Comprehensive energy system planning method based on energy flow-carbon flow integrated modeling

Abstract

The present application relates to a comprehensive energy system planning method based on energy flow-carbon flow integrated modeling, comprising the following steps: step one: establishing an energy flow model based on energy hub standardization modeling; step two: establishing a carbon emission flow model based on energy hub standardization modeling; step three: establishing a comprehensive energy system planning model considering economic efficiency and annual total carbon emission of the comprehensive energy system, the present application can effectively analyze the interaction characteristics of energy flow and carbon emission flow of various types of energy, and can more accurately calculate the carbon emission of each energy equipment and the entire comprehensive energy system. The planning method simultaneously considers economic efficiency and annual total carbon emission, which can adjust the selection and capacity planning of energy equipment, and can more accurately analyze the influence of energy producers and consumers on the carbon emission of the comprehensive energy system.

Description

Technical Field

[0001] This invention relates to a comprehensive energy system planning method based on integrated energy flow-carbon flow modeling, and belongs to the field of integrated energy system planning technology for industrial parks. Background Technology

[0002] Integrated energy systems play a crucial role in the energy sector's low-carbon emission reduction efforts, offering advantages in multi-energy complementarity and effectively improving the comprehensive utilization of energy. The planning of integrated energy systems exhibits a "carbon lock-in" effect, with planning results having a long-term impact on carbon emissions in specific regions. In integrated energy system modeling, existing research primarily focuses on energy flow modeling, with limited integration of energy flow and carbon emission flow modeling. Furthermore, in integrated energy system planning, existing research mainly considers capacity allocation under deterministic energy equipment conditions, with less consideration of the impact of stochastic energy equipment selection on planning results. Moreover, the large-scale emergence of energy producers and consumers presents new challenges to traditional carbon emission flow calculation methods based on the energy consumer perspective. Summary of the Invention

[0003] To overcome the shortcomings of existing research, this paper analyzes the interaction characteristics of energy flow and carbon emission flow in a park's integrated energy system under standardized modeling. It considers the energy equipment selection and capacity planning problems of the integrated energy system under unknown energy equipment conditions, and also considers the operation optimization problem of the integrated energy system under carbon emission constraints. A planning method for integrated energy system based on integrated energy flow-carbon flow modeling is proposed.

[0004] The integrated energy system planning method based on integrated energy flow-carbon flow modeling includes the following steps:

[0005] Step 1: Establish an energy flow model based on standardized modeling of energy hubs;

[0006] Step 2: Establish a carbon emission flow model based on standardized modeling of energy hubs;

[0007] Step 3: Establish a comprehensive energy system planning model that takes into account both economic efficiency and the total annual carbon emissions of the comprehensive energy system.

[0008] Step one specifically includes:

[0009] To describe the topological hierarchical structure of the energy hub, an m×n dimensional component mounting matrix X is introduced. m×n :

[0010]

[0011] Where m represents the number of layers in the energy hub, n represents the total number of energy devices, and x mn Indicates the installation status of device n at the m-th layer of the energy hub, x mn=1 indicates that device n is installed on the m-th floor, x mn =0 indicates that device n does not exist on the m-th layer of the energy hub;

[0012] For each time step and for each form of energy, two sets of m×n dimensional matrices are introduced to describe the input and output power of the system components:

[0013]

[0014] in, and Let represent the input power and output power of device n at the m-th layer of the energy hub during time period t, with respect to energy form γ (e = electricity, g = gas, h = heat, c = cold).

[0015] Step two specifically includes:

[0016] The carbon emission flow of energy conversion equipment is subject to the following conservation law: the total carbon flow rate at the input port equals the total carbon flow rate at the output port. The conservation expression for the carbon emission flow of energy conversion equipment is as follows:

[0017]

[0018] in, and These represent the input and output port carbon densities (PCI) of energy conversion device I with respect to energy form γ1, respectively. and This represents the input power and output power of energy conversion device I with respect to energy form γ2;

[0019] For spacer-type connecting elements, the carbon emission flow conservation expression is as follows:

[0020]

[0021] in, and These represent the input and output carbon densities of energy conversion device I with respect to energy form γ, respectively. and This represents the input power and output power of energy conversion device I with respect to energy form γ.

[0022] For an integrated energy system that includes energy storage systems and renewable energy devices, the carbon emission flow is calculated as follows:

[0023] No action: Carbon emissions are zero at this time.

