A method for determining the size of the erosion wear index Ke of coal

Abstract

The present invention discloses a method for discriminating the magnitude of the erosion wear index Ke of coal, which includes the steps of: 1. Obtaining the as-received ash content A of coal ar , the as-received oxygen O ar and the coal ash components SiO 2 (%), Al 2 O 3 (%); 2. Calculating the sum SSiAl of silicon and aluminum components, the ratio RSiAl of silicon and aluminum components, the sum SCSiAl of silicon and aluminum components in coal, the ratio ROSi of oxygen to silicon, the silicon CSi in coal, the aluminum CAl in coal, and the ratio ROCSi of oxygen to silicon in coal; 3. Discriminating the magnitude of the erosion wear index Ke of coal according to the magnitudes of the index values in step 2. The method of the present invention is simple and fast. The research results are obtained through statistical analysis of a large amount of test data in the laboratory, with high discrimination accuracy and high engineering application value. It can guide the fuel procurement and blended coal combustion in power plants, improve the adaptability of the coal entering the furnace to the coal pulverizing system, be conducive to improving the equipment life of the coal pulverizing system, the load-carrying capacity and combustion economy of the boiler, and saving the equipment maintenance cost.

Description

Technical Field

[0001] The present invention relates to the technical field of coal wear performance, and specifically relates to a method for judging the size of the erosion wear index Ke of coal, which is applicable to anthracite, lean coal, bituminous coal and lignite. Background Art

[0002] According to the "DL / T466-2017 Guide for the Selection of Power Plant Ball Mills and Pulverizing Systems", the erosion wear index Ke of coal is one of the important reference indicators for the selection of ball mill types. When Ke is greater than 5, it is recommended to use a steel ball mill. For lignite, when Ke is greater than 3.5, it is not recommended to use a medium-speed ball mill.

[0003] In actual operation of power plants, the erosion wear index Ke of coal is basically not tested, and this index needs to be tested in a professional institution. At present, only one scientific research unit in China can conduct this project test. Therefore, it is very difficult to monitor the erosion wear index Ke of incoming coal during the daily operation of power plants. When the erosion wear index Ke of the coal being burned does not match the equipment, it is easy to cause wear of the grinding parts and related equipment of the ball mill, resulting in wear of the grinding parts of the ball mill, a decrease in the output of the ball mill, and coarser pulverized coal, affecting the load-carrying capacity and combustion economy of the unit. Summary of the Invention

[0004] In order to overcome the above-mentioned disadvantages of the prior art, a method for judging the size of the erosion wear index Ke of coal, which is applicable to anthracite, lean coal, bituminous coal and lignite.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for judging the size of the erosion wear index Ke of coal, which is applicable to anthracite, lean coal, bituminous coal and lignite, includes the following steps:

[0007] The first step: Obtain the as-received ash content A ar , as-received oxygen O ar and coal ash components SiO 2 , Al 2 O 3 , all in units of %.

[0008] The second step: Calculate the sum of silicon and aluminum components SSiAl, the ratio of silicon to aluminum components RSiAl, the sum of silicon and aluminum components in coal SCSiAl, the ratio of oxygen to silicon ROSi, the silicon in coal CSi, the aluminum in coal CAl, and the ratio of oxygen to silicon in coal ROCSi. The units of the sum of silicon and aluminum components, the sum of aluminum components, silicon in coal CSi, and aluminum in coal Cal are all %.

[0009] The third step: Judge the size of the erosion wear index ke of the coal sample according to the sum of silicon and aluminum components SSiAl. The specific principles and judgment methods are as follows:

[0010] 1) SSiAl < 60%: If SCSiAl < 10, then ke < 3.5; otherwise, 3.5 ≤ ke < 5.0.

[0011] 2) 60 ≤ SSiAl < 70%: First, determine the size of Ke based on the amount of aluminum CAl in the coal. If CAl > 6, then ke > 5. Then, determine the size of Ke based on the value of RSiAl. If RSiAl < 3.5, ke < 3.5; otherwise, 3.5 ≤ ke ≤ 5.0.

[0012] 3) 70 ≤ SSiAl < 80%: If RSiAl ≥ 3.9 or CSi > 18.5, then ke > 5; otherwise, Ke ≤ 5.0.

[0013] 4) SSiAl ≥ 80%: First, determine the size of Ke based on the values of RSiAl and CSi. If RSiAl ≥ 3.6 or CSi > 25, then ke > 5. Then, determine the size of Ke based on the value of ROSi. If ROSi ≥ 0.2, then Ke < 3.5; otherwise, 3.5 ≤ ke ≤ 5.0.

[0014] A further improvement of the present invention lies in that the calculation formula for the sum of silicon and aluminum components SSiAl is:

[0015] SSiAl = SiO 2 + Al 2 O 3 (Formula 1).

