煤基天然气C_3/MRC液化工艺优化研究

Study on Coal-based Gas C_3/MRC Liquefaction Process Optimization

针对煤基天然气(SNG)设计了一种C3/MRC液化工艺,考察了丙烷制冷循环和混合冷剂制冷循环中各冷箱温度分布对液化功耗的影响,煤基天然气节流压力对液化率的影响,对比了不同组成原料气的液化比功耗。研究结果表明:C3/MRC液化工艺适用于煤基天然气,且冷箱热流体出口温度分布对液化功耗影响较大;BOG气体中H2含量随节流后压力增高而增大;液化煤基天然气的单位功耗高于气田天然气。优化后煤基天然气的液化率达到94.95%,比功耗为0.34 k W·h/kg LNG。

The C_3/MRC liquefaction process is designed for Synthetic Natural Gas(SNG).Analyzed are effects of temperature distribution of different cold boxes in propane refrigerant cycles and mixed refrigerant cycles on liquefaction power consumption and effects of SNG throttling pressure on liquefaction rate and compared is liquefaction power consumption of feed gases with different components.Study results show that C_3/MRC liquefaetion process applies to SNG and thermal fluid outlet temperatures of cold boxes have great effect on liquefaction power consumption.Additionally,H_2 content in BOG gas increases as after-throttling pressure grows and the unit consumption of liquefied SNG is higher than natural gas from gas field.The liquefaction rate of SNG after optimization can reach 94.95%with a power consumption rate of 0.34kW·h/Kg LNG.