Experimental Study of Heat Transfer in the Interwall Space of a Cryogenic Tank with Powder Insulation

Abstract

Currently, double-wall cryogenic non-isothermal tanks with vacuum-powder or vacuum-multilayer insulation are used in storage and transportation of such cryogenic liquids as liquid nitrogen, oxygen and liquefied natural gas. If the inner vessel is disrupted, the liquid spills into the heat-insulating space and evaporates as a result of heat inflow from the environment. This increases pressure in the thermal insulation space. To ensure functioning of the tank, it is necessary to limit pressure increase in the heat-insulating space. Results of experiments on evaporation of the liquid nitrogen entering the space filled with powder insulation were presented (expanded perlite was considered in the experiments). Experiments were carried out on a laboratory model simulating the tank heat-insulating space. Nature of the cryogenic liquid distribution in the powder insulation volume was determined, possibility of the cryogenic liquid direct contact with the walls of the tank was shown, and the tank walls temperatures and the cryogenic products evaporation intensity over time were determined. Based on the work results, physical and mathematical model of the emergency process development in the interwall space of a cryogenic tank associated with violation of the inner vessel tightness and subsequent spill of cryogenic liquid into the heat-insulating space was refined