A Study Of Characteristics About Heat Transfer And Thermal Mixing Of Plate Heat Exchanger

Plate heat exchanger is a kind of heat-exchange equipment that takes corrugated board as the heat transfer surface and use convection and heat conduction as the main mean. Plate heat exchanger has a high heat coefficient, but its flow resistance is relatively large, so how to achieve the best matching of heat transfer performance and flow resistance in the design of plate heat exchanger is the main direction of heat exchanger optimization and improvement. Plate heat exchanger has complex flow pass shapes and various plate forms, the traditional experimental methods is difficult to meet the requirements of the more and more complex application conditions. Take numerical simulation method to analyse plate heat exchanger’s heat transfer and flow characteristics can get the heat transfer and flow results of multigroup models under various setting conditions in a short period of time, greatly reducing the experiment cost and experiment time.According to the three main parameters of traditional herringbone corrugated plate heat exchanger channels, bulid mutigroup physical models, for the corrugated plate heat exchanger’s inside channels whose wave angle β=30°～80°, wave height h=3mm～7mm, wave spacing λ=10mm～25mm to calculate by numerical simulation, get the temperature contour, velocity contour and pressure contour under different entrance velocity, obtain the key numerical value in the boundary and flow of the simulation results. Calculate the corresponding Nusselt number Nu, heat transfer factor j, pressure drop △P, friction factor f and other key evaluation parameters, draw the corresponding curves and anaylse the effect of the three main parameters of corrugated plate on the heat exchanger performance and resistance characteristics. The conclusions are as follows:in the corrugation angle β=60°, wave height h=5mm, wave spacing λ=20mm, thermal and resistance characteristics for herringbone symmetric corrugated plate heat exchanger is the best.Based on the theory of thermal mixing, take different angle combination β1-β2 as the variables, and take M-type and H-type thermal mixing as the object for numerical simulation, get the temperature contour, velocity contour and pressure contour under different entrance velocity, obtain the key numerical value in the boundary and flow of the simulation results. Calculate the corresponding Nusselt number Nu, heat transfer factor j, pressure drop △P, friction factor f and other key evaluation parameters, draw the corresponding curves and compare with the curve of single plate whose wave angle β=60°, analyse the impact of various thermal mixing conditions on the heat exchanger performance. The conclusions are as follows:in M-type, the comprehensive performance of combination 30°～60°is better; in H-type, the comprehensive performance of combination 60°～70° is better. Need to be attention, thermal mixing is a kind of middle-group application method, not an absolute optimal, so the specific application needs to choose according to the working requirement.