A direct carbon emission measurement method for large oil-filled transformer operation process based on oil chromatography characteristic gas

Abstract

The present invention provides a method for calculating direct carbon emissions during the operation of a large oil-filled transformer based on oil chromatogram characteristic gases. The method can rely on the oil chromatogram characteristic gas analysis data of the oil-filled transformer in operation, calculate the increments of greenhouse gas components under normalized conditions according to the length of operation time, and convert the increments of greenhouse gas components within the time scale into the transformer carbon dioxide emission rate, and simultaneously calculate the direct carbon emission intensity of the transformer operation process. The method can make full use of a large amount of oil chromatogram data of transformers in operation of power companies, has the advantages of wide application range, simple operation, and can carry out data comparison and verification of transformer equipment of the same model and working condition, and provides a quantitative basis for the evaluation of the direct carbon emission intensity of large oil-filled transformers during operation.

Description

Technical Field

[0001] The present invention belongs to the field of carbon emission calculation, and relates to a method for directly calculating carbon emission during the operation of a large oil-filled transformer based on oil chromatography characteristic gas. Background Art

[0002] Large oil-filled transformers are typical multi-component, multi-type material equipment, which contains a large amount of liquid and solid insulating materials. During the operation of the equipment, according to the functional characteristics of the transformer, its carbon emission intensity mainly depends on two aspects: one is the no-load loss level; the other is the degradation rate of the insulating medium. As far as the normal operation of the equipment is concerned, its direct greenhouse gas emissions mainly come from the natural degradation of the insulating materials (caused by heat and electric field effects) or fault damage. Among them, there is still no clear conclusion on the amount of greenhouse gases generated by the degradation of dry insulating materials such as insulating oil, epoxy resin, glass fiber, and insulating paper under operating conditions. Therefore, in the relevant technical field, it is urgent to seek a method for measuring direct carbon emissions during the operation of the transformer that can be quantified and measured, so as to make up for the missing links in the existing carbon emission measurement and evaluation. Summary of the invention

[0003] The present invention provides a method for calculating direct carbon emissions during the operation of a large oil-filled transformer based on oil chromatogram characteristic gases. The method can rely on the oil chromatogram characteristic gas analysis data of the oil-filled transformer in operation to calculate the direct carbon emission intensity during the transformer operation process, thereby providing a quantitative basis for evaluating the direct carbon emission intensity of a large oil-filled transformer during operation.

[0004] A method for directly calculating carbon emissions during the operation of a large oil-filled transformer based on oil chromatography characteristic gases comprises the following steps:

[0005] Step 1: Collect oil samples from the operating transformer and record the oil temperature during sampling;

[0006] Step 2: Perform oil chromatography analysis on the transformer oil sample to obtain the component content of characteristic gases, which include carbon dioxide, methane, hydrogen, carbon monoxide, ethane, ethylene, and acetylene;

[0007] Step 3: Convert the concentrations of carbon dioxide and methane obtained in step 2 into carbon dioxide equivalent concentrations;

[0008] Step 4: Compare the carbon dioxide equivalent concentration calculated from the current sampling of the operating transformer in step 3 with the historical data. The oil temperature of the two sets of data to be compared should be the same when sampling. Calculate the increase in the direct carbon emission concentration of the transformer during the interval between the two samplings.

[0009] Step 5: Calculate the direct carbon emission rate of the transformer based on the increment of direct carbon emission concentration of the transformer calculated in step 4, combined with the transformer oil weight and the number of transformer utilization hours between two sampling intervals;

[0010] Step 6: Based on the direct carbon emission concentration increment of the transformer calculated in step 4, the data in all sampling periods during the operation of the transformer are counted to calculate the direct carbon emission intensity of the transformer operation process.

[0011] Furthermore, in step 3, the concentrations of carbon dioxide and methane obtained in step 2 are uniformly converted into carbon dioxide equivalent concentrations, and the calculation formula is as follows:

[0012] M=M 二氧化碳 G 二氧化碳 +M 甲烷 G 甲烷

[0013] M-carbon dioxide equivalent concentration, uL / L;

[0014] M 二氧化碳 -Characteristic gas carbon dioxide concentration, uL / L;

[0015] G 二氧化碳 -Characterization factor of the global warming potential of characteristic gas carbon dioxide, with a value of 1;

[0016] M 甲烷 - Characteristic gas methane concentration, uL / L;

[0017] G 甲烷 -The global warming potential characterization factor of the characteristic gas methane is 28.

