Power load carbon emission calculation method

Abstract

The invention discloses a power load carbon emission calculation method, and belongs to the technical field of power carbon emission calculation. Comprising the following steps: uploading basic data by a power load end, and carrying out energy consumption calculation on each power load system; selecting the most accurate carbon emission factor according to the basic data; and solving the optimal carbon emission factor for various energy sources of the power load system by adopting an improved grey wolf optimization algorithm. Or a main fuel emission factor default value method is adopted to replace a carbon emission factor to participate in calculation. And calculating the total carbon emission by considering the global warming potential value. According to the power load carbon emission calculation method, the power load carbon emission can be calculated by performing data acquisition and calculation on the energy consumption of different power load types and the renewable energy generating capacity and selecting the most accurate carbon emission factor. The method is suitable for calculating the carbon emission of various types of power loads, the calculation method and device are easy to implement, and good practicability is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power carbon emission calculation, and particularly relates to a method for calculating power load carbon emissions. Background Art

[0002] Under the dual-carbon goal, the energy industry is the main battlefield, and the power industry is the main front. The power grid is at the core hub position of the vertical professional management of the power system from generation, transmission, transformation, distribution to use, and also plays an important role in the backbone network and centralized management in the operation of the new power system with flexible interaction among the source, network, load, and storage. It plays an irreplaceable core hub role in promoting the dual-carbon goal. It is necessary to rely on its core position in power supply to analyze power data and other relevant carbon emission data in real time, calculate, monitor, and measure carbon emissions by region, industry, and in real time, lay a solid foundation for the tracking of carbon footprints, and contribute to the realization of the dual-carbon goal. In recent years, the Chinese government has made a series of positive commitments represented by the realization of the "dual-carbon" goal for global climate governance issues, and put forward higher requirements for the allocation of carbon emission responsibilities in various regions of China. At present, there are certain uncertainties in the default values of emission factors involved in carbon emission calculations, and the calculation results may deviate from the actual situation. Therefore, the traditional standard calculation method of carbon emissions is difficult to meet the requirements. Summary of the Invention

[0003] In view of the above existing technical problems, based on the actual operation of the power market and carbon market, the present invention provides a method for calculating power load carbon emissions, which can provide a reliable reference for power carbon emission calculation. In the spatial dimension, different power load systems are divided to avoid the problems of large calculation coverage area, lack of timeliness in carbon intensity management, and failure to consider the development differences of renewable energy power generation types and quantities in different regions; in the time dimension, the present invention calculates by region and time, considering problems such as the time-varying characteristics of renewable energy power generation, and ensuring that the data has no lag.

[0004] The object of the present invention is achieved by the following technical solutions:

[0005] A method for calculating power load carbon emissions of the present invention includes the following steps:

[0006] 1) Determine the power load activity level data: First, define the scope and region of the power load system, define the carbon emission unit process, and collect the activity level data of the carbon emission unit process;

[0007] 2) Data analysis: Classify various energy sources according to the power load type, and determine the power consumption and power generation of each energy source;

[0008] 3) Determine the carbon emission factor corresponding to each energy source;

[0009] Determine the optimal carbon emission factor types for various energy sources in the power load system, and then calculate the most accurate carbon emission factors through calculation, including the average emission factor of the regional power grid, the emission factor calculated based on the emission reduction of new energy power generation, and the default value of the emission factor of the main fuel;

[0010] When the most accurate emission factor cannot be obtained, use the default value of the main fuel emission factor of the calculated power load instead;

[0011] 6) According to the power load activity level data and its optimal carbon emission factor, considering the global warming potential, use the formula in step 5) to calculate the total carbon emissions generated by the activity;

[0012] 7) Power load carbon emissions = ∑ 电力负荷各类能源 Power load activity level data × carbon emission factor / default value of main fuel emission factor × global warming potential value.

[0013] In step 1), clarify the various energy sources required for different power load types, and according to the formula in step 5), calculate the carbon emissions generated by each energy source separately and add them up to obtain the carbon emissions of the power load.

[0014] Furthermore, in step 1), the power load activity level data includes the energy types included in the power load and their installed capacities, and the energy consumption is calculated by drawing the corresponding power load curve, energy consumption curve or through the following formula:

[0015] W y = α av P js T n

[0016] In the formula: α av - Annual average active load factor, P js - Active calculated load; T n - Annual actual working hours.

