Carbon emission accounting method based on carbon footprint

Abstract

The invention discloses a carbon footprint-based carbon emission accounting method, which comprises a power grid enterprise total carbon emission accounting method in a preset area, and comprises the following steps: firstly, selecting the preset area as a carbon emission accounting object, setting a power grid enterprise in the preset area, and setting the power grid enterprise in the preset area as a carbon emission accounting object; determining a carbon emission source of the power grid enterprise; then, acquiring power grid enterprise data in the preset area: establishing a carbon emission measurement and calculation model based on the carbon emission source and the power grid enterprise data; and based on the carbon emission measurement and calculation model, calculating the total carbon emission of the power grid enterprise in the preset area. Compared with the prior art, the detailed accounting method for the carbon emission of the preset area and the power grid enterprise is provided. By adopting the method, the carbon emission of the preset region and the power grid enterprises in the region can be accurately calculated, and a scientific basis is provided for making a carbon reduction strategy.

Description

Technical Field

[0001] The present invention belongs to the technical field of carbon emission accounting, and in particular relates to a carbon emission accounting method based on carbon footprint. Background Art

[0002] Based on the purpose of building a new power system and promoting clean and low-carbon energy transformation, building a systematic carbon emission accounting method for a selected region and the power grid companies in the region has become a necessary research topic, which is of great significance and practical application value to the long-term development of the power grid. The carbon emission accounting method lacking in the existing technology is relatively simple and lacks a systematic carbon emission accounting method.

[0003] Therefore, it is necessary to provide a new carbon emission accounting method based on carbon footprint to solve the above technical problems. Summary of the invention

[0004] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and disclose a carbon emission accounting method based on carbon footprint to solve the technical problem in the prior art of lacking a systematic carbon emission accounting method for a selected area and the power grid companies within the area.

[0005] The technical solution adopted by the present invention to solve its technical problem is: a carbon emission accounting method based on carbon footprint, the carbon emission accounting method based on carbon footprint includes a total carbon emission accounting method for power grid enterprises in a preset area, and the total carbon emission accounting method for power grid enterprises in the preset area includes the following steps: first, a preset area is selected as the carbon emission accounting object, and a power grid enterprise is arranged in the preset area, and the carbon emission source of the power grid enterprise is determined; then, the power grid enterprise data in the preset area is obtained: then, based on the carbon emission source and the power grid enterprise data, a carbon emission calculation model is established; based on the carbon emission calculation model, the total carbon emissions of the power grid enterprises in the preset area are calculated.

[0006] Compared with the prior art, the present invention provides a detailed calculation method for carbon emissions in a preset region (such as a selected province) and industry (grid companies). The present invention can accurately calculate the carbon emissions of the preset region and the power grid companies in the region, providing a scientific basis for formulating carbon reduction strategies. Based on future clean energy development goals and changes in energy consumption structure, the present invention can dynamically predict carbon emissions and provide data support for long-term planning. Through carbon emission accounting and result analysis, the present invention can provide strong support for governments and enterprises to make scientific and reasonable carbon reduction decisions, facilitate the construction of a new power system, and promote the clean and low-carbon transformation of energy, which is of great significance and practical application value to the long-term development of the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A flowchart of a carbon emission accounting method based on carbon footprint in a specific embodiment of the present invention;

[0008] Figure 2 A block diagram of a carbon emission accounting method based on carbon footprint in a specific embodiment of the present invention;

[0009] Figure 3 The embodiment of the present invention is: a curve diagram showing the relationship between carbon dioxide emissions from power transmission and distribution in Heilongjiang Province and grid loss and power generation from 2011 to 2023;

[0010] Figure 4 In the embodiment of the present invention: a graph of the total carbon emissions of power grid facilities in Heilongjiang Province from 2019 to 2023;

[0011] Figure 5 In the embodiment of the present invention: a trend chart of carbon emissions in Heilongjiang Province from 2019 to 2022;

[0012] Figure 6 This is a trend chart of carbon emissions from various industries and residents' lives in Heilongjiang Province from 2019 to 2022 in an embodiment of the present invention. DETAILED DESCRIPTION

[0013] The present invention is described in detail below in conjunction with the various embodiments shown in the accompanying drawings, but it should be noted that these embodiments are not limitations of the present invention, and any equivalent transformations or substitutions in functions, methods, or structures made by ordinary technicians in the field based on these embodiments are all within the scope of protection of the present invention.

[0014] The present invention discloses a carbon emission accounting method based on carbon footprint, and the carbon emission accounting method based on carbon footprint includes a total carbon emission accounting method for power grid enterprises in a preset area, and the total carbon emission accounting method for power grid enterprises in the preset area has the following steps: first, a preset area is selected as a carbon emission accounting object, and power grid enterprises are arranged in the preset area, and the carbon emission sources of the power grid enterprises are determined; then, the data of the power grid enterprises in the preset area are obtained; then, a carbon emission calculation model is established based on the carbon emission sources and the power grid enterprise data; based on the carbon emission calculation model, the total carbon emissions of the power grid enterprises in the preset area are calculated.

[0015] According to a specific implementation manner of the present invention, the methods adopted when establishing the carbon emission calculation model include data mining and comparison with the same industry; the power grid enterprise data include: grid loss electricity, proportion of fossil energy power generation and number of substations; the carbon emission calculation model includes: grid facility carbon emission calculation model, building facility carbon emission calculation model and transportation facility carbon emission calculation model; the grid facility carbon emission calculation model consists of a grid loss electricity carbon emission part and a SF6 carbon emission part; the building facility carbon emission calculation model consists of an office building carbon emission part and a substation room carbon emission part; the transportation facility carbon emission calculation model consists of an engineering vehicle part used for operation, maintenance and production and a business vehicle part used for office; the office building carbon emission part consists of the following parts: carbon emissions from purchased natural gas, carbon emissions from purchased heat, carbon emissions from purchased electricity and carbon emissions from air-conditioning refrigerants.

[0016] According to a specific embodiment of the present invention, the preset area is a province, and the carbon emission part of the network loss electricity includes the total carbon dioxide emission E caused by power transmission and distribution. 网损C , E 网损C =AD 网损 ×EF 网损 Where, E 网损C is the total amount of carbon dioxide emissions caused by power transmission and distribution, unit: tCO2e; AD 网损 The power loss in transmission and distribution, unit: MWh; EF 网损 is the carbon emission factor of the power grid, unit: tCO2 / MWh; where: the amount of power loss in transmission and distribution AD 网损 :AD 网损 =EL 供电 -EL 售电 ; In the formula, AD 网损 The power loss in transmission and distribution, unit: MWh; EF 供电 is the power supply, unit: MWh; EL 售电 is the electricity sold, unit: MWh; among which, EL 供电 =EL 上网 +EL 输入 -EL 输出 ; In the formula, EL 上网 The power plant grid-connected electricity, unit: MWh; EL 输入 The electricity imported from other provinces, unit: MWh; EL 输出 The unit is MWh, which is the electricity output to other provinces. The carbon emission factor EF of the power grid is 电网 : The carbon emissions from grid loss are calculated by multiplying the grid loss electricity by the grid carbon emission factor.

