High-pressure gas storage hole model test device and method

Abstract

The invention provides a high-pressure air storage hole model test device and method, and belongs to the technical field of new energy compressed air energy storage. The test device comprises a test module, a confining pressure module, an integral foundation and a pressurization module; the test module is of a cylindrical structure, a closed cavity is formed in the middle of the test module, a sealing layer, a lining layer and a rock surrounding layer are sequentially arranged from inside to outside, and the test module is provided with a monitoring sensor; the confining pressure module comprises a plurality of confining pressure devices annularly arranged between the test module and the overall foundation, each confining pressure device comprises an elastic element and a pressure applying device, the pressure applying devices are connected with the overall foundation, and the elastic elements are located between the pressure applying devices and the test module and apply external loads to the test module; the pressurizing module is communicated with the closed cavity, high-pressure gas is introduced into the closed cavity, and an internal load is applied to the test module. The high-pressure gas storage model test device can truly reflect the conditions of internal and external loads borne by the high-pressure gas storage, adopts a modular thought in the design scheme, is suitable for multiple test working condition types, and is simple and convenient to operate and low in test cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy compressed air energy storage, and in particular relates to a model test device and method for a high-pressure gas storage cave. Background Art

[0002] In recent years, with the rapid increase in demand for new energy grid connection and peak-shaving and valley-filling of power grids, energy storage technology has received more and more attention. Among them, compressed air energy storage technology has the advantages of good safety and large energy storage scale, and has broad development prospects. Artificial excavation of underground gas storage is a major gas storage method for compressed air energy storage, with significant advantages such as flexible site selection and wide application range. At present, underground gas storage caverns for compressed air energy storage need to withstand high internal pressure alternating loads of more than 10MPa, and are subject to the combined effects of temperature and pressure, and the stress state is very complex. At present, the design of the sealing lining structure of underground gas storage caverns for compressed air energy storage is not mature, and there is no standard method to follow. How to optimize the design of the sealing lining of the high-pressure gas storage cavern has become a key issue that must be solved in the construction of compressed air energy storage power stations. At present, there are no domestic standards to follow in these aspects, and there is no relevant design experience.

[0003] In order to deeply study the stress characteristics of the sealing lining structure of the high-pressure gas storage cavern and provide guidance for the design of the high-pressure gas storage cavern, it is urgent to carry out experimental research under various design schemes. The limitations of conducting in-situ tests at the engineering site are large, the cost of a single test is high, and the surrounding rock conditions are not representative enough; the use of numerical simulation and other methods has problems such as high sensitivity of parameter values ​​and lack of credibility. Summary of the invention

[0004] The invention provides a high-pressure gas storage cave model test device and method, which has the advantages of accurate test simulation, low test cost, simple operation, multiple simulated working conditions, etc.

[0005] The present invention provides a high-pressure gas storage cave model test device, comprising a test module, a confining pressure module, an integral foundation and a pressurizing module, wherein the test module is provided with a monitoring sensor; The test module is a cylindrical structure, the middle part of which is a closed cavity, and from the inside to the outside, there are a sealing layer, a lining layer, and a surrounding rock layer; The confining pressure module is a plurality of confining pressure devices arranged in an annular manner between the test module and the overall foundation, each confining pressure device includes an elastic element and a pressure device, the pressure device is connected to the overall foundation, and the elastic element is located between the pressure device and the test module to apply an external load to the test module; The pressurizing module is connected to the sealed cavity, and high-pressure gas is introduced into the sealed cavity to apply internal load to the test module.

[0006] Furthermore, the inner diameter of the test module is R , the height is H The thickness of the lining layer ist 2. The thickness of the surrounding rock layer is t 3, where: R= 0.3m~1m, H= 1~2 R , t 2 = 0.1~0.2 R , t 3 = 1.5~2.5 R .

[0007] Furthermore, the thickness of the sealing layer is t 1. The stiffness of each elastic element is k ,but k The value of satisfies: , In the formula, K is the unit elastic resistance coefficient of the simulated surrounding rock; the number of confining pressure devices is N .

[0008] Furthermore, the elastic element has the property of being deformed by external force and returning to its original shape after the external force is removed, such as a spring, a hairspring, a leaf spring, etc.

[0009] Furthermore, the surrounding rock layer is simulated by artificially preparing concrete, by adding steel sand to increase the elastic modulus, and by adding rubber particles to reduce the elastic modulus, so as to simulate the rock around the cave with different moduli. An interlayer can be added inside the surrounding rock layer to artificially simulate the joint and fissure structure.

