Electricity-gas-hydrogen coupling ammonia production system planning method considering uncertainty of new energy

Abstract

The invention discloses an electricity-gas-hydrogen coupling ammonia production system planning method considering uncertainty of new energy, and belongs to the field of energy system planning. The method comprises the steps that interaction between wind and light power generation and a power grid and carbon emission in the whole ammonia synthesis process are considered, and an electricity-gas-hydrogen coupling ammonia production energy system basic model is constructed; considering the condition of non-uniform power output of typical daytime new energy in seasons, a carbon capture module and a seasonal hydrogen storage tank are additionally arranged, and an electricity-gas-hydrogen coupling ammonia production energy system is constructed; a chance constraint method is adopted to process the uncertainty of wind and light power generation, an electricity-gas-hydrogen coupling ammonia production planning model under a new energy uncertainty scene is constructed, and the effectiveness of the model is verified through example analysis. According to the method, the situation that new energy output is not uniform in typical seasonal daytime is considered, cross-seasonal hydrogen energy peak regulation is achieved, the uncertainty of the new energy is handled through the chance constraint method, and the advantages of the system in the aspects of synthesis ammonia carbon reduction and new energy consumption are effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of energy system planning, in particular to an electricity-gas-hydrogen coupled ammonia system planning method considering new energy uncertainty. BACKGROUND

[0002] The synthetic ammonia industry has high energy consumption density and large product demand, and is an important raw material in the agricultural and chemical industries, playing an irreplaceable role in supporting global food and chemical production. As the largest downstream utilization channel of the hydrogen industry chain in China, the direct carbon emissions of the synthetic ammonia industry reached 219 million tons in 2022, accounting for 2.2% of the total emissions in China. At present, synthetic ammonia in China is mainly used in agriculture, industry and energy storage. The agricultural sector is used as a raw material for nitrogen fertilizer production, the industrial sector is used for the production of chemicals such as nitric acid and caprolactam, and the emerging energy storage scenario focuses on seasonal peak shaving needs.

[0003] At present, the synthetic ammonia industry in China is still dominated by coal-to-ammonia (C2A) and gas-to-ammonia (G2A), but the "Development Plan for the Petrochemical and Chemical Industry (2016-2020)" was issued in 2016, which clearly stated that new synthetic ammonia plants using anthracite and natural gas as raw materials would no longer be built. In 2022, the "Guidelines for the Implementation of Energy Conservation, Emission Reduction and Carbon Reduction Upgrading in Key Areas of High Energy-consuming Industries" was issued, emphasizing energy conservation and carbon reduction in the synthetic ammonia industry and proposing the development of green and low-carbon energy ammonia production technology research and demonstration. The relatively mature electric ammonia technology route first undergoes electrolysis to produce hydrogen, and then uses a Haber synthesis ammonia reactor to synthesize ammonia from nitrogen and hydrogen. The electric methane technology route synthesizes methane from carbon dioxide and hydrogen after electrolysis. However, current projects using renewable energy to produce hydrogen for ammonia production are small or still in the start-up phase, with no large-scale operation cases with production capacity exceeding 105 t / a. Therefore, under the "double carbon" target, considering the coupling relationship between traditional chemical industry and electric-hydrogen new energy system, clean electric energy replacement technologies such as power-to-ammonia (P2A) will become the main path for decarbonization of synthetic ammonia, promoting the consumption and peak shaving of renewable energy power and realizing a low-carbon and efficient electric-hydrogen-ammonia storage and utilization chain.

[0004] In recent years, the installed capacity of renewable energy in various regions has gradually expanded. By dynamically adjusting the production mode and capacity configuration, and adjusting the actual power demand according to the wind and light output characteristics, the flexibility of the synthetic ammonia system can improve the local consumption rate of new energy and reduce the comprehensive operation cost of the system. In addition, as described in the second chapter, due to the uneven seasonal distribution of wind and light resources, in the season with abundant new energy power output, there is an excess of on-grid phenomenon in the power generation peak period, which not only leads to excess on-grid penalty fees, causing the system cost to rise, but also affects the stability of the upper power grid operation, restricting the large-scale application of renewable energy. Considering the uncertainty of new energy, an electricity-gas-hydrogen coupled ammonia system planning method is provided. SUMMARY

[0005] In view of the shortcomings of the prior art, the present application provides an electricity-gas-hydrogen coupled ammonia system planning method considering the uncertainty of new energy, which can realize cross-seasonal hydrogen energy peak shaving, and provides a solution for electricity-gas-hydrogen coupled ammonia planning under high penetration of new energy, thereby relieving the burden of renewable energy consumption of the power system and reducing the carbon footprint of the entire energy system.

[0006] The object of the present application can be achieved by the following technical solutions:

[0007] The electricity-gas-hydrogen coupled ammonia system planning method considering the uncertainty of new energy comprises the following steps:

[0008] S1, considering the interaction between wind and light generation and the power grid, a basic model of the ammonia system is established

[0009] Considering the interaction between wind and light generation and the power grid and the carbon emissions in the whole process of synthetic ammonia, a basic model of the electricity-gas-hydrogen coupled ammonia energy system is established;

[0010] S2, considering the uneven new energy power output on the typical day of the season, the model device is supplemented

[0011] Considering the uneven new energy power output on the typical day of the season, a carbon capture module and a seasonal hydrogen storage tank are added to build an electricity-gas-hydrogen coupled ammonia energy system;

[0012] S3, opportunity constraint processing of wind and light uncertainty

[0013] The opportunity constraint method is used to process the uncertainty of wind and light generation, and an electricity-gas-hydrogen coupled ammonia planning model under the uncertainty of new energy is constructed with the economic optimization as the target;

[0014] S4, example verification of model effectiveness.

[0015] As a preferred technical solution of the present application, in step S1,

[0016] The constraint of the natural gas hydrogen production section in the basic model of the electricity-gas-hydrogen coupled ammonia energy system is:

[0017] The relationship between the desulfurization energy consumption and the natural gas volume flow is as follows:

[0018] (1)

[0019] In the formula, represents the desulfurization power consumption of the natural gas at time t; represents the unit power consumption of desulfurization; represents the natural gas flow injected by the natural gas hydrogen production section at time t;

[0020] In the steam reforming reaction, 1 mol of natural gas can generate 3 mol of hydrogen, so the relationship between the energy consumption of steam reforming and the gas flow is as follows:

[0021] (2)

[0022] (3)

[0023] In the formula, represents the heat consumption of steam reforming at time t; represents the unit heat consumption of steam reforming; represents the hydrogen flow in the mixed gas after steam reforming at time t; represents the conversion rate of the steam reforming process;

[0024] The role of high and low temperature change is to further convert the carbon monoxide generated in the steam reforming reaction into carbon dioxide and hydrogen, and 1 mol of carbon monoxide can generate 1 mol of hydrogen. Therefore, the relationship between the energy consumption of high and low temperature change and the gas flow is as follows:

[0025] (4)

[0026] (5)

[0027] In the formula, represents the heat consumption of high and low temperature change at time t; represents the unit heat consumption of high and low temperature change; represents the hydrogen volume flow in the mixed gas after high and low temperature change at time t; represents the conversion rate of the high and low temperature change process;

[0028] The relationship between the electricity consumption of the mixed gas decarburization using PSA adsorption to separate carbon dioxide in the gas and the gas flow is as follows:

[0029] (6)

[0030] (7)

