Method for judging whether thermal performance measurement numerical value of coke is changed or not

Abstract

The invention relates to a method for judging whether a coke thermal performance measurement numerical value changes or not, which comprises the following steps: counting coke thermal strength measurement numerical values under different working conditions to obtain CRI values under different CSR distribution conditions, and forming a sample T1 and a sample T2; performing equal variance test on the sample T1 and the sample T2 to obtain a first test result; performing double-sample t test and Welch's t test on the sample T1 and the sample T2 to obtain a second test result; and determining whether the coke thermal performance index is changed or not according to the first test result and the second test result. According to the method, the stability of the coke thermal performance data can be effectively and scientifically judged by utilizing the isovariance test, the Welch's t test and the double-sample t test, so that the change conditions of the coke thermal performance data under two measurement working conditions are obtained, the guidance on control indexes is completed, and the coal blending cost is prevented from being increased due to deviation of the measured data.

Description

Technical Field

[0001] The present invention relates to the technical field of blast furnace ironmaking, and in particular to a method for judging whether a measured value of coke thermal properties has changed. Background Art

[0002] Coke is a key raw material for blast furnace ironmaking, and its thermal strength influences the furnace's air permeability. Coke with excellent thermal properties maintains a well-defined block structure within the blast furnace, stabilizing the porosity between charge layers and allowing gas to flow smoothly through the charge bed, ensuring good air permeability and facilitating reduction reactions within the furnace. Coke with excellent thermal properties provides stable support for the blast furnace charge, enabling it to descend evenly and steadily, ensuring the continuity and stability of blast furnace production and preventing problems such as poor charge descent, overhanging charge, and collapsing charge, which can seriously impact the furnace's smooth operation.

[0003] In actual production, when the measuring equipment is repaired or updated or a new sample preparation method or measuring method is adopted, there is currently no effective way to determine whether the quality of the sample coke has changed significantly under the premise that the same test data is obtained under two different working conditions. Summary of the Invention

[0004] To solve the above problem, an embodiment of the present invention aims to provide a method for determining whether the measured value of the thermal properties of coke has changed.

[0005] A method for determining whether a value of a coke thermal property measurement has changed comprises:

[0006] Step 1: Statistically analyze the coke thermal strength values ​​under different working conditions to obtain the CRI values ​​under different CSR distribution conditions;

[0007] Step 2: Select a CSR interval, and obtain the coke CRI data under operating condition I within the determined CSR interval to form sample T1, and obtain the coke CRI data under operating condition II within the determined CSR interval to form sample T2;

[0008] Step 3: Perform an equal variance test on sample T1 and sample T2 to obtain the first test result;

[0009] Step 4: When the population variances of sample T1 and sample T2 are equal, perform a two-sample t-test on sample T1 and sample T2 to obtain the second test result;

[0010] Step 5: When the population variances of sample T1 and sample T2 are not equal, perform Welch's t test on sample T1 and sample T2 to obtain the second test result;

[0011] Step 6: Determine whether the thermal performance index of the coke has changed based on the first test result and the second test result.

[0012] Preferably, step 4: when the population variances of sample T1 and sample T2 are equal, performing a two-sample t-test on sample T1 and sample T2 to obtain a second test result includes:

[0013] Step 4.1: Calculate the statistic based on the means in samples T1 and T2;

[0014] Step 4.2: Calculate the degrees of freedom based on the sample sizes in samples T1 and T2;

[0015] Step 4.3: Obtain the second test result based on the statistic and degrees of freedom.

[0016] Preferably, in step 4.1, the statistical calculation formula is:

[0017]

[0018] in, represents the mean of sample T1, represents the mean of sample T2, n1 represents the sample size of sample T1, n2 represents the sample size of sample T2, and t represents the statistic;

[0019] It represents the pooled variance, and its calculation formula is:

[0020]

[0021] in, represents the variance of sample T1, represents the variance of sample T1.

[0022] Preferably, in step 4.2, the calculation formula of the degree of freedom is:

[0023] df = n1 + n2 - 2

[0024] Where df represents the degrees of freedom, n1 represents the sample size of sample T1, and n2 represents the sample size of sample T2.

