Electric field enhanced underground hydrogen storage system and method

Abstract

The invention belongs to the technical field of underground hydrogen storage engineering, and particularly discloses an electric field enhanced underground hydrogen storage system and method. The method is used for solving the problems of low injection-production efficiency and small hydrogen storage capacity of a conventional injection-production mode in the current underground hydrogen storage project. Comprising an injection-production well, a first electrode column module and a second electrode column module, the injection-production well is used for injection and production of hydrogen, the first electrode column module represents one electrode of an electric field, and the second electrode column module represents the other opposite electrode of the electric field; the first electrode column module and the second electrode column module are respectively provided with equal quantity of charges with different numbers and are positioned on two sides with the same distance from an injection-production well, and a non-uniform electric field is formed in a reservoir. By applying an extra electric field, hydrogen molecules are polarized, induced dipoles are generated, then under the action of the electric field, the hydrogen flowing speed is increased, the hydrogen storage capacity is increased, and the hydrogen injection and production efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of underground hydrogen storage engineering, and in particular relates to an electric field enhanced underground hydrogen storage system and method. Background Art

[0002] Traditional hydrogen storage methods mainly include high-pressure gas tanks, cryogenic liquid hydrogen storage, and chemical storage (such as metal hydrides). Although these methods have achieved short-term storage of hydrogen to a certain extent, they have obvious limitations. High-pressure gas tanks require complex equipment to maintain a high-pressure state, and the storage capacity is limited; cryogenic liquid hydrogen storage requires extremely low temperatures, high energy consumption and complex technology; although chemical storage has better stability, the release and re-adsorption process of hydrogen is less efficient. Therefore, traditional hydrogen storage methods are difficult to meet the demand for large-scale, long-term storage of hydrogen under the future zero-carbon goal.

[0003] Underground hydrogen storage, as an emerging hydrogen storage technology, is gradually gaining attention. The core idea of ​​this technology is to use underground geological structures (such as salt caverns, depleted oil and gas reservoirs, and aquifers) as storage media, inject hydrogen into the ground for long-term storage, and flexibly extract it during peak energy demand periods or special periods. Underground hydrogen storage has many significant advantages. First, its storage capacity far exceeds that of traditional methods and can meet industrial-scale hydrogen storage needs. Secondly, the underground storage environment has natural isolation and stability, which can effectively reduce the risk of hydrogen leakage. In addition, the combination of underground hydrogen storage and existing oil and gas storage and transportation infrastructure further reduces the cost of technological transformation and the application threshold. Therefore, underground hydrogen storage technology has shown broad application prospects in the future transformation of the energy structure.

[0004] Although underground hydrogen storage has many advantages, it also faces a series of technical challenges. Among them, how to improve the injection and production rate and storage efficiency of hydrogen is one of the key issues. In underground hydrogen storage projects, the conventional injection method is to use ground equipment to pressurize hydrogen and inject it into the formation through the wellbore. The conventional extraction method is to use the reservoir pressure to reduce the pressure and recover it through the wellbore. The hydrogen flow rate in this conventional hydrogen injection and production method is relatively low, and hydrogen can only be stored at the density under the conditions of formation temperature and pressure, and the hydrogen storage capacity is relatively small. Summary of the invention

[0005] One object of the present invention is to provide an electric field enhanced underground hydrogen storage system to effectively solve the problems of low injection and production efficiency and small hydrogen storage capacity existing in conventional injection and production methods in current underground hydrogen storage projects.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] An electric field enhanced underground hydrogen storage system comprises an injection and production well, a first electrode column module and a second electrode column module; the injection and production well is used for the injection and production of hydrogen, the first electrode column module represents an electrode of the electric field, and the second electrode column module represents another opposite electrode of the electric field; the first electrode column module and the second electrode column module respectively carry equal but opposite charges and are located on both sides of the injection and production well at the same distance, thereby forming a non-uniform electric field in the reservoir.

[0008] Furthermore, the injection and production wells extend from the surface well field deep into the reservoir and are located in the middle of the entire electric field enhanced underground hydrogen storage system.

