Geothermal energy comprehensive utilization system and method

Abstract

The invention provides a geothermal energy comprehensive utilization system and method, and relates to the technical field of geothermal energy utilization. A user heat exchange component; the first heat exchange side of the heat pump unit is connected with the coaxial sleeve geothermal well through a geothermal well water outlet pipeline and a geothermal well water inlet pipeline, and the second heat exchange side of the heat pump unit is connected with the user heat exchange component through a user water supply pipeline and a user water return pipeline; the buried pipe heat exchanger is connected with the geothermal well water inlet pipeline and the geothermal well water outlet pipeline through a buried pipe water inlet pipeline and a buried pipe water outlet pipeline respectively; the problem that in the prior art, in areas with large building density and unbalanced cooling and heating loads, a conventional shallow geothermal resource exploitation mode and a conventional medium-deep geothermal resource exploitation mode are used for geothermal heating and refrigeration, and the long-term efficient and stable operation effect cannot be achieved is solved.

Description

Technical Field

[0001] This invention belongs to the field of geothermal energy utilization technology, and more specifically, relates to a comprehensive geothermal energy utilization system and method. Background Technology

[0002] Geothermal resources are a renewable and clean energy source with large reserves, wide distribution within the Earth, and strong stability. They are currently widely used in heating, cooling, power generation, and bathing.

[0003] Geothermal resources can be divided into shallow geothermal resources and medium-deep geothermal resources according to depth. Shallow geothermal resources refer to the energy contained in shallow rock, soil, or water at a depth of 200m. This part of the energy is low-grade energy, and the annual temperature remains almost unchanged throughout the year. It is usually developed and utilized using ground source heat pump systems, which can be used for both heating and cooling. However, it has problems such as poor anti-interference ability and large footprint, which limits its application in areas with high building density and high land costs. In addition, in areas with uneven heating and cooling loads, due to the poor thermal recovery capacity of the soil, long-term use will lead to soil thermal imbalance, causing cold or hot accumulation problems, resulting in reduced efficiency of heat pump units and inability to guarantee long-term stable and efficient operation.

[0004] Medium-deep geothermal resources refer to the energy contained in soil and rock at depths of 1000m-3000m. Medium-deep geothermal energy reserves are large, and compared to shallow geothermal energy, the water temperature is higher, and the soil has a strong heat recovery capacity. Application methods can be divided into hydrothermal and heat exchange types. The heat exchange type does not require the extraction of geothermal fluids; it uses a shell-and-tube heat exchanger to extract heat from the medium-deep soil, avoiding the need to extract deep underground hot water and preventing problems such as water level drop and land subsidence caused by excessive water extraction. It also occupies a significantly smaller area than shallow geothermal systems, making it suitable for areas with high building density. This is a relatively recent exploratory development method. However, it is generally only suitable for winter heating and cannot provide cooling, limiting its application scenarios.

[0005] Therefore, in areas with high building density and uneven heating and cooling loads, conventional geothermal heating and cooling systems cannot achieve long-term, efficient, and stable operation. There is an urgent need to develop a more efficient geothermal energy development, utilization, and operation scheme. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a comprehensive geothermal energy utilization system and method. This addresses the problem that conventional shallow and medium-deep geothermal resource extraction methods for geothermal heating and cooling in areas with high building density and uneven heating and cooling loads cannot achieve long-term, efficient, and stable operation.

[0007] To achieve the above objectives, the present invention provides a geothermal energy comprehensive utilization system, comprising:

[0008] Coaxial casing geothermal well;

[0009] User heat exchange components;

[0010] The heat pump unit has a first heat exchange side connected to the coaxial casing geothermal well via a geothermal well outlet pipe and a geothermal well inlet pipe, and a second heat exchange side connected to the user heat exchange component via a user water supply pipe and a user water return pipe.

[0011] A buried pipe heat exchanger is connected to the geothermal well inlet pipe and the geothermal well outlet pipe via a buried pipe inlet pipe and a buried pipe outlet pipe, respectively.

[0012] Optionally, it also includes a buried pipe outlet bypass pipe, the two ends of which are connected to the buried pipe outlet pipe and the geothermal well inlet pipe, respectively.

[0013] Optionally, the geothermal well inlet pipe, the geothermal well outlet pipe, the buried pipe inlet pipe, the buried pipe outlet pipe, the user water supply pipe, and the user return water pipe are respectively equipped with a first data acquisition module, a second data acquisition module, a third data acquisition module, a fourth data acquisition module, a fifth data acquisition module, and a sixth data acquisition module.

