Construction method for transforming abandoned coal roadway into compressed air storage

Abstract

The present application relates to a kind of construction methods of waste coal lane is transformed into compressed air storage, comprising the following steps: the outer periphery of the loss area of predetermined surrounding rock is grouted and reinforced, to form outer periphery closed area;The outer periphery surrounding rock of roadway hance and arch bottom is grouted and reinforced, to be first inside closed area, first inside closed area is filled between the outer periphery closed area and the position of roadway hance and arch bottom;The outer periphery surrounding rock of roadway arch top is grouted and reinforced, to form second inside closed area;The surrounding rock between outer periphery closed area, first inside closed area and second inside closed area is sealed by water, to form high pressure water area;Insulation sealing layer is constructed in the inner side of roadway lining;The both ends of roadway are sealed using blocking piece, the method of the present application ensures the sealing property and gas storage capacity of gas storage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressed air energy storage, in particular to a construction method for transforming abandoned coal lane into compressed air storage. BACKGROUND

[0002] Transforming abandoned coal lane into compressed air storage helps to promote the deep application of energy storage technology. For the construction of coal lane compressed air storage, ensuring the stability, sealing, durability and long-term stability of the structure within the cyclic injection and production cycle is the most critical construction requirement.

[0003] The existing patent No. CN 109356650 A, a method for compressed air energy storage using underground coal mine lane, provides a method for compressed air energy storage using underground coal mine lane, grouting and reinforcing the surrounding rock damage zone, constructing reinforced concrete lining and making steel lining on the inner side of the lining, setting up steel barriers and outer concrete barriers to seal the two ends of the lane, and placing flexible gas storage bags in the lane for compressed air storage and retrieval. On the one hand, the lane originally has a lining structure, and the method of pouring circular lining and grouting on the outside greatly reduces the cross-sectional area of the lane, to some extent, compresses the gas storage space of the coal lane, and increases the construction cost. Moreover, the damage zone of the surrounding rock is prone to develop to the deep part, which is not conducive to controlling the deformation of the surrounding rock, and the reinforcement effect is not good. On the other hand, for a huge space with a volume of hundreds of thousands of cubic meters, the bearing pressure resistance (10 MPa pressure cycle alternation) and long-term durability of the flexible gas storage bag require high performance of the material, and the reliability needs to be verified. At the same time, the flexible gas storage bag is connected to the gas inlet pipeline and the gas outlet pipeline, and once the bag leaks, the replacement of the bag will cause serious waste of compressed air. In addition, the use of steel barriers and steel lining on the inner surface of the lining causes high heat conduction coefficient, resulting in large heat loss, and the decrease of the temperature of the compressed air in the gas storage will cause the corresponding decrease of the pressure of the compressed air, resulting in serious energy loss. SUMMARY

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide a construction method for transforming abandoned coal lane into compressed air storage, which has good reinforcement effect and can avoid leakage of compressed air, and has small energy loss.

[0005] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme:

[0006] The embodiment of the present application provides a construction method for transforming abandoned coal lane into compressed air storage, comprising the following steps:

[0007] Grouting and reinforcing the periphery of the pre-determined surrounding rock damage zone to form an outer closed area;

[0008] The surrounding rock of the arch waist and the arch bottom is grouted to form a first inner side closed area, which is filled between the outer closed area and the position of the arch waist and the arch bottom of the roadway.

[0009] The surrounding rock between the outer closed area, the first inner side closed area and the second inner side closed area is sealed by water injection to form a high-pressure water area.

[0010] A heat preservation sealing layer is constructed on the inner side of the roadway lining.

[0011] The two ends of the roadway are sealed by the sealing member.

[0012] Optionally, the outer closed area construction method is as follows: first, the anchor rod is constructed, the grouting anchor rod penetrates the surrounding rock damage area and then penetrates the hard surrounding rock outside the surrounding rock damage area, and then the surrounding rock damage area outside is grouted by using the grouting pipe to form the outer closed area.

[0013] Optionally, the outer closed area grouting reinforcement adopts a retreating grouting process, the grouting pipe of the arch waist and the arch bottom is retreated to a set position to perform the first inner side closed area grouting reinforcement, and the grouting pipe of the arch top is retreated to a set position to perform the second inner side closed area grouting reinforcement.

