Optimized operation method of integrated energy system and integrated energy system

Abstract

The invention provides an optimized operation method of an integrated energy system and the integrated energy system, and belongs to the technical field of energy systems, and the method comprises the following steps: supplying carbon dioxide captured by CCS equipment to a P2G system; after surplus electric energy generated by renewable energy sources is converted into hydrogen by an electrolytic cell in the P2G system, part of hydrogen and carbon dioxide provided by the CCS equipment are converted into methane through methanation equipment; the other part of hydrogen is injected into a natural gas pipeline and used for combustion of a gas unit and providing electric power for CCS equipment; the comprehensive energy system supplies energy based on a low-carbon economic operation model; the low-carbon economic operation model is constructed by taking the cost of the minimized integrated energy system and the net carbon emission as objective functions, and the low-carbon economic operation model uses a stepped carbon transaction model to constrain the carbon emission. Cyclic utilization of carbon resources is achieved, and the utilization rate of renewable energy sources is increased; carbon emission is reduced, and the system is driven to operate at the lowest cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy systems, in particular to a comprehensive energy system optimization operation method and a comprehensive energy system. BACKGROUND

[0002] With the increasing global concern about climate change, the low-carbon operation of comprehensive energy systems has become one of the key paths to achieve sustainable development goals. However, in the process of promoting this goal, the current technology and management method faces a series of complex challenges.

[0003] Traditional comprehensive energy system optimization methods mainly focus on the efficient conversion and utilization of multiple energy forms such as electricity, heat, and gas, and improve overall energy efficiency through these multi-energy coupling mechanisms. However, this mode is highly dependent on gas turbine units, and although they are more environmentally friendly than pure coal-fired power generation in some cases, their carbon emission intensity is still high, making it difficult to meet increasingly stringent low-carbon emission standards. In addition, the current fixed carbon price mechanism fails to effectively reflect the actual impact of different emission entities, and this approach not only lacks specificity but also fails to provide sufficient economic incentives for high-emission entities to take more active emission reduction measures.

[0004] Therefore, there is an urgent need for a comprehensive energy system optimization operation method to address the high carbon emission intensity and lack of specificity of the fixed carbon price mechanism in the prior art. SUMMARY

[0005] The present application provides a comprehensive energy system optimization operation method and a comprehensive energy system to solve the defects of high carbon emission intensity and lack of specificity of the fixed carbon price mechanism in the prior art.

[0006] The present application provides a comprehensive energy system optimization operation method, comprising the following steps: The carbon dioxide captured by the CCS device is supplied to the P2G system; The electrolytic cell in the P2G system converts surplus renewable energy into hydrogen, and then converts a part of the hydrogen and the carbon dioxide provided by the CCS device into methane through a methanation device; another part of the hydrogen is injected into the natural gas pipeline for gas turbine combustion and to provide power for the CCS device; The comprehensive energy system supplies energy based on a low-carbon economic operation model; the low-carbon economic operation model is constructed with the lowest cost and net carbon emission of the comprehensive energy system as the objective function, and the low-carbon economic operation model uses a stepwise carbon trading model to constrain carbon emissions.

[0007] According to the comprehensive energy system optimization operation method provided by the present application, the low-carbon economic operation model is as follows: ; in, , for t The electrolytic cell consumes power and generates hydrogen at that time; This is the calorific value of hydrogen. , , These represent the amount of carbon dioxide released by gas turbines, gas boilers, and thermal power units, respectively. The amount of carbon dioxide captured by the CCS device; , The operating efficiency of the electrolytic cell and the CCS equipment; , , These are the total power consumed by the CCS device, the fixed energy consumption, and the capture energy consumption, respectively. Energy consumption per unit of carbon dioxide captured; , These represent the amounts of carbon dioxide used for methanation and storage, respectively. , for t The amount of hydrogen supplied to the gas turbine and the gas boiler at all times; The amount of methane synthesized by the P2G system; This refers to the amount of carbon dioxide purchased externally.

[0008] According to the integrated energy system optimization operation method provided by the present invention, the tiered carbon trading model adjusts the hourly carbon emission allowance in real time; at the end of the settlement period, settlement is carried out based on the user's hourly carbon emission allowance and actual carbon emissions.

[0009] According to a method for optimizing the operation of an integrated energy system provided by the present invention, the tiered carbon trading model is settled based on the following formula: ; in, for t The cost of carbon trading at any given time; The base price for tiered carbon trading; L The length of the carbon emission range; The percentage increase in carbon trading prices; The compensation coefficient; for t The actual carbon emissions at any given moment.

[0010] According to the integrated energy system optimization operation method provided by the present invention, the objective function is as follows: ; in, for operation and maintenance costs; for wind and light punishment costs; for the involved step carbon trading costs; for the cost of new carbon sequestration; for the net carbon dioxide emissions; for the energy purchasing cost of the integrated energy system.

[0011] The application also provides an integrated energy system, comprising: a CCS device for capturing carbon dioxide and supplying a P2G system; a P2G system for converting surplus renewable energy into hydrogen, and then converting part of the hydrogen and carbon dioxide provided by the CCS device into methane through a methanation device; and injecting another part of the hydrogen into a natural gas pipeline for gas turbine combustion and providing power for the CCS device; The integrated energy system supplies energy based on a low-carbon economic operation model; the low-carbon economic operation model is constructed with the minimum cost and net carbon emissions of the integrated energy system as the objective function, and the low-carbon economic operation model uses a step carbon trading model to constrain carbon emissions.

