Simulation And Optimization On The Performance Of Metal Mesh Regenerator Based On Monte Carlo Method

To reduce energy consumption of heating and air conditioning systems is very important for building energy efficiency. As a small-capacity heat driven heat pump technology, VM cycle heat pump can make full use of low-grade energy which help reducing environmental pollution and saving energy consumption. Since the regenerator plays a key role on the performance and efficiency of VM cycle heat pump, this paper takes metal mesh regenerator as the objective, and uses theoretical calculations and numerical simulation methods to analyze the performance of the heat characteristic of regenerator.Based on the working principle and calculation parameters of VM cycle heat pump, the stacked metal-mesh regenerator was selected as the typical type, upon which the preliminary design was carried out. After setting the length and diameter of the regenerator and using a 300-mesh stainless steel as the filler material, the efficiency and losses of the regenerator were calculated, and the result shows the efficiency of regenerator is 0.949.According to this fact, it is feasible to use the stacked metal mesh regenerator and improve its efficiency to some extent.To improve the efficiency of regenerator, the heat transfer process inside the regenerator was simulated and analyzed in the perspective of the microscopic molecular, with the parameters of the existing literature and the Monte Carlo method. Comparing the experimental results and the simulation results, we can get that the average error is about 1.16 percent. At the same time, the change of temperature and regenerator efficiency in a cycle was analyzed. When the operating temperatures of the VM cycle heat pump cold and heat regenerator are between 260 K ~ 320 K and 350 K ~ 800 K respectively, the temperature is the linear distribution along axis; when they are at 255 K ~ 260 K and 330 K ~ 350 K, the temperature is a nonlinear change; when the operating temperatures are between 250 K ~ 255 Kand 320K ~ 330 K, temperature is almost constant within the regenerator. The corresponding regenerator efficiency also changes at different times, but the chang e extent is smaller. So we can choose the appropriate structure parameters to improve the efficiency of the regenerator.Regenerator porosity and aspect ratio are important structural parameters for the stacked metal mesh regenerator. Heat source temperature, system pressure, rotational speed, volume ratio are analyzed to study the changes of regenerator porosity, aspect ratio and mesh shape. Under the calculation conditions in this paper, the results shows that the optimum range of porosity is 0.58-0.6; the best aspect ratio is in the range of 4-7. The corresponding operating conditions of VM cycle heat pump are as follow: the heat source temperature is 770-790 K, the system average pressure is 9.0-9.4MPa, the volume ratio is 9.2-9.6, the rotational speed is in the range of 670-690 rpm. At this time, the efficiency of the regenerator is 0.98 5, which is 3.79% higher than that of the initial design.