[0009] The first electrode column module is located on one side of the injection and production well, and its height is equal to the reservoir thickness of the underground hydrogen storage structure.

[0010] The second electrode column module is located on the other side of the injection and production well opposite to the first electrode column module, and its height is equal to the reservoir thickness of the underground hydrogen storage structure.

[0011] Another object of the present invention is to provide an electric field enhanced underground hydrogen storage method, which adopts the electric field enhanced underground hydrogen storage system described in the above embodiment; hydrogen is injected into the reservoir of the underground hydrogen storage structure through the injection and production well, and during the injection process, the hydrogen is polarized in the non-uniform electric field formed by the first electrode column module and the second electrode column module, and the positive and negative charge centers of the hydrogen no longer coincide, generating an induced dipole; hydrogen molecules form induced charges of equal amount and opposite sign; the two induced charges are subjected to the electrostatic attraction and electrostatic repulsion of the non-uniform electric field with different magnitudes and opposite directions, so that the hydrogen forms a directional acceleration moving toward the first electrode column module or the second electrode column module.

[0012] Hydrogen is extracted to the ground through injection and production wells. During the extraction process, the positive and negative poles of the non-uniform electric field are changed according to the set frequency, so that the hydrogen forms a directional acceleration moving toward the injection and production wells.

[0013] Furthermore, the transformation of the positive and negative poles of the non-uniform electric field indicates that the charge properties of the first electrode column module and the second electrode column module are transformed into positive and negative.

[0014] Furthermore, during the injection process, hydrogen will enter the reservoir half area controlled by the first electrode column module and the reservoir half area controlled by the second electrode column module through the injection and production wells respectively. At this time, the first electrode column module displays positive electricity and the second electrode column module displays negative electricity.

[0015] Hydrogen is polarized in the non-uniform electric field formed by the first electrode column module and the second electrode column module, and the positive and negative charge centers of hydrogen no longer coincide, generating an induced dipole; hydrogen molecules form induced charges of equal magnitude and opposite signs, generating positive charges along the direction of the electric field lines and negative charges along the opposite direction of the electric field lines.

[0016] In the reservoir half area controlled by the first electrode column module, the electric field density at the location where the negative charge of the hydrogen molecule is located is larger, while the electric field density at the location where the positive charge is located is smaller. Therefore, the electrostatic attraction force on the negative charge of the hydrogen molecule is greater than the electrostatic repulsion force on the positive charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the first electrode column module. Therefore, the hydrogen generates an acceleration toward the first electrode column module, and the flow rate of the hydrogen increases.

[0017] In the reservoir half area controlled by the second electrode column module, the electric field density at the location where the positive charge of the hydrogen molecule is located is larger, while the electric field density at the location where the negative charge is located is smaller. Therefore, the electrostatic attraction force on the positive charge of the hydrogen molecule is greater than the electrostatic repulsion force on the negative charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the direction of the second electrode column module. Therefore, the hydrogen generates an acceleration toward the second electrode column module, and the flow rate of the hydrogen increases.

[0018] Therefore, during the hydrogen injection process, the hydrogen in the reservoir half area controlled by the first electrode column module will accelerate to flow toward the first electrode column module, and the hydrogen in the reservoir half area controlled by the second electrode column module will accelerate to flow toward the second electrode column module.

[0019] Furthermore, during the production process of hydrogen, hydrogen will enter the injection and production wells from the reservoir half area controlled by the first electrode column module and the reservoir half area controlled by the second electrode column module respectively, and then be recovered to the surface well site.

[0020] The positive and negative poles of the non-uniform electric field are changed so that the first electrode column module displays negative electricity and the second electrode column module displays positive electricity. At this time, the hydrogen is still in the polarization state before the electric field is changed.

[0021] In the reservoir half area controlled by the first electrode column module, the electric field density at the location where the negative charge of the hydrogen molecule is located is larger, while the electric field density at the location where the positive charge is located is smaller. Therefore, the electrostatic repulsion force on the negative charge of the hydrogen molecule is greater than the electrostatic attraction force on the positive charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the injection and production wells. Therefore, hydrogen generates acceleration toward the injection and production wells, and the flow rate of hydrogen increases.

