Experiment Of Plate Freezing Machine Based On Jet Pump With R507A

Jet pump for refrigeration system has been more than 100 years of history,its main use is divided into three categories: In place of the compressor of system,the ejector evaporator is used to pressurize the air or to increase the quantity of the evaporator.This study is based on the second applications that instead of throttling device in the refrigeration system,ejector refrigerant low-pressure circulation barrel so that the evaporator liquid supply times.With basis of the experiments on the original scientific research team,the jet pump liquid supply system is applied to the freezing capacity of 1.3 tons of large flat frozen machine under touch screen control and do freeze performance analysis.The main purpose of this research is comparing original freezing machine thermal expansion valve system and liquid supplying system of jet pump.Jet pump system and concrete is divided into two types: one for liquid circulation,the jet liquid supply bucket under the condition of refrigerant jet pump after throttling by gas-liquid separation and then feed liquid supply bucket the evaporation plate(Model I).Two,without the jet for liquid barrels,jet pump after the throttle refrigerant directly into the evaporation plate(Model II).Three kinds of liquid circulation mode,a preliminary analysis of preliminary determination and system simulation of the refrigeration coefficient analysis of frozen analysis,freezing rate of the freezing process of freezing time and power consumption of jet pump ejection coefficient,were compared under different conditions,the performance of three systems.Specific conclusions are as follows:1.The analysis from the perspective of energy consumption,under full load,the energy consumption of the jet pump for liquid way of operation is 80.1kW·h,the energy consumption of the thermal expansion valve for liquid operation mode is 84.9kW·h,the energy consumption of the jet pump for liquid way(mode II)operation is 93.3kW·h.2.From the perspective of freezing time,jet pump for liquid(mode I)freeze time is 128 minutes,the freezing time of thermal expansion valve system is 135 minutes,the freezing time of jet pump for liquid(mode II)is 190 minutes.Jet pump for liquid mode I use the shortest time,compared with the thermal expansion valve for liquid,freezing rate increased by 5.1%.3.From the analysis of the temperature distribution of frozen goods,frozen goods in all experimental center temperature is approaching-18? for the freezing end point,thermal expansion valve system is the earliest and most complete freezing late completion time difference of nearly 35 min,jet pump for liquid system of difference is about 30 min,the jet pump liquid feeding system for phase II way about 90min;freezing completed,thermal expansion valve for hydraulic system of frozen minimum temperature of-36,the maximum temperature difference of 18 degrees,the jet pump for liquid way of frozen under the lowest temperature of-31,the maximum temperature difference of 13 degrees,the jet pump for liquid way II system the lowest temperature of-43 and the maximum temperature difference of 27 degrees.4.Compared the performance of three liquid supply mode system under part load,from the analysis of the freezing time,shorten the time of freezing expansion valve system for 15 min low than thermal load conditions,but the energy consumption per unit of frozen goods increased by 0.008kW·h,the increment percentage is 7.6%.When the liquid supply system of jet pump is in operation,the shortening time is 11 min,and the energy consumption per unit frozen product is increased by 0.01kW·h,the increment percentage is about 10.2%.When the liquid supply system of jet pump is running,the freezing time is shortened by 62 min,the energy consumption per unit mass of frozen product is increased by 0.014 kW,and the increment percentage is about 12.1%.5.The jet coefficient of the jet pump in two kinds of liquid supply is measured experimentally.Under the condition of full load,the injection coefficient of jet pump(mode I)is 1.13,and the ejector coefficient of jet pump(mode II)is 1.18.Under the condition of partial load,the injection coefficient of jet pump is 0.14,and the ejector coefficient of jet pump(mode II)is 0.6.The preliminary measurement of the heat balance valve coefficient of refrigeration unit system(COP),under full load,jet pump for liquid way of system I is 1.21,jet pump liquid supply system II ejection coefficient is 1.18,thermal expansion valve for hydraulic system is 1.19.Under the condition of partial load,the injection coefficient of jet pump is 1.15,the ejector coefficient of jet pump system is 1.11 and the liquid supply system of thermal expansion valve is 1.12.