A supercritical ammonia rankine cycle heat engine system based on lunar soil heat storage

Abstract

The present application relates to a kind of supercritical ammonia rankine cycle heat engine systems based on lunar soil heat storage, comprising: lunar soil particle circulation: low temperature lunar soil particle enters particle receiver, condenser array device heats lunar soil particle, high temperature lunar soil enters lunar soil heat storage tank and is stored or heat exchanged, and low temperature lunar soil after heat exchange enters particle receiver again and is heated;Ammonia Rankine cycle: supercritical ammonia enters turbine and expands and does work, and gaseous ammonia after work enters the heat fluid passage of regenerator and is cooled to gas-liquid coexisting ammonia, gas-liquid coexisting ammonia enters radiation radiator and is cooled to liquid ammonia, liquid ammonia enters pump and is pressurized, and again enters the cold fluid passage of regenerator and is exchanged to supercritical ammonia, supercritical ammonia enters lunar soil heat storage tank and is further exchanged, and again enters turbine and expands and does work;Helium circulation: high pressure helium transports low temperature lunar soil particle into particle receiver, and the heat storage and heat dissipation effect of the present application are more excellent, and the overall quality is lighter.

Description

Technical Field

[0001] This invention relates to the field of lunar engine equipment, and in particular to a supercritical ammonia-ranken cycle thermal engine system based on lunar soil heat storage. Background Technology

[0002] Lunar exploration has entered a new phase, with propulsion systems becoming a key supporting technology. However, the extreme lunar environment presents severe challenges to propulsion systems. The lunar night, lasting up to 14 days, limits the use of solar energy, the vacuum environment makes heat dissipation difficult, and the extreme temperature differences between day and night require propulsion systems to have extremely high adaptability. Existing power generation solutions all have limitations under high power demands: photovoltaic modules cannot provide continuous power during the lunar night; radioisotope thermoelectric generators have limited power; fuel cells need to carry large amounts of fuel, increasing mission costs and complexity; and while nuclear power plants have high power output capabilities, their research and development and launch costs are high, and safety challenges are significant, making practical application difficult in the short term.

[0003] Against this backdrop, thermal engines based on lunar soil heat storage have shown broad application prospects due to their stable power supply and high safety. However, existing solutions generally face significant challenges in heat storage and dissipation, resulting in large system weights and impacting practical feasibility. Summary of the Invention

[0004] The purpose of this invention is to provide a supercritical ammonia Rankine cycle thermal engine system based on lunar soil heat storage. The supercritical ammonia Rankine cycle thermal engine system has good heat storage and heat dissipation effects, and is lightweight, thus having good applicability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A supercritical ammonia-ranken cycle thermal engine system based on lunar soil heat storage includes: a lunar soil heat storage tank, a particle receiver, a turbine, a regenerator, a pump, a radiant radiator, and a concentrator array device.

[0007] Lunar soil particle circulation: Low-temperature lunar soil particles enter the particle receiver, the concentrating mirror array device heats the lunar soil particles, high-temperature lunar soil particles enter the lunar soil heat storage tank for heat storage or heat exchange, and the low-temperature lunar soil after heat exchange enters the particle receiver again for heating.

[0008] Ammonia Rankine Cycle: Supercritical ammonia enters the turbine and expands to do work. The gaseous ammonia after doing work enters the hot fluid channel of the regenerator and is cooled into gas-liquid coexisting ammonia. The gas-liquid coexisting ammonia enters the radiant radiator and is cooled into liquid ammonia. The liquid ammonia enters the pump and is pressurized. It then enters the cold fluid channel of the regenerator to exchange heat and become supercritical ammonia. The supercritical ammonia enters the lunar soil heat storage tank for further heat exchange and then enters the turbine again to expand and do work.

[0009] Helium circulation: High-pressure helium gas transports the low-temperature lunar soil particles into the particle receiver.

[0010] Preferably, it also includes a pellet feeder and a fluidized bed conveying device. The low-temperature lunar soil particles in the lunar soil heat storage tank first enter the pellet feeder and then enter the pellet receiver through the fluidized bed conveying device.

[0011] Preferably, it also includes a particle separator, wherein the high-temperature lunar soil particles in the particle receiver first enter the particle separator for separation, and then enter the lunar soil heat storage tank for heat exchange.

