摘要
针对混合制冷剂循环液化天然气流程能耗高、效率低的现状,运用HYSYS软件对液化流程模型进行优化,分析评价表明,压缩机、冷却器、多股流换热器、节流阀及混合器的损失依次减少。探讨了流体压力、温度、压缩比等参数对压缩过程不可逆性的影响,第一段压缩机出口压力为1 074 k Pa、压缩比为2.02,第二段压缩机进口温度为40℃、压缩比为3.63时,最小压缩机比功耗、损失为5.98 k Wh/kmol、15 840.06 k W。优化换热器操作,保持夹点温差、对数平均温差约3、5℃,换热器损失减少41%。借助分析原料气的CP-T分布,在满足不同温区所需冷量的基础上,合理配置制冷剂组分,调整制冷剂蒸发压力可降低换热过程损失。
Aiming at the current situation of high energy consumption and low utilization efficiency during the mixed refrigerant cycle of natural gas liquefaction process, HYSYS software was adopted to optimize the liquefaction model. The analysis and evaluation results demonstrated that the exergy loss of compressors, cooler, multi-stream heat exchanger, throttle valves and mixer decreased successively. The irreversibility influence of compression process between various parameters including fluid pressure, temperature and compression ratio was discussed. When the outlet pressure and compression ratio of the first stage compressor, the inlet temperature and compression ratio of the second stage compressor was 1 074 kPa, 2. 02,40℃ and 3.63, respectively, the minimal specific power consumption and exergy loss of the compressors was 5.98 kWh/kmol and 15 840. 06 kW. The heat exchanger operation was optimized. The pinch temperature difference and logarithmic mean temperature difference was adjusted as 3℃ ,5℃. The exergy loss of heat exchanger would reduce 41%. The rational component allocation and evaporating pressure regulation of refrigerants could effectually reduce exergy loss under the condition of satisfying the requirement for different temperature area in virtue of the Cp-T properties distribution of feed gas.
出处
《现代化工》
CAS
CSCD
北大核心
2015年第9期172-175,共4页
Modern Chemical Industry
基金
陕西省科学技术研究发展计划项目(2014K15-01-06)
陕西省教育厅科学研究计划项目(14JK1572)
关键词
液化天然气
混合制冷剂循环
炯分析
节能降耗
liquefied natural gas
mixed refrigerant cycle
exergy analysis
energy consumption reduction
