Power supply system mounted on survey vehicle

Abstract

To provide a power supply device which can be mounted on a lunar rover, and can supply power necessary and sufficient for traveling operation of the lunar rover and power necessary in an emergency.SOLUTION: A high-temperature waste heat type power supply device 33 using a fuel cell 1, which is mounted on a lunar rover 34 that travels on the lunar surface, includes a fuel cell device 23 that mounts the fuel cell 1, an exhaust heat device 24 that exhausts heat generated by the fuel cell 1 to a surrounding environment, and an emergency cooling device 25 that stores water generated by the fuel cell 1 and absorbs the heat generated by the fuel cell 1. When the amount of heat generated by the fuel cell 1 exceeds the amount of heat that can be removed by the heat removal device 24, the water stored in the emergency cooling device 25 absorbs the amount of heat generated by the fuel cell 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply device mounted on a vehicle used to explore the moon (hereinafter referred to as a lunar rover). [Background technology]

[0002] Manned and unmanned lunar rovers are being considered for use in travelling and transporting goods on the lunar surface.

[0003] This lunar rover is required to travel at a certain speed over rough terrain, including slopes on the moon's surface, and is equipped with a power supply unit to provide the electricity necessary for its travel.

[0004] The power supply device to be installed in the lunar rover and to supply power for running is expected to use a fuel cell that generates electricity using oxygen gas and hydrogen gas as fuel.

[0005] This fuel cell-based power supply unit has a large amount of power per unit mass (Wh / kg) and can be made compact, making it an excellent power supply unit for lunar rovers, which have many restrictions on the mass and size of their onboard equipment.

[0006] Furthermore, since hydrogen and oxygen can be obtained by electrolyzing water, which is presumed to be available in the polar regions of the moon, it is reasonable from the standpoint of refueling to adopt a fuel cell that uses hydrogen and oxygen as fuel for the lunar rover's power supply unit.

[0007] For example, Non-Patent Documents 1 and 2 show a manned pressurized rover system (similar to a lunar rover) that is currently under study, and it is envisioned that a fuel cell using hydrogen and oxygen as fuel will be used as the power source for driving.

[0008] However, the lunar rover is currently in the planning stage, and no specific and quantitative design reports have been found for the power supply unit to be installed in the lunar rover. [Prior art documents] [Patent documents]

[0009] [Non-patent literature]

[0010] [Non-Patent Document 1] FY2021 Space Development and Utilization Promotion Research and Development Report (Development of Energy-Related Technologies on the Lunar Surface (Technical Issues Summary)), Mitsubishi Research Institute, Japan Space Forum

[0011] [Non-patent document 2] Status of manned pressurized rovers (initial results and future challenges), Japan Aerospace Exploration Agency (JAXA) Summary of the Invention [Problem to be solved by the invention]

[0012] The use of fuel cells as a power source for lunar rovers, which will travel and explore the surface of the moon for long periods of time (for example, several months), is being considered.

[0013] On Earth, the type of fuel cell commonly used to power automobiles and other vehicles is the polymer electrolyte fuel cell (hereinafter referred to as PEFC). Technological development of PEFC is also progressing, and it is expected that lunar rovers will also be equipped with power supplies using PEFC.

[0014] PEFCs operate at relatively low temperatures of around 90 degrees Celsius, so there are few restrictions on the materials that can be used in the structure of the PEFC, and they have excellent features such as excellent starting properties and ease of handling.

[0015] However, when using PEFCs in the power supply for lunar rovers, the following problems arise: 1. The power supply may not be able to release heat into the surrounding environment. 2. The heat dissipation device would be large and heavy, making it difficult to install on a lunar rover.

[0016] <1. The power supply may not be able to radiate heat to the surrounding environment.> Fuel cells generate a large amount of heat when generating electricity. On Earth, the heat generated by this fuel cell is released into the atmosphere, into cooling water (freshwater or seawater), through the water produced and discharged by the fuel cell, and into the surrounding environment by thermal radiation.

[0017] On the other hand, on the surface of the moon, the atmosphere and cooling water cannot be obtained from the surrounding environment. In addition, the water discharged from the fuel cell is valuable in the lunar rover and is recovered and used as drinking water for the crew or sanitary water (water used for sanitary management of the crew's bodies, etc.), so it cannot be used as a medium for heat dissipation.

[0018] Therefore, the heat emitted from the fuel cells installed on the lunar rover will be released into the surrounding environment by radiation alone. However, since the surface temperature of the Moon during the day can reach around 110 degrees Celsius, a heat release device that uses a PEFC as its heat source, which has an operating temperature of around 90 degrees Celsius, may not be able to release heat to the lunar surface by radiation.

[0019] 2. The heat dissipation device would be large and heavy, making it difficult to install on a lunar rover. The heat dissipation device that uses PEFC as a heat source and is installed on the lunar rover must be positioned so that it dissipates heat only into space, where it can dissipate heat even during the daytime on the moon.For this reason, the heat dissipation device that uses PEFC as a heat source and is installed on the lunar rover must be limited to being installed at the zenith of the lunar rover.

[0020] The heat dissipation device aimed at space has an upper limit of about 90 degrees Celsius, the operating temperature of PEFC, so the heat dissipation surface area required to dissipate the heat while the lunar rover is running would be large and heavy, and the heat dissipation device would occupy the top of the lunar rover. Therefore, the heat dissipation device that uses PEFC as a heat source and is installed on the lunar rover will interfere with the installation of various sensors, communication equipment, solar panels, etc., which need to be installed on top of the lunar rover.

