两次节流循环在丙烯再液化系统中的热力分析

在传统LPG船再液化系统中采用两级压缩一次节流中间不完全冷却循环的基础上提出了两级压缩两次节流中间不完全冷却的再液化循环.结合两种节流方式的压力—热焓（p-h）图进行了理论分析,并且基于丙烯液化石油气船的实例,进行了两种节流方式的热力分析,计算出了再液化系统在一次节流和两次节流时的单位制冷量、制冷系数、压缩机功耗等一系列数据并进行了比较.结果表明,在相同条件下,两次节流循环与一次节流循环相比,单位制冷量提高了1.66％,理论制冷系数提高了2.24％,压缩机消耗的理论功率降低了2.19％.使用两次节流的再液化系统可以减少设备的体积与重量,节约成本与船上有限的空间.

Thermodynamic Analysis on Two Throttle Cycles in Propylene Re-liquefaction System

On the basis of two stages compression with one throttle incomplete intermediate cooling system in the traditional LPG ship reliquefaction system, the two stages＇ compression with two throttles incomplete intermediate cooling reliquefaction system are proposed Combining the pressum-enthalpy （p-h） map of the two kinds of throttles, the theoletical analysis is carried out. And based on a case of liquefied petroleum gas ship of propylene, the thermal analysis of two kinds of throttles is carried out. The refrigeration capacity, refrigeration coefficient, compressor power consumption and so on are calculated The results show that under the same conditions, the two throttles cycle compared with a throttle cycle, the refrigerating capacity of unit is increased by 1.66%, theoretical refrigeration coefficient increases by 2.24%, and the theoretical power of compressor consumption decreases 2.19%. The reliquefaction system of two throttles can reduce the volume and weight of the equipment, and save the cost and the limited space of ships.