Transformer full life cycle carbon footprint accounting method under dual-carbon background

Abstract

The invention discloses a transformer full-life-cycle carbon footprint accounting method under a dual-carbon background, and aims to solve the problem that a carbon footprint accounting framework of a current core electrical equipment transformer is imperfect and cannot effectively support an electric power company to carry out low-carbon purchase of material products. Firstly, mainstream carbon footprint accounting schemes at home and abroad are combed, and a classical carbon accounting method and a calculation process are summarized; then, a carbon footprint accounting implementation path and an accounting model of the transformer from'cradle 'to'tomb' are introduced in an emphasized manner, and carbon footprint composition of four high-efficiency common transformers in production, assembly, transportation, use and recovery stages of the state grid Xinjiang electric power limited company is analyzed; and finally, suggestions are provided for the carbon reduction path of the transformer from two aspects of function substitution and technical carbon reduction.

Description

Technical Field

[0001] The present invention relates to the field of carbon footprint accounting for the whole life cycle of transformers, and particularly to a method for carbon footprint accounting for the whole life cycle of transformers under the background of dual carbon goals. Background Art

[0002] As a new economic model, low-carbon economy encompasses production methods, distribution mechanisms, exchange systems, and consumption patterns with low emissions, low energy consumption, and low pollution, and penetrates all aspects of social reproduction. It aims to build a clean and efficient energy structure, promote the effective utilization of energy and resources, and strive to achieve a significant reduction in greenhouse gas emissions, even reaching the ideal state of "zero emissions".

[0003] In the scope of contemporary economic activities, industrial manufactured goods contribute significantly to the total global carbon emissions at every stage of their life cycle, becoming one of the core contributors to this environmental problem. The concept of product carbon footprint comprehensively covers the total amount of greenhouse gases released and potentially removed through technological means during the entire life cycle of a product, starting from raw material extraction, through production, assembly, logistics, daily use, to final recycling and disposal. This indicator is based on carbon dioxide equivalent to measure the specific contribution of a product to global warming. The ways to quantify and reduce product carbon footprint are the research focus of domestic and foreign scholars. Xu Yiming proposed a product carbon footprint accounting method applicable to copper smelting enterprises based on the life cycle method, and analyzed the emission reduction links and optimization paths of copper smelting enterprises. Peng Xin et al. took large-scale refining and chemical integration equipment as the research object, and used process mechanism, industrial big data and artificial intelligence technologies to study the carbon footprint accounting scheme for the entire refining and chemical integration process. Li Chun et al. adopted the life cycle assessment method to construct a carbon footprint accounting model of coal-to-ammonia synthesis from "cradle to gate", and carried out carbon footprint accounting and emission reduction measures analysis based on the production data of domestic coal-to-ammonia synthesis enterprises obtained through research. Wang Haibo et al. proposed energy consumption indicators for battery production and material production links, and initially constructed a management system for the recycling and carbon footprint accounting of waste lithium-ion batteries. Taking the corn production in Shanxi Province as the research object, the dynamic changes and accounting methods of the carbon footprint of corn planting in Shanxi were studied based on the life cycle assessment method, providing a theoretical basis for corn planting in Shanxi Province. Lei Yao et al. deeply analyzed the multiple factors affecting product carbon footprint, and then creatively proposed a static analysis strategy to provide a solid theoretical support and practical methodological framework for accurately evaluating product carbon footprint. The importance of accurate carbon footprint accounting in preventing developed economies from transferring their emissions to other countries through trade. As one of the core electrical equipment, distribution transformers play an important role in ensuring the normal power supply of electrical equipment and the safety and reliability of the power system. Over the years, the procurement volume has been high, making it representative and exemplary for carrying out carbon footprint and low-carbon evaluation work. At present, the exploration of carbon footprint accounting strategies for transformers in China is still insufficient, and the comprehensiveness and depth of the research need to be further strengthened. Among them, some existing technologies effectively calculate the carbon emissions of transformers from "cradle" to "gate", but do not consider the carbon emissions in the transportation, use and recycling stages of transformers.

[0004] On the basis of the in-depth study mentioned above, the primary task of this research is to systematically analyze the detailed process and implementation strategy of carbon footprint accounting for typical transformers. Subsequently, comprehensive collection and detailed analysis of the transformer supply chain data of State Grid Xinjiang Electric Power Co., Ltd. are carried out, and combined with the life cycle assessment technology, the carbon footprints of four typical transformers are quantitatively calculated to ensure the accuracy and reliability of the research results. This not only provides valuable carbon footprint data and accounting samples for State Grid Xinjiang Electric Power Co., Ltd., but also promotes the extensive participation of its entire supply chain, thus stimulating collaborative innovation and continuous progress within the supply chain.

