System and method for compressing and storing gas

Abstract

A compression system and method for compressing a gas at a temperature higher than the temperature of subterranean soil within the earth is described. The system includes a gas compression vessel disposed underground within the earth. The gas compression container has a thermally conductive wall having a circular cross-section inside. The outer side of the walls is surrounded by a layer of thermally conductive material to maintain the compressed gas within the gas compression container at the temperature of the soil during air compression and storage. The system also includes a water supply container disposed underground within the earth and a water pressurization system disposed at a pressurized water line connecting the water supply container to the gas compression container. The system also includes a water flow distributor disposed within the gas compression container, the water flow distributor including at least one nozzle configured to direct a flow of water pumped into the gas compression container along an inner side of the thermally conductive wall in a direction in which the inner side has a circular cross-section.

Description

Technical Field

[0001] The present invention generally relates to systems and methods for compressing and storing gases. Background Art

[0002] It is known that compressed gas can be stored and used for a variety of purposes. For example, stored compressed gas can be used in the glass and plastic container industry. However, due to the operating nature of the injection molding machines that use compressed air, the compressed air consumption in glass and plastic container production plants is irregular. Each injection molding machine needs to briefly spray high-pressure air every few seconds (once per injection). When multiple such machines are arranged on a production line, the air consumption curve is unstable and irregular. A typical factory includes a compression queue, in which a motor-driven compressor compresses a specific gas, such as air. Due to the unstable and irregular consumption curve of compressed air, running the compressor to supply high-pressure air will often result in long downtimes, resulting in energy waste. The irregular behavior of the consumption curve can be alleviated by increasing the operating pressure, but this will also result in energy waste. Therefore, the use of large-capacity tanks that contain and store compressed air can provide a solution that can overcome the above problems.

[0003] Furthermore, the potential energy stored by the compressed gas can be used to generate electricity. Potential energy can be collected, for example, from natural energy sources, which are virtually inexhaustible and available all over the world in various forms, such as wind, solar, tidal and wave energy. Energy obtained from natural energy sources can be stored in the form of the potential energy of compressed gas so that it can be released as needed when electricity is needed.

[0004] Generally, various compressed air storage systems are known for storing compressed gas. For example, gas storage tanks can be constructed on the surface, underground, and underwater.

[0005] Gas pressurization is a challenge for all industries. When compressing a gas adiabatically, i.e. reducing the gas volume in a thermally isolated system, heat is generated in addition to the increase in gas pressure. On the other hand, when all the heat generated by gas compression is continuously removed from the compressed gas during the compression process by heat exchange with the surroundings, the process is isothermal.

[0006] At the same rate of volume reduction, the energy required for isothermal gas compression is significantly less than the energy required for adiabatic compression. In other words, when the gas volume is reduced by the same amount, the work done on the gas during adiabatic compression is greater than the work done on the gas during isothermal compression.

[0007] Conventional compressors usually operate under nearly adiabatic conditions because the heat generated during the compression process cannot be fully exchanged with the surrounding environment within the time frame of compression. Therefore, isothermal compressors can be a more efficient alternative for compressed air energy storage (CAES) technology.

[0008] During the compression process, various heat transfer mechanisms can be used to remove heat energy from the compressed gas. For example, to achieve isothermal compression, a liquid spray or foam can be injected into the compression chamber and mixed with the air to absorb the resulting heat of compression. In this case, the heat energy in the gas compressed in the pressure vessel can be transferred to the liquid or foam used to compress the gas.

[0009] U.S. Patent Application Publication No. 2019 / 107126 describes a near-isothermal system and method for compressing a gas. A low-pressure gas is drawn into a container through a source gas inlet. A liquid is pumped into the container through a liquid inlet so that the low-pressure gas is compressed to produce a high-pressure gas. To make the compression approximately isothermal, the liquid inlet may be a nozzle that forms a spray of the liquid entering the container. The gas may be vapor, and the liquid may strip the vapor from the gas.

[0010] U.S. Patent Application Publication No. 2012 / 0102935 describes a compressed air system including a hydraulic actuator that can be used to compress gas in a pressure vessel. The actuator can be actuated to move a liquid into the pressure vessel so that the liquid compresses the gas in the pressure vessel. In such a compressor system, heat can be transferred to the liquid used to compress the air during the compression process. The compressor system may include a liquid purification system that can be used to remove at least a portion of the liquid to which heat energy has been transferred so that the liquid can be cooled and then recirculated within the system. Summary of the invention

[0011] Although prior art exists in the field of adiabatic and isothermal compression systems, further improvements are needed in the art to provide more efficient compression systems. Therefore, it would be useful to have a novel gas compression system having an improved and / or optimized heat dissipation mechanism during the gas compression process.

[0012] The present invention partially eliminates the disadvantages of existing gas compression systems and provides a new method of compressing gas by utilizing the equilibrium of the gas temperature with the earth's subsoil temperature.

[0013] It is known that the temperature of the ambient air above the ground varies over time from night to day. For example, in a desert, the ambient air temperature can vary between 10°C during night to 40°C during day. However, it is known that at depths greater than about 30 feet (9.12 m) below the surface, the soil temperature remains relatively constant throughout the year.

[0014] For example, an experimental investigation of underground ground temperature (GB Reddy, International Journal of Ambient Energy, 2000, Vol. 21, No. 4, pp. 196-202) shows that the soil ground temperature at a depth of more than 10 feet (3.04 meters) remains relatively constant throughout the year. In particular, at a depth of 10 feet, the average ground temperature of the soil is 75.12°F (23.96°C) in summer and 75.87°F (24.37°C) in winter. For daily ambient air temperature changes, the average temperature of the underground soil is lower than the average temperature of the ambient air on the ground. The temperature difference between the ambient air and the soil temperature 10 feet underground can be 8°F to 17°F (4.4°C to 9.4°C).

