, replacing such a system is not an exercise for the faint of heart. This is not a fan with a radiator to change.

Freon installation

Small refrigerator that fits directly onto the heating component. They are effective, but in computers they are mainly used exclusively for overclocking. Knowledgeable people say that he has more flawsthan merits. First, condensation that appears on parts colder than the environment. How do you like the prospect of liquid appearing inside the holy of holies? Increased power consumption, complexity and considerable price are lesser disadvantages, but from this they also do not become advantages.

Open cooling systems

They use dry ice, liquid nitrogen or helium in a special tank (glass) installed directly on the cooled component. It is used by the Kulibins for the most extreme overclocking or overclocking, in our opinion. The disadvantages are the same - high cost, complexity, etc. +1 is very significant. The glass must be constantly refilled and periodically run to the store for its contents.

Cascade cooling systems

Two or more cooling systems connected in series (for example, radiator + freon). These are the most difficult cooling systems to implement, which are able to work without interruption, unlike all others.

Combined cooling systems

These combine the cooling elements of various types of systems. An example of combined ones is Waterchppers. Water chippers \u003d liquid + freon. Antifreeze circulates in the liquid cooling system and, in addition to it, is also cooled by a freon unit in the heat exchanger. Even more difficult and expensive. The difficulty is that thermal insulation is needed for this entire system, but this unit can be used for the simultaneous effective cooling of several components at once, which is quite difficult to implement in other cases.

Systems with Peltellier elements

They are never used on their own and, besides, they have the least efficiency. Their principle of operation was described by Cheburashka when he invited Gena to carry the suitcases (“Let me carry the suitcases, and you will carry me”). The Peltellier element is mounted on a heating component and the other side of the element is cooled by another, usually air or liquid cooling system. Since cooling to temperatures below ambient is possible, the problem of condensation is relevant in this case. Peltellier elements are less efficient than freon cooling, but at the same time they are quieter and do not create vibrations like refrigerators (freon).

If you have never noticed, then inside your system unit, the most violent activity is constantly in full swing: the current runs back and forth, the processor counts, the memory remembers, the programs are running, the hard disk spins. The computer works, in a word. From the school physics course, we know that the passing current heats the device, and if the device heats up, then this is not good. In the worst case, it will simply burn out, and in the best case, it will just work hard. (This is a really common reason for a weak braking system). It is in order to avoid such troubles that several types of various cooling systems are provided inside your system unit. At least for the most important components.

Cooling the system unit

How is cooling done? Mostly by air. When you turn on the computer, it starts to hum - the fan turns on (very often there are several of them), then it dies down. After a few minutes of operation, when your system reaches a certain temperature threshold, the fan turns on again. And so all the time. The largest and most noticeable fan inside the system unit simply blows hot air out of the box, which cools everything taken together, including components that are difficult to install their own cooling system, such as a hard drive. According to the laws of the same physics, cooled air enters the place of the heated air through special ventilation holes in the front of the system unit. More precisely, the one that has simply not yet had time to warm up. Cooling the inside of the computer, it heats up by itself and comes out through the openings in the side and / or rear panel of the system unit.

CPU cooling

The processor, as a very important and constantly loaded component of your iron friend, has a personal cooling system. It consists of two components - a radiator and a fan, of course smaller than the one we just talked about. The radiator is sometimes called a heat sink, in accordance with its main functional activity - it dissipates heat from the processor (passive cooling), and a small rotator from above blows heat from the radiator (active cooling). In addition, the processor is lubricated with special thermal grease, which maximizes heat transfer from the processor to the heatsink. The fact is that the surfaces of both the processor and the heatsink, even after polishing, have notches of about 5 microns. As a result of these notches, a thin air layer with very low thermal conductivity remains between them. It is these gaps that are covered with a paste made of a substance with a high thermal conductivity coefficient. The paste has a limited shelf life, so it needs to be changed. It is convenient to do this at the same time as cleaning the system unit, which we will talk about a little below, especially since the old paste can generally have the opposite effect.

Cooling the graphics card

A modern graphics card is a computer inside a computer. The cooling system is extremely necessary for her. Simple and cheap video cards may not have a cooling system, but modern video adapters for gaming monsters necessarily need a refreshing coolness, perhaps even more than you do in a forty-degree heat.

Dust contamination

Along with the air from the room, dust enters your system unit. Moreover, even in a regularly cleaned and ventilated room, the dust, wonderfully, is enough to entangle your brand new twist from nowhere with long, unpleasant woolen shags from nowhere. This has the opposite effect - the air vents are clogged, and the “shags” (besides the fact that they physically do not allow the fan to spin) will warm your computer no worse than a mink coat to the processor itself, and not only in tropical heat, but also in a polar blizzard. A person, as far as I know, suffers from hypothermia, but a computer may well get sick from overheating. We treat the poor fellow about once every six months not with antibiotics and hot tea with raspberries, but with a vacuum cleaner. Preferably purchased from a special computer store. The usual, in very extreme cases, will do, but you should be extremely careful with static electricity. Internal components don't like it very much.

