Preparation method of comprehensive sample for accounting coal element carbon content

Abstract

The invention discloses a preparation method of a comprehensive sample for accounting the content of elemental carbon in fire coal. The preparation method comprises the following steps: obtaining and combining the granularity of each split sample for measuring the content of elemental carbon in fire coal, parameter information of coal as fired corresponding to each split sample and the weight of each split sample in an air drying state; according to the parameter information of the as-fired coal corresponding to each split sample and the weight of each split sample in an air drying state, calculating the calibrated air drying basis moisture of each split sample, and then calculating the air drying basis converted sample quantity of the as-fired coal raw coal corresponding to each split sample; according to the air drying basis converted sample quantity of the raw coal as fired corresponding to each split sample, calculating the mass fraction of each split sample when the comprehensive sample is combined; and according to the mass fraction of each sample when the comprehensive sample is combined, combining the samples to obtain the comprehensive sample. The method for determining the combination proportion of the comprehensive samples for accounting the coal element carbon content is high in practical applicability, simple in calculation process and accurate in result, has high practical application value and provides a basis for accurately accounting the coal element carbon content.

Description

Technical Field

[0001] The invention belongs to the technical field of coal sample collection in thermal power plants, and in particular relates to a method for preparing a comprehensive sample for calculating the elemental carbon content of coal. Background Art

[0002] The fossil fuel used by thermal power companies is coal. When calculating the carbon dioxide emissions from coal combustion during the statistical period, the consumption of coal is measured by a qualified belt scale or pressure-resistant metering coal feeder, and the elemental carbon content of coal can be obtained in one of three ways: 1) daily testing; 2) testing for each batch; 3) monthly sub-sample testing. In addition, the elemental carbon content of coal should be tested by a testing agency or laboratory that has been certified by CMA or CNAS, and the accreditation includes elemental carbon content. For method 1) daily testing and method 2) each batch testing, the daily sample volume sent to the testing agency is large and the cost increases dramatically, the testing cycle is long, the efficiency is low, and it is not conducive to the actual production management of fuel. Therefore, thermal power companies currently calculate the monthly elemental carbon content of coal mainly by method 3) monthly sub-sample testing, that is, the coal samples collected daily by a certain proportion are combined and mixed as monthly test samples, which are used to test the elemental carbon content as the monthly elemental carbon content of coal.

[0003] The "Guidelines for Accounting and Reporting of Greenhouse Gas Emissions for Enterprises - Power Generation Facilities (Revised 2022 Edition)" clearly states that when merging monthly subsamples for testing, before merging and mixing, the mass of each subsample should be proportional to the mass of the raw coal entering the furnace and the benchmark should be consistent. In actual application, the commonly used benchmarks for coal samples are as-received basis and air-dried basis. The as-received basis refers to the original state of the coal, and the nominal maximum particle size of the coal entering the furnace is generally 25 mm and above. The as-received basis storage volume of coal samples with a particle size of 25 mm must not be less than 40 kg. Taking 5 coals entering the furnace per day as an example, the amount of coal samples in the original state that need to be stored must not be less than 200 kg, and the amount of raw coal stored per month is nearly 6,000 kg, which is not conducive to implementation and difficult to store. The coal samples in the as-received basis state have a large particle size, and further sample preparation and crushing to a smaller particle size are required for sample reduction, and the crushing process is prone to cause total moisture loss, which deviates from the benchmark of the as-received basis state. The air-dried basis state refers to the state of the coal sample when a coal sample of a certain particle size reaches a state of equilibrium with the air humidity. The coal samples in the air-dried state include general analysis samples with a particle size of 0.2 mm and reference samples with a particle size of 3 mm. The general analysis samples of 0.2 mm are small in size. During the storage for one month, the coal quality is prone to oxidation and deterioration, which can easily lead to deviations in the test results. Therefore, the monthly coal reduction samples of thermal power companies are obtained by merging and mixing reference samples with a particle size of 3 mm. The 3 mm reference sample is generally 700g to 900g, which is easy to store and manage. Thermal power companies use the 3 mm reference sample of the daily coal entering the furnace to calculate the combined ratio according to the weighted average of the proportion of the daily raw coal entering the furnace in the month to generate monthly reduction samples as samples for calculating the carbon content of the coal. However, the 3 mm reference sample of the coal entering the furnace is not consistent with the benchmark of its raw coal sample. Especially when the external moisture content of the daily raw coal sample is greatly different, the combined ratio has a large deviation, resulting in the measurement value of the calculated element carbon content of the monthly combined sample not being consistent with the actual emission. Summary of the invention