[0017] Furthermore, in step 1), when the power load contains light load renewable energy, calculate the power generation of the light load through the following formula, where:

[0018] The annual power generation of the photovoltaic system is calculated according to the following formula:

[0019] E pv = IK E (1 - K s )A P

[0020] In the formula: E pv is the annual power generation of the photovoltaic system (kWh); I is the annual solar radiation illuminance on the surface of the photovoltaic cell (kWh / m 2 );KE is the conversion efficiency (%) of the photovoltaic cell; K s is the loss efficiency (%) of the photovoltaic system; A p is the net area of the photovoltaic panel of the photovoltaic system (m 2 );

[0021] Furthermore, in the step 1), when the power load contains wind load renewable energy, the power generation of the wind load is calculated through the following formula:

[0022] The annual power generation of the wind turbine is calculated as follows:

[0023]

[0024] C R (z) = K R ln(z / z0)

[0025] A w = 5D 2 / 4

[0026]

[0027]

[0028] In the formula: E wt is the annual power generation (kWh) of the wind turbine; ρ is the air density, taking 1.225 kg / m 3 ; C R (z) is the roughness coefficient calculated according to the height; K R is the site factor; z0 is the surface roughness coefficient; V0 is the annual available average wind speed (m / s); A w is the windward area of the wind turbine blade (m 2 ); D is the diameter of the wind turbine blade (m); EPF is the factor calculated according to the hourly wind speed in the typical meteorological year data; APD is the annual average energy density (W / m 2 ); V i is the hourly wind speed (m / s); K WT is the conversion efficiency of the wind turbine.

[0029] Furthermore, for the determination of the accurate carbon emission factor in the step 3), first select the most suitable carbon emission factor type for this energy; adopt the improved grey wolf optimization algorithm, which uses a convergence factor that changes according to the cosine law, and at the same time introduces a proportional weight update of the grey wolf position based on the step-size Euclidean distance, so as to accelerate the convergence speed of the algorithm to select the optimal carbon emission factor type; and provide three calculation methods for the emission factor, namely: calculating the regional grid average emission factor according to different power load types, calculating the emission factor according to the new energy power generation emission reduction, and the default value of the main fuel emission factor.

[0030] Furthermore, the specific steps of the improved grey wolf optimization algorithm are as follows:

[0031] Step 1: Set the population size N and the maximum number of iterations t max , and randomly generate parameters such as a, A, and C;

[0032] Step 2: Randomly initialize the grey wolf population within the search space;

[0033] Step 3: Calculate the fitness values of all grey wolf individuals in the population, sort them according to the fitness values, select the top three best wolves, and record their positions X α , X β and X δ ;

[0034] Step 4: Update the positions of other grey wolf individuals in the population through formulas (1), (2), and (3);

[0035]

[0036]

[0037]

[0038] Step 5: Calculate a through formula (4), and then update the values of A and C through formulas (5) and (6);

[0039]

[0040] A = 2a·r1 - a (5)

[0041] C = 2·r2 (6)

[0042] In the formula, assume that the number of grey wolf populations is N, t represents the current number of iterations, the position of the i-th grey wolf is X i , the global optimal solution is α, the sub-optimal solution is β, the third optimal solution is δ, other individuals are ω, W1, W2, and W3 respectively represent the learning rates of ω wolves towards α, β, and δ wolves; a initial and a final are the initial value and the final value of the convergence factor a, take a initial = 2, a final = 0, n is the decreasing exponent, 0 < n ≤ 1; A and C are coefficient vectors, r1 and r2 are both random vectors between [0, 1], and the position D of other grey wolves in the population is jointly determined by the positions of α, β, and δ;

[0043] Step 6: Judge whether the algorithm meets the end condition. If the predetermined maximum number of iterations t max is reached, then stop the calculation and output the optimal position X α, otherwise, repeat steps 3 to 5.

[0044] Further, calculating the average emission factor of its regional power grid according to different types of power loads:

[0045]

[0046] In the formula: EF grid，i : The average CO2 emission factor of regional power grid i, kgCO2 / kWh; Em grid，i : The direct CO2 emissions generated by power generation within the geographical scope covered by regional power grid i, tCO2; EF grid，j : The average CO2 emission factor of regional power grid j that sends net power to regional power grid i, kgCO2 / kWh; E imp，j，i : The amount of power that regional power grid j sends net to regional power grid i, MWh; EF k : The average CO2 emission factor of power generation in country k that exports net power to regional power grid i, kgCO2 / kWh; E imp，k，i : The amount of power that country k exports net to regional power grid i, MWh; E grid，i : The total annual power generation within the geographical scope covered by regional power grid i, MWh; i: One of the regional power grids in Northeast, North China, East China, Central China, Northwest, and South China; j: Other regional power grids that send net power to regional power grid i; k: Other countries that export net power to regional power grid i.