[0014] Optionally, after the outer closed area grouting reinforcement is completed, the geophysical detection method is used to evaluate the reinforcement effect, and the positions that do not meet the requirements are supplemented with grouting.

[0015] Optionally, after the first inner side closed area and the second inner side closed area grouting reinforcement is completed, the detection hole method is combined with the borehole television to evaluate the grouting reinforcement effect, and the positions that do not meet the requirements are supplemented with grouting, wherein the set detection hole corresponding to the position of the arch top is reserved for subsequent water injection sealing, and the other detection holes are sealed.

[0016] Optionally, the water pressure of the high-pressure water area formed by water injection is greater than the maximum air pressure in the roadway chamber.

[0017] Optionally, the heat preservation sealing layer comprises a corrosion prevention layer, a waterproof layer, a heat preservation layer and a sealing layer which are sequentially constructed on the inner side of the roadway lining.

[0018] Optionally, the sealing member adopts a concrete air plug, the outer end surface of the concrete air plug is sequentially provided with a heat preservation layer and a sealing layer, the outer periphery of the concrete air plug is bound with an inflatable film bag, and after the concrete air plug is inserted into the end of the roadway, cement-silicate double slurry is injected into the inflatable film bag to seal the gap between the concrete air plug and the roadway lining.

[0019] Optionally, the concrete air plug is provided with an annular protruding structure, and the annular protruding structure is located outside the inflatable film bag.

[0020] Further, the outer side of the annular convex structure comprises a first surface and a second surface distributed at a set included angle, and the sum of the included angles of the first surface and the second surface with the concrete gas plug axis is less than 90 degrees.

[0021] Optionally, the plugging member is provided with a gas injection pipeline, a gas release pipeline and a maintenance channel.

[0022] The beneficial effects of the present application are as follows:

[0023] 1. The construction method of the present application forms an outer closed area by grouting and reinforcing the outer side of the damaged area of the surrounding rock and constructing anchor rods, so that the surrounding rock forms a load-bearing ring, the pressure of part of the surrounding rock is transferred to the outside of the damaged area, and the peripheral fissure water is isolated from entering the damaged area, which can prevent the extension of the damaged area of the surrounding rock to the deep, effectively control the deformation of the surrounding rock, and ensure the grouting reinforcement effect. Meanwhile, the construction method of the present application does not need to set a flexible gas storage bag, avoiding the defects of using a flexible gas storage bag. Under the premise of not using a flexible gas storage bag, in order to ensure the sealing of compressed air, a high-pressure water area is set, and since compressed air leakage generally occurs at the vault position, the high-pressure water area is set at the corresponding position of the vault. The compressed air is sealed by the inner closed area and the high-pressure water area, and the external goaf water is difficult to penetrate into the storage, thereby ensuring the sealing property of the gas storage.

[0024] 2. The construction method of the present application, the inner side of the original lining of the roadway is constructed with a heat preservation sealing layer, which is sealed by the high-pressure water area, the inner closed area and the heat preservation sealing layer. Moreover, the plugging member is also provided with a heat preservation layer and a sealing layer, which reduces the heat exchange and heat conduction between the gas storage and the lining and the surrounding rock. Compared with the steel barrier and the steel lining layer set on the surface of the lining, the heat loss of the storage is greatly reduced, and the energy conversion efficiency is improved. Moreover, the heat preservation sealing layer set on the inner side of the lining further reduces the possibility of leakage of high-pressure gas in the storage, forming a reliable storage reinforcement and sealing technology system.

[0025] 3. The construction method of the present application, only a sealing heat preservation layer is constructed on the inner side of the lining, which comprises a corrosion prevention layer, a waterproof layer, a heat preservation layer and a sealing layer. Compared with the traditional construction method, the cross-sectional area is reduced to a smaller extent, and the roadway has sufficient gas storage space, which ensures the gas storage capacity on the basis of the safety and stability of the storage. BRIEF DESCRIPTION OF DRAWINGS

[0026] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the application, and together with the description of the exemplary embodiments of the application, explain the application, and do not constitute an improper limitation of the application.

