A rural integrated energy system capacity configuration method considering hydrogen-carbon synergy

Abstract

The application discloses a kind of rural integrated energy system capacity configuration methods considering hydrogen-carbon cooperation, belong to integrated energy system planning and optimization configuration technical field, the technical scheme of the present application is to construct the system architecture including photovoltaic power generation unit, biomass biogas tank unit, gas power generation unit, gas heating unit, carbon capture and utilization unit, hydrogen energy storage unit and multiple energy storage units;Establish the capacity optimization configuration model with the minimum system total cost minimization as target, objective function covers equipment investment, annual operation cost, annual resource purchase cost, annual sales revenue, annual government subsidies, annual carbon tax expenditure and annual light loss;Equipment operation constraint, energy balance constraint, multi-substance balance constraint and standby capacity constraint are set for the model;Based on the load data and resource data of typical day, the model is solved using mixed integer linear programming algorithm, to obtain the optimal configuration capacity of various equipment.

Description

Technical Field

[0001] This invention belongs to the field of integrated energy system planning and optimization configuration technology, specifically involving capacity optimization configuration technology for rural distributed integrated energy systems. Background Technology

[0002] Rural areas possess abundant renewable resources such as solar and biomass energy, providing natural conditions for developing distributed integrated energy systems. Currently, most rural energy systems still rely primarily on traditional energy utilization methods, and the complementary and synergistic effects between different energy forms have not been fully realized. Furthermore, research on the application of advanced technologies such as carbon capture and utilization and hydrogen energy storage in rural settings is relatively limited.

[0003] Existing research on rural integrated energy system planning largely focuses on the combined optimization of traditional technologies such as photovoltaic power generation, biomass energy utilization, and energy storage batteries, without simultaneously incorporating carbon capture and utilization and hydrogen energy storage into the system integration scope. Rural biomass anaerobic fermentation and gas utilization processes generate large amounts of carbon dioxide. If this carbon dioxide could be captured and used for greenhouse gas fertilizer or methanation, a beneficial resource recycling model could be formed. However, the economic viability of small-scale carbon capture equipment and system integration schemes lack quantitative evaluation. Research on hydrogen energy storage mainly targets large-scale centralized projects, while rural areas are characterized by small-scale loads and dispersed energy consumption, making the capacity matching and functional positioning of small-scale hydrogen energy systems unclear.

[0004] At the level of capacity optimization, existing methods do not incorporate carbon capture, carbon recycling and hydrogen storage into a unified optimization framework, making it impossible to fully assess the comprehensive benefits of the coordinated operation of multiple energy carriers and failing to meet the actual needs of low-carbon and high-efficiency development of rural energy systems. Summary of the Invention

[0005] The purpose of this invention is to provide a capacity configuration method for rural integrated energy systems that considers hydrogen-carbon synergy, in order to solve the problem that existing rural integrated energy systems do not simultaneously integrate carbon capture and utilization with hydrogen energy storage, and that the capacity optimization framework does not cover multi-material synergy.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A method for configuring the capacity of a rural integrated energy system that considers hydrogen-carbon synergy includes the following steps:

[0008] A rural integrated energy system architecture was constructed, resulting in a system topology that includes multiple types of energy conversion and storage units;

[0009] Based on the system topology, a capacity optimization configuration model is established with the goal of minimizing the total annual cost of the system.

[0010] Set multi-dimensional constraints for the capacity optimization configuration model;

[0011] Based on load and resource data of a typical day, the capacity optimization configuration model is solved to obtain the optimal configuration capacity of various equipment in the rural integrated energy system.

[0012] In one possible implementation, the step of constructing a rural integrated energy system architecture to obtain a system topology containing multiple types of energy conversion and storage units includes:

[0013] Integrate photovoltaic power generation units, biomass biogas digester units, gas-fired power generation units, gas-fired heating units, carbon capture and utilization units, hydrogen energy storage units, and various energy storage units to construct a comprehensive rural energy system architecture;

[0014] The carbon capture and utilization unit captures carbon dioxide generated during gas-fired power generation and gas-fired heating, and stores all the captured carbon dioxide in a carbon storage tank.

[0015] The electrolyzer, fuel cell, and hydrogen storage tank in the hydrogen energy storage unit are used to achieve the conversion and storage of electricity-hydrogen-electricity.

[0016] Energy storage batteries, methane storage tanks, carbon storage tanks, and hydrogen storage tanks are integrated into the rural integrated energy system architecture as various energy storage units.

[0017] The carbon storage tank is used to store carbon dioxide captured by the carbon capture device, and the carbon dioxide is released according to the greenhouse gas fertilizer demand, resulting in a system topology that includes multiple energy conversion and storage units.

[0018] In one possible implementation, the step of establishing a capacity optimization configuration model based on the system topology with the objective of minimizing the system's total annual cost includes:

[0019] The initial investment in various types of equipment in the system is converted using an equal-amount capital recovery factor to obtain the equivalent annual value of the equipment investment.

[0020] The annual operation and maintenance costs of various equipment in the statistical system are used to obtain the annual operation and maintenance cost.

[0021] The annual resource acquisition cost is calculated by summing the costs of biomass raw materials, electricity purchased from the power grid, and heat purchased from the heating network in the statistical system.

[0022] The annual sales revenue is calculated by summing the revenue from the sale of excess methane and the sales of oxygen produced as a byproduct of electrolysis cells in the statistical system.

[0023] The operating subsidy is calculated based on the photovoltaic power generation, biomass power generation, electrolyzer power consumption, and fuel cell power generation.

[0024] The one-time investment subsidy is calculated based on the investment amount in carbon capture equipment and fuel cells;

[0025] The annual government subsidy is obtained by summing the operating subsidy and the one-time investment subsidy.

[0026] The annual carbon tax expenditure is calculated based on the emissions tax levied on uncaptured carbon dioxide in the statistical system.

[0027] The potential revenue loss caused by annual curtailment of solar power in the statistical system is obtained as the annual curtailment loss.

[0028] By integrating the annual value of equipment investment, annual operation and maintenance costs, annual resource acquisition costs, annual sales revenue, annual government subsidies, annual carbon tax expenditures, and annual curtailment losses, a capacity optimization configuration model is established with the goal of minimizing the total annual cost of the system.

[0029] In one possible implementation, the step of setting multi-dimensional constraints for the capacity optimization configuration model includes:

[0030] Set equipment operation constraints for the capacity optimization configuration model, including capacity constraints and ramp-up constraints for various types of equipment;

[0031] Energy balance constraints are set for the capacity optimization configuration model, including electrical energy balance constraints and thermal energy balance constraints.

[0032] Multi-substance balance constraints are set for the capacity optimization configuration model, including methane balance constraints, carbon dioxide balance constraints and hydrogen balance constraints.

[0033] By setting standby capacity constraints for the capacity optimization configuration model, a capacity optimization configuration model with multi-dimensional constraints is obtained.