[0047] Further, calculating the emission factor according to the emission reduction amount of new energy power generation:

[0048]

[0049] In the formula: EF grid，OMsimple，y is the simple electricity marginal emission factor OM (tCO2 / MWh) of the power system where the emission reduction project is located in the yth year; EG y is the total net power generation of the power system in the yth year, that is, the total power supplied to the power grid by all other units except for units with low operating costs / must-run units (MWh); FC i，y is the total consumption of fuel i by the above units in the yth year (mass or volume unit); NCV i，y is the average low calorific value of fuel i in the yth year (GJ / mass or volume unit); EF C02，i，y is the CO2 emission factor of fuel i in the yth year (tCO2 / GJ); i is the type of fossil fuel consumed for power generation in the power system in the yth year; y is each year in the most recent three years for which data is available when submitting the project.

[0050] Further, the default value of the main fuel emission factor:

[0051] EFCO2，i，mass = EF CO2，i，beat × HV i

[0052] Wherein: EF CO2，imaxs is the CO2 emission factor of fuel i based on mass or volume; EF CO2，i，beat is the CO2 emission factor of fuel i based on the calorific value of the fuel; HV i is the calorific value of fuel i based on weight or volume;

[0053] Among them, the CO2 emission factor of the fuel based on the calorific value is determined by two factors: the oxidation rate of fuel combustion and the carbon content of the fuel. The formula relationship is as follows:

[0054]

[0055] Wherein: EF CO2，i，beat is the CO2 emission factor of fuel i based on the calorific value of the fuel (tons of CO2 / MJ); OX i is the oxidation rate of fuel i during combustion (%); C i is the carbon content value of fuel i based on the calorific value (grams of carbon / MJ); is the conversion factor between carbon and CO2; 10 -6 is the conversion factor between grams and tons;

[0056] The calorific value HV of the fuel i based on weight or volume i , uses the average low calorific value provided in the China Energy Statistical Yearbook as the default value. When the calorific value of the fuel is not provided in the China Energy Statistical Yearbook, the calorific value of the fuel is calculated by the following formula:

[0057] HV i = CF i，tce × 29307

[0058] Wherein: HV i is the calorific value of the fuel based on weight or volume (MJ / ton or MJ / 10,000 m3); CF i，tce is the reference conversion factor provided for the fuel in the "Report on the Status of Energy Utilization" of key energy-consuming units; if the reference conversion factor is a value range rather than a single value, the median of the conversion factor value range is used as the conversion factor to calculate the calorific value; 29307 is the calorific value of each ton of standard coal (MJ).

[0059] Furthermore, in step 4), the global warming potential value uses the global warming potential value (100 years) of the Second Report of the Intergovernmental Panel on Climate Change in 1995 as the default value, or is selected according to the requirements of the greenhouse gas project participated in. The beneficial effects of the present invention are:

[0060] 1. The present invention provides a carbon emission calculation model based on the energy balance of electric power loads. This model calculates carbon emissions through mathematical equations based on the relationship between energy consumption and carbon emissions, that is, it proposes a tool guide for calculating carbon emissions caused by the energy consumption of different electric power loads, including calculation methods of energy consumption and other contents. These contents can help the electric power industry calculate more efficiently the carbon emissions caused by the energy consumption of different types of electric power loads, and are of great significance for promoting carbon neutrality and energy conservation and emission reduction.

[0061] 2. The present invention uploads basic data from the electric power load side, calculates the energy consumption of each electric power load system. If renewable energy such as wind and solar loads is adopted, the power generation of the renewable energy system needs to be calculated. Select the most accurate carbon emission factor according to the basic data: use the improved grey wolf optimization algorithm to solve the optimal carbon emission factor for various types of energy in the electric power load system. If the exact carbon emission factor still cannot be determined, the present invention proposes a method for calculating the default value of the main fuel emission factor to participate in the calculation instead of the carbon emission factor. According to the above calculation results, considering the global warming potential value, the calculation of the total carbon emissions can be completed. The carbon emission calculation method for electric power loads of the present invention can calculate the carbon emissions of electric power loads by collecting and calculating the energy consumption of different types of electric power loads and the power generation of renewable energy, and selecting the most accurate carbon emission factor. The present invention is applicable to calculating the carbon emissions of various types of electric power loads, and its calculation method and device are simple to implement and have good practicability.

[0062] 3. The present invention can select the most applicable emission factor according to the actual situation of different electric power loads, avoid deviation, and finally calculate the total carbon emissions generated by the activity, which can be customized according to actual needs.

[0063] 4. The present invention aims to implement the sharing of carbon emission responsibilities and contribute to the realization of the national carbon neutrality goal. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a flowchart of a method for calculating the carbon emissions of an electric power load according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0065] The following further illustrates the present invention with reference to the drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the embodiments given are not intended to limit the present invention.