[0012] According to the application, the low-carbon economic operation model is as follows: ; wherein, , is t the power consumption of the electrolytic cell and the generated hydrogen; is the combustion heat value of hydrogen; , , are the amounts of carbon dioxide released by the gas turbine, the gas boiler, and the thermal power unit, respectively; is the amount of carbon dioxide captured by the CCS device; , are the operation efficiencies of the electrolytic cell and the CCS device; , , are the total power consumption, fixed energy consumption, and capture energy consumption of the CCS device, respectively; is the energy consumption per unit of carbon dioxide captured; , are the amounts of carbon dioxide used for methanation and sequestration, respectively; , is t the amount of hydrogen supplied to the gas turbine and the gas boiler at the moment; The amount of methane synthesized for the P2G system; The amount of carbon dioxide purchased.

[0013] According to the comprehensive energy system optimization operation system provided by the present application, the stepwise carbon trading model adjusts the carbon emission quota of each hour in real time; at the end of the settlement period, the carbon emission quota of each hour of the user and the actual carbon emission amount are cleared based on the carbon emission quota of each hour of the user.

[0014] According to the comprehensive energy system optimization operation system provided by the present application, the stepwise carbon trading model is cleared based on the following formula: ; Wherein, The carbon trading cost at the moment t; t The actual carbon emission amount at the moment t. The stepwise carbon trading base price; L The carbon emission interval length; The carbon trading price growth range; The compensation coefficient; The carbon trading cost of the stepwise carbon trading; t The actual carbon emission amount at the moment t.

[0015] According to the comprehensive energy system optimization operation system provided by the present application, the objective function is as follows: ; Wherein, The operation and maintenance cost; The penalty cost of abandoned wind and light; The stepwise carbon trading cost involved; The new carbon sequestration cost; The net carbon emission amount of carbon dioxide; The energy purchasing cost of the comprehensive energy system.

[0016] The application provides a comprehensive energy system optimization operation method and a comprehensive energy system, wherein carbon dioxide captured by a CCS device is supplied to a P2G system; an electrolytic cell in the P2G system converts surplus electric energy generated by renewable energy into hydrogen, and then a part of the hydrogen and the carbon dioxide provided by the CCS device are converted into methane through a methanation device; another part of the hydrogen is injected into a natural gas pipeline and used for combustion of a gas turbine unit to provide power for the CCS device; the comprehensive energy system supplies energy based on a low-carbon economic operation model; the low-carbon economic operation model is constructed with the lowest cost and net carbon emission of the comprehensive energy system as an objective function, and the low-carbon economic operation model uses a step-by-step carbon trading model to constrain carbon emission. According to the scheme, the carbon dioxide released by a gas turbine of the CCS device is supplied to the P2G system as a reaction raw material to synthesize methane, the hydrogen generated by the P2G system and the methane are supplied to the gas turbine as fuel, a circulation link of electricity-gas-carbon is constructed, carbon resource circulation utilization is realized, renewable energy utilization rate is improved, and therefore the operation benefit of the comprehensive energy system is improved; meanwhile, a step-by-step carbon trading mechanism is introduced, carbon emission cost is endogenously segmented and priced, carbon emission is reduced, and the comprehensive energy system is driven to operate at the lowest cost. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0018] Figure 1 is a flowchart of the comprehensive energy system optimization operation method provided by the application; Figure 2 is a flowchart of solving the low-carbon economic operation model provided by the application; Figure 3 is a structural diagram of the comprehensive energy system provided by the application; Figure 4 is a comparison diagram of total costs of the comprehensive energy system under different hydrogen mixing ratios provided by the application; Figure 5 is a comparison diagram of carbon emissions of the comprehensive energy system under different hydrogen mixing ratios provided by the application; Figure 6 is a diagram of distribution of hydrogen mixing power and load provided by the application; Figure 7 is a diagram of costs and carbon emissions of the comprehensive energy system under different carbon prices provided by the application. DETAILED DESCRIPTION

[0019] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0020] It should be noted that, in the description of the embodiments of the present application, the terms "comprise", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitation, the element defined by the statement "comprising a" does not exclude the presence of another identical element in the process, method, article or device comprising the element. The terms "upper", "lower" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise explicitly specified and limited, the terms "mount", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be connected internally between two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0021] The terms "first", "second" and the like in the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second" and the like are generally of a kind, and are not limited to the number of objects, for example, the first object can be one or more. In addition, "and / or" means at least one of the connected objects, and the character " / ", generally means that the front and rear associated objects are in a "or" relationship.

[0022] Figure 1 is a flowchart of the comprehensive energy system optimization operation method provided by the present application, as shown in Figure 1 The method comprises the following steps: S110, supplying carbon dioxide captured by the CCS device to the P2G system; S120, the electrolytic tank in the P2G system converts the surplus electric energy generated by the renewable energy into hydrogen, and then converts part of the hydrogen and the carbon dioxide provided by the CCS device into methane through a methanation device; another part of the hydrogen is injected into a natural gas pipeline for combustion of a gas turbine unit and provides power for the CCS device.

