A method of predicting a base flowability curve at a specified ramp rate

Abstract

A method for predicting the base flowability curve at a specified heating rate, establishing a standard flow characteristic parameter TS 3、 TMF 3、 TR 3、 MF 3 and V daf 、 R max 、 G 、 Y The standard flow characteristic parameter prediction function between the extreme point coordinates of the standard base flowability curve ( TMF 3, MF 3) and the intersection coordinates with the X axis ( TS 3, 0), ( TR 3, 0), matches the base flowability curve mathematical model F ( T ) to obtain the standard base flowability curve; Establish different R max specified heating rates HR i flow characteristic parameters TS i 、 TMF i 、 TR i 、 MF i and the prediction function relationship with the standard flow characteristic parameter, obtain the extreme point coordinates of the base flowability curve at the specified heating rate ( TMF i , MF i ) and the intersection coordinates with the X axis ( TS i , 0), ( TR i , 0), match the base flowability curve mathematical model F ( T ) to obtain the base flowability curve at the specified heating rate HR i .

Description

Technical Field

[0001] This invention relates to the technical field of coal quality characteristic evaluation, and in particular to a method for predicting the basic flowability curve of coal with different degrees of coalification at a specified heating rate. Background Technology

[0002] The steel industry is one of the pillar industries of my country's national economy, and coke plays an irreplaceable role as the structural support for the blast furnace during smelting. With the continuous development of advanced low-carbon ironmaking technologies such as large-scale blast furnaces, pulverized coal injection, and blast furnace hydrogen metallurgy, the steel industry's requirements for coke quality are becoming increasingly stringent. Coking plants are forced to increase their use of high-quality coking coal to ensure that coke quality meets standards. However, high-quality coking coal resources with good caking and coking properties are extremely scarce. Therefore, to protect high-quality coking coal and achieve sustainable development, the scientific and efficient utilization of coal resources is the main way for coking plants to reduce costs and increase efficiency.

[0003] Compared to non-coking coal, coking coal is unique in that it exists in a plastic stage at 400–500℃ during the carbonization process. The physicochemical changes that occur during this stage are the manifestation of the coking coal's caking properties and ultimately affect the quality of the coke. Unfortunately, the coal matrix in this temperature range has a transient spatial network structure, making it impossible to obtain in-situ samples for characterization and analysis. This hinders the establishment and development of evaluation indicators for coking coal quality.

[0004] Basic fluidity reflects the flow properties of the colloidal mass formed during coal pyrolysis and is the most important process indicator characterizing the thermoplasticity of coking coal. According to GB / T 25213-2010, the basic fluidity of coal can be determined, yielding a curve of fluidity versus temperature or time. Furthermore, several characteristic parameters can be calculated, including initial softening temperature, maximum fluidity temperature, solidification temperature, maximum fluidity, and plasticity temperature range, thereby evaluating the coal's quality properties.

[0005] Figure 8 The figure shows the basic fluidity curve of coal, where, TS This refers to the initial softening temperature of coal. TMF This refers to the maximum fluidity temperature of coal. TR This refers to the coal's solidification temperature. MF The maximum fluidity of coal; TS , TMF The curves within the temperature range are used to represent the softening and decomposition process of the coal matrix. TMF , TRThe curves within the temperature range are used to represent the solidification process of the mobile phase in the coal matrix.

[0006] However, for coking enterprises, the coal quality evaluation data that is easier to obtain are basic state indicators such as industrial analysis, petrographic composition, cohesion index and plastic layer index. They use basic fluidity less often and do not have a comprehensive and in-depth understanding of it.

[0007] Establishing an intrinsic correlation between basic state indicators and process indicators allows for a more comprehensive evaluation of coal quality characteristics. More importantly, the thermoplasticity of coking coal changes significantly with the heating rate, thus affecting the caking strength of coke. Therefore, predicting the basic flowability curve at a specified heating rate is of guiding significance for coking enterprises to adjust the heating regime in real time, thereby adjusting the caking and coking properties of the coal fed into the furnace. Summary of the Invention

[0008] The purpose of this invention is to provide a method for predicting the basic flowability curve at a specified heating rate. By using basic coal quality evaluation indicators to predict the basic flowability curve at a specified heating rate, this method can guide the industry to understand the thermoplastic properties of coking coal and adjust the heating regime in real time to directionally control the flowability of coal entering the furnace in order to produce high-quality coke.

[0009] To achieve the above objectives, the present invention employs the following specific method to predict coal-based fluidity curves at a specified heating rate:

[0010] 1) Determination of volatile matter in coal V daf Maximum vitrinite reflectance R max Cohesion index G and gelatinous index Y ;

[0011] 2) Using the basic flowability curve at a heating rate of 3 K / min as the standard basic flowability curve, set the initial softening temperature at a heating rate of 3 K / min. TS 3. Maximum flowability temperature TMF 3. Curing temperature TR 3 and maximum flowability MF 3 represents the standard flow characteristic parameters. Establish the relationship between the standard flow characteristic parameters and... V daf , R max , G , Y The standard flow characteristic parameter prediction function is used to obtain the coordinates of the extreme points of the standard basic flowability curve. TMF 3, MF 3) and the standard basic flowability curve and X The coordinates of the intersection of the axes (TS 3, 0) and ( TR 3, 0);

[0012] 3) Match the mathematical model of the basic flowability curve using the coordinates of the extreme points and intersection points. F ( T ), to obtain the standard basic fluidity curve of coal;

[0013] 4) Establish specified heating rates for different maximum vitrinite reflectivities. HR i Downflow characteristic parameters TS i , TMF i , TR i , MF i By relating the predicted function to the standard flow characteristic parameters, the coordinates of the extreme points of the basic flowability curve at the specified heating rate are obtained. TMF i , MF i ) and basic flowability curve and X The coordinates of the intersection of the axes ( TS i ,0) and ( TR i ,0);

[0014] 5) Using the coordinates of the extreme point ( TMF i , MF i ) and the coordinates of the intersection point ( TS i ,0) and ( TR i ,0) Matching the basic flowability curve mathematical model F ( T ), to obtain the specified heating rate HR i Basic fluidity curve of coal.

