Effects of throttle and heater input for reducing pressure surging in a liquid hydrogen tank pressurizer

Abstract

Ensuring uniform flow from a liquid hydrogen storage vessel to a consumer requires pressure maintenance within ullage space. Large changes in volume during vaporization of liquid hydrogen allow a percentage of flow to be diverted from the consumer for tank ullage pressure maintenance. The return state of the hydrogen should be close to saturated vapor at comparable volumetric flow rates for liquid extraction and smooth operation. This paper details the theory, design, and experimental performance of a hydrogen pressurization system for controlling this return state. A cartridge heater, throttle, and manual valve are utilized to vaporize, reduce pressure and pressure oscillations, and control flow. Experimental measurements are compared with theoretical predictions for liquid nitrogen and liquid hydrogen flows. The end results demonstrate the performance of the heater and throttle for pressure maintenance of ullage within a liquid hydrogen tank.