[0027] Figure 1 is a schematic diagram of the grouting reinforcement reconstruction of the outer closed area of the embodiment 1 of the present application;

[0028] Figure 2 This is a schematic diagram of the grouting reinforcement and modification of the first inner closed area and the second inner closed area in Embodiment 1 of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of the anti-corrosion layer, waterproof layer, heat insulation layer and sealing layer on the inner side of the lining in Embodiment 1 of the present invention;

[0030] Figure 4 This is a schematic diagram of a concrete air plug according to Embodiment 1 of the present invention;

[0031] Figure 5 This is a cross-sectional view of the concrete air plug in Embodiment 1 of the present invention;

[0032] Among them, 1. Anchor bolt, 2. Outer enclosure zone, 3. Surrounding rock damage zone, 4. Lining structure, 5. First sequence grouting pipe, 6. Second inner enclosure zone, 7. Second sequence grouting pipe, 8. Water curtain borehole, 9. High-pressure water zone, 10. Third sequence grouting pipe, 11. First inner enclosure zone, 12. Anti-corrosion layer, 13. Waterproof layer, 14. Thermal insulation layer, 15. Sealing layer, 16. Compressed air chamber, 17. Concrete air plug, 18. First included angle β1, 19. Second included angle β2, 20. Expansion membrane bag, 21. Maintenance channel, 22. Air injection pipe, 23. Air release pipe. Detailed Implementation

[0033] Example 1:

[0034] This embodiment provides a construction method for converting an abandoned coal roadway into a compressed air storage facility, including the following steps:

[0035] Step 1: Conduct a comprehensive evaluation of the location of the compressed air storage in the abandoned coal roadway and obtain the surrounding rock damage zone 3.

[0036] Specifically, the following assessments are conducted: engineering geological evaluation of the gas storage cavern (strata distribution, topography, lithology, geological structure, earthquake history, etc.), evaluation of groundwater hydrogeological conditions, evaluation of the stability of the overlying rock strata, evaluation of the permeability of the surrounding rock, and evaluation of the treatment of hazardous gases in the mine.

[0037] A detailed investigation was conducted into existing methods, technologies, and theories for selecting sites for compressed air energy storage facilities in abandoned mines. Based on geological surveys, core descriptions, drilling and logging data analysis, and indoor test parameter measurements, studies were carried out on the following aspects: engineering geological evaluation of the storage cavern (strata distribution, topography, lithology, geological structure, seismic history, etc.), evaluation of groundwater hydrogeological conditions, evaluation of the stability of the overlying strata, evaluation of the permeability of the surrounding rock, and evaluation of the treatment of hazardous gases in the mine. At the same time, the distribution of surrounding photovoltaic or wind power and the distribution of power load centers were comprehensively considered to analyze the impact and suitability characteristics of the storage facility construction, which must meet the three basic principles of safety and reliability, technical feasibility, and economic rationality.

[0038] According to the conclusion of the geological evaluation, the surrounding rock damage area 3 range is drawn.

[0039] The above method can be used with existing methods and will not be described in detail here.

[0040] Step 2: Grouting reinforcement is performed in the peripheral area of the surrounding rock loss area 3 to form a peripheral closed area 2.

[0041] Step 2.1: As shown in Figure 1 , anchor rods 1 are constructed along the two side haunches and arch feet. The anchor rods 1 penetrate into the hard surrounding rock outside the surrounding rock loss area 3 after passing through the surrounding rock loss area 3, which can transfer part of the surrounding rock pressure outside the surrounding rock loss area 3, inhibit the development of the surrounding rock damage area 3 to the deep part, effectively control the deformation of the surrounding rock, and the anchor rod parameters (such as anchor rod specifications, mechanical parameters, etc.) are determined according to the size of the damage area.

[0042] Step 2.2: Grouting reinforcement is performed in the peripheral area of the surrounding rock loss area 3. Specifically, the peripheral closed area 2 is formed by grouting through the first sequence of grouting pipes 5. The tunnel deformation is monitored and warned in real time during the grouting process, and the grouting parameters are monitored online. After grouting is completed, the reinforcement effect is evaluated by geophysical detection method.

