In-situ test device and test method for deformation of surrounding rock of reservoir of energy storage power station

Abstract

The invention relates to an energy storage power station reservoir surrounding rock deformation in-situ test device and method, the test device comprises a rock sample, a cylinder is drilled in the center of the rock sample, and a reservoir is formed; concrete test blocks are poured on the two sides of the rock sample in the width direction, and strain sensors are arranged on the two side faces of the rock sample in the width direction and located between the rock sample and the concrete test blocks; a sealing rubber cylinder filled with oil is placed in the underground storage and connected with an oil pump, and the oil pump circularly pressurizes the interior of the underground storage to conduct surrounding rock deformation-pressure monitoring. The method is an in-situ test, and can be used for correcting a laboratory scale rock constitutive model according to recorded strain data; the constitutive model of the surrounding rock can be used for numerical calculation, and long-term mechanical response of the reservoir surrounding rock under the action of compressed air cyclic load; the technology is mature, the rock mass of an engineering project can be selected for testing, the rock constitutive model in the specific compressed air energy storage environment is corrected, the operation technology difficulty is small, and large-scale application and popularization can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of compressed air energy storage, and more specifically, to an in-situ test device and experimental method for surrounding rock deformation of a storage power station cavern. Background Art

[0002] Compressed air energy storage is a technology that compresses and stores air and releases it for power generation during peak electricity consumption periods. Its core components include a compression system, a turbine system, a heat exchange system, and a storage device. The operating principle of this system is that during off-peak electricity consumption, a compressor is used to compress air and store it in an underground gas storage cavern; during peak electricity consumption, the compressed air is released, and electric energy is generated by the expansion machine to supply power to users.

[0003] Currently, large-scale caverns mainly include five types: depleted oil and gas reservoirs, underground aquifers, abandoned mines, abandoned salt caverns, and artificial-lined caverns. However, there are fractures and a large amount of hydrocarbons in depleted oil and gas reservoirs, and the contact of air may lead to the formation of flammable and explosive substances; underground aquifers contain impurities such as sand and gravel, which may damage equipment; abandoned mines are usually in soft rock formations, and the stability of the surrounding rock is poor; abandoned salt caverns have a large volume and natural sealing characteristics, and the construction cost is relatively low. Compared with abandoned salt caverns, although the construction cost of artificial-lined caverns is slightly higher, the site selection is more flexible, so they have broad application prospects.

[0004] The mechanical response of the surrounding rock of the cavern and the law of surrounding rock deformation are the core factors affecting the stability of the rock-lined cavern. During the operation period of the power station, due to the frequent and rapid charging and discharging of air in the underground cavern, the surrounding rock is under the action of long-term loads. Therefore, it is necessary to evaluate the long-term mechanical response and stability of the surrounding rock of the cavern. The time-dependent mechanical model of rock is the basic basis and key component for the long-term stability analysis of underground caverns, which can describe the long-term deformation law of rock and be used for the calculation of the long-term mechanical response of the surrounding rock of the cavern. Summary of the Invention

[0005] To solve the above problems, the present invention provides an in-situ test device and experimental method for surrounding rock deformation of a storage power station cavern, and obtains the time-dependent mechanical model of fatigue creep of the in-situ surrounding rock through the strain results of the in-situ surrounding rock under cyclic loads.

[0006] The technical solution adopted by the present invention is: an in-situ test device for surrounding rock deformation of a storage power station cavern, characterized in that: it includes a rock sample, a cylinder is drilled at the central position of the rock sample to form a cavern; concrete test blocks are poured on both sides in the width direction of the rock sample, strain sensors are arranged on both side surfaces in the width direction of the rock sample, and the strain sensors are located between the rock sample and the concrete test blocks; a sealed rubber cylinder filled with oil is placed in the cavern, the sealed rubber cylinder is connected to an oil pump, and the oil pump pressurizes cyclically into the cavern interior for surrounding rock deformation-pressure monitoring.

[0007] Preferably, the shortest distance D1 from the edge of the chamber to the edge of the rock sample is greater than 5 times the diameter D of the cylinder.