[0004] In order to overcome the technical problem in the prior art that the measured values ​​of the calculated element carbon content of the monthly combined samples are inconsistent with the actual emissions, the purpose of the present invention is to provide a method for preparing a comprehensive sample for calculating the carbon content of coal. The comprehensive sample prepared by this method can accurately calculate the calculated element carbon content of the monthly combined samples, so that the measured values ​​of the calculated element carbon content of the monthly combined samples are consistent.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a comprehensive sample for calculating the elemental carbon content of coal comprises the following steps:

[0007] Obtain the particle size of each subsample combined for determining the elemental carbon content of the coal, the parameter information of the incoming coal corresponding to each subsample, and the weight of each subsample in an air-dried state;

[0008] According to the parameter information of the incoming coal corresponding to each sub-sample and the weight of each sub-sample in the air-dry state, calculate the calibrated air-dried basis moisture of each sub-sample when combining the comprehensive samples;

[0009] According to the calibrated air-dried basis moisture of each sub-sample, calculate the air-dried basis converted sample quantity of the raw coal entering the furnace corresponding to each sub-sample;

[0010] Calculate the mass fraction of each sub-sample when merging the comprehensive sample according to the air-dried basis converted sample quantity of the raw coal entering the furnace corresponding to each sub-sample;

[0011] According to the mass fraction of each sub-sample when merging the comprehensive sample, combine the sub-samples to obtain the comprehensive sample.

[0012] Furthermore, the particle size of each sample is 3 mm or 0.2 mm.

[0013] Furthermore, the parameter information of the coal fed into the furnace corresponding to each sample includes the raw coal consumption m of the coal fed into the furnace corresponding to each sample. i , the corresponding received basic moisture content of the coal entering the furnace is M ar,i， Air dried basis moisture content of each sample M ad,i And the original weight of each sample m s,i .

[0014] Furthermore, the weight of each sample in an air-dried state is the weight of each sample when it is placed in an air-room temperature environment to reach an air-dried state.

[0015] Furthermore, the air-dried state is the air-dried state achieved by placing each subsample in an air room temperature environment according to the GB / T474 standard method.

[0016] Furthermore, the calibration air-dried moisture of each sample Calculated by the following formula:

[0017]

[0018] In the formula, is the weight of each sample in air-dry state, m s,i is the original weight of each sample.

[0019] Further, according to the calibrated air-dried basis moisture of each sub-sample, the air-dried basis converted sample quantity of the raw coal entering the furnace corresponding to each sub-sample is calculated, including the following steps:

[0020] According to the calibrated air-dried basis moisture of each sample, calculate the surface moisture of the raw coal corresponding to each sample;

[0021] According to the surface moisture of the raw coal corresponding to each sample, calculate the air-dried basis converted sample quantity of the raw coal corresponding to each sample.

[0022] Furthermore, the surface moisture M of the raw coal corresponding to each sample is s.i Calculated by the following formula:

[0023]

[0024] M s.i ——Surface moisture of the i-th raw coal sample fed into the furnace, in %;

[0025] M ar,i ——The received basis moisture of the raw coal sample of the i-th coal fed into the furnace, in %;

[0026] ——the calibrated air-dried basis moisture of each sub-sample when combining the comprehensive samples, in %;

[0027] i——the number of samples.

[0028] Furthermore, the air-dried basis converted sample volume m of the raw coal fed into the furnace corresponding to each sub-sample zs,i Calculated by the following formula:

[0029] m zs,i =m i ×(100-M s,i ) / 100

[0030] In the formula, m i is the raw coal consumption corresponding to each sample, m s,i is the original weight of each sample.

