Study On Heat Pump Water Heater Performance And Condensation Heat Transfer Of Horizontal Ring Channel Of R417A

With the rapid development of the global economy,energy depletion and environmen-tal pollution has become the world's two major issues of common concern,from the per-spective of sustainable development,effective reduction of building hot water energy con-sumption is one of the important development topics.Heat pump water heater with high ef-ficiency,energy saving,environmental protection and many other advantages,and the re-frigerant on its operating performance has a great impact.In this study,R417A is used as the refrigerant,and the temperature of the inlet of the condenser is 20?60? and the flow rate is 0.6?1.0m3/h.The temperature,compressor pres-sure,input power,Calculate the total heat transfer of the condenser,the total heat transfer coefficient,heat pump water heater heating capacity,heating performance coefficient,the compressor suction,exhaust pressure,input power.The relationship between the heat trans-fer performance of the condenser,the inlet water temperature of the condenser and the in-fluent flow rate,and the convective heat transfer coefficient hw of the water side were ana-lyzed under the conditions of cyclic heating and DC heating.The relationship between Nu-osai number Nu and Reynolds number.At the same time,the refrigerant R417A and R134a in the heat pump water heater in the heat,COP,power and compressor suction,exhaust pressure and other performance comparison,the two refrigerant in the air source heat pump in the advantages and disadvantages.Finally,according to the collected data and the water side heat transfer coefficient hw,the condensation heat transfer coefficient of R417A in the horizontal annular channel and the local heat transfer coefficient of each measuring point are calculated,and the existing working fluid is used in the horizontal casing Condensation in the condenser to verify the heat transfer.The results show:(1)The total heat transfer coefficient,the total heat transfer coefficient,the heating capacity and the heating coefficient COP decrease with the increase of the inlet water tem-perature when the inlet flow rate of the condenser is constant,and the compressor suction and exhaust pressure are input The power increases with the inlet water temperature.When the inlet flow rate of the condenser is constant,the hw and Nu increase with the increase of Re in the horizontal casing.When the inlet water temperature is constant,The total heat transfer capacity of the condenser,the total heat transfer coefficient,the heating capacity of the heat pump water heater and the heating coefficient coefficient COP increase with the increase of the influent flow rate,while the compressor suction and exhaust pressure and input power are in accordance with the inlet water temperature Increase and decrease.(2)Compared with R417A and R134a,the R134a system has lower suction and ex-haust pressure than R417A system under the same operating conditions,and the input pow-er is low.But R417A system in the heat and COP is significantly better than the R134a sys-tem.(3)As the condensation process continuing,the temperature of the refrigerant in the annular channel decreases along the way,and ultimately tends to gentle state.The heat transfer coefficient of the refrigerant on the refrigerant side decreases with the increase of the influent temperature.When the influent temperature is constant,the heat transfer coeffi-cient of the horizontal casing The same heat flow density,the greater the heat flux density,the greater the local condensation heat transfer coefficient,but also can get the same water flow,the same heat flux density,the local heat flow density,The condensing heat transfer coefficient decreases with the decrease of the dryness of the refrigerant.(4)The condensing heat transfer coefficient of R417A is calculated by the condensing heat transfer of Cavallini and Yu-Koyama mixed refrigerant.The results show that the re-sults of R417A and the results are in agreement with each other.The results show that Cav-allini The correlation can better predict the experimental results.