[0008] Preferably, the width S1 of the concrete test block is greater than the width S of the rock sample.

[0009] Preferably, the strain sensors are arranged in a scattered manner along the edge of the chamber.

[0010] An experimental method for an in-situ test device for surrounding rock deformation of a storage power station chamber of the present invention is characterized in that:

[0011] S1. Select in-situ rock mass for cutting to make a rock sample with height H, width S, and length L;

[0012] S2. Drill a cylinder with diameter D along the width direction of the rock sample to make a chamber;

[0013] S3. Place a sealed rubber cylinder filled with oil in the chamber, and the sealed rubber cylinder is connected to an oil pump;

[0014] S4. Strain sensors are arranged on both side surfaces in the width direction of the rock sample, and the strain sensors are arranged in a scattered manner along the edge of the chamber;

[0015] S5. Pour concrete on both sides in the width direction of the rock sample;

[0016] S6. The oil pump pressurizes the inside of the chamber in a circulating manner to conduct surrounding rock deformation-pressure monitoring;

[0017] S7. According to the strain data recorded in step S6, it is used to correct the rock constitutive model at the laboratory scale.

[0018] The beneficial effects achieved by the present invention are:

[0019] 1. Record the actual deformation of the surrounding rock of the chamber under the action of cyclic load of compressed air;

[0020] 2. Observe the influence range of the surrounding rock deformation of the chamber under the action of cyclic load of compressed air;

[0021] 3. The present invention is an in-situ test. According to the recorded strain data, it can be used to correct the rock constitutive model at the laboratory scale;

[0022] 4. The surrounding rock constitutive model can be used for numerical calculation of the long-term mechanical response of the surrounding rock of the chamber under the action of cyclic load of compressed air;

[0023] 5. The technology on which the present invention is based is mature. Rock mass of engineering projects can be selected for tests to correct the rock constitutive model under specific environments of compressed air energy storage. The operation technical difficulty is small, and it can be widely promoted and applied. Description of the Drawings

[0024] Figure 1 It is the overall layout diagram of the device of the present invention;

[0025] Figure 2 This is the layout diagram of the rock sample surface monitoring system of the present invention;

[0026] Figure 3 This is the schematic diagram of the pressure application process of the cross-section of the device of the present invention;

[0027] In the figure: 1. Rock sample; 2. Concrete test block; 3. Cavern; 4. Rubber sealing cylinder; 5. Strain sensor. Specific embodiments

[0028] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] As Figures 1-3 shown, an in-situ test device for surrounding rock deformation of an energy storage power station cavern of the present invention includes a rock sample 1. A cylinder is drilled at the central position of the rock sample 1 to form a cavern 3; concrete test blocks 2 are poured on both sides in the width direction of the rock sample 1, and strain sensors 5 are arranged on both side surfaces in the width direction of the rock sample 1. The strain sensors 5 are located between the rock sample 1 and the concrete test blocks 2; an oil-filled sealed rubber cylinder 4 is placed in the cavern 3, and the sealed rubber cylinder 4 is connected to an external oil pump. The oil pump pressurizes the inside of the cavern 3 in a cycle to monitor the surrounding rock deformation - pressure.

[0030] The rock sample 1 is made by cutting an in-situ rock mass into a cube with a height of H, a width of S, and a length of L; the cavern 3 is selected at the central position of the rock sample 1, and a cylinder with a diameter of D is drilled along the width S direction of the rock sample; the concrete test blocks 2 are poured on both sides of the rock sample 1 along the width direction to ensure the sealing of the cavern 3, and the width of the concrete test blocks 2 is S1; the strain sensors 5 are arranged on both sides of the rock sample 1 along the width direction and are located between the rock sample 1 and the concrete test blocks 2.

[0031] In this embodiment, to minimize the influence of the boundary as much as possible, it is necessary to ensure that the shortest distance D1 from the edge of the cavern 3 to the edge of the rock sample 1 is greater than 5 times the diameter D of the cylinder.

[0032] In this embodiment, it is necessary to ensure that the width S1 of the concrete test block 2 is greater than the width S of the rock sample 1 to ensure the sealing of the cavern 3.