[0022] In the reservoir half area controlled by the second electrode column module, the electric field density at the location where the positive charge of the hydrogen molecule is located is larger, while the electric field density at the location where the negative charge is located is smaller. Therefore, the electrostatic repulsion force on the positive charge of the hydrogen molecule is greater than the electrostatic attraction force on the negative charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the injection and production wells. Therefore, hydrogen generates acceleration toward the injection and production wells, and the flow rate of hydrogen increases.

[0023] Therefore, in the short time of changing the positive and negative poles of the non-uniform electric field, the hydrogen in the reservoir half area controlled by the first electrode column module will accelerate to flow to the injection and production well, and the hydrogen in the reservoir half area controlled by the second electrode column module will also accelerate to flow to the injection and production well; the short time means no more than 10 -12 Second.

[0024] Further, after the long time of changing the positive and negative poles of the non-uniform electric field, the hydrogen will be polarized again according to the current electric field distribution, generating positive charges along the direction of the electric field lines and negative charges in the opposite direction of the electric field lines. At this time, the stress state of the hydrogen is similar to the stress state of the hydrogen during the injection process, and the hydrogen has a tendency to flow to the first electrode column module and the second electrode column module; the long time means greater than 10 -12 seconds; during the hydrogen production process, in order to prevent hydrogen from flowing to the first electrode column module and the second electrode column module, it is necessary to change the positive and negative poles of the non-uniform electric field again so that the hydrogen is always accelerated to flow to the injection and production well.

[0025] Therefore, during the extraction process, hydrogen needs to be 12 The frequency of Hz transforms the positive and negative poles of the non-uniform electric field to prevent hydrogen from flowing to the first electrode column module and the second electrode column module, and keeps the hydrogen flowing to the injection and production well at an accelerated speed.

[0026] Compared with the prior art, the beneficial technical effects of the present invention are:

[0027] The present invention symmetrically arranges a first electrode column module and a second electrode column module with equal but opposite charges on both sides of the injection and production well, applies an additional electric field, polarizes hydrogen molecules, and generates induced dipoles. Then, under the action of the electric field, the hydrogen flow rate is increased, the hydrogen storage capacity is increased, and the hydrogen injection and production efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the equipotential line distribution of a non-uniform electric field.

[0029] Figure 2 This is a schematic diagram of the forces acting on hydrogen molecules in a non-uniform electric field during hydrogen injection.

[0030] Figure 3 This is a schematic diagram of the forces acting on hydrogen molecules in a short period of time when the direction of the non-uniform electric field changes during the hydrogen extraction process.

[0031] Figure 4 This is a schematic diagram of the forces acting on hydrogen molecules after a long period of time when the direction of the non-uniform electric field is changed during the hydrogen extraction process. DETAILED DESCRIPTION

[0032] Embodiment 1: The electric field enhanced underground hydrogen storage system includes an injection and production well, a first electrode column module and a second electrode column module.

[0033] The injection and production wells are used for the injection and production of hydrogen. The injection and production wells extend from the surface well field deep into the reservoir and are located in the middle of the entire electric field enhanced underground hydrogen storage system.

[0034] The first electrode column module represents an electrode of the electric field, such as a positive electrode or a negative electrode; the first electrode column module is located on one side of the injection and production well, and its height is equal to the reservoir thickness of the underground hydrogen storage structure. The second electrode column module represents another opposite electrode of the electric field, such as a negative electrode or a positive electrode; the second electrode column module is located on the other side of the injection and production well opposite to the first electrode column module, and its height is equal to the reservoir thickness of the underground hydrogen storage structure.

[0035] The first electrode column module and the second electrode column module carry equal but opposite charges and are located at the same distance from the injection and production wells, forming a non-uniform electric field in the reservoir. In this embodiment, the first electrode column module and the second electrode column module are both about 300 meters away from the injection and production wells. Figure 1 As shown, the closer the area is to the first electrode column module and the second electrode column module, the denser the electric field lines are, the higher the electric potential is, and the greater the electric field force on the charge is.

