5th Class Power Engineering Practice Exam

In a refrigeration system, the compressor plays a critical role by increasing the temperature and pressure of the refrigerant. This process is essential for the refrigeration cycle to function properly. When the refrigerant leaves the evaporator, it is in a low-pressure, low-temperature gaseous state. The compressor takes this refrigerant gas and compresses it, which fundamentally reduces its volume and simultaneously raises its pressure and temperature.

This increase in pressure is vital because it prepares the refrigerant for the next stage in the cycle, which is the condenser. In the condenser, the high-pressure refrigerant releases heat to the environment and transforms back into a liquid state as it cools down. By increasing the temperature and pressure, the compressor ensures that the refrigerant can effectively release its heat in the condenser, thus enabling the refrigeration system to remove heat from the area it is meant to cool.

While release of heat, decreasing pressure, and absorption of heat from the environment are important processes in the overall refrigeration cycle, they do not accurately describe the function of the compressor itself, which particularly focuses on elevating the pressure and temperature of the refrigerant.