Study On The Enhanced Desorption Process Of Solar Energy Adsorption Refrigeration And Operation Characteristics Of Mass Transfer Pump

To alleviate energy and environmental problems and develop adsorption refrigeration technology with solar energy as the driving source is one of the ways of green refrigeration.However,in the desorption process of refrigeration system,the pressure in the adsorption bed rises in the desorption process and the mass transfer efficiency of the mass transfer pump is low.In order to improve the operation efficiency and stability of the refrigeration system,in view of the above problems,this paper conducts the following research work:(1)For the enhanced mass transfer mode of mass transfer pump for solar adsorption refrigeration system with photovoltaic power supply,the operation characteristics of mass transfer pump and photovoltaic power supply system are explored and analyzed.The results show that the operating characteristics of the mass transfer pump at different speeds are explored,and the power of the mass transfer pump operating at the maximum speed is the smallest.The 40 W photovoltaic power supply system with battery pack can stably maintain the continuous operation of mass transfer pump in sunny cloudless and cloudy weather.(2)In the enhanced mass transfer mode,the pressure of the adsorption bed was higher than that in the natural mass transfer mode at the beginning of the desorption process.The desorption performance was explored and compared with the natural mass transfer and the direct enhanced mass transfer by synergistic mass transfer of the natural channel and the enhanced channel in combination with the advantages of the two mass transfer modes.Through the mass transfer mode of the combination of natural and enhanced mass transfer modes,within 10 min after the start of the desorption process,the pressure of the adsorption bed rapidly decreased from 27.1k Pa to 20.6 k Pa.The mass of desorption was 29.37% higher than that of the natural mass transfer mode,and higher than that of the direct enhanced mass transfer by8.82%.(3)Under natural weather conditions,the energy needed by the mass transfer pump is provided by the photovoltaic power supply system,and the performance evaluation of the enhanced mass transfer system with photovoltaic power supply is carried out.The 40 W photovoltaic power supply system with 24 V battery pack can maintain the continuous and stable operation of the mass transfer pump,and the photoelectric conversion efficiency of the desorption process is 13.4%.Under the same cooling water temperature,the desorption quality of refrigerant in enhanced mass transfer mode was at least 5.65% higher than that in natural mass transfer mode.(4)In the adsorption refrigeration system with methanol-activated carbon as working pair,the mass flow rate of mass transfer pump in the desorption process is at a low level because the desorbed refrigerant is high-temperature methanol vapor.Firstly,to cooling the desorbed high temperature methanol vapor,and then the mass transfer is enhanced by the mass transfer pump.This method is based on the ideal gas state equation proposed by Clapeyron.When the cooling temperature at 20 °C,the average pressure of the adsorption bed with the desorption process is 21.9 k Pa,and the coefficient of performance(COP)of the system is 0.169.However,the mass transfer pump in the desorption process at 20 °C is prone to cavitation phenomenon,which damages the life of the mass transfer pump.