空分系统压缩余热自利用方法的比较研究

Study on Self-Utilization Method of Compression Heat in Air Separation Units

利用热驱动制冷循环回收压缩余热,将制取冷量用于冷却各级空压机入口空气,从而实现压缩余热“自利用”,是降低空压机组能耗,促进空分装备低耗化的有效途径之一。本文主要构建了基于有机朗肯–蒸气压缩制冷的空压流程(ORVC-ACS)和基于吸收式制冷的空压流程(ARS-ACS)的热力学模型,对比分析了环境温、湿度和冷冻水出口温度对两种压缩余热自利用系统的性能影响。结果显示,当气候条件发生波动时,采用ORVC回收压缩余热可产生更高的节能效益,节能率可达3.5%,而ARS-ACS的节能率仅为2.6%。此外,高冷冻水输送温度更有利于ORVC-ACS的节能效果,六万等级空分系统的节能量最高可达854 k W。

Using thermally driven refrigeration cycle to recover compression heat from the air com-pression process for producing cooling capacity,and the generated cooling capacity is further used to cool the compressed air.This approach is called‘self-utilization of compression waste heat’,which is an effective solution to reduce the energy consumption for air compression.In this paper,ab-sorption refrigeration based(ARS-ACS)and organic Rankine-vapor compression refrigeration based air compression system(ORVC-ACS)are presented and their thermodynamic model are developed.The effect of ambient condition and chilled water temperature on the performance of the presented systems are analyzed and compared.The results show that when ambient condition fluctuates,the energy saving rate of ORVC-ACS is up to 3.5%,while the value is 2.6%for the ARS-ACS.In addi-tion,higher chilled water temperature is beneficial for the energy saving performance of ORVC-ACS.Taking the 60000 m 3/h air separation units as a case study,the compression power saving of the ORVC-ACS reaches 854 kW.