Raw coal / commercial coal carbon emission monitoring method based on equivalent particle size

Abstract

The invention discloses a raw coal / commercial coal carbon emission monitoring method based on an equivalent particle size. The method comprises the following steps: (1) screening raw coal / commercial coal into n particle size intervals according to particle size equal difference values; (2) measuring the average residual methane content of the particle coal in each particle size interval; (3) if the difference coefficient between the average residual methane content of the particle coal in each particle size interval and the average residual methane content of the raw coal / commercial coal is greater than 5%, returning to the step (1), adjusting the particle size interval and circulating the steps (1)-(3); (4) if the difference coefficient is less than 5%, determining that the interval particle size of the particle size interval is an equivalent particle size; and (5) screening the coal samples according to the equivalent particle size interval, measuring the average residual methane content of the raw coal and the average residual methane content of the commercial coal, and calculating the unit cycle methane emission of the coal preparation plant or the open pit coal mine through a difference value. The method can be used for determining the target particle size interval for measuring the residual methane content of the particle coal in the emission boundary range of a coal mine coal preparation plant or an open pit coal mine, and further calculating the methane emission amount of the coal preparation plant or the open pit coal mine.

Description

Technical Field

[0001] The present invention relates to a raw coal / commercial coal carbon emission monitoring method, specifically a raw coal / commercial coal carbon emission monitoring method based on equivalent particle size, which is used to monitor the carbon emission of raw coal / commercial coal in a coal preparation plant or open-pit coal mine, and belongs to the technical field of energy carbon emission reduction monitoring. Background Art

[0002] Methane fugitive emissions from post-mine activities in underground coal mines and carbon emissions from open-pit mining activities are the two main sources of carbon emissions from coal mines.

[0003] There is a lack of methane measurement methods for post-mine activities in underground coal mines and open-pit coal mines based on actual measurements at home and abroad. The existing emission factor method does not distinguish between differences in coal seam gas content and cannot accurately reflect the actual carbon emissions of mines. However, to carry out carbon emission measurement in coal preparation plants or open-pit coal mines based on actual sampling and measurement, the first choice is to measure and calculate the difference in gas content per unit weight of particle coal entering and leaving the boundary. However, according to changes in the mining environment (temperature, humidity, air pressure) and underground mining conditions (coal type, mining depth), it is necessary to continuously sample, screen, and measure the residual gas content of raw coal and commercial coal. The work intensity is high and the duration is long, which is not conducive to the accurate measurement of carbon emissions. In order to avoid repeated sampling and measurement, the determination of equivalent particle size can provide a basis for particle size selection for sampling measurement, directly determine the sampling target particle size, and avoid the problem of cumbersome actual operation caused by multiple sampling. Summary of the invention

[0004] The purpose of the present invention is to provide a raw coal / commercial coal carbon emission monitoring method based on equivalent particle size, which can be used to determine the target particle size range for measuring the residual methane content of particulate coal within the emission boundary range of a coal preparation plant or an open-pit coal mine, thereby providing sampling method guidance for measuring carbon emissions from coal preparation plants or open-pit coal mines.

[0005] In order to achieve the above object, the present invention provides a method for monitoring carbon emissions of raw coal / commercial coal based on equivalent particle size, comprising the following steps:

[0006] ① The raw coal / commercial coal sample is screened into n particle size intervals according to the particle size and equal difference;

[0007] ② Measure the mass percentage of samples in each particle size range, and measure the average residual methane content of the particle coal in each particle size range by multiple measurements;

[0008] ③ Compare the average residual methane content of each particle size interval. If the difference coefficient λ between the average residual methane content of the granular coal in each particle size interval and the average residual methane content of the raw coal / commercial coal is greater than 5%, return to step ①, adjust the particle size interval and repeat steps ①-③;

[0009] ④ If the difference coefficient λ between the average residual methane content of granular coal in a certain particle size interval and the average residual methane content of raw coal / commercial coal is less than 5%, then the particle size interval is identified as an equivalent particle size interval, and the interval particle size of the equivalent particle size interval is the equivalent particle size; if the difference coefficients of the average residual methane content of granular coal in multiple particle size intervals and the average residual methane content of raw coal / commercial coal are all less than 5%, then the interval with the smallest difference coefficient is the equivalent particle size interval;

[0010] ⑤ According to a certain period (month, quarter, year), the raw coal samples are screened out from the coal mine mouth belt according to the equivalent particle size range, and the average residual methane content of the raw coal is measured; similarly, the average residual methane content of the commercial coal is measured at the outlet of the commercial coal bunker. Combining the weight data of commercial coal and raw coal, the unit cycle methane emissions of the coal preparation plant or open-pit coal mine are calculated by difference calculation.

