Heating cooling circulator is a process that refrigerant transfers heat from low temperature state to high temperature state, so that its cooling can reach the state of low temperature environment, thus maintaining the low temperature state and realizing the refrigeration process. In the heating process of heating cooling circulator, heat is the process of heating with heat conducting oil to provide heat source, because the low temperature state is impossible to provide heat as the high temperature state.

Refrigeration cycle includes compression refrigeration cycle, absorption refrigeration cycle, adsorption refrigeration cycle, steam jet refrigeration cycle and semiconductor refrigeration cycle, etc. Heating cooling circulator of Wuxi Guanya mainly adopts compressor refrigeration cycle. In the compressed air refrigeration cycle, two constant pressure processes are used to replace the two constant temperature processes of reverse Carnot cycle, so it can be regarded as reverse Brayton cycle. In engineering application, compressor can be piston type or impeller type. After entering the compressor, the air from the heating and refrigeration cycle equipment is adiabatically compressed, and the temperature rises above the ambient temperature. Then it enters the cooler and transfers the heat to the cooling water at a constant pressure, the temperature is equal to the ambient temperature. Then the expander is introduced to adiabatic expansion, and the temperature is further reduced to below the temperature of the heating and refrigeration cycle equipment. Then it enters the heating and refrigeration cycle equipment, which absorbs heat at constant pressure (the heat absorbed is called refrigeration capacity), and completes the cycle.

After the refrigerant is vaporized and absorbs heat from the heating cooling circulator at constant pressure (at this time the working medium is usually dry saturated steam or near dry saturated steam), it enters the compressor to compress in adiabatic state, the temperature exceeds the ambient temperature, and then enters the condenser to heat the ambient medium at equal pressure. In the condenser, the superheated refrigerant vapor is first isobarically cooled to the saturated temperature corresponding to the current pressure, then continues isobaric (which is also isothermal) condensation to the saturated liquid state. It enters the throttle valve, adiabatic throttle at the throttle valve to reduce temperature and pressure to the wet saturated vapor state corresponding to the starting pressure of the cycle, and then enters the heating and refrigeration cycle equipment to gasify and absorb heat to complete the cycle.