[0066] Embodiment: This example uses a certain iron and steel enterprise as an example to illustrate how to calculate the carbon emissions of electric power loads.

[0067] 1) Determine the activity level data: First, define the scope and area of the power load system, define the carbon emission unit process (including scope and year), and collect the activity level data of the carbon emission unit process (including the types and quantities of energy used in the power load system, such as fuel oil, coal, natural gas, etc.). A certain steel enterprise in Guangdong Province in this embodiment is an industrial power load and used energy such as raw coal, electricity, wind power, and photovoltaic power in 2022. Among them, the purchased raw coal was put into thermal power generation for energy conversion. In addition to self-generated electricity, the enterprise also purchased electricity. The types and quantities of energy used by the steel enterprise can be obtained through the energy utilization status report filled in the energy report system for key energy-consuming units.

[0068] Draw the power load curve and power energy consumption curve according to the basic data or calculate the energy consumption W according to the following formula y :

[0069] W y = α av P js T n

[0070] In the formula: α av - Annual average active load factor. For electricity, it generally takes 0.7 - 0.75; P js - Active calculation load; T n - Annual actual working hours.

[0071] Calculation of renewable energy power generation: This invention mainly considers the power load generated by wind and photovoltaic power, and the calculation method is as follows.

[0072] ① The annual power generation of the photovoltaic system can be calculated according to the following formula:

[0073] E pv = IK E (1 - K s )A P

[0074] In the formula: E pv is the annual power generation of the photovoltaic system (kWh); I is the annual solar irradiance on the surface of the photovoltaic cell (kWh / m 2 ); K E is the conversion efficiency of the photovoltaic cell (%); K s is the loss efficiency of the photovoltaic system (%); A p is the net area of the photovoltaic panel of the photovoltaic system (m 2 ).

[0075] ② The annual power generation of the wind turbine can be calculated according to the following formula:

[0076]

[0077] CR K(z) = K R ln(z / z0)

[0078] A w = 5D 2 / 4

[0079]

[0080]

[0081] Where: E wt is the annual power generation of the wind turbine (kWh); ρ is the air density, taken as 1.225 kg / m 3 ; C R (z) is the roughness coefficient calculated based on height; K R is the site factor; z0 is the surface roughness coefficient; V0 is the annual available average wind speed (m / s); A w is the windward area of the fan blade (m 2 ); D is the diameter of the fan blade (m); EPF is the factor calculated based on the hourly wind speed in the typical meteorological year data; APD is the annual average energy density (W / m 2 ); V i is the hourly wind speed (m / s); K WT is the conversion efficiency of the wind turbine.

[0082] 2) Data analysis: Classify various energy sources according to the type of power load, and determine the power consumption and the power generation of each energy source;

[0083] 3) Determine the carbon emission factor corresponding to each energy source;

[0084] The carbon emission factor refers to the amount of greenhouse gas emissions per unit consumption of a certain energy source, and is an important data required for estimating carbon emissions. Therefore, use the emission factor that best reflects the actual situation of the power load:

[0085] First, determine the type of optimal carbon emission factor for various energy sources in the power load system, which is obtained through the improved grey wolf optimization algorithm (CGWO). This algorithm uses a convergence factor that changes according to the cosine law to balance the global search and local search capabilities of the algorithm. At the same time, it introduces a proportional weight update of the grey wolf position based on the step-length Euclidean distance, thereby accelerating the convergence speed of the algorithm and determining the optimal type of carbon emission factor;

[0086] Then calculate the most accurate carbon emission factors: including the average emission factor of the regional power grid, the emission factor calculated based on the emission reduction of new energy power generation, and the default value of the emission factor of the main fuel;

[0087] When the most accurate emission factor cannot be obtained, the default value of the calculated main fuel emission factor of the power load is used instead;

[0088] The specific steps of the improved grey wolf optimization algorithm (CGWO) are as follows:

[0089] Step 1 Set the population size N and the maximum number of iterations t max , and randomly generate parameters such as a, A, and C;

[0090] Step 2 Randomly initialize the grey wolf population within the search space;

[0091] Step 3 Calculate the fitness values of all grey wolf individuals in the population, sort them according to the fitness values, select the top three best wolves, and record their positions X α , X β and X δ ;

[0092] Step 4 Update the positions of other grey wolf individuals in the population using formulas (1), (2), and (3);

[0093]

[0094]

[0095]

[0096] Step 5 Calculate a using formula (4), and then update the values of A and C using formulas (5) and (6);

[0097]

[0098] A = 2a·r1 - a (5)