[0033] In this embodiment, strain sensors 5 need to be arranged on both side surfaces in the width direction of the rock sample 1. The strain sensors 5 are arranged in a scattered manner spreading outwards from the periphery of the outer wall of the cavern 3 to obtain the strain of the surrounding rock under the action of the load.

[0034] An experimental method for an in-situ test device for surrounding rock deformation of an energy storage power station cavern of the present invention is characterized in that:

[0035] S1. Select in-situ rock mass for cutting to make a rock sample 1 with height H, width S and length L;

[0036] S2. Drill a cylinder with diameter D along the width direction of the rock sample 1 to make a tunnel 3;

[0037] S3. Place a sealed rubber cylinder 4 filled with oil in the tunnel 3, and the sealed rubber cylinder 4 is connected to an oil pump;

[0038] S4. Strain sensors 5 are arranged on both side surfaces in the width direction of the rock sample 1, and the strain sensors 5 are spread out along the edge of the tunnel 3;

[0039] S5. Pour concrete 2 on both sides in the width direction of the rock sample 1;

[0040] S6. The oil pump pressurizes the inside of the tunnel 3 in a cycle to conduct surrounding rock deformation-pressure monitoring;

[0041] S7. Use the strain data recorded in step S6 to correct the laboratory-scale rock constitutive model.

[0042] Here, it should be noted that the description of the above technical solution is exemplary, and this specification can be embodied in different forms and should not be construed as limited to the technical solution described herein. On the contrary, providing these descriptions will make the disclosure of the present invention thorough and complete, and will fully convey the scope disclosed in this specification to those skilled in the art. In addition, the technical solution of the present invention is only limited by the scope of the claims.

[0043] Finally, it should be pointed out that the above embodiments are only relatively representative examples of the present invention. Obviously, the present invention is not limited to the above embodiments and there can be many variations. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention should be considered as belonging to the protection scope of the present invention.

Claims

1. An in-situ test device for surrounding rock deformation of a energy storage power station chamber, characterized in that: It includes a rock sample (1). A cylinder is drilled at the central position of the rock sample (1) to form a cavern (3). Concrete test blocks (2) are poured on both sides in the width direction of the rock sample (1). Strain sensors (5) are arranged on both side surfaces in the width direction of the rock sample (1), and the strain sensors (5) are located between the rock sample (1) and the concrete test blocks (2). A sealed rubber cylinder (4) filled with oil is placed in the cavern (3), and the sealed rubber cylinder (4) is connected to an oil pump. The oil pump pressurizes the inside of the cavern (3) in a circulating manner to conduct surrounding rock deformation-pressure monitoring.

2. The in-situ test device for the surrounding rock deformation of the energy storage power station cavern as described in claim 1, characterized in that: The shortest distance D1 from the edge of the cavern (3) to the edge of the rock sample (1) is greater than 5 times the diameter D of the cylinder.

3. The in-situ test device for surrounding rock deformation of the energy storage power station chamber according to claim 1, wherein: The width S1 of the concrete test block (2) is greater than the width S of the rock sample (1).

4. The in-situ test device for surrounding rock deformation of the energy storage power station chamber according to claim 1, characterized in that: The strain sensors (5) are spread out along the edge of the cavern (3).

5. An experimental method for an in-situ test device for surrounding rock deformation of a cavern in an energy storage power station, characterized in that: S1. Select an in-situ rock mass for cutting to make a rock sample (1) with a height H, a width S, and a length L; S2. Drill a cylinder with a diameter D along the width direction of the rock sample (1) to make a cavern (3); S3. Place a sealed rubber cylinder (4) filled with oil in the cavern (3), and the sealed rubber cylinder (4) is connected to an oil pump; S4. Arrange strain sensors (5) on both side surfaces in the width direction of the rock sample (1), and the strain sensors (5) are spread out along the edge of the cavern (3); S5. Pour concrete (2) on both sides in the width direction of the rock sample (1); S6. The oil pump pressurizes the inside of the cavern (3) in a circulating manner to conduct surrounding rock deformation-pressure monitoring; S7. Use the strain data recorded in step S6 to correct the laboratory-scale rock constitutive model.

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