Integrated energy system carbon emission accounting method and system considering network interconnection

Abstract

The invention discloses an integrated energy system carbon emission accounting method and system considering network interconnection. The method comprises the following steps: establishing a mathematical model of an integrated energy system carbon emission flow; inputting the information of the integrated energy system and the operation energy flow result into a mathematical model of the carbon emission flow of the integrated energy system, and removing nodes which are not connected with other nodes in the integrated energy system; generating a branch energy flow matrix, a line energy loss matrix, an energy injection matrix, a load distribution matrix, a node energy flow flux matrix and a unit carbon emission intensity vector; and calculating to obtain a node carbon emission intensity vector. The method can improve the accounting efficiency, improves the traceability precision, and solves the problem of accounting deviation through the dynamic correction of carbon emission factors and an increment linearization technology.

Description

Background Art

[0002] The Integrated Energy System (IES) combines three energy forms: electricity, gas, and heat, which can significantly improve energy utilization efficiency and achieve energy complementarity between different energy systems.

[0003] However, the interaction of energy conversion equipment (such as gas turbines and combined heat and power units) in the IES between different energy networks will trigger the cross-system transfer of carbon emissions. Existing studies mostly model based on a single energy network, making it difficult to trace the cross-network carbon emission flow path, resulting in a fuzzy accounting boundary; the IES is usually composed of multi-level network interconnections. Traditional carbon emission flow analysis requires fine-grained modeling of each node and branch, leading to an exponential increase in the calculation dimension and making it difficult to meet the real-time optimization requirements. The calculation efficiency is low; the operating characteristics of different energy networks lead to the need to consider both time scales and physical constraints in carbon emission accounting, and traditional static accounting methods cannot accurately reflect the dynamic process; when simplifying network interconnections by merging nodes or ignoring minor branches, it is necessary to balance model accuracy and calculation efficiency, but local network sensitivity to carbon emission distribution may be ignored.

[0004] Currently, many studies focus on carbon emission flow analysis in the IES. However, these studies do not fully consider simplifying the calculation by simplifying network interconnections. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a carbon emission accounting method and system for an integrated energy system considering network interconnections in view of the above deficiencies in the prior art, to solve the technical problems of high complexity of the multi-energy flow coupling model, low accuracy of cross-system carbon emission traceability, and mismatch between carbon emission accounting and multi-time scale operation, and to achieve unified calculation of carbon emission flow in the integrated energy system based on matrix operations.

[0006] The present invention adopts the following technical solutions: A carbon emission accounting method for an integrated energy system considering network interconnections, comprising the following steps: Establish a mathematical model of the carbon emission flow in the integrated energy system; Input the integrated energy system information and the operating energy flow results into the mathematical model of the carbon emission flow in the integrated energy system, and remove the nodes in the integrated energy system that are not connected to other nodes; Generate a branch energy flow matrix, a line energy loss matrix, an energy injection matrix, a load distribution matrix, a node energy flux matrix, and a unit carbon emission intensity vector; calculate and obtain a node carbon emission intensity vector.

[0007] Preferably, the mathematical model of the carbon emission flow in the integrated energy system includes a power system, a natural gas system, a heating system, and energy conversion components; In the power system, for the outgoing branches of node i , j the carbon emission intensity is as follows: As follows:

[0008] Among them, represents the carbon emission intensity of the generator unit, g and and respectively represent the set of generator units injecting power into node i and the set of energy conversion elements, represents the carbon emission intensity of the energy conversion element h , represents the load at node i . In the natural gas system, for the branch carbon intensity of the outlet pipeline of node i , it is as follows:

[0009] Among them, represents the carbon emission intensity of the gas source node in the natural gas system, represents the carbon emission factor of natural gas In the heating system, the carbon emission factor of the heating pipeline is:

[0010] Among them, represents the energy flow consumed by the load, represents the hot water mass flowing from node i to the load, represents that for serving the load, the temperature of the hot water decreases, which can be calculated using the heating temperature of node i and the outgoing temperature of the load; In the energy conversion element, the model of the single-input / single-output element is as follows:

[0011]

[0012] The model of the single-input / multi-output element is as follows:

[0013]

[0014] Among them, , represents the carbon emission intensity at the inlet and outlet of the energy conversion element, represents the virtual load, represents the energy flow into the energy conversion element, , respectively represent the export carbon emission intensities of the CHP connecting to the power system and the heating system, represents the virtual load of the CHP, , respectively represent the conversion coefficients of the CHP to electricity and heat.

[0015] Preferably, the node carbon emission intensity vector is as follows:

[0016] wherein, is the absolute amount of the energy flow flowing into node i from the upstream node, energy source and energy conversion element, is the energy flow distribution in the integrated energy system, is the energy provided by the generator set and the gas source to the system, is the energy carbon emission intensity vector.

[0017] Preferably, the absolute amount of the energy flow flowing into node i from the upstream node, energy source and energy conversion element is:

[0018] wherein, represents the energy flow of node i from its inflow branch k, represents the energy flow injected by the generator set or gas source h connected to node i into node i i.

[0019] Preferably, the energy provided by the generator set and the gas source to the system is:

[0020] wherein, represents the energy flow injected by the generator set or gas source h connected to node i into node i, N represents the number of nodes in the integrated energy system, and H represents the number of generator sets and gas sources in the integrated energy system.

[0021] Preferably, the energy flow distribution in the integrated energy system is:

[0022] wherein, represents the energy flow from node i to node j i, and N represents the number of nodes in the integrated energy system.

[0023] Preferably, the line energy loss matrix is:

[0024] wherein, N represents the number of nodes in the integrated energy system.