[0025] Preferably, the step 5: when the population variances of sample T1 and sample T2 are not equal, performing Welch's t test on sample T1 and sample T2 to obtain a second test result includes:

[0026] Step 5.1: Calculate the Welch's t-test statistic based on the sample variance;

[0027] Step 5.2: Calculate the degrees of freedom for the Welch's t-test based on the sample variance;

[0028] Step 5.3: Step 4.3: Obtain the second test result based on the Welch's t test statistic and the Welch's t test degrees of freedom.

[0029] Preferably, in step 5.1, the Welch's t test statistic calculation formula is:

[0030]

[0031] in, represents the variance of sample T1, represents the variance of sample T1, X1 represents the mean of sample T1, represents the mean of sample T2, n1 represents the sample size of sample T1, n2 represents the sample size of sample T2, and t represents the Welch's t test statistic.

[0032] Preferably, in step 5.2, the calculation formula for the degrees of freedom of Welch's t-test is:

[0033]

[0034] Here, df represents the degrees of freedom of Welch's t-test.

[0035] The present invention also provides an electronic device, comprising a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and runnable on the processor, wherein the transceiver, the memory, and the processor are connected via the bus, and wherein the computer program, when executed by the processor, implements the steps in the above-mentioned method for determining whether the measured value of the thermal properties of coke has changed.

[0036] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps in the above-mentioned method for determining whether the measured value of the thermal properties of coke has changed are implemented.

[0037] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0038] The present invention relates to a method for judging whether a measured value of coke thermal properties has changed. Compared with the prior art, the present invention can effectively and scientifically judge the stability of coke thermal property data through the Welch's t-test, the Welch's t-test and the two-sample t-test, thereby obtaining the change of coke thermal property data under two measuring conditions, completing the guidance of control indicators, and preventing the coal blending cost from increasing due to the "deviation" of the measured data.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 A flow chart of a method for determining whether a value of a coke thermal property measurement has changed provided by the present invention;

[0042] Figure 2 This is the result diagram of the equal variance test provided by the present invention. DETAILED DESCRIPTION

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature identified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0045] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0046] See also Figure 1A method for determining whether a value of a coke thermal property measurement has changed comprises:

[0047] Step 1: Statistically analyze the coke thermal strength values ​​under different working conditions to obtain the CRI values ​​under different CSR distribution conditions;

[0048] Step 2: Select a CSR interval, and obtain the coke CRI data under operating condition I within the determined CSR interval to form sample T1, and obtain the coke CRI data under operating condition II within the determined CSR interval to form sample T2;

[0049] Step 3: Perform an equal variance test on sample T1 and sample T2 to obtain the first test result;

[0050] The Two-Sample Test for Equal Variances is used to determine whether the variances of two independent samples are equal. Common test methods include the F test and the Levene test.

[0051] The F test is applicable when both samples come from a normal distribution. The steps are as follows:

[0052] Assumptions:

[0053] Null hypothesis H 0 :σ1 2 =σ2 2

[0054] Alternative hypothesis H 1 :σ1 2 ≠σ2 2

[0055] Compute the test statistic:

[0056] F=s1 2 / s2 2

[0057] where s1 2 and s2 2 are the variances of the two samples respectively.

[0058] Determine the critical value:

[0059] According to the significance level α and the degrees of freedom (n 1 -1,n 2 -1), check the F distribution table.

[0060] decision making:

[0061] If the F value falls within the rejection region, reject the null hypothesis. Otherwise, do not reject the null hypothesis.

[0062] Levene's test

[0063] Applicable to non-normal distribution data. The steps are as follows:

[0064] Assumptions:

[0065] oNull hypothesis H0:σ1 2 =σ2 2

[0066] oAlternative hypothesis H1:σ1 2 ≠σ2 2

[0067] Compute the test statistic:

[0068]

[0069] in, is the mean of the samples in group i, is the Z in the i-th group of samples ij The mean of For all Z ij The mean of .

[0070] Determine the critical value:

[0071] According to the significance level α and degrees of freedom (k-1, Nk), check the F distribution table.

[0072] decision making:

[0073] If the W value falls in the rejection region, reject the null hypothesis.

