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℃ 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.