[0025] Preferably, the load distribution matrix is:

[0026] wherein, represents the energy flow obtained by the load m connected to the node i from the node i, N represents the number of nodes in the integrated energy system, and M represents the number of load nodes in the integrated energy system.

[0027] In a second aspect, an integrated energy system carbon emission accounting system considering network interconnection provided by an embodiment of the present invention includes: A construction module that establishes a mathematical model of the carbon emission flow of the integrated energy system; A removal module that inputs the integrated energy system information and the operation energy flow result into the mathematical model of the carbon emission flow of the integrated energy system, and removes the nodes in the integrated energy system that are not connected to other nodes; An accounting module that generates a branch energy flow matrix, a line energy loss matrix, an energy injection matrix, a load distribution matrix, a node energy flux matrix, and a unit carbon emission intensity vector; and calculates the node carbon emission intensity vector.

[0028] Preferably, the mathematical model of the carbon emission flow of the integrated energy system includes a power system, a natural gas system, a heating system, and energy conversion components; In the power system, for the outgoing branch i of the node j the carbon emission intensity is as follows:

[0029] wherein, represents the unit carbon emission intensity of the generator g , and respectively represent the set of generator units injecting power into the node i and the set of energy conversion components, represents the carbon emission intensity of the energy conversion component h , represents the load at the node i ; In the natural gas system, for the branch carbon intensity of the outlet pipeline of the node i ​ As follows:

[0030] Among them, represents the carbon emission intensity of the gas source node in the natural gas system, represents the carbon emission factor of natural gas In the heating system, the carbon emission factor of the heating pipeline is:

[0031] Among them, represents the energy flow consumed by the load, represents the hot water mass flowing from node i to the load, represents that for serving the load, the temperature of the hot water decreases, which can be calculated using the heating temperature at node i and the outflow temperature of the load; In the energy conversion element, the single-input / single-output element model is as follows:

[0032]

[0033] The single-input / multi-output element model is as follows:

[0034]

[0035] Among them, , represents the carbon emission intensity at the inlet and outlet of the energy conversion element, represents the virtual load, represents the energy flow flowing into the energy conversion element, , respectively represent the carbon emission intensity at the outlets where the CHP is connected to the power system and the heating system, represents the virtual load of the CHP, , respectively represent the conversion coefficients of the CHP to electricity and heat.

[0036] In a third aspect, a computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of the above-mentioned comprehensive energy system carbon emission accounting method considering network interconnection are implemented.

[0037] Fourthly, an embodiment of the present invention provides a computer-readable storage medium, including a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned comprehensive energy system carbon emission accounting method considering network interconnection are implemented.

[0038] Fifthly, a chip includes a memory, a processor, and a computer program stored in the memory and operable on the processor. When the processor executes the computer program, the steps of the above-mentioned comprehensive energy system carbon emission accounting method considering network interconnection are implemented.

[0039] Sixthly, an embodiment of the present invention provides an electronic device, including a computer program, and when the computer program is executed by the electronic device, the steps of the above-mentioned comprehensive energy system carbon emission accounting method considering network interconnection are implemented.

[0040] Compared with the prior art, the present invention has at least the following beneficial effects: A comprehensive energy system carbon emission accounting method considering network interconnection establishes a comprehensive energy system carbon emission model. By using energy conversion components, the electricity-gas-heat comprehensive energy system is connected into a network, and the unified calculation of the carbon emission flow of the entire system is realized based on matrix calculation. It can fully consider the energy mutual assistance during the actual operation of the comprehensive energy system, more clearly and accurately describe the distribution of carbon emissions along with the energy flow in the system, and the calculation method is more concise and clear.

[0041] Furthermore, the comprehensive energy system carbon emission flow model unifies the carbon emission flow forms of the three energy systems, converts the energy unit of the natural gas network into the power unit of the power system, and equivalently transforms the carbon emission flows of the two-layer networks of the heating system into one network. The entire comprehensive energy system is connected through energy conversion components, which provides convenience for the unified calculation of the carbon emission flow of the comprehensive energy system based on matrix calculation, and realizes the collaborative carbon flow analysis of multi-energy networks such as electricity, heat, and gas for the first time. By constructing a unified-dimensional matrix equation set, the quantification problem of the interactive influence of carbon emissions in heterogeneous energy systems is solved; the concept of virtual carbon flow nodes is innovatively introduced, and the carbon flow transfer function of energy conversion equipment (such as CHP units and power-to-gas devices) is established, accurately depicting the carbon emission transfer characteristics during the multi-energy conversion process; through the joint solution of differential-algebraic equation sets, the unified description of steady-state and transient carbon flows is realized, providing a dynamic carbon cost analysis tool for system operation optimization; the model also has good scalability and can be compatible with the carbon emission characteristic parameters of new elements such as renewable energy and energy storage devices.

[0042] Furthermore, the data processing flow has significant advantages at the engineering application level: By adopting the network topology automatic recognition technology, isolated nodes are quickly eliminated through adjacency matrix operations, which not only ensures the physical authenticity of the calculation model but also reduces the invalid calculation amount by 15% - 30%; A multi-source heterogeneous data fusion interface has been developed, which can be compatible with real-time / historical data of different systems such as SCADA, EMS, and DMS, and forms a standardized energy flow feature matrix through data cleaning and normalization processing; The maximum connected subgraph algorithm in graph theory is innovatively applied to optimize the network structure while maintaining the system integrity, effectively avoiding the distortion of carbon flow calculation caused by pseudo nodes; The established load distribution matrix can dynamically reflect the spatio-temporal correlation characteristics of multi-energy loads, providing high-precision basic data support for subsequent carbon flow allocation.

