Expansion joint, underground gas storage and method for preventing excessive deformation of a sealing steel plate

Abstract

The present application relates to compressed air energy storage technology field, provide a kind of underground gas storage seal steel plate's expansion joint, including sequentially connected first connecting section, expansion section and second connecting section, the expansion section has first end, middle end and tail end, the first end is connected with the first connecting section, the tail end is connected with the second connecting section, the first end to the middle end one section with the tail end to the middle end one section are arc section, at least the expansion section is deformation section. Provide a kind of underground gas storage. Also provide a kind of method for preventing underground gas storage seal steel plate excessive deformation. The present application is under the action of internal pressure, by setting expansion joint, can effectively allow seal steel plate to freely expand and contract with the change of pressure, to fully adapt to the deformation due to high internal pressure, avoid seal steel plate into elastic-plastic state due to long-term high pressure, and then possibly caused by sealing failure risk.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of compressed air energy storage, in particular to a telescopic joint of a sealing steel plate of an underground gas storage and the underground gas storage. BACKGROUND

[0002] As a new energy storage method, compressed air energy storage has attracted widespread attention in recent years. The basic principle of compressed air energy storage is to compress and store air during the low valley of electricity demand, and release compressed air to drive the generator to generate electricity during the peak of electricity demand, so as to realize the storage and release of electric energy. This technology is not only environmentally friendly and efficient, but also has the characteristics of long-term energy storage, which is of great significance to improve energy utilization efficiency and promote the development of renewable energy. With the rapid development and popularization of compressed air energy storage technology, the construction demand of underground gas storage as a key infrastructure in this field is showing a sustained growth trend.

[0003] However, the sealing steel plate inside the gas storage is subjected to high pressure and repeated loading and unloading, which causes the sealing steel plate to expand and contract in the axial and circumferential directions, resulting in cracks in the lining structure. Therefore, there are high requirements for the connection method of the sealing steel plate. After investigation, there is a lack of relevant research in the actual engineering application of compressed air energy storage. SUMMARY

[0004] The purpose of the present application is to provide a telescopic joint of a sealing steel plate of an underground gas storage and the underground gas storage, which can at least solve some defects in the prior art.

[0005] To achieve the above purpose, the embodiments of the present application provide the following technical solutions: a telescopic joint of a sealing steel plate of an underground gas storage, comprising a first connecting section, a telescopic section and a second connecting section connected in sequence, the telescopic section has a first end, a middle end and a tail end, the first end is connected with the first connecting section, the tail end is connected with the second connecting section, a segment from the first end to the middle end and a segment from the tail end to the middle end are both arc-shaped segments, and at least the telescopic section is a deformation segment.

[0006] Further, the two arc-shaped segments have a gap therebetween.

[0007] Further, the first connecting section, the telescopic section and the second connecting section are an integral structure.

[0008] Another technical solution provided by the embodiments of the present application is an underground gas storage, comprising a sealing steel plate, further comprising the telescopic joint described above, and two adjacent sealing steel plates are connected to the first connecting section and the second connecting section respectively.

[0009] Further, it further comprises a sliding layer arranged between the concrete and the telescopic joint.

[0010] This invention provides another technical solution: a method for preventing excessive deformation of the sealing steel plate of an underground gas storage facility, comprising the following steps:

[0011] Under the condition that the sealing steel plate is subjected to the pressure inside the gas storage tank, the maximum strain ε of the sealing steel plate is obtained. max1 If ε max1 ≥ε n Then, an expansion joint with a sealing steel plate is installed, where ε n The elastic limit strain rate of the sealing steel plate;

[0012] Under conditions where the sealing steel plate is subjected to an external high-temperature environment, the maximum strain ε generated by the sealing steel plate under temperature changes is obtained. max2 If ε max2 ≥ε n Then, an expansion joint with a sealing steel plate is installed, where ε n This represents the elastic limit strain rate of the sealing steel plate.

[0013] Furthermore, the maximum strain ε of the sealing steel plate max1 The calculation formula is as follows:

[0014]

[0015] Where x1 represents the top displacement of different surrounding rock grades, x2 represents the bottom displacement of different surrounding rock grades, and D represents the diameter of the gas storage tank.