[0015] In the above method of the present invention, the basic fluidity curve is composed of a coal softening and decomposition stage curve and a coal solidification and condensation stage curve, wherein:

[0016] The coal softening and decomposition stage curve represents the initial softening temperature. TS To maximum flow temperature TMF The mathematical model of a curve in interval segments F ( T )satisfy:

[0017] ;

[0018] The coal solidification and polycondensation stage curve is the temperature of maximum fluidity. TMF To curing temperature TR The mathematical model of a curve in interval segments F ( T )satisfy:

[0019] .

[0020] Specifically, at a heating rate of 3 K / min as specified in the national standard GB / T 25213-2010, the flowability curve mathematical model was used to... F ( T The standard basic fluidity curve of coal can be obtained, including:

[0021] Coal softening and decomposition stage curves:

[0022] ;

[0023] Coal solidification and polycondensation stage curves:

[0024] .

[0025] For any given heating rate HR i Then, through the mathematical model of the basic mobility curve... F ( T The basic flowability curve of coal at the specified heating rate can be obtained, including:

[0026] Coal softening and decomposition stage curves:

[0027] ;

[0028] Coal solidification and polycondensation stage curves:

[0029] .

[0030] The standard flow characteristic parameters established in the method described in this invention TS 3. TMF 3. TR 3. MF 3 and V daf , R max , G , Y The standard flow characteristic parameter prediction function is:

[0031] TS 3 = 0.28 V daf ) 2 -18.79V daf +710.32;

[0032] TMF 3 = -2.45 V daf +529.32;

[0033] TR 3 = -0.13( V daf ) 2 +5.23 V daf +455.11;

[0034] log MF 3 = 1.125 × [-0.005( V daf ) 2 +0.305 V daf -2.132×exp(-0.02 Y +0.02 G -3.095( R max ) 2 +6.864 R max -0.358]-8.16.

[0035] The standard flow characteristic parameter prediction function of the present invention is based on data of more than 120 kinds of industrial coking coal, and its prediction accuracy is above 0.98.

[0036] Furthermore, the method of the present invention establishes a specified heating rate for different maximum vitrinite reflectivities. HR i Downflow characteristic parameters TS i , TMF i , TR i , MF i Compared with standard flow characteristic parameters TS 3. TMF 3. TR 3. MF The prediction function relationship for 3 is as follows:

[0037] a) When the maximum vitrinite reflectance R max When the percentage is between 0.61% and 0.89%:

[0038] TSi = TS 3 + 0.985 × ( HR i -3);

[0039] TMF i = TMF 3 + 5.405 × ( HR i -3);

[0040] TR i = TR 3 + 8.340 × ( HR i -3);

[0041] MF i = MF 3 + 6.63 × ( HR i -3);

[0042] b) When the maximum vitrinite reflectance R max When the percentage is between 0.90% and 1.19%:

[0043] TS i = TS 3 + 0.128 × ( HR i -3);

[0044] TMF i = TMF 3 + 4.347 × ( HR i -3);

[0045] TR i = TR 3 + 6.824 × ( HR i -3);

[0046] MFi = MF 3 + 68.569 × ( HR i -3);

[0047] c) When the maximum vitrinite reflectance R max When the percentage is between 1.20% and 1.39%:

[0048] TS i = TS 3 + 0.189 × ( HR i -3);

[0049] TMF i = TMF 3 + 1.985 × ( HR i -3);

[0050] TR i = TR 3 + 6.560 × ( HR i -3);

[0051] MF i = MF 3 + 939.795 × ( HR i -3);

[0052] d) When the maximum vitrinite reflectance R max When the percentage is between 1.40% and 1.60%:

[0053] TS i = TS 3 + 0.843 × ( HR i -3);

[0054] TMF i = TMF 3 + 5.102 × ( HRi -3);

[0055] TR i = TR 3 + 7.305 × ( HR i -3);

[0056] MF i = MF 3 + 47.132 × ( HR i -3).

[0057] Similarly, the predicted function relationship between the flow characteristic parameters and the standard flow characteristic parameters at the specified heating rate of the present invention is established based on data from more than 50 kinds of industrial coal, and the correlation coefficient is above 0.99.

[0058] In the method for predicting the basic mobility curve at a specified heating rate described in this invention, the coal can be any coal with the highest vitrinite reflectance. R max =0.61%~1.60%, a single type of coal with fluidity characteristics.

[0059] More specifically, the coal may include, but is not limited to, any one of gas coal, fat coal, coking coal, or lean coal.

[0060] In this invention, the volatile matter of the coal V daf Maximum vitrinite reflectance R max Cohesion index G and gelatinous index Y The determination strictly follows the national standards GB / T 212-2008, GB / T 40485-2021, GB / T 5447-2014 and GB / T 479-2016.

[0061] Furthermore, in the method of the present invention, the specified heating rate... HR i The preferred range is 0–10 K / min.

