Study On Numerical Simulation Of Fluid Flow And Heat Transfer Of Plate-Fin Heat Exchangers In Equipment LNG5

Heat transfer and flow resistance characteristics of plate fin heat exchanger mainly depends on Surface Activity of fin, consequently the surface activity is the basis of accurate design of plate-fin heat exchanger.Cryogenic heat exchanger of refrigerant mixture with phase-change, compared to heat exchangers for general case, the working process is complex, not only change of thermal properties is acuity, but also thermal properties is difficult to accurate determination. It is difficult to experiment of the condensation and boiling phenomena, consequently numerical simulation has more advantage. Meat structure is complex in plate-fin heat exchanger. Not only need build reasonable, simplified geometric model and calculation model, but also need hardware conditions and calculation time. Three total dimensional numerical simulation is impossible to realize of flow in the plate-fin heat exchanger.Firstly, this paper study based on two familiar surfaces of fins, by FLUENT simulation and analysis the influence of different structural parameters and different Reynolds number on heat transfer and flow resistance. Get curves of surface activity of two fins in different structural parameters and different Reynolds number. Analysis impact of structure parameters on heat transfer and flow resistance, such as fin height, fin pitch, fin thickness and the length of truncature of offset strip fin, and such as open percentage of fin with apertures, analysis and compare of characteristics of two fins is obtained.The calculation of the thermal properties of mixtures was done using SRK equation. Divide range of temperature of two phase flow with phase-change into three, get the piecewise curve for properties of mixtures. And write data of the physical properties of material to database of FLUENT, using it as physical data of Numerical simulation. Do research on numerical simulation on piecewise mode of plate-fin heat exchanger H304 in natural gas liquefaction systems LNG5 by FLUENT. Get relationship of heat-transfer coefficient and pressure gradient vs temperature. By comparison with MUSE, the method is available. The conclusions obtained here may provide some theoretical guidances for the design of plate-fin heat exchanger.