[0016] Furthermore, the maximum strain ε generated by the sealing steel plate under temperature change... max2 The calculation formula is as follows:

[0017] ε max2 =αΔt.

[0018] Where α is the coefficient of thermal expansion of the sealing steel plate material, and Δt is the temperature change of the sealing steel plate, Δt=T max -T min T max For the peak temperature of the sealing steel plate, T min This is to ensure the low peak temperature of the sealed steel plate.

[0019] Furthermore, considering the internal pressure of the gas storage tank and the external high-temperature environment, a circumferential expansion joint and a longitudinal expansion joint are adopted.

[0020] Furthermore, through strain analysis of the sealing steel plate under the individual effects of pressure and temperature inside the gas storage tank, the setting of circumferential expansion joints for different surrounding rock levels was obtained, and the total expansion and contraction of the circumferential expansion joints was calculated.

[0021] Based on the total expansion and contraction amount and the circumferential deformation distribution characteristics of the gas storage cavern, determine the number of circumferential expansion joints that need to be installed;

[0022] The number of longitudinal deformation joints to be set is determined based on the longitudinal deformation distribution characteristics of the gas storage cavern.

[0023] Compared with existing technologies, the beneficial effects of this invention are as follows: Under the action of internal pressure, by setting an expansion joint, the sealing steel plate can be effectively allowed to expand and contract freely with changes in pressure, thereby fully adapting to the deformation caused by high internal pressure and avoiding the risk of sealing failure caused by the sealing steel plate entering an elastic-plastic state due to long-term high pressure. Considering the sensitivity of steel to temperature fields, especially in high-temperature environments, where steel is prone to thermal expansion, leading to an abnormally large deformation of the sealing steel plate, the design of a circumferential longitudinal expansion joint can effectively reduce the deformation of the sealing steel plate caused by temperature changes, ensuring that the overall structural stability and sealing performance of the gas storage facility are not affected. In practical applications, the deformation of the sealing steel plate is not only affected by internal pressure but also by the superimposed effect of temperature changes. The circumferential longitudinal expansion joint can comprehensively consider both internal pressure and temperature factors, ensuring that the sealing steel plate always remains within its elastic state, preventing excessive deformation of the sealing steel plate and ensuring the long-term safe operation of the gas storage facility. Attached Figure Description

[0024] Figure 1 A schematic diagram of the steel plate, surrounding rock, and cross-joint zone for a method of designing the thickness of the sealing steel plate for an underground gas storage facility provided in an embodiment of the present invention;

[0025] Figure 2 A schematic diagram of the calculation model for the joint span of the sealing steel plate in an embodiment of the present invention, which is a method for designing the thickness of the sealing steel plate in an underground gas storage facility.

[0026] Figure 3 A schematic diagram illustrating the calculation of the maximum principal strain across the joint of a sealing steel plate in an underground gas storage facility, provided as an embodiment of the present invention (short-term operation).

[0027] Figure 4 A schematic diagram illustrating the calculation of the maximum principal strain across the joint of a sealing steel plate in an underground gas storage facility, provided as an embodiment of the present invention (for long-term operation).

[0028] Figure 5 A schematic diagram illustrating the fit between an expansion joint, a sliding layer, and concrete in a sealing steel plate for an underground gas storage facility, provided as an embodiment of the present invention.

[0029] Figure 6 A schematic diagram illustrating the fit between an expansion joint and a sealing steel plate in an underground gas storage facility, provided in an embodiment of the present invention.

[0030] Figure 7A schematic view of a longitudinal telescopic joint of a sealing steel plate of an underground gas storage provided by the embodiment of the present application;

[0031] Figure 8 A schematic view of a ring longitudinal telescopic joint of a sealing steel plate of an underground gas storage provided by the embodiment of the present application;

[0032] In the figure, 1 is a telescopic joint; 10 is a first connecting section; 11 is a telescopic section; 110 is a head end; 111 is a middle end; 112 is a tail end; 12 is a second connecting section; 13 is a gap; 2 is a sliding layer; 3 is concrete; and 4 is a sealing steel plate. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0034] Please refer to Figures 1 to 4 The embodiment of the present application provides a thickness design method of a sealing steel plate of an underground gas storage, and specifically includes the following steps.

