Goaf CO2 sealed storage warehouse construction and grouting filling fire preventing and extinguishing method

Abstract

The invention discloses a goaf CO2 sealed storage warehouse construction and grouting filling fire preventing and extinguishing method, and belongs to the technical field of goaf filling. The goaf CO2 sealed storage depot comprises a CO2 storage depot unit, a solid waste filling column and inflation-grouting equipment, an inflation bag is arranged in the CO2 storage depot unit, the inflation bag is movably connected in the CO2 storage depot unit, the CO2 sealed storage depot is constructed in the goaf through the inflation bag, alkaline solid waste and mineralized slurry, and the storage depot is used for supporting a roof rock stratum and storing CO2. Large-scale recycling of the alkaline solid waste can be achieved through the sealed storage warehouse, the storage warehouse is used for supporting the goaf roof rock stratum and storing CO2, the roof rock stratum is prevented from collapsing and endangering mine production safety, CO2 emission is reduced, the greenhouse effect is improved, and cooperative treatment of goaf fire and CO2 storage is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of goaf filling, and in particular to a method for constructing a CO 2 sealing repository and grouting filling for fire prevention and extinguishment in a goaf. Background Art

[0002] Due to the large-scale coal mining, the stress environment of the surrounding rock mass of the stope has changed, resulting in the bending deformation and collapse of the roof rock strata, thus causing surface subsidence, which not only endangers the safety of mine production, but also causes ecological problems such as the loss of surface water resources, land desertification, and coal spontaneous combustion. At the same time, the consumption of coal resources will emit a large amount of carbon dioxide, leading to the aggravation of the greenhouse effect.

[0003] Building green mines and developing green mining have become an inevitable requirement for the development of the coal mining industry. The use of filling mining technology is an important technical measure to achieve this goal. While realizing filling mining in the working face, how to effectively protect the stability of the roof rock strata in the goaf, avoid the deformation and collapse of the roof rock strata, and prevent the spontaneous combustion of the remaining coal in the goaf are key issues that need to be considered during the filling mining process; moreover, while achieving stable CO 2 sequestration in the goaf, how to find a solution for the coordinated governance of goaf filling mining and CO 2 has become a research hotspot in the field. Summary of the Invention

[0004] In order to effectively protect the stability of the roof rock strata in the goaf, prevent the spontaneous combustion of the remaining coal in the goaf, and while achieving stable CO 2 sequestration in the goaf, and realizing the coordinated governance of goaf filling mining and CO 2 the present invention provides a method for constructing a CO 2 sealing repository and grouting filling for fire prevention and extinguishment in a goaf, and the specific technical solution is as follows:

[0005] A CO 2 sealing repository in a goaf includes a CO 2 storage unit, a solid waste filling column, and an air injection - grouting device. An air bag is arranged in the CO 2 storage unit. The air bag is an airtight structure for inflation, and the air bag is movably connected in the CO 2 storage unit; a number of solid waste filling columns are arranged along the working face, and the CO 2 storage unit is configured between the solid waste filling columns. The air injection - grouting device is connected to the CO 2 storage unit to inflate it and inject mineralized slurry into the position between the top of the air bag and the roof rock strata.

[0006] Preferably, the airbag includes an inner bag structure and an outer bag structure. The inner bag structure is an airtight layer made of a thin film material; the outer bag structure is a load-bearing layer made of an aramid fiber composite material, and the bottom of the airbag is fixedly arranged on the connecting plate.

[0007] Preferably, the airbag is in an arch structure as a whole, and a thin film structure covers the upper arc surface of the airbag.

[0008] Preferably, two adjacent airbags arranged longitudinally along the working face are connected by a connecting device, and the air inlet of the airbag is connected to an air injection - grouting device.

[0009] A method for CO 2 sequestration in a goaf, used to construct a CO 2 sequestration repository in the above - mentioned goaf. This method includes the following steps:

[0010] S1. Determine the setting parameters of the CO 2 sequestration repository and the airbag according to the layout of the coal mining face;

[0011] S2. Divide the working face into several groups of mining blocks, arrange the mining roadways in the mining blocks, and carry out the mining of the working face;

[0012] S3. During the mining process of the working face, construct solid waste filling strips and solid waste filling columns on the working face. The solid waste filling strips are arranged transversely along the working face, and the solid waste filling columns are arranged longitudinally along the working face. There are several solid waste filling columns arranged transversely along the working face, and there is a spacing between adjacent solid waste filling columns. The CO 2 sequestration repository units are arranged between the solid waste filling columns; as the working face is continuously mined, repeat the arrangement of the solid waste filling columns and the CO 2 sequestration repository units;

