Air Cooled Condensing Unit Simulation And Experimental Research

With the development of the economic and the improvement of people’s living standard, the refrigeration equipments have become the indispensable parts in daily life. The energy and environmental problems the equipments brought with are gradually shown. Further improving the energy efficiency of the refrigeration equipments is imperative from the perspective of energy saving and environmental protection. Most countries take it seriously, and develop energy-saving regulations to improve the refrigeration equipments energy efficiency one by one. To lead the market, the manufacturers should innovate ceaselessly, and develop the products which are energy-saving and environmental friendly. The researches on the high-efficiency and energy-saving of the refrigeration devices are important.The computer simulation for refrigeration devices can help us save time and energy during the performance researches on refrigeration devices, and it is important in the design optimization of the refrigeration system on the background of energy-saving and environmental protection.Air-cooled condensing unit is researched in this paper. The condensing unit is composed of a compressor and a condenser. It can be widely used because it can be used in various kind of Refrigeration unit, and adapt to various kind of temperature requirements. The characteristics of the unit on variable working condition were researched. In the fixed environment temperature (20℃)(while changing the evaporation temperature) and the fixed evaporation temperature (-7℃)(while changing the environment temperature) conditions, the condensing unit were tested respectively, and the analysis of the influences of the environment temperature and evaporation temperature on compressor condensing unit on each performance parameter were made. The condensing unit adopts R404A as refrigerant. At the same time, simulation models were established, which includes refrigerant model, a compressor model and a condenser model. Based on Martin-Hou equation, the theoretical physical property model of R404A was established, the model was validated, the error is less than5%, to meet the needs of the refrigeration system simulation. The compressor mathematic model is based on ANSI/ARI540, the coefficients were fitted using least square method, the model was verified combined with the experimental datum, the result shows that the maximum error is7%. The mathematical mode of the condenser was established based according to the enthalpy, the one-dimensional steady-state mathematical model of both the refrigerant side and air side of were solved, the model was also verified combined with the experimental results with an maximum error3%, and the condenser heat transfer and flow characteristics were analyzed. The paper provides reference for performance research and the design of the condensing unit.