A method for discriminating a coal type for a power generation boiler

Abstract

The application discloses a method for distinguishing coal types for power generation boilers, which comprises the following steps: first, obtaining the dry ash-free basis volatile matter V daf , the received basis volatile matter V ar , the dry ash-free basis carbon C daf , the dry ash-free basis hydrogen H daf , the dry ash-free basis oxygen O daf , and the air dry basis moisture M ad ; second, calculating the coal type coefficients k1 and k2; and third, distinguishing the coal type. The application can distinguish the type of the coal sample only by using the conventional coal quality detection results, and the method is simple.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal classification, in particular to a method for distinguishing coal types for power generation boilers, which is suitable for anthracite, lean coal, bituminous coal, long flame coal and lignite. BACKGROUND

[0002] Coal is an important energy and chemical raw material, and plays an extremely important role in people's life and industrial and agricultural production. To rationally develop and utilize coal resources, it is necessary to classify coal scientifically and practically.

[0003] At present, the coal is classified in detail in GB 5751-1986 Chinese Coal Classification, and for coal with V daf > 37% and G ≤ 5, P M is needed to distinguish whether it is bituminous coal or lignite (or long flame coal); for coal with 30% < P M ≤ 50%, Q gr，maf is needed to distinguish whether it is lignite or long flame coal.

[0004] The existing technology needs professional index testing to determine long flame coal and lignite, which is complicated and time-consuming. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the present application relates to a method for distinguishing coal types for power generation boilers, which is suitable for anthracite, lean coal, bituminous coal, long flame coal and lignite.

[0006] To achieve the above purpose, the present application adopts the following technical scheme, and the specific steps are as follows:

[0007] A method for distinguishing coal types for power generation boilers, comprising the following steps:

[0008] Step 1: obtain the dry ash-free volatile matter V daf , %; received base volatile matter V ar , %; dry ash-free carbon C daf , %; dry ash-free hydrogen H daf , %; dry ash-free oxygen O daf , % and air-dry base moisture M ad , %;

[0009] Step 2: calculate the coal type coefficients k1 and k2;

[0010] Step 3: distinguish the coal type.

[0011] The further improvement of the present application is that the method is suitable for anthracite, lean coal, bituminous coal, long flame coal and lignite.

[0012] The further improvement of the present application is that in the second step, the calculation formula of the coal type coefficient k1 is as follows:

[0013]

[0014] The further improvement of the present application is that in the second step, the calculation formula of the coal type coefficient k2 is as follows:

[0015] k2 = H daf + O daf (2).

[0016] The further improvement of the present application is that in the third step, it is judged whether it is lignite: if k1 < 3.5 and k2 ≥ 22, it is judged to be lignite; the auxiliary judgment index V ar ≥ 20%, 64% ≤ C daf ≤ 77%, 4.3% ≤ H daf ≤ 7%, 17% ≤ O daf ≤ 26%.

[0017] The further improvement of the present application is that in the third step, it is judged whether it is bituminous coal and long flame coal: if 3.5 ≤ k1 < 6.5, it is judged to be bituminous coal and long flame coal; if yes, it is further judged whether it is bituminous coal or long flame coal;

[0018] A. if M ad ≥ 12% or 10% < M ad ≤ 12%, and O daf ≥ 14%, it is judged to be long flame coal; the auxiliary judgment index V ar ≥ 18%, 72% ≤ C daf ≤ 82%, 3.0% ≤ H daf ≤ 5.0%, 13% ≤ O daf ≤ 18%;

[0019] B. otherwise, it is judged to be bituminous coal; the auxiliary judgment index V ar ≥ 15%, 82% ≤ C daf ≤ 91%, 3.0% ≤ H daf ≤ 5.2%, 11% ≤ O daf ≤ 17%.

[0020] The further improvement of the present application is that in the third step, it is judged whether it is lean coal: if 6.5 ≤ k1 < 13 and V daf ≥ 10%, it is judged to be lean coal; the auxiliary judgment index V ar ≤ 23%, 82% ≤ C daf ≤ 91%, 3.0% ≤ H daf≤5.2%, 3%≤O daf ≤8.5%.

[0021] A further improvement of this invention lies in the third step, regarding whether it is anthracite: if k1≥13, then it is determined to be anthracite; the auxiliary discrimination index V... ar ≤10%, 88%≤C daf ≤99%, 1%≤H daf ≤4.5%, O daf If the content is ≤3.3%, it is classified as anthracite.

