How automobile cooling system works II

                  In the last post I explained about automobile cooling system . Now i am continuing
from where I left last.

          In this post I will explain the working of various components of cooling system.

          The following are the main components of a water cooled engine.

• Water jackets.
• Thermostat valve.
• Radiator.
• Radiator cap(pressure cap)
• Surge tank..
• Cooling fan.
• Water pump

        Water Jackets
                     
                      Water jackets are the ports in the walls of cylinder block and cylinder head for the 
passage of  cooling water. The cooling water passes from these ports and carries the excess heat 
from the engine.

    Thermostat Valve

               The Thermostat valve is used to regulate the circulate of water in the cooling system to maintain a normal working temperature of engine. 
              it consists of a valve , spring and wax .When temperature increases the wax melts and the valve opens and the water starts flowing to radiator. when the engine is cool, thermostat prevents the flow of water to the radiator. the water circulates inside the jackets only and working temperature is maintained. when engine temperature increases the thermostat valve opens and the water flow to the radiator. The valve opens between 85 to 100 degree Celsius depend on the manufacturer's specification.

           the thermostat valve consists of a wax filled pellet which contrast when cool and expands when hot. when the temperature rises the wax melts and  allow the water to flow.when temperature decreases the wax contrast and the valve is closed by a spring retainer. 

Radiator.
              radiator is used to cool the hot water coming from engine. The water cools down with the contact of air.
The radiator consists of an upper tank, a lower tank and core.

The hot water enters in the upper tank of radiator and flows to the lower tank  through the core.
while the water passes through core the heat from water is removed.

How Automobile Cooling System Works (part 1)

             Heat is generated in the I C engine  due to combustion of fuel and rubbing of reciprocating parts,  This heat needs to be removed from the engine to work the engine normally . If this heat is not removed the engine will cease to work ,because the molecules of the metal expands when heated , expand molecules increases friction between parts and over expansion of molecules results in struck of engine parts.  Thus there is need of a system to remove excess heat from engine and maintain an optimum working temperature.

               The engine cooling system works on the principle of second law of thermodynamic i.e heat transfer from a body of higher temperature to a body of lower temperature.  The heat transfers in three mediums  Conduction,  convection  , radiation.
     
         When heat is exchanged between two metal bodies in contact it is conduction.
     
        When a liquid is used as a medium of heat transfer  this system is  termed as convection. When air is used as a medium of heat transfer it is known as radiation.

          the heat generated inside the IC engine is converted into work  and  an amount of heat is carried  out by exhaust gases, to remove the left over heat a cooling system is required.

          Currently  there are two types of cooling systems used in automobile engines viz.
1. Air cooled.
2.liquid cooled.

 Air cooled engine.
            The air cooled system is ideal for single cylinder  or v twin engine .In air cooled engine the atmospheric air carries away the heat generated by engine , The air acts as a medium of heat transfer in this types of engines.


          

Cooling fins  are attached to engine block to enhance the cooling process, the cold atmospheric 

air touches the cooling  fins and carries away the heat waves  (as shown in the above picture).

  Limitations of air cooling system

   

            The air cooled system can only be used in single cylinder or v twin engine of two wheeler only, because the air can't reach all the cylinder walls of multi cylinder engine. In cars there is no 

enough contact of engine to the atmospheric air, Thus air cooling system is not suitable here.

   Liquid cooled engine

           

               In Liquid cooled engine a liquid (Water)  is used to carry away the heat from engine.

      In water cooled engine water is used as a medium to carry away the heat from engine.

The engine block has water ports or water jackets through which the cooling water passes.

  additives in cooling water

             

                The water alone is not sufficient for  the engine cooling due to the following reasons.

•           In cool weather areas the cooling water may get freeze.
•           Water starts boiling and evaporates due to high engine temperature, .  
•           Water can corrode the engine parts.

Considering these factors additives are mixed in cooling water. These additives are:-

• Anti freezing agent.
• Anti corrosion  agent.

Anti freezing agent

           

             To lower the freezing temperature of cooling water an anti freezing agent is added, generally 

Ethylene glycol is used as anti freezing agent. Ethylene glycol not only lowers the freezing point of 

water, it also raises the boiling point of water.

Anti corrosion  agent.

     

             To  protect the metal parts of engine from corrosion, an anti corrosive agent is added in the coolant, generally silicates are added as  anti corrosion agent.

