Geothermal energy storage system

Abstract

This application relates to a geothermal energy storage system. A geothermal extraction device is used to extract geothermal energy. A first heat exchange device includes a first heat-releasing module and a first heat-absorbing module capable of heat exchange. The first heat-releasing module is connected to the geothermal extraction device and is used to transfer geothermal energy to a first working fluid in the first heat-absorbing module. The inlet of a compressor is connected to the outlet of the first heat-absorbing module, and the compressor is used to pressurize the first working fluid. A heat storage device is connected to the outlet of the compressor and is used to store the heat of the first working fluid. The inlet of a first expander is connected to the heat storage device, and the first expander is used to cool and depressurize the first working fluid. The first expander is driven by the compressor. A cold storage device is connected to the outlet of the first expander and is used to store the cold energy of the first working fluid. The inlet of the first heat-absorbing module is connected to the cold storage device. Compared with traditional technologies, this system effectively improves the utilization efficiency of geothermal energy.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a geothermal energy storage system. Background Technology

[0002] Geothermal energy is a renewable energy source that is abundant, stable, reliable, clean, and pollution-free. It has irreplaceable advantages in long-term energy storage and grid peak shaving, and has become a research hotspot and development focus in the energy field.

[0003] In traditional technologies, geothermal energy storage systems primarily utilize geothermal water extracted from geothermal wells for heat exchange, and then return the exchanged geothermal water to the wells, repeating this process to extract and store heat. However, this operating mode suffers from significant heat loss, reducing the utilization efficiency of geothermal energy and hindering the full realization of its resource advantages. Summary of the Invention

[0004] Therefore, it is necessary to provide a geothermal energy storage system to address the problem that traditional geothermal energy storage systems suffer from severe heat loss, which reduces the utilization efficiency of geothermal energy.

[0005] The technical solution is as follows: A geothermal energy storage system, comprising: A geothermal extraction device, wherein the geothermal extraction device is used to extract geothermal energy; The first heat exchange device includes a first heat release module and a first heat absorption module capable of heat exchange. The first heat release module is connected to the geothermal extraction device and is used to transfer geothermal energy to a first working fluid in the first heat absorption module. The compressor has its inlet connected to the outlet of the first heat absorption module, and the compressor is used to pressurize the first working fluid. A heat storage device, which is connected to the outlet of the compressor, is used to store the heat of the first working fluid; A first expander, the inlet of which is connected to the heat storage device, is used to cool and depressurize the first working fluid, and is driven by the compressor; and A cold storage device is connected to the outlet of the first expander and is used to store the cold energy of the first working fluid. The inlet of the first heat absorption module is connected to the cold storage device.

[0006] In the aforementioned geothermal energy storage system, geothermal energy collected by the geothermal extraction device is transferred from the first heat release module to the first working fluid in the first heat absorption module, raising the temperature of the working fluid. The heated working fluid then enters the compressor through the compressor inlet, where it is pressurized and further heated before being discharged into the heat storage device, thus storing the heat. The working fluid, having completed its heat release, then enters the first expander, where it is cooled and depressurized. The work output by the first expander in cooling and depressurizing the working fluid is transferred to the compressor, effectively reducing the energy consumption of the compressor during the pressurization process. Subsequently, the working fluid is discharged from the first expander outlet to a cold storage device, transferring its own cooling capacity to the cold storage device for storage, ultimately achieving simultaneous storage and utilization of both heat and cold energy. Compared to traditional technologies, this geothermal energy storage system utilizes the work done by the first expander to feed back to the compressor, reducing energy consumption during the pressurization of the working fluid, and simultaneously storing both heat and cold energy, avoiding energy waste and effectively improving the utilization efficiency of geothermal energy.

[0007] In one embodiment, the geothermal energy storage system further includes a second heat exchange device, which includes a second heat release module and a second heat absorption module capable of heat exchange. The inlet of the second heat release module is connected to the heat storage device, the outlet of the second heat release module is connected to the inlet of the first expander, the inlet of the second heat absorption module is connected to the outlet of the first heat absorption module, and the outlet of the second heat absorption module is connected to the compressor.

[0008] In one embodiment, the geothermal energy storage system further includes a third heat exchange device and a power generation device. The third heat exchange device includes a third heat release module and a third heat absorption module capable of heat exchange. The inlet of the third heat release module is connected to the heat storage device, and the outlet of the third heat absorption module is connected to the power generation device.

