Dual-layer optimization method and system of hydrogen-ammonia integrated energy system considering multi-energy grid coupling

Abstract

The present application relates to the technical field of comprehensive energy system optimization, and specifically discloses a hydrogen-ammonia comprehensive energy system double-layer optimization method and system considering multi-energy network coupling, which comprises the following steps: constructing a hydrogen-ammonia comprehensive energy system model, taking a hydrogen-ammonia comprehensive energy system operator as a leader and the hydrogen-ammonia comprehensive energy system as a follower, constructing an upper-layer leader target function by formulating the transaction prices of five kinds of energy, i.e., electricity, heat, gas, hydrogen and cold, so as to maximize the own benefit in the process of transaction with users and energy supply sides, constructing a lower-layer follower target function by formulating the output plans of various types of units according to the energy prices formulated by the upper layer, so as to maximize the own benefit, and solving the upper-layer and lower-layer target functions to obtain the optimal output of various types of units; and the present application uses a ladder-type green certificate-carbon transaction mechanism to encourage the scheduling of the system to realize low carbonization and economization.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of integrated energy system optimization, and particularly relates to a hydrogen-ammonia integrated energy system double-layer optimization method and system considering multi-energy network coupling. BACKGROUND

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

[0003] Current integrated energy system research mainly focuses on the collaborative optimization of traditional energy forms such as electricity, heat, and gas. A few advanced systems attempt to include hydrogen energy carriers, but the integration of ammonia energy as a zero-carbon fuel and energy storage medium is still in the experimental stage. In terms of energy transmission and distribution networks, existing models generally use simplified topological structures (such as a 10-node electric-thermal combined network), and have not established a multi-scale coupled network architecture that considers power grid flow constraints, heat and cold network transmission delays, and gas and hydrogen network pressure dynamics. Load-side management focuses on electricity and heat demand response, while price elasticity regulation of gas, hydrogen, and cold loads has not yet formed a systematic solution, making it difficult to smooth multi-energy flow chain disturbances when high volatility renewable energy is connected.

[0004] Existing carbon reduction technologies rely too much on basic carbon trading mechanisms, making it difficult to achieve three-dimensional coordination of carbon capture (source-side unit emission reduction), step-by-step green certificate-carbon trading (policy incentive dispatch), and load-side carbon flow tracking (node carbon potential assessment), resulting in a lack of closed-loop optimization chain for source-grid-load carbon reduction resources, significantly weakening the effectiveness of system-level carbon reduction. In addition, existing carbon flow operations focus on calculating the node carbon potential and carbon emissions of the electric and thermal load sides along with the power grid and heat grid, and few studies involve carbon flow operation and carbon potential analysis of the electric-thermal-gas grid.

[0005] In addition, existing unit collaborative optimization often focuses on optimal unit operation under fixed time-of-use energy prices, making it difficult to coordinate the interests of upstream energy suppliers and park operators, and the solution process is prone to local optimization, resulting in loss of interest. SUMMARY

[0006] In order to solve the above problems, the present application provides a hydrogen-ammonia comprehensive energy system double-layer optimization method and system considering multi-energy network coupling, which integrates renewable energy such as wind power, photovoltaic, photo-thermal, hydrogen energy, ammonia energy and the like as clean electricity or heat source, introduces combined heat and power units, ammonia production devices and ammonia fuel cells, electrolytic cell hydrogen production, methanation devices, photo-thermal steam turbines, electricity, heat, gas, hydrogen, cold or ammonia energy storage, and multi-type energy conversion and storage equipment such as compressed air refrigeration, to meet the multi-unit and load demand; a step green certificate-carbon trading mechanism is used to encourage the dispatch of the system to be more low-carbon, the carbon flow calculation theory is used to quantify the carbon reduction contribution of the carbon reduction means to the load side; a master-slave game framework is adopted, the upper layer solves the global profit optimization of the hydrogen-ammonia comprehensive energy operator by a projection optimization algorithm, and the lower layer calls a Gurobi solver to realize low-carbon economic dispatch of the hydrogen-ammonia comprehensive energy system.

[0007] In some embodiments, the following technical solutions are adopted:

[0008] A hydrogen-ammonia comprehensive energy system double-layer optimization method considering multi-energy network coupling, comprising:

[0009] A hydrogen-ammonia comprehensive energy system model is constructed, which includes wind turbine generators, photovoltaic, photo-thermal units, combined heat and power units, gas boilers, electricity, heat, gas, hydrogen, cold and ammonia energy storage systems, ammonia fuel cells, methanation natural gas production devices, carbon capture and storage devices, electric refrigeration equipment, hydrogen electrolytic cells and electric ammonia production equipment;

[0010] A step green certificate-carbon trading mechanism is established to guide the hydrogen-ammonia comprehensive energy system to operate in the direction of reducing carbon emissions; considering five types of loads including cold, heat, electricity, gas and hydrogen, a price incentive demand response is used to stimulate the five types of loads to complete reduction, substitution and transfer; considering six energy flows including cold, heat, electricity, gas, hydrogen and ammonia, carbon flow operations of the power system, heat network and gas network are respectively performed;

[0011] The hydrogen-ammonia comprehensive energy system operator is taken as a leader and the hydrogen-ammonia comprehensive energy system is taken as a follower, the upper leader sets the transaction prices of five types of energy including electricity, heat, gas, hydrogen and cold to maximize its own benefits in the process of transaction with users and energy supply sides, and an upper comprehensive energy operator objective function is constructed; the lower follower sets the output plans of each type of unit according to the energy prices set by the upper layer to maximize its own benefits, and a lower hydrogen-ammonia comprehensive energy system objective function is constructed;

[0012] The upper and lower objective functions are solved to obtain the optimal output of each type of unit.

[0013] In other embodiments, the following technical solutions are adopted:

[0014] A hydrogen-ammonia comprehensive energy system double-layer optimization system considering multi-energy network coupling comprises:

[0015] A model construction module is configured to construct a hydrogen-ammonia comprehensive energy system model, the hydrogen-ammonia comprehensive energy system model comprising wind turbine generators, photovoltaic, photothermal unit, combined heat and power unit, gas boiler, electricity, heat, gas, hydrogen, cold and ammonia energy storage system, ammonia fuel cell, methanation natural gas, carbon capture and storage device, electric refrigeration equipment, hydrogen electrolyzer and electric ammonia production equipment;

[0016] A carbon flow calculation module is configured to guide the hydrogen-ammonia comprehensive energy system to run in the direction of reducing carbon emissions by establishing a ladder green certificate-carbon trading mechanism; considering five types of loads of cold, heat, electricity, gas and hydrogen, using price incentive demand response to stimulate five types of loads to complete reduction, substitution and transfer; considering six energy flows of cold, heat, electricity, gas, hydrogen and ammonia, respectively performing carbon flow operation of the power system, heat network and gas network;

[0017] A target function construction module is configured to take the hydrogen-ammonia comprehensive energy system operator as a leader and the hydrogen-ammonia comprehensive energy system as a follower, the upper leader formulating the transaction prices of five types of energy of electricity, heat, gas, hydrogen and cold to maximize its own benefits in the process of transaction with users and energy supply sides, and constructing an upper comprehensive energy operator target function; the lower follower formulating the output plans of each type of unit according to the energy prices formulated by the upper layer to maximize its own benefits, and constructing a lower hydrogen-ammonia comprehensive energy system target function;

[0018] An optimization solution module is configured to solve the upper and lower target functions to obtain the optimal output of each type of unit.

