All-season CO2 life-suitable environment temperature maintaining system suitable for lunar cabin and control method of all-season CO2 life-suitable environment temperature maintaining system
By adopting a full-season CO2 life-suitable ambient temperature maintenance system in the lunar module, using lunar soil as a heat source/cold source, combined with CO2 circulation and energy storage technology, the challenge of temperature maintenance in the cabin under complex thermal environments on the lunar body is solved, and comfortable heat and cold management is achieved, reducing energy consumption.
Patent Information
- Application Number
- CN202510069861.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-16
- Publication Date
- 2025-04-11
AI Technical Summary
The moon's complex and variable thermal environment and huge day-night temperature differences make maintaining a safe temperature in the lunar module a major challenge, making it difficult to provide comfortable heat and cooling for human production and life.
The full-season CO2 life-suitable ambient temperature maintenance system, including CO2 circuits and energy storage systems, uses the deep and surface layers of the lunar soil as heat sources/cold sources, and switches the moon night and moon day cycle modes through compressors and CO2 working fluid pumps, and combines the PID controller and phase change energy storage module to achieve accurate heat and cold management.
Effectively maintain the internal temperature of the lunar module within a safe range, provide comfortable heat and cooling, reduce energy consumption, and ensure the thermal comfort of the lunar module and the smooth progress of production and life.
Smart Images
Figure CN119802875A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of refrigeration and heat pumps, and in particular relates to an all-season CO2 life-suitable environment temperature maintenance system applicable to a lunar module and a control method thereof. Background Art
[0002] Deep space exploration and lunar activities are inevitable trends in the future development of mankind. Humans are conducting relevant research on the construction of a lunar base. However, the moon has a complex and changeable thermal environment, and the atmosphere on the lunar surface is thin and close to a vacuum. Existing studies have shown that the lunar surface temperature near the lunar equator reaches a maximum of about 390 K at noon during the lunar day, and reaches a minimum of about 110 K during the lunar night, with a huge temperature difference between day and night.
[0003] In this drastic and hot environment, how to ensure that the internal temperature of the living module is within the range allowed for safe operation and provide comfortable heat and cooling for human production and life has become a major challenge facing research at this stage. Therefore, a new life-suitable environment temperature maintenance system suitable for the lunar module is urgently needed. Summary of the invention
[0004] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide an all-season CO2 life-suitable environment temperature maintenance system and a control method thereof suitable for the lunar module. The present invention can ensure that the internal temperature of the living module is within the range permitted for safe operation and provide comfortable heat and cooling for human production and life.
[0005] To achieve the above object, the present invention adopts the following technical solutions: A CO2 life-suitable environment temperature maintenance system suitable for an all-season lunar module comprises a CO2 circuit, wherein the CO2 circuit comprises a compressor, a CO2 working fluid pump, a lunar module heat exchanger, a lunar soil deep underground pipe heat exchanger and a gas-liquid separator, wherein the outlet of the compressor is provided with a lunar night circulation stop valve and is connected to a first heat exchange channel of the lunar module heat exchanger, and the air intake of the compressor is connected to the gas phase outlet of the gas-liquid separator; the inlet of the CO2 working fluid pump is connected to the liquid phase outlet of the gas-liquid separator, the outlet of the CO2 working fluid pump is provided with a lunar day circulation stop valve and is connected to the first heat exchange channel of the lunar module heat exchanger, the outlet of the first heat exchange channel of the lunar module heat exchanger is connected to the lunar soil deep underground pipe heat exchanger and an electronic expansion valve is provided on the connected pipeline, and the lunar soil deep underground pipe heat exchanger is connected to the inlet of the gas-liquid separator.
[0006] Preferably, the all-season CO2 life-suitable environment temperature maintenance system applicable to the lunar module of the present invention also includes an energy storage system, which includes a lunar module energy storage circulation heat exchanger, an electronic pump, a phase change energy storage module, a four-way reversing valve and a lunar soil surface buried pipe heat exchanger, the inlet and outlet of the first heat exchange channel of the lunar module energy storage circulation heat exchanger are respectively connected to the B port of the four-way reversing valve and the inlet of the electronic pump, the outlet of the electronic pump is connected to the phase change energy storage module, the outlet of the phase change energy storage module is connected to the D port of the four-way reversing valve and the inlet of the lunar soil surface buried pipe heat exchanger; the outlet of the lunar soil surface buried pipe heat exchanger is connected to the A port of the four-way reversing valve; the second heat exchange channel of the lunar module energy storage circulation heat exchanger is connected to the outlet of the fan.
[0007] Preferably, the all-season CO2 life-suitable environment temperature maintenance system applicable to the lunar module of the present invention also includes a first PID controller, a second PID controller and a third PID controller. The signal input end of the first PID controller is connected to the temperature detection unit of the air outlet of the lunar module heat exchanger, and the signal output end of the first PID controller is connected to the compressor for controlling the speed of the compressor; the signal input end of the second PID controller is connected to the temperature detection unit of the air outlet of the lunar module heat exchanger, and the signal output end of the second PID controller is connected to the CO2 working fluid pump for controlling the speed of the CO2 working fluid pump; the signal input end of the third PID controller is connected to the pressure detection unit at the compressor outlet, and the signal output end of the third PID controller is connected to the electronic expansion valve for controlling the opening of the electronic expansion valve.
[0008] Preferably, the lunar soil deep buried pipe heat exchanger is set at a depth of less than 2m from the lunar surface.
