LNG storage tank pile foundation heat exchanger ground loop system

Abstract

The application discloses an LNG storage tank pile foundation heat exchanger ground loop system, which comprises an energy pile system, heat exchange pipes, an air conditioning system and an air-temperature type gasifier; the output end of the energy pile system is connected with the air conditioning system and the air-temperature type gasifier through heat exchange pipelines and supplies energy for the air conditioning system and the air-temperature type gasifier; the system further comprises a plurality of inspection wells and pipeline wells; the energy pile system comprises a plurality of energy piles, and the energy piles are all provided with heat exchange pipes; and the water inlet of the heat exchange pipe is connected with the water inlet pipe of the inspection well. In the application, the heat exchange pipes in the energy pile system are divided into different zones, the heat exchange pipes in different zones are connected with the inspection wells, the pipeline is graded, the pipeline wells are arranged and connected with the inspection wells, the plurality of inspection wells are gathered, and the heat exchange pipes are convenient to overhaul.

Description

Technical Field

[0001] This invention relates to the field of geothermal application technology for LNG receiving terminals, and more specifically to a ground loop system for a pile foundation heat exchanger of an LNG storage tank. Background Technology

[0002] Since the summer of 2022, extreme high temperatures have caused power shortages in parts of the country. LNG receiving terminals, being crucial large-scale power supply units, contain numerous power-consuming processes and facilities. Their normal operation relies heavily on a stable power source. On one hand, government-allocated and guaranteed power supplies serve as basic power guarantees for these enterprises. On the other hand, as state-owned enterprises bearing the heavy responsibility of regional energy stability, they must adhere to the principle of "self-sufficiency." Effective energy reduction and emission reduction in production and operation are also essential. With the continuous increase in my country's demand for green and clean energy, the construction speed of liquefied natural gas (LNG) receiving terminals has accelerated. However, large storage tanks have the disadvantage of huge energy consumption, necessitating reasonable energy-saving and emission-reduction measures, including the development of shallow geothermal energy.

[0003] Existing patent publication number CN 217130967 U discloses a heat exchange system for an LNG receiving terminal, including an energy pile system, an air conditioning system, an ambient air vaporizer, heat exchange tubes, a first heat exchange device, and a second heat exchange device. The energy pile system includes multiple energy piles, with the two ends of the water pipes of the multiple energy piles respectively connected to the heat exchange tubes. The first heat exchange device is connected to the heat exchange tubes. The piping of the air conditioning system is connected to the first heat exchange device. The heat exchange tubes are connected to the second heat exchange device, and the second heat exchange device is connected to the ambient air vaporizer.

[0004] However, the heat exchange pipes of its energy pile system are all directly connected to the heat exchange device. Due to the complexity of the pipelines in the energy pile system and their direct connection to the heat exchange device, it is impossible to directly identify which part of the pipeline is faulty and carry out repairs once a problem occurs, which increases the difficulty of repairs. Summary of the Invention

[0005] The technical problem to be solved by this invention is how to facilitate the maintenance of heat exchange systems.

[0006] This invention solves the above-mentioned technical problems through the following technical means: a ground loop system for an LNG storage tank pile foundation heat exchanger, comprising an energy pile system, heat exchange pipes, an air conditioning system, and an ambient air vaporizer. The output end of the energy pile system is connected to the air conditioning system and the ambient air vaporizer through heat exchange pipes and supplies them with energy. It also includes multiple inspection wells and pipeline wells. The energy pile system includes multiple energy piles, each of which is equipped with a heat exchange pipe. The inlet of the heat exchange pipe is connected to the inlet pipe of the inspection well, and the outlet of the heat exchange pipe is connected to the outlet pipe of the inspection well. The return water end and the outlet water end of the inspection well are respectively connected to the return water end and the supply water end of the pipeline well through a return water main pipe and a supply water main pipe.

[0007] By dividing the heat exchange tubes in the energy pile system into zones and setting up multiple inspection wells, the heat exchange tubes in different zones are connected to the inspection wells, thus achieving hierarchical management of the pipelines. By setting up pipeline wells and connecting them to inspection wells, the multiple inspection wells are aggregated, which facilitates the maintenance of the heat exchange tubes and reduces the difficulty of maintenance.