[0024] Charging and discharging: The amount of carbon stored in the energy storage device at this time is as follows:

[0025]

[0026] in, Let be the amount of carbon stored in the i-th energy storage device at time t. Let be the carbon concentration in the i-th energy storage device at time t. Let be the remaining energy in the i-th energy storage device at time t-1. Let be the input power of the i-th energy storage device at time t. Let e ​​be the output power of the i-th energy storage device at time t. j,t Average carbon flux density during charging of energy storage devices, Let be the average carbon flux density in the i-th energy storage device at time t, and Δt be the sampling time interval, which is 1 hour.

[0027] Step three specifically includes:

[0028] The objective function of integrated energy system planning includes the equivalent annual investment cost and the annual operating cost;

[0029] F = min(C) inv +C ope )

[0030] Among them, C inv C is the equivalent annual value investment cost. ope The annual operating cost of the integrated energy system;

[0031] The constraints on the total annual carbon emissions of the integrated energy system are as follows:

[0032]

[0033] in, For the last layer, the nth device corresponds to the carbon emission intensity of the output port of energy form γ. Let M be the energy output of the last layer device n at time t corresponding to energy form γ, and M be a constant.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] This invention can effectively analyze the interaction characteristics of energy flow and carbon emission flow of various energy sources, and can more accurately calculate the carbon emissions of individual energy devices and the entire integrated energy system. The planning method, which simultaneously considers economic efficiency and total annual carbon emissions, allows for adjustments to the selection and capacity planning of energy devices, and enables a more accurate analysis of the impact of energy production and consumption on the carbon emissions of the integrated energy system. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a diagram illustrating the overall architecture of the integrated energy system planning method based on integrated energy flow-carbon flow modeling of this invention.

[0038] Figure 2 This is a schematic diagram of the integrated energy system optimization planning method of the present invention, which takes into account both economic efficiency and the total annual carbon emissions of the integrated energy system.

[0039] Figure 3 This is a schematic diagram of the planning results under scenario 2 of the present invention;

[0040] Figure 4 This is a graph showing the calculated energy flow and carbon flow results under scenario 1 of the present invention;

[0041] Figure 5 This is a graph showing the calculated energy flow and carbon flow results under scenario 2 of this invention;

[0042] Figure 6 This is a graph showing the calculated energy flow and carbon flow results under scenario 3 of the present invention;

[0043] Figure 7 This is a diagram showing the calculated energy flow and carbon flow results under scenario 4 of the present invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] The specific steps of a comprehensive energy system planning method based on integrated energy flow-carbon flow modeling are as follows:

[0046] Step 1: Establish an energy flow model based on standardized modeling of energy hubs;

[0047] Step 2: Establish a carbon emission flow model based on standardized modeling of energy hubs;

[0048] Step 3: Establish a comprehensive energy system planning model that takes into account both economic efficiency and the total annual carbon emissions of the comprehensive energy system.

[0049] Step one specifically includes:

[0050] To describe the topological hierarchical structure of the energy hub, an m×n dimensional component mounting matrix X is introduced. m×n :

[0051]

[0052] Where m represents the number of layers in the energy hub, n represents the total number of energy devices, and x mn Indicates the installation status of device n at the m-th layer of the energy hub, x mn =1 indicates that device n is installed on the m-th floor, x mn =0 indicates that device n does not exist on the m-th layer of the energy hub;

[0053] For each time step and for each form of energy, two sets of m×n dimensional matrices are introduced to describe the input and output power of the system components:

[0054]

[0055] in, and Let represent the input power and output power of device n at the m-th layer of the energy hub during time period t, with respect to energy form γ (e = electricity, g = gas, h = heat, c = cold).

[0056] The integrated energy system based on standardized modeling comprises four units: energy conversion equipment, energy storage equipment, spaced connection elements, and renewable energy equipment.

[0057] Energy flow modeling for energy conversion equipment:

[0058] (1) Cogeneration

[0059]

[0060]

[0061] in, For gas-fired power input in combined heat and power (CHP) These represent the electrical and thermal output power of the combined heat and power (CHP) system, η. e,CHP η h,CHP These refer to the electrical and thermal energy conversion efficiencies of combined heat and power (CHP).

[0062] (2) Heat pump

[0063]

[0064] in, The electrical input power of the heat pump, η is the heat energy output power of the heat pump. h,EHPThis refers to the heat energy conversion efficiency of the heat pump.

