吸收LNG冷能的丙烷冷凝器低温传热性能

利用丙烷作为中间介质回收LNG冷量是解决LNG冷能利用过程中大温差传热问题的有效途径。对超临界LNG丙烷在冷凝器中的传热进行理论研究。根据丙烷所处的状态将LNG与丙烷的传热分为过热区、两相流区及过冷区。通过参数分析研究丙烷入口温度、冷凝器尺寸、丙烷流量等对冷凝器整体传热结果的影响规律。结果表明:适量增大LNG流量、减小丙烷通道的尺寸有利于LNG冷量的回收,而过热丙烷的入口温度对LNG冷量的回收影响不大;提高冷凝器传热效能的途径包括:找出最佳丙烷入口温度、适当减小丙烷流量以及减小丙烷通道尺寸。

Low-temperature thermal performance of propane condenser for recovering LNG cryogenic energy

Using propane to recover LNG cold energy is an effective way to avoid the problem of heat transfer with large temperature difference. The heat transfer between supercritical LNG and propane in the condenser was theoretically investigated, which is significant for the utilization of LNG cold energy. According to the propane state, LNG-propane heat transfer area can be divided into overheating region, two-phase region and sub-cooling liquid region. By means of parameter analysis method, the effects of some main parameters (propane inlet temperature, condenser size, propane flow rate) on the overall heat transfer performance of condenser were discussed. The results show that properly increasing LNG mass flow rate and decreasing channel width are beneficial to the recovery of LNG cold energy, while the effect of inlet temperature of propane gas on the recovery of LNG cold energy turns out to be little. The approaches that can improve the condenser effectiveness include determining the optimal propane inlet temperature, properly decreasing the propane mass flow rate and decreasing the width of propane-side channel.