[0031] Furthermore, the mass fraction of each sample when merging the comprehensive sample is w i Calculated by the following formula:

[0032]

[0033] In the formula, m zs,i The air-dried basis converted sample quantity of the raw coal entering the furnace corresponding to each sub-sample.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] First, the use of the reserve sample of coal entering the furnace to reduce and merge the comprehensive carbon emission samples is more practical than the raw coal samples entering the furnace. The sample volume of the reserve sample is less than that of the raw coal sample, and the storage volume is greatly reduced, which is convenient for storage. The reduction and merging process is easier to operate than the mixing of raw coal samples, and the uniformity is higher.

[0036] Second, the calculation process is simple. The surface moisture is calculated by using the air-dried basis moisture and as-received basis moisture parameters of the general analysis sample. The calculation is simple and the method is reliable.

[0037] 3. Accurate results. Before merging the comprehensive sample, each sub-sample is air-dried and reaches an air-dry state, which avoids the influence of the change of air-dried basis moisture on the moisture baseline state of the sample caused by the change of ambient temperature when the sub-samples are combined to prepare the comprehensive sample. The method can achieve the consistency of the benchmark of each scaled-down sample of the coal entering the furnace before merging and mixing. Compared with the guideline requirement that the mass of each scaled-down sample should be proportional to the mass of the raw coal sample of the coal entering the furnace, the benchmark is the received basis. This method achieves accurate calculation of the merging ratio by converting the mass of the raw coal sample of the coal entering the furnace and assuming the coal sample mass in the air-dry basis state when each sub-sample reaches an air-dry state, providing a basis for accurately calculating the elemental carbon content of the coal. DETAILED DESCRIPTION

[0038] In order to facilitate the understanding of the present invention, the present invention is described more comprehensively below. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly and comprehensively understood.

[0039] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0040] The present invention provides a method for preparing a comprehensive sample for calculating the element carbon content, comprising the following steps:

[0041] Step 1: Determine the particle size of each subsample of the air-dried composite sample to be combined for determining the elemental carbon content of coal, 3 mm or 0.2 mm;

[0042] Step 2: Collect the raw coal consumption m corresponding to each sample i , the corresponding received basic moisture content of the coal entering the furnace is M ar,i , the air-dried basis moisture of each sample at that time M ad,i , the weight of each sample at that time, that is, the original weight of each sample m s,i ;

[0043] Step 3: On the day of merging the comprehensive samples, place each subsample in an air room temperature environment according to the GB / T474 standard method to reach an air-dried state, and record the weight of each subsample at this time, that is, the weight of each subsample in the air-dried state.

[0044] Step 4: Calculate the calibrated air-dried basis moisture of each subsample on the day of the combined comprehensive test based on the original weight of each subsample and the weight of each subsample in the air-dried state

[0045]

[0046] Step 5: According to the calibrated air-dried basis moisture of each sample, calculate the surface moisture M of the raw coal corresponding to each sample according to the following formula: s.i ,

[0047]

[0048] M s.i ——Surface moisture of the i-th raw coal sample fed into the furnace, in %;

[0049] M ar,i ——The received basis moisture of the raw coal sample of the i-th coal fed into the furnace, in %;

[0050] ——the calibrated air-dried basis moisture of each sub-sample when combining the comprehensive samples, in %;

[0051] i——the number of samples.

[0052] Step 6: According to the surface moisture of the raw coal corresponding to each sample, calculate the air-dried basis equivalent sample volume m of the raw coal corresponding to each sample according to the following formula: zs,i :

[0053] m zs,i =m i ×(100-M s,i ) / 100

[0054] Step 7: Calculate the mass fraction w of each sample when merging the comprehensive sample according to the air-dried basis converted sample quantity of the raw coal entering the furnace corresponding to each sample. i :

[0055]

[0056] The following are specific embodiments.

[0057] Example 1: Calculate the proportion of each subsample of the 3mm reference subsample of the daily coal fed into a power plant and the combined monthly carbon emission verification comprehensive sample.