[0009] The present invention also provides a control method for the all-season CO2 life-suitable environment temperature maintenance system applicable to the lunar module as described above, including a moon night cycle and a moon day cycle, wherein the moon night cycle and the moon day cycle can be switched, wherein: In the moon-night cycle mode, the moon-night cycle stop valve is opened and the moon-day cycle stop valve is closed; the gaseous CO2 in the gas-liquid separator enters the compressor, and the high-temperature and high-pressure CO2 compressed by the compressor transmits heat to the lunar module through the heat exchanger in the lunar module, and then passes through the electronic expansion valve to throttle to a low-temperature and low-pressure two-phase state and enters the lunar soil deep buried pipe heat exchanger. The two-phase CO2 absorbs heat from the lunar soil through the lunar soil deep buried pipe heat exchanger and evaporates, and then returns to the compressor through the gas-liquid separator to complete the moon-night cycle; During the lunar day cycle mode, the lunar night cycle stop valve is closed and the lunar day cycle stop valve is opened; the liquid CO2 in the gas-liquid separator enters the CO2 working fluid pump, and the CO2 working fluid pump sends the liquid CO2 to the heat exchanger in the lunar module to absorb excess heat inside the lunar module. The liquid CO2 absorbs heat and evaporates through the heat exchanger in the lunar module to become high-dryness two-phase CO2 or CO2 superheated gas. At this time, the electronic expansion valve is fully open, and the high-dryness two-phase CO2 or CO2 superheated gas at the outlet of the heat exchanger in the lunar module is passed into the deep buried pipe heat exchanger in the lunar soil to dissipate heat to the low-temperature lunar soil, and then returns to the CO2 working fluid pump through the gas-liquid separator to complete the lunar day cycle.
[0010] Optimally, the thermal demand coefficient of the lunar module for cooling and heating as follows:
[0011] In the formula, is the solar radiation intensity, is the temperature inside the lunar module, , Set the temperature for the lunar module; when When the moon module needs to be heated, the moon night stop valve opens, and the CO2 circuit enters the moon night mode to provide heat for the moon module. when When , it means that the lunar module needs to be refrigerated. At this time, the lunar day shut-off valve opens, the compressor starts running, and the CO2 circuit enters the lunar day mode to provide cooling for the lunar module.
[0012] when When , it indicates that the lunar module is at a suitable temperature, and stops providing heat or cooling to the lunar module.
[0013] Preferably, when the all-season CO2 life-suitable environment temperature maintenance system for the lunar module as described above also includes the above-mentioned energy storage system, the control method includes an energy storage cycle, and the energy storage cycle uses the shallow soil on the lunar surface as a heat source or a cold source to store energy, specifically including: During the lunar day cycle, the A port and C port of the four-way reversing valve are connected, and the B port and D port are disconnected; the phase change energy storage material in the phase change energy storage module flows through the lunar soil surface buried pipe heat exchanger under the pumping of the electronic pump, and the phase change energy storage material exchanges heat with the high-temperature soil on the lunar surface and absorbs heat and heats up. The phase change energy storage material after absorbing heat and heating enters the phase change energy storage module to complete the heat storage cycle; During the lunar day cycle, port A and port C of the four-way reversing valve are connected, and port B and port D are disconnected; the phase change energy storage material flows through the lunar soil surface buried pipe heat exchanger under the pumping of the electronic pump, and the phase change energy storage material exchanges heat with the low-temperature soil on the lunar surface and releases heat and cools down. After releasing heat and cooling, the phase change energy storage material enters the phase change energy storage module to complete the cold storage cycle.
[0014] Preferably, based on the above solution, the control method of the present invention further includes an energy release mode, in which the cold or heat stored in the phase change energy storage module can be released, specifically including: During the lunar day cycle, the B port and the D port of the four-way reversing valve are connected, and the A port and the C port are disconnected. The low-temperature phase change energy storage material in the phase change energy storage module flows through the first heat exchange channel of the lunar module energy storage cycle heat exchanger, realizing the transfer of cold energy from the phase change energy storage material to the lunar module, and releasing the stored cold energy. During the lunar day cycle, the B port and the D port of the four-way reversing valve are connected, and the A port and the C port are disconnected. The high-temperature phase change energy storage material in the phase change energy storage module flows through the first heat exchange channel of the lunar module energy storage cycle heat exchanger, realizing the transfer of heat from the phase change energy storage material to the lunar module and releasing the stored heat.
[0015] Preferably, when the present invention is applicable to the all-season CO2 life-suitable environment temperature maintenance system of the lunar module as described above and further includes the above-mentioned first PID controller, second PID controller and third PID controller, the control method further includes the following process: In the lunar day cycle mode, the first PID controller and the second PID controller are turned off, and the third PID controller is turned on; in the lunar night cycle mode, the first PID controller and the second PID controller are turned on, and the third PID controller is turned off; During the lunar day cycle, the third PID controller is started. If the error between the lunar module air supply temperature and the set value satisfies that: the absolute value of the difference between the real-time collected lunar module air inlet temperature and the set value of the lunar module air inlet temperature is above the preset value, the speed of the CO2 working fluid pump is changed according to the calculation of the third PID controller; if the error between the lunar module air supply temperature and the set value satisfies that: the absolute value of the difference between the real-time collected cabin air inlet temperature and the set value of the cabin air inlet temperature is less than the preset value, the speed of the CO2 working fluid pump remains unchanged; During the moon-night cycle, the third PID controller is started to adjust the opening of the electronic expansion valve according to the difference between the optimal exhaust pressure of the compressor and the real-time exhaust pressure of the compressor. If the difference between the optimal exhaust pressure of the compressor and the real-time exhaust pressure of the compressor is above the preset value, the opening of the electronic expansion valve is changed according to the calculation of the third PID controller; if the difference between the optimal exhaust pressure of the compressor and the real-time exhaust pressure of the compressor is less than the preset value, the opening of the electronic expansion valve remains unchanged; After the third PID controller works for a preset time, the first PID controller is started. If the error between the lunar module air supply temperature and the set value satisfies: the absolute value of the difference between the real-time lunar module inlet air temperature and the set value of the lunar module inlet air temperature is above the preset value, the speed of the compressor is changed according to the calculation of the first PID controller; if the error between the lunar module air supply temperature and the set value satisfies: the absolute value of the difference between the real-time lunar module inlet air temperature and the set value of the lunar module inlet air temperature is less than the preset value, the speed of the compressor remains unchanged.