Cleaning the cooling system

The first sign of a badly working system or not working at all is that the fan does not “hum” and the system unit is warming up. By the way, this is a common reason for the computer to shutdown itself or the system is too slow, and the diagnosis is so simple that it may not come to mind. And it starts: updating drivers, scanning with an antivirus, hardware updating of the system, purchasing additional modules random access memory and other unhappy body movements. Is it funny? Rather sad. We urgently open the patient and see what is inside him. It is advisable before that to look for the exact algorithm for the procedure in the technical documentation from the motherboard manufacturers.

In principle, there is nothing difficult in cleaning the system unit. You need to turn off the computer, not forgetting to unplug the power cord, disassemble the system unit and carefully clean all the insides of dust. The stores sell special vacuum cleaners that are best for doing this. Most of the dust accumulates on the heatsink with a fan and near the vents on the system unit. Carefully remove dust accumulations from them and lubricate them if necessary (remove the sticker from the fan and drip a few drops onto the fan axis). Not bad oil will do for sewing machines... In addition, it is necessary to clean the processor from the old thermal paste and spread a new one on it. We repeat the same steps with the video card and the fan of the system unit. It remains to assemble the computer and use it for a few more months before re-cleaning the system unit. Laptops also need to be cleaned, and judging from my experience - a little more often than stationary ones (the small distances between the components inside the laptop and the consumption of cookies and sandwiches next to it do their dirty work for your beloved). Many users can easily cope with this procedure without the help of computer specialists, but it is better not to rush, especially with laptops, if you do not feel confident enough. Risks: static electricity can damage the motherboard, processor or anything else, and you yourself, due to inexperience, can easily damage something important. Jokes, jokes, but you really need to do this, otherwise problems may appear just an immeasurable amount.

If you cleaned your computer but did not bring any noticeable relief, you may need to install a stronger cooling system. In the easiest case, an additional fan can help. To find out the degree of heating of system components, you can look at the motherboard manufacturer's website. It is possible that there you will find special software that will help determine this. The average performance for the processor is 30-50 degrees, and in the load mode up to 70. Winchester should not be heated more than 40 degrees. More accurate indicators should be checked in the technical documentation.

In conclusion, I want to say that in 90 (if not more) percent of cases, a standard standard cooling system is quite suitable. Owners of powerful servers really need to rush between quality and price, as well as implement a cooling system in their computer (sometimes it is quite risky and not at all easy). gaming computers and fans of overclocking experiments. If you buy a computer for home or office, you just need to ask what is inside it, so that the manufacturer's possible savings do not creep out sideways for you.

(ICE) and their components are exposed to strong heating during the operation of various vehicles. Moreover, both overheating and hypothermia of the motor can provoke its failure. In this regard, one of the most important tasks for the developers of power units is to ensure the optimal thermal regime of their operation. A well-organized engine cooling system contributes to obtaining the best operational parameters ICEs, which include:

1. Maximum power.
2. Minimum fuel consumption.
3. Extended service life.

Influence of temperature parameters on motor operation

In one working cycle, the temperature in the internal combustion engine cylinders changes from 80 ... 120 degrees Celsius during the admission of the combustible mixture to 2000 ... 2200 degrees Celsius during its combustion. In this case, the power unit heats up quite a lot.

If the motor is not cooled sufficiently during operation, then its parts become very hot and change in size. The volume of engine oil poured into the crankcase is also significantly reduced (due to burnout). As a result, friction increases between interacting parts, which leads to their rapid wear or even jamming.

However, hypothermia of the internal combustion engine also adversely affects its operation. Condensation of fuel vapors occurs on the cylinder walls of a cold engine, which, washing away the lubricant layer, liquefy engine oillocated in the crankcase.

To eliminate the negative consequences associated with a violation of the thermal regime, cooling systems are designed so as to exclude overheating and overcooling of the motor during operation.

As a result, the chemical properties of the latter deteriorate, which contributes to:

• increased consumption of engine oil;
• intensive wear of rubbing surfaces;
• a drop in the power of the power unit;
• increased fuel consumption.

Classification

When the motor is running, it is necessary to ensure the removal of 25 to 35% of the generated heat. For its effective absorption (removal), water, air or a special liquid (antifreeze, antifreeze) are most often used. The coolant material determines how the power package is cooled.

There are systems:

1. Forced air cooling.
2. Closed loop liquid cooling.

Liquid cooling system

Currently, a closed, closed-loop liquid cooling system is used for efficient cooling of automobile engines.

Design

Without fail, the system contains an expansion tank, which serves to compensate for changes in the volume of the liquid when its temperature changes. In addition, a coolant is poured through it.