[0005] As an indicator to measure the total carbon emissions, the carbon footprint has gradually become an important standard for evaluating the environmental impacts of individuals, products and enterprises. It covers three levels: individual carbon footprint, product carbon footprint and enterprise carbon footprint, comprehensively reflecting the direct or indirect impacts of human activities on the environment. The individual carbon footprint is defined as the total amount of greenhouse gas emissions accumulated from various activities and behaviors in daily life, including an individual's energy consumption, transportation mode, eating habits and the impacts of other activities on the environment. The product carbon footprint refers to the greenhouse gas emissions generated by a product throughout its life cycle, including direct and indirect emissions, such as energy consumption in the production stage, raw material collection, manufacturing process, transportation, energy consumption in the use stage, and treatment in the waste stage. The enterprise carbon footprint refers to the total amount of greenhouse gas emissions generated by an enterprise during its entire operation process. This includes the direct emissions of the enterprise, such as carbon dioxide emissions generated by the combustion of fuels such as coal and gasoline, and indirect emissions, such as electricity consumption in the production process and transportation emissions in the supply chain. Summary of the Invention

[0006] To solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a method for accounting the carbon footprint of transformers throughout their life cycle under the background of dual carbon.

[0007] To achieve the above purpose, the technical solution of the present invention is as follows:

[0008] The method for accounting the carbon footprint of transformers throughout their life cycle under the background of dual carbon includes the following steps: selecting the transformer model, selecting and screening transformer data, and building a carbon accounting model;

[0009] Step 1: Selecting the transformer model

[0010] Based on the specific requirements and product type preferences of the purchasing party, the transformers are classified according to multiple criteria such as energy efficiency grade, dry-type and oil-immersed classification, capacity specification, anti-pollution ability rating, iron core structure type, operating temperature range, and applicable altitude range. These criteria affect the material composition of the transformer, the energy consumption during the production process, and the final carbon emission footprint. By comprehensively considering the procurement plan in the past three years and the data provided by various manufacturers based on the material code in the extensive market research, four high-performance transformers were finally determined as the key research objects;

[0011]

[0012] Step 2: Selection and Screening of Transformer Data

[0013] When evaluating the carbon footprint of a transformer, on the one hand, it is necessary to collect detailed information covering all activities and material flows within the entire life cycle of the transformer; on the other hand, it is to collect the CO2 equivalent released when quantifying the conversion of unit mass of substances or energy. The process of collecting transformer carbon footprint data mainly includes: raw material acquisition stage, manufacturing and assembly stage, transportation stage, usage stage, recycling and disposal stage. (1) In the raw material acquisition stage of the transformer, it is necessary to systematically collect the specific types of various parts and their corresponding weight data. In addition, the carbon emission coefficients of various materials must be obtained to accurately calculate their carbon footprints in the subsequent life cycle assessment. (2) In the manufacturing and assembly stage of the transformer, it is necessary to record in detail the direct greenhouse gas emissions and related data in this stage, including the energy consumption during the manufacturing process. In addition, the types of energy required and their consumption during the assembly process should also be collected to comprehensively evaluate the overall carbon footprint and provide a scientific basis for optimizing the process and reducing emissions. (3) In the transportation stage, it is necessary to comprehensively collect the transportation distance from the production location to the customer-specified location to evaluate the logistics efficiency; determine the carbon emission factors of the transportation vehicles used to ensure the calculation of greenhouse gas emissions during transportation; record the total mass of the transformers transported to the customer to analyze their overall contribution to the environmental impact. (4) In the usage stage, it is necessary to systematically collect the energy consumption, including the electricity consumption of the transformer during operation, to evaluate its operating efficiency; record the energy emission factors and calculate the corresponding emission coefficients according to different energy sources to quantify the greenhouse gas emissions; collect the direct greenhouse gas emissions to monitor the greenhouse gases such as carbon dioxide released during the use of the transformer and provide an important basis for evaluating its environmental impact. (5) In the recycling and disposal stage, it is necessary to systematically collect the energy consumption during the recycling process, including the use of electricity and other energy sources, to evaluate the energy efficiency of resource recycling; collect the direct greenhouse gas emissions during the recycling process to monitor the greenhouse gas emissions such as carbon dioxide generated during the recycling operation.

[0014] The detailed collection process of transformer carbon footprint data is as follows Figure 3As shown in the figure. The process of collecting transformer carbon footprint data mainly includes: raw material acquisition stage, manufacturing and assembly stage, transportation stage, usage stage, recycling and disposal stage. (1) In the raw material acquisition stage of the transformer, it is necessary to systematically collect the specific types of various parts and their corresponding weight data. In addition, the carbon emission coefficients of various materials must be obtained to accurately calculate their carbon footprints in the subsequent life cycle assessment. (2) In the manufacturing and assembly stage of the transformer, it is necessary to record in detail the direct greenhouse gas emissions and related data in this stage, including the energy consumption in the manufacturing process. In addition, the types of energy required in the assembly process and their consumption amounts should also be collected to comprehensively evaluate the overall carbon footprint and provide a scientific basis for optimizing the process and reducing emissions. (3) In the transportation stage, the transportation distance from the production location to the customer-specified location should be comprehensively collected to evaluate the logistics efficiency; determine the carbon emission factors of the transportation vehicles used to ensure the calculation of greenhouse gas emissions during transportation; record the total mass of the transformers transported to the customers to analyze their overall contribution to the environmental impact. (4) In the usage stage, it is necessary to systematically collect the energy consumption, including the electricity consumption of the transformer during operation, to evaluate its operation efficiency; record the energy emission factors and calculate the corresponding emission coefficients according to different energy sources to quantify the greenhouse gas emissions; collect the direct greenhouse gas emissions and monitor the greenhouse gases such as carbon dioxide released by the transformer during use to provide an important basis for evaluating its environmental impact. (5) In the recycling and disposal stage, it is necessary to systematically collect the energy consumption in the recycling process, including the use of electricity and other energy required, to evaluate the energy efficiency of resource recycling; collect the direct greenhouse gas emissions in the recycling process and monitor the greenhouse gas emissions such as carbon dioxide generated during the recycling operation.

