The Solar Hot Water Supply System for an Inhabited Base Located at the Moon Poles

Abstract

The use of the environmentally friendly solar thermal energy runs into some problems during practical realization of the power systems due to the difficulties of accumulating and storing the produced thermal energy during the lunar night. The paper deals with a solar hot water supply system for a life support system of the lunar bases located at the peaks of eternal light of the North and South Poles of the Moon and able to maintain hot water temperature during a lunar year taking into account the solar eclipses at the Moon. Solar hot water supply system includes a solar collector in the form of an annular cylinder with an axis perpendicular to the surface of the Moon with hydrogen coolant and seasonal storage heater located in lunar soil filled with crushed regolith to maintain hot water temperature during the periods without sun illumination. Design parameters as well as the system efficiency have been evaluated on the basis of the developed mathematical model and computer simulation of dynamic conditions for the system located at the ridge of Peary crater at the North Pole and the ridges of Shackleton and De Gerlache craters and Malapert Mountain at the South Pole of the Moon. It is shown that for the North Pole the water temperature at the lunar base reaches the required level at the end of the first lunation and practically does not change during the solar eclipse due to the presence of heat in the solar system. When the solar system is located in any peak of eternal light at the South Pole, the time it takes for the system to reach the required thermal regime does not exceed 4 lunations, while the required level of hot water is provided throughout the year. It is noted that due to the presence of dark intervals in the southern peaks of eternal light, significantly larger areas of the mid-solar collector and twice the size of the heat accumulator are required compared to the North Pole.