[0008] As a preferred technical solution, the energy pile system also includes an inlet pipe and a return pipe, which are respectively connected to the inlet pipe and outlet pipe of the inspection well.

[0009] As a preferred technical solution, the inspection well is equipped with a water distributor cylinder and a water collector cylinder. One end of the water distributor cylinder is connected to the water inlet pipe, and the other end is connected to the water supply pipe of the pipeline well through the main water supply pipe. One end of the water collector cylinder is connected to the return water pipe, and the other end is connected to the return water pipe of the pipeline well through the main return water pipe.

[0010] As a preferred technical solution, the number of energy piles is 120, and two energy piles are connected in series to form a heat exchange branch. Each heat exchange branch has an inlet pipe and an outlet pipe. The inlet pipe of the heat exchange branch is connected to one end of the water distributor cylinder, and the outlet pipe of the heat exchange branch is connected to one end of the water collector cylinder.

[0011] As a preferred technical solution, the inspection well includes two first inspection wells and two second inspection wells. The first inspection wells are 14-branch inspection wells, and the second inspection wells are 16-branch inspection wells. The two first inspection wells and the two second inspection wells are centrally symmetrically distributed.

[0012] As a preferred technical solution, a static balance valve is provided on the water outlet pipe connected to the water collector cylinder, a butterfly valve is provided on the water inlet pipe connected to the water distributor cylinder, and an air release valve is also connected to the water outlet pipe through a conversion joint.

[0013] As a preferred technical solution, the pipeline well is provided with a first water supply main pipe, a second water supply main pipe and a first return water main pipe and a second return water main pipe that are interconnected. The first water supply main pipe is connected to the water distributor cylinder of the inspection well through the water supply main pipe, and the first return water main pipe is connected to the water collector cylinder through the return water main pipe.

[0014] As a preferred technical solution, butterfly valves are provided on the first water supply main, the second water supply main, the first return water main, and the second return water main.

[0015] As a preferred technical solution, the first water supply main pipe, the second water supply main pipe, the first return water main pipe, and the second return water main pipe are all equipped with air release valves. The first water supply main pipe and the first return water main pipe are also equipped with water drain valves. The energy pile includes a steel cage, a heat exchange pipe, a stress sensor, and a strain sensor. The heat exchange pipe is wound and fixed inside the steel cage. The stress sensor and the strain sensor are both fixed inside the steel cage. The steel cage forms the pile body after concrete is poured.

[0016] As a preferred technical solution, in summer, the butterfly valves on the first water supply main and the first return main are opened, while the butterfly valves on the second water supply main and the second return main are closed. Water in the heat exchange pipes of the energy pile system sequentially enters the inspection well and the pipe well, and then enters the air conditioning system through the first water supply main to exchange heat with the refrigerant circulating within it. The hot water after heat exchange flows through the first return main into the pipe well and the inspection well, and then back into the heat exchange pipes of the energy pile system. In winter, the butterfly valves on the first water supply main and the first return main are closed, while the butterfly valves on the second water supply main and the second return main are opened. The water in the heat exchange pipes of the energy pile system sequentially enters the inspection well and the pipeline well, and then enters the air conditioning system through the first water supply main pipe to exchange heat with the refrigerant circulating inside. The hot water after heat exchange enters the pipeline well and the inspection well through the first return water main pipe and then flows back into the heat exchange pipes of the energy pile system. The water in the remaining heat exchange pipes of the energy pile system sequentially enters the inspection well and the pipeline well, and then enters the ambient temperature vaporizer through the second water supply main pipe to heat the vaporized natural gas. The heated water enters the pipeline well and the inspection well through the second return water main pipe and then flows back into the heat exchange pipes of the energy pile system.

[0017] The advantages of this invention are:

[0018] (1) In this invention, by dividing the heat exchange tubes in the energy pile system into zones and setting up multiple inspection wells, the heat exchange tubes in different areas are connected to the inspection wells, thus realizing the hierarchical classification of the pipeline. By setting up the pipeline wells and connecting them to the inspection wells, the summarization of multiple inspection wells is realized, which facilitates the maintenance of the heat exchange tubes.

[0019] (2) In this invention, by setting up a static balance valve, an air release valve and a conversion joint, hydraulic balance between different branches and free rotation and flexible switching operation between different energy pile areas can be achieved.