[0015] To pursue the accuracy and reliability of research results, usually the unprocessed raw data is directly used for calculation and analysis.

[0016] Step 3: Establishment of carbon accounting model

[0017] Through comprehensively considering the environmental impact in the transformer manufacturing process, a detailed quantitative analysis of the entire life cycle of the product is carried out;

[0018] 1), Raw material acquisition stage of the transformer

[0019] Suppose in the raw material acquisition stage of the transformer, n kinds of materials and m kinds of energy are required. When the transformer is scrapped and recycled, the recycling of some materials can reduce the carbon emissions of the transformer. Define the raw material utilization rate of the transformer as η ij , and the carbon footprint G M in the raw material acquisition stage of the transformer can be expressed as follows:

[0020]

[0021] In the formula, Mi is the demand for the i-th type of raw material, E j is the demand for the j-th type of energy, MEF i is the production emission coefficient of the i-th type of material, EF j is the production emission coefficient of the j-th type of energy.

[0022] 2), Transformer manufacturing and assembly stage

[0023] Assume that in the production, manufacturing, and assembly process of the transformer, the consumption of n types of energy and the emission of m types of greenhouse gases are involved. The carbon footprint G of this stage P mainly includes energy consumption and greenhouse gas emissions, and can be expressed as:

[0024]

[0025] In the formula, E i is the total energy of the i-th type of energy consumed in the transformer manufacturing and assembly process, O j is the amount of the j-th type of greenhouse gas emitted, EF i is the energy emission coefficient, GWP j is the global warming potential coefficient.

[0026] 3), Transformer transportation stage

[0027] In the consideration of the carbon footprint in the logistics link of the transformer, the decisive factors include the selection of the transportation method, the weight of the transformer, and the transportation distance. The final carbon footprint derived from this stage can be accurately calculated according to Equation (4):

[0028]

[0029] In the formula, Mi is the mass of the transported transformer, Di is the transportation distance, EFi is the carbon emission coefficient of the transportation vehicle for the transformer, and Oi is the direct emission of greenhouse gases.

[0030] 4), Transformer usage stage

[0031] During the operation cycle of the transformer, its carbon footprint G U mainly comes from the consumption of electric energy and the direct release of greenhouse gases. Specifically, the carbon footprint emissions contributed by the consumption of electric energy are closely related to the daily actual electric energy consumption E, the operation duration Tw, and the electricity emission coefficient EF of the region where it is located. These three show a direct positive correlation. Its quantitative expression can be reconstructed as:

[0032]

[0033] 5), Transformer recycling and disposal stage

[0034] In the recycling and disposal process of transformers, the carbon footprint G R is mainly composed of two aspects: material loss and energy consumption. At this stage, it is necessary to deeply analyze how the recycled materials of the disassembled components affect the carbon footprint in the raw material collection, production, and assembly processes, which can be expressed as:

[0035]

[0036] Based on the above analysis, the carbon footprint quantification model of the transformer can be expressed as:

[0037] G = G M + G P + G T + G U + G R (7).

[0038] Compared with the existing technology, the beneficial effects of the present invention are as follows:

[0039] The present invention has significant beneficial effects in the carbon footprint accounting of the transformer's entire life cycle. First of all, the current carbon footprint accounting framework for core electrical equipment is relatively loose, lacking systematicness and practicality, and it is difficult to support power companies in effectively conducting low-carbon procurement. By sorting out the mainstream carbon footprint accounting schemes at home and abroad and summarizing the classic carbon accounting methods, the present invention establishes a more scientific and perfect accounting framework. The implementation of this framework enables power companies to more comprehensively evaluate the carbon emissions of transformers in various stages such as production, transportation, use, and recycling, thereby providing reliable data support for low-carbon procurement. Secondly, the present invention elaborates in detail the implementation path and its model of the carbon footprint accounting of the transformer's entire life cycle. This targeted research not only improves the accuracy of the accounting but also provides practical operation guidance for power enterprises, which can effectively reduce their carbon emissions. Finally, the suggestions put forward from two aspects of functional substitution and technological carbon reduction can guide power companies to pay more attention to the application of low-carbon technologies when purchasing and using transformers, promoting the green transformation of the overall industry. These innovative practices lay the foundation for the sustainable development of the power industry. Description of the Drawings

[0040] Figure 1 Flow chart of transformer carbon footprint accounting;

[0041] Figure 2 Implementation path diagram of transformer carbon footprint accounting;