[0014] Optionally, the first data acquisition module includes a first flow sensor, a first pressure sensor, and a first temperature sensor; the second data acquisition module includes a second flow sensor, a second pressure sensor, and a second temperature sensor; the third data acquisition module includes a third flow sensor, a third pressure sensor, and a third temperature sensor; the fourth data acquisition module includes a fourth flow sensor, a fourth pressure sensor, and a fourth temperature sensor; the fifth data acquisition module includes a fifth flow sensor, a fifth pressure sensor, and a fifth temperature sensor; and the sixth data acquisition module includes a sixth flow sensor, a sixth pressure sensor, and a sixth temperature sensor.

[0015] Optionally, the user water supply pipeline, the geothermal well outlet pipeline, and the buried pipe inlet pipeline are respectively equipped with a first circulation pump, a second circulation pump, and a third circulation pump.

[0016] Optionally, the geothermal well outlet pipe, the buried pipe outlet bypass pipe, the geothermal well inlet pipe, the end of the buried pipe inlet pipe near the geothermal well inlet pipe, the user water supply pipe, the user return water pipe, the end of the buried pipe outlet pipe near the geothermal well outlet pipe, the end of the geothermal well outlet pipe, the end of the buried pipe outlet pipe near the buried pipe heat exchanger, and the end of the buried pipe inlet pipe near the buried pipe heat exchanger are respectively equipped with a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a seventh valve, an eighth valve, a ninth valve, and a tenth valve.

[0017] Optionally, the system further includes a control unit, wherein the first data acquisition module, the second data acquisition module, the third data acquisition module, the fourth data acquisition module, the fifth data acquisition module, the sixth data acquisition module, the first valve, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, the seventh valve, the eighth valve, the ninth valve, and the tenth valve are connected to the control unit.

[0018] Optionally, the coaxial casing geothermal well includes a central pipe and an annular pipe. The central pipe is disposed inside the annular pipe, and the bottom of the central pipe is higher than the bottom of the annular pipe, so that the lower end of the central pipe is connected to the lower end of the annular pipe. The geothermal well outlet pipe and the geothermal well inlet pipe are respectively connected to the central pipe and the annular pipe.

[0019] The present invention also provides a method for comprehensive utilization of geothermal energy, utilizing the above-mentioned comprehensive geothermal energy utilization system, characterized in that it includes:

[0020] In summer, cooling is carried out separately using buried pipe heat exchangers;

[0021] During the first heat load phase in winter, heating is provided by combining coaxial casing geothermal wells and buried pipe heat exchangers.

[0022] During the second heat load stage in winter, when the heat load is lower than that of the first heat load stage, heating is provided separately using coaxial casing geothermal wells.

[0023] Optionally, when the geothermal energy comprehensive utilization system further includes a buried pipe outlet bypass pipe, the two ends of which are respectively connected to the buried pipe outlet pipe and the geothermal well inlet pipe, the geothermal energy comprehensive utilization method further includes:

[0024] During the third heat load stage in winter, when the heat load is lower than the second heat load stage, coaxial casing geothermal wells are used for heating and the tailwater of the heating system is used to supplement the heat of the stratum where the buried pipe heat exchanger is located.

[0025] This invention provides a geothermal energy comprehensive utilization system and method, the beneficial effects of which are as follows: The geothermal energy comprehensive utilization system has a coaxial casing geothermal well and a buried pipe heat exchanger, which are used for the development and utilization of medium-deep geothermal resources and shallow geothermal resources, respectively. Through heat exchange between the first heat exchange side and the second heat exchange side of the heat pump unit, the coaxial casing geothermal well and the buried pipe heat exchanger can be operated independently or jointly, forming heat exchange with the user's heat exchange components, thereby realizing the supply of heat or cooling to the user's heat exchange components. The geothermal energy comprehensive utilization system can flexibly choose to operate the coaxial casing geothermal well and the buried pipe heat exchanger independently or jointly according to the heating and cooling demand. It can independently exploit and utilize medium-deep geothermal resources and shallow geothermal resources or jointly exploit and utilize both, thereby making the exploitation and utilization of geothermal resources more flexible and comprehensive, and achieving the effect of long-term, efficient and stable operation.

[0026] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0027] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0028] Figure 1 A schematic diagram of a geothermal energy integrated utilization system according to Embodiment 1 of the present invention is shown.

[0029] Figure 2 A flowchart of a geothermal energy comprehensive utilization method according to Embodiment 2 of the present invention is shown.