[0018] Furthermore, the greenhouse gas components carbon dioxide, methane and the corresponding global warming potential characterization factor values ​​in step three are determined according to the contents of Appendix 8.A of the Fifth Report of the IPCC. If the identification of greenhouse gas components and the corresponding global warming potential characterization factor values ​​in the IPCC or relevant national standards change, the carbon dioxide equivalent concentration calculation is combined with the characteristic gas components of the transformer oil chromatographic analysis, and hydrogen, carbon monoxide, ethane, ethylene and acetylene are added for calculation;

[0019] The calculation formula is modified as follows:

[0020] M=∑M i G i

[0021] M-carbon dioxide equivalent concentration, uL / L;

[0022] M i - Greenhouse characteristic gas concentration, uL / L;

[0023] G i -Characterization factors of the global warming potential of greenhouse gases.

[0024] Furthermore, in step 4, the increment of the direct carbon emission concentration of the transformer during the interval between two samplings is calculated, and the calculation formula is as follows:

[0025] M c =M i -M i-1

[0026] M c -Direct carbon emission concentration increment of operating transformers, uL / L;

[0027] M i -The carbon dioxide equivalent concentration of this sampling, uL / L;

[0028] M i-1 -The carbon dioxide equivalent concentration of the last sample, uL / L.

[0029] Furthermore, in step 5, the direct carbon emission rate of the transformer is calculated using the following formula:

[0030]

[0031] T-the maximum utilization hours of the transformer between two sampling intervals, h;

[0032] P i - The continuous and stable load of the transformer in operation for a certain period of time, MVA;

[0033] t i -Stable load P of transformer in operation i Duration, h;

[0034] P r - Rated capacity of transformers in operation, MVA;

[0035] M v -Direct carbon emission rate of operating transformers, t / h;

[0036] M c -The increase in direct carbon emission concentration of operating transformers during the interval between two samplings, uL / L;

[0037] N o -Oil weight of transformer in operation, t;

[0038] A o -Transformer oil density, t / L;

[0039] A c -Carbon dioxide gas density, t / uL.

[0040] Furthermore, in step 6, the direct carbon emission intensity of the transformer operation process is calculated using the following formula:

[0041]

[0042] M T -Direct carbon emission intensity during transformer operation, t;

[0043] M ci -The increase in direct carbon emission concentration of operating transformers during the interval between two samplings, uL / L;

[0044] N o -Oil weight of transformer in operation, t;

[0045] A o -Transformer oil density, t / L;

[0046] A c -Carbon dioxide gas density, t / uL.

[0047] Compared with the prior art, the present invention has the following advantages and effects:

[0048] 1. This method has high accuracy. By conducting insulation aging tests on single solid and liquid insulation materials of transformers under actual operation simulation conditions in the laboratory, greenhouse gases such as carbon dioxide were collected and their emissions were measured. A total of 1,587 data samples were collected, and the average error between the experimental measurement value and the calculated value of this method was 3.6%. 314 transformer samples of the same manufacturer, model and working condition in the power grid were collected, with an average deviation of 1.3%;

[0049] 2. This method can rely on the oil chromatographic characteristic gas analysis data of the oil-filled transformer in operation, calculate the increment of greenhouse gas components under normalized conditions according to the length of operation time, and convert the increment of greenhouse gas components within this time scale into the transformer carbon dioxide emission rate, thereby solving the problem of direct carbon emission intensity measurement during the transformer operation process;