[0015] Therefore, since the earth can act as an "infinite" thermal capacitor, the present invention teaches the use of the earth as a heat pump in the air compression process.

[0016] The present invention provides a novel compression system for gas compression. The gas compression system of the present invention is most useful for compressing gas having a temperature higher than the temperature of the subsoil in the earth, because the gas compression system is based on reducing the temperature of the gas to the subsoil temperature during the compression process. In this case, the energy required for gas compression is significantly less than that required for isothermal compression, not to mention less than that required for adiabatic compression of the same rate of volume reduction. Therefore, during the gas compression process, the work done on the gas by the system of the present invention is less than the work done for the same volume reduction of the gas in both isothermal and adiabatic processes.

[0017] According to one embodiment of the present invention, the compression system includes a gas compression container arranged underground in the earth. The gas compression container is configured to accumulate and store potential energy in the form of compressed gas and pressurized water. The gas compression container has a heat-conducting wall. The gas compression container has a circular cross-section of the inner side of the heat-conducting wall at least in the upper part of the gas compression container. The outer side of the heat-conducting wall of the gas compression container is surrounded by a layer of heat-conducting material filling the space between the outer side and the earth's soil, so as to keep the compressed gas in the gas compression container at the temperature of the soil during air compression and storage.

[0018] According to one embodiment of the present invention, the compression system includes a water supply container arranged underground in the earth and configured to hold water. The water supply container has a thermally conductive wall. The outer side of the thermally conductive wall of the water supply container is surrounded by another layer of thermally conductive material that fills the space between the outer side and the surrounding soil so as to maintain the water in the water supply container at the temperature of the soil.

[0019] According to one embodiment of the present invention, the heat-conducting material of the layer of heat-conducting wall surrounding the gas compression container and the water supply container has sufficient adhesive properties to adhere to the heat-conducting wall and the soil. Such an arrangement makes it possible to promote heat exchange from the heat-conducting wall to the soil via the heat-conducting material of the layer surrounding the heat-conducting wall.

[0020] According to one embodiment of the present invention, the compression system includes a pressurized water line hydraulically coupled to a gas compression container and a water supply container. The pressurized water line is configured to provide hydraulic communication between the gas compression container and the water supply container.

[0021] According to one embodiment of the present invention, the compression system includes a water pressurization system arranged on a pressurized water pipeline. The water pressurization system includes a pump configured to controllably pump water from a water supply container into a gas compression container so as to maintain a desired water flow rate through the pressurized water pipeline.

[0022] According to one embodiment of the present invention, the compression system includes a water flow distributor arranged in the gas compression container. The water flow distributor is connected to the water pressurization system via a pressurized water pipeline. The water flow distributor includes one or more nozzles, which are configured to guide the water flow pumped into the gas compression container to flow along the inner side of the heat-conducting wall of the gas compression container in a direction having a circular cross-section on the inner side. Such an arrangement enables the water flow in the gas compression container to circulate along the inner side.

[0023] According to one embodiment of the present invention, the compression system further comprises an intake manifold pneumatically coupled to the gas compression container to provide gas into the gas compression container for compression.

[0024] According to one embodiment of the present invention, the compression system further comprises an intake valve arranged on the intake manifold, and the intake valve is configured to control the supply of gas into the gas compression container.

[0025] According to one embodiment of the present invention, the compression system further comprises a gas supply system, which is arranged on the intake manifold and pneumatically coupled to the gas compression container. The gas supply system is configured to supply gas to the gas compression container for compression.

[0026] According to one embodiment of the present invention, the compression system further comprises a water inlet line hydraulically coupled to the water supply container. The water inlet line is configured to supply water to the water supply container.

[0027] According to one embodiment of the present invention, the compression system further comprises a water inlet valve arranged on the water inlet pipeline, and the water inlet valve is configured to control the water supply to the water supply container.

[0028] According to one embodiment of the present invention, the compression system further comprises a control system coupled to the water pressurization system arranged on the pressurized water pipeline, and the control system is configured to regulate the flow of water pumped into the gas compression container through the pressurized water pipeline.

[0029] According to one embodiment of the present invention, the control system includes a gas pressure sensor disposed in a gas compression container and configured to generate a gas pressure sensor signal indicating the pressure of the compressed gas in the gas compression container.

[0030] According to one embodiment of the present invention, the control system further comprises an electronic controller operably coupled to the water pressurization system and the gas pressure sensor. In operation, when the gas pressure in the gas compression container is less than a predetermined pressure of the compressed gas, the electronic controller is responsive to the gas pressure sensor signal and is capable of generating a control signal for actuating the pump of the water pressurization system.

[0031] According to one embodiment of the present invention, the compression system further comprises a compressed gas exchange manifold. The compressed gas exchange manifold is pneumatically coupled to the gas compression container. The gas exchange manifold is configured to supply compressed gas to a user at a desired pressure.

[0032] According to one embodiment of the present invention, the compression system further comprises a gas release valve arranged on the compressed gas exchange manifold, wherein the gas release valve is configured to control the supply of compressed gas to a user.

[0033] According to one embodiment of the present invention, the compression system further comprises a drainage line. The drainage line is hydraulically coupled to the gas compression container. The drainage line is configured to remove water accumulated at the bottom of the gas compression container after the gas is compressed.

[0034] According to one embodiment of the present invention, the compression system further comprises a gas pump and an air supply manifold. The gas pump is configured to provide air to the gas compression container at a desired pressure. The air supply manifold is pneumatically coupled to the gas pump and the air intake manifold. The air supply manifold is configured to supply the air provided by the gas pump to the gas compression container at a desired pressure, which should be sufficient to remove water accumulated at the bottom of the gas compression container through a drainage line after gas compression.