[0034] In one possible implementation, the step of setting power balance constraints for the capacity optimization configuration model includes:

[0035] Photovoltaic power generation, gas generator power generation, fuel cell power generation, energy storage battery discharge, and grid power purchase are used as the system's power sources;

[0036] The electrical load consumption, the power consumption of carbon capture equipment, the power consumption of electrolyzers, and the charging of energy storage batteries are considered as the system's power consumption.

[0037] Based on the power sources and power consumption, real-time power balance constraints are set for the system to ensure that the total power on the generation side is equal to the total power on the consumption side.

[0038] In one possible implementation, the step of setting thermal balance constraints for the capacity optimization configuration model includes:

[0039] The system uses gas-fired boiler heating and heat purchased from the heat network as its heat energy sources.

[0040] Heat load consumption is considered as system heat energy consumption;

[0041] Based on the heat energy sources and heat energy consumption, real-time heat energy balance constraints are set for the system.

[0042] In one possible implementation, the step of setting methane balance constraints and hydrogen balance constraints for the capacity optimization configuration model includes:

[0043] The methane produced by the biogas digester and the gas released from the methane storage tank are used as the methane source for the system.

[0044] The methane consumed by the gas-fired power generation unit, the methane consumed by the gas-fired heating unit, the gas filling of the methane storage tank, and the methane sold externally are considered as the system's methane sink;

[0045] Based on the methane source and methane sink, set the real-time methane balance constraint conditions for the system;

[0046] The hydrogen source for the system is the hydrogen produced by the electrolyzer and the venting of the hydrogen storage tank.

[0047] The hydrogen consumption of the fuel cell and the filling of the hydrogen storage tank are used as the hydrogen sink of the system.

[0048] Based on the hydrogen source and hydrogen sink, the real-time hydrogen balance constraint conditions of the system are set.

[0049] In one possible implementation, the step of setting carbon dioxide balance constraints for the capacity optimization configuration model includes:

[0050] The carbon dioxide separated from the biogas digester, the carbon dioxide emitted by the gas-fired power generation unit, the carbon dioxide emitted by the gas-fired heating unit, and the gas released from the carbon storage tank are used as carbon sources for the system.

[0051] The carbon sink system is used to fill the carbon storage tank with gas, supply carbon dioxide to greenhouse gas fertilizer, and directly release carbon dioxide into the atmosphere.

[0052] The carbon dioxide captured by the carbon capture device is implicitly represented by the amount of gas filling the carbon storage tank, and a constraint condition is set that all the captured carbon dioxide is stored in the carbon storage tank.

[0053] Based on the constraints of carbon source, carbon sink and carbon capture, the real-time carbon dioxide balance constraint conditions of the system are set.

[0054] In one possible implementation, the step of setting standby capacity constraints for the capacity optimization configuration model includes:

[0055] The total system reserve capacity is obtained by summing the reserve capacity of the gas generator, the fuel cell, the energy storage battery, and the grid reserve capacity.

[0056] The system's total reserve capacity is set to be no less than a preset proportion of the electrical load demand after taking into account prediction errors.

[0057] In one possible implementation, the step of solving the capacity optimization configuration model based on typical daily load and resource data to obtain the optimal configuration capacity of various equipment in the rural integrated energy system includes:

[0058] Obtain hourly electricity load data, hourly heat load data, hourly photovoltaic power output data, time-of-use electricity price data, heat price data, and biomass feedstock price data for typical days;

[0059] A mixed-integer linear programming algorithm is used to solve the capacity optimization configuration model using a commercial solver.

[0060] It outputs the optimal configuration capacity of photovoltaic power generation units, biomass biogas digester units, gas-fired power generation units, gas-fired heating units, carbon capture and utilization units, hydrogen energy storage units, and various energy storage units.

[0061] Compared with existing technologies, the advantages of this invention are as follows: The rural integrated energy system architecture constructed by this invention simultaneously incorporates carbon capture and utilization units and hydrogen energy storage units into the system scope, integrating photovoltaic power generation, biomass energy utilization, gas-fired power generation for heating, and various energy storage forms to form a multi-energy complementary system covering multiple energy carriers. Compared with existing systems that only use combinations of traditional energy technologies, this architecture can achieve the recycling of carbon and hydrogen elements, improve the absorption capacity of renewable energy, and reduce dependence on fossil fuels.

[0062] The capacity optimization configuration model established in this invention aims to minimize the total annual cost of the system, comprehensively considering various economic factors such as equipment investment, operation and maintenance, resource procurement, product sales, government subsidies, carbon tax expenditures, and curtailment losses. Compared with optimization methods that do not fully incorporate the above economic factors, this model can more accurately reflect the actual operating cost of the system, providing a quantitative basis for the rational allocation of equipment capacity.

[0063] The constraints set by this invention cover multiple dimensions, including equipment operation, energy balance, multi-substance balance, and reserve capacity, clearly defining the real-time balance relationship of electrical energy, thermal energy, methane, carbon dioxide, and hydrogen. Compared with existing methods that only consider a single energy balance, this constraint system can ensure the stability of the system under the coordinated operation of multiple substances, avoiding operational failures caused by imbalances in substance supply and demand.

[0064] In practical applications, systems configured using the method of this invention have lower annual comprehensive costs, higher energy self-sufficiency rates, and lower solar curtailment rates compared to systems that do not simultaneously integrate carbon capture and utilization and hydrogen energy storage. Experimental data show that systems that simultaneously incorporate carbon cycling and hydrogen energy storage can effectively reduce carbon emissions and improve the overall economic and environmental benefits of the system while ensuring the reliability of power and heat supply. Attached Figure Description

[0065] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0066] Figure 1 This is one of the flowcharts of the capacity configuration method for a rural integrated energy system considering hydrogen-carbon synergy in an embodiment of the present invention;

[0067] Figure 2 This is a schematic diagram of the rural integrated energy system architecture according to an embodiment of the present invention;

[0068] Figure 3 This is a power balance stacking diagram for scenario C4 in an embodiment of the present invention;

[0069] Figure 4 This is a thermal power balance stacking diagram for scenario C4 in an embodiment of the present invention;

[0070] Figure 5 This is a scenario-based C4 methane equilibrium stacking diagram and a methane storage variation curve from an embodiment of the present invention.

[0071] Figure 6 This is a scenario-based C4 carbon balance stacking diagram and a carbon storage variation curve diagram according to an embodiment of the present invention.

[0072] Figure 7 This is a scenario-based C4 hydrogen balance stacking diagram and hydrogen storage capacity variation curve of an embodiment of the present invention;

[0073] Figure 8 This is the second flowchart of the capacity configuration method for a rural integrated energy system considering hydrogen-carbon synergy, according to an embodiment of the present invention. Detailed Implementation

[0074] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0075] Example:

[0076] It should be noted that the terms "comprising" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products, or devices.

[0077] See Figure 8 This embodiment provides a capacity configuration method for a rural integrated energy system that considers hydrogen-carbon synergy, including the following steps:

[0078] Step 101: Construct a rural integrated energy system architecture to obtain a system topology that includes multiple types of energy conversion and storage units.

[0079] Specifically, the architecture of a rural integrated energy system can be a multi-energy complementary system structure that integrates various renewable energy sources and energy storage technologies; the system topology can be the energy and material flow connection relationship between various devices within the system.