[0074] Step 4: When the population variances of sample T1 and sample T2 are equal, perform a two-sample t-test on sample T1 and sample T2 to obtain the second test result;

[0075] Furthermore, the step 4 includes:

[0076] Step 4.1: Calculate the statistic based on the means in samples T1 and T2;

[0077] In step 4.1, the statistical calculation formula is:

[0078]

[0079] in, represents the mean of sample T1, represents the mean of sample T2, n1 represents the sample size of sample T1, n2 represents the sample size of sample T2, and t represents the statistic;

[0080] It represents the pooled variance, and its calculation formula is:

[0081]

[0082] in, represents the variance of sample T1, represents the variance of sample T1.

[0083] Step 4.2: Calculate the degrees of freedom based on the sample sizes in samples T1 and T2;

[0084] In step 4.2, the degree of freedom is calculated as follows:

[0085] df = n1 + n2 - 2

[0086] Where df represents the degrees of freedom, n1 represents the sample size of sample T1, and n2 represents the sample size of sample T2.

[0087] Step 4.3: Obtain the second test result based on the statistic and degrees of freedom.

[0088] In step 4.3, the hypothesis testing steps are:

[0089] 1. Null hypothesis (H0): μ1 = μ2 (there is no significant difference in the means of the two groups).

[0090] 2. Look up the table and calculate the p-value: Based on the degrees of freedom and t-value, obtain the p-value and determine whether to reject H0 (usually p<0.05 is significant).

[0091] Step 5: When the population variances of sample T1 and sample T2 are not equal, perform Welch's t test on sample T1 and sample T2 to obtain the second test result;

[0092] Furthermore, the step 5 includes:

[0093] Step 5.1: Calculate the Welch's t-test statistic based on the sample variance;

[0094] In step 5.1, the Welch's t test statistic calculation formula is:

[0095]

[0096] in, represents the variance of sample T1, represents the variance of sample T1, represents the mean of sample T1, represents the mean of sample T2, n1 represents the sample size of sample T1, n2 represents the sample size of sample T2, and t represents the Welch's t test statistic.

[0097] Step 5.2: Calculate the degrees of freedom for the Welch's t-test based on the sample variance;

[0098] In step 5.2, the degrees of freedom for the Welch's t-test are calculated as:

[0099]

[0100] Here, df represents the degrees of freedom of Welch's t-test.

[0101] Step 5.3: Obtain a second test result based on the Welch's t test statistic and the Welch's t test degrees of freedom. In the present invention, the test result can be determined by looking up a table.

[0102] Step 6: Determine whether the thermal performance index of the coke has changed based on the first test result and the second test result.

[0103] The present invention is further described below with reference to specific embodiments:

[0104] (1) Compile statistics (according to the format in Table 1 below) for the measured data on the thermal properties of coke over a period of time. The horizontal rows represent different CSR intensity intervals (in this example, the statistics are performed with a step size of 1). The corresponding blanks are filled with the mean CRI value within that intensity interval and the total number of CRI measurement data within that intensity interval.

[0105] Table 1

[0106]

[0107] (2) To ensure a large number of samples, this example selects CRI data with an intensity between 67 and 68 for analysis. As can be seen from the table above, there are 109 coke CRI data with a CSR between 67 and 68 under operating condition I, which constitute sample T1. There are 36 coke CRI data under operating condition II, which constitute sample T2.

[0108] (3) Perform an equal variance test on the two samples. First, perform a normality test on the two sets of data. For samples that conform to the normal distribution, use the Levene method to perform an equal variance test. Figure 2 As shown, the P value is less than 0.05, indicating that the variances of the two samples are not equal.

[0109] (4) Perform a mean test on the two samples. To determine whether the variances of the two samples are unequal, Welch's t test is used. The test results are shown in Table 2-3. From the mean test results of the two samples, there is a significant difference between the two sample means (P value is 0.000, rejecting the null hypothesis).

[0110] Table 2

[0111] Method I 109 23.142 0.337 0.032 Method II 36 24.647 0.705 0.12

[0112] Table 3

[0113] T-value degrees of freedom P-value -12.35 40 0.000

[0114] (5) Based on the above results, the following conclusion can be drawn: Under the same CSR conditions, the CRI data measured under Condition I have a smaller variance and a lower mean than the CRI data measured under Condition II. This indicates that the measurement stability under Condition II is not as good as that under Condition I, and the CRI is too high. Therefore, the coke CRI index established under Condition I can no longer be used for control.