[0022] The present invention has at least the following beneficial technical effects:

[0023] ① The type of coal sample can be determined simply by using conventional coal quality testing results. ② The relevant coal quality index ranges for different coal types have been determined, which can be used to evaluate the accuracy and precision of the test results. ③ This invention is derived from extensive research and summarization of coal quality testing results for different coal types, and can guide coal quality testing and its industrial applications. ④ It clearly stipulates that this invention method can be used for conventional coal types, while special consideration is required for special coal types. Detailed Implementation

[0024] Exemplary embodiments of this disclosure will now be described in more detail. While exemplary embodiments of this disclosure have been shown, it should be understood that this disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of this disclosure and to fully convey the scope of this disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features described herein can be combined with each other. The invention will now be described in detail with reference to embodiments.

[0025] Example 1: Coal Sample 1

[0026] Step 1: Obtain the dry ash-free volatile matter V of the coal sample. daf (%), Received volatile matter V ar (%), Dry Ash-Free Carbon C daf (%), Dry Ash-Free Hydrogen H daf (%), Dry Ash-Free Oxygen daf (%), air-dried basis moisture M ad (%)

[0027] Coal sample 1: V daf =49.93%, received volatile matter V ar =31.81%, dry ash-free carbon C daf =72.64%, dry ash-free base hydrogen H daf =4.88%, dry ash-free basic oxygen O daf=21.68%, air-dried basis moisture M ad =23.16%;

[0028] Step 2: Calculate the coal type coefficients k1 and k2, see equation (1) for details.

[0029]

[0030] k2=H daf +O daf =4.88 + 21.68 = 26.56(2)

[0031] The third step is to identify the type of coal.

[0032] (1) First, determine whether it is lignite: if k1 < 3.5 and k2 ≥ 22, then it is determined to be lignite. Auxiliary discrimination index V ar ≥20%, 64%≤C daf ≤77%, 4.3%≤H daf ≤7%, 17%≤O daf ≤26%;

[0033] Coal sample 1 satisfies k1 = 2.73 < 3.5 and k2 = 26.56 ≥ 22, therefore it is classified as lignite;

[0034] V ar =31.83≥20%, 64%≤C daf =72.64%≤77%, 4.3%≤H daf =4.88% ≤ 7%

[0035] 17% ≤ O daf =21.68≤26%, all coal quality indicators meet the requirements. Therefore, coal sample 1 is identified as lignite.

[0036] (2) Then determine whether it is bituminous coal or long-flame coal: If 3.5≤k1<6.5, then determine whether it is bituminous coal or long-flame coal. If it is, then determine whether it is bituminous coal or long-flame coal.

[0037] A. If M ad ≥12% or 10% <M ad ≤12%, and O daf If the content is ≥14%, it is classified as long-flame coal. Auxiliary discrimination index V ar ≥18%, 72%≤C daf ≤82%, 3.0%≤H daf ≤5.0%, 13%≤O daf ≤18%;

[0038] B. Otherwise, classify it as bituminous coal. Auxiliary discrimination index V ar ≥15%, 82%≤Cdaf ≤91%, 3.0%≤H daf ≤5.2%, 11%≤O daf ≤17%;

[0039] (3) Then determine whether it is lean coal: if 6.5≤k1<13 and V daf If the percentage is ≥10%, it is classified as lean coal. Auxiliary discrimination index V. ar ≤23%, 82%≤C daf ≤91%, 3.0%≤H daf ≤5.2%, 3%≤O daf ≤8.5%;

[0040] (4) Finally, determine whether it is anthracite: If k1 ≥ 13, then it is determined to be anthracite. Auxiliary discrimination index V ar ≤10%, 88%≤C daf ≤99%, 1%≤H daf ≤4.5%, O daf If the content is ≤3.3%, it is classified as anthracite.

[0041] (5) If none of the above characteristics are met, then it is another special type of coal. If the coal type is determined but the auxiliary indicators are not met, it indicates that some of the tested coal quality indicators are mismatched.

[0042] Example 1: Coal Sample 2

[0043] Step 1: Obtain the dry ash-free volatile matter V of the coal sample. daf (%), Received volatile matter V ar (%), Dry Ash-Free Carbon C daf (%), Dry Ash-Free Hydrogen H daf (%), Dry Ash-Free Oxygen daf (%), air-dried basis moisture M ad (%)

[0044] Coal sample 2: V daf =30.41%, received volatile matter V ar =21.11%, dry ash-free carbon C daf =80.84%, dry ash-free base hydrogen H daf =3.72%, dry ash-free basic oxygen O daf =14.08%, air-dried basis moisture M ad =11.41%;

[0045] Step 2: Calculate the coal type coefficients k1 and k2, see equation (1) for details.

[0046]

[0047] k2=H daf +O daf =3.72 + 14.08 = 17.80(2)

[0048] The third step is to identify the type of coal.