[0035] According to one embodiment of the present invention, the compression system further comprises a venturi pump. The venturi pump is arranged on the pressurized water line. The venturi pump comprises a venturi air manifold. The venturi air manifold is connected to the pressurized water line. The venturi air manifold is configured to provide air to the venturi pump. The venturi pump comprises a venturi nozzle connected to the pressurized water line. The venturi nozzle comprises an expansion portion. The expansion portion has an inlet cross section and an outlet cross section. The area of ​​the inlet cross section is smaller than the area of ​​the outlet cross section.

[0036] The venturi nozzle is configured to (i) receive a fluid flow including water from a water pressurization system through a pressurized water line 31 and air provided by a venturi air manifold; and (ii) increase the pressure of the air in the fluid to a predetermined value through a diverging portion.

[0037] According to another aspect of the present invention, there is provided a method for compressing a gas having a temperature higher than a subsoil temperature within the earth. The method comprises reducing the temperature of the gas to a subsoil temperature within the earth during the compression process.

[0038] According to one embodiment of the present invention, reducing the temperature of the gas during the compression process includes activating a water pressurizing system for controllably pumping water from a water supply container into the gas compression container through a water flow distributor. Due to the activation of the water pressurizing system, the water flow pumped into the gas compression container can be guided to flow along the inner side of the heat conductive wall of the gas compression container in a direction having a circular cross-section on the inner side, so that the water flow in the gas compression container circulates along the inner side.

[0039] The circulation of water flow can enhance the heat exchange between the gas and water and the heat-conducting walls of the gas compression container during the gas compression process. Since the underground soil temperature is lower than the temperature of the compressed gas, the heat extracted from the gas into the water can be further transferred from the water to the earth's soil via the layer of heat-conducting material surrounding the gas compression container.

[0040] The method also includes supplying compressed gas to a user at a desired pressure. According to one embodiment of the present invention, the method includes providing a compressed gas exchange manifold to the system. The compressed gas exchange manifold is pneumatically coupled to a gas compression container. The gas exchange manifold is configured to supply compressed gas from the compression container to a user at a desired pressure.

[0041] According to one embodiment of the present invention, the method includes providing a gas release valve to the system. The gas release valve is arranged on the compressed gas exchange manifold and is configured to control the supply of compressed gas to the user.

[0042] According to one embodiment of the invention, the method includes providing a drainage line to the system, the drainage line being hydraulically coupled to the gas compression container. The drainage line is configured to remove water accumulated at the bottom of the gas compression container after gas compression so that the system can be used for a new compression cycle.

[0043] According to one embodiment of the present invention, the method includes providing a gas pump capable of providing air at a required pressure to the system, and an air supply manifold pneumatically coupled to the gas pump and the intake manifold. The air supply manifold is configured to supply the air provided by the gas pump to the gas compression container at a certain pressure, which is sufficient to remove the water accumulated at the bottom of the gas compression container. When necessary, the water is removed through a drainage line after the gas is compressed.

[0044] According to one embodiment of the present invention, the method further comprises removing water accumulated at the bottom of the gas compression container after the gas is compressed. The removal of water is achieved by supplying air into the gas compression container by a gas pump at a certain pressure, and the pressure is sufficient to remove the water accumulated at the bottom of the gas compression container through a drainage pipeline.

[0045] According to one embodiment of the present invention, the method includes providing a venturi pump to the system, which is arranged on a pressurized water line. The venturi pump includes a venturi air manifold connected to the pressurized water line. The venturi air manifold is configured to provide air to the venturi pump. The venturi pump includes a venturi nozzle connected to the pressurized water line. The venturi nozzle includes an expansion portion having an inlet cross section and an outlet cross section. The area of ​​the inlet cross section is smaller than the area of ​​the outlet cross section. The venturi nozzle is configured to (i) receive a fluid flow comprising water passing through the pressurized water line from a water pressurization system and air provided by the venturi air manifold; and (ii) raise the pressure of the air in the fluid to a predetermined value through the expansion portion.

[0046] The method further includes increasing the pressure of the air to a predetermined value by means of a venturi pump.

[0047] There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description that follows may be better understood, and in order that the present contribution to the art may be better appreciated. Other details and advantages of the invention will be set forth in the detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to better understand the subject matter disclosed herein and to illustrate how it may be implemented in practice, embodiments will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

[0049] Figure 1 and Figure 2illustrates a schematic cross-sectional side view of a gas compression system according to some embodiments of the present invention;

[0050] Figure 3 and Figure 4 illustrates a schematic cross-sectional side view of a gas compression system operating in a multi-cycle manner according to some embodiments of the present invention;

[0051] Figure 5 and Figure 6 Illustrated Figure 1 and Figure 2 a schematic cross-sectional side view of a gas compression system of , and correspondingly also including a venturi nozzle; and

[0052] Figure 7 and Figure 8 Illustrated Figure 3 and Figure 4 Schematic cross-sectional side view of a gas compression system, including a venturi nozzle. DETAILED DESCRIPTION

[0053] The principles and operation of the gas compression system according to the present invention can be better understood with reference to the accompanying drawings and the accompanying description. It should be understood that these drawings are provided for illustrative purposes only and are not intended to be limiting. It should be noted that, for the sake of clarity, the drawings illustrating examples of the system of the present invention are not drawn to scale and are not proportional. It should be noted that the boxes and other elements in the figures are intended only to be functional entities, so that the functional relationships between the entities are shown, rather than any physical connections and / or physical relationships. Examples of construction are provided for the selected elements. It should be understood by those skilled in the art that the examples provided have suitable alternatives that can be utilized.