[0062] Experiments have verified that the standard flow characteristic parameters ( ) at a heating rate of 3 K / min in the method described in this invention are... TS 3. TMF 3. TR 3. MF3) The relative error between the predicted and measured values, and the specified heating rate. HR i Flow characteristic parameters under ( TS i , TMF i , TR i , MF i The relative errors between the predicted and measured values ​​are all within the repeatability limits specified in the national standard GB / T 25213-2010.

[0063] The prediction method of this invention establishes the correlation between the basic state index of coal and the basic fluidity dynamic index, which helps to improve the automation and intelligent detection level of coal quality characteristics in coking enterprises, and at the same time provides a theoretical basis for establishing a scientific coal quality evaluation system.

[0064] Furthermore, the method of this invention can predict the basic flowability curve at any specified heating rate. This is not only of great significance for clarifying the influence mechanism of heating rate on the coal pyrolysis reaction process and volatile reaction pathway, but also provides technical support for coking enterprises to directionally control the coking coal coking process, develop coke oven heating matching technology based on the coal blending structure, and customize the production of high-quality coke. Attached Figure Description

[0065] Figure 1 This is a schematic flowchart of the method for predicting the basic flowability curve at a specified heating rate according to the present invention.

[0066] Figure 2 This is the basic flowability curve of lean coal in Example 1 at a heating rate of 3K / min.

[0067] Figure 3 This is the basic flowability curve of lean coal in Example 1 at a heating rate of 9 K / min.

[0068] Figure 4 This is the basic flowability curve of the gas coal in Example 2 at a heating rate of 3K / min.

[0069] Figure 5 This is the basic flowability curve of the gas coal in Example 2 at a heating rate of 5 K / min.

[0070] Figure 6 This is the basic flowability curve of coking coal in Example 3 at a heating rate of 3K / min.

[0071] Figure 7 This is the basic flowability curve of coking coal in Example 3 at a heating rate of 7 K / min.

[0072] Figure 8 This is a basic fluidity curve of coal. Implementation

[0073] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention, so that those skilled in the art can better understand and utilize the present invention, and are not intended to limit the scope of protection of the present invention.

[0074] Unless otherwise specified, the production processes, experimental methods, or testing methods involved in the embodiments of this invention are all conventional methods in the prior art, and their names and / or abbreviations are all conventional names in the field, which are very clear and distinct in the relevant application areas. Those skilled in the art can understand the conventional process steps based on the names and apply the corresponding equipment to implement them according to conventional conditions or conditions recommended by the manufacturer.

[0075] The various instruments, equipment, raw materials or reagents used in the embodiments of this invention are not subject to any special restrictions on their source. They are all conventional products that can be purchased through regular commercial channels and can be prepared according to conventional methods known to those skilled in the art.

[0076] Figure 1 A flowchart illustrating the specific implementation of the basic flowability curve prediction method under a specified heating rate according to the present invention is provided.

[0077] according to Figure 1 The process, specifically, involves predicting the coal-based fluidity curve at a specified heating rate using the following method.

[0078] 1) Determine the volatile matter content of coal according to the methods in national standards GB / T 212-2008, GB / T 40485-2021, GB / T 5447-2014 and GB / T479-2016 respectively. V daf Maximum vitrinite reflectance R max Cohesion index G and gelatinous index Y ;

[0079] 2) Initial softening temperature at a heating rate of 3 K / min TS 3. Maximum flowability temperature TMF 3. Curing temperature TR 3 and maximum flowability MF 3 is used as the standard flow characteristic parameter. V daf , R max , G ,Y Substituting these values ​​into the following standard flow characteristic parameter prediction functions, we obtain the coordinates of the extreme points of the standard basic flowability curve at a heating rate of 3 K / min. TMF 3, MF 3) and the standard basic flowability curve and X The coordinates of the intersection of the axes ( TS 3, 0) and ( TR 3, 0):

[0080] TS 3 = 0.28 V daf ) 2 -18.79 V daf +710.32;

[0081] TMF 3 = -2.45 V daf +529.32;

[0082] TR 3 = -0.13( V daf ) 2 +5.23 V daf +455.11;

[0083] log MF 3 = 1.125 × [-0.005( V daf ) 2 +0.305 V daf -2.132×exp(-0.02 Y +0.02 G -3.095( R max ) 2 +6.864 R max -0.358]-8.16;

[0084] 3) Match the following basic flowability curve mathematical model with the coordinates of the above extreme points and intersection points. F ( T The standard basic flowability curve of coal at a heating rate of 3K / min, as specified in national standard GB / T 25213-2010, was obtained, including:

[0085] Coal softening and decomposition stage curves:

[0086] ;

[0087] Coal solidification and polycondensation stage curves:

[0088] ;

[0089] 4) Establish specified heating rates for different maximum vitrinite reflectivities. HR i Downflow characteristic parameters TS i , TMF i , TR i , MF i Relationship with the prediction function of standard flow characteristic parameters:

[0090] a) Maximum vitrinite reflectance R max =0.61%~0.89%

[0091] TS i = TS 3 + 0.985 × ( HR i -3);

[0092] TMF i = TMF 3 + 5.405 × ( HR i -3);

[0093] TR i = TR 3 + 8.340 × ( HR i -3);

[0094] MF i = MF 3 + 6.63 × ( HR i -3);

[0095] b) Maximum vitrinite reflectance R max =0.90%~1.19%

[0096] TS i =TS 3 + 0.128 × ( HR i -3);

[0097] TMF i = TMF 3 + 4.347 × ( HR i -3);