[0011] In the present invention, the calculation formula for the average residual methane content of raw coal / commercial coal is:

[0012]

[0013] Where: n = 1, 2, 3, 4, 5...j, representing j particle size spaces respectively;

[0014] C n is the average residual methane content corresponding to the nth particle size interval, m 3 / t;

[0015] X n is the mass percentage of raw coal / commercial coal in the nth particle size interval, %;

[0016] The calculation formula of the difference coefficient λ is:

[0017] λ=C 原煤 / 商品煤 -C j / C 原煤 / 商品煤 (2)

[0018] Where: C j is the average residual methane content corresponding to the equivalent particle size range, which is generally the average value of the residual gas content of the granular coal in this range tested more than three times, m 3 / t;

[0019] The mass percentage of raw coal / commercial coal in the nth particle size interval X n The calculation formula is:

[0020]

[0021] Where: M n is the mass of the sample in the nth particle size interval.

[0022] The formula for calculating the methane emissions per unit cycle of a coal preparation plant or open-pit coal mine is:

[0023] Q=C 原煤 ×W 原煤 -C 商品煤 ×W 商品煤 (4)

[0024] Where: W 原煤 / W 商品煤 is the weight of raw coal / commercial coal in a certain period, t.

[0025] In the present invention, when testing the raw coal, the initial value of the n particle size intervals in step ① should be greater than or equal to 7, that is, the raw coal is divided into 7 particle size intervals from small to large particle size;

[0026] When testing commercial coal, the initial value of the n particle size intervals in step ① should be greater than or equal to 2, that is, the commercial coal is divided into 2 particle size intervals from small to large according to the coal particle size.

[0027] In the present invention, when the raw coal is tested, the particle size interval adjustment in step ③ is to adjust the upper and lower limits of the particle size of each interval without reducing the number of particle size intervals n, and the particle size range of each interval is equal.

[0028] In the present invention, during the raw coal testing, the raw coal sampling location in step ① should be selected from the exit belt of the main wellhead on the ground, and the commercial coal sample should be selected from the coal out-of-mine loading truck.

[0029] In the present invention, the sampling times of raw coal / commercial coal samples should be at least 5 times, and the mass of a single sampling should be at least 10 kg.

[0030] After the equivalent particle size is initially determined, when there are significant changes in environmental factors (seasons) and production factors (mining area, output, and type of coal produced) in the mining area, the equivalent particle size must be retested and corrected.

[0031] Compared with the prior art, the present invention provides a method for determining an equivalent particle size range for the determination of residual methane content in granular coal within the emission boundary range of a coal preparation plant or an open-pit coal mine, avoiding the cumbersome process of multiple screening, weight determination and average value calculation for each sampling. The present invention can determine the equivalent particle size representing the average value of the gas content, and then calculate the methane emission of the coal preparation plant or open-pit coal mine. The granular coal of the target particle size can be obtained by sampling and screening once, which speeds up the operation process of the actual measurement technology of carbon emission monitoring data, and is conducive to the accurate measurement and popularization of carbon emission monitoring within the emission boundary range of a coal preparation plant or an open-pit coal mine. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1This is a schematic diagram of the flow chart of the methane emission calculation method of the present invention;

[0033] Figure 2 Schematic diagram of raw coal / commercial coal screening. DETAILED DESCRIPTION

[0034] The present invention will be further described below in conjunction with the accompanying drawings.

[0035] like Figure 1 As shown, a method for monitoring carbon emissions of raw coal / commercial coal based on equivalent particle size comprises the following steps:

[0036] ① The raw coal / commercial coal sample is screened into n particle size intervals according to the particle size and equal difference;

[0037] ② Measure the mass percentage of samples in each particle size range, and measure the average residual methane content of the particle coal in each particle size range by multiple measurements;

[0038] ③ Compare the average residual methane content of each particle size interval. If the difference coefficient λ between the average residual methane content of the granular coal in each particle size interval and the average residual methane content of the raw coal / commercial coal is greater than 5%, return to step ①, adjust the particle size intervals and then repeat steps ①-③;

[0039] ④ If the difference coefficient λ between the average residual methane content of granular coal in a certain particle size interval and the average residual methane content of raw coal / commercial coal is less than 5%, then the particle size interval is identified as an equivalent particle size interval, and the interval particle size of the equivalent particle size interval is the equivalent particle size; if the difference coefficients of the average residual methane content of granular coal in multiple particle size intervals and the average residual methane content of raw coal / commercial coal are all less than 5%, then the interval with the smallest difference coefficient is the equivalent particle size interval;

[0040] ⑤ According to a certain period (month, quarter, year), the raw coal samples are screened out from the coal mine mouth belt according to the equivalent particle size range, and the average residual methane content of the raw coal is measured; similarly, the average residual methane content of the commercial coal is measured at the outlet of the commercial coal bunker. Combining the weight data of commercial coal and raw coal, the unit cycle methane emissions of the coal preparation plant or open-pit coal mine are calculated by difference calculation.

