Comprehensive energy system low-carbon economic dispatching method considering carbon capture and multi-type energy collaborative operation

Abstract

The invention relates to an electric power system, and discloses a comprehensive energy system low-carbon economic dispatching method considering carbon capture and multi-type energy collaborative operation, which comprises the following steps: establishing a system carbon transaction model, counting the initial carbon quota of each device in the system and the carbon emission of each link, and bringing the carbon emission cost into the total system operation cost; establishing a carbon capture power plant operation model, counting the initial carbon quota of each device in the system and the carbon emission of each link, and bringing the carbon emission cost into the total system operation cost; according to the method, a comprehensive energy system low-carbon economic dispatching model is constructed, minimization of the total economic operation cost of the system is taken as a target function, and multiple constraint conditions including power balance constraint, wind power generation constraint, carbon capture power plant operation constraint, energy conversion equipment operation constraint and energy storage equipment operation constraint are comprehensively considered at the same time. According to the method, the wind power absorption capability and the energy utilization efficiency of the system are improved.

Description

Technical Field

[0001] The present invention relates to the field of electric power, and specifically to a low-carbon economic dispatching method for an integrated energy system considering carbon capture and coordinated operation of multiple types of energy sources. Background Art

[0002] With the increasingly serious problem of global warming and the promotion of the "dual carbon" goal, the power industry, especially the traditional mode mainly based on thermal power generation, urgently needs to transform towards low-carbon and clean directions. Under this background, the integrated energy system with multi-energy complementarity and multi-source coordination is regarded as a key technical path due to its significant emission reduction potential. Considering China's long-term energy structure relying on coal, exploring how to achieve the coexistence of efficient utilization of renewable energy and clean coal power generation and promote the coordinated development of high-carbon energy and low-carbon energy has become an important topic for promoting the low-carbon economic transformation of the integrated energy system (IES). The application of carbon capture technology provides a feasible solution for the cleanization of coal-fired power generation. Traditional coal-fired power plants can be transformed into carbon capture power plants (CCPP) by installing carbon capture devices. This technology is not only applicable to coal-fired power plants but also can be used for the low-carbon transformation of combined heat and power units, thus effectively reducing the carbon emissions of the system.

[0003] In addition, the carbon trading market also plays a key role in promoting the low-carbon transformation of energy. Therefore, under the framework of the carbon market, it is of great significance to study the low-carbon economic dispatching of the integrated energy system considering carbon capture. By establishing a flexible operation model of a carbon capture power plant including a liquid storage tank and combining the coordinated utilization of multiple types of energy sources, the low-carbon operation potential and high-efficiency energy utilization advantages of the system can be fully explored, providing strong support for realizing the low-carbon transformation of the energy system. Summary of the Invention

[0004] The present invention proposes an optimized dispatching method for an integrated energy system for refined modeling of a carbon capture power plant under the background of carbon trading. By introducing a liquid storage tank to transform the traditional carbon capture power plant, the operation flexibility of the power plant is significantly improved. This method takes the minimization of the sum of carbon trading costs, carbon sequestration costs, coal combustion costs, and gas purchase costs as the optimization goal, and constructs a low-carbon economic dispatching model. This model fully explores the emission reduction potential of the integrated energy system with multi-energy complementarity and multi-source coordination, and at the same time improves the wind power accommodation capacity and energy utilization efficiency of the system, providing technical support for realizing the low-carbon, economic, and efficient operation of the energy system.

[0005] The above technical problems of the present invention are mainly solved by the following technical solutions:

[0006] A low-carbon economic dispatching method for an integrated energy system considering refined modeling of a carbon capture power plant, comprising the following steps:

[0007] Step 1: Establish a system carbon trading model, count the initial carbon quotas of each device in the system and the carbon emissions of each link, and incorporate the carbon emission cost into the total operating cost of the system.

[0008] Step 2: Establish a flexible operation model of a carbon capture power plant with a liquid storage tank in the integrated energy system, count the initial carbon quotas of each device in the system and the carbon emissions of each link, incorporate the carbon emission cost into the total operating cost of the system, refine the carbon capture process, including considering the carbon emission source devices, restricting the absorption and treatment efficiency, and introducing the design of the liquid storage tank to transfer the energy consumption of the carbon capture process, and restrict the solution outflow and maximum capacity of the rich liquid tank and the lean liquid tank.