[0010] Furthermore, the sealed chamber is sealed by respectively providing a top cover and a bottom cover at both ends of the test module, the top cover and the bottom cover are steel structures, lifting rings are provided on the surfaces of the top cover and the bottom cover, sealing pads are provided between the top cover and the test module and between the bottom cover and the test module, and are fixed to the test module by fixing screws.

[0011] Furthermore, the monitoring sensor includes a stress gauge arranged on the inner side of the sealing layer, a displacement sensor arranged on the upper surface of the surrounding rock layer and a pressure sensor arranged on the lower surface of the top cover.

[0012] Furthermore, the pressure-applying device is a device or equipment that can provide pressure, such as a hydraulic system, a screw system, a cylinder system, etc.

[0013] Furthermore, the pressure-applying device adopts a hydraulic system, and an inner sleeve and an outer sleeve are arranged on the outside of the elastic element. The inner sleeve is fixed on the test module, and the outer sleeve is connected to the hydraulic system. The hydraulic system is arranged on the overall basis, and the two ends of the elastic element are respectively fixed on the inner sleeve and the outer sleeve; the inner sleeve and the outer sleeve are both composed of an upper and lower petal, and a corresponding concave and convex sliding groove is arranged between the inner sleeve and the outer sleeve.

[0014] Furthermore, the hydraulic support of the hydraulic system can extend to a length of L , compress the elastic element to generate pressure, simulate the external confining pressure, length L Calculate as follows: , In the formula, P To simulate the external pressure of surrounding rock.

[0015] Furthermore, the integral foundation is a cast-in-place concrete structure, a metal structure, etc. The integral foundation consists of an external foundation, a bottom foundation and piers. The middle part of the external foundation is a groove, the bottom of the groove is a base plate foundation, a test module is placed in the groove, and a pier is set between the test module and the base plate foundation to support the test module.

[0016] Furthermore, the thickness of the external foundation t 4 Satisfaction: t 4 ≥ 3 R .

[0017] Furthermore, the pressurizing module includes a pressurizing pipe and a pressurizing air pump. One end of the pressurizing pipe is connected to the closed cavity, and the other end is connected to the pressurizing air pump. The pressure range of the high-pressure gas filled into the closed cavity of the test module by the pressurizing module is 0~10MPa.

[0018] Accordingly, the present invention also proposes a high-pressure gas storage cave model test method, which is carried out using the above-mentioned high-pressure gas storage cave model test device and includes the following steps: (1) Preparation of test module The test module preparation sequence is as follows: (a) Determine the material parameters of the sealing layer, lining layer and surrounding rock layer according to the test requirements; (b) The surrounding rock layer and lining layer are installed by positioning and installing through formwork casting. The sealing layer can be used as the inner formwork for casting the lining layer; (c) Install monitoring sensors on the test module; (d) Complete the installation of the top cover and the bottom cover by fixing the screws; (2) Test module installation The test module is transported to the test site, and the test module is moved to the top of the overall foundation by a crane, and slowly lowered to the top of the pier to reach the installation position; (3) Installation of confining pressure module Install the inner sleeve and the outer sleeve of the confining pressure module in place, and install the spring according to the selected surrounding rock design parameters; (4) Pressure test and analysis The pressure test is carried out in stages from low to high pressure. The pressure stabilization time in each stage is not less than 10 minutes. After obtaining the test data, the mechanical properties of each layer of the test model under high-pressure gas storage state are analyzed and studied.

[0019] The beneficial effects of the present invention are as follows: (1) The high-pressure gas storage model test device of the present invention can truly reflect the internal and external pressure loads of the high-pressure gas storage reservoir. The design test is flexible. The sealing layer, lining layer, and surrounding rock layer are easy to replace. The external confining pressure can change parameters according to needs, and is applicable to a variety of test conditions. (2) Easy to operate. The test module can be hoisted out as a whole and installed in place after the construction and installation of the sealing layer, lining layer and surrounding rock layer are completed; (3) The experimental cost is low, each module in the device can be used repeatedly for a long time, and consumables are few. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional schematic diagram of a high-pressure gas storage cave model test device of the present invention; Figure 2 It is a schematic plan view of a high-pressure gas storage cave model test device of the present invention; Figure 3 A three-dimensional schematic diagram of a high-pressure gas storage cave model test device of the present invention; Figure 4 A cross-sectional schematic diagram of a test module of a high-pressure gas storage cave model test device of the present invention; Figure 5 A three-dimensional schematic diagram of a confining pressure module of a high-pressure gas storage cave model test device of the present invention; Figure 6 It is a schematic diagram of the composition of the confining pressure module components of a high-pressure gas storage cave model test device of the present invention.