[0080] The step of constructing a rural integrated energy system architecture to obtain a system topology containing multiple types of energy conversion and storage units includes:

[0081] Integrate photovoltaic power generation units, biomass biogas digester units, gas-fired power generation units, gas-fired heating units, carbon capture and utilization units, hydrogen energy storage units, and various energy storage units to construct a comprehensive rural energy system architecture;

[0082] The carbon capture and utilization unit captures carbon dioxide generated during gas-fired power generation and gas-fired heating, and stores all the captured carbon dioxide in a carbon storage tank.

[0083] The electrolyzer, fuel cell, and hydrogen storage tank in the hydrogen energy storage unit are used to achieve the conversion and storage of electricity-hydrogen-electricity.

[0084] Energy storage batteries, methane storage tanks, carbon storage tanks, and hydrogen storage tanks are integrated into the rural integrated energy system architecture as various energy storage units.

[0085] The carbon storage tank is used to store carbon dioxide captured by the carbon capture device, and the carbon dioxide is released according to the greenhouse gas fertilizer demand, resulting in a system topology that includes multiple energy conversion and storage units.

[0086] Specifically, a photovoltaic power generation unit can be a photovoltaic module array that converts solar energy into electrical energy; a biomass biogas digester unit can be a device that converts biomass raw materials into biogas through anaerobic fermentation; a gas-fired power generation unit can be a gas-fired generator set that burns methane to generate electricity; a gas-fired heating unit can be a gas-fired boiler that burns methane for heating; a carbon capture and utilization unit can be a device that captures carbon dioxide from flue gas and utilizes it as a resource; a hydrogen energy storage unit can be a system that realizes the mutual conversion and storage of electrical energy and hydrogen energy; an energy storage battery can be an electrochemical energy storage device that stores electrical energy; a methane storage tank can be a pressure vessel that stores methane gas; a carbon storage tank can be a pressure vessel that stores carbon dioxide gas; and a hydrogen storage tank can be a pressure vessel that stores hydrogen gas.

[0087] For example, the mathematical models of each device are as follows: (1) Photovoltaic power generation model

[0088] Assume the original number of photovoltaic modules in the rural integrated energy system is . Rated power is The number of newly added photovoltaic modules is Rated power is If the rated power of a single module is 550 W (the dimensions of a single module are 2.3 m × 1.1 m), then the total rated power of the photovoltaic system is... It is derived from the following expression: ;

[0089] The number of new photovoltaic modules is an integer decision variable, which is limited by the available land area.

[0090] In the formula: This represents the total area of ​​newly added photovoltaic modules; This represents the maximum installable photovoltaic area.

[0091] Calculate the maximum power point tracking (MPPT) power output of photovoltaic power based on the per-unit output curve. :

[0092] In the formula: This represents the per-unit value of photovoltaic power output during time period t.

[0093] Actual photovoltaic output can be adjusted below the MPPT power, subject to the following constraints:

[0094] In the formula: and These represent the actual photovoltaic power generation and the curtailed power during time period t, respectively.

[0095] (2) Biomass biogas digester model

[0096] The original rural system was equipped with an anaerobic digester, which converted biomass raw materials into biogas and separated CH4 and CO2 in a fixed ratio (6:4). Its gas production met the following relationship: ;

[0097] In the formula: , and The figures represent the biogas production of the biogas digester during time period t and the volumes of CH4 and CO2 within it (m³). 3 ); The amount of biomass raw material (kg) put into the biogas digester during time period t. Gas production rate (m 3 / kg).

[0098] Considering the actual capacity for collecting and transporting biomass raw materials in rural areas, and ensuring the continuous operation of biogas digesters, the following constraints should also be added:

[0099] In the formula: , These represent the maximum and minimum biomass feedstock processing capacity (kg) of the biogas digester for each time period.

[0100] (3) Gas generator model

[0101] The rural system originally had one set of equipment with a capacity of... The power generation capacity of a gas-fired generator set can be expressed as:

[0102] In the formula: Let t be the electrical power generated by the gas generator during time period t; For power generation efficiency; The lower heating value of CH4 (kWh / m³) 3 ); The volume of CH4 consumed by the gas generator during time period t.

[0103] The CO2 emissions from gas-fired power generation are:

[0104] In the formula: The CO2 emitted by the gas generator during time period t; Carbon emission factor (m3 CO2 / m 3 CH4).

[0105] In addition, gas generators must also meet capacity constraints and ramping constraints during operation: ;

[0106] In the formula: and These represent the downhill and uphill ramp rates of the gas generator, respectively.

[0107] (4) Gas boiler model

[0108] The village originally had one set of equipment with a capacity of... The thermal power of a gas-fired boiler unit can be expressed as:

[0109] In the formula: The heat output of the gas-fired boiler during time period t; For thermal efficiency; The volume of CH4 consumed by the gas-fired boiler during time period t.

[0110] The CO2 emissions from a gas-fired boiler are:

[0111] In the formula: This represents the CO2 emitted by the gas-fired boiler during time period t.

[0112] Similar to gas generators, gas boilers also need to meet capacity constraints and ramp-up constraints during operation: ;

[0113] In the formula: and These represent the downhill and uphill ramp rates of the gas-fired boiler, respectively.

[0114] (5) Carbon capture equipment model

[0115] Carbon capture equipment is used to capture CO2 emitted from gas generators and gas boilers. Its operation is governed by the following equation: ; ; ;

[0116] In the formula: The volume of CO2 captured by the carbon capture device during time period t (m³) 3 ); For carbon capture efficiency; The power consumption of the carbon capture equipment during time period t; The power consumption factor (kWh / m³) of carbon capture equipment 3 CO2); The configuration capacity of the carbon capture equipment; and These represent the downhill and uphill ramp rates of the carbon capture equipment, respectively.

[0117] (6) Electrolytic cell model

[0118] An electrolyzer produces H2 by electrolyzing water using electrical energy. The power consumption during time period t is... With hydrogen production and oxygen production It is given by the following formula: ;

[0119] In the formula: The power consumption coefficient for hydrogen production (kWh / m³) 3 H2).

[0120] In addition, its operation must also meet capacity constraints and ramping constraints: ;

[0121] In the formula: The configuration capacity of the electrolytic cell; This is the minimum operating power of the electrolytic cell; and These represent the downward and upward ramp rates of the electrolytic cell, respectively.

[0122] (7) Fuel cell model

[0123] Fuel cells generate electricity by consuming hydrogen; their power output during time period t is... Hydrogen consumption The following relationship must be satisfied:

[0124] In the formula: For fuel cell power generation efficiency; The lower heating value of H2 (kWh / m³) 3 ); H2 density (kg / m³) 3 ).

[0125] Its operation must meet capacity constraints and ramping constraints: ;

[0126] In the formula: Rated power for fuel cells; This represents the minimum operating power for a fuel cell; and These represent the downhill and uphill ramp rates of the fuel cell, respectively.