[0041] In the present invention, the calculation formula for the average residual methane content of raw coal / commercial coal is:

[0042]

[0043] Where: n = 1, 2, 3, 4, 5...j, representing j particle size spaces respectively;

[0044] C nis the average residual methane content corresponding to the nth particle size interval, m 3 / t;

[0045] X n is the mass percentage of raw coal / commercial coal in the nth particle size interval, %;

[0046] The calculation formula of the difference coefficient λ is:

[0047] λ=C 原煤 / 商品煤 -C j / C 原煤 / 商品煤 (2)

[0048] Where: C j is the average residual methane content corresponding to the equivalent particle size range, which is generally the average value of the residual gas content of the granular coal in this range tested more than three times, m 3 / t;

[0049] The mass percentage of raw coal / commercial coal in the nth particle size interval X n The calculation formula is:

[0050]

[0051] Where: M n is the mass of the sample in the nth particle size interval.

[0052] The formula for calculating the methane emissions per unit cycle of a coal preparation plant or open-pit coal mine is:

[0053] Q=C 原煤 ×W 原煤 -C 商品煤 ×W 商品煤 (4)

[0054] Where: W 原煤 / W 商品煤 is the weight of raw coal / commercial coal in a certain period, t.

[0055] In the present invention, when testing the raw coal, the initial value of the n particle size intervals in step ① should be greater than or equal to 7, that is, the raw coal is divided into 7 particle size intervals from small to large particle size;

[0056] When testing commercial coal, the initial value of the n particle size intervals in step ① should be greater than or equal to 2, that is, the commercial coal is divided into 2 particle size intervals from small to large according to the coal particle size.

[0057] In the present invention, when the raw coal is tested, the particle size interval adjustment in step ③ is to adjust the upper and lower limits of the particle size of each interval without reducing the number of particle size intervals n, and the particle size range of each interval is equal.

[0058] In the present invention, during the raw coal testing, the raw coal sampling location in step ① should be selected from the exit belt of the main wellhead on the ground, and the commercial coal sample should be selected from the coal out-of-mine loading truck.

[0059] In the present invention, the sampling times of raw coal / commercial coal samples should be at least 5 times, and the mass of a single sampling should be at least 10 kg.

[0060] After the equivalent particle size is initially determined, when there are significant changes in environmental factors (seasons) and production factors (mining area, output, and type of coal produced) in the mining area, the equivalent particle size must be retested and corrected.

[0061] Example 1

[0062] The present invention relates to a raw coal (commercial coal) carbon emission monitoring method based on equivalent particle size, which is used for measuring the residual methane content of particle coal within the emission boundary range of a coal preparation plant or an open-pit coal mine, and comprises the following steps:

[0063] ① The raw coal (commercial coal) sample (15 kg) was screened into 10 particle size intervals according to the particle size, namely [0-3mm], [3-6mm], [6-9mm], [9-12mm], [12-15mm], [15-18mm], [18-21mm], [21-24mm], [24-27mm] and [>27mm].

[0064] ② The mass percentages of samples in each particle size range were measured, which were [0-3mm, 15%], [3-6mm, 12%], [6-9mm, 8%], [9-12mm, 5%], [12-15mm, 3%], [15-18mm, 5%], [18-21mm, 4%], [21-24mm, 15%], [24-27mm, 10%] and [>27mm, 23%]. The average residual methane content of the raw coal (commercial coal) in each particle size range was measured by three measurements, as shown in Table 1.

[0065] Table 1 Raw coal particle size distribution and test results

[0066]

[0067]

[0068] ③ The average residual methane content of raw coal is calculated by formula (1) and formula (3) to be 2.034m 3 / t.

[0069] ④ By comparing with formula (2), it is found that the difference coefficient λ corresponding to 15mm-18mm is 4.8%, so the particle size range [15mm-18mm] is recognized as the equivalent particle size range.

[0070] The above steps are repeated 5 times. If the measurement results are the same, the particle size in the range of [15mm-18mm] is considered to be the equivalent particle size.

[0071] In the next year, the average residual gas content of raw coal will be based on this particle size.

