Double-stage planning method and system for salt cavern integrated energy system

Abstract

The invention discloses a salt cavern integrated energy system two-stage planning method and system, and relates to the technical field of integrated energy system planning, and the method comprises the steps: constructing an integrated energy system model containing different hydrogen storage salt cavern unit types, and taking the minimization of the total cost of an integrated energy system, the carbon dioxide emission amount and the salt mine resource occupation amount as objective functions; introducing cushion gas constraint and exhaust constraint of the hydrogen storage salt cavern unit, and constructing a double-stage planning model; monthly planning simulation is carried out with monthly as a time interval, and the ratio of the hydrogen storage amount of each hydrogen storage salt cavern unit at the end of each time period to the maximum expansion amount of the salt cavern is determined; and taking the ratio as a newly added input, carrying out annual planning simulation by taking hours as a time interval under the hydrogen storage capacity constraint constructed based on the newly added input, and determining a system planning strategy including hydrogen storage salt cavern unit combination operation. Utilization of the salt cavern built under the complex geological condition is improved, the advantages of the salt cavern hydrogen storage link are fully played, and low-carbon economical operation is achieved.

Description

Technical Field

[0001] This invention relates to the field of integrated energy system planning technology, and in particular to a two-stage planning method and system for salt cavern integrated energy systems. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Utilizing stable cavities formed by the dissolution of underground salt layers to store high-pressure hydrogen has advantages such as large capacity, good sealing, high pressure resistance, and high recycling rate, and has been initially applied.

[0004] Currently used salt cavern construction methods are limited, such as constructing salt caverns based solely on abandoned old cavities (e.g., single-well single-cavity old cavities or interconnected old cavities), or constructing salt caverns based solely on artificially created technologies like conventional wellbore cavity salt caverns, large-well cavity salt caverns, or dual-well single-cavity reservoir salt caverns. However, this approach fails to provide optimal construction solutions tailored to the specific characteristics of salt mine conditions in different regions. Under complex geological conditions, a single salt cavern construction method cannot meet construction requirements and cannot effectively utilize local salt resources. Furthermore, existing methods suffer from long dissolution processes, imprecise shape control, and low salt layer utilization rates, hindering the effective realization of the scalability and economic advantages of salt cavern hydrogen storage.

[0005] Furthermore, in integrated energy systems containing hydrogen storage salt cavern units, if the salt cavern is forcibly vented under insufficient pressure, its walls will experience abnormal stress, potentially leading to collapse, cracks, or gas leakage. Additionally, since the salt cavern unit inputs or releases hydrogen through a well, its maximum venting capacity per unit time is limited by factors such as wellhead area and gas pressure. Ignoring these limitations can easily cause operating results to exceed the physical limits of the hydrogen storage salt cavern unit's intake and exhaust, resulting in equipment overload or energy supply interruptions. Summary of the Invention

[0006] To address the aforementioned issues, this invention proposes a two-stage planning method and system for integrated salt cavern energy systems. By considering various hydrogen storage salt cavern units based on different salt cavern construction technologies, the optimal system planning strategy, including the combined operation of hydrogen storage salt cavern units, is determined. This improves the utilization of salt caverns constructed under complex geological conditions, fully leverages the advantages of the hydrogen storage component in salt caverns, and achieves low-carbon and economical operation.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a two-stage planning method for a salt cavern integrated energy system, comprising: A comprehensive energy system model is constructed that includes different types of hydrogen storage salt cavern units. The objective function is to minimize the total cost of the comprehensive energy system, carbon dioxide emissions, and salt mine resource consumption. The hydrogen storage constraints, cushion gas constraints, and exhaust constraints of the hydrogen storage salt cavern units are introduced as constraints to construct a two-stage planning model. Based on the two-stage planning model, with the operating parameters of the integrated energy system model and salt mine resources as inputs, monthly planning simulations are performed at monthly intervals to determine the ratio of the hydrogen storage capacity of each type of hydrogen storage salt cavern unit to the maximum expansion capacity of the salt cavern at the end of each time period. Using the ratio as a new input, and under the hydrogen storage constraint constructed based on the new input, a year-round planning simulation is conducted at hourly intervals to determine the system planning strategy that includes the combined operation of hydrogen storage salt cavern units.

[0008] As an alternative implementation method, the mathematical model and hydrogen storage constraints of the hydrogen storage salt cavern unit are as follows: ; ; in, yes t Time of the first i Hydrogen storage capacity of a hydrogen storage salt cavern unit; yes t- 1st moment i Hydrogen storage capacity of a hydrogen storage salt cavern unit; and They represent t Time of the first i Hydrogen charging power and hydrogen discharging power of a hydrogen storage salt cavern unit; , and They represent t Time of the first i Hydrogen charging conversion efficiency, hydrogen degassing conversion efficiency, and self-loss efficiency of a hydrogen storage salt cavern unit; and They are the first i The maximum hydrogen storage capacity and maximum charging / discharging power of the hydrogen storage salt cavern unit; It is the first i The upper limit of the installed capacity of a hydrogen storage salt cavern unit.

[0009] As an alternative implementation method, the gas constraint of the hydrogen storage salt cavern unit is as follows: ; ; in, Indicates the first i The required percentage of cushion gas for safe operation of a hydrogen storage salt cavern unit; It is a 0-1 variable; when the hydrogen storage salt cavern unit meets the cushion gas requirements... A value of 1 indicates that the hydrogen storage salt cavern unit can safely release hydrogen at this time. When the hydrogen storage salt cavern unit does not meet the cushion gas requirements... A value of 0 indicates that the hydrogen storage salt cavern unit cannot release hydrogen at this time; express t Time of the first i Hydrogen release power of a hydrogen storage salt cavern unit; yes t Time of the first i Hydrogen storage capacity of a hydrogen storage salt cavern unit; and They are the first i The maximum hydrogen storage capacity and maximum charge / discharge power of the hydrogen storage salt cavern unit.