[0030] Explanation of reference numerals in the attached figures:

[0031] 1. Coaxial casing geothermal well; 2. First data acquisition module; 3. Second data acquisition module; 4. Third data acquisition module; 5. Fourth data acquisition module; 6. Fifth data acquisition module; 7. Sixth data acquisition module; 8. First valve; 9. Second valve; 10. Third valve; 11. Fourth valve; 12. Heat pump unit; 13. Fifth valve; 14. First circulation pump; 15. User heat exchange component; 16. Sixth valve; 17. Seventh valve; 18. Eighth valve; 19. Second circulation pump; 20. Third circulation pump; 21. Ninth valve; 22. Tenth valve; 23. Buried pipe heat exchanger; 24. Control unit; 25. Geothermal well outlet pipe; 26. Geothermal well inlet pipe; 27. Buried pipe inlet pipe; 28. 29. Buried water outlet pipe; 30. User water supply pipe; 31. User return water pipe; 101. Central pipe; 102. Ring pipe; 201. First flow sensor; 202. First pressure sensor; 203. First temperature sensor; 301. Second flow sensor; 302. Second pressure sensor; 303. Second temperature sensor; 401. Third flow sensor; 402. Third pressure sensor; 403. Third temperature sensor; 501. Fourth flow sensor; 502. Fourth pressure sensor; 503. Fourth temperature sensor; 601. Fifth flow sensor; 602. Fifth pressure sensor; 603. Fifth temperature sensor; 701. Sixth flow sensor; 702. Sixth pressure sensor; 703. Sixth temperature sensor. Detailed Implementation

[0032] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0033] To address the problem that conventional shallow and medium-deep geothermal resource extraction methods for geothermal heating and cooling in areas with high building density and uneven heating and cooling loads cannot achieve long-term, efficient, and stable operation, this invention provides a comprehensive geothermal energy utilization system, comprising:

[0034] Coaxial casing geothermal well;

[0035] User heat exchange components;

[0036] The heat pump unit has its first heat exchange side connected to the coaxial casing geothermal well via the geothermal well outlet pipe and the geothermal well inlet pipe, and its second heat exchange side connected to the user's heat exchange components via the user's water supply pipe and the user's water return pipe.

[0037] The buried pipe heat exchanger is connected to the geothermal well's inlet and outlet pipes via a buried pipe inlet pipe and a buried pipe outlet pipe, respectively.

[0038] Specifically, this geothermal energy integrated utilization system has a coaxial casing geothermal well and a buried pipe heat exchanger, which are used for the development and utilization of medium-deep and shallow geothermal resources, respectively. Through heat exchange between the first and second heat exchange sides of the heat pump unit, the coaxial casing geothermal well and the buried pipe heat exchanger can operate independently or in combination, forming heat exchange with the user's heat exchange components, thereby realizing heating or cooling for the user's heat exchange components. This geothermal energy integrated utilization system can flexibly choose to operate the coaxial casing geothermal well and the buried pipe heat exchanger independently or in combination according to heating and cooling needs. It can independently exploit and utilize medium-deep and shallow geothermal resources or jointly exploit and utilize both, thus making the exploitation and utilization of geothermal resources more flexible and comprehensive, and achieving long-term, efficient and stable operation.

[0039] Optionally, it also includes a buried pipe outlet bypass pipe, the two ends of which are connected to the buried pipe outlet pipe and the geothermal well inlet pipe, respectively.

[0040] Specifically, the installation of the buried pipe outlet bypass pipe connects the buried pipe outlet pipe and the geothermal well inlet pipe, providing a branch loop for the geothermal well outlet pipe after heat exchange in a coaxial sleeve. This allows a portion of the water output from the geothermal well outlet pipe to circulate once inside the buried pipe heat exchanger, and then flow back to the geothermal well outlet pipe through the buried pipe outlet bypass pipe, achieving the effect of using the heating tailwater to supplement shallow geothermal resources.

[0041] Optionally, a first data acquisition module, a second data acquisition module, a third data acquisition module, a fourth data acquisition module, a fifth data acquisition module, and a sixth data acquisition module are respectively installed on the geothermal well inlet pipe, the geothermal well outlet pipe, the buried pipe inlet pipe, the buried pipe outlet pipe, the user water supply pipe, and the user return water pipe.

[0042] Specifically, the first to sixth data acquisition modules detect the medium conditions inside the pipeline at different locations, so as to facilitate the subsequent control of the valves on each pipeline, thereby switching operating strategies and controlling the operating status.

[0043] Optionally, the first data acquisition module includes a first flow sensor, a first pressure sensor, and a first temperature sensor; the second data acquisition module includes a second flow sensor, a second pressure sensor, and a second temperature sensor; the third data acquisition module includes a third flow sensor, a third pressure sensor, and a third temperature sensor; the fourth data acquisition module includes a fourth flow sensor, a fourth pressure sensor, and a fourth temperature sensor; the fifth data acquisition module includes a fifth flow sensor, a fifth pressure sensor, and a fifth temperature sensor; and the sixth data acquisition module includes a sixth flow sensor, a sixth pressure sensor, and a sixth temperature sensor.