[0020] (3) In this invention, by using the energy pile heat exchange system in the LNG receiving station area, it can not only support the upper structure, but also provide the heat required for the LNG reheating and export process, thereby improving the energy utilization rate. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of a ground loop system for an LNG storage tank pile foundation heat exchanger, provided in an embodiment of the present invention.

[0022] Figure 2 This is a top view of the energy pile structure of an LNG storage tank pile foundation heat exchanger ground loop system provided in an embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the first pipeline well structure of a ground loop system for an LNG storage tank pile foundation heat exchanger provided in an embodiment of the present invention;

[0024] Figure 4 A ground loop system for an LNG storage tank pile foundation heat exchanger is provided as an embodiment of the present invention. Figure 3 A schematic diagram of the AA cross-sectional structure;

[0025] Figure 5 A ground loop system for an LNG storage tank pile foundation heat exchanger is provided as an embodiment of the present invention. Figure 3 A schematic diagram of the BB cross-sectional structure;

[0026] Figure 6 This is a schematic diagram of the second pipeline well structure of a ground loop system for an LNG storage tank pile foundation heat exchanger provided in an embodiment of the present invention;

[0027] Figure 7 A ground loop system for an LNG storage tank pile foundation heat exchanger is provided as an embodiment of the present invention. Figure 6 Schematic diagram of CC cross-section structure;

[0028] Figure 8 A ground loop system for an LNG storage tank pile foundation heat exchanger is provided as an embodiment of the present invention. Figure 6 Schematic diagram of the DD cross-sectional structure;

[0029] Figure 9 This is a schematic diagram of the pipeline well structure of a ground loop system for an LNG storage tank pile foundation heat exchanger, provided in an embodiment of the present invention.

[0030] Figure 10A ground loop system for an LNG storage tank pile foundation heat exchanger is provided as an embodiment of the present invention. Figure 9 A schematic diagram of the EE structure;

[0031] Figure 11 A ground loop system for an LNG storage tank pile foundation heat exchanger is provided as an embodiment of the present invention. Figure 9 A schematic diagram of the FF structure;

[0032] Figure 12 This is a schematic diagram of the energy pile structure of an LNG storage tank pile foundation heat exchanger ground loop system provided in an embodiment of the present invention;

[0033] Reference numerals: 1. Energy pile system; 11. Energy pile; 1101. Reinforcing cage; 1102. Heat exchanger tube; 1103. Stress sensor; 1104. Strain sensor; 12. Inlet pipe; 13. Outlet pipe; 2. Air conditioning system; 3. Ambient air vaporizer; 4. Connecting pipeline; 5. Inspection well; 501. Water distributor cylinder; 502. Water collector cylinder; 503. Static balancing valve; 504. Air vent valve; 505. Adapter joint; 51. First inspection well; 52. Second inspection well; 53. 54. Manhole for inspection well; 6. Sump pit for pipe well; 7. Pipe well; 8. Water supply main; 9. First water supply main; 10. Second water supply main; 11. Return water main; 12. First return water main; 13. Second return water main; 14. Manhole for pipe well; 15. Sump pit; 16. Main return water pipe; 17. Main water supply pipe; 18. Pressure gauge; 19. Thermometer; 10. Butterfly valve; 11. Waterproof sleeve; 12. Inlet end of water collector cylinder; 13. Outlet end of water distributor cylinder; 14. Drain valve. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] See Figure 1 and Figure 2A ground loop system for an LNG storage tank pile foundation heat exchanger includes an energy pile system 1, an air conditioning system 2, an ambient air vaporizer 3, connecting pipes 4, inspection wells 5, and pipeline wells 6. The system is divided into zones based on the number of energy piles 11 within the energy pile system 1, and multiple inspection wells 5 are installed. In this embodiment, four inspection wells 5 are used as an example. The return water and outlet water of the energy pile system 1 are respectively collected in the four inspection wells 5 of their corresponding zones. The return water and outlet water of the inspection wells 5 are connected to the return water and supply water of the pipeline wells 6 through a return water main pipe 7 and a supply water main pipe 8, respectively. The pipeline wells 6 are connected to the air conditioning system 2 in the plant front area and the ambient air vaporizer 3 in the vaporization zone via connecting pipes 4 for heating or cooling. The multiple inspection wells 5 facilitate future maintenance. (See reference...) Figure 8 The manhole 5 is equipped with a water distributor cylinder 501, a water collector cylinder 502, a static balance valve 503, an air release valve 504 and a conversion joint 505, which realizes the hydraulic balance between different branches and the free rotation and flexible switching operation between different energy pile areas.

