Study On Thermal Performance Of New Refrigerant In Medium-high Temperature Water Source Heat Pump

Industrial production such as food drying,sterilization,heat treatment,paper drying,oil extraction,there are a lot of 30 ~ 60 ? waste heat resources.If you can use these waste heat,not only can improve energy efficiency,but also greatly reduce energy waste and environmental pollution.Heat pump as an important means of energy recovery,has been widely used to produce 60 ? below the normal temperature heat source,but in the pursuit of higher temperature in the study of high temperature heat pump has not yet made a breakthrough,with R11,R114,R142 b and other CFCs and HCFCs high-temperature refrigerant have been banned,R134 a,R152a and other common HFC class refrigerant maximum heat output temperature is insufficient,making R245 fa as the main component of the pure working or mixed refrigerant to become high-temperature heat pump technology development Focus.In this paper,the theoretical calculation model of high temperature water source heat pump is established.Based on the call of physical properties of REFPROP thermo-physical calculation software,the calculation program is compiled by MATLAB,and the theoretical calculation objects R134 a,R245fa,R1234 ze,R134a / R245 fa and the new environmentally friendly mixed refrigerant R1234 ze / R245 fa.The pure working fluid R245 fa has lower exhaust pressure and exhaust temperature at the same condensing temperature and has a higher heating COP,but its unit volume In order to compensate for this deficiency,we have mixed the R1234 ze and R245 fa,and the new working fluid has excellent performance in the safety,environmental protection and high temperature conditions.In order to further expand the application of R245fa-based pure working fluid and mixed refrigerant in the field of high-temperature heat pump applications,while improving the thermal performance of high-temperature heat pump unit,we have high temperature heat pump expansion valve control system is optimized.The new refrigerant expansion valve control system,control.On the basis of the theoretical calculation and the optimization of the experimental platform,we carried out the experiment of supercharging experiment with the R245 fa working fluid high temperature heat pump test bed.The optimum temperature of the unit was optimized and the temperature of the heat pump was raised with R245 fa as the working fluid.Under the current experimental conditions,the effluent temperature reached 105.8 ?.Experiments show that the optimized expansion valve control method can improve the cycle performance of the heat pump unit,such as water temperature,heating capacity and heating COP.Based on R245 fa as the main component of the high temperature heat pump system,with the potential to enhance the maximum water temperature,has a broad application prospects.