[0021] Conversely, a lunar rover equipped with a heat dissipation device that uses PEFC as a heat source and is limited in size so as not to interfere with other equipment on the lunar rover will not be able to obtain sufficient power from the power supply because it will not be able to obtain sufficient heat dissipation performance, which will limit the driving performance of the lunar rover and also limit the operational plan for the lunar rover.

[0022] It is possible to miniaturize the heat dissipation device by using a heat pump or the like to increase the temperature of the heat dissipation surface of the heat dissipation device and thereby increase the amount of heat dissipated from the heat dissipation device, but this has problems such as the need for electricity to operate equipment such as a heat pump, an increase in the mass of equipment such as a heat pump, and an increase in the number of parts, making the power supply device more complex. [Means for solving the problem]

[0023] In order to solve the above problems, the high-temperature heat rejection type power supply device according to the present invention is a high-temperature heat rejection type power supply device using a fuel cell to be mounted on a lunar rover that travels on the surface of the moon, and is composed of a fuel cell device that mounts the fuel cell, a heat rejection device that rejects the heat generated by the fuel cell to the surrounding environment, and an emergency cooling device that stores water produced by the fuel cell so that the water can absorb the heat generated by the fuel cell, When heat exhaustion is required that exceeds the amount of heat that the heat exhaust device can exhaust, the water stored in the emergency cooling device absorbs the amount of heat generated by the fuel cell. [Effects of the Invention]

[0024] <Heat can be dissipated to the lunar surface during the day> High-temperature exhaust heat type power supply devices use fuel cells with a higher operating temperature than PEFCs, such as solid oxide fuel cells (hereinafter referred to as SOFCs), which have an operating temperature of approximately 800 to 1000 degrees Celsius.

[0025] A heat dissipation device that uses a PEFC as its heat source, which has an operating temperature of around 90 degrees Celsius, cannot dissipate heat to the lunar surface during the daytime, when the surface temperature is around 110 degrees Celsius. However, a heat dissipation device that uses an SOFC as its heat source, which has an operating temperature of around 800 to 1000 degrees Celsius, can dissipate a sufficient amount of heat to the surrounding environment, including the lunar surface during the daytime, thanks to the small heat dissipation surface of the heat dissipation device.

[0026] The heat dissipation device, which uses PEFC as a heat source and cannot dissipate heat to the lunar surface during the day, will be installed at the zenith of the lunar rover to dissipate heat into space.

[0027] On the other hand, the heat dissipation device of the high-temperature heat dissipation type power supply unit can also dissipate heat to the lunar surface during the daytime, so small, high-performance heat dissipation devices can be installed not only at the zenith of the lunar rover, but also in any part of the lunar rover, including under the floor.

[0028] <Compact and lightweight heat dissipation device can be installed on lunar rovers> For example, the area of ​​the heat dissipation surface of a heat dissipation device that uses a PEFC as a heat source and is installed facing outer space (assuming the temperature of the heat dissipation surface is 90 degrees Celsius) can be reduced to less than one-hundredth of that of a heat dissipation surface of a heat dissipation device that uses an SOFC as a heat source and is installed facing the lunar surface at 110 degrees Celsius, which can dissipate the same amount of heat (assuming the temperature of the heat dissipation surface is 900 degrees Celsius).

[0029] Therefore, the heat exhaust device of the high-temperature heat exhaust type power supply device can be made extremely small and lightweight compared to the heat exhaust device of a power supply device using a PEFC.

[0030] In addition, other features include: The emergency cooling device that constitutes the high-temperature heat dissipation type power supply unit can process the waste heat by absorbing the heat generated by the fuel cell with water stored in the emergency cooling unit in the event that the power supply unit needs to generate more power than usual in an emergency, or when more heat needs to be dissipated than the heat dissipation unit can dissipate.

[0031] Furthermore, the high-temperature heat rejection type power supply device can have a simple configuration, being composed only of a fuel cell device, a heat rejection device, and an emergency cooling device, and does not have any other device for rejecting heat such as a heat pump. [Brief explanation of the drawings]

[0032] [Figure 1] High temperature exhaust heat type power supply device [Figure 2] Lunar rover drive system using high-temperature exhaust power supply [Figure 3] Example of high-temperature exhaust heat type power supply unit installed on a lunar rover [Figure 4] Other configurations of high-temperature exhaust heat type power supply units DETAILED DESCRIPTION OF THE INVENTION

[0033] The high-temperature heat rejection type power supply device is composed of a fuel cell device, a heat rejection device, and an emergency cooling device.

[0034] <Fuel cell device> The fuel cell device is composed of a fuel cell, a fuel cell radiator with a heat radiation amount adjustment function, and a fuel cell bottom radiator with a heat radiation amount adjustment function.

[0035] The fuel cells used are of a type that operates at a relatively high temperature. For example, SOFCs (operating temperatures are approximately 800 to 1000 degrees Celsius) and molten carbonate fuel cells (operating temperatures are approximately 600 to 700 degrees Celsius) are used.

[0036] The fuel cell is supplied with hydrogen gas and oxygen gas as fuel, and generates electricity while emitting water and heat.

