摘要
本文基于准稳态计算模型,提出了一种精馏型自复叠制冷系统降温速度的优化方法。以最大制冷量为优化目标,得到给定混合工质浓度时降温过程最佳吸气压力曲线,采用分段调节吸气压力的方法来匹配该曲线,从而减少降温时间,在此基础上可进一步优化混合工质浓度提高降温速度。该方法应用于箱内空气温度由20℃降至-100℃的试验箱降温过程,采用摩尔比例为0.35/0.25/0.15/0.25的R50/R1150/R290/R600a混合工质,结合最优吸气压力切换参数:两个切换温度(-20℃和-105℃)和三个切换压力(700 kPa、600 kPa和550 kPa)可以达到最短的降温时间。研究结果还表明不同蒸发温度区间所需的最优浓度不同,在降温过程中调节工质的浓度,则可以减少降温时间。该优化方法可为其它混合工质制冷系统降温过程研究提供参考。
Based on a quasi-steady-state simulation model,a method to optimize the cooling-down rate of an auto-cascade refrigeration system operating with a rectifying column and multi-component mixed refrigerant is proposed in the paper.Targeted on the maximum cooling capacity,the opti-mal suction pressure-evaporating temperature curve for a specified mixed refrigerant concentration can be obtained,which can be matched by the sectional suction pressure adjustment in the prac-tical applications to reduce the overall cooling-down time,and the concentration of mixed refrig-erant can be optimized to further improve the cooling-down rate based on this way.The fastest overall cooling-down time is achieved using the R50/R1150/R290/R600a as the mixed refrigerant(0.35/0.25/0.15/0.25 by mole)and corresponding shifting parameters(including two shifting temper-atures−20℃ and−105℃)and three shifting suction pressure 700 kPa,600 kPa and 550 kPa for the sectional suction pressure adjustment,when the air temperature in the test chamber is dropped from 20℃ to−100℃.Calculation results also show that the optimal concentrations are different for different evaporating temperatures,and the cooling-down rate can be improved further if the concen-tration of the mixed refrigerant can be adjusted during the cooling-down process.The optimization methods used in this paper can also provide references for researches on cooling-down processes of other refrigeration systems using multi-component mixed refrigerants.
作者
张靖鹏
王勤
宋琦
罗介霖
陈光明
ZHANG Jingpeng;WANG Qin;SONG Qi;LUO Jielin;CHEN Guangming(Institute of Refrigeration and Cryogenics,Zhejiang University,Key Laboratory of Refrigeration and Cryogenic Technology of Zhejiang Province,Hangzhou 310027,China;Institute of microsatellite Innovation,Chinese Academy of sciences,Shanghai 201304,China;Beijing Institute of Space Launch Technology,Beijing 100076,China)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2024年第3期635-643,共9页
Journal of Engineering Thermophysics
基金
国家自然科学基金(No.51976179)。
关键词
混合工质
自复叠
精馏
降温过程
准稳态
mixed refrigerant
auto-cascade refrigeration system
rectification
cooling-down pro-cess
quasi-steady-state