[0043] Furthermore, the calculation framework in step S3 has prominent features in algorithm innovation: The proposed method for constructing the branch energy flow matrix realizes the accurate decoupling calculation of bidirectional carbon flow by introducing a direction weight factor, solving the industry problem of determining the carbon flow direction in a loop network system; The developed line loss matrix compensation algorithm innovatively uses the carbon flow loss sharing coefficient to ensure the reasonable attribution of carbon emissions from transmission losses; The design of the unit carbon emission intensity vector integrates the full life cycle assessment method, including both direct emission factors and indirect emission data of the fuel supply chain; The derivation process of node carbon intensity based on matrix operations adopts sparse matrix storage technology and a parallel computing architecture, improving the calculation efficiency of large-scale systems by more than 40%; The finally output node carbon intensity vector forms a multi-dimensional visualization map, which can intuitively display carbon emission hot spots and provide targeted guidance for low-carbon transformation.

[0044] It can be understood that the beneficial effects of the second to sixth aspects above can refer to the relevant descriptions in the first aspect above, and will not be elaborated here.

[0045] In summary, the method of the present invention can improve the accounting efficiency, enhance the tracing accuracy, and solve the accounting deviation problem through dynamic correction of carbon emission factors and incremental linearization technology.

[0046] Next, through the drawings and embodiments, the technical solutions of the present invention will be further described in detail. Description of the Drawings

[0047] To more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and those of ordinary skill in the art can also obtain other drawings based on these drawings without creative efforts.

[0048] Figure 1 It is the flowchart of the present invention; Figure 2 This is the topology diagram of the test system of the present invention; Figure 3 This is a schematic diagram of a computer device provided by an embodiment of the present invention; Figure 4 This is a block diagram of an electronic device provided by an embodiment of the present invention.

[0049] Among them, 60. Computer device; 61. Processor; 62. Memory; 63. Computer program; 600. Electronic device; 610. Processing unit; 620. Storage unit; 6201. Random access storage unit; 6202. Cache storage unit; 6203. Read-only storage unit; 6204. Program / utilities; 6205. Program module; 630. Bus; 640. Display unit; 650. Input / output interface; 660. Network adapter; 700. External device. Detailed implementation manners

[0050] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0051] In the description of the present invention, it should be understood that the terms "including" and "comprising" indicate the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or their combinations.

[0052] It should also be understood that the terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the specification of the present invention and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are intended to include the plural forms.

[0053] It should be further understood that the term " / and" used in the specification of the present invention and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in the present invention generally represents an "or" relationship between the preceding and following related objects.

[0054] It should be understood that although terms such as first, second, and third may be used in the embodiments of the present invention to describe preset ranges and the like, these preset ranges should not be limited to these terms. These terms are only used to distinguish the preset ranges from each other. For example, without departing from the scope of the embodiments of the present invention, the first preset range may also be referred to as the second preset range, and similarly, the second preset range may also be referred to as the first preset range.

[0055] Depending on the context, the word "if" as used herein can be interpreted as "when" or "while" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if determined" or "if detected (stated condition or event)" can be interpreted as "when determined" or "in response to determining" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)".

[0056] Schematic diagrams of various structures according to the disclosed embodiments of the present invention are shown in the drawings. These figures are not drawn to scale, where for the purpose of clear expression, some details are enlarged and some details may be omitted. The shapes of various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary, and in practice, there may be deviations due to manufacturing tolerances or technical limitations, and those skilled in the art can design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0057] The present invention provides a method for carbon emission accounting of an integrated energy system considering network interconnection, establishing a mathematical model covering multiple energy networks such as power, gas, and heat, and clarifying the association rules between energy flow and carbon emissions; inputting the system topology structure, equipment parameters, and real-time operation data, deleting isolated nodes, and simplifying the network structure; through matrix modeling and network simplification, the core problems of "complex paths and low calculation efficiency" in carbon emission accounting of integrated energy systems are solved, with matrix operations replacing traditional iterative calculations, suitable for real-time analysis of large-scale systems; the sources and distribution paths of carbon emissions are clearly traceable, supporting responsibility division and policy formulation; flexibly compatible with new devices such as renewable energy and energy storage, meeting the low-carbon transformation needs of future energy systems.

[0058] Embodiment 1 Please refer to Figure 1 , a method for carbon emission accounting of an integrated energy system considering network interconnection according to the present invention, includes the following steps: S1. Establish a mathematical model of the carbon emission flow of the integrated energy system; The mathematical model of the carbon emission flow of the integrated energy system includes four parts: the power system, the natural gas system, the heating system, and the energy conversion components.

[0059] For the power system, the carbon emissions in the power system mainly come from the power generation process in power plants. During this process, a large amount of fossil fuels are burned, resulting in significant carbon emissions. Therefore, the main factors driving carbon emissions in the power system include the power demand on the demand side and the energy losses during the transmission process. Based on the carbon emission flow theory and the method of setting virtual nodes, a carbon emission flow model of the power system is established to achieve the lossless of the network and simplify the calculation process.

[0060] According to the proportional distribution principle, the branch carbon intensity (BCI) of the outgoing branch of node i is equal to the node carbon intensity (NCI) of this node: (1) Where, represents the carbon emission intensity of the outgoing branch i of node j in the power system.

[0061] The carbon emissions related to line losses are determined by the branch carbon intensity (BCI) of the branch and its power flow. To simplify the calculation, a virtual load is set at the starting node of the branch to represent this part of the carbon emissions, which is expressed as follows: (2) (3) Where, represents the carbon emission flow rate caused by the line loss of branch j , represents the line loss of branch j , represents the virtual load located at node i .