[0099] C = 2·r2 (6)

[0100] In the formula, assume the number of grey wolf populations is N, t represents the current number of iterations, the position of the i-th grey wolf is X i , the global optimal solution is α, the sub-optimal solution is β, the third optimal solution is δ, other individuals are ω, W1, W2, and W3 respectively represent the learning rates of ω wolves towards α, β, and δ wolves; a initial and a final are the initial value and the final value of the convergence factor a, take a initial = 2, a final = 0, n is the decreasing exponent, 0 < n ≤ 1; A and C are coefficient vectors, r1 and r2 are both random vectors between [0, 1], and the position D of other grey wolves in the population is jointly determined by the positions of α, β, and δ;

[0101] Step 6 Determine whether the algorithm meets the end condition. If the predetermined maximum number of iterations t is reachedmax , the calculation stops and the optimal position X is output. α , otherwise, steps 3 to 5 are repeatedly executed.

[0102] The present invention calculates the average emission factor of the regional power grid according to different types of power loads. If new energy power generation is adopted, the emission factor needs to be calculated according to the emission reduction amount of new energy power generation. When the most accurate emission factor cannot be obtained, the default value of the emission factor built in the present invention is used, and the province and year of the power load are respectively selected, and each province has different power factors and heat factors. Because the "Report on Energy Utilization Status" of key energy-consuming units requires each power load enterprise to report data, the calculation tool sets options in the selectable years. According to the currently available data, the default emission factor for heat and the default emission factor for power are provided, and the missing emission factor is replaced by the emission factor of the previous year. The following provides the specific calculation formulas for various carbon emission factors and the default values of emission factors:

[0103] ① Average emission factor of the regional power grid:

[0104]

[0105] In the formula: EF grid,i : Average CO2 emission factor of regional power grid i, kgCO2 / kWh; Em grid,i : Direct CO2 emissions generated by power generation within the geographical scope covered by regional power grid i, tCO 2； EF grid,j : Average CO2 emission factor of regional power grid j that net sends out electricity to regional power grid i, kgCO2 / kWh; E imp,j,i : Electricity that regional power grid j net sends out to regional power grid i, MWh; EF k : Average CO2 emission factor of power generation in country k that net exports electricity to regional power grid i, kgCO2 / kWh; E imp,k,i : Electricity that country k net exports to regional power grid i, MWh; E grid,i : Total annual power generation within the geographical scope covered by regional power grid i, MWh; i: One of the regional power grids in Northeast, North China, East China, Central China, Northwest China, and South China; j: Other regional power grids that net send out electricity to regional power grid i; k:

[0106] Other countries that net export electricity to regional power grid i.

[0107] ②Calculating the emission factor based on the emission reduction of new energy power generation: When a new energy power facility generates one degree of electricity, the corresponding carbon emissions reduction is calculated in a rather complex way. Logically speaking, such emission factors can only be applied to calculate the emission reduction of a project when developing a new energy power emission reduction project. The Department of Climate Change Response of the Ministry of Ecology and Environment has studied and determined the baseline emission factors of the China regional power grid for emission reduction projects in 2019. The emission factor calculation methods include the electricity marginal emission factor (OM) and the capacity marginal emission factor (BM), which are calculated based on the total net power generation, fuel type, and total fuel consumption of all power plants (excluding low operating cost / must-run units) in the power system. Among them, in the calculation process of OM, the selection of net power generation, fuel consumption, and fuel parameters follows the conservative principle. In the calculation process of BM, the determination of new unit samples, the power generation of new units, and the selection of the emission factor per unit of electricity follow the conservative principle. Based on the total net power generation, fuel type, and fuel consumption of all power plants (excluding low operating cost / must-run units) in the power system, the formula is as follows:

[0108]

[0109] In the formula: EF grid，OMsimple，y is the simple electricity marginal emission factor OM (tCO2 / MWh) of the power system where the emission reduction project is located in the yth year; EG y is the total net power generation of the power system in the yth year, that is, the total electricity supplied to the power grid by all other units excluding low operating cost / must-run units (MWh); FC i，y is the total consumption of fuel i by the above-mentioned units in the yth year (mass or volume unit); NCV i，y is the average low calorific value of fuel i in the yth year (GJ / mass or volume unit); EF CO2，i，y is the CO2 emission factor of fuel i in the yth year (tCO2 / GJ); i is the type of fossil fuel consumed for power generation in the power system in the yth year; y is each year in the most recent three years for which data can be obtained when submitting the project.