[0012] Preferably, it also includes a pressure tank and a compressor;

[0013] Helium circulation: High-pressure helium enters the fluidized bed conveying device and conveys the low-temperature lunar soil particles to the particle receiver. The helium and high-temperature lunar soil particles enter the particle separator for separation. The separated helium first enters the pressure tank and then enters the compressor for compression to form high-pressure helium. The high-pressure helium then enters the fluidized bed conveying device again to convey the low-temperature lunar soil particles.

[0014] Preferably, the lunar soil heat storage tank has a mutually isolated lunar soil storage chamber and an ammonia gas channel. The high-temperature lunar soil particles separated by the particle separator enter the upper part of the lunar soil storage chamber, and the lunar soil in the lower part of the lunar soil storage chamber enters the particle feeder.

[0015] The supercritical ammonia from the cold fluid channel of the regenerator enters the ammonia gas channel for heat exchange, and the supercritical ammonia after heat exchange re-enters the turbine to do work.

[0016] Preferably, the particle separator is a cyclone separator, which separates high-temperature lunar soil particles and helium gas by rotation. The high-temperature lunar soil particles fall along the inner wall of the particle separator into the lunar soil heat storage tank, and the helium gas is discharged along the center of the particle separator into the pressure tank.

[0017] Preferably, it also includes an AC motor. Supercritical ammonia enters the turbine and expands to do work, driving the turbine to rotate. The turbine drives the pump to rotate, and the pump drives the AC motor to generate electricity.

[0018] Preferably, during lunar daytime, lunar soil particles are heated into high-temperature lunar soil particles in the particle receiver, and the high-temperature lunar soil particles enter the lunar soil heat storage tank for heat storage.

[0019] During lunar night, the high-temperature lunar soil particles in the lunar soil heat storage tank exchange heat with supercritical ammonia.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0021] The aforementioned technical solution provides a supercritical ammonia Rankine cycle thermal engine system based on lunar soil heat storage. Low-temperature lunar soil particles enter a particle receiver, where a concentrator array heats the particles to a high temperature. The high-temperature particles then enter a lunar soil heat storage tank to exchange heat with supercritical ammonia. The supercritical ammonia then enters a turbine to expand and perform work. The ammonia, after performing work, enters the hot fluid channel of a regenerator and is cooled into a gas-liquid coexisting ammonia state. This gas-liquid coexisting ammonia state then enters a radiant radiator to be cooled into liquid ammonia. The liquid ammonia state enters a pump for pressurization and then enters the cold fluid channel of the regenerator to exchange heat again, becoming supercritical ammonia. Finally, the supercritical ammonia enters the lunar soil heat storage tank again. The hot tank further exchanges heat to achieve circulation. The low-temperature lunar soil can be heated by a concentrating mirror array device and can be stored in the lunar soil heat storage tank. The gas-liquid coexisting ammonia can be dissipated through a radiant radiator. The heat storage and heat dissipation effects are both excellent, with high thermal efficiency, reducing the heat storage and heat dissipation requirements. In addition, the low-temperature lunar soil particles enter the particle receiver through high-pressure helium, reducing the overall mass. The lunar soil particles can be flexibly controlled in speed by entering the particle receiver through helium, resulting in a large temperature rise. Furthermore, by utilizing the low gravity characteristics of the lunar surface, the power consumption for transporting particles is significantly reduced compared to Earth. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a supercritical ammonia-ranken cycle thermal engine system based on lunar soil thermal storage, provided as an embodiment of the present invention.

[0023] 1. Lunar soil heat storage tank; 2. Particle receiver; 3. Turbine; 4. Regenerator; 5. Pump; 6. Radiant radiator; 7. Concentrating mirror array device; 8. Particle feeder; 9. Fluidized bed conveying device; 10. Particle separator; 11. Pressure tank; 12. Compressor; 13. AC motor. Detailed Implementation

[0024] The present invention will now be described in more detail with reference to the accompanying drawings. It should be noted that the following description of the present invention with reference to the accompanying drawings is merely illustrative and not restrictive. Various different embodiments can be combined with each other to form other embodiments not shown in the following description.

[0025] Please see Figure 1 The supercritical ammonia Rankine cycle thermal engine system based on lunar soil heat storage provided by the present invention includes a lunar soil heat storage tank 1, a particle receiver 2, a turbine 3, a regenerator 4, a pump 5, a radiant radiator 6, a concentrator array device 7, a particle feeder 8, a fluidized bed conveying device 9, a particle separator 10, a pressure tank 11, a compressor 12, and an AC motor 13.