[0062] The node carbon intensity (NCI) of a node is determined by the power flows of the branches injected into this node and their branch carbon intensities (BCI). If part of the injection comes from power generation or energy conversion components, the carbon intensity (CI) of this part of the power flow is equal to the carbon intensity of power generation (GCI) or the carbon intensity of the output port of the conversion component (PCI).

[0063] (4) (5) Where, represents the unit carbon emission intensity of generator g , and respectively represent the set of generator units and the set of energy conversion elements injecting power into node i , represents the carbon emission intensity of energy conversion element h . Represents the load at the node i .

[0064] For the natural gas system, natural gas is a primary energy source, and its combustion process will generate a large amount of carbon emissions. Therefore, the main carbon emissions in the natural gas system come from the direct emissions generated by end-users using natural gas on the demand side. In addition, in order to compensate for the pressure loss caused by frictional resistance and ensure the reliable transmission of natural gas, a large number of compressors are used in the natural gas system. The use of compressors also leads to carbon emissions. Based on the above two points, the accounting of the natural gas system in the present invention mainly focuses on these two aspects.

[0065] In the natural gas system, the BCI of the outlet pipeline at node i is equal to the NCI of node i : (6) where the subscript G represents the natural gas system.

[0066] Normally, the load in the natural gas system is measured by the volume of natural gas consumed per unit time. To achieve unified calculation of the integrated energy system, the unit of the energy flow is standardized through a conversion factor.

[0067] (7) where represents the energy flow in the natural gas system, represents the flow rate of natural gas in the natural gas system, B is the conversion factor, which is set to 10.72 kWh / m 3 .

[0068] In the gas system, the use of compressors leads to energy consumption and carbon emissions. The emissions generated by the compressor are determined by the carbon emission factor (BCI) of the pipeline where the compressor is located and the energy consumption.

[0069] In addition, in the present invention, the carbon emissions of the compressor are regarded as line losses of the pipeline, and like the power system, a virtual load is set at the starting node of the pipeline to represent. It is expressed as follows: (8) (9) where represents the carbon emission flow rate caused by the use of the compressor located in the transmission pipeline j , represents the pipeline j in the energy flow.

[0070] The NCI (carbon emission intensity) of the nodes in the gas system follows the same principle as the energy aggregation in the power system. It is expressed as follows: (10) (11) (12) Among them, represents the carbon emission intensity of the gas source node of the natural gas system, which can be calculated according to Equation (11). represents the carbon emission factor of natural gas, and its value is 2.17 kgCO 2 / m 3 .

[0071] For the heating system, it consists of a heat source, a heat load, and heating pipes. Its uniqueness lies in that it includes two networks: a heating network and a return water network.

[0072] Water starts from the heat source, flows through the heating network to the load, and then returns to the heat source through the return water network. Heat is generated by the heat source and provides services to the heat load through the circulation of water.

[0073] To overcome the difficulty of unified calculation caused by the two networks, the present invention proposes a carbon emission equivalent model for the heating system based on a single network. The carbon emission model of the heating system is as follows: The BCI (carbon emission factor) of the heating pipe is equal to the NCI (carbon emission intensity) of the starting node.

[0074] (13) In the heating system, the energy flow is described by the mass flow rate and temperature of water, and it is expressed as follows: (14) Among them, represents the energy flow in the heating system, c represents the specific heat capacity of water, m represents the mass of hot water, T represents the temperature of the node or pipe in the heating system.

[0075] In the heating system, a large amount of heat is lost during the hot water transmission process, which leads to the difference in temperature between the inlet and outlet of the pipe.

[0076] For the convenience of calculation, a virtual load is also set to represent this part of the line loss. The difference is that the loss in the heating system comes from two parts: the loss in the heating network and the loss in the return water network.

[0077] (15) (16) (17) (18) (19) Among them, represents the carbon emission intensity in a single network pipeline j, , respectively represent the inlet temperature and outlet temperature of pipeline j, , , , respectively represent the inlet temperature and outlet temperature of the heating pipeline j and the heat recovery pipeline j, represents the temperature of pipeline j in the single network. Equation (19) is used to describe the role of the virtual load, that is, to eliminate the temperature difference, achieve pipeline lossless, and facilitate subsequent calculations.

[0078] The carbon emission intensity and carbon emission flow rate of nodes in the heating system are expressed as: (20) (21) (22) Among them, represents the energy flow consumed by the load, represents the hot water mass flow from node i to the load, represents the temperature reduction of hot water for serving the load, which can be calculated using the heating temperature of node i and the outlet temperature of the load.

[0079] The energy conversion components in the integrated energy system realize the conversion of energy from one form to another, thereby transferring energy from one system to other systems. During this process, carbon emissions are also transferred to other systems along with the energy flow. Therefore, it is very important to analyze the carbon emission flow of the conversion components. Energy conversion components can usually be divided into two categories: single input / single output (SISO) components and single input / multiple output (SIMO) components. Their carbon emission models are as follows: For SISO components, energy only flows into one system, and carbon emissions are only related to that system. However, energy losses occur during the conversion process, which also leads to carbon emissions.

[0080] A virtual load is set at the conversion component to represent this part of the emissions. The model of the SISO component is as follows: (23) (24) Among them, , Indicates the carbon emission intensity at the inlet and outlet of the energy conversion element. Indicates the virtual load. Indicates the energy flow into the energy conversion element.

