Two-phase Thermal Regulation System of a Manned Spacecraft

摘要

Because of increasing interest of manned space exploration, continuous development of space technologies and space vehicles is needed. The most important aspect that should be considered at first is development of perspective life support and cooling systems that are essential on every spacecraft. Modern space cooling systems can be divided on two rather common: single-circuit and double-circuit. The single-circuit system consists of only one hydraulic pipeline, that goes straight from inner space of the space craft to the outer space, so this type should be used commonly for unmanned space crafts, because its unsafety. Safer modern cooling system consists of two hydraulic circuits with pumps: internal and external. They are connected by a heat exchanger. So the internal circuit collects extra heat using heat exchangers and transmits it into the external hydraulic circuit by the heat exchanger. The external circuit throws this heat to the outer space using radiation heat exchanger. As known from Stefan-Boltzmann equation it is possible to decrease area of radiator if its temperature could be increased. It is evident, that if temperature of coolant in the space radiator could be increased, it is possible to improve mass-size characteristics of the radiator, the cooling system and the space vehicle in common. Common cooling system uses external one-phase hydraulic circuit. A two-phase hydraulic system, that works as a refrigeration machine could be more effective. In such system the heat exchanger and radiator fulfill the role of evaporator and condenser of the refrigeration machine respectively. It is possible to increase considerably the temperature on a surface of the radiator on account of a compressor in the circuit that compresses the refrigerant after evaporator. In comparison with common system, we can reach a growth of the heat flow from the radiator in 3,0 times approximately, which will cause the decreasing of radiator's area.