[0009] In one embodiment, the geothermal energy storage system further includes a fourth heat exchange device, which includes a fourth heat release module and a fourth heat absorption module capable of heat exchange. The inlet of the fourth heat release module is connected to the geothermal extraction device, and the fourth heat release module is used to transfer geothermal energy to a second working fluid in the fourth heat absorption module. The inlet of the fourth heat absorption module is connected to the power generation device, and the outlet of the fourth heat absorption module is connected to the inlet of the third heat absorption module.

[0010] In one embodiment, the geothermal energy storage system further includes a fifth heat exchange device, which includes a fifth heat absorption module and a fifth heat release module capable of heat exchange. The inlet of the fifth heat absorption module is connected to the cold storage device, the inlet of the fifth heat release module is connected to the outlet of the power generation device, and the outlet of the fifth heat release module is connected to the inlet of the fourth heat absorption module.

[0011] In one embodiment, the power generation device includes a second expander and a generator. The inlet of the second expander is connected to the outlet of the third heat absorption module, and the outlet of the second expander is connected to the fifth heat release module. The second expander is used to cool and depressurize the second working fluid, and the generator is driven by the second expander.

[0012] In one embodiment, the geothermal energy storage system further includes a sixth heat exchange device, which includes a sixth heat release module and a sixth heat absorption module capable of heat exchange. The inlet of the sixth heat release module is connected to the heat storage device. The power generation device further includes a third expander connected to a generator drive. The inlet of the sixth heat absorption module is connected to the outlet of the second expander, and the outlet of the sixth heat absorption module is connected to the inlet of the third expander. The outlet of the third expander is connected to the inlet of the fifth heat release module. The third expander is used to cool and depressurize the second working fluid.

[0013] In one embodiment, the cold storage device includes a seventh heat-absorbing module and a seventh heat-releasing module capable of heat exchange. The inlet of the seventh heat-absorbing module is connected to the outlet of the first expander, and the outlet of the seventh heat-absorbing module is connected to the inlet of the first heat-absorbing module. The inlet of the seventh heat-releasing module is connected to the outlet of the fifth heat-absorbing module, and the outlet of the seventh heat-releasing module is connected to the inlet of the fifth heat-absorbing module.

[0014] In one embodiment, the heat storage device includes an eighth heat-releasing module and an eighth heat-absorbing module capable of heat exchange. The inlet of the eighth heat-releasing module is connected to the outlet of the compressor, the outlet of the eighth heat-releasing module is connected to the inlet of the first expander, the inlet of the eighth heat-absorbing module is connected to the outlet of the third heat-releasing module, and the outlet of the eighth heat-absorbing module is connected to the inlet of the third heat-releasing module.

[0015] In one embodiment, the geothermal extraction device includes a production well and an injection well connected in series, the inlet of the first heat release module and the inlet of the fourth heat release module are both connected to the production well, and the outlet of the first heat release module and the outlet of the fourth heat release module are both connected to the injection well. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the geothermal energy storage system in one embodiment of this application.

[0018] Figure 2 This is a partial structural schematic diagram of a geothermal energy storage system in one embodiment of this application.

[0019] Figure 3 This is a schematic diagram of another part of the geothermal energy storage system in one embodiment of this application.

[0020] Attached image annotations: 100. Geothermal extraction device; 110. Production well; 120. Injection well; 210. First heat exchanger; 211. First heat release module; 212. First heat absorption module; 220. Second heat exchanger; 221. Second heat release module; 222. Second heat absorption module; 230. Third heat exchanger; 231. Third heat release module; 232. Third heat absorption module; 240. Fourth heat exchanger; 241. Fourth heat release module; 242. Fourth heat absorption module; 250. Fifth heat exchanger; 251. Fifth heat release module; 252. Fifth heat absorption module 260. Heat exchange module; 261. Sixth heat release module; 262. Sixth heat absorption module; 310. Compressor; 320. Electric motor; 410. Heat storage device; 411. Eighth heat release module; 412. Eighth heat absorption module; 420. Cold storage device; 421. Seventh heat release module; 422. Seventh heat absorption module; 500. First expander; 610. Second expander; 620. Generator; 630. Third expander; 640. Fourth expander; 700. Storage tank; 810. First valve body; 820. Second valve body. Detailed Implementation

[0021] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0022] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0023] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0024] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0026] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0027] Please see Figure 1 and Figure 2 One embodiment of this application provides a geothermal energy storage system, including a geothermal extraction device 100, a first heat exchange device 210, a compressor 310, a heat storage device 410, a first expander 500, and a cold storage device 420. The geothermal extraction device 100 is used to extract geothermal energy; the first heat exchange device 210 includes a first heat release module 211 and a first heat absorption module 212 capable of heat exchange. The first heat release module 211 is connected to the geothermal extraction device 100 and is used to transfer geothermal energy to a first working fluid in the first heat absorption module 212; the inlet of the compressor 310 is connected to the first heat storage device 410. The outlet of the heat absorption module 212 is connected to the compressor 310 for pressurizing the first working fluid; the heat storage device 410 is connected to the outlet of the compressor 310 for storing the heat of the first working fluid; the inlet of the first expander 500 is connected to the heat storage device 410 for cooling and depressurizing the first working fluid, and the first expander 500 is driven to connect to the compressor 310; the cold storage device 420 is connected to the outlet of the first expander 500 for storing the cold energy of the first working fluid, and the inlet of the first heat absorption module 212 is connected to the cold storage device 420.