[0031] In the formula, represents the power consumption of PSA decarburization at time t; represents the unit power consumption of PSA decarburization; represents the carbon dioxide volume flow in the mixed gas after high-low temperature shift at time t;

[0032] The purpose of the methanation reaction is to eliminate carbon monoxide in the mixed gas, and 3 mol of hydrogen is consumed to convert 1 mol of carbon monoxide, so the relationship between the hydrogen flow consumed by the methanation reactor and the power consumption is as follows:

[0033] (8)

[0034] (9)

[0035] (10)

[0036] (11)

[0037] In the formula, represents the power consumption of the methanation reactor at time t; represents the hydrogen flow consumed by the methanation reactor to remove carbon monoxide at time t; represents the power consumption rate of the methanation reactor; represents the carbon monoxide volume flow in the mixed gas after high-low temperature shift at time t;

[0038] The actual hydrogen produced by the natural gas hydrogen production section is equal to the hydrogen in the mixed gas after high-low temperature shift minus the hydrogen consumed in the methanation reaction, and the total constraint is as follows:

[0039] (12)

[0040] (13)

[0041] (14)

[0042] (15)

[0043] In the formula, represents the total power consumption of the natural gas hydrogen production section at time t, represents the total heat consumption of the natural gas hydrogen production section at time t, represents the total capacity of the natural gas hydrogen production section; represents the hydrogen flow produced by the natural gas hydrogen production section at time t.

[0044] As a preferred technical solution of the present application: in step S1,

[0045] The constraints for the ammonia synthesis section in the basic model of the electro-gas-hydrogen coupled ammonia production energy system are as follows:

[0046] The ammonia synthesis process first requires the production of nitrogen as a reaction feedstock. The PSA nitrogen generation unit uses air as feedstock. Based on the difference in adsorption rates of nitrogen and oxygen molecules in the air by carbon molecular sieves, and combined with a rapid circulation process of pressure adsorption and depressurization desorption, high-purity nitrogen required for the ammonia synthesis process is obtained. The relationship between the power consumption of PSA nitrogen generation and the nitrogen flow rate consumed in the ammonia synthesis reaction is as follows:

[0047] (16)

[0048] (17)

[0049] In the formula, This represents the power consumption for PSA nitrogen production at time t; This indicates the unit power consumption for PSA nitrogen production; The density of nitrogen gas is expressed as 1.25 kg / m³. This represents the nitrogen flow rate injected into the ammonia synthesis reactor at time t; Indicates the capacity of the PSA nitrogen generator;

[0050] The mixed gas needs to be compressed before entering the ammonia synthesis reactor. 1 mol of nitrogen gas mixed with 3 mol of hydrogen gas can produce 2 mol of ammonia gas. Therefore, the relationship between the power consumption of the compressor and the ammonia synthesis yield, as well as the relationship between the ammonia synthesis yield and the gas flow rate, are as follows:

[0051] (18)

[0052] (19)

[0053] (20)

[0054] (twenty one)

[0055] In the formula, This indicates the power consumption of the compressor at time t; This indicates the unit power consumption of the compressor; This represents the ammonia production at time t; This represents the flow rate of hydrogen injected into the ammonia synthesis reactor at time t; The density of ammonia is expressed as 0.771 kg / m³. Indicates the compressor's capacity;

[0056] The ammonia synthesis reaction of nitrogen and hydrogen must be carried out at high temperature and high pressure, but since it is an exothermic reaction, part of the released heat can be directly recycled and utilized by the reactor, so the relationship between the heat consumption of ammonia synthesis and the ammonia production is as follows:

[0057] (22)

[0058] (23)

[0059] In the formula, represents the heat consumption of ammonia synthesis at time t; represents the efficiency of the ammonia synthesis reactor; represents the heat released by the ammonia synthesis reactor at time t; represents the recovery rate of heat released by the ammonia synthesis reactor; represents the heat released by the ammonia synthesis reactor to synthesize 1 kg of ammonia;

[0060] The ammonia synthesis section has an hourly production upper limit, and the total constraint is as follows:

[0061] (24)

[0062] (25)

[0063] (26)

[0064] In the formula, represents the electricity consumption of the ammonia synthesis section at time t; represents the maximum production capacity of the ammonia synthesis section; represents the upper / lower limit of the hourly production of the ammonia synthesis section; represents the positive / negative ramp rate of ammonia production.

[0065] As a preferred technical solution of the present application: in step S1,

[0066] The electrolysis water hydrogen production section in the electricity-gas-hydrogen coupled ammonia production energy system basic model is constrained:

[0067] When multiple electrolytic cells are used to produce hydrogen, the actual power can continuously vary within the range of 5% to 100%, so the constraints of the hydrogen flow and input electric power of the electrolytic cell are as follows:

[0068] (27)

[0069] (28)

[0070] In the formula, represents the operating efficiency of the electrolytic cell; represents the electric power of the electrolytic cell at time t; Low heating value of hydrogen; represents the hydrogen flow rate produced by the electrolyzer at time t, represents the capacity of the electrolyzer.

[0071] As a preferred technical solution of the present application: in step S1,

[0072] The operation constraints of each device in the electricity-gas-hydrogen coupled ammonia production energy system basic model are:

[0073] Fan / photovoltaic:

[0074] The wind-solar power output is first used to meet the entire ammonia production process. If there is a surplus, it is transmitted to the power grid. The on-grid power within the rated power can obtain profit, and the part exceeding the rated power needs to pay a penalty. Considering the predicted value and actual utilization power constraints of the fan / photovoltaic power output:

[0075] (29)

[0076] (30)

[0077] (31)

[0078] (32)

[0079] In the formula, represents the actual power output of the fan / photovoltaic at time t; represents the predicted power output of the fan / photovoltaic at time t; represents the on-grid power of the fan / photovoltaic at time t; represents the on-grid trading power of the fan / photovoltaic at time t; represents the on-grid penalty power of the fan / photovoltaic at time t; represents the upper limit of the on-grid trading power of the fan / photovoltaic at time t;

[0080] Gas boiler:

[0081] Using hydrogen-mixed natural gas instead of pure natural gas, the gas boiler using hydrogen-mixed natural gas as fuel is modeled as follows:

[0082] (33)

[0083] (34)

[0084] In the formula, represents the volume fraction of hydrogen in hydrogen-mixed natural gas;

[0085] Electric boiler:

[0086] The relationship between the power consumption and the heating capacity of the electric boiler is as follows:

[0087] (35)

[0088] (36)

[0089] where, represents the thermal output of the electric boiler at time t; represents the heating efficiency of the electric boiler; represents the installed capacity of the electric boiler;

[0090] Gas turbine:

[0091] Similarly, the gas turbine also uses hydrogen-mixed natural gas instead of pure natural gas. By mixing 10% hydrogen into natural gas, the carbon monoxide and nitrogen oxide emissions of the gas turbine can be reduced by 60% and 14%, respectively. The modeling of the gas turbine using hydrogen-mixed natural gas as fuel is as follows:

[0092] (37)

[0093] (38)

[0094] (39)

[0095] where, represents the electric output of the gas turbine at time t; represents the power generation efficiency of the gas turbine; represents the gas flow in the gas turbine at time t; represents the thermal output of the gas turbine; represents the thermal-to-electric ratio of the gas turbine; represents the minimum electric output of the gas turbine; represents the installed capacity of the gas turbine;

[0096] Organic Rankine cycle power generation:

[0097] The organic Rankine cycle can recover the waste heat generated during the natural gas hydrogen production process and convert it into electrical energy. The relationship between power generation and waste heat recovery is as follows:

[0098] (40)

[0099] where, represents the power generation of the organic Rankine cycle at time t; represents the power generation efficiency of the organic Rankine cycle; represents the waste heat recovery rate;

[0100] Hydrogen storage tank:

[0101] The remaining electric energy is converted into hydrogen at the peak of new energy generation, and the hydrogen in the hydrogen storage tank can be used as raw material for ammonia synthesis or mixed to form hydrogen-mixed natural gas fuel. The storage capacity of the hydrogen storage tank and the volume flow of injected and extracted hydrogen are limited, and the hydrogen storage tank model constraints are as follows:

[0102] (41)

[0103] (42)

[0104] (43)

[0105] (44)

[0106] In the formula, represents the existing storage state of the hydrogen storage tank at time t; represents the charging / discharging efficiency of the hydrogen storage tank; represents the hydrogen flow rate out of the hydrogen storage tank at time t; represents the minimum / maximum storage state of the hydrogen storage tank; represents the charging / discharging rate of the hydrogen storage tank; represents the capacity of the hydrogen storage tank.

[0107] As a preferred technical solution of the present application, in step S2,

[0108] The carbon capture module is specifically as follows:

[0109] The carbon capture module includes a carbon capture device and a storage device, adopts a post-combustion capture technology, and the carbon dioxide is derived from natural gas hydrogen production, gas boilers and gas turbines. The specific mathematical model is as follows:

[0110] (45)

[0111] (46)

[0112] (47)

[0113] (48)

[0114] In the formula, represents the electric power consumed by the carbon capture device at time t; represents the electric power consumed by the carbon capture device when capturing carbon dioxide at time t; represents the installed capacity of the carbon capture device; represents the energy consumption for capturing unit carbon dioxide; represents the carbon capture level at time t; represents the carbon emission coefficient of natural gas; represents the total amount of carbon dioxide captured at time t.

[0115] As a preferred technical solution of the present application: in step S2,

[0116] The seasonal hydrogen storage tank is specifically as follows:

[0117] The energy storage value of the seasonal hydrogen storage tank at each time in a typical day of each season is determined by the hydrogen storage value at the previous time and the hydrogen storage and discharge power,

[0118] The initial energy storage of the seasonal hydrogen storage tank in each typical day of each season is equal to the cumulative hydrogen charging and discharging amount of the previous typical day of the season, and the initial energy storage state of the first typical day is the cumulative hydrogen charging and discharging amount of the last typical day of the season, and the specific formula is as follows:

[0119] (49)

[0120] (50)

[0121] (51)

[0122] (52)

[0123] (53)

[0124] In the formula, represents a typical day of a season; represents the maximum number of typical days; represents the number of d typical days; represents the gas storage state of the seasonal hydrogen storage tank at time t in d typical day; represents the charging / discharging efficiency of the seasonal hydrogen storage tank; represents the hydrogen flow rate flowing into / out of the seasonal hydrogen storage tank at time t in d typical day; represents the minimum / maximum storage state of the seasonal hydrogen storage tank; represents the charging / discharging rate of the seasonal hydrogen storage tank; represents the capacity of the seasonal hydrogen storage tank.

[0125] As a preferred technical solution of the present application: in step S3,

[0126] The system constraints of the electricity-gas-hydrogen coupled ammonia production planning model are:

[0127] Hydrogen is produced by natural gas reforming and electrolytic cell, heat energy is derived from gas boiler, electric boiler and gas turbine, electric energy is derived from fan, photovoltaic, gas turbine, organic Rankine cycle power generation and grid purchase, the newly added carbon capture equipment and storage equipment capture the electric energy consumed in the process, the seasonal hydrogen storage tank and the conventional hydrogen storage tank can be operated simultaneously to provide hydrogen raw material, the system electric, heat, gas, hydrogen balance is as follows:

[0128] (54)

[0129] (55)

[0130] (56)

[0131] (57).

[0132] As a preferred technical scheme of the present application: in step S3,

[0133] The objective function of the electricity-gas-hydrogen coupling ammonia production planning model is:

[0134] The construction idea of the objective function is to minimize the total cost of system operation while meeting the annual production of synthetic ammonia, and the objective function is composed of the cost of newly added equipment , equipment operation and maintenance cost , carbon emission cost , carbon capture cost , wind and light power generation cost , gas purchase cost , electricity purchase cost , wind and light power generation income and wind and light power grid penalty , the specific objective function is as follows:

[0135] (58)

[0136] The cost of newly added equipment:

[0137] The product of unit depreciation cost and equipment installed capacity is used to measure the cost of energy system configuration equipment, only the depreciation cost of newly added equipment is considered, and the existing equipment is not considered:

[0138] (59)

[0139] In the formula, represents the unit depreciation cost;

[0140] The equipment operation and maintenance cost:

[0141] The device operation and maintenance cost includes the device maintenance and repair cost, which can be represented as the product of the operation and maintenance unit price and the device power consumption. The specific calculation formula is as follows:

[0142] (60);

[0143] Carbon emission cost:

[0144] The carbon emission cost can be represented as the product of the carbon price and the carbon dioxide emission amount. The carbon emission cost formula is updated as follows:

[0145] (61);

[0146] Carbon capture cost:

[0147] The carbon capture module includes carbon capture and carbon sequestration, and its cost is related to the mass of captured carbon dioxide. Therefore, the carbon capture cost is represented as the product of the unit carbon capture cost and the total amount of captured and sequestered carbon dioxide. The specific formula is as follows:

[0148] (62)

[0149] In the formula, represents the unit carbon capture cost;

[0150] Wind and solar power generation cost:

[0151] Without considering the wind and solar construction cost, only the operation and maintenance cost is calculated:

[0152] (63)

[0153] In the formula, represents the wind turbine / photovoltaic operation and maintenance cost;

[0154] Gas purchase cost:

[0155] The gas purchase cost can be represented as the product of the natural gas purchase price and the total gas consumption:

[0156] (64)

[0157] In the formula, represents the natural gas purchase price;

[0158] Electricity purchase cost:

[0159] The electricity purchase cost can be represented as the product of the hourly industrial electricity purchase price and the corresponding time electricity consumption:

[0160] (65)

[0161] In the formula, represents the industrial electricity purchase price at time t;

[0162] Wind-solar electricity sale revenue:

[0163] The wind-solar electricity sale revenue can be expressed as the product of the transaction price of wind-solar electricity sale to the grid and the sale electricity quantity, and the revenue is represented as a negative value in the cost function:

[0164] (66)

[0165] In the formula, represents the transaction price of wind-solar electricity sale to the grid;

[0166] Wind-solar grid connection penalty:

[0167] The wind-solar grid connection penalty can be expressed as the product of the penalty price of wind-solar excess grid connection and the excess grid connection electricity quantity:

[0168] (67)

[0169] In the formula, represents the penalty price of wind-solar excess grid connection.