           The engine coolant is a composition of  water , anti freezing agent and anti corrosion agent.

Working system

               The cooling system consist of the following parts.

• Water jackets.
• Thermostat valve.
• Radiator.
• Radiator cap(pressure cap)
• Coolant tank.
• Cooling fan.
• Water pump. 

           The coolant passes from the water jackets in the engine block and absorbs the engine heat,

after absorbing the heat the water becomes  hot , the hot water is send to radiator for cooling. The 

cooling fan cools the water in the radiator. Water pump is used to pump the cool water inside the engine.

                   The rest of the system will be explained in my next post please submit your mail id in the top box to get update about my new post.   . 

How to improve fuel efficiency of your vehicle.

             Most of us are very much conscious about fuel consumption of our vehicles , the
modern engines have a good fuel efficiency. There may be variation between manufacturer's
expected mileage and actual mileage , when the variation is high then something is going wrong
under the hood.High fuel consumption not only burn hole in your pocket , it also harms our
 environment.
            At first we have to find why your engine is burning too much of fuel, then we will discuss
the remedy for it. Here I am listing some of the possible causes of high fuel consumption .

1. Heavy load on the vehicle :  Your vehicle consumes more fuel when it carries heavy load,
heavy load requires more torque, to generate high torque more fuel is required.

  Remedy : Don't overload your vehicle and remove heavy weight accessories from the vehicle.

2. Improper tire inflation :your vehicle consumes more fuel when Tires are under inflated . 

 

    Remedy :   Maintain proper tire inflation  ,Follow your manufacturer's  recommendation for
correct inflation of tires.

3. Clogged Air filter :  The  Air filter  of your car may get clogged with dust particles and other
impurities which reduce  the air flow to the engine .Clogged air filter also reduces the performance
of the engine.

     Remedy : Clean or replace the air filter  as required . 

4.Poor or dirty spark plugs(Petrol Engine) : The spark plugs gets weaker due to dirt and carbon amounts  deposit  on the spark plug electrodes and point, due to this deposits the fuel doesn't burns properly , Which results in heavy fuel consumption. 

     Remedy : Clean or replace spark plug as required, also adjust proper electrodes gaps.

       5. poor  engine oil quality :  The engine oil  becomes  weaker by time , Weaker engine oil 

doesn't properly lubricate the moving parts. Due to weaker lubrication the friction between moving 

parts increases, Increase friction results in increased  fuel consumption. 

    Remedy :    Replace engine oil regularly at recommended interval of time.and use manufacturer's recommended oil grade.

           Note : Not changing engine oil at proper interval may damage the engine parts.

6. driving on bad roads:  fuel efficiency also depends on the quality of road, Vehicle consumes 

more fuel on bad and rough roads .

    

    Remedy :  Avoid driving on bad roads prefer to take alternate route.

7. driving in heavy traffic :  Vehicle  consumes more fuel in heavy traffic roads.

      Remedy :   take alternate route to reach your destination.

 8. Untrained driver :   The fuel efficiency also depends on driving skills, It is observed that
same vehicle  gives different fuel efficiency result by  changing driver.

   Remedy : change the driving style, Take lessons to drive effectively.

9. driving with clutch:  Driving  vehicle with clutch pedal  pressed consumes more fuel .
Driving with pressed clutch pedal also reduces Clutch life.

  Remedy :  Use clutch only when required.

10. driving with low speed gear:   a vehicle consumes more fuel on accelerating in lower gear. 

  Remedy :  Shift to highest possible gear.

  11. long idling : keeping the engine running without moving the vehicle for long time consumes

a lot of fuel. 

  Remedy :   turn off the engine when idling time is more

Note :  Regular service and better driving increases the fuel efficiency of vehicle and 

also increases engine life. Do maintain your vehicle as per manufacturer's recommendation.

Welcome to aakautoengr's blog

Welcome to aakautoengr's blog

   Hello, all! I am Ahmed Ali Khan, and I am in the automobile engineering profession. I have 13 years of experience to support my profession. Come learn about the latest technologies in the automotive industry, get tips on vehicle operation, and important maintenance tips. This subject is very dear to me: sharing my experiences and knowledge so that you too can enjoy this wonderful world of automobiles to its fullest potential. Whether you are an engineer, a car enthusiast, or simply someone who wants to learn more about this world of autos, this blog is absolutely for you. Follow as we learn together about the mechanics, innovations, and maintenance of vehicles.