[0013] S4. Use an air injection - grouting device to inflate the CO 2 sequestration repository units, and then carry out grouting. The internal space of the airbag in the CO 2 sequestration repository unit serves as the CO 2 sequestration space;

[0014] S5. As the working face is mined and advanced, after the CO 2 sequestration repository units arranged transversely along the working face are constructed, continue to construct the CO 2 sequestration repository units longitudinally along the working face. During the construction of subsequent CO 2 sequestration repository units, the mineralized slurry filled in the front - end CO 2 sequestration repository units gradually solidifies;

[0015] S6. Repeat the above CO 2The construction cycle of the reservoir unit is completed to construct a local reservoir group. An air discharge and CO injection device is set in the local reservoir group, and then CO is injected into the reservoir group by the CO injection device to complete the storage of CO. 2 Preferably, the parameters determined in step S1 include: the span of the CO storage repository, the width of the solid waste filling column, and the size of the air bag; 2 Among them, the method for determining the span of the CO storage repository is as follows: 2 Among them, the calculation method of the span a of the CO storage repository is: 2 In the formula, a is the span of the CO storage repository, m; h is the thickness of the basic roof rock layer, m; R is the ultimate tensile strength of the basic roof; q is the weight of the basic roof and the overlying load, MPa;

[0016] Preferably, the parameters determined in step S1 include: the span of the CO storage repository, the width of the solid waste filling column, and the size of the air bag; 2 Among them, the method for determining the width of the solid waste filling column is:

[0017] In the formula, b is the width of the solid waste filling column, m; γ is the average unit weight of the roof rock layer, MN / m; H is the mining depth, m; a is the span of the CO2 storage repository, m; r is the plastic zone of the filling strip; the strength σ of the filling column = fP, generally taking the safety factor f ≥ 2.5; P is the average load borne by the filling column; 2 The length and width of the air bag are the same as those of the reservoir unit. The cross-sectional curve of the air bag is a catenary equation:

[0018] Among them, the calculation method of the span a of the CO storage repository is: 2 In the formula, a is the span of the CO storage repository, m; h is the thickness of the basic roof rock layer, m; R is the ultimate tensile strength of the basic roof; q is the weight of the basic roof and the overlying load, MPa; max Among them, the method for determining the width of the solid waste filling column is:

[0019]

[0020] In the formula, a is the span of the CO storage repository, m; h is the thickness of the basic roof rock layer, m; R is the ultimate tensile strength of the basic roof; q is the weight of the basic roof and the overlying load, MPa; max Among them, the method for determining the width of the solid waste filling column is: 2 In the formula, b is the width of the solid waste filling column, m; γ is the average unit weight of the roof rock layer, MN / m; H is the mining depth, m; a is the span of the CO2 storage repository, m; r is the plastic zone of the filling strip; the strength σ of the filling column = fP, generally taking the safety factor f ≥ 2.5; P is the average load borne by the filling column; T Among them, the method for determining the width of the solid waste filling column is:

[0021] In the formula, b is the width of the solid waste filling column, m; γ is the average unit weight of the roof rock layer, MN / m; H is the mining depth, m; a is the span of the CO2 storage repository, m; r is the plastic zone of the filling strip; the strength σ of the filling column = fP, generally taking the safety factor f ≥ 2.5; P is the average load borne by the filling column;

[0022]

[0023] In the formula, b is the width of the solid waste filling column, m; γ is the average unit weight of the roof rock layer, MN / m; H is the mining depth, m; a is the span of the CO2 storage repository, m; r is the plastic zone of the filling strip; the strength σ of the filling column = fP, generally taking the safety factor f ≥ 2.5; P is the average load borne by the filling column; 3 ; H is the mining depth, m; a is the span of the CO2 storage repository, m; r is the plastic zone of the filling strip; the strength σ of the filling column = fP, generally taking the safety factor f ≥ 2.5; P is the average load borne by the filling column; p The length and width of the air bag are the same as those of the reservoir unit. The cross-sectional curve of the air bag is a catenary equation: s In the formula, y is the catenary equation; f is the calculated rise of the arch; m is the arch axis coefficient. s In the formula, y is the catenary equation; f is the calculated rise of the arch; m is the arch axis coefficient. s In the formula, y is the catenary equation; f is the calculated rise of the arch; m is the arch axis coefficient.

[0024] The length and width of the air bag are the same as those of the reservoir unit. The cross-sectional curve of the air bag is a catenary equation:

[0025]

[0026] In the formula, y is the catenary equation; f is the calculated rise of the arch; m is the arch axis coefficient. 1 In the formula, y is the catenary equation; f is the calculated rise of the arch; m is the arch axis coefficient.

