In the previous article we saw that there are four main components of heat pump: compressor, condenser, expansion valve and evaporator. Now let us have a look at all the components of the heat pump, which will also help you understand the exact working of the heat pump.
Compressor is the one of the most important parts of the heat pump. Inside the compressor the refrigerant is compressed to extremely high pressures, where its temperature is also increased. The refrigerant enters the compressor at low pressure and low temperature in gaseous state and leaves the compressor at high pressure and high temperature in gaseous state.
Types of Compressors
There are two types of compressors: reciprocating compressors and rotary compressors. The reciprocating compressors have piston and cylinder arrangement similar to the reciprocating engine. While the reciprocating engine produces power by consuming fuel, the reciprocating compressor produces compression by consuming power. In fact the compressor can also be driven directly by the engine. The reciprocating action of the piston inside the cylinder helps in compressing the refrigerant. The rotary compressors have a rotor, which rotates inside the closed chamber and compresses the incoming refrigerant.
The compressors consume power for their operation. It has been found that the reciprocating compressors consume more power than the rotary compressors. Even the noise generated by the reciprocating compressors is more than the rotary compressors. Further, the rotary compressors are found to require less maintenance than the reciprocating compressors. Due to these factors, the rotary compressors have been fast replacing the reciprocating compressors not only in the heat pumps but also the air conditioners.
As per the second law of thermodynamics, the heat flows from source or the reservoir at high temperature to sink or reservoir at low temperature. To transfer the heat from low temperature reservoir to high temperature reservoir external work has to be supplied. In the heat pump the heat is transferred from atmosphere at low temperature to the room at high temperature, hence some external work should be supplied to it.
The external work to the heat pump is supplied in the form of electric power to the compressor. It is the compressor that consumes the maximum amount of electricity in the heat pump, refrigerator, freezer and the air conditioner. The compressor performs the vital function of compressing the refrigerant which eventually enables the refrigerant to absorb the heat from low temperature reservoir and deliver to the high temperature reservoir.
This post is part of the series: Heat Pumps
- What is Heat Pump?
- Difference between Heat Pumps and Refrigerators
- Various Components of the Heat Pump – Part 1
- Various Components of the Heat Pump – Part 2
- Various Components of the Heat Pump – Part 3
- Various Components of the Heat Pump: Part 4
- Coefficient of Performance of the Heat Pumps
- Difference between the Heat Pump and the Air-Conditioner