[0043] The peripheral closed area 2 is formed by grouting through the first sequence of grouting pipes 5. The grouting should be continuous and uniform, and the grouting process adopts a retreating type. The grouting pipe slurry diffusion range is designed to be 1 m, and the grouting pressure is 0.5-1.0 MPa. Cement single liquid slurry is used, with a strength of P.O 42.5, and a ratio of W:C = 1:1. The single-hole grouting pressure reaches the designed final pressure and continues to grout for more than 10 minutes, and the single-hole grouting can be completed. The single-hole grouting amount is the same as the designed grouting amount, and the grouting can be completed when the grouting amount is less than 20-30 L / min.

[0044] Real-time monitoring and early warning of tunnel deformation during grouting requires monitoring the stability of the tunnel surrounding rock in the grouting treatment section. Convergence gauge is used to measure the subsidence of the tunnel vault and the convergence of the two sides. Four monitoring points are arranged for the vault subsidence and convergence of the two sides of the surrounding rock. The interval between each monitoring section is 3 m, and a total of 6 sections are arranged. The influence of grouting on the stability of the surrounding rock is monitored, and the grouting reinforcement effect is analyzed through real-time monitoring of the deformation of the surrounding rock.

[0045] In terms of online monitoring of grouting parameters, the grouting pressure and flow during grouting are monitored. According to the changes in the grouting pressure and flow of the grouting hole, the grouting pressure is ensured not to be too large, and the grouting amount reaches the designed value. According to the design scheme, the grouting diffusion range is strictly controlled to ensure the grouting effect.

[0046] The grouting effect is evaluated by geophysical detection method after grouting. Before grouting reinforcement, the damaged zone 3 of surrounding rock is broken, has high porosity and strong water enrichment, electromagnetic waves are refracted and reflected multiple times on the gap interface, resulting in electromagnetic wave attenuation, and the radar image shows that the energy attenuation is significant. After grouting, the overall performance of the surrounding rock is improved, the porosity is reduced, the energy dissipation of electromagnetic wave reflection at the interface is reduced, and the energy attenuation shown by the radar image is not as strong as before grouting, and the reflected wave shows the characteristics of homogeneous performance, i.e. flat, continuous and good isotropy, which indirectly verifies the grouting reinforcement effect.

[0047] After the evaluation is passed, the backward grouting is completed, and the grouting pipe is pulled back to other positions to be reinforced for subsequent sequence grouting. If the grouting effect does not meet the design requirements, supplementary grouting should be carried out.

[0048] Step 3: as shown in Figure 2 The surrounding rock of the arch waist and the arch bottom is grouted and reinforced, forming a first inner side closed area 11, and the surrounding rock of the arch top is grouted and reinforced, forming a second inner side closed area 6.

[0049] Specifically:

[0050] The first inner side closed area 11 and the second inner side closed area 6 are formed by grouting through the second sequence grouting pipe 10 and the third sequence grouting pipe 7. After grouting, the reinforcement effect is comprehensively analyzed and evaluated based on the inspection hole method and borehole television, combined with statistical analysis of the spatial distribution of grouting quantity. After the grouting effect evaluation is passed, a part of the inspection holes are plugged, and the inspection holes at the arch top position are reserved for subsequent high-pressure water injection.

[0051] First, the first inner side closed area 11 corresponding to the arch waist and the arch bottom is grouted and reinforced by the third sequence grouting pipe 10, which is obtained by pulling back the first sequence grouting pipe 5 corresponding to the arch waist and the arch bottom using the backward grouting process.

[0052] Then, the second inner side closed area 6 of the arch top periphery is grouted and reinforced by the second sequence grouting pipe 7, which is obtained by pulling back the first sequence grouting pipe 5 corresponding to the arch top using the backward grouting process.

[0053] After grouting, the reinforcement effect is comprehensively analyzed and evaluated based on the inspection hole method and borehole television, combined with statistical analysis of the spatial distribution of grouting quantity.