[0127] (8) Energy storage battery model

[0128] The village originally had one set of equipment with a capacity of... The plan includes adding more energy storage batteries to match the increase in renewable energy, with a new capacity of [missing information]. The total capacity of the energy storage battery for:

[0129] The power constraints of energy storage batteries are expressed as follows: ;

[0130] In the formula: , and These represent the output power, charging power, and discharging power of the energy storage battery during time period t. , The variable is 0-1, representing the charge / discharge state of the energy storage battery during time period t; and These are the maximum charge and discharge rates of the energy storage battery, respectively.

[0131] The state-of-charge (SOC) operating constraints of energy storage batteries are expressed as follows: ;

[0132] In the formula: The state of charge of the energy storage battery during time period t; , These are the charging and discharging efficiencies of the energy storage battery, respectively. , These are the minimum and maximum charge levels of the energy storage battery, respectively. In addition, to meet the requirements of daily cycle operation, the state of charge at the beginning and end of each day is set to be equal, which is set to 50% capacity.

[0133] (9) Methane storage tank model

[0134] Methane storage tanks are used to balance the production and consumption needs of CH4, and their storage capacity meets the following dynamic balance:

[0135] In the formula: , and These represent the storage capacity, filling capacity, and venting capacity of the methane storage tank during time period t (m³). 3 These parameters also need to meet the following constraints: ;

[0136] In the formula: Configuration capacity (m³) of methane storage tank 3 ); , The variable is 0-1, representing the charging and discharging status of the methane storage tank during time period t; , These represent the minimum and maximum gas storage capacities of the methane storage tank, respectively. , These represent the maximum charging and discharging rates for the methane storage tank. These constraints ensure the daily cycle requirements are met and prevent charging and discharging from occurring simultaneously.

[0137] (10) Carbon storage tank model

[0138] Carbon storage tanks are used to balance CO2 production and consumption needs, and the following constraints apply: ; ;

[0139] The expressions and variable definitions are based on the methane storage tank model, and will not be elaborated here.

[0140] (11) Hydrogen storage tank model

[0141] Hydrogen storage tanks are used to balance the production and consumption needs of H2. Similar to methane and carbon storage tanks, hydrogen storage tanks also involve the following constraints:

[0142] ;

[0143] The expressions and variable definitions are based on the methane storage tank model, and will not be elaborated here.

[0144] Step 102: Based on the system topology, establish a capacity optimization configuration model with the goal of minimizing the total annual cost of the system.

[0145] Specifically, the capacity optimization configuration model can be a mathematical optimization model used to solve for the optimal configuration capacity of various types of equipment.

[0146] The step of establishing a capacity optimization configuration model based on the system topology with the objective of minimizing the total annual cost of the system includes:

[0147] The initial investment in various types of equipment in the system is converted using an equal-amount capital recovery factor to obtain the equivalent annual value of the equipment investment.

[0148] The annual operation and maintenance costs of various equipment in the statistical system are used to obtain the annual operation and maintenance cost.

[0149] The annual resource acquisition cost is calculated by summing the costs of biomass raw materials, electricity purchased from the power grid, and heat purchased from the heating network in the statistical system.

[0150] The annual sales revenue is calculated by summing the revenue from the sale of excess methane and the sales of oxygen produced as a byproduct of electrolysis cells in the statistical system.

[0151] The operating subsidy is calculated based on the photovoltaic power generation, biomass power generation, electrolyzer power consumption, and fuel cell power generation.

[0152] The one-time investment subsidy is calculated based on the investment amount in carbon capture equipment and fuel cells;

[0153] The annual government subsidy is obtained by summing the operating subsidy and the one-time investment subsidy.

[0154] The annual carbon tax expenditure is calculated based on the emissions tax levied on uncaptured carbon dioxide in the statistical system.

[0155] The potential revenue loss caused by annual curtailment of solar power in the statistical system is obtained as the annual curtailment loss.

[0156] By integrating the annual value of equipment investment, annual operation and maintenance costs, annual resource acquisition costs, annual sales revenue, annual government subsidies, annual carbon tax expenditures, and annual curtailment losses, a capacity optimization configuration model is established with the goal of minimizing the total annual cost of the system.

[0157] Specifically, the equal-payment capital recovery factor can be a factor that converts the initial investment in equipment into an equivalent annual value; the equivalent annual value of equipment investment can be the annual equivalent expenditure calculated based on the service life of the initial investment in equipment; the annual operation and maintenance cost can be the total annual operation and maintenance cost of all types of equipment in the system; the annual resource acquisition cost can be the total annual cost of purchasing all types of energy and raw materials in the system; the annual sales revenue can be the total annual revenue from the sale of surplus energy and by-products in the system; the operation subsidy can be an annual subsidy based on the actual power generation or power consumption of the system; the one-time investment subsidy can be a one-time subsidy for specific equipment investment; the annual carbon tax expenditure can be the tax payable by the system for the annual emission of uncaptured carbon dioxide; and the annual curtailment loss can be the potential economic loss caused by the curtailment of solar power in the system in the year.

[0158] For example, with the optimization objective of minimizing the system's total annual cost, the following factors are considered: annual investment value, operation and maintenance costs, resource acquisition costs, sales revenue, government subsidies, carbon tax expenditures, and curtailment losses. The objective function expression is as follows:

[0159] The specific composition of each component in the formula is as follows:

[0160] (1) Annual value of investment

[0161] The initial investment of each piece of equipment is converted to an equivalent annual value using an equal-amount capital recovery factor. The equipment considered includes: new photovoltaic systems, carbon capture equipment, electrolyzers, fuel cells, new energy storage batteries, methane storage tanks, carbon storage tanks, and hydrogen storage tanks. The calculation formula is as follows: ;

[0162] In the formula: is the capital recovery factor for the equal installment payment of equipment of type i; d is the discount rate, taken as 10%; The service life of the i-th type of equipment; The unit investment cost of equipment of type i; Let be the configuration capacity of the i-th type of device.

[0163] (2) Annual operation and maintenance costs

[0164] Maintenance costs are calculated on a fixed annual rate, proportional to equipment capacity or processing power, and apply to all equipment mentioned in Section 2.2. The calculation formula is as follows:

[0165] In the formula: The unit operation and maintenance cost of equipment of type j; Let be the capacity or processing capability variable for the j-th type of equipment.

[0166] (3) Annual resource acquisition cost

[0167] The annual resource costs incurred during the system's operation period include: biomass raw material costs, electricity purchase costs from the power grid, and heat purchase costs from external heating networks. These costs are accumulated monthly.

[0168] In the formula: This represents the number of days in the m-th month; This refers to the unit price of biomass raw materials; Time-of-use pricing; This is the price for hot items.

[0169] (4) Annual sales revenue

[0170] The system generates annual revenue by selling excess methane and oxygen produced as a byproduct of the electrolyzer:

[0171] In the formula: , These are the unit prices for methane and oxygen, respectively.