[0050] 3. This method can make full use of a large amount of oil chromatography data of transformers in operation in power companies. It has a wide range of applications, is simple to operate, and can be used to compare and verify data of transformer equipment of the same manufacturer, model, and operating conditions. It provides a quantitative basis for the direct carbon emission intensity evaluation of large oil-filled transformers during operation, and determines the carbon emission baseline level and equipment with abnormal insulation status. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a flow chart of a method for directly calculating carbon emissions during the operation of a large oil-filled transformer based on oil chromatography characteristic gases according to the present invention. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0053] Reference Figure 1 , a certain rated capacity P r For a 240MVA transformer in operation, the oil weight is N o The oil sample was collected twice in a certain period of time, and the oil temperature was 40℃. According to the oil chromatography test results, the carbon dioxide concentration M 二氧化碳1 6460uL / L, M 二氧化碳2 is 7812uL / L, methane concentration M 甲烷1 15uL / L, M 甲烷2 The oil density of transformer A is 30.9uL / L. During the two sampling intervals, the running time t1 of P1 at 40% load is 500h, the running time t2 of P2 at 60% load is 1000h, and the running time t3 of P3 at 80% load is 200h. o 8.95×10 -4 t / L, carbon dioxide density A c is 1.977×10 -12 t / uL.

[0054] According to the calculation steps and formula:

[0055] 1. According to step 3, the carbon dioxide equivalent concentrations of the two samples are M1 = M 二氧化碳1 G 二氧化碳 +M 甲烷1 G 甲烷 =6460+15×28=6880uL / L, M2=M 二氧化碳2 G 二氧化碳 +M 甲烷2 G 甲烷 =7812+30.9×28=8677.2uL / L;

[0056] 2. According to step 4, the increment of transformer direct carbon emission concentration between two sampling intervals is M c =M2-M1=8677.2-6880=1797.2uL / L

[0057] 3. According to step 5, the maximum utilization hours of the transformer within the time interval between two samplings is T = (P1t1+P2t2+P3t3) / P r =(0.4×500×240+0.6×1000×240+0.8×200×240)÷240=960h;

[0058] 4. According to step 5, the direct carbon emission rate M of the operating transformer during the interval between two samplings v =M c N o A c / A o / T=1797.2×30×1.977×10 -12 ÷8.95÷10 -4 ÷960=1.24×10 -7 t / h;

[0059] 5. According to step 6, the direct carbon emission intensity of the transformer operation process during the two sampling intervals is M = M c N o A c / A o =1797.2×30×1.977×10 -12 ÷8.95÷10 -4 =1.19×10 -4 t.

[0060] When there are three or more samplings, that is, when there are two or more time intervals, the direct carbon emissions of the transformer during the entire operation process can be calculated and accumulated for each interval. For example, if one more sampling is added to the above example, for the convenience of calculation and understanding, assuming that the concentration difference of carbon dioxide and methane is consistent with the above example, then according to steps three to four, M c2 =M3-M2=M2-M1=M c1 =1797.2uL / L; accordingly, according to step 6, the direct carbon emission intensity of the transformer operation process during three samplings, i.e., two sampling intervals, can be obtained as M=M c1 N o A c / A o +M c2 N o A c / A o =1.24×10 -7 +1.24×10 -7 =2.48×10 -7 t / h. If the sampling times continue to increase, the same can be applied.

[0061] According to the characteristics that the gas from the deterioration of the insulation material of the oil-filled transformer is dissolved in oil, the present invention proposes a method for calculating direct carbon emissions during the operation of a large oil-filled transformer based on the characteristic gas of the oil chromatography. By conducting insulation aging tests under actual operation simulation conditions on single solid and liquid insulation materials of the transformer in the laboratory, greenhouse gases such as carbon dioxide are collected and their emissions are measured. 1587 data samples are collected, and the average error between the experimental measurement value and the calculated value of this method is 3.6%; 314 samples of transformers of the same manufacturer, model and working condition in the power grid are collected, with an average deviation of 1.3%. Therefore, the model of the present invention is simple and has high accuracy. During the actual operation of the transformer, the direct carbon emission intensity of the transformer operation process can be theoretically calculated through the oil chromatography data that is easy to sample, and the carbon emission baseline level and the equipment with abnormal insulation status can be judged through the measurement data of the operating transformers of the same manufacturer, model and working condition.

[0062] In addition, it should be noted that the specific embodiments described in this specification are only specific implementation methods of the present invention, but the protection scope of the present invention is not limited thereto. The names of the parameters involved may be different, and equivalent or simple changes made based on the principles described in the concept of the present invention should all be covered within the protection scope of the present invention.