[0016] Preferably, the compressor optimal exhaust pressure Calculated by the following formula:
[0017] in, is the evaporation temperature, is the air inlet temperature of the heat exchanger in the lunar module, is the lunar ambient temperature; is the temperature inside the lunar module, , , , , is the empirical coefficient.
[0018] Compared with the prior art, the present invention has the following beneficial effects: The present invention is applicable to the all-season CO2 life-suitable environment temperature maintenance system of the lunar module, and a CO2 loop is provided, and a deep lunar soil ground-embedded pipe heat exchanger is provided in the CO2 loop, wherein the temperature of the deep lunar soil where the deep lunar soil ground-embedded pipe heat exchanger is located hardly changes with the alternation of day and night on the moon, and is basically maintained at -20°C, making it possible to apply the lunar module life-suitable environment temperature maintenance system with lunar soil as a heat source / heat sink. CO2 has excellent heating capacity, a wide range of adaptable temperature zones, a low standard boiling point, a large operating density, a large unit volume refrigeration capacity, easy miniaturization, a small low-temperature viscosity, good fluidity, and a large thermal conductivity, and is suitable as a working refrigerant for the lunar module ground-source heat pump. In the present invention, the moon-night cycle mode of CO2 can be realized by a compressor to heat the lunar module, so that the internal temperature of the lunar module is within the range permitted for safe operation; the moon-day cycle mode of CO2 can be realized by a CO2 working fluid pump to dissipate heat and cool the lunar module, so that the internal temperature of the lunar module is within the range permitted for safe operation. In summary, the present invention can ensure that the temperature inside the living cabin is within the permitted range for safe operation and provide comfortable heat and cooling for human production and life. It can be seen that the present invention has well solved the problem that the moon has a complex and changeable thermal environment, the temperature varies greatly between day and night, and the thermal management of the lunar cabin faces severe challenges. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art; obviously, the drawings described below are some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0020] Figure 1 Schematic diagram of an all-season CO2 life-suitable environment temperature maintenance system applicable to a lunar module in an embodiment of the present invention; Figure 2 is a flow chart of the moon-night cycle mode system in an embodiment of the present invention; Figure 3 is a flow chart of the lunar-day cycle mode system in an embodiment of the present invention; Figure 4 It is an integrated thermal management control system for maintaining a temperature of a CO2 life-suitable environment in all seasons for a lunar module in an embodiment of the present invention; Figure 5 This is a schematic diagram of the integrated thermal management system flow of the all-season CO2 life-suitable environment temperature maintenance system with energy storage in an embodiment of the present invention; Figure 6 This is a flow chart of the moon-night cycle + cold storage mode system in an embodiment of the present invention; Figure 7 This is a flow chart of the moon-night cycle + heat release mode system in an embodiment of the present invention; Figure 8 This is a flow chart of the lunar-day cycle + heat storage mode system in an embodiment of the present invention; Fig. 9 It is a flow chart of the lunar-day cycle + heat storage mode system in an embodiment of the present invention.
[0021] In the figure, 1. compressor; 2. CO2 working fluid pump; 3. heat exchanger in the lunar module; 4. electronic expansion valve; 5. deep underground pipe heat exchanger in the lunar soil; 6. gas-liquid separator; 7. lunar night circulation stop valve; 8. lunar day circulation stop valve; 9. fan; 10. lunar module energy storage circulation heat exchanger; 11. electronic pump; 12. phase change energy storage module; 13. four-way reversing valve; 14. lunar soil surface buried pipe heat exchanger. DETAILED DESCRIPTION
[0022] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.
[0023] See also Figure 1 The all-season CO2 life-suitable environment temperature maintenance system for the lunar module of this embodiment includes a CO2 circuit: the CO2 circuit includes a compressor 1, a CO2 working fluid pump 2, a heat exchanger 3 in the lunar module, an electronic expansion valve 4, a deep lunar soil buried pipe heat exchanger 5, a gas-liquid separator 6, a moon night cycle stop valve 7, a moon day mode stop valve 8, a fan 9, a lunar module and pipelines connecting various components; in the CO2 circuit, the outlet of the compressor 1 is connected to the first heat exchange channel of the heat exchanger 3 in the lunar module, and the air intake of the compressor 1 is connected to the gas phase outlet of the gas-liquid separator 6 ; The inlet of the CO2 working fluid pump 2 is connected to the liquid phase outlet of the gas-liquid separator 6, and the outlet of the CO2 working fluid pump 2 is connected to the first heat exchange channel of the heat exchanger 3 in the lunar module. The outlet of the first heat exchange channel of the heat exchanger 3 in the lunar module is connected to the deep lunar soil buried pipe heat exchanger 5 through the electronic expansion valve 4, and the deep lunar soil buried pipe heat exchanger 5 is connected to the inlet of the gas-liquid separator 6; the second heat exchange channel of the heat exchanger 3 in the lunar module is connected to the fan 9; the moon night cycle stop valve 7 and the moon day cycle stop valve 8 are used to switch the system's moon night cycle mode and moon day cycle mode.
