液化天然气冷量的特性及在汽车制冷中的回收利用

Cold Exergy Characteristics of Liquefied Natural Gas and Its Recovery and Application in Automobile Refrigeration System

对“绿色”汽车燃料———液化天然气 (LNG)具有的冷量及其影响因素进行了分析 .结果表明 :在不同系统压力下 ,随着环境温度的升高 ,LNG冷量不断增大 ;在同一环境温度下 ,随着系统压力的增大 ,LNG冷量迅速降低 ,当压力p大于 2MPa时 ,LNG冷量已经很小 .基于LNG冷量特性 ,首次提出将该冷量进行回收 ,用于汽车制冷 (如低温冷冻、冷藏或汽车空调 ) ,以替代传统的蒸汽压缩制冷装置 ,减少额外功的输入 ,从而节约大量的能源 ,同时还可以有效减少噪声污染 ,避免氟里昂制冷剂泄漏造成的臭氧层破坏及温室效应 。

Green fuel liquefied natural gas(LNG) possesses plenty of cold exergy. The cold exergy and its affecting factors are analyzed. The results indicate that under different system pressure, the cold exergy of LNG increases constantly with the ambient temperature increasing. And under the same ambient temperature, the cold exergy of LNG decreases rapidly with system pressure increasing. When the system pressure is high above 2 MPa, the cold exergy is very low. Based on the analysis of cold exergy characteristics of LNG, recovery and application of cold exergy in auto refrigeration, such as low temperature frost, cold storage and air conditioning are put forward. The cold exergy recovering system of LNG, instead of the traditional vapor compressing refrigeration system, needs no extra work exergy. Once the system is practically applied, much energy can be saved. Noise pollution, ozone layer destroying and greenhouse effect caused by CFC leak can be effectively decreased.