[0019] In some other embodiments, the following technical solutions are adopted:

[0020] A terminal device comprises a processor and a memory, the processor being used to implement instructions; the memory is used to store a plurality of instructions, the instructions being suitable for being loaded and executed by the processor to implement the hydrogen-ammonia comprehensive energy system double-layer optimization method considering multi-energy network coupling.

[0021] In some other embodiments, the following technical solutions are adopted:

[0022] A computer readable storage medium has a plurality of instructions stored therein, the instructions being suitable for being loaded and executed by the processor of a terminal device to implement the hydrogen-ammonia comprehensive energy system double-layer optimization method considering multi-energy network coupling.

[0023] Compared with the prior art, the hydrogen-ammonia comprehensive energy system double-layer optimization method considering multi-energy network coupling has the following beneficial effects:

[0024] (1) The present application is oriented to industrial parks, fully considers the output characteristics of renewable energy such as wind power, photovoltaic, and photothermal, and realizes the mutual conversion between electricity-heat-gas-cold-hydrogen-ammonia on the basis of electricity by introducing cold heat and power cogeneration devices, hydrogen electrolysis tanks, electric ammonia, ammonia fuel cells, electric refrigeration, hydrogen methanation, electricity, heat, gas, hydrogen, ammonia and cold energy storage equipment, gas boilers and other facilities, realizes the efficient collaboration of multiple energies, reduces the dependence on the upper energy network, improves the consumption rate of new energy, and reduces carbon emissions.

[0025] (2) The present application introduces a carbon capture unit on the power generation side to reduce carbon emissions of the generator set, and uses harmful greenhouse gas CO2 as the input energy of the hydrogen methanation equipment to realize clean conversion of carbon; a step-by-step green certificate-carbon trading strategy is introduced in the scheduling of the hydrogen-ammonia comprehensive energy system, which promotes the scheduling results to develop in the direction of low carbon by combining the clean properties of green certificate trading and the punishment characteristics of carbon trading.

[0026] (3) The present application designs a 33-node electricity-6-node heat-6-node gas-6-node hydrogen-4-node cold network (33E-6H-6G-6Hy-4C) system, which fully considers the dynamic energy flow and time delay characteristics of various energy networks, and realizes the coupling and collaboration between various energies; at the same time, a carbon flow operation framework of electricity-heat-gas network is introduced, so that the carbon reduction means can take effect on the load side, and it is convenient for subsequent carbon emission reduction evaluation and the addition of node carbon potential demand response; then, an integrated demand response strategy is introduced to meet the energy reduction and time shift of the five demand loads of electricity, heat, gas, cold and hydrogen, and further to suppress the influence of large load fluctuation on the integrated energy system.

[0027] (4) The present application uses master-slave game as the optimization framework of multi-energy industrial park, establishes a double-layer collaborative scheduling model, introduces an integrated energy operator to realize upper energy network management, and the lower layer is a hydrogen-ammonia integrated energy system; the upper leader aims to maximize its own income in the process of trading with users and energy supply side by formulating the trading prices of five kinds of energy of electricity, heat, gas, hydrogen and cold, and the lower follower formulates the output plan of each type of unit according to the energy price formulated by the upper layer to maximize its own income.

[0028] At the same time, a projection optimization algorithm is used to solve the multi-dimensional strong nonlinear problem of the upper operator, which solves the problem that the existing heuristic algorithm is easy to fall into local optimum.

[0029] Other features and advantages of the additional aspects of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1A flow chart of a double-layer optimization method of a hydrogen-ammonia comprehensive energy system considering multi-energy network coupling in an embodiment of the present application;

[0031] Figure 2 A schematic diagram of a hydrogen-ammonia comprehensive energy system collaborative operation architecture in an embodiment of the present application;

[0032] Figure 3 A schematic diagram of an E33-H6-G6-Hy6-C4 energy network coupling topology in an embodiment of the present application;

[0033] Figure 4 A schematic diagram of a hydrogen-ammonia comprehensive energy system master-slave game architecture in an embodiment of the present application;

[0034] Figure 5 A double-layer joint solution flow chart of a projection optimization algorithm-Gurobi solver in an embodiment of the present application. DETAILED DESCRIPTION

[0035] It should be noted that the following detailed description is illustrative only and is intended to provide further description of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0036] It should be noted that the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and it should be further understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of a feature, step, operation, device, component and / or combinations thereof.

[0037] Embodiment one

[0038] In one or more embodiments, a double-layer optimization method of a hydrogen-ammonia comprehensive energy system considering multi-energy network coupling is disclosed, which combines Figure 1 , and specifically includes the following processes:

[0039] S101: A hydrogen-ammonia comprehensive energy system model is constructed, which includes wind turbines, photovoltaic, photothermal units, combined heat and power units, gas boilers, electricity, heat, gas, hydrogen, cold and ammonia energy storage systems, ammonia fuel cells, methanation natural gas production, carbon capture and storage devices, electric refrigeration equipment, hydrogen electrolysis cells and electric ammonia production equipment.

[0040] In this embodiment, a multi-energy complementary integrated energy system including cold, heat, electricity, gas, hydrogen and ammonia is constructed for the multi-type energy demand characteristics of the industrial park. The system integrates wind power, photovoltaic, photo-thermal, hydrogen energy, ammonia energy and other renewable energy as clean power or heat source. The system introduces combined heat and power units, ammonia production devices and ammonia fuel cells, electrolytic cell hydrogen production, methanation devices, photo-thermal steam turbines, electricity, heat, gas, hydrogen, cold and ammonia energy storage and compressed air refrigeration and other multi-type energy conversion and storage equipment to meet the multi-unit and load demand.

[0041] Specifically, in combination with Figure 2 The hydrogen-ammonia integrated energy system includes electricity, heat, gas, hydrogen, cold and ammonia, which is driven by photovoltaic, wind power and photo-thermal three renewable energy sources, and considers the demand response of electricity, heat, gas, hydrogen and cold load to reduce the impact of excessive load fluctuation on the system.

[0042] The hydrogen-ammonia integrated energy system includes combined heat and power units (CCHP), gas boilers (GB), electricity, heat, gas, hydrogen, cold and ammonia energy storage, ammonia fuel cells, natural gas produced by methanation, carbon capture and storage, electric refrigeration, hydrogen electrolysis and electric ammonia production. The CCHP unit includes a gas turbine, a waste heat recovery unit, a heat refrigeration device, which can convert natural gas into electricity, heat and cold. The GB can convert natural gas into heat energy. The carbon capture and storage device is used to modify the CCHP and GB to absorb part of their carbon emissions. The hydrogen produced by the electrolytic cell is used to convert waste carbon dioxide into clean methane fuel to supply the gas load, CCHP and GB. Part of the electricity is converted into ammonia energy by an air separation ammonia production device. This part of the ammonia energy is used to supply the ammonia fuel cell to generate electricity, further realizing the time shift of electricity and meeting the demand of electricity load. In addition, the byproduct heat generated by the ammonia production is connected to the heat network to participate in the circulation of heat energy. The cold load is supplied by the CCHP, compressed air refrigeration equipment and cold storage tank. In order to further reduce the carbon emissions of the source side equipment, the gas turbine in the CCHP and the GB are modified to burn hydrogen. Under the condition of supplying the same combustion heat value, part of the carbon emissions is reduced.

[0043] It should be noted that the interaction between the hydrogen-ammonia integrated energy system and the upper electricity, heat and gas network is mutual. Since hydrogen energy is converted from excess electricity, there is almost no surplus, so there is only hydrogen purchase from the upper hydrogen network, but no hydrogen sales link. In addition, since the cold load demand in the region is usually less than the electricity, heat and gas load, there is no purchase and sale link of the upper cold network. Ammonia energy acts as a transfer link between electricity, hydrogen and heat, and plays a role in stabilizing the fluctuation of electricity and heat load, so there is no upper ammonia supplier and ammonia load.

