Checking Calculation And Numerical Simulation Research Of Shell And Tube Heat Exchanger

Heat-exchanger is one of the most important components in the modern industry. Theperformance of the heat-exchanger decides the operating conditions of the whole system. Sothe performance improvement of a heat-exchanger becomes the key point during its designprocess. This paper have studied the performance of a heat-exchanger with the method oftheoretical analysis and with the help of the commercial software FLUENT.This paper studied the computational method of the heat-exchanger’s performance.,andpreliminarily completed the development of the performance checking software for theshell-and-tube heat exchanger. The calculation modules for the tube heat transfer filmcoefficient and efficiency-unit number were established respectively, which is based on theanalysis of the calculation method for heat transfer. The pressure drop performancecalculation module was established, through the study of the pressure drop calculation methodfor the shell side and the tube side. Besides, the heat exchanger interface program was written,in order to facilitate the application of engineering. The software can be used for theengineering check calculation of the shell-and-tube heat exchanger (single segment baffle),which has a certain value of the engineering.Secondly, some heat-exchanger in the aerospace oil system should be made intorectangular compact heat-exchanger, limited by the operation environment. And theperformance calculation method of these heat-exchangers is rather different from that of thegeneral size circular shell and tube heat exchanger. The performance calculation method forthis kind of heat-exchangers was studied, and then the corresponding checking program wasestablished. Besides the oil system test bench was built, on which experimental study ofrectangular heat exchanger was done to test the accuracy of this program.Lastly, this paper has studied the different heights of the cut and spacings of baffle inshell-and-tube heat exchangers, using numerical simulation method. The law of the flow andheat transfer of the fluid on the heat-exchanger’s shell side, with the baffle cut heightincreasing, and the performance curves of the heat-exchanger is given, which varies with thecut height changing between0.2D-0.4D (D represents the shell’s diameter), then the optimalcut height is given under the current conditions. Then, the situation of the flow and heattransfer of the fluid on the heat-exchanger’s shell side, when the baffle spacing becomes smaller, and the trend of the heat-exchanger performance is analyzed with different numbersof the baffles, then the optimum number of the baffles for the heat-exchanger is got. Furtherresearch on the calculation results is done, analyzing the law of the pressure drop within thecut area and the pressure drop percentage shared by the cross-flow area, in one shell sideflow unit, with the cut height and the baffle distance varied.