[0010] As an alternative implementation method, the exhaust constraints for the hydrogen storage salt cavern unit are: ; ; in, It is the maximum gas volume that can pass through the i-th type of hydrogen storage salt cavern unit per unit time under the wellhead restriction; and They represent t Time of the first i Hydrogen charging power and hydrogen discharging power of a hydrogen storage salt cavern unit; and These are the gas pressure and temperature inside the salt cavern of the i-th type of hydrogen storage salt cavern unit; It is the specific heat ratio of hydrogen; It is an exclusion coefficient; It is the specific gravity of the gas air; This is a unit conversion factor; Let be the wellhead area of ​​the i-th type of hydrogen storage salt cavern unit.

[0011] As an alternative implementation method, the salt mine resource occupancy for: ; in, and These are the conversion coefficient of the economic value of salt mine resources per unit of newly constructed salt caverns and the unit conversion coefficient, respectively. The number of types of hydrogen storage salt cavern units; Let be the rated installed capacity of the i-th type of hydrogen storage salt cavern unit.

[0012] As an alternative implementation method, the hydrogen storage capacity constraint is: ; in, This is the ratio of hydrogen storage capacity to the maximum expansion capacity of the salt cavern; t1 refers to the last hour of each month in a year. It is time t1. i Hydrogen storage capacity of a hydrogen storage salt cavern unit; It is the first i The maximum hydrogen storage capacity of this type of hydrogen storage salt cavern unit.

[0013] Secondly, the present invention provides a two-stage planning system for a salt cavern integrated energy system, comprising: The model building module is configured to build a comprehensive energy system model that includes different types of hydrogen storage salt cavern units. The objective function is to minimize the total cost of the comprehensive energy system, carbon dioxide emissions, and salt mine resource consumption. The hydrogen storage constraints, cushion gas constraints, and exhaust constraints of the hydrogen storage salt cavern units are introduced as constraints to build a two-stage planning model. The first-stage planning module is configured to be based on a two-stage planning model, taking the operating parameters of the integrated energy system model and salt mine resources as inputs, and performing monthly planning simulations at monthly intervals to determine the ratio of the hydrogen storage capacity of each type of hydrogen storage salt cavern unit to the maximum expansion capacity of the salt cavern at the end of each time period. The second-stage planning module is configured to take the ratio as a new input and, under the hydrogen storage capacity constraint constructed based on the new input, perform annual planning simulation at hourly intervals to determine the system planning strategy including the combined operation of hydrogen storage salt cavern units.

[0014] Thirdly, the present invention provides an electronic device including a memory and a processor, and computer instructions stored in the memory and running on the processor, wherein the computer instructions, when executed by the processor, perform the method described in the first aspect.

[0015] Fourthly, the present invention provides a computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in the first aspect.

[0016] Fifthly, the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the method described in the first aspect.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention proposes a two-stage planning method and system for integrated salt cavern energy systems. Considering both the renovation of existing old caverns and the construction of new artificial salt caverns, it explores five salt cavern construction technologies with different applicable geographical conditions, unit costs, and operational characteristics: single-well single-cavity old-cavity salt caverns, interconnected old-cavity salt caverns, conventional well-cavity salt caverns, large-well-cavity salt caverns, and dual-well single-cavity salt caverns. An integrated energy system model is constructed, encompassing different types of hydrogen storage salt cavern units, with each type corresponding to a specific salt cavern construction technology. Then, using the minimization of the total integrated energy system cost, carbon dioxide emissions, and salt mine resource occupancy as objective functions, and incorporating cushion gas constraints based on the operational characteristics of the hydrogen storage salt cavern units, as well as exhaust constraints derived from fluid dynamics formulas, a two-stage planning model is constructed. By setting different time scales, the accuracy and realism of the planning results are improved. This addresses the problem of low salt mine resource utilization due to the scarcity of high-quality storage sites in traditional salt cavern construction technologies, enhances the utilization of salt caverns constructed under complex geological conditions, fully leverages the advantages of the hydrogen storage component in salt caverns, and achieves low-carbon and economical operation.

[0018] This invention addresses the seasonal and long-term energy storage characteristics of hydrogen storage cavern units by proposing a two-stage planning model. The first and second stages use monthly and hourly timescales respectively, and partial operational results from the first stage are used as new input parameters for progressive simulation in the second stage. At a short timescale, this model enables refined modeling of the hydrogen storage cavern unit. Compared to conventional above-ground hydrogen storage tank models, it incorporates cushion gas constraints and maximum exhaust gas constraints per unit time, in addition to considering conventional hydrogen storage equipment operational constraints. At a long timescale, given the seasonal and long-term characteristics of cavern hydrogen storage, setting different timescales for planning simulation improves the realism and accuracy of the results. This allows for the provision of optimal cavern construction technology combinations tailored to the specific characteristics of salt mine conditions in different regions, effectively utilizing salt mine resources.

[0019] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0021] Figure 1 Here is a flowchart of the two-stage planning method for a salt cavern integrated energy system provided in Embodiment 1 of the present invention; Figure 2This is a schematic diagram of the integrated energy system model framework provided in Embodiment 1 of the present invention. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0024] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, unless the context clearly indicates otherwise, the singular form is intended to include the plural form as well. Furthermore, it should be understood that the terms “comprising” and “including”, and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0025] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0026] Example 1 Currently, salt caves are mainly constructed through two methods: obtaining salt caves by modifying abandoned old caves and obtaining salt caves through artificial construction.

