Indirect testing method for non-condensable gas amount of gravity driven two-phase fluid loop

Abstract

The invention discloses an indirect testing method for the non-condensable gas amount of a gravity driven two-phase fluid loop. By the adoption of the indirect testing method, the non-condensable gas amount of the gravity driven two-phase fluid loop in the moon-day period can be obtained. The indirect testing method comprises the following steps: firstly, analyzing to confirm that the non-condensable gas amount of the gravity driven two-phase fluid loop corresponds to the temperature difference of an evaporator and a liquid reservoir one to one, calibrating the relationship of the temperature difference of the non-condensable gas amount and the evaporator and the liquid reservoir, so as to obtain a relationship curve, and acquiring the non-condensable gas amount of the gravity driven two-phase fluid loop according to the temperature difference of the evaporator and the liquid reservoir and the calibrated relationship curve in the operation process of the practical gravity driven two-phase fluid loop. The method is simple to realize, the non-condensable gas amounts of the gravity driven two-phase fluid loop in a plurality of moon-day periods can be effectively acquired.

Description

technical field [0001] The invention relates to the technical field of spacecraft thermal control, in particular to an indirect test method for the noncondensable gas volume of a gravity-driven two-phase fluid circuit. Background technique [0002] In the lunar (or planetary) landing exploration activities, due to the large temperature difference between day and night on the surface of the moon and the lack of electrical energy for the probe during the moon night, in order to solve the problem of the survival of the probe during the moon night, the thermal control design scheme of the isotope nuclear heat source + gravity-driven two-phase fluid circuit is adopted. , the system composition of the gravity-driven two-phase fluid circuit is as follows figure 1 As shown, it includes an evaporator 1 (including a wire mesh evaporator 7, a liquid diverter 8 and a vapor confluence 9), a vapor pipeline 2, a condensation pipeline 3, a liquid reservoir 4, a liquid pipeline 6 and a contr...

AI Technical Summary

Problems solved by technology

Due to the complexity of the two-phase flow, it is impossible to accurately analyze the contents of the liquid ammonia working medium in the wire mesh evaporator 7, the steam confluence 9, the steam pipeline 2 and the condensation pipeline 3, so it is impossible to determine the non-condensing fluid in the liquid reservoir 4. The volume of gas, the volume of non-condensable gas cannot be calculated according to the ideal gas state equation

[0004] At present, the Chinese aerospace industry has proposed an equivalent simulation of a gravity heat pipe to simulate the decomposition process of ammonia working fluid at high temperature in a gravity-driven two-phase fluid circuit, and obtained the non-condensable gas volume test of the gravity heat pipe. However, the above method has the following problems: it can only simulate the amount of non-condensable gas produced by the decomposition of ammonia during the day of one month, and cannot evaluate the amount of non-condensable gas produced by decomposition during the second, third... months

Because during the operation of the first lunar night, all the non-condensable gases are accumulated in the gas space of the liquid receiver. After the second lunar day, the control valve 5 is closed, the gravity-driven two-phase fluid circuit stops running, and the temperature of the evaporator 1 begins to rise. Ammonia begins to decompose, and at the same time, because the liquid receiver 4 accumulates non-condensable gas, the concentration is relatively high, and the non-condensable gas will diffuse along the condensation pipeline 3 and the steam pipeline 2 to the evaporator 1, resulting in an increase in the concentration of non-condensable gas in the evaporator 1 Large, the decomposition of ammonia is inhibited to a certain extent, so the method of testing non-condensable gas with gravity heat pipe cannot be used to obtain the amount of non-condensable gas in the gravity-driven two-phase fluid circuit after many months of daylight

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