[0024] This embodiment is applicable to the CO2 loop cycle of the all-season CO2 life-suitable environment temperature maintenance system of the lunar module. The CO2 loop cycle of the integrated thermal management system can be switched between the lunar night cycle and the lunar day cycle model. The specific working method of this embodiment is as follows: The moon-night cycle mode process is as follows Figure 2 As shown, when in the moon-night cycle mode, the moon-night cycle stop valve 7 is opened, the moon-day cycle stop valve 8 is closed, the compressor 1 is opened, and the CO2 working fluid pump 2 is closed; the gaseous CO2 in the gas-liquid separator 6 enters the compressor 1, and the high-temperature and high-pressure CO2 fluid compressed by the compressor 1 enters the heat exchanger 3 in the lunar module, and the heat exchanger 3 in the lunar module exchanges heat with the air blown in by the fan 9, transports heat to the lunar module, and heats the air in the lunar module. The CO2 fluid in the heat exchanger 3 in the lunar module after releasing heat passes through the electronic expansion valve 4 and is throttled to a low-temperature and low-pressure two-phase state, and then enters the deep buried pipe heat exchanger 5 in the lunar soil, and enters the gas-liquid separator 6 after absorbing heat and evaporating from the deep lunar soil (the temperature is basically maintained at -10°C, and does not change with the change of moon day and moon night), and performs gas-liquid separation. The separated gaseous CO2 enters the air intake of the compressor 1, completing the entire moon-night cycle; The lunar day cycle mode process is as follows Figure 3As shown, in the lunar day cycle mode, the lunar day cycle stop valve 8 is opened, the lunar night cycle stop valve 7 is closed, the compressor 1 is closed, the CO2 working fluid pump 2 is opened, and the electronic expansion valve 4 is fully opened; the low-temperature CO2 liquid (i.e., the liquid phase CO2 working fluid inlet) inside the gas-liquid separator 6 is pumped by the CO2 working fluid pump 2 and enters the heat exchanger 3 in the lunar module for heat exchange, and the low-temperature CO2 fluid exchanges heat with the relatively high-temperature cabin air, absorbing the excess heat inside the lunar module, and the liquid phase CO2 absorbs heat and evaporates It becomes high-dryness two-phase CO2 or CO2 superheated gas, bringing coldness to the lunar module; the heated CO2 fluid (high-dryness two-phase CO2 or CO2 superheated gas) passes through the outlet of the lunar module heat exchanger 3 and the fully opened electronic expansion valve 4 without throttling, and directly enters the deep underground pipe heat exchanger 5 of the lunar soil, exchanges heat with the low-temperature lunar soil, and dissipates heat to the lunar soil. After the heat exchange is completed, the low-temperature CO2 fluid enters the gas-liquid separator 6, and the liquid phase enters the CO2 working fluid pump 2, completing the lunar day cycle; A further improvement of the present invention is that the heat exchange between lunar soil and CO2 working medium is carried out in the form of buried pipes; Furthermore, the temperature of the lunar soil below a depth of 2m from the lunar surface is basically maintained at -20°C. In the lunar night mode, the low-temperature and low-pressure CO2 after throttling by the electronic expansion valve 4 absorbs heat and evaporates from the relatively high-temperature lunar soil, realizing the heat transfer process from the relatively high-temperature lunar soil to the interior of the lunar module that needs heat; in the lunar day mode, the lunar surface temperature can be as high as 390K, and the liquid CO2 working fluid absorbs heat from the relatively high-temperature heat exchanger in the lunar module. The high-dryness two-phase CO2 or CO2 superheated gas is directly pumped into the lunar soil buried pipe heat exchanger through the CO2 working fluid pump 2 to release heat to the low-temperature lunar soil, realizing the refrigeration function of the interior of the lunar module; In the embodiment of the present invention, the heat demand coefficient is defined as :
[0025] In the formula, is the solar radiation intensity, is the temperature inside the lunar module, is the lunar ambient temperature, Set the temperature for the lunar module; The current temperature state of the lunar module and the future temperature change trend are taken into consideration, which is suitable as the judgment condition for the heating and cooling demand of the lunar module; When , it indicates that the lunar module needs to be heated. At this time, the moon night stop valve 8 is opened, and the CO2 circuit enters the moon night mode to provide heat for the lunar module; When , it means that the lunar module needs to be refrigerated. At this time, the lunar day stop valve 7 is opened, the compressor 1 starts to run, and the CO2 circuit enters the lunar day mode to provide cooling for the lunar module; when When , it indicates that the lunar module is at a suitable temperature, and stops providing heat or cooling to the lunar module.