[0170] As a preferred technical solution of the present application: in step S3,

[0171] The new energy uncertainty processing of the electricity-gas-hydrogen coupling ammonia planning model is:

[0172] The opportunity constraint method is adopted to process the uncertainty of renewable energy:

[0173] The original constraint of wind-solar output is:

[0174] (68)

[0175] Assuming that the deviation of actual wind-solar output is a normal distribution with a mean of 0 and a standard deviation of , denoted as , then , assuming that the confidence level of the constraint satisfies , then:

[0176] (69)

[0177] Converting to the standard normal distribution has:

[0178] (70)

[0179] That is,

[0180] (71)

[0181] In the formula, represents the cumulative distribution function under the standard normal distribution,

[0182] The two-sided inverse function can be obtained as follows:

[0183] (72)

[0184] wherein, denotes the inverse function of the cumulative distribution function of the standard normal distribution,

[0185] The transformation can be obtained as follows:

[0186] (73)

[0187] According to the above, the constraint condition of the wind and light power output can be modified as follows:

[0188] (74)

[0189] wherein, denotes the standard deviation of the actual output deviation of the wind turbine / photovoltaic at time t; denotes the confidence degree that should be met by the wind turbine / photovoltaic output under the scenario.

[0190] Compared with the prior art, the present application has the beneficial effects that:

[0191] The method can realize reasonable configuration of various energies in the ammonia production system, realize efficient operation of the energy system and sustainable utilization of energy. Through flexible scheduling of each energy in the electric-hydrogen coupled ammonia production system, new energy close to 100% can be consumed while meeting the stable production of synthetic ammonia, and the economic efficiency and flexibility of the system are improved. BRIEF DESCRIPTION OF DRAWINGS

[0192] Figure 1 is the method flowchart of the present application;

[0193] Figure 2 is the electric-gas-hydrogen coupled ammonia energy system structure diagram in the present application;

[0194] Figure 3 is the structure flowchart of the present application;

[0195] Figure 4 is the wind power normalized prediction value table diagram;

[0196] Figure 5 is the photovoltaic normalized prediction value table diagram;

[0197] Figure 6 is the time-of-use electricity price table diagram;

[0198] Figure 7 The planning result table diagram of the present embodiment. DETAILED DESCRIPTION

[0199] The application will be described in further detail below with reference to the drawings and specific embodiments:

[0200] As Figures 1-3 shown, the application proposes an electricity-gas-hydrogen coupled ammonia production system planning method considering new energy uncertainty, including the following steps:

[0201] S1, considering the interaction of wind and solar power generation and power grid, a basic model of ammonia production system is established

[0202] Comprehensively considering the interaction of wind and solar power generation and power grid and the carbon emission in the whole process of ammonia synthesis, a basic model of electricity-gas-hydrogen coupled ammonia production energy system is established;

[0203] Step S1 is as follows:

[0204] The basic model of electricity-gas-hydrogen coupled ammonia production energy system includes natural gas hydrogen production section constraints, ammonia synthesis section constraints, water electrolysis hydrogen production section constraints and equipment operation constraints, which are as follows:

[0205] I. The natural gas hydrogen production section constraint is:

[0206] The relationship between desulfurization energy consumption and natural gas volume flow is as follows:

[0207] (1)

[0208] In the formula, represents the natural gas desulfurization power consumption at time t; represents the unit power consumption of desulfurization; represents the natural gas flow injected by the natural gas hydrogen production section at time t.

[0209] In the steam reforming reaction, 1 mol of natural gas can generate 3 mol of hydrogen, so the relationship between the energy consumption of steam reforming and the gas flow is as follows:

[0210] (2)

[0211] (3)

[0212] In the formula, represents the steam reforming heat consumption at time t; represents the unit heat consumption of steam reforming; represents the hydrogen flow in the mixed gas after steam reforming at time t; represents the conversion rate of the steam reforming process.

[0213] The role of high and low temperature change is to further convert the carbon monoxide generated in the steam reforming reaction into carbon dioxide and hydrogen, and 1 mol of carbon monoxide can generate 1 mol of hydrogen. Therefore, the relationship between the energy consumption of high and low temperature change and the gas flow is as follows:

[0214] (4)

[0215] (5)

[0216] wherein, represents the heat consumption of high-low temperature shift at time t; represents the unit heat consumption of high-low temperature shift; represents the hydrogen volume flow rate in the mixed gas after high-low temperature shift at time t; represents the conversion rate of high-low temperature shift process.

[0217] The PSA adsorption is used to separate carbon dioxide in the gas in the mixed gas decarburization, and the relationship between the electricity consumption and the gas flow rate is as follows:

[0218] (6)

[0219] (7)

[0220] wherein, represents the electricity consumption of PSA decarburization at time t; represents the unit electricity consumption of PSA decarburization; represents the carbon dioxide volume flow rate in the mixed gas after high-low temperature shift at time t.

[0221] The purpose of the methanation reaction is to eliminate carbon monoxide in the mixed gas, and 3 mol of hydrogen is consumed to convert 1 mol of carbon monoxide, so the relationship between the hydrogen flow rate consumed by the methanation reactor and the electricity consumption is as follows:

[0222] (8)

[0223] (9)

[0224] (10)

[0225] (11)

[0226] wherein, represents the electricity consumption of the methanation reactor at time t; represents the hydrogen flow rate consumed by the methanation reactor to remove carbon monoxide at time t; represents the electricity consumption rate of the methanation reactor; represents the carbon monoxide volume flow rate in the mixed gas after high-low temperature shift at time t.

[0227] The actual hydrogen produced in the natural gas hydrogen production section is equal to the hydrogen in the mixed gas after high-low temperature shift minus the hydrogen consumed in the methanation reaction, and the total constraint is as follows:

[0228] (12)

[0229] (13)

[0230] (14)

[0231] (15)

[0232] wherein, represents the total power consumption of the natural gas hydrogen production section at time t, represents the total heat consumption of the natural gas hydrogen production section at time t, represents the total capacity of the natural gas hydrogen production section; represents the hydrogen flow produced by the natural gas hydrogen production section at time t.

[0233] II. The synthesis ammonia section is constrained as follows:

[0234] The synthesis ammonia section first needs to produce nitrogen gas as a reaction raw material. The PSA nitrogen production device uses air as a raw material, and based on the difference in adsorption rate of nitrogen molecules and oxygen molecules in air by carbon molecular sieve, combined with the rapid circulation process of pressurized adsorption and depressurized desorption, high-purity nitrogen gas required by the synthesis ammonia process is obtained. The relationship between the power consumption of the PSA nitrogen production and the nitrogen flow consumed by the synthesis ammonia reaction is as follows:

[0235] (16)

[0236] (17)

[0237] wherein, represents the power consumption of the PSA nitrogen production at time t; represents the unit power consumption of the PSA nitrogen production; represents the nitrogen density, taken as 1.25 kg / m3; represents the nitrogen flow injected into the synthesis ammonia reactor at time t; represents the capacity of the PSA nitrogen production machine.

[0238] The mixed gas needs to be compressed before entering the synthesis ammonia reactor. 1 mol of nitrogen gas mixed with 3 mol of hydrogen gas can generate 2 mol of ammonia gas, so the relationship between the power consumption of the compressor and the synthesis ammonia production and the relationship between the synthesis ammonia production and the gas flow are as follows:

[0239] (18)

[0240] (19)

[0241] (20)

[0242] (21)

[0243] wherein, represents the power consumption of the compressor at time t; represents the specific power consumption of the compressor; represents the ammonia production at time t; represents the hydrogen flow rate injected into the ammonia synthesis reactor at time t; represents the ammonia density, taken as 0.771 kg / m3; represents the capacity of the compressor.

