A grey box model of screw ground source heat pump unit has been established and operating characteristics of the unit using R22 refrigerants were simulated. The effects on refrigerating capacity, heating capacity, power consumption of the compressor and COP on conditions of cooling and heating have been analyzed with different inlet water temperature of evaporator and inlet water temperature of condenser. Results show that main factor which affecting COP of heat pump unit is inlet water temperature of condenser. The change of refrigerating capacity and heating capacity are mainly caused by inlet water temperature of evaporator. Measures can be done to decrease the inlet water temperature of condenser when the unit operates for a long time and to increase inlet water temperature of evaporator on very hot or very cold conditions.

The mathematical models of the cold-water screw unit used on cold storage has been established.The operating condition of the unit which working at partial load has been simulated,with different return water temperature of condenser.The influence from the return water temperature of condenser on the cooling capacity and power consumption on the condition of different capacity of compressor has been analyzed, when the evaporation temperature is-10°C.The fact that the operational cost can be significantly reduced if the night cool storage technology is adopted.

An automatic test system of airflow performance in refrigerator transportation vehicle is proposed and constructed. The wind velocity field of loading area of empty refrigerated compartment is test in this research. The distribution characteristics of the tri-dimensional wind velocity field are analyzed. The plenty vortex areas in the back part of the recurvature area of the refrigerated compartment is beneficial to the uniformity of the temperature field, the flow fields of the loading area are obviously influenced by vortex areas and the face that the area below the return air inlet is most probably one of the temperature blind angles are concluded.

The mathematical models of the storage refrigeration system of cold-water screw unit has been established.The operating condition of the unit and the system which working at partial load has been simulated,with different return water temperature of condenser.The influence from the return water temperature of condenser on the COP of the unit and system on the condition of different capacity of compressor has been analyzed, when the evaporation temperature is -10°C.The fact that it’s better to use start and stop operation with upload and download step by step rather than operate on the condition of low capacity of compressor, and that it’s beneficial for systemic energy conservation to use the variable frequency pump have been concluded.