[0021] In the figure: 1 is the test module, 2 is the confining pressure module, 3 is the overall foundation, and 4 is the pressurization module; 101 is a sealing layer, 102 is a lining layer, 103 is a surrounding rock layer, 104 is a top cover, 105 is a bottom cover, 106 is a sealing pad, 107 is a fixing screw, 108 is a lifting ring, 109a is a strain gauge, 109b is a displacement sensor, and 109c is a pressure sensor; 201 is a spring, 202 is an inner sleeve, 203 is an outer sleeve, 204 is an outer sleeve bottom plate, 205 is an inner sleeve bottom plate, 206 is a bolt, 207 is a hydraulic support, and 208 is a slide groove; 301 is the external foundation, 302 is the buttress, and 303 is the bottom plate foundation; 401 is a pressurized pipeline, and 402 is a pressurized air pump. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to the accompanying drawings and implementation examples.

[0023] like Figure 1 to Figure 6 As shown, this embodiment introduces a high-pressure gas storage cave model test device, including a test module 1, a confining pressure module 2, an overall foundation 3 and a pressurization module 4.

[0024] like Figure 4 As shown, the test module 1 is a cylinder structure, with a sealing layer 101 at the innermost side, and a lining layer 102 and a surrounding rock layer 103 outward in sequence; a top cover 104 and a bottom cover 105 are installed at both ends of the cylinder, and a sealing pad 106 is arranged between the top cover 104 and the cylinder, and between the bottom cover 105 and the cylinder, and is fixed to the cylinder by a fixing screw 107. The inner diameter of the test module 1 is 0.5m and the height is 0.8m.

[0025] The sealing layer 101 is made of butyl rubber with a thickness of 2 mm and is adhered to the inner side of the lining layer 102 by means of structural adhesive. In subsequent testing conditions of other materials, the butyl rubber sealing layer 101 can be removed and replaced with other thicknesses or other materials.

[0026] The lining layer 102 is arranged inside the surrounding rock layer 103 and is made of C30 concrete with a thickness of 8 cm. The concrete grade, thickness, etc. can be changed later according to the test conditions.

[0027] The surrounding rock layer 103 is simulated by artificially prepared concrete with a thickness of 0.8 m. A certain proportion of steel sand is added to increase the elastic modulus to simulate hard rock. In other test conditions, rubber particles can also be added to reduce the elastic modulus to simulate softer surrounding rock.

[0028] like Figure 4 As shown, the top cover 104 and the bottom cover 105 are steel structures with a minimum thickness of 25 mm, which can meet the pressure-bearing requirements; for easy movement, lifting rings 108 are installed on the top cover 104 and the bottom cover 105.

[0029] like Figure 4 As shown, the monitoring sensor includes a stress gauge 109a arranged on the inner side of the sealing layer 101, a displacement sensor 109b arranged on the upper surface of the surrounding rock layer 103 and a pressure sensor 109c arranged on the lower surface of the top cover 104.

[0030] like Figure 5 As shown, the confining pressure module 2 is 40 confining pressure devices arranged in a ring between the test module 1 and the integral foundation 3, each confining pressure device includes a pair of springs 201 and a hydraulic system, and an inner sleeve 202 and an outer sleeve 203 are provided on the outer side of the spring 201, wherein the inner sleeve 202 is fixed to the test module 1 through an inner bottom plate 205, and the outer sleeve 203 is fixed to one end of a hydraulic support 207 of the hydraulic system through an outer bottom plate 204, and the other end of the hydraulic support 207 is fixed to the integral foundation 3 with bolts, and one end of the spring 201 is fixed to the inner bottom plate 205, and the other end is fixed to the outer bottom plate 204.

[0031] like Figure 6 As shown, both the inner sleeve 202 and the outer sleeve 203 can be divided into two upper and lower parts, and the internal spring 201 can be replaced after opening. The springs 201 with different stiffness play a role in simulating different surrounding rock elasticity in the module. In this embodiment, the stiffness of each spring 201 is 130MN / m, which is used to simulate the external surrounding rock effect with a unit elastic resistance coefficient of 1500MPa / m.