[0044] Specifically, each data acquisition module collects the flow rate, pressure, and temperature data of the medium in the corresponding pipeline.

[0045] Optionally, the user's water supply pipeline, the geothermal well outlet pipeline, and the buried pipe inlet pipeline are respectively equipped with a first circulation pump, a second circulation pump, and a third circulation pump.

[0046] Specifically, the circulation of the heat exchange medium between the coaxial casing geothermal well and the heat pump unit, between the buried pipe heat exchanger and the heat pump unit, and between the user's heat exchange components and the heat pump unit is driven by the first to the third circulation pumps, and the operating parameters of each circulation pump are adjustable.

[0047] Optionally, the geothermal well outlet pipe, the buried pipe outlet bypass pipe, the geothermal well inlet pipe, the end of the buried pipe inlet pipe near the geothermal well inlet pipe, the user water supply pipe, the user return water pipe, the end of the buried pipe outlet pipe near the geothermal well outlet pipe, the end of the geothermal well outlet pipe, the end of the buried pipe outlet pipe near the buried pipe heat exchanger, and the end of the buried pipe inlet pipe near the buried pipe heat exchanger are respectively equipped with a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a seventh valve, an eighth valve, a ninth valve, and a tenth valve.

[0048] Specifically, the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, and tenth valves are electrically controlled valves, which are electrically connected to the control unit. The control unit can remotely control the opening and closing status of each valve to achieve the effect of regulating the water flow path.

[0049] Optionally, it also includes a control unit, and a first data acquisition module, a second data acquisition module, a third data acquisition module, a fourth data acquisition module, a fifth data acquisition module, a sixth data acquisition module, a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a seventh valve, an eighth valve, a ninth valve, and a tenth valve connected to the control unit.

[0050] Specifically, the control unit can control the opening and closing status of each valve based on the data collected by each data acquisition module. The opening and closing status includes the adjustment of the opening degree.

[0051] Optionally, the coaxial casing geothermal well includes a central pipe and an annular pipe. The central pipe is located inside the annular pipe, and the bottom of the central pipe is higher than the bottom of the annular pipe, so that the lower end of the central pipe is connected to the lower end of the annular pipe. The geothermal well outlet pipe and the geothermal well inlet pipe are connected to the central pipe and the annular pipe, respectively.

[0052] Specifically, the medium inside the coaxial casing geothermal well enters the annular tube, exchanges heat with the formation, and obtains geothermal energy. Then, it enters the central tube from the lower end of the annular tube and flows out from the central tube, completing the circulation of the medium.

[0053] The present invention also provides a method for comprehensive utilization of geothermal energy, utilizing the above-mentioned comprehensive geothermal energy utilization system, characterized in that it includes:

[0054] In summer, cooling is carried out separately using buried pipe heat exchangers;

[0055] During the first heat load phase in winter, heating is provided by combining coaxial casing geothermal wells and buried pipe heat exchangers.

[0056] During the second heat load stage in winter, when the heat load is lower than that of the first heat load stage, heating is provided separately using coaxial casing geothermal wells.

[0057] Specifically, based on the aforementioned geothermal energy integrated utilization system, this geothermal energy integrated utilization method can implement different cooling or heating strategies in summer and winter according to different cooling or heating needs.

[0058] Optionally, when the geothermal energy comprehensive utilization system also includes a buried pipe outlet bypass pipe, and both ends of the buried pipe outlet bypass pipe are connected to the buried pipe outlet pipe and the geothermal well inlet pipe respectively, the geothermal energy comprehensive utilization method also includes:

[0059] During the third heat load stage in winter, when the heat load is lower than the second heat load stage, coaxial casing geothermal wells are used for heating and the tailwater of the heating system is used to supplement the heat of the stratum where the buried pipe heat exchanger is located.

[0060] Specifically, by breaking down the winter heating demand, the working strategy of the aforementioned geothermal energy integrated utilization system can be further selected based on the size of the heat load. The first heat load stage, the second heat load stage, and the third heat load stage can correspond to high, medium, and low heating demands, respectively. During the low heating demand period in winter, the medium-deep geothermal energy extracted and utilized by the coaxial casing geothermal well has redundancy while meeting the heating demand. The redundant heat energy can be used to supplement the geothermal energy of shallow strata, avoiding the imbalance of cold and heat in shallow strata and causing cold or hot accumulation problems.

[0061] Example 1

[0062] like Figure 1 As shown, the present invention provides a geothermal energy comprehensive utilization system, comprising:

[0063] Coaxial casing geothermal well 1;

[0064] User heat exchange component 15;

[0065] The heat pump unit 12 has a first heat exchange side connected to the coaxial casing geothermal well 1 through the geothermal well outlet pipe 25 and the geothermal well inlet pipe 26, and a second heat exchange side connected to the user heat exchange component 15 through the user water supply pipe 30 and the user return water pipe 31.

