一种混合制冷剂循环(MRC)液化天然气流程的理论分析

将天然气液化有利于天然气的运输、有利于边远天然气的回收并能降低天然气的储存成本。在天然气液化流程中 ,用得最多的液化循环是混合制冷剂循环液化天然气流程。它具有机组设备少、流程简单、投资省及管理方便等优点。为此 ,对这类流程进行了理论分析。系统介绍了一带回热的典型混合制冷剂循环液化天然气流程的计算方法 ;并进行了全流程的模拟 ,得到了流程各节点压力、温度、焓、熵、气液两相流量、总流量、气液两相摩尔分率 ;同时还计算了流程中压缩机耗功、丙烷预冷量、制冷剂流量、各换热器的换热量等表示流程性能的参数

A THEORETICAL ANALYSIS OF NATURAL GAS LIQUIFYING PROCESS BY MIXED REF RIGERANT CYCLE

Liquified natural gas is favorable for transportation and recovery of the natural gas in remote area,as well as for reducing gas storage cost.The mixed refrigerant cycle (MRC) is a process of gas liquefaction most frequently used in practice,which has the advantages of less equipments,simple process,less investment and convenient management,etc.For this reason,a theoretical analysis of the MRC process is made and a calculation method for a typical gas liquefaction process by MRC with heat recuperation is systematically introduced.A simulation of the whole process is made,obtaining the pressure,temperature,enthalpy and entropy at each nodal point,the vapour liquid two phase flow rate,the total flow rate and the vapour liquid two phase molal fraction.The parameters reflecting the performance of the process,namely,the consumed power at the compressor,the precooling propane quantity,the refrigerant flow rate and the heat exchange quantity in the heat exchanger,etc.,are calculated also.