[0027] By remodeling abandoned old wells, the time required to obtain salt caverns can be reduced, and the construction cost of salt caverns can be lowered to some extent. Most common salt cavern remodeling cases involve single-well, single-cavity old wells. This type of old well remodeling has advantages such as relatively mature technology, short remodeling cycle, and strong operational independence. However, this type of old well remodeling technology has high requirements, such as: geological conditions, requiring a good caprock, few and small-scale adjacent faults and fractures; cavity conditions, requiring a certain cavity volume to meet economic requirements, meeting safety pillar requirements with adjacent cavities, and ensuring no cross-contamination between cavities, and having a roof of a certain thickness; and surface conditions, requiring a safe distance between the wellhead and surrounding buildings.

[0028] Single-well, single-cavity old cavities are relatively rare. Most salt mines initially used this method but later transitioned to interconnected wells. Therefore, abandoned old cavities of this type can be upgraded into salt caverns using interconnected wells. Compared to single-well, single-cavity old cavities, these salt caverns offer advantages such as abundant resources for modification and high modification efficiency.

[0029] Therefore, the salt caverns converted from abandoned old caverns considered in this embodiment include single-well, single-cavity old cavern salt caverns and interconnected old cavern salt caverns between wells.

[0030] Besides renovating abandoned salt caverns, in areas with limited salt cavern resources, artificial cavern construction can be used to obtain salt caverns for hydrogen storage technology. Currently, the most commonly used technique for artificially constructing salt caverns is conventional wellbore cavern construction. Conventional wellbore cavern construction typically uses a wellbore structure of 508mm + 339.7mm + 244.5mm, resulting in a relatively small wellbore diameter. Consequently, the water injection and drainage volume during cavern construction is small, the construction speed is slow, and the cycle is long, which cannot meet the construction requirements of underground gas storage facilities.

[0031] Furthermore, using conventional wellbore construction methods in deeper salt layers presents significant technical challenges, including increased injection-production well completion risks due to greater depth and complex geological conditions. Scholars have demonstrated that large-diameter wellbore construction and dual-well wellbore construction schemes offer substantial advantages in addressing these technical issues. Large-diameter wellbore construction typically employs a wellbore structure of 762mm + 508mm + 339.7mm, with a larger diameter to meet the needs of high-volume, rapid cavity creation and high-volume gas production and injection. Dual-well single-cavity wellbore construction usually involves two conventional wells corresponding to one cavity, allowing for simultaneous injection and production during cavity creation, and also meeting the requirements for rapid cavity creation.

[0032] Therefore, the salt caverns obtained by artificial construction technology considered in this embodiment include conventional wellbore cavity salt caverns, large wellbore cavity salt caverns, and dual-well single-cavity reservoir salt caverns.

[0033] Based on the above analysis, this embodiment provides a two-stage planning method for a salt cavern integrated energy system, such as... Figure 1 As shown, it includes: A comprehensive energy system model is constructed that includes different types of hydrogen storage salt cavern units. The objective function is to minimize the total cost of the comprehensive energy system, carbon dioxide emissions, and salt mine resource consumption. The hydrogen storage constraints, cushion gas constraints, and exhaust constraints of the hydrogen storage salt cavern units are introduced as constraints to construct a two-stage planning model. Based on the two-stage planning model, with the operating parameters of the integrated energy system model and salt mine resources as inputs, monthly planning simulations are performed at monthly intervals to determine the ratio of the hydrogen storage capacity of each type of hydrogen storage salt cavern unit to the maximum expansion capacity of the salt cavern at the end of each time period. Using the ratio as a new input, and under the hydrogen storage constraint constructed based on the new input, a year-round planning simulation is conducted at hourly intervals to determine the system planning strategy that includes the combined operation of hydrogen storage salt cavern units.

[0034] like Figure 2The diagram shows a comprehensive energy system model that includes different types of hydrogen storage salt cavern units, specifically: renewable energy units, conventional thermal power units, electric energy storage units, combined heat and power units, electrolyzer units, fuel cell units, hydrogen storage salt cavern units, and thermal storage tank units.

[0035] Among them, renewable energy units, conventional thermal power units, fuel cell units, energy storage units, and combined heat and power units provide electrical load, and the excess electricity generated by various power units is stored by energy storage units; renewable energy units provide hydrogen load and heat load through electrolyzer units, fuel cell units, combined heat and power units, and thermal storage tank units provide heat load, and hydrogen storage salt cavern units store hydrogen energy, which can meet hydrogen load demand across time scales; hydrogen energy will also be fed into fuel cell units and hydrogen storage salt cavern units for storage, and heat energy will also be fed into thermal storage tank units for storage.

[0036] Each type of hydrogen storage salt cavern unit corresponds to a salt cavern construction technology, specifically five salt cavern construction technologies: single-well single-cavity old-cavity salt cavern, interconnected old-cavity salt cavern between wells, conventional well-hole cavity-building salt cavern, large-well-hole cavity-building salt cavern, and dual-well single-cavity storage salt cavern.

[0037] In this embodiment, the integrated energy system model, which includes different types of hydrogen storage salt cavern units, is based on the conventional power system and also considers electrolysis system (EL) and fuel cell (FC) units, and is equipped with hydrogen storage salt cavern units to complete the hydrogen energy link and the electric-hydrogen coupling part.