[0037] The fuel cell is housed in a pressure vessel covered with heat insulating material, and in order to dissipate some of the heat generated by the fuel cell, the pressure vessel is provided with a fuel cell bottom radiator with a heat dissipation amount adjustment function on the bottom surface and a fuel cell radiator with a heat dissipation amount adjustment function on a part other than the bottom surface, facing in a direction that allows heat dissipation according to the location where the fuel cell is installed.

[0038] The fuel cell radiator with heat dissipation adjustment function and the fuel cell bottom radiator with heat dissipation adjustment function have a movable device such as a louver or shutter, and can adjust the amount of heat dissipation by adjusting the area of ​​the heat dissipation surface exposed to the surrounding environment.

[0039] <Heat dissipation device> The heat dissipation device is composed of a radiator with a heat radiation amount adjustment function and a condenser with a heat radiation amount adjustment function.

[0040] The radiator with heat radiation amount adjustment function radiates a part of the heat of the gas extracted from the inside of the fuel cell and sent from the fuel cell device through a gas pipe to the surrounding environment.

[0041] A heat sink with a heat dissipation adjustment function has a movable device such as a louver or shutter, and, if necessary, a device that adjusts or restricts the gas flow path of the heat sink.By adjusting the area and temperature of the part of the heat sink that contributes to heat dissipation, the amount of heat released into the surrounding environment can be adjusted.

[0042] The condenser with heat radiation amount adjustment function liquefies the moisture contained in the gas by radiating part of the heat of the gas sent from the radiator with heat radiation amount adjustment function through the gas pipe to the surrounding environment. The liquefied water is sent to the emergency cooling system via water piping.

[0043] A condenser with a heat dissipation adjustment function has a movable device such as a louver or shutter, and, if necessary, a device that adjusts or restricts the gas flow path of the condenser, and can adjust the amount of heat emitted by adjusting the area and temperature of the part of the condenser that contributes to heat dissipation.

[0044] <Emergency cooling device> The emergency cooling device has a water tank that stores water sent from the condenser with heat radiation adjustment function via a water pipe.

[0045] This water tank has a radiator that can adjust the area of ​​the part that contributes to heat dissipation exposed to the surrounding environment using a movable device such as a louver or shutter, and can adjust the temperature of the stored water by adjusting the amount of heat exchanged with the surrounding environment. The water tank is also equipped with a heater, so that the stored water can be heated if its temperature drops.

[0046] The emergency cooling device has a gas pipe provided so as to be able to exchange heat with the water in the water tank. If necessary, high-temperature gas extracted from the fuel cell can be passed through this gas pipe, allowing the water in the water tank to absorb the waste heat from the fuel cell.

[0047] In an emergency, when the fuel cell needs to output a large amount of power or when heat exhaust is required that exceeds the amount of heat that can be dissipated from the heat exhaust device, the emergency cooling device absorbs the heat exhausted from the fuel cell using water stored in a water tank. [Example]

[0048] Figure 1 shows an overview of a high-temperature heat dissipation type power supply unit.

[0049] The high-temperature heat rejection type power supply device 33 is composed of a fuel cell device 23, a heat rejection device 24, and an emergency cooling device 25, and each device is connected via multiple gas pipes 9, water pipes 10, and emergency cooling pipes 35.

[0050] The fuel cell device 23 is composed of a fuel cell 1, a fuel cell radiator 2 with a heat dissipation adjustment function, a fuel cell underside radiator 3 with a heat dissipation adjustment function, and a dust prevention device 4 that prevents the adhesion of regolith (dust on the surface of the moon) and the like that is kicked up as the lunar rover 34 (see Figure 3) moves.

[0051] The fuel cell 1 uses hydrogen gas and oxygen gas as fuel. Hydrogen gas and oxygen gas can be obtained by electrolyzing water, which is thought to be available on the lunar surface, and so they may be available on the lunar surface.

[0052] The fuel cell 1 is supplied with the required amounts of hydrogen gas and oxygen gas, each adjusted to an appropriate pressure by a gas pressure and supply amount adjusting device 14, from a hydrogen tank 12 and an oxygen tank 13 via a gas pipe 15.

[0053] The fuel cell 1 generates electricity by reacting the supplied hydrogen gas and oxygen gas, and the electricity is supplied to the wheel drive control device 27 (see Figure 2) via the electric wire 21, causing the lunar rover 34 (see Figure 3) to move.

[0054] In addition, the high-temperature gas inside the fuel cell 1, including the water produced by the fuel cell 1, is sent to the heat dissipation device 24 via the gas piping 9, and in the radiator 5 with heat dissipation adjustment function, which is a component of the heat dissipation device 24, a portion of the heat is dissipated from the high-temperature gas to the surrounding environment, and then sent to the condenser 6 with heat dissipation adjustment function, which is also a component of the heat dissipation device 24, and as a result of further dissipating a portion of the heat to the surrounding environment, the moisture contained in the gas is liquefied and the gas and water are separated.

[0055] Because heat needs to be dissipated by radiation in the daytime lunar environment of approximately 110 degrees Celsius, and in order to make the heat dissipation device 24 small and lightweight, fuel cells that operate at as high a temperature as possible, such as SOFCs (operating temperature of approximately 800 to 1000 degrees Celsius) or molten carbonate fuel cells (operating temperature of approximately 600 to 700 degrees Celsius), are used.

