Study On Heating Performance Of Radiant-convective Wall Plate Heat Exchanger

In recent years,with the improvement of people's living standards,the requirements of people for the quality of indoor environment are becoming more and more strictly.The air conditioning system in the building is transition from functional equipment to comfort equipment.Compared with the traditional blowing type terminal equipment with poor comfort,the terminal device of radiation heat transfer emerged as the times require,due to its good characteristics of non contact heat transfer and comfort.Reasonably,in order to improve the indoor thermal comfort and reduce the heat transfer area,a wall plate heat exchanger which combined forced convection with radiation heat transfer was proposed,and its performance was tested and simulated by numerical simulation.In this paper,based on the direct expansion air source heat pump system test bench,the heating performance test of the wall plate heat exchanger was carried out.Through the study of the air temperature of the wall plate heat exchanger,the surface temperature distribution of the wall panel and the heat exchange of each part,the influence of the air supply on the heating performance of the wall plate heat exchanger was analyzed.The experimental results showed that the average surface temperature of the wall panel decreases with the increase of the air supply volume.Secondly,this paper used the ANSYS software to simulate the heating performance of the wall plate heat exchanger and compared it with the experimental results.By comparing the air temperature of the wall panel heat exchanger and the radiation surface temperature distribution of the wall panel,the reliability of the model was verified.Then the model was used to study the influence of the height of the fin,the distance of the fin and the center distance of the refrigerant pipe on the heating performance of the wall plate heat exchanger.Through the numerical simulation of the wall plate heat exchanger with different structural parameters,the heat transfer,the convective heat transfer and the resistance loss in the air duct were obtained.The simulation results were analyzed,and the influence rule of each structure size on heating performance was concluded.Finally,the orthogonal test method was used to optimize the structure size of the fin height,fin spacing,and the center distance of the refrigerant pipe center of the wall plate heat exchanger.The average and extreme difference was calculated according to the typical three factor and three level orthogonal table,and the optimal junction was obtained by comparison and analysis.The research work of this subject will provide a useful reference for the design,selection and application of wall panel heat exchangers in practical projects.