A Parameter Optimization Method for Compressed Air Energy Storage Salt Cavern System under Adiabatic Conditions

Abstract

This invention discloses a parameter optimization method for a compressed air energy storage salt cavern system under adiabatic conditions, belonging to the technical field of compressed air energy storage system engineering design. The method includes the following steps: analyzing the power grid demand and calculating the target total power generation; determining the feasible domain of geological safety pressure and pre-setting the operating pressure range of the salt cavern system; introducing a simplified adiabatic venting model and back-calculating the salt cavern volume of the salt cavern system, and calculating the total mass of air released by the salt cavern system and related parameters of the turbine and compressor, and making preliminary selection of compressor and turbine based on the calculation results; constructing a dynamic model describing the pressure decay of the salt cavern system as mass flows out, and calculating the actual power generation per unit volume of the salt cavern system and the actual total energy release of the salt cavern system; setting power generation matching and multi-constraint verification rules and a hierarchical iterative optimization mechanism to obtain the optimal design parameters. This invention achieves efficient matching of system parameters and improves design reliability by coupling the calculation of various design parameters.

Description

Technical Field

[0001] This invention relates to the field of compressed air energy storage system engineering design technology, specifically to a method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions. Background Technology

[0002] Compressed air energy storage, due to its large scale, long lifespan, and low environmental dependence, has become one of the key supporting technologies for building new power systems and solving the problem of renewable energy consumption. Among them, salt caverns formed by water dissolution in deep underground salt rock layers are used as air storage containers. They have excellent creep characteristics, damage self-healing ability, and extremely high sealing performance, making them the preferred solution for high-pressure air storage. However, existing compressed air energy storage salt cavern gas storage technologies suffer from the following problems in design: First, traditional design methods often use isothermal or quasi-static assumptions to estimate energy density, neglecting the nonlinear pressure decay with mass outflow during adiabatic venting and the impact of gas temperature drop on work capacity. This leads to overly optimistic energy density estimates and mismatches between turbine and compressor equipment selection and actual output. Second, geological safety assessment and thermal system design are disconnected. The operating pressure range of the salt cavern is determined solely based on geomechanics, without considering the coupled effects of turbine variable operating efficiency, pipeline losses, and afterburning parameters on effective production capacity. This easily results in insufficient geological safety margins or equipment operating in inefficient zones. Third, existing design processes lack a systematic parameter optimization mechanism, relying heavily on trial and error, making it difficult to efficiently coordinate the nonlinear constraints between pressure boundaries, geological parameters, equipment selection, and salt cavern volume. Therefore, improvements to the design technology of compressed air energy storage salt cavern gas storage are urgently needed.

[0003] To address the aforementioned technical problems in the design of compressed air energy storage salt caverns, Chinese patent application CN121809890A discloses a method for optimizing the operating pressure and storage capacity of compressed air energy storage salt caverns. This method achieves an optimal balance between energy storage density, economy, and safety by establishing a multi-parameter coupled optimization model that comprehensively considers geological conditions, equipment performance, and safety standards. However, this patented solution cannot perform equipment selection and storage capacity estimation based solely on grid demand and geological conditions. It requires directly estimating the storage capacity under known equipment parameters, which may lead to mismatches between equipment parameters and energy storage requirements in practical applications. Furthermore, this solution lacks a dynamic feedback mechanism between geomechanical boundaries, thermal equipment characteristics, and energy storage demand indicators during the storage capacity optimization process. It fails to form a hierarchical iterative closed-loop optimization logic, making it difficult to simultaneously achieve a multi-objective balance between geological safety, equipment efficiency, and energy storage requirements. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a method for optimizing the parameters of a compressed air energy storage salt cavern system under adiabatic conditions.

[0005] The technical solution adopted in this invention is as follows: A method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions, comprising the following steps: S1. Analyze the power grid demand, determine the basic parameters of the power grid according to the power grid peak-shaving dispatch instructions, and calculate the target total power generation. S2. Obtain key geological parameters of salt rock and determine the feasible domain of geological safety pressure based on the mechanical properties of salt rock. S3. Within the feasible geological safety pressure range, the operating pressure range of the salt cavern system is preset. S4. Introduce a simplified model of adiabatic venting of the salt cavern system, and back-calculate the salt cavern volume of the salt cavern system based on the operating pressure range of the salt cavern system and the target total power generation. S5. Based on the operating pressure range, volume, and inflation / deflation time of the salt cavern system, calculate the total mass of air released by the salt cavern system, the required mass flow rate and output power of the turbine, and the required mass flow rate and input power of the compressor. Based on the calculation results, make a preliminary selection of the compressor and turbine, and record the equipment parameters of the selected compressor and turbine. S6. Based on the principles of unsteady aerodynamics and engineering thermodynamics under adiabatic conditions, a dynamic model describing the pressure decay of the salt cavern system as mass flows out is constructed. The gas release process is solved by integral calculation in combination with the operating pressure range of the salt cavern system and the initially selected equipment parameters of the compressor and turbine to obtain the actual power generation per unit volume of the salt cavern system and the actual total energy release of the salt cavern system. S7. Set the capacity matching and multiple constraint verification rules. If the verification passes, output the design parameters of the salt cave system, including the salt cave volume and operating pressure range of the salt cave system, and the equipment parameters of the compressor and turbine. If the verification fails, construct the sensitivity matrix of the design parameters to the actual power generation per unit volume of the salt cave system, set the correction order of the design parameters, perform step-by-step correction on each design parameter according to the correction order, and recalculate the actual total energy release of the salt cave system until the verification passes.

[0006] Furthermore, in step S1, the following basic parameters need to be determined according to the power grid peak-shaving dispatch instruction: duration of off-peak period. This refers to the continuous inflation time allowed by the power grid; peak period duration. This refers to the time required by the power grid for continuous gas release for power generation; the target power generation capacity. This refers to the output power of the salt cavern system under rated operating conditions; the target power generation time. Its duration is consistent with the peak period. The inflation and deflation times of the salt cavern system are determined based on the duration of the power grid's off-peak and peak periods, with the inflation duration being... satisfy: Deflating time satisfy: .

[0007] Furthermore, the target total electrical energy generated in step S1 for: .

[0008] Furthermore, the maximum working pressure within the feasible geological safety pressure range determined in step S2. for: ; Minimum working pressure in the feasible region of geological safety pressure for: ; Geological ultimate pressure ratio for: ; in, This represents the vertical stress of the original rock at the depth where the salt cave is located, and , The average density of the overlying rock strata. The depth at which the geometric center of the salt cavern is located. It is the acceleration due to gravity. To ensure a safety factor against breakage, This is the creep resistance safety factor.