[0065] (3) Gas boiler

[0066]

[0067] in, The gas energy input power of the gas boiler, η is the thermal energy output power of the gas boiler. h,AB The thermal energy conversion efficiency of a gas boiler.

[0068] (4) Hot Boiler

[0069]

[0070] in, The electrical input power of the boiler. η is the thermal energy output power of the boiler. h,EB This refers to the thermal energy conversion efficiency of a boiler.

[0071] (5) Electric refrigeration unit

[0072]

[0073] in, The electrical input power of the electric chiller. η is the cooling energy output power of the electric chiller. c,CERG This refers to the energy conversion efficiency of the electric chiller.

[0074] (6) Thermal refrigeration machine

[0075]

[0076] in, The thermal energy input power of the thermal chiller. η is the cooling energy output power of the thermal chiller. c,WARG The energy conversion efficiency of a thermal refrigeration machine.

[0077] The input power constraints of energy conversion equipment can be summarized as follows:

[0078]

[0079] in, Let be the maximum input power of device n at layer m with respect to energy form γ (e = electricity, g = gas, h = heat, c = cold).

[0080] Energy flow modeling of spacer connection elements

[0081] The placeholder connecting element is only for ease of modeling and has no actual physical meaning. Its model can be represented as follows:

[0082]

[0083] in, and Let be the input and output power of device n at layer m with respect to energy form γ.

[0084] Energy storage devices

[0085] For an energy storage element n with energy form γ, its input-output relationship is expressed as follows:

[0086]

[0087] Among them, SOC mn,t This represents the state of charge of energy storage device n located at the m-th layer at time t; and These represent the charging and discharging efficiencies of energy storage device n, respectively; Δt represents the unit time span, which is taken as 1 hour in this paper; C j Let n be the energy storage capacity of the energy storage element.

[0088] The corresponding input and output power constraints of the energy storage devices are as follows:

[0089]

[0090]

[0091] in, and These represent the upper and lower limits of the output power of the energy storage device n with respect to the energy form γ, respectively.

[0092] The state of charge of energy storage devices must satisfy the following constraints:

[0093]

[0094] in, and SOC n The upper and lower limits of the state of charge of the energy storage element n are represented; T is the total number of time periods in a day, which is 24 in this paper.

[0095] Renewable energy equipment

[0096] The output constraints for renewable energy equipment are as follows:

[0097]

[0098] in, Let n be the output power of energy storage device n located on the m-th layer at time t. The maximum possible output power of energy storage device n located on the m-th layer at time t.

[0099] Step two specifically includes:

[0100] Since the carbon emission factor of distributed renewable energy is relatively small, it can usually be represented as 0. Therefore, the components that need to be modeled for carbon emission flows in integrated energy systems include energy conversion devices, spaced connection devices, and energy storage devices.

[0101] Modeling carbon emission flow of energy conversion equipment: The carbon emission flow of energy conversion equipment is subject to the following conservation law: the total carbon flow rate at the input port is equal to the total carbon flow rate at the output port. For energy conversion equipment, its carbon emission flow conservation expression is as follows:

[0102]

[0103] in, and These represent the input and output port carbon densities (PCI) of energy conversion device I with respect to energy form γ1, respectively. and This represents the input power and output power of energy conversion device I with respect to energy form γ2;

[0104] Carbon emission flow modeling for spaced-out connectors: The carbon emission flow conservation expression for spaced-out connectors is as follows:

[0105]

[0106] in, and These represent the input and output carbon densities of energy conversion device I with respect to energy form γ, respectively. and This represents the input power and output power of energy conversion device I with respect to energy form γ.

[0107] Carbon emission flow modeling for energy storage components: The carbon emission flow of an integrated energy system that includes energy storage systems and renewable energy devices is calculated as follows:

[0108] Because integrated energy systems incorporate a large amount of distributed renewable energy, they can be viewed as large-scale energy producers and consumers. From the perspective of energy producers and consumers, calculating the carbon emission flow of energy storage systems is a major challenge in calculating the carbon emission flow of integrated energy systems. The method for calculating the carbon emission flow of an integrated energy system that includes energy storage systems and renewable energy devices is as follows:

[0109] No action: Carbon emissions are zero at this time.