[0036] See Figure 12 The energy pile system 1 includes multiple energy piles 11, inlet pipes 12, and outlet pipes 13. For example, in an LNG receiving station project, there are two 100,000 cubic meter storage tanks, hereinafter referred to as Tank 1# and Tank 2#. Each tank has 300 concrete-filled piles, each 53 meters long. Of these, 180 are ordinary piles, evenly distributed in the center. These are reinforced concrete bored piles with a diameter of 1.2 meters. In this embodiment, two tanks are included. Taking the energy pile system 1 for one tank as an example, the energy pile system 1 includes 120 energy piles 11. 1. Through preliminary tests and calculations, 120 outer pile foundations were selected for conversion into energy piles 11. The 120 energy piles 11 are arranged in a double-layer ring, distributed outside the ordinary pile foundations. The inner ring of energy piles 11 has a radius of 32,500 mm and contains 56 piles, while the outer ring of energy piles 11 has a radius of 36,100 mm and contains 64 piles. Selecting the outer pile foundations and converting them into energy piles 11 facilitates future maintenance. At the same time, due to the high density of the pile foundations, selecting some pile foundations for conversion can achieve the best heat exchange effect.

[0037] In this embodiment, two energy piles 11 are used as a group. The buried pipe length of the LNG storage tank pile is 50 meters. The heat exchange pipe 1102 in a single pile is arranged in a 3U-shaped pipe. The heat exchange pipes 1102 of the two groups of energy piles 11 are connected in series to form a branch with an inlet pipe 12 and an outlet pipe 13. The inlet pipe 12 and outlet pipe 13 of each group of energy piles 11 are connected to the water distributor cylinder 501 and the water collector cylinder 502 in the inspection well 5 in their corresponding area.

[0038] See Figure 12Each energy pile 11 includes a steel cage 1101, a heat exchange pipe 1102, a stress sensor 1103, and a strain sensor 1104. The heat exchange pipe 1102 is arranged in a 3U shape. The steel cage 1101 is fitted inside the borehole, which is formed in the soil. The heat exchange pipe 1102 is wrapped around the inside of the steel cage 1101. The stress sensor 1103 is welded and fixed to the side of the steel bar to be tested in the steel cage 1101 to detect the stress of the steel bar. The strain sensor 1104 is tied to the steel bar of the steel cage 1101 to detect the strain of the concrete. After the heat exchange pipe 1102, stress sensor 1103, and strain sensor 1104 are all arranged on the steel cage 1101, the concrete is poured after the borehole to form the pile foundation.

[0039] In actual construction, the reinforcing cage 1101 is made in sections, and the heat exchange tubes 1102 are installed on the sections of the reinforcing cage 1101. When connecting the sections of the reinforcing cage 1101 as a whole, the heat exchange tubes 1102 of different sections are connected after the adjacent sections of the reinforcing cage 1101 are connected.

[0040] See Figure 12 The heat exchange tube 1102 includes a top heat exchange tube section, a middle heat exchange tube section, and a bottom heat exchange tube section. In this embodiment, both the middle heat exchange tube section and the bottom heat exchange tube section are configured in a 3U shape. The reinforcing cage 1101 includes a top reinforcing cage section, a middle reinforcing cage section, and a bottom reinforcing cage section. The top heat exchange tube section is wound around the top reinforcing cage section, the middle heat exchange tube section is wound around the middle reinforcing cage section, and the bottom heat exchange tube section is wound around the bottom reinforcing cage section. The bottom of the top heat exchange tube section is connected and communicates with the top of the middle heat exchange tube section, and the bottom of the middle heat exchange tube section is connected and communicates with the top of the bottom heat exchange tube section.