[0110] ③Calculation of the default value of the main fuel emission factor: Emission factors can generally be divided into emission factors based on fuel calorific value and emission factors based on fuel weight or volume. The corresponding relationship between the two is as follows:

[0111] EF CO2，i，mass = EF CO2，i，beat × HV i

[0112] In the formula: EF CO2，i，mass is the CO2 emission factor of fuel i based on mass or volume; EF CO2，i，beat is the CO2 emission factor of fuel i based on fuel calorific value; HV iis the calorific value of fuel i based on weight or volume.

[0113] Among them, the CO2 emission factor of fuel based on calorific value is determined by two factors: the oxidation rate of fuel combustion and the carbon content of the fuel. The formula relationship is as follows:

[0114]

[0115] In the formula: EF CO2，i，beat is the CO2 emission factor of fuel i based on fuel calorific value (tons of CO2 / MJ); OX i is the oxidation rate of fuel i during combustion (%); C i is the carbon content value of fuel i based on calorific value (grams of carbon / MJ); is the conversion factor between carbon and CO2; 10 -6 is the conversion factor between grams and tons.

[0116] The oxidation rate refers to the ratio of carbon in the fuel being oxidized during combustion. Although most of the carbon is emitted in gaseous form during the combustion process of fixed sources, a small part of the carbon will be converted into residual ash, soot or fixed particles. It is generally considered that the remaining carbon will be stored indefinitely. The default value of the oxidation rate is updated according to the reference method in the "Compilation Guide for Provincial Greenhouse Gas Inventories (Trial)" to replace the original value of 100%.

[0117] The fuel carbon content refers to the total carbon content contained in the unit fuel. The physically present carbon in the fuel is the basic chemical principle for generating CO2 during combustion. The fuel carbon content data of the reference method and the sector method are provided respectively in the "Provincial Inventory Guide". For most fuels, the present invention adopts the default carbon content of various fuels to make it unified with the value of the oxidation rate.

[0118] The fuel calorific value refers to the heat released when the fuel burns. The oxidation of carbon in hydrocarbons is the main source of heat during combustion. The calorific value of fuel is divided into the higher heating value and the lower heating value. The higher heating value includes the heat released when the water vapor in combustion condenses into water, while the lower heating value is the heat when the moisture in combustion exists in gaseous form. When calculating CO2 emissions, it is necessary to ensure that the carbon content value of the fuel based on calorific value and the fuel calorific value used have the same heat basis, that is, both are the higher heating value or both are the lower heating value. The present invention adopts the average lower heating value provided in the "China Energy Statistical Yearbook" (hereinafter referred to as the "Energy Yearbook") as the default value. When the calorific value of the fuel is not provided in the "Energy Yearbook", the fuel calorific value is calculated by the following formula:

[0119] HV i =CF i，tce ×29307

[0120] In the formula: HV iis the calorific value of the fuel based on weight or volume (MJ / t or MJ / 10,000 m³); CF i，tce is the reference conversion factor provided for the fuel in the "Energy Utilization Status Report" of key energy-consuming units. If the reference conversion factor is a value range rather than a single value, the median of the conversion factor value range is used as the conversion factor to calculate the calorific value; 29307 is the calorific value of each ton of standard coal (MJ).

[0121] Based on the fuel classification system in the "Energy Utilization Status Report" of key energy-consuming units, the default carbon content value and carbon oxidation rate parameters provided by the reference method in the "Provincial Inventory Guide", the average low calorific value in the "Energy Yearbook", and the reference conversion coefficient in the "Energy Utilization Status Report" of key energy-consuming units, applying the above formula, the default value of the CO2 emission factor of the fuel can be calculated.

[0122] 4) According to the power load activity level data and its optimal solution carbon emission factor, considering the global warming potential, use the following formula to calculate the total carbon emissions generated by the activity;

[0123] Carbon emissions of power load = ∑ 电力负荷各类能源 Power load activity level data × Carbon emission factor / Default value of main fuel emission factor × Global warming potential value.

[0124] Wherein: The global warming potential is to compare different greenhouse gases with carbon dioxide to see their impact on the climate, and is used to calculate the carbon dioxide emission equivalent. Generally, the impact of 1 unit of CO2 on global warming within 100 years is used as the conversion benchmark between different greenhouse gases. With the progress of scientific research on climate change, the global warming potential of greenhouse gases may change. The present invention defaults to using the global warming potential value (100 years) of the Second Report of the Intergovernmental Panel on Climate Change in 1995 as the default value, and other values can also be selected according to the requirements of the greenhouse gas project participated in. The steel enterprise in this embodiment has not participated in any greenhouse gas management projects for the time being, and there are no special reporting requirements for the global warming potential of greenhouse gases, so the default selection is made.