[0026] On the basis of the above scheme, the present invention can also be provided with the following devices for control, including: The moon-night cycle lunar module air supply temperature PID controller is recorded as the first PID controller. The first PID controller is turned on in the moon-night cycle mode, and the input is the moon module air supply temperature , the output is the speed of the compressor 1; specifically, the signal input end of the first PID controller is connected to the temperature detection unit of the air outlet of the lunar module heat exchanger 3, and the signal output end of the first PID controller is connected to the compressor for controlling the speed of the compressor; The lunar module air supply temperature PID controller for the lunar day cycle is recorded as the second PID controller. The second PID controller is turned on in the lunar day cycle mode, and the input is the lunar module air supply temperature , the output is the speed of the CO2 working fluid pump; specifically, the signal input end of the second PID controller is connected to the temperature detection unit of the air outlet of the lunar module heat exchanger 3, and the signal output end of the second PID controller is connected to the CO2 working fluid pump to control the speed of the CO2 working fluid pump; The compressor exhaust pressure PID controller is recorded as the third PID controller. The third PID controller is turned on in the moon-night cycle mode, and the input is the compressor exhaust pressure , the output is the opening of the electronic expansion valve; specifically, the signal input end of the third PID controller is connected to the pressure detection unit at the compressor outlet, and the signal output end of the third PID controller is connected to the electronic expansion valve for controlling the opening of the electronic expansion valve.
[0027] In the moon-day cycle mode, the first PID controller and the second PID controller are turned off, and the third PID controller is turned on; in the moon-night cycle mode, the first PID controller and the second PID controller are turned on, and the third PID controller is turned off; During the lunar day cycle, the third PID controller is started. If the error between the lunar module air supply temperature and the set value satisfies that: the absolute value of the difference between the real-time collected lunar module air inlet temperature and the set value of the lunar module air inlet temperature is above the preset value, the speed of the CO2 working fluid pump is changed according to the calculation of the third PID controller; if the error between the lunar module air supply temperature and the set value satisfies that: the absolute value of the difference between the real-time collected cabin air inlet temperature and the set value of the cabin air inlet temperature is less than the preset value, the speed of the CO2 working fluid pump remains unchanged; During the moon-night cycle, the third PID controller is started, and the control system adjusts the opening of the electronic expansion valve according to the difference between the optimal exhaust pressure of the compressor and the real-time exhaust pressure of the compressor. If the difference between the optimal exhaust pressure of the compressor and the real-time exhaust pressure of the compressor is above the preset value, the opening of the electronic expansion valve is changed according to the calculation of the third PID controller; if the difference between the optimal exhaust pressure of the compressor and the real-time exhaust pressure of the compressor is less than the preset value, the opening of the electronic expansion valve remains unchanged; After the third PID controller works for a preset time, the first PID controller is started. If the error between the lunar module air supply temperature and the set value satisfies: the absolute value of the difference between the lunar module air inlet temperature collected in real time and the set value of the lunar module air inlet temperature is above the preset value, the compressor speed is changed according to the calculation of the first PID controller; if the error between the lunar module air supply temperature and the set value satisfies: the absolute value of the difference between the lunar module air inlet temperature collected in real time and the set value of the lunar module air inlet temperature is less than the preset value, the compressor speed remains unchanged; Among them, the target value of the third PID controller is the optimal exhaust pressure of the transcritical CO2 system compressor 1; the optimal exhaust pressure as follows:
[0028]
[0029] In the formula, is the evaporation temperature, is the air inlet temperature of the lunar module, is the lunar ambient temperature; is the temperature inside the lunar module, , , , , is the empirical coefficient; On the basis of the above scheme, the present invention can also add a phase change energy storage circuit to realize energy storage and release. The phase change energy storage circuit includes: a lunar module energy storage cycle heat exchanger 10, an electronic pump 11, a phase change energy storage module 12, a four-way reversing valve 13, and a lunar soil surface buried pipe heat exchanger 14; the outlet of the electronic pump 11 is connected to the phase change energy storage module 12, and the outlet of the phase change energy storage module is respectively connected to the D port of the four-way reversing valve 13 and the inlet of the lunar soil surface buried pipe heat exchanger 14; the outlet of the lunar soil surface buried pipe heat exchanger 14 is connected to the A port of the four-way reversing valve 13; the inlet and outlet of the first heat exchange channel of the lunar module energy storage cycle heat exchanger 10 are respectively connected to the B port of the four-way reversing valve 13 and the inlet of the electronic pump 11; the second heat exchange channel of the lunar module energy storage cycle heat exchanger is connected to the outlet of the fan 9; The phase change energy storage loop can store energy with the shallow soil on the lunar surface as a heat source or a cold source. After adding the energy storage loop, the energy release mode can be realized, and the cold or heat stored in the phase change energy storage module 12 can be released, and the CO2 loop can be used to release cold and store heat during the lunar day cycle, and release heat and store cold during the lunar night cycle, and assist the CO2 circulation loop to perform thermal management on the lunar module. Specifically, the energy storage type all-season CO2 life suitable environment temperature maintenance system applicable to the lunar module in this embodiment works as follows: The process of the moon night cold storage mode is as follows Figure 6 As shown, when in the moon night cold storage mode, the moon night circulation stop valve 7 of the CO2 loop is opened, the moon