What connects the engine to the radiator

How an engine cooling system works

The Video Course teaches you everything about modern cars.

A car engine produces a lot of heat when it is running, and must be cooled continuously to avoid engine damage.

Generally this is done by circulating coolant liquid usually water mixed with an antifreeze solution through special cooling passages. Some engines are cooled by air flowing over finned cylinder casings.

A water-cooled cooling system

A water-cooled engine block and cylinder head have interconnected coolant channels running through them. At the top of the cylinder head all the channels converge to a single outlet.

Unwanted heat is passed from the radiator into the air stream, and the cooled liquid then returns to an inlet at the bottom of the block and flows back into the channels again.

Usually the pump sends coolant up through the engine and down through the radiator, taking advantage of the fact that hot water expands, becomes lighter and rises above cool water when heated. Its natural tendency is to flow upwards, and the pump assists circulation.

The tubes pass through holes in a stack of thin sheet-metal fins, so that the core has a very large surface area and can lose heat rapidly to the cooler air passing through it.

On older cars the tubes run vertically, but modern, low-fronted cars have crossflow radiators with tubes that run from side to side.

In an engine at its ordinary working temperature, the coolant is only just below normal boiling point.

The risk of boiling is avoided by increasing the pressure in the system, which raises the boiling point.

The extra pressure is limited by the radiator cap, which has a pressure valve in it. Excessive pressure opens the valve, and coolant flows out through an overflow pipe.

In a cooling system of this type there is a continual slight loss of coolant if the engine runs very hot. The system needs topping up from time to time.

How the fan helps

The radiator needs a constant flow of air through its core to cool it adequately. When the car is moving, this happens anyway; but when it is stationary a fan is used to help the airflow.

To overcome this, some cars have a viscous coupling a fluid clutch worked by a temperature sensitive valve that uncouples the fan until the coolant temperature reaches a set point.

When the engine warms up, the wax melts, expands and pushes the valve open, allowing coolant to flow through the radiator.

When the engine stops and cools, the valve closes again.

Water expands when it freezes, and if the water in an engine freezes it can burst the block or radiator. So antifreeze usually ethylene glycol is added to the water to lower its freezing point to a safe level.

Antifreeze should not be drained each summer; it can normally be left in for two or three years.

Air-cooled engine cooling systems

In an air-cooled engine, the block and cylinder head are made with deep fins on the outside.

Air-cooling through fins

Frequently a duct runs all around the fins, and an engine-driven fan blows air through the duct to take heat away from the fins.

A temperature-sensitive valve controls the amount of air being pushed around by the fan, and keeps the temperature constant even on cold days.

How Radiator Works in Automobile? – Easiest Explanation

Table of Contents

How does a Radiator Work?

A Radiator has a number of flat and thin pipes arranged horizontally one below the other. Water flows through these pipes along their length. But how does the water flowing through these pipes gets cool so fast? So to increase the heat exchange from water to air, we have fins brazed between the flat surfaces of these pipes. These fins between the pipes look like a dense sine wave (trigonometric function). Thus increasing the surface area that comes in contact with air and increasing the heat exchange.

Is it all we have in a radiator to exchange heat? Then no, we are not done yet.

High end car radiators are a bit more sophisticated, we have fins like structures inside the radiator pipes. These are added to create turbulence in the water flowing through them. The water flowing through pipes without internal fins is streamline. Thus the heat exchange will be between the outer layer of water and the air. As the outer layer of water gets cooler, It reducing the temperature difference between air and water as a result, the rate of heat exchange will decrease.

Whereas in the radiator pipes with internal fins, water molecules that exchange heat with air get mixed up with hot water, due to turbulence created by these fins. Thus keeping the temperature of the whole water uniform and high. In this way, a greater amount of heat could be exchanged and coolant gets cooler at a really very fast pace.

What is the function of a pressure cap in a Radiator?