[0017] According to a specific embodiment of the present invention, the SF 6 The algorithm for the carbon emission part is as follows:

[0018] In the formula, E SF6 It is the sulfur hexafluoride emission generated during the repair and decommissioning of sulfur hexafluoride equipment, unit: tCO2e; REC 容量,i is the sulfur hexafluoride capacity of retired equipment i, expressed in nameplate data, unit: kg; REC 回收,i is the actual amount of sulfur hexafluoride recovered from retired equipment i, unit: kg; REC 容量,j The sulfur hexafluoride capacity of the repaired equipment j, expressed as nameplate data, unit: kg; REC 回收,j The actual amount of sulfur hexafluoride recovered for repairing equipment j, unit: kg; GWP SF6 is the greenhouse gas potential of sulfur hexafluoride, which is 23,900.

[0019] According to a specific embodiment of the present invention, the carbon emission of the purchased natural gas is part of the carbon emission of the catering gas of the power grid enterprise. 燃气C , E 燃气C =Q 气 × 气 ×h 气 ×β 气 ×44 / 12; where E 燃气C is the carbon emission of gas used in catering by power grid enterprises, unit: tCO2e; Q 气 is the gas consumption, unit: t; r 气 is the average low calorific value of natural gas, which is 38931 kJ / kg; h 气 is the carbon content per unit calorific value, which is 15.32tC / TJ; 气 is the carbon oxidation rate, which is 99%.

[0020] According to a specific embodiment of the present invention, the calculation method of the carbon emissions of purchased heat is as follows: 热力C =AD 热水 ×EF 热 Where, E 热力C is the carbon emission of heat, unit: tCO2e; AD 热水 The heat contained in the purchased heat, unit: GJ; EF 热 The carbon emission factor for heat is 0.11tCO 2 / GJ; of which: purchased heat AD 热水 The calculation method is as follows:

[0021] First, calculate the hot water flow rate based on the heat load, q = (0.86 × Q) / (T 供 -T 回 );where q is the flow rate of hot water, unit: kg / h; Q is the heat load, unit: W, unit: W / m2 The heating index and unit is m 2 The product of the heating area; T 供 、T 回 are the supply and return water temperatures, with values ​​of 52°C and 35°C respectively;

[0022] Then, calculate the hot water quality, the formula is: M W =q×t×10 -3 ; In the formula, M W is the quality of hot water, unit: t; t is the heating time, unit: h;

[0023] Then calculate the heat content of hot water according to its quality, the formula is: AD 热水 =M W ×(T 供 -20)×4.1868×10 -3 ; In the formula, AD 热水 is the heat contained in hot water, unit: GJ; 4.1868 is the specific heat capacity of water at normal temperature and pressure, unit: kJ / (kg·℃).

[0024] According to a specific embodiment of the present invention, the calculation method of carbon emissions from purchased electricity is as follows: 电能C =E 电 ×EF 网损 Where, E 电能C The total amount of carbon dioxide emissions caused by the purchase of electricity, in tons of carbon dioxide; EF 网损 EF is the carbon emission factor of the power grid, unit: tons of carbon dioxide / MWh 网损 = 0.5703 tons of carbon dioxide / MWh; AD 电 The amount of electricity purchased, in megawatt-hours; E 电 =Q 电 ×s 电 ×t 电 Where Q 电 is the electricity load per unit building area, unit: watt / square meter, s 电 is the building area, unit: square meters; t 电 It is the annual electricity consumption time, unit: hour.

[0025] According to a specific embodiment of the present invention, the calculation method of carbon emissions of air-conditioning refrigerant is as follows: In the formula, C 制冷剂 is the carbon emissions generated by the use of refrigerants, unit: tCO2e / y; m r is the refrigerant charge of the equipment, unit: kg / unit; y e is the service life of the equipment, unit: y; GMP r is the global warming potential of refrigerant r.

[0026] According to a specific implementation of the present invention, a fuel vehicle is selected from the transportation facility carbon emission calculation model, and the carbon emission of fuel in transportation of the power grid enterprise is calculated according to the following formula: E 燃油C =Q 油 × 油 ×h 油 ×β 油 ×44 / 12; where E 燃油C The carbon emissions of fuel used in transportation of power grid enterprises; Q 油 is the fuel consumption, unit: ton; r 油 is the average low calorific value of gasoline, h 油 Carbon content per unit calorific value, unit: tC / TJ, β 油 is the carbon oxidation rate.

[0027] According to a specific embodiment of the present invention, the carbon emission accounting method based on carbon footprint also includes a preset regional carbon emission accounting method, and the preset regional carbon emission accounting method is: the preset regional carbon emission is calculated by the following formula:

[0028] In the formula, E CO2-燃烧 Combustion of fossil fuels CO 2 Emissions, in tons CO 2 ; i is the type of fossil fuel; j is the serial number of the combustion facility; AD i,j is the consumption of fossil fuel type i burned in combustion facility j, in tons for solid or liquid fuels and in volume under standard conditions for gaseous fuels. The volume under non-standard conditions needs to be converted to that under standard conditions for calculation; CC i,j is the carbon content of fossil fuel i burned in facility j, expressed in tons of carbon per ton of fuel for solid and liquid fuels and tons of carbon per 10,000 Nm2 for gaseous fuels. 3 Unit: standard coal combustion value is 0.67 tons of carbon / ton; OF i,j is the carbon oxidation rate of fossil fuel i in combustion facility j, dimensionless, ranging from 0 to 1; the carbon oxidation rate of coal is 99%; 44 / 12 is CO 2 Conversion factor to molecular weight of carbon.

[0029] The following is combined with Figure 1-6 , and taking Heilongjiang Province as an example of the preset area, the present invention is further explained.

[0030] like Figure 1 The specific technical solution of the present invention is as follows: A carbon emission accounting method based on carbon footprint comprises the following steps:

[0031] S0. Determine the preset area as Heilongjiang Province, and trace the carbon emissions of power grid companies in Heilongjiang Province.

[0032] According to the official website, Heilongjiang Power Grid Corporation's core business is the construction and operation of the Heilongjiang Power Grid, and its power supply business area covers the entire province. The reporting entity's greenhouse gas emission accounting boundary includes direct emissions and indirect emissions related to its production and business activities. Among them, direct emissions include greenhouse gas emissions generated by fuel combustion and industrial production processes; indirect emissions include greenhouse gas emissions caused by the use of purchased electricity and heat. The emission source analysis of Heilongjiang Power Grid Corporation is shown in Table 1 below.

