真空闪蒸制取冰浆系统(火用)分析

采用已有的计算冷量以及损失的公式,对实验室用真空闪蒸制取冰浆系统进行了(火用)分析。利用EES软件,对真空闪蒸法冰浆制备系统中的4个关键环节(冷水冰水混合、真空室内喷雾闪蒸、捕水器内蒸汽凝结成霜、制冷机制备低温盐水)进行计算,得出各个环节(火用)损失以及整个系统的(火用)效率。结果表明:实验用真空室内喷雾闪蒸环节的(火用)效率较高,捕水器内蒸汽凝结成霜的(火用)效率较低,制冷机组制备低温盐水(火用)效率最低,(火用)损最大,导致整个系统的效率相对较低。为了改善真空闪蒸制取冰浆系统的能耗,应对低温盐水制备环节进行优化或采用其他方式替代该环节。

Exergy analysis on ice slurry production system by water spray evaporation in vacuum environment

Based on available formulas for cold exergy and exergy loss,exergy analysis was performed for a laboratory-scale vacuum evaporation system to produce ice slurry.By using EES software,calculations were carried out for the mixing of cold water and icy water in the system,spray and evaporation in the vacuum chamber,vapor condensation in the water trap,and saline coolant production with a chiller.The exergy losses and exergy efficiencies were obtained for the three of them and the whole system.The results show that the spray and evaporation in the vacuum chamber has the highest exergy efficiency and the vapor condensation in the water trap has lower efficiency. The lowest exergy efficiency and largest exergy losses occur in the saline production with a chiller,resulting in lower efficiency of the whole system.In order to improve the exergy efficiency of the system,the saline coolant production with a chiller should be optimized or to be replaced by other means.