[0066] The buried pipe heat exchanger 23 is connected to the geothermal well inlet pipe 26 and the geothermal well outlet pipe 25 through the buried pipe inlet pipe 27 and the buried pipe outlet pipe 28, respectively.

[0067] In this embodiment, the installation depth of the coaxial casing geothermal well 1 is 1000-3000m, and the installation depth of the buried pipe heat exchanger 23 is 100-200m.

[0068] Optionally, it also includes a buried pipe outlet bypass pipe 29, the two ends of which are connected to the buried pipe outlet pipe 28 and the geothermal well inlet pipe 26, respectively.

[0069] Optionally, a first data acquisition module 2, a second data acquisition module 3, a third data acquisition module 4, a fourth data acquisition module 5, a fifth data acquisition module 6, and a sixth data acquisition module 7 are respectively installed on the geothermal well inlet pipe 26, the geothermal well outlet pipe 25, the buried pipe inlet pipe 27, the buried pipe outlet pipe 28, the user water supply pipe 30, and the user return water pipe 31.

[0070] Optionally, the first data acquisition module 2 includes a first flow sensor 201, a first pressure sensor 202, and a first temperature sensor 203; the second data acquisition module 3 includes a second flow sensor 301, a second pressure sensor 302, and a second temperature sensor 303; the third data acquisition module 4 includes a third flow sensor 401, a third pressure sensor 402, and a third temperature sensor 403; the fourth data acquisition module 5 includes a fourth flow sensor 501, a fourth pressure sensor 502, and a fourth temperature sensor 503; the fifth data acquisition module 6 includes a fifth flow sensor 601, a fifth pressure sensor 602, and a fifth temperature sensor 603; and the sixth data acquisition module 7 includes a sixth flow sensor 701, a sixth pressure sensor 702, and a sixth temperature sensor 703.

[0071] Optionally, the user water supply pipe 30, the geothermal well outlet pipe 25, and the buried pipe inlet pipe 27 are respectively equipped with a first circulation pump 14, a second circulation pump 19, and a third circulation pump 20.

[0072] Optionally, the following valves are respectively provided: a first valve 8, a second valve 9, a third valve 10, a fourth valve 11, a fifth valve 13, a sixth valve 16, a seventh valve 17, an eighth valve 18, a ninth valve 21, and a tenth valve 22 for the geothermal well outlet pipe 25, the buried pipe outlet bypass pipe 29, the geothermal well inlet pipe 26, the buried pipe inlet pipe 27 near the geothermal well inlet pipe 26, the user supply pipe 30, the user return pipe 31, the buried pipe outlet pipe 28 near the geothermal well outlet pipe 25, the geothermal well outlet pipe 25, the buried pipe outlet pipe 28 near the buried pipe heat exchanger 23, and the buried pipe inlet pipe 27 near the buried pipe heat exchanger 23.

[0073] Optionally, it also includes a control unit 24, and the first data acquisition module 2, the second data acquisition module 3, the third data acquisition module 4, the fourth data acquisition module 5, the fifth data acquisition module 6, the sixth data acquisition module 7, the first valve 8, the second valve 9, the third valve 10, the fourth valve 11, the fifth valve 13, the sixth valve 16, the seventh valve 17, the eighth valve 18, the ninth valve 21, and the tenth valve 22 are connected to the control unit 24.

[0074] Optionally, the coaxial casing geothermal well 1 includes a central pipe 101 and an annular pipe 102. The central pipe 101 is disposed inside the annular pipe 102, and the bottom of the central pipe 101 is higher than the bottom of the annular pipe 102, so that the lower end of the central pipe 101 is connected to the lower end of the annular pipe 102. The geothermal well outlet pipe 25 and the geothermal well inlet pipe 26 are respectively connected to the central pipe 101 and the annular pipe 102.

[0075] Example 2

[0076] like Figure 2 As shown, the present invention also provides a method for comprehensive utilization of geothermal energy, utilizing the above-mentioned comprehensive utilization system of geothermal energy, characterized in that it includes:

[0077] In summer, cooling is carried out separately using the buried pipe heat exchanger 23;

[0078] During the first heat load phase in winter, heating is provided by combining coaxial casing geothermal well 1 and buried pipe heat exchanger 23.

[0079] During the second heat load stage in winter, when the heat load is lower than that of the first heat load stage, the coaxial casing geothermal well 1 is used for heating alone.