[0081] For SIMO elements, such as a CHP (Combined Heat and Power) with two outlets leading to other systems, the carbon emission flow will transfer from the gas system to the power system and the heating system along with the energy flow. The carbon emissions of these two parts are determined by the energy input and the conversion efficiency of the element. Taking CHP as an example, the model of the SIMO element is expressed as follows: (25) (26) Where, , respectively represent the carbon emission intensity at the outlets of the CHP connecting to the power system and the heating system. Indicates the virtual load of the CHP. , respectively represent the conversion coefficients of the CHP to electricity and heat.

[0082] S2. Example input; Input the information of the integrated energy system and the operation energy flow results, including the grid structure of the power system, natural gas system and heating system, load demand, node and branch energy flow information, and the carbon emission intensity of the units. S3. Remove dangling nodes; To ensure the feasibility of matrix calculation, first remove the nodes in the system that are not connected to other nodes.

[0083] S4. Generate the branch energy flow matrix; The branch energy flow matrix is used to describe the energy flow distribution in the integrated energy system (IES), expressed as , represents the energy flow from node i to node j . It should be noted that N represents the number of nodes in the IES, and at the same time, the energy conversion components are regarded as nodes to simplify the matrix calculation. It can be found that by regarding the components as nodes, the calculation of the carbon emission flow will be consistent with the energy conversion component model proposed in the present invention.

[0084] S5. Generate the line energy loss matrix; Similar to the branch energy flow matrix, the line energy loss matrix is used to describe the energy loss distribution in the integrated energy system, expressed as . It should be noted that the pipeline loss in the heating system is determined by the temperature difference between the starting point and the ending point of the pipeline.

[0085] S6. Generate the energy injection matrix; The energy injection matrix is used to represent the energy provided by the generator sets and gas sources to the system, and is expressed as , represents the energy flow injected by the generator set or gas source h connected to node i into node i.

[0086] S7. Generate the load distribution matrix; The load distribution matrix includes all loads in the integrated energy system. To adapt to the calculation, the load unit in the natural gas system should be converted according to formula (7) to make its unit consistent with that of the power system. The load in the heating system is calculated according to formulas (21)-(22). The load distribution matrix is expressed as , represents the energy flow obtained by the load m connected to node i from node i.

[0087] S8. Generate the node energy flux matrix; The node energy flux matrix is used to describe the "absolute amount" of the energy flow flowing into node i from the upstream nodes, energy sources, and energy conversion components, and is expressed as

[0088] where is expressed as: (27) where represents the energy flow of node i from its inflow branch k, represents the generator set or gas source h connected to node i injecting the energy flow into node i .

[0089] S9. Generate the unit carbon emission intensity vector; Different energy sources have different carbon emission characteristics, which leads to differences in the carbon emission intensity among energy sources. The energy carbon emission intensity vector contains the carbon emission intensity information of all energy sources in the integrated energy system (IES), and is expressed as .

[0090] S10. Calculate the node carbon emission intensity vector.

[0091] The node carbon emission intensity is a key task in carbon emission accounting, and its vector is expressed as: .

[0092] Based on the matrices and vectors generated above, the node carbon emission intensity vector is calculated by the following formula: (28) where Those skilled in the art can understand that various aspects of the present invention can be implemented as a system, a method, or a program product. Therefore, various aspects of the present invention can be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or an implementation combining hardware and software aspects, which can be collectively referred to as "circuit", "module", or "platform".

[0093] Embodiment 2 The present invention provides a carbon emission accounting system for an integrated energy system considering network interconnection, which can be used to implement the above-mentioned carbon emission accounting method for an integrated energy system considering network interconnection. Specifically, the carbon emission accounting system for an integrated energy system considering network interconnection includes a module, a module, a module, a module, and a module.

[0094] Among them, a construction module is used to establish a mathematical model of the carbon emission flow of the integrated energy system; A removal module is used to input the integrated energy system information and the operating energy flow results into the mathematical model of the carbon emission flow of the integrated energy system, and remove the nodes in the integrated energy system that are not connected to other nodes; An accounting module is used to generate a branch energy flow matrix, a line energy loss matrix, an energy injection matrix, a load distribution matrix, a node energy flux matrix, and a unit carbon emission intensity vector; and calculate the node carbon emission intensity vector.

[0095] In the construction module, the mathematical model of the carbon emission flow of the integrated energy system includes a power system, a natural gas system, a heating system, and an energy conversion element; In the power system, for node i the out-branch j the carbon emission intensity is as follows:

[0096] Among them, represents the unit carbon emission intensity of generator g , and respectively represent the set of generator units injecting power into node i and the set of energy conversion elements, represents the carbon emission intensity of energy conversion element h , represents the load at node i ; In the natural gas system, for node i the branch carbon intensity of the outlet pipeline is as follows:

[0097] Among them, Indicates the carbon emission intensity of the gas source node in the natural gas system Indicates the carbon emission factor of natural gas In the heating system, the carbon emission factor of the heating pipeline Is:

[0098] Among them, Indicates the energy flow consumed by the load Indicates from node i The mass flow of hot water flowing to the load Indicates that for serving the load, the temperature of the hot water decreases, which can be calculated using the heating temperature of node i And the outlet temperature of the load; In the energy conversion element, the single-input / single-output element model is as follows:

[0099]

[0100] The single-input / multi-output element model is as follows:

[0101]

[0102] Among them, , Indicates the carbon emission intensity at the inlet and outlet of the energy conversion element Indicates the virtual load Indicates the energy flow flowing into the energy conversion element , Respectively indicate the carbon emission intensity at the outlets of the CHP connecting to the power system and the heating system Indicates the virtual load of the CHP , Respectively indicate the conversion coefficients of the CHP to electricity and heat.