[0054] Based on the grouting situation, inspection holes are installed at grouting locations within the grouting area where weak points may exist. The inspections are conducted from the following two aspects: ① Checking the core sampling: Complete rock cores are obtained from the inspection holes using a core drilling rig. The filling and consolidation strength of the grouting material in the core are checked to verify the grouting reinforcement effect. ② Testing the formation permeability after grouting: After the inspection holes are constructed, dilute grout is injected into them, and the amount of grout absorbed is observed to measure the permeability of the grout-reinforced formation. The number of inspection holes should generally be at least 5% of the number of grouting holes. The permeability coefficient (for water) of the grouted material should be less than 8-10 m / s.

[0055] In terms of borehole television detection, the borehole is used to observe the rock and soil, fissures and other features inside the borehole. This allows for a direct assessment of the integrity of the strata and the cementation of the grouting reinforced rock mass. It serves as a supplementary verification method to the inspection borehole and helps to verify the effectiveness of the grouting reinforcement.

[0056] By analyzing the grouting volume and spatial distribution characteristics of each drilling sequence, weak points in the pre-grouting reinforcement were identified, and the grouting reinforcement effect of the surrounding rock damage zone 3 was systematically evaluated and analyzed. For example, the grouting volume of subsequent sequences was significantly lower than that of previous sequences, indicating that the loose voids in front of the tunnel face were significantly filled through the previous grouting, reducing the grout consumption in the later stages and demonstrating a significant grouting reinforcement effect. The spatial distribution characteristics of the grouting volume reflect the filling effect of the grout in the grouting reinforcement ring around the coal roadway. When the grouting volume distribution is relatively uniform, and holes with large and small grouting volumes are spaced apart, the grout forms a uniform and stable grouting reinforcement body around the coal roadway, effectively reducing grouting blind zones.

[0057] After the grouting effect is deemed satisfactory, some of the inspection holes will be sealed, while the inspection holes at the top of the arch will be retained as water curtain borehole 8 for subsequent high-pressure water injection.

[0058] Step 4: Establish high-pressure water zone 9. Inject high-pressure water into the water curtain borehole 8 at the arch, so that the space between the outer sealing zone 2 and the first inner sealing zone 11 and the second inner sealing zone 6 is filled with high-pressure fissure water, which enhances the ability of the arch to prevent air leakage, while preventing water outside the outer sealing zone 2 from seeping into the solidified body.

[0059] like Figure 2 As shown, high-pressure water is injected through water curtain borehole 8, filling the space between the outer sealing zone 2 and the second inner sealing zone 6 and the first inner sealing zone 11 with high-pressure fissure water, thus forming a high-pressure water zone 9. The design water pressure in the high-pressure water zone 9 is higher than the maximum air pressure inside the chamber, i.e., the water pressure is greater than 10 MPa. The high-pressure water zone 9 can enhance the ability of the arch portion 6 of the second inner sealing zone to prevent air leakage, while preventing water from outside the outer sealing zone 2 from seeping into the reinforced body formed by the grouting of the first and second inner sealing zones.

[0060] The construction method in this embodiment does not require the use of flexible gas storage bags, thus avoiding the defects associated with their use. In order to ensure the sealing of compressed air without the use of flexible gas storage bags, a high-pressure water zone is set up. Since compressed air leakage usually occurs at the arch position, the high-pressure water zone is set up at the corresponding position on the arch. The compressed air is sealed together by the inner sealing zone and the high-pressure water zone, making it difficult for water accumulated in the old external void to penetrate into the storage tank, thus ensuring the airtightness of the gas storage.

[0061] Step 5: As Figure 3 As shown, an insulation and sealing layer is constructed on the inner side of the existing lining. This insulation and sealing layer includes an anti-corrosion layer 12, a waterproof layer 13, an insulation layer 14, and a sealing layer 15. During construction, the anti-corrosion layer, waterproof layer, insulation layer, and sealing layer are applied sequentially. Figure 3 As shown, the anti-corrosion layer 12 can be made of tar-epoxy resin for corrosion protection, and the coating has anti-flow function. The waterproof layer 13 can be made of polymer-modified bitumen waterproof membrane or synthetic polymer waterproof membrane. The thermal insulation layer 14 is made of 10cm thick rigid polyurethane, and the sealing layer 15 is made of 1cm thick fiberglass.

[0062] The anti-corrosion layer 12 and the waterproof layer 13 ensure a water-free environment. The waterproof layer 13 is laid in a circumferential, full-width manner. The design of the insulation layer 14 and the sealing layer 15 provides a good insulation and sealing environment.