[0032] To simulate an external confining pressure of about 5 MPa, the hydraulic support 207 of each hydraulic system is extended by about 3.5 mm, and the spring 201 is compressed to generate a corresponding external pressure. The hydraulic support 207 is electrically controlled to ensure that the extension of each hydraulic support 207 is equal.

[0033] like Figure 6 As shown, a corresponding groove 208 is provided between the inner sleeve 202 and the outer sleeve 203, a groove is provided on the inner wall of the outer sleeve 203, and a protrusion matching the groove is provided on the outer wall of the inner sleeve 202, which can prevent circumferential rotation.

[0034] like Figure 3 As shown, the integral foundation 3 is a cast-in-place concrete structure, which is a square in plane, with a side length of about 8m and a vertical height of about 1.5m. The integral foundation 3 consists of an external foundation 301, a bottom foundation 303 and piers 302. The outermost part is the external foundation 301, which has a radial thickness of about 1.8m. The middle part of the external foundation 301 is a groove, and the bottom of the groove is the bottom plate foundation 303, which has a thickness of about 0.5m. The test module 1 is placed in the groove, and 8 piers 302 are set between the test module 1 and the bottom plate foundation 303 to support the test module 1.

[0035] like Figure 1As shown, the pressurization module 4 includes a pressurization pipe 401 and a pressurization air pump 402. One end of the pressurization pipe 401 is connected to the top cover 104 and is opened by a valve control, and the other end is connected to the pressurization air pump 402. The pressurization module 4 can fill high-pressure air into the interior of the test module 1, and the maximum pressure range is about 10MPa.

[0036] The present invention fills the blank of high-pressure gas storage model test equipment and can truly reflect the load conditions of the high-pressure gas storage reservoir; the design scheme adopts a modular approach, is applicable to many types of test conditions, is easy to operate, and has low test costs.

[0037] This embodiment also introduces a high-pressure gas storage cave model test method, which is carried out using the above-mentioned high-pressure gas storage cave model test device, and includes the following steps: (1) Preparation of test module Test module 1 can be prepared in a factory workshop outside the test site, and the preparation sequence is as follows: (a) Determine the material parameters of the sealing layer 101, the lining layer 102 and the surrounding rock layer 103 according to the test requirements; (b) The surrounding rock layer 103 and the lining layer 102 are installed by positioning and installing them through the formwork casting method, and the sealing layer 101 can be used as the inner side formwork for casting the lining layer 102; (c) Monitoring sensors, including strain gauges, displacement sensors, pressure sensors, etc., are installed in the test module; the strain gauge 109a is installed on the inner side of the sealing layer 101 to monitor the strain of the sealing layer 101; the displacement sensor 109b is installed on the upper surface of the surrounding rock layer 103 to monitor the displacement of the surrounding rock layer 103; the pressure sensor 109c is installed on the lower surface of the top cover 104 to monitor the pressure in the closed cavity.

[0038] (d) Installing the top cover 104 and the bottom cover 105 by fixing the screws; (2) Test module installation Transport the test module 1 to the test site, move the test module 1 to the top of the integral foundation 3 by a crane, and slowly lower it to the top of the pier 302 to reach the installation position; (3) Installation of confining pressure module 2 Install the inner sleeve 202 and the outer sleeve 203 of the confining pressure module 2 in place, and install the spring 201 according to the selected surrounding rock design parameters; (4) Pressure test and analysis The pressure test is carried out in stages from low to high pressure. The pressure stabilization time in each stage is not less than 10 minutes to ensure the test effect and safety. After obtaining the test data, the mechanical properties of each layer of the test model under high-pressure gas storage state are analyzed and studied.

[0039] The above description is only used to illustrate a specific implementation case of the present invention, and is not used to limit the applicable scope of the present invention. All equivalent changes or modifications made by those skilled in the art without departing from the spirit and principle of the present invention shall still be covered by the scope of the claims of the present invention.

Claims

1. A high-pressure gas storage cave model test device, characterized in that: It includes test module, confining pressure module, integral foundation and pressurization module; The test module is a cylindrical structure, the middle part of which is a closed cavity, and from the inside to the outside, there are a sealing layer, a lining layer, and a surrounding rock layer. The test module is provided with a monitoring sensor; The confining pressure module is a plurality of confining pressure devices arranged in an annular manner between the test module and the overall foundation, each confining pressure device includes an elastic element and a pressure device, the pressure device is connected to the overall foundation, and the elastic element is located between the pressure device and the test module to apply an external load to the test module; The pressurizing module is connected to the sealed cavity, and high-pressure gas is introduced into the sealed cavity to apply internal load to the test module.