[0056] The fuel cell 1 is housed in a pressure vessel, which has a fuel cell bottom radiator 3 with a heat dissipation adjustment function that dissipates heat downward toward the lunar surface, and a fuel cell radiator 2 with a heat dissipation adjustment function that is arranged to dissipate heat toward the surrounding environment other than the downward direction.

[0057] Furthermore, when a heat dissipation device 24 with sufficient heat dissipation capacity is used, the number of fuel cell radiators 2 with heat dissipation adjustment function and the fuel cell underside radiators 3 with heat dissipation adjustment function can be reduced, made smaller, or even omitted.

[0058] The fuel cell radiator 2 with heat dissipation adjustment function and the fuel cell underside radiator 3 with heat dissipation adjustment function have movable devices such as louver-shaped or shutter-shaped devices, and can adjust the amount of heat dissipation by changing the area of ​​the heat dissipation surface that contributes to heat dissipation.

[0059] The fuel cell device 23 is expected to be mounted on the lunar rover 34 (see FIG. 3) in a position close to the lunar surface to improve accessibility during maintenance and to avoid interfering with the mounting of other equipment on the lunar rover 34 (see FIG. 3).

[0060] Therefore, the fuel cell radiator 2 with heat dissipation adjustment function and the fuel cell underside radiator 3 with heat dissipation adjustment function are equipped with a dust prevention device 4 as necessary, as there is concern that problems such as a decrease in heat dissipation performance due to the adhesion of regolith and the like that is kicked up as the lunar rover 34 (see Figure 3) moves and a loss of the heat dissipation adjustment function may occur.

[0061] By adjusting the louver- or shutter-shaped movable devices to minimize the heat dissipation from the fuel cell radiator 2 with heat dissipation adjustment function and the fuel cell underside radiator 3 with heat dissipation adjustment function, the entire fuel cell 1 is covered with heat insulating material, protecting the fuel cell 1 from the low-temperature environment in the lunar environment at night when the surface temperature drops to around minus 100 degrees Celsius.

[0062] The fuel cell radiator 2 with heat dissipation adjustment function and the fuel cell bottom radiator 3 with heat dissipation adjustment function adjust the heat dissipation amount by adjusting a louver-shaped or shutter-shaped movable device based on the following conditions. - Operation status of fuel cell 1 (information on the amount of heat that needs to be dissipated and the amount of water produced) -Information on the amount of heat emitted by the heat dissipation device 24 - Information on the surrounding lunar environment - Information such as the travelling speed of the lunar rover 34 (see Figure 3) (The heat dissipation performance of the fuel cell bottom radiator 3 with heat dissipation amount adjustment function and the fuel cell radiator 2 with heat dissipation amount adjustment function changes depending on the surrounding lunar environment and the moving speed of the lunar rover 34 (see Figure 3).)

[0063] The heat dissipation device 24 is composed of a radiator 5 with a heat radiation amount adjustment function and a condenser 6 with a heat radiation amount adjustment function.

[0064] The heat exhaust device 24 takes in high-temperature gas containing moisture from the fuel cell device 23 via the gas piping 9, dissipates part of the heat of the gas into the surrounding lunar environment, and liquefies the moisture contained in the gas to separate the gas from the water.

[0065] The radiator 5 with heat dissipation adjustment function takes in high-temperature internal gas containing moisture generated by the fuel cell 1 from the fuel cell device 23 via gas piping 9, and dissipates a portion of the heat from the high-temperature gas to the surrounding lunar environment by thermal radiation.

[0066] The heat radiator 5 with heat dissipation amount adjustment function has a movable device such as a louver or shutter, or a device that adjusts or restricts the gas flow path, and the amount of heat radiated can be changed by adjusting the area and temperature of the part of the heat radiator 5 with heat dissipation amount adjustment function that contributes to heat dissipation.

[0067] If dust prevention measures are required for the radiator 5 with heat radiation amount adjustment function, a dust prevention device similar to the dust prevention device 4 provided in the fuel cell device 23 is attached.

[0068] The moisture-containing gas from which a portion of the heat has been removed by the radiator 5 with heat radiation amount adjustment function is sent to the condenser 6 with heat radiation amount adjustment function through the gas pipe 9.

[0069] The condenser 6 with heat radiation adjustment function radiates a portion of the heat from the gas sent through the gas pipe 9 to the surrounding lunar environment, thereby lowering the temperature of the gas containing moisture to below the boiling point of water, liquefying the moisture and separating the gas from the water.

[0070] Condenser 6 with heat dissipation amount adjustment function has a louver-shaped or shutter-shaped movable device similar to radiator 5 with heat dissipation amount adjustment function, or a device that adjusts or restricts the gas flow path on the heat dissipation surface, and by adjusting the area and temperature of the part of condenser 6 with heat dissipation amount adjustment function that contributes to heat dissipation, the amount of heat dissipated to the external environment can be varied.

[0071] If dust prevention measures are required for the condenser 6 with heat radiation amount adjustment function, a dust prevention device similar to the dust prevention device 4 provided in the fuel cell device 23 is attached.

[0072] The water liquefied and separated from the gas in the condenser 6 with heat radiation adjustment function is sent to the emergency cooling device 25 via the water pipe 10.