[0098] TR i = TR 3 + 6.824 × ( HR i -3);

[0099] MF i = MF 3 + 68.569 × ( HR i -3);

[0100] c) Maximum vitrinite reflectance R max =1.20%~1.39%

[0101] TS i = TS 3 + 0.189 × ( HR i -3);

[0102] TMF i = TMF 3 + 1.985 × ( HR i -3);

[0103] TR i = TR 3 + 6.560 × ( HR i -3);

[0104] MF i =MF 3 + 939.795 × ( HR i -3);

[0105] d) Maximum vitrinite reflectance R max =1.40%~1.60%

[0106] TS i = TS 3 + 0.843 × ( HR i -3);

[0107] TMF i = TMF 3 + 5.102 × ( HR i -3);

[0108] TR i = TR 3 + 7.305 × ( HR i -3);

[0109] MF i = MF 3 + 47.132 × ( HR i -3);

[0110] 5) Specify the heating rate HR i Substituting these values ​​into the prediction function relationship corresponding to the maximum vitrinite reflectance of coal, the coordinates of the extreme points of the basic mobility curve of coal at the specified heating rate are obtained. TMF i , MF i ) and basic flowability curve and X The coordinates of the intersection of the axes ( TS i ,0) and ( TR i ,0);

[0111] 6) Using the coordinates of the extreme point ( TMF i , MFi ) and the coordinates of the intersection point ( TS i ,0) and ( TR i ,0) Matching the basic flowability curve mathematical model F ( T ), to obtain the specified heating rate HR i The basic fluidity curve of coal includes:

[0112] Coal softening and decomposition stage curves:

[0113] ;

[0114] Coal solidification and polycondensation stage curves:

[0115] .

[0116] The method described above for predicting the basic flowability curve at a specified heating rate is suitable for any maximum vitrinite reflectance. R max =0.61%~1.60%, a single type of coal with fluidity characteristics.

[0117] The method described above for predicting the basic flowability curve at a specified heating rate is suitable for any maximum vitrinite reflectance. R max =0.61%~1.60%, a single type of coal with flow characteristics. It can cover various commonly used coking coals, including gas coal, 1 / 3 coking coal, gas-rich coal, fat coal, coking coal, and lean coal, with a wide range of coalification degrees and wide application scope.

[0118] The basic flowability curve prediction method established in this invention can realize the process evaluation of coking coal characteristics in conventional coking production and provide a theoretical basis for the scientific control of heating regime in the production process. Example

[0119] Example 1

[0120] A type of lean coal (LL) from the Lvliang area of ​​Shanxi Province was selected, with an ash content (dry basis) of 7.05 wt.%, a sulfur content (dry basis) of 2.39 wt.%, and a carbon content (dry ash-free basis) of 89.08 wt.%.

[0121] According to national standards GB / T 212-2008, GB / T 40485-2021, GB / T 5447-2014 and GB / T 479-2016, four state indicators of lean coal LL were determined: volatile matter, maximum vitrinite reflectance, caking index and plastic layer index.

[0122] The specific measurement results are as follows:V daf =19.49%, R max =1.514%, G =73、 Y =12mm.

[0123] Substituting the obtained state indices into the standard flow characteristic parameter prediction function provided by this invention at a heating rate of 3K / min, the standard flow characteristic parameters are calculated respectively. TS 3. TMF 3. TR 3 and log MF 3, and further calculate MF 3.

[0124] TS 3 = 0.28 V daf ) 2 -18.79 V daf +710.32 = 450.4℃;

[0125] TMF 3 = -2.45 V daf +529.32 = 481.6℃;

[0126] TR 3 = -0.13( V daf ) 2 +5.23 V daf +455.11 = 507.7℃;

[0127] log MF 3 = 1.125 × [-0.005( V daf ) 2 +0.305 V daf -2.132×exp(-0.02 Y +0.02 G -3.095( R max ) 2 +6.864 R max -0.358]-8.16 =1.92,

[0128] Right now: MF 3 = 83.2dd / min.

[0129] Thus, the coordinates of three key points on the standard basic flowability curve of lean coal LL at a heating rate of 3 K / min were obtained: the coordinates of the extreme point (481.6, 83.2), and the coordinates of the standard basic flowability curve and... X The coordinates of the intersection points of the axes are (450.4, 0) and (507.7, 0).

[0130] Match the above extreme points and intersection coordinates to the following basic formula flow rate curve mathematical model. F ( T ),include:

[0131] Coking coal softening and decomposition stage curves:

[0132] ;

[0133] Coking coal solidification and polycondensation stage curve:

[0134] .

[0135] get Figure 2 The curve shown is the predicted flowability curve of lean coal LL standard formula at a heating rate of 3K / min as specified in the national standard GB / T 25213-2010.

[0136] The standard basic flowability of lean coal (LL) was determined using a Preiser Scientific Instruments PL-6100 plasticity analyzer, in accordance with the national standard GB / T 25213-2010. 5.0 g of coal sample with a particle size of 0.2–0.425 mm was loaded into a coal steamer with an inserted agitator and compacted with a 1 kg dynamic load. The steamer was fixed on the plasticity analyzer and lowered into a molten solder bath preheated to 300°C for heating. The heating rate was controlled at 3°C / min throughout the process, up to 540°C. A constant rotational torque was applied to the agitator, and the rotational speed of the agitator at the corresponding temperature was recorded; this was the standard basic flowability.