[0054] Reference Figure 1 , illustrates a schematic cross-sectional view of a gas compression system 10 according to an embodiment of the present invention. The gas compression system 10 of the present invention can be advantageous for compressing gases having a temperature higher than the underground soil temperature within the earth, and can also be successfully used to store compressed gases and pressurized water. Examples of gases used for compression in the gas compression system 10 include, but are not limited to, air, nitrogen, etc.

[0055] The compression system 10 includes a gas compression container 11 disposed underground in the earth 13. The gas compression container 11 has a thermally conductive wall 111 and is configured to accumulate and store potential energy in the form of compressed gas 14 and pressurized water 15. It should be understood that, in general, the gas compression container 11 can be constructed of a suitable metal or composite material with a wall thickness suitable for withstanding the strain caused by the gas-hydraulic pressure inside the gas compression container 11 on the wall.

[0056] According to one embodiment of the present invention, the gas compression container 11 has a substantially spherical shape at least in the upper part 17 of the gas compression container 11, and the inner side 16 of the heat-conducting wall 111 has a substantially circular cross-section. The term "substantially" as used herein with respect to the spherical shape / circular shape means that the degree of deviation from "sphericity" and "circularity" is small enough so as not to significantly damage the spherical shape / circular shape. For the purposes of the present invention, such an approximation can be interpreted, for example, as including a deviation of at least 20% of the diameter of the upper part 17, as long as the deviation does not lead to a significant change in the performance of the gas compression system 10. The exact degree of deviation from the spherical shape / circular shape may depend on the specific circumstances.

[0057] According to one embodiment of the invention, the gas compression container 11 has an outer side 18 of a heat-conducting wall 111 surrounded by a layer 19 of heat-conducting material, which fills the space between the outer side 18 and the soil of the earth 13. The heat-conducting material has adhesive properties sufficient to adhere to the heat-conducting wall 111 and the soil, so as to promote heat exchange from the heat-conducting wall 111 to the soil via the layer 19 of heat-conducting material. Such an arrangement allows the compressed gas 14 to be maintained during compression and storage in the gas compression container 11 at the temperature of the soil during air compression and storage.

[0058] According to one embodiment of the present invention, the compression system 10 further comprises a water supply container 21 arranged underground within the earth 13. The water supply container 21 has a heat conductive wall 211 and is configured to contain water 212 that can be supplied to the gas compression container 11. The water supply container 21 has an outer side 23 of the heat conductive wall 211 surrounded by another layer 24 of heat conductive material, which fills the space between the outer side 23 and the surrounding earth 13 soil. The heat conductive material of the layer 24 has adhesive properties sufficient to adhere to the heat conductive wall 211 and the soil, so as to promote heat exchange from the heat conductive wall 211 to the soil via the heat conductive material of the layer 24. Such an arrangement allows the water 212 in the water supply container 21 to be maintained at the temperature of the soil.

[0059] It should be noted that as the texture of dry soil becomes finer, its thermal conductivity tends to increase. This is because the thermal conductivity of air is about one-hundredth of the thermal conductivity of solid soil particles. Finer soils have more particle-to-particle contact and smaller insulating air gaps between particles than coarse-grained soils, and therefore have higher thermal conductivity. Examples of thermally conductive materials suitable for layers 19 and 24 include, but are not limited to, cement-based binder materials containing thermally conductive additives, such as fine metal powders, compacted sand, thermally conductive plastics, and the like.

[0060] According to one embodiment of the present invention, the compression system 10 further includes a pressurized water line 31 hydraulically coupled to the gas compression container 11 and the water supply container 21. The pressurized water line 31 is configured to provide hydraulic communication between the gas compression container 11 and the water supply container 22.

[0061] According to one embodiment of the present invention, the compression system 10 further includes a water pressurizing system 41 and a pressurizing water valve 32 arranged on the pressurizing water line 31. The water pressurizing system 41 includes a pump (not shown) configured to pump water 212 from the water supply container 21 into the gas compression container 11 when the pressurizing water valve 32 is opened, so that a desired flow rate of water is maintained through the pressurizing water line 31. The pressurizing water valve 32 is configured to control the supply of pumped water and, after gas compression is completed, prevent the compressed gas from being released from the gas compression container 11 through the water pressurizing system 41. In the gas compression container 11, the water 15 is pressurized, thereby also compressing the gas 14. The compressed gas 14 is stored in the gas compression container 11 at a high pressure.

[0062] According to one embodiment of the present invention, the compression system 10 further includes a water flow distributor 81 arranged in the gas compression container 11. The water flow distributor 81 is connected to the water pressurization system 41 via the pressurized water pipeline 31. The water flow distributor 81 includes one or more nozzles 82, which are configured to guide the water flow pumped into the gas compression container 11 to flow along the inner side 16 of the heat conductive wall 111 of the gas compression container 11 in a direction in which the inner side 16 has a circular cross-section. Such an arrangement enables the water flow in the gas compression container 11 to circulate along the inner side 16.

[0063] According to one embodiment of the present invention, the compression system 10 further includes an intake manifold 52, which is pneumatically coupled to the gas compression container 11 to provide gas to the gas compression container 11 for compression. The compression system 10 further includes an intake valve 53 arranged on the intake manifold 52 and configured to control the supply of gas to the gas compression container 11.

[0064] According to one embodiment of the present invention, in order to facilitate the provision of gas into the gas compression container 11, the compression system 10 further includes a gas supply system 51 arranged on the intake manifold 52 and pneumatically coupled to the gas compression container 11. The gas supply system 51 may include a fan (not shown) or any other blowing device, which is coupled to a gas source and is configured to collect gas from the gas source and provide the collected gas into the gas compression container 11 for further compression. When the gas is air, the gas supply system 51 is configured to collect atmospheric air and deliver it to the gas compression container 11.