[0042] Figure 3 Collection and screening of transformer carbon footprint data;

[0043] Figure 4 Composition of the carbon footprint of 10kV oil-immersed transformers;

[0044] Figure 5Carbon footprint composition of 10kV dry-type transformers. Specific implementation manners

[0045] Experimental example: As Figures 1-5 shown: Under the dual-carbon background, the accounting method for the carbon footprint of the transformer throughout its life cycle is as follows:

[0046] The accounting methods of carbon footprint vary according to different evaluation objects and purposes. Currently, the main methods include the input-output method (I-OA) and the life cycle assessment method (LCA), etc. Among them, due to its comprehensiveness and in-depthness, the life cycle assessment method is widely used in the accounting of product carbon footprint. This method starts from the entire life cycle of the product from production, use to disposal, comprehensively considers the carbon emissions in each stage, and ensures the accuracy and integrity of the accounting.

[0047] Input-output method

[0048] As a carbon footprint assessment strategy with a clear structure, I-OA relies on a detailed input-output table framework to accurately track the details of a company's resource inputs and outputs within a specific time span, and further constructs a rigorous mathematical model to quantify and analyze various consumption efficiency factors. This method has extremely strong versatility, widely covering multiple fields such as industrial manufacturing, commodity circulation, commercial operation, residential life, and government operations, and can also extend to the estimation of individual carbon footprints in socio-economic units. The calculation expression is as follows:

[0049] C = c(I - A)'Y(1)

[0050] In the formula, C is the final demand satisfied by each department; Y is the greenhouse gas emissions; c is the direct emission coefficient matrix, representing the amount of greenhouse gas directly emitted per unit of currency output; I is the identity matrix; A is the direct consumption coefficient matrix; Y is the final demand vector of the organization or department.

[0051] Life cycle assessment method

[0052] LCA is a systematic method aimed at quantifying the comprehensive environmental impact of products, services, or production processes. The implementation process is shown in Figure 1 . The LCA method deeply analyzes each stage of the product from "cradle" to "grave", including production, transportation, use, recycling, etc., providing a comprehensive understanding of environmental impacts. In specific practices, LCA usually takes PAS2050:2008 as the criterion.

[0053] Carbon footprint calculation process

[0054] The carbon footprint of the transformer covers the greenhouse gas emissions in all links of the entire life cycle from production to disposal. It reflects the contribution of the transformer to climate change throughout its life cycle. The calculation process is as Figure 1as shown

[0055] The calculation process mainly includes steps such as transformer model selection, carbon accounting model construction, transformer data acquisition and screening, and numerical accounting. (1) In the transformer model selection link, first conduct a detailed data investigation and demand analysis to clarify the specific requirements and technical indicators of the project. This stage includes a comprehensive assessment of user needs, environmental conditions, load characteristics, and future development trends. Secondly, based on the investigation results, select the transformer model, choosing a suitable model and specifications to ensure that its performance, efficiency, and economy meet the project requirements. In addition, the determination of the system boundary is also an important part of this link, clarifying the position and role of the transformer in the entire system to ensure its coordinated operation with other equipment. Through the above steps, the optimal selection of the transformer can be achieved, thereby improving the stability and reliability of the overall system. (2) In the transformer carbon accounting model construction link, first conduct a comprehensive investigation of transformer suppliers. This process involves in-depth analysis of the production capacity, technical level, environmental protection measures of different suppliers, and the carbon emission characteristics of the materials they provide. Secondly, summarize and analyze the information on the material production process. This stage includes sorting and modeling the detailed carbon emission data of the transformer in each link of production, transportation, use, and recycling to identify the main carbon emission sources. Finally, based on the above investigation and analysis results, construct a scientific and reasonable transformer carbon footprint accounting model. (3) In the transformer data acquisition and screening link, first conduct a comprehensive data investigation and integration. This process involves collecting various types of data related to the transformer, including but not limited to production parameters, material properties, operating conditions, and environmental impact factors. Secondly, weigh the feasibility and accuracy of the collected data. By establishing data evaluation criteria, analyze the reliability and applicability of each data source to ensure that the data used can accurately reflect the actual situation of the transformer. (4) In the transformer carbon footprint numerical accounting and result application link, first conduct carbon footprint numerical accounting, based on scientific accounting methods and models, systematically evaluate the greenhouse gas emissions generated by the transformer in each stage of its life cycle (including production, transportation, use, and recycling). Secondly, formulate a specimen of the accounting report, as a standardized document, to record in detail the accounting process, methods, and results for easy review, comparison, and reference. Finally, establish a carbon footprint data accumulation mechanism for typical model transformers, collect and sort out the carbon emission data of different model transformers to promote data sharing and application in the industry.

[0056] Transformer Carbon Footprint Accounting

[0057] Summarize the transformer carbon footprint accounting steps as: transformer model selection, carbon accounting model construction, transformer data selection and screening, numerical accounting, and calculation results and application. The specific implementation path is as Figure 2 shown

[0058] Goal and Scope Determination

[0059] Based on the specific requirements and product type preferences of the purchaser, the transformers are classified according to multiple criteria such as energy efficiency grade, dry-type and oil-immersed classification, capacity specification, anti-pollution ability rating, core structure type, operating temperature range, and applicable altitude range. These criteria affect the material composition of the transformer, the energy consumption during the production process, and the final carbon emission footprint. By comprehensively considering the procurement plans of State Grid Xinjiang Electric Power Co., Ltd. in the past three years and the data provided by various manufacturers based on the material code in the extensive market research, four high-performance transformers are finally determined as the key research objects.