[0009] Step 3: Construct a low-carbon economic dispatch model for the integrated energy system, with the minimum total economic operating cost of the system as the objective function, and comprehensively consider various constraint conditions, including power balance constraints, wind power generation constraints, carbon capture power plant operation constraints, energy conversion device operation constraints, and energy storage device operation constraints.

[0010] Step 4: When solving the low-carbon economic dispatch model, first initialize the operating parameters of each device in the system, the energy prices of electricity and natural gas. Input the load curves of the three energy sources of electricity, heat, and natural gas and the wind power output data. Finally, linearize the optimization model and solve it using a solver.

[0011] Method implementation description

[0012] Carbon trading model:

[0013] The carbon trading model of the integrated energy system mainly consists of two parts: the carbon emission function and the carbon emission quota function.

[0014] 1) Carbon emission function

[0015] The carbon emission function mainly consists of two parts: the carbon emission function of the power supply part and the carbon emission function of the heat supply part. The carbon emission function of device i in the t-th period is shown in the formula:

[0016] E CO2 (i,t) = ω e P e (i,t) + ω h φ h-e P h (i,t)(9)

[0017] In the formula: E CO2 (i,t) is the carbon emission of device i in the t-th period; ω e is the carbon emission per unit of power supply; P e(i, t) is the power supply of device i in the t-th period; ω h is the carbon emission per unit heat supply; φ e-h is the electro-thermal conversion coefficient; P h (i, t) is the heat supply of device i in the t-th period.

[0018] 2) Carbon emission quota function

[0019] The calculation formula of the carbon emission quota function of the device is as follows:

[0020] E0(i, t) = χ e P e (i, t) + χ h φ h-e P h (i, t)(10)

[0021] In the formula: E0(i, t) is the carbon emission quota function of device i in the t-th period; χ e is the carbon emission quota coefficient for power generation; χ h is the carbon emission quota coefficient for heat generation.

[0022] Operating model of carbon capture power plant:

[0023] In order to solve the problem that the carbon emissions of coal-fired units increase during the peak power supply demand period, and increasing the carbon capture intensity may lead to a decrease in the net output of the power plant, making it difficult to meet both carbon capture and power supply demands simultaneously, this paper proposes an improved scheme. A group of lean liquid tanks and rich liquid tanks are added between the absorption tower and the regeneration tower of the traditional carbon capture power plant. Through the design of the liquid storage tank, the amount of solution flowing in and out of the absorption tower and the regeneration tower can be adjusted, so that the amount of carbon processed by the regeneration tower no longer needs to be strictly matched with the amount of carbon absorbed by the absorption tower, thus significantly improving the operating flexibility of the carbon capture power plant. Ensure that the power plant can still supply power stably at high load, and realize the coordinated optimization of carbon capture and power production. The following is the flexible operating model of the carbon capture power plant:

[0024]

[0025] In the formula: E G (i, t) is the CO2 input of carbon capture power plant i in the t-th period; S CCPP is the set of carbon capture power plants; is the set of devices that generate CO2 emissions, including coal-fired units and combined heat and power units; is the CO2 emission of device i in the t-th period; E ab (i, t), E re (i, t) are the CO2 absorption amount of the absorption tower and the CO2 treatment amount of the regeneration tower of carbon capture power plant i in the t-th period respectively; μ ab 、μre are the absorption and regeneration efficiencies respectively; λ(t) is the flue gas diversion ratio in the t-th period; E rich (i, t) is the CO2 outflow from the rich liquid tank of carbon capture power plant i in the t-th period; E cap (i, t) is the carbon capture amount of carbon capture power plant i in the t-th period; is the carbon capture operation energy consumption coefficient of carbon capture power plant i; P G (i, t) is the total power of carbon capture power plant i in the t-th period; P e (i, t) is the clean output power of carbon capture power plant i in the t-th period; is the carbon capture power of carbon capture power plant i in the t-th period; P base (i, t) is the fixed loss power of equipment i in the t-th period; c coal is the coal consumption cost per unit power generation of the carbon capture power plant, f Ebuy (i, t) is the energy purchase cost of the carbon capture power plant.

[0026] The liquid storage tank model of the carbon capture system is as follows:

[0027]

[0028] In the formula: is the density of the CO2 solution in the rich liquid tank; v rich (t), v poor (t) are the solution outflow amounts of the rich liquid tank and the lean liquid tank respectively in the t-th period; S rich (t), S poor (t) are the solution storage amounts of the rich liquid tank and the lean liquid tank respectively in the t-th period; S rich,max , S poor,max are the maximum solution storage amounts of the rich liquid tank and the lean liquid tank.