[0026] The lunar soil heat storage tank 1 has a lunar soil storage chamber and an ammonia gas channel that are isolated from each other, and the boundary between the lunar soil storage chamber and the ammonia gas channel can be made of a material with good heat exchange performance. The lunar soil storage chamber is used to hold lunar soil particles. Specifically, lunar soil can be excavated and screened by an automated collection robot, and then quantitatively injected into the lunar soil storage chamber through a closed conveying system to complete the filling. The ammonia gas channel is used for the flow of supercritical ammonia, and the supercritical ammonia located in the ammonia gas channel can exchange heat with the lunar soil particles in the lunar soil storage chamber.

[0027] Crucially, during lunar daytime, lunar regolith particles store heat, but they do not exchange heat with ammonia. During lunar nighttime, however, the regolith particles cease heat storage and can exchange heat with ammonia. Therefore, the helium cycle operates during lunar daytime and ceases during lunar nighttime.

[0028] It is important to understand that ammonia, as the working fluid in a supercritical Rankine cycle, possesses several significant thermodynamic advantages: its compression work in the liquid state is minimal, resulting in a large net work output; its enthalpy drop is significant during expansion in the supercritical region, leading to ample energy release. More importantly, ammonia releases a large amount of latent heat of phase change upon entering the two-phase region after expansion, giving the regenerator a stronger heat exchange capacity. Therefore, the supercritical ammonia Rankine cycle maintains high thermal efficiency even under medium- and low-temperature heat source conditions, making it particularly suitable for the energy conversion needs of medium-temperature energy environments such as lunar geothermal storage.

[0029] The pellet feeder 8 is connected to the lower side of the lunar soil heat storage tank 1, so the low-temperature lunar soil particles after heat exchange can enter the pellet feeder 8. Specifically, the lunar soil particles can enter the front end of the pellet feeder 8 from the lunar soil heat storage tank 1 under the action of gravity. The fluidized bed conveying device 9 is connected to the pellet feeder 8, so the low-temperature lunar soil particles in the pellet feeder 8 can enter the fluidized bed conveying device 9. Specifically, the pellet feeder 8 can be a screw conveyor, which transports the low-temperature lunar soil particles in the pellet feeder 8 to the fluidized bed conveying device 9 by rotation. In addition, the outlet of the compressor 12 is connected to the lower side of the fluidized bed conveying device 9, so the high-pressure helium gas from the compressor 12 can drive the low-temperature lunar soil particles to move upward along the fluidized bed conveying device 9, ultimately causing the low-temperature lunar soil particles to enter the pellet receiver 2.

[0030] Specifically, the fluidized bed conveying device 9 may include a vertically arranged conveying pipe and a uniformly distributed gas plate located at the bottom of the pipe. By injecting fluidizing gas below the gas plate, a gas-solid two-phase flow is formed, achieving the suspension and lifting of lunar soil particles. The airflow lifts the particles from the bottom of the conveying pipe, conveys them upward along the conveying pipe, and finally delivers them to the particle receiver 2. The fluidized bed conveying device 9 has a simple structure, can adapt to the low gravity and vacuum environment of the moon, and effectively ensures the stable conveying of lunar soil particles and the transfer of heat energy.

[0031] The concentrator array 7 reflects and focuses sunlight onto the particle receiver 2, thereby increasing the temperature of the lunar regolith particles within the receiver 2. It is important to note that the particle receiver 2 contains both lunar regolith particles and helium. Helium exhibits excellent stability and will not react with the lunar regolith particles even when heated by the concentrator array 7. The concentrator array 7 achieves uniform heating, improves thermal efficiency, and reduces the need for complex heating structures.

[0032] The particle separator 10 can be connected to the upper side of the lunar soil heat storage tank 1. When the temperature of the lunar soil particles rises to a specified temperature, the high-temperature lunar soil particles and helium gas can enter the particle separator 10 together. Specifically, the particle separator 10 can be a cyclone separator, which separates the high-temperature lunar soil particles and helium gas by rotation. The high-temperature lunar soil particles fall along the inner wall of the particle separator 10 into the lunar soil heat storage tank 1 for heat exchange.

[0033] Helium gas is discharged from the center of particle separator 10 into pressure tank 11, and then enters pressure tank 11 through pipeline. It then enters compressor 12 for pressurization to form high-pressure helium gas, which then enters fluidized bed conveying device 9 for circulation.

[0034] In addition, the helium was assembled on Earth and launched to the moon along with the entire system.