[0009] Furthermore, the operating pressure range of the salt cavern system in step S3 includes the maximum and minimum operating pressures of the salt cavern system. The maximum operating pressure of the salt cavern system... for: ; Minimum operating pressure of salt cavern system for: ; The operating pressure ratio of the salt cavern system is: ; in, This is the maximum working pressure adjustment coefficient for the salt cavern system, and ; This is the minimum operating pressure adjustment coefficient for the salt cavern system, and ; Must meet .

[0010] Furthermore, the simplified model for adiabatic venting of the salt cavern system established in step S4 is as follows: ; in, This is an estimated value for the electricity generated per unit volume of the salt cavern system. The variable index for gas release from salt caverns. Estimated overall efficiency of salt cavern system; Based on the estimated power generation per unit volume of the salt cavern system, the volume of the salt cavern can be calculated by reverse engineering. for: .

[0011] Furthermore, in step S5, the total mass of air released by the salt cavern system for: ; in, The gas constant is The temperature of the salt cavern gas at the minimum operating pressure. The temperature of the salt cavern gas at maximum working pressure; mass flow rate of turbine for: ; Single-stage turbine output power for: ; The output power of a multi-stage turbine is calculated separately for each turbine stage and then summed. in, This refers to the isobaric specific heat capacity under standard atmospheric pressure. This refers to the turbine inlet temperature. This refers to the turbine outlet temperature. For turbine mechanical efficiency, For generator efficiency; compressor mass flow rate for: ; compressor input power The calculation is performed using an isentropic compression model, namely: ; in, This refers to the compressor inlet temperature. This refers to the compressor outlet temperature. This refers to the isentropic efficiency of the compressor.

[0012] Furthermore, the dynamic model established in step S6 regarding the pressure decay of the salt cavern system as mass flows out is an energy density calculation model, expressed as: ; in, For the salt cavern system in Instantaneous pressure at any moment This refers to the air density inside the salt cavern. Introducing the interstage efficiency coupling coefficient of turbines Interstage enthalpy drop distribution coefficient Ideal expansion term and back pressure loss term Analytical solution of the energy density calculation model for the salt cavern system: Turbine stage efficiency coupling coefficient for: ; in, This refers to the isobaric specific heat capacity at the outlet pressure of the low-pressure stage turbine. This refers to the inlet temperature of the low-pressure stage turbine. Air-fuel ratio; Interstage enthalpy drop distribution coefficient for: ; in, This refers to the isobaric specific heat capacity at the inlet pressure of the high-pressure stage turbine. This refers to the isobaric specific heat capacity at the outlet pressure of the low-pressure stage turbine. This refers to the inlet temperature of the high-pressure stage turbine. This refers to the inlet temperature of the low-pressure stage turbine. This refers to the inlet pressure of the high-pressure stage turbine. The outlet pressure of the low-pressure stage turbine. The thermal insulation index of the high-pressure stage turbine; Ideal expansion term for: ; Back pressure loss term for: ; in, For turbine back pressure, This is the pipeline pressure loss coefficient. The thermal insulation index for low-pressure turbines; Actual electricity generated per unit volume of salt cavern system for: ; The actual total energy released by the salt cavern system is: ; in, This is the molar mass of air.

[0013] Furthermore, the capacity matching rule set in step S7 is: when At the same time, it meets the capacity matching requirements; The multi-constraint verification rules set in step S7 include: Geological safety constraint verification: During the entire venting process, the salt cavern system... Instantaneous pressure at any moment The following must always be satisfied: ,and ; At the same time, geological safety constraints also need to be met: ; ; in, This sets a new upper limit for the operating pressure of salt cavern systems. This sets a new lower limit for the operating pressure of salt cavern systems. The maximum allowable outlet pressure of the compressor. This is the minimum allowable inlet pressure for the turbine. Equipment constraint verification includes the turbine minimum intake pressure constraint and the compressor exhaust pressure constraint; the turbine minimum intake pressure constraint is: ; in, This is the minimum allowable inlet pressure for the turbine. Compressor discharge pressure constraints: ; Energy balance constraints: ; in, For the salt cavern system in Instantaneous power generation at any given moment; Convergence constraints: ; in, For the number of iterations, For the first The salt cavern volume calculated in the next iteration. For the first The salt cave volume calculated in the next iteration, and The convergence threshold is set to a value of 0.005 to 0.1.

[0014] Furthermore, in step S7, when the verification fails, the sensitivity of the influence of each design parameter on the actual power generation per unit volume is analyzed, and the optimization order of each design parameter is determined in combination with the actual engineering situation; after the optimization order of each design parameter is determined, iterative optimization is performed according to the priority order until the verification passes. The optimization order for each design parameter is as follows: The first priority is to adjust the operating pressure range of the salt cavern system, including increasing the maximum working pressure. and reduce minimum working pressure ; The second priority is adjusting geological parameters, including adjusting the depth of the geometric center of the salt cavern. Adjusting the fracture resistance safety factor or creep resistance safety factor ; The third priority is adjusting pipeline parameters, equipment parameters, and inflation / deflation time, including adjusting the pipeline pressure loss coefficient. air-fuel ratio Turbine stage pressure ratio Turbine stage number, turbine and compressor equipment efficiency, and salt cavern system charging time; The fourth priority is adjusting the salt cavern volume parameters, including increasing the salt cavern volume. .

[0015] The beneficial effects of this invention are as follows: (1) This invention proposes a parameter optimization method for compressed air energy storage salt cavern system under adiabatic conditions, which breaks down the professional barriers between geological engineering and thermal engineering, incorporates geomechanical boundaries, fluid mechanical properties and thermodynamic cycles into a unified mathematical optimization framework, and couples the calculation of various design parameters to realize the equipment selection and storage capacity estimation of salt cavern system based only on power grid demand and geological conditions. At the same time, it effectively avoids the geological safety risks or equipment performance mismatch problems that may be caused by traditional single-perspective design, and improves the design reliability. (2) In the parameter optimization process, the present invention introduces an analytical calculation model under adiabatic process. Compared with the traditional isothermal estimation method, it can more accurately capture the impact of pressure fluctuation on the storage volume of salt cavern system, greatly reduce the theoretical error of energy estimation, and adapt to the peak shaving needs of different power grid scenarios. (3) In the parameter optimization process, this invention introduces capacity matching rules and multiple constraint verification rules, and establishes a dynamic feedback mechanism between geomechanical boundaries, thermal equipment characteristics and energy storage demand indicators. It also uses sensitivity analysis strategy to perform hierarchical iterative optimization of pressure boundaries, geological parameters and equipment parameters to ensure that the storage volume of the salt cavern system can meet the power grid demand. At the same time, it also solves the technical problem that safety, functionality and economy are difficult to balance in the traditional design process. Attached Figure Description

[0016] Figure 1 This is a flowchart of the present invention; Figure 2 This is a flowchart illustrating the verification and optimization of various design parameters in this invention; Figure 3 This is the pressure change curve obtained by iterative optimization using the first priority scheme in Embodiment 1 of the present invention; Figure 4 This is a surface showing the change in salt cavern volume with the maximum working pressure and pressure ratio of the salt cavern system in Embodiment 2 of the present invention. Detailed Implementation

[0017] This invention provides a method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions. To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0018] This embodiment provides a method for optimizing the parameters of a compressed air energy storage salt cavern system under adiabatic conditions. The specific implementation steps are as follows.