[0244] The ammonia synthesis from nitrogen and hydrogen must be carried out at high temperature and high pressure, but since it is an exothermic reaction, part of the heat released can be directly recovered by the reactor and used, so the relationship between the heat consumption of ammonia synthesis from nitrogen and hydrogen and the ammonia production is as follows:

[0245] (22)

[0246] (23)

[0247] wherein, represents the heat consumption of the ammonia synthesis at time t; represents the efficiency of the ammonia synthesis reactor; represents the heat released by the ammonia synthesis reactor at time t; represents the recovery rate of the heat released by the ammonia synthesis reactor; represents the heat released to synthesize 1 kg of ammonia.

[0248] The ammonia synthesis section has an hourly production upper limit, the total constraints are as follows:

[0249] (24)

[0250] (25)

[0251] (26)

[0252] wherein, represents the power consumption of the ammonia synthesis section at time t; represents the maximum production capacity of the ammonia synthesis section; represents the upper / lower limit of the hourly production of the ammonia synthesis section; represents the positive / negative ramp rate of the ammonia production.

[0253] III. Constraints of the water electrolysis hydrogen production section:

[0254] When multiple electrolytic cells are used to produce hydrogen, the actual power can continuously vary within the range of 5% to 100%, so the constraints of the hydrogen flow rate produced by the electrolytic cells and the input electric power are as follows:

[0255] (27)

[0256] (28)

[0257] wherein, represents the operation efficiency of the electrolyzer; represents the electric power of the electrolyzer at time t; represents the low heat value of hydrogen; represents the hydrogen flow rate produced by the electrolyzer at time t, represents the capacity of the electrolyzer.

[0258] Four, the equipment operation constraints are:

[0259] 1) Fan / photovoltaic

[0260] The wind and light electric output is first used to meet the whole process of ammonia production, if there is surplus, it is transmitted to the power grid, and the on-grid power within the rated power can obtain profit, and the part exceeding the rated power needs to pay penalty. The study considers the predicted value and actual utilization power constraints of fan / photovoltaic electric output:

[0261] (29)

[0262] (30)

[0263] (31)

[0264] (32)

[0265] wherein, represents the actual electric output of the fan / photovoltaic at time t; represents the predicted electric output of the fan / photovoltaic at time t; represents the on-grid power of the fan / photovoltaic at time t; represents the on-grid transaction power of the fan / photovoltaic at time t; represents the on-grid penalty power of the fan / photovoltaic at time t; represents the upper limit of the on-grid transaction power of the fan / photovoltaic at time t.

[0266] 2) Gas boiler

[0267] The system uses hydrogen-mixed natural gas instead of pure natural gas, and the gas boiler using hydrogen-mixed natural gas as fuel is modeled as follows:

[0268] (33)

[0269] (34)

[0270] wherein, represents the volume ratio of hydrogen in the mixed hydrogen natural gas.

[0271] 3) Electric boiler

[0272] The relationship between the power consumption and the heating capacity of the electric boiler is as follows:

[0273] (35)

[0274] (36)

[0275] wherein, represents the thermal output of the electric boiler at time t; represents the heating efficiency of the electric boiler; represents the installed capacity of the electric boiler.

[0276] 4) Gas turbine

[0277] The gas turbine also uses mixed hydrogen natural gas instead of pure natural gas. By mixing 10% hydrogen into natural gas, the carbon monoxide and nitrogen oxide emissions of the gas turbine can be reduced by 60% and 14%, respectively. The modeling of the gas turbine using mixed hydrogen natural gas as fuel is as follows:

[0278] (37)

[0279] (38)

[0280] (39)

[0281] wherein, represents the electric output of the gas turbine at time t; represents the power generation efficiency of the gas turbine; represents the gas flow in the gas turbine at time t; represents the thermal output of the gas turbine; represents the thermal-to-electric ratio of the gas turbine; represents the minimum electric output of the gas turbine; represents the installed capacity of the gas turbine.

[0282] 5) Organic Rankine cycle power generation

[0283] A large amount of low-grade waste heat is generated during the natural gas hydrogen production process, which is difficult to be directly recycled as thermal energy. The organic Rankine cycle can be used to recover and utilize the waste heat generated during the natural gas hydrogen production process and convert it into electrical energy. The relationship between the power generation and the waste heat recovery is as follows:

[0284] (40)

[0285] wherein, represents the power of the organic Rankine cycle at time t; represents the power of the organic Rankine cycle at time t; represents the power of the organic Rankine cycle at time t;

[0286] 6) hydrogen storage tank

[0287] To cope with the intermittency of renewable energy, a hydrogen storage tank is provided in the model, which can store the excess electricity generated during the peak period of new energy power generation. The hydrogen in the hydrogen storage tank can be used as raw material for ammonia synthesis, or can be mixed to form hydrogen-mixed natural gas fuel. The storage capacity of the hydrogen storage tank and the volume flow rate of the injected and extracted hydrogen are both limited. The constraints of the hydrogen storage tank model are as follows:

[0288] (41)

[0289] (42)

[0290] (43)

[0291] (44)

[0292] wherein, represents the existing storage state of the hydrogen storage tank at time t; represents the charging / discharging efficiency of the hydrogen storage tank; represents the hydrogen flow rate flowing out of the hydrogen storage tank at time t; represents the minimum / maximum storage state of the hydrogen storage tank; represents the charging / discharging rate of the hydrogen storage tank; represents the capacity of the hydrogen storage tank.

[0293] S2, considering the uneven new energy power output on a typical seasonal day, the model equipment is supplemented

[0294] Considering the uneven new energy power output on a typical seasonal day, a carbon capture module and a seasonal hydrogen storage tank are added, and an electricity-gas-hydrogen coupled ammonia production energy system is constructed;

[0295] Step S2 is as follows:

[0296] I. The carbon capture module is as follows:

[0297] The carbon capture module comprises a carbon capture device and a storage device, and coupling of the natural gas ammonia production and the carbon capture technology can greatly reduce the carbon dioxide emission. Current mainstream carbon capture and storage technologies are mainly divided into three categories: pre-combustion capture technology, post-combustion capture technology and oxygen-enriched combustion technology. The existing energy system scheduling planning research mainly uses the post-combustion capture technology, that is, the adsorbent is used to adsorb and store the carbon dioxide in the flue gas after combustion, which has simple principle and low cost. The present application considers the post-combustion capture technology, and the carbon dioxide is derived from natural gas hydrogen production, gas boiler and gas turbine, and the specific mathematical model is as follows:

[0298] (45)

[0299] (46)

[0300] (47)

[0301] (48)

[0302] In the formula, represents the electric power consumed by the carbon capture device at time t; represents the electric power consumed by the carbon capture device when capturing carbon dioxide at time t; represents the installed capacity of the carbon capture device; represents the energy consumption of capturing unit carbon dioxide; represents the carbon capture level at time t; represents the carbon emission coefficient of natural gas; represents the total amount of carbon dioxide captured at time t.

[0303] II. Seasonal hydrogen storage tank is as follows:

[0304] The operation mechanism of the seasonal hydrogen storage tank is similar to that of the conventional hydrogen storage tank. In each seasonal typical day, the energy storage value at each time is determined by the hydrogen storage value at the previous time and the hydrogen storage and hydrogen release power.