Temperature of engine goes way much higher than 100 degree centigrade, and water is used as a coolant in cars. But the water starts boiling at 100 degrees and gets converted into steam. And steam does not exchange heat at a good pace. So how water can be used as a coolant.

Imagine if pressure in the radiator goes on increasing it could bust the radiator pipes, to short out this problem, pressure cap is equipped with a spring at its bottom, which gets lifted up as the pressure reaches around 15psi, so pressure cap acts as a valve and releases the pressure to overflow tank when it exceeds the limit of 15 psi.

Transmission Oil Cooling

Ever heard of transmission oil used in gearbox and power-steering going into the radiator. In high payload vehicles, we have to cool down the transmission oil and we use our radiator to remove the heat from this oil. The side of the inlet port of the radiator is called hot side as hot water from the engine enters from this side, as water moves through pipes and gets cool and gets out of the radiator through outlet port called cold side. So we have a cylindrical structure on the cool side of the radiator through which transmission oil circulates thus exchanges its heat with cold water.

You must also know?

We add anti-freezing additives to the water to prevent it from freezing in winters, especially in Europe, and to prevent the engine from corrosion.

For better explanation about how radiator works in automobile watch the video given below:

How car cooling system work? What are the parts included in it?

Share

Hello, Guys today I will explain the How car cooling system work? and what are the parts included in it

Water Pump

Water Pump is the pump that pumps the coolant to the engine. The serpentine belt in the engine drives the impeller in the water pump. The centrifugal force is used to send the coolant outside as it spins, causing the coolant to be drawn from the centre. The coolant leaving the pump flows through the engine block then into water jackets, then into the radiator and finally back to the pump, and this cycle continues.

Radiator

The radiator is situated right at the nose of the car, which helps the car’s engine to cool down when it is heated up. It is a heat exchanger which transfers heat generated from the engine to the atmosphere. The radiator consists of the inlet port, an outlet port, a drain plug and a radiator pressure cap and a fan behind the radiator.

Thermostat

The thermostat is a regulating valve that controls the flow of the coolant into the radiator and maintains the optimum engine temperature. It is always covered with coolant to sense the temperature. It has a primary disc valve, secondary disc valve, wax chamber and a rod that is pressed against it.

Heater Core

It is a radiator-like device that also is a heat exchanger, which transfers the heat from the coolant to the air which flows inside the cabin. If the heater of your car’s cabin is on the hot coolant from the engine is passed through a winding tube to the heater core.

Coolant Temperature sensor

The coolant temperature sensor is used to monitor the engine temperature. It consists of a sensing probe and an electrical connector. In some engine, there might be multiple sensors. The data from this is used to control the radiator fan and also update the temperature gauge in the driver console. ECU also uses this data to manage fuel injection and ignition timing.

Most Coolant temperature sensor is negative temperature coefficient type, which means as the temperature increases the resistance will decrease.

Coolant

A coolant is a liquid mixture of glycol and water. As the coolant absorbs the heat from the cylinder and reaches a high temperature then it is passed through the thermostat which is an inlet for the radiator.

The coolant then reaches the radiator and the cool air from the outside lowers the temperature of the coolant and it is then sent to the engine using the lower hose and the cycle is repeated.

How does the Car Cooling system work?

The cooling mechanism is the most essential part of the car engine. The combustion and friction of parts generate a lot of heat. The temperature has to manage inside to keep the engine sustainable.

The engine generates power by converting the chemical energy of the fuel to heat energy by combustion, this process creates a lot of heat which pushes the piston down and the power is generated. Some of the heat is carried away by the exhaust gases via the exhaust valve, but some of the remaining heat is absorbed by the engine itself which raises the temperature.

Now the water pump pumps the coolant to the system. The coolant which runs through the water jacket(a safe passage for the coolant to flow without entering into the cylinder) absorbs the heat from the engine, to cool down the temperature to an operating range.

Now the coolant has absorbed the heat from the engine but the thermostat will not allow the coolant to flow into the radiator until the temperature is raised above the engine operating temperature i.e around 180 to 200° celsius. In the meantime, if the heater inside the cabin is turned on the coolant is made to flow through the heater core via a bypass hose into the cabin.