[0044] The regional industrial integrated energy system in this embodiment can achieve efficient synergy of multiple energy sources, reduce dependence on the upper-level energy grid, improve the absorption rate of new energy sources, and reduce carbon emissions.

[0045] In this embodiment, the model for the integrated hydrogen-ammonia energy system is established as follows:

[0046] The energy production, conversion, and decarbonization equipment of the hydrogen-ammonia integrated energy system includes wind turbines, photovoltaics, solar thermal power units, CCHP, GB, electricity, heat, gas, hydrogen, cooling and ammonia energy storage, ammonia fuel cells, methanation to natural gas, hydrogen electrolyzers, carbon capture and storage, electric refrigeration, etc.

[0047] (1) Photovoltaic power generation model:

[0048] The output power of a photovoltaic power generator depends primarily on the intensity of solar radiation. It can be modeled as:

[0049] (1)

[0050] in, The photoelectric conversion efficiency of photovoltaics. The area of ​​the photovoltaic panel. Light intensity.

[0051] (2) Wind power generation model:

[0052] The output power of a photovoltaic power generator depends primarily on the intensity of solar radiation. It can be modeled as:

[0053] (2)

[0054] in, Represents overall air density. It is the wind energy utilization coefficient. It is the swept area. It's wind speed. , and These represent cut-in, cut-out, and rated wind speed, respectively.

[0055] (3) Solar thermal power generation model:

[0056] Concentrated solar power (CSP) primarily utilizes a concentrator field to collect solar thermal energy. In this embodiment, a portion of the thermal energy is transferred to the heating network, while the remaining thermal energy is used to power a steam turbine. Its output thermal power can be modeled as follows:

[0057] (3)

[0058] (4)

[0059] (5)

[0060] where, represents the thermal-electric conversion efficiency of the steam turbine, represents the power generation heat distributed to the steam turbine by the solar-thermal power station, represents the heat provided to the steam turbine by the heat network, represents the total heat received by the solar-thermal power station, represents the heat supplied to the heat network by the solar-thermal power station, represents the solar-thermal conversion efficiency, represents the area of the solar-thermal mirror field.

[0061] (4) CCHP model:

[0062] The CCHP unit includes a gas turbine, a waste heat recovery, and an absorption refrigeration three modules, which can be modeled as:

[0063] (6)

[0064] (7)

[0065] (8)

[0066] where, represents the power generation power, is the power generation efficiency, is the natural gas consumption, is the total waste heat power, is the heating ratio, is the cooling ratio, is the refrigeration coefficient, is the output cold power.

[0067] (5) GB model:

[0068] The GB unit can convert natural gas into heat to input into the heat network or supply to the heat load, and output the heat power which can be modeled as:

[0069] (9)

[0070] where, represents the low calorific value of natural gas, represents the consumption of natural gas, represents the boiler thermal efficiency.

[0071] (6) Electricity, heat, gas, hydrogen, cold and ammonia energy storage:

[0072] The energy storage device needs to meet the SOC constraint, the charge-discharge exclusion constraint, the power constraint and the energy constraint, aiming to provide flexible power buffer for the integrated energy system, which can be modeled as:

[0073] (10)

[0074] (11)

[0075] (12)

[0076] (13)

[0077] (14)

[0078] wherein, S represents the set of energy storage systems, consisting of electric energy storage elec, thermal energy storage therm, gas energy storage gas, hydrogen energy storage hydro, cold energy storage cool and ammonia energy storage ammonia; and respectively represent the state of charge and discharge, and respectively represent the charge and discharge power of the energy storage set, and represent the upper limit of charge and discharge of the energy storage set, is the energy of the energy storage set, and respectively represent the upper and lower limits of the energy of the energy storage set, and respectively represent the charge and discharge efficiency of the energy storage set, is the self-discharge rate.

[0079] (7) Hydrogen production by electrolysis:

[0080] The electrolyzer can convert electrical energy into hydrogen energy, which is modeled as:

[0081] (15)

[0082] wherein, is the hydrogen production, is the electrolyzer efficiency, is the power consumption of the electrolyzer, is the electric-hydrogen conversion coefficient of hydrogen.

[0083] (8) Ammonia production device and ammonia fuel cell:

[0084] The air separation ammonia production device can use the nitrogen separated from the air and the hydrogen produced by the hydrogen electrolyzer to produce ammonia, and the ammonia fuel cell can use the produced ammonia to produce electric energy. For air separation ammonia production, the process can be modeled as:

[0085] (16)

[0086] (17)

[0087] (18)

[0088] wherein, represents the electricity consumption of ammonia production, represents the electricity consumption rate of nitrogen production, represents the molar mass of ammonia, and represent the upper and lower limits of the electricity consumption of ammonia production, respectively, represents the efficiency of ammonia production. represents the consumption of nitrogen, represents the consumption of hydrogen, and represent the molar mass of nitrogen and hydrogen, respectively, represents the production of ammonia.

[0089] The ammonia fuel cell can be modeled as:

[0090] (19)

[0091] (20)

[0092] (21)

[0093] wherein, is the power generation of the ammonia fuel cell, is the heat generated by ammonia production, and represent the efficiency of the ammonia fuel cell and the heat generated by ammonia production, respectively, is the mass power conversion coefficient of ammonia, represents the consumption mass of ammonia, and represent the upper and lower limits of the power production of the ammonia fuel cell, respectively.

[0094] (9) Carbon capture and carbon sequestration device:

[0095] The carbon capture and carbon sequestration device can modify specific units to sequester the carbon dioxide emitted by these units in a solution storage through flue gas diversion, shower capture, and other operations to supply hydrogen methanation and other equipment. This process is modeled as:

[0096] (22)

[0097] (23)

[0098] where, represents the power of electricity or heat generation of the unit retrofitted with carbon capture, including CCHP, GB; represents the flue gas split ratio, represents the efficiency of the absorption tower, represents the energy consumption coefficient of the absorption tower, and represent the operating energy consumption and fixed energy consumption of the carbon capture plant, respectively, is the total energy consumption of the carbon capture plant, and represent the lean liquid volume and rich liquid volume, and the subscripts in and out represent the input liquid and output liquid, and represent the captured and regenerated CO2, respectively, represents the CO2 absorption coefficient of the alcohol amine solution, is the density of CO2.

[0099] (10) Methanation for natural gas:

[0100] Methanation can convert hydrogen and carbon dioxide into natural gas, and the volume of CO2 consumed in this process is the same as the volume of methane produced, which is modeled as:

[0101] (24)

[0102] where, is the volume of natural gas produced, is the amount of hydrogen consumed, and represent the calorific values of hydrogen and natural gas, respectively, represents the density of natural gas, is the efficiency of the reactor.

[0103] (11) Electric refrigeration:

[0104] Electric refrigerators produce cold by consuming electricity, which is modeled as:

[0105] (25)

[0106] (26)

[0107] where, and are the upper limit of the input electric power of the electric refrigerator and the refrigeration coefficient, respectively, Pout is the output cold power, Pin is the input electric power.

[0108] (12) Hydrogen-doped combustion:

[0109] The gas turbine and the GB in this embodiment are modified to hydrogen-doped combustion, with a ratio of 0-20% dynamic hydrogen doping, which is modeled as:

[0110] (27)

[0111] where, Ω mix CHP and GB, Pin is the input power of the mixed gas, and are the volume power conversion coefficients of hydrogen and natural gas, respectively, represents the hydrogen-doping ratio of the unit, and are the electric and thermal efficiencies of the units in the set, respectively, is the hydrogen density, and are the gas and hydrogen consumptions of the units in the set, respectively.

