A method for automatically detecting water leakage in blast furnaces

Abstract

This invention discloses an automatic method for detecting blast furnace leaks, comprising the following steps: collecting and storing blast furnace data; periodically calculating and storing the top gas volume, hydrogen content in the belly gas, and hydrogen utilization rate based on the blast furnace data; comparing the average hydrogen utilization rate over the most recent statistical periods to determine whether the hydrogen content in the top gas has increased; comparing the average ratio (CC2) of carbon monoxide to carbon dioxide content in the top gas over the most recent statistical periods to determine whether the blast furnace has experienced pipeline leaks; if no pipeline leaks have occurred in the blast furnace, and the calculated hydrogen content in the top gas has increased, then alerting the blast furnace operator that there may be a leak in the blast furnace.

Description

Technical Field

[0001] This invention belongs to the field of blast furnace ironmaking technology, specifically relating to a method for automatically detecting water leakage in blast furnaces. Background Technology

[0002] Blast furnace production involves high temperatures and harsh operating environments, necessitating the installation of cooling water pipes in the furnace body, waist, belly, and hearth for cooling. However, the complex production environment of a blast furnace also corrodes the cooling equipment, which must withstand not only high-temperature corrosion but also mechanical wear from the furnace charge and the scouring effect of high-speed gas flow. Typically, after a period of operation, leaks and damage to the cooling water pipes will occur, often easily overlooked by blast furnace operators in their early stages. Minor leaks can lead to gas flow disturbances, significant temperature fluctuations, and increased fuel ratios; severe leaks can result in furnace cooling and hearth freezing. Therefore, early detection of leaks or damage to the cooling walls, prompting blast furnace operators to take appropriate measures, directly impacts the normal smelting process and the longevity of the blast furnace. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention proposes an automatic method for detecting blast furnace water leakage. This method utilizes changes in blast furnace air volume, oxygen enrichment, and top gas composition, along with changes in blast furnace condition and hydrogen utilization rate, to help blast furnace operators promptly determine whether there is water leakage in the cooling wall of the blast furnace.

[0004] The technical solution is as follows:

[0005] A method for automatically detecting water leakage in a blast furnace includes the following steps:

[0006] Collect and store blast furnace data;

[0007] The amount of gas at the top of the furnace, the hydrogen content in the gas in the belly of the furnace, and the hydrogen utilization rate are periodically calculated and stored based on the blast furnace data.

[0008] Compare the average hydrogen utilization rate over the most recent statistical periods to determine whether the hydrogen content in the top gas has increased.

[0009] The average value of the ratio of carbon monoxide content to carbon dioxide content in the top gas of the blast furnace (CC2) is compared with the value of CC2 over the most recent statistical periods to determine whether there is a pipeline leak in the blast furnace.

[0010] If there is no pipeline leak in the blast furnace, and the calculated volume fraction of H2 in the top gas increases, the blast furnace operator should be alerted that there may be a water leak in the blast furnace.

[0011] Furthermore, the blast furnace data includes: oxygen-containing blast volume, oxygen enrichment of the blast furnace, hydrogen content in the top gas, nitrogen content in the top gas, pulverized coal carrier gas volume, pulverized coal injection volume, hydrogen content in pulverized coal, blast humidity, carbon dioxide content in the top gas, and carbon monoxide content in the top gas.

[0012] Furthermore,

[0013] The formula for calculating the amount of gas at the furnace top is:

[0014] VTOP=[(BV5M-k1*BVO)*k2+BVINJ*k3] / N2

[0015] The formula for calculating the hydrogen content in the furnace gas is as follows:

[0016] VBSH2=[k4*WINJ*INJH+k5*BV5M*MOI]*k6

[0017] The formula for calculating the hydrogen utilization rate is as follows:

[0018] ETAH2=k7*[VBSH2-(k8*VTOP*H2)] / VBSH2

[0019] Wherein, BV5M is the oxygen-containing air volume; BVO is the oxygen enrichment volume; H2 is the hydrogen content in the top gas; N2 is the nitrogen content in the top gas; BVINJ is the coal powder carrier gas volume; WINJ is the coal powder injection volume; INJH is the hydrogen content in the coal powder; and k1 to k8 are coefficients.

[0020] Furthermore, by comparing the average hydrogen utilization rate over the most recent statistical periods, the method for determining whether the hydrogen content in the top gas has increased is as follows:

[0021] Set a statistical period, calculate and store the average hydrogen utilization rate within each statistical period;

[0022] Take the average value of hydrogen utilization rate for the most recent three statistical periods, and denot it as ETAH2(k), ETAH2(k-1), and ETAH2(k-2), and output the calculation results of ETAH2(k)-ETAH2(k-1) and ETAH2(k)-ETAH2(k-2);

[0023] The two calculation results are compared with the set first threshold. If either of the two calculation results is less than the first threshold, it is considered that the hydrogen content in the top gas has increased.