[0033] Table 1 Analysis of emission sources of Heilongjiang power grid enterprises

[0034]

[0035] The types of greenhouse gases emitted by the reporting entity include CO 2 and SF 6 Sulfur hexafluoride (SF 6 ) gas is widely used in electrical equipment used during power transmission and distribution due to its excellent electrical insulation and arc extinguishing properties, but SF 6 The greenhouse effect of the gas is CO 2 According to the "Guidelines for Calculation and Reporting of Greenhouse Gas Emissions of China's Power Grid Enterprises (Trial)", the use of SF 6 There will also be leakage during the operation of the equipment, but the gas leakage rate is low and difficult to monitor, so this part of the emission is not considered for the time being. 6 Emissions are only calculated using SF 6 Emissions from equipment repair and decommissioning.

[0036] In order to more clearly identify and quantify the carbon emission sources of power grid companies and prevent omissions, this project sorts them out according to the business scope of power grid companies and into three categories: power grid facilities, building facilities, and transportation facilities.

[0037] Carbon emissions from power grid facilities mainly come from emissions caused by transmission and distribution losses, as well as SF 6 Fugitive emissions from equipment during repair and decommissioning.

[0038] (1) Emissions caused by transmission and distribution losses

[0039] Emissions caused by transmission and distribution losses refer to the CO2 emissions generated in the power production process due to power losses caused by resistance loss and corona loss of the lines, no-load loss (iron loss), load loss (copper loss) and stray loss of transformers, and other factors such as insulation leakage during the transmission and distribution of electricity in the power grid. 2 emission.

[0040] (2) SF 6 Fugitive emissions

[0041] Since SF 6 It has excellent arc extinguishing and insulation properties and is widely used in high-voltage switches, transformers, mutual inductors, lightning arresters, inflatable cables, etc. as insulation and arc extinguishing media.

[0042] The carbon emission sources and influencing factors of power grid facilities are shown in Table 2.

[0043] Table 2 Carbon emission sources and influencing factors of power grid facilities

[0044]

[0045] Carbon emissions from building facilities mainly come from office buildings in the power system, corporate canteens, and other buildings such as equipment rooms and duty rooms. The factors affecting carbon emissions refer to the carbon emissions generated during the energy consumption of electricity, heat, gas, etc. in the above buildings. The sources of carbon emissions from building facilities and their influencing factors are shown in Table 3 below.

[0046] Table 3 Carbon emission sources and influencing factors of building facilities

[0047]

[0048] The carbon emission sources of transportation facilities mainly come from the official vehicles and engineering vehicles of enterprises, and the energy involved includes gasoline, diesel, natural gas and electricity. The carbon emission sources and influencing factors of transportation facilities are shown in Table 4.

[0049] Table 4 Carbon emission sources and influencing factors of transportation facilities

[0050]

[0051] S1. Obtain the data of Heilongjiang power grid enterprises, including network loss, proportion of fossil energy power generation, number of substations of various voltage levels, etc.

[0052] S2. Based on carbon footprint, data mining, industry comparison and other methods are used to establish carbon emission calculation models for power grid facilities, building facilities and transportation facilities, such as Figure 2 shown.

[0053] The calculation method of carbon emissions from power grid facilities described in S21 and S2 is: Carbon emissions from power grid facilities = Carbon emissions from grid loss + SF 6 Carbon emissions.

[0054] S22. The carbon emission accounting method for building facilities described in S2 is: carbon emission of building facilities = carbon emission of office buildings + carbon emission of substation buildings.

[0055] The carbon emissions from grid loss electricity mentioned in S211 and S21 include the electricity loss from transmission and distribution and the carbon emission factor of the grid.

[0056] The carbon dioxide generated in the transmission of electric energy mainly comes from the greenhouse gas emissions caused by the power loss on the transmission and distribution lines. The loss is calculated by the power supply and power sales. The specific calculation formula is as follows:

[0057] The emissions generated by power transmission and distribution losses of power grid enterprises are calculated as follows:

[0058] E 网损C =AD 网损 ×EF 网损 (1)

[0059] In the formula, E 网损C is the total amount of carbon dioxide emissions caused by power transmission and distribution (tCO2e); AD 网损 is the amount of electricity lost in transmission and distribution (MWh); EF 网损 is the grid carbon emission factor (tCO2 / MWh).

[0060] S2111, the amount of power AD lost in the power transmission and distribution 网损 :

[0061] AD 网损 =EL 供电 -EL 售电 (2)

[0062] In the formula, AD 网损 is the amount of electricity lost in transmission and distribution (MWh); EF 供电 is the electricity supply (MWh); EL 售电 is the electricity sold (MWh).

[0063] The power supply calculation formula is as follows:

[0064] EL 供电 =EL 上网 +EL 输入 -EL 输出 (3)

[0065] In the formula, EL 上网 EL is the power plant grid-connected electricity (MWh); 输入 is the amount of electricity imported from other provinces (MWh); EL 输出 To export electricity (MWh) to other provinces.

[0066] S2112, the grid carbon emission factor EF 电网: The carbon emissions from grid losses are calculated by multiplying the grid loss electricity by the grid carbon emission factor. When calculating the carbon emissions from grid losses of Heilongjiang power grid enterprises in 2023, the emission factor adopts the 2022 grid-wide carbon emission factor of 0.5703tCO2 / MWh stipulated in the "Notice on Doing a Good Job in Reporting and Verifying Greenhouse Gas Emissions of Some Key Industries from 2023 to 2025" issued by the Ministry of Ecology and Environment in 2023. When calculating the carbon emissions from grid losses of enterprises in 2025 and 2030, considering the changes in the power generation structure caused by the high proportion of new energy access to the grid, the original grid emission factor cannot accurately reflect the carbon emission level of the Heilongjiang power grid. Therefore, the annual fossil energy share is used to correct the regional emission factor.

[0067] According to the "Outline of the 14th Five-Year Plan for National Economic and Social Development of Heilongjiang Province and the Long-Term Goals for 2035" and the "Research Report on China's Carbon Peak before 2030", the development ratio of clean energy in my country is obtained. Heilongjiang Province basically keeps pace with my country's development. It can be seen that the proportion of clean energy power generation will reach 53% and 48% in 2025 and 2030. It is concluded that the grid emission factors in 2025 and 2030 are 0.4820 and 0.4365tCO2 / MWh respectively.

[0068] From 2011 to 2023, the carbon dioxide emissions from power transmission and distribution are calculated based on the power grid loss in Heilongjiang Province and the proportion of fossil energy power generation. The total carbon dioxide emissions from power transmission and distribution in Heilongjiang Province from 2019 to 2023 are shown in Table 5 below.