[0036] In this embodiment, the first electrode column module and the second electrode column module both include an electrode column made of steel and a power supply device. The electrode column is energized by the power supply device so that the electrode column has positive and negative poles. When the power supply device is an AC power supply, the positive and negative poles of the electrode column can be alternately changed.

[0037] Embodiment 2: Electric field enhanced underground hydrogen storage method, using the electric field enhanced underground hydrogen storage system described in Embodiment 1. In the underground hydrogen storage project, hydrogen is injected into the reservoir of the underground hydrogen storage structure through the injection well.

[0038] (1) During the hydrogen injection process, hydrogen will enter the reservoir half area controlled by the first electrode column module and the reservoir half area controlled by the second electrode column module through the injection and production wells. At this time, the first electrode column module displays positive electricity and the second electrode column module displays negative electricity. Hydrogen is polarized in the non-uniform electric field formed by the first electrode column module and the second electrode column module. The positive and negative charge centers of hydrogen no longer coincide, generating an induced dipole. Hydrogen molecules form induced charges of equal magnitude and opposite signs, generating positive charges along the direction of the electric field lines and negative charges along the opposite direction of the electric field lines, such as Figure 2 shown.

[0039] In the reservoir half area controlled by the first electrode column module, the electric field density is greater at the location where the negative charge of the hydrogen molecule is located, while the electric field density is smaller at the location where the positive charge is located. Therefore, the electrostatic attraction force on the negative charge of the hydrogen molecule is greater than the electrostatic repulsion force on the positive charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the first electrode column module. Therefore, the hydrogen generates an acceleration toward the first electrode column module, and the flow rate of the hydrogen increases.

[0040] In the reservoir half area controlled by the second electrode column module, the electric field density is greater at the location where the positive charge of the hydrogen molecule is located, while the electric field density is smaller at the location where the negative charge is located. Therefore, the electrostatic attraction force on the positive charge of the hydrogen molecule is greater than the electrostatic repulsion force on the negative charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the second electrode column module. As a result, the hydrogen generates an acceleration toward the second electrode column module, and the flow rate of the hydrogen increases.

[0041] Therefore, during the hydrogen injection process, the hydrogen in the reservoir half area controlled by the first electrode column module will accelerate to flow toward the first electrode column module, and the hydrogen in the reservoir half area controlled by the second electrode column module will accelerate to flow toward the second electrode column module. The combined force exerted on the hydrogen not only causes the hydrogen to generate an acceleration toward the electrode column, increasing the flow rate of the hydrogen, but also has the effect of compressing the hydrogen in the reservoir, increasing the hydrogen storage capacity of the reservoir.

[0042] (2) During the production process of hydrogen, hydrogen will enter the injection and production wells from the reservoir half area controlled by the first electrode column module and the reservoir half area controlled by the second electrode column module, and then be recovered to the surface well site.

[0043] The positive and negative poles of the non-uniform electric field are changed so that the first electrode column module displays negative electricity and the second electrode column module displays positive electricity. Figure 3 As shown, at this time the hydrogen is still in the polarization state before the electric field is changed.

[0044] In the reservoir half area controlled by the first electrode column module, the electric field density at the location of the negative charge of the hydrogen molecule is greater, while the electric field density at the location of the positive charge is smaller. Therefore, the electrostatic repulsion force on the negative charge of the hydrogen molecule is greater than the electrostatic attraction force on the positive charge, and the resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the injection and production well. As a result, hydrogen generates an acceleration toward the injection and production well, and the flow rate of hydrogen increases.

[0045] In the reservoir half area controlled by the second electrode column module, the electric field density at the location where the positive charge of the hydrogen molecule is located is greater, while the electric field density at the location where the negative charge is located is smaller. Therefore, the electrostatic repulsion force on the positive charge of the hydrogen molecule is greater than the electrostatic attraction force on the negative charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the injection and production well. As a result, hydrogen generates an acceleration toward the injection and production well, and the flow rate of hydrogen increases.