[0028] In the aforementioned geothermal energy storage system, the geothermal energy collected by the geothermal extraction device 100 is transferred by the first heat release module 211 to the first working fluid in the first heat absorption module 212, raising the temperature of the first working fluid. The heated first working fluid then enters the compressor 310 through its inlet, is pressurized and heated by the compressor, and is discharged from its outlet into the heat storage device 410 to achieve heat storage. The first working fluid, having completed heat release, then enters the first expander 500, where it is cooled and depressurized. The work output by the first expander 500 in cooling and depressurizing the first working fluid is transferred to the compressor 310, effectively reducing the energy consumption of the compressor 310 during the pressurization process. Subsequently, the first working fluid is discharged from the outlet of the first expander 500 to the cold storage device 420, transferring its own cooling capacity to the cold storage device 420 for storage, ultimately achieving simultaneous storage and utilization of heat and cooling capacity. Compared with traditional technologies, the above-mentioned geothermal energy storage system uses the work done by the first expander to feed back to the compressor 310, reducing the energy consumption when pressurizing the first working fluid, and can simultaneously store heat and cold, avoiding energy waste and effectively improving the utilization efficiency of geothermal energy.

[0029] In some embodiments, the first expander 500 and the compressor 310 are connected by a coupling to achieve a drive connection; the first working fluid is cooled and depressurized in the expander so that the expander impeller does work, the rotor rotates and drives the coupling to rotate, the coupling is connected to the input shaft of the compressor 310 so that the compressor impeller is driven to rotate through the input shaft of the compressor 310, thereby reducing the energy consumption in the process of pressurizing the first working fluid.

[0030] Optionally, the geothermal extraction device 100 can extract geothermal energy by burying underground pipes, drilling wells, or collecting underground steam, as long as the geothermal energy can be led out to the first heat release module 211. No specific limitation is made here.

[0031] Optionally, the first working medium can be air, carbon dioxide, helium, or a liquid such as water; no specific limitation is made here.

[0032] In some embodiments, in the first heat exchange device 210, the first heat release module 211 and the first heat absorption module 212 adopt a partitioned heat exchange, that is, the working fluid in the first heat release module 211 and the working fluid in the first heat absorption module 212 flow separately and do not come into contact with each other. They only transfer heat through the wall, so that the pressure and temperature of the working fluid inside each module are independently controllable and the heat exchange reliability is high.

[0033] Understandably, the heat exchange forms of the second heat exchange device 220, the third heat exchange device 230, the fourth heat exchange device 240, the fifth heat exchange device 250 and the sixth heat exchange device 260 in the following embodiments are similar to those of the first heat exchange device 210 described above, and will not be repeated here.

[0034] In one embodiment, the heat storage device 410 contains a working fluid for storing heat (i.e., the fourth working fluid hereinafter). When the first working fluid flows through the heat storage device 410, the first working fluid transfers its own heat to the working fluid in the heat storage device 410 to achieve heat storage, while the temperature of the first working fluid itself decreases. Similarly, the cold storage device 420 contains a working fluid for storing cold energy (i.e., the third working fluid hereinafter). When the first working fluid flows through the cold storage device 420, the first working fluid transfers its own cold energy to the working fluid in the cold storage device 420 to achieve cold energy storage, while the temperature of the first working fluid itself increases.

[0035] Furthermore, after the first working fluid is cooled and depressurized in the first expander 500, its temperature can reach about 0°C. When the first working fluid flows through the cold storage device 420, its own temperature rises to transfer the cold energy to the working fluid in the cold storage device, and then flows back to the first heat absorption module 212. This process is repeated to achieve the circulation of the first working fluid.

[0036] In one embodiment, the geothermal energy storage system further includes an electric motor 320, which supplies electrical energy to the compressor 310 to enable the compressor 310 to operate.

[0037] Furthermore, the electric motor 320 is used to connect to an external renewable energy field to reduce the operating cost of the geothermal energy storage system, making it clean, environmentally friendly, and effectively reducing pollutant emissions.