[0305] The initial energy storage of the seasonal hydrogen storage tank in each seasonal typical day is equal to the cumulative hydrogen charging and discharging amount of the previous seasonal typical day, and the initial energy storage state of the first typical day is the cumulative hydrogen charging and discharging amount of the last seasonal typical day, and the specific formula is as follows:

[0306] (49)

[0307] (50)

[0308] (51)

[0309] (52)

[0310] (53)

[0311] in which, denotes a typical day of a season; denotes the maximum number of typical days; denotes the number of d typical days; denotes the storage state of the seasonal hydrogen storage tank at t time of d typical day; denotes the charging / discharging efficiency of the seasonal hydrogen storage tank; denotes the hydrogen flow rate flowing into / out of the seasonal hydrogen storage tank at t time of d typical day; denotes the minimum / maximum storage state of the seasonal hydrogen storage tank; denotes the charging / discharging rate of the seasonal hydrogen storage tank; denotes the capacity of the seasonal hydrogen storage tank

[0312] S3, opportunity constraint handles wind and light uncertainty

[0313] An opportunity constraint method is used to handle wind and light power generation uncertainty, an economic optimization is taken as a target, and an electric-gas-hydrogen coupled ammonia planning model under new energy uncertainty scenarios is constructed;

[0314] Step S3 is specifically as follows:

[0315] The electric-gas-hydrogen coupled ammonia planning model includes system constraints, a target function and new energy uncertainty processing, and is specifically as follows:

[0316] I. The system constraint is:

[0317] In the system, hydrogen is produced by natural gas reforming and electrolytic tank in cooperation, heat energy is derived from gas boiler, electric boiler and gas turbine, electric energy is derived from wind turbine, photovoltaic, gas turbine, organic Rankine cycle power generation and grid purchase. The newly added carbon capture module needs to consume electric energy in the capture process. The seasonal hydrogen storage tank and the conventional hydrogen storage tank can be operated simultaneously to provide hydrogen raw materials. The system electric, heat, gas and hydrogen balance is shown as follows:

[0318] (54)

[0319] (55)

[0320] (56)

[0321] (57)

[0322] II. The target function is:

[0323] The construction idea of the objective function is to minimize the total cost of system operation while meeting the annual ammonia production. The objective function is mainly composed of the cost of new equipment , equipment operation and maintenance cost , carbon emission cost , carbon capture cost , wind and solar power generation cost , gas purchase cost , electricity purchase cost , wind and solar power sales revenue and wind and solar power grid penalty . The specific objective function is as follows:

[0324] (58)

[0325] 1) The cost of new equipment

[0326] The product of unit depreciation cost and equipment installed capacity is used to measure the cost of energy system configuration equipment. In order to better measure the effectiveness of new equipment in economy, only the depreciation cost of new equipment is considered in this chapter, and the existing equipment is not considered:

[0327] (59)

[0328] In the formula, represents the unit depreciation cost.

[0329] 2) Equipment operation and maintenance cost

[0330] The equipment operation and maintenance cost includes the maintenance and maintenance cost of each equipment, which can be represented as the product of its operation and maintenance unit price and equipment power consumption. The specific calculation formula is as follows:

[0331] (60)

[0332] 3) Carbon emission cost

[0333] The carbon emission cost can be represented as the product of carbon price and carbon dioxide emission. Since the carbon capture link added in this section sequesters part of the carbon dioxide, the actual carbon emission needs to be reduced from the carbon dioxide emission of natural gas hydrogen production, gas boiler and gas turbine. The formula of carbon emission cost is updated as follows:

[0334] (61)

[0335] 4) Carbon capture cost

[0336] Carbon capture includes two main links of carbon capture and sequestration, and its cost is mainly related to the mass of captured carbon dioxide. Therefore, the carbon capture cost is represented as the product of unit carbon capture cost and the total amount of captured and sequestered carbon dioxide, and the specific formula is as follows:

[0337] (62)

[0338] where, represents the unit carbon capture cost.

[0339] 5) Wind-solar power generation cost

[0340] Without considering the wind-solar construction cost, only the operation and maintenance cost is calculated:

[0341] (63)

[0342] where, represents the wind turbine / solar PV operation and maintenance cost.

[0343] 6) Gas purchase cost

[0344] The gas purchase cost can be represented as the product of the natural gas purchase price and the total gas consumption:

[0345] (64)

[0346] where, represents the natural gas purchase price.

[0347] 7) Electricity purchase cost

[0348] The electricity purchase cost can be represented as the product of the hourly industrial electricity purchase price and the corresponding time point electricity consumption:

[0349] (65)

[0350] where, represents the industrial electricity purchase price at time t.

[0351] 8) Wind-solar electricity sale revenue

[0352] The wind-solar electricity sale revenue can be represented as the product of the wind-solar electricity sale transaction price to the grid and the sale electricity quantity, and the revenue is represented as a negative value in the cost function:

[0353] (66)

[0354] where, represents the wind-solar electricity sale transaction price to the grid.

[0355] 9) Wind-solar grid connection penalty

[0356] The wind-solar grid connection penalty can be represented as the product of the penalty electricity price for wind-solar excess grid connection and the excess grid connection electricity quantity:

[0357] (67)

[0358] where, Penalty price of wind and solar over-generation.

[0359] Third, the uncertainty of new energy is processed as:

[0360] Considering the long time span in planning work, there are errors between actual output and predicted output of renewable energy, that is, there is a certain uncertainty, which further affects the planning results. The opportunity constraint method is adopted to process the uncertainty of renewable energy:

[0361] The original constraint of wind and solar output is:

[0362] (68)

[0363] Assuming that the deviation of actual wind and solar output is a normal distribution with mean 0 and standard deviation , denoted as , then . Assuming that the confidence level of the constraint is , then:

[0364] (69)

[0365] Convert to standard normal distribution:

[0366] (70)

[0367] That is

[0368] (71)

[0369] In the formula, is the cumulative distribution function under the standard normal distribution.

[0370] Take the inverse function of both sides to get:

[0371] (72)

[0372] In the formula, is the inverse function of the cumulative distribution function of the standard normal distribution.

[0373] Convert to get:

[0374] (73)

[0375] In summary, the constraint condition of wind and solar power output can be modified as follows:

[0376] (74)

[0377] In the formula, is the standard deviation of the actual output deviation of the wind turbine / solar cell at time t. represents the confidence that the fan / pv output should meet in this scenario.

[0378] S4, example verification model effectiveness.

[0379] As Figures 4-7 shown, to verify the effectiveness of the model in decarburization of synthetic ammonia and new energy consumption, considering the production status of the synthetic ammonia industry, this section takes a synthetic ammonia industrial park in Jiangsu as the optimization object for scenario verification. The annual output of the synthetic ammonia industrial park is 80,000 tons, and the output in spring, summer, autumn and winter accounts for 40%, 30%, 20% and 10% of the total output respectively.

[0380] To verify the effectiveness of the electric-gas-hydrogen coupled scheduling method, the synthetic ammonia industrial park is taken as the object for example analysis, and it is found that the electric-gas-hydrogen coupled ammonia production system of the application can realize nearly 100% new energy consumption while meeting the smooth production of synthetic ammonia, and the addition of carbon capture and seasonal hydrogen storage tanks can help the system operation cost to be reduced by 0.3% and 10.4% respectively, and with the maturity of related technologies and the rise of carbon price, the economic advantage of carbon capture will gradually expand; the seasonal hydrogen storage tank can realize peak shaving and valley filling across seasons, further improving the flexibility of the system. The necessity of the electric-gas-hydrogen coupled ammonia production planning method proposed in the patent is verified.

[0381] Therefore, based on the above method, the application can realize the reasonable configuration of various energies in the ammonia production system, realize the efficient operation of the energy system and the sustainable utilization of energy. Through flexible scheduling of each energy in the electric-gas-hydrogen coupled ammonia production system, nearly 100% new energy consumption can be realized while meeting the smooth production of synthetic ammonia, and the economic efficiency and flexibility of the system are improved.

