Compared Analysis of Calculation and Simulation on Heat Transfer Characteristics in PCM Heat Exchange Unit, Part I: Thermal Storage Process

摘要

Based on the temperature change and thermal storage processes of PCM phase change energy storage unit, the PCM channel number of which is 39, the plate spacing is 0.01 m, the air channel is 40 with its plate spacing of 0.003 m, and the unit length is total of 1.62 m. MATLAB solution about the above PCM energy storage unit was performed according to the model and physical property data, and the numerical simulation was carried out by using Fluent software. The theoretical calculation and numerical simulation were compared and analyzed. It is found that only in the case of smaller or larger flow rate working conditions, the solution results of MATLAB for the increase rate of the average temperature of the phase change material inside the system is quite different from the FLUENT simulation resu the comparison of the phase change process degree of advancement is found that at a higher flow rate, the difference between the two results is small, but the difference is larger when the flow rate is smaller; the comparison result of the PCM liquid rate is different under the small flow rate condition. However, the comparative analysis of heat storage shows that the maximum error does not exceed 10%. It can be seen that the flow rate conditions in the model and working conditions are the obvious factors affecting the two results, but the calculation and simulation results can more accurately describe the heat storage characteristics of the PCM phase change energy storage unit, which was calculated in nearly 90% ranges of working conditions, which can prove that the results of MATLAB and FLUENT are consistent.