[0027] Preferably, a number of solid waste filling strips are arranged parallel to the working face, and a number of solid waste filling columns are arranged perpendicular to the working face. An interval roadway is arranged between two adjacent solid waste filling columns arranged longitudinally along the working face, and a sealing device is arranged at the end of the interval roadway.

[0028] Preferably, in step S4, air is injected into the air bag by an air injection-grouting device until the air bag is fully inflated, and then mineralized slurry is injected between the top of the air bag and the roof rock formation. During the solidification process of the mineralized slurry, a filling body with a cross-section of a catenary-like arch is formed due to the support of the air bag, and the arched space serves as a CO 2 sequestration site.

[0029] Preferably, after the construction of the local reservoir group is completed, all the gas in the air bag of the previous reservoir group is released, and the air bag is recovered for the construction of the next reservoir group; alkaline solid waste filling is used to replace the original sealing device, and a gas reserved pipeline is arranged.

[0030] More preferably, during the operation of the reservoir, the internal CO 2 pressure value of the reservoir is monitored through a pressure vacuum gauge. When it is detected that the gas pressure in the reservoir decreases, that is, the CO 2 concentration decreases, the CO 2 injection pipeline valve is opened to refill CO 2 , and further sequester CO 2 ; when the CO 2 sequestration potential of the alkaline solid waste and mineralized slurry for constructing the reservoir is exhausted, the arched space inside the reservoir continues to sequester CO 2 in the form of physical sequestration.

[0031] The gob CO 2 sequestration reservoir construction and grouting filling fire prevention method provided by the present invention has the following beneficial effects: The system and method for using the reservoir to support the roof rock formation and sequester CO 2 realize a collaborative treatment approach for large-scale disposal of alkaline solid waste, goaf reuse, and CO 2 sequestration. This method can not only construct a CO 2 sequestration reservoir in the goaf by using the air bag, alkaline solid waste, and mineralized slurry, realizing large-scale reuse of alkaline solid waste, but also using the reservoir to support the roof rock formation of the goaf and sequester CO 2 , preventing the roof rock formation from collapsing and endangering the safety of mine production, reducing the emission of CO 2 , reducing the greenhouse effect, and realizing the collaborative treatment of goaf control and CO 2 sequestration. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 For CO 2Schematic diagram of the structure of the sealed repository;

[0033] Figure 2 Schematic diagram of the structure of the air-filled bag;

[0034] Figure 3 Schematic diagram of the layout of the air injection - grouting pipeline;

[0035] Figure 4 Schematic diagram of the structure of the local repository group.

[0036] In the figure: 1 - CO 2 Repository unit; 2 - Solid waste filling column; 3 - Air-filled bag; 4 - Extraction roadway; 5 - Solid waste filling strip; 6 - Longwall face; 7 - Spacing roadway; 8 - Sealing door; 9 - Main air injection - grouting pipeline; 10 - Branch air injection - grouting pipeline; 11 - Main air discharge pipeline; 12 - CO 2 Main injection pipeline; 13 - Air discharge pipeline; 14 - CO 2 Injection pipeline. Detailed implementation manners

[0037] Combined with Figures 1 to 4 shown, the detailed implementation manners of a gob CO 2 sealed repository construction and grouting filling fire prevention and extinguishing method provided by the present invention are described.

[0038] Example 1

[0039] A gob CO 2 sealed repository, comprising a CO 2 repository unit 1, a solid waste filling column 2 and an air injection - grouting device, wherein a air-filled bag 3 is arranged in the CO 2 repository unit, the air-filled bag 3 is an air-filled and sealed structure, and the air-filled bag 3 is movably connected in the CO 2 repository unit 1. A plurality of solid waste filling columns 2 are arranged along the working face, the CO 2 repository unit is arranged between the solid waste filling columns, and the air injection - grouting device is connected to the CO 2 repository unit to inflate and inject mineralized slurry into the position between the top of the air-filled bag 3 and the roof rock stratum. It uses the CO 2 sealed repository to support the roof rock stratum of the gob, and at the same time realizes the sealing of CO 2 , not only preventing the roof rock stratum from collapsing and endangering the safety of mine production, but also reducing the emission of CO 2 , reducing the greenhouse effect, and realizing the coordinated treatment of gob treatment and CO 2 sealing.

[0040] Specifically, gob CO 2A number of solid waste filling columns 2 are sequentially arranged in the sealed repository. The solid waste filling columns 2 are intermittently arranged as the working face advances. CO 2 The storage unit 1 is arranged between two adjacent solid waste filling columns 2. Since the inflatable bag 3 is arranged in the CO 2 storage unit 1, the inflatable bag 3 is inflated through the inflating - grouting equipment. The inflatable bag 3 inflates and expands. Then, the mineralized slurry is injected between the inflatable bag 3 and the roof rock formation. After the mineralized slurry solidifies, the inflatable bag 3 is removed, and thus the construction of the CO 2 storage unit is completed. CO 2 The sealed repository can play a role in supporting and protecting the goaf and serve as a place for CO 2 physical sequestration.