[0029] Low-carbon economic dispatch model of the integrated energy system:

[0030] 1 Objective function

[0031] The model takes the minimum total economic operation cost of the integrated energy system as the objective function, and the total economic operation cost function f of the integrated energy system total is shown in Equation 1.4.

[0032] f total = f1 + f2 + f3 (12)

[0033] In the formula: f1 is the equipment operation cost function; f2 is the carbon trading cost function, and f3 is the carbon sequestration cost function.

[0034] 1) Equipment operation cost function

[0035] The equipment operation cost function includes the operation cost function of energy production and consumption equipment and the energy purchase equipment function. Among them, including carbon capture power plants and wind farms, the curtailment penalty cost of the wind farm is regarded as the operation cost function of the energy production and consumption equipment.

[0036]

[0037] In the formula: S T is the set of time periods; S EP is the set of energy production and consumption equipment; S Ebuy is the set of energy purchase equipment.

[0038] 2) Carbon trading cost function

[0039]

[0040] In the formula: is the carbon trading price; is the carbon emission function, and E0 is the carbon emission quota function.

[0041] i) Park carbon emission function

[0042] Park carbon emission function The calculation formula is as follows:

[0043]

[0044] ii) Park carbon emission quota function

[0045] The calculation formula of the park carbon emission quota function E0 is as follows:

[0046]

[0047] In the formula: S0 is the set of equipment for allocating carbon quotas. In this model, the set of equipment for allocating carbon quotas includes carbon capture power plants and combined heat and power units; E0(i,t) is the carbon emission quota obtained by equipment i for power generation and heat production in the t-th time period.

[0048] 3) Carbon sequestration cost function

[0049] f3 = δ(E cap - E P2G )

[0050] In the formula: δ is the cost of sequestering unit CO2, and E P2G is the amount of CO2 absorbed by power-to-gas.

[0051] 2 Constraints

[0052] 1) Power balance constraint

[0053] The system-level constraint is the power balance of electricity, heat, and gas respectively.

[0054]

[0055] Where: S N is the set of devices; P g (i, t) is the gas supply of device i in the t-th period; P eL (i, t), P hL (i, t), P gl (i, t) are the electricity, heat, and gas consumption (loads) of device i in the t-th period respectively; P EL (t), P HL (t), P GL (t) are the electricity load, heat load, and gas load of the park in the t-th period respectively.

[0056] 2) Wind power generation constraint

[0057]

[0058] Where: P WT (i, t) is the actual wind power of the wind farm in the t-th period, and P qf (i, t) is the abandoned wind of the wind farm in the t-th period.

[0059] 3) Carbon capture power plant operation constraint

[0060] The total power of the coal-fired units in the carbon capture power plant needs to be less than the upper limit of equipment operation. The operating energy consumption of the carbon capture system and the flue gas diversion ratio of the carbon capture system need to meet the following constraints:

[0061]

[0062] Where: P G,max (i) is the maximum power upper limit of carbon capture power plant i; τ i is the operating condition coefficient of carbon capture power plant i; λ max , λ min are the maximum and minimum diversion ratios of the flue gas diversion device of the carbon capture power plant.

[0063] 4) Energy conversion equipment operation constraint

[0064] The energy conversion equipment involved in this system includes power-to-gas and combined heat and power, and the input power needs to meet the equipment capacity constraint.

[0065] i) Power-to-gas P2G

[0066] The operating constraint conditions of the power-to-gas equipment are as follows. Among them, the CO2 raw materials used by the power-to-gas equipment all come from carbon capture.

[0067]

[0068] Where: η h,i(P2G) is the efficiency of converting electrical energy to thermal energy of the power-to-gas device i; η g,i(P2G) is the efficiency of converting electrical energy to gas energy of the power-to-gas device i; P eL,max (i) is the maximum value of the electrical power consumed by device i; is the CO2 consumption coefficient of the power-to-gas device i.

[0069] ii) Combined heat and power CHP

[0070] The system adopts a combined heat and power unit model with adjustable heat-to-power ratio.

[0071]

[0072] Where: η i(CHP) is the overall efficiency of the combined heat and power device i; κ min,i(CHP) , κ max,i(CHP) are the upper and lower limits of the heat-to-power ratio of the combined heat and power device i respectively; P gL,max (i) is the maximum gas load of device i.

