Experimental Study On The HPD Type Offset Strip Fins And Development Of Plate Fin Heat Exchanger

Due to the high heat transfer efficiency,compact structure and good adaptability,the Plate-fin heat exchanger is widely applied in many fields,such as aerospace Technology,petrochemical industry,air-conditioning refrigeration,building and new energy sources.As the core original of plate-fin heat exchanger,the heat transfer performance of offset strip fin has great influence on the performance of heat transfer.Compared with the traditional LPD(Low Pressure Direction)type offset fins,HPD(High Pressure Direction)type offset strip fins offer many advantages,for instance,the bigger area of secondary heat transfer,good adaptability,strong economy,and better heat transfer performance,but there is less open study on HPD type offset strip fins,and the medium is single-phase fluid.Taken the single layer fin as test specimen,the test rig to measure the HPD type offset strip fins heat transfer characteristics is set up.When the medium is a single-phase fluid,obtains law about main structure and size of fin on the heat transfer and resistance properties: when velocity is same,height?spacing?width and thickness is smaller,the convection heat transfer coefficient and the pressure drop increases,and the establishment of the experimental formula of HPD type offset strip fins heat transfer factor and the resistance factor,to predict the experimental data using the experimental correlations,predicted results agree well with the experimental data;when the medium for two-phase fluid,influence of gas velocity and the gas-liquid ratio on heat transfer and resistance properties: when the oil flow rate constant and gas-liquid ratio at 0.1~0.62,gas superficial velocity and the gas-liquid ratio increases,the convection heat transfer coefficient and the pressure drop increases,establish HPD type offset strip fins bubble flow,the convection heat transfer coefficient calculation model and calculation model of pressure drop,using two the model is used to predict the data.Based on the experimental study on heat transfer and resistance of HPD type offset fins,the design program of the fin plate heat exchanger is developed by Java language.The experimental design using the design procedures,design procedure is well consistent with the experimental data to verify the reliability of the process design of plate-fin heat exchanger.