[0065] According to one embodiment of the present invention, the compression system 10 further includes a compressed gas exchange manifold 55 pneumatically coupled to the gas compression container 11 and a gas release valve 54 disposed on the compressed gas exchange manifold 55. The compressed gas exchange manifold 55 is configured to supply the compressed gas 14 to the user at a desired pressure. Figure 1 In the embodiment shown in , the compressed gas exchange manifold 55 is a pipeline directly connected to the gas compression container 11.

[0066] When necessary for safety reasons, the gas compression container 11 may also include one or more safety valves (not shown), which can be automatically opened when the pressure in the gas compression container 11 exceeds a certain pressure level during the gas compression process.

[0067] According to one embodiment of the present invention, the compression system 10 further includes a water inlet line 61 drawn from a water source and hydraulically coupled to the water supply container 21. The water inlet line 61 is configured to supply water to the water supply container 21. The compression system 10 further includes a water inlet valve 62 disposed on the water inlet line 61 and configured to control the water supply to the water supply container 21.

[0068] According to one embodiment of the present invention, the compression system 10 also includes a control system 71, which is connected to the water pressurization system 41 arranged on the pressurized water pipeline 31 and is configured to adjust the flow rate of water 212 pumped into the gas compression container 11 through the pressurized water pipeline 31.

[0069] According to one embodiment of the present invention, the control system 71 includes a gas pressure sensor 72 disposed in the gas compression container 11, and an electronic controller 700 operably connected to the water pressurization system 41 and the gas pressure sensor 72. The electronic controller 700 can be implemented as, for example, electronic hardware, computer software, or a combination of both. The gas pressure sensor 72 is configured to generate a gas pressure sensor signal indicating the pressure of the compressed gas 14 in the gas compression container 11. As long as the gas pressure in the gas compression container 11 is less than the predetermined pressure of the compressed gas, the electronic controller 700 responds to the gas pressure sensor signal and is able to generate a control signal for operating the water pump of the water pressurization system 41 to deliver water 212 to the gas compression container 11.

[0070] In operation, the gas compression container 11 can be inflated by flushing gas through the intake manifold 52. In order to facilitate the supply of gas to the gas compression container 11, a gas supply system 51 connected to a gas source (not shown) and arranged on the intake manifold 52 can be used to collect gas from the gas source and provide the collected gas to the gas compression container 11 for further compression.

[0071] When necessary, gas can also be added using one or more pneumatic compressors (not shown), which can be part of the system or located on a removable infrastructure (not shown). When necessary, gas can also be refilled by increasing the amount of gas 14 contained in the gas compression container 11 to replenish any gas that may be lost during operation of the compression system 10.

[0072] When the gas is air, it can be collected from the atmosphere. For example, the temperature of the air can be in the range of about 25°C to 40°C, with an initial pressure of 1 atm. During filling with air or any other desired gas, the pressurized water valve 32 and the gas release valve 54 are closed.

[0073] The water supply container 21 is then filled with water via the water inlet line 61. Since the water supply container 21 has a heat-conducting wall 211 surrounded by a heat-conducting material between the outer side 23 of the gas compression container 11 and the surrounding soil, after a certain period of time, the temperature of the water 212 inside the water supply container 21 can be consistent with the ground temperature of the soil, which temperature can be, for example, in the range of about 20°C to 25°C.

[0074] In the present invention, the term "about" means within a statistically significant numerical range. The permissible variation included in the term "about" depends on the specific system under consideration and can be easily understood by a person skilled in the art. For the purpose of the present invention, such approximation can be interpreted, for example, as including a deviation of at least 20%, as long as the performance of the gas storage system 10 does not change significantly due to the deviation.

[0075] After the gas compression container 11 is filled with gas and the water supply container 21 is filled with water, the water pressurizing system 41 is started, and when the pressurized water valve 32 is opened and the air inlet valve 53 and the gas release valve 54 are closed, water is controllably pumped from the water supply container 21 to the gas compression container 11. The electronic controller 700 controls so that the water through the pressurized water pipeline 31 maintains a desired flow rate. The water pressurizing system 41 is operated when the gas pressure in the gas compression container 11 is lower than the predetermined pressure of the compressed gas 14. In the gas compression container 11, the water 15 is pressurized, thereby also compressing the gas 14. The compressed gas 14 can be stored in the gas compression container 11 at a high pressure after compression.

[0076] The operating principle of the system of the present invention is based on reducing the temperature of the gas to the underground soil temperature in the earth during the compression process. Therefore, the water flow provided from the water supply container 21 to the gas compression container 11 by the water pressurization system 41 is provided to the water flow distributor 81. The nozzle 82 of the water flow distributor 81 guides the water flow pumped to the gas compression container 11 to flow along the inner side 16 of the heat conductive wall 111 of the gas compression container 11 in the direction in which the inner side 16 has a circular cross-section. The flow rate of the water and the surface curvature of the inner side 16 of the heat conductive wall 111 should have predetermined values, which are required to make the water flow inside the gas compression container 11 circulate along the inner side 16 due to the centripetal force of the water in the water flow. The circulation of the water flow can enhance the heat exchange between the gas 14 in the compression process and the heat conductive wall 111 of the gas compression container 11. Since the underground soil temperature is lower than the temperature of the compressed gas and the temperature of the pressurized water, the heat extracted from the gas 14 is transferred to the water via the layer of thermally conductive material 19 surrounding the gas compression container 11 and further from the water to the soil of the earth 13.

[0077] Since the gas inlet valve 53 and the gas release valve 54 are closed, the gas 14 is trapped in the upper portion 17 of the gas compression container 11 between the water level and the top of the gas compression container 11. As the water level in the gas compression container 11 rises, the gas 14 is compressed, and the gas temperature can be further increased compared to the initial temperature of the gas before compression.

