Speaker
Description
Process line rupture leading to pressurization of the vacuum enclosure with released gas is one of the failure cases that must to be analysed during the design of the cryogenic systems and devices. The selection of the number and size of the pressure relief devices (PRD) that protect the enclosure against excessive overpressure requires, among others, an assessment of heat transfer between enclosure and released gas. The theoretical value of the heat transfer coefficient can be estimated based on the natural convection equation including Grashof and Prandtl criteria numbers. However, in the literature there is a lack of experiments and research data presenting heat transfer processes during the loss of vacuum insulation. An experiment confirming theoretical considerations was proposed at the Wroclaw University of Science and Technology. The test stand enables measurement of the temperature profile along the enclosure pipe during vacuum degradation with liquid nitrogen, providing input data for the determination of the experimental heat transfer coefficient. This paper presents theoretical analysis, description of the test stand, procedure and preliminary results of the experiments.