[0069] Table 5 Total CO2 emissions from power transmission and distribution in Heilongjiang Province from 2011 to 2021

[0070]

[0071] According to the above table, the relationship curve between the carbon dioxide emissions from power transmission and distribution and the grid loss and power generation in Heilongjiang Province from 2019 to 2023 is shown in Figure 3 .

[0072] In summary, in the past five years, the total amount of carbon dioxide emissions from power transmission and distribution in Heilongjiang Province fluctuated greatly in 2021 and 2022. In 2021, the total amount of carbon dioxide emissions from power transmission and distribution rose to 3.4816 million tons, and in 2022, the total amount of carbon dioxide emissions from power transmission and distribution fell to 531,800 tons.

[0073] S212, SF described in S1 6 Carbon emissions: Power grid company SF 6 The scope of accounting for fugitive carbon emissions is to use SF 6 Emissions from equipment repair and decommissioning. 6 The amount of SF is the capacity of the repaired and retired equipment minus the actual recovery amount. 6Fugitive carbon emissions are SF 6 The amount of emissions is multiplied by its greenhouse gas potential (23900). 6 Leakages will also occur during the operation of equipment, but the gas leakage rate is low and difficult to monitor, so the accounting method of power grid companies does not currently take this part of the emissions into account.

[0074]

[0075] In the formula, E SF6 The sulfur hexafluoride emissions (tCO 2 e);REC 容量,i is the sulfur hexafluoride capacity of the retired equipment i, expressed as nameplate data (kg); REC 回收,i is the actual amount of sulfur hexafluoride recovered from the retired equipment i (kg); REC 容量,j The sulfur hexafluoride capacity of repaired equipment j, expressed as nameplate data (kg); REC 回收,j Actual amount of sulfur hexafluoride recovered to repair equipment j (kg); GWP SF6 The greenhouse gas potential of sulfur hexafluoride is 23,900.

[0076] According to the number of substations of various voltage levels in Heilongjiang Power Grid in 2023, the average number of GIS bays per substation of 66kV, 220kV and 500kV and the SF per GIS bay are estimated. 6 The filling volume is calculated based on the annual GIS interval maintenance ratio of 0.5%, and the SF of all substations that need maintenance in Heilongjiang Power Grid in 2023 is calculated. 6 The filling volume is about 33.34 tons. Heilongjiang Power Grid Company needs to overhaul substation SF in 2023 6 The calculation of filling volume is shown in Table 6 below.

[0077] Table 6 SF of substations that need to be overhauled by Heilongjiang power grid enterprises in 2023 6 Filling volume calculation

[0078]

[0079] According to SF 6 The 4% leakage rate during the maintenance process was calculated to be the SF 6 The amount of escape is 1.33 tons, SF 6 Fugitive carbon emissions amounted to 31,900 tons, accounting for approximately 2.02% of grid loss carbon emissions.

[0080] Based on the carbon dioxide emissions from the power loss of Heilongjiang power grid over the years, the SF 6The total carbon dioxide emissions from Heilongjiang power transmission and distribution from 2019 to 2023 are shown in Table 7 below.

[0081] Table 7 Total CO2 emissions from power transmission and distribution in Heilongjiang Province from 2011 to 2023

[0082]

[0083] Total carbon emissions from power grid facilities: Based on grid loss and SF 6 Carbon emissions, the total carbon emissions of Heilongjiang power grid facilities from 2011 to 2023 are shown in Table 8.

[0084] Table 8 Total carbon emissions from power grid facilities in Heilongjiang Province from 2011 to 2023

[0085]

[0086] It can be seen that the total carbon emissions of power grid facilities in Heilongjiang Province from 2011 to 2023 are Figure 4 .

[0087] In summary, the carbon emissions from Heilongjiang power grid facilities fluctuated greatly in the past five years, with a surge and a sharp drop in 2021 and 2022, reaching 3.5518 million tons and 542,500 tons respectively; in the other three years, carbon emissions remained stable, with carbon emissions around 1.5 million tons.

[0088] The carbon emissions of office buildings described in S221 and S22 = carbon emissions from purchased natural gas (gas cookers) + carbon emissions from purchased heat (heating) + carbon emissions from purchased electricity (office) + carbon emissions from refrigerants (air conditioning).

[0089] The carbon emissions of the substation building described in S222 and S22 = carbon emissions of purchased heat (heating) + carbon emissions of purchased electricity (office) + carbon emissions of refrigerants (air conditioning).

[0090] S2211, S221 carbon emission accounting method for purchased gas: In terms of building facilities, the carbon emissions of power grid enterprises mainly come from gas stoves and gas water heaters in the company canteens. Natural gas, as a clean energy, is compared with other fossil energy sources. Its carbon emissions during combustion are relatively small, but not zero. According to the "China Power Generation Enterprise Greenhouse Gas Emissions Accounting Method and Reporting Guide (Trial)", the formula for calculating carbon dioxide emissions from natural gas is as follows:

[0091] E 燃气C =Q 气 × 气 ×h 气 ×β 气 ×44 / 12 (5)

[0092] In the formula, E 燃气C Carbon emissions from catering gas used by power grid enterprises (tCO 2 e); Q 气 is the gas consumption (t); r 气 is the average low calorific value of natural gas, which is 38931 (kJ / kg); h 气 is the carbon content per unit calorific value, which is 15.32 (tC / TJ); 气 is the carbon oxidation rate, which is 99%.

[0093] According to the official website of State Grid Heilongjiang Electric Power Co., Ltd., as of 2019, the total employment of Heilongjiang power grid enterprises was 55,000. According to the data of the seventh national census, compared with the data of the sixth census in 2010, the permanent population of Heilongjiang has decreased by 6.4639 million, a decrease of 16.87%. The average annual growth rate is -1.83%. Taking into account the population loss, the population change of power grid enterprises is estimated, that is, the population in 2023 will be 51,100. Assuming that the dining rate in the enterprise is 70%, the number of diners will be 35,800. The gas consumption per person per day is 0.01m 3 , based on 250 working days per year, the natural gas consumed in catering is about 89,400 cubic meters, or 64.13 tons. According to the gas carbon emission accounting formula, the natural gas carbon emissions of Heilongjiang power grid enterprises are about 138.85 tons.

[0094] Calculation method for carbon emissions from purchased heat described in S2212, S221 and S222: Similar to power loss, carbon emissions from heat of power grid enterprises refer to the carbon dioxide emissions generated by the combustion of fossil fuels in the production process of heat purchased in places such as office buildings and electronic equipment rooms. According to the calculation method of standard DB11 / T1787-2020, the carbon emissions from heat can be obtained as follows:

[0095] E 热力C =AD 热水 ×EF 热 (6)

[0096] In the formula, E 热力C is the carbon emission of heat (tCO 2 e);AD 热水 is the heat content of purchased heat (GJ); EF 热 The carbon emission factor for heat is 0.11tCO 2 / GJ.