[0035] After heat exchange in lunar soil storage tank 1, supercritical ammonia expands and performs work inside turbine 3, thereby driving turbine 3 to operate. Turbine 3 drives pump 5, which in turn drives AC motor 13 to generate electricity. This electricity can power the basic life support system of the lunar base and supply power to scientific instruments and communication equipment. In addition, fluidized bed conveying device 9, helium circulation, etc., only operate during lunar daytime and have low power consumption, so they can be powered by the equipped solar panels.

[0036] After exiting turbine 3, the ammonia enters the hot fluid channel of regenerator 4 for heat exchange and is cooled to a gaseous state. The gaseous ammonia is then cooled to a liquid state through radiant radiator 6. The liquid ammonia enters pump 5 for pressurization and then enters the cold fluid channel of regenerator 4 for heat exchange to become supercritical ammonia. The supercritical ammonia enters lunar soil heat storage tank 1 for further heat exchange and then enters turbine 3 again to expand and do work, thus completing one cycle.

[0037] In addition, it should be clear that since the lunar surface is a vacuum, heat cannot be dissipated through convection. Therefore, this invention uses radiative heat dissipation. The heat of the ammonia working fluid is quickly transferred to the radiative heat sink 6 through heat pipes. The radiative heat sink 6 dissipates heat through radiation by using its large surface area and the temperature difference with the environment.

[0038] In summary, the supercritical ammonia Rankine cycle thermal engine system based on lunar soil thermal storage provided in this embodiment includes a lunar soil particle cycle, an ammonia Rankine cycle, and a helium cycle, as detailed below:

[0039] Lunar soil particle circulation: Low-temperature lunar soil particles in lunar soil heat storage tank 1 first enter particle feeder 8, then enter particle receiver 2 via fluidized bed conveyor 9. Concentrating mirror array device 7 heats the low-temperature lunar soil particles, while the high-temperature particles enter particle separator 10 for separation. The separated high-temperature particles then enter lunar soil heat storage tank 1 for heat storage or exchange. The low-temperature lunar soil particles after heat exchange then re-enter particle feeder 8. It is important to note that during lunar daytime, the high-temperature lunar soil particles store heat in lunar soil heat storage tank 1 but do not exchange heat; during lunar nighttime, the high-temperature lunar soil particles do not store heat in lunar soil heat storage tank 1, but do exchange heat.

[0040] Ammonia Rankine Cycle: Supercritical ammonia enters turbine 3, expands and does work. The gaseous ammonia after doing work enters the hot fluid channel of regenerator 4 and is cooled into gas-liquid coexisting ammonia. The gas-liquid coexisting ammonia is cooled into liquid ammonia by radiant radiator 6. The liquid ammonia enters pump 5 for pressurization, and then enters the cold fluid channel of regenerator 4 for heat exchange to become supercritical ammonia. The supercritical ammonia enters lunar soil heat storage tank 1 for further heat exchange, and then enters turbine 3 again to expand and do work.

[0041] Helium circulation: High-pressure helium enters the fluidized bed conveying device 9 and conveys the low-temperature lunar soil particles to the particle receiver 2. Then, the helium and high-temperature lunar soil particles enter the particle separator 10 for separation. The separated helium first enters the pressure tank 11 and then enters the compressor 12 for compression to form high-pressure helium. The high-pressure helium then enters the fluidized bed conveying device 9 again to convey the low-temperature lunar soil particles.

[0042] This invention achieves direct and efficient thermal conversion of solar energy into lunar soil particles by dynamically introducing lunar soil particles into a fluidized bed conveying device 9 and using a concentrating mirror array device 7 to efficiently heat the particle receiver 2, significantly improving heat storage efficiency and temperature rise rate. The invention uses compressed helium to drive the circulation of lunar soil particles and incorporates a particle separator 10 to separate the helium from the high-temperature lunar soil particles, allowing the particles to continuously flow back to the lunar soil heat storage tank 1 for heat exchange. Compared to traditional static heat storage structures, this invention combines dynamic transport with directional heating, ensuring that the lunar soil particles are always in a highly efficient heating state, thus improving the overall heat storage capacity and dynamic response speed of the system. Furthermore, during lunar night, the heat stored in the lunar soil heat storage tank 1 can be used to generate electricity, solving the problem that existing technologies such as photovoltaic power generation cannot generate electricity during lunar night.

