Experimental Study On The Performance Of A Heat Recovery Heat Pump Chiller And Water Heater

With the rapid development of economy and the improvement in people's quality of life,the use of air conditioning has become more widespread.Traditional air-conditioning system has high energy consumption,single function and easy to cause environmental pollution.The condensing heat recovery technology of air conditioning is a feasible technology because it can use condensing heat to make domestic hot water for free while cool about summer,which not only solves the waste of energy,but also avoids environmental pollution.In this paper,according to the shortcomings of traditional air conditioning,the condensation heat recovery technology of air conditioning is adopted,and a heat recovery heat pump chiller and hot water unit is proposed,and its theoretical analysis and experimental research are carried out.The main work contents are as follows:(1)The research status of condense heat recovery air system are introduced,in view of the shortcomings of present air conditioning heat pump units,we design a new form of hot poor heat pump,which can realize various operation modes: separate refrigeration mode,refrigeration + heat recovery mode,separate hot water production mode,separate heating mode,heating + heated recovery mode.(2)The equipment selection and theoretical analysis of the experimental prototype were carried out,the experimental platform was built,and experimental research was carried out on each operating mode.(3)Based on the analysis of the experimental data,the optimized design was carried out and the experimental test was conducted again in view of the shortcomings of the unit.The original unit and the improved unit were compared and analyzed.The test data analysis shows that the results are as follows:(1)In the separate refrigeration mode,taking the nominal working condition as an example,the average performance coefficient(EER)is 2.82,which is 14.5% different from the performance coefficient(EER)under the theoretical design refrigeration condition,and the maximum refrigerating capacity is 10.82 k W,which is 34% different from the customized refrigerating capacity of the unit.(2)In the refrigeration + heat recovery mode,the maximum hot water outlet temperature was 42? when the unit was running in the full heat recovery mode.With the change of operation time,the coefficient of performance(EER)decreased by 29.2%,the coefficient of performance(COP)decreased by 27.3%,and the coefficient of performance(COPz)decreased by 28.3%.When hot water temperature of 40? is set by the total heat recovery mode switch to the part of the heat recovery mode of optimal switching points,when the unit operation of heat recovery mode,when the hot water temperature of 40? respectively opened fan at low speed,medium speed faned,the fan running three groups of experimental data was analyzed,and suggestions only open fan runs at low speed,relatively short operation time was 125 min,power consumption is relatively small as 7.3 k Wh,average heat recovery rate is relatively high at 63%,the highest coefficient of performance(EER)of 6.92.(3)In the separate hot water production mode,the maximum exhaust temperature of the unit is 67.2?,which solves the problem that the exhaust temperature of other units is too high in the separate hot water production mode,so that the unit can run stably and the average coefficient of performance(COP)of the unit can reach 4.03.(4)In the heating + heat recovery mode,the average heat recovery rate is 27%,and the average coefficient of performance(COP)is 2.93.When two water heat exchangers act as condensers at the same time,they not only meet the indoor heating demand,but also provide hot water for people to live.(5)To improve the unit separated cool mode and cool + heat recovery experiment data testing,by sorting the original unit and the improvement of experimental data concluded: In a separate cool mode,improve unit the coefficient of performance(EER)to an average of 3.19,than the original unit of the average coefficient of performance(EER)increased by 13.1%;In refrigeration + heated recovery mode,the unit running full heat recovery mode,from the point of the heating water temperature,improve the unit to initial water temperature is 25? water heated to 55?,fully meet the demand of hot water temperature,from the point of the unit performance,improve unit of heat recovery is also significantly increased by an average of 10.1%,the average coefficient of performance(COPz)increased by 13.8%;In the partial heat recovery mode of unit operation(low speed fan operation),from the perspective of operation time,the operation time of the improved unit is shortened by 20 min compared with that of the original unit.From the perspective of performance,the average heat recovery of the improved unit is increased by 12.6% and the average coefficient of performance(COPz)is increased by 21.7%.