[0073] 5) Operation constraints of energy storage devices

[0074] The model of the energy storage device needs to consider the storage capacity constraint, single - charge / discharge constraint, charge - discharge state complementary constraint, and cycle storage capacity conservation constraint. The operation constraint expressions of electrical energy, thermal energy, and gas energy storage devices are as follows:

[0075]

[0076] Where: S(i,t) is the storage capacity of the energy storage device i in the t - th time period; P cha (i,t), P dis (i,t) are the charge and discharge powers of the energy storage device i in the t - th time period respectively; η cha (i), η dis (i) are the charge and discharge energy efficiencies of the energy storage device i respectively; S max (i), S min (i) are the upper and lower limits of the capacity of the energy storage device i respectively; P cha,max (i), P dis,min (i) are the maximum single - charge and discharge energies of the energy storage device i respectively; u cha (i,t), u dis (i,t) are charge - discharge state 0, 1 variables, indicating that the energy storage device cannot charge and discharge simultaneously.

[0077] Model solution:

[0078] The low-carbon economic dispatch model of the integrated energy system established by the present invention is a mixed-integer non-linear model. After initializing the parameters of each device in the system, energy prices, input power, heat, gas load curves, and wind power output, it is necessary to linearize the non-linear terms in the model and then call a commercial solver to solve the mixed-integer linear model.

[0079] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0080] (1) The present invention constructs an integrated energy system integrating carbon capture technology, giving full play to the flexible operation characteristics of the liquid storage carbon capture power plant. Through the design of the liquid storage tank, the energy consumption in the carbon capture process can be effectively transferred, so as to meet the power supply demand and carbon capture demand of the power plant simultaneously during the peak load period. This design enables the power plant to flexibly adjust the net output according to the fluctuations of wind power and become an ideal power source for coordinated operation with wind power, further improving the overall flexibility and stability of the system.

[0081] (2) The carbon trading mechanism has a positive guiding role in the popularization of carbon capture technology. Within a reasonable carbon price range, appropriately increasing the carbon trading benchmark price helps to improve the carbon capture level, promote the transformation of the energy structure towards a cleaner direction, and significantly reduce the carbon emissions of the system. However, it should be noted that too high or too low carbon price will have an adverse impact on the low-carbon economic operation of the system. Therefore, it is necessary to formulate a scientific and reasonable carbon price policy to achieve the balance of economic benefits and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 It is a schematic diagram of the energy supply structure of the integrated energy system according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0083] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0084] Please refer to Figure 1 , in the embodiment of the present invention, a low-carbon economic dispatch method for an integrated energy system considering the refined modeling of a carbon capture power plant includes the following steps:

[0085] Step 1, establish a system carbon trading model, count the initial carbon quotas of each device in the system and the carbon emissions of each link, and incorporate the carbon emission cost into the total operating cost of the system;

[0086] Step 2: Establish an operation model for the carbon capture power plant, count the initial carbon quotas of each device in the system and the carbon emissions of each link, and incorporate the carbon emission cost into the total operating cost of the system;

[0087] Step 3: Construct a low-carbon economic dispatch model for the integrated energy system, with the minimum total economic operating cost of the system as the objective function, and comprehensively consider various constraints, including power balance constraints, wind power generation constraints, carbon capture power plant operation constraints, energy conversion device operation constraints, and energy storage device operation constraints;

[0088] Step 4: When solving the low-carbon economic dispatch model, first initialize the operating parameters of each device in the system, the energy prices of electricity and natural gas. Input the load curves of the three energy sources of electricity, heat, and natural gas and the wind power output data. Finally, linearize the optimization model and solve it using a solver.

[0089] Method implementation description

[0090] Carbon trading model:

[0091] The carbon trading model of the integrated energy system mainly consists of two parts: the carbon emission function and the carbon emission quota function.

[0092] Carbon emission function

[0093] The carbon emission function mainly consists of two parts: the carbon emission function of the power supply part and the carbon emission function of the heat supply part. The carbon emission function of device i in the t-th time period is as shown in the formula:

[0094]

[0095] In the formula: is the carbon emission of device i in the t-th time period; ω e is the carbon emission per unit of power supply; P e (i,t) is the power supply of device i in the t-th time period; ω h is the carbon emission per unit of heat supply; φ e-h is the electro-thermal conversion coefficient; P h (i,t) is the heat supply of device i in the t-th time period.

[0096] Carbon emission quota function

[0097] The calculation formula for the carbon emission quota function of the device is as follows:

[0098] E0(i,t) = χ e P e (i,t) + χ h φ h-e P h (i,t)(18)

[0099] where: \(E_0(i,t)\) is the carbon emission quota function of device \(i\) in the \(t\) - th period; \(\chi\) e is the carbon emission quota coefficient for power generation; \(\chi\) h is the carbon emission quota coefficient for heat production.