[0024] Furthermore, the method for determining whether a blast furnace pipeline leak has occurred is to compare the average value of the ratio of carbon monoxide to carbon dioxide content in the top gas over the most recent statistical periods (CC2).

[0025] Set a statistical period, calculate and store the average value of the ratio of carbon monoxide content to carbon dioxide content in the furnace top gas within each statistical period, denoted as CC2;

[0026] Take the average value of CC2 for the most recent three statistical periods, and denote it as CC2(k), CC2(k-1), CC2(k-2), and output the calculation results of CC2(k)-CC2(k-1) and CC2(k)-CC2(k-1);

[0027] The two calculation results are compared with the set second threshold. If both calculation results are less than the second threshold, it is considered that no pipeline leakage has occurred in the blast furnace.

[0028] Furthermore, it also includes taking the water replenishment curve of the furnace top expansion tank, taking the slope data of the most recent statistical periods, and if the change value of its slope is greater than the set third threshold, it is considered that there is a possibility of water leakage in the blast furnace.

[0029] The automatic blast furnace leakage detection method of the present invention can periodically extract hydrogen utilization rate and the ratio of carbon monoxide content to carbon dioxide content in the top gas from blast furnace data, and help blast furnace operators to timely determine whether there is a cooling wall leakage in the blast furnace based on the changing patterns of the two. Attached Figure Description

[0030] Figure 1 This is a flowchart of the method for automatically detecting blast furnace water leakage according to the present invention. Detailed Implementation

[0031] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, primarily used to illustrate the embodiments and to explain the operating principles of the embodiments in conjunction with the relevant descriptions in the specification. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention. Components in the drawings are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0032] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] like Figure 1 As shown in the figure, this embodiment provides a method for automatically detecting blast furnace water leakage, including the following steps:

[0035] Step S1: Collect and store blast furnace data.

[0036] The blast furnace data includes: oxygen-containing blast volume, oxygen enrichment level, hydrogen content in the top gas, nitrogen content in the top gas, pulverized coal carrier gas volume, pulverized coal injection rate, hydrogen content in pulverized coal, blast humidity, carbon dioxide content in the top gas, and carbon monoxide content in the top gas. The hydrogen content in the top gas represents the volume fraction of hydrogen in the top gas; the rest are similar.

[0037] All data is collected and stored through the blast furnace's data acquisition system. In this embodiment, various types of data are collected in a five-minute sampling period, the average value over five minutes is calculated, and then stored for subsequent analysis and further calculations.

[0038] Step S2: Periodically calculate the amount of gas at the top of the blast furnace, the hydrogen content in the gas in the belly of the blast furnace, and the hydrogen utilization rate based on the blast furnace data.

[0039] In practice, based on the sampling data at each time point, data such as the amount of gas at the top of the furnace, the hydrogen content in the gas in the belly of the furnace, and the hydrogen utilization rate are calculated.

[0040] The formula for calculating the amount of gas at the furnace top is:

[0041] VTOP=[(BV5M-BVO / 60)*79+BVINJ*100] / N2

[0042] The formula can be expressed as:

[0043] VTOP=[(BV5M-k1*BVO)*k2+BVINJ*k3] / N2

[0044] The formula for calculating the hydrogen content in the furnace gas is:

[0045] VBSH2=[WINJ*(1000 / 60)*INJH / 1000+BV5M*MOI*0.001

[0046] [*(2 / 18)]*11.2

[0047] The formula can be expressed as:

[0048] VBSH2=[k4*WINJ*INJH+k5*BV5M*MOI]*k6

[0049] The formula for calculating hydrogen utilization rate is:

[0050] ETAH2=[VBSH2-(VTOP*60*H2 / 100)] / VBSH2*100

[0051] The formula can be expressed as:

[0052] ETAH2=k7*[VBSH2-(k8*VTOP*H2)] / VBSH2

[0053] Wherein, BV5M is the oxygen-containing air volume; BVO is the oxygen enrichment volume; H2 is the hydrogen content in the top gas; N2 is the nitrogen content in the top gas; BVINJ is the pulverized coal carrier gas volume; WINJ is the pulverized coal injection volume; INJH is the hydrogen content in the pulverized coal; k1~k8 are set constants or obtained through empirical data.

[0054] All of the above data are calculated every 5 minutes and then stored.

[0055] Step 3: Compare the average hydrogen utilization rate over the most recent statistical periods to determine whether the hydrogen content in the top gas has increased.

[0056] In practice, the average of the hydrogen utilization rate over the most recent three periods is first calculated and denoted as ETAH215, which represents the average hydrogen utilization rate over 15 minutes, and then stored. The statistical period can be adjusted as needed, such as to 20 minutes or 30 minutes.