[0097] Including: Purchased heat AD 热水 The calculation method is as follows:

[0098] The first step is to calculate the hot water flow rate based on the heat load. The formula is as follows:

[0099] q=(0.86×Q) / (T 供 -T 回 ) (7)

[0100] Where q is the flow rate of hot water (kg / h); Q is the heat load (W), and heating index (W / m 2 ) and heating area (m 2 ) product; T 供 、T 回 They are the supply water and return water temperatures, and their values ​​are 52℃ and 35℃ respectively.

[0101] The second step is to calculate the quality of hot water. The heating period in Heilongjiang Province is from October 20th to April 20th of the following year, a total of 6 months. According to the Heilongjiang Province Urban Heating Regulations, the boiler heating operation time must not be less than 16 hours per day. Therefore, if the heating is 16 hours per day, the total heating time is 2912 hours. The hot water quality is calculated as follows:

[0102] M W =q×t×10 -3 (8)

[0103] Where M W is the mass of hot water (t); t is the heating time (h).

[0104] The third step is to calculate the heat content of hot water according to its quality. The formula is as follows:

[0105] AD 热水 =M W ×(T 供 -20)×4.1868×10 -3 (9)

[0106] In the formula, AD 热水 is the heat contained in hot water (GJ); 4.1868 is the specific heat capacity of water at room temperature and pressure (kJ / (kg·℃)).

[0107] Heilongjiang Power Grid Corporation has 21 departments at its headquarters, directly manages 33 units, employs 55,000 people, owns 97 power office buildings and 873 substations.

[0108] When calculating thermal carbon emissions, it is necessary to count the building area. According to data surveys, the building areas of power supply companies in different regions and at different levels are shown in Table 9.

[0109] Table 9 Survey of building areas of power grids in different regions and levels

[0110]

[0111] According to the survey data of substations of different voltage levels in different regions, it can be seen that due to different status, different scales, different distances from towns, and whether there are resident offices, there are large differences in the building area and ancillary building area. Based on the survey data, the total building area of ​​different power office buildings and substations varies greatly, which is mainly related to the administrative region level of the building, whether it is newly built, and the number of floors above and below the ground. Combined with the survey data, the ground building area of ​​the provincial power building in Heilongjiang Province is 8750m 2 , total construction area 20626m 2 It is estimated that the total construction area of ​​single buildings at the provincial, municipal, district and county levels in Heilongjiang Province is 20,000m 2 、17000m 2 , 8000m 2 The total building area of ​​heating for 550kV, 220kV and 66kV voltage level substations is 620m 2 、309m 2 、215m 2 .

[0112] Combined with the research data of Central South Electric Power Design Institute, the substation building related parameters and values ​​of this project are obtained. The substation related parameters and values ​​are shown in Table 10 below.

[0113] Table 10 Substation related parameters and values

[0114]

[0115] Heilongjiang Province has a total of 12 prefecture-level cities and 1 regional administrative office; there are 67 counties (cities), including 21 county-level cities; there are 908 townships, including 334 townships and 574 towns; there are 407 sub-district offices (as of December 2023).

[0116] Heilongjiang Power Grid Company has 17 provincial, 13 municipal, and 67 district and county office buildings, 24 500kV, 154 220kV, and 695 66kV substations, with a total construction area of ​​1.3089 million m 2 .

[0117] Based on the total building area and number of buildings in Heilongjiang Power Grid, the estimated total building area of ​​Heilongjiang Power Grid is shown in Table 11 below.

[0118] Table 11 Estimated total floor area of ​​Heilongjiang Power Grid office buildings

[0119]

[0120] Table 12 Estimation of total building area of ​​heating supply for Heilongjiang power grid substation

[0121]

[0122] According to the relevant regulations on heating in Heilongjiang Province, the heating area for commercial users, government agencies, enterprises, institutions and social groups is calculated based on the building area of ​​the heat-using buildings. Therefore, the heating area is calculated based on the actual demand area.

[0123] According to the industry standard "Urban Heating Pipeline Design Standard" issued by the Ministry of Housing and Urban-Rural Development, the heating heat index of office buildings is 60-80W / m 2 , this project takes the value of 70W / m 2 According to the heating area estimation of Heilongjiang power companies, the annual heat consumption of Heilongjiang power grid companies in 2023 is 10.12287 million tons. According to the thermal carbon emission formula, the thermal carbon emissions of buildings in Heilongjiang power grid companies are 149,200 tons.

[0124] The carbon emission accounting method for purchased electricity described in S2213, S221 and S222: The total carbon emission from electricity used in building facilities is usually calculated using the following formula.

[0125] E 电能C =E 电 ×EF 网损 (10)

[0126] In the formula, E 电能C The total amount of carbon dioxide emissions caused by the purchase of electricity (tons of carbon dioxide); AD 电 The amount of electricity purchased (MWh); EF 网损 It is the carbon emission factor of the power grid (tons of carbon dioxide / MWh). According to the "Notice on Doing a Good Job in the Management of Greenhouse Gas Emission Reports of Power Generation Enterprises from 2023 to 2025" issued by the Ministry of Ecology and Environment on February 7, 2023, the value is 0.5703 tons of carbon dioxide / MWh.

[0127] E 电 =Q 电 ×s 电 ×t 电 (11)

[0128] In the formula, Q 电 is the electricity load per unit building area (W / m2), s 电 is the building area (square meters), t 电 The electricity consumption time in the whole year is calculated as 250 working days and 10 hours per day, that is, t 电 2500 hours.

[0129] The electricity consumption within power grid enterprises is usually mainly for lighting, air conditioning, computers, and elevators. This part of electricity consumption can be accurately calculated based on the nameplate parameters and the annual and monthly usage profile. In addition, air conditioners have greenhouse gas emissions from refrigerants.

[0130] According to the national standard "Urban Power Planning Specifications", the load index value per unit building area of ​​public buildings mainly depends on the type, function, grade, scale and degree of perfection of the power equipment required to be configured in the public buildings. According to the survey and analysis of the current power consumption status of public buildings in more than 50 cities in my country (as shown in Table 13), the power load per unit area of ​​each type of building is shown in Table 14.

[0131] Table 13 Survey on the current status of electricity consumption in urban public buildings in my country (Unit: W / m 2 )

[0132]

[0133] Table 14 Examples of electricity load in individual public buildings (unit: W / m 2 )

[0134]

[0135] Based on the above public building electricity load, and the administrative office load is lower than the commercial office building, the electricity load per unit building area of ​​the office building of the Heilongjiang power grid enterprise is estimated to be 60W / m 2 According to the electricity carbon emission formula, the carbon emissions from building electricity of power grid enterprises in Heilongjiang Province are 112,000 tons.