[0023] In the embodiment of the present application, the integrated energy system supplies energy based on a low-carbon economic operation model; the low-carbon economic operation model is constructed with the minimum cost and net carbon emission of the integrated energy system as the objective function, and the low-carbon economic operation model uses a stepwise carbon trading model to constrain carbon emissions.

[0024] It should be noted that the execution subject of the integrated energy system optimization operation method provided by the embodiment of the present application is the integrated energy system.

[0025] Figure 3 is a structural schematic diagram of the integrated energy system provided by the present application. Figure 3 An example structural schematic diagram is shown. For the purpose of description, the architecture drawn is only an example of a suitable environment, and does not impose any limitation on the use range or function of the present application.

[0026] In the embodiment of the present application, the constructed low-carbon economic operation model combines the P2G (Power-to-Gas) system, the CCS (Carbon Capture and Storage) device and the GT (Gas Turbine) hydrogen-doped, converts the surplus electric energy generated by the renewable energy into hydrogen through the electrolytic tank in the P2G system, part of the generated hydrogen is converted into combustible gas methane through the methanation device, and another part is directly injected into the natural gas pipeline, mixed with the gas and sent to the gas turbine unit for combustion to generate power and heat. The gas turbine unit provides power for the CCS device during the combustion process for capturing the generated carbon dioxide In addition, the stepwise carbon trading model is introduced to constrain the system carbon emissions, effectively promoting the internalization of the cost of carbon emissions, encouraging enterprises to adopt more environmentally friendly production methods, thereby achieving effective control of greenhouse gas emissions. In order to further constrain the system carbon emissions, a double-objective function is established with the minimum total cost and the minimum net carbon emission of the system, and a low-carbon economic operation model of the integrated energy system considering stepwise carbon trading and hydrogen-doped gas is constructed.

[0027] Figure 2 is a flowchart of the solution of the low-carbon economic operation model provided by the present application, as Figure 2 shown, the optimal solution of the double objective is obtained by using the triangular decomposition method.

[0028] The method for optimizing operation of the integrated energy system provided by the embodiment of the present application supplies carbon dioxide captured by a CCS device to a P2G system; an electrolytic cell in the P2G system converts surplus electric energy generated by renewable energy into hydrogen, and then converts part of the hydrogen and carbon dioxide provided by the CCS device into methane through a methanation device; another part of the hydrogen is injected into a natural gas pipeline for combustion of a gas turbine unit and for providing power for the CCS device; the integrated energy system supplies energy based on a low-carbon economic operation model; the low-carbon economic operation model is constructed with the lowest cost and net carbon emission of the integrated energy system as an objective function, and uses a step-by-step carbon trading model to constrain carbon emission. The present scheme supplies carbon dioxide released by a gas turbine of a CCS device to a P2G system as a reaction raw material to synthesize methane, and supplies hydrogen generated by the P2G system and methane to the gas turbine as fuel, thereby constructing a circular link of electricity-gas-carbon, realizing recycling of carbon resources, improving renewable energy utilization rate, and thus improving operation efficiency of the integrated energy system; meanwhile, a step-by-step carbon trading mechanism is introduced to endogenize carbon emission cost through segmented pricing, thereby reducing carbon emission and driving the integrated energy system to operate at the lowest cost.

[0029] In optional embodiments, the low-carbon economic operation model is as follows: ; Wherein, , is the consumed power of the electrolytic cell and the generated hydrogen; t is the combustion heat value of the hydrogen; , , , are the amounts of carbon dioxide released by the gas turbine, the gas boiler and the thermal power unit, respectively; is the amount of carbon dioxide captured by the CCS device; , are the operation efficiencies of the electrolytic cell and the CCS device; , , are the total power consumed by the CCS device, the fixed energy consumption and the capture energy consumption, respectively; is the energy consumption for capturing unit carbon dioxide; , are the amounts of carbon dioxide used for methanation and sequestration, respectively; , is the amount of hydrogen supplied to the gas turbine and the gas boiler at the moment; t is the amount of methane synthesized by the P2G system; is the amount of externally purchased carbon dioxide. ​

[0030] Further, the hydrogen-doped gas turbine model is shown as follows: The hydrogen-doped gas turbine model is shown as follows: ; wherein, , is the output electric and heat power of the hydrogen-doped gas turbine at the moment; t is the natural gas consumption of the hydrogen-doped gas turbine at the moment; , t , , is the electric and heat efficiency of the gas turbine; , is the maximum and minimum power output of the gas turbine when the gas turbine supplies power alone; , , is the electric-heat conversion efficiency; , is the combustion heat value of hydrogen and natural gas; is the hydrogen-doping volume ratio of the hydrogen-doped gas turbine; , is the upper and lower limit of the hydrogen-doping ratio of the gas turbine.

