In previous years, several high-power micro-satellites below ~100 kg have been developed for high-functional spacecraft. This paper proposes a functional and high-power thermal control system with no power supply and ...In previous years, several high-power micro-satellites below ~100 kg have been developed for high-functional spacecraft. This paper proposes a functional and high-power thermal control system with no power supply and a simple configuration for micro-satellite: 100 W, 3 U. The proposed system consists of a heat storage panel (HSP) with pitch type CFRP (Carbon Fiber Reinforced Polymer), a micro loop heat pipe (m-LHP) and a flexible re-deployable radiator (FRDR) as an active thermal control system. The aim of this research is to try not only to verify the thermal control devices, but also to perform a water phase change experiment as a payload using an electric power generation of 100 W in space environment. In this paper, the basic design of the satellite, the analysis of the feasibility by the thermal mathematical model, and the fabrication of thermal test model including water phase chamber are reported. The main results of thermal analysis as feasibility verification showed that the paddles could absorb the thermal energy up to 97 W at the solar input of 180 W, and the operating temperature of bus equipment became within the allowable temperature range (0°C - 40°C). At thermal vacuum test, the difference between the analysis and the experiment for the temperature history of water due to the discordance for the value of thermal conductance was discussed.展开更多
This paper presents fabrication and testing of a multiple-evaporator and multiple-condenser loop heat pipe (MLHP) with polytetrafluoroethylene (PTFE) porous media as wicks. The MLHP has two evaporators and two condens...This paper presents fabrication and testing of a multiple-evaporator and multiple-condenser loop heat pipe (MLHP) with polytetrafluoroethylene (PTFE) porous media as wicks. The MLHP has two evaporators and two condensers in a loop heat pipe in order to adapt to various changes of thermal condition in spacecraft. The PTFE porous media was used as the primary wicks to reduce heat leak from evaporators to compensation chambers. The tests were conducted under an atmospheric condition. In the tests that heat loads are applied to both evaporators, the MLHP was stably operated as with a LHP with a single evaporator and a single condenser. The relation between the sink temperature and the thermal resistance was experimentally evaluated. In the test with the heat load to one evaporator, the heat transfer from the heated evaporator to the unheated evaporator was confirmed. In the heat load switching test, in which the heat load is switched from one evaporator to another evaporator repeatedly, the MLHP could be stably operated. The loop operation with the large temperature difference between the heat sinks was also tested. From this result, the stable operation of the MLHP in the various conditions was demonstrated. It was also found that a flow regulator which prevents the uncondensed vapor from the condensers is required at the inlet of the common liquid line when one condenser has higher temperature and cannot condense the vapor in it.展开更多
文摘In previous years, several high-power micro-satellites below ~100 kg have been developed for high-functional spacecraft. This paper proposes a functional and high-power thermal control system with no power supply and a simple configuration for micro-satellite: 100 W, 3 U. The proposed system consists of a heat storage panel (HSP) with pitch type CFRP (Carbon Fiber Reinforced Polymer), a micro loop heat pipe (m-LHP) and a flexible re-deployable radiator (FRDR) as an active thermal control system. The aim of this research is to try not only to verify the thermal control devices, but also to perform a water phase change experiment as a payload using an electric power generation of 100 W in space environment. In this paper, the basic design of the satellite, the analysis of the feasibility by the thermal mathematical model, and the fabrication of thermal test model including water phase chamber are reported. The main results of thermal analysis as feasibility verification showed that the paddles could absorb the thermal energy up to 97 W at the solar input of 180 W, and the operating temperature of bus equipment became within the allowable temperature range (0°C - 40°C). At thermal vacuum test, the difference between the analysis and the experiment for the temperature history of water due to the discordance for the value of thermal conductance was discussed.
文摘This paper presents fabrication and testing of a multiple-evaporator and multiple-condenser loop heat pipe (MLHP) with polytetrafluoroethylene (PTFE) porous media as wicks. The MLHP has two evaporators and two condensers in a loop heat pipe in order to adapt to various changes of thermal condition in spacecraft. The PTFE porous media was used as the primary wicks to reduce heat leak from evaporators to compensation chambers. The tests were conducted under an atmospheric condition. In the tests that heat loads are applied to both evaporators, the MLHP was stably operated as with a LHP with a single evaporator and a single condenser. The relation between the sink temperature and the thermal resistance was experimentally evaluated. In the test with the heat load to one evaporator, the heat transfer from the heated evaporator to the unheated evaporator was confirmed. In the heat load switching test, in which the heat load is switched from one evaporator to another evaporator repeatedly, the MLHP could be stably operated. The loop operation with the large temperature difference between the heat sinks was also tested. From this result, the stable operation of the MLHP in the various conditions was demonstrated. It was also found that a flow regulator which prevents the uncondensed vapor from the condensers is required at the inlet of the common liquid line when one condenser has higher temperature and cannot condense the vapor in it.
