JPH08269513A - Detection of water leakage in blasting tuyere - Google Patents

Abstract

PURPOSE: To reduce the equipment cost by judging whether the difference between each actually measured value and a preset prescribed reference value drainage quantity from each blasting tuyere has varied a prescribed value or larger, or not. CONSTITUTION: In the first step 11, a water flow rate reference value and a setting value in each tuyere Tn is read in. Progressing to the following step 12, an actual measured value of drainage quantity by the flow meter of a drainage pipe in the tuyere is read in. Progressing to the following step 13, the reference value is substracted from the actual measured value of the drainage quantity to calculate the flow rate difference. In the step 14, the adding value to the flow rate difference is calculated. In the step 15, whether the absolute value of the flow rate difference is a threshold value or more, is judged. In the step 16, at the time of judging what the absolute value of the flow rate difference added value is less than the threshold value, it is judged that the water leakage is developed, and a water leakage alarm is sounded. By this method, the suitable reference value is set.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuyere leak detection method used for, for example, leaking of cooling water from a blowing tuyere of a blast furnace.

[0002]

2. Description of the Related Art Conventionally, as a technique for detecting water leakage at a blast furnace tuyere, a method is known in which a plurality of flow meters are used to measure the differential flow rate of cooling water to the blast tuyere. This conventional technology utilizes the phenomenon that the flow rate of wastewater decreases as compared to the feedwater flow rate when inundation occurs in the blast furnace due to the leakage of tuyere, and the flow rate difference between the water supply and wastewater exceeds a predetermined threshold. Detects the presence of mouth damage.

As another conventional technique, a flow meter such as a Karman vortex type flow meter is installed in either one of the