[0137] The measured standard flow characteristic parameters of lean coal LL are as follows: TS 3=443.0℃ TMF 3 = 481.7℃ TR 3=508.3℃ and MF 3 = 75.0dd / min, from which we obtain Figure 2 The figure shows the measured flowability curve of lean coal LL standard formula at a heating rate of 3K / min as specified in the national standard GB / T 25213-2010.

[0138] Figure 2 The difference between the predicted value and the measured value: ∆ TS 3=7.4℃, ∆ TMF 3 = 0.1℃, ∆ TR3 = 0.6℃, both within the repeatability limit (8℃) specified in the national standard GB / T 25213-2010. δ ( MF 3) = 9.8%, which is also within the repeatability limit (30%; 10~100dd / min) specified in the national standard GB / T25213-2010.

[0139] Based on the maximum vitrinite reflectance of lean coal LL R max =1.514%, select the maximum vitrinite reflectance. R max The predicted functional relationship between flow characteristic parameters and standard flow characteristic parameters at a specified heating rate of 1.40% to 1.60% is obtained by substituting the specified heating rate... HR i =9K / min, calculate the flow characteristic parameters at a specified heating rate of 9K / min. TS 9. TMF 9. TR 9 and MF 9:

[0140] TS 9 =450.4 +0.843×(9-3) =455.46℃;

[0141] TMF 9 =481.6 +5.102×(9 -3) =512.21℃;

[0142] TR 9 =507.7 +7.305×(9 -3) =551.53℃;

[0143] MF 9 =83.2 +47.132×(9 -3) =365.99dd / min.

[0144] The coordinates of the extreme point (512.21, 365.99) on the basic flowability curve of lean coal LL at a specified heating rate of 9 K / min were obtained, along with the basic flowability curve and... X The coordinates of the intersection points of the axes are (455.46, 0) and (551.53, 0).

[0145] Match the above extreme points and intersection coordinates to the following basic formula flow rate curve mathematical model. F ( T),include:

[0146] Coking coal softening and decomposition stage curves:

[0147] ;

[0148] Coking coal solidification and polycondensation stage curve:

[0149] .

[0150] get Figure 3 The figure shows the predicted flowability curve of lean coal based on the LL method at a heating rate of 9 K / min.

[0151] The basic flowability of lean coal (LL) was determined using a Preiser Scientific Instruments PL-6100 plasticity analyzer, in accordance with the national standard GB / T 25213-2010. 5.0 g of coal sample with a particle size of 0.2–0.425 mm was loaded into a coal steamer with an inserted agitator and compacted with a 1 kg dynamic load. The steamer was fixed on the basic plasticity analyzer and lowered into a molten solder bath preheated to 300°C for heating. The heating rate was controlled at 9°C / min throughout the process, up to 540°C. A constant rotational torque was applied to the agitator, and the rotational speed of the agitator at the corresponding temperature was recorded; this was the basic flowability.

[0152] The measured flow characteristic parameters of lean coal LL are as follows: TS 9 = 450.8℃ TMF 9 = 510.3℃ TR 9 = 550.4℃ and MF 9 = 380.9dd / min, from which we obtain Figure 3 The figure shows the LL-based flowability curve of lean coal at a measured heating rate of 9 K / min.

[0153] Figure 3 The difference between the predicted value and the measured value: ∆ TS 9 = 4.66℃, ∆ TMF 9 = 1.91℃, ∆ TR 9 = 1.13℃, both within the repeatability limit (8℃) specified in the national standard GB / T 25213-2010. δ ( MF 9) = 4.1%, which is also within the repeatability limit (25%; 100~1000dd / min) specified in the national standard GB / T25213-2010.

[0154] Figure 2 and Figure 3The repeatability of the predicted and measured basic flowability is within the range specified in the national standard GB / T 25213-2010, proving the accuracy of the method of predicting the basic flowability curve at a specified heating rate in this invention.

[0155] Example 2

[0156] A type of gas coal, JXH, from Gujiao area in Shanxi Province, was selected. Its ash content (dry basis) was 7.69 wt.%, sulfur content (dry basis) was 0.63 wt.%, and carbon content (dry ash-free basis) was 83.99 wt.%.

[0157] According to national standards GB / T 212-2008, GB / T 40485-2021, GB / T 5447-2014 and GB / T 479-2016, four state indicators of gas coal JXH were determined: volatile matter, maximum vitrinite reflectance, bonding index and plastic layer index.

[0158] The specific measurement results are as follows: V daf =44.01%, R max =0.65%, G =63、 Y =11.5mm.

[0159] Substituting the obtained state indices into the standard flow characteristic parameter prediction function provided by this invention at a heating rate of 3K / min, the standard flow characteristic parameters are calculated respectively. TS 3. TMF 3. TR 3 and log MF 3, and further calculate MF 3.

[0160] TS 3 = 0.28 V daf ) 2 -18.79 V daf +710.32 = 404.39℃;

[0161] TMF 3 = -2.45 V daf +529.32 = 432.99℃;

[0162] TR 3 = -0.13( V daf ) 2 +5.23 V daf +455.11 = 459.77℃;

[0163] log MF 3 = 1.125 × [-0.005( V daf ) 2 +0.305 V daf -2.132×exp(-0.02 Y +0.02 G -3.095( R max ) 2 +6.864 R max -0.358]-8.16 =1.97,

[0164] Right now: MF 3 = 93.4dd / min.

[0165] Thus, the coordinates of three key points on the standard basic flowability curve of gas coal JXH at a heating rate of 3 K / min were obtained: the coordinates of the extreme point (432.99, 93.4), and the coordinates of the standard basic flowability curve and... X The coordinates of the intersection points of the axes are (404.39, 0) and (459.77, 0).