[0100] Operating model of carbon capture power plant:

[0101] To solve the problem that the carbon emissions of coal - fired units increase during the peak power supply demand period, and increasing the carbon capture intensity may lead to a decrease in the net output of the power plant, making it difficult to meet both carbon capture and power supply demands simultaneously, this paper proposes an improved scheme. A group of lean liquid tanks and rich liquid tanks are added between the absorption tower and the regeneration tower of the traditional carbon capture power plant. Through the design of the liquid storage tank, the amount of solution flowing in and out of the absorption tower and the regeneration tower can be adjusted, so that the amount of carbon processed by the regeneration tower no longer needs to be strictly matched with the amount of carbon absorbed by the absorption tower, thus significantly improving the operating flexibility of the carbon capture power plant. Ensure that the power plant can still supply power stably at high loads, and achieve the coordinated optimization of carbon capture and power production. The following is the flexible operating model of the carbon capture power plant:

[0102]

[0103] where: \(E\) G (i,t) is the CO₂ input of carbon capture power plant \(i\) in the \(t\) - th period; \(S\) CCPP is the set of carbon capture power plants; is the set of devices that generate CO₂ emissions, including coal - fired units and combined heat and power units; is the CO₂ emission of device \(i\) in the \(t\) - th period; \(E\) ab (i,t), \(E\) re (i,t) are the CO₂ absorption amount of the absorption tower and the CO₂ treatment amount of the regeneration tower of carbon capture power plant \(i\) in the \(t\) - th period respectively; \(\mu\) ab , \(\mu\) re are the absorption and regeneration efficiencies respectively; \(\lambda(t)\) is the flue gas diversion ratio in the \(t\) - th period; \(E\) rich (i,t) is the CO₂ outflow amount of the rich liquid tank of carbon capture power plant \(i\) in the \(t\) - th period; \(E\) cap (i,t) is the carbon capture amount of carbon capture power plant \(i\) in the \(t\) - th period; is the carbon capture operation energy consumption coefficient of carbon capture power plant \(i\); \(P\) G (i,t) is the total power of carbon capture power plant \(i\) in the \(t\) - th period; \(P\) e (i,t) is the clean output power of carbon capture power plant \(i\) in the \(t\) - th period; is the carbon capture power of carbon capture power plant \(i\) in the \(t\) - th period; \(P\) base (i,t) is the fixed loss power of device \(i\) in the \(t\) - th period; \(c\) coalThe coal consumption cost per unit power generation of the carbon capture power plant, f Ebuy (i, t) is the energy purchase cost of the carbon capture power plant.

[0104] The liquid storage tank model of the carbon capture system is as follows:

[0105]

[0106] In the formula: ρ CO2 is the density of the CO2 solution in the rich liquid tank; v rich (t), v poor (t) are the solution outflow rates of the rich liquid tank and the lean liquid tank respectively in the t-th time period; S rich (t), S poor (t) are the solution storage amounts of the rich liquid tank and the lean liquid tank respectively in the t-th time period; S rich,max , S poor,max are the maximum solution storage amounts of the rich liquid tank and the lean liquid tank.

[0107] Low-carbon economic dispatch model of the integrated energy system:

[0108] 1 Objective function

[0109] The model takes the minimum total economic operation cost of the integrated energy system as the objective function, and the total economic operation cost function f of the integrated energy system is as shown in Equation 1.4. total As shown in Equation 1.4.

[0110] f total = f1 + f2 + f3(20)

[0111] In the formula: f1 is the equipment operation cost function; f2 is the carbon trading cost function, and f3 is the carbon sequestration cost function.

[0112] Equipment operation cost function

[0113] The equipment operation cost function includes the energy production and consumption equipment operation cost function and the energy purchase equipment function. Among them, it includes the carbon capture power plant and the wind farm, and the curtailment penalty cost of the wind farm is regarded as the operation cost function of this energy production and consumption equipment.

[0114]

[0115] In the formula: S T is the set of time periods; S EP is the set of energy production and consumption equipment; S Ebuy is the set of energy purchase equipment.

[0116] Carbon trading cost function

[0117]

[0118] In the formula: is the carbon trading price; is the carbon emission function, and E0 is the carbon emission quota function.