[0031] The hydrogen-doped gas boiler model is shown as follows: ; wherein, is the output heat power of the hydrogen-doped gas boiler at the moment; t is the natural gas consumption of the gas boiler at the moment; is the hydrogen consumption of the gas boiler at the moment; t is the heat efficiency of the gas boiler; is the hydrogen-doping ratio of the gas boiler; t is the hydrogen-doping volume ratio of the hydrogen-doped gas turbine; , is the upper and lower limit of the hydrogen-doping ratio of the gas boiler. In an optional embodiment, the step-by-step carbon trading model adjusts the carbon emission quota every hour in real time; at the end of the settlement period, the carbon emission quota of each user per hour is cleared based on the actual carbon emission. In the embodiment of the present application, the step-by-step carbon trading mechanism is refined to the hour, and the total carbon emission is controlled as the target, the optimized carbon quota and the corresponding carbon emission are performed every hour, and the hourly settlement is performed after a period.

[0032]

[0033] In the embodiment of the present application, the step-by-step carbon trading mechanism is refined to the hour, and the total carbon emission is controlled as the target, the optimized carbon quota and the corresponding carbon emission are performed every hour, and the hourly settlement is performed after a period.

[0034] ​​Specifically, multiple price tiers are set based on different carbon emission levels; each tier corresponds to a specific carbon emission range and a corresponding carbon price. Higher emissions correspond to higher carbon prices, thus incentivizing carbon emission reduction. Before the cycle begins, initial hourly carbon emission allowances are allocated to each participant based on historical data and predictive models. Actual hourly carbon emissions are monitored in real time, and subsequent hourly allowances are dynamically adjusted based on actual emissions to ensure that total emissions throughout the cycle do not exceed the predetermined target. Advanced optimization algorithms (such as linear programming, dynamic programming, or machine learning algorithms) are used to calculate the optimal hourly carbon emission levels and trading strategies based on current market prices, energy consumption patterns, and weather forecasts. At the end of each settlement cycle (e.g., after one day or one week), the actual carbon emissions and carbon allowance usage for each hourly period are settled.

[0035] The integrated energy system optimization operation method provided by this invention can manage carbon emissions more flexibly and effectively by refining the tiered carbon trading mechanism down to the hour, thereby promoting energy conservation and emission reduction.

[0036] In an optional embodiment, the main carbon emission sources in the integrated energy system are thermal power units, GT (gas turbine) and GB (gas boiler). Thermal power units output electrical power, GT outputs both thermal and electrical power, while GB only outputs thermal power. Carbon emission allowances are allocated to each unit based on its total power generation and thermal output. The carbon emission allowances are shown in the following formula: ; in, This represents the total carbon emission allowance for the IES. , , These are carbon allowances for thermal power plants, GT, and GB, respectively. , , These represent the output power of the thermal power plant, GT, and GB at time t, respectively. , Carbon emission quotas per unit output power for thermal power units and gas turbine units.

[0037] In this embodiment of the invention, the carbon emission sources in the integrated energy system consist of thermal power units and gas turbine units. The actual carbon emission is obtained by subtracting the carbon dioxide captured by the CCS equipment, and the model is shown in the following formula: ; ; ; in, , These are the molar mass coefficients of CH4 and CO2 per unit volume, respectively. , For GT, GB t The amount of CH4 consumed at any given time; for t The amount of carbon dioxide captured by the CCS device at any given time; , , This represents the total carbon emissions from thermal power units, GT, and GB. The amount of carbon dioxide captured by the CCS device; , The carbon emission intensity of thermal power units and gas turbine units.

[0038] Furthermore, the tiered carbon trading model is settled based on the following formula: ; in, for t The cost of carbon trading at any given time; The base price for tiered carbon trading; L The length of the carbon emission range; The percentage increase in carbon trading prices; The compensation coefficient; for t The actual carbon emissions at any given moment.

[0039] The integrated energy system optimization operation method provided in this invention achieves a positive correlation between price and emission by dividing carbon emission ranges and setting differentiated trading prices based on the scale of carbon emissions.

[0040] In addition, the electric boiler model is shown below: ; in, , They are respectively EB The output thermal power and input electrical power of an electric boiler; for EB Energy conversion efficiency.

[0041] The energy storage device model is as follows: ; in, , They are respectively t The storage capacity of energy storage and thermal storage devices at all times; , They are respectively The storage capacity of energy storage and thermal storage devices at all times; , respectively the charging and discharging efficiency of the battery; 、 respectively the charging and discharging power of the battery; 、 respectively the charging and discharging efficiency of the thermal tank; 、 respectively the charging and discharging power of the thermal tank.

[0042] In optional embodiments, the objective function is as follows: ; wherein, is the operation and maintenance cost; is the wind and solar curtailment penalty cost; is the carbon trading cost involved; is the new carbon sequestration cost; is the net carbon emission of carbon dioxide; is the energy purchase cost of the integrated energy system.

[0043] Herein, ; The operation and maintenance cost of each device is as follows: ; wherein, ; T is the time scale, for example, 24 h ; 、 、 respectively the device start-up, device shut-down and maintenance cost coefficient; is a binary variable representing the device operation state; is the t period i power of the device; 、 、 respectively the cost coefficient of the natural gas storage, the battery and the thermal tank; 、 、 respectively the t period natural gas storage amount, the battery power and the thermal tank heat.