[0078] Due to the heat exchange, the circulating water flow can absorb the heat generated by the gas during the compression process, and this heat can be further transferred to the soil of the earth 13 through the layer 19 of heat-conducting material. Since the heat capacity of the earth is large, the heat in the heat exchange process can be completely dissipated, so as not to cause the temperature of the earth to rise. Therefore, the gas temperature can be reduced from the initial temperature to the underground soil temperature in the earth, so that a more efficient compression cycle can be achieved compared with isothermal and adiabatic compression.

[0079] Although Figure 1 The gas compression container 11 shown in the drawing has a generally spherical shape in the upper part 17, with the inner side of the heat conducting wall 111 having a generally circular cross section in a vertical plane, and another gas compression container having a generally cylindrical shape in the upper part is also envisaged.

[0080] Reference Figure 2 , illustrates a schematic cross-sectional view of a gas compression system 200 according to another embodiment of the present invention. The gas compression system 200 and Figure 1 The gas compression system 10 in FIG. 200 is different in that it comprises a gas compression container 311 having a cylindrical shape. Therefore, in the gas compression system 200, the circular cross section of the inner side of the heat conducting wall 411 of the gas compression container 311 is realized in a horizontal plane.

[0081] In this embodiment, the nozzle 82 of the water flow distributor 81 is configured to guide the water flow pumped into the inner side of the wall 411 of the gas compression container 311 to flow in a horizontal direction (i.e., the inner side has a substantially circular cross-section in the horizontal direction). Thus, the water flow provided by the water flow distributor 81 circulates in the gas compression container 311 along the inner side wall 411 thereof on a horizontal plane and flows downward in a spiral shape to the bottom of the gas compression container 311 under the action of gravity.

[0082] Also refer to Figure 3 and Figure 4 , which illustrates schematic cross-sectional views of gas compression systems 300 and 400 according to other embodiments of the present invention. Figure 1 and Figure 2 The difference between the gas compression systems 10 and 200 in FIG. 1 is that these systems also include a drain line 92, thereby enabling the systems 300 and 400 to operate in a multi-cycle mode. In a multi-cycle mode, as described above with reference to Figure 1 and Figure 2 As discussed, after removing the water accumulated during the gas compression process in the first cycle, the system is ready to supply water for a newly running compression cycle.

[0083] Drain line 92 is hydraulically coupled to a gas compression container ( Figure 1 11 and Figure 2 311 in the gas compression container 11). The drain line 92 is configured to remove the water 15 accumulated at the bottom of the gas compression container 11 and 311 after the gas is compressed (i.e., when the system is not compressing the gas). A drain valve 91 is arranged on the drain line 92. The drain valve 91 is configured to regulate the removal of the water 15 from the gas compression container 11 and 311.

[0084] The compression systems 300 and 400 include a gas pump 56. The gas pump 56 is configured to supply air to the gas compression containers 11 and 311 (after gas compression) at a desired pressure, which is sufficient to remove the water 15 accumulated at the bottom of the gas compression containers 11 and 311 through the drain line 92. The compression systems 300 and 400 include an air supply manifold 58. The air supply manifold 58 is pneumatically coupled to the gas pump 56 and the intake manifold 52. The air supply manifold 58 is configured to supply the air provided by the gas pump 56 to the gas compression containers 11 and 311 at a desired pressure, which is sufficient to remove the water 15 accumulated at the bottom of the gas compression containers 11 and 311.

[0085] According to one embodiment of the present invention, the compression system 300 and the compression system 400 include a gas pump valve 57 disposed on the air supply manifold 58. The gas pump valve 57 is configured to regulate the air supply to the gas compression containers 11 and 311. The gas pump valve 57 is also configured to prevent gas from escaping (unwanted flow) from the gas compression containers 11 and 311 through the air supply manifold 58.

[0086] Also refer to Figure 5 and Figure 6 , which illustrates schematic cross-sectional views of gas compression systems 500 and 600 according to other embodiments of the present invention. Figure 1 and Figure 2 The difference between the gas compression systems 10 and 200 in FIG. 1 is that these systems include a venturi pump 33. The venturi pump 33 is arranged on the pressurized water line 31 to form a part of the pressurized water line 31. The venturi pump 33 includes a venturi air manifold 34. The venturi air manifold 34 is connected to the pressurized water line 31 and is configured to provide air to the venturi pump 33. The venturi pump 33 includes a venturi nozzle 35 connected to the pressurized water line 31. The venturi pump 33 is configured to mix water with the gas sucked through the venturi air manifold 34. The venturi nozzle 35 includes an expansion portion having an inlet cross section and an outlet cross section. The area of ​​the inlet cross section is smaller than the area of ​​the outlet cross section.

[0087] The venturi nozzle 35 is configured to (i) receive a fluid flow including water passing through the pressurized water line 31 from the water pressurization system 41 and air provided by the venturi air manifold 34; and (ii) increase the pressure of the air in the fluid to a predetermined value through the expansion portion.

[0088] The increase in air pressure can be evaluated based on Bernoulli's principle, which states that when air flows through a dilated section, the local pressure must increase.

[0089] It will be appreciated that the venturi pump 33 may provide a means for supplying a compressed gas to the gas container ( Figure 3 11 and Figure 4 311) provides another route for compressed gas in addition to the gas provided by the gas supply system 51.

[0090] Also refer to Figure 7 and Figure 8 , which illustrates schematic cross-sectional views of gas compression systems 700 and 800 according to other embodiments of the present invention. Specifically, Figure 7 The embodiment shown in can be considered as Figure 3 and Figure 5 A combination of the embodiments shown in . Figure 8 The embodiment shown in can be considered as Figure 4 and Figure 6 A combination of the embodiments shown in .