[0119] i) Carbon emission function of the park

[0120] Carbon emission function of the park The calculation formula is as follows:

[0121]

[0122] ii) Carbon emission quota function of the park

[0123] The calculation formula of the carbon emission quota function E0 of the park is as follows:

[0124]

[0125] In the formula: S0 is the set of equipment for allocating carbon quotas. In this model, the set of equipment for allocating carbon quotas includes carbon capture power plants and combined heat and power units; E0(i,t) is the carbon emission quota obtained by equipment i for power generation and heat production in the t-th period.

[0126] Carbon sequestration cost function

[0127] f3 = δ(E cap -E P2G )

[0128] In the formula: δ is the cost of sequestering a unit of CO2, and E P2G is the amount of CO2 absorbed by power-to-gas.

[0129] 2 Constraints

[0130] Power balance constraint

[0131] The system-level constraint is the power balance of electricity, heat, and gas respectively.

[0132]

[0133] In the formula: S N is the set of equipment; P g (i,t) is the gas supply volume of equipment i in the t-th period; P eL (i,t), P hL (i,t), P gl (i,t) are the electricity, heat, and gas consumption (loads) of equipment i in the t-th period respectively; P EL (t), P HL (t), P GL (t) are the electricity load, heat load, and gas load of the park in the t-th period respectively.

[0134] Wind power generation constraint

[0135]

[0136] Where: P WT (i, t) is the actual wind power of the wind farm in the t-th period, P qf (i, t) is the abandoned wind of the wind farm in the t-th period.

[0137] Operating constraints of carbon capture power plants

[0138] The total power of the coal-fired units in the carbon capture power plant needs to be less than the upper limit of equipment operation. The operating energy consumption of the carbon capture system and the flue gas split ratio of the carbon capture system need to meet the following constraints:

[0139]

[0140] Where: P G,max (i) is the maximum power upper limit of carbon capture power plant i; τ i is the operating condition coefficient of carbon capture power plant i; λ max 、λ min are the maximum and minimum split ratios of the flue gas splitting device of the carbon capture power plant.

[0141] Operating constraints of energy conversion equipment

[0142] The energy conversion equipment involved in this system includes power-to-gas and combined heat and power, and the input power needs to meet the equipment capacity constraints.

[0143] i) Power-to-gas P2G

[0144] The operating constraint conditions of the power-to-gas equipment are as follows. Among them, the CO2 raw materials used by the power-to-gas equipment all come from carbon capture.

[0145]

[0146] Where: η h,i(P2G) is the efficiency of converting electrical energy to thermal energy of power-to-gas equipment i; η g,i(P2G) is the efficiency of converting electrical energy to gas energy of power-to-gas equipment i; P eL,max (i) is the maximum value of the electrical power consumed by equipment i; is the CO2 consumption coefficient of power-to-gas equipment i.

[0147] ii) Combined heat and power CHP

[0148] The system adopts a combined heat and power unit model with adjustable heat-to-power ratio.

[0149]

[0150] Where: η i(CHP) is the comprehensive efficiency of combined heat and power equipment i; κ min,i(CHP) 、κ max,i(CHP)They are the upper and lower limits of the heat - electricity ratio of the combined heat and power generation equipment i; P gL,max (i) is the maximum gas load of equipment i.

[0151] Operating constraints of energy storage equipment

[0152] The model of the energy storage equipment needs to consider the storage capacity constraint, single - charge / discharge constraint, complementary constraint of storage and release states, and periodic storage quantity conservation constraint. The operating constraint expressions of electric energy, thermal energy, and gas energy storage equipment are as follows:

[0153]

[0154] In the formula: S(i,t) is the storage capacity of energy storage equipment i in the t - th time period; P cha (i,t), P dis (i,t) are the charging and discharging powers of energy storage equipment i in the t - th time period respectively; η cha (i), η dis (i) are the charging and discharging efficiencies of energy storage equipment i respectively; S max (i), S min (i) are the upper and lower limits of the capacity of energy storage equipment i respectively; P cha,max (i), P dis,min (i) are the maximum single - charge and single - discharge powers of energy storage equipment i respectively; u cha (i,t), u dis (i,t) are charge - discharge state 0, 1 variables, indicating that the energy storage equipment cannot charge and discharge simultaneously.

[0155] Model solution:

[0156] The low - carbon economic dispatch model of the integrated energy system established by the present invention is a mixed - integer non - linear model. After initializing the parameters of each device in the system, energy prices, input curves of electric energy, thermal energy, gas energy loads, and wind power output, it is necessary to linearize the non - linear terms in the model, and then call a commercial solver to solve the mixed - integer linear model.

