Introduction Of Refrigeration And Air Conditioning

Question 1

What is the relation between COP of heat pump and refrigerator?

Answer 1

(COP)HP=1+(COP)RE

Question 2

What are different methods of refrigeration?

Answer 2

1. Evaporative Cooling
2. Dissolution of salts in water
3. Ice refrigeration
4. Throttling process

Question 3

What are the different mechanical refrigeration system?

Answer 3

1. VCRS(Vapour Compression Refrigeration System)
2. VARS (Vapour Absorption Refrigeration System)
3. Air Refrigeration
4. Stream jet Refrigeration

Question 4

What are the different parts of domestic refrigeration (VACRS Cycle).

Answer 4

1. Compressor
2. Condensor
3. Capillary tube
4. Evaporator

Question 5

Explain the working of VCRS cycle.

Answer 5

Process 1 to 2 ( COMPRESSION)
The refrigerant vapour at low pressure and temperature in dry state is drawn from evaporator during suction stroke of the compressor . The compressor constricts the vapour, thus raising pressure and temperature.
Process 2 to 3(CONDENSATION)
The vapour refrigerant at high pressure and temperature, coming from compressor is used into condensor coil which is located at the back side of the refrigerator. The hot refrigerant passes through these coils and meets cool air (from surrounding), thus getting converted into liquid form.
Process 3 to 4 (EXPANSION/THROTTLING)
The high pressure refrigerant in the liquid state is throtted in the capillary tube. This capillary tube is a copper tube of low diameter and long length. Thus due to friction , the high pressure of the liquid is converted to low pressure of the liquid.
Process 4 to 1(EVAPORATION)
The wet vapour after expansion process passes through the evaporator coil inside the refrigerator. The refrigerant absorbs heat from the food stuff , gets cooled and liquid phase of the refrigerant is converted to vapour phase.