混合制冷剂制冷工艺在石油伴生气液化上的应用

Application of Mixed Refrigerant Liquefaction Process in a Small Scale Petroleum Associated Gas Liquefaction System

小型天然气液化装置的制冷循环以带膨胀机的制冷循环和单级混合制冷剂循环为主,目前随着单级混合制冷剂流程研究的深入和使用的增多,装置越来越简单,投资越来越少,相对于膨胀循环流程的劣势很小,而能耗比膨胀循环更是要低40%左右,可有效降低系统的运行费用。石油伴生气的组份特点使得烃类制冷剂容易获得,应该优先采用单级混合制冷剂循环。在液化系统中设置分离塔,利用混合制冷剂本身就是混合物质的特点,不需要将各种冷剂提纯,就可以组合成多种冷剂配制方法,还可以根据不同的气源条件进行优化设计,解决了以往采用混合冷剂制冷循环的冷剂配比、采购、储运问题。

The gas expansion refrigerant cycle and single-stage mixed refrigerant cycle（ SMR） are the main liquefaction process in small scale natural gas liquefaction plant. Now by the deep research and application of SMR,the natural gas liquefaction plant of MRC is simpler,and with less investment. This makes the advantage of SMR be more obvious than gas expansion refrigerant cycle. The energy consumption of SMR is lower than about forty percent,which can effectively reduce the operating costs. Petroleum associated gas contains many heavy hydrocarbons,which make the hydrocarbon refrigerants easily available. The petroleum associate gas liquefaction plants should give priority to SMR. The hydrocarbons separation columns are set in the liquefaction plant. Because the mixed refrigerants are made up of many hydrocarbons,the refrigerants are not necessary to be purified by any pure hydrocarbon refrigerants. The parameters of separation column can be optimal designed on the base of different gas conditions. This will solve the make-up,purchase,storage and transportation of the mixed refrigerants in the mixed refrigerant liquefaction plant.