[0038] Please see Figure 1 and Figure 2 In one embodiment, the geothermal energy storage system further includes a second heat exchange device 220, which includes a second heat release module 221 and a second heat absorption module 222 capable of heat exchange. The inlet of the second heat release module 221 is connected to the heat storage device 410, the outlet of the second heat release module 221 is connected to the inlet of the first expander 500, the inlet of the second heat absorption module 222 is connected to the outlet of the first heat absorption module 212, and the outlet of the second heat absorption module 222 is connected to the compressor 310.

[0039] After being pressurized by the compressor 310, the first working fluid transfers some of its heat to the heat storage device 410, and then enters the second heat release module 221 to transfer the heat to the first working fluid in the first heat absorption module 212. This preheats the first working fluid before it enters the compressor 310, resulting in a higher temperature of the first working fluid after being pressurized by the compressor 310. This fully utilizes the heat of the first working fluid after being pressurized by the compressor 310, thereby improving heat generation efficiency and heat utilization rate.

[0040] Understandably, the second heat exchange device 220 is used to preheat the first working fluid before it enters the compressor 310, thereby making full use of the residual heat of the first working fluid after passing through the heat storage device 410 and improving the heat utilization rate.

[0041] Please see Figures 1 to 3 In one embodiment, the geothermal energy storage system further includes a third heat exchange device 230 and a power generation device. The third heat exchange device 230 includes a third heat release module 231 and a third heat absorption module 232 capable of heat exchange. The inlet of the third heat release module 231 is connected to the heat storage device 410, and the outlet of the third heat absorption module 232 is connected to the power generation device.

[0042] The thermal storage device 410 can transfer heat to the third heat release module 231, the third heat release module 231 transfers heat to the third heat absorption module 232, and the third heat absorption module 232 then transfers heat to the power generation device for power generation. Thus, the thermal energy stored in the thermal storage device 410 is converted into electrical energy, improving the practicality of the geothermal energy storage system.

[0043] Furthermore, the working fluid containing heat stored in the heat storage device 410 flows to the third heat release module 231 and transfers the heat to the third heat absorption module 232. The third heat absorption module 232 transfers the heat to the power generation device for power generation, thereby realizing the process of converting thermal energy into electrical energy.

[0044] Please see Figure 1 In one embodiment, the geothermal extraction device 100 is located underground for collecting geothermal energy.

[0045] Optionally, the power generation device can be a combination of a steam turbine and a generator 620, or a combination of an expander and a generator 620, as long as it can convert thermal energy into electrical energy, and no specific limitation is made here.

[0046] Please see Figures 1 to 3 In one embodiment, the geothermal energy storage system further includes a fourth heat exchange device 240, which includes a fourth heat release module 241 and a fourth heat absorption module 242 capable of heat exchange. The inlet of the fourth heat release module 241 is connected to the geothermal extraction device 100, and the fourth heat release module 241 is used to transfer geothermal energy to the second working fluid in the fourth heat absorption module 242. The inlet of the fourth heat absorption module 242 is connected to the power generation device, and the outlet of the fourth heat absorption module 242 is connected to the inlet of the third heat absorption module 232.

[0047] The geothermal extraction device 100 transfers geothermal energy through the fourth heat release module 241 to the second working fluid in the fourth heat absorption module 242. The second working fluid flows out of the fourth heat absorption module 242 to the third heat absorption module 232. In this way, geothermal energy can be used to preheat the second working fluid that does not flow into the third heat absorption module 232. This not only makes full use of geothermal energy, but also makes the heat of the second working fluid flowing out of the third heat absorption module 232 to the power generation device higher, thereby improving the power generation efficiency.

[0048] Furthermore, the second working fluid transfers heat to the power generation device for power generation, and then flows back to the fourth heat absorption module 242 through the power generation device, and so on, to achieve continuous power generation.

[0049] Please see Figures 1 to 3 In one embodiment, the geothermal energy storage system further includes a first valve body 810 and a second valve body 820. The first valve body 810 controls the connection between the geothermal extraction device 100 and the first heat release module 211, and the second valve body 820 controls the connection between the geothermal extraction device 100 and the fourth heat release module 241. Geothermal energy is a sustainable heat source, and the geothermal extraction device 100 can continuously collect it. When the geothermal energy storage system needs to store geothermal energy, the first valve body 810 is opened and the second valve body 820 is closed, so that the first working fluid transports the geothermal energy collected by the geothermal extraction device 100 to the heat storage device 410 for storage during its flow. When it is necessary to release the geothermal energy stored in the heat storage device 410, the first valve body 810 is closed and the second valve body 820 is opened, so that the geothermal energy collected by the geothermal extraction device 100 heats the second working fluid, thereby realizing time-segmented energy storage and release, and further improving the utilization efficiency of geothermal energy.

