The invention discloses a high-pressure-
helium obtaining method for a liquid-
hydrogen temperature zone and the method is mainly used for providing low-temperature
helium for a ground test
system of a carrier-
rocket cold-
helium pressurization
system. An applied device mainly includes a liquid-
nitrogen heat exchanger, an upper
volute,
titanium bottles, a lower
volute and a liquid-
hydrogen dewar. Each
titanium bottle is provided with an upper opening and a lower opening, which are connected to the upper and lower
volute respectively. The liquid-
hydrogen dewar is a vacuum
powder heat insulation structure. A preparation process of the low-temperature helium is as follows: firstly, the
titanium bottles are filled with normal-temperature helium to XMPa and then
liquid nitrogen and
liquid hydrogen are injected to the liquid-
nitrogen heat exchanger and the liquid-hydrogen dewar and then the titanium bottles are filled with helium which undergoes temperature reduction by the liquid-
nitrogen heat exchanger so that the pressures of the titanium bottles rise to be slightly higher than XXMPa; the inflation is stopped and the helium is made to stand so as to reduce temperature and reduce pressure and then the titanium
bottle inflation and standing processes are repeated until the pressures in the titanium bottles are stabilized to XXMPa without an obvious lowering trend; and if a needed
helium temperature is lower than 21K, deflation of the titanium bottles can be carried out firstly after preparation of the XXMPa helium is completed and the helium can be used after the temperature is reduced to a needed value. The titanium
bottle inflation and deflation structure is high in reliability and the titanium bottles can be used for a plurality of times and consumption of
liquid hydrogen and helium in a test process is reduced so that an objective of reducing test cost and improving test security is achieved.