[0073] The radiator 5 with heat radiation amount adjustment function and the condenser 6 with heat radiation amount adjustment function adjust the amount of heat radiation based on the following information by using a louver-shaped or shutter-shaped movable device or a function that adjusts or restricts the gas flow path on the heat radiation surface. - Operating status of fuel cell 1 (amount of heat required to be exhausted, amount of water produced) The temperature, pressure, and flow rate of the gas sent from the fuel cell device 23 Lunar environment - Travel speed of Lunar Rover 34 (see Figure 3) (The heat dissipation performance of the heat dissipation adjusting radiator 5 and the heat dissipation adjusting condenser 6 changes depending on the lunar environment and the moving speed of the lunar rover 34 (see Figure 3).)

[0074] The emergency cooling device 25 has a water tank 7 with a heat radiation adjustment function that stores water sent through a water pipe 10.

[0075] The water tank 7 with heat dissipation adjustment function has a movable device such as a louver or shutter, and has a radiator that can adjust the amount of heat exchanged by changing the area of ​​the heat dissipation surface that exchanges heat with the surrounding environment.

[0076] To prevent the water stored in the water tank 7 with heat dissipation adjustment function from freezing or boiling, or to maintain the temperature of the stored water at a desired temperature, the water tank 7 with heat dissipation adjustment function exchanges heat with the surrounding environment using a radiator as necessary.

[0077] The water tank 7 with heat dissipation adjustment function has a heater, and if the water temperature drops because it is not possible to maintain the target temperature through heat exchange with the surrounding environment on the lunar surface, the heater can heat the water.

[0078] The water stored in the heat radiation adjusting water tank 7 is taken out via the water pipe 10 as needed to be used as drinking water for the crew and as sanitary water.

[0079] The water tank 7 with heat dissipation adjustment function has emergency cooling piping 35, and if necessary, the high-temperature gas extracted from the fuel cell device 23 can be taken in without passing through the heat exhaust device 24 and cooled using water stored in the water tank 7 with heat dissipation adjustment function.

[0080] When heat dissipation is required that exceeds the amount of heat that can be dissipated by the heat dissipation device 24, the blower 11 attached to the emergency cooling piping 35 is operated, high-temperature gas is guided from the fuel cell device 23 to the emergency cooling piping 35, and the heat of the gas can be absorbed by the water stored in the water tank 7 with heat dissipation adjustment function until the temperature of the water stored in the water tank 7 with heat dissipation adjustment function rises to a predetermined temperature (a set temperature below the boiling point).

[0081] As a method for treating a larger amount of waste heat by the emergency cooling device 25, The emergency cooling device 25 can process even larger amounts of heat by absorbing the heat required to vaporize the water stored in the water tank 7 with heat radiation adjustment function from the gas sent to the water tank 7 with heat radiation adjustment function via the emergency cooling piping 35.

[0082] When the water stored in the water tank 7 with heat dissipation adjustment function evaporates, the pressure inside the water tank 7 with heat dissipation adjustment function rises, and when it reaches a predetermined pressure, the safety valve 36 is activated and gas containing water vapor is released into the external environment via the emergency exhaust pipe 37.

[0083] This heat dissipation method using the heat of vaporization of water stored in the water tank 7 with heat dissipation adjustment function is an unavoidable heat dissipation method in emergencies, as some of the water and gas inside the water tank 7 with heat dissipation adjustment function will be lost.

[0084] In FIG. 1, a device for adjusting the amount of gas inside the water tank 7 with heat radiation amount adjustment function is omitted.

[0085] FIG. 2 shows an outline of a drive system using a high-temperature exhaust heat type power supply device 33 mounted on a lunar rover 34 (see FIG. 3).

[0086] The drive system configuration shown in Figure 2 has two high-temperature heat rejection type power supply units 33, and even if one of the high-temperature heat rejection type power supply units 33 fails, the lunar rover 34 (see Figure 3) can still run.

[0087] It should be noted that devices related to power supply switching in the event that one of the high-temperature exhaust type power supply devices 33 fails are omitted in FIG.

[0088] The two high-temperature exhaust heat type power supply units 33 are supplied with hydrogen gas and oxygen gas from a hydrogen tank 12 and an oxygen tank 13 via gas piping 15, with the pressure and supply rate adjusted by a gas pressure and supply rate adjustment device 14.

[0089] The electric power generated by the fuel cell device 23 is sent to a motor 28 via a wheel drive control device 27 to drive wheels 29 .

[0090] The electric power generated by the fuel cell device 23 can be used for purposes other than driving the wheels, and is extracted as needed (power output (reserve power) 32).

[0091] The water stored in the emergency cooling device 25 constituting the fuel cell device 23 is extracted as needed via the water piping 10 for use as drinking water or sanitary water for the crew (water supply and water replenishment 22).

[0092] When water is to be filled into the emergency cooling device 25 constituting the fuel cell device 23, or when the amount of water stored in the emergency cooling device 25 decreases, water is supplied to the emergency cooling device 25 via the water piping 10 as needed (Water Supply and Water Replenishment 22).

[0093] The power required for the lunar rover 34 (see Figure 3) to travel on the lunar surface fluctuates rapidly depending on the conditions on the lunar surface and the drive demands on the lunar rover 34, but the high-temperature exhaust heat type power supply device 33 uses a battery or the like to respond to this rapidly changing power demand. It should be noted that the device using a battery or the like to respond to sudden fluctuations in power demand is omitted from FIG.