[0080] Optionally, when the geothermal energy comprehensive utilization system further includes a buried pipe outlet bypass pipe 29, and both ends of the buried pipe outlet bypass pipe 29 are connected to the buried pipe outlet pipe 28 and the geothermal well inlet pipe 26 respectively, the geothermal energy comprehensive utilization method further includes:

[0081] During the third heat load stage in winter when the heat load is lower than the second heat load stage, the coaxial casing geothermal well 1 is used for heating and the tailwater of the heating is used to supplement the heat of the stratum where the buried pipe heat exchanger 23 is located.

[0082] In summary, when implementing the geothermal energy comprehensive utilization method provided by this invention, the aforementioned geothermal energy comprehensive utilization system allows for four operating strategies based on the heat load, thus providing four geothermal energy utilization strategies:

[0083] Strategy 1: Utilize shallow geothermal energy for cooling during the summer.

[0084] During operation, the fourth valve 11, the seventh valve 17, the ninth valve 21, the tenth valve 22, the fifth valve 13, the sixth valve 16, the third circulation pump 20, and the first circulation pump 14 need to be opened via the control unit 24, while the remaining circulation pumps and valves are closed. The shallow geothermal side circulating water enters the buried pipe heat exchanger 23 through the buried pipe inlet pipe 27, and then connects to the heat pump unit 12 through the buried pipe outlet pipe 28 to complete the circulation. The circulating water on the user heat exchange component 15 side is sent from the heat pump unit 12 to the user heat exchange component 15 through the user water supply pipe 30, and then returned to the heat pump unit 12 through the user return water pipe 31 to complete the circulation. The circulation method for the user heat exchange component 15 side in other strategies is the same as in Strategy 1.

[0085] During operation, the fifth data acquisition module 6 and the sixth data acquisition module 7 collect cooling data from the user's heat exchange component 15 and upload the data to the control unit 24. The control unit 24 can calculate the cooling load of the user's heat exchange component 15 and adjust the operating parameters of the third circulation pump 20, the first circulation pump 14, and the heat pump unit 12 according to the load and meteorological parameters. The third data acquisition module 4 and the fourth data acquisition module 5 collect real-time cooling data from the buried pipe heat exchanger 23 and upload the data to the control unit 24. The control unit 24 can calculate the cumulative cooling capacity of the buried pipe heat exchanger 23 throughout its entire life cycle.

[0086] Strategy 2: Utilize a combination of medium-deep and shallow geothermal energy for heating during the high heat load period in winter.

[0087] During operation, the control unit 24 needs to open the first valve 8, the third valve 10, the fourth valve 11, the fifth valve 13, the sixth valve 16, the seventh valve 17, the eighth valve 18, the ninth valve 21, the tenth valve 22, the first circulating pump 14, the second circulating pump 19, and the third circulating pump 20, and close the remaining valves. The circulating water on the medium-deep geothermal side enters the upper end of the annular pipe 102 through the geothermal well inlet pipe 26 from the heat pump unit 12. The circulating water enters the central pipe 101 from the bottom of the coaxial heat exchange geothermal well, and then enters the heat pump unit 12 through the geothermal well outlet pipe to complete the circulation. The circulating water on the shallow geothermal side enters the buried pipe inlet pipe 27 from the geothermal well inlet pipe 26 and flows into the buried pipe heat exchanger 23. Then it flows from the buried pipe outlet pipe 28 into the geothermal well outlet pipe 25 and finally connects to the heat pump unit 12.

[0088] During operation, the fifth data acquisition module 6 and the sixth data acquisition module 7 collect heating data from the user's heat exchange component 15 and upload the data to the control unit 24. The control unit 24 can calculate the heat load on the user's heat exchange component 15 and adjust the operating parameters of the first circulation pump 14, the second circulation pump 19, the third circulation pump 20, and the heat pump unit 12 based on the load and meteorological parameters. At the same time, the opening of the fourth valve 11 and the seventh valve 17 can be adjusted to regulate the auxiliary heating of shallow geothermal energy. The third data acquisition module 4 and the fourth data acquisition module 5 collect real-time heat extraction data from the buried pipe heat exchanger 23 and upload the data to the control unit 24. The control unit 24 can calculate the cumulative heat extraction of the buried pipe heat exchanger 23 throughout its entire life cycle.

[0089] Strategy 3: Utilize medium-deep geothermal heating during the low heat load period in winter, and supplement the heat using the tailwater from the heating system.

[0090] During operation, the control unit 24 needs to open the first valve 8, the second valve 9, the third valve 10, the fourth valve 11, the fifth valve 13, the sixth valve 16, the eighth valve 18, the ninth valve 21, the tenth valve 22, the first circulating pump 14, the second circulating pump 19, and the third circulating pump 20, and close the remaining valves. The circulating water from the medium-deep geothermal side completes heat exchange from the coaxial heat exchange geothermal well and enters the heat pump unit 12 from the upper end of the central pipe 101 through the medium-deep geothermal well outlet pipe 25. Then it flows out from the geothermal well inlet pipe 26. Part of the circulating water flows directly to the ring pipe 102 to complete the circulation, while the other part of the circulating water passes through the buried pipe inlet pipe 27, the buried pipe heat exchanger 23, the buried pipe outlet pipe 28, and the buried pipe outlet bypass pipe 29 before reconnecting to the geothermal well inlet pipe 26 and finally flowing to the ring pipe 102 to complete the circulation.