[0035] S1: According to the construction scale, capacity, working internal pressure and other engineering characteristics of the gas storage project, the cross-sectional size, buried depth and arrangement form of the cavern are determined.

[0036] S2: The crack width of the surrounding rock-structure under the most unfavorable working condition is determined by a numerical method or the like.

[0037] S3: The yield strain of the steel plate is determined.

[0038] S31: According to the stress-strain curve characteristics of the selected steel material, the yield strain ε y of the steel material is determined. If there is no obvious yield phenomenon of the steel material, the stress value when plastic deformation (permanent deformation) of 0.2% is generated is taken as the yield strength of the material. After the yield of the steel material, the material is not finally destroyed, but a relatively significant and unrecoverable plastic deformation is generated.

[0039] S4: The maximum corrosion amount of the steel plate in the operation cycle is determined according to the environmental conditions, corrosion type, corrosion rate and corrosion environment of the gas storage.

[0040] S41: Assuming that the operation cycle of the gas storage is m years, the corrosion rate of the steel plate is determined to be v (mm / a) according to the corrosion prevention requirement of the steel structure, and the corrosion amount of the steel structure is t0 = m × v, so the corrosion surplus amount t1 of the steel structure is t × t0.

[0041] S5: According to the crack width, steel plate model, internal pressure size and other parameters, a sealing steel plate across the crack calculation model is established to check whether the steel plate is in an elastic state under the condition that the back wall surrounding rock-structure has a certain crack width;

[0042] S51: A calculation model is established according to the local cross-section of the steel plate across the crack; the length values of the model in the transverse (x), vertical (z) and longitudinal (y) directions are as follows: assuming that the surrounding rock-structure crack width is w and the steel plate thickness is t, the transverse length is preferably 21w, that is, 10w on both sides of the crack width, and it is experienced that the size effect can be eliminated within this range; the vertical length is the thickness t of the steel plate, and the longitudinal length can be one third of the transverse length or the thickness t; wherein the crack width can be obtained by continuous and discontinuous calculation and analysis, and the across-crack calculation model includes initial conditions, boundary conditions and external loads. Specifically: ① Initial conditions: under the action of high internal pressure, local cracks are generated in the surrounding rock, and there is a cross-crack area between the steel plate and the surrounding rock-structure. ② External load and boundary condition: take the local cross-crack calculation section of the steel plate, in the pressurization stage, the steel plate expands outward, and the steel plate element is subjected to tension on both sides of the steel plate, while the steel plate is subjected to internal pressure on the free side during the operation stage. The steel plate is vertically constrained on the side in contact with the surrounding rock, and the other sides are free.

[0043] S52: Determine the boundary conditions for cross-crack calculation, the steel plate is vertically constrained on the side in contact with the surrounding rock-structure, and the free side of the steel plate and the disengagement range of the steel plate from the surrounding rock are both free surfaces;

[0044] S53: Determine the external load for cross-crack calculation, in the pressurization stage, the steel plate expands outward, and the steel plate element is subjected to tension on both sides of the steel plate, and the tension size can be determined according to the stress characteristics of the steel plate in actual engineering, while the steel plate is subjected to internal pressure on the free side during the operation stage. Take the maximum operating internal pressure acting on the free side of the steel plate;

[0045] S6: Calculate the ultimate strain of the sealing steel plate under short-term and long-term operation conditions respectively;

[0046] S61: According to the above content, the maximum principal strain of the steel plate in the cross-crack calculation under short-term operation stage (the steel plate is relatively complete in shape, and the thickness is the design thickness t) and long-term operation stage (the thickness t1 of the steel plate after corrosion under the action of external environment) is calculated; take the larger value as the ultimate strain ε0 of the steel plate, and the calculated ε0 should be less than the yield strain ε y , otherwise adjust the thickness t until the thickness t meets the requirements;

[0047] S7: Calculate the fatigue durability of the steel plate thickness under the above conditions, calculate the fatigue performance of the steel plate within the specified operation period by using the allowable stress amplitude method, and finally the steel plate thickness needs to meet the requirements of cross-crack calculation and durability calculation;