[0041] The inflatable bag 3 includes an inner bag structure and an outer bag structure. The inner bag structure is an airtight layer composed of a thin film material, and the outer bag structure is a load - bearing layer composed of aramid fiber composite material. Thus, the inflatable bag 3 has the advantages of light weight and small folding volume, which is not only convenient for installation but also convenient for subsequent recovery. The aramid fiber composite material used as the structural load - bearing material has high strength. Its density is 1.44 - 1.47 g / cm 3 , the elastic modulus is 54 - 200 GPa, and the tensile strength is 2.0 - 3.4 GPa. The outer bag structure can withstand the pressure brought by injecting the mineralized slurry.

[0042] As Figure 2 shown, the overall structure of the inflatable bag 3 adopted in this embodiment is a circular arch structure. The upper arc surface of the inflatable bag 3 is covered with multiple layers of detachable film structures. After use, it can be supplemented, which can protect the inflatable bag 3 and facilitate the separation of the inflatable bag 3 from the solidified mineralized slurry.

[0043] The bottom of the inflatable bag 3 is fixedly arranged on a rigid bottom plate. The rigid bottom plate is made of carbon fiber composite material, with a density of 1.5 - 2.0 g / cm 3 , the elastic modulus is 200 - 700 GPa, and the tensile strength is 2.0 - 7.0 GPa. The bottom plate can be composed of multiple connecting plates connected together. The multiple connecting plates are connected by hinges, which is convenient for folding transportation.

[0044] The inflatable bag 3 can make the filling body form an arch structure, improve the support strength of the filling body for the roof rock formation, and form an arch - shaped internal space as a place for CO 2 physical sequestration. At the same time, the inflatable bag 3 can be reused multiple times, reducing the filling cost.

[0045] The inflatable bag 3 can move within the CO 2 storage unit 1, which is convenient for subsequent recovery and repeated use. The inflatable bag 3 in the CO 2The moving method inside the storage unit 1 can be as follows: Connecting devices are installed at both ends of the bottom plate, and the air-filled bags 3 are connected to each other through the connecting devices. The air-filled bag 3 near the hydraulic support end is connected to the electric winch installed on the hydraulic support. When the air-filled bag 3 needs to be moved, the electric winch is started to drag and move the air-filled bag 3.

[0046] The moving method of the air-filled bag 3 can also be to install a driving device on the bottom plate at the bottom of each air-filled bag 3 and start the driving device through remote control for movement.

[0047] In addition, the air-filled bag 3 can be a closed structure made of multiple layers of flexible composite materials with an air-filled space inside.

[0048] Combined Figure 3 、 Figure 4 As shown, a method for constructing and sealing a CO 2 sealing storage repository in the goaf

[0049] A method for constructing and sealing a CO 2 sealing storage repository in the goaf, including the following steps:

[0050] S1. Determine the setting parameters of the CO 2 sealing storage repository and the air-filled bag 3 according to the specific conditions of the working face;

[0051] S2. Divide the working face into several groups of mining blocks, arrange the extraction roadway 4 in the mining blocks, and carry out the mining of the working face;

[0052] S3. During the mining process of the working face, construct the solid waste filling strip 5 and the solid waste filling column 2 on the working face. The solid waste filling strip 5 is arranged horizontally along the working face, and the solid waste filling column 2 is arranged longitudinally along the working face. And several solid waste filling columns 2 are arranged horizontally along the working face, with a spacing between adjacent solid waste filling columns 2. The CO 2 storage unit 1 is arranged between the solid waste filling columns 2; As the working face is continuously mined, the setting of the solid waste filling column 2 and the CO 2 storage unit 1 is repeated;

[0053] S4. Use the air injection - grouting equipment to inflate the CO 2 storage unit 1, and then carry out grouting. The internal space of the air-filled bag 3 in the CO 2 storage unit 1 serves as the CO 2 sealing space;

[0054] S5. As the working face is mined and advanced, after the CO 2 storage unit 1 arranged horizontally along the working face is constructed, continue to construct the CO 2 storage unit 1 along the longitudinal direction of the working face. In the subsequent CO 2During the construction of the storage unit 1, the CO at the front end 2 The mineralized slurry filled in the storage unit 1 gradually solidifies;

[0055] S6. Repeat the above CO 2 storage unit construction cycle to complete the construction of the local storage group, set up air discharge and CO 2 injection equipment in the local storage group, and then use the CO 2 injection equipment to inject CO into the storage group 2 , and complete the CO 2 sequestration.