When the coolant passing through the thermostat is around 180° F the wax starts to melt. The melting causes expansion of wax which in turn pushes the rod and thus opening the valve and then allowing coolant to pass through. As soon as the coolant passes outside the thermostat, the switch in the thermostat actuates the fan behind the radiator.

The coolant enters the upper tank of the radiator via an upper hose. Due to high temperature, there is a high chance of high pressure building up, which will stop the coolant from entering the upper tank. When the pressure is beyond the recommended value, the pressure regulation valve opens and allows the high pressurized coolant to flow into the coolant overflow tank

The coolant inside the radiator will cool down due to the air flowing through the space between the flat tubes. The fan in the radiator increases the cool air thus increasing the heat transfer rate. The fins on the flat tube also increase heat rate transfer, thus cooling the air more quickly.

When coolant is in the lower tank of the radiator it is completely cooled off and sent back into the engine and the cycle continues.

So this how the car cooling system work, hope this helps you understand your car a little better.

Car Radiators: What Are They and How to Maintain Them

A car’s engine continuously heats up while in use, and if it becomes close to a dangerously high temperature there is a risk of a sudden explosion. Therefore, it is necessary to cool it down to a suitable temperature such as between 80 and 100 degrees Celsius, and this is where the radiator comes into play—it helps to cool down the engine to an appropriate temperature. Most modern engines are water-cooled in general, except some are air-cooled or electric cars such as with the Nissan Leaf. Here, we break down the components of a water-cooled engine radiator as well as how to maintain it.

Water-cooled Engine Radiator Components

A water-cooled engine has a coolant made of water in the water jacket around a cylinder, and it circulates to prevent the engine from overheating. A radiator is placed in the middle between the water pump outlet and inlet so that the performance of it is optimized. The whole route consists of the radiator, radiator hose, water pump, thermostat, and cooling fan. A lot of narrow passages for a coolant flow through the main body of radiator, which are called cores.
The purpose is to enhance the cooling effect by increasing the area of water passing through each core. The radiator itself merely doesn’t work—let’s have a look at each component of the radiator-related parts so that we can clearly understand each role. In combination with these parts, the purpose of radiator is fulfilled.

Cooling Fan

While running, the engine’s temperature is lowered with fresh air, but cooling only by air is insufficient for times such as during traffic jams in which the engine is not in motion and still generating heat. Therefore, the necessity of a cooling fan arises. It increases the quantity of air flow in front of the radiator, and enhances the cooling efficiency to a satisfactory level.

Water Pump

The water pump circulates coolant liquid in the water jackets around the engine, the radiator itself, and its sub-tank so that the cooled coolant in the radiator runs back to the water jackets smoothly.

Thermostat

The thermostat helps to keep the coolant stay within a fixed temperature of a designated range. It also stops the water flow to prevent coolants from circulating within the radiator in cases such as severe cold weather. When an engine gets heat-up, its water temperature accordingly increases, and it opens a water outlet fully when the temperature of coolant becomes approximately above 80 degrees Celsius, allowing the coolant liquid to circulate.

Radiator Cap

Above: A car’s radiator cap

The temperature of the coolant can sometimes rise to 120 degrees Celsius. A pressure valve and a vacuum valve are located in the radiator cap respectively, and when pressure goes up due to the expansion of coolant liquid the pressure valve opens and moves an amount of coolant liquid flowing into the radiator into the reservation tank. When the pressure decreases, the vacuum valve opens and returns the coolant liquid into the radiator. In addition, it suppresses the boiling of the coolant liquid by keeping it at a constant pressure.

How to Maintain a Radiator

1. Check the Coolant Often

Above: Examples of car coolants

When the water level of the coolant decreases and gets dirty with rust and water scale, it mostly causes overheating of the engine. We recommend to change the coolant liquid every two years. When rust and water scale are in bad condition, let’s wash them out with a radiator cleaner.

