摘要
随着液化石油气（LPG）使用量日益增长,海上液化汽运输正飞速的发展,使得国内外对LPG 船的需求急剧增加.其中,半冷半压式LPG 船则是国内制造较多的船型,再液化系统则是该船型的关键设备.为再液化系统的设计提供参考,从LPG 船可以运输的液货工质种类入手,选择相适应的制冷循环类型.通过推导,得出两级压缩和单级压缩系统理论循环的热力计算公式.经过计算得出循环的热力参数.通过分析比较不同液货工质在不同设计压力下的制冷系数,给出系统中液货罐设计压力的选择办法.
With the growing use of the liquefied petroleum gas （LPG）, fast development of liquefied gas transportation at sea, the demand forLPG ship at home and abroad are greatly increased. Lots of cold half pressure type LPG has been manufactured by our country.Re-liquefied system is avery important equipment on this kind of ship. In order to provide references for the design of theliquefaction system. Based on the types of working medium, choosing matched refrigerating cycle. By derivation, the theoreticalformula is calculated two-stage compression and single-stage compression system. Through thermodynamic calculation ofthermodynamic parameters, through analyzing and comparing different liquid working medium under different design pressureand the capacity of refrigeration coefficient, provide references for the design of the re-liquefaction system.