[0050] Please see Figure 1 In one embodiment, the third heat absorption module 232 is provided with at least two modules connected in series to achieve more thorough heating of the second working fluid.

[0051] Furthermore, the second working fluid changes from a liquid to a gaseous state under the heating of the third heat exchanger 230. The gaseous second working fluid has a higher temperature and pressure, and can do more work after entering the second expander 610, thereby improving the power generation efficiency of the power generation device.

[0052] Please see Figure 1 and Figure 3 In one embodiment, the geothermal energy storage system further includes a fifth heat exchange device 250, which includes a fifth heat absorption module 252 and a fifth heat release module 251 capable of heat exchange. The inlet of the fifth heat absorption module 252 is connected to the cold storage device 420, the inlet of the fifth heat release module 251 is connected to the outlet of the power generation device, and the outlet of the fifth heat release module 251 is connected to the inlet of the fourth heat absorption module 242.

[0053] After the gaseous second working fluid transfers heat to the power generation device, it flows into the fifth heat release module 251. The cold storage device 420 transfers the stored cold energy to the fifth heat absorption module 252 to cool the gaseous second working fluid in the fifth heat release module 251, causing the gaseous second working fluid to turn into a liquid state. Then, the liquid second working fluid is transported to the fourth heat absorption module 242 to realize the reciprocating circulation of the second working fluid. This arrangement can reduce the pressure of the second working fluid during the transportation process, thereby reducing the power consumption of the device used to transport the second working fluid and further reducing the overall power consumption of the geothermal energy storage system.

[0054] As an explanation, the fifth heat exchange device 250 can convert the gaseous second working fluid into a liquid state, effectively reducing the volume of the second working fluid. This results in lower power consumption for the working fluid pump when transporting the second working fluid. The cooling capacity in the fifth heat exchange device 250 comes from the cold storage device 420, which in turn receives cooling capacity from the first working fluid after it has been expanded by the first expander 500. Thus, during the expansion and cooling process of the first working fluid, the first expander 500 can not only output power to the compressor 310 to reduce its power consumption, but also provide cooling capacity to convert the gaseous second working fluid into a liquid state, thereby further reducing the overall power consumption of the geothermal energy storage system.

[0055] Please see Figure 3 In one embodiment, the power generation device includes a second expander 610 and a generator 620. The inlet of the second expander 610 is connected to the outlet of the third heat absorption module 232, and the outlet of the second expander 610 is connected to the fifth heat release module 251. The second expander 610 is used to cool and depressurize the second working fluid, and the generator 620 is driven to the second expander 610.

[0056] The second expander 610 can cool and depressurize the second working fluid to convert the thermal energy carried by the second working fluid into mechanical energy, thereby driving the generator 620 to generate electricity.

[0057] Specifically, the high-temperature second working fluid is rapidly depressurized within the second expander 610 to cause the volume of the second working fluid to expand rapidly, thereby driving the rotor to rotate and converting the pressure and heat energy of the second working fluid into mechanical energy. Since the generator 620 is connected to the second expander 610, the mechanical energy of the second expander 610 can be effectively transferred to the engine, thereby realizing power generation.

[0058] Furthermore, the rotor of the second expander 610 is coaxial with or connected to the rotor of the generator 620 via a coupling. The second working fluid enters the second expander 610 and drives the rotor to rotate, thereby driving the rotor of the generator 620 to rotate, so as to convert thermal energy into mechanical energy and then into electrical energy for output.

[0059] In one embodiment, at least two second expanders 610 are provided and connected in series, thereby improving the utilization rate of heat from the second working fluid.

[0060] Please see Figure 3 In one embodiment, the geothermal energy storage system further includes a sixth heat exchange device 260, which includes a sixth heat release module 261 and a sixth heat absorption module 262 capable of heat exchange. The inlet of the sixth heat release module 261 is connected to the heat storage device 410. The power generation device further includes a third expander 630 driven and connected to the generator 620. The inlet of the sixth heat absorption module 262 is connected to the outlet of the second expander 610, and the outlet of the sixth heat absorption module 262 is connected to the inlet of the third expander 630. The outlet of the third expander 630 is connected to the inlet of the fifth heat release module 251. The third expander 630 is used to cool and depressurize the second working fluid.