[0091] Gas compression systems 700 and 800 with Figure 3 and Figure 4 The difference between the gas compression systems 300 and 400 in FIG. 1 is that these systems include a venturi pump 33. The venturi pump 33 is arranged on the pressurized water pipeline 31 to form a part of the pressurized water pipeline 31. The venturi pump 33 includes a venturi air manifold 34. The operation of the venturi pump 33 is described above with reference to FIG. Figure 5 and Figure 6 Described.

[0092] According to some embodiments, from a gas compression container ( Figure 3 and Figure 7 11) and ( Figure 4 and Figure 8 The removal of water 15 from the gas compression containers 11 and 311 can be completed in one step or in two steps. In particular, when the gas pressure in the gas compression containers 11 and 311 is low, the removal of water 15 is performed in one step. The gas pump 56 is operated, the gas pump valve 57 is set to open, and air is supplied to the gas compression containers 11 and 311 (through the air supply manifold 58). The supplied air increases the pressure in the gas compression containers 11 and 311, so that the water 15 is removed.

[0093] Therefore, those skilled in the art to which the present invention pertains will appreciate that, although the present invention has been described in terms of preferred embodiments, the concepts upon which the present disclosure is based may be readily utilized as a basis for designing other structures, systems and processes for carrying out the several purposes of the present invention.

[0094] Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0095] Reference numerals and signs appearing in the accompanying claims are merely illustrative and have no limiting effect on the scope of the claims.

[0096] Finally, it should be noted that the words "comprising," "having," and "including," as used throughout the appended claims, should be interpreted to mean "including but not limited to."

[0097] Therefore, it is important that the scope of the present invention should not be interpreted as being limited by the exemplary embodiments described herein. Other variations are possible within the scope of the present invention as defined by the appended claims. Other combinations and sub-combinations of features, functions, elements and / or characteristics may be claimed by modifying existing claims or presenting new claims in this application or related applications. Such modified or new claims, whether they are for different combinations or for the same combination, whether different in scope, wider in scope, narrower in scope, or the same in scope as the original claims, are also considered to be included in the subject matter of this specification.

Claims

1. A compression system for compressing a gas having a temperature higher than that of underground soil in the earth, the compression system comprising: a gas compression container (11, 311) arranged underground within the earth (13), the gas compression container (11, 311) being configured to accumulate and store potential energy in the form of compressed gas (14) and pressurized water (15); The gas compression container (11, 311) has a heat-conducting wall (111, 411); wherein the gas compression container (11, 311) has a circular cross-section of the inner side (16) of the heat-conducting wall (111, 411) at least in the upper part (17) of the gas compression container (11); wherein the outer side (18) of the heat-conducting wall (111, 411) of the gas compression container (11) is surrounded by a layer (19) of heat-conducting material filling the space between the outer side (18) and the soil of the earth (13) so as to maintain the compressed gas (14) in the gas compression container (11, 311) at the temperature of the soil during air compression and storage; a water supply container (21) arranged underground in the earth (13) and configured to contain water (212); The water supply container (21) has a heat-conducting wall (211); wherein the outer side (23) of the heat-conducting wall (211) of the water supply container (21) is surrounded by another layer (24) of heat-conducting material filling the space between the outer side (23) and the surrounding soil so as to maintain the water (212) in the water supply container (21) at the temperature of the soil; a pressurized water line (31) hydraulically coupled to the gas compression container (11, 311) and the water supply container (21) and configured to provide hydraulic communication between the gas compression container (11, 311) and the water supply container (21); a water pressurizing system (41), the water pressurizing system being arranged on the pressurized water pipeline (31), the water pressurizing system (41) comprising a pump, the pump being configured to controllably pump water from the water supply container (21) into the gas compression container (11, 311) so as to maintain a desired flow rate of the water through the pressurized water pipeline (31); and A water flow distributor (81), which is arranged in the gas compression container (11, 311) and is connected to the water pressurization system (41) via the pressurized water pipeline (31), and the water flow distributor (81) includes at least one nozzle (82), and the at least one nozzle is configured to guide the water flow pumped into the gas compression container (11, 311) to flow along the inner side (16) of the heat-conducting wall (111, 411) of the gas compression container (11, 311) in the direction in which the inner side (16) has the circular cross-section, so that the water flow in the gas compression container (11, 311) circulates along the inner side (16).

2. Compression system according to claim 1, wherein the gas compression container (11) has a substantially spherical shape in the upper part (17).

3. The compression system according to claim 1, wherein the gas compression container (311) has a substantially cylindrical shape in the upper part (17).

4. A compression system according to any one of claims 1 to 3, wherein the thermally conductive material of the layer (19) has adhesive properties sufficient to adhere to the thermally conductive wall (111, 411) and the soil, thereby promoting heat exchange from the thermally conductive wall (111, 411) to the soil via the thermally conductive material of the layer (19).

5. The compression system according to any one of claims 1 to 4, wherein the thermally conductive material of the layer (24) has adhesive properties sufficient to adhere to the thermally conductive wall (211) and the soil, thereby promoting heat exchange from the thermally conductive wall (211) to the soil via the thermally conductive material of the layer (24).

6. The compression system according to any one of claims 1 to 5, further comprising: An intake manifold (52) pneumatically coupled to the gas compression container (11, 311) to provide gas to the gas compression container (11, 311) for compression; and An intake valve (53) is arranged on the intake manifold (52) and is configured to control the supply of gas to the gas compression container (11, 311).

7. The compression system according to claim 6 further comprises a gas supply system (51), which is arranged on the intake manifold (52) and pneumatically connected to the gas compression container (11, 311), and the gas supply system (51) is configured to supply gas to the gas compression container (11, 311) for compression.

8. The compression system according to any one of claims 1 to 7, further comprising: a water inlet line (61) hydraulically coupled to the water supply container (21) and configured to supply water to the water supply container (21); and A water inlet valve (62) is arranged on the water inlet pipeline (61) and is configured to control the water supply to the water supply container (21).

