| Scroll compressor is widely used in air conditioning,heat pump,refrigeration and other fields because of its small size,light weight and few parts.However,due to the working process of the scroll compressor is approximately adiabatic,the working process is continuous,the unit heat dissipation area is small and there is no good heat dissipation device and other shortcomings,it will cause the thermal deformation of the orbiting scroll and fixed scroll,resulting in poor sealing effect,increased leakage,increased friction loss,decreased reliability of the whole machine,and shortened life.How to effectively cool the scroll compressor and improve the reliability of the whole machine is the direction of future efforts.In this paper,the floating fixed scroll compressor for air conditioning in computer room is taken as the research object.According to its working characteristics,the changes of refrigeration capacity,power and energy efficiency ratio of compressor under different working conditions are analyzed.Aiming at the problem that the temperature of the back of the fixed scroll of the floating fixed scroll compressor is too high and concentrated at the exhaust pipe,a floating fixed scroll back pressure mechanism(new mechanism)with heat dissipation structure is proposed.The mathematical model of heat transfer between the back pressure mechanism of the original prototype and the cavity of the new mechanism is studied,and the heat transfer of the two mechanisms under different working conditions is calculated.Then the CFD simulation of the two mechanisms is carried out,and the temperature distribution of the back of the fixed scroll under the temperature field of the heat transfer model is analyzed.In order to make the simulation results closer to reality,the temperature field of the two heat transfer models is coupled with the temperature field in the compression chamber,and the temperature cloud diagram and temperature distribution of the coupled temperature field are obtained.After comparative analysis,it is found that the new mechanism still has the problem that the heat dissipation efficiency is not high enough and the heat dissipation efficiency is greatly affected by the working conditions.Therefore,it is further optimized on the basis of the new mechanism.The optimized floating fixed scroll back pressure mechanism(optimized mechanism)is simulated and calculated,and the temperature distribution law of the optimized mechanism under the temperature field of the heat transfer model and the temperature distribution law of the fixed scroll under the coupled temperature field are obtained.The research shows that the cooling capacity,power and energy efficiency ratio of the scroll compressor for air conditioning in the computer room are greatly affected by the external environment temperature.With the decrease of the external environment temperature,the cooling capacity of the compressor increases,the power decreases,and the energy efficiency ratio of the air conditioning increases.By adding a heat dissipation structure to the floating fixed scroll back pressure mechanism,the heat transfer of the fixed scroll back is increased.Under the temperature field of the heat transfer model,the temperature distribution of the back of the fixed scroll along the radius direction changes from the high temperature-medium temperature of the original mechanism to the high temperature-low temperature-medium temperature of the new mechanism,which changes the phenomenon that the heat is concentrated at the exhaust pipe.When the temperature field of the heat transfer model is coupled with the temperature field in the compression chamber,the temperature of the fixed scroll of the two mechanisms gradually decreases from the inside to the outside,and the temperature of the fixed scroll of the new mechanism is lower than that of the original mechanism.The optimized mechanism can significantly improve the heat transfer efficiency of the heat dissipation structure by replacing the air in the heat dissipation structure of the new mechanism with R410 A refrigerant with higher heat transfer efficiency.By connecting the inlet of the heat dissipation structure to the gas-liquid separator and using the refrigerant at a constant suction temperature for heat dissipation,the heat dissipation efficiency can be effectively improved.Through the comparative analysis of the temperature distribution of the coupling temperature field,the heat concentration range of the central exhaust hole position of the optimized mechanism is significantly smaller than that of the new mechanism,and the temperature of the edge of the fixed scroll is also reduced.It can be seen that the optimized mechanism has better heat dissipation efficiency. |
