Pressure and evaporation rate in a closed LNG tank

Experiments on the tank pressure, evaporation volume and evaporation rate were carried out in a closed tank with LNG (liquefied natural gas). The results show that there exists a non-uniform temperature field, where the temperature in gas phase is higher than that at gas-liquid interface, and the temperature at gas-liquid interface is higher than that in the bulk phase of liquid. Under the experimental conditions, the maximum temperature difference among the above three parts is about 2-3°C when the initial filling rate is 0.475. There exits a critical initial filling rate. When the initial filling rate is lower than the critical value, the daily evaporation volume and evaporation rate increase with time; when the initial filling rate is larger than the critical value, they first increase with time and then decrease.