[0058] (1) Step 1: The particle size of each subsample used to combine the air-dried composite sample for monthly carbon emission verification is 3 mm;

[0059] (2) Step 2: There are two 3mm samples of coal for inspection on two days in the month, that is, two sub-samples. The corresponding raw coal consumption mi , the corresponding received basic moisture content of the coal entering the furnace is M ar,i， The air-dried moisture content of the two samples at that time is M ad,i , the weight of the two samples at that time is m s,i , see the table below;

[0060]

[0061] (3) Step 3: On the day of combining the comprehensive samples, place each subsample in an air-drying state at room temperature according to the GB / T474 standard method, and record the weight of the two subsamples when they are air-dried. See the table below;

[0062]

[0063] (4) Step 4: Calculate the calibrated air-dried basis moisture of the two samples on the day of the combined sample Calibration air-dried moisture of the first aliquot:

[0064]

[0065] Calibration air-dried moisture of the second aliquot:

[0066]

[0067] (5) Step 5: Calculate the surface moisture M of the raw coal corresponding to the two samples s.i ,

[0068] The surface moisture of the first raw coal fed into the furnace is M s.1 :

[0069] The surface moisture of the second raw coal fed into the furnace is M s.2 : (6) Step 6: Calculate the air-dried equivalent sample volume m of the raw coal for the two samples zs,i :

[0070] Air-dried basis converted sample volume of the first coal fed into the furnace m zs,1 :m zs,1 =m1×(100-M s,1 ) / 100

[0071] =2000×(100-1.05) / 100

[0072] =1979.00(t)

[0073] Air-dried basis converted sample volume of the second coal fed into the furnace m zs,2 :m zs,2 =m2×(100-M s,2 ) / 100

[0074] =1000×(100-2.22) / 100

[0075] =977.80(t)

[0076] (7) Step 7: Calculate the mass fraction w of the two 3 mm sub-samples when merging the composite sample i :

[0077] The mass fraction w1 of the first 3mm sample of coal in the comprehensive sample:

[0078]

[0079] The mass fraction w2 of the second 3mm sample of coal in the comprehensive sample:

[0080]

[0081] The calculation results show that: 66.93:33.07=2.02:1, which is close to the ratio of raw coal entering the furnace of 2000:1000=2:1.

[0082] Example 2: Calculate the proportion of each sub-sample of the 3mm reference sub-sample of the daily coal fed into a power plant and the combined monthly carbon emission verification comprehensive sample.

[0083] (1) Step 1: The particle size of each subsample used to combine the air-dried composite sample for monthly carbon emission verification is 3 mm;

[0084] (2) Step 2: There are two 3mm samples of coal for inspection on two days in the month, that is, two sub-samples. The corresponding raw coal consumption m i , the corresponding received basic moisture content of the coal entering the furnace is M ar,i， The air-dried moisture content of the two samples at that time is M ad,i , the weight of the two samples at that time is m s,i , see the table below;

[0085]

[0086] (3) Step 3: On the day of combining the comprehensive samples, place each subsample in an air-drying state at room temperature according to the GB / T474 standard method, and record the weight of the two subsamples when they are air-dried. See the table below;

[0087]

[0088] (4) Step 4: Calculate the calibrated air-dried basis moisture of the two samples on the day of the combined sample

[0089] Calibration air-dried moisture of the first aliquot:

[0090]

[0091] Calibration air-dried moisture of the second aliquot:

[0092]

[0093] (5) Step 5: Calculate the surface moisture M of the raw coal corresponding to the two samples s.i ,

[0094] The surface moisture of the first raw coal fed into the furnace is M s.1 : The surface moisture of the second raw coal fed into the furnace is M s.2 : (6) Step 6: Calculate the air-dried equivalent sample volume m of the raw coal for the two samples zs,i :

[0095] Air-dried basis converted sample volume of the first coal fed into the furnace m zs,1 :m zs,1 =m1×(100-M s,1 ) / 100

[0096] =2000×(100-1.05) / 100

[0097] =1979.00(t)