[0112] S102: By establishing a stepped green certificate-carbon trading mechanism, guide the hydrogen-ammonia integrated energy system to run in the direction of reducing carbon emissions; considering five types of loads, cold, heat, electricity, gas and hydrogen, use price incentive demand response to stimulate five types of loads to complete reduction, substitution and transfer; considering six energy flows, cold, heat, electricity, gas, hydrogen and ammonia, respectively, carbon flow calculation of power system, heat network and gas network.

[0113] In this embodiment, by establishing a stepped green certificate-carbon trading mechanism, guide the hydrogen-ammonia integrated energy system to run in the direction of reducing carbon emissions, as follows:

[0114] The stepped carbon trading market can guide the hydrogen-ammonia integrated energy system to run in the direction of reducing carbon emissions by rewarding and punishing carbon emissions within a certain range.

[0115] This embodiment uses the baseline method to allocate the carbon quota of the hydrogen-ammonia integrated energy system proposed, and the modeling of carbon trading is as follows:

[0116] (28)

[0117] where, represents the carbon quota of the hydrogen-ammonia integrated energy system, represents the carbon emission quota obtained by all carbon emission units (gas turbine, GB), Carbon quota factor of elements in all carbon emission units set, The power generation of these units.

[0118] Since the gas turbine and the GB in this embodiment are carbon capture modified, the actual carbon emissions of the system can be represented as:

[0119] (29)

[0120] Where, represents the total carbon emissions of the system, represents the carbon emissions generated by external power purchase, represents the carbon emissions generated by the system itself, represents the carbon emissions captured by the carbon capture unit, represents the carbon emission intensity of external power purchase.

[0121] Therefore, the carbon emission right of the hydrogen-ammonia integrated energy system can be calculated as:

[0122] (30)

[0123] The stepped carbon trading cost is represented as:

[0124] (31)

[0125] Where, represents the base price of carbon trading, represents the price increase, represents the length of the carbon emission interval.

[0126] Similar to the stepped carbon emission mechanism, one green certificate represents 1 MWh of renewable energy on-grid power, so the green certificates held by the hydrogen-ammonia integrated energy system are modeled as:

[0127] (32)

[0128] (33)

[0129] Where, is the green certificate quota, represents the green certificate quota factor, is the electricity load, is the actual number of green certificates obtained by the hydrogen-ammonia integrated energy system, represents the power generation of the gas turbine of the photo-thermal power station; 、 represent the power generation of photovoltaic and wind power respectively.

[0130] Therefore, the tradable green certificates are:

[0131] (34)

[0132] The costs of tiered green certificates are similar to those of carbon trading, and will not be elaborated upon here. The green certificate mechanism can supplement excess carbon emission rights by offsetting a portion of carbon emissions. The tiered green certificate-carbon trading mechanism is modeled as follows:

[0133] (35)

[0134] (36)

[0135] in, Carbon emissions offset by green certificates. and These represent the carbon emissions from coal-fired power and renewable energy sources, respectively. Carbon emission rights representing green certificates in joint carbon trading.

[0136] In the above formula Replacing the tiered carbon trading mechanism This allows for a tiered green certificate-carbon trading mechanism.

[0137] In this embodiment, five types of loads—cooling, heating, electricity, gas, and hydrogen—are considered. Price-incentive demand response is used to stimulate these five types of loads to reduce, replace, and shift, specifically as follows:

[0138] Electricity, heat, and cooling loads are interchangeable within certain limits, as are gas and hydrogen. Furthermore, all five loads can be reduced and time-shifted within certain limits; this process is modeled as follows:

[0139] (37)

[0140] (38)

[0141] (39)

[0142] (40)

[0143] (41)

[0144] in, , , , and These represent the electricity, heat, cooling, gas, and hydrogen loads after the demand response, respectively. The subscript "base" indicates the corresponding base load. , , , , These represent the load transfer amounts for electricity, heat, cold, gas, and hydrogen, respectively. , , , , These represent the reductions possible for electricity, heat, cooling, gas, and hydrogen loads, respectively. , , , , , , , These represent the substitutable quantities for electrical load to thermal load, electrical load to cold load, thermal load to electrical load, thermal load to cold load, cold load to electrical load, cold load to thermal load, gas load to hydrogen load, and hydrogen load to gas load, respectively.

[0145] The constraints for each load type under the integrated demand response are as follows:

[0146] (42)

[0147] (43)

[0148] (44)

[0149] (45)

[0150] (46)

[0151] (47)

[0152] in, and Represents the upper and lower limits of electrical load transfer. This represents the upper limit of the electrical load that can be reduced. and These represent the upper limits of transferable electrical and hydrogen loads, respectively. The same applies to other loads, which will not be elaborated here.

[0153] In this embodiment, six energy flows—cold, heat, electricity, gas, hydrogen, and ammonia—are considered, and carbon flow calculations are performed for the power system, heating network, and gas network, respectively. Specifically:

[0154] 1. First, establish the E33-H6-G6-Hy6-C4 energy grid coupled topology.

[0155] This embodiment of the hydrogen-ammonia integrated energy system considers six energy flows: cold, heat, electricity, gas, hydrogen, and ammonia. The power grid uses an IEEE 33-node topology based on DC power flow; the heating network uses a 6-node heating network considering heating network delay characteristics and hot water return; the gas network uses a Belgian 6-node gas network considering gas pressure and gas flow direction; the cold network is modeled with 4 nodes; and the hydrogen network is similar to the gas network, with 6 nodes. Figure 3 As shown, the power grid includes two wind power plants, two photovoltaic plants, an ammonia fuel cell, a P2A (Power-to-Action) system, electric energy storage, solar thermal power, a CCS (Concentrated Solar Power System), an upstream power grid, and an ISA (Insulated Air System) for power generation or consumption. The heating network includes thermal storage tanks, waste heat recovery devices in the CCHP (Concentrated Heat Recovery Unit), the upstream heating network, and GB (Gas Storage Unit). The gas network includes an upstream gas network, a methanation unit, and gas storage tanks. The hydrogen network includes an upstream hydrogen network, an electrolyzer, and hydrogen storage tanks. The cooling network includes absorption refrigeration units in the CCHP and ISA units. In the E33-H6-G6-Hy6-C4 energy grid coupled topology, the CCHP is the key hub connecting the power-heat-gas-cooling network. The hydrogen network supplies hydrogen to the methanation unit in the gas network, the heating network supplies steam turbines in the CSP (Concentrated Solar Power System) in the grid, and the CSP and ammonia plant in the grid supply heat to the heating network. The ISA in the grid, while serving as an electrical load, is also the input cooling equipment for the cooling network. The coordinated operation and close coupling of these devices enable the hydrogen-ammonia integrated energy system to achieve multi-energy utilization and low-carbon operation.

[0156] (1) Power network modeling:

[0157] The power network proposed in this embodiment only considers DC power flow, that is, only active power and phase angle, as detailed below:

[0158] (48)

[0159] in, and Representing nodes respectively i and j phase angle, Representative node i and j The trend between and Representative node i and j Minimum and maximum power flow values ​​between them. and Representing nodes respectively i The minimum and maximum phase angles, The phase angle representing the reference node. Represents a node i and nodes j The impedance between them.

[0160] (2) Cold and hot network modeling:

[0161] The cold and hot water networks proposed in this example take into account temperature losses, both networks utilize the temperature drop and rise model of the water supply pipe, as follows:

[0162] (49)

[0163] where, and represent the inlet and outlet water temperatures of the pipe i in the cold and hot water networks, respectively, represents the ambient temperature, represents the pipe heat transfer coefficient, represents the length of the pipe i , represents the pipe mass coefficient, represents the mass of water in the pipe.