[0061] After being expanded and depressurized by the second expander 610, the temperature of the second working fluid decreases, and it enters the sixth heat absorption module 262. The heat storage device 410 transfers heat to the sixth heat release module 261, and the sixth heat release module 261 transfers heat to the sixth heat absorption module 262 to heat the second working fluid in the sixth heat absorption module 262. The heated second working fluid then enters the third expander 630, which cools and depressurizes the second working fluid to convert the thermal energy carried by the second working fluid into mechanical energy, thereby driving the generator 620 to generate electricity. This configuration allows the third expander 630 to release more mechanical energy to power the generator 620, further improving the power generation efficiency of the power generation device.

[0062] In one embodiment, the second expander 610 is provided with a high-pressure expander cylinder, the third expander 630 is provided with a medium-pressure expander cylinder, and a fourth expander 640 is arranged downstream of the third expander 630, the fourth expander 640 being provided with a low-pressure expander cylinder.

[0063] Please see Figure 1 and Figure 2 In one embodiment, the cold storage device 420 includes a seventh heat-absorbing module 422 and a seventh heat-releasing module 421 capable of heat exchange. The inlet of the seventh heat-absorbing module 422 is connected to the outlet of the first expander 500, and the outlet of the seventh heat-absorbing module 422 is connected to the inlet of the first heat-absorbing module 212. The inlet of the seventh heat-releasing module 421 is connected to the outlet of the fifth heat-absorbing module 252, and the outlet of the seventh heat-releasing module 421 is connected to the inlet of the fifth heat-absorbing module 252.

[0064] After the first expander 500 expands and cools the first working fluid, the first working fluid flows into the seventh heat absorption module 422 to transfer its own cooling capacity to the seventh heat release module 421. This allows the cooling capacity of the first working fluid to be transferred to the fifth heat absorption module 252 to cool the gaseous second working fluid in the fifth heat release module 251, causing the gaseous second working fluid to turn into a liquid. The liquid second working fluid is then transported to the fourth heat absorption module 242 to achieve the reciprocating cycle of the second working fluid.

[0065] Please see Figures 1 to 3 In one embodiment, a third working fluid flows between the seventh heat-releasing module 421 and the fifth heat-absorbing module 252. The cooling capacity of the first working fluid is transferred to the third working fluid in the seventh heat-releasing module 421 via the seventh heat-absorbing module 422. The third working fluid then transfers its cooling capacity to the second working fluid in the fifth heat-releasing module 251 via the fifth heat-absorbing module 252, thereby cooling the second working fluid and causing it to change from a gaseous state to a liquid state, thus reducing the energy consumption for transporting the second working fluid.

[0066] Optionally, the third working medium can be water, ethylene glycol, etc., depending on the storage and cooling temperature.

[0067] Please see Figures 1 to 3 In one embodiment, the heat storage device 410 includes an eighth heat release module 411 and an eighth heat absorption module 412 capable of heat exchange. The inlet of the eighth heat release module 411 is connected to the outlet of the compressor 310, and the outlet of the eighth heat release module 411 is connected to the inlet of the first expander 500. The inlet of the eighth heat absorption module 412 is connected to the outlet of the third heat release module 231, and the outlet of the eighth heat absorption module 412 is connected to the inlet of the third heat release module 231.

[0068] After the compressor 310 pressurizes the first working fluid, the first working fluid flows into the eighth heat release module 411 to transfer its own heat to the eighth heat absorption module 412, thereby transferring the heat of the first working fluid to the third heat release module 231 to heat the second working fluid in the third heat absorption module 232, and then generating electricity through the power generation device.

[0069] Please see Figures 1 to 3 In one embodiment, the inlet of the sixth heat-releasing module 261 is connected to the outlet of the eighth heat-absorbing module 412, and the outlet of the sixth heat-releasing module 261 is connected to the inlet of the eighth heat-absorbing module 412.

[0070] Please see Figures 1 to 3In one embodiment, a fourth working fluid flows between the eighth heat-absorbing module 412 and the third heat-releasing module 231. The heat of the first working fluid is transferred to the fourth working fluid in the eighth heat-absorbing module 412 via the eighth heat-releasing module 411 to heat the fourth working fluid. The heated fourth working fluid flows to the third heat-releasing module 231 to heat the second working fluid in the third heat-absorbing module 232, thereby heating the second working fluid into a gaseous state for subsequent expansion and work.

[0071] Optionally, the second working medium can be water, organic solvent, supercritical carbon dioxide, etc., depending on the system temperature and pressure. The fourth working medium can be molten salt, high-temperature heat transfer oil, etc., depending on the heat storage temperature.

[0072] Please see Figure 1 In one embodiment, the geothermal extraction device 100 includes a production well 110 and an injection well 120 connected to each other. The inlet of the first heat release module 211 and the inlet of the fourth heat release module 241 are both connected to the production well 110, and the outlet of the first heat release module 211 and the outlet of the fourth heat release module 241 are both connected to the injection well 120.