2. Check the Fan Belt

Above: Example of a car’s radiator fan belt

The tension of a fan belt which moves a cooling fan can be checked by hand. Push the middle of the fan belt using your thumb, and if it can be pushed down to between 13-20mm, it means that the current tension of the belt is OK. When it is damaged to the extent that the rubber part melts and slips, the turn cycle of the fan is jeopardized which can lead to overheating and should be replaced.

3. Check the Radiator Hose

Any cracks, slacks, or distortion of the radiator hose can cause water leakage, so it is recommended to regularly check the condition of the hose in order to prevent any unnecessary incidents.

What to Do When Your Car Overheats

If your car overheats, immediately find a safe place to pull over as soon as possible. Carefully open the bonnet, and keep an eye on the entire engine until you can visibly see that the water temperature has begun to fall. Never open the radiator cap, because there is a risk of high temperature steam shooting out and causing severe injury. If you can see that the amount of coolant is low, fill it to the designated level when the engine has cooled down.

For this purpose, it is also recommended to always carry a dispenser of water in your vehicle in case of overheating emergencies. If the coolant seems to be at an adequate level, the cause of overheating may be due to damage to the water pump due to its crucial role in circulating the coolant liquid as previously mentioned.

Looking for more authentic new and used autoparts? Click the button below to visit BE FORWARD Autoparts and browse through the thousands of quality parts available.

Radiator Types and Construction [Applications, Working Principle, Merits & Demerits]

What is Radiator?

Radiator Types and Construction :- In common language, the radiators are referred to as heat exchangers which are used to transfer the thermal energy from one medium to the other with a purpose of cooling and heating. A radiator consists of a large amount of cooling surface which contains a huge quantity of air that gets spread through the effect of water in order to cool down.

The radiator is found having a wide range of application in an automobile industry as there are various uses that cool the temperatures of an internal combustion engine in the automobile. These are popularly used in piston-engine aircraft, motorcycles and stationary generating plants. The material used in making of a radiator is usually copper and brass due to their high heat conductivity.

Types of Radiator

It is important to know about the types of radiator. So scroll down to know about the two types of radiators.

1. Tubular Type Core

The tubular type core radiators comprises of the upper and the lower tanks which are connected with a series of tubes which is used for passing water. Fins are usually placed across the tubes in order to improve the transfer of heat.

As water passes through all the tubes in a tubular radiator even if one tube gets clogged, the effect of cooling for the entire tube is lost. The tubular radiator type is constructed from steel which is then powder painted and is mounted with a stainless tubular heating element that is joined in an insulating plate.

It is advised that this type of radiator should only operate in high power as it becomes too hot on the surface. Also it should be equipped with a protection grate.

2. Cellular Type Core

The cellular type core is the radiator wherein the air passes through the tubes and the water flows through the spaces available between them. The core consists of a large number of individual air molecules which are surrounded by the effect of water and due to its appearance, the cellular type is usually known as a honeycomb radiator.

Construction of Radiator

The construction of a radiator consists of the below mentioned components which work in order to make a radiator efficient.

1. Upper Tank : (Radiator Types and Construction)

The coolant gets heated by absorbing the heat of the engine, wherein the liquid expands and creates pressure in the radiator exceedingly. This pressure is responsible for causing the coolant to get higher as compared to the pressure cap which is important to prevent the leakage of the excess coolant which needs to be captured safely. The fluid which is in excess flows into the pipe and then moves into the overflow tank.

The engine of the vehicle emits heat which is settled by the action of the coolant. After this the coolant gets contracted instead of expanding which results in increasing the volume of the coolant. The effect of vacuum takes place wherever the pressure is found decreasing and allows easy excess of the coolant in the overflow tank so that it can back and then it can return to the radiator. The material of the tanks could be brass, plastic, polyamide etc.

2. Lower Tank : (Radiator Types and Construction)

Once it has been passed through the tubes which radiate heat, the fins in the body of the radiator the bottom tank receives the cooling water.