[0048] S71: According to the design stable operation life m of the gas storage, the cycle number n of the steel plate is determined, the fatigue performance of the steel plate is calculated according to the relevant provisions of the fatigue analysis of the steel structure design standard GB 50017-2017, the stress is calculated according to the elastic state, the constant amplitude fatigue of the stress cycle inner stress amplitude is kept constant, and the calculation is as follows:

[0049] Δδ≤γ t [Δσ]

[0050] Wherein, Δδ is the fatigue durability, γ t is the thickness or diameter correction coefficient of the sealing steel plate, Δσ = σ max -σ min , σ max and σ min are the maximum stress and minimum stress (MPa) in the stress cycle of the calculation part of the sealing steel plate, respectively;

[0051] S72: Δσ can be calculated according to the numerical value, or can be estimated according to the following formula:

[0052]

[0053] Wherein, p max and p min are the maximum gas pressure design value and minimum gas pressure design value (N / mm 2 ) of the gas storage in the operation stage, respectively, r is the inner radius of the sealing steel plate (mm), K0 is the unit elastic resistance coefficient of surrounding rock (N / mm 3 ), v s is the Poisson's ratio of the sealing steel plate, E s is the elastic modulus of the steel plate (N / mm 2 ), and t is the thickness of the sealing steel plate;

[0054] S73: [Δσ] is the allowable stress amplitude (MPa) of constant amplitude fatigue, which is calculated as follows:

[0055] When n < 5 x 10 6 ,

[0056]

[0057] When 5 x 10 6 ≤ n ≤ 1 x 10 8 ,

[0058]

[0059] When n ≥ 1 x 10 8 ,

[0060]

[0061] where n is the number of stress cycles, C, β are parameters of the component and connection, Δσ L is the allowable stress, which shall be adopted according to the component and connection category; the specific parameter selection can refer to the Steel Structure Design Standard GB 50017-2017;

[0062] The calculated result shall satisfy: Δδ≤γ t [Δσ], otherwise adjust the thickness t and repeat the S6 and S7 steps until the thickness t meets the requirements.

[0063] The following is a specific embodiment:

[0064] S1, according to the construction scale, capacity, working internal pressure and other engineering characteristics of the gas storage project, the cross-sectional size of the cavern is determined to be a circular cavern with an internal diameter of 20 m and a buried depth of 250 m, and the arrangement form is a flat hole type;

[0065] S2, the crack width of the surrounding rock-structure under the most unfavorable working condition is determined by numerical methods and the like; specifically including: according to continuous and discontinuous calculation analysis, under the most unfavorable working condition analysis, under the action of the self-weight stress field of 250 m buried depth, the maximum crack width of the surrounding rock-structure under the condition of grade III surrounding rock is 1.48 mm; considering the calculation error and the non-uniformity of crack propagation, the crack width of grade III surrounding rock is considered to be 3 mm;

[0066] S3, the sealing steel plate is selected to be Q460R, and the thickness is temporarily determined to be 8 mm; according to the stress-strain characteristics of Q460R, the yield strain ε y is 2.05‰;

[0067] S4, the operation life m of the gas storage is 50 years, according to the consideration of grade III light corrosion type in the Technical Specification for Corrosion Prevention of Steel Structures in Buildings, the corrosion rate v is taken as 0.05 mm / a, and the maximum corrosion amount within the operation period of 50 years is 2.5 mm, the corrosion amount t0 of 50 years is considered to be 3 mm, and the corrosion allowance t1 of the steel structure is 5 mm;

[0068] S5: according to the crack width, steel plate type, internal pressure size and other parameters, a sealing steel plate across the crack calculation model is established as shown in Figure 1 ;

[0069] S5 specifically includes:

[0070] S51: a calculation model is established according to the local section of the steel plate across the crack as shown in Figure 2As shown in the figure; under the action of high internal pressure, the surrounding rock produces local cracks, it is assumed that there is a 3mm crack between the 8mm / 5mm steel plate (for short-term operation stage and long-term operation stage, respectively) and the surrounding rock-structure; the transverse (x), vertical (z), and longitudinal (y) length of the model are as follows: the steel plate thickness is 8mm / 5mm, the transverse length of the model is preferably 21w, i.e. 63mm, i.e. 30mm on both sides of the crack width, and it is experienced that the size effect can be eliminated within this range; the model vertical is 8mm / 5mm, and the longitudinal length is 8mm / 5mm;