Claims

1. A method for directly calculating carbon emissions during the operation of large oil-filled transformers based on oil chromatographic characteristic gases, characterized in that The steps include: Step 1: Collect oil samples from the operating transformer and record the oil temperature during sampling; Step 2: Perform oil chromatography analysis on the transformer oil sample to obtain the component content of characteristic gases, which include carbon dioxide, methane, hydrogen, carbon monoxide, ethane, ethylene and acetylene; Step 3: Convert the concentrations of carbon dioxide and methane obtained in step 2 into carbon dioxide equivalent concentrations; Step 4: Compare the carbon dioxide equivalent concentration calculated from the current sampling of the operating transformer in step 3 with the historical data. The oil temperature of the two sets of data to be compared should be the same when sampling. Calculate the increase in the direct carbon emission concentration of the transformer during the interval between the two samplings. Step 5: Calculate the direct carbon emission rate of the transformer based on the increment of direct carbon emission concentration of the transformer calculated in step 4, combined with the transformer oil weight and the number of transformer utilization hours between two sampling intervals; Step 6: According to the direct carbon emission concentration increment of the transformer calculated in step 4, the data in all sampling periods during the operation of the transformer are counted to calculate the direct carbon emission intensity during the operation of the transformer; In step 3, the concentrations of carbon dioxide and methane obtained in step 2 are uniformly converted into carbon dioxide equivalent concentrations. The calculation formula is as follows: M=M 二氧化碳 G 二氧化碳 +M 甲烷 G 甲烷 M-carbon dioxide equivalent concentration, uL / L; M 二氧化碳 -Characteristic gas carbon dioxide concentration, uL / L; G 二氧化碳 -Characterization factor of the global warming potential of characteristic gas carbon dioxide, with a value of 1; M 甲烷 - Characteristic gas methane concentration, uL / L; G 甲烷 - Characterization factor of the global warming potential of characteristic gas methane, the value is 28; In step 4, the direct carbon emission concentration increment of the transformer during the two sampling intervals is calculated using the following formula: M ci =M i -M i-1 M ci -Direct carbon emission concentration increment of operating transformers, uL / L; M i -The carbon dioxide equivalent concentration of this sampling, uL / L; M i-1 -The carbon dioxide equivalent concentration of the last sampling, uL / L; In step 5, the direct carbon emission rate of the transformer is calculated using the following formula: T-the maximum utilization hours of the transformer between two sampling intervals, h; P i - The continuous and stable load of the transformer in operation for a certain period of time, MVA; t i -Stable load P of transformer in operation i Duration, h; P r - Rated capacity of transformers in operation, MVA; M v -Direct carbon emission rate of operating transformers, t / h; M ci -The increase in direct carbon emission concentration of operating transformers during the interval between two samplings, uL / L; N o -Oil weight of transformer in operation, t; A o -Transformer oil density, t / L; A c -Carbon dioxide gas density, t / uL; In step 6, the direct carbon emission intensity of the transformer operation process is calculated using the following formula: M T -Direct carbon emission intensity during transformer operation, t; M ci -The increase in direct carbon emission concentration of operating transformers during the interval between two samplings, uL / L; N o -Oil weight of transformer in operation, t; A o -Transformer oil density, t / L; A c -Carbon dioxide gas density, t / uL.

2. According to claim 1, a method for directly calculating carbon emissions during the operation of a large oil-filled transformer based on oil chromatography characteristic gas, characterized in that: The greenhouse gas components of carbon dioxide, methane and the corresponding global warming potential characterization factor values ​​in step 3 are determined according to the contents of Appendix 8.A of the Fifth Report of the IPCC. If the identification of greenhouse gas components and the corresponding global warming potential characterization factor values ​​in the IPCC or relevant national standards change, the carbon dioxide equivalent concentration calculation is combined with the characteristic gas components of the transformer oil chromatographic analysis, and hydrogen, carbon monoxide, ethane, ethylene and acetylene are added for calculation; The calculation formula is modified as follows: M=ΣM i G i M-carbon dioxide equivalent concentration, uL / L; M i - Greenhouse characteristic gas concentration, uL / L; G i -Characterization factors of the global warming potential of greenhouse gases.

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