[0094] FIG. 3 shows a design example in which a lunar rover 34 is equipped with the drive system shown in FIG.

[0095] The lunar rover 34 has been studied in accordance with the required specifications of a manned pressurized rover system (same as the lunar rover 34) shown in Non-Patent Document 2, and the high-temperature exhaust heat type power supply unit 33 installed therein will supply the necessary and sufficient power for the manned pressurized rover system (same as the lunar rover 34) to operate.

[0096] The lunar rover 34 shown in FIG. 3 is a design example in which hydrogen and oxygen, which are fuels, are loaded in the required amounts before operation.

[0097] It is also possible to design a regenerative power system that includes a sufficiently large solar cell and a regenerator that can electrolyze water using the electricity obtained from the solar cell to produce hydrogen and oxygen.

[0098] The high-temperature heat exhaust type power supply device 33 is composed of a fuel cell device 23 , a heat exhaust device 24 , and an emergency cooling device 25 .

[0099] The heat exhaust device 24 is composed of a heat exhaust device 5 with a heat radiation amount adjustment function and a condenser 6 with a heat radiation amount adjustment function.

[0100] The lunar rover 34 needs to travel at speeds of several tens of kilometers per hour over rough terrain, including slopes on the lunar surface, and it is estimated that the power required for the lunar rover 34 to travel is up to 50 kW.

[0101] The requirements for the high-temperature exhaust heat type power supply device 33 that is mounted on the lunar rover 34 and supplies the power necessary for traveling, and the specifications of the high-temperature exhaust heat type power supply device 33 that meet these requirements, are set as follows.

[0102] <Power requirements for Lunar Rover 34 to run> Rated power: 50KW (continuous power supply for one Lunar Rover 34) Maximum power: 100KW (power supply for one lunar rover 34 for one hour) <Specifications for the high-temperature exhaust heat type power supply unit 33 to be installed on the lunar rover 34> Two high-temperature exhaust power supply units 33 are installed on the lunar rover 34. Rated output of high-temperature exhaust heat type power supply unit 33: 25 kW (per unit, continuous) Maximum output of high-temperature exhaust heat power supply unit 33: 50 kW (each unit can supply maximum power for one hour even if no heat is exhausted to the external environment) Type of fuel cell 1 that constitutes high-temperature exhaust heat type power supply device 33: SOFC Power generation efficiency of fuel cell 1 that constitutes high-temperature exhaust heat type power supply unit 33: 50% Operating temperature of the fuel cell 1 constituting the high-temperature exhaust heat type power supply device 33: 800 degrees Celsius to 1000 degrees Celsius Internal pressure of the fuel cell 1 constituting the high-temperature exhaust heat type power supply device 33: 0.5 MPa to 5 MPa

[0103] In addition, in the study of the example of mounting the high-temperature heat rejection type power supply unit 33 on a lunar rover 34 shown in Figure 3, the power consumed by the control equipment, fans, and opening and closing of each valve that make up the high-temperature heat rejection type power supply unit 33 is ignored.

[0104] The reason why the minimum internal pressure of the fuel cell 1 (the internal pressure of the radiator 5 with heat radiation amount adjustment function, the condenser 6 with heat radiation amount adjustment function, and the emergency cooling device 25 is the same) is set to 0.5 MPa is as follows: This is to set the boiling point of the water stored in the emergency cooling device to about 150 degrees Celsius so that the water will not boil even if the temperature of the water stored in the emergency cooling device 25 rises due to the influence of the daytime lunar surface temperature environment, which reaches about 110 degrees Celsius.

[0105] In order for the emergency cooling device 25 to absorb more heat, the internal pressure of the water tank 7 with heat radiation adjustment function that constitutes the emergency cooling device 25 can be increased to raise the boiling point temperature of the stored water and increase the temperature change of the water when absorbing heat.

[0106] However, as the internal pressure of fuel cell 1 increases, it becomes more difficult to design the mechanical strength of fuel cell 1 and to adjust the pressure of the fuel gas (hydrogen gas and oxygen gas) supplied to fuel cell 1, so the maximum internal pressure of fuel cell 1 is designed to be limited to 5 MPa.

[0107] Furthermore, when the internal pressure of the fuel cell 1 (the internal pressure of the radiator 5 with heat dissipation adjustment function, the condenser 6 with heat dissipation adjustment function, and the emergency cooling device 25 is the same) is the maximum pressure of 5 MPa, the boiling point of water is 265 degrees Celsius.

[0108] The fuel cell 1 has a power generation efficiency of 50% and a rated output of 25 kW per fuel cell. Therefore, when the fuel cell 1 operates at its rated output, 25 kW of heat must be exhausted per fuel cell.

[0109] The fuel cell 1 has a fuel cell radiator 2 with heat dissipation adjustment function and a fuel cell underside radiator 3 with heat dissipation adjustment function, which radiate heat toward the lunar surface laterally of the lunar rover 34 and toward outer space, as well as toward the lunar surface below the lunar rover 34.

[0110] The total area of ​​the parts of the fuel cell radiator with heat dissipation adjustment function 2 and the fuel cell underside radiator with heat dissipation adjustment function 3 that contribute to heat dissipation is approximately 0.7 square meters, and they can dissipate heat of up to 12 kW even when the temperature on the moon's surface is 110 degrees Celsius.