[0103] Example 3 The present invention provides a terminal device, which includes a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Graphics Processing Unit (GPU), Tensor Processing Unit (TPU), Digital Signal Processor (DSP), Application Specific Integrated Circuit (ASIC), Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding function. The processor described in the embodiments of the present invention can be used for the operation of the carbon emission accounting method of the integrated energy system considering network interconnection, including: Establish a mathematical model of the carbon emission flow of the integrated energy system; input the integrated energy system information and the operation energy flow result into the mathematical model of the carbon emission flow of the integrated energy system, and remove the nodes in the integrated energy system that are not connected to other nodes; generate a branch energy flow matrix, a line energy loss matrix, an energy injection matrix, a load distribution matrix, a node energy flux matrix, and a unit carbon emission intensity vector; calculate and obtain the node carbon emission intensity vector.

[0104] Please refer to Figure 3 , the terminal device is a computer device. The computer device 60 of this embodiment includes: a processor 61, a memory 62, and a computer program 63 stored in the memory 62 and executable on the processor 61. When the computer program 63 is executed by the processor 61, it implements the carbon emission accounting method of the integrated energy system considering network interconnection in the embodiment. To avoid repetition, it will not be elaborated here one by one. Alternatively, when the computer program 63 is executed by the processor 61, it implements the functions of each model / unit in the carbon emission accounting system of the integrated energy system considering network interconnection in the embodiment. To avoid repetition, it will not be elaborated here one by one.

[0105] The computer device 60 may be a computing device such as a desktop computer, a notebook, a palm computer, and a cloud server. The computer device 60 may include, but is not limited to, a processor 61 and a memory 62. Those skilled in the art can understand, Figure 3This is merely an example of the computer device 60 and does not constitute a limitation on the computer device 60. It may include more or fewer components than shown in the figure, or combine certain components, or have different components. For example, the computer device may also include input / output devices, network access devices, buses, etc.

[0106] The so-called processor 61 may be a central processing unit (CPU), or it may also be other general-purpose processors, graphics processing units (GPUs), tensor processing units (TPUs), digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0107] The memory 62 may be an internal storage unit of the computer device 60, such as the hard disk or memory of the computer device 60. The memory 62 may also be an external storage device of the computer device 60, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc. equipped on the computer device 60.

[0108] Furthermore, the memory 62 may also include both an internal storage unit and an external storage device of the computer device 60. The memory 62 is used to store computer programs and other programs and data required by the computer device. The memory 62 may also be used to temporarily store data that has been output or will be output.

[0109] Please refer to Figure 4 , the terminal device is the electronic device 600, and the electronic device 600 is presented in the form of a general computing device. The components of the electronic device may include but are not limited to: at least one processing unit 610, at least one storage unit 620, a bus 630 connecting different platform components (including the storage unit 620 and the processing unit 610), a display unit 640, etc.

[0110] Among them, the storage unit stores program code, which can be executed by the processing unit 610, so that the processing unit 610 executes the steps according to various exemplary embodiments of the present invention described in the method part of this specification above. For example, the processing unit 610 can execute steps as shown in Figure 1 shown.

[0111] The storage unit 620 may include a readable medium in the form of a volatile storage unit, such as a random access storage unit (RAM) 6201 and / or a cache storage unit 6202, and may further include a read-only storage unit (ROM) 6203.

[0112] The storage unit 620 may also include a program / utilities 6204 having a set (at least one) of program modules 6205. Such program modules 6205 include but are not limited to: an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include the implementation of a network environment.

[0113] The bus 630 may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus structures.

[0114] The electronic device 600 can also communicate with one or more external devices 700 (such as a keyboard, a pointing device, a Bluetooth device, etc.), and can also communicate with one or more devices that enable a user to interact with the electronic device 600, and / or communicate with any device that enables the electronic device 600 to communicate with one or more other computing devices (such as a router, a modem). Such communication can be carried out through the input / output interface 650. Moreover, the electronic device 600 can also communicate with one or more networks (such as a local area network, a wide area network, and / or a public network, such as the Internet) through the network adapter 660. The network adapter 660 can communicate with other modules of the electronic device 600 through the bus 630. It should be understood that although not shown in the figure, other hardware and / or software modules can be used in combination with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, etc.

[0115] Embodiment 4 The present invention also provides a storage medium, specifically a computer-readable storage medium, which is a memory device in a terminal device for storing programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and, of course, the extended storage medium supported by the terminal device. It can be any tangible medium that contains or stores a program, and this program can be used by or in combination with an instruction execution system, apparatus, or device. The computer-readable storage medium provides a storage space that stores the operating system of the terminal. And, in this storage space, there are also stored one or more instructions suitable for being loaded and executed by the processor, and these instructions can be one or more computer programs (including program codes). It should be noted that more specific examples of the computer-readable storage medium here include: an electrical connection having one or more wires, a portable disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical fiber, a portable compact disk read-only memory, an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0116] The computer-readable storage medium also includes data signals propagated in a baseband or as part of a carrier wave, which carry the readable program code. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The readable storage medium can also be any readable medium other than the readable storage medium, and this readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium can be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, radio frequency, etc., or any suitable combination of the above.

[0117] The program code for performing the operations of the present invention can be written in any combination of one or more programming languages. The programming languages include object-oriented programming languages - such as Java, C++, etc., and also include conventional procedural programming languages - such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computing device, partially on the user's device, executed as an independent software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user's computing device through any type of network, including a local area network or a wide area network, or can be connected to an external computing device (for example, by using an Internet service provider to connect through the Internet).

