实际气体效应在宽压力范围内液氦温区的回热式制冷规律研究  

Study of Real Gas Effects on Regenerative Refrigeration in the Liquid Helium Temperature Range under Various Pressure Conditions

作　　者：葛立春 曹强 王苗苗 王智平 陈昱吉 王鹏程 王博 赵钦宇 甘智华 GE Lichun;CAO Qiang;WANG Miaomiao;WANG Zhiping;CHEN Yuji;WANG Pengcheng;WANG Bo;ZHAO Qinyu;GAN Zhihua(Institute of Refrigeration and Cryogenics,School of Mechanical Engineering,Tongji University,Shanghai 201804,China;Cryogenics Center,Zhejiang University City College,Hangzhou 310058,China;Institute of Refrigeration and Cryogenics,College of Energy Engineering,Zhejiang University,Hangzhou 310058,China)

机构地区：[1]同济大学机械与能源工程学院制冷与低温工程研究所,上海201804 [2]浙江大学城市学院低温中心,杭州310058 [3]浙江大学能源工程学院制冷与低温工程研究所,杭州310058

出　　处：《真空与低温》2025年第2期202-207,共6页Vacuum and Cryogenics

基　　金：国家自然科学基金(52176018、52006190);上海市自然科学基金(23ZR1464600);浙江省自然科学基金(LZ22E060003)。

摘　　要：相关研究分析了实际气体效应对回热器的影响,并推导出了回热器COP(理论冷循环效率)的表达方式。此前研究大多限于1~2 MPa压力范围,缺乏在更高和更低压下COP的变化及损失情况。在拓宽的压力范围,计算了变压力下回热器的COP及rCOP(相对卡诺效率)。结果表明,冷端温度在5~25 K时,随着压力的降低,rCOP呈U形变化,例如在5 K时,当压力为2.5 MPa、1.0 MPa、0.01 MPa,rCOP分别为19.6%、15.32%、97.64%,rCOP取最小值时所对应的压力接近临界压力0.228 MPa(0.19~0.23 MPa)。在25 K之上,压力减小时,rCOP上升。例如热端温度固定在40 K,当冷端温度为20 K时,当压力为2.5 MPa、1.0 MPa、0.01 MPa,rCOP分别为65.7%、81.7%、99.4%。但5 K之下且压力较大时,规律相反。评估了低压带来的问题,如功率密度小、损失较大。压力较大时理论计算、REGEN模拟的rCOP都比较高。计算和模拟得到的r COP相比于实验数据更大,证明实际过程损失更大。The influence of real gas effects on the performance of regenerator heat exchangers has been analyzed.An expression for the coefficient of performance(COP)of regenerators is derived.The existing body of research has been largely confined to pressures between 1 and 2 MPa,with a notable absence of insight into the manner in which the COP undergoes alteration and the nature of losses at pressures that are both higher and lower than this range.By extending the pressure range,the coefficient of performance(COP)and relative Carnot efficiency(rCOP)of regenerators under conditions of variable pressure are determined.The results demonstrate that when the cold end temperature is between 5 and 25 K,the rCOP displays a U-shaped variation with decreasing pressure.To illustrate,at a cold end temperature of 5 K,the rCOP values are 19.6%,15.32%,and 97.64%at pressures of 2.5 MPa,1.0 MPa,and 0.01 MPa,respectively,with the minimum rCOP occurring near the critical pressure of 0.228 MPa(0.19~0.23 MPa).Above 25 K,the relative COP increases as pressure decreases.To illustrate,when the hot end temperature is fixed at 40 K,the rCOP values are 65.7%,81.7%,and 99.4%at pressures of 2.5 MPa,1.0 MPa,and 0.01 MPa,respectively,when the cold end temperature is 20 K.However,below 5 K and at higher pressures,the trend is reversed.Furthermore,the issues associated with low pressure are assessed,such as low power density and significant losses.At higher pressures,both theoretical calculations and regenerative energy simulations yield higher rCOP values.The rCOP obtained from calculations and simulations is larger than the experimental data,confirming that losses are more substantial in practical applications.

关 键 词：实际气体效应 宽压力 回热式 rCOP 

分 类 号：TB657[一般工业技术—制冷工程]