When it attains a significant temperature then the thermostat releases water at 180 degrees Fahrenheit. The water is found losing 100 degree Fahrenheit depending upon the ambient air temperature and the efficiency of the radiator meanwhile it reaches the bottom tank. The water pump holds this cooled water as a back-up which can get back in the block when it is again heated up.

3. Tubes : (Radiator Types and Construction)

When it is on its way to the opposite tank, the coolant gets passed through the radiator tubes. This is how it transfers heat to the tubes that transfer the heat to the fins which are attached amongst the rows. The head of fins transfers the heat flow to the ambient air.

The tubes of radiator are mostly made up of brass. The use of aluminium increases over the vast majority of vehicular radiator applications.

4. Filler cap : (Radiator Types and Construction)

When the coolant expands the high temperature of the coolant leads to an increase in the pressure in the cooling system. The coolant is supressed in the tank which increases the amount of pressure in the tank.

There is a pressure relief valve which is used to open the filler cap, which allows the air to escape. The partial vacuum which is formed in the cooling system whenever the coolant temperature reaches to normal it causes a vacuum in the tank as the Coolant gets extracted from the tank.

5. Fins : (Radiator Types and Construction)

Fins are referred to as the surfaces which are used to increase the rate of to or fro heat transfer from the environment which is then extended from the surface by increasing the convection. Fins on the other hand also increase the surface area which can be an economical solution to transfer problems of heat.

Working Principle of A Radiator

Cooling System in Engine

Here you will get to learn how a radiator gets cold which is installed in the front side of the car. The front side of the car includes an engine, a water pump and a thermostat. Once the car is started, the coolant starts running through the engine and as the engine warms up the coolant starts getting heated and the hot coolant is send to the radiator in order let it cool down. Once it gets cool, then the coolant goes back into the engine.

1. Thea Fan

The fan is usually mounted at the backside of the radiator on the water pump shaft. Once the engine runs at a low speed it can certainly be insufficient to produce the desired cooling from the nature. This is the main purpose of a fan. This is one of the most important component which plays a vital role in cooling the engine.

2. Thermostat

The thermostat is responsible for cooling the coolant which runs through the engine. Once the temperature of the coolant is increased and the engine is warmed up then the thermostat is responsible for detecting it and then it passes the coolant back through the radiator after which the coolant will cool through the radiator. This is how a thermostat is used to detect the temperature and work to decrease its temperature.

3. Water Pump

The water pump is used to increase the velocity of the water which is circulating. Once the low-temperature coolant passes through the water pump it pumps the coolant back into the engine. This is how a water pump works in cooling the engine and the coolant.

You Can Drive a Car Without Radiator?

A car can work without a radiator but on the other end is quite risky and is not suggested. The car is safe until the engine is not heated or over heated. In case you do not run it on longer routes for the engine to get too hot, then it is not at all an issue but in case the car gets overheated you will have to immediately shut down the car and let it to cool off.

Talking about the theory, the radiators are completely optional as air cooled engines have existed for a very long period. These radiators comprises of cooling fins which are used to extract the heat and release it into the air. Whereas, in case the car is designed to require a radiator one would definitely need one so removing it won’t be beneficial.

What Cause of Overheating Engine?

Overheating in an engine is caused due to an insufficient quantity of water present in the cooling system. One more reason for overheating is the clogged radiator condition which does not let the water pass, belt slipping, imperative thermostat, late ignition timing, incorrect valve timing, pre-ignition, bearing being too tight, low engine oil, clogging of the exhaust system etc.

How to Recognize a Bad Radiator?

Merits Of Radiator

Here are some of the merits of a Radiator which are mentioned below. Scroll down to know more:

Demerits of Radiator

Knowing the merits are not sufficient, therefore one must know about the demerits of a radiator which are as follows:

Applications Of Radiator

For a learner it is very important to know the usage as well as the application of Radiator. So scroll down to know some of the most common applications of radiator:

Image Source :- britannica