[0172] (5) Annual government subsidies

[0173] The subsidy income consists of two parts: first, an operating subsidy, provided based on actual power generation or consumption, covering subsidies for photovoltaic power generation, biomass power generation, carbon capture rewards, electricity subsidies for electrolyzers, and fuel cell power generation; second, a one-time investment subsidy, provided as a percentage of the investment in carbon capture equipment and fuel cells, which is also converted to an equivalent annual value using a capital recovery factor. In other words:

[0174] In the formula: , , , These are the unit subsidy prices for photovoltaic power generation, gas-fired power generation, electricity used in electrolytic cells, and fuel cell power generation, respectively. The unit price for carbon capture incentives; , These are the investment subsidy ratios for carbon capture equipment and fuel cells, respectively.

[0175] (6) Annual carbon tax expenditure

[0176] A carbon tax will be levied on CO2 emitted directly without being captured.

[0177] In the formula: This is the unit price for carbon tax.

[0178] (7) Annual curtailment loss

[0179] To incentivize the system to maximize the absorption of photovoltaic power generation, curtailment losses are factored into the total cost. The potential revenue loss due to curtailment is estimated based on the grid purchase price for the corresponding curtailment period:

[0180] Step 103: Set multi-dimensional constraints for the capacity optimization configuration model.

[0181] Specifically, multi-dimensional constraints can be various restrictions that ensure the safe and stable operation of the system.

[0182] The step of setting multi-dimensional constraints for the capacity optimization configuration model includes:

[0183] Set equipment operation constraints for the capacity optimization configuration model, including capacity constraints and ramp-up constraints for various types of equipment;

[0184] Energy balance constraints are set for the capacity optimization configuration model, including electrical energy balance constraints and thermal energy balance constraints.

[0185] Multi-substance balance constraints are set for the capacity optimization configuration model, including methane balance constraints, carbon dioxide balance constraints and hydrogen balance constraints.

[0186] By setting standby capacity constraints for the capacity optimization configuration model, a capacity optimization configuration model with multi-dimensional constraints is obtained.

[0187] Specifically, equipment operation constraints can be conditions that limit the operating status and output power of equipment; capacity constraints can be restrictions that prevent the output power of equipment from exceeding its rated capacity; ramp constraints can be restrictions that prevent the change in output power of equipment between adjacent time periods from exceeding a set value; energy balance constraints can be conditions that ensure that the energy supply and demand of the system are equal in real time; multi-material balance constraints can be conditions that ensure that the supply and demand of various working fluids in the system are equal in real time; and standby capacity constraints can be standby capacity requirements that ensure the reliability of the system's power supply.

[0188] Furthermore, the step of setting power balance constraints for the capacity optimization configuration model includes:

[0189] Photovoltaic power generation, gas generator power generation, fuel cell power generation, energy storage battery discharge, and grid power purchase are used as the system's power sources;

[0190] The electrical load consumption, the power consumption of carbon capture equipment, the power consumption of electrolyzers, and the charging of energy storage batteries are considered as the system's power consumption.

[0191] Based on the power sources and power consumption, real-time power balance constraints are set for the system to ensure that the total power on the generation side is equal to the total power on the consumption side.

[0192] Specifically, the source of system power can be any link in the system that generates power; the consumption of system power can be any link in the system that consumes power; and the real-time power balance constraint can be a mathematical expression that requires the total power on the generation side to be equal to the total power on the consumption side at any given time.

[0193] Furthermore, the step of setting thermal energy balance constraints for the capacity optimization configuration model includes:

[0194] The system uses gas-fired boiler heating and heat purchased from the heat network as its heat energy sources.

[0195] Heat load consumption is considered as system heat energy consumption;

[0196] Based on the heat energy sources and heat energy consumption, real-time heat energy balance constraints are set for the system.

[0197] Specifically, the source of system heat energy can be any link in the system that generates heat energy; the consumption of system heat energy can be any link in the system that consumes heat energy; and the real-time heat energy balance constraint can be a mathematical expression that requires the total power on the heat-generating side to be equal to the total power on the heat-consuming side at any given time.

[0198] Furthermore, the step of setting methane balance constraints and hydrogen balance constraints for the capacity optimization configuration model includes:

[0199] The methane produced by the biogas digester and the gas released from the methane storage tank are used as the methane source for the system.

[0200] The methane consumed by the gas-fired power generation unit, the methane consumed by the gas-fired heating unit, the gas filling of the methane storage tank, and the methane sold externally are considered as the system's methane sink;

[0201] Based on the methane source and methane sink, set the real-time methane balance constraint conditions for the system;

[0202] The hydrogen source for the system is the hydrogen produced by the electrolyzer and the venting of the hydrogen storage tank.

[0203] The hydrogen consumption of the fuel cell and the filling of the hydrogen storage tank are used as the hydrogen sink of the system.

[0204] Based on the hydrogen source and hydrogen sink, the real-time hydrogen balance constraint conditions of the system are set.

[0205] Specifically, a system methane source can be any stage within the system that produces methane; a system methane sink can be any stage within the system that consumes or stores methane; a system hydrogen source can be any stage within the system that produces hydrogen; and a system hydrogen sink can be any stage within the system that consumes or stores hydrogen.

[0206] Furthermore, the step of setting carbon dioxide balance constraints for the capacity optimization configuration model includes:

[0207] The carbon dioxide separated from the biogas digester, the carbon dioxide emitted by the gas-fired power generation unit, the carbon dioxide emitted by the gas-fired heating unit, and the gas released from the carbon storage tank are used as carbon sources for the system.

[0208] The carbon sink system is used to fill the carbon storage tank with gas, supply carbon dioxide to greenhouse gas fertilizer, and directly release carbon dioxide into the atmosphere.

[0209] The carbon dioxide captured by the carbon capture device is implicitly represented by the amount of gas filling the carbon storage tank, and a constraint condition is set that all the captured carbon dioxide is stored in the carbon storage tank.

[0210] Based on the constraints of carbon source, carbon sink and carbon capture, the real-time carbon dioxide balance constraint conditions of the system are set.

[0211] Specifically, a system carbon source can be any stage within the system that generates carbon dioxide; a system carbon sink can be any stage within the system that consumes or stores carbon dioxide; and carbon capture constraints can be restrictions that require all carbon dioxide captured by carbon capture equipment to be stored in carbon storage tanks and not directly emitted.

[0212] Furthermore, the step of setting standby capacity constraints for the capacity optimization configuration model includes:

[0213] The total system reserve capacity is obtained by summing the reserve capacity of the gas generator, the fuel cell, the energy storage battery, and the grid reserve capacity.

[0214] The system's total reserve capacity is set to be no less than a preset proportion of the electrical load demand after taking into account prediction errors.

[0215] Specifically, the standby capacity of a gas generator can be the difference between the rated capacity of the gas generator and its current output; the standby capacity of a fuel cell can be the difference between the rated capacity of the fuel cell and its current output; the standby capacity of an energy storage battery can be the current discharge capacity of the energy storage battery; the standby capacity of the power grid can be the difference between the maximum power purchase capacity of the power grid and the current power purchase capacity; the total standby capacity of the system can be the sum of the above four types of standby capacity; and the preset ratio can be the minimum standby rate requirement for ensuring power supply reliability.

