Multi-Objective Structural Optimisation of Immersion Heat Pump Water Heater Tank Based on Genetic Algorithm

The temperature and velocity fields in the tank of an immersed heat pump water heater under static heating were simulated and calculated by using the FLUENT module of ANSYS numerical simulation software in a transient state. When the other structures are not changed, the spiral pipe diameter is 60mm, the spiral pitch of the lower tank is 20mm and the spiral pitch of the upper tank is 70mm, the time required to heat the water to 328K is the shortest, 250s, and the temperature stratification phenomenon is relieved, the temperature difference is 6.56°C. On the basis of the optimized structure obtained from the single factor analysis, the test points are re-fitted and the response surface prediction is fitted. The optimal solution was obtained by using genetic algorithm and compared with the single factor analysis method to optimize the structure of the water tank. The optimal structure parameters are the lower spiral pitch 210mm, inlet mass flow rate 0.8kg/s, tube diameter 59.483mm, at this time, the temperature difference of the internal water when heated to 328k is 4.95°C, which is 24.5% lower than that of the single-factor analysis, so the optimal tank structure obtained by genetic algorithm is better than that combined with the single-factor analysis to mitigate the temperature stratification The optimal tank structure obtained by the genetic algorithm can alleviate the temperature stratification phenomenon better than the structure parameters combined by the single-factor analysis.