[0125] Since the present invention takes into account the global warming potential, after obtaining the carbon emissions, it can also provide an energy report analysis for the enterprise for reference.

[0126] The above-described embodiments are only preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention. The protection scope of the present invention is subject to the claims.

Claims

1. A method for calculating carbon emissions of electric loads, characterized in that: It includes the following steps: 1) Determine the power load activity level data: First, define the scope and area of the power load system, define the carbon emission unit process, and collect the activity level data of the carbon emission unit process; 2) Data analysis: Classify various types of energy according to the power load type, and determine the power consumption and the power generation of each energy source; 3) Determine the carbon emission factor corresponding to each energy source; Determine the optimal carbon emission factor types for various energy sources in the power load system, and then calculate the most accurate carbon emission factor through calculation, including the regional grid average emission factor, the emission factor calculated based on the new energy power generation emission reduction, and the default value of the main fuel emission factor; When the most accurate emission factor cannot be obtained, use the calculated default value of the main fuel emission factor of the power load instead; 4) According to the power load activity level data and its optimal solution carbon emission factor, considering the global warming potential, use the formula in step 5) to calculate the total carbon emissions generated by the activity; 5) Carbon emissions of power load = ∑ 电力负荷各类能源 Activity level data of power load × Carbon emission factor / Default value of main fuel emission factor × Global warming potential value. In step 1), clarify the various types of energy required for different power load types, and calculate the carbon emissions generated by each type of energy according to the formula in step 5) and add them up to obtain the carbon emissions of the power load.

2. The power load carbon emission calculation method according to claim 1, wherein: In step 1), the power load activity level data includes the energy types included in the power load and their installed capacities, and the power consumption is calculated by drawing the corresponding power load curve, energy consumption curve or through the following formula: W y = α av P js T n Where: α av — Annual average active load factor, P js — Calculated active load; T n — Annual actual working hours.

3. The power load carbon emission calculation method according to claim 1 or 2, characterized in that: In step 1), when the power load contains light load renewable energy, the power generation of the light load is calculated through the following formula, where: The annual power generation of the photovoltaic system is calculated according to the following formula: E pv = IK E (1 - K s )A P Where: E pv is the annual power generation of the PV system (kWh); I is the annual solar irradiance on the surface of the PV cell (kWh / m 2 ); K E is the conversion efficiency of the PV cell (%); K s is the loss efficiency of the PV system (%); A p is the net area of the PV panels of the PV system (m 2 ).

4. The power load carbon emission calculation method according to claim 1 or 2, characterized in that: In step 1), when the power load contains wind load renewable energy, the power generation of the wind load is calculated through the following formula: The annual power generation of the wind turbine is calculated according to the following formula: C R (z) = K R ln(z / z0) A w = 5D 2 / 4 where: E wt is the annual power generation of the wind turbine (kWh); ρ is the air density, taking 1.225 kg / m 3 ; C R (z) is the roughness coefficient calculated based on height; K R is the site factor; z0 is the surface roughness coefficient; V0 is the annual average available wind speed (m / s); A w is the windward area of the fan blade (m 2 ); D is the diameter of the fan blade (m); EPF is the factor calculated based on the hourly wind speed in the typical meteorological year data; APD is the annual average energy density (W / m 2 ); V i is the hourly wind speed (m / s); K WT is the conversion efficiency of the wind turbine generator set.

5. The method for calculating carbon emissions of electric loads according to claim 1, wherein: In step 3), to determine the accurate carbon emission factor, first select the most suitable carbon emission factor type for this energy source; Adopt an improved grey wolf optimization algorithm, which uses a convergence factor that changes according to the cosine law, and at the same time introduces a proportional weight update of the grey wolf position based on the step-size Euclidean distance, so as to accelerate the convergence speed of the algorithm to select the optimal carbon emission factor type; And provide three emission factor calculation methods, namely: calculate its regional grid average emission factor according to different power load types, calculate the emission factor according to the new energy power generation emission reduction, and the default value of the main fuel emission factor.