[0136] Calculation method for carbon emissions from air conditioning refrigerants in S2214, S221 and S222:

[0137] Greenhouse gas emissions from the use of refrigerants in air-conditioning systems should be calculated as follows:

[0138]

[0139] In the formula, C 制冷剂 The carbon emissions from using refrigerants (tCO 2 e / y); m r is the refrigerant charge of the equipment (kg / unit); e is the equipment service life (y); GMP r is the global warming potential of refrigerant r. See Table 15 for the global warming potential of common types of refrigerants. See Table 16 for the use of market research refrigerants.

[0140] Table 15 Global warming potential of common types of refrigerants

[0141]

[0142] Table 16 Market Research on Refrigerant Usage

[0143]

[0144] Generally speaking, the service life of the compressor is 80,000 hours. If it is operated 24 hours a day, the service life of the central air conditioner is about 9.1 years. If it only works 12 hours a day, the service life is about 18 years. Of course, the central air conditioner components and equipment will also be corroded and dirty, which will affect the cooling effect. Therefore, the general central air conditioner equipment can relatively guarantee its benign operation time of about 12-15 years. e The value is 15y.

[0145] At present, the main types of air conditioning refrigerants used in the Chinese market are R22, R410A and R32, among which R32 accounts for a large proportion. The refrigerant type used in the air conditioning of Heilongjiang power enterprises is set to be R32; the air conditioning cooling power of common office buildings is 3510W, and the cooling area is about 20m 2 According to the greenhouse gas emission formula generated by the use of refrigerants in air-conditioning systems, the carbon emissions generated by air-conditioning refrigerants in Heilongjiang Power Grid Company are 5,919.46 tons.

[0146] After calculation, the annual electricity consumption of Heilongjiang power grid enterprises totaled 196,300 MWh, and the carbon emissions from electricity were 112,000 tons; the carbon emissions generated by the use of refrigerants in the air-conditioning systems of Heilongjiang power grid enterprises were 5,919.46 tons, with a total carbon emissions of 117,900 tons.

[0147] Based on the above calculations, the total carbon emissions of building facilities are calculated as follows:

[0148] E 建筑C =E 电能C +E 燃气C +E 热力C +C 制冷剂 (13)

[0149] Carbon emission accounting of building facilities: Based on the carbon emission accounting results of electricity, gas and heat, the total carbon emission of building facilities of Heilongjiang Power Grid enterprises is. The specific accounting results are shown in Table 17 below.

[0150] Table 17 Statistical table of air conditioning system parameters of power grid enterprise substation

[0151]

[0152] S23. Calculation method of carbon emissions from transportation facilities: For power grid companies and their employees, their transportation facilities mainly include three aspects: engineering vehicles used for operation, maintenance and production, official vehicles used for office work, and employees’ private cars. Among them, employees’ private cars are employees’ private property, not the property of power grid companies, so carbon emissions accounting is not required.

[0153] According to the "Guidelines for Calculating and Reporting Greenhouse Gas Emissions of Power Generation Enterprises in China (Trial)", first calculate the fuel consumption of fuel vehicles:

[0154] W=L×v×t×n×α (14)

[0155] In the formula, L is fuel consumption, which is 0.1 liters / kilometer; v is vehicle speed, which is 40 kilometers / hour; t is driving time, which is 3010 hours; n is the number of fuel vehicles; α is a fixed coefficient, which is 0.2.

[0156] Secondly, the formula for calculating the carbon dioxide emissions of fuel vehicles is as follows:

[0157] E 燃油C =Q 油 × 油 ×h 油 ×β 油 ×44 / 12 (15)

[0158] In the formula, E 燃油C The carbon emissions of fuel used in transportation of power grid enterprises; Q 油 is the fuel consumption (tons); r 油 is the average low calorific value of gasoline, h 油 is the carbon content per unit calorific value (tC / TJ), β 油 is the carbon oxidation rate, and its values ​​are shown in Table 18 below.

[0159] Table 18 Carbon content and carbon oxidation rate of fossil fuels per unit calorific value

[0160]

[0161] Note: (1) The low heating value data is from the China Greenhouse Gas Inventory Study;

[0162] (2) The data on carbon content per unit calorific value and fuel carbon oxidation rate are derived from the “Guidelines for the Compilation of Provincial Greenhouse Gas Inventories (Trial)”.

[0163] The carbon emission sources of transportation facilities of power grid enterprises are mainly engineering vehicles used for operation, maintenance and production and official vehicles used for office work. Assuming that Heilongjiang Power Grid Company has 2,000 gasoline vehicles and 400 diesel vehicles, according to the calculation method of carbon emission factors for gasoline and diesel in the "Guidelines for Greenhouse Gas Emissions Accounting and Reporting of Power Generation Enterprises in China (Trial)", the carbon emission factors of gasoline and diesel after accounting are 2.206tCO2 / m 3 、2.673tCO2 / m 3 The fuel consumption for transportation is the product of the number of motor vehicles, the annual mileage of motor vehicles and the fuel consumption per 100 kilometers of motor vehicles. The gasoline and diesel consumption of Heilongjiang Power Grid Company's transportation facilities in 2023 will be 4816000m 3 、963200m 3 , it is calculated that the carbon emissions of gasoline and diesel of Heilongjiang power grid enterprises are approximately 10,800 and 2,200 tons, totaling 13,100 tons.

[0164] Calculation of total carbon emissions of power grid enterprises: Based on the carbon emissions of power grid enterprises in various dimensions, the total carbon emissions of Heilongjiang power grid enterprises are calculated as shown in Table 19 below.

[0165] Table 19 Carbon emission accounting results of Heilongjiang power grid enterprises

[0166]

[0167] As can be seen from the table above, the total carbon emissions of Heilongjiang enterprises are currently 1.8937 million tons, of which the carbon emissions from power grid facilities account for as high as 85.20%, followed by carbon emissions from building facilities, accounting for 14.11%. Carbon emissions from transportation facilities account for only 0.69%.

[0168] S3. Calculation method of carbon emissions in Heilongjiang Province: The carbon emissions generated by energy consumption in Heilongjiang Province (converted into standard coal) is the total carbon emissions in Heilongjiang Province. According to the "Carbon Dioxide Emission Calculation Method and Data Verification Table" issued by the National Development and Reform Commission, fossil fuel combustion CO 2 Emission calculation method, CO2 from fossil fuel combustion 2 Emissions are based on the fossil fuel combustion of each combustion facility within the enterprise boundary, multiplied by the corresponding fuel carbon content and carbon oxidation rate, and then accumulated layer by layer. The formula is as follows:

[0169]

[0170] In the formula, E CO2-燃烧 Combustion of fossil fuels CO 2 Emissions, in tons CO 2 ; i is the type of fossil fuel; j is the serial number of the combustion facility; AD i,jis the consumption of fossil fuel type i burned in combustion facility j, in tons for solid or liquid fuels and in volume under standard conditions for gaseous fuels (10,000 Nm 3 ) is the unit, and the volume under non-standard conditions must be converted into standard conditions for calculation; CC i,j is the carbon content of fossil fuel i burned in facility j, expressed in tons of carbon per ton of fuel for solid and liquid fuels and tons of carbon per 10,000 Nm2 for gaseous fuels. 3 Unit: standard coal combustion value is 0.67 tons of carbon / ton; OF i,j is the carbon oxidation rate of fossil fuel i in combustion facility j, dimensionless, ranging from 0 to 1; the carbon oxidation rate of coal is 99%; 44 / 12 is CO 2 Conversion factor to molecular weight of carbon (C).

