Research On Variable Operating Characteristics Of R290 Room Air Conditioning Rolling Rotor Compressor

In the context of the increasingly serious global greenhouse effect and refrigerant replacement has entered the "Kigali Amendment Time",As an environmentally friendly refrigerant with excellent refrigeration performance,R290 is likely to become a common refrigerant for room air conditioners in the future,and the current room air conditioners mainly use rolling-rotor compressors.In order to promote the process of marketization,it is necessary to carry out research on the characteristics of variable operating conditions of R290 dedicated rolling rotor compressors.The main work is as follows:The comparison and analysis of thermodynamic properties,economical and physical properties of R290 and current refrigerants used in domestic room air conditioners are made,and their respective cycle performance under air-conditioning and variable working conditions are analyzed;At the same time,the thermodynamic and dynamic analysis of the R290 rolling-rotor compressor was carried out;Finally,the R290 rolling-rotor compressor performance test bench was set up to study the variation law of R290 rolling-rotor compressor performance parameters under the variable operating conditions in the suction temperature range of 15 to 41?,pressure ratio of 2.67 to 3.85,evaporation temperature of 3 to 12?,and subcooling of 4.3 to 12.3?.Through processing and analysis of experimental data,it is found that the higher the intake temperature of the compressor,the lower the power,and the larger the values of cooling capacity,COP,exhaust temperature,electrical efficiency and comprehensive efficiency coefficient;and the volumetric efficiency does not basically increase with the intake temperature;for variable evaporation temperature conditions,the values of refrigeration capacity,power,and exhaust temperature increase with the increase of the evaporation temperature,while COP,volumetric efficiency,electrical efficiency and comprehensive efficiency coefficient decrease with the increase of the evaporation temperature;under the variable pressure ratio conditions,the exhaust temperature increases with the increase of the pressure ratio,and the power increases with the increase of the pressure ratio under the conditions of variable condensing pressure,but decreases with the increase of the pressure ratio under the conditions of variable evaporation pressure,and the values of cooling capacity o COP,volumetric efficiency,electrical efficiency and comprehensive efficiency coefficient decrease with the increase of the pressure ratio;under the condition of changing subcooling,the increase of subcooling increases the cooling capacity and COP without affecting other performance parameters.In addition,based on the experimental results,suggestions are made for the performance optimization of the R290 rolling-rotor compressor and verified by the compressor-specific design simulation software.The study found that thinning the cylinder head exhaust valve seat and lowering the cylinder height will improve the compressor performance,and the best size of the exhaust hole diameter needs to be found to optimize the compressor performance.