[0164] The mixed temperature of the cold and hot water in the cold and hot water networks is modeled as:

[0165] (50)

[0166] (51)

[0167] (52)

[0168] (53)

[0169] where, and are the mixed water temperatures at the nodes k of the inlet and return pipes, respectively, and represent the inlet and return water temperatures of the pipe i , and represent the inlet and return flow rates of the pipe i , and represent the outlet water temperatures of the inlet and return pipes i , respectively.

[0170] The relationship between the heat source, heat load, and water temperature in the heating network is as follows:

[0171] (54)

[0172] (55)

[0173] where, is the specific heat capacity of water, and The water flow rates flowing into the heat load node and out of the heat source node are the water flow rates. Represents heat load, and This represents the unit's heat consumption power and the heat source's heat production power in the system, explained in detail below.

[0174] The relationship between the cold source, cooling load, and water temperature in a cold network is similar to that in a heating network, so it will not be elaborated here.

[0175] (3) Gas and hydrogen network modeling:

[0176] The natural gas network and hydrogen network mentioned in this embodiment are similar in principle, and the relationship between the constrained gas flow rate and the node gas pressure is as follows:

[0177] (56)

[0178] (57)

[0179] (58)

[0180] in, For gas and hydrogen network nodes i and j The gas flow rate in the pipeline between The direction of airflow in the gas and hydrogen grids. It refers to air pressure; min and max are the lower and upper limits, respectively.

[0181] 2. Calculation of carbon flow in electricity, heat, and gas networks:

[0182] To evaluate proposed carbon reduction strategies such as carbon capture and storage-methanation and tiered green certificates-carbon trading on the load side, this embodiment establishes a carbon flow calculation model under energy grid coupling. Since the hydrogen and cooling grids do not generate carbon emissions, the carbon flow calculation only considers the electricity, heat, and gas grids. Specifically, it fully considers the output characteristics of various energy production and conversion equipment in the dynamic operation of the hydrogen-ammonia integrated energy system, and takes into account load changes under integrated demand response. Through the definition and calculation of nodal carbon potential, along with the power flow of the electricity, heat, and gas grids, it calculates the carbon potential and load carbon emissions of each node in the coupled energy grid, fully visualizing the carbon flow of the coupled energy grid at every moment to efficiently quantify the carbon reduction effect and provide a foundation for subsequent nodal carbon potential demand response.

[0183] (1) Calculation of carbon flow in power system:

[0184] In the IEEE 33-bus power system, the carbon potential of each node is determined by the active power injection from the generators and transmission lines connected to that node. This process is modeled as follows:

[0185] (59)

[0186] where, is the set of thermal generating units connected to node n , is the carbon intensity of thermal generating unit h , is the active power of unit h , and represent the carbon flow rate and power of branch flowing into node n , respectively.

[0187] The nodal carbon potential vector of carbon-emitting units in the grid is represented as:

[0188] (60)

[0189] where, e N represents the nodal carbon potential of the i th carbon-emitting unit.

[0190] The nodal carbon potential vector of all nodes is represented as:

[0191] (61)

[0192] where, is the active power flow matrix, is the transpose of the branch power flow distribution matrix, is the unit injection power flow matrix.

[0193] (2) Heat network carbon flow calculation:

[0194] Similar to the power system, the carbon potential of each node in the 6-node heat network system used in this embodiment is determined by the heat power injection of the heat-emitting units and heat pipes connected to the node, and this process is modeled as:

[0195] (62)

[0196] where, is the set of thermal generating units connected to node n , is the carbon intensity of thermal generating unit h , is the active power of unit h , and These represent the inflow nodes in the heating network. n The carbon flow rate and thermal power of the branch pipes; This represents the set of pipe branches through which hot water flows into node n.

[0197] In a heating network, the node carbon potential vector of units that generate carbon emissions. It is represented as:

[0198] (63)

[0199] in, e N Representing the i The node carbon potential of a thermal power unit that generates carbon emissions.

[0200] The nodal carbon potential vector of all nodes It is represented as:

[0201] (64)

[0202] in, The active flux matrix, This is the transpose of the heat network power flow distribution matrix. Injecting a power flow matrix into the thermal power unit.

[0203] (3) Calculation of carbon flow in the gas network:

[0204] In a 6-node gas supply system, the carbon potential of each gas network node is determined by the gas source and gas flow rate connected to that node, expressed as:

[0205] (65)

[0206] in, For nodes g Airflow into the node from the connected pipes g All pipes p The set, For nodes g Connected gas source w gather, gas source w carbon emission intensity, and Pipes p And the source of gas w airflow rate and These represent the inflow nodes in the gas network. n The carbon flow rate and gas power of the branch gas pipeline.

[0207] In a gas network, different gas sources have different carbon emission intensities, and their nodal carbon potential vectors... is expressed as:

[0208] (66)

[0209] wherein, represents the carbon emission intensity of the gas source, G represents the number of gas sources generating carbon emissions.

[0210] the node carbon potential energy vector of all nodes in the gas network is expressed as:

[0211] (67)

[0212] wherein, is an active flow matrix of the gas network, is a transpose of the gas network power flow distribution matrix, is a gas source injection power flow matrix.

[0213] The embodiment introduces carbon capture units on the carbon emission reduction level to capture the carbon emissions of the source side units, and jointly uses a methanation device to produce clean methane, hydrogen-doped combustion is performed on the gas turbine and the gas boiler to reduce part of the carbon emissions, a stepped green certificate-carbon trading mechanism is used to encourage the dispatch of the system to be more low-carbon, and a carbon flow calculation theory is used to quantify the carbon emission reduction contribution of the carbon emission reduction means to the load side.

[0214] The embodiment designs a 33-node electric-6-node thermal-6-node gas-6-node hydrogen-4-node cold network (33E-6H-6G-6Hy-4C) system, fully considers the dynamic energy flow and time delay characteristics of various energy networks, realizes the coupling and cooperation between various types of energy, introduces a carbon flow operation framework of the electric-thermal-gas network, so that the carbon emission reduction means can take effect on the load side, and the subsequent carbon emission reduction evaluation and node carbon potential demand response can be added. Price incentive demand response is introduced on the load side, and the time-shiftable and reducible characteristics of the load are used to reduce the influence of the source-load mismatch of the five types of energy, i.e., electricity, heat, gas, hydrogen and cold, on the system.

[0215] S103: The hydrogen-ammonia integrated energy system operator is taken as a leader, and the hydrogen-ammonia integrated energy system is taken as a follower. The upper leader formulates the transaction prices of the five types of energy, i.e., electricity, heat, gas, hydrogen and cold, to maximize the own benefit in the process of transaction with the user and the energy supply side, and constructs an upper integrated energy operator target function. The lower follower formulates the output plans of various types of units according to the energy prices formulated by the upper layer, to maximize the own benefit, and constructs a lower hydrogen-ammonia integrated energy system target function.