[0038] Specifically, it includes the following:

[0039] 1. Electrolyzers can produce hydrogen by electrolyzing water, converting surplus green electricity generated by renewable energy units in the power system into hydrogen energy, thus promoting the consumption of renewable energy in the power system. The hydrogen energy produced in this process can be directly used for hydrogen load supply or stored in hydrogen storage equipment.

[0040] Based on the different classifications of electrolytes, common electrolyzers are mainly divided into alkaline electrolyzers, solid oxide electrolyzers, and proton exchange membrane electrolyzers. Different types of electrolyzers have different costs and operating parameters.

[0041] The mathematical formulas and related constraints characterizing the energy conversion of an electrolyzer are as follows: (1); (2); in, , and They represent t Time of the first iThe power consumption of the electrolytic cell unit, the rated power connected to the grid, and the power output of hydrogen; and They represent the first i The maximum installed capacity of the electrolyzer unit and the conversion efficiency from electrical energy to hydrogen energy; It has a low calorific value, taken as 33.3 kWh / kg.

[0042] Furthermore, it is essential to ensure that the electricity supplied to the electrolyzer is green electricity, meaning that the relevant electricity is generated from renewable energy units. The relevant constraints are expressed as follows: (3); in, and They are t The actual transmission power of wind turbines and photovoltaic units at any given time; This refers to the number of types of electrolytic cell units.

[0043] The operation of electrolytic cell units should also meet flexibility constraints, introducing continuous variables. and They represent t Time of the first i The grid-connected and off-grid capacities of various electrolytic cell units are determined, and the following constraints are met: (4); (5); in, express t- 1st moment i The rated power of the electrolytic cell unit connected to the grid.

[0044] Flexibility constraints include output constraints, ramping constraints, and minimum start-stop time constraints.

[0045] The output constraint is as follows: (6); In the formula, and The first i Minimum and maximum output coefficients of the electrolytic cell unit under its rated capacity.

[0046] The climbing constraint is: (7); (8); In the formula, and They represent the first i The upward and downward slopes per unit capacity of the electrolytic cell-like unit; and They represent the first i The start-up ramp-up limit and shutdown ramp-up limit of the electrolytic cell-like unit can be set to... ; express t+ 1st moment i Off-grid capacity of electrolytic cell units; express t- 1st moment i The power consumption of a type of electrolytic cell unit.

[0047] The minimum start-stop time constraint is: (9); (10); In the formula, and Representing the first i Minimum start-up and minimum shutdown times for electrolytic cell-like units; express t+ 1st moment i Grid-connected capacity of various electrolytic cell units; express Time of the first i The grid-connected capacity of the electrolytic cell unit; T is the total time.

[0048] 2. Fuel cell units can convert excess hydrogen energy in a hydrogen energy system into electrical energy to supply electrical loads, thereby improving energy utilization and providing flexibility to the power system.

[0049] The mathematical formula characterizing the energy conversion of a fuel cell unit is as follows: (11); (12); in, , and They represent t Time of the first i The power of the fuel cell unit in generating electricity, its rated grid-connected power, and its power consumption of hydrogen. and They represent the first i The maximum installed capacity of the fuel cell unit and the conversion efficiency from hydrogen energy to electricity.

[0050] The flexibility constraints of fuel cell units are as follows: (13); (14); (15); (16); (17); (18); (19); In the formula, and They represent t Time of the first i The grid-connected and off-grid capacities of various fuel cell units; and The first i Minimum and maximum output coefficients of fuel cell generator units per unit rated capacity; and They represent the first i Upslope and downslope of unit capacity for fuel cell-like units; and These represent the start-up ramp-up limit and shutdown ramp-up limit for the i-th type of fuel cell unit, respectively, and can be set to... ; and These represent the minimum start-up time and minimum shutdown time of the i-th type of fuel cell unit, respectively. express t- 1st moment i The rated power of a fuel cell unit connected to the grid; They represent t+ 1st moment i Off-grid capacity of fuel cell units; express t- 1st moment i The power of electrical energy generated by a fuel cell unit; express t+ 1st moment i Grid-connected capacity of fuel cell units; express Time of the first i The grid-connected capacity of various fuel cell units.

[0051] 3. Hydrogen storage salt cavern units store excess hydrogen in the hydrogen energy system and release hydrogen when needed, achieving peak shaving and valley filling across time.

[0052] Traditional hydrogen storage salt cavern units involve integer variables, namely: (20); (twenty one); in, yes tTime of the first i Hydrogen storage capacity of a hydrogen storage salt cavern unit; yes t- 1st moment i Hydrogen storage capacity of a hydrogen storage salt cavern unit; and Represent t Time of the first i Hydrogen charging power and hydrogen discharging power of a hydrogen storage salt cavern unit; , and They represent t Time of the first i Hydrogen charging conversion efficiency, hydrogen degassing conversion efficiency, and self-loss efficiency of a hydrogen storage salt cavern unit; and They are the first i The maximum hydrogen storage capacity and maximum charging / discharging power of the hydrogen storage salt cavern unit; It is a 0-1 variable. A value of 1 indicates that the hydrogen storage salt cavern unit is in a hydrogen charging state. A value of 0 indicates that the hydrogen storage salt cavern unit is in a hydrogen release state.

[0053] This embodiment incorporates the operating cost of the hydrogen storage salt cavern unit into the objective function, which enables the transformation of the hydrogen storage salt cavern unit model from a mixed-integer linear programming model to a linear programming model, thereby reducing the complexity of the mathematical model and improving the model solution speed.

