液化天然气冷能构成及其利用方式探讨

Analysis on liquefied natural gas cryogenic energy composition and discussion on its utilization

液化天然气(LNG)在汽化过程中会释放大量冷能,如果这部分冷能被成功回收利用,其节能效果和对系统效率的提高都十分显著。文中对LNG冷能从冷量和冷量的角度进行分析,把LNG冷能回收方式分为冷量回收与冷量回收,揭示了目前各种LNG冷能回收利用形式的能量利用实质:发电、空分中主要是利用LNG的冷量;冷藏、空调和制干冰利用了LNG的冷量。最后对不同的冷能回收系统提出指导性建议:动力回收系统中,应充分利用其在低温下的高品质能量;冷量回收系统中应减少跑冷。

Plenty of cryogenic energy is released during liquefied natural gas （LNG） gasification process. The effect on energy-saving and system efficiency is prominent if the cryogenic energy can be recovered for effective utilization. The cold energy of LNG consists of cold exergy and cooling capacity. LNG cold energy recovery methods were divided into cold exergy utilization and cooling capacity recovery. The energy utilization essence of the recovery and utilization of LNG cold energy was also clarified. Power plant and air separation system utilize the LNG cold exergy. Refrigerated storage, air conditioning unit and dry ice production process use the cooling capacity of LNG. Some guiding suggestions were also brought forward for LNG cold energy recovery system. In the power recovery system, high quality energy under low temperature should be utilized reasonably. Decreasing cold loss is very important in the cooling capacity utilization unit.