[0098] Air-dried basis converted sample volume of the second coal fed into the furnace m zs,2 :m zs,2 =m2×(100-M s,2 ) / 100

[0099] =1000×(100-20.50) / 100

[0100] =795.00(t)

[0101] (7) Step 7: Calculate the mass fraction w of the two 3 mm sub-samples when merging the composite sample i :

[0102] The mass fraction w1 of the first 3mm sample of coal in the comprehensive sample:

[0103]

[0104] The mass fraction w2 of the second 3mm sample of coal in the comprehensive sample:

[0105]

[0106] The calculation results show that: 71.34:28.66=2.49:1, which is quite different from the ratio of 2000:1000=2:1 of the raw coal entering the furnace.

[0107] Comparative Example 1: The carbon emissions are calculated using the raw coal ratio in the sample reduction ratio.

[0108] The actual carbon emissions are calculated as follows:

[0109] As-received carbon content C of subsample 1 ar，1 =50%, total water content M ar，1 =6%, air-dried basis moisture M ad，1 =5.50%, air dried carbon content C ad，1 =50.27%, coal sample volume 2000 tons (t);

[0110] The received carbon content of subsample 2 is C ar，2 =60%, total moisture M ar，2 =12%, air-dried basis moisture M ad，2 =10.80%, air dried basis carbon content C ad，2 =60.82%, coal sample volume 1000 tons (t); actual emission is calculated as follows:

[0111] E 燃烧，实际 =2000×0.50×0.99×44 / 12+1000×0.60×0.99×44 / 12=5808(tCO2)

[0112] The carbon emissions calculated by using the raw coal volume ratio for the sample reduction ratio are as follows:

[0113] Total moisture content of sample 1 M ar，1 =6%, air-dried basis C ad，1 =50.27%, total moisture content of sample 2 M ar，2 = 12%, air dried basis carbon content C ad，2 =74.80%. The weighted average of the total moisture content of the two samples is M ar，加权=13.48%, if the two 3mm samples are combined at a mass ratio of 2:1, the weighted average of the air-dried basis moisture content M ad，加权 =(2×5.50+1×10.8) / 3=7.27(%), then the air-dried carbon content of the combined sample is C ad，合并 =(2×50.27+1×74.80) / 3=58.45(%), the converted value of the received carbon content of the combined sample is C ar，合并 =58.45×(100-13.48) / (100-7.27)=54.54(%).

[0114] The carbon emissions calculated in this way are:

[0115] E 燃烧，核算 =3000×0.5454×0.99×44 / 12=5939.41(tCO2)

[0116] It can be seen that if the 3mm reference sample is reduced according to the original coal volume, the calculated carbon emissions of 5,939.41 tons of carbon dioxide when the actual coal consumption is 3,000 tons differ from the actual emissions of 5,808 tons of carbon dioxide by 131.41 tons of carbon dioxide. Taking two 600MW units as an example, the annual coal consumption is about 2 million tons. The calculated carbon emissions differ from the actual emissions by about 87,600 tons.

[0117] Comparative Example 2: The carbon emissions were calculated using the method of the present invention at the reduced scale of the reference sample.

[0118] The actual carbon emissions are calculated as follows:

[0119] As-received carbon content C of subsample 1 ar，1 =50%, total water content M ar，1 =6%, air-dried basis moisture M ad，1 =5.50%, air dried carbon content C ad，1 =50.27%, coal sample volume 2000 tons (t);

[0120] The received carbon content of subsample 2 is C ar，2 =60%, total moisture M ar，2 =28.45%, air-dried basis moisture M ad，2 =10.80%, air dried basis carbon content C ad，2 =74.80%, coal sample volume 1000 tons (t); actual emission is calculated as follows:

[0121] E 燃烧，实际 =2000×0.50×0.99×44 / 12+1000×0.60×0.99×44 / 12=5808(tCO2)

[0122] The carbon emissions calculated by the method of the present invention are calculated as follows:

[0123] According to the method of the present invention: the total water content M of the sample 1 ar，1 =6%, converted to air-dried basis moisture Air dry basis carbon content Total moisture content of sample 2 M ar，2 =28.45%, converted to air-dried basis moisture Carbon content on air dry basis The weighted average of the total moisture content of the two samples is M ar，加权 =13.48%. If the combined ratio of the two 3 mm samples is calculated according to the present invention to obtain a mass ratio of 2.49:1, the weighted average water content on an air-dried basis is M ad，加权 =(2.49×5.00+1×10.0) / 3.49=6.43(%), then the air-dried carbon content of the combined sample is C ad，合并 =(2.49×50.53+1×75.47) / 3.49=57.68(%), the converted value of the received carbon content of the combined sample is C ar，合并 =57.68×(100-13.48) / (100-6.43)=53.33(%).

[0124] The carbon emissions calculated in this way are:

[0125] E 燃烧，核算 =3000×0.5333×0.99×44 / 12=5807.64(tCO2)

[0126] It can be seen from this that if the 3mm reference sample is reduced according to the reduction ratio determined by the method of the present invention when merging the comprehensive sample, the elemental carbon content is calculated to be 53.33%, and the calculated carbon dioxide emissions are 5807.64 tons. Because the calculation process retains two decimal places, if it is rounded to the unit place, the result is 5808 tons, which is consistent with the actual carbon dioxide emissions of 5808 tons.

[0127] Example 3: Calculate the proportion of each subsample of the 3mm reference subsample of the daily coal fed into a power plant and the combined monthly carbon emission verification sample.

[0128] Step 1: The particle size of each sub-sample used to combine the air-dried composite sample for monthly carbon emission verification is 3 mm;

[0129] Step 2: There are two days of 3mm samples of coal for inspection in the month, that is, there are two sub-samples. The corresponding raw coal consumption m i , the corresponding received basic moisture content of the coal entering the furnace is M ar,i， The air-dried moisture content of the two samples at that time is M ad,i , the weight of the two samples at that time is ms,i , see the table below;

[0130]

[0131] Step 3: On the day of combining the comprehensive samples, place each subsample in an air room temperature environment according to the GB / T474 standard method to reach an air-dried state, and record the weight of the two subsamples when they reach the air-dried state See the table below;

[0132]

[0133] Step 4: Calculate the calibrated air-dried moisture of the two samples on the day of the combined sample

[0134] Calibration air-dried moisture of the first aliquot:

[0135]

[0136] Calibration air-dried moisture of the second aliquot:

[0137]

[0138] Step 5: Calculate the surface moisture M of the raw coal corresponding to the two samples s.i ,

[0139] The surface moisture of the first raw coal fed into the furnace is M s.1 :

[0140] The surface moisture of the second raw coal fed into the furnace is M s.2 :

[0141] Step 6: Calculate the air-dried basis equivalent sample volume m of the raw coal entering the furnace corresponding to the two sub-samples zs,i :

[0142] Air-dried basis converted sample volume of the first coal fed into the furnace m zs,1 :m zs,1 =m1×(100-M s,1 ) / 100

[0143] =2000×(100-1.05) / 100

[0144] =1979.00(t)

[0145] Air-dried basis converted sample volume of the second coal fed into the furnace m zs,2 :m zs,2 =m2×(100-Ms,2 ) / 100

[0146] =1000×(100-23.88) / 100

[0147] =761.20(t)

[0148] Step 7: Calculate the mass fraction w of the two 3 mm sub-samples when merging the composite sample i :

[0149] The mass fraction w1 of the first 3mm sample of coal in the comprehensive sample:

[0150]

[0151] The mass fraction w2 of the second 3mm sample of coal in the comprehensive sample:

[0152]

[0153] The calculation results show that: 72.22:27.78=2.60:1, which is quite different from the ratio of 2000:1000=2:1 of the raw coal entering the furnace.

[0154] Comparative Example 3: Before preparing the comprehensive sample, the sample was not weighed to determine whether there was a change in moisture, that is, the impact of air-dried basis moisture on the calculated carbon emissions.