[0216] This embodiment proposes a hydrogen-ammonia integrated energy system double-layer collaborative scheduling model based on principal-agent game. The hydrogen-ammonia integrated energy system operator is taken as the leader, and the hydrogen-ammonia integrated energy system is taken as the follower to solve the decision variables of each party when pursuing their own maximum benefit. The upper leader aims to maximize its own revenue in the process of trading with users and energy supply side by formulating the transaction prices of five kinds of energy, i.e. electricity, heat, gas, hydrogen and cold. The lower follower formulates the output plan of each type of unit according to the energy price formulated by the upper layer to maximize its own revenue. In addition, in the solving process of the lower layer, in addition to the source side unit being carbon capture modified to achieve the purpose of carbon reduction, the influence of multi-element energy flow transformation and utilization such as carbon trading, green certificate and hydrogen-ammonia on the carbon reduction potential of hydrogen-ammonia gas integrated energy system will be quantitatively evaluated. Finally, the carbon emission flow and node carbon potential of the load side of the multi-energy coupled energy network will be calculated according to the real-time carbon flow of the electricity-heat-gas network to quantify the role of various carbon reduction methods from the perspective of the load side.

[0217] (1) Upper integrated energy operator objective function:

[0218] Objective function of hydrogen-ammonia integrated energy operator Mainly includes energy sales revenue , energy purchase cost , and interaction cost with superior energy , wherein the superior energy network includes electricity, heat, gas and hydrogen network, and the specific expression is as follows:

[0219] (68)

[0220] The energy sales revenue is modeled as:

[0221] (69)

[0222] Wherein, , , , and represent the electricity, heat, gas, hydrogen and cold energy sales revenue, , , , and represent the electricity, heat, gas, hydrogen and cold load after demand response, , , , and represent the electricity, heat, gas, hydrogen and cold energy selling price formulated by the upper integrated energy operator, , , and represent the set of electricity, heat, gas, and hydrogen consuming devices in the hydrogen-ammonia integrated energy system, respectively.

[0223] The integrated energy operator proposed in this embodiment contains the interaction costs of electricity, heat, gas, and hydrogen. It is worth mentioning that the interaction of hydrogen only contains the purchase interaction cost. This is because the hydrogen-ammonia integrated energy system needs a large amount of hydrogen energy as the energy conversion medium of the heterogeneous energy flow system, so the sale of hydrogen is ignored, and the supply of cold energy completely relies on the self-consistency of the system, so the interaction with the upper cold network is ignored. The energy interaction cost with the upper energy network is modeled as:

[0224] (70)

[0225] are the interaction costs with the upper power grid, the upper heat grid, the upper gas grid, and the hydrogen seller, respectively, represent the time-of-use electricity price and the on-grid electricity price, respectively, represent the upper and lower limits of the heat price, respectively, represent the upper and lower limits of the gas price, respectively, represents the upper limit of the hydrogen price; represent the purchased and sold electricity power to the upper power grid, respectively, represent the purchased and sold heat power to the upper heat grid, respectively, represent the purchased and sold natural gas volume to the upper gas grid, respectively, represents the purchased hydrogen mass to the hydrogen seller.

[0226] The energy purchase cost of the upper operator to the hydrogen-ammonia integrated energy system proposed in this embodiment contains five energy forms of electricity, heat, gas, hydrogen, and cold, which is modeled as:

[0227] (71)

[0228] wherein, represent the set of power generation, heat generation, gas source, hydrogen production, and refrigeration devices in the hydrogen-ammonia integrated energy system, respectively, ​​​​​​​​​​​​​​​​​​respectively represent the purchase price of electricity, heat, gas, hydrogen and cold energy from the upper energy operator to the lower hydrogen-ammonia integrated energy system.

[0229] The set of various energy production and consumption devices in the hydrogen-ammonia integrated energy system is represented as:

[0230] (72)

[0231] wherein, is the photovoltaic power generation power, is the wind power generation power, it is worth noting that in the power grid topology in the present patent, photovoltaic and wind power have two stations respectively, which will not be repeated here; is the power generation power of the solar thermal power station, which is the sum of the power generation power obtained by the heat supply of the heat network to the gas turbine and the power generation power obtained by the direct heat supply of the solar thermal power station to the gas turbine, is the power generation power of the CCHP unit, is the discharge power of the electric energy storage, is the power generation power of the ammonia fuel cell; is the discharge power of the electric energy storage, represents the energy consumption of the carbon capture plant, is the energy consumption of the electrolytic cell, represents the energy consumption of ammonia production, represents the power consumption of the electric refrigeration unit; , , , and represent the heat power of CCHP, GB, heat discharge of heat energy storage, heat production of ammonia production and heat power of CSP delivered to the heat network respectively; , and represent the heat power of heat charging of heat energy storage, heat for absorption refrigeration and heat power of the heat network delivered to the steam turbine in the CSP station respectively; represents the volume of natural gas produced by hydrogen methanation; and represent the hydrogen consumption volume of the gas unit in CCHP and the GB respectively; and represent the hydrogen discharge amount of the hydrogen storage tank and the hydrogen production amount of the electrolytic cell respectively; , , and represent the hydrogen mixing amount of GB and CCHP, the hydrogen charging amount of the hydrogen storage tank and the hydrogen consumption amount of the ammonia production unit respectively; and represent the carbon dioxide production amount of the CCHP unit and the GB unit respectively; , , and These represent the amount of carbon dioxide captured in the carbon capture and storage unit, the amount of carbon dioxide consumed in the methanation unit, the amount of carbon dioxide captured by the carbon capture unit, and the amount of carbon dioxide released, respectively. , and These represent the cooling power of electric refrigeration, absorption refrigeration, and cold energy storage, respectively. This represents the cooling capacity of the cold storage tank.

[0232] (2) Objective function of the lower-level hydrogen-ammonia integrated energy system:

[0233] The coordinated operation of all units within the hydrogen-ammonia integrated energy system belongs to the underlying community of interests, and its objective function is expressed as follows:

[0234] (73)

[0235] (74)

[0236] in, This represents the energy sales cost of the lower-level hydrogen-ammonia integrated energy system. , , , and These represent the energy purchase costs from the upper-level energy operator to the lower-level hydrogen-ammonia integrated energy system. This represents the revenue from selling energy from the lower-level energy system to the upper-level operator, which is the energy purchase cost for the upper-level operator. Represents the operation and maintenance cost of the underlying system. This represents the tiered cost of green certificates and carbon trading.

[0237] The operation and maintenance cost expression for Elasticsearch is as follows:

[0238] (75)

[0239] in, , and These represent the operation and maintenance costs of power generation, heating, and energy storage equipment, respectively. , and These represent the operation and maintenance cost coefficients for these three types of equipment. Among them, the equipment requiring operation and maintenance for electric power includes steam turbines, ammonia fuel cells, gas turbines in CCHP, and hydrogen electrolyzers in solar thermal power plants; the equipment requiring maintenance for thermal power includes waste heat recovery boilers and GB in CCHP; and the energy storage equipment mainly includes six types: electric, thermal, gas, cold, hydrogen, and ammonia.

[0240] S104: Solve the objective functions of the upper and lower layers to obtain the optimal output of each type of unit.

[0241] The proposed dual-layer optimized operation strategy for the hydrogen-ammonia integrated energy system in this embodiment involves two stakeholders. The upper-level hydrogen-ammonia integrated energy system operator aims to maximize its own profits by setting day-ahead prices for five energy sources—electricity, heat, gas, hydrogen, and cooling—to increase its revenue from energy sales to users and reduce its energy purchase costs from the lower-level hydrogen-ammonia integrated energy system. Furthermore, the upper-level energy operator needs to facilitate energy exchange between the lower-level hydrogen-ammonia integrated energy system and the upper-level energy grid. This means selling excess energy to the upper-level energy grid to generate revenue, and purchasing insufficient energy to supplement system consumption. This patent establishes energy exchange with the upper-level energy grid for electricity, heat, gas, and hydrogen, where electricity, heat, and gas are bidirectional, while hydrogen can only be purchased from the upper-level hydrogen grid. It is worth noting that while the upper-level hydrogen-ammonia integrated energy operator gains profits, it also bears the risks associated with energy price fluctuations and power supply interruptions, especially when the lower-level system experiences energy shortages, at which point the upper-level operator must bear the energy purchase costs from the upper-level energy grid. The goal of the lower-level hydrogen-ammonia integrated energy system is to achieve multi-energy complementarity and coordinated scheduling based on the energy buying and selling prices set by the upper-level energy operator, maximizing its own interests while ensuring energy supply and demand balance. Therefore, the game process between the upper and lower systems can be summarized as follows: under the premise of maximizing the upper-level's gains, the lower-level system follows the upper-level's optimization results to optimize its own gains. This process is called a master-slave game, and the framework diagram of the entire process is shown below. Figure 4 middle.