[0382] The above is only a preferred embodiment of the application, and does not limit the application in any other form, and any modification or equivalent change made according to the technical essence of the application still falls within the scope of the application claimed.

Claims

1. A method for planning an electricity-gas-hydrogen coupled ammonia production system considering new energy uncertainty, characterized in that, Comprise the following steps: S1, considering the interaction of wind and light power generation and power grid, establish the basic model of ammonia production system Comprehensive consideration of wind and light power generation and power grid interaction and carbon emissions in the whole process of ammonia synthesis, establish the basic model of electric-gas-hydrogen coupled ammonia production energy system; S2, considering the uneven new energy power output of seasonal typical day, model equipment supplement Considering the uneven new energy power output of seasonal typical day, add carbon capture module and seasonal hydrogen storage tank, build electric-gas-hydrogen coupled ammonia production energy system; S3, opportunity constraint processing wind light uncertainty The opportunity constraint method is used to process the uncertainty of wind and light power generation, and the economic optimization is taken as the target to build the electric-gas-hydrogen coupled ammonia production planning model under the uncertainty of new energy; S4, example verifies the effectiveness of the model.

2. The method of claim 1, wherein the method further comprises: In step S1, The constraint of natural gas hydrogen production section in the basic model of electric-gas-hydrogen coupled ammonia production energy system is: The relationship between desulfurization energy consumption and natural gas volume flow is as follows: （1） In the formula, represents the power consumption of natural gas desulfurization at time t; represents the unit power consumption of desulfurization; represents the natural gas flow injected into the natural gas hydrogen production section at time t; In the steam reforming reaction, 1 mol of natural gas can generate 3 mol of hydrogen, so the relationship between the energy consumption of steam reforming and the gas flow is as follows: （2） （3） wherein represents the steam reforming heat consumption at time t; represents the unit heat consumption of steam reforming; represents the hydrogen flow rate in the mixed gas after steam reforming at time t; represents the conversion rate of the steam reforming process; The role of high and low temperature change is to further convert the carbon monoxide generated in the steam reforming reaction into carbon dioxide and hydrogen. It is known that 1 mol of carbon monoxide can generate 1 mol of hydrogen. Therefore, the relationship between the energy consumption of high and low temperature shift and the gas flow is as follows: （4） （5） In the formula, represents the heat consumption of high-low temperature shift at time t; represents the unit heat consumption of high-low temperature shift; represents the hydrogen volume flow rate in the mixed gas after high-low temperature shift at time t; represents the conversion rate of high-low temperature shift process; The mixed gas decarbonization adopts PSA adsorption to separate carbon dioxide in the gas, and the relationship between its power consumption and gas flow is as follows: （6） （7） In the formula, represents the PSA decarburization power consumption at time t; represents the unit power consumption of PSA decarburization; represents the carbon dioxide volume flow rate in the high-low temperature shifted mixed gas at time t; The purpose of methanation reaction is to eliminate carbon monoxide in mixed gas. 3 mol of hydrogen is consumed to convert 1 mol of carbon monoxide. Therefore, the relationship between the hydrogen flow consumed by the methanation reactor and the power consumption is as follows: （8） （9） （10） （11） In the formula, represents the power consumption of the methane reactor at time t; represents the hydrogen flow consumed by the methane reactor for removing carbon monoxide at time t; represents the power consumption rate of the methane reactor; represents the carbon monoxide volume flow in the mixed gas after high-low temperature shift at time t; The actual hydrogen produced by the natural gas hydrogen production section is equal to the hydrogen in the mixed gas after high and low temperature shift minus the hydrogen consumed in the methanation reaction. The total constraint is as follows: （12） （13） （14） （15） In the formula, represents the total power consumption of the natural gas hydrogen production section at time t, represents the total heat consumption of the natural gas hydrogen production section at time t, represents the total capacity of the natural gas hydrogen production section; represents the hydrogen flow produced by the natural gas hydrogen production section at time t.

3. The method for planning the electricity-gas-hydrogen coupled ammonia production system considering new energy uncertainty according to claim 1, characterized in that, In step S1, The constraint of ammonia synthesis section in the basic model of electric-gas-hydrogen coupled ammonia production energy system is: The ammonia synthesis section first needs to produce nitrogen as a raw material. The PSA nitrogen production device uses air as a raw material. Based on the difference in adsorption rate of carbon molecular sieve to nitrogen molecules and oxygen molecules in air, combined with the rapid cycle process of pressurized adsorption and reduced desorption, high-purity nitrogen required by the ammonia synthesis process is obtained. The relationship between the power consumption of PSA nitrogen production and the nitrogen flow consumed by the ammonia synthesis reaction is as follows: （16） （17） wherein, represents the power consumption of PSA nitrogen production at time t; represents the unit power consumption of PSA nitrogen production; represents the nitrogen density, taken as 1.25 kg / m3; represents the nitrogen flow rate injected into the synthetic ammonia reactor at time t; represents the capacity of the PSA nitrogen generator; The mixed gas needs to be compressed before entering the ammonia synthesis reactor. 1 mol of nitrogen mixed with 3 mol of hydrogen can generate 2 mol of ammonia. Therefore, the relationship between the power consumption of the compressor and the ammonia production, and the relationship between the ammonia production and the gas flow are as follows: （18） （19） （20） （21） wherein, represents the power consumption of the compressor at time t; represents the specific power consumption of the compressor; represents the production of synthetic ammonia at time t; represents the hydrogen flow rate injected into the synthetic ammonia reactor at time t; represents the ammonia gas density, taken as 0.771 kg / m3; represents the capacity of the compressor; The nitrogen-hydrogen ammonia synthesis reaction must be carried out at high temperature and high pressure, but since it is an exothermic reaction, part of the released heat can be directly recycled and utilized by the reactor. Therefore, the relationship between the heat consumption of nitrogen-hydrogen ammonia synthesis and the ammonia production is as follows: （22） （23） wherein, represents the heat consumption for synthesizing ammonia at time t; represents the efficiency of the ammonia synthesis reactor; represents the heat released from the ammonia synthesis reactor at time t; represents the recovery rate of the heat released from the ammonia synthesis reactor; represents the heat released for synthesizing 1 kg of ammonia; There is an upper limit to the hourly production of the ammonia synthesis section. The total constraint is as follows: （24） （25） （26） In the formula, represents the power consumption of the ammonia synthesis section at time t; represents the maximum production capacity of the ammonia synthesis section; represents the upper / lower limit of the hourly production of the ammonia synthesis section; represents the positive / negative ramp rate of the ammonia production.

4. The method of claim 1, wherein the method further comprises: In step S1, The constraint of water electrolysis hydrogen production section in the basic model of electric-gas-hydrogen coupled ammonia production energy system is: When multiple electrolytic cells are used to produce hydrogen, the actual power can continuously vary within the range of 5% to 100%. Therefore, the constraints of the hydrogen flow produced by the electrolytic cell and the input electric power are as follows: （27） （28） wherein represents the operating efficiency of the electrolyzer; represents the electric power of the electrolyzer at time t; represents the lower calorific value of hydrogen; represents the hydrogen flow rate produced by the electrolyzer at time t, represents the capacity of the electrolyzer.