[0019] S1. Analyze the power demand of the power grid, determine the basic parameters of the power grid according to the power grid peak-shaving dispatch instructions, and calculate the target total power generation.

[0020] Specifically, this step requires determining the following basic parameters based on the power grid peak-shaving dispatch instructions: duration of off-peak periods. (h) refers to the continuous inflation time allowed by the power grid; peak period duration. (h) refers to the time during which the power grid requires continuous gas release for power generation; the target power generation capacity. (MW) refers to the output power of the salt cavern system under rated operating conditions; target power generation time. (h), which is consistent with the duration of the peak period.

[0021] Based on the aforementioned power grid parameters, the target total electrical energy generation is calculated as follows: (1).

[0022] In addition, regarding the inflation and deflation time of the salt cavern system, its inflation duration... satisfy: Deflating time satisfy: For preliminary estimation, the following can be taken: , .

[0023] S2. Obtain key geological parameters of salt rock and determine the feasible domain of geological safety pressure based on the mechanical properties of salt rock.

[0024] Specifically, this step requires first conducting a geological survey of the target salt cavern mining area and obtaining relevant key geological parameters from the geological survey report, including: the geometric center depth of the salt cavern. That is, the vertical depth of the center of the salt cavern from the Earth's surface; the average density of the overlying rock strata. This refers to the weighted average density of all strata rocks from the surface to the top of the salt cavern, typically ranging from 2300 to 2600 kg / m³ in engineering applications. 3 ).

[0025] Based on the determination of the aforementioned key geological parameters, the feasible region for geological safety pressure is calculated according to the mechanical properties of salt rock geology. The specific steps are as follows: Based on rock mechanics principles, the pressure of the overlying strata and the vertical stress of the original rock at the depth where the salt cave is located are calculated. (Geostatic pressure, unit Pa) is: (2); in, The density is the average density of the overlying rock strata, expressed in kg / m³. The depth of the geometric center of the salt cavern, in meters; m / s² is the acceleration due to gravity. This pressure represents the vertical principal stress of the formation in an undisturbed state and is the benchmark for judging the pressure-bearing capacity of salt caverns; The maximum permissible working pressure in geology is calculated based on the hydraulic fracturing criterion in rock mechanics. (Upper limit for fracture resistance) When the minimum principal stress of the salt cavern surrounding rock exceeds the tensile strength of the surrounding rock, tensile failure of the surrounding rock will occur. Therefore, a fracture resistance safety factor is introduced. Its physical meaning is the ratio of the maximum permissible working pressure to the pressure of the overlying strata. Based on the mechanical properties of salt rock, The value range is 0.80~0.85 (with a certain safety margin). Therefore, the maximum permissible working pressure in the geological conditions is: (3); The minimum permissible working pressure in geology is calculated based on creep failure criteria or strength theories in rock mechanics (such as the Mohr-Coulomb criterion). (Lower limit of creep resistance) When the pressure inside the salt cavern is too low, the deviatoric stress (the difference between the ground stress and the internal pressure) on the surrounding rock becomes too large, which can cause dislocation slippage in the salt rock crystal structure, leading to accelerated creep and even cavity shrinkage. Therefore, a creep resistance safety factor is introduced. Its value ranges from 0.20 to 0.30. Therefore, the minimum permissible working pressure for geological conditions is: (4); The above , It is usually calculated by back-calculating the comprehensive coefficient that ensures the safety level of a certain target (such as a safety factor ≥1.5~3.0) after numerical simulation of triaxial compression test and creep test of indoor salt rock samples combined with geostress data of the target mining area.

[0026] Based on the above-determined maximum and minimum working pressures for geological conditions, the feasible range for geological safety pressure is determined as follows: (5).

[0027] The aforementioned feasible geological safety pressure range serves as the boundary for the operating pressure of the compressed air energy storage salt cavern system.

[0028] Furthermore, based on the aforementioned maximum and minimum permissible working pressures, the geological limit pressure ratio is determined as follows: (6); This ratio, from a geological perspective, limits the theoretically achievable maximum pressure variation range of the salt cavern system and is also one of the determining factors of the theoretical upper limit of energy density.

[0029] S3. Within the feasible range of geological safety pressure, a pre-defined operating pressure range for the salt cavern system is established, and the operating pressure ratio is calculated based on the maximum and minimum working pressures within the operating pressure range.

[0030] Specifically, the principle for presetting the operating pressure range of the salt cavern system in this step is: to avoid the initial design directly touching the geological boundary, resulting in insufficient space for subsequent optimization, within the geologically safe and feasible region. It has a narrower initial operating range and a safety margin.

[0031] The operating pressure range of a salt cavern system includes its maximum and minimum operating pressures. The maximum operating pressure of the salt cavern system... for: (7); in, This is the maximum working pressure adjustment coefficient for the salt cavern system, and , Ensure that the upper limit of the working pressure of the salt cavern system is lower than the maximum working pressure allowed by the geology (fracture-inducing pressure). When the preset working pressure of the salt cavern system is close to the lower limit of the feasible range of geological safety pressure, it is safer but may reduce the energy density. When it is close to the upper limit of the feasible range of geological safety pressure, the energy density is higher but the risk is slightly increased.

[0032] Minimum operating pressure of salt cavern system for: (8); in, This is the minimum operating pressure adjustment coefficient for the salt cavern system, and , Ensure that the lower limit of the operating pressure of the salt cavern system is higher than the minimum geologically permissible operating pressure (creep critical pressure), while also meeting the minimum turbine inlet pressure. Relative to the constraint of minimum working pressure of the salt cavern: , This is the pipeline pressure loss coefficient; if this condition is not met, it needs to be appropriately increased. .

[0033] Based on the determined operating pressure range of the salt cavern system, the operating pressure ratio of the salt cavern system is calculated according to its maximum and minimum working pressures: (9); in, Must meet .