[0044] The energy purchase cost is as follows: wherein, F gas 、 F g respectively the system natural gas purchase cost and the system fuel cost; a, b, c are the energy consumption parameters of the coal-fired unit; PB,t The total power generated by the system; C gas The price per unit of natural gas; Q GT,t Q GB,t Q P2G,t These represent the natural gas consumption of GT, GB, and P2G, respectively; Q L,t Let t be the gas load of the system at time t.

[0045] The penalty cost for curtailing wind and solar power is shown in the following formula: ; in, Reduce the penalty coefficient for renewable energy; , These represent power reductions for wind power and solar power, respectively.

[0046] The cost of reward-based carbon trading is shown in the following formula: ; in, , These are the carbon dioxide emissions and carbon emission intensity of the heat-generating units, respectively. , , The thermal power of gas turbines, gas-fired boilers, and electric boilers; The amount of carbon dioxide emitted by thermal power units; This represents the cost coefficient for the carbon trading market. The total electrical power of the integrated energy system; This refers to the electrical power of the gas turbine. A , B These are the carbon emission allowances per unit power of electrical and thermal energy, respectively.

[0047] Tiered carbon trading costs As shown below: ; The costs of carbon sequestration are as follows: ; in, for t The total amount of carbon dioxide captured by the CCS device at any given time; for t The amount of carbon dioxide consumed by the methanation of the P2G system at any given time.

[0048] Net carbon emissions are shown below: ; in, for t The amount of CO2 released by coal-fired power units at all times; , GT, GB in t the amount of CO2 released at the moment.

[0049] In addition, the low-carbon economy operation model also has the following constraint conditions: Electric power balance constraint: ; wherein, Pnet is the net output power of the power plant; Pwind is the wind power output; Ppv is the photovoltaic power output; Pbat is the battery discharge; Pload is the electrical load; Pboiler is the electrical consumption of the electric boiler; Pcc is the electrical consumption of the carbon capture device; Pbat is the battery discharge; Pload is the electrical load.

[0050] Thermal power balance constraint: ; wherein, Pgt is the heat output power of the gas turbine; Pgb is the heat output power of the gas boiler; Pboiler is the heat output power of the electric boiler; Ptank is the heat release power of the heat storage tank; Ptank is the heat storage power of the heat storage tank; Phl is the heat load.

[0051] Gas power balance constraint: ; wherein, Peg is the amount of natural gas produced by the electric-gas conversion; Pgas is the amount of natural gas purchased; Pgt is the consumption of natural gas by the gas turbine; Pgb is the consumption of natural gas by the gas boiler; Phl is the gas load.

[0052] Upper and lower limits of unit output power constraint: ; wherein, , , Pmax and Pmin are the maximum and minimum output powers of the unit i , respectively.

[0053] Power ramping constraint of each unit in the system: ; wherein, ; , Respectively, the unit i Maximum upward and downward ramping power.

[0054] Hydrogen balance constraint: Where, is t hydrogen generated by the electrolyzer at time t; is t hydrogen released by the hydrogen storage device at time t; is t hydrogen used for methanation at time t; is t hydrogen used for the gas turbine at time t; is t hydrogen used for the gas boiler at time t; is t hydrogen charged into the hydrogen storage device at time t.

[0055] Hydrogen storage device constraints within the system: Where, , represents t the charging and discharging state of the hydrogen storage device at time t, which is a 0-1 variable; , is t the amount of H2 charged and discharged by the hydrogen storage device at time t; , represents the upper and lower limits of the capacity of the hydrogen storage device; is t the capacity of the hydrogen storage device at time t; , is the initial capacity and the final capacity of the hydrogen storage device within 24 hours.

[0056] ​​In summary, the comprehensive energy system optimization operation method provided by the application can effectively improve the utilization rate of renewable energy, realize energy translation effect, CCS can capture CO2 released by GT to be used as raw material for P2G reaction, H2 and methane generated by P2G are used as fuel for GT, three equipment coupling modeling realizes full utilization of energy, and improves the operation benefit of IES. When the hydrogen blending ratio of GB is fixed, the cost decreases and stagnates when the hydrogen blending ratio of GT is greater than 0.18; the carbon emission curve tends to be stable when the hydrogen blending ratio of GB is greater than 0.15 and the hydrogen blending ratio of GT is 0.16, and carbon emission rebound occurs when the hydrogen blending ratio is greater than 0.19; in order to remove the fixed hydrogen blending ratio “hydrogen for electricity” constraint, a hydrogen storage tank is further added for flexible hydrogen blending test of the gas turbine unit, the total cost is reduced, and the carbon emission is reduced. Considering the optimization operation mode of the comprehensive energy system under the ladder carbon trading mechanism, the ladder carbon trading cost is higher than the traditional carbon trading cost, and the yield of the sold carbon emission right is much higher than that of the traditional carbon trading mechanism, which can better adjust the output of each device in the IES, reduce carbon emission, and make the IES run at the lowest cost.

[0057] The comprehensive energy system optimization operation method provided by the application will be described below in combination with Figure 2 , Figures 4-7 , and a specific comprehensive energy system. The total cost and carbon emission of different hydrogen blending ratios of the gas turbine are shown in Figure 4 and Figure 5 .