5. The method for planning the electricity-gas-hydrogen coupled ammonia production system considering new energy uncertainty according to claim 1, characterized in that, In step S1, The operation constraints of each device in the basic model of the electric-gas-hydrogen coupled ammonia production energy system are as follows: Wind turbine / photovoltaic: The wind turbine / photovoltaic power output is first used to meet the entire ammonia production process. If there is a surplus, it is transmitted to the power grid. The on-grid power within the rated power can obtain profit, and the part exceeding the rated power needs to pay a penalty. The wind turbine / photovoltaic power output prediction value and the actual utilization power constraint are considered: （29） （30） （31） （32） wherein, represents the actual electrical output of the wind turbine / photovoltaic at time t; represents the predicted electrical output of the wind turbine / photovoltaic at time t; represents the on-grid electrical quantity of the wind turbine / photovoltaic at time t; represents the on-grid transaction electrical quantity of the wind turbine / photovoltaic at time t; represents the on-grid penalty electrical quantity of the wind turbine / photovoltaic at time t; represents the upper limit of the on-grid transaction electrical quantity of the wind turbine / photovoltaic at time t; Gas boiler: Using hydrogen-mixed natural gas instead of pure natural gas, the gas boiler using hydrogen-mixed natural gas as fuel is modeled as follows: （33） （34） In the formula, represents the volume ratio of hydrogen in the mixed hydrogen natural gas; Electric boiler: The relationship between the power consumption and the heating capacity of the electric boiler is as follows: （35） （36） In the formula, represents the heat output of the electric boiler at time t; represents the heating efficiency of the electric boiler; represents the installed capacity of the electric boiler; Gas turbine: The gas turbine also uses hydrogen-mixed natural gas instead of pure natural gas. Only by mixing 10% of hydrogen into natural gas, the carbon monoxide and nitrogen monoxide emissions of the gas turbine can be reduced by 60% and 14%, respectively. The gas turbine using hydrogen-mixed natural gas as fuel is modeled as follows: （37） （38） （39） In the formula, represents the electric output of the gas turbine at time t; represents the electric efficiency of the gas turbine; represents the gas flow in the gas turbine at time t; represents the thermal output of the gas turbine; represents the thermal-electric ratio of the gas turbine; represents the minimum electric output of the gas turbine; represents the installed capacity of the gas turbine; Organic Rankine cycle power generation: The organic Rankine cycle can recover the waste heat generated in the natural gas hydrogen production process and convert it into electrical energy. 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The storage capacity of the hydrogen storage tank is limited. The storage capacity of the hydrogen storage tank is limited. The storage capacity of the hydrogen storage tank is limited. The storage capacity of the hydrogen storage tank is limited. The storage capacity of the hydrogen （41） （42） （43） （44） In the formula, represents the existing gas storage state of the hydrogen storage tank at time t; represents the charging / discharging efficiency of the hydrogen storage tank; represents the hydrogen flow rate flowing out of the hydrogen storage tank at time t; represents the minimum / maximum storage state of the hydrogen storage tank; represents the charging / discharging rate of the hydrogen storage tank; represents the capacity of the hydrogen storage tank.

6. The method for planning the electricity-gas-hydrogen coupled ammonia production system considering new energy uncertainty according to claim 1, characterized in that, ​ ​ ​ （45） （46） （47） （48） wherein, represents the electrical power consumed by the carbon capture device at time t; represents the electrical power consumed by the carbon capture device to capture carbon dioxide at time t; represents the installed capacity of the carbon capture device; represents the energy consumption per unit of carbon dioxide captured; represents the carbon capture level at time t; represents the carbon emission factor of natural gas; represents the total amount of carbon dioxide captured at time t.

7. The method for planning an ammonia production system coupled with electricity, gas, and hydrogen considering the uncertainty of new energy according to claim 1, wherein, ​ ​ ​ ​ （49） （50） （51） （52） （53） wherein, denotes a typical day of a season; denotes a maximum number of typical days; denotes a number of d typical days; denotes a storage state of the seasonal hydrogen storage tank at time t on d typical day; denotes a charging / discharging efficiency of the seasonal hydrogen storage tank; denotes a hydrogen flow rate into / out of the seasonal hydrogen storage tank at time t on d typical day; denotes a minimum / maximum storage state of the seasonal hydrogen storage tank; denotes a charging / discharging rate of the seasonal hydrogen storage tank; denotes a capacity of the seasonal hydrogen storage tank.

8. The method of claim 1, 2, 5, 6, 7, wherein, ​ ​ ​ （54） （55） （56） （57）。 9.The method of claim 1, wherein, ​ ​ The construction idea of the objective function is to minimize the total cost of system operation while meeting the annual ammonia production, and the objective function is composed of the cost of new equipment , the cost of equipment operation and maintenance , the cost of carbon emission , the cost of carbon capture , the cost of wind and solar power generation , the cost of gas purchase , the cost of electricity purchase , the income of wind and solar power sales , and the penalty of wind and solar power grid connection , and the specific objective function is as follows: （58） ​ ​ （59） In the formula, represents the unit depreciation cost; ​ ​ （60）； ​ The carbon emission cost can be expressed as the product of carbon price and carbon emission, and the formula is updated as follows: （61）； Carbon capture cost: The carbon capture module includes carbon capture and carbon sequestration, and its cost is related to the mass of captured carbon dioxide. Therefore, the carbon capture cost is expressed as the product of unit carbon capture cost and the total amount of captured and sequestrated carbon dioxide, and the specific formula is as follows: （62） wherein represents the cost per unit of carbon capture; Wind and solar power generation cost: Without considering the construction cost of wind and solar power, only the operation and maintenance cost is calculated: （63） In the formula, represents the fan / pv O&M cost; Gas purchase cost: The gas purchase cost can be expressed as the product of natural gas purchase price and total gas consumption: （64） In the formula, represents the natural gas purchase price; Electricity purchase cost: The electricity purchase cost can be expressed as the product of hourly industrial electricity purchase price and corresponding electricity consumption at that time: （65） In the formula, represents the industrial electricity purchase price at time t; Wind and solar power sale revenue: The wind and solar power sale revenue can be expressed as the product of the transaction price of wind and solar power sold to the grid and the sale quantity, and the revenue is represented as a negative value in the cost function: （66） In the formula, represents the transaction price of the wind-solar power generation sold to the power grid; Wind and solar power grid connection penalty: The wind and solar power grid connection penalty can be expressed as the product of the penalty price of wind and solar power over-generation and the over-generation quantity: （67） In the formula, represents the penalty price of wind and light excess on-grid.

10. The method for planning an ammonia production system coupled with electricity, gas, and hydrogen considering the uncertainty of new energy according to claim 1, wherein, In step S3, The new energy uncertainty processing of the electricity-gas-hydrogen coupled ammonia planning model is as follows: The opportunity constraint method is used to process the uncertainty of renewable energy: The original constraint of wind and solar power output is: （68） Assume that the deviation of actual wind and light output is subject to normal distribution with mean value of 0 and standard deviation of , denoted as , then , assume that the confidence level of the constraint satisfies , then: （69） After converting to standard normal distribution, we have: （70） That is （71） In the formula, denotes the cumulative distribution function under the standard normal distribution, Taking the inverse function on both sides, we get: （72） In the formula, denotes the inverse function of the cumulative distribution function of the standard normal distribution, After conversion, we get: （73） In summary, the constraint conditions of wind and solar power output can be modified as follows: （74） In the formula, represents the standard deviation of the actual wind turbine / photovoltaic power output deviation at time t; represents the confidence level that the wind turbine / photovoltaic power output should meet under this scenario.

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