Heat pump air dryer

A heat pump air dryer is a drying device based on a heat pump. Wet air undergoes a cooling and dehumidification process in the evaporator, and condensed water is discharged through a drainage device to achieve the purpose of drying.

Working principle of heat pump air dryer:

(1) Compression process: Low temperature and low-pressure refrigerant gas is compressed into high-temperature and high-pressure gas by a compressor. At this point, the work of the compressor is converted into the internal energy of the refrigerant gas, causing an increase in temperature and pressure. Thermodynamically, it is called an insulation process.

(2) Condensation process: High temperature and high pressure refrigerant gas from the compressor passes through the condenser and is continuously heated by wind or water to condense into medium to high temperature and high pressure refrigerant liquid. When the refrigerant liquefies, its temperature decreases but its pressure remains constant. Thermodynamically, it is called an isobaric process.

(3) Throttling process: The medium high temperature and high pressure refrigerant liquid coming out of the condenser passes through the throttling device and becomes a low-temperature and low-pressure refrigerant liquid. Thermodynamically, it is called an isentropic process.

(4) Evaporation process: The low-temperature and low-pressure refrigerant liquid from the throttling device of the heat pump air dryer flows through the evaporator, continuously absorbing the heat of air or water into the room and evaporating into low-temperature and low-pressure refrigerant gas. The absorbed heat becomes the latent heat of the refrigerant. Although the temperature did not rise much, the internal energy increased significantly. Due to the small change in pressure, it is thermodynamically referred to as an isobaric process.