[0058] The parameters of each device in the comprehensive energy system are shown in Table 1.

[0059] Table 1 Parameters of each device in the IES

[0060] In order to optimize the hydrogen blending ratio, the distribution of hydrogen blending consumption and corresponding power and net power load are shown in Figure 6 , and the following seven scenes shown in Table 2 are set for comparison and analysis.

[0061] Table 2 Scene comparison table

[0062] Table 3 Operation cost and carbon emission of the total system under different scenes

[0063] As shown in Table 3 above, the total operation cost of scenario 1 is the highest, 486107 yuan, and the total operation cost of scenario 5 is the lowest, 208489 yuan. The total cost of scenario 2 considering CCS is reduced by 42.017% compared with scenario 1, but the coal consumption cost and operation and maintenance cost are increased by 101086 yuan and 14422 yuan respectively compared with scenario 1. This is because CCS can capture the CO2 released by the unit operation, and the capture of CO2 can obtain the corresponding carbon quota, thereby obtaining high income under the reward and punishment type ladder carbon trading mechanism. The total carbon emission of scenario 2 is 414.776 t more than that of scenario 1, but the net carbon emission is 79.51 t less. This is because the coal consumption cost of scenario 1 is originally low, so the amount of CO2 emitted by combustion is small, and the CCS is considered in scenario 2, so most of the CO2 is captured and stored, so the net carbon emission is lower than that of scenario 1.

[0064] To verify the low carbon characteristics and economy of hydrogen blending, scenario 3 considers hydrogen blending technology for gas turbine units based on scenario 2, and scenario 4 adds hydrogen storage tank device based on scenario 3. As can be seen from Table 3 above, the coal consumption cost, operation and maintenance cost, and gas purchase cost of scenario 3 are lower than those of scenario 2, the total cost is reduced by 13867 yuan, and the net carbon emission is reduced by about 10 t. It can be seen that hydrogen blending for gas turbine units can reduce the output of thermal power units, thereby reducing carbon emissions. Scenario 4 considering hydrogen storage tank can meet the hydrogen blending demand of gas turbine units at any time, thereby reducing the gas purchase cost by about 58690 yuan. This is because the calorific value of hydrogen is higher than that of natural gas, and the hydrogen storage tank enables the hydrogen blending unit to maintain the maximum proportion of hydrogen blending, thereby greatly reducing the energy consumption of the gas turbine unit. At the same time, the further reduction of the output of thermal power units leads to the reduction of carbon emissions of the unit, thereby reducing the carbon trading cost by 12952 yuan compared with scenario 3 To verify the carbon emission constraint effect of the tiered carbon trading mechanism, three comparative scenarios were set up based on a fixed hydrogen blending ratio: Scenario 4, Scenario 6, and Scenario 7. As shown in Table 3, Scenario 4 has the lowest total cost of 209,032 yuan, while Scenario 7 has the highest total cost of 366,161 yuan. However, Scenario 4 has the highest total carbon emissions and net carbon emissions, at 628.96 t and 125.8 t respectively, while Scenario 7 has the lowest, at 492.52 t and 98.52 t respectively. This is because the carbon trading mechanism will mobilize the output of thermal power plants and CCS systems in the system. Therefore, the coal consumption costs and operation and maintenance costs of Scenario 4 and Scenario 6 are higher than those of Scenario 7. Increasing unit output leads to a larger base of carbon emissions. Combined with CCS, more carbon allowances can be obtained, and the coordinated carbon trading mechanism can yield high carbon trading costs. Comparing scenarios 4 and 6, the coal consumption, operation and maintenance, and energy purchase costs in scenario 4 are 219 yuan, 757 yuan, and 1377 yuan higher than in scenario 6, respectively, which is not much different. However, the carbon trading cost in scenario 4 is 64,117 yuan higher than in scenario 6. It can be seen that the benefits of selling carbon emission rights through the tiered carbon trading mechanism are far greater than those of the traditional carbon trading mechanism. It can better regulate the output of each device in the IES and enable the IES to operate at the lowest cost while reducing carbon emissions.

[0065] In summary, the combined operation mode of CCS-P2G-hydrogen blending units can fully utilize renewable energy, effectively reduce natural gas energy consumption, and lower the system's net carbon emissions, realizing the advantages of IES in terms of low carbon and economy.

[0066] like Figure 4 As shown, with a fixed hydrogen doping ratio in GB, the total cost decreases as the hydrogen doping ratio in GT increases, but the marginal benefit gradually converges. When the hydrogen doping ratio in GB is 0.2, the cost decrease stagnates after the hydrogen doping ratio in GT exceeds 0.18. Figure 5 As shown, carbon emissions exhibit a non-linear characteristic with varying hydrogen blending ratios. When the GB hydrogen blending ratio is higher than 0.15, the carbon emission curve tends to plateau after the GT hydrogen blending ratio reaches 0.16, and a rebound in carbon emissions occurs when the hydrogen blending ratio exceeds 0.19. Simultaneously, the difference in total cost and carbon emissions between different GB hydrogen blending ratios significantly decreases as the GT hydrogen blending ratio increases. In summary, adopting a fixed hydrogen blending strategy requires combining the carbon quota allocation mechanism with unit output synergy optimization to rationally determine the hydrogen blending ratio of GT and GB, so as to achieve both economic efficiency and reasonable carbon emission guidance for the Integrated Power System (IES).