[0242] To solve the proposed two-layer optimization model, a novel projection optimization algorithm is used to solve the multidimensional, strongly nonlinear problem of the upper-layer operator, while the lower-layer uses the Gurobi commercial solver to solve the mixed linear integer programming model. The master-slave game-theoretic solution process based on the projection optimization algorithm and the Gurobi solver proposed in this patent is as follows: Figure 5 As shown. Specifically, the initial value matrix of each dimension variable is obtained through the initialization of the projection algorithm, with a size of... N p× N d, where N p and N d represents the population size and dimension of the projection algorithm, respectively. Then, based on the initialized energy prices, the optimal scheduling rate of the lower-level model is calculated. This process is completed using the Gurobi solver. Subsequently, the solved scheduling results are substituted into the upper-level model to calculate the upper-level objective function. NThe p objective functions are compared, and the optimal upper-level decision variable corresponding to the optimal objective function is selected. In the next iteration, the change of the upper-level decision variable depends on the best decision variable of the last iteration and the position updating mechanism of the algorithm. This cycle continues until the maximum number of iterations is reached. It is worth mentioning that the elite preservation strategy is used in each iteration to preserve the decision variable corresponding to the best objective function that appears, to ensure the effectiveness of the optimization. When the upper-level optimization reaches the maximum number of iterations, the upper-level best objective function value is output, and the upper-level optimal decision variable is substituted into the lower level to calculate the lower-level best objective function value.

[0243] Embodiment Two

[0244] In one or more embodiments, a kind of hydrogen ammonia comprehensive energy system double-layer optimization system considering multi-energy grid coupling is disclosed, comprising:

[0245] A model construction module is configured to construct a hydrogen ammonia comprehensive energy system model, the hydrogen ammonia comprehensive energy system model comprising wind turbine, photovoltaic, photothermal unit, combined heat and power unit, gas boiler, electricity, heat, gas, hydrogen, cold and ammonia energy storage system, ammonia fuel cell, methanation natural gas, carbon capture and storage device, electric refrigeration equipment, hydrogen electrolyzer and electric ammonia equipment;

[0246] A carbon flow calculation module is configured to guide the hydrogen ammonia comprehensive energy system to run in the direction of reducing carbon emissions by establishing a ladder green certificate-carbon trading mechanism; considering five types of loads of cold, heat, electricity, gas and hydrogen, using price incentive demand response to stimulate five types of loads to complete reduction, substitution and transfer; considering six energy flows of cold, heat, electricity, gas, hydrogen and ammonia, respectively performing carbon flow operation of power system, heat network and gas network;

[0247] A target function construction module is configured to take the hydrogen ammonia comprehensive energy system operator as the leader and the hydrogen ammonia comprehensive energy system as the follower. The upper leader sets the transaction prices of five types of energy of electricity, heat, gas, hydrogen and cold to maximize its own benefits in the process of transaction with users and energy supply side, and constructs an upper comprehensive energy operator target function. The lower follower sets the output plan of each type of unit according to the energy price set by the upper layer to maximize its own benefits, and constructs a lower hydrogen ammonia comprehensive energy system target function;

[0248] An optimization solution module is configured to solve the upper and lower target functions to obtain the optimal output of each type of unit.

[0249] Embodiment Three

[0250] In one or more embodiments, a terminal device is disclosed, comprising a processor and a memory, the processor being configured to implement instructions; the memory being configured to store a plurality of instructions adapted to be loaded and executed by the processor to implement the method for hydrogen-ammonia integrated energy system double-layer optimization considering multi-energy grid coupling as described in Embodiment I.

[0251] In some other embodiments, a computer-readable storage medium is disclosed, wherein a plurality of instructions are stored, the instructions being adapted to be loaded and executed by a processor of a terminal device to implement the method for hydrogen-ammonia integrated energy system double-layer optimization considering multi-energy grid coupling as described in Embodiment I.

[0252] The above description of the specific embodiments of the present application in conjunction with the accompanying drawings is not intended to limit the scope of protection of the present application. Those skilled in the art should understand that various modifications or variations can be made to the technical solutions of the present application without departing from the scope of protection of the present application.

Claims

1. A bi-level optimization method for hydrogen-ammonia integrated energy system considering multi-energy grid coupling, characterized in that, The method comprises the following steps: A hydrogen-ammonia integrated energy system model is constructed, and the hydrogen-ammonia integrated energy system model comprises a wind turbine, a photovoltaic device, a photothermal unit, a combined cooling, heating and power unit, a gas boiler, an electricity storage system, a heat storage system, a gas storage system, a hydrogen storage system, a cold storage system, an ammonia storage system, an ammonia fuel cell, a methanation natural gas device, a carbon capture and storage device, an electric refrigeration device, a hydrogen electrolyzer and an electric ammonia production device; A stepped green certificate-carbon trading mechanism is established to guide the hydrogen-ammonia integrated energy system to operate in the direction of reducing carbon emissions; considering five types of loads, namely, cold, heat, electricity, gas and hydrogen, a price incentive type demand response is used to stimulate the five types of loads to complete reduction, substitution and transfer; considering six energy flows, namely, cold, heat, electricity, gas, hydrogen and ammonia, carbon flow operations of the power system, the heat network and the gas network are respectively performed; A hydrogen-ammonia integrated energy system operator is taken as a leader, and the hydrogen-ammonia integrated energy system is taken as a follower; an upper leader sets a transaction price of five types of energy, namely, electricity, heat, gas, hydrogen and cold, to maximize the own benefit in the process of transaction with users and energy supply sides, and an upper integrated energy operator target function is constructed; a lower follower sets an output plan of each type of unit according to the energy price set by the upper leader to maximize the own benefit, and a lower hydrogen-ammonia integrated energy system target function is constructed; The upper and lower target functions are solved to obtain optimal outputs of each type of unit. The five types of loads, namely, cold, heat, electricity, gas and hydrogen, are considered, and a price incentive type demand response is used to stimulate the five types of loads to complete reduction, substitution and transfer, and specifically, constraints of each type of load under the comprehensive demand response are as follows: ； ； ； ； ； wherein, , , , and respectively represent the electricity, heat, cooling, gas and hydrogen load after demand response, the subscript base represents the corresponding base load, , , , , respectively represent the electricity, heat, cooling, gas and hydrogen load transfer amount, , , , , respectively represent the electricity, heat, cooling, gas and hydrogen load reducible amount, , , , , , , , respectively represent the electricity load to heat load, electricity load to cooling load, heat load to electricity load, heat load to cooling load, cooling load to electricity load, cooling load to heat load, gas load to hydrogen load and hydrogen load to gas load substitutable amount; The carbon flow operations of the power system, the heat network and the gas network are respectively performed, and specifically, an E33-H6-G6-Hy6-C4 energy network coupling topology is established, and modeling of the power grid, the heat network, the gas network, the hydrogen network and the cold network is respectively performed to form a multi-energy network coupling topology. wherein, and represent upper and lower limits of the amount of electrical load transfer, represent upper limits of the amount of electrical load that can be reduced, and represent upper limits of the amount of electrical load and hydrogen load, respectively, and the remaining loads are the same. The stepped green certificate-carbon trading mechanism is established, and specifically, a carbon price is set according to the carbon emission of each type of unit, and a carbon price ladder is established. The lower hydrogen-ammonia integrated energy system target function is constructed, and specifically, a hydrogen-ammonia integrated energy system objective function is constructed. where the nodal carbon potential energy vector of all nodes of the power system is represented as: ； wherein, is the active flow matrix, is the transpose of the branch flow distribution matrix, is the unit injection flow matrix, is the node carbon potential vector of the units generating carbon emissions; a node carbon potential energy vector of all nodes of the heat network is represented as: ； wherein, is the active flow matrix, is the transpose of the heat network flow distribution matrix, is the heat power plant injection flow matrix, is the unit node carbon potential vector that generates carbon emissions; a node carbon potential energy vector for all nodes in the gas network is represented as: ； wherein, is the active flow matrix of the gas network, is the transpose of the gas network flow distribution matrix, is the gas source injection flow matrix, is the carbon potential vector of the different gas source nodes.