[0072] After the equivalent particle size is determined, when there are significant changes in environmental factors (seasons) and production factors (mining area, output, and type of coal produced) in the mining area, the equivalent particle size must be retested according to the equivalent particle size determination method of the present invention.

[0073] According to the coal preparation plant process, the particle size of commercial coal has been screened by the coal preparation plant and is generally divided into two particle size ranges, as shown in Table 2.

[0074] Table 2 Example 1 Commercial coal particle size distribution and test results

[0075] Particle size distribution / mm 0-6 6-15 Mass percentage / % 60 40 <![CDATA[Residual gas content / m 3 / t]]> 1.1 0.8

[0076] The average residual methane content of commercial coal is calculated by formula (1) and formula (3) to be 0.98m 3 / t.

[0077] In summary, the raw coal output in that year was 6 million tons and the commercial coal output was 5.4 million tons. According to formula (4), the methane carbon emissions in that year were: 6×10 6 *2.034-5.4×10 6 *0.98=6.948×10 6 (m 3 ).

[0078] Example 2

[0079] The present invention relates to a method for determining the equivalent particle size of raw coal (commercial coal) for carbon emission monitoring, which is used for determining the residual methane content of granular coal within the emission boundary range of a coal preparation plant or an open-pit coal mine, comprising the following steps:

[0080] ① The raw coal (commercial coal) sample (15 kg) was screened into 10 particle size intervals according to the particle size, namely [0-3mm], [3-6mm], [6-9mm], [9-12mm], [12-15mm], [15-18mm], [18-21mm], [21-24mm], [24-27mm] and [>27mm].

[0081] ② Measure the mass percentage of samples in each particle size range, and measure the average residual methane content of the raw coal (commercial coal) in each particle size range by three measurements, as shown in Table 3.

[0082] Table 3 Example 2 Raw coal particle size distribution and test results

[0083] Particle size distribution / mm 0-3 3-6 6-9 9-12 12-15 15-18 18-21 21-24 24-27 >27 Mass percentage / % 5 12 8 15 13 5 4 5 20 13 <![CDATA[Gas content / m 3 / t]]> 1.3 1.2 1.3 1.8 1.8 2.5 2.6 2.6 2.5 2.6

[0084] ③ The average residual methane content of raw coal is calculated by formula (1) and formula (3) to be 2.014m 3 / t. There is no particle size range where the difference coefficient λ between the average residual methane content of granular coal and the average residual methane content of raw coal / commercial coal is less than 5%. The interval adjustment is divided into 11 intervals, namely [0-2mm], [2-4mm], [4-6mm], [6-8mm], [8-12mm], [12-14mm], [14-16mm], [16-18mm], [18-20mm], [20-22mm] and [>22mm], as shown in Table 4.

[0085] Table 4 Example 2 Adjusted Raw Coal Particle Size Distribution and Test Results

[0086] Particle size distribution / mm 0-2 2-4 4-6 6-8 8-10 12-14 14-16 16-18 18-20 20-22 >22 Mass percentage / % 4 10 8 13 12 11 8 5 6 12 11 <![CDATA[Gas content / m 3 / t]]> 1.3 1.2 1.3 1.7 1.8 1.8 2.5 2.6 2.6 2.5 2.6

[0087] ⑤ The average residual methane content of raw coal is calculated by formula (1) and formula (3) to be 1.735m 3 / t.

[0088] ④ By comparing with formula (2), it is found that the difference coefficient λ corresponding to 8mm-14mm is 3.6%, and the difference coefficient λ corresponding to 6mm-8mm is 2.1%. Although there are multiple intervals with difference coefficients less than 5%, the difference coefficient corresponding to 6mm-8mm is the smallest, so the particle size interval [6mm-8mm] is recognized as the equivalent particle size interval.

[0089] In the next year, the average residual gas content of raw coal will be based on this particle size. After the equivalent particle size is determined, when there are significant changes in environmental factors (seasons) and production factors (mining areas, output, and types of coal) in the mining area, the equivalent particle size should be retested according to the equivalent particle size determination method of the present invention.

[0090] According to the coal preparation plant process, the particle size of commercial coal has been screened by the coal preparation plant and is generally divided into two ranges, as shown in Table 5.

[0091] Table 5 Example 2 Commercial coal particle size distribution and test results

[0092] Particle size distribution / mm 0-6 6-15 Mass percentage / % 65 35 <![CDATA[Residual gas content / m 3 / t]]> 1.0 0.66

[0093] The average residual methane content of commercial coal is calculated by formula (1) and formula (3) to be 0.89m 3 / t.