[0056] Through the airbag 3, alkaline solid waste and mineralized slurry, carry out CO 2 sealed storage repository construction and CO 2 sequestration. First, as the working face advances, intermittently construct solid waste filling columns in the goaf to initially construct the CO 2 storage unit, then arrange the airbag 3 inside the CO 2 storage unit and inflate it, then inject mineralized slurry between the outside of the airbag 3 and the roof rock stratum. After the mineralized slurry solidifies, remove the airbag 3, and the construction of the CO 2 storage unit is completed; when the storage group is constructed, inject CO 2 gas for sequestration. The alkaline solid waste materials and mineralized slurry for constructing the storage repository react with CO 2 to undergo carbonation reaction, which can permanently sequester CO 2 , so that the sealed storage repository can play a supporting and protective role for the goaf and serve as a place for CO 2 physical sequestration.

[0057] Embodiment 2

[0058] On the basis of Embodiment 1, a method for constructing and sequestering a CO2 sealed storage repository in a goaf is provided, including the following steps:

[0059] S1. Determine the specific parameters of the CO 2 storage unit 1 and the airbag 3 according to the specific situation of the longwall working face 6. The specific parameters include: CO 2 span of the sealed storage repository, width of the solid waste filling column, and size of the airbag 3.

[0060] Among them, the method for determining the span of the CO 2 sealed storage repository is as follows:

[0061] Since the length dimension of the CO 2 sealed storage repository is much larger than the limit span dimension of the roof, the roof can be regarded as a beam fixed at both ends, and the limit span a when the basic roof beam fails max The calculation method is:

[0062]

[0063] Wherein, a max is the CO 2 sequestration repository span, m; h is the thickness of the main roof rock stratum, m; R T is the ultimate tensile strength of the main roof; q is the weight of the main roof and the overlying load, MPa.

[0064] The method for determining the width of the solid waste filling column is as follows:

[0065] Due to the influence of overlying rock pressure, a certain plastic zone will appear on both sides of the solid waste filling column, and the core area of the filling column will be reduced. Therefore, when considering the plastic zone on both sides of the solid waste filling column, the theoretical calculation formula for the width of the filling column is:

[0066]

[0067] Wherein, b is the width of the solid waste filling column, m; γ is the average unit weight of the roof rock stratum, MN / m 3 ; H is the mining depth, m; a is the CO2 sequestration repository span, m; r p is the plastic zone of the filling strip; the strength of the filling column σ s = f s P, generally taking the safety factor f s ≥2.5; P is the average load borne by the filling column.

[0068] The method for determining the size of the air bag 3 is as follows:

[0069] Since the air bag 3 is arranged inside the storage unit, the length and width of the air bag 3 are the same as those of the storage unit; and the cross-sectional curve equation of the air bag 3 is obtained approximately from the catenary equation of the catenary arch:

[0070]

[0071] Wherein, y 1 is the catenary equation; f is the calculated rise of the arch; m is the arch axis coefficient.

[0072] S2. Divide the longwall face 6 into several groups of mining blocks, and arrange the mining roadways 4 within the mining blocks. The longwall mining method is used for coal mining in the face.

[0073] S3. During the mining process of the longwall face 6, construct the solid waste filling strip 5 and the solid waste filling column 2 in the face. The solid waste filling strip 5 is arranged parallel to the longwall face 6, and the solid waste filling column 2 is arranged perpendicular to the longwall face 6. A number of solid waste filling columns 2 are arranged in sequence and at uniform intervals.

[0074] In this embodiment, the length of the solid waste filling column 2 is set to 10 m, and the width is set to 5 m; CO 2 The storage unit 1 is arranged between adjacent solid waste filling columns 2, CO 2 The span of the storage unit 1, that is, the distance between two adjacent solid waste filling columns 2, is set to 5 m, and then CO 2 An air bag 3 is arranged in the storage unit 1 to complete the construction of the CO 2 Storage unit.

[0075] In addition, the process of intermittently constructing the solid waste filling column 2 in the vertical longwall working face 6 can be recorded as construction cycle one, and each construction of the CO 2 Storage unit 1 is a cycle; then, along with the mining process, the process of construction cycle one is repeated longitudinally along the working face, and during the cycle process, an air bag 3 is placed between adjacent solid waste filling columns 2, and an interval roadway 7 is arranged between adjacent two cycles, and the width of the interval roadway 7 is set to 2 m.