[0166] Match the above extreme points and intersection coordinates to the following basic formula flow rate curve mathematical model. F ( T ),include:

[0167] Coking coal softening and decomposition stage curves:

[0168] ;

[0169] Coking coal solidification and polycondensation stage curve:

[0170] .

[0171] get Figure 4 The curve shown is the predicted flowability curve of JXH standard basic formula gas coal at a heating rate of 3K / min as specified in the national standard GB / T 25213-2010.

[0172] The standard basic flowability of gas coal JXH was determined using a Preiser Scientific Instruments PL-6100 plasticity analyzer, in accordance with the national standard GB / T 25213-2010. 5.0 g of coal sample with a particle size of 0.2–0.425 mm was loaded into a coal steamer with an inserted agitator and compacted with a 1 kg dynamic load. The steamer was fixed on the basic plasticity analyzer and lowered into a molten solder bath preheated to 300°C for heating. The heating rate was controlled at 3°C / min throughout the process until 540°C was reached. A constant rotational torque was applied to the agitator, and the rotational speed of the agitator at the corresponding temperature was recorded; this was the standard basic flowability.

[0173] The measured standard flow characteristic parameters of JXH gas coal are as follows: TS 3=396.7℃ TMF 3 = 434.8℃ TR 3 = 464.3℃ and MF 3 = 74.7dd / min, from which we obtain Figure 4 The figure shows the measured flowability curve of gas coal JXH standard basic formula at a heating rate of 3K / min as specified in the national standard GB / T 25213-2010.

[0174] Figure 4 The difference between the predicted value and the measured value: ∆ TS 3 = 7.69℃, ∆ TMF 3 = 1.81℃, ∆ TR 3 = 4.53℃, both within the repeatability limit (8℃) specified in the national standard GB / T 25213-2010. δ ( MF 3) = 20.0%, which is also within the repeatability limit (30%; 10~100dd / min) specified in the national standard GB / T 25213-2010.

[0175] Based on the maximum vitrinite reflectance of gas coal JXH R max =0.65%, select the maximum vitrinite group reflectance. R max The predicted functional relationship between the flow characteristic parameters and the standard flow characteristic parameters at a specified heating rate under the condition of 0.61% to 0.89% is obtained by substituting the specified heating rate... HR i =5K / min, calculate the flow characteristic parameters at a specified heating rate of 5K / min. TS 5. TMF 5. TR 5 and MF 5:

[0176] TS 5 =404.39 +0.985×(5 -3) = 406.36℃;

[0177] TMF 5 =432.99 +5.405×(5 -3) = 443.80℃;

[0178] TR 5 =459.77 +8.340×(5 -3) = 476.45℃;

[0179] MF 5 =93.4 +6.63×(5 -3)=106.66dd / min.

[0180] The coordinates of the extreme point (443.80, 106.66) on the basic flowability curve of gas coal JXH at a specified heating rate of 5 K / min were obtained, along with the basic flowability curve and... X The coordinates of the intersection points of the axes are (406.36, 0) and (476.45, 0).

[0181] Match the above extreme points and intersection coordinates to the following basic formula flow rate curve mathematical model. F ( T ),include:

[0182] Coking coal softening and decomposition stage curves:

[0183] ;

[0184] Coking coal solidification and polycondensation stage curve:

[0185] .

[0186] get Figure 5 The curve shown is the JXH-based flowability curve of gas coal at a predicted heating rate of 5 K / min.

[0187] The basic flowability of gas coal JXH was determined using a Preiser Scientific Instruments PL-6100 plasticity analyzer, in accordance with the national standard GB / T 25213-2010. 5.0 g of coal sample with a particle size of 0.2–0.425 mm was loaded into a coal steamer with an inserted agitator and compacted with a 1 kg dynamic load. The steamer was fixed on the basic plasticity analyzer and lowered into a molten solder bath preheated to 300°C for heating. The heating rate was controlled at 5°C / min throughout the process, up to 540°C. A constant rotational torque was applied to the agitator, and the rotational speed of the agitator at the corresponding temperature was recorded; this was the basic flowability.

[0188] The measured flow characteristic parameters of JXH gas coal are as follows: TS 5 = 402.8℃ TMF 5 = 445.3℃ TR 5 = 475.4℃ and MF 5 = 102.7dd / min, from which we obtain Figure 5 The figure shows the JXH-based flowability curve of gas coal at a measured heating rate of 5 K / min.

[0189] Figure 5 The difference between the predicted value and the measured value: ∆ TS 5 = 3.56℃, ∆ TMF 5 = 1.5℃, ∆ TR 5 = 1.05℃, both within the repeatability limit (8℃) specified in the national standard GB / T 25213-2010. δ ( MF 5) = 3.7%, which is also within the repeatability limit (25%; 100~1000dd / min) specified in the national standard GB / T25213-2010.

[0190] Example 3

[0191] A type of coking coal, SQ, from Linfen area of ​​Shanxi Province was selected. Its ash content (dry basis) was 11.05 wt.%, sulfur content (dry basis) was 0.55 wt.%, and carbon content (dry ash-free basis) was 89.54 wt.%.

[0192] According to national standards GB / T 212-2008, GB / T 40485-2021, GB / T 5447-2014 and GB / T 479-2016, four state indicators of coking coal SQ were determined: volatile matter, maximum vitrinite reflectance, caking index and plastic layer index.