[0171] Total carbon emissions in Heilongjiang Province: According to the statistical yearbook on the official website of the Heilongjiang Provincial Bureau of Statistics, the total energy consumption in Heilongjiang Province from 2019 to 2022 was 116.1389 million tons of standard coal, 115.2506 million tons of standard coal, 121.9165 million tons of standard coal and 120.3500 million tons of standard coal respectively. The carbon emissions of Heilongjiang Province from 2019 to 2022 are calculated according to the carbon emission calculation formula for fossil fuel combustion as shown in Table 20.

[0172] Table 20 Carbon emissions in Heilongjiang Province from 2019 to 2022

[0173]

[0174] According to the carbon emission accounting results of Heilongjiang Province, a trend chart of total energy consumption and total carbon emissions is drawn, such as Figure 5 shown.

[0175] In the past four years, Heilongjiang Province's carbon emissions have fluctuated and shown an upward trend, with an average annual growth rate of 1.19%. By 2022, Heilongjiang Province's total carbon emissions will reach 292.7032 million tons.

[0176] S4. Calculate the carbon emissions of power grid companies: Calculate the total carbon emissions of Heilongjiang power grid companies based on the establishment of carbon emission measurement models for power grid facilities, building facilities, and transportation facilities.

[0177] Table 21 Comprehensive energy balance of various industries in Heilongjiang Province from 2019 to 2022

[0178]

[0179] Carbon emissions from various industries and residents' lives in Heilongjiang Province: Carbon emissions in Heilongjiang Province are analyzed from the perspectives of carbon emissions from three major industries and residents' lives. The three major industries are divided into agriculture, industry and services. According to the statistical yearbook on the official website of the Heilongjiang Provincial Bureau of Statistics, energy consumption data for the three major industries in Heilongjiang Province can be obtained. Among them, the secondary industry consumes the most energy, followed by residents' life consumption and the tertiary industry; the primary industry consumes the least energy. Details of energy consumption in each dimension are shown in Table 21:

[0180] According to the calculation formula of carbon emissions from fossil fuel combustion, the carbon emissions generated by various industries and residents' lives in Heilongjiang Province from 2019 to 2022 were calculated and the trend was shown as follows: Figure 6 .

[0181] Table 22 Carbon emissions from various industries and residents’ lives in Heilongjiang Province from 2019 to 2022

[0182]

[0183] From 2019 to 2022, carbon emissions from various industries and residents' lives in Heilongjiang Province showed a gradual increasing trend. The secondary industry had the largest carbon emissions, with an average annual carbon emissions of more than 15 million tons, accounting for more than 50% of Heilongjiang Province's total carbon emissions; the tertiary industry had the least carbon emissions, accounting for about 5%.

[0184] S5. Based on the carbon emission accounting results and regional development plans, formulate scientific and reasonable carbon reduction strategies, including adjustments to the energy consumption structure, increasing the proportion of clean energy, and transforming energy-saving technologies.

[0185] It should be noted that, in the above implementation, step S0 is a pre-step of step S1.

[0186] The above implementation method is based on carbon footprint and establishes a carbon emission accounting method for power grid facilities, building facilities, and transportation facilities; based on the Heilongjiang power grid enterprise data including grid loss electricity, the proportion of fossil energy power generation, the number of substations of various voltage levels, etc., data mining, comparison with the same industry and other methods are used to establish a carbon emission calculation model for power grid facilities, building facilities, and transportation facilities, and the total carbon emissions in Heilongjiang Province and the carbon emissions of State Grid Heilongjiang Electric Power Co., Ltd. in 2023 are calculated.

[0187] In summary, the present invention solves the problem that detailed accounting methods for specific regions (such as Heilongjiang Province) and specific industries (such as power grid companies) need to be further improved. The present invention can accurately calculate the carbon emissions of Heilongjiang Province and power grid companies, and provide a scientific basis for formulating carbon reduction strategies. Based on future clean energy development goals and changes in energy consumption structure, the present invention can dynamically predict carbon emissions and provide data support for long-term planning. Through carbon emission accounting and result analysis, the present invention can provide strong support for governments and enterprises to make scientific and reasonable carbon reduction decisions.

[0188] The series of detailed descriptions listed above are only specific descriptions of feasible implementation methods of the present invention. They are not intended to limit the scope of protection of the present invention. Any equivalent implementation methods or changes that do not deviate from the technical spirit of the present invention should be included in the scope of protection of the present invention.

[0189] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A carbon emission accounting method based on carbon footprint, characterized in that: The carbon emission accounting method based on carbon footprint includes a total carbon emission accounting method for power grid enterprises in a preset area. The total carbon emission accounting method for power grid enterprises in the preset area has the following steps: first, a preset area is selected as a carbon emission accounting object, and a power grid enterprise is arranged in the preset area, and the carbon emission source of the power grid enterprise is determined; then, the power grid enterprise data in the preset area is obtained; then, a carbon emission calculation model is established based on the carbon emission source and the power grid enterprise data; based on the carbon emission calculation model, the total carbon emissions of the power grid enterprise in the preset area are calculated.

2. The carbon emission accounting method based on carbon footprint according to claim 1 is characterized in that: The methods used to establish the carbon emission calculation model include data mining and comparison with the same industry; The power grid enterprise data include: grid loss electricity, proportion of fossil energy power generation and number of substations; the carbon emission calculation model includes: grid facility carbon emission calculation model, building facility carbon emission calculation model and transportation facility carbon emission calculation model; the grid facility carbon emission calculation model consists of a grid loss electricity carbon emission part and a SF6 carbon emission part; the building facility carbon emission calculation model consists of an office building carbon emission part and a substation room carbon emission part; the transportation facility carbon emission calculation model consists of an engineering vehicle part used for operation, maintenance and production and a business vehicle part used for office work; the office building carbon emission part consists of the following parts: carbon emissions from purchased natural gas, carbon emissions from purchased heat, carbon emissions from purchased electricity and carbon emissions from refrigerants for air conditioning.