day circulation stop valve 8 is closed, the compressor 1 is turned on, and the CO2 working fluid pump 2 is turned off; the A port and the C port of the coolant loop four-way reversing valve 13 are connected, the B port and the D port are disconnected, and the electronic pump 11 is turned on; the phase change material in the phase change energy storage module 12 enters the lunar soil surface buried pipe heat exchanger 14 under the action of the electronic pump 11 to exchange heat with the low-temperature surface lunar soil, and the obtained low-temperature phase change material is stored in the phase change energy storage module 12 to complete the moon night cold storage cycle; The process of the moon night heat release mode is as follows Figure 7 As shown, when in the moon night heat release mode, the moon night circulation stop valve 7 of the CO2 loop is opened, the moon day circulation stop valve 8 is closed, the compressor 1 is turned on, and the CO2 working fluid pump 2 is turned off; the A port and the C port of the coolant loop four-way reversing valve 13 are disconnected, the B port and the D port are connected, and the electronic pump 11 is turned on; the high-temperature phase change material pump in the phase change energy storage module 12 is driven to enter the lunar module energy storage cycle heat exchanger 10, and heat is exchanged with the relatively low-temperature air in the cabin blown out by the fan 9, which plays a role in preheating the air, and increases the temperature of the air exchanged with the CO2 in the heat exchanger 3 in the lunar module, thereby improving the system energy consumption and completing the moon night heat release cycle; The process of the lunar daytime heat storage mode is as follows Figure 8 As shown, when in the lunar day mode, the lunar day cycle stop valve 8 of the CO2 loop is opened, the lunar night cycle stop valve 7 is closed, the compressor 1 is closed, the CO2 working fluid pump 2 is turned on, and the electronic expansion valve 4 is fully opened; the A port and the C port of the coolant loop four-way reversing valve 13 are connected, the B port and the D port are disconnected, and the electronic pump 11 is turned on; the phase change material in the phase change energy storage module 12 enters the lunar soil surface buried pipe heat exchanger 14 driven by the electronic pump 11 to exchange heat with the high-temperature surface lunar soil, and the obtained high-temperature phase change material is stored in the phase change energy storage module 12 to complete the lunar day heat storage cycle; The process of the lunar day cooling mode is as follows Fig. 9As shown, when in the lunar day mode, the lunar day cycle stop valve 8 of the CO2 loop is opened, the lunar night cycle stop valve 7 is closed, the compressor 1 is closed, the CO2 working fluid pump 2 is turned on, and the electronic expansion valve 4 is fully opened; the A port and the C port of the coolant loop four-way reversing valve 13 are disconnected, the B port and the D port are connected, and the electronic pump 11 is turned on; the high-temperature phase change material in the phase change energy storage module 12 enters the lunar module energy storage cycle heat exchanger 10 under the drive of the electronic pump 11, and exchanges heat with the relatively high-temperature air in the cabin blown out by the fan 9, which plays a role in precooling the air, reduces the temperature of the air exchanged with CO2 in the heat exchanger 3 in the lunar module, and completes the lunar day cooling cycle; It can be seen from the above scheme that the present invention solves the problem of ensuring that the internal temperature of the living module is within the permitted range of safe operation on the moon where the temperature difference between day and night is huge, and providing comfortable heat and cold for human production and life. The combined switching of the lunar day and lunar night modes realizes the rapid and accurate distribution of heat and cold in the lunar day and lunar night environments, and proposes a thermal management system with energy storage, which utilizes the heat and cold of the lunar soil surface, reduces the energy consumption of the lunar module life-suitable environment temperature maintenance system, and ensures the thermal comfort in the lunar module and the smooth progress of the lunar module production and life. In addition, by setting the first PID controller, the second PID controller, and the third PID controller, the system dynamically adjusts the compressor speed and the opening of the electronic expansion valve according to the set lunar module air supply temperature while ensuring the normal exhaust temperature; at the same time, according to the optimal exhaust pressure empirical formula, the exhaust pressure of the system is controlled to the optimal value to improve the energy consumption ratio of the system; at the same time, a set of energy storage cycles based on the coolant circuit is proposed, which can store heat and cold during the lunar day and lunar night, and generate cold and release heat during the lunar night and lunar day, and assist the CO2 circulation circuit to perform efficient and accurate thermal management of the lunar module; a heat demand index is proposed to indicate the lunar module's perception of the demand for cold and heat, and by collecting operating and external operating parameters such as the lunar module temperature, ambient temperature, and solar radiation intensity, the current state of the system is judged, and then the thermal management system is adjusted to automatically adapt to the cold and heat needs of the lunar module.
[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A CO2 life-suitable environment temperature maintenance system for all seasons in a lunar module, characterized in that: The invention comprises a CO2 circuit, which comprises a compressor (1), a CO2 working fluid pump (2), a lunar module heat exchanger (3), a lunar soil deep underground pipe heat exchanger (5) and a gas-liquid separator (6). The outlet of the compressor (1) is provided with a lunar night circulation stop valve (7) and is connected to a first heat exchange channel of the lunar module heat exchanger (3). The air intake of the compressor (1) is connected to a gas phase outlet of the gas-liquid separator (6). The inlet of the CO2 working fluid pump (2) is connected to a liquid phase outlet of the gas-liquid separator (6). The outlet of the CO2 working fluid pump (2) is provided with a lunar day circulation stop valve (8) and is connected to the first heat exchange channel of the lunar module heat exchanger (3). The outlet of the first heat exchange channel of the lunar module heat exchanger (3) is connected to the lunar soil deep underground pipe heat exchanger (5), and an electronic expansion valve (4) is provided on the connected pipeline. The lunar soil deep underground pipe heat exchanger (5) is connected to the inlet of the gas-liquid separator (6).