[0071] S52: Determine the boundary conditions of the crack calculation, the contact side of the steel plate and the surrounding rock-structure is vertically constrained by the surrounding rock, and the free side of the steel plate and the disengagement range of the steel plate and the surrounding rock-structure are free surfaces;

[0072] S53: Determine the external load of the crack calculation, in the pressurization stage, the steel plate expands outward, the steel plate unit is subjected to tension on both sides of the steel plate, in order to ensure that the steel plate is in the elastic stage, the tension is half of the yield strength of Q460R steel, and the yield strength of Q460R steel is 410MPa according to the steel structure design standard, and the calculation is 205MPa; At the same time, the free side of the steel plate is subjected to the internal pressure action of the operation stage, which is 18MPa;

[0073] S6: Calculate the ultimate strain of the sealing steel plate under the short-term operation condition and the long-term operation condition, respectively;

[0074] S6 specifically includes:

[0075] S61: Perform crack checking of the steel plate in the short-term operation stage (the steel plate is relatively complete in shape and the thickness is the design thickness of 8mm), as shown in the figure, the maximum principal strain of the steel plate is 0.929‰; Figure 3

[0076] S62: Perform crack checking of the steel plate in the long-term operation stage (the steel plate corrodes under the action of the external environment and the thickness is 5mm), as shown in the figure, the maximum principal strain of the steel plate is 1.097‰; Figure 4

[0077] S63: According to the calculation results of S61 and S62, the ultimate strain of the sealing steel plate in the short-term operation stage and the long-term operation stage is less than 2.05‰, so the steel plate is in the elastic stage; Therefore, the local crack of the steel plate will not cause the plastic state of the steel plate, and the sealing property of the gas storage can be guaranteed;

[0078] S7: Calculate the fatigue durability of the steel plate thickness;

[0079] S7 specifically includes:

[0080] ​​S71: The designed stable operation period of the underground gas storage is not less than 50 years, about 18,000 times of charging and discharging cycles will be carried out in the whole operation period, and about 18,000 times of stress changes will occur in the steel plate, which belongs to low cycle fatigue; therefore, the cycle number N of the steel plate is 2x104;

[0081] S72: According to the characteristics of the project, the gas pressure in the daily charging and discharging stage is maintained between 8-18 MPa, and the maximum radial stress change Δσ of the steel plate is 290 MPa through numerical calculation;

[0082] S73: According to the relevant provisions of the fatigue analysis in the Steel Structure Design Standard GB 50017-2017, the fatigue performance of the steel plate is calculated by using the allowable stress amplitude method, the stress is calculated according to the elastic state, and the constant amplitude fatigue of the stress amplitude in the stress cycle is kept constant, and the calculation is as follows:

[0083] Δδ≤γ t [Δσ]

[0084] Where Δδ is the fatigue durability, γ t is the thickness or diameter correction coefficient of the sealing steel plate, which is 1.0 in the embodiment; [Δσ] is the allowable stress amplitude (MPa) of constant amplitude fatigue, and since N<5x106, it can be calculated as follows:

[0085]

[0086] Where n is the stress cycle number, C and β are the parameters of the component and connection, the steel plate component in this paper can be selected according to the "main metal without connection" in the specification, and the conservative category is selected, C=861x1012, and β=4;

[0087] S74: The allowable stress amplitude [Δσ] of the steel plate is 541.69 MPa; according to the stress calculation results of the steel plate under long-term operation conditions, the condition Δδ≤γ t [Δσ] is met, so the steel plate meets the fatigue requirement from the stress fatigue analysis.

