Simulation And Optimization On The Performance Of Stacked Metallic Bead Regenerator

VM cycle heat pump is based on the principle of a closed gas regenerative cycle work which can efficiently use of low-grade energy, with save energy and protect the ecological environment characteristics. Its internal regenerator is alternating flow regenerator flow characteristics of different structural forms are quite different, which have a decisive impact on the performance of VM heat pump. Stacking metal beads regenerator has high thermal efficiency, but also has a large flow resistance loss and other shortcomings, therefore this paper, Lattice Boltzmann methods is applied for the performance analysis and optimization of VM cycle heat pumps stacked metal bead type regenerator.VM cycle heat pump is a valveless regenerator regenerator, its internal flow is unstable flow. Characterization of stacked metal beads regenerator structural characteristic parameters included the unit sphere diameter and length of the heat transfer area and other operational parameters which consist of operating frequency, inflation pressure and inlet temperature.According to the literature data, preliminary calculations is made for the external structure is cylindrical,stainless steel filler metal stacked beads regenerator, the result shows the heat flow resistance loss is 766.13 W, regenerator efficiency is 0.96, VM cycle heat pump COP is 1.76.In order to solve the problem of the large flow loss of the stacked metal bead,this paper use two-dimensional lattice Boltzmann method nine-speed simulation models to simulate the velocity and pressure fields of porous media.Simulation results show that: the velocity and pressure distributions exhibit sine law. According to the simulation results fit the drag coefficient of correlation, and correlation with other literatures obtained are compared.The regenerator flow resistance loss is taken as the goal, under the given range of parameters, the effects of inlet temperature, air pressure, operating frequency, aspect ratio, the heat recovery device parameters such as length and diameter of the sphere to obtain the operating frequency and a long path ratio is the main factor, followed by the regenerator spherical diameter and length, the smaller the impact of the inlet t emperature and air pressure.Discussed the impact of regenerator efficiency and VM system COP by the above parameters within the optimal range of parameters characteristic parameters, to ensure minimal loss of flow resistance in the case. When the regenerator length is 0.08 m, inflation pressure is 8MPa, operating frequency is 400rad/min, the regenerator aspect ratio is about 1.5, the sphere diameter is 0.4×10-3m and the inlet temperature is about 600 K, the calculated flow resistive losses caused by 766.13 W down to 547 W, regenerator efficiency increase from 0.96 to 0.98, VM system COP increase from the 1.76 to 2.1. According to hausen solution derived a new solution of the regenerator loss calculation formula,that can be used to calculate the optimal regenerator loss.