[0110] Charging and discharging: The amount of carbon stored in the energy storage device at this time is as follows:

[0111]

[0112]

[0113] in, Let be the amount of carbon stored in the i-th energy storage device at time t. Let be the carbon concentration in the i-th energy storage device at time t. Let be the remaining energy in the i-th energy storage device at time t-1. Let be the input power of the i-th energy storage device at time t. Let e ​​be the output power of the i-th energy storage device at time t. j,t The average carbon flux density during the charging of energy storage devices, Let be the average carbon flux density in the i-th energy storage device at time t, and Δt be the sampling time interval, which is 1 hour.

[0114]

[0115] in, Let be the remaining energy in the i-th energy storage device at time t. Let η be the output power of the i-th energy storage device at time t. ES,Chr The input efficiency of energy storage devices. Let η be the output power of the i-th energy storage device at time t. ES,Dis This refers to the output efficiency of the energy storage device.

[0116] Step three specifically includes:

[0117] Objective function: The objective function of integrated energy system planning includes the equivalent annual investment cost and the annual operating cost;

[0118] F = min(C) inv +C ope )

[0119] Among them, C inv C is the equivalent annual value investment cost. ope The annual operating cost of the integrated energy system;

[0120] The mathematical expression for the equivalent annual value investment cost is as follows:

[0121]

[0122] Among them, C unit,j Let τ be the unit capacity cost of the j-th device, β be the discount rate, and τ be the cost per unit capacity. j For the lifespan of the j-th device, x mn This represents the installation status of device n on the m-th layer within the energy hub, where 1 indicates installation and 0 indicates non-installation.

[0123] The mathematical expression for the annual operating cost of an integrated energy system is as follows:

[0124]

[0125] Where D is the total number of days in a year, N is the total number of scenes, and p(s) is the probability of scene s occurring. This indicates that the input power of the first-layer device n in the energy hub corresponds to the energy form γ.

[0126] Constraints

[0127] The constraints of integrated energy system planning include investment constraints, operational constraints, and carbon emission constraints.

[0128] Investment constraints:

[0129] Within the energy hub, there are constraints on the number of times each component can be installed:

[0130]

[0131]

[0132] Where, N c N s N r N p It is a collection consisting of energy conversion equipment, energy storage equipment, renewable energy equipment, and spaced connection elements, x mn This represents the installation status of device n on the m-th layer within the energy hub, where 1 indicates installation and 0 indicates non-installation.

[0133] Operational constraints:

[0134] Based on the energy hub model, the operational constraints of the park's integrated energy system are as follows:

[0135] The input power constraints for the energy hub are as follows:

[0136]

[0137] in, P γ,in and These represent the maximum and minimum input power of the energy hub γ, respectively. This represents the total input power of energy γ from all devices in the first layer of the energy hub.

[0138] The power balance constraints within the energy hub are as follows:

[0139]

[0140]

[0141] in, Let γ be the total input power of all devices on the (m+1)th layer of the energy hub at time t. Let γ be the total output power of all devices on the m-th layer of the energy hub at time t. Let γ be the total output power of all devices in the last layer of the energy hub at time t. Let γ be the energy load demand at time t.

[0142] Carbon emission constraints:

[0143] The carbon emission constraints for energy hubs are as follows:

[0144]

[0145]

[0146] in, Let the carbon emission intensity of the input port of the (m+1)th layer device n corresponding to the energy form γ be denoted as . For the (m+1)th layer device n, the input power corresponds to the energy form γ. Let the carbon emission intensity of the output port of the m-th layer device n corresponding to the energy form γ be denoted as . Let n be the output power of the m-th layer device corresponding to energy form γ. For the last layer, the nth device corresponds to the carbon emission intensity of the output port of energy form γ. Let M be the energy output of the last layer device n at time t corresponding to energy form γ, where M is a constant.

[0147] Solving the above model yields the corresponding integrated energy system planning scheme.

[0148] Example 1

[0149] This invention proposes an optimized planning method for an integrated energy system that balances economic efficiency and the total annual carbon emissions of the integrated energy system. The proposed method is applied to an integrated energy system in a certain industrial park. The load types include cooling, heating, and electricity, and the integrated energy system does not contain any energy equipment. The natural gas price is 300 yuan / MWh. Electricity prices are divided into peak, off-peak, and high-peak prices: off-peak price is 378.4 yuan / MWh (22:00-8:00 the next day), peak price is 1206.4 yuan / kWh (13:00-15:00, 19:00-21:00), and high-peak price is 901.4 yuan / MWh. The discount rate is 0.06, and the number of energy hub layers is set to 3. The carbon emission factor for grid electricity is set to 0.581 tCO2 / MWh, the carbon emission factor for natural gas is set to 0.75 tCO2 / MWh, and the initial average carbon emission flux density for energy storage equipment is 0.5 tCO2 / MWh. The economic and physical parameters of each candidate energy equipment are shown in Table 1, and the possible capacity specifications of each candidate energy equipment are shown in Table 2.