[0216] For example, (1) constraints on electricity and heat purchases

[0217] The electricity purchased from the grid should meet the following constraints:

[0218] In the formula: This represents the amount of electricity purchased by the integrated energy system from the grid during time period t; This indicates the maximum amount of electricity that can be purchased.

[0219] Similarly, the purchased calories should meet the following requirements:

[0220] In the formula: This represents the amount of heat purchased by the integrated energy system from the heating network during time period t; This indicates the maximum amount of heat that can be purchased.

[0221] (2) Reserve capacity constraints

[0222] To ensure system power supply reliability, sufficient reserve capacity must be reserved to cope with prediction errors. The total reserve capacity of the system during time period t. Backup power generation from gas Fuel cell backup Backup energy storage batteries and power grid reserves constitute:

[0223] The calculation methods for each spare component are as follows:

[0224] Biomass power generation backup: The difference between the rated capacity and current output of a gas generator, i.e. ;

[0225] Fuel cell standby: The difference between the rated capacity and the current output of a fuel cell, i.e. ;

[0226] Backup energy storage batteries: Current discharge capacity, constrained by discharge rate and state of charge, i.e. ;

[0227] Grid reserve: The difference between the grid's maximum power purchase capacity and the current power purchase volume, i.e. .

[0228] The total system reserve capacity must be no less than a certain percentage of the load demand after taking into account forecasting errors.

[0229] In the formula: Reserve ratio; This refers to the load forecasting error coefficient. Let t be the electrical load during time period t.

[0230] (3) Energy balance

[0231] The system needs to achieve real-time power balance, meaning the power generated and consumed are equal. In the entire system, power generation includes photovoltaics, gas generators, fuel cells, discharging of energy storage batteries, and grid purchases; power consumption includes electrical loads, carbon capture equipment, electrolyzers, and charging of energy storage batteries. Therefore, the power balance equation is:

[0232] In addition, real-time heat energy balance must be maintained. Heat generation occurs through gas-fired boilers and purchased heat from the heating network; heat consumption occurs solely through heat load. The balance equation is as follows:

[0233] In the formula: Let t be the heat load of the system during time period t.

[0234] (4) Multi-material equilibrium constraints

[0235] The system needs to maintain a real-time balance of the three working fluids: CH4, CO2, and H2.

[0236] Methane balance:

[0237] Methane sources include venting from biogas digesters and methane storage tanks; destinations include gas generators, gas boilers, filling methane storage tanks, and selling excess methane. The balance equation is:

[0238] In the formula: For CH4 sold by the system during time period t, it must meet the upper limit constraint:

[0239] In the formula: This represents the maximum amount of methane sold per unit time period.

[0240] Carbon balance:

[0241] Carbon dioxide sources include biogas digesters, emissions from gas-fired generators, emissions from gas-fired boilers, and venting from carbon storage tanks; destinations include carbon storage tank refilling, crop fertilization, and direct emissions. The balance equation is as follows:

[0242] In the formula: The amount of gas fertilizer used by the system during time period t; Let t represent the total carbon emissions of the system during time period t.

[0243] It is important to note that while CO2 captured by carbon capture devices does not participate in the carbon balance, it is implicitly present as a hidden variable in the process. All captured CO2 must be stored; it cannot be used directly and must not be emitted. Therefore:

[0244] All CO2 released from the carbon storage tank will be used for gas fertilizer and must not be emitted.

[0245] Meanwhile, referring to the above formula, all uncaptured CO2 is assumed to be emitted, and some of the emitted CO2 may also come from biogas:

[0246] Hydrogen balance:

[0247] Hydrogen sources include venting from the electrolyzer and hydrogen storage tanks; destinations include refilling fuel cells and hydrogen storage tanks. The balance equation is:

[0248] Step 104: Based on the load data and resource data of a typical day, solve the capacity optimization configuration model to obtain the optimal configuration capacity of various equipment in the rural integrated energy system.

[0249] Specifically, the load data and resource data for a typical day can be hourly data representing the electricity and heat consumption characteristics and renewable energy output characteristics of different seasons; the optimal configuration capacity can be the installed capacity of various equipment that minimizes the total annual cost of the system.

[0250] The step of solving the capacity optimization configuration model based on typical daily load and resource data to obtain the optimal configuration capacity of various equipment in the rural integrated energy system includes:

[0251] Obtain hourly electricity load data, hourly heat load data, hourly photovoltaic power output data, time-of-use electricity price data, heat price data, and biomass feedstock price data for typical days;

[0252] A mixed-integer linear programming algorithm is used to solve the capacity optimization configuration model using a commercial solver.

[0253] It outputs the optimal configuration capacity of photovoltaic power generation units, biomass biogas digester units, gas-fired power generation units, gas-fired heating units, carbon capture and utilization units, hydrogen energy storage units, and various energy storage units.

[0254] Specifically, typical daily data can be hourly data representing the characteristics of electricity and heat consumption and renewable energy output in different seasons; mixed integer linear programming algorithms can be algorithms used to solve linear optimization problems containing integer and continuous variables; commercial solvers can be professional software tools used to solve large-scale mathematical optimization problems, such as Gurobi or CPLEX.

[0255] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0256] Figure 1 This is a flowchart of the capacity configuration method for a rural integrated energy system considering hydrogen-carbon synergy, according to an embodiment of the present invention. The flowchart clearly shows the complete implementation steps of the method in the order of execution: constructing a rural integrated energy system architecture that includes multiple types of energy conversion and storage units; establishing a capacity optimization configuration model with the goal of minimizing the total annual cost of the system; setting multi-dimensional constraints for the model that cover equipment operation, energy balance, multi-material balance, and reserve capacity; solving the model using a mixed integer linear programming algorithm based on typical daily load and resource data; and finally outputting the optimal configuration capacity of various types of equipment.

[0257] Figure 2 This is a schematic diagram of the rural integrated energy system architecture according to an embodiment of the present invention. The diagram fully presents the system's constituent units and the energy and material transmission relationships between them. The system includes a photovoltaic power generation unit, a biomass biogas digester unit, a gas-fired power generation unit, a gas-fired heating unit, a carbon capture and utilization unit, a hydrogen energy storage unit, and various energy storage units such as energy storage batteries, methane storage tanks, carbon storage tanks, and hydrogen storage tanks. Different arrows in the diagram indicate the transmission paths of electricity, heat, biomass, CO2, CH4, and H2 flows, visually demonstrating the circulation and conversion processes of six energy and material carriers—electricity, heat, gas, hydrogen, carbon, and biomass—within the system.

[0258] Figure 3 This is a power balance stacking diagram for scenario C4 of this invention. The diagram uses time as the horizontal axis and power as the vertical axis to illustrate the typical hourly balance between power generation and consumption during a day. Power generation includes photovoltaic (PV) power generation, energy storage battery discharge, gas-fired power generation, grid power purchase, and fuel cell power generation. PV power generation is concentrated during the daytime, while fuel cells primarily supply power at night and during periods of insufficient PV output. Power consumption includes electrical load, power consumption by carbon capture equipment, power consumption by the electrolyzer, and energy storage battery charging. The electrolyzer operates during the daytime when PV output is sufficient, effectively absorbing excess PV power, while the energy storage battery achieves peak shaving and valley filling through charging and discharging.