2. The hydrogen-ammonia integrated energy system bi-level optimization method considering multi-energy grid coupling of claim 1, wherein, The upper and lower target functions are solved to obtain optimal outputs of each type of unit, and specifically, a master-slave game is used as an optimization framework of the multi-energy industrial park, an integrated energy operator is introduced to realize upper energy network management, the lower layer is a hydrogen-ammonia integrated energy system, the upper system operator is a leader, and the lower integrated energy system is a follower; on the premise of maximizing the interests of the leader, the maximum interests of the follower are realized; the upper layer uses a projection optimization algorithm to realize global optimization, the lower layer uses a Gurobi commercial solver to solve a mixed linear integer programming problem, and through continuous iteration of the upper and lower layers, the interests of the integrated energy operator and the industrial integrated energy system are maximized under the premise of low carbon. ； ； wherein, is the carbon emission offset by green certificates, and represent the carbon emission from coal and new energy, respectively, represents the carbon emission right of green certificate joint carbon trading, represents the total carbon emission of the system, represents the carbon quota of the hydrogen-ammonia integrated energy system, is the green certificate quota.

3. The method of claim 1, wherein, Constructing an upper-level integrated energy operator objective function Specifically: ； wherein, is the revenue from selling energy, is the cost of buying energy, is the interaction cost of the superior energy.

4. The method of claim 1, wherein, The method comprises the following steps: ； wherein, represents the energy selling cost of the underlying hydrogen-ammonia integrated energy system, represents the energy purchasing cost of the underlying hydrogen-ammonia integrated energy system to the upper-level energy operator, represents the energy selling revenue of the hydrogen-ammonia integrated energy system to the upper-level operator, i.e. the energy purchasing cost of the upper-level operator; represents the operation and maintenance cost of the underlying hydrogen-ammonia integrated energy system, represents the stepwise green certificate-carbon trading cost.

5. The method of claim 1, wherein, A model construction module is configured to construct a hydrogen-ammonia integrated energy system model, and the hydrogen-ammonia integrated energy system model comprises a wind turbine, a photovoltaic device, a photothermal unit, a combined cooling, heating and power unit, a gas boiler, an electricity storage system, a heat storage system, a gas storage system, a hydrogen storage system, a cold storage system, an ammonia storage system, an ammonia fuel cell, a methanation natural gas device, a carbon capture and storage device, an electric refrigeration device, a hydrogen electrolyzer and an electric ammonia production device; ​ 6. A bi-level optimization system for hydrogen-ammonia integrated energy system considering multi-energy grid coupling, characterized in that, ​ ​ The carbon flow calculation module is configured to guide the hydrogen-ammonia integrated energy system to run in the direction of reducing carbon emissions by establishing a stepped green certificate-carbon trading mechanism; considering five types of loads of cold, heat, electricity, gas and hydrogen, using price incentive demand response to stimulate five types of loads to complete reduction, substitution and transfer; considering six energy flows of cold, heat, electricity, gas, hydrogen and ammonia, respectively performing carbon flow operation of the power system, the heat network and the gas network; The objective function construction module is configured to take the hydrogen-ammonia integrated energy system operator as a leader and the hydrogen-ammonia integrated energy system as a follower, the upper leader formulates the transaction prices of five types of energy of electricity, heat, gas, hydrogen and cold to maximize the own benefit in the process of trading with the user and the energy supply side, and constructs an upper integrated energy operator objective function; the lower follower formulates the output plan of each type of unit according to the energy price formulated by the upper layer to maximize the own benefit, and constructs a lower hydrogen-ammonia integrated energy system objective function; The optimization solving module is configured to solve the upper and lower objective functions to obtain the optimal output of each type of unit; the five types of loads of cold, heat, electricity, gas and hydrogen are considered, and price incentive demand response is used to stimulate five types of loads to complete reduction, substitution and transfer, specifically as follows: ； ； ； ； ； wherein, , , , and respectively represent the electricity, heat, cooling, gas and hydrogen load after demand response, the subscript base represents the corresponding base load, , , , , respectively represent the electricity, heat, cooling, gas and hydrogen load transfer amount, , , , , respectively represent the electricity, heat, cooling, gas and hydrogen load reducible amount, , , , , , , , respectively represent the electricity load to heat load, electricity load to cooling load, heat load to electricity load, heat load to cooling load, cooling load to electricity load, cooling load to heat load, gas load to hydrogen load and hydrogen load to gas load substitutable amount; The constraint of each load under integrated demand response is as follows: wherein, and represent upper and lower limits of the amount of electrical load transfer, represent upper limits of the amount of electrical load that can be reduced, and represent upper limits of the amount of electrical load and hydrogen load, respectively, and the rest of the load is the same. The carbon flow operation of the power system, the heat network and the gas network is performed respectively, specifically as follows: An E33-H6-G6-Hy6-C4 energy network coupling topology is established, and modeling of the power grid, the heat network, the gas network, the hydrogen network and the cold network is performed respectively to form a multi-energy network coupling topology; where the nodal carbon potential energy vector of all nodes of the power system is represented as: ； wherein, is the active flow matrix, is the transpose of the branch flow distribution matrix, is the unit injection flow matrix, is the node carbon potential vector of the units generating carbon emissions; a node carbon potential energy vector of all nodes of the heat network is represented as: ； wherein, is the active flow matrix, is the transpose of the heat network flow distribution matrix, is the heat power plant injection flow matrix, is the plant node carbon potential vector that generates carbon emissions; a node carbon potential energy vector for all nodes in the gas network is represented as: ； wherein, is the active flow matrix of the gas network, is the transpose of the gas network flow distribution matrix, is the gas source injection flow matrix, is the carbon potential vector of the different gas source nodes.

7. A terminal device comprising a processor and a memory, the processor configured to implement instructions; the memory configured to store a plurality of instructions, the terminal device characterized by, The instructions are adapted to be loaded and executed by the processor to perform the hydrogen-ammonia integrated energy system double-layer optimization method considering multi-energy network coupling according to any one of claims 1-5.

8. A computer-readable storage medium having stored therein a plurality of instructions, wherein the instructions, when executed by a processor, cause the processor to perform operations comprising: The instructions are adapted to be loaded and executed by the processor of the terminal device to perform the hydrogen-ammonia integrated energy system double-layer optimization method considering multi-energy network coupling according to any one of claims 1-5.

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