Experimental Study On Processing Quality Of Fins In Plate-fin Heat Exchanger

This paper presents a new method for the fin quality evaluation. Get the fluid-friction characteristic curve of the fin used in the plate-fin heat exchange to evaluate the quality of the machined fins.A wind-tunnel testing system for the plate-fin heat exchanger performance test has been set up, including air system and measuring system. The device can autometically record the temperature, air flow and pressure drop. Many experiments were carried out to get the fluid-friction characteristic curve of fins. On the basis of these experiment datas, sum up the surface standard fluid-friction characteristic curve range of the plate-fin heat exchanger fin. Compare the new machined fin fluid-friction characteristic curve with the same type fin standard fluid-friction characteristics curve range to evaluate the quality of the machined fins. If within the range, the new machined fin is qualified, or is not.In order to validate this new testing method used to test the fin quality of the plate-fin heat exchanger, the main research work and conclusions of the paper are as follows:1. To get the fluid-friction characteristic curve of the fin used in the plate-fin heat exchanger, we designed a DC blast wind-tunnel and set up the wind-tunnel testing system, including the air system and measuring system.2. In the wind-tunnel experiment stage, a series of experiments have been carried out on lots of 95J1202 model serrated fins. Many groups relation of Reynolds number and friction factor have been obtained. We get the standard curve through calculating and analyzing and then draw the figure. Make error analysis to the testing result to calculate the deviate value of the qualified fins during some confidence interval. So we get the standard curve and the deviate value which is used to evaluate the quality of the fins.3. Analyse the rules that the quality of fins machined by the same reamer change along with the machined fin teeth increase. We get that the friction factor increases with the time at the same Reynold number. When the abrasion of reamer is enough, there is a stable stage in which the quality of fins is identical. When a new reamer is replaced, the quality of fins machined by the new reamer aren't identical, the biggest distinction of the friction factor is thirty-eight percent at the same Reynold number.4. The results find that fin teeth, thickness and width of the fin affect the fluid-friction characteristics performance. Whether the fin is washed can also affect.