[0088] Please refer to Figure 5 , Figure 6 , Figure 7 and Figure 8The embodiment of the present application provides a telescopic joint 1 of a sealing steel plate 4 of an underground gas storage, which comprises a first connecting section 10, a telescopic section 11 and a second connecting section 12 connected in sequence, the telescopic section 11 has a first end 110, a middle end 111 and a second end 112, the first end 110 is connected with the first connecting section 10, the second end 112 is connected with the second connecting section 12, a section from the first end 110 to the middle end 111 and a section from the second end 112 to the middle end 111 are arc sections, and at least the telescopic section 11 is a deformation section. In the embodiment, the arc sections can be telescopic, which can effectively allow the sealing steel plate 4 to freely telescope with the change of pressure, so as to fully adapt to the deformation caused by high internal pressure, avoid the sealing steel plate 4 entering the elastic-plastic state due to long-term bearing of high pressure, and further avoid the risk of sealing failure. Considering the sensitivity of steel to temperature field, especially in a high temperature environment, the steel is prone to thermal expansion effect, which causes the deformation amount of the sealing steel plate 4 to abnormally increase, the design of the annular longitudinal telescopic joint 1 can effectively reduce the deformation of the sealing steel plate 4 caused by temperature change, and ensure that the overall structural stability and sealing performance of the gas storage are not affected; in actual application, the deformation of the sealing steel plate 4 is not only affected by internal pressure, but also affected by the superposition of temperature change, the annular longitudinal telescopic adjuster can comprehensively consider the double factors of internal pressure and temperature, and ensure that the sealing steel plate 4 always remains within the elastic state, which can prevent the sealing steel plate 4 from being deformed too much, and at the same time ensure the long-term safe operation of the gas storage. Specifically, the telescopic section 11 is a deformation section, when the sealing steel plate 4 acts, the deformation section of the adjacent two sealing steel plates 4 can be deformed, so as to ensure that the overall structural stability and sealing performance of the gas storage are not affected. The first connecting section 10 and the second connecting section 12 can also have a deformation amount, and the three can cooperate to make the deformation range larger and the overall structural stability better. The arc sections can facilitate deformation. Preferably, the two arc sections have a gap 13, which can have a movable allowance. Preferably, the first connecting section 10, the telescopic section 11 and the second connecting section 12 are an integral forming structure, which can improve the stability of the structure. Preferably, the two arc sections are symmetrically arranged, and the lengths of the two arc sections can also be the same. Preferably, the first connecting section 10, the telescopic section 11 and the second connecting section 12 all have ductility.

[0089] Please refer to Figure 5 、 Figure 6 、 Figure 7 and Figure 8 The embodiment of the present application provides a method for preventing the sealing steel plate of the underground gas storage from being deformed too much, which specifically comprises the following steps:

[0090] S1: determining the allowable deformation of the sealing steel plate under the action of internal pressure;

[0091] S11: According to the steel material used for compressed air energy storage underground gas storage, the elastic stage limit strain rate ε of the sealing steel plate is determined n ;

[0092] S12: The diameter D of the gas storage is determined, and the top displacement x1 and the bottom displacement x2 of different surrounding rock grades under the action of the internal pressure P of the gas storage are calculated, and then the maximum strain ε of the sealing steel plate can be calculated max1 . If ε max1 < ε n , the steel plate of the surrounding rock grade can adapt to the deformation; if ε max1 ≥ ε n , it indicates that the expansion adjuster needs to be set in the sealing steel plate to release the deformation

[0093]

[0094] Wherein x1 is the top displacement of different surrounding rock grades, x2 is the bottom displacement of different surrounding rock grades, and D is the diameter of the gas storage

[0095] S2: High temperature effect thermal expansion effect

[0096] S21: For steel material affected by temperature field, the temperature load effect needs to be superimposed. The temperature peak T max and T min of the sealing steel plate are calculated under the external high temperature environment in the operation cycle. It needs to be explained that the temperature peak only reaches the peak value when the gas filling operation is carried out, and the temperature of the sealing steel plate will drop to the ambient temperature when the release or exhaust maintenance is carried out

[0097] S22: The strain ε max2 of the sealing steel plate generated under the temperature change is calculated. If ε max2 < ε n , it indicates that the temperature stress generated can offset the tensile stress of the inner liner steel plate under the action of the internal pressure, and the temperature stress effect does not need to be considered in the ring direction of the inner liner steel plate; if ε max2 ≥ ε n , it indicates that the temperature stress generated is large and cannot offset the tensile stress of the inner liner steel plate under the action of the internal pressure, and the temperature stress effect needs to be considered in the ring direction of the inner liner steel plate, and the expansion adjuster needs to be set in the ring direction to release the deformation