[0054] Furthermore, there are currently two common methods for obtaining salt caverns: one is by modifying abandoned old cavities, and the other is by artificially constructing new salt caverns. For obtaining salt caverns by modifying abandoned old cavities, single-well, single-cavity modification technology is typically used; for artificially constructing new salt caverns, conventional well drilling technology is typically used. However, both methods have certain shortcomings and require high-quality salt deposits. The salt layer thickness and depth in the target study area have limited reserves that meet the corresponding technical requirements, thus limiting the use of salt caverns for hydrogen storage. This embodiment proposes a system that considers multiple salt cavern acquisition technologies and plans the combination of these technologies. This expands the range of usable salt deposits (different technologies have different salt deposit requirements; considering more technologies increases the amount of salt deposits that meet the requirements), alleviating the limitation on hydrogen storage caused by a shortage of suitable salt deposits. Simultaneously, since the new capacity of the salt cavern unit is limited by the volume of the old cavities suitable for reservoir construction or the salt deposit reserves in the study area, an inequality constraint is added to the maximum hydrogen storage capacity of the hydrogen storage salt cavern unit. Therefore, the linearized mathematical model of the hydrogen storage salt cavern unit is: (twenty two); (twenty three); in, It is the firsti The upper limit of the installed capacity of the hydrogen storage salt cavern unit is determined by the volume of the old cavity or the salt mine reserves in the study area that are suitable for this type of salt cavern acquisition method.

[0055] In addition, this embodiment adds cushion gas constraint and exhaust constraint to the traditional hydrogen storage salt cavern unit model.

[0056] Specifically: When a salt cavern is forcibly vented under insufficient pressure, its walls will experience abnormal stress, leading to problems such as collapse, cracks, or gas leakage. Cushion gas can provide pressure support when gas is released from the salt cavern, which is crucial for maintaining the minimum pressure threshold within the cavern. This ensures the stability and sealing of the salt cavern structure, preventing the aforementioned problems.

[0057] Therefore, this embodiment introduces cushion gas constraint for salt cavern hydrogen storage units: (twenty four); (25); in, Indicates the first i The required percentage of cushion gas for safe operation of a hydrogen storage salt cavern unit; It is a 0-1 variable; when the hydrogen storage salt cavern unit meets the cushion gas requirements... A value of 1 indicates that the hydrogen storage salt cavern unit can safely release hydrogen at this time. When the hydrogen storage salt cavern unit does not meet the cushion gas requirements... A value of 0 indicates that the hydrogen storage salt cavern unit cannot release hydrogen at this time.

[0058] Furthermore, the maximum discharge rate per unit time of the hydrogen storage cavern unit, which inputs or releases hydrogen through a well, is limited by factors such as wellhead area and gas pressure. To prevent the system's operating results from exceeding the physical limits of the hydrogen storage cavern unit's intake and exhaust, thus causing equipment overload or energy supply interruption, this embodiment combines parameters such as wellhead area and gas pressure, and uses fluid dynamics formulas to calculate its upper limit for exhaust, thereby restricting relevant operating variables. The resulting exhaust constraint is as follows: (26); (27); in, It is the maximum gas volume that can pass through the i-th type of hydrogen storage salt cavern unit per unit time under the wellhead restriction; and These are the gas pressure and temperature inside the salt cavern of the i-th type of hydrogen storage salt cavern unit; It is the specific heat ratio of hydrogen; This is the exclusion coefficient, which is usually taken as 0.85-0.95; The density is the specific gravity of air. In this embodiment, the hydrogen stored in the hydrogen storage salt cavern unit is at this point. The value is 0.069; This is a unit conversion factor; Let be the wellhead area of ​​the i-th type of hydrogen storage salt cavern unit.

[0059] In this embodiment, in addition to the hydrogen energy-related aspects mentioned above, waste heat recovery from electrolyzers and fuel cell units, combined heat and power units, and thermal storage tanks are also considered to improve the hydrogen-thermal coupling and electric-thermal coupling aspects.

[0060] Specifically, it includes the following:

[0061] 1. Combined heat and power (CHP) units can generate electricity and heat simultaneously. The heat can be used for heating, industrial steam, or hot water, thereby improving energy efficiency.

[0062] In the thermal energy system section, combined heat and power (CHP) units should meet the following requirements: (28); In the formula, and They are t Time of the first i The heat production capacity and power transmission capacity of a combined heat and power unit; It is the first i The conversion coefficient of heat energy generated by a combined heat and power unit.

[0063] 2. Waste heat recovery process.

[0064] In an electrolyzer unit, in addition to converting electrical energy into hydrogen energy during operation, a portion of the energy is also converted into heat energy. This allows for the recovery of some waste heat to meet heat load requirements.

[0065] The waste heat recovery process of the electrolytic cell unit is represented as follows: (29); In the formula, yes t Time of the first i The heat output of the electrolytic cell unit; It is the first i The conversion efficiency of waste heat recovery in electrolytic cell units; Indicates the first i The conversion efficiency of an electrolyzer unit from electrical energy to hydrogen energy; Indicates the first i The power consumption of a type of electrolytic cell unit.

[0066] The waste heat recovery process of a fuel cell unit is represented as follows: (30); In the formula, yest Time of the first i The heat output of this type of fuel cell unit; It is the first i The conversion efficiency of waste heat recovery in fuel cell units; Indicates the first i The conversion efficiency of a fuel cell unit from hydrogen energy to electrical energy; Indicates the first i The power of the electrolyzer unit to output hydrogen; It has a low calorific value, taken as 33.3 kWh / kg; It has a low calorific value, taken as 33.3 kWh / kg.