[0060] Table 1 Four High-efficiency Transformers of State Grid Xinjiang Electric Power Co., Ltd.

[0061]

[0062] System Boundary Analysis and Determination

[0063] The whole life cycle of high-performance transformers covers the complete process from resource exploration and mining to component manufacturing, transformer integration and assembly, actual application until final recycling and disposal. Accordingly, the present invention deeply analyzes the operating characteristics of distribution transformers in key links such as manufacturing production, logistics distribution, on-site construction and installation, continuous operation and maintenance, and post-retirement recycling and disposal. At the same time, the definition of the transformer system boundary is clarified, that is, it covers the whole process from its birth to final abandonment.

[0064] Transformer Data Collection and Screening

[0065] When evaluating the carbon footprint of a transformer, on the one hand, it is necessary to collect detailed information covering all activities and material flows throughout the transformer's life cycle; on the other hand, it is to collect data for quantifying the equivalent amount of CO2 released during the conversion of unit mass of substances or energy. The process of collecting transformer carbon footprint data mainly includes: raw material acquisition stage, manufacturing and assembly stage, transportation stage, usage stage, and recycling stage. (1) In the raw material acquisition stage of the transformer, it is necessary to systematically collect the specific types of various parts and their corresponding weight data. In addition, the carbon emission coefficients of various materials must be obtained to accurately calculate their carbon footprints in subsequent life cycle assessments. (2) In the manufacturing and assembly stage of the transformer, it is necessary to detail the direct greenhouse gas emissions and related data in this stage, including the energy consumption during the manufacturing process. In addition, the types of energy required and their consumption amounts during the assembly process should also be collected to comprehensively evaluate the overall carbon footprint and provide a scientific basis for optimizing processes and reducing emissions. (3) In the transportation stage, the transportation distance from the production location to the customer-specified location should be comprehensively collected to evaluate logistics efficiency; determine the carbon emission factors of the transportation vehicles used to ensure the calculation of greenhouse gas emissions during transportation; record the total mass of the transformers transported to the customer to analyze their overall contribution to environmental impact. (4) In the usage stage, it is necessary to systematically collect the energy consumption, including the electricity consumption of the transformer during operation, to evaluate its operating efficiency; record the energy emission factors and calculate the corresponding emission coefficients based on different energy sources to quantify greenhouse gas emissions; collect the direct greenhouse gas emissions and monitor the greenhouse gases such as carbon dioxide released during the use of the transformer to provide an important basis for evaluating its environmental impact. (5) In the recycling stage, it is necessary to systematically collect the energy consumption during the recycling process, including the use of electricity and other energy sources, to evaluate the energy efficiency of resource recycling; collect the direct greenhouse gas emissions during the recycling process and monitor the emissions of greenhouse gases such as carbon dioxide generated during the recycling operation.

[0066] The detailed collection process for transformer carbon footprint data is as Figure 3As shown in the figure. The process of collecting transformer carbon footprint data mainly includes: raw material acquisition stage, manufacturing and assembly stage, transportation stage, usage stage, and recycling and disposal stage. (1) In the raw material acquisition stage of the transformer, it is necessary to systematically collect the specific types of various parts and their corresponding weight data. In addition, the carbon emission coefficients of various materials must be obtained to accurately calculate their carbon footprints in subsequent life cycle assessments. (2) In the manufacturing and assembly stage of the transformer, it is necessary to record in detail the direct greenhouse gas emissions and related data in this stage, including the energy consumption in the manufacturing process. In addition, the types of energy required in the assembly process and their consumption amounts should also be collected to comprehensively evaluate the overall carbon footprint and provide a scientific basis for optimizing processes and reducing emissions. (3) In the transportation stage, it is necessary to comprehensively collect the transportation distance from the production location to the customer-specified location to evaluate logistics efficiency; determine the carbon emission factors of the transportation vehicles used to ensure the calculation of greenhouse gas emissions during transportation; record the total mass of the transformers transported to the customers to analyze their overall contribution to environmental impact. (4) In the usage stage, it is necessary to systematically collect the energy consumption, including the power consumption of the transformer during operation, to evaluate its operating efficiency; record the energy emission factors and calculate the corresponding emission coefficients based on different energy sources to quantify greenhouse gas emissions; collect the direct greenhouse gas emissions and monitor the greenhouse gases such as carbon dioxide released by the transformer during use to provide an important basis for evaluating its environmental impact. (5) In the recycling and disposal stage, it is necessary to systematically collect the energy consumption in the recycling process, including the use of electricity and other energy required, to evaluate the energy efficiency of resource recycling; collect the direct greenhouse gas emissions in the recycling process and monitor the greenhouse gas emissions such as carbon dioxide generated during the recycling operation.