[0193] The specific measurement results are as follows: V daf =20.20% R max =1.210% G=55、 Y =13mm.

[0194] Substituting the obtained state indices into the standard flow characteristic parameter prediction function provided by this invention at a heating rate of 3K / min, the standard flow characteristic parameters are calculated respectively. TS 3. TMF 3. TR 3 and log MF 3, and further calculate MF 3.

[0195] TS 3 = 0.28 V daf ) 2 -18.79 V daf +710.32 = 445.01℃;

[0196] TMF 3 = -2.45 V daf +529.32 = 479.83℃;

[0197] TR 3 = -0.13( V daf ) 2 +5.23 V daf +455.11 = 507.7℃;

[0198] log MF 3 = 1.125 × [-0.005( V daf ) 2 +0.305 V daf -2.132×exp(-0.02 Y +0.02 G -3.095( R max ) 2 +6.864 R max -0.358]-8.16 =3.26,

[0199] Right now: MF 3 = 1820.32dd / min.

[0200] Thus, the coordinates of three key points on the standard basic flowability curve of coking coal SQ at a heating rate of 3 K / min were obtained: the coordinates of the extreme point (479.83, 1820.32), and the coordinates of the standard basic flowability curve and... XThe coordinates of the intersection points of the axes are (445.01, 0) and (507.7, 0).

[0201] Match the above extreme points and intersection coordinates to the following basic formula flow rate curve mathematical model. F ( T ),include:

[0202] Coking coal softening and decomposition stage curves:

[0203] ;

[0204] Coking coal solidification and polycondensation stage curve:

[0205] .

[0206] get Figure 6 The figure shows the standard basic fluidity curve of coking coal SQ at a heating rate of 3 K / min as specified in the national standard GB / T 25213-2010.

[0207] The standard basic flowability (SQ) of coking coal was determined using a Preiser PL-6100 plasticity analyzer, in accordance with the national standard GB / T 25213-2010. 5.0 g of coal sample with a particle size of 0.2–0.425 mm was loaded into a coal steamer with an inserted agitator and compacted with a 1 kg dynamic load. The steamer was fixed on the plasticity analyzer and lowered into a molten solder bath preheated to 300°C for heating. The heating rate was controlled at 3°C / min throughout the process, up to 540°C. A constant rotational torque was applied to the agitator, and the rotational speed of the agitator at the corresponding temperature was recorded; this was the standard basic flowability.

[0208] The measured standard flow characteristic parameters of coking coal SQ are as follows: TS 3=447.0℃ TMF 3 = 476.7℃ TR 3=508.3℃ and MF 3 = 1640.0dd / min, from which we obtain Figure 6 The figure shows the measured SQ standard formula fluidity curve of coking coal at a heating rate of 3K / min as specified in the national standard GB / T 25213-2010.

[0209] Figure 6 The difference between the predicted value and the measured value: ∆ TS 3 = 1.99℃, ∆ TMF 3 = 3.13℃, ∆ TR 3 = 0.6℃, both within the repeatability limit (8℃) specified in the national standard GB / T 25213-2010. δ ( MF3) = 9.9%, which is also within the repeatability limit (20%; >1000dd / min) specified in the national standard GB / T25213-2010.

[0210] Based on the maximum vitrinite reflectance of coking coal SQ R max =1.210%, select the maximum vitrinite reflectance. R max The predicted functional relationship between flow characteristic parameters and standard flow characteristic parameters at a specified heating rate of 1.20% to 1.39% is obtained by substituting the specified heating rate... HR i =7K / min, calculate the flow characteristic parameters at a specified heating rate of 7K / min. TS 7. TMF 7. TR 7 and MF 7:

[0211] TS 7 =445.01+0.189×(7-3)=445.76℃;

[0212] TMF 7 =479.83+1.985×(7-3)=487.77℃;

[0213] TR 7 =507.7 + 6.560 × (7 - 3) = 533.94℃;

[0214] MF 7 =1820.32+939.795×(7-3)=5579.5dd / min.

[0215] The coordinates of the extreme point (487.77, 5579.5) on the basic flowability curve of coking coal SQ at a specified heating rate of 7 K / min were obtained, along with the coordinates of the basic flowability curve and the coordinates of the extreme point (487.77, 5579.5). X The coordinates of the intersection points of the axes are (455.76, 0) and (533.94, 0).

[0216] Match the above extreme points and intersection coordinates to the following basic formula flow rate curve mathematical model. F ( T ),include:

[0217] Coking coal softening and decomposition stage curves:

[0218] ;

[0219] Coking coal solidification and polycondensation stage curve:

[0220] .

[0221] get Figure 7 The figure shows the predicted SQ-based fluidity curve of coking coal at a heating rate of 7 K / min.

[0222] The basic flowability (SQ) of coking coal was determined using a Preiser Scientific Instruments PL-6100 plasticity analyzer, in accordance with the national standard GB / T 25213-2010. 5.0 g of coal sample with a particle size of 0.2–0.425 mm was loaded into a coal steamer with an inserted agitator and compacted with a 1 kg dynamic load. The steamer was fixed on the basic plasticity analyzer and lowered into a molten solder bath preheated to 300°C for heating. The heating rate was controlled at 7°C / min throughout the process, up to 540°C. A constant rotational torque was applied to the agitator, and the rotational speed of the agitator at the corresponding temperature was recorded; this was the basic flowability.