[0034] S4. Introduce a simplified model of adiabatic venting for the salt cavern system, and infer the salt cavern volume based on the operating pressure range of the salt cavern system and the target total power generation.

[0035] Specifically, this step uses a simplified adiabatic venting model that assumes the venting process is a polytropic process and satisfies the following assumptions: The parameters are constant; back pressure (i.e., assumed to be vented into vacuum) and pipeline losses are ignored; turbine stage matching details are ignored; and a system overall efficiency coefficient is introduced. This simplified model is used to approximate the actual loss; it is only used for the initial estimation of salt cavern volume, and the subsequent step S6 will use the complete analytical model for recalculation.

[0036] The simplified model for adiabatic venting described above is as follows: (10); in, This is an estimated value for the electricity generated per unit volume of the salt cavern system. The gas release polytropic index for salt caverns ranges between that of the isothermal and adiabatic indices. It depends on the gas release rate and the heat transfer conditions of the surrounding rock; the faster the gas release, the larger the cavity, and the worse the thermal conductivity of the surrounding rock. The larger; This is a comprehensive efficiency estimate for the salt cavern system, used to offset the combined effects of turbine efficiency, generator efficiency, piping losses, and afterburning gain, with a value ranging from 0.35 to 0.55; additionally, when When the value is between 0.35 and 0.45, it corresponds to a conservative scheme with lower equipment efficiency, no afterburner, and higher pipe loss. When the value is between 0.45 and 0.55, it corresponds to an advanced solution with high-efficiency equipment, supplementary combustion, and low pipe loss.

[0037] Based on the estimated power generation per unit volume of the salt cavern system described above, the volume of the salt cavern can be calculated. for: (11).

[0038] The salt cave volume obtained from the above reverse calculation can be recorded as the initial estimated value of the salt cave volume. This value forms the basis for subsequent matching and precise calculation of parameters for compressor and turbine equipment.

[0039] S5. Based on the operating pressure range, volume, and inflation / deflation time of the salt cavern system, calculate the total mass of air released by the salt cavern system, the required mass flow rate and output power of the turbine, and the required mass flow rate and input power of the compressor. Based on the calculation results, make a preliminary selection of the compressor and turbine, and record the equipment parameters of the selected compressor and turbine.

[0040] Specifically, in this step, the total mass of air released by the salt cavern system is the mass of air released from the salt cavern in a complete venting process, which is calculated based on the gas storage mass or residual gas mass of the salt cavern system under the maximum and minimum operating pressures within the operating pressure range.

[0041] The gas storage mass of the salt cavern system at the maximum operating pressure within the operating pressure range is: (12); The residual gas mass of the salt cavern system at the minimum operating pressure within the operating pressure range is: (13); The total mass of air released by the salt cavern system for: (14); in, The gas constant is expressed in J / kg·K. The temperature of the salt cavern gas at minimum operating pressure, in Kelvin (K). Temperature of the salt cavern gas at maximum operating pressure, in Kelvin (K).

[0042] The temperature of the salt cavern gas at the maximum operating pressure is determined by the final stage discharge temperature of the compressor. If the rated outlet temperature of the selected compressor model is known, it can be used directly; otherwise, it can be estimated using the isentropic compression formula, i.e.: (15); The temperature of the salt cavern gas at the aforementioned minimum operating pressure is determined by the relationship of the adiabatic venting process, namely: (16); in, This refers to the compressor inlet temperature, usually taken as ambient temperature, in Kelvin (K). The compression ratio is... , This is the compressor inlet pressure, usually atmospheric pressure, in Pa. The isentropic efficiency of the compressor (0.80~0.88 is taken in the initial selection). It is the ratio of the specific heat capacity at constant pressure to the specific heat capacity at constant volume.

[0043] average mass flow rate per unit time of turbine for: (17); Turbine output power The output power of a single-stage turbine is calculated using an isentropic expansion model. (For multi-level cases, calculations must be performed at each level followed by summation) The result is: (18); in, The duration of venting in the salt cavern system, in hours; Specific heat capacity at standard atmospheric pressure, expressed in J / kg·K; This refers to the turbine inlet temperature, expressed in Kelvin (K), and is determined by the rated value of the turbine model. Turbine outlet temperature, in Kelvin (K). The mechanical efficiency of the turbine, with a value ranging from 0.95 to 0.98, is used to characterize the degree of mechanical losses in bearings, gearboxes, etc. The generator efficiency is 0.96 to 0.98, which is used to characterize the degree of electromagnetic conversion loss in the generator.

[0044] The turbine outlet temperature mentioned above was calculated using the isentropic expansion formula: (19); in, This is the turbine inlet pressure, and The unit is Pa; This is the pipeline pressure loss coefficient, with a value ranging from 0.85 to 0.95. For the salt cavern system in The instantaneous work pressure at any moment; This refers to the turbine outlet pressure, also known as the turbine back pressure. The pressure is usually taken as 101325 Pa (atmospheres). The isentropic efficiency of the turbine has a value ranging from 0.85 to 0.92.

[0045] average mass flow rate of compressor per unit time for: (20); compressor input power The calculation is performed using an isentropic compression model, namely: (twenty one); in, This is the compressor inlet temperature, in Kelvin (K), usually taken as ambient temperature. The compressor outlet temperature, in Kelvin (K). The isentropic efficiency of the compressor, with a value ranging from 0.80 to 0.88, represents the irreversible loss during the compression process.

[0046] In addition, the compressor outlet temperature mentioned above was calculated using the isentropic compression formula: (twenty two); in, This is the compressor inlet pressure, usually atmospheric pressure, in Pa. The compressor outlet pressure is measured in Pa. The compressor outlet pressure must be matched with or slightly higher than the current pressure of the salt cavern system to achieve effective inflation.

[0047] Based on the calculated turbine mass flow rate and output power, and compressor mass flow rate and input power, compressor and turbine models that meet the flow rate and power requirements are initially selected from the equipment manufacturer's sample, and the rated parameters of the corresponding equipment (including efficiency, temperature, pressure, number of stages, etc.) are recorded for accurate calculation in subsequent steps.

[0048] S6. Based on the principles of unsteady aerodynamics and engineering thermodynamics under adiabatic conditions, a dynamic decay model describing the pressure of the salt cavern system as mass flows out is constructed, which is the energy density calculation model. The gas release process is solved by integration in combination with the operating pressure range of the salt cavern system and the initially selected equipment parameters of the compressor and turbine to obtain the actual power generation per unit volume of the salt cavern system and the actual total energy release of the salt cavern system.

