低温液体蒸发气再液化系统内BOG动态分析研究

BOG dynamic analysis and research of cryogenic liquid boil off gas reliquefaction system

低温液体蒸发气再液化系统漏热引起的储罐内低温液体蒸发气(BOG)蒸发速率和压力有效控制是试验正常进行的关键,通过对储罐内低温液体的热响应分析,建立罐内低温液体和BOG计算模型,对制冷机关闭情况下储罐内压力(BOG压力)和BOG蒸发速率随储存时间的变化过程进行数值计算。结果表明:随着储存时间的增大,储罐内压力升高、压力增长速率加快、BOG蒸发速率减小;液氮和BOG温度升高对储罐内压力升高速率具有显著的影响;制冷机可以实现对罐内压力和BOG量的调节控制。为制冷机控制方案的制定和后续开展低温液体BOG再液化试验研究提供理论基础。

The effective controlling of storage tank boil off gas （BOG） evaporation rate and pressure caused by the heat leakage of cryogenic liquid boil off gas reliquefaction system is the key to the experiment. By the thermal response analysis of storage tank cryogenic liquid, the calculation models of storage tank cryogenic liquid and BOG were established, and when the refrigerating machine was shut down, the changing process of the storage tank pressure （ BOG pressure） and BOG evaporation rate along with the storage time was numerically calculated. The result shows that with the increasing of storage time, the storage tank pressure and pressure increasing rate will increase, the BOG evaporation rate will reduces; the increasing of liquid nitrogen and BOG temperature has a significant impact on the storage tank pressure increasing rate ; the refrigerating machine can adjust and control the storage tank pressure and BOG amount. These results can provide a theoretical basis for the formulation of refrigerating machine controlling plan and the following studying of cryogenic liquid BOG reliquefaction experiment.