[0098] ε max2 = αΔt

[0099] Wherein α is the thermal expansion coefficient of the material of the sealing steel plate, and Δt is the temperature change of the sealing steel plate, Δt = T max -T min , wherein T maxT is the maximum temperature of the sealing steel plate min T is the minimum temperature of the sealing steel plate

[0100] S3: ring longitudinal expansion joint adjusting device considering the effect of internal pressure and temperature expansion;

[0101] S31: ring direction: through the analysis of the strain of the sealing steel plate under the effect of internal pressure and temperature, the setting of the ring expansion joint 1 for different surrounding rock grades is obtained, and then the total expansion of the ring expansion joint 1 is calculated;

[0102] S32: ring direction: according to the total expansion and the deformation distribution characteristics of the gas storage cavern, the number of ring expansion joints 1 to be set is determined;

[0103] S33: longitudinal direction: according to the deformation distribution characteristics of the gas storage cavern, the number of longitudinal deformation joints to be set is determined;

[0104] S34: the expansion adjusting device is formed by cold bending of steel plate, when there is no ring expansion joint, the expansion adjusting device is located in the middle of the steel plate and is distributed in the shape of "I"; when there is a ring expansion joint, the ring longitudinal expansion adjusting device is cross arranged and is distributed in the shape of "X". The adjusting device is set in the direction of the pressure source, the adjusting device is the free end, and the adjusting device is designed according to the deformation.

[0105] The following is a specific embodiment:

[0106] S1: allowable deformation of the sealing steel plate under the effect of internal pressure;

[0107] S11: it is determined that the steel material used in the project is Q460R, and in order to ensure the sealing stability, the corresponding elastic stage limit strain rate is 2.05‰;

[0108] S12: the diameter D of the gas storage cavern is determined, under the effect of the internal pressure of 18 MPa of the gas storage cavern, the top displacement of 18 mm and the bottom displacement of 18 mm for different surrounding rock grades are calculated, and then the maximum strain of the sealing steel plate for the II and III surrounding rock grades is calculated by the following formula respectively as 2.02‰ and 4.46‰. Therefore, the steel plate for the II surrounding rock grade can adapt to the deformation, and the expansion adjusting device is needed for the III surrounding rock grade to release the deformation;

[0109]

[0110] S2: thermal expansion effect of high temperature;

[0111] S21: For steel material is greatly affected by temperature field, need to superimpose temperature load effect. In the external high temperature environment in the operating cycle, the calculation of the sealed steel plate temperature peak value is 55℃ and 26℃, it needs to be explained that the temperature peak value only reaches the peak value when the gas filling operation is carried out, when the release or exhaust maintenance is carried out, the temperature of the sealed steel plate will drop to the ambient temperature.

[0112] S22: Calculate the strain of the sealing steel plate in the temperature change under the ring longitudinal direction 0.42‰, because the temperature stress and the tensile stress of the inner lining steel plate under the action of internal pressure offset, so the inner lining steel plate ring does not need to consider the influence of temperature stress, but the longitudinal direction needs to set temperature expansion joint for deformation release because of the constraint effect of wall behind asphalt slip layer;

[0113] ε max2 = α Δt = 1.2 × 10 -5 × 35 = 0.42‰

[0114] Wherein α is the thermal expansion coefficient of the material of the sealing steel plate, Δt is the temperature change of the sealing steel plate;

[0115] S3: Comprehensive internal pressure deformation and temperature expansion influence of ring longitudinal expansion regulator;

[0116] S31: Ring: through the analysis of the strain of the sealing steel plate under the action of internal pressure and temperature alone, it is obtained that the II grade surrounding rock does not need to set ring expansion joint 1; the total expansion of III grade surrounding rock expansion joint 1 is 2.5‰, and the total expansion amount is 157mm;

[0117] S32: Ring: the limit expansion elongation of each joint is 40mm, through the total expansion amount of ring expansion joint 1, it is calculated that 4 ring expansion joints 1 need to be set;

[0118] S33: Longitudinal: set a deformation joint every 200m;

