车载LNG储罐蒸发率的理论与试验

Experiment and theory of evaporation rate in cryogenic cylinder of LNG vehicle

为研究车载LNG低温绝热气瓶内液体的蒸发规律,以200 L高真空多层绝热气瓶为例,采用液氮(LN2)为工质,进行了一系列LN2日蒸发率试验。列出根据实验系统结构参数得到的相关传热学计算结果,包括试验系统分别贮存LN2和LNG各项漏热及理论蒸发率。对理论计算与实验结果进行比较,通过理论计算结果与LN2蒸发率实验结果对LNG试验蒸发率作了预测。根据大气压力下进行的各种充满率的LN2蒸发率实验,拟合出了系统蒸发率与充满率的关系曲线,并分析了系统中环境温度和压力对蒸发率的影响规律。

In order to investigate the evaporation rule in cryogenic cylinder of LNG vehicle, a series of experiments were conducted to test the evaporation rate of a 200 L cryogenic liquid nitrogen cylinder. With the experimental system parameters, the calculation results of heat transfer were presented including the heat leakage and theoretical evaporation rate of the system when filled with liquid nitrogen and LNG respectively. LNG evaporation rate was predicted according to the comparison between theoretical calculations of LNG evaporation rate and experimental results of LN2. Based on the results of experiments under various fill level and atmospheric pressure, the curves of relation between daily evaporation rate and fill level in the system were fitted. Moreover, the effect of environment temperature and storage pressure on the daily evaporation rate of cryogenic cylinder was analyzed.