[0094] In summary, the raw coal output in that year was 6 million tons and the commercial coal output was 5.4 million tons. According to formula (4), the methane carbon emissions in that year were: 6×10 6 *1.735-5.4×10 6 *0.89=5.604×10 6 (m 3 ).

Claims

1. A method for monitoring carbon emissions from raw coal / commercial coal based on equivalent particle size, characterized in that: The following steps are involved: ① The raw coal / commercial coal sample is screened into n particle size intervals according to the particle size and equal difference; ② Measure the mass percentage of samples in each particle size range, and measure the average residual methane content of the particle coal in each particle size range by multiple measurements; ③ Compare the average residual methane content of each particle size interval. If the difference coefficient λ between the average residual methane content of the granular coal in each particle size interval and the average residual methane content of the raw coal / commercial coal is greater than 5%, return to step ①, adjust the particle size interval and repeat steps ①-③; ④ If the difference coefficient λ between the average residual methane content of granular coal in a certain particle size interval and the average residual methane content of raw coal / commercial coal is less than 5%, then the particle size interval is identified as an equivalent particle size interval, and the interval particle size of the equivalent particle size interval is the equivalent particle size; if the difference coefficients of the average residual methane content of granular coal in multiple particle size intervals and the average residual methane content of raw coal / commercial coal are all less than 5%, then the interval with the smallest difference coefficient is the equivalent particle size interval; ⑤ According to a certain period, the raw coal samples are screened out from the coal mine outlet belt according to the equivalent particle size range, and the average residual methane content of the raw coal is measured; similarly, the average residual methane content of the commercial coal is measured at the outlet of the commercial coal bunker, and the methane emissions per unit period of the coal preparation plant or open-pit coal mine are calculated by difference calculation based on the weight data of the commercial coal and raw coal.

2. A method for monitoring carbon emissions of raw coal / commercial coal based on equivalent particle size according to claim 1, characterized in that: The calculation formula for the average residual methane content of raw coal / commercial coal is: Where: n = 1, 2, 3, 4, 5...j, representing j particle size spaces respectively; C n is the average residual methane content corresponding to the nth particle size interval, m 3 / t; X n is the mass percentage of raw coal / commercial coal in the nth particle size interval, %; The calculation formula of the difference coefficient λ is: λ=C 原煤 / 商品煤 -C j / C 原煤 / 商品煤 (2) Where: C j is the average residual methane content corresponding to the equivalent particle size range, which is generally the average value of the residual gas content of the granular coal in this range tested more than three times, m 3 / t; The mass percentage of raw coal / commercial coal in the nth particle size interval X n The calculation formula is: Where: M n is the mass of the sample in the nth particle size interval; The formula for calculating the methane emissions per unit cycle of a coal preparation plant or open-pit coal mine is: Q=C 原煤 ×W 原煤 -C 商品煤 ×W 商品煤 (4) Where: W 原煤 / W 商品煤 is the weight of raw coal / commercial coal in a certain period, t.

3. A method for monitoring carbon emissions of raw coal / commercial coal based on equivalent particle size according to claim 1 or 2, characterized in that: When testing the raw coal, the initial value of the n particle size intervals in step ① should be greater than or equal to 7, that is, the raw coal is divided into 7 particle size intervals from small to large particle size; When testing commercial coal, the initial value of the n particle size intervals in step ① should be greater than or equal to 2, that is, the commercial coal is divided into 2 particle size intervals from small to large according to the coal particle size.

4. A method for monitoring carbon emissions of raw coal / commercial coal based on equivalent particle size according to claim 3, characterized in that: When testing the raw coal, the particle size interval adjustment in step ③ is to adjust the upper and lower limits of the particle size of each interval without reducing the number of particle size intervals n, and the particle size range of each interval is equal.

5. The method for monitoring carbon emissions of raw coal / commercial coal based on equivalent particle size according to claim 3, characterized in that: When testing the raw coal, the raw coal sampling location in step ① should be selected from the exit belt of the main wellhead on the ground, and the commercial coal sample should be selected from the coal loading truck out of the mine.

6. The method for monitoring carbon emissions of raw coal / commercial coal based on equivalent particle size according to claim 3, characterized in that: The sampling frequency of raw coal / commercial coal samples should be at least 5 times, and the mass of a single sample should be at least 10kg.

7. The method for monitoring carbon emissions of raw coal / commercial coal based on equivalent particle size according to claim 3, characterized in that: After the equivalent particle size is initially determined, if there are significant changes in environmental and production factors in the mining area, the equivalent particle size must be retested and revised.

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