[0067] 3. Similar to conventional hydrogen storage equipment, the mathematical model of the thermal storage tank unit is as follows: (31); (32); in, yes t Time of the first i The heat storage capacity of the thermal storage tank unit yes t- 1st moment i The heat storage capacity of the thermal storage tank unit yes t Time of the first i The heat storage capacity of the thermal storage tank unit and Represent t Time of the first i The power of the thermal storage tank unit for charging thermal energy and the power for releasing thermal energy; , and They represent t Time of the first i The conversion efficiency of the energy charging process, the conversion efficiency of the energy releasing process, and the self-loss efficiency of the thermal storage tank unit; and They are the first i The maximum stored thermal energy and maximum charging / discharging power of the thermal storage tank unit.

[0068] 4. The integrated energy system model should also satisfy power balance constraints, hydrogen energy balance constraints, and heat balance constraints. The relevant mathematical models are as follows: (33); (34); (35); In the formula, It is the power generation capacity of the i-th type of conventional thermal power unit at time t; yes t Time of the first i The power transmission capacity of a combined heat and power unit; and These are the charging power and discharging power of the i-th type of energy storage unit at time t, respectively. , and These are the electrical load, hydrogen load, and thermal load of the study area at time t, respectively, for the prospective year. , , , and These are the number of types of conventional thermal power units, combined heat and power units, electric energy storage units, fuel cell units, and hydrogen storage salt cavern units; and They are t The actual transmission power of wind turbines and photovoltaic units at any given time.

[0069] In this embodiment, to avoid the traditional model focusing only on economic efficiency while ignoring the impact on the environment and salt resources, the objective function of this embodiment considers the total cost of the integrated energy system, carbon dioxide emissions, and salt resource occupancy. By introducing carbon emission and salt resource economic conversion coefficients to unify the dimensions, the synergistic optimization of economic benefits, environmental friendliness, and resource sustainability is achieved.

[0070] The objective function is: (36); In the formula, , and These represent the total cost of the integrated energy system, carbon dioxide emissions, and salt mine resource consumption, respectively.

[0071] Carbon dioxide emissions are: (37); in, It is the economic conversion coefficient for carbon dioxide emissions per unit capacity of conventional thermal power units of type i; For time intervals; yes t Time of the first i The power transmission capacity of a combined heat and power unit; It is the economic conversion coefficient of carbon dioxide emissions per unit capacity of the i-th type of cogeneration unit; Let be the actual output power of the i-th type of conventional thermal power unit at time t.

[0072] The amount of salt mine resources occupied is: (38); in, and These are the conversion coefficient of the economic value of salt mine resources per unit of newly constructed salt caverns and the unit conversion coefficient, respectively. This represents the rated power of the i-th type of hydrogen storage salt cavern unit.

[0073] The total cost of the integrated energy system is: (39); in, , and These represent the total costs of the electrical system, hydrogen system, and thermal system, respectively. Specifically: (40); (41); (42); In the formula, , , , , , , , and These represent the relevant costs incurred by conventional thermal power units, combined heat and power units, wind power units, photovoltaic units, electric energy storage units, electrolyzer units, fuel cell units, hydrogen storage salt cavern units, and thermal storage tank units, respectively.

[0074] The relevant costs of each unit are included in the corresponding unit construction costs and unit operating costs. In addition, the unit start-up costs are also considered for conventional thermal power units and cogeneration units.

[0075] The specific mathematical expression is: (43); (44); (45); (46); (47); (48); (49); (50); (51); In the formula, , , and These are the amortized investment cost, fixed operating cost, variable operating cost, and start-up cost per unit capacity of the i-th type of conventional thermal power unit; This refers to the existing rated capacity of conventional thermal power units of type i; It is the operating capacity of the i-th type of conventional thermal power unit at time t; , , and These are the amortized investment cost, fixed operating cost, variable operating cost, and start-up cost per unit capacity of the i-th type of cogeneration unit; This refers to the existing rated capacity of the i-th type of cogeneration unit; It is the operating capacity of the i-th type of cogeneration unit at time t; , and These are the amortized investment cost per unit capacity of wind turbine units, fixed operation and maintenance costs, and existing installed capacity. , and These are the amortized investment cost per unit capacity of the photovoltaic unit, the fixed operation and maintenance cost, and the existing installed capacity. and These are the amortized investment cost and fixed operation and maintenance cost per unit capacity of the i-th type of electric energy storage unit; Indicates the first i The power consumption of the electrolytic cell unit; and These are the amortized investment cost and fixed operation and maintenance cost per unit capacity of the i-th type of electrolytic cell unit, respectively. and These are the amortized investment cost and fixed operation and maintenance cost per unit capacity of the i-th type of fuel cell unit; Indicates the first i The power of electrical energy generated by a fuel cell unit; and These are the amortized investment cost and fixed operation and maintenance cost per unit capacity of the i-th type of hydrogen storage salt cavern unit; and These are the amortized investment cost and fixed operation and maintenance cost per unit capacity of the i-th type of thermal storage tank unit; This represents the total rated installed capacity of the i-th type of conventional thermal power units; Let be the actual output power of the i-th type of conventional thermal power unit at time t; This represents the total rated installed capacity of the i-th type of conventional thermal power units; This represents the total rated installed capacity of the wind turbine units; This refers to the total rated installed capacity of the photovoltaic power generation units; This refers to the rated power of the i-th type of energy storage unit; Let t be the actual discharge power of the i-th type of energy storage unit; Let be the actual charging power of the i-th type of energy storage unit at time t; This refers to the rated power of the type i hydrogen storage salt cavern unit; The rated power of the i-th type of thermal storage tank unit.

