基于S-CO_(2)的强化壳管式蓄热单元传热性能优化

Heat Transfer Performance Optimization of Enhanced Shell-Tube Thermal Storage Units Based on S-CO_(2)

为了了解壳管式蓄热单元的传热性能,提出了一种强化壳管式蓄热单元传热性能的优化方法。对不同的换热流体(HTF)进行优质选择,并基于回归正交试验对相变蓄热单元结构参数进行优化。结果表明:回归方程满足试验的显著性和失拟性检验,验证结果与计算结果的相对误差在1%以内;采用800℃、20 MPa的超临界二氧化碳(S-CO_(2))和管径比为0.666 3的组合形式最优;优化后的蓄热单元获得的最高储热量为2 674.52 kJ,比优化前增加约39.5%,传热速率范围从1.76 kW降到0.007 kW。

In order to understand the heat transfer performance of shell-tube thermal storage units,an optimization method to improve the thermal storage performance of shell-tube phase change thermal storage units was proposed.First,a high-quality selection of different HTFs was performed and the structural parameters of the shell-tube phase change thermal storage units were optimized based on regression orthogonal tests.Results show that the regressed equation satisfies the significance and lack-of-fit test,and the validation results are within 1% error of the equation calculation.A combination of supercritical CO_(2)(S-CO_(2)) at 800 ℃ and 20 MPa and a tube diameter ratio of 0.666 3 is optimal.The optimized thermal storage unit obtains a maximum heat storage capacity of 2 674.52 kJ with an increase of about 39.5% compared to the pre-optimization,and the heat transfer rate decreases from 1.76 kW to 0.007 kW.