[0111] The radiator 5 with heat radiation amount adjustment function has a heat radiation surface of about 1 square meter, and radiates a maximum of 5 kW of heat from the gas sent from the fuel cell device 23 to the external environment.

[0112] The condenser 6 with heat radiation amount adjustment function has a heat radiation surface of about 1.6 square meters, dissipates heat of up to 7 kW, liquefies the moisture contained in the gas sent from the radiator 5 with heat radiation amount adjustment function, and separates the gas from the water. The water separated from the gas in the condenser 6 with heat radiation adjustment function is sent to the emergency cooling device 25.

[0113] The emergency cooling device 25 stores the water sent from the condenser 6 with heat radiation amount adjustment function. The water stored in the emergency cooling device 25 is used as a medium for absorbing the exhaust heat of the fuel cell device 23, and also as drinking water and sanitary water as needed.

[0114] Each emergency cooling device 25 stores up to 200 liters of water. The temperature of the stored water is maintained at around 50 degrees Celsius by the radiator of the water tank 7 with heat radiation adjustment function that constitutes the emergency cooling device 25 exchanging heat with outer space or the surrounding lunar environment, or by heating it with a heater as needed.

[0115] If necessary, the emergency cooling device 25 can absorb heat from the gas coming from the fuel cell device 23 until the temperature of the water stored therein reaches 250 degrees Celsius.

[0116] If the amount of water stored in one emergency cooling device 25 is 200 liters and the temperature difference of the water when absorbing heat is 200 degrees (the temperature of the water stored in the emergency cooling device 25 rises from 50 degrees Celsius to 250 degrees Celsius), each emergency cooling device 25 can absorb approximately 50 kWh of heat. This is equivalent to the amount of exhaust heat generated for two hours when one fuel cell device 23 operates at its rated output (25 kW).

[0117] The emergency cooling device 25 and the heat exhaust device 24 can be combined depending on the situation to share and process the exhaust heat of the fuel cell device 23.

[0118] FIG. 4 shows another configuration of a high-temperature exhaust heat type power supply device.

[0119] A high-temperature heat rejection type power supply device 59 having another configuration shown in FIG. 4 is made up of a fuel cell device 123, a heat rejection device 57, and a water cooling device 58.

[0120] The fuel cell device 123 is the same as the fuel cell device 23 of the high-temperature exhaust heat type power supply device 33 .

[0121] The heat dissipation device 57 takes in high-temperature gas containing moisture sent from the fuel cell device 123 via the gas piping 109 into a gas radiator 51 with heat dissipation amount adjustment function (same as the radiator 5 with heat dissipation amount adjustment function) that constitutes the heat dissipation device 57, and dissipates part of the heat of the gas into the surrounding environment.

[0122] The gas is then directly blown into water stored in a water tank 52 with a heat radiation adjustment function that constitutes a heat exhaust device 57 to lower the temperature, and the water contained in the gas is liquefied, separating the gas from the water.

[0123] The liquid water separated in the heat radiation amount adjustment water tank 52 accumulates in the lower part of the heat radiation amount adjustment water tank 52, and the gas accumulates in the upper part of the heat radiation amount adjustment water tank 52.

[0124] The gas accumulated in the upper part of the water tank 52 with heat radiation amount adjustment function is returned to the fuel cell device 123 via the blower 111 and the gas pipe 109 .

[0125] The liquid water that accumulates at the bottom of the water tank 52 with heat dissipation adjustment function is sent via water piping 110 to the water radiator 53 with heat dissipation adjustment function, where it exchanges heat with the external environment, and then is returned to the water tank 52 with heat dissipation adjustment function via the water piping 110 by the pump 60.

[0126] In the high-temperature heat rejection type power supply unit 59 of another configuration, the water contained in the gas is liquefied by removing part of the heat from the gas in the water tank 52 with heat rejection adjustment function, so when the high-temperature heat rejection type power supply unit 59 of another configuration is operating to generate power, the radiator equipped in the water tank 52 with heat rejection adjustment function and the water radiator 53 with heat rejection adjustment function always reject heat to the external environment.

[0127] The radiator of the water tank 52 with heat dissipation adjustment function has a movable device such as a louver or shutter, similar to the radiator 5 with heat dissipation adjustment function, and by adjusting the area and temperature of the part of the radiator of the water tank 52 with heat dissipation adjustment function that contributes to heat dissipation, the amount of heat exchanged with the external environment can be adjusted.

[0128] In addition, the water radiator 53 with heat dissipation amount adjustment function can adjust the amount of heat exchanged with the external environment by using a movable device such as a louver or shutter, similar to the radiator 5 with heat dissipation amount adjustment function, or a device that adjusts or restricts the water flow path on the heat dissipation surface, to adjust the area and temperature of the part of the heat dissipation surface of the water radiator 53 with heat dissipation amount adjustment function that contributes to heat dissipation.

[0129] The temperature of the water inside the water tank 52 with heat dissipation amount adjustment function is kept at a constant temperature (for example, 50 degrees Celsius) by adjusting the amount of heat exchanged between the water tank 52 with heat dissipation amount adjustment function and the water radiator 53 with heat dissipation amount adjustment function and the external environment.