[0115] The present invention also provides an electronic device, comprising a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and runnable on the processor, wherein the transceiver, the memory, and the processor are connected via the bus, and is characterized in that when the computer program is executed by the processor, the steps in the above-mentioned method for determining whether the value of the thermal performance measurement of coke has changed are implemented. Compared with the prior art, the beneficial effects of the electronic device provided by the present invention are the same as the beneficial effects of the method for determining whether the value of the thermal performance measurement of coke has changed described in the above-mentioned technical solution, and are not elaborated here.

[0116] The present invention also provides a computer-readable storage medium having a computer program stored thereon, characterized in that when the computer program is executed by a processor, the steps in the above-mentioned method for determining whether the measured value of the thermal properties of coke has changed are implemented. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided by the present invention are the same as the beneficial effects of the method for determining whether the measured value of the thermal properties of coke has changed described in the above-mentioned technical solution, and will not be elaborated here.

[0117] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solution that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for determining whether a value of a coke thermal property measurement has changed, characterized in that: include: Step 1: Statistically analyze the coke thermal strength values ​​under different working conditions to obtain the CRI values ​​under different CSR distribution conditions; Step 2: Select a CSR interval, and obtain the coke CRI data under operating condition I within the determined CSR interval to form sample T1, and obtain the coke CRI data under operating condition II within the determined CSR interval to form sample T2; Step 3: Perform an equal variance test on sample T1 and sample T2 to obtain the first test result; Step 4: When the population variances of sample T1 and sample T2 are equal, perform a two-sample t-test on sample T1 and sample T2 to obtain the second test result; Step 5: When the population variances of sample T1 and sample T2 are not equal, perform Welch's t test on sample T1 and sample T2 to obtain the second test result; Step 6: Determine whether the thermal performance index of the coke has changed based on the first test result and the second test result.

2. The method for determining whether a value of a coke thermal property measurement has changed according to claim 1, wherein: Step 4: When the population variances of sample T1 and sample T2 are equal, performing a two-sample t-test on sample T1 and sample T2 to obtain a second test result includes: Step 4.1: Calculate the statistic based on the means in samples T1 and T2; Step 4.2: Calculate the degrees of freedom based on the sample sizes in samples T1 and T2; Step 4.3: Obtain the second test result based on the statistic and degrees of freedom.

3. The method for determining whether a value of a coke thermal property measurement has changed according to claim 2, wherein: In step 4.1, the statistical calculation formula is: in, represents the mean of sample T1, represents the mean of sample T2, n1 represents the sample size of sample T1, n2 represents the sample size of sample T2, and t represents the statistic; It represents the pooled variance, and its calculation formula is: in, represents the variance of sample T1, represents the variance of sample T1.

4. The method for determining whether a value of a coke thermal property measurement has changed according to claim 3, wherein: In step 4.2, the degree of freedom is calculated as follows: df = n1 + n2 - 2 Where df represents the degrees of freedom, n1 represents the sample size of sample T1, and n2 represents the sample size of sample T2.

5. The method for determining whether a value of a coke thermal property measurement has changed according to claim 1, wherein: Step 5: When the population variances of sample T1 and sample T2 are not equal, performing Welch's t test on sample T1 and sample T2 to obtain a second test result includes: Step 5.1: Calculate the Welch's t-test statistic based on the sample variance; Step 5.2: Calculate the degrees of freedom for the Welch's t-test based on the sample variance; Step 5.3: Step 4.3: Obtain the second test result based on the Welch's t test statistic and the Welch's t test degrees of freedom.

6. The method for determining whether a value of a coke thermal property measurement has changed according to claim 5, characterized in that: In step 5.1, the Welch's t test statistic calculation formula is: in, represents the variance of sample T1, represents the variance of sample T1, represents the mean of sample T1, represents the mean of sample T2, n1 represents the sample size of sample T1, n2 represents the sample size of sample T2, and t represents the Welch's t test statistic.

7. The method for determining whether a value of a coke thermal property measurement has changed according to claim 6, wherein: In step 5.2, the degrees of freedom for the Welch's t-test are calculated as: Here, df represents the degrees of freedom of Welch's t-test.

8. An electronic device comprising a bus, a transceiver, a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the transceiver, the memory, and the processor are connected via the bus, wherein: When the computer program is executed by the processor, the steps of the method for determining whether a value of a coke thermal property measurement has changed are implemented as described in any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for determining whether a value of a coke thermal property measurement has changed are implemented as described in any one of claims 1 to 7.

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