[0155] The actual carbon emissions are calculated as follows:

[0156] As-received carbon content C of subsample 1 ar，1 =50%, total water content M ar，1 =6%, air-dried basis moisture M ad，1 =5.50%, air dried carbon content C ad，1 =50.27%, coal sample volume 2000 tons (t);

[0157] The received carbon content of subsample 2 is C ar，2 =60%, total moisture M ar，2 =28.45%, air-dried basis moisture M ad，2 =10.80%, air dried basis carbon content C ad，2 =74.80%, coal sample volume 1000 tons (t); actual emission is calculated as follows:

[0158] E 燃烧，实际 =2000×0.50×0.99×44 / 12+1000×0.60×0.99×44 / 12=5808(tCO2)

[0159] Before preparing the comprehensive sample, the sample was not weighed. When calculating the sample reduction ratio, the sample 1 air-dried basic moisture M ad，1 =5.50%, air-dried basis moisture content of sample 2 M ad，2 =10.80%, then the calculation results of carbon emissions are as follows:

[0160] The surface moisture of the first raw coal fed into the furnace is M s.1 :

[0161] The surface moisture of the second raw coal fed into the furnace is M s.2 :

[0162] Calculate the air-dried basis equivalent sample volume m of the raw coal fed into the furnace corresponding to the two sub-samples zs,i :

[0163] Air-dried basis converted sample volume of the first coal fed into the furnace m zs,1 :m zs,1 =m1×(100-M s,1 ) / 100

[0164] =2000×(100-0.53) / 100

[0165] =1989.40(t)

[0166] Air-dried basis converted sample volume of the second coal fed into the furnace m zs,2 :m zs,2 =m2×(100-M s,2 ) / 100

[0167] =1000×(100-19.79) / 100

[0168] =802.09(t)

[0169] Calculate the mass fraction w of the two 3 mm sub-samples when merging the composite sample i :

[0170] The mass fraction w1 of the first 3mm sample of coal in the comprehensive sample:

[0171]

[0172] The mass fraction w2 of the second 3mm sample of coal in the comprehensive sample:

[0173]

[0174] The determined merger ratio is: 71.27:28.73=2.48:1.

[0175] When the two samples are divided into two parts to prepare the total sample, they have reached the air-dried state. At this time, the total moisture content of the sample 1 is M ar，1 =6%, air dried basis moisture Air dry basis carbon content Total moisture content of sample 2 M ar，2 =28.45%, air-dried basis moisture M ad，2 = 6.00%, air dried basis carbon content The weighted average of the total moisture content of the two samples is M ar，加权 =13.48%. The weighted average of the air-dried moisture content of the two 3mm samples is M. ad，加权 =(2.48×5.00+1×6.00) / 3.48=5.29(%), then the air-dried carbon content of the combined sample is C ad，合并 =(2.48×50.53+1×78.83) / 3.48=58.66(%), the converted value of the received carbon content of the combined sample is C ar，合并 =58.66×(100-13.48) / (100-5.29)=53.59(%).

[0176] The carbon emissions calculated in this way are:

[0177] E 燃烧，核算 =3000×0.5359×0.99×44 / 12=5835.96(tCO2)

[0178] It can be seen from this that: before preparing the comprehensive sample, the sample was not weighed, and the original air-dried basic moisture value was used to calculate the sample reduction ratio. When preparing the comprehensive sample, the air-dried basic moisture of each sample changed, and even reached the air-dry state. At this time, if the sample reduction ratio calculated by the original air-dried basic moisture value is still used for sample preparation, the carbon emissions of 5835.96 tons of carbon dioxide calculated when the actual coal consumption is 3,000 tons differ from the actual emissions of 5808 tons of carbon dioxide by 27.96 tons of carbon dioxide. Taking two 600MW units as an example, the annual coal consumption is about 2 million tons. The carbon emissions calculated in this way differ from the actual emissions by about 18,640 tons.

[0179] The method for determining the comprehensive sample merging ratio for calculating the elemental carbon content of coal in the present invention has strong practical applicability, simple calculation process, accurate results, high practical application value, and provides a basis for accurately calculating the elemental carbon content of coal.