[0046] Therefore, in the short time (10 -12Within 10 seconds, the hydrogen in the reservoir half controlled by the first electrode column module will accelerate to flow to the injection and production well, and the hydrogen in the reservoir half controlled by the second electrode column module will also accelerate to flow to the injection and production well. Under the action of the non-uniform electric field, the combined force exerted on the hydrogen causes the hydrogen to generate an acceleration toward the injection and production well, pushing the hydrogen into the injection and production well, and improving the flow speed and recovery efficiency of the hydrogen.

[0047] (3) During the long period of time (greater than 10 -12 After 10 seconds, the hydrogen will be polarized again according to the current electric field distribution, generating positive charges along the direction of the electric field lines and negative charges in the opposite direction of the electric field lines, such as Figure 4 As shown. At this time, the stress state of hydrogen is similar to the stress state of hydrogen during the injection process, and hydrogen has a tendency to flow toward the first electrode column module and the second electrode column module. During the hydrogen production process, in order to prevent hydrogen from flowing toward the first electrode column module and the second electrode column module, it is necessary to change the positive and negative poles of the non-uniform electric field again so that hydrogen always accelerates to flow toward the injection and production well.

[0048] Therefore, during the extraction process, hydrogen needs to be 12 Hz transforms the positive and negative poles of the non-uniform electric field to prevent hydrogen from flowing to the first electrode column module and the second electrode column module, and keeps hydrogen flowing to the injection and production well at an accelerated speed. The transformation of the positive and negative poles of the non-uniform electric field means changing the charge property of the electrode column from positive to negative, or from negative to positive.

[0049] The present invention realizes electric field-enhanced underground hydrogen storage and is applied in underground hydrogen storage projects, which is beneficial to improving injection and production efficiency and increasing hydrogen storage capacity.

[0050] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. An electric field enhanced underground hydrogen storage system, characterized in that: It includes an injection and production well, a first electrode column module and a second electrode column module; The injection and production well is used for the injection and production of hydrogen, the first electrode column module represents one electrode of the electric field, and the second electrode column module represents another opposite electrode of the electric field; The first electrode column module and the second electrode column module respectively carry equal and opposite charges and are located on both sides at the same distance from the injection and production wells, thereby forming a non-uniform electric field in the reservoir.

2. The electric field enhanced underground hydrogen storage system according to claim 1, characterized in that: The injection and production wells extend from the surface well field into the reservoir and are located in the middle of the entire electric field enhanced underground hydrogen storage system; The first electrode column module is located on one side of the injection and production well, and its height is equal to the reservoir thickness of the underground hydrogen storage structure; The second electrode column module is located on the other side of the injection and production well opposite to the first electrode column module, and its height is equal to the reservoir thickness of the underground hydrogen storage structure.

3. An electric field enhanced underground hydrogen storage method, characterized in that: An electric field enhanced underground hydrogen storage system according to any one of claims 1 to 2; Hydrogen is injected into the reservoir of the underground hydrogen storage structure through the injection well. During the injection process, the hydrogen is polarized in the non-uniform electric field formed by the first electrode column module and the second electrode column module, and the positive and negative charge centers of the hydrogen no longer coincide, generating an induced dipole; the hydrogen molecules form induced charges of equal magnitude and opposite sign; the electrostatic attraction and electrostatic repulsion of the two induced charges are different in magnitude and opposite in direction due to the non-uniform electric field, causing the hydrogen to form a directional acceleration moving toward the first electrode column module or the second electrode column module; Hydrogen is extracted to the ground through injection and production wells. During the extraction process, the positive and negative poles of the non-uniform electric field are changed according to the set frequency, so that the hydrogen forms a directional acceleration moving toward the injection and production wells.

4. The electric field enhanced underground hydrogen storage method according to claim 3, characterized in that: The positive and negative poles of the transformed non-uniform electric field represent the positive and negative transformation of the charge properties of the first electrode column module and the second electrode column module.