[0016] A further improvement of the present invention lies in that the calculation formula for the silicon-aluminum component ratio RSiAl is:

[0017]

[0018] A further improvement of the present invention lies in that the calculation formula for the sum of silicon and aluminum components SCSiAl in the coal is:

[0019]

[0020] A further improvement of the present invention lies in that the calculation formula for the oxygen-silicon ratio ROSi is:

[0021]

[0022] A further improvement of the present invention lies in that the calculation formula for the silicon CSi in the coal is:

[0023]

[0024] A further improvement of the present invention lies in that the calculation formula for the aluminum CAl in the coal is:

[0025]

[0026] A further improvement of the present invention lies in that the calculation formula of the ratio of oxygen to silicon in coal, ROCSi, is:

[0027]

[0028] The present invention has at least the following beneficial technical effects:

[0029] A method provided by the present invention for discriminating the erosion wear index Ke of coal is applicable to anthracite, lean coal, bituminous coal and lignite.

[0030] The advantages of the present invention are as follows: ① The erosion wear index of a coal sample can be discriminated based on the conventional coal quality detection indexes of the coal, and the method is simple and fast. ② The result is obtained through statistical analysis of the test results of a large number of laboratories, with high calculation accuracy and high engineering application value. ③ It can guide the fuel procurement and blended coal combustion in power plants, improve the adaptability of the coal entering the furnace to the coal pulverizing system, increase the service life of the grinding parts of the coal mill, and improve the load-carrying capacity and combustion economy of the boiler. Specific embodiments

[0031] The exemplary embodiments of the present disclosure will be described in detail below. These embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0032] Example 1 - Prediction of the erosion wear index Ke of Sample 1

[0033] The present invention will be further described in detail below with reference to the embodiments.

[0034] First step: Obtain the as-received ash content A ar (%), the as-received oxygen O ar (%), and the coal ash components SiO 2 (%), Al 2 O 3 (%);

[0035] Coal quality data of Sample 1: A ar = 3.86%, O ar = 10.72%, SiO 2 = 36.62%, Al 2 O 3 = 12.08%;

[0036] Step 2: Calculate the sum of silicon and aluminum components SSiAl (%), the silicon-aluminum component ratio RSiAl ( / ), the sum of silicon and aluminum components in coal SCSiAl (%), the oxygen-silicon ratio ROSi ( / ), the silicon in coal CSi (%), the aluminum in coal CAl (%), and the ratio of oxygen to silicon in coal ROCSi ( / ). See specific formulas (1) to (7) for details.

[0037] SSiAl = SiO 2 + Al 2 O 3 = 36.62 + 12.08 = 48.70 (Formula 1)

[0038]

[0039]

[0040]

[0041]

[0042]

[0043]

[0044] Step 3: Determine the size of the erosion wear index ke of the coal sample according to the sum of silicon and aluminum components SSiAl. The specific principles and determination methods are as follows:

[0045] 1) SSiAl < 60%: If SCSiAl < 10, then ke < 3.5; otherwise 3.5 ≤ ke < 5.0;

[0046] 2) 60 ≤ SSiAl < 70%: First, determine the size of Ke according to the size of aluminum CAl in coal. If CAl > 6, then ke > 5; then determine the size of Ke according to the size of RSiAl. If RSiAl < 3.5, ke < 3.5, and in other cases 3.5 ≤ ke ≤ 5.0;

[0047] 3) 70 ≤ SSiAl < 80%: If RSiAl ≥ 3.9 or CSi > 18.5, then ke > 5; otherwise Ke ≤ 5.0;

[0048] 4) SSiAl ≥ 80%: First, determine the size of Ke according to the size of RSiAl and CSi. If RSiAl ≥ 3.6 or CSi > 25, then ke > 5; then determine the size of Ke according to the size of ROSi. If ROSi ≥ 0.2, then Ke < 3.5, and in other cases 3.5 ≤ ke ≤ 5.0.

[0049] According to the calculation result of the second step, SSiAl = 48.70 < 60%, which belongs to the first case. For sample 1, SCSiAl = 1.88 < 10, then it is determined that ke < 3.5. The actual test result of the erosion wear index Ke of sample 1 is 0.70. It can be seen that the determination result of the present invention is consistent with the actual test result.

[0050] Prediction of the Erosion Wear Index Ke of Sample 2 in Example 2

[0051] Step 1: Obtain the as-received ash content A ar (%), as-received oxygen O ar (%), and coal ash components SiO 2 (%), Al 2 O 3 (%);

[0052] Coal quality data of sample 2: A ar = 13.76%, O ar = 8.17%, SiO 2 = 57.22%, Al 2 O 3 = 16.90%;

[0053] Step 2: Calculate the sum of silicon and aluminum components SSiAl (%), the ratio of silicon to aluminum components RSiAl ( / ), the sum of silicon and aluminum components in coal SCSiAl (%), the ratio of oxygen to silicon ROSi ( / ), silicon in coal CSi (%), aluminum in coal CAl (%), and the ratio of oxygen to silicon in coal ROCSi ( / ). See specific formulas (1) to (7) for details.