[0041] Based on the geothermal distribution, in order to efficiently develop and utilize shallow geothermal energy and reduce interference with pile foundation construction, namely the deformation of heat exchange pipe 1102 caused by concrete pouring, the heat exchange pipe 1102 in this embodiment adopts a 3U-shaped arrangement. Specifically, in the shallow underground layer, within the range from the ground surface to 1.5m underground, the heat exchange pipe 1102 is a straight pipe. In the range below 1.5m underground, which is the ground insulation zone, the heat exchange pipe 1102 adopts a 3U-shaped arrangement, and the joints are connected using electrofusion technology.

[0042] The application process of pile foundations includes the following steps:

[0043] S0, steel cage 1101 segmented fabrication;

[0044] S1. Arrangement of heat exchanger tubes 1102: After the steel cage 1101 is fabricated in sections, it is tied to the inside of the steel cage 1101 with cable ties according to the design, and the tying density is not less than 1 cable tie / m. The heat exchanger tubes 1102 are lowered into the steel cage 1101 in sections. Before splicing the steel cage 1101, the heat exchanger tubes 1102 are filled with water to prevent them from being flattened by the concrete after lowering. The upper and lower heat exchanger tubes 1102 are connected using electrofusion technology. The steel is then installed after the joint of the heat exchanger tubes 1102 has cooled sufficiently. The main reinforcement bars of the reinforcement cage 1101 are connected, and the stirrups at the connection are supplemented. During the welding of the stirrups, appropriate protective measures are taken to avoid heat damage to the heat exchange tube 1102. The heat exchange tube 1102 is moved radially outward from the inside of the reinforcement cage at a distance of 1.5m below the design ground elevation, but always remains inside the reinforcement cage 1101 to avoid damage to the heat exchange tube caused by pile cutting. The length of the heat exchange tube extending out of the ground is not less than 1.5m. After sealing, it is wrapped with iron sheet and the corresponding positioning marks are made.

[0045] S2. Conduct a water pressure test, which includes the following steps: First, conduct a water pressure test on the current condition of each supply and return water branch of the energy pile 11. Under the test pressure, stabilize the pressure for at least 30 minutes. After stabilization, the pressure drop should not exceed 3%, and there should be no leakage. Second, after connecting the inlet pipe 12 and outlet pipe 13 of each group of energy piles 11 to the manifold cylinder 501 and collector cylinder 502 of the inspection well 5, conduct a second water pressure test before backfilling. Under the test pressure, stabilize the pressure for at least 2 hours, and there should be no leakage. Third, after all the energy pile ground source heat pump systems are installed, flushed, vented, and backfilled, conduct a third water pressure test. Under the test pressure, stabilize the pressure for at least 12 hours, and the pressure drop should not exceed 3%. The water pressure test should be conducted using a manual pump to slowly increase the pressure. During the pressure increase process, observation and inspection should be carried out continuously to ensure there is no leakage. Air pressure testing should not be used to replace water pressure testing. After the pipeline installation is completed and passes the pressure test, the system should be flushed. The flushing flow rate should be twice the design flow rate.

[0046] S3. Sensor arrangement: Each energy pile 11 is divided into 12 sections, from top to bottom, named "Section 1" to "Section 12"; vertical stress sensors 1103 and strain sensors 1104 are symmetrically arranged on the same section. The stress sensor 1103 is a vibrating wire type rebar gauge, with a total of 24 per pile (12 on one side), welded to the side of the rebar to be tested to monitor the stress of the rebar; the strain sensor 1104 is a strain gauge, with a total of 24 per pile (12 on one side), tied to the rebar to detect the strain of the concrete.

[0047] See Figures 3 to 8The inspection well 5 includes two first inspection wells 51 with 14 branches and two second inspection wells 52 with 16 branches. Both the first inspection wells 51 and the second inspection well 52 are underground structures and each has an inspection well manhole 53. The first inspection well 51 is equipped with a water distributor cylinder 501 and a water collector cylinder 502. The input end of the water distributor cylinder 501 is connected to the water supply pipe of the pipeline well 6 through the main water supply pipe 8. The output end 17 of the water distributor cylinder 501 is connected to the inlet pipe 12 of the 14 sets of energy piles 11 in the area. The input end 16 of the water collector cylinder 502 is connected to the outlet pipe 16 of the 14 sets of energy piles 11 in the area. 3. The output end of the water collector cylinder 502 is connected to the return water pipe of the pipe well 6 through the return water main pipe 7. The water collector cylinder 502 is equipped with a pressure gauge 9 and a thermometer 10. The outlet pipe 13 connected to the water collector cylinder 502 is equipped with a static balance valve 503. The inlet pipe 12 connected to the water distributor cylinder 501 is equipped with a butterfly valve to ensure the overall hydraulic balance of the outdoor energy pile buried pipe system and realize the switching operation of different sections. The outlet pipe 13 is also connected to an air release valve 504 through a conversion joint 505 to release the air in the designated branch pipe and ensure that the heat exchange effect of the branch is maintained well.