[0076] In the conventional operation method, using equation (36) as the objective function and an hourly time interval, a simulation of 8760 hours throughout the year is directly performed. This calculation method only restricts the hydrogen storage capacity of the hydrogen storage salt cavern unit to be equal at the first and last moments, and cannot well reflect and guarantee the characteristics of the hydrogen storage salt cavern unit across seasonality and long cycles. In view of this, this embodiment proposes a two-stage planning method for integrated energy systems.

[0077] Specifically: In the first stage, the integrated energy system model operating parameters and salt mine resources are used as inputs. The integrated energy system model operating parameters include various unit operating parameters, various unit cost parameters, various load values ​​and wind and solar resources. Equation (36) is used as the objective function, and the planning simulation is carried out for 12 months of the year with monthly time intervals. The ratio of hydrogen storage capacity to capacity expansion at the end of each time period of the hydrogen storage salt cavern unit is determined and incorporated as a new input parameter into the known quantity of the next stage.

[0078] It's important to clarify that the capacity expansion here is related to the salt mine resource utilization in the objective function. Salt mine resource utilization refers to the salt content, while capacity expansion refers to the maximum hydrogen storage capacity of the hydrogen storage salt cavern unit. The relationship between the two is that the volume of salt mine resources consumed is equal to the volume of the maximum hydrogen storage capacity of the newly built salt cavern.

[0079] In the second stage, the hydrogen storage capacity constraint is generated by combining the new input parameters obtained in the first stage: (52); in, These are new input parameters obtained from the first stage; t1 refers to the last hour of each month in a year, i.e. ; It is time t1. i Hydrogen storage capacity of a hydrogen storage salt cavern unit; It is the first i The maximum hydrogen storage capacity of this type of hydrogen storage salt cavern unit.

[0080] Again, using equation (36) as the objective function, the newly added input parameters obtained in the first stage are added to the original input. Planning simulations are carried out for 8760 hours throughout the year with an hourly interval to determine the system planning strategy including the combined operation of hydrogen storage salt cavern units. This strategy refers to the combination of various units in the integrated energy system, including the combination scheme of various salt cavern construction technologies.

[0081] Compared to conventional operation, the two-stage planning method proposed in this embodiment requires, in addition to specifying the hydrogen storage capacity of the hydrogen storage salt cavern unit, also... In addition to ensuring that the beginning and end times are equal, a constraint on the amount of hydrogen stored at the end of each month has been added. The parameters of the newly added hydrogen storage constraint are derived from the operation results of the first phase, which can ensure the cross-seasonal and long-cycle characteristics of the hydrogen storage salt cavern unit, making the operation results more realistic and accurate.

[0082] Example 2 This embodiment provides a two-stage planning system for a salt cavern integrated energy system, including: The model building module is configured to build a comprehensive energy system model that includes different types of hydrogen storage salt cavern units. The objective function is to minimize the total cost of the comprehensive energy system, carbon dioxide emissions, and salt mine resource consumption. The hydrogen storage constraints, cushion gas constraints, and exhaust constraints of the hydrogen storage salt cavern units are introduced as constraints to build a two-stage planning model. The first-stage planning module is configured to be based on a two-stage planning model, taking the operating parameters of the integrated energy system model and salt mine resources as inputs, and performing monthly planning simulations at monthly intervals to determine the ratio of the hydrogen storage capacity of each type of hydrogen storage salt cavern unit to the maximum expansion capacity of the salt cavern at the end of each time period. The second-stage planning module is configured to take the ratio as a new input and, under the hydrogen storage capacity constraint constructed based on the new input, perform annual planning simulation at hourly intervals to determine the system planning strategy including the combined operation of hydrogen storage salt cavern units.

[0083] It should be noted that the above modules correspond to the steps described in Embodiment 1, and the examples and application scenarios implemented by the above modules and the corresponding steps are the same, but are not limited to the content disclosed in Embodiment 1. It should also be noted that the above modules, as part of the system, can be executed in a computer system such as a set of computer-executable instructions.

[0084] In further embodiments, the following is also provided: An electronic device includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, wherein the computer instructions, when executed by the processor, perform the method described in Embodiment 1. For brevity, further details are omitted here.

[0085] It should be understood that in this embodiment, the processor can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0086] Memory may include read-only memory and random access memory, and provides instructions and data to the processor. A portion of memory may also include non-volatile random access memory. For example, memory may also store information about the device type.

[0087] A computer-readable storage medium for storing computer instructions, which, when executed by a processor, perform the method described in Embodiment 1.

[0088] The method in Example 1 can be directly implemented by a hardware processor, or implemented by a combination of hardware and software modules within the processor. The software modules can reside in readily available storage media in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method. To avoid repetition, a detailed description is not provided here.

[0089] A computer program product includes a computer program that, when executed by a processor, implements the method described in Embodiment 1.

[0090] The present invention also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as instructions included in program modules, which execute in a device on a target real or virtual processor to perform the processes / methods described above. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or divided among program modules as needed. The machine-executable instructions for the program modules can execute within a local or distributed device. In a distributed device, the program modules can reside in both local and remote storage media.

[0091] The computer program code used to implement the methods of the present invention may be written in one or more programming languages. This computer program code may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the computer or other programmable data processing device, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a computer, partially on a computer, as a stand-alone software package, partially on a computer and partially on a remote computer, or entirely on a remote computer or server.

[0092] In the context of this invention, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, and the like. Examples of signals may include electrical, optical, radio, sound, or other forms of propagation signals, such as carrier waves, infrared signals, etc.