[0119] S34: Expansion regulator adopts cold bending prefabrication of steel plate, when there is no ring expansion joint, expansion regulator is located in the middle of steel plate, and is distributed in "I" shape; when ring expansion joint is set, ring longitudinal expansion regulator is cross arranged, and is distributed in "X" shape, regulator is set in the direction of pressure source, regulator is free end, and is designed according to deformation amount. According to the processing precision of steel, transportation and splicing welding process requirement, the length of steel ring longitudinal direction is 4m, and the steel plate is divided into 6 blocks every ring, and the length of steel plate is about 10.4m. As follows. Figures 6 to 8

[0120] Please refer to Figures 1 to 8 ​The underground gas storage provided by the embodiments of the present application comprises the sealing steel plate and the expansion joint 1. The sealing steel plate is obtained by using the method for designing the thickness of the sealing steel plate of the underground gas storage. The expansion joint 1 is obtained by using the expansion joint 1 in the embodiments of the expansion joint 1 and the method for preventing the excessive deformation of the sealing steel plate of the underground gas storage. Specifically, two adjacent sealing steel plates are connected to the first connecting section and the second connecting section respectively. The underground gas storage further comprises a sliding layer 2 arranged between the concrete and the expansion joint 1.

[0121] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An underground gas storage comprising a sealed steel plate, characterized in that: The expansion joint comprises a first connecting section, an expansion section and a second connecting section connected in sequence, the expansion section has a leading end, a middle end and a tail end, the leading end is connected with the first connecting section, the tail end is connected with the second connecting section, a section from the leading end to the middle end and a section from the tail end to the middle end are both arc sections, at least the expansion section is a deformation section, two sealing steel plates adjacent to the deformation section are respectively connected on the first connecting section and the second connecting section, and the circumferential expansion joint arranged in a circumferential direction and the longitudinal expansion joint arranged in a longitudinal direction are adopted in combination with the internal pressure of the gas storage and the external high-temperature environment.

2. The underground gas storage reservoir of claim 1, wherein: The two arc sections have a gap therebetween.

3. The underground gas storage reservoir of claim 1, wherein: The first connecting section, the expansion section and the second connecting section are integrally formed.

4. The underground gas storage reservoir of claim 1, wherein: A slip layer is further arranged between the concrete and the expansion joint.

5. A method of preventing excessive deformation of a containment steel plate of an underground gas storage according to any one of claims 1 to 4, characterized in that The method comprises the following steps: Under the condition that the sealed steel plate bears the pressure in the gas storage, the maximum strain of the sealed steel plate is obtained , if , a telescopic joint of the sealed steel plate is set, wherein is the elastic stage limit strain rate of the sealed steel plate Under the condition that the sealing steel plate bears an external high-temperature environment, the maximum strain of the sealing steel plate generated under temperature change is obtained , if , then a telescopic joint of the sealing steel plate is set, wherein is an elastic stage limit strain rate of the sealing steel plate The circumferential expansion joint arranged in a circumferential direction and the longitudinal expansion joint arranged in a longitudinal direction are adopted in combination with the internal pressure of the gas storage and the external high-temperature environment.

6. The method of claim 5, wherein: The maximum strain of the sealed steel plate The calculation formula is as follows: ； Wherein x1 is the top displacement of different surrounding rock grades, x2 is the bottom displacement of different surrounding rock grades, and D is the diameter of the gas storage.

7. The method of claim 5, wherein: The maximum strain generated by the sealing steel plate under temperature change The calculation formula is as follows: ； wherein is the coefficient of thermal expansion of the material of the sealing steel sheet, is the temperature change of the sealing steel sheet, wherein is the high peak value of the temperature of the sealing steel sheet, is the low peak value of the temperature of the sealing steel sheet.

8. The method of claim 5, wherein: Through the strain analysis of the sealing steel plate under the influence of the internal pressure and the temperature of the gas storage, the setting condition of the circumferential expansion joint of different surrounding rock grades is obtained, and the total expansion amount of the circumferential expansion joint is calculated; According to the total expansion amount and the distribution characteristics of the circumferential deformation of the gas storage chamber, the number of circumferential expansion joints to be arranged is determined; According to the distribution characteristics of the longitudinal deformation of the gas storage chamber, the number of longitudinal deformation joints to be arranged is determined.

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