[0067] To pursue the accuracy and reliability of research results, raw and unprocessed data is usually directly used for calculation and analysis.

[0068] Transformer Carbon Footprint Accounting Model

[0069] By comprehensively considering the environmental impacts in the manufacturing process of transformers, the present invention conducts a detailed quantitative analysis of the entire life cycle of the product.

[0070] Transformer Raw Material Acquisition Stage

[0071] Assume that in the raw material acquisition stage of the transformer, n types of materials and m types of energy are required. When the transformer is scrapped and recycled, the recycling of some materials can reduce the carbon emissions of the transformer. Define the raw material utilization rate of the transformer as η ij , the carbon footprint G M in the raw material acquisition stage of the transformer can be expressed as follows:

[0072]

[0073] In the formula, Mi is the demand for the i-th type of raw material, E j is the demand for the j-th type of energy, MEF i is the production emission coefficient of the i-th type of material, EF j is the production emission coefficient of the j-th type of energy.

[0074] Transformer manufacturing and assembly stage

[0075] Assume that in the production, manufacturing, and assembly process of transformers, the consumption of n types of energy and the emission of m types of greenhouse gases are involved. The carbon footprint G of this stage P mainly includes energy consumption and greenhouse gas emissions, and can be expressed as:

[0076]

[0077] In the formula, E i is the total energy of the i-th type of energy consumed in the transformer manufacturing and assembly process, O j is the amount of the j-th type of greenhouse gas emitted, EF i is the energy emission coefficient, GWP j is the global warming potential coefficient.

[0078] Transformer transportation stage

[0079] In the consideration of the carbon footprint in the logistics link of transformers, the decisive factors include the selection of transportation methods, the weight of transformers, and the transportation distance. The final carbon footprint derived from this stage can be accurately calculated according to Equation (4):

[0080]

[0081] In the formula, M i is the mass of the transported transformer, D i is the transportation distance, EF i is the carbon emission coefficient of the transportation vehicle for transporting transformers, O i is the direct emission of greenhouse gases.

[0082] Transformer usage stage

[0083] During the operation cycle of the transformer, its carbon footprint G U is mainly composed of the consumption of electric energy and the direct release of greenhouse gases. Specifically, the carbon footprint emissions contributed by the consumption of electric energy are closely related to the daily actual electric energy consumption E, the operation duration T w and the electricity emission coefficient EF of the region where it is located. These three show a direct positive correlation. Its quantitative expression can be reconstructed as:

[0084]

[0085] Transformer Recycling and Disposal Stage

[0086] In the recycling and disposal process of transformers, the carbon footprint G R is mainly composed of two aspects: material loss and energy consumption. At this stage, it is necessary to deeply analyze how the recycled materials of the disassembled parts affect the carbon footprint in the raw material collection, production, and assembly processes, which can be expressed as:

[0087]

[0088] Based on the above analysis, the carbon footprint quantification model of transformers can be expressed as:

[0089] G = G M + G P + G T + G U + G R (7)

[0090] Transformer Carbon Footprint Analysis

[0091] Oil-Immersed Transformer

[0092] The carbon footprint of the oil-immersed transformer from "cradle" to "gate" was calculated, and the specific composition is as Figure 4 shown. Taking the 10kV oil-immersed transformer as an example, the production processes of copper wire, silicon steel sheet, transformer oil, steel plate, and copper foil are the main carbon emission sources. For 100kVA and 200kVA transformers, their carbon footprints are 3000.29kg CO2e and 5464.07kg CO2e respectively. Compared with the 100kVA transformer, when the capacity is increased to 200kVA, the CO2 emissions generated by copper wire increase significantly to 1639.22kg CO2e, almost doubling compared to the previous level of 810.08kg CO2e; at the same time, the carbon emissions of silicon steel sheets also increase significantly to 1289.49kg CO2e, surging by about 2.9 times compared to the original value of 443.69kg CO2e. This significant change reveals the sharp increase in the demand for copper wire and silicon steel sheets due to the expansion of transformer capacity. Therefore, special attention should be paid to the optimization of these two types of components in the carbon emission reduction strategy. In addition, it is worth noting that the carbon emission contribution of oil-immersed transformers during their production and assembly processes is relatively low, which provides a potential consideration direction for further reducing the overall carbon footprint.

[0093] Next, the carbon footprint inventory of the 10kV oil-immersed transformer in the transportation stage, use stage, and recycling and disposal stage was obtained, as shown in Table 2.

[0094] Table 2 Carbon Footprint Inventory of 10kV Oil-Immersed Transformer in Transportation Stage, Use Stage, and Recycling and Disposal Stage

[0095]

[0096] Through the above analysis and data collection, the carbon footprints of 100 kVA / 10 kV and 200 kVA / 10 kV oil-immersed transformers in each life cycle are shown in Table 3. The total carbon footprints of 100 kVA / 10 kV and 200 kVA / 10 kV transformers are 2.353×10 6 kgCO2e and 4.681×10 6 kgCO2e respectively. By calculating the carbon footprint of 10 kV transformers, it can be seen that in the whole life cycle, the use stage and the transportation stage contribute the most significantly to the carbon footprint of transformers. The main factors affecting carbon emissions in this stage are power consumption, transportation energy mode, and transformer quality, etc.