[0093] Those skilled in the art will recognize that the units and algorithm steps described in connection with the various examples of this embodiment can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0094] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A two-stage planning method for a salt cavern integrated energy system, characterized in that, include: A comprehensive energy system model is constructed that includes different types of hydrogen storage salt cavern units. The objective function is to minimize the total cost of the comprehensive energy system, carbon dioxide emissions, and salt mine resource consumption. The hydrogen storage constraints, cushion gas constraints, and exhaust constraints of the hydrogen storage salt cavern units are introduced as constraints to construct a two-stage planning model. Based on the two-stage planning model, with the operating parameters of the integrated energy system model and salt mine resources as inputs, monthly planning simulations are performed at monthly intervals to determine the ratio of the hydrogen storage capacity of each type of hydrogen storage salt cavern unit to the maximum expansion capacity of the salt cavern at the end of each time period. Using the ratio as a new input, and under the hydrogen storage constraint constructed based on the new input, a year-round planning simulation is conducted at hourly intervals to determine the system planning strategy that includes the combined operation of hydrogen storage salt cavern units.

2. The two-stage planning method for a salt cavern integrated energy system as described in claim 1, characterized in that, The mathematical model and hydrogen storage constraints for the hydrogen storage salt cavern unit are as follows: ； ； in, yes t Time of the first i Hydrogen storage capacity of a hydrogen storage salt cavern unit; yes t- 1st moment i Hydrogen storage capacity of a hydrogen storage salt cavern unit; and They represent t Time of the first i Hydrogen charging power and hydrogen discharging power of a hydrogen storage salt cavern unit; , and They represent t Time of the first i Hydrogen charging conversion efficiency, hydrogen degassing conversion efficiency, and self-loss efficiency of a hydrogen storage salt cavern unit; and They are the first i The maximum hydrogen storage capacity and maximum charging / discharging power of the hydrogen storage salt cavern unit; It is the first i The upper limit of the installed capacity of hydrogen storage salt cavern units.

3. The two-stage planning method for a salt cavern integrated energy system as described in claim 1, characterized in that, The gas constraint of the hydrogen storage salt cavern unit is as follows: ； ； in, Indicates the first i The required percentage of cushion gas for safe operation of a hydrogen storage salt cavern unit; It is a 0-1 variable; when the hydrogen storage salt cavern unit meets the cushion gas requirements... A value of 1 indicates that the hydrogen storage salt cavern unit can safely release hydrogen at this time. When the hydrogen storage salt cavern unit does not meet the cushion gas requirements... A value of 0 indicates that the hydrogen storage salt cavern unit cannot release hydrogen at this time; express t Time of the first i Hydrogen release power of a hydrogen storage salt cavern unit; yes t Time of the first i Hydrogen storage capacity of a hydrogen storage salt cavern unit; and They are the first i The maximum hydrogen storage capacity and maximum charge / discharge power of the hydrogen storage salt cavern unit.

4. The two-stage planning method for a salt cavern integrated energy system as described in claim 1, characterized in that, The exhaust constraints for hydrogen storage salt cavern units are: ； ； in, It is the maximum gas volume that can pass through the i-th type of hydrogen storage salt cavern unit per unit time under the wellhead restriction; and They represent t Time of the first i Hydrogen charging power and hydrogen discharging power of a hydrogen storage salt cavern unit; and These are the gas pressure and temperature inside the salt cavern of the i-th type of hydrogen storage salt cavern unit; It is the specific heat ratio of hydrogen; It is an exclusion coefficient; It is the specific gravity of the gas air; This is a unit conversion factor; Let be the wellhead area of ​​the i-th type of hydrogen storage salt cavern unit.

5. The two-stage planning method for a salt cavern integrated energy system as described in claim 1, characterized in that, Salt mine resource usage for: ； in, and These are the conversion coefficient of the economic value of salt mine resources per unit of newly constructed salt caverns and the unit conversion coefficient, respectively. The number of types of hydrogen storage salt cavern units; The rated power of the i-th type of hydrogen storage salt cavern unit.

6. The two-stage planning method for a salt cavern integrated energy system as described in claim 1, characterized in that, Hydrogen storage capacity constraints are: ； in, This is the ratio of hydrogen storage capacity to the maximum expansion capacity of the salt cavern; t1 refers to the last hour of each month in a year. It is time t1. i Hydrogen storage capacity of a hydrogen storage salt cavern unit; It is the first i The maximum hydrogen storage capacity of this type of hydrogen storage salt cavern unit.

7. A two-stage planning system for a salt cavern integrated energy system, characterized in that, include: The model building module is configured to build a comprehensive energy system model that includes different types of hydrogen storage salt cavern units. The objective function is to minimize the total cost of the comprehensive energy system, carbon dioxide emissions, and salt mine resource consumption. The hydrogen storage constraints, cushion gas constraints, and exhaust constraints of the hydrogen storage salt cavern units are introduced as constraints to build a two-stage planning model. The first-stage planning module is configured to be based on a two-stage planning model, taking the operating parameters of the integrated energy system model and salt mine resources as inputs, and performing monthly planning simulations at monthly intervals to determine the ratio of the hydrogen storage capacity of each type of hydrogen storage salt cavern unit to the maximum expansion capacity of the salt cavern at the end of each time period. The second-stage planning module is configured to take the ratio as a new input and, under the hydrogen storage capacity constraint constructed based on the new input, perform annual planning simulation at hourly intervals to determine the system planning strategy including the combined operation of hydrogen storage salt cavern units.

8. An electronic device, characterized in that, It includes a memory and a processor, as well as computer instructions stored in the memory and running on the processor, which, when executed by the processor, perform the method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, Used to store computer instructions, which, when executed by a processor, perform the method described in any one of claims 1-6.

10. A computer program product, characterized in that, Includes a computer program, which, when executed by a processor, implements the method described in any one of claims 1-6.

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