2. The all-season CO2 life-suitable environment temperature maintenance system for the lunar module according to claim 1, characterized in that: It also comprises an energy storage system, the energy storage system comprising a lunar module energy storage cycle heat exchanger (10), an electronic pump (11), a phase change energy storage module (12), a four-way reversing valve (13) and a lunar soil surface buried pipe heat exchanger (14); the inlet and outlet of a first heat exchange channel of the lunar module energy storage cycle heat exchanger (10) are respectively connected to the B port of the four-way reversing valve (14) and the inlet of the electronic pump (11); the outlet of the electronic pump (11) is connected to the phase change energy storage module (12); the outlet of the phase change energy storage module (12) is connected to the D port of the four-way reversing valve (13) and the inlet of the lunar soil surface buried pipe heat exchanger (14); the outlet of the lunar soil surface buried pipe heat exchanger (14) is connected to the A port of the four-way reversing valve (13); and the second heat exchange channel of the lunar module energy storage cycle heat exchanger (10) is connected to the outlet of the fan (9).
3. The all-season CO2 life-suitable environment temperature maintenance system for the lunar module according to claim 1, characterized in that: The system also comprises a first PID controller, a second PID controller and a third PID controller, wherein the signal input end of the first PID controller is connected to a temperature detection unit at an air outlet of a lunar module heat exchanger (3), and the signal output end of the first PID controller is connected to a compressor (1) for controlling the rotation speed of the compressor (1); the signal input end of the second PID controller is connected to the temperature detection unit at the air outlet of the lunar module heat exchanger (3), and the signal output end of the second PID controller is connected to a CO2 working fluid pump (2) for controlling the rotation speed of the CO2 working fluid pump (2); the signal input end of the third PID controller is connected to a pressure detection unit at an outlet of the compressor (1), and the signal output end of the third PID controller is connected to an electronic expansion valve (4) for controlling the opening degree of the electronic expansion valve (4).
4. The all-season CO2 life-suitable environment temperature maintenance system for the lunar module according to claim 1, characterized in that: The lunar soil deep layer buried pipe heat exchanger (5) is arranged at a depth of less than 2 m from the lunar surface.
5. A control method for maintaining a CO2 life-suitable environment temperature in all seasons for a lunar module according to any one of claims 1 to 4, characterized in that: Including moon night cycle and moon day cycle, moon night cycle and moon day cycle can be switched, among which: In the moon-night cycle mode, the moon-night cycle stop valve (7) is opened and the moon-day cycle stop valve (8) is closed; the gaseous CO2 in the gas-liquid separator (6) enters the compressor (1); the high-temperature and high-pressure CO2 compressed by the compressor (1) transmits heat to the moon cabin through the heat exchanger (3) in the moon cabin, and then passes through the electronic expansion valve (4) to be throttled to a low-temperature and low-pressure two-phase state and enters the moon soil deep buried pipe heat exchanger (5); the two-phase CO2 absorbs heat from the moon soil through the moon soil deep buried pipe heat exchanger (5) and evaporates, and then passes through the gas-liquid separator (6) and returns to the compressor (1), completing the moon-night cycle; In the lunar day cycle mode, the lunar night cycle stop valve (7) is closed and the lunar day cycle stop valve (8) is opened; the liquid CO2 in the gas-liquid separator (6) enters the CO2 working fluid pump (2), and the CO2 working fluid pump (2) sends the liquid CO2 to the heat exchanger (3) in the lunar module to absorb excess heat inside the lunar module. The liquid CO2 absorbs heat and evaporates through the heat exchanger (3) in the lunar module to become high-dryness two-phase CO2 or CO2 superheated gas. At this time, the electronic expansion valve (4) is fully open, and the high-dryness two-phase CO2 or CO2 superheated gas at the outlet of the lunar module heat exchanger (3) is passed into the lunar soil deep buried pipe heat exchanger (5) to dissipate heat to the low-temperature lunar soil, and then returns to the CO2 working fluid pump (2) through the gas-liquid separator (6), completing the lunar day cycle.
6. The control method of the all-season CO2 life-suitable environment temperature maintenance system applicable to the lunar module according to claim 5 is characterized in that: Thermal demand coefficients of the lunar module for cooling and heating as follows: In the formula, is the solar radiation intensity, is the temperature inside the lunar module, is the lunar ambient temperature, Set the temperature for the lunar module; when When , it indicates that the lunar module needs to be heated. At this time, the moon night stop valve (8) opens, and the CO2 circuit enters the moon night mode to provide heat for the lunar module; when When , it indicates that the lunar module needs to be refrigerated. At this time, the lunar day stop valve (7) opens, the compressor (1) starts to run, and the CO2 circuit enters the lunar day mode to provide cooling for the lunar module; when When , it indicates that the lunar module is at a suitable temperature, and stops providing heat or cooling to the lunar module.
7. The control method of the all-season CO2 life-suitable environment temperature maintenance system applicable to the lunar module according to claim 5 is characterized in that: The all-season CO2 life-suitable environment temperature maintenance system for the lunar module also includes an energy storage system, the energy storage system including a lunar module energy storage cycle heat exchanger (10), an electronic pump (11), a phase change energy storage module (12), a four-way reversing valve (13) and a lunar soil surface buried pipe heat exchanger (14), wherein the inlet and outlet of the first heat exchange channel of the lunar module energy storage cycle heat exchanger (10) are respectively connected to the B port of the four-way reversing valve (14) and the electronic pump (11). The inlet of the lunar module is connected to the inlet of the electronic pump (11), the outlet of the electronic pump (11) is connected to the phase change energy storage module (12), the outlet of the phase change energy storage module (12) is connected to the D port of the four-way reversing valve (13) and the inlet of the lunar soil surface buried pipe heat exchanger (14); the outlet of the lunar soil surface buried pipe heat exchanger (14) is connected to the A port of the four-way reversing valve (13); the second heat exchange channel of the lunar module energy storage cycle heat exchanger (10) is connected to the outlet of the fan (9); The control method includes an energy storage cycle, wherein the energy storage cycle uses the shallow soil on the lunar surface as a heat source or a cold source to store energy, specifically including: During the lunar day cycle, the A port and the C port of the four-way reversing valve (13) are connected, and the B port and the D port are disconnected; the phase change energy storage material in the phase change energy storage module (12) flows through the lunar soil surface buried pipe heat exchanger (14) under the pumping of the electronic pump (11), and the phase change energy storage material exchanges heat with the high-temperature soil on the lunar surface and absorbs heat to increase its temperature. After absorbing heat and increasing its temperature, the phase change energy storage material enters the phase change energy storage module (12), completing the heat storage cycle; During the lunar day cycle, the A port and the C port of the four-way reversing valve (13) are connected, and the B port and the D port are disconnected; the phase change energy storage material flows through the lunar soil surface buried pipe heat exchanger (14) under the pumping of the electronic pump (11), and the phase change energy storage material exchanges heat with the low-temperature soil on the lunar surface and releases heat to cool down. After releasing heat and cooling down, the phase change energy storage material enters the phase change energy storage module (12), completing the cold storage cycle.