[0097] Table 3 Carbon footprints of oil-immersed transformers in each life cycle

[0098]

[0099] Dry-type transformer

[0100] The carbon footprint composition of dry-type transformers from "cradle" to "gate" is accounted for as Figure 5 shown. Taking the 10 kV dry-type transformer as an example, the carbon footprints in the raw material acquisition stage and the manufacturing and assembly stage are mainly composed of the carbon emissions of copper wires, silicon steel sheets, copper production processes, and the energy consumption in production and assembly. The carbon footprints of 800 kVA and 1250 kVA transformers are 11,439.63 kg CO 2 e and 16,846.72 kgCO 2 e respectively. Compared with the 800 kVA transformer, after the 1250 kVA transformer increases its capacity, the carbon emissions of silicon steel sheets, energy consumption in production and assembly, and copper foils all increase by nearly 1.6 times. Different from oil-immersed transformers, the change in capacity has little impact on the carbon emissions of copper wires. When comparing oil-immersed transformers with dry-type transformers, it is found that the carbon emissions caused by the energy consumed in the production and assembly process of the latter account for a more significant proportion, reaching about 18%. Therefore, for the carbon emission reduction strategy of dry-type transformers, attention should be focused on the optimization and improvement of their production and assembly processes.

[0101] Next, the carbon footprint inventories of 10 kV dry-type transformers in the transportation stage, use stage, and recycling and treatment stage are obtained as shown in Table 4.

[0102] Table 4 Carbon footprint inventories of 10 kV dry-type transformers in the transportation stage, use stage, and recycling and treatment stage

[0103]

[0104] Through the above analysis and data collection, the carbon footprints of 800 kVA / 10 kV and 1250 kVA / 10 kV dry-type transformers in each life cycle can be calculated as shown in Table 5. The total carbon footprints of 800 kVA / 10 kV and 1250 kVA / 10 kV dry-type transformers are 2.353×10 6 kgCO2e and 4.681×10 6 kgCO2e respectively. By calculating the carbon footprint of 10 kV transformers, in the whole life cycle, the use stage and transportation stage contribute the most significantly to the carbon footprint of transformers. The main factors affecting carbon emissions in this stage are power consumption, transportation energy mode and transformer quality, etc.

[0105] Table 5 Carbon Footprints of Dry-Type Transformers in Each Life Cycle

[0106]

[0107] Analysis of Carbon Emission Reduction Paths for Transformers

[0108] Energy Supply Substitution

[0109] Optimize the site near the transformer, develop new energy such as wind and solar power on the building roof and green space to maintain the normal operation of the transformer, which can realize the substitution of clean energy for the electricity consumption of the transformer and reduce carbon emissions. Considering the volatility and intermittency of new energy power generation, it is estimated that the average annual carbon emission reduction of the transformer power supply facilities in State Grid Xinjiang Electric Power Co., Ltd. after being replaced by clean power is 60 tons, and the carbon emission can be reduced by 1500 tons in 30 years of the whole life cycle. At the same time, green plants can also be planted around the transformer to achieve "carbon neutrality" of the transformer. At the same time, high-efficiency transformers have less loss during the power transmission process, can reduce the waste of electric energy, improve the energy efficiency of the system. By selecting high-efficiency transformers, energy consumption can be reduced and carbon emissions can be reduced.

[0110] Carbon Emission Reduction by Technology

[0111] (1) Use natural ester oil transformers

[0112] Natural ester oil transformers are transformers containing environmentally friendly insulating media. Natural ester oil is completely biodegradable and has less impact on the environment. Compared with traditional mineral oil, natural ester oil will not pollute the soil and water sources and has better environmental protection. Moreover, natural ester oil has high insulation performance, can effectively prevent electric leakage and short circuit of electrical equipment, protect the safe operation of the equipment, and has reliable insulation performance. And as a kind of renewable energy, the carbon emissions in the production and use process of natural ester oil are relatively low. Using natural ester oil transformers can effectively reduce carbon emissions during the operation of transformers and meet the requirements of low-carbon environmental protection.

[0113] (2) Intelligent Monitoring and Management System

[0114] Introduce an intelligent monitoring system and a remote management platform to monitor the operating status and performance parameters of the transformer in real time. The intelligent monitoring system can achieve remote monitoring, fault diagnosis and prediction of the transformer, optimize the operation strategy, reduce energy consumption and carbon emissions. Through data analysis and intelligent algorithms, the operating parameters of the transformer are adjusted in a timely manner to improve the operating efficiency and reduce carbon emissions.

[0115] The present invention deeply sorts out the carbon footprint accounting methods and models of existing products, mainly describes the research status and implementation path of product carbon footprint accounting, and proposes a more applicable transformer carbon footprint accounting scheme and a transformer carbon reduction path for distribution network transformers, supporting the construction of a green modern digital and intelligent supply chain of State Grid Xinjiang Electric Power Co., Ltd.

[0116] As mentioned above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any change or replacement that is thought of without creative labor should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope defined by the claims.