[0076] Sealing doors 8 are arranged at both ends of the interval roadway 7, and an air injection - grouting pipeline is arranged close to the roof rock formation. Through the sealing door 8, the CO 2 Storage unit 1 is relatively isolated from the outside world. The arranged air injection - grouting pipeline can first inflate the air bag 3, and then grout the CO 2 Storage unit 1.

[0077] The air injection - grouting pipeline includes an air injection - grouting main pipeline 9 and air injection - grouting branch pipelines 10. A plurality of air injection - grouting branch pipelines 10 are arranged, and the ends are arranged in the CO 2 Storage unit 1. The other ends of the air injection - grouting branch pipelines 10 are connected to the air injection - grouting main pipeline 9. The air bags 3 between adjacent two cycles are connected end to end through the connecting devices on the floor, and the air inlets of the air bags 3 are connected to the air injection - grouting pipelines arranged in the interval roadway 7.

[0078] With the continuous mining of the working face, the setting of the solid waste filling column 2 and the CO 2 Storage unit 1 is repeated; when the storage unit is constructed to cycle ten, the storage units from construction cycle one to construction cycle ten are recorded as the first group of storage units, and the air bag 3 of the tenth cycle is connected to the electric winch installed on the hydraulic support.

[0079] Both the solid waste filling strip 5 and the solid waste filling column 2 are composed of alkaline solid waste materials.

[0080] S4. First, use the air injection - grouting pipeline to inject air into the air bag 3 until the air bag 3 is fully inflated, then disconnect the connection between the air bag 3 and the pipeline, and then use the air injection - grouting pipeline to inject mineralized slurry between the top of the air bag and the roof rock formation.

[0081] During the injection process of the mineralized slurry, part of it will penetrate into the solid waste filling column 2. After solidification, it can improve the support strength of the solid waste filling column 2 for the roof rock formation. During the solidification process of the mineralized slurry, due to the support of the air bag 3, a filling body with a cross-section similar to a catenary arch bridge will be formed. This structure can improve the support strength of the filling body for the roof rock formation and form an arched space as a place for physical sequestration of CO 2 physical sequestration.

[0082] S5. As the working face is mined and advanced, CO 2 After the construction of the CO storage unit 1 is completed, continue to construct the CO storage unit 1 along the longitudinal direction of the working face. During the solidification process of the mineralized slurry in the first group of CO storage units, continue to construct the CO storage units from cycle eleven to cycle twenty, and there is no need to place the air bag 3 between adjacent solid waste filling columns 2 again, and the preliminary construction of the second group of CO storage units is completed again. 2 When the mineralized slurry filled in the first group of CO storage units solidifies, release some air in the air bag 3 to separate the air bag 3 from the solidified mineralized slurry. Then start the electric winch to horizontally move the air bag 3 in the first group of CO storage units to the inside of the second group of CO storage units, and then connect the inflation port of the air bag 3 to the inflation-grouting pipeline arranged in the interval roadway 7, and repeat S4 to complete the construction of the second group of CO storage units.

[0083]

[0084] By controlling the filling materials, meet the sequestration conditions such as the strength and anti-seepage of the filling body; by controlling the structure of the storage unit and the storage group, ensure the stability and safety of the sequestration space; by utilizing the carbonation reaction of alkaline solid waste, ensure the safe sequestration of CO. In addition, this system not only realizes the sequestration of CO 2 but also ensures the safety and stability of CO sequestration. 2 sequestration. 2 2 2

[0085] S6. Repeat the above-mentioned construction cycle process of the CO storage unit to complete the construction of the first local storage group. And during the construction of the CO storage unit, install a pressure vacuum gauge at the highest level of the storage group to discharge the air inside the storage group and detect the ambient pressure during the injection of CO 2 to judge the air discharge and CO injection situation. 2 2 2

[0086] ​​​​​​​When the construction of the last group of storage units is completed, all the air in the inflatable bag 3 is released, and the inflatable bag 3 is recovered for the construction of the storage units inside the second storage group. Then, an alkaline solid waste filling strip is constructed along the parallel longwall working face.

[0087] S7. After the preliminary construction of the first local storage group is completed, the sealing doors 8 installed at both ends of the interval roadway 7 are removed for the construction of the second local storage group. Then, the interval roadway is filled with alkaline solid waste materials to replace the seal, and reserved pipelines are arranged as channels for air discharge and CO 2 injection. Meanwhile, main air discharge pipelines 11 and CO 2 injection main pipelines 12 are arranged on both sides of the goaf and are respectively connected to the air discharge pipeline 13 and the CO 2 injection pipeline 14. Valves are set and closed, thus forming a CO 2 sealed storage group in which the internal storage units are interconnected and the inside and outside are isolated from each other.