5. The electric field enhanced underground hydrogen storage method according to claim 4, characterized in that: During the injection process, hydrogen will enter the reservoir half area controlled by the first electrode column module and the reservoir half area controlled by the second electrode column module through the injection and production wells. At this time, the first electrode column module displays positive electricity and the second electrode column module displays negative electricity. Hydrogen is polarized in the non-uniform electric field formed by the first electrode column module and the second electrode column module. The positive and negative charge centers of hydrogen no longer coincide, generating an induced dipole. Hydrogen molecules form induced charges of equal magnitude and opposite signs, generating positive charges along the direction of the electric field lines and negative charges in the opposite direction of the electric field lines. In the reservoir half area controlled by the first electrode column module, the electric field density at the location where the negative charge of the hydrogen molecule is located is greater, while the electric field density at the location where the positive charge is located is smaller. Therefore, the electrostatic attraction force on the negative charge of the hydrogen molecule is greater than the electrostatic repulsion force on the positive charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the first electrode column module. Therefore, the hydrogen generates an acceleration toward the first electrode column module, and the flow speed of the hydrogen increases. In the reservoir half area controlled by the second electrode column module, the electric field density at the location where the positive charge of the hydrogen molecule is located is greater, while the electric field density at the location where the negative charge is located is smaller. Therefore, the electrostatic attraction force on the positive charge of the hydrogen molecule is greater than the electrostatic repulsion force on the negative charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the second electrode column module. Therefore, the hydrogen generates an acceleration toward the second electrode column module, and the flow speed of the hydrogen increases; Therefore, during the hydrogen injection process, the hydrogen in the reservoir half area controlled by the first electrode column module will accelerate to flow toward the first electrode column module, and the hydrogen in the reservoir half area controlled by the second electrode column module will accelerate to flow toward the second electrode column module.

6. The electric field enhanced underground hydrogen storage method according to claim 5, characterized in that: During the production process, hydrogen enters the injection well from the reservoir half area controlled by the first electrode column module and the reservoir half area controlled by the second electrode column module, and then is recovered to the surface well site; The positive and negative poles of the non-uniform electric field are changed so that the first electrode column module displays negative electricity and the second electrode column module displays positive electricity. At this time, the hydrogen is still in the polarization state before the electric field is changed; In the reservoir half area controlled by the first electrode column module, the electric field density at the location where the negative charge of the hydrogen molecule is located is greater, while the electric field density at the location where the positive charge is located is smaller. Therefore, the electrostatic repulsion force on the negative charge of the hydrogen molecule is greater than the electrostatic attraction force on the positive charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the injection and production wells. Therefore, hydrogen generates acceleration toward the injection and production wells, and the flow rate of hydrogen increases; In the reservoir half area controlled by the second electrode column module, the electric field density at the location where the positive charge of the hydrogen molecule is located is greater, while the electric field density at the location where the negative charge is located is smaller. Therefore, the electrostatic repulsion force on the positive charge of the hydrogen molecule is greater than the electrostatic attraction force on the negative charge. The resultant force on the hydrogen molecule is not zero, and the direction of the resultant force is toward the injection and production wells. Therefore, hydrogen generates acceleration toward the injection and production wells, and the flow rate of hydrogen increases; Therefore, within a short period of time after the positive and negative poles of the non-uniform electric field are changed, the hydrogen in the reservoir half area controlled by the first electrode column module will accelerate to flow to the injection and production well, and the hydrogen in the reservoir half area controlled by the second electrode column module will also accelerate to flow to the injection and production well; the short period of time means no more than 10 -12 Second.

7. The electric field enhanced underground hydrogen storage method according to claim 6, characterized in that: After a long time of changing the positive and negative poles of the non-uniform electric field, the hydrogen will be polarized again according to the current electric field distribution, generating positive charges along the direction of the electric field lines and negative charges in the opposite direction of the electric field lines; the long time means more than 10 -12 Second; During the hydrogen production process, in order to prevent hydrogen from flowing to the first electrode column module and the second electrode column module, it is necessary to change the positive and negative poles of the non-uniform electric field again so that the hydrogen is always accelerated to flow to the injection and production well.

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