[0259] Figure 4This is a stacked diagram of the heat power balance in scenario C4 of this invention, illustrating the typical hourly heat generation and consumption balance during the day. Heat generation includes heating from a gas-fired boiler and heat purchased from a heating network, with the latter being the primary heat source. The gas-fired boiler operates only as a supplementary heat source during periods of high heat load. Heat consumption is represented by the system heat load, and the diagram clearly shows the trend of heat load variation over time, as well as the output distribution of the two heating methods at different times.

[0260] Figure 5 The diagram shows a C4 methane balance stack and a methane storage quantity change curve, representing a scenario from an embodiment of the present invention. The left-hand stack shows the dynamic changes of methane sources and sinks hourly during a typical day. Methane sources include biogas (CH4) produced by the biogas digester and gas released from the methane storage tank. Methane destinations include consumption by gas-fired boilers, consumption by gas-fired power generation, refilling of the methane storage tank, and sale of excess methane. The right-hand curve shows the change in methane storage quantity over time. The biogas digester produces methane stably throughout the day. During the daytime, when the gas generator is off, methane is stored in the methane storage tank, and the methane storage quantity continuously increases. At night, when the gas generator is running, the methane storage tank releases gas to replenish methane demand, and the methane storage quantity decreases accordingly.

[0261] Figure 6 The diagram shows a C4 carbon balance stacked graph and a carbon storage change curve for a typical daytime scenario. The left-hand stacked graph illustrates the dynamic changes of carbon sources and sinks hourly. Carbon sources include CO2 separated from biogas digesters, CO2 emitted from gas-fired power generation, CO2 emitted from gas-fired boilers, and gas released from carbon storage tanks. Carbon destinations include carbon storage tank refilling, greenhouse gas fertilizer supply, and direct carbon emissions. The carbon capture device captures CO2 emitted from gas-fired power generation and gas-fired boilers and stores it in the carbon storage tank. The carbon storage tank releases CO2 for greenhouse gas fertilizer supply during peak daytime demand periods. The right-hand curve shows the trend of carbon storage over time, with carbon storage increasing at night when the carbon capture device is running and decreasing during daytime greenhouse gas fertilizer release periods.

[0262] Figure 7 The diagram shows the hydrogen balance stack and hydrogen storage variation curve for scenario C4, an embodiment of the present invention. The left-hand stack shows the dynamic changes of hydrogen sources and sinks during a typical day. Hydrogen sources include hydrogen production from the electrolyzer and venting from the hydrogen storage tank. Hydrogen destinations include hydrogen consumption by the fuel cell and refilling of the hydrogen storage tank. During the day, the electrolyzer uses surplus photovoltaic power to produce hydrogen, which is stored in the hydrogen storage tank. At night, when the fuel cell is running, the hydrogen storage tank vents to provide hydrogen. The right-hand curve shows the variation of hydrogen storage over time. Hydrogen storage continuously increases during the daytime hydrogen production period of the electrolyzer and gradually decreases during the nighttime hydrogen consumption period of the fuel cell, forming a daytime cycle characteristic that highly matches the photovoltaic power output cycle.

[0263] A specific embodiment uses a typical village in northern my country as an example, applying the above-mentioned capacity optimization configuration method to verify the effectiveness and economy of the present invention. Twelve typical days (one day per month) with a time resolution of one hour were selected for the village to determine the electrical load and photovoltaic output sequences. The heat load was generated based on the electrical load combined with the characteristics of the northern climate. The demand for gas fertilizer was determined based on the sunrise and sunset cycle and crop growth patterns. To achieve regular equipment shutdown and maintenance, the following operational constraints were set: The gas generator is shut down from 9:00 to 17:00 daily, and can operate during other times. The electrolyzer operates from 10:00 to 18:00 daily, with a power output not less than 30% of the rated power. The fuel cell operates from 18:00 to 8:00 the next day daily, with a power output not less than 10% of the rated power. To compare the impact of different technology combinations, the following five operating scenarios were set: C0 is the baseline scenario, without configuring any new equipment. C1 is a traditional rural integrated energy system, only adding photovoltaics, energy storage batteries, and methane storage tanks, without considering carbon cycling and hydrogen storage. C2 incorporates carbon cycling based on C1. C3 incorporates hydrogen energy storage in addition to C1. C4 considers both carbon cycle and hydrogen energy storage in addition to C1.

[0264] Table 1. Equipment capacity optimization results for C1-C4

[0265] Table 2 Optimization results of key indicators for each scenario

[0266] The equipment capacity optimization results for each scenario are shown in Table 1, and the key economic indicators are shown in Table 2. Comparative analysis shows that C0 has the highest overall cost and the lowest self-sufficiency rate. C1 has a significantly lower overall cost and a higher self-sufficiency rate than C0. C2 introduces carbon cycling on the basis of C1, further reducing the overall cost. C3 introduces hydrogen energy storage, with an overall cost between C1 and C2, and a self-sufficiency rate close to that of C2. C4 incorporates both carbon cycling and hydrogen energy storage, achieving the lowest overall cost, the highest self-sufficiency rate, and the lowest curtailment rate among all scenarios. This indicates that the hydrogen-carbon synergistic scheme proposed in this invention has the best economic efficiency and renewable energy utilization level.

[0267] Select the C4 scenario, which offers the best overall benefits, and draw an hourly balance stacking diagram for a typical day, such as... Figures 3 to 7 As shown. By Figure 3 Therefore, in terms of power balance, photovoltaic power output is concentrated during the day, electrolytic cells operate from 10:00 to 18:00 to effectively absorb photovoltaic power, fuel cells generate electricity at night to make up for the power shortage, and energy storage batteries play a role in peak shaving and valley filling. Figure 4 Therefore, in terms of heat energy balance, the heat load is mainly met by purchased heat, with the gas-fired boiler only serving as a supplement. Figure 5Therefore, regarding methane balance, the biogas digester produces methane stably throughout the day. During the day, the gas generator is shut down, and the methane is stored or sold. At night, the gas generator runs, and the methane storage tank is vented to replenish the supply. Figure 6 Therefore, in terms of carbon balance, the system's main carbon sources are CO2 separated from the biogas digester and CO2 emitted during combustion. The carbon capture equipment captures the CO2 emitted during combustion and stores it in a carbon storage tank, prioritizing its use in greenhouse gas fertilization, with the remainder being sealed off. Figure 7 As can be seen, regarding hydrogen balance, the electrolyzer produces hydrogen during the day, and the hydrogen is stored in the hydrogen storage tank. At night, the fuel cell consumes hydrogen from the storage tank and releases gas, resulting in a diurnal cycle of increasing hydrogen storage during the day and decreasing it at night, which coincides with the photovoltaic power generation cycle. The above operating characteristics verify the correctness and effectiveness of the model established in this invention.