[0088] Two adjacent CO 2 injection pipelines 14 and two air discharge pipelines 13 are arranged at intervals of 5 storage units.

[0089] S8. Open the control valve on the air discharge pipeline 13, and use the ground vacuum negative pressure station to exhaust all the air inside the storage group. Then, close the valve of the air discharge pipeline 13, open the valve of the CO 2 injection pipeline 14, and use the ground CO 2 compressor to inject CO 2 into the storage group; when the CO 2 injection is completed, close the valve of the CO 2 injection pipeline 14, and the storage group enters the CO 2 physical-chemical sequestration stage.

[0090] In the initial stage of the operation of the sealed storage, the alkaline solid waste and mineralized slurry used to construct the storage will react with CO 2 to undergo carbonation reaction, thus achieving the permanent sequestration of CO 2 .

[0091] In the initial stage of the storage operation, the CO 2 pressure value inside the storage can be monitored through a pressure vacuum gauge. When it is detected that the gas pressure inside the storage decreases, i.e., the CO 2 concentration decreases, the valve of the CO 2 injection pipeline 14 can be opened to refill CO 2 for further sequestration of CO 2 . In the later stage of the storage operation, when the CO 2 sequestration potential of the alkaline solid waste and mineralized slurry used to construct the storage is exhausted, the arched space inside the storage will continue to sequester CO2 .

[0092] A system and method for constructing a CO 2 sequestration repository in a goaf by using an air-filled bag, alkaline solid waste, and mineralized slurry, and using the repository to support the roof rock formation and sequester CO 2 , thereby obtaining a collaborative treatment approach for realizing large-scale disposal of alkaline solid waste, reusing the goaf, and sequestering CO 2 . While using the longwall mining method, the present invention fills the goaf with alkaline solid waste. Not only can a CO 2 sequestration repository be constructed in the goaf by using an air-filled bag, alkaline solid waste, and mineralized slurry, realizing large-scale reuse of alkaline solid waste and solving the problem of stacking alkaline solid waste; and the repository is used to support the roof rock formation of the goaf and sequester CO 2 , reducing the emission of CO 2 and reducing the greenhouse effect; moreover, it can prevent the roof rock formation from collapsing and endangering the safety of mine production, prevent the goaf from collapsing and damaging the ground environment, and reduce the waste of land resources and environmental pollution.

[0093] Moreover, the air-filled bag 3 can make the filling body form an arch structure, improve the support strength of the filling body for the roof rock formation, and form an arch internal space as the place for physical sequestration of CO 2 , and at the same time, the air-filled bag 3 can be reused multiple times, reducing the filling cost.

[0094] When the constructed repository group sequesters CO 2 , the alkaline substances in the filling body used to construct the repository group can react with CO 2 to undergo a carbonation reaction, and can permanently sequester CO 2 ; when the CO 2 sequestration potential of the alkaline substances is exhausted, the internal enclosed space of the repository group will sequester CO 2 in a physical sequestration manner, reducing the emission of carbon dioxide to a greater extent and effectively reducing the greenhouse effect. By controlling the filling materials, the CO 2 sequestration conditions such as the strength and anti-seepage of the filling body are met. By controlling the structure of the repository unit and the repository group, the stability and safety of the CO 2 sequestration space are ensured; by using the carbonation reaction of alkaline solid waste, the safe sequestration of CO 2 is ensured.

[0095] 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 those skilled in the art within the scope of the essence of the present invention should also fall within the protection scope of the present invention.

Claims

1. A CO2 storage storage device in a goaf, characterized in that: It includes a CO2 storage unit, a solid waste filling column and an inflation-grouting device. The CO2 storage unit is provided with an inflation bag, which is an inflatable sealing structure and is movably connected to the CO2 storage unit. Several solid waste filling columns are arranged along the working surface, and the CO2 storage unit is configured between the solid waste filling columns. The inflation-grouting equipment is connected to the CO2 storage unit for inflation, and injects mineralized slurry into the position between the top of the inflation bag and the roof rock layer.

2. A goaf CO2 storage storage according to claim 1, characterized in that: The inflatable bag comprises an inner bag structure and an outer bag structure. The inner bag structure is an airtight layer formed of a film material; the outer bag structure is a load-bearing layer formed of an aramid fiber composite material. The bottom of the inflatable bag is fixedly arranged on a connecting plate.

3. A goaf CO2 storage storage according to claim 1, characterized in that: The inflatable bag is an arched structure as a whole, and the upper arc surface of the inflatable bag is covered with a film structure.

4. The goaf CO2 storage storage according to claim 1, characterized in that: Two adjacent inflatable bags arranged longitudinally along the working surface are connected via a connecting device, and the inflation ports of the inflatable bags are connected to the inflation-grouting equipment.