[0048] The function of the static balancing valve 503 is to regulate the hydraulic balance of different branches in the buried pipe of the energy pile foundation, so that the pressure and flow of the designated branch can be stabilized and balanced in the cylinder of the water collector 502 and the water distributor 501. In addition, the static balancing valve 503 has a shut-off function. According to the needs of on-site use, if maintenance is required, the corresponding supply and return water branch can be located in the corresponding inspection well to realize shut-off, maintenance, and hydraulic balance. It can also switch between different areas according to the geothermal conditions. Intermittent debugging can be performed during the later operation of the system. The conversion joint 505 is used to connect and switch between static balancing valves 503 and vent valves 504 of different sizes. The thermometer 10 is used to realize the normal monitoring of the heat exchange system, clearly reflecting the circulating water temperature in the buried pipe of the energy pile at all times, and providing supply and return water temperature parameter values. Butterfly valves 14 are used for pipe valves with a nominal diameter greater than DN50, and gate valves are used for valves with a nominal diameter less than or equal to DN50. The working pressure of all valves should not be less than 1MPa and the working temperature should not be less than 100℃. When installing various valves, care should be taken to configure the operating handle in an easy-to-operate position.

[0049] To ensure reliable system operation, the above-mentioned step S2 should be performed for water pressure testing before and after the installation of the energy pile system 11, and the test should meet the standard requirements.

[0050] The second inspection well 52 has the same structure as the first inspection well 51, the difference being the number of branches in its corresponding area. The second inspection well 52 is equipped with a water distributor cylinder 501 and a water collector cylinder 502. The input end of the water distributor cylinder 501 is connected to the water supply pipe of the pipeline well 6 through the main water supply pipe 8. The output end of the water distributor cylinder 501 is connected to the inlet pipe 12 of the 14 sets of energy piles 11 in this area. The input end of the water collector cylinder 502 is connected to the outlet pipe 13 of the 14 sets of energy piles 11 in this area. The output end of the water collector cylinder 502 is connected to the return pipe of the pipeline well 6 through the return water main pipe 7. A pressure gauge and a thermometer are installed on the water collector cylinder 502. A static balance valve 503 is installed on the outlet pipe 13 connected to the water collector cylinder 502. A butterfly valve is installed on the inlet pipe 12 connected to the water distributor cylinder 501.

[0051] See Figure 9 , Figure 10 , Figure 11 The top of the pipe well 6 has a manhole 63 for personnel to enter the pipe well 6. A sump 64 is located at the bottom. The connecting pipeline 4 includes two water supply mains 61 and two return mains 62, which are interconnected: a first water supply main 611, a second water supply main 612, and a first return main 621 and a second return main 622. The first water supply main 611 and the first return main 621 supply the plant front area, while the second water supply main 612 and the second return main 622 supply the gasification area. The main water supply pipe 8 and the main return main 7 of storage tank #1 are connected to the first water supply main 611 and the first return main 621, respectively. The main water supply pipe 8 and the main return main 7 of storage tank #2 are connected to the first water supply main 611 and the first return main 621, respectively. The second water supply main 612 is connected to the second return water main 622. The butterfly valves 14 in the pipe well 6 are respectively labeled as butterfly valve V1, butterfly valve V2, butterfly valve V3, and butterfly valve V4. Butterfly valve V1 is installed on the first water supply main 611, butterfly valve V3 is installed on the second water supply main 612, butterfly valve V2 is installed on the first return water main 621, and butterfly valve V4 is installed on the second return water main 622. Butterfly valve V1 is located between the connection between the main water supply pipe 8 of tank #2 and the first water supply main 611 and the connection between the main water supply pipe 8 of tank #1 and the first water supply main 611. Butterfly valve V2 is located between the connection between the return water main 7 of tank #2 and the first return water main 621 and the connection between the return water main 7 of tank #1 and the first return water main 621.