Claims

1. The carbon footprint accounting method for transformers throughout their life cycle under the dual carbon background is characterized by: The steps are: transformer model selection, transformer data selection and screening, and carbon accounting model construction; Step 1: Transformer model selection Based on the specific needs and product type preferences of the purchaser, transformers were classified according to energy efficiency level, dry and oil-immersed classification, capacity specification, anti-pollution rating, core structure type, operating temperature range and applicable altitude range; four high-performance transformers were finally determined as the research objects. Step 2: Transformer data selection and screening When evaluating the carbon footprint of a transformer, on the one hand, it is necessary to collect information covering the activities and material flows during the entire life cycle of the transformer; on the other hand, it is necessary to collect information used to quantify the CO2 equivalent released when a unit mass of material or energy is converted; directly use unprocessed raw data for calculation and analysis; Step 3: Carbon accounting model construction By comprehensively considering the environmental impact of the transformer manufacturing process, a detailed quantitative analysis of the entire life cycle of the product was conducted; 1) Transformer raw material acquisition stage Assume that in the raw material acquisition stage of the transformer, n materials and m energy sources are required; When the transformer is scrapped and recycled, the recycling of some materials can reduce the carbon emissions of the transformer; the raw material utilization rate of the transformer is defined as η ij , the carbon footprint of transformer raw material acquisition stage G M It can be expressed as follows: Where M i is the demand for the i-th type of raw materials, E j is the energy demand of the jth category, MEF i is the production emission factor of the i-th type of material, EF j is the emission factor for the jth type of energy production; 2) Transformer manufacturing and assembly stage Assume that the production and assembly of transformers involves the consumption of n types of energy and the emission of m types of greenhouse gases; the carbon footprint of this stage is G P It mainly includes energy consumption and greenhouse gas emissions, which can be expressed as: In the formula, E i is the total energy of the i-th energy consumed in the transformer manufacturing and assembly process, O j is the amount of greenhouse gas emitted by the jth type, EF i is the energy emission factor, GWP j is the global warming potential; 3) Transformer transportation stage In the consideration of the carbon footprint of transformer logistics, the decisive factors include the choice of transportation mode, the focus of the transformer and the transportation distance. The final carbon footprint derived from this stage can be accurately calculated according to formula (4): Where M i is the mass of the transformer being transported, D i is the transport distance, EF i is the carbon emission coefficient of the transformer transported by vehicles, O i is the direct greenhouse gas emissions; 4) Transformer use stage During the transformer's operating life, its carbon footprint G U The core composition of is derived from the consumption of electricity and the direct release of greenhouse gases; specifically, the carbon footprint emissions contributed by electricity consumption are closely related to the actual daily electricity consumption E and the operating time T. w and the electricity emission factor EF of the region, the three show a direct positive correlation; their quantitative expression can be reconstructed as: 5) Transformer recycling and processing stage In the recycling and disposal of transformers, the carbon footprint G R The composition mainly covers two aspects: material loss and energy consumption. At this stage, it is necessary to deeply analyze how the recycled materials of disassembled parts affect the carbon footprint of raw material collection, production and assembly, which can be expressed as: From the above analysis, the carbon footprint quantification model of the transformer can be expressed as: G=G M +G P +G T +G U +G R (7)。 2. The method according to claim 1, characterized in that: The transformer data selection process mainly includes: raw material acquisition stage, manufacturing and assembly stage, transportation stage, use stage, and recycling stage; (1) In the raw material acquisition stage of the transformer, the specific types of various parts and their corresponding weight data must be systematically collected; in addition, the carbon emission coefficients of various materials must be obtained in order to accurately calculate their carbon footprints in subsequent life cycle assessments; (2) In the manufacturing and assembly stage of the transformer, the direct greenhouse gas emissions and related data of this stage must be recorded in detail, including the energy consumption in the manufacturing process; in addition, the types of energy required in the assembly process and their consumption should be collected to comprehensively evaluate the overall carbon footprint and provide a scientific basis for optimizing the process and reducing emissions; (3) In the transportation stage, the transportation distance from the production site to the customer's designated location should be comprehensively collected to evaluate the logistics efficiency; determine the carbon footprint of the means of transportation used; Emission factors should be collected to ensure that greenhouse gas emissions during transportation are calculated; the total mass of the transformer transported to the customer should be recorded in order to analyze its overall contribution to the environmental impact; (4) During the use phase, it is necessary to systematically collect energy consumption, including the electricity consumption of the transformer during operation, to evaluate its operating efficiency; record energy emission factors and calculate the corresponding emission coefficients based on different energy sources to quantify greenhouse gas emissions; collect direct greenhouse gas emissions and monitor greenhouse gases such as carbon dioxide released by the transformer during use to provide an important basis for evaluating its environmental impact; (5) During the recycling and processing phase, it is necessary to systematically collect energy consumption during the recycling process, including the use of required electricity and other energy, to evaluate the energy efficiency of resource recovery; collect direct greenhouse gas emissions during the recycling process and monitor greenhouse gas emissions such as carbon dioxide generated during the recycling operation.

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