Numerical Simulation For3D Flow Field On Flow And Heat Transfer Performance Of The Marine Heat Exchangers

The heat exchanger is the equipment that used in hot and cold fluidheat exchange, widely used in various industrial fields. Shell and tube heatexchanger due to the relatively simple structure, large capacity, highsecurity, becomes the most commonly heat exchanger structure used inships. Based on the closed cabin of the ship, through the hot air with tankoutside seawater for convective heat transfer, using the numericalsimulation, then acquired the velocity field, temperature field andpressure field distribution of the heat exchanger, the results wereanalyzed and compared to the impact on the overall performance of theproposed heat exchanger baffle plate structure parameter optimizationand heat exchanger inlet velocity. The maining contents of the study areas follows:1. Through analysis the heat transfer situation for the closed cabinship, choosing suitable heat exchanger type for the air and sea water heattransfer, then arranging the tube side and shell side flow path.2. Through the Pro/ENGINEER software for the heat exchanger for3Dmodeling, and then the model is introduced into the computational fluiddynamics software FLUENT to carry on the numerical simulation; in orderto avoid the constant heat flux and constant wall temperature pipe causedthe wall boundary condition and heat transfer convection inside andoutside the tube differences, in the numerical calculation, the shell andtube air sea heat convection were coupling calculated. 3. Through the numerical simulation results, two kinds of heatexchange tube arrangement on the heat exchanger were analyzed andcompared for different number of different baffle, baffle gap height andinlet speed. The results show that, with the increase of the number of thebaffle plate, pressure drop and heat exchanger is bigger, the effect of heattransfer is getting better and better; with the increase of the baffle plategap height, the pressure loss of the heat exchanger decreases gradually,gradually decreased heat exchange effect; and increase imports of speed,it will bring increased heat transfer performance improve and resistanceloss.4. Through the J-K factor method, when the heat exchanger externalstructure for this defined value, the best overall performance is the fourbaffle plate number and the40%shell diameter for the baffle plate gapheight, and the heat exchange tube arrangement is significantly betterusing the triangle heat exchanger.Through the work of this thesis, the impact of various factors on theair-sea water heat exchanger performance preliminary understanding, andprovide theoretical support to the further design. Through theestablishment of a heat exchanger model simulation of internal flow field,and we can find out in advance the problems, to significantly reduce theconsumption of financial and material resources, give full play to theadvantage of the simulation.