[0049] Specifically, in this step, the dynamic decay model of the salt cavern system pressure with mass outflow is constructed by assuming that the salt cavern venting process follows a polytropic process equation. ( (where the constant is used), then in infinitesimal time... The quality of air flowing out of the salt cavern Changes in salt cavern pressure as a result Satisfy the following expression: (twenty three); in, For the salt cavern system in Instantaneous pressure at any moment This refers to the air density inside the salt cavern. The variability index for gas release from salt caverns ranges between the isothermal index and the adiabatic index.

[0050] Introducing the interstage efficiency coupling coefficient of turbines Interstage enthalpy drop distribution coefficient Ideal expansion term and back pressure loss term The energy density calculation model of the salt cavern system described above is solved analytically.

[0051] The above turbine stage efficiency coupling coefficient for: (twenty four); in, The isobaric specific heat capacity at the outlet pressure of the low-pressure stage turbine, in J / kg·K; The inlet temperature of the low-pressure stage turbine, in K; The air-fuel ratio is the ratio of the mass of fuel entering the turbine to the mass of air output from the salt cavern system to the turbine within the same time period. This is a mass flow rate correction term, reflecting the gain contribution of the mass of afterburning fuel to the total amount of working fluid passing through the low-pressure turbine.

[0052] The above-mentioned inter-stage enthalpy drop distribution coefficient for: (25); in, The isobaric specific heat capacity at the inlet pressure of the high-pressure stage is expressed in J / kg·K. The isobaric specific heat capacity at the outlet pressure of the low-pressure stage, in J / kg·K; The inlet temperature of the high-pressure stage turbine, in K; The inlet temperature of the low-pressure stage turbine is expressed in K, and the inlet temperatures of the high-pressure stage turbine and the low-pressure stage turbine are determined according to the rated values ​​of the selected turbine model. This refers to the inlet pressure of the high-pressure stage turbine. This is the outlet pressure of the low-pressure stage turbine, in Pa. The thermal insulation index of the high-pressure stage turbine; Let be the ideal expansion efficiency function of the high-pressure stage turbine. This is the ratio of the inlet enthalpy values ​​of the high-pressure stage and the low-pressure stage turbines; The higher the value, the higher the proportion of the high-pressure stage turbine in the total power.

[0053] The above ideal expansion term for: (26); The above ideal expansion term describes the gas expansion from pressure within the salt cavern under ideal conditions where the back pressure is absolute vacuum. Expand to All the thermodynamic potential energy released; This term reflects the nonlinear determining effect of pressure ratio on the mass of released gas.

[0054] Back pressure loss term for: (27); in, Turbine back pressure (atmospheric pressure), unit: Pa; The pressure loss coefficient of the pipeline is when The smaller the value, the greater the pipeline resistance and the higher the loss rate. The larger the volume, the higher the actual electrical energy produced per unit volume. The lower; The thermal insulation index of the low-pressure stage turbine, the index term This demonstrates the coupled amplification effect of the mismatch between the salt cavern venting variability index and the low-pressure turbine adiabatic index on energy loss.

[0055] The back pressure loss term mentioned above represents the unusable energy remaining due to the inability of the gas to expand indefinitely because of the presence of back pressure and pipeline losses.

[0056] The actual electrical energy produced per unit volume of the salt cavern system (i.e., energy density) is: (28); And when , hour, , Approaching the upper limit of the ideal adiabatic expansion energy density; Therefore, the actual total energy released by the salt cavern system is: (29); in, The value represents the molar mass of air, expressed in kg / mol.

[0057] S7. Set the capacity matching and multiple constraint verification rules. If the verification passes, output the design parameters of the salt cave system, including the salt cave volume and operating pressure range of the salt cave system, and the equipment parameters of the compressor and turbine. If the verification fails, construct the sensitivity matrix of the design parameters to the actual power generation per unit volume of the salt cave system, set the correction order of the design parameters, perform step-by-step correction on each design parameter according to the correction order, and recalculate the actual total energy release of the salt cave system until the verification passes.

[0058] Specifically, the capacity matching rule set in this step is: when At the same time, it meets the capacity matching requirements.

[0059] The multi-constraint verification rules set in this step include: Geological safety constraints mean that the salt cavern system remains in place throughout the entire gas release process. Instantaneous pressure at any moment The following must always be satisfied: ,and (30); in, Through differential equations get, For the salt cavern system in The mass flow rate that is constantly output to the turbine, i.e.: (31); in, for The mass flow rate of fuel entering the turbine at all times; In addition, the above-mentioned geological safety constraint verification needs to be carried out at discrete time points to ensure that there is no boundary violation; At the same time, geological safety constraints also need to be met: (32); (33); This ensures a new upper limit for the operating pressure of the salt cavern system. It neither fracturing the geological layer nor exceeding the compressor's maximum discharge pressure (compressor's rated discharge pressure); simultaneously, it sets a new lower limit for the operating pressure of the salt cavern system. It neither induces geological creep nor fails to maintain the minimum allowable inlet pressure of the turbine; in, This sets a new upper limit for the operating pressure of salt cavern systems. This sets a new lower limit for the operating pressure of salt cavern systems. The maximum allowable outlet pressure of the compressor. This is the minimum allowable inlet pressure for the turbine. Equipment capacity constraints include minimum turbine inlet pressure constraints and compressor exhaust pressure constraints; the minimum turbine inlet pressure constraint is: (34); in, This is the minimum permissible inlet pressure for the turbine (provided by the equipment manufacturer; below this value may cause surge or a sharp drop in efficiency). Compressor discharge pressure constraints: (35); That is, the outlet pressure of the compressor under rated operating conditions. It must be able to reach the maximum operating pressure of the salt cavern system; if multi-stage compression is used, the exhaust pressure of the final stage must be verified. Energy balance constraints: (36); in, For the salt cavern system in The instantaneous power generation at any given moment can be obtained by interpolating the instantaneous inlet pressure of the turbine through the turbine characteristic curve; Convergence constraints: (37); in, For the number of iterations, For the first The salt cavern volume calculated in the next iteration. For the first The salt cave volume calculated in the next iteration, and The convergence threshold is set to a value of 0.005 to 0.1.

[0060] If all the above capacity matching rules and multi-constraint verification rules are met, the verification passes and the design parameters of the salt cave system, including the salt cave volume and operating pressure range, and the selection parameters of the compressor and turbine, are output. If any rule is not met, the verification fails and optimization continues.

[0061] If the validation fails, first construct the design parameter vector. Then, the dimensionless sensitivity matrix of the actual electrical energy generated per unit volume is constructed as follows: (38); (39).

[0062] The higher the sensitivity mentioned above, the greater the impact of the parameter change on energy density, that is, the greater the impact on the actual power generation per unit volume.