[0067] Load distribution of hydrogen doping ratio in different scenarios as follows Figure 6As shown, the hydrogen consumption power is significantly reduced under the variable hydrogen blending ratio mode compared to the fixed hydrogen blending ratio. The mechanism is that during periods of high net load, the forced output of the gas turbine unit is suppressed by reducing the hydrogen blending ratio. Although the dynamic hydrogen blending strategy increases some operating and adjustment costs, the increase in carbon trading costs can effectively compensate for these costs, thus improving the overall system economy. Considering that hydrogen storage tanks can achieve the effect of "load shifting," it is possible to maximize hydrogen blending in the hydrogen blending units, further optimizing the system based on dynamic hydrogen blending.

[0068] System costs and carbon emissions under different carbon base prices, such as Figure 7 As shown, for the tiered carbon trading mechanism, the carbon trading base price exhibits a significant threshold effect on the system's carbon emissions: when the base price is below 150 yuan / t, the carbon emission intensity decreases linearly with increasing base price. This is because carbon quota trading revenue drives the system to prioritize CO2 capture through CCS technology, reducing carbon emissions. When the base price exceeds 150 yuan / t, the carbon emission intensity tends to stabilize, but residual carbon emissions remain due to CCS capture efficiency constraints. In contrast, the traditional carbon trading mechanism requires a base price of 220 yuan / t to achieve stable carbon emission trends. The tiered carbon trading mechanism, through its tiered reward and penalty mechanism, achieves strict carbon emission constraints at lower base price levels, demonstrating that the tiered carbon trading mechanism significantly outperforms the traditional fixed carbon price mechanism in constraining carbon emissions. From a cost perspective, the total system cost of the tiered carbon trading mechanism drops to approximately 12,000 yuan at a base price of 300 yuan / t, a 45.5% reduction compared to the 22,000 yuan of the traditional mechanism, verifying the good economic efficiency of the tiered carbon trading mechanism.

[0069] In summary, the combined operation of P2G, CCS, and gas turbine units represents an innovative model for efficiently utilizing renewable energy and achieving low carbon emissions. However, carbon capture and storage technologies carry the risk of CO2 leakage, while for P2G systems, it increases operating costs, resulting in poor economic efficiency. This invention primarily utilizes CO2 captured by CCS to supply P2G for methane synthesis, enabling on-site utilization of CO2 generated by CCS, constructing an "electricity-gas-carbon" cycle, and achieving carbon resource recycling and deep integration of renewable energy.

[0070] The integrated energy system provided in the embodiments of the present invention is described below. The integrated energy system described below and the integrated energy system optimization operation method described above can be referred to each other.

[0071] The optimized operation device for this integrated energy system may include, but is not limited to: CCS equipment is used to capture carbon dioxide and supply it to the P2G system; The P2G system is used to convert surplus electricity generated from renewable energy into hydrogen, and then convert a portion of the hydrogen into methane through a methanation device using carbon dioxide provided by the CCS equipment; the other portion of the hydrogen is injected into a natural gas pipeline for combustion in a gas turbine unit and to provide electricity to the CCS equipment. The integrated energy system supplies energy based on a low-carbon economic operation model; the low-carbon economic operation model is constructed with the objective function of minimizing the cost and net carbon emissions of the integrated energy system, and the low-carbon economic operation model uses a tiered carbon trading model to constrain carbon emissions.

[0072] In an optional embodiment, the low-carbon economic operation model is as follows: ; in, , for t The electrolytic cell consumes power and generates hydrogen at that time; This is the calorific value of hydrogen. , , These represent the amount of carbon dioxide released by gas turbines, gas boilers, and thermal power units, respectively. The amount of carbon dioxide captured by the CCS device; , The operating efficiency of the electrolytic cell and the CCS equipment; , , These are the total power consumed by the CCS device, the fixed energy consumption, and the capture energy consumption, respectively. Energy consumption per unit of carbon dioxide captured; , These represent the amounts of carbon dioxide used for methanation and storage, respectively. , for t The amount of hydrogen supplied to the gas turbine and the gas boiler at all times; The amount of methane synthesized by the P2G system; This refers to the amount of carbon dioxide purchased externally.

[0073] In an optional embodiment, the tiered carbon trading model adjusts the hourly carbon emission allowance in real time; at the end of the settlement period, settlement is carried out based on the user's hourly carbon emission allowance and actual carbon emissions.

[0074] In an optional embodiment, the tiered carbon trading model is settled based on the following formula: ; in, for tThe cost of carbon trading at any given time; The base price for tiered carbon trading; L The length of the carbon emission range; The percentage increase in carbon trading prices; The compensation coefficient; for t The actual carbon emissions at any given moment.

[0075] In an optional embodiment, the objective function is as follows: ; in, For operation and maintenance costs; The cost of penalizing the abandonment of wind and solar power; The costs involved in tiered carbon trading; For the new carbon sequestration cost; Net carbon dioxide emissions; The energy purchase cost of the integrated energy system.