[0091] During operation, the third data acquisition module 4 and the fourth data acquisition module 5 collect real-time heat replenishment data of the buried pipe heat exchanger 23 and upload the data to the control unit 24. The control unit 24 can calculate the cumulative heat replenishment of the buried pipe heat exchanger 23 throughout its entire life cycle. The fifth data acquisition module 6 and the sixth data acquisition module 7 collect heating data from the user's heat exchange component 15 and upload the data to the control unit 24. The control unit 24 can calculate the heat load on the user's heat exchange component 15 and adjust the operating parameters of the first circulation pump 14, the second circulation pump 19, the third circulation pump 20, and the heat pump unit 12 based on the load and meteorological parameters. At the same time, the opening of the second valve 9 and the seventh valve 17 can be adjusted. Based on the cumulative heat extraction, heat replenishment, and cooling of the buried pipe heat exchanger 23 collected by the control unit 24, the current shallow geothermal heat gap can be calculated, and based on this, the heat replenishment from the medium-deep geothermal layer to the shallow geothermal layer can be adjusted.

[0092] Strategy 4: Utilize medium-deep geothermal energy for heating during the medium-load phase of winter.

[0093] During operation, the control unit 24 needs to open the first valve 8, the third valve 10, the fifth valve 13, the sixth valve 16, the eighth valve 18, the first circulation pump 14, and the second circulation pump 19, and close the remaining valves and circulation pumps. The circulating water on the medium-deep geothermal side completes heat exchange from the coaxial heat exchange geothermal well and enters the heat pump unit 12 from the upper end of the central pipe 101 through the medium-deep geothermal well outlet pipe 25. Then it flows out from the geothermal well inlet pipe 26 and the circulating water flows to the annular pipe 102 to complete the circulation.

[0094] During operation, the fifth data acquisition module 6 and the sixth data acquisition module 7 collect heating data from the user's heat exchange component 15 side and upload the data to the control unit 24. The control unit 24 can calculate the heat load on the user's heat exchange component 15 side and adjust the operating parameters of the first circulation pump 14, the second circulation pump 19, and the heat pump unit 12 according to the load and meteorological parameters.

[0095] The geothermal energy comprehensive utilization system and method provided by this invention adopts a geothermal energy utilization system that couples medium-deep geothermal energy with shallow geothermal energy, and is particularly suitable for high-density building areas where the winter heat load is greater than the summer cooling load. In summer, shallow geothermal energy is used for cooling, while in winter, based on the load conditions, four heating operation strategies are designed to fully utilize medium-deep geothermal energy as a heating and supplementary heat source, and use shallow geothermal energy for peak shaving. The system design allows for intelligent adjustment of geothermal energy extraction and distribution under different seasons and load demands, thereby optimizing energy consumption and improving the overall energy efficiency of the system. The operation strategy can be adjusted according to user load demands, changing the heating mode. During high-load periods, the shallow buried pipe heat exchanger 23 can be activated for auxiliary heating, which can reduce the load required by the medium-deep coaxial casing geothermal well 1 and reduce construction costs. The control unit 24 can integrate advanced data acquisition and processing functions, enabling real-time monitoring of the system's operating status and automatic adjustment of the operation strategy according to load changes and meteorological conditions. This intelligent management not only improves the system's operating efficiency but also reduces the complexity of manual operation. Furthermore, the system employs a strategy of using the tailwater from medium-deep geothermal heating to supplement shallow geothermal heat during low-load winter periods. This effectively maintains soil thermal balance, avoids soil temperature imbalance caused by long-term unidirectional heat extraction, and ensures long-term stable operation of the system. This comprehensive geothermal energy utilization system and method are particularly suitable for urban areas with high building density and uneven heating and cooling loads. The system design takes into account the limited land resources and small building spacing in urban areas, maximizing the utilization of geothermal resources within a limited space through the efficient heat exchange technology of medium-deep geothermal wells. The system's efficient operation strategy and intelligent management further improve the utilization efficiency of geothermal energy, reduce users' energy costs, and have significant economic benefits. Simultaneously, the widespread application of the system helps reduce dependence on fossil fuels and greenhouse gas emissions, which is of great significance for promoting energy structure transformation and achieving regional sustainable development.