[0063] Based on the sensitivity matrix analysis, the sensitivity of each design parameter to the actual power generation per unit volume is analyzed. Combined with the ease of engineering implementation and economic cost, the optimization order of each design parameter is determined. Specifically, by analyzing the sensitivity of each design parameter to the actual power generation per unit volume, the operating pressure range and volume of the salt cavern system exhibit high sensitivity, but adjusting the salt cavern volume is costly; geological parameters exhibit medium sensitivity, and adjusting them through engineering measures is relatively low-cost and easy to implement; adjustments to equipment and pipeline parameters exhibit low sensitivity, and their cost is relatively low and easy to implement. By combining sensitivity with engineering practice, the optimization order of each design parameter is determined. After the optimization order of each design parameter is determined, iterative calculations are performed according to priority until verification is passed. The specific optimization process is as follows: Figure 2 As shown.

[0064] The first priority is to adjust the operating pressure range of the salt cavern system, including increasing the maximum working pressure of the salt cavern system. and reduce the minimum operating pressure of the salt cavern system .

[0065] Specifically, when adjusting the maximum working pressure of the salt cavern system, the pressure increment is as follows: (40); And the maximum operating pressure of the salt cavern system meets the following requirements: (41); in, This is the initial preset value for the maximum working pressure of the salt cavern system. This is the pressure adjustment coefficient, and Use a value of 0.004~0.01; After each adjustment of the maximum working pressure, it is necessary to simultaneously verify whether the compressor's final stage discharge pressure supports the new pressure. If not supported, the compressor adjustment in the third priority will be triggered.

[0066] Specifically, when adjusting the minimum operating pressure of the salt cavern system, the pressure reduction step size is as follows: (42); Furthermore, the minimum operating pressure of the salt cavern system meets the following requirements: (43); in, This is the initial preset value for the minimum operating pressure of the salt cavern system. This is the pressure adjustment coefficient, and Use a value of 0.004~0.01; In addition, after the first priority adjustment mentioned above, return to step S3 and recalculate and verify in the order of steps S4→S5→S6→S7.

[0067] The second priority is adjusting geological parameters, including adjusting the depth of the geometric center of the salt cavern. Adjusting the fracture resistance safety factor or creep resistance safety factor .

[0068] Specifically, adjust the burial depth of the geometric center of the salt cavern. At that time, the depth increment step is: (44); Furthermore, the upper limit of the geometric center burial depth of salt caverns is limited by the actual distribution of salt layers in the mining area and must not exceed the maximum mineable burial depth; in, The initial depth of the salt cavern's geometric center. This is the depth adjustment factor. Take a value of 0.05 to 0.10.

[0069] Specifically, the safety factor is adjusted primarily by introducing wellbore reinforcement engineering measures (such as grouting reinforcement and microseismic monitoring). Increase to 0.85~0.90, or Reduce to 0.15~0.20, and set the step size for each increase or decrease in the safety factor as follows: .

[0070] In addition, the adjustment of the geometric center burial depth or safety factor of the salt caverns will ultimately affect the feasible domain of geological safety pressure, and thus affect the setting of the operating pressure range of the salt cavern system. Therefore, after the second priority adjustment, we return to step S2 and recalculate and verify in the order of steps S3→S4→S5→S6→S7.

[0071] The third priority is adjusting pipeline parameters, equipment parameters, and inflation / deflation time, mainly including adjusting the pipeline pressure loss coefficient. air-fuel ratio Turbine stage pressure ratio Turbine stage number, turbine and compressor equipment efficiency, charging time, etc.

[0072] Specifically, adjusting the pipeline pressure loss coefficient mainly involves optimizing pipeline characteristics, such as increasing the diameter of the injection and production tubing, using low-flow-resistance valves, and shortening the distance between the wellbore and the turbine, in order to improve the pipeline pressure loss coefficient. The step size for each increment of this coefficient is: ; Its upper limit is .

[0073] For adjusting the air-fuel ratio, the main approach is to increase the air-fuel ratio, with the increment being: ; Its upper limit is limited by the material's temperature resistance limit and the combustion chamber design.

[0074] For the turbine stage pressure ratio, the main focus is on increasing this ratio, with the increment being: ; and The range is usually controlled between 3 and 5.

[0075] The aforementioned adjustment of the interstage pressure ratio of the turbine can make the enthalpy drop distribution between the high-pressure stage and the low-pressure stage more balanced, thereby improving the overall efficiency.

[0076] For turbine stage adjustment, the number of stages can be increased step by step to optimize the pressure ratio distribution of each stage, so that the system maintains high efficiency throughout the sliding pressure operation (pressure gradually decreases) process, thereby improving the turbine mechanical efficiency and generator efficiency of the turbine unit.

[0077] For turbine and compressor equipment efficiency, the main focus is on improving equipment efficiency by selecting high-efficiency equipment. Specifically, this involves improving the mechanical efficiency of the turbine. Generator efficiency turbine isentropic efficiency compressor isentropic efficiency To improve the efficiency of each of the above processes, the step size for each increase is: .

[0078] Regarding inflation / deflation time, the main focus is on extending the inflation time. The increment size is: ; Its upper limit shall not exceed the duration of the power grid off-peak period.

[0079] The extended inflation time mentioned above is mainly to reduce the compressor flow rate, which may allow the salt cavern system to be inflated to a higher pressure.

[0080] After the third priority adjustment mentioned above, return to step S5 and recalculate and verify in the order of steps S6→S7.

[0081] The fourth priority is adjusting the salt cavern volume parameter, mainly to increase the salt cavern volume. The increment size each time is: (45); in, This is the initial estimate of the salt cavern volume. This is the salt cavern volume adjustment coefficient, and Take a value of 0.05~0.10; Its upper limit is limited by geological structure, cavity construction technology and economics.

[0082] The above-mentioned salt cavern volume adjustment can be used in engineering to adjust the water-soluble cavity creation scheme (such as increasing the circulation time, expanding the cavity diameter) or the multi-cavity interconnection scheme.

[0083] After the fourth priority adjustment mentioned above, return to step S4 and recalculate and verify in the order of steps S5→S6→S7.

[0084] After iterative optimization according to the first to fourth priority order mentioned above, if the calculation results converge and simultaneously satisfy the capacity matching and multi-constraint verification rules, the verification passes, and the optimal design parameters are output, including: Salt cavern volume (m) 3 ); Salt cavern system operating pressure range (Pa); Compressor and turbine selection parameters include model, rated flow, power, efficiency, inlet and outlet temperatures, number of stages, etc. Auxiliary system configuration, including pipe diameter, valve specifications, and afterburner system parameters.