[0052] See Figure 11Static balancing valves 503 and venting valves 504 are installed on the main water supply pipe 8 and main water return pipe 7 of tank #1 and tank #2. Venting valves 504 are installed on the first water supply main pipe 611, the second water supply main pipe 612, the first water return main pipe 621, and the second water return main pipe 622. Drain valves 18 are also installed on the first water supply main pipe 611 and the first water return main pipe 621. It should be noted that in this embodiment, the pipes entering the inspection well 5 and the pipe well 6 are all fitted with waterproof sleeves 15 to enhance the sealing between the pipes and the inspection well 5 and the pipe well 6.

[0053] Operating instructions: In summer, open butterfly valves V1 and V2, and close butterfly valves V3 and V4. Energy piles 11 of storage tanks #1 and #2 will pump the low-temperature water from underground to the surface and supply it to the administrative building in the front area of ​​the plant. In winter, open butterfly valves V3 and V4, and close butterfly valves V1 and V2. The high-temperature water in the underground insulation area will be pumped to the surface and supplied by energy piles 11 of storage tank #1 to the gasification area, and energy piles 11 of storage tank #2 to the front area of ​​the plant.

[0054] Specifically: In summer, butterfly valves V1 and V2 on the first water supply main 611 and the first return main 621 are opened, while butterfly valves V3 and V4 on the second water supply main 612 and the second return main 622 are closed. Water in the heat exchange pipe 1102 of the energy pile system sequentially enters the inspection well 5 and the pipe well 6, and then enters the air conditioning system 2 through the first water supply main 611 to exchange heat with the refrigerant circulating inside. The hot water after heat exchange enters the pipe well 6 and the inspection well 5 through the first return main 621 and then flows back into the heat exchange pipe 1102 of the energy pile system. In winter, butterfly valves V1 and V2 on the first water supply main 611 and the first return main 621 are closed, while butterfly valves V3 and V4 on the second water supply main 612 and the second return main 622 are opened. Water from the heat exchange pipe 1102 of the No. 1 storage tank in the energy pile system enters the inspection well 5 and the pipeline well 6 in sequence through the first water supply main pipe 611 into the air conditioning system 2 and exchanges heat with the refrigerant circulating inside it. The hot water after heat exchange enters the pipeline well 6 and the inspection well 5 in sequence through the first return water main pipe 621 and then flows back into the heat exchange pipe 1102 of the energy pile system. Water from the heat exchange pipe 1102 of the No. 2 storage tank in the energy pile system enters the inspection well 5 and the pipeline well 6 in sequence through the second water supply main pipe 612 into the ambient temperature vaporizer 3 and heats the vaporized natural gas. The heated water enters the pipeline well 6 and the inspection well 5 in sequence through the second return water main pipe 622 and then flows back into the heat exchange pipe 1102 of the energy pile system.

[0055] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A ground loop system for an LNG storage tank pile foundation heat exchanger, comprising an energy pile system, heat exchange pipes, an air conditioning system, and an ambient air vaporizer, wherein the output end of the energy pile system is connected to the air conditioning system and the ambient air vaporizer via heat exchange pipes, and supplies energy to them, characterized in that, It also includes multiple inspection wells and pipe wells. Each inspection well is equipped with a water distributor cylinder and a water collector cylinder. The energy pile system includes multiple energy piles, each of which is equipped with a heat exchange pipe. Two energy piles are connected in series to form a heat exchange branch. Each of the multiple heat exchange branches has an inlet pipe and an outlet pipe. The inlet pipe of the heat exchange branch is connected to one end of the water distributor cylinder, and the other end of the water distributor cylinder is connected to the water supply pipe of the pipe well through the main water supply pipe. The outlet pipe of the heat exchange branch is connected to one end of the water collector cylinder, and the other end of the water collector cylinder is connected to the return water pipe of the pipe well through the main return water pipe. The inspection wells include two first inspection wells and two second inspection wells.

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