[0157] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above - mentioned exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non - restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

[0158] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A low-carbon economic dispatching method for an integrated energy system considering carbon capture and coordinated operation of multiple types of energy, characterized in that: The steps include: Step 1: Establish a carbon trading model for the integrated energy system, count the initial carbon quota of each device in the system, and the carbon emissions of each link, and include the carbon emission cost in the total system operation cost; Step 2: Establish a flexible operation model of a carbon capture power plant with a liquid storage tank, refine the carbon capture process, including considering the source equipment of carbon emissions, constraining the CO2 absorption and treatment efficiency, and introducing the design of the liquid storage tank to transfer the energy consumption of the carbon capture process, and constrain the solution outflow and maximum capacity of the rich liquid tank and the lean liquid tank; Step 3: construct a low-carbon economic dispatch model for the integrated energy system, with the objective function of minimizing the total economic operating cost of the system, while taking into account a variety of constraints, including power balance constraints, wind power generation constraints, carbon capture power plant operation constraints, energy conversion equipment operation constraints, and energy storage equipment operation constraints; Step 4, when solving the low-carbon economic dispatch model, first initialize the operating parameters of each device in the system, the energy prices of electricity and natural gas, input the load curves of the three energy sources of electricity, heat and natural gas and wind power output data, and finally, linearize the optimization model and use the solver to solve it.

2. According to claim 1, a low-carbon economic dispatching method for an integrated energy system considering carbon capture and coordinated operation of multiple types of energy is characterized in that: The carbon trading model of the comprehensive energy system consists of two parts: carbon emission function and carbon emission quota function; The carbon emission function consists of two parts: the carbon emission function of the power supply part and the carbon emission function of the heating part. The carbon emission function of equipment i in the tth period is shown as follows: Where: is the carbon emission of equipment i in the tth period; ω e Carbon emissions for powering a unit; P e (i,t) is the power supply of device i in the tth time period; ω h is the carbon emission per unit of heating; e-h is the electrothermal conversion coefficient; P h (i,t) is the heat supply of equipment i in the tth time period; The calculation formula of carbon emission quota function is as follows: E0(i,t)=χ e P e (i,t)+χ h φ h-e P h (i,t) (2) Where: E0(i,t) is the carbon emission quota function of equipment i in the tth period; e is the carbon emission quota coefficient for electricity generation; h is the carbon emission quota coefficient for heat production.

3. According to claim 1, a low-carbon economic dispatching method for an integrated energy system considering carbon capture and coordinated operation of multiple types of energy is characterized in that: The flexible operation model of the carbon capture power plant with liquid storage tanks: Where: E G (i,t) is the CO2 input of carbon capture power plant i in the tth period; S CCPP assemble for carbon capture plants; A collection of equipment that produces CO2 emissions, including coal-fired units and combined heat and power units; is the CO2 emission of equipment i in the tth period; E ab (i,t),E re (i, t) are the CO2 absorption capacity of the absorption tower and the CO2 treatment capacity of the regeneration tower of the carbon capture power plant i in the tth period respectively; μ ab , μ re are the absorption and regeneration efficiencies respectively; λ(t) is the flue gas split ratio in the tth period; E rich (i,t) is the CO2 outflow from the rich liquid tank in the tth period of the carbon capture power plant i; E cap (i,t) is the carbon capture amount of carbon capture power plant i in the tth period; is the carbon capture operation energy consumption coefficient of carbon capture power plant i; P G (i,t) is the total power of carbon capture power plant i in the tth period; P e (i,t) is the clean output power of carbon capture power plant i in the tth period; is the carbon capture power of carbon capture power plant i in the tth period; P base (i,t) is the fixed power loss of device i in the tth period; c coal is the coal-fired cost per unit of electricity generated by the carbon capture power plant, f Ebuy (i,t) is the energy purchase cost of the carbon capture power plant; The carbon capture system tank model is as follows: Where: v is the density of CO2 solution in the rich liquid tank; rich (t), v poor (t) are the outflow of solution from the rich liquid tank and the lean liquid tank in the tth period; S rich (t), S poor (t) the solution storage capacity of the rich liquid tank and the lean liquid tank in the tth period respectively; S rich,max , S poor,max It is the maximum solution storage capacity of the rich liquid tank and the lean liquid tank.