[0150] Table 1. Economic and physical parameters of each candidate energy equipment

[0151]

[0152]

[0153] Table 2 Possible capacity specifications for each candidate energy equipment

[0154]

[0155] To illustrate the effectiveness of the method of the present invention, two scenarios are set up for comparison:

[0156] Scenario 1: Without considering carbon emission constraints

[0157] Scenario 2: Considering carbon emission constraints

[0158] The integrated energy system planning schemes under the two scenarios are solved separately, and the relevant economic indicators and carbon emission indicators are compared, as shown in Table 3.

[0159] Table 3 Comparison of relevant indicators under different scenarios

[0160]

[0161]

[0162] To analyze the impact of carbon emission constraints on the planning results, a comparison was made of equivalent annual investment costs, annual operating costs, and total annual carbon emissions. Table 3 shows that compared to the equivalent annual investment costs in Scenario 1, the equivalent annual investment costs in Scenario 2 increased by approximately 10.13%, while the annual operating costs decreased by 0.1977 billion yuan, and total annual carbon emissions decreased by 23.25%. This indicates that Scenario 2, considering carbon emission constraints, allows for more rational utilization of various energy sources and reduces the total annual carbon emissions of the integrated energy system.

[0163] Carbon flow calculation results for different representative scenarios are shown below. Figure 4-7 .

[0164] In summary, the integrated energy flow-carbon flow modeling method can effectively analyze the interaction characteristics of energy flow and carbon emission flow for various energy sources, and can more accurately calculate the carbon emissions of individual energy devices and the entire integrated energy system. The planning method, which simultaneously considers economic efficiency and total annual carbon emissions, allows for adjustments to the selection of energy devices and capacity planning, and can more accurately analyze the impact of energy production and consumption on the carbon emissions of the integrated energy system.

[0165] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A comprehensive energy system planning method based on integrated energy flow-carbon flow modeling, characterized by: Includes the following steps: Step 1: Establish an energy flow model based on standardized modeling of energy hubs; Step one specifically includes: Describe the topological hierarchical structure of the energy hub, and introduce a Dimensional component mounting matrix : in, Indicates the number of layers in the energy hub. Indicates the total number of energy devices. Indicates the energy hub number Layer equipment Installation status, Indicates device Installed in the layer, Indicates the energy hub number Layer does not have devices ; For each moment and each form of energy, two sets are introduced. A 3D matrix describes the input and output power of system components: in, and They represent Time Period Energy Hub Layer equipment Regarding energy forms Input power and output power of (e=electricity, g=gas, h=heat, c=cold); Step 2: Establish a carbon emission flow model based on standardized modeling of energy hubs; Step two specifically includes: The carbon emission flow of energy conversion equipment is subject to the following conservation law: the total carbon flow rate at the input port equals the total carbon flow rate at the output port. The conservation expression for the carbon emission flow of energy conversion equipment is as follows: in, and These represent energy conversion devices. Regarding energy forms The input / output port carbon density PCI; and Indicates energy conversion equipment Regarding energy forms Input power and output power; For spacer-type connecting elements, the carbon emission flow conservation expression is as follows: in, and These represent energy conversion devices. Regarding energy forms The carbon density at the input and output ports; and Indicates energy conversion equipment Regarding energy forms Input power and output power; Step 3: Establish a comprehensive energy system planning model that takes into account both economic efficiency and the total annual carbon emissions of the comprehensive energy system.

2. The integrated energy system planning method based on integrated energy flow-carbon flow modeling according to claim 1, characterized in that: Step three specifically includes: The objective function of integrated energy system planning includes the equivalent annual investment cost and the annual operating cost; in, The cost is the equivalent annual value of the investment. The annual operating cost of the integrated energy system; The constraints on the total annual carbon emissions of the integrated energy system are as follows: in, For the last layer Equipment corresponds to energy form The carbon emission intensity at the output port, For the last layer of equipment exist Time corresponds to energy form Energy output, It is a constant.

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