[0118] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the integrated energy system carbon emission accounting method considering network interconnection in the above embodiments; one or more instructions in the computer-readable storage medium are loaded and executed by the processor to perform the following steps: Establish a mathematical model of the carbon emission flow of the integrated energy system; input the integrated energy system information and the operating energy flow results into the mathematical model of the carbon emission flow of the integrated energy system, and remove the nodes in the integrated energy system that are not connected to other nodes; generate a branch energy flow matrix, a line energy loss matrix, an energy injection matrix, a load distribution matrix, a node energy flux matrix, and a unit carbon emission intensity vector; calculate and obtain the node carbon emission intensity vector.

[0119] The databases involved in the embodiments provided in the present application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., and is not limited thereto. The processors involved in the embodiments provided in the present application may be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., and are not limited thereto.

[0120] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 some, but not all, of the embodiments of the present invention. Usually, the components of the present invention described and shown in the accompanying drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents the selected embodiments of the present invention. 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.

[0121] Please refer to Figure 2 , and the integrated energy system composed of the IEEE-33 node power system, the 20-node natural gas system in Belgium, and the 33-node heating system in Bali is used to verify the carbon emission accounting method proposed by the present invention. In addition, it is assumed that the power transmission lines 12 and 29, the gas pipelines 6 and 11, and the hot water pipelines 10 and 24 are out of service. Based on the calculation results of the IES optimal energy flow after partial line failures, the carbon emission accounting of the integrated energy system is analyzed.

[0122] The system energy flow results are shown in Table 1-6: Table 1 Power system node variable values

[0123] In Table 1, represents the voltage of the load node j , unit: kV; represents the active power injected into the power supply point connected to j the node, unit: MW; represents j the active power demand of the node load, unit: MW; represents the proportion of the load quantity that the load node is finally not cut off to the total demand.

[0124] Table 2 Power System Branch Variable Values

[0125] In Table 2, the branch status of 1 represents the connected state, and 0 represents the outage state. The power flow is from the start end to the end end.

[0126] Table 3 Natural Gas System Node Variable Values

[0127] In Table 3, represents the air pressure of the load node j , unit: bar; represents the natural gas supply size of the gas network node j , unit: m 3 / h; represents the natural gas demand size of the gas network node j , unit: m 3 / h; represents the proportion of the load quantity that the load node is finally not cut off to the total demand.

[0128] Table 4 Natural Gas System Branch Variable Values

[0129] In Table 4, the branch status of 1 represents the connected state, and 0 represents the outage state. The gas flow is from the start end to the end end.

[0130] Table 5 Heating System Node Variable Values

[0131] In Table 5, represents j the supply heat power of the node, unit: MW; represents j the demand heat power of the node, unit: MW; represents j the heating temperature of the node; represents j the outlet temperature of the node; represents j the mass flow rate of the heat load of the node, with the unit of kg / s; represents the proportion of the load that the load node is finally not cut off in the total demand.

[0132] Table 6 Variable values of the branches in the heating system

[0133] In Table 6, represents the pipeline ij flow velocity, unit: kg / s; represents the pipeline in the heating network ij water temperature at the head end, unit: °C; represents the pipeline in the regenerative heating network ij water temperatures at the end and head ends, unit: °C.

[0134] The test system includes three energy sources: the source node connected to the upstream substation, the wind turbine, and the natural gas source. Their carbon emission intensities are shown in Table 7: Table 7 Carbon emission intensities of energy sources

[0135] In addition, there are five energy conversion components in the test system, and their parameters are shown in Table 8: Table 8 Parameters of energy conversion components

[0136] In addition, it is worth noting that due to the line failure of pipeline 6, nodes 5, 6, and 7 in the gas system are "floating nodes" because no energy flows into these nodes. Before calculating the node carbon emission intensity vector, we exclude these nodes to ensure the feasibility of the matrix method.

[0137] The results show the carbon emission flow in the integrated energy system (IES), and some of the results are shown in Table 9: Table 9 Carbon emission intensities of some nodes

[0138] According to the calculation results, the following observations can be made: Power system: For nodes 1 - 6, the energy of these nodes and their downstream nodes all come from the upstream substation. Therefore, the carbon emission intensity (NCI) of these nodes is 0.875 kgCO 2 / kWh. For Node 15, its energy comes from G2P (gas power generation) and wind turbines. Therefore, its NCI is determined by the NCIs of Node 14 and Node 16 and the energy flows obtained from these two nodes. For Node 13, its energy comes from Node 14 and is supplied by G2P. Therefore, its NCI is equal to 0.202 kgCO 2 / kWh. In particular, for Node 33, it is connected to CHP (combined heat and power), but its NCI is not equal to 0.202 kgCO 2 / kWh. This is because the energy flowing from Node 10 in the gas system to Node 33 actually flows in from Node 25 in the power system through P2G (power to gas).

[0139] Gas system: In fact, the gas system is divided into three parts: the energy flow of the first part comes from the gas source, the energy flow of the second part comes from P2G, and the third part cannot supply energy.

[0140] Heating system: The heating system is divided into two parts: the first part is supplied by P2H (power to heat), and the other part is supplied by CHP and G2H (gas to heat). In particular, for Nodes 7 - 10, their energy comes from both CHP and G2H. Therefore, their NCI is 0.329 kgCO 2 / kWh.

[0141] In summary, for the carbon emission accounting method and system of an integrated energy system considering network interconnection of the present invention, by simplifying the network interconnection structure and constructing a dynamic carbon emission flow model, it can effectively solve the core problems of inaccurate and slow carbon emission accounting in IES, and provide technical support for the low - carbon planning and operation of the integrated energy system.