2. The high-pressure gas storage cave model test device according to claim 1 is characterized in that: The inner diameter of the test module is R , the height is H The thickness of the lining layer is t 2. The thickness of the surrounding rock layer is t 3, where: <h2 style=";text-align:left;direction:ltr"> R= <h2 style=";text-align:left;direction:ltr"> 0.3m~1m, H= 1~2 R ， t 2 = 0.1~0.2 R ， t 3 = 1.5~2.5 R 。 3. The high-pressure gas storage cave model test device according to claim 2 is characterized in that: The thickness of the sealing layer is t 1. The stiffness of each elastic element is k ,but k The value of satisfies: , In the formula, K is the unit elastic resistance coefficient of the simulated surrounding rock; the number of confining pressure devices is N .

4. The high-pressure gas storage cave model test device according to claim 1, characterized in that: The sealed chamber is sealed by respectively setting a top cover and a bottom cover at both ends of the test module, the top cover and the bottom cover are steel structures, lifting rings are set on the surfaces of the top cover and the bottom cover, sealing pads are set between the top cover and the test module, and between the bottom cover and the test module, and are fixed to the test module by fixing screws.

5. The high-pressure gas storage cave model test device according to claim 1, characterized in that: The pressure-applying device adopts a hydraulic system, and an inner sleeve and an outer sleeve are arranged on the outside of the elastic element. The inner sleeve is fixed on the test module, and the outer sleeve is connected to the hydraulic system. The hydraulic system is arranged on the overall basis, and the two ends of the elastic element are respectively fixed on the inner sleeve and the outer sleeve; the inner sleeve and the outer sleeve are both composed of an upper and lower petal, and a corresponding concave and convex sliding groove is arranged between the inner sleeve and the outer sleeve.

6. The high-pressure gas storage cave model test device according to claim 5, characterized in that: The hydraulic support of the hydraulic system can extend to a length of L , compress the elastic element to generate pressure, simulate the external confining pressure, length L Calculate as follows: ， In the formula, P To simulate the external pressure of surrounding rock.

7. The high-pressure gas storage cave model test device according to claim 2 is characterized in that: The integral foundation is a cast-in-place concrete structure, which consists of an external foundation, a bottom foundation and piers. The middle of the external foundation is a groove, the bottom of the groove is a base plate foundation, a test module is placed in the groove, and a pier is set between the test module and the base plate foundation to support the test module.

8. The high-pressure gas storage cave model test device according to claim 7, characterized in that: The thickness of the external foundation t 4 Satisfaction: t 4 ≥ 3 R .

9. The high-pressure gas storage cave model test device according to claim 1, characterized in that: The pressurizing module includes a pressurizing pipe and a pressurizing air pump. One end of the pressurizing pipe is connected to the closed cavity, and the other end is connected to the pressurizing air pump. The pressure range of the high-pressure gas filled into the closed cavity by the pressurizing module is 0~10MPa.

10. A high-pressure gas storage cave model test method, characterized in that: The high-pressure gas storage cave model test device according to any one of claims 1 to 9 comprises the following steps: (1) Preparation of test module The test module preparation sequence is as follows: (a) Determine the material parameters of the sealing layer, lining layer and surrounding rock layer according to the test requirements; (b) The surrounding rock layer and lining layer are installed by positioning and installing through formwork casting, and the sealing layer serves as the inner formwork for casting the lining layer; (c) Install monitoring sensors on the test module; (d) Complete the installation of the top cover and the bottom cover by fixing the screws; (2) Test module installation The test module is transported to the test site, and the test module is moved to the top of the overall foundation by a crane, and slowly lowered to the top of the pier to reach the installation position; (3) Installation of confining pressure module Install the inner sleeve and the outer sleeve of the confining pressure module in place, and install the elastic element according to the selected surrounding rock design parameters; (4) Pressure test and analysis The pressure test is carried out in stages from low to high pressure. The pressure stabilization time in each stage is not less than 10 minutes. After obtaining the test data, the mechanical properties of the test model under high-pressure gas storage state are analyzed and studied.

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