[0073] The working fluid flowing out from the first heat release module 211 and the fourth heat release module 241 enters the injection well 120 and flows to the production well 110 via the injection well 120. During this process, the working fluid absorbs geothermal heat so that the working fluid in the production well 110 has a certain amount of heat, thereby heating the first working fluid and the second working fluid through the first heat release module 211 and the fourth heat release module 241 respectively.

[0074] Further, please refer to Figure 1 The geothermal energy storage system also includes a storage tank 700. The inlet of the storage tank 700 is connected to the outlet of the first heat release module 211 and the outlet of the fourth heat release module 241. The outlet of the storage tank 700 is connected to the injection well 120. A fifth working fluid flows between the injection well 120, the production well 110, the first heat release module 211, the fourth heat release module 241 and the storage tank 700. The fifth working fluid in the injection well 120 flows to the production well 110 and absorbs geothermal heat. Then it flows through the production well 110 to the first heat release module 211 and the fourth heat release module 241 to heat the first and second working fluids. Then it enters the storage tank 700. The storage tank 700 delivers the fifth working fluid to the injection well 120. This process is repeated to heat the first and second working fluids.

[0075] Optionally, the injection well 120 and the production well 110 can be connected by a pipeline or by an underground fissure, as long as the fifth working medium can absorb geothermal heat; no specific limitation is made here.

[0076] Understandably, in the above embodiments, all devices and modules are connected by pipelines. The specific details regarding the connection between pipelines and the valve configurations on the pipelines can be found in [reference needed]. Figures 1 to 3 This will not be elaborated further here.

[0077] Furthermore, working fluid pumps are installed between the storage tank and the injection well 120, between the production well 110 and the fourth heat release module 241, between the production well 110 and the first heat release module 211, between the fourth heat absorption module 242 and the third heat absorption module 232, between the fifth heat absorption module 252 and the seventh heat release module 421, and between the third heat release module 231 and the eighth heat absorption module 412. The working fluid pumps are used to drive the flow of the working fluid to realize the operation of the geothermal energy storage system.

[0078] In one embodiment, the first medium passes through the first heat-absorbing module 212, where its temperature rises to 120°C. It then enters the second heat-absorbing module 222, where its temperature rises to 250°C. It then enters the compressor 310, where its temperature rises to 550°C. Finally, it enters the eighth heat-releasing module 411, where its temperature drops to 280°C. It then enters the second heat-releasing module 221, where its temperature drops to 150°C. It then enters the first expander 500, where its temperature drops to 0°C. Finally, it enters the seventh heat-absorbing module 422, where its temperature rises to 30°C. It then enters the first heat-absorbing module 212, completing the energy storage cycle.

[0079] In one embodiment, the second working fluid enters the fourth heat-absorbing module 242, where its temperature rises to 100°C. After passing through the working fluid pump, its pressure increases. Subsequently, it enters three third heat-absorbing modules 232 in succession, where its temperature rises from 100°C to 200°C, then from 200°C to 350°C and changes from liquid to gas. Finally, it rises from 350°C to 500°C and enters the second expander 610 to do work, where its temperature drops to 60°C and its pressure decreases. It then enters the fifth heat-releasing module 251, where its temperature decreases and it condenses from gas to liquid. Finally, it flows back to the fourth heat-absorbing module 242 via the working fluid pump. This process is repeated to complete the energy release cycle.

[0080] Furthermore, the working fluid pump at the inlet of injection well 120 and the working fluid pump at the outlet of production well 110 are both variable frequency pumps. The flow rate of the pumps is adjusted according to the heat load to keep the outlet temperature of the first heat exchange device 210 stable.

[0081] In one embodiment, the third heat release module 231 of different third heat exchange devices 230 is also provided with a heat supply port, and a valve body is provided at the heat supply port to realize heat supply to the outside. Since multiple third heat release modules 231 are connected in series, the temperature of the heat supply port of each third heat release module 231 is different, thereby enabling the third heat exchange device 230 to output a fourth working fluid at different temperatures and realize heat supply at different temperatures.

[0082] Furthermore, the seventh heat release module 421 of the cold storage device 420 is provided with a cooling port to directly extract the third working fluid to achieve cooling.