[0096] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A geothermal energy comprehensive utilization system, characterized in that, include: Coaxial casing geothermal well; User heat exchange components; The heat pump unit has a first heat exchange side connected to the coaxial casing geothermal well via a geothermal well outlet pipe and a geothermal well inlet pipe, and a second heat exchange side connected to the user heat exchange component via a user water supply pipe and a user water return pipe. A buried pipe heat exchanger is connected to the geothermal well inlet pipe and the geothermal well outlet pipe via a buried pipe inlet pipe and a buried pipe outlet pipe, respectively.

2. The geothermal energy comprehensive utilization system according to claim 1, characterized in that, It also includes a buried pipe outlet bypass pipe, the two ends of which are connected to the buried pipe outlet pipe and the geothermal well inlet pipe, respectively.

3. The geothermal energy comprehensive utilization system according to claim 2, characterized in that, The geothermal well inlet pipe, the geothermal well outlet pipe, the buried pipe inlet pipe, the buried pipe outlet pipe, the user water supply pipe, and the user return water pipe are respectively equipped with a first data acquisition module, a second data acquisition module, a third data acquisition module, a fourth data acquisition module, a fifth data acquisition module, and a sixth data acquisition module.

4. The geothermal energy comprehensive utilization system according to claim 3, characterized in that, The first data acquisition module includes a first flow sensor, a first pressure sensor, and a first temperature sensor; the second data acquisition module includes a second flow sensor, a second pressure sensor, and a second temperature sensor; the third data acquisition module includes a third flow sensor, a third pressure sensor, and a third temperature sensor; the fourth data acquisition module includes a fourth flow sensor, a fourth pressure sensor, and a fourth temperature sensor; the fifth data acquisition module includes a fifth flow sensor, a fifth pressure sensor, and a fifth temperature sensor; and the sixth data acquisition module includes a sixth flow sensor, a sixth pressure sensor, and a sixth temperature sensor.

5. The geothermal energy comprehensive utilization system according to claim 4, characterized in that, The user water supply pipeline, the geothermal well outlet pipeline, and the buried pipe inlet pipeline are respectively equipped with a first circulation pump, a second circulation pump, and a third circulation pump.

6. The geothermal energy comprehensive utilization system according to claim 5, characterized in that, The geothermal well outlet pipe, the buried pipe outlet bypass pipe, the geothermal well inlet pipe, the end of the buried pipe inlet pipe near the geothermal well inlet pipe, the user water supply pipe, the user return water pipe, the end of the buried pipe outlet pipe near the geothermal well outlet pipe, the end of the geothermal well outlet pipe, the end of the buried pipe outlet pipe near the buried pipe heat exchanger, and the end of the buried pipe inlet pipe near the buried pipe heat exchanger are respectively equipped with a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a seventh valve, an eighth valve, a ninth valve, and a tenth valve.

7. The geothermal energy comprehensive utilization system according to claim 6, characterized in that, It also includes a control unit, wherein the first data acquisition module, the second data acquisition module, the third data acquisition module, the fourth data acquisition module, the fifth data acquisition module, the sixth data acquisition module, the first valve, the second valve, the third valve, the fourth valve, the fifth valve, the sixth valve, the seventh valve, the eighth valve, the ninth valve, and the tenth valve are connected to the control unit.

8. The geothermal energy comprehensive utilization system according to claim 1, characterized in that, The coaxial casing geothermal well includes a central pipe and an annular pipe. The central pipe is disposed inside the annular pipe, and the bottom of the central pipe is higher than the bottom of the annular pipe, so that the lower end of the central pipe is connected to the lower end of the annular pipe. The geothermal well outlet pipe and the geothermal well inlet pipe are respectively connected to the central pipe and the annular pipe.

9. A method for comprehensive utilization of geothermal energy, utilizing the geothermal energy comprehensive utilization system according to any one of claims 1-8, characterized in that, include: In summer, cooling is carried out separately using buried pipe heat exchangers; During the first heat load phase in winter, heating is provided by combining coaxial casing geothermal wells and buried pipe heat exchangers. During the second heat load stage in winter, when the heat load is lower than that of the first heat load stage, heating is provided separately using coaxial casing geothermal wells.

10. The method for comprehensive utilization of geothermal energy according to claim 9, characterized in that, When the geothermal energy comprehensive utilization system further includes a buried pipe outlet bypass pipe, and the two ends of the buried pipe outlet bypass pipe are respectively connected to the buried pipe outlet pipe and the geothermal well inlet pipe, the geothermal energy comprehensive utilization method further includes: During the third heat load stage in winter, when the heat load is lower than the second heat load stage, coaxial casing geothermal wells are used for heating and the tailwater of the heating system is used to supplement the heat of the stratum where the buried pipe heat exchanger is located.

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