[0130] When it is necessary to process the waste heat from the fuel cell 101 that exceeds the capacity of the heat dissipation device 57 and the water cooling device 58, the waste heat is absorbed by allowing the temperature of the water stored in the water tank 52 with heat dissipation adjustment function to rise (for example, from 50 degrees Celsius to 250 degrees Celsius).

[0131] The high-temperature heat exhaust type power supply device 59 having another configuration has the feature that the gas piping 109 can be made simpler and lighter than the condenser 6 with heat radiation amount adjustment function that constitutes the high-temperature heat exhaust type power supply device 33.

[0132] By designing water radiator 53 with heat radiation amount adjustment function to have sufficient heat radiation capacity, the radiator of water tank 52 with heat radiation amount adjustment function can be omitted.

[0133] Moreover, by providing water tank 52 with heat radiation amount adjustment function with sufficient heat radiation capacity, water radiator 53 with heat radiation amount adjustment function can be omitted. [Industrial Applicability]

[0134] The high-temperature heat rejection type power supply unit can be installed on a lunar rover and can supply sufficient power for the lunar rover to operate.In addition, the water stored in the high-temperature heat rejection type power supply unit absorbs the exhaust heat, making it possible to supply power for lunar rover operations that require greater power, and even in situations where sufficient heat cannot be rejected, such as in emergencies.

[0135] The high-temperature heat rejection type power supply unit can reject heat sufficiently even in the daytime lunar environment, is small and lightweight, and can be mounted in a location that does not interfere with other equipment on the lunar rover.

[0136] This invention contributes to the realization of lunar rovers and promotes lunar exploration and subsequent exploration plans for planets, satellites, etc.

[0137] It will also contribute to the development of related industries involved in the development and manufacturing of lunar rovers and other related space equipment, as well as the improvement of their technological capabilities. [Explanation of symbols]

[0138] 1 fuel cell 2 Fuel cell radiator with heat radiation adjustment function 3 Fuel cell bottom radiator with heat radiation adjustment function 4 Dust control device 5 Heatsink with heat radiation adjustment function 6. Condenser with heat radiation adjustment function 7. Water tank with heat dissipation adjustment function 8. Lunar surface 9 Gas piping 10 Water piping 11 Blower 12 Hydrogen Tank 13 Oxygen Tank 14 Gas pressure and supply volume adjustment device 15 Gas piping 16 Heat radiation from fuel cell devices 17 Heat radiation from a heat sink with heat radiation amount adjustment function 18 Heat radiation from a condenser with heat radiation control function 19 Heat radiation from a water tank with heat radiation control function 20 Power Output 21 Electric wire 22 Water Supply and Refills 23 Fuel cell equipment 24 Heat dissipation device 25 Emergency Cooling System 26 Gas valve 27 Wheel drive control device 28 Motor 29 wheels 30 Water valve 32 Power output (standby power) 33 High-temperature heat exhaust type power supply device 34 Lunar Rover 35 Emergency cooling piping 36 Safety valve 37 Emergency exhaust piping 51 Gas radiator with heat radiation adjustment function 52 Water tank with heat dissipation adjustment function 53 Water radiator with heat radiation adjustment function 54 Heat radiation from a gas radiator with heat radiation adjustment function 55 Heat radiation from a water tank with heat radiation control function 56 Heat radiation from a water radiator with heat radiation adjustment function 57 Heat dissipation device 58 Water cooling system 59 Other high-temperature exhaust heat type power supply units 60 Pump 101 Fuel Cell 102 Fuel cell radiator with heat radiation adjustment function 103 Fuel cell bottom radiator with heat radiation adjustment function 104 Dust control equipment 108 Moon Surface 109 Gas Pipe 110 Water piping 111 Blower 112 Hydrogen Tank 113 Oxygen Tank 114 Gas pressure and supply volume adjustment device 115 Gas piping 116 Heat radiation from fuel cell devices 120 Power Output 121 Electric wire 122 Water Supply and Refills 123 Fuel cell equipment

Claims

1. A high-temperature heat rejection type power supply device using a fuel cell to be mounted on a lunar rover that travels on the surface of the moon, comprising a fuel cell device, a heat rejection device that rejects heat generated by the fuel cell to the surrounding environment, and an emergency cooling device that stores water produced by the fuel cell so that the water can absorb the heat generated by the fuel cell, When heat exhaustion is required that exceeds the amount of heat that the heat exhaust device can exhaust, the water stored in the emergency cooling device absorbs the amount of heat generated by the fuel cell.

2. 2. The high-temperature heat rejection type power supply device according to claim 1, wherein the fuel cell device uses a fuel cell whose operating temperature is equal to or higher than the maximum daytime temperature on the surface of the moon, and has a radiator that can reject the heat generated by the fuel cell from the fuel cell device to the surrounding environment, including the lunar surface, by direct radiation.

3. 2. The high-temperature heat dissipation type power supply device according to claim 1, characterized in that the fuel cell device, the heat dissipation device, and the emergency cooling device are capable of adjusting the amount of heat dissipation by varying the area of ​​the radiator that contributes to heat dissipation that is exposed to the external environment using a movable device such as a louver or shutter.

4. 2. The high-temperature heat rejection type power supply device according to claim 1, characterized in that the emergency cooling device has the functions of storing the water produced by the fuel cell in a water tank that constitutes the emergency cooling device, adjusting the temperature of the water, and absorbing the heat generated by the fuel cell with the water.

Images