[0083] Furthermore, both the second expander 610 and the third expander 630 are equipped with heating ports to extract the second working fluid and directly supply heat, thereby realizing the comprehensive supply of cold, heat and electrical energy and the cascade utilization of energy.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A geothermal energy storage system, characterized in that, include: A geothermal extraction device, wherein the geothermal extraction device is used to extract geothermal energy; The first heat exchange device includes a first heat release module and a first heat absorption module capable of heat exchange. The first heat release module is connected to the geothermal extraction device and is used to transfer geothermal energy to a first working fluid in the first heat absorption module. The compressor has its inlet connected to the outlet of the first heat absorption module, and the compressor is used to pressurize the first working fluid. A heat storage device, which is connected to the outlet of the compressor, is used to store the heat of the first working fluid; The first expander has its inlet connected to the heat storage device. The first expander is used to cool and depressurize the first working fluid. The first expander is driven by the compressor. as well as A cold storage device is connected to the outlet of the first expander and is used to store the cold energy of the first working fluid. The inlet of the first heat absorption module is connected to the cold storage device.

2. The geothermal energy storage system according to claim 1, characterized in that, The geothermal energy storage system further includes a second heat exchange device, which includes a second heat release module and a second heat absorption module capable of heat exchange. The inlet of the second heat release module is connected to the heat storage device, the outlet of the second heat release module is connected to the inlet of the first expander, the inlet of the second heat absorption module is connected to the outlet of the first heat absorption module, and the outlet of the second heat absorption module is connected to the compressor.

3. The geothermal energy storage system according to claim 1, characterized in that, The geothermal energy storage system also includes a third heat exchange device and a power generation device. The third heat exchange device includes a third heat release module and a third heat absorption module capable of heat exchange. The inlet of the third heat release module is connected to the heat storage device, and the outlet of the third heat absorption module is connected to the power generation device.

4. The geothermal energy storage system according to claim 3, characterized in that, The geothermal energy storage system further includes a fourth heat exchange device, which includes a fourth heat release module and a fourth heat absorption module capable of heat exchange. The inlet of the fourth heat release module is connected to the geothermal extraction device. The fourth heat release module is used to transfer geothermal energy to the second working fluid in the fourth heat absorption module. The inlet of the fourth heat absorption module is connected to the power generation device, and the outlet of the fourth heat absorption module is connected to the inlet of the third heat absorption module.

5. The geothermal energy storage system according to claim 4, characterized in that, The geothermal energy storage system further includes a fifth heat exchange device, which includes a fifth heat absorption module and a fifth heat release module capable of heat exchange. The inlet of the fifth heat absorption module is connected to the cold storage device, the inlet of the fifth heat release module is connected to the outlet of the power generation device, and the outlet of the fifth heat release module is connected to the inlet of the fourth heat absorption module.

6. The geothermal energy storage system according to claim 5, characterized in that, The power generation device includes a second expander and a generator. The inlet of the second expander is connected to the outlet of the third heat absorption module, and the outlet of the second expander is connected to the fifth heat release module. The second expander is used to cool and depressurize the second working fluid, and the generator is driven by the second expander.

7. The geothermal energy storage system according to claim 6, characterized in that, The geothermal energy storage system further includes a sixth heat exchange device, which includes a sixth heat release module and a sixth heat absorption module capable of heat exchange. The inlet of the sixth heat release module is connected to the heat storage device. The power generation device further includes a third expander connected to a generator drive. The inlet of the sixth heat absorption module is connected to the outlet of the second expander, and the outlet of the sixth heat absorption module is connected to the inlet of the third expander. The outlet of the third expander is connected to the inlet of the fifth heat release module. The third expander is used to cool and depressurize the second working fluid.

8. The geothermal energy storage system according to claim 5, characterized in that, The cold storage device includes a seventh heat-absorbing module and a seventh heat-releasing module capable of heat exchange. The inlet of the seventh heat-absorbing module is connected to the outlet of the first expander, and the outlet of the seventh heat-absorbing module is connected to the inlet of the first heat-absorbing module. The inlet of the seventh heat-releasing module is connected to the outlet of the fifth heat-absorbing module, and the outlet of the seventh heat-releasing module is connected to the inlet of the fifth heat-absorbing module.

9. The geothermal energy storage system according to claim 3, characterized in that, The heat storage device includes an eighth heat release module and an eighth heat absorption module capable of heat exchange. The inlet of the eighth heat release module is connected to the outlet of the compressor, and the outlet of the eighth heat release module is connected to the inlet of the first expander. The inlet of the eighth heat absorption module is connected to the outlet of the third heat release module, and the outlet of the eighth heat absorption module is connected to the inlet of the third heat release module.

10. The geothermal energy storage system according to claim 4, characterized in that, The geothermal extraction device includes a production well and an injection well connected to each other. The inlet of the first heat release module and the inlet of the fourth heat release module are both connected to the production well, and the outlet of the first heat release module and the outlet of the fourth heat release module are both connected to the injection well.

Images