5. A fire prevention and extinguishing method for CO2 storage in goaf, characterized in that: Used to construct a goaf CO2 storage and sealing storage as described in any one of claims 1 to 4, the method comprises the following steps: S1. Determine the setting parameters of the CO2 storage and inflatable bag according to the layout of the coal mining face; S2. Divide the working face into several groups of mining blocks, arrange mining tunnels in the mining blocks, and carry out mining on the working face; S3. During the mining process of the working face, solid waste filling strips and solid waste filling columns are constructed on the working face. The solid waste filling strips are arranged horizontally along the working face, and the solid waste filling columns are arranged longitudinally along the working face. Several solid waste filling columns are arranged horizontally along the working face, and there is a spacing between adjacent solid waste filling columns. The CO2 storage unit is arranged between the solid waste filling columns; as the working face is continuously mined, the arrangement of the solid waste filling columns and the CO2 storage unit is repeated; S4. The CO2 storage unit is inflated using an inflatable - grouting device, and then grouting is performed. The internal space of the inflatable bag within the CO2 storage unit is used as a CO2 storage space; S5. As the working face is mined, after the CO2 storage unit set along the horizontal direction of the working face is constructed, the CO2 storage unit is constructed along the longitudinal direction of the working face. During the subsequent construction of the CO2 storage unit, the mineralized slurry filled in the front CO2 storage unit gradually solidifies; S6. Repeat the above-mentioned CO2 storage unit construction cycle process to complete the construction of the local storage group, set up air exhaust and CO2 injection equipment in the local storage group, and then use the CO2 injection equipment to inject CO2 into the storage group to complete the storage of CO2.

6. A fire prevention and extinguishing method for CO2 storage in goaf according to claim 5, characterized in that: The parameters determined in step S1 include: the span of the CO2 storage reservoir, the width of the solid waste filling column and the size of the inflatable bag; Among them, the method for determining the span of the CO2 storage reservoir is: The CO2 storage storage span is a max The calculation method is: In the formula, a max is the span of the CO2 storage reservoir, m; h is the thickness of the basic top rock layer, m; R T is the ultimate tensile strength of the basic top; q is the weight of the basic top and its overlying load, MPa; The method for determining the width of the solid waste filling column is as follows: Where b is the width of the solid waste filling column, m; γ is the average bulk density of the top rock layer, MN / m 3 ; H is the mining depth, m; a is the span of the CO2 storage reservoir, m; r p is the plastic zone of the filling strip; the strength of the filling column σ s =f s P, generally takes safety factor f s ≥2.5; P is the average load borne by the packed column; The length and width of the inflatable bag are the same as those of the reservoir unit, and the cross-sectional curve of the inflatable bag is the catenary equation: In the formula, y1 is the catenary equation; f is the calculated sagittal height of the arch; and m is the arch axis coefficient.

7. A fire prevention and extinguishing method for CO2 storage in goaf according to claim 5, characterized in that: A plurality of solid waste filling strips are arranged parallel to the working surface, a plurality of solid waste filling columns are arranged perpendicular to the working surface, an interval tunnel is arranged between two adjacent solid waste filling columns arranged longitudinally along the working surface, and a sealing device is arranged at the end of the interval tunnel.

8. A fire prevention and extinguishing method for CO2 storage in goaf according to claim 5, characterized in that: In step S4, air is injected into the airbag by means of an inflation-grouting device until the airbag is fully expanded, and then mineralized slurry is injected between the top of the airbag and the roof rock layer. During the solidification process, the mineralized slurry forms a filling body with a catenary arch bridge-like cross-section due to the support of the airbag, and the arched space serves as a CO2 storage place.

9. A fire prevention and extinguishing method for CO2 storage in goaf according to claim 5, characterized in that: When the construction of a local storage group is completed, all the gas in the inflation bag of the previous storage group is released, and the inflation bag is recovered for the construction of the next storage group; alkaline solid waste is used to fill the original sealing device, and a gas reserve pipeline is set up.

10. A fire prevention and extinguishing method for storing CO2 in goaf as claimed in claim 5, characterized in that: During the operation of the reservoir, the CO2 pressure value inside the reservoir is monitored by a pressure vacuum gauge. When it is detected that the gas pressure in the reservoir is reduced, that is, the CO2 concentration is reduced, the CO2 injection pipeline valve is opened to add CO2 again to further seal the CO2. When the CO2 storage potential of the alkaline solid waste and mineralized slurry used to construct the reservoir is exhausted, the arched space inside the reservoir continues to seal CO2 in the form of physical sealing.

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