ppt of rac.pptx

8/10/2019 ppt of rac.pptx

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Sunil Bisoyee (MER066)

Premnath Tiwari (MER067)

Suraj ku. Nayak (MER068)

K D garki panigrahy (MER069)

Annada Sankar Samal(MER070)


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Air conditioning is the process of

altering the properties of

air(temperature and humidity) to more

comfortable conditions, typically with

the aim of the distributing the

conditioned air to occupied space to

improve thermal comfort and Indore

air quality.


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Stopped in traffic on a may afternoon.

Sweat drips all over your body.

Hands feel like they are about to slip away from the steering wheel due to s

Need a luxurious and a comfortable ride.

Why dontyou attach an automotive air conditioning system to your ride, w

all new cars produced since 2010 are equipped with.


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The function of air conditioner is to maintain the life environment in a c

condition. Therefore, complete air conditioning involves:

i. Temperature control

ii. Air circulation control

iii. Humidity control

iv. Air purification


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A container provided with a tap is placed in a well-insulated box.

A liquid that will vaporize readily at atmospheric temperature is placed in the c

When the tap is opened, the liquid in the container will take away the heat n

vaporization from the air inside the box, turn into a gas and escape outside

At this time, the temperature of the air inside the box will become lower tha

the tap was opened.

We can cool objects in this way


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Main function- to cool and remove humidity from air inside the car. Parts of a typical car AC system are:

(i)Compressor

(ii)Condenser

(iii)Receiver or Dryer

(iv)Expansion valve(v)Evaporator


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This is the heart of our a/c system.

The compressor is what takes the refrigerant (the gas)

and pressurizes it so it will cool the air. It's run by an

engine belt. The compressor also has an electrically

operated clutch that turns the compressor on and off as

you demand more cool air.

Any liquid or dirt allow to enter the compressor will

cause damage.


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The condenser is basically a radiator, and itserves the same purpose as the one in our car: to

radiate heat out of the system.

The refrigerant enters the condenser as a

pressurized gas from the compressor. The process of

pressurizing the gas and moving it to the condenser

creates heat, but air flowing around the twisting tubes

of the condenser cool the refrigerant down until itforms a liquid again.

Imagine the case of steam, cooling down and

condensing back into water.

The liquid refrigerant is now a high-pressure

liquid and nearly ready to cool the car.


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As it moves out of the condenser, the liquid goes through a little r

installed in the line. This receiver-dryer contains desiccants, small g

that attract water.

In the receiver-dryer, they remove any water that has entered the

If the water is allowed to remain and possibly form ice crystals, it can

the air conditioning system.


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Receiver/Dryer


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The accumulator is fitted between the evaporator and the

compressor. But first, the refrigerant needs to be preppedfor the evaporator.

ACCUMULATOR


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Here the pressure of refrigerant is reduced causing expansion of the liquid,resulting in further cooling.

Slowly the liquid reverts back into a gaseous form.

Also the valve reduces pressure on the refrigerant so it can easily moveinto the evaporator.

The valve senses pressure and regulates the flow of refrigerant,which allows the system to operate steadily.


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5-EVAPORATOR

Radiator like device buried deep under

the dashboard. Refrigerant gas enters the evaporator

coils and absorbs the heat inside thecars cabin and moves out of the coils.

A fan blowing over the outside of theevaporator coil blows cool air into thepassenger compartment.

Thus the evaporator takes humidity outof the air in the car, which helps you feelcool

EVAPORATOR


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Malfunctions evident in following ways:

Noise

Seizure

Leaks

High inlet & low discharge pressures


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ReceiverExpansion

valveEvaporator

CompressorCondenser

Liquid

refrigerant

High Pressure,

High Temperature

Low Pressure

Low Temperature

Liquid

refrigerant

Gaseous

refrigerantL

Low

High Pressure

High Temperature

Gaseous

refrigerant

Liquid

refrigerant

Refrigeration Cycle


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Car air conditioners are classified according to the air conditioner mounting location and by the functions of the air conditioner.

1-Dash Type:

The air conditioner unit in this type is normally installed udash panel.


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2-Trunk Type

The air conditioner units is installed in the

trunk.

3-Dual Type

The cold air is blown out from the front and rear

of the car interior


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A device for leading the fresh outside air into the car, that also serve

ventilating the car.Types of Ventilator

Natural flow-through ventilator

Intake of external air into the vehicles interior due to the air pressuregenerated by the vehicles movement

Forced air ventilator (Boost Ventilator)An electric fan or similar device is used to force air through the vehicl


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An AC system not only cools the cabin, it removes dust and dirt, leaving onfresh air.

One has to remember to use only environment friendly refrigerants and avo

as much as possible.

The AC system can be recharged by adding fresh refrigerant and removing

remaining one.

Care must be taken in the disposal of refrigerants as they may affect the so

etc.,

Its also necessary to check the AC system for leaks as it may lead to the lo

refrigerant as well as environmental hazards.


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