Flow field uniformity analysis and structural optimization of coal pyrolysis heat exchanger

Abstract

The design of heat exchanger structure relies more on experience and lacks a guiding method. In view of this, this paper takes existing heat exchanger design structure as the research object minimizing mean square error of velocity at the outlet of coal pyrolysis heat exchanger. Optimization parameters are selected according to characteristics of model structure, and a three-dimensional model is established for each parameter value. The CFD numerical simulation method is used for trial calculation, and simulation results were numerically analyzed. The optimization parameters are taken as independent variables, numerical analysis results of mean square error are used as dependent variables to fit function curve and obtain function equation. Taguchi method is used to design an orthogonal experiment to obtain the weights of optimization parameters on objective function. Then the function equation is weighted to obtain a weighting function. Finally, genetic algorithm program is developed to find the optimal solution. Qualitative and quantitative analysis show that optimal solution results in a 36% reduction in the mean squared velocity at outlet of heat exchanger. The research results have a great significance to the design of heat exchangers.