3. The carbon emission accounting method based on carbon footprint according to claim 2 is characterized in that: The preset area is a province, and the carbon emission part of the network loss electricity includes the total carbon dioxide emissions caused by power transmission and distribution E 网损C , E 网损C =AD 网损 ×EF 网损 Where, E 网损C is the total amount of carbon dioxide emissions caused by power transmission and distribution, unit: tCO2e; AD 网损 The power loss in transmission and distribution, unit: MWh; EF 网损 is the carbon emission factor of the power grid, unit: tCO2 / MWh; where: the amount of power loss in transmission and distribution AD 网损 :AD 网损 =EL 供电 -EL 售电 ; In the formula, AD 网损 The power loss in transmission and distribution, unit: MWh; EF 供电 is the power supply, unit: MWh; EL 售电 is the electricity sales, unit: MWh; EL 供电 =EL 上网 +EL 输入 -EL 输出 ; In the formula, EL 上网 The power plant grid-connected electricity, unit: MWh; EL 输入 The electricity imported from other provinces, unit: MWh; EL 输出 The unit is MWh, which is the electricity output to other provinces. The carbon emission factor EF of the power grid is 电网 : The carbon emissions from grid loss are calculated by multiplying the grid loss electricity by the grid carbon emission factor.

4. The carbon emission accounting method based on carbon footprint according to claim 3 is characterized in that: The algorithm for the SF6 carbon emission part is as follows: In the formula, E SF6 It is the sulfur hexafluoride emission generated during the repair and decommissioning of sulfur hexafluoride equipment, unit: tCO2e; REC 容量,i is the sulfur hexafluoride capacity of retired equipment i, expressed as nameplate data, unit: kg; REC 回收,i is the actual amount of sulfur hexafluoride recovered from retired equipment i, unit: kg; REC 容量,j The sulfur hexafluoride capacity of the repaired equipment j is expressed as the nameplate data, unit: kg; REC 回收,j The actual amount of sulfur hexafluoride recovered from repairing equipment j, unit: kg; GWP SF6 is the greenhouse gas potential of sulfur hexafluoride, which is 23,900.

5. The carbon emission accounting method based on carbon footprint according to claim 4 is characterized in that: The carbon emissions of purchased natural gas are part of the carbon emissions of gas used in catering by power grid enterprises. 燃气C , E 燃气C =Q 气 × 气 ×h 气 ×β 气 ×44 / 12; where E 燃气C is the carbon emission of gas used in catering by power grid enterprises, unit: tCO2e; Q 气 is the gas consumption, unit: t; r 气 is the average low calorific value of natural gas, which is 38931 kJ / kg; h 气 is the carbon content per unit calorific value, which is 15.32tC / TJ; 气 is the carbon oxidation rate, which is 99%.

6. The carbon emission accounting method based on carbon footprint according to claim 5 is characterized in that: The calculation method of carbon emissions from purchased heat is as follows: 热力C =AD 热水 ×EF 热 Where, E 热力C is the carbon emission of heat, unit: tCO2e; AD 热水 is the heat content of purchased heat, unit: GJ; EF 热 The carbon emission factor for heat is 0.11tCO2 / GJ; among which: purchased heat AD 热水 The calculation method is as follows: First, calculate the hot water flow rate based on the heat load, q = (0.86 × Q) / (T 供 -T 回 );where q is the flow rate of hot water, unit: kg / h; Q is the heat load, unit: W, unit: W / m 2 The heating index and unit is m 2 The product of the heating area; T 供 , T 回 are the supply and return water temperatures, with values ​​of 52°C and 35°C respectively; Then, calculate the hot water quality, the formula is: M W =q×t×10 -3 ; In the formula, M W is the mass of hot water, unit: t; t is the heating time, unit: h; Then calculate the heat content of hot water according to its quality, the formula is: AD 热水 =M W ×(T 供 -20)×4.1868×10 -3 ; In the formula, AD 热水 is the heat contained in hot water, unit: GJ; 4.1868 is the specific heat capacity of water at normal temperature and pressure, unit: kJ / (kg·℃).

7. The carbon emission accounting method based on carbon footprint according to claim 6 is characterized in that: The calculation method of carbon emissions from purchased electricity is as follows: 电能C =E 电 ×EF 网损 Where, E 电能C The total amount of carbon dioxide emissions caused by the purchase of electricity, in tons of carbon dioxide; EF 网损 EF is the carbon emission factor of the power grid, unit: tons of carbon dioxide / MWh 网损 = 0.5703 tons of carbon dioxide / MWh; AD 电 The amount of electricity purchased for use, in megawatt-hours; Where: E 电 =Q 电 ×s 电 ×t 电 Where Q 电 is the electricity load per unit building area, unit: watt / square meter, s 电 is the building area, unit: square meters; t 电 It is the annual electricity consumption time, unit: hour.

8. The carbon emission accounting method based on carbon footprint according to claim 7 is characterized in that: The calculation method of carbon emissions of air-conditioning refrigerants is as follows: In the formula, C 制冷剂 is the carbon emissions from the use of refrigerants, unit: tCO2e / y; m r is the refrigerant charge of the equipment, unit: kg / unit; y e is the service life of the equipment, unit: y; GMP r is the global warming potential of refrigerant r.

9. The carbon emission accounting method based on carbon footprint according to claim 8, characterized in that: Select fuel vehicles from the transportation facility carbon emission calculation model, and calculate the carbon emissions of fuel in the transportation of power grid enterprises according to the following formula; E 燃油C =Q 油 × 油 ×h 油 ×β 油 ×44 / 12; where E 燃油C The carbon emissions of fuel used in transportation of power grid enterprises; Q 油 is the fuel consumption, unit: ton; r 油 is the average low calorific value of gasoline, h 油 Carbon content per unit calorific value, unit: tC / TJ, β 油 is the carbon oxidation rate.

10. The carbon emission accounting method based on carbon footprint according to any one of claims 1 to 9, characterized in that: The carbon emission accounting method based on carbon footprint also includes a preset regional carbon emission accounting method, and the preset regional carbon emission accounting method is: the preset regional carbon emission is calculated by the following formula: In the formula, E CO2-燃烧 is the CO2 emission from fossil fuel combustion, in tons of CO2; i is the type of fossil fuel; j is the combustion facility number; AD i,j is the consumption of fossil fuel type i burned in combustion facility j, in tons for solid or liquid fuels and in volume under standard conditions for gaseous fuels. The volume under non-standard conditions needs to be converted to that under standard conditions for calculation; CC i,j is the carbon content of fossil fuel i burned in facility j, expressed in tons of carbon per ton of fuel for solid and liquid fuels and tons of carbon per 10,000 Nm2 for gaseous fuels. 3 Unit: standard coal combustion value is 0.67 tons of carbon / ton; OF i,j is the carbon oxidation rate of fossil fuel i in combustion facility j, dimensionless, ranging from 0 to 1; the carbon oxidation rate of coal is 99%; 44 / 12 is the molecular weight conversion coefficient of CO2 and carbon.

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