[0085] Example 1

[0086] Based on the parameter optimization method for compressed air energy storage salt cavern systems under adiabatic conditions described above, the parameters of a certain salt cavern system are optimized. The main parameters of this salt cavern system are set as follows: Electricity demand parameters: target total electricity generation 5×10 12 J, approximately 1389 MWh, duration of low period It lasts for 8 hours, with peak hours lasting for 8 hours. The target power generation time is 6 hours. It lasts for 6 hours; Geological parameters: Geometric center burial depth of salt caverns It is 800m. Flow parameters: air-fuel ratio 0.02; average density of overlying strata 2400 kg / m 3 Safety factor against cracking The creep safety factor is 0.82. It is 0.25. Efficiency parameter: Turbine mechanical efficiency The power generation efficiency is 0.98. The isentropic efficiency of the compressor is 0.90. The estimated overall efficiency of the salt cavern system is 0.84. Take 0.50; Pipeline pressure loss coefficient Take 0.95; Turbine pressure parameters: Inlet pressure of high-pressure stage turbine 1.35×10 6 Pa, low-pressure turbine outlet pressure 3.31×10 5 Pa, back pressure 1.00×10 5 Pa; Temperature parameters: High-pressure stage turbine inlet temperature The inlet temperature of the low-pressure stage turbine is 437.16 K. The temperature of the salt cavern gas at maximum operating pressure is 325.16 K. It is 313.16K; Thermodynamic parameters: Salt cavern gas release polyvariance index Take 1.556 as the isobaric specific heat capacity at the inlet pressure of the high-pressure stage turbine. The isobaric specific heat capacity at the outlet pressure of the low-pressure stage turbine is 1018.0239 J / kg·K. The molar mass of air is 1005.5777 J / kg·K. Take 0.02897 kg / mol as the gas constant. The adiabatic index of the high-pressure stage turbine is 8.3140 J / mol·K. Take 1.3926, the adiabatic index of the low-pressure stage turbine. Take 1.3994.

[0087] In addition, by consulting the literature for key geological parameters of salt rock, the maximum working pressure within the feasible geological safety pressure range was determined to be 1.54 × 10⁻⁶. 7 Pa, minimum working pressure is 4.71×10 6 Pa, and thus the initial maximum working pressure of the salt cavern system within the feasible geological safety pressure region was determined to be 1.2 × 10 Pa. 7 Pa, minimum working pressure is 6.0 × 10 6 Pa.

[0088] Based on the above parameters, the actual total energy release of the salt cavern system was calculated to be 2.6 × 10⁻⁶. 11 J, approximately 72.2 MWh, is far less than the target total generated electricity. The required production capacity was not met, and the verification failed. Therefore, the first priority solution was adopted: optimization by adjusting the operating pressure range of the salt cavern system. Specifically, during optimization, the maximum working pressure of the salt cavern system was adjusted by returning to step S3, and steps S5, S6, and S7 were executed sequentially until the verification was met, at which point the calculation stopped, and the optimized design parameters were obtained. The iterative process of the maximum working pressure of the salt cavern system is as follows: Figure 3 As shown, the iteration calculation stopped after 50 iterations. At this point, the actual total energy release reached the target total power generation requirement. Furthermore, multiple constraint checks were performed, and the maximum operating pressure of the optimized salt cavern system was determined to be 1.45 × 10⁻⁶. 7 Pa, minimum working pressure is 6.0 × 10 6 Pa, salt cavern volume is 3.0 × 10 5 m 3 .

[0089] Example 2

[0090] The difference between Example 2 and Example 1 is that, in order to demonstrate the effect of the working pressure and pressure ratio of the salt cavern system on the salt volume, this example expands the adjustment range, increasing the maximum working pressure of the salt cavern system from 1.05 × 10⁻⁶. 7 Pa gradually increased to 1.46 × 10 7 Pa, the pressure ratio is controlled between 0.1 and 0.8 (the maximum and minimum working pressures of the salt cavern system are actually adjusted synchronously), then return to step S4 to recalculate the salt cavern volume, and obtain as follows. Figure 4 The surface showing the change in salt cavern volume with the maximum working pressure and pressure ratio of the salt cavern system is then executed sequentially in steps S5, S6, and S7 to verify each point on the surface. From this changing surface, the actual total energy release that can meet the target total power generation requirements can be selected. At the same time, points verified by multiple constraints are obtained, resulting in multiple sets of design parameters. Designers can further select relatively low-cost design parameters from these parameters based on actual engineering conditions.

[0091] It should be noted that any parts not mentioned in this invention can be achieved by using or referencing existing technologies.

[0092] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions, characterized in that, Including the following steps: S1. Analyze the power grid demand, determine the basic parameters of the power grid according to the power grid peak-shaving dispatch instructions, and calculate the target total power generation. S2. Obtain key geological parameters of salt rock and determine the feasible domain of geological safety pressure based on the mechanical properties of salt rock. S3. Within the feasible geological safety pressure range, the operating pressure range of the salt cavern system is preset. S4. Introduce a simplified model of adiabatic venting of the salt cavern system, and back-calculate the salt cavern volume of the salt cavern system based on the operating pressure range of the salt cavern system and the target total power generation. S5. Based on the operating pressure range, volume, and inflation / deflation time of the salt cavern system, calculate the total mass of air released by the salt cavern system, the required mass flow rate and output power of the turbine, and the required mass flow rate and input power of the compressor. Based on the calculation results, make a preliminary selection of the compressor and turbine, and record the equipment parameters of the selected compressor and turbine. S6. Based on the principles of unsteady aerodynamics and engineering thermodynamics under adiabatic conditions, a dynamic decay model describing the pressure of a salt cavern system as mass flows out is constructed. The gas release process is solved by integral calculation in combination with the operating pressure range of the salt cavern system and the initially selected equipment parameters of the compressor and turbine to obtain the actual power generation per unit volume of the salt cavern system and the actual total energy release of the salt cavern system. S7. Set the capacity matching and multiple constraint verification rules. If the verification passes, output the salt cave system design parameters, including the salt cave volume and operating pressure range of the salt cave system, and the equipment parameters of the compressor and turbine. If the verification fails, a sensitivity matrix of the design parameters to the actual power generation per unit volume of the salt cavern system is constructed, and the correction order of the design parameters is set. The step-by-step correction of each design parameter is performed according to the correction order, and the actual total energy release of the salt cavern system is recalculated until the verification passes.