[0268] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0269] The above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made based on the essence of the content of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for capacity configuration of a rural integrated energy system considering hydrogen-carbon synergy, characterized in that, Includes the following steps: A rural integrated energy system architecture was constructed, resulting in a system topology that includes multiple types of energy conversion and storage units; Based on the system topology, a capacity optimization configuration model is established with the goal of minimizing the total annual cost of the system. Set multi-dimensional constraints for the capacity optimization configuration model; Based on load and resource data of a typical day, the capacity optimization configuration model is solved to obtain the optimal configuration capacity of various equipment in the rural integrated energy system.

2. The method according to claim 1, characterized in that, The step of constructing a rural integrated energy system architecture to obtain a system topology containing multiple types of energy conversion and storage units includes: Integrate photovoltaic power generation units, biomass biogas digester units, gas-fired power generation units, gas-fired heating units, carbon capture and utilization units, hydrogen energy storage units, and various energy storage units to construct a comprehensive rural energy system architecture; The carbon capture and utilization unit captures carbon dioxide generated during gas-fired power generation and gas-fired heating, and stores all the captured carbon dioxide in a carbon storage tank. The electrolyzer, fuel cell, and hydrogen storage tank in the hydrogen energy storage unit are used to achieve the conversion and storage of electricity-hydrogen-electricity. Energy storage batteries, methane storage tanks, carbon storage tanks, and hydrogen storage tanks are integrated into the rural integrated energy system architecture as various energy storage units. The carbon storage tank is used to store carbon dioxide captured by the carbon capture device, and the carbon dioxide is released according to the greenhouse gas fertilizer demand, resulting in a system topology that includes multiple energy conversion and storage units.

3. The method according to claim 1, characterized in that, The step of establishing a capacity optimization configuration model based on the system topology with the objective of minimizing the system's total annual cost includes: The initial investment in various types of equipment in the system is converted using an equal-amount capital recovery factor to obtain the equivalent annual value of the equipment investment. The annual operation and maintenance costs of various equipment in the statistical system are used to obtain the annual operation and maintenance cost. The annual resource acquisition cost is calculated by summing the costs of biomass raw materials, electricity purchased from the power grid, and heat purchased from the heating network in the statistical system. The annual sales revenue is calculated by summing the revenue from the sale of excess methane and the sales of oxygen produced as a byproduct of electrolysis cells in the statistical system. The operating subsidy is calculated based on the photovoltaic power generation, biomass power generation, electrolyzer power consumption, and fuel cell power generation. The one-time investment subsidy is calculated based on the investment amount in carbon capture equipment and fuel cells; The annual government subsidy is obtained by summing the operating subsidy and the one-time investment subsidy. The annual carbon tax expenditure is calculated based on the emissions tax levied on uncaptured carbon dioxide in the statistical system. The potential revenue loss caused by annual curtailment of solar power in the statistical system is obtained as the annual curtailment loss. By integrating the annual value of equipment investment, annual operation and maintenance costs, annual resource acquisition costs, annual sales revenue, annual government subsidies, annual carbon tax expenditures, and annual curtailment losses, a capacity optimization configuration model is established with the goal of minimizing the total annual cost of the system.

4. The method according to claim 1, characterized in that, The step of setting multi-dimensional constraints for the capacity optimization configuration model includes: Set equipment operation constraints for the capacity optimization configuration model, including capacity constraints and ramp-up constraints for various types of equipment; Energy balance constraints are set for the capacity optimization configuration model, including electrical energy balance constraints and thermal energy balance constraints. Multi-substance balance constraints are set for the capacity optimization configuration model, including methane balance constraints, carbon dioxide balance constraints and hydrogen balance constraints. By setting standby capacity constraints for the capacity optimization configuration model, a capacity optimization configuration model with multi-dimensional constraints is obtained.

5. The method according to claim 4, characterized in that, The step of setting power balance constraints for the capacity optimization configuration model includes: Photovoltaic power generation, gas generator power generation, fuel cell power generation, energy storage battery discharge, and grid power purchase are used as the system's power sources; The electrical load consumption, the power consumption of carbon capture equipment, the power consumption of electrolyzers, and the charging of energy storage batteries are considered as the system's power consumption. Based on the power sources and power consumption, real-time power balance constraints are set for the system to ensure that the total power on the generation side is equal to the total power on the consumption side.

6. The method according to claim 4, characterized in that, The step of setting thermal balance constraints for the capacity optimization configuration model includes: The system uses gas-fired boiler heating and heat purchased from the heat network as its heat energy sources. Heat load consumption is considered as system heat energy consumption; Based on the heat energy sources and heat energy consumption, real-time heat energy balance constraints are set for the system.

7. The method according to claim 4, characterized in that, The step of setting methane balance constraints and hydrogen balance constraints for the capacity optimization configuration model includes: The methane produced by the biogas digester and the gas released from the methane storage tank are used as the methane source for the system. The methane consumed by the gas-fired power generation unit, the methane consumed by the gas-fired heating unit, the gas filling of the methane storage tank, and the methane sold externally are considered as the system's methane sink; Based on the methane source and methane sink, set the real-time methane balance constraint conditions for the system; The hydrogen source for the system is the hydrogen produced by the electrolyzer and the venting of the hydrogen storage tank. The hydrogen consumption of the fuel cell and the filling of the hydrogen storage tank are used as the hydrogen sink of the system. Based on the hydrogen source and hydrogen sink, the real-time hydrogen balance constraint conditions of the system are set.

8. The method according to claim 4, characterized in that, The step of setting carbon dioxide balance constraints for the capacity optimization configuration model includes: The carbon dioxide separated from the biogas digester, the carbon dioxide emitted by the gas-fired power generation unit, the carbon dioxide emitted by the gas-fired heating unit, and the gas released from the carbon storage tank are used as carbon sources for the system. The carbon sink system is used to fill the carbon storage tank with gas, supply carbon dioxide to greenhouse gas fertilizer, and directly release carbon dioxide into the atmosphere. The carbon dioxide captured by the carbon capture device is implicitly represented by the amount of gas filling the carbon storage tank, and a constraint condition is set that all the captured carbon dioxide is stored in the carbon storage tank. Based on the constraints of carbon source, carbon sink and carbon capture, the real-time carbon dioxide balance constraint conditions of the system are set.

9. The method according to claim 4, characterized in that, The step of setting standby capacity constraints for the capacity optimization configuration model includes: The total system reserve capacity is obtained by summing the reserve capacity of the gas generator, the fuel cell, the energy storage battery, and the grid reserve capacity. The system's total reserve capacity is set to be no less than a preset proportion of the electrical load demand after taking into account prediction errors.

10. The method according to claim 1, characterized in that, The step of solving the capacity optimization configuration model based on typical daily load and resource data to obtain the optimal configuration capacity of various equipment in the rural integrated energy system includes: Obtain hourly electricity load data, hourly heat load data, hourly photovoltaic power output data, time-of-use electricity price data, heat price data, and biomass feedstock price data for typical days; A mixed-integer linear programming algorithm is used to solve the capacity optimization configuration model using a commercial solver. It outputs the optimal configuration capacity of photovoltaic power generation units, biomass biogas digester units, gas-fired power generation units, gas-fired heating units, carbon capture and utilization units, hydrogen energy storage units, and various energy storage units.

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