Predicting BOG rate in cryogenic containers at different liquid levels based on a single test.

As the boil-off gas (BOG) rate is tested to evaluate the thermal insulation performance of cryogenic containers at a 90 % liquid level in standard. This study aims to predict the BOG rate of cryogenic containers at different liquid levels based on a single test. If the BOGs at a 90 % liquid level can be evaluated based on the BOG test at a low liquid level, the large amount of working medium can be saved to reduce the test cost and the equilibration time can be shortened to improve the test efficiency. In this study, the QHALW (heat absorbed by the liquid from its corresponding outer wall) and QHTVL (heat transferred from the corresponding wall of the vapor to the liquid) are analysed to establish the energy equation of the liquid in the BOG test, indicating latent heat of BOG in cryogenic containers includes the QHALW and QHALW. Therefore, the equation between the latent heat of BOG and the two parts of heat isbuilt to predict BOGs at different liquid levels with the tested BOG. The maximum error of the experimental results is not more than 7.0 %, which shows that the BOG is successfully predicted at different liquid levels with a single-tested BOG. [ABSTRACT FROM AUTHOR]