[0180] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0181] In addition, it should be understood that although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of ​​the present invention, and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a comprehensive sample for calculating the elemental carbon content of coal, characterized in that: The following steps are involved: Obtain the particle size of each subsample combined for determining the elemental carbon content of the coal, the parameter information of the incoming coal corresponding to each subsample, and the weight of each subsample in an air-dried state; According to the parameter information of the incoming coal corresponding to each sub-sample and the weight of each sub-sample in the air-dry state, calculate the calibrated air-dried basis moisture of each sub-sample when combining the comprehensive samples; According to the calibrated air-dried basis moisture of each sub-sample, calculate the air-dried basis converted sample quantity of the raw coal entering the furnace corresponding to each sub-sample; Calculate the mass fraction of each sub-sample when merging the comprehensive sample according to the air-dried basis converted sample quantity of the raw coal entering the furnace corresponding to each sub-sample; According to the mass fraction of each sub-sample when merging the comprehensive sample, combine the sub-samples to obtain the comprehensive sample.

2. The method for preparing a comprehensive sample for calculating the elemental carbon content of coal according to claim 1, characterized in that: The particle size of each sample is 3mm or 0.2mm.

3. The method for preparing a comprehensive sample for calculating the elemental carbon content of coal according to claim 1, characterized in that: The parameter information of the coal fed into the furnace corresponding to each sample includes the raw coal consumption m of the coal fed into the furnace corresponding to each sample i , the corresponding received basic moisture content of the coal entering the furnace is M ar,i , the air-dried basis moisture of each sample M ad,i And the original weight of each sample m s,i .

4. The method for preparing a comprehensive sample for calculating the elemental carbon content of coal according to claim 1, characterized in that: The weight of each sample in an air-dried state is the weight of each sample when it is placed in an air-room temperature environment to reach an air-dried state.

5. The method for preparing a comprehensive sample for calculating the elemental carbon content of coal according to claim 1, characterized in that: The air-dried state is the air-dried state achieved by placing each sample in an air room temperature environment according to the GB / T474 standard method.

6. The method for preparing a comprehensive sample for calculating the elemental carbon content of coal according to claim 1, characterized in that: Calibrated air-dried moisture content of each sample Calculated by the following formula: In the formula, is the weight of each sample in air-dry state, m s,i is the original weight of each sample.

7. The method for preparing a comprehensive sample for calculating the elemental carbon content of coal according to claim 1, characterized in that: According to the calibrated air-dried basis moisture of each sub-sample, the air-dried basis converted sample quantity of the raw coal entering the furnace corresponding to each sub-sample is calculated, including the following steps: According to the calibrated air-dried basis moisture of each sample, calculate the surface moisture of the raw coal corresponding to each sample; According to the surface moisture of the raw coal corresponding to each sample, calculate the air-dried basis converted sample quantity of the raw coal corresponding to each sample.

8. The method for preparing a comprehensive sample for calculating the elemental carbon content of coal according to claim 7, characterized in that: The surface moisture M of the raw coal corresponding to each sample s.i Calculated by the following formula: M s.i ——Surface moisture of the i-th raw coal sample fed into the furnace, in %; M ar,i ——The received basis moisture of the raw coal sample of the i-th coal fed into the furnace, in %; ——the calibrated air-dried basis moisture of each sub-sample when combining the comprehensive samples, in %; i——the number of samples.

9. The method for preparing a comprehensive sample for calculating the elemental carbon content of coal according to claim 7, characterized in that: Air-dried basis converted sample volume of raw coal for each sub-sample m zs,i Calculated by the following formula: m zs,i =m i ×(100-M s,i ) / 100 In the formula, m i is the raw coal consumption corresponding to each sample, m s,i is the original weight of each sample.

10. The method for preparing a comprehensive sample for calculating the elemental carbon content of coal according to claim 1, characterized in that: The mass fraction of each subsample when merging the comprehensive sample w i Calculated by the following formula: In the formula, m zs,i The air-dried basis converted sample quantity of the raw coal entering the furnace corresponding to each sub-sample.

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