8. The control method of the all-season CO2 life-suitable environment temperature maintenance system applicable to the lunar module according to claim 7 is characterized in that: It also includes an energy release mode, in which the cold or heat stored in the phase change energy storage module (12) can be released, specifically including: During the lunar day cycle, the B port and the D port of the four-way reversing valve (13) are connected, and the A port and the C port are disconnected, and the low-temperature phase change energy storage material in the phase change energy storage module (12) flows through the first heat exchange channel of the lunar module energy storage cycle heat exchanger (10), thereby realizing the transfer of cold energy from the phase change energy storage material to the lunar module, and releasing the stored cold energy; During the lunar day cycle, the B port and the D port of the four-way reversing valve (13) are connected, and the A port and the C port are disconnected, and the high-temperature phase change energy storage material in the phase change energy storage module (12) flows through the first heat exchange channel of the lunar module energy storage cycle heat exchanger (10), thereby realizing the transfer of heat from the phase change energy storage material to the lunar module and releasing the stored heat.
9. The control method of the all-season CO2 life-suitable environment temperature maintenance system applicable to the lunar module according to claim 5 is characterized in that: The all-season CO2 life-suitable environment temperature maintenance system suitable for a lunar module also includes a first PID controller, a second PID controller and a third PID controller, wherein a signal input end of the first PID controller is connected to a temperature detection unit at an air outlet of a lunar module heat exchanger (3), and a signal output end of the first PID controller is connected to a compressor (1) for controlling the rotation speed of the compressor (1); a signal input end of the second PID controller is connected to a temperature detection unit at an air outlet of the lunar module heat exchanger (3), and a signal output end of the second PID controller is connected to a CO2 working fluid pump (2) for controlling the rotation speed of the CO2 working fluid pump (2); a signal input end of the third PID controller is connected to a pressure detection unit at an outlet of the compressor (1), and a signal output end of the third PID controller is connected to an electronic expansion valve (4) for controlling the opening degree of the electronic expansion valve (4); The control method further comprises: In the lunar day cycle mode, the first PID controller and the second PID controller are turned off, and the third PID controller is turned on; in the lunar night cycle mode, the first PID controller and the second PID controller are turned on, and the third PID controller is turned off; During the lunar day cycle, the third PID controller is started. If the error between the lunar module air supply temperature and the set value satisfies that: the absolute value of the difference between the lunar module air inlet temperature collected in real time and the set value of the lunar module air inlet temperature is greater than a preset value, the rotation speed of the CO2 working fluid pump (2) is changed according to the calculation of the third PID controller; if the error between the lunar module air supply temperature and the set value satisfies that: the absolute value of the difference between the cabin air inlet temperature collected in real time and the set value of the cabin air inlet temperature is less than a preset value, the rotation speed of the CO2 working fluid pump (2) is maintained unchanged; During the moon-night cycle, the third PID controller is started to adjust the opening of the electronic expansion valve (4) according to the difference between the optimal exhaust pressure of the compressor (1) and the real-time exhaust pressure of the compressor (1); if the difference between the optimal exhaust pressure of the compressor (1) and the real-time exhaust pressure of the compressor (1) is greater than a preset value, the opening of the electronic expansion valve (4) is changed according to the calculation of the third PID controller; if the difference between the optimal exhaust pressure of the compressor (1) and the real-time exhaust pressure of the compressor (1) is less than the preset value, the opening of the electronic expansion valve (4) remains unchanged; After the third PID controller has been operating for a preset time, the first PID controller is started. If the error between the lunar module air supply temperature and the set value satisfies that: the absolute value of the difference between the lunar module air inlet temperature collected in real time and the set value of the lunar module air inlet temperature is greater than a preset value, the speed of the compressor (1) is changed according to the calculation of the first PID controller; if the error between the lunar module air supply temperature and the set value satisfies that: the absolute value of the difference between the lunar module air inlet temperature collected in real time and the set value of the lunar module air inlet temperature is less than a preset value, the speed of the compressor (1) is maintained unchanged.
10. The control method of the all-season CO2 life-suitable environment temperature maintenance system applicable to the lunar module according to claim 5, characterized in that: Optimum exhaust pressure of compressor (1) Calculated by the following formula: in, is the evaporation temperature, is the air inlet temperature of the heat exchanger in the lunar module, is the lunar ambient temperature; is the temperature inside the lunar module, , , , , is the empirical coefficient.
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