[0063] Only a sealing and insulation layer is constructed on the inner side of the lining. The sealing and insulation layer includes an anti-corrosion layer, a waterproof layer, an insulation layer, and a sealing layer. Compared with traditional construction methods, the cross-sectional area is reduced to a smaller extent, and the tunnel has sufficient gas storage space to ensure gas storage capacity.

[0064] Step 6: Seal both ends of the tunnel using sealing components.

[0065] Specifically, such as Figures 4-5 As shown, a concrete air plug is fabricated at the end of the tunnel as a sealing component. An insulation layer 14 and a sealing layer 15 are applied to the outer end face of the concrete air plug 17, and an expansion membrane bag 20 is tied around the concrete air plug 17. The concrete air plug 17 and the expansion membrane bag 20 form an expansion plug. After installation, a cement-water glass double-liquid grout is injected into the expansion membrane bag 20. After the expansion membrane bag 20 expands, it seals the gap between the concrete air plug 17 and the lining.

[0066] like Figure 4 , Figure 5 As shown, the concrete air plug 17 and the expansion membrane bag 20 form an expansion air plug. The end face of the concrete air plug is sequentially covered with an insulation layer 14 and a sealing layer 15. The insulation layer 14 is made of rigid polyurethane with a thickness of 5-10cm, and the sealing layer 15 is made of fiberglass with a thickness of 1-2cm.

[0067] The sealing is performed through a high-pressure water area, an inner sealing area and a heat-insulating sealing layer, and the sealing member is also provided with a heat-insulating layer and a sealing layer, so that heat exchange and heat conduction between the gas storage and the lining and surrounding rock are reduced, the heat loss of the storage is greatly reduced, the energy conversion efficiency is improved, the heat-insulating sealing layer arranged on the inner side of the lining further reduces the possibility of high-pressure gas leakage of the storage, and a reliable storage reinforcing and sealing technology system is formed.

[0068] The concrete air plug 17 is provided with an annular boss located outside the inflatable membrane bag, and the maximum cross-sectional area of the annular boss is greater than that of the end of the roadway, so as to enhance the sealing effect of the concrete air plug. The outer side surface of the annular boss comprises first and second surfaces distributed at a set angle, and the angles between the first and second surfaces and the axis of the concrete air plug 17 are first and second angles β118 and β219 respectively, and the sum of the two angles is less than 90°. The inflatable membrane bag 20 is bound around the concrete air plug 17. After installation, cement-silicate double-liquid quick-setting slurry is injected into the inflatable membrane bag, and the inflatable membrane bag is inflated to squeeze the gap between the air plug and the lining.

[0069] The maintenance channel 21, the gas injection pipeline 22 and the gas release pipeline 23 are arranged inside the concrete air plug 17. The gas injection pipeline 22 and the gas release pipeline 23 are provided with air flow meters, pressure gauges, thermometers as monitoring elements and closed switches, which are used to monitor the temperature and internal pressure in the compressed air chamber 16.

[0070] The working principle of the embodiment is as follows: when the energy is stored by inflation, the compressed air enters the compressed air chamber 16 through the gas injection pipeline 22, and the temperature, internal pressure and other information are recorded through the monitoring elements on the gas injection pipeline 22. The stress of the heat-insulating sealing layer is transmitted to the surrounding rock through the original lining structure 4, and the surrounding rock mass is the main bearer of high internal pressure, which bears the load transmitted by the original lining. The storage is a completely sealed system, and the gas is always sealed in the chamber and does not contact the surrounding rock. Among them, the high-pressure water area 8, the sealing layer 15 and the concrete air plug 17 with the inflatable membrane bag enhance the ability of the storage to prevent gas leakage and ensure the sealing effect of the storage. The heat-insulating layer 14 formed by the hard polyurethane with a thickness of 10 cm reduces the heat exchange and heat conduction between the gas storage and the lining and surrounding rock, greatly reduces the heat loss of the storage, and improves the energy conversion efficiency. The structural system composed of the anchor rod 1, the outer sealing area 2, the first inner sealing area 11, the second inner sealing area 6 and the original lining structure 4 ensures the overall stability of the storage. The construction method of the embodiment effectively ensures the stability, sealing, durability and long-term stability of the storage in the cycle of injection and production.