6. The method for calculating carbon emissions of electric loads according to claim 5, characterized in that: The specific steps of the improved grey wolf optimization algorithm are as follows: Step 1: Set the population size N and the maximum number of iterations t max , and randomly generate parameters such as a, A, and C; Step 2 Randomly initialize the grey wolf population in the search space; Step 3 Calculate the fitness values of all gray wolf individuals in the population, sort them according to the fitness values, select the top three best wolves, and record their positions X α , X β and X δ ; Step 4 Update the positions of other grey wolf individuals in the population through formulas (1), (2) and (3); Step 5 Calculate a through formula (4), and then update the values of A and C through formulas (5) and (6); A = 2a·r1 - a (5) C＝2·r2 (6) Wherein, it is assumed that the number of grey wolf populations is N, t represents the current iteration number, and the position of the i-th grey wolf is X i , the global optimal solution is α, the sub-optimal solution is β, the third optimal solution is δ, and other individuals are ω. W1, W2, and W3 respectively represent the learning rates of ω wolves towards α, β, and δ wolves; a initial and a final are the initial value and the final value of the convergence factor a. Take a initial = 2, a final = 0, n is the decreasing exponent, 0 < n ≤ 1; A and C are coefficient vectors, r1 and r2 are both random vectors between [0, 1], and the position D of other grey wolves in the population is jointly determined by the positions of α, β, and δ; Step 6: Determine whether the algorithm meets the end condition. If the predefined maximum number of iterations t is reached max , stop the calculation and output the optimal position X α , otherwise, repeat steps 3 to 5.

7. The power load carbon emission calculation method according to claim 5, wherein: The calculation of the regional grid average emission factor according to different power load types: Where: EF grid,i : Average CO2 emission factor of regional power grid i, kgCO2 / kWh; Em grid,i : Direct CO2 emissions generated from power generation within the geographical scope covered by regional power grid i, tCO2; EF grid,j : Average CO2 emission factor of regional power grid j that sends net power to regional power grid i, kgCO2 / kWh; E imp,j,i : Net power sent from regional power grid j to regional power grid i, MWh; EF k : Average CO2 emission factor of power generation in country k that exports net power to regional power grid i, kgCO2 / kWh; E imp,k,i : Net power exported from country k to regional power grid i, MWh; E grid,i : Annual total power generation within the geographical scope covered by regional power grid i, MWh; i: One of the regional grids in Northeast, North China, East China, Central China, Northwest and South China; j: Other regional grids that net send electricity to regional grid i; k: Other countries that net export electricity to regional grid i.

8. The power load carbon emission calculation method according to claim 5, wherein: The calculation of the emission factor according to the new energy power generation emission reduction: Where: EF grid,OMsimple,y is the simple electricity marginal emission factor OM (tCO2 / MWh) of the power system where the emission reduction project is located in the y-th year; EG y is the total net electricity generation of the power system in the y-th year, that is, the total electricity supplied to the power grid by all units other than those with low operating costs / must-run units (MWh); FC i,y is the total consumption of fuel i by the above units in the y-th year (mass or volume unit); NCV i,y is the average net calorific value of fuel i in the y-th year (GJ / mass or volume unit); EF CO2,i,y is the CO2 emission factor of fuel i in the y-th year (tCO2 / GJ); i is the type of fossil fuel consumed for power generation in the power system in the y-th year; y is each year in the most recent three years for which data is available when submitting the project.

9. The method for calculating carbon emissions of electric loads according to claim 5, characterized in that: The default value of the main fuel emission factor: EF CO2，i，mass = EF CO2，i，beat × HV i where: EF CO2,i.mass is the CO2 emission factor of fuel i based on mass or volume; EF CO2,i,beat is the CO2 emission factor of fuel i based on the calorific value of the fuel; HV i is the calorific value of fuel i based on weight or volume; Among them, the CO2 emission factor based on the calorific value of the fuel is determined by two factors: the oxidation rate of fuel combustion and the carbon content of the fuel, and the formula relationship is as follows: where: EF CO2,i,beat is the CO2 emission factor of fuel i based on the fuel calorific value (tons of CO2 / MJ); OX i is the oxidation rate of fuel i during combustion (%); C i is the carbon content value of fuel i based on the calorific value (grams of carbon / MJ); is the conversion factor between carbon and CO2; 10 -6 is the conversion factor between grams and tons; The calorific value HV of said fuel i based on weight or volume i , the average net calorific value provided in the China Energy Statistical Yearbook is used as the default value. When the calorific value of the fuel is not provided in the China Energy Statistical Yearbook, the calorific value of the fuel is calculated using the following formula: HV i = CF i，tce × 29307 Where: HV i is the calorific value of the fuel based on weight or volume (MJ / t or MJ / 10,000 m³); CF i，tce is the reference conversion factor provided for the fuel in the "Report on Energy Utilization Status" of key energy-consuming units; if the reference conversion factor is a value range rather than a single value, the median of the conversion factor value range is used as the conversion factor to calculate the calorific value; 29307 is the calorific value of each ton of standard coal (MJ).

10. The power load carbon emission calculation method according to claim 1, wherein: In the said step 4), the global warming potential value uses the global warming potential value (100 years) of the second report of the Intergovernmental Panel on Climate Change in 1995 as the default value, or is selected according to the requirements of the greenhouse gas project participated in.

Images