Thermodynamic Simulation Of Compound Condensation Process In HP/AC Systems

Compared to the conventional air conditioning system, the air conditioning system with compound condensation process can produce the sanitary hot water,it have the advantages of recovering the condensation heat, improving the refrigerate capability, reducing the exhaust temperature of the compressor. However, there are still some problems needed to be solved in the development process of air conditioning system with the compound condensation process. They are as follows: Due to the addition of the sanitary hot water supply equipment, the system operating parameter has been changed, the system may not operating smoothly; the system component may not match rationally, it lead to the energy waste; the blindness of choosing the operating parameter of the combined sanitary hot water supply system and the condenser; there are no simple and convenient method to evaluate and test the performance of the system; the system characteristic with alternative refrigerant is different to the R22system. And due to the big temperature gap change of the condensation process, the heat transfer process is vary with the operating time. In order to solve these problems, this paper separately analyzed the principle and characteristic of water condensing+water condensing mode and air condensing+water condensing mode of the compound condensing process. It include the performance exam of four aspects:the decentralized water-cooling chiller unit, the air cooling heat pump unit, the muti-function heat pump system and the substitute refrigerate in the compound condensation process.Firstly, the exergy analysis method has also been employed to analysis the two condensers condensation process. The dynamic models of the temperature improve of the sanitary hot water and the compound condensation process has been established based on the decentralized chiller unit. The calculation methods about the exergy efficiency of the sanitary hot water and the compound condensation unit have been given out. The period of the sanitary hot water temperature from the initial input temperature to the temperature the user demand was taken as a calculation circle. Then the performance of the system can be evaluated. The problem that the compound condensation process cannot described and simulated by the traditional thermodynamics is solved. The SIMULINK software is employed to build the simulation model. The experiment dates have been employed to exam the dynamic model. The relationship of the outlet temperature of sanitary hot water, the exergy efficiency of the system, and the outlet pressure of the compressor versus the operation time has been gotten. Then, the optimal mass flow of the sanitary hot water under the given condensation temperature and maximum exergy efficiency of the compound condensation process have been gotten.Secondly, the finite-time thermodynamics and the exergy analysis method have been employed to analysis the two condensers condensation process. The decentralized models of the temperature improve of the sanitary hot water and the compound condensation process has been established based on the air-cooling heat pump unit. The SIMULINK software is employed to build the simulation model. The experiment dates have been employed to exam the cumulative model.Thirdly, the performance of the unit muti-function heat pump system has been analysis. The experiment data has been used to exam the simulation model of the compound condensation process in the air-cooling heat pump unit. Then, the test method has been given out based on the cases about the air-cooling heat pump.Finally, the applying trend of the alternative refrigerant in the compound condensation process has been discussed. The decentralized simulation model of the alternative refrigerant in the air-cooling heat pump system has been build. It is based on the SIMULINK. The system operation characteristics with the R407C and R410A have been tested separately. And they were compared with the R22system. Following that, the AC/HP system model with nature refrigerant CO2is established according to the paper published. Then, the simulation model of the refrigerate cycle is built with SIMULINK. After the testify of the refrigerate cycle with CO2, the compound condensation process with CO2is established and tested, and theoretical basis is provided for the applying of the alternative refrigerate in the compound condensation process.