[0071] When the compressed air needs to be released, the compressed air in the chamber can be released through the gas release pipeline.

[0072] The above descriptions are only the preferred embodiments of the present application, and are not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A construction method for converting a waste coal roadway into a compressed air reservoir, characterized by, The method comprises the following steps: Grouting and reinforcing the periphery of the predetermined surrounding rock damage zone to form a peripheral closed zone; Grouting and reinforcing the periphery of the arch waist and arch bottom of the roadway to form a first inner closed zone, which is filled between the peripheral closed zone and the arch waist and arch bottom of the roadway; and grouting and reinforcing the periphery of the arch top of the roadway to form a second inner closed zone; Sealing the surrounding rock between the peripheral closed zone, the first inner closed zone and the second inner closed zone by water injection to form a high-pressure water zone; Constructing a heat preservation sealing layer on the inner side of the roadway lining; Blocking the two ends of the roadway by blocking members.

2. A method of converting a spent coal roadway into a compressed air reservoir according to claim 1, wherein, The construction method of the peripheral closed zone is as follows: first, the anchor rod is constructed, the anchor rod penetrates through the surrounding rock damage zone and then penetrates into the hard surrounding rock outside the surrounding rock damage zone, and then the grouting pipe is used to grout and reinforce the periphery of the surrounding rock damage zone to form the peripheral closed zone.

3. A method of converting a spent coal roadway into a compressed air reservoir according to claim 1, wherein, The grouting and reinforcing of the peripheral closed zone adopts a retreating grouting process, the grouting pipe of the arch waist and arch bottom is retreated to the set position, and then the grouting and reinforcing of the first inner closed zone is performed, and the grouting pipe of the arch top is retreated to the set position, and then the grouting and reinforcing of the second inner closed zone is performed.

4. A method of converting a spent coal roadway into a compressed air reservoir according to claim 1, wherein, After the grouting and reinforcing of the peripheral closed zone is completed, the geophysical detection method is used to evaluate the reinforcing effect, and supplementary grouting is performed on the positions that do not meet the requirements.

5. A method of converting a spent coal roadway into a compressed air reservoir according to claim 1, wherein, After the grouting and reinforcing of the first inner closed zone and the second inner closed zone are completed, the detection hole method is combined with the borehole television to evaluate the grouting and reinforcing effect, and supplementary grouting is performed on the positions that do not meet the requirements, wherein the set detection hole corresponding to the position of the arch top is reserved for subsequent water injection sealing, and the other detection holes are blocked.

6. A method of converting a spent coal roadway into a compressed air reservoir according to claim 1, wherein, The water pressure of the high-pressure water zone formed by water injection is greater than the maximum air pressure in the roadway chamber.

7. A method of converting a spent coal roadway into a compressed air reservoir according to claim 1, wherein, The heat preservation sealing layer comprises a corrosion prevention layer, a waterproof layer, a heat preservation layer and a sealing layer which are sequentially constructed on the inner side of the roadway lining.

8. A method of converting a spent coal roadway into a compressed air reservoir according to claim 1, wherein, The blocking member adopts a concrete air plug, the outer end surface of the concrete air plug is sequentially provided with a heat preservation layer and a sealing layer, the outer periphery of the concrete air plug is bound with an expansion film bag, and after the concrete air plug is inserted into the end part of the roadway, cement-silicate double slurry is injected into the expansion film bag to seal the gap between the concrete air plug and the roadway lining.

9. A method of converting a spent coal roadway into a compressed air reservoir according to claim 8, wherein, The concrete air plug is provided with an annular protruding structure, and the annular protruding structure is located outside the expansion film bag. Further, the outer side surface of the annular protruding structure comprises a first surface and a second surface which are distributed at a set included angle, and the sum of the included angles of the first surface and the second surface with the axis of the concrete air plug is less than 90°.

10. A method of converting a spent coal roadway into a compressed air reservoir according to claim 1, wherein, The blocking member is provided with a gas injection pipeline, a gas release pipeline and a maintenance channel.

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