[0057] Take the three most recent ETAH215 values ​​and denote them as ETAH215(k), ETAH215(k-1), and ETAH215(k-2).

[0058] Compare the relationship between ETAH215(k)-ETAH215(k-1) or ETAH215(k)-ETAH215(k-2) and the set threshold 1. If either of them is less than the threshold 1, the hydrogen content in the furnace top gas is considered to have increased. The threshold 1 is a parameter limit based on empirical data, and its specific value is not limited here.

[0059] In practice, it is also necessary to eliminate changes in hydrogen content caused by pipeline travel.

[0060] Step S4: Compare the average value of the ratio of carbon monoxide content to carbon dioxide content in the top gas of the blast furnace over the most recent statistical periods (CC2) to determine whether the blast furnace has experienced pipeline leakage.

[0061] CO: Carbon monoxide content in the top gas; CO2: Carbon dioxide content in the top gas; CC2 = CO / CO2.

[0062] CC2's calculation cycle is 5 minutes.

[0063] In practice, the average value of the three most recent CC2 values ​​is first calculated and recorded as CC215, which is the 15-minute average of the ratio of CO to CO2 content in the top gas of the furnace, and then stored.

[0064] Take the three most recent CC215 values ​​and denote them as CC215(k), CC215(k-1), and CC215(k-2), respectively.

[0065] Compare the calculation results of CC215(k)-CC215(k-1) and CC215(k-1)-CC215(k-2) with the set threshold 2. If both calculation results are less than the threshold 2, it is considered that no pipeline leakage has occurred in the blast furnace. Similarly, the threshold 2 is a parameter limit made based on empirical data, and the specific value of the threshold 2 is not limited here.

[0066] Steps S3 and S4 are not in any particular order.

[0067] Step S5: If there is no pipeline leak in the blast furnace, and the hydrogen content in the top gas is calculated to be increased, the blast furnace operator should be alerted that there may be a water leak in the blast furnace. At this time, the piping operator needs to go to the site to confirm the specific leak point and take appropriate measures to deal with it.

[0068] To further determine the extent of blast furnace leakage, the following measures can be taken:

[0069] Step S6: Take the water replenishment curve of the furnace top expansion tank, and take the most recent slope data. If the change value of its slope Δμ is greater than the set threshold 3, it indicates that the water replenishment has suddenly accelerated, and there is also a possibility of leakage. Similarly, threshold 3 is a parameter limit made based on empirical data, and the specific value of threshold 2 is not limited here.

[0070] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A method for automatically detecting water leakage in a blast furnace, characterized in that, Includes the following steps: Collect and store blast furnace data; the blast furnace data includes: oxygen-containing blast volume, oxygen enrichment of the blast furnace, hydrogen content in the top gas, nitrogen content in the top gas, pulverized coal carrying capacity, pulverized coal injection rate, hydrogen content in pulverized coal, blast humidity, carbon dioxide content in the top gas, and carbon monoxide content in the top gas. The amount of gas at the top of the furnace, the hydrogen content in the gas in the belly of the furnace, and the hydrogen utilization rate are periodically calculated and stored based on the blast furnace data. To determine whether the hydrogen content in the top gas has increased, the average hydrogen utilization rate of the most recent statistical periods is compared. Specifically, a statistical period is set, and the average hydrogen utilization rate of each statistical period is calculated and stored. The average hydrogen utilization rate of the most recent three statistical periods is taken and denoted as ETAH2(k), ETAH2(k-1), and ETAH2(k-2), and the calculation results of ETAH2(k)-ETAH2(k-1) and ETAH2(k)-ETAH2(k-2) are output. The two calculation results are compared with a set first threshold. If either of the two calculation results is less than the first threshold, the hydrogen content in the top gas is considered to have increased. The average value of CC2 over the most recent statistical periods is compared to determine whether a pipeline leak has occurred in the blast furnace. CC2 is the ratio of carbon monoxide to carbon dioxide in the top gas. Specifically, a statistical period is set, the average value of CC2 in each statistical period is calculated and stored, and the average value of CC2 over the most recent three statistical periods is taken and denoted as CC2(k), CC2(k-1), and CC2(k-2). The calculation results of CC2(k)-CC2(k-1) and CC2(k-1)-CC2(k-2) are output. The two calculation results are compared with a set second threshold. If both calculation results are less than the second threshold, it is considered that no pipeline leak has occurred in the blast furnace. If there is no pipeline leak in the blast furnace, but the hydrogen content in the top gas increases, the blast furnace operator should be alerted that there may be a water leak in the blast furnace.

2. The method for automatically detecting blast furnace leakage as described in claim 1, characterized in that: It also includes obtaining the water replenishment curve of the furnace top expansion tank, taking the slope data of the most recent statistical periods, and if the change value of its slope is greater than the set third threshold, it is considered that there is a possibility of water leakage in the blast furnace.

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