[0054] SSiAl = SiO 2 + Al 2 O 3 = 57.22 + 16.90 = 74.12 (Formula 1)

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061] Step 3: Determine the magnitude of the erosion wear index ke of the coal sample according to the sum of silicon and aluminum components SSiAl. The specific principles and determination methods are as follows:

[0062] 1) SSiAl < 60%: If SCSiAl < 10, then ke < 3.5; otherwise, 3.5 ≤ ke < 5.0;

[0063] 2) 60 ≤ SSiAl < 70%: First, determine the size of Ke based on the size of CAl in the coal. If CAl > 6, then ke > 5. Then, determine the size of Ke based on the size of RSiAl. If RSiAl < 3.5, ke < 3.5; otherwise, 3.5 ≤ ke ≤ 5.0;

[0064] 3) 70 ≤ SSiAl < 80%: If RSiAl ≥ 3.9 or CSi > 18.5, then ke > 5; otherwise, Ke ≤ 5.0.

[0065] 4) SSiAl ≥ 80%: First, determine the size of Ke based on the size of RSiAl and CSi. If RSiAl ≥ 3.6 or CSi > 25, then ke > 5. Then, determine the size of Ke based on the size of ROSi. If ROSi ≥ 0.2, then Ke < 3.5; otherwise, 3.5 ≤ ke ≤ 5.0.

[0066] According to the calculation result of the second step, SSiAl = 74.12 < 80%, belonging to the third case. For sample 2, RSiAl = 3.39 < 3.9 and SCSiAl = 10.20 < 18.5, so it is determined that Ke ≤ 5.0. The actual test result of the erosion wear index Ke of sample 2 is 2.88. It can be seen that the determination result is consistent with the actual test result.

[0067] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A method for determining the size of the erosion wear index Ke of coal, characterized in that, this method is applicable to anthracite, lean coal, bituminous coal and lignite, and includes the following steps: Step 1: Obtain the as-received ash content A of coal ar , the as-received oxygen O ar and the coal ash components SiO 2 , Al 2 O 3 , with the unit of all being %; Step 2: Calculate the sum of silicon and aluminum components SSiAl, the ratio of silicon to aluminum components RSiAl, the sum of silicon and aluminum components in coal SCSiAl, the ratio of oxygen to silicon ROSi, the silicon content in coal CSi, the sum of silicon and aluminum components, the sum of aluminum components. The units of the silicon content in coal CSi and the aluminum content in coal CAl are all %. Step 3: Determine the size of the erosion wear index ke of the coal sample according to the sum of silicon and aluminum components SSiAl. The specific principles and determination methods are as follows: 1) SSiAl < 60%: If SCSiAl < 10, then ke < 3.5; otherwise, 3.5 ≤ ke < 5.0; 2) 60 ≤ SSiAl < 70%: First, determine the size of Ke according to the size of the aluminum content CAl in coal. If CAl > 6, then ke > 5; then, determine the size of Ke according to the size of RSiAl. If RSiAl < 3.5, ke < 3.5; in other cases, 3.5 ≤ ke ≤ 5.0; 3) 70 ≤ SSiAl < 80%: If RSiAl ≥ 3.9 or CSi > 18.5, then ke > 5; otherwise, Ke ≤ 5.0; 4) SSiAl ≥ 80%: First, determine the size of Ke according to the size of RSiAl and CSi. If RSiAl ≥ 3.6 or CSi > 25, then ke > 5; then, determine the size of Ke according to the size of ROSi. If ROSi ≥ 0.2, then Ke < 3.5; in other cases, 3.5 ≤ ke ≤ 5.

0.

2. A method for determining the size of the erosion wear index Ke of coal according to claim 1, characterized in that, the calculation formula for the sum of silicon and aluminum components SSiAl is: SSiAl = SiO 2 + Al 2 O 3 (Formula 1).

3. A method for determining the size of the erosion wear index Ke of coal according to claim 1, characterized in that, the calculation formula for the ratio of silicon to aluminum components RSiAl is:

4. A method for determining the size of the erosion wear index Ke of coal according to claim 1, characterized in that, the calculation formula for the sum of silicon and aluminum components in coal SCSiAl is:

5. A method for determining the size of the erosion wear index Ke of coal according to claim 1, characterized in that, the calculation formula for the ratio of oxygen to silicon ROSi is:

6. A method for determining the size of the erosion wear index Ke of coal according to claim 1, characterized in that, the calculation formula for the silicon content in coal CSi is:

7. A method for determining the size of the erosion wear index Ke of coal according to claim 1, characterized in that, the calculation formula for the aluminum content in coal CAl is:

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