[0076] It should be noted that the integrated energy system provided in this embodiment of the invention can execute the integrated energy system optimization operation method described in any of the above embodiments during specific operation, which will not be elaborated in this embodiment.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing the operation of a comprehensive energy system, characterized in that, include: Carbon dioxide captured by the CCS equipment is supplied to the P2G system; The electrolyzer in the P2G system converts surplus electricity generated from renewable energy into hydrogen. A portion of the hydrogen is then converted into methane via a methanation device, along with carbon dioxide supplied by the CCS equipment. The remaining hydrogen is injected into a natural gas pipeline for combustion in a gas turbine unit and to provide power to the CCS equipment. The integrated energy system supplies energy based on a low-carbon economic operation model; the low-carbon economic operation model is constructed with the objective function of minimizing the cost and net carbon emissions of the integrated energy system, and the low-carbon economic operation model uses a tiered carbon trading model to constrain carbon emissions.

2. The method for optimizing the operation of a comprehensive energy system according to claim 1, characterized in that, The low-carbon economic operation model is as follows: ； in, , for t The electrolytic cell consumes power and generates hydrogen at that time; This is the calorific value of hydrogen. , , These represent the amount of carbon dioxide released by gas turbines, gas boilers, and thermal power units, respectively. The amount of carbon dioxide captured by the CCS device; , The operating efficiency of the electrolytic cell and the CCS equipment; , , These are the total power consumed by the CCS device, the fixed energy consumption, and the capture energy consumption, respectively. Energy consumption per unit of carbon dioxide captured; , These represent the amounts of carbon dioxide used for methanation and storage, respectively. , for t The amount of hydrogen supplied to the gas turbine and the gas boiler at all times; The amount of methane synthesized by the P2G system; This refers to the amount of carbon dioxide purchased externally.

3. The method for optimizing the operation of a comprehensive energy system according to claim 1, characterized in that, The tiered carbon trading model adjusts the hourly carbon emission allowance in real time; at the end of the settlement period, settlement is carried out based on the user's hourly carbon emission allowance and actual carbon emissions.

4. The method for optimizing the operation of a comprehensive energy system according to claim 3, characterized in that, The tiered carbon trading model is settled based on the following formula: ； in, for t The cost of carbon trading at any given time; The base price for tiered carbon trading; L The length of the carbon emission range; The percentage increase in carbon trading prices; This is the compensation coefficient; for t The actual carbon emissions at any given moment.

5. The method for optimizing the operation of a comprehensive energy system according to claim 4, characterized in that, The objective function is as follows: ； in, For operation and maintenance costs; The cost of penalizing the abandonment of wind and solar power; The costs involved in tiered carbon trading; For the new carbon sequestration cost; Net carbon dioxide emissions; The energy purchase cost of the integrated energy system.

6. An integrated energy system, characterized in that, include: CCS equipment is used to capture carbon dioxide and supply it to the P2G system; The P2G system is used to convert surplus electricity generated from renewable energy into hydrogen, and then convert a portion of the hydrogen into methane through a methanation device using carbon dioxide provided by the CCS equipment; the other portion of the hydrogen is injected into a natural gas pipeline for combustion in a gas turbine unit and to provide electricity to the CCS equipment. The integrated energy system supplies energy based on a low-carbon economic operation model; the low-carbon economic operation model is constructed with the objective function of minimizing the cost and net carbon emissions of the integrated energy system, and the low-carbon economic operation model uses a tiered carbon trading model to constrain carbon emissions.

7. The integrated energy system according to claim 6, characterized in that, The low-carbon economic operation model is as follows: ； in, , for t The electrolytic cell consumes power and generates hydrogen at that time; This is the calorific value of hydrogen. , , These represent the amount of carbon dioxide released by gas turbines, gas boilers, and thermal power units, respectively. The amount of carbon dioxide captured by the CCS device; , The operating efficiency of the electrolytic cell and the CCS equipment; , , These are the total power consumed by the CCS device, the fixed energy consumption, and the capture energy consumption, respectively. Energy consumption per unit of carbon dioxide captured; , These represent the amounts of carbon dioxide used for methanation and storage, respectively. , for t The amount of hydrogen supplied to the gas turbine and the gas boiler at all times; The amount of methane synthesized by the P2G system; This refers to the amount of carbon dioxide purchased externally.

8. The integrated energy system according to claim 6, characterized in that, The tiered carbon trading model adjusts the hourly carbon emission allowance in real time; at the end of the settlement period, settlement is carried out based on the user's hourly carbon emission allowance and actual carbon emissions.

9. The integrated energy system according to claim 8, characterized in that, The tiered carbon trading model is settled based on the following formula: ； in, for t The cost of carbon trading at any given time; The base price for tiered carbon trading; L The length of the carbon emission range; The percentage increase in carbon trading prices; This is the compensation coefficient; for t The actual carbon emissions at any given moment.

10. The integrated energy system according to claim 9, characterized in that, The objective function is as follows: ； in, For operation and maintenance costs; The cost of penalizing the abandonment of wind and solar power; The costs involved in tiered carbon trading; For the new carbon sequestration cost; Net carbon dioxide emissions; The energy purchase cost of the integrated energy system.

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