Study On Variable Working Conditions Of Quasi Two-stage Compression Refrigeration System With Intermediate Air Supplement

Under low temperature conditions,the use of intermediate air supply technology can effectively reduce the pressure ratio of the compressor,improve the cooling/heating performance of the refrigeration/heat pump system,reduce the exhaust temperature of the compressor,and improve the overall performance coefficient of the system.In this paper,the quasi-two-stage compression refrigeration system with intermediate air supply is applied to the field of refrigeration and refrigeration,and the feasibility of the application of intermediate air supply technology is studied by combining theoretical analysis and experimental verification.In terms of theoretical analysis,theoretical models are established for important components such as scroll compressors,condensers,throttle valves and evaporators.In terms of experimental verification,a quasi-two-stage compression refrigeration system with intermediate air supply is built.This topic studies:the condensation temperature is 30°C,the evaporation temperature is-18°C,-15°C,-12°C,-10°C and the evaporation temperature is-10°C,the condensation temperature is 30°C,35°C,40°C,45°C Under the working condition of ℃,the relative air supply pressure,relative air supply volume and quasi-first-stage compression internal volume ratio are aligned with the effects of the cooling capacity,compressor power consumption,COP and discharge temperature of the two-stage compression refrigeration system.The research results show that: when the relative air supply pressure is 1.2～1.6,the cooling capacity has a maximum value;when the relative air supply pressure increases by 0.2,the compressor power consumption increases by 3%～5%;the higher the relative air supply pressure,the higher the COP.Small;the higher the relative air supply pressure,the better the effect on reducing the compressor discharge temperature.When the relative air supply volume is0.6～1.2,the cooling capacity has a maximum value;under the same working conditions,the larger the relative air supply volume,the greater the compressor power consumption,and the compressor power consumption increases by 10% for every 0.2 increase in the relative air supply volume-12%;the exhaust gas temperature increases first and then decreases with the increase of the relative air supply amount.When the relative air supply ratio is 0.2～0.3,the exhaust gas temperature reaches the maximum value;with the increase of the relative air supply amount,the COP presents the highest value.The downward trend,the rate of decline gradually decreases.The larger the quasi-first-stage compression internal volume ratio,the greater the cooling capacity;when the internal volume ratio increases from 1.0 to 2.0,the compressor power consumption is reduced by 30%～37.8%,and the COP is increased by 1 to 1.1 times.It provides theoretical support for the research of intermediate air supply technology in the field of freezing and refrigeration.Through theoretical calculation and experimental research,this topic researches the performance of the quasi-two-stage compression refrigeration system under different working conditions,and explores the effect of different intermediate air supply parameters on the performance of the quasi-two-stage compression refrigeration system.