| It is an urgent and important issue for people to seek sustainable energy and efficient utilization way.The characteristics of air source was environmental-friendly,zero price and inexhaustible reverse.Conventional air source heat pump system appeared a series of problems in the process of running,including the difficulty of leasing heat load for outdoor equipment in high temperature,frosting in low temperature and the decline of energy efficiency.To solve the above problems and increase thermal efficiency,this paper presents a novel wet packing heat-exchanging device outdoors for refrigeration and heating.By the combining method of theory and experiment,this paper investigated heat transfer performance of heat exchanger and heat pump system.Above all,a three dimensional heat transfer model was proposed based on the Poppe method to simulate the heat transfer process of this heat exchanging equipment.The theoretical model was validated with the experimental data and the relative error is less than 10%.The result showed that this theoretical model is accurate.In the summer of northeast China,the heat transfer performance of this heat exchanger under dry and wet condition was tested and a series of the factors was investigated including the working medium temperature,spray water,the air temperature and humidity etc.The experiment results reveal that the overall heat transfer coefficient of the heat exchanger can be nearly constant in a wide range of the working medium temperatures.Heat transfer rate increases constantly with the increases of air and sparkling water flow rates and an optimal sparkling density of 0.588L/(m~2·s)was determined for this novel heat exchanger.Manufactured condoms and temperature distribution of the packing heat-exchanging equipment were actually investigated and analyzed.In addition,here optimizes structure parameters of the heat exchanger device,including the tube center spacing,height of packing,and fin efficiency by the utilization of numerical simulation and other structure parameters were analyzed and summarized further.The study found that temperature along the Y axis appeared great fluctuation.This technology of connection and assembly between packing and thermal conductive plate is poor.The optimal tube center spacing of three sections in aligned arrangement is 4-4.5 cm.The appropriate height range calculated by theory is from 4 to 5 cm.Finally,on the basis of optimizing the structure and improving processing technology,the paper designed and set up air source heat pump system with a new packing heat exchanger.Heat transfer performance of the heat pump system was investigated in the condition of collecting heat.The performance curve of COP–inlet air temperature with different ratio of gas and liquid is obtained by experiments,and the laws of the curve are analyzed and explained in this paper.Experimental result showed that the optimum combination of inlet air and spray solution volume flow rate was 10000 m~3/h,0.5 L/min and 1 L/min during the inlet air temperature range from-5?to 3?.Besides,the heat pump system operated well in easy-frosting weather. |
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