[0043] Meanwhile, the system innovatively constructs a Rankine cycle using supercritical ammonia as the working fluid. Through two-stage heating via regenerator 4 and lunar soil storage tank 1, the ammonia reaches a high-temperature, high-pressure supercritical state before entering turbine 3, significantly improving the enthalpy difference of the working fluid and the cycle efficiency. Combined with radiant radiator 6, the system can achieve closed-loop operation with working fluid condensation in the low-temperature vacuum environment of the moon, solving key technical bottlenecks of traditional power generation systems such as difficulty in heat dissipation on the lunar surface, low thermal efficiency, and complex energy conversion paths. It has advantages such as high efficiency, in-situ sustainability, and strong environmental adaptability.

[0044] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A supercritical ammonia Rankine cycle heat engine system based on lunar soil heat storage, characterized in that, It comprises: a lunar soil heat storage tank (1), a particle receiver (2), a turbine (3), a regenerator (4), a pump (5), a radiation radiator (6), a condenser array device (7); Lunar soil particle circulation: low-temperature lunar soil particles enter the particle receiver (2), the condenser array device (7) heats the lunar soil particles, and high-temperature lunar soil particles enter the lunar soil heat storage tank (1) for heat storage or heat exchange, and low-temperature lunar soil after heat exchange enters the particle receiver (2) for heating again; Ammonia Rankine cycle: supercritical ammonia enters the turbine (3) to expand and do work, and the gaseous ammonia after work enters the heat fluid channel of the regenerator (4) to cool to gas-liquid coexisting ammonia, and the gas-liquid coexisting ammonia enters the radiation radiator (6) to cool to liquid ammonia, and the liquid ammonia enters the pump (5) to pressurize, and then enters the cold fluid channel of the regenerator (4) to exchange heat to supercritical ammonia, and the supercritical ammonia enters the lunar soil heat storage tank (1) for further heat exchange, and then enters the turbine (3) to expand and do work again; Helium cycle: high-pressure helium transports low-temperature lunar soil particles into the particle receiver (2); It also comprises a fluidized bed conveying device (9) and a particle separator (10), and the high-temperature lunar soil particles in the particle receiver (2) first enter the particle separator (10) for separation, and then enter the lunar soil heat storage tank (1) for heat exchange; It also comprises a gas tank (11) and a compressor (12); Helium cycle: high-pressure helium enters the fluidized bed conveying device (9) and transports low-temperature lunar soil particles into the particle receiver (2), helium and high-temperature lunar soil particles enter the particle separator (10) together for separation, the separated helium first enters the gas tank (11), and then enters the compressor (12) for compression to form high-pressure helium, and the high-pressure helium enters the fluidized bed conveying device (9) to transport low-temperature lunar soil particles again.

2. The supercritical ammonia Rankine cycle heat engine system of claim 1, wherein, It also comprises a particle feeder (8), and the low-temperature lunar soil particles in the lunar soil heat storage tank (1) first enter the particle feeder (8), and then enter the particle receiver (2) through the fluidized bed conveying device (9).

3. The supercritical ammonia Rankine cycle heat engine system of claim 2, wherein, The lunar soil heat storage tank (1) has a lunar soil storage cavity and an ammonia gas channel which are isolated from each other, the high-temperature lunar soil particles separated by the particle separator (10) enter the upper part of the lunar soil storage cavity, and the lunar soil in the lower part of the lunar soil storage cavity enters the particle feeder (8); The supercritical ammonia from the cold fluid channel of the regenerator (4) enters the ammonia gas channel for heat exchange, and the heat-exchanged supercritical ammonia enters the turbine (3) for work again.

4. The supercritical ammonia Rankine cycle heat engine system of claim 1, wherein, The particle separator (10) is a cyclone separator, which separates high-temperature lunar soil particles and helium by rotation, the high-temperature lunar soil particles fall along the inner wall of the particle separator (10) to the lunar soil heat storage tank (1), and the helium is discharged along the center of the particle separator (10) to the gas tank (11).

5. The supercritical ammonia Rankine cycle heat engine system of claim 1 wherein, Also comprising an alternating current motor (13), supercritical ammonia enters the turbine (3) to expand and work, drives the turbine (3) to run, the turbine (3) drives the pump (5) to run, the pump (5) drives the alternating current motor (13) to generate electricity.

6. The supercritical ammonia Rankine cycle heat engine system of claim 1 wherein, During the lunar day, the lunar soil particles in the particle receiver (2) are heated into high-temperature lunar soil particles, and the high-temperature lunar soil particles enter the lunar soil heat storage tank (1) for heat storage. During the lunar night, the high-temperature lunar soil particles in the lunar soil heat storage tank (1) exchange heat with supercritical ammonia.

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