2. The method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions according to claim 1, characterized in that, In step S1, the following basic parameters need to be determined according to the power grid peak-shaving dispatch instructions: duration of off-peak period. This refers to the continuous inflation time allowed by the power grid; peak period duration. This refers to the time required by the power grid for continuous gas release for power generation; the target power generation capacity. This refers to the output power of the salt cavern system under rated operating conditions; the target power generation time. Its duration is consistent with the peak period; The inflation and deflation times of the salt cavern system are determined based on the duration of the power grid's off-peak and peak periods, with the inflation duration being... satisfy: Deflating time satisfy: .

3. The method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions according to claim 2, characterized in that, The target total electrical energy generated in step S1 for: 。 4. The method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions according to claim 3, characterized in that, The maximum working pressure within the feasible geological safety pressure region determined in step S2. for: ； Minimum working pressure in the feasible region of geological safety pressure for: ； Geological ultimate pressure ratio for: ； in, This represents the vertical stress of the original rock at the depth where the salt cave is located, and , The average density of the overlying rock strata. The depth at which the geometric center of the salt cavern is located. It is the acceleration due to gravity. To ensure a safety factor against breakage, This is the creep resistance safety factor.

5. The method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions according to claim 4, characterized in that, The operating pressure range of the salt cavern system in step S3 includes the maximum and minimum operating pressures of the salt cavern system. The maximum operating pressure of the salt cavern system... for: ； Minimum operating pressure of salt cavern system for: ； The operating pressure ratio of the salt cavern system is: ； in, This is the maximum working pressure adjustment coefficient for the salt cavern system, and ; This is the minimum operating pressure adjustment coefficient for the salt cavern system, and ; Must meet .

6. The method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions according to claim 5, characterized in that, The simplified model of adiabatic venting of the salt cavern system established in step S4 is as follows: ； in, This is an estimated value for the electricity generated per unit volume of the salt cavern system. The variable index for gas release from salt caverns. Estimated overall efficiency of salt cavern system; Based on the estimated power generation per unit volume of the salt cavern system, the volume of the salt cavern can be calculated by reverse engineering. for: 。 7. The method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions according to claim 6, characterized in that, In step S5, the total mass of air released by the salt cavern system for: ； in, The gas constant is... The temperature of the salt cavern gas at the minimum operating pressure. The temperature of the salt cavern gas at maximum working pressure; mass flow rate of turbine for: ； Single-stage turbine output power for: ； The output power of a multi-stage turbine is calculated separately for each turbine stage and then summed. in, This refers to the isobaric specific heat capacity under standard atmospheric pressure. This refers to the turbine inlet temperature. This refers to the turbine outlet temperature. For turbine mechanical efficiency, For generator efficiency; compressor mass flow rate for: ； compressor input power The calculation is performed using an isentropic compression model, namely: ； in, This refers to the compressor inlet temperature. This refers to the compressor outlet temperature. This refers to the isentropic efficiency of the compressor.

8. The method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions according to claim 7, characterized in that, The dynamic model of pressure decay in the salt cavern system established in step S6 as mass flows out is an energy density calculation model, and its expression is: ； in, For the salt cavern system in Instantaneous pressure at any moment This refers to the air density inside the salt cavern. Introducing the interstage efficiency coupling coefficient of turbines Interstage enthalpy drop distribution coefficient Ideal expansion term and back pressure loss term Analytical solution of the energy density calculation model for the salt cavern system: Turbine stage efficiency coupling coefficient for: ； in, This refers to the isobaric specific heat capacity at the outlet pressure of the low-pressure stage turbine. This refers to the inlet temperature of the low-pressure stage turbine. Air-fuel ratio; Interstage enthalpy drop distribution coefficient for: ； in, This refers to the isobaric specific heat capacity at the inlet pressure of the high-pressure stage turbine. This refers to the isobaric specific heat capacity at the outlet pressure of the low-pressure stage turbine. This refers to the inlet temperature of the high-pressure stage turbine. This refers to the inlet temperature of the low-pressure stage turbine. This refers to the inlet pressure of the high-pressure stage turbine. The outlet pressure of the low-pressure stage turbine. The thermal insulation index of the high-pressure stage turbine; Ideal expansion term for: ； Back pressure loss term for: ； in, For turbine back pressure, This is the pipeline pressure loss coefficient. The thermal insulation index for low-pressure turbines; Actual electricity generated per unit volume of salt cavern system for: ； The actual total energy released by the salt cavern system is: ； in, This is the molar mass of air.

9. The method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions according to claim 8, characterized in that, The capacity matching rule set in step S7 is: when At the same time, it meets the capacity matching requirements; The multi-constraint verification rules set in step S7 include: Geological safety constraint verification: During the entire venting process, the salt cavern system... Instantaneous pressure at any moment The following must always be satisfied: ,and ; At the same time, geological safety constraints also need to meet the following requirements: ； ； in, This sets a new upper limit for the operating pressure of salt cavern systems. This sets a new lower limit for the operating pressure of salt cavern systems. The maximum allowable outlet pressure of the compressor. This is the minimum permissible inlet pressure for the turbine; Equipment constraint verification includes the turbine minimum intake pressure constraint and the compressor exhaust pressure constraint; the turbine minimum intake pressure constraint is: ； in, This is the minimum permissible inlet pressure for the turbine; Compressor discharge pressure constraints: ； Energy balance constraints: ； in, For the salt cavern system in Instantaneous power generation at any given moment; Convergence constraints: ； in, For the number of iterations, For the first The salt cavern volume calculated in the next iteration. For the first The salt cave volume calculated in the next iteration, and The convergence threshold is set to a value of 0.005 to 0.

1.

10. The method for optimizing parameters of a compressed air energy storage salt cavern system under adiabatic conditions according to claim 9, characterized in that, In step S7, when the verification fails, the sensitivity of the influence of each design parameter on the actual power generation per unit volume is analyzed, and the optimization order of each design parameter is determined in combination with the actual engineering situation. Once the optimization order of each design parameter is determined, iterative optimization is performed according to priority until the verification is passed; The optimization order for each design parameter is as follows: The first priority is to adjust the operating pressure range of the salt cavern system, including increasing the maximum working pressure. and reduce minimum working pressure ; The second priority is adjusting geological parameters, including adjusting the depth of the geometric center of the salt cavern. Adjusting the fracture resistance safety factor or creep resistance safety factor ; The third priority is adjusting pipeline parameters, equipment parameters, and inflation / deflation time, including adjusting the pipeline pressure loss coefficient. air-fuel ratio Turbine stage pressure ratio Turbine stage number, turbine and compressor equipment efficiency, and salt cavern system charging time; The fourth priority is adjusting the salt cavern volume parameters, including increasing the salt cavern volume. .

Images