4. According to claim 1, a low-carbon economic dispatching method for an integrated energy system considering carbon capture and coordinated operation of multiple types of energy is characterized in that: The low-carbon economic dispatch model of the comprehensive energy system: Objective function: The model takes the minimum total economic operation cost of the integrated energy system as the objective function. The total economic operation cost function of the integrated energy system is f total As shown in formula (4): <h2 style=";text-align:left;direction:ltr">f<h2 style=";text-align:left;direction:ltr"> total <h2 style=";text-align:left;direction:ltr"> =f1+f2+f3 (4) Where: f1 is the equipment operation cost function; f2 is the carbon trading cost function; f3 is the carbon storage cost function; The equipment operation cost function includes the energy production and consumption equipment operation cost function and the energy purchase equipment function, including carbon capture power plants and wind farms. The wind farm's wind abandonment penalty cost is regarded as the operation cost function of the energy production and consumption equipment: Where: S T is the set of time periods; S EP It is a collection of energy production and consumption equipment; S Ebuy To purchase energy equipment collection; Carbon trading cost function: Where: is the carbon trading price; is the carbon emission function, E0 is the carbon emission quota function; Park carbon emissions function The calculation formula is as follows: The calculation formula of the park carbon emission quota function E0 is as follows: Where: S0 is the set of equipment to which carbon quotas are allocated. In this model, the set of equipment to which carbon quotas are allocated includes carbon capture power plants and cogeneration units; E0(i,t) is the carbon emission quota allocated to equipment i for electricity and heat production in the tth period; Carbon Sequestration Cost Function f3=δ(E cap -E P2G ) Where: δ is the cost of storing unit CO2, E P2G The amount of CO2 absorbed by power-to-gas conversion; Constraints: Power balance constraints: The system-level constraints are the power balance of electricity, heat, and gas: Where: S N is a collection of devices; g (i,t) is the gas supply of equipment i in the tth time period; P eL (i,t),P hL (i,t),P gl (i, t) are the electricity, heat and gas consumption (load) of equipment i in the tth period; P EL (t), P HL (t), P GL (t) are the electricity load, heat load and gas load of the park in the th period respectively; Wind power generation constraints: Where: P WT (i, t) is the actual wind power of the wind farm in the tth period, P qf (i,t) is the wind power plant’s wind abandonment in the tth period; Carbon capture power plant operation constraints: The total power of coal-fired units in the carbon capture power plant must be less than the upper limit of equipment operation. The operating energy consumption of the carbon capture system and the flue gas diversion ratio of the carbon capture system must meet the following constraints: Where: P G,max (i) is the maximum power limit of carbon capture power plant i; τ i is the operating coefficient of carbon capture power plant i; max , min The maximum and minimum values ​​of the diversion ratio of the flue gas diversion device of the carbon capture power plant; Energy conversion equipment operating constraints: The energy conversion equipment involved in this system includes power-to-gas and cogeneration, and the input power must meet the equipment capacity constraints: i) Power-to-Gas (P2G) The operating constraints of the power-to-gas plant are as follows, where the CO2 raw materials used in the power-to-gas plant all come from carbon capture; Where: η h,i(P2G) is the efficiency of converting electrical energy into thermal energy in the power-to-gas device i; η g,i(P2G) P is the efficiency of the power-to-gas device in converting electrical energy into gas energy; eL,max (i) is the maximum value of the electrical power consumed by device i; is the CO2 consumption coefficient of the power-to-gas equipment i; ii) Combined Heat and Power (CHP) The system adopts a combined heat and power unit model with adjustable heat-to-electricity ratio: Where: η i(CHP) is the comprehensive efficiency of the cogeneration equipment i; κ min,i(CHP) , κ max,i(CHP) are the upper and lower limits of the heat-to-electricity ratio of cogeneration equipment i; P gL,max (i) is the maximum value of the equipment i gas load; Energy storage equipment operation constraints: The model of energy storage equipment needs to consider storage capacity constraints, single charging / energy constraints, storage and release state complementarity constraints, and periodic reserve conservation constraints. The operation constraint expressions of electrical energy, thermal energy, and gas energy storage equipment are as follows: Where: S(i,t) is the storage capacity of energy storage device i in the tth period; P cha (i,t),P dis (i, t) are the charging and discharging power of energy storage device i in the tth period respectively; η cha (i), η dis (i) are the charging and discharging efficiencies of energy storage device i; S max (i) S min (i) are the upper and lower limits of the capacity of energy storage device i; P cha,max (i) P dis,min (i) are the single maximum charging and discharging power of energy storage device i; u cha (i,t),u dis (i, t) is a variable of charge and discharge status 0, 1, indicating that the energy storage device cannot charge and discharge at the same time.

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