The system also includes:

• the water jacket of the power unit (the space between the double walls of the cylinder block and its head in places where excessive heat is removed);
• temperature sensor;
• bimetallic or electronic thermostat that ensures the optimum temperature in the system;
• centrifugal pump-pump, providing forced circulation of coolant in the system;
• a fan that increases the flow of oncoming air to the main radiator of the system;
• a radiator that transfers heat to the environment;
• a heater radiator designed to transfer heat directly to the passenger compartment;
• a control device built into the vehicle dashboard.

Operating principle

Coolant is poured into the system through the expansion tank. Circulating constantly inside the system, it removes heat from component parts motors that heat up during operation, heats up, enters the radiator, cools in the radiator with the counterflow of air and returns back.

The fan turns on when necessary, increasing the cooling efficiency. For closed cooling systems, the temperature of the coolant should not exceed 126 degrees Celsius. Thus, the optimal thermal mode of operation of the power unit is ensured.

Additional functions

In addition to its main task - heat removal from heating elements, the liquid engine cooling system also provides:

• Warming up the power unit in the cold season

Modern liquid cooling systems have two circuits through which the coolant can circulate. This is done so that at the time of starting a cold engine, when its parts and the liquid itself have low temperature, the circulation of the coolant was carried out in a small circle (past the radiator).

This is provided by a thermostat, which at the moment when the temperature rises to a certain level (70-80 degrees Celsius), opens, allowing the coolant to circulate in a large circle (through the radiator). Thus, an accelerated engine warm-up process is carried out.

• Heating the air in the car

In the cold season, with the help of a hot coolant, the air in the car is heated. For this, there is an additional radiator installed in the cabin and equipped with its own fan. With their help, the heat taken from the hot fluid is distributed throughout the entire interior.

• Reducing the temperature of the air injected into the cylinders

Especially for engines equipped with turbochargers, two-circuit systems are provided, in which one circuit provides cooling of the liquid, and the other - cooling the air.

In addition, the coolant cooling circuit is also a two-circuit system, one circuit of which cools the cylinder head, and the other cools the block itself.

This is due to the fact that in a turbocharged engine the temperature of the cylinder head should be 15 ... 20 degrees Celsius below the temperature of the block itself. A special feature of this cooling system is that each circuit is controlled by its own thermostat.

Advantages and disadvantages

Almost everyone has a liquid engine cooling system modern cars... Fundamentally different from air cooling systems, it guarantees:

• uniform and fast warming up of the power unit;
• efficient heat dissipation in any engine operating conditions;
• reduction in power costs;
• stable thermal mode of motor operation;
• the possibility of using the generated heat to heat the air in the cabin, etc.

Among the few disadvantages of a liquid cooling system are:

• the need for regular maintenance and the complexity of repair;
• increased sensitivity to temperature changes.

Malfunctions and remedies

All liquid cooling systems are characterized by typical malfunctions... The most common are:

1. jamming of the thermostat in the closed position (fluid circulation is carried out in a small circle);
2. pump breakdown;
3. damage to the outlet valve built into the expansion tank plug;
4. coolant leakage due to depressurization of the system (damage to seals, corrosion, etc.).
5. In addition, quite often the thermostat gets stuck in the "Open" position (the coolant circulates in a large circle), which increases the warm-up time of a cold motor and contributes to the instability of the thermal regime during its further operation.

All these faults are characterized by a significant increase in the operating temperature of the power unit, which can lead to boiling of the coolant and overheating of the motor.

All defects are eliminated by replacing faulty and / or damaged parts or components.

Air cooling system

Vehicles were equipped with air-cooled motors in the 50-70s of the last century. Typical representatives of such cars are "Zaporozhets" or FIAT 500. Nowadays, air-cooled engines are practically not found in the automotive industry.

Design and principle of operation

Structurally, the forced air cooling system is mounted in engine compartment vehicle and consists of:

• suction or blower fan;
• guide ribs of the engine cooling jacket;
• governing bodies ( throttle valvesthat control the air supply or a clutch that regulates the fan speed in automatic mode);
• a temperature sensor installed in the power unit;
• control device displayed on dashboard in the car.

The motor is cooled by oncoming cold air. To enhance its flow, a blower type fan is most often used. It enhances the flow of cold, dense air and ensures its supply in large quantities at low energy costs.

The exhaust fan requires a lot of power, but provides a more uniform heat transfer from the parts of the power unit.

Advantages and disadvantages

Forced air cooled motors differ in:

• simplicity of design;
• low requirements for changes in ambient temperature;
• light weight;
• uncomplicated maintenance.

The disadvantages of an air cooling system include:

• large loss of motor power, which is spent on ensuring the operation of the fan;
• high noise level during fan operation;
• insufficient cooling individual elements engine due to uneven airflow;
• inability to use excess heat to heat the passenger compartment.