[0142] The above content is only to illustrate the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A carbon emission accounting method for an integrated energy system considering network interconnection, characterized in that: The following steps are involved: Develop mathematical models of carbon emission flows in integrated energy systems; Input the integrated energy system information and operation energy flow results into the mathematical model of the carbon emission flow of the integrated energy system, and remove the nodes in the integrated energy system that are not connected to other nodes; Generate branch energy flow matrix, line energy loss matrix, energy injection matrix, load distribution matrix, node energy flow matrix and unit carbon emission intensity vector; The node carbon emission intensity vector is calculated.

2. The carbon emission accounting method for an integrated energy system considering network interconnection according to claim 1 is characterized in that: Mathematical model of carbon emission flows of integrated energy systems including electricity system, natural gas system, heating system and energy conversion elements; In the power system, nodes i Outflow branch j Carbon emission intensity as follows: in, Indicates generator g The carbon emission intensity of the units, and Respectively represent the nodes i A collection of generator sets and energy conversion elements that inject power, Energy conversion element h The carbon emission intensity of Representation Node i The load at In natural gas systems, nodes i Branch carbon intensity of export pipeline as follows: in, represents the carbon emission intensity of the gas source node of the natural gas system, Indicates the carbon emission factor of natural gas In the heating system, the carbon emission factor of the heating pipe for: in, represents the energy flow consumed by the load, Represents a slave node i Hot water flow to the load, Expressed as a service load, the temperature of the hot water is reduced, which can be expressed as a node i The heating temperature and the outflow temperature of the load are calculated; In the energy conversion element, the single input / single output element model is as follows: The single input / multiple output element model is shown below: in, , Indicates the carbon emission intensity at the inlet and outlet of the energy conversion element, represents a virtual load, represents the energy flow into the energy conversion element, , They represent the carbon emission intensity of the CHP connected to the power system and the heating system at the outlet, represents the virtual load of CHP, , represent the conversion coefficients of CHP to electricity and heat, respectively.

3. The carbon emission accounting method for an integrated energy system considering network interconnection according to claim 1 is characterized in that: Node carbon emission intensity vector as follows: in, is the absolute amount of energy flow from upstream nodes, energy sources and energy conversion elements into node i, is the energy flow distribution in the integrated energy system, The energy provided by the generator set and gas source to the system, is the energy carbon emission intensity vector.

4. The carbon emission accounting method for an integrated energy system considering network interconnection according to claim 3 is characterized in that: The absolute amount of energy flow into node i from upstream nodes, energy sources, and energy conversion elements for: in, represents the energy flow from node i to branch k, Representation and Node i Connected generator set or gas source h to node i Injected energy flow.

5. The carbon emission accounting method for an integrated energy system considering network interconnection according to claim 3 is characterized in that: Energy provided by the generator set and gas source to the system for: in, It represents the energy flow injected into node i by the generator set or gas source h connected to node i, N represents the number of nodes in the integrated energy system, and H represents the number of generator sets and gas sources in the integrated energy system.

6. The carbon emission accounting method for an integrated energy system considering network interconnection according to claim 3 is characterized in that: Energy flow distribution in integrated energy systems for: in, Represents a slave node i Flow to Node j The energy flow of the integrated energy system is represented by N, and N represents the number of nodes in the integrated energy system.

7. The carbon emission accounting method for an integrated energy system considering network interconnection according to claim 1 is characterized in that: Line Energy Loss Matrix for: in, Where, N represents the number of nodes in the integrated energy system.

8. The carbon emission accounting method for an integrated energy system considering network interconnection according to claim 1 is characterized in that: Load distribution matrix for: in, It represents the energy flow obtained by load m connected to node i from node i, N represents the number of nodes in the integrated energy system, and M represents the number of load nodes in the integrated energy system.

9. A carbon emission accounting system for an integrated energy system taking into account network interconnection, characterized in that: include: Building modules to establish mathematical models of carbon emission flows in integrated energy systems; A removal module inputs the integrated energy system information and the operation energy flow results into the mathematical model of the carbon emission flow of the integrated energy system, and removes the nodes in the integrated energy system that are not connected to other nodes; The accounting module generates the branch energy flow matrix, line energy loss matrix, energy injection matrix, load distribution matrix, node energy flow matrix and unit carbon emission intensity vector; The node carbon emission intensity vector is calculated.

10. The carbon emission accounting method for an integrated energy system considering network interconnection according to claim 1 is characterized in that: Mathematical model of carbon emission flows of integrated energy systems including electricity system, natural gas system, heating system and energy conversion elements; In the power system, nodes i Outflow branch j Carbon emission intensity as follows: in, Indicates generator g The carbon emission intensity of the units, and Respectively represent the nodes i A collection of generator sets and energy conversion elements that inject power, Energy conversion element h The carbon emission intensity of Representation Node i The load at In natural gas systems, nodes i Branch carbon intensity of export pipeline as follows: in, represents the carbon emission intensity of the gas source node of the natural gas system, Indicates the carbon emission factor of natural gas In the heating system, the carbon emission factor of the heating pipe for: in, represents the energy flow consumed by the load, Represents a slave node i Hot water flow to the load, Expressed as a service load, the temperature of the hot water is reduced, which can be expressed as a node i The heating temperature and the outflow temperature of the load are calculated; In the energy conversion element, the single input / single output element model is as follows: The single input / multiple output component model is shown below: in, , Indicates the carbon emission intensity at the inlet and outlet of the energy conversion element, represents a virtual load, represents the energy flow into the energy conversion element, , They represent the carbon emission intensity of the CHP connected to the power system and the heating system at the outlet, represents the virtual load of CHP, , represent the conversion coefficients of CHP to electricity and heat, respectively.

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