[0049] (1) First, determine whether it is lignite: if k1 < 3.5 and k2 ≥ 22, then it is determined to be lignite. Auxiliary discrimination index V ar ≥20%, 64%≤C daf ≤77%, 4.3%≤H daf ≤7%, 17%≤O daf ≤26%;

[0050] Coal sample 2 satisfies k1 = 4.54 > 3.5, but does not meet the lignite condition, proceed to the next step;

[0051] (2) Then determine whether it is bituminous coal or long-flame coal: If 3.5≤k1<6.5, then determine whether it is bituminous coal or long-flame coal. If it is, then determine whether it is bituminous coal or long-flame coal.

[0052] A. If M ad ≥12% or (10%) <M ad ≤12%, and O daf If the content is ≥14%, it is classified as long-flame coal. Auxiliary discrimination index V ar ≥18%, 72%≤C daf ≤82%, 3.0%≤H daf ≤5.0%, 13%≤O daf ≤18%;

[0053] B. Otherwise, classify it as bituminous coal. Auxiliary discrimination index V ar ≥15%, 82%≤C daf ≤91%, 3.0%≤H daf ≤5.2%, 11%≤O daf ≤17%;

[0054] If coal sample 2 satisfies 3.5≤k1=4.54<6.5, then it can be identified as bituminous coal or long-flame coal.

[0055] 10% of coal sample 2 <M ad =11.41≤12%, and O daf If the content is ≥14.08%, it is classified as long-flame coal.

[0056] Auxiliary discriminant index V ar =21.11≥18%, 72%≤C daf =80.84≤82%, 3.0%≤H daf =3.72≤5.0%, 13%≤0 daf=14.08≤18%, both meet the requirements.

[0057] Therefore, coal sample 2 is identified as long-flame coal.

[0058] (3) Then determine whether it is lean coal: if 6.5≤k1<13 and V daf If the percentage is ≥10%, it is classified as lean coal. Auxiliary discrimination index V. ar ≤23%, 82%≤C daf ≤91%, 3.0%≤H daf ≤5.2%, 3%≤O daf ≤8.5%;

[0059] (4) Finally, determine whether it is anthracite: If k1 ≥ 13, then it is determined to be anthracite. Auxiliary discrimination index V ar ≤10%, 88%≤C daf ≤99%, 1%≤H daf ≤4.5%, O daf If the content is ≤3.3%, it is classified as anthracite.

[0060] If none of the above characteristics are met, then it is another special type of coal. If the coal type is determined but the auxiliary indicators are not met, it indicates that some of the tested coal quality indicators are mismatched.

[0061] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A method for identifying the type of coal used in power generation boilers, characterized in that, Includes the following steps: Step 1: Obtain the dry ash-free volatile matter V of the coal sample. daf ,%; received volatile matter V ar %, % Dry ash-free carbon C daf %, % Dry ash-free hydrogen H daf %, % Dry ash-free base oxygen O daf %, and air-dried basis moisture M ad ,% Step 2: Calculate the coal type coefficients k1 and k2; the formula for calculating the coal type coefficient k1 is as follows: (1) The formula for calculating the coal type coefficient k2 is as follows: (2) Step 3: Identify the type of coal, including: Determining whether it is lignite: If k1 < 3.5 and k2 ≥ 22, and the auxiliary discrimination index V ar ≥20%, 64%≤C daf ≤77%, 4.3%≤H daf ≤7% and 17%≤O daf If the content is ≤26%, it is classified as lignite; Determine whether it is bituminous coal or long-flame coal: If 3.5≤k1<6.5, then determine whether it is bituminous coal or long-flame coal; if so, then determine whether it is bituminous coal or long-flame coal. If M ad ≥12%, and auxiliary discriminant V ar ≥18%, 72%≤C daf ≤82%, 3.0%≤H daf ≤5.0% and 13%≤O daf If the concentration is ≤18%, it is classified as long-flame coal; or 10%... <M ad ≤12% and O daf ≥14%, and auxiliary discriminant index V ar ≥18%, 72%≤C daf ≤82%, 3.0%≤H daf ≤5.0% and 13%≤O daf If the content is ≤18%, it is classified as long-flame coal; otherwise, the auxiliary discrimination index V ar ≥15%, 82%≤C daf ≤91%, 3.0%≤H daf ≤5.2% and 1%≤O daf ≤17%, classified as bituminous coal; Determine if it is lean coal: If 6.5 ≤ k1 < 13 and V daf ≥10%, and auxiliary discriminant V ar ≤23%, 82%≤C daf ≤91%, 3.0%≤H daf ≤5.2% and 3%≤O daf If the content is ≤8.5%, it is classified as lean coal; Is it anthracite? If k1≥13, and the auxiliary discrimination index V ar ≤10%, 88%≤C daf ≤99%, 1%≤H daf ≤4.5% and O daf If the content is ≤3.3%, it is classified as anthracite.

2. The method for determining the type of coal used in a power generation boiler according to claim 1, characterized in that, This method is applicable to anthracite, lean coal, bituminous coal, long-flame coal, and lignite.

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