9. A compression system according to any one of claims 1 to 8, further comprising a control system (71), which is connected to the water pressurization system (41) arranged on the pressurized water pipeline (31) and is configured to regulate the flow rate of the water (212) pumped into the gas compression container (11, 311) through the pressurized water pipeline (31).

10. The compression system according to claim 9, wherein the control system (71) comprises: a gas pressure sensor (72) disposed within the gas compression container (11, 311) and configured to generate a gas pressure sensor signal indicative of the pressure of the compressed gas (14) in the gas compression container (11, 311); and An electronic controller (700) is operably connected to the water pressurizing system (41) and the gas pressure sensor (72), the electronic controller (700) responding to the gas pressure sensor signal and capable of generating a control signal for actuating the pump of the water pressurizing system (41) when the gas pressure in the gas compression container (11, 311) is less than a predetermined pressure of the compressed gas.

11. The compression system according to any one of claims 1 to 10, further comprising: a compressed gas exchange manifold (55) pneumatically coupled to the gas compression container (11), the gas exchange manifold (55) being configured to supply the compressed gas (14) from the compression container (11) to a user at a desired pressure; and A gas release valve (54) is arranged on the compressed gas exchange manifold (55) and is configured to control the supply of the compressed gas (14) to the user.

12. The compression system according to any one of claims 1 to 11, further comprising: a drain line (92) hydraulically coupled to the gas compression container (11, 311), the drain line (92) being configured to remove water (15) accumulated at the bottom of the gas compression container (11, 311) after gas compression; a gas pump (56) configured to provide air at a desired pressure; An air supply manifold (58) pneumatically coupled to the gas pump (56) and the intake manifold (52), the air supply manifold (58) being configured to supply air provided by the gas pump (56) into the gas compression container (11, 311) at a pressure sufficient to remove water (15) accumulated at the bottom of the gas compression container (11, 311) through the drain line (92) after gas compression.

13. The compression system according to any one of claims 1 to 12, further comprising: a venturi pump (33), the venturi pump being arranged on the pressurized water pipeline (31); The venturi pump (33) comprises: a venturi air manifold (34) coupled to the pressurized water line (31), the venturi air manifold (34) being configured to provide air to the venturi pump (33); and A venturi nozzle (35) is connected to the pressurized water line (31), the venturi nozzle (35) comprising a diverging portion having an inlet cross section and an outlet cross section, the inlet cross section having an area smaller than the outlet cross section; the venturi nozzle (35) is configured to (i) receive a fluid flow comprising water passing through the pressurized water line (31) from the water pressurization system (41) and air provided by the venturi air manifold (34); and (ii) raise the pressure of the air in the fluid to a predetermined value through the diverging portion.

14. A method for compressing a gas having a temperature higher than that of underground soil in the earth, the method comprising reducing the temperature of the gas to that of underground soil in the earth during compression.

15. The compression method according to claim 14, comprising: Providing a compression system according to any one of claims 1 to 10; The water pressurizing system (41) is started to controllably pump water from the water supply container (21) into the gas compression container (11, 311) through the water flow distributor (81) so as to guide the water flow pumped into the gas compression container (11, 311) to flow along the inner side (16) of the heat-conducting wall (111, 411) of the gas compression container (11, 311) in the direction in which the inner side (16) has the circular cross-section, so that the water flow in the gas compression container (11, 311) circulates along the inner side (16), thereby reducing the temperature of the gas during the compression process.

16. The compression method according to claim 15, further comprising: Providing the system with a compressed gas exchange manifold (55), which is pneumatically coupled to the gas compression container (11), the gas exchange manifold (55) being configured to supply the compressed gas (14) from the compression container (11) to a user at a desired pressure; as well as providing the system with a gas release valve (54), the gas release valve being arranged on the compressed gas exchange manifold (55) and being configured to control the supply of the compressed gas (14) to the user; as well as The compressed gas (14) is supplied to the user at a desired pressure through the compressed gas exchange manifold (55).

17. The compression method according to claim 15 or 16, further comprising: providing the system with a drain line (92) hydraulically coupled to the gas compression container (11, 311), the drain line (92) being configured to remove water (15) accumulated at the bottom of the gas compression container (11, 311) after gas compression; providing the system with a gas pump (56) configured to provide air at a desired pressure; providing the system with an air supply manifold (58), the air supply manifold being pneumatically coupled to the gas pump (56) and the intake manifold (52), the air supply manifold (58) being configured to supply air provided by the gas pump (56) into the gas compression container (11, 311) at a pressure sufficient to remove water (15) accumulated at the bottom of the gas compression container (11, 311) through the drain line (92) after gas compression; and The water (15) accumulated at the bottom of the gas compression container (11, 311) is removed after the gas is compressed by supplying air into the gas compression container (11, 311) at a certain pressure through the gas pump (56), and the pressure is sufficient to remove the water (15) accumulated at the bottom of the gas compression container (11, 311) through the drainage pipeline (92).

18. The compression method according to any one of claims 15 to 17, further comprising: Providing the system with a venturi pump (33) arranged on the pressurized water line (31); The venturi pump (33) comprises: a venturi air manifold (34) coupled to the pressurized water line (31), the venturi air manifold (34) being configured to provide air to the venturi pump (33); and a venturi nozzle (35) coupled to the pressurized water line (31), the venturi nozzle (35) comprising a diverging portion having an inlet cross section and an outlet cross section, the inlet cross section having an area smaller than an area of ​​the outlet cross section; the venturi nozzle (35) being configured to (i) receive a fluid flow comprising water passing through the pressurized water line (31) from the water pressurization system (41) and air provided by the venturi air manifold (34); and (ii) increasing the pressure of the air in the fluid to a predetermined value through the expansion portion; and The pressure of the air is increased to a predetermined value by the Venturi pump (33).

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