[0223] The measured flow characteristic parameters of coking coal SQ are as follows: TS 7 = 451.4℃ TMF 7 = 480.6℃ TR 7 = 557.4℃ and MF 7 = 5380.9dd / min, from which we obtain Figure 7 The figure shows the SQ-based fluidity curve of coking coal at a measured heating rate of 7 K / min.

[0224] Figure 7 The difference between the predicted value and the measured value: ∆ TS 7 = 4.36℃, ∆ TMF 7 = 7.17℃, ∆ TR 7 = 3.46℃, both within the repeatability limit (8℃) specified in the national standard GB / T 25213-2010. δ ( MF 7) = 3.6%, which is also within the repeatability limit (20%; >1000dd / min) specified in the national standard GB / T25213-2010.

[0225] The above embodiments of the present invention do not describe all details exhaustively, nor do they limit the present invention to the embodiments described above. Various changes, modifications, substitutions, and variations made by those skilled in the art to these embodiments without departing from the principles and spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for predicting a basic flowability profile at a specified heating rate, the method comprising: 1) Determination of volatile matter in coal V daf Maximum vitrinite reflectance R max Cohesion index G and gelatinous index Y ; 2) Using the basic flowability curve at a heating rate of 3 K / min as the standard basic flowability curve, set the initial softening temperature at a heating rate of 3 K / min. TS 3. Maximum flowability temperature TMF 3. Curing temperature TR 3 and maximum flowability MF 3 represents the standard flow characteristic parameters. Establish the relationship between the standard flow characteristic parameters and... V daf , R max , G , Y The standard flow characteristic parameter prediction function is used to obtain the coordinates of the extreme points of the standard basic flowability curve. TMF 3, MF 3) and the standard basic flowability curve and X The coordinates of the intersection of the axes ( TS 3, 0) and ( TR 3, 0); The standard flow characteristic parameters TS 3. TMF 3. TR 3. MF 3 and V daf , R max , G , Y The standard flow characteristic parameter prediction function is: ； ； ； ； 3) Match the mathematical model of the basic flowability curve using the coordinates of the extreme points and intersection points. F ( T ), to obtain the standard basic fluidity curve of coal; 4) Establish specified heating rates for different maximum vitrinite reflectivities. HR i Downflow characteristic parameters TS i , TMF i , TR i , MF i By relating the predicted function to the standard flow characteristic parameters, the coordinates of the extreme points of the basic flowability curve at the specified heating rate are obtained. TMF i , MF i ) and basic flowability curve and X The coordinates of the intersection of the axes ( TS i ,0) and ( TR i ,0); Specified heating rates were established for different maximum vitrinite reflectivities. HR i Downflow characteristic parameters TS i , TMF i , TR i , MF i Compared with standard flow characteristic parameters TS 3. TMF 3. TR 3. MF The prediction function relationship for 3 is: a) When the maximum vitrinite reflectance R max When the percentage is between 0.61% and 0.89%: ； ； ； ； b) When the maximum vitrinite reflectance R max When the percentage is between 0.90% and 1.19%: ； ； ； ； c) When the maximum vitrinite reflectance R max When the percentage is between 1.20% and 1.39%: ； ； ； ； d) When the maximum vitrinite reflectance R max When the percentage is between 1.40% and 1.60%: ； ； ； ； 5) Using the coordinates of the extreme point ( TMF i , MF i ) and the coordinates of the intersection point ( TS i ,0) and ( TR i ,0) Matching the basic flowability curve mathematical model F ( T ), to obtain the specified heating rate HR i Basic fluidity curve of coal.

2. The method for predicting the basic flowability curve at a specified heating rate according to claim 1, characterized in that: The basic fluidity curve consists of a coal softening and decomposition stage curve and a coal solidification and condensation stage curve, wherein: The coal softening and decomposition stage curve represents the initial softening temperature. TS To maximum flow temperature TMF The mathematical model of a curve in interval segments F ( T )satisfy: ； The coal solidification and polycondensation stage curve is the temperature of maximum fluidity. TMF To curing temperature TR The mathematical model of a curve in interval segments F ( T )satisfy: 。 3. The method for predicting the basic flowability curve at a specified heating rate according to claim 2, characterized in that... At a heating rate of 3 K / min as specified in national standard GB / T 25213-2010, the basic flowability curve mathematical model was used. F ( T Obtain the standard basic fluidity profile of coal, including: Coal softening and decomposition stage curves: ； Coal solidification and polycondensation stage curves: 。 4. The method for predicting the basic flowability curve at a specified heating rate according to claim 2, characterized in that for Arbitrary heating rate HR i Through the mathematical model of the basic mobility curve F ( T Obtaining the basic flowability curve of coal at the specified heating rate includes: Coal softening and decomposition stage curves: ； Coal solidification and polycondensation stage curves: 。 5. The method for predicting the basic flowability curve at a specified heating rate according to claim 1, characterized in that: The coal in question has any maximum vitrinite reflectance. R max =0.61%~1.60%, a single type of coal with fluidity characteristics.

6. The method for predicting the basic flowability curve at a specified heating rate according to claim 5, characterized in that: The coal mentioned is any one of gas coal, fat coal, coking coal, or lean coal.

7. The method for predicting the basic flowability curve at a specified heating rate according to claim 1, characterized in that: The volatile matter of the coal V daf Maximum vitrinite reflectance R max Cohesion index G and gelatinous index Y Tested according to national standards GB / T 212-2008, GB / T 40485-2021, GB / T 5447-2014 and GB / T 479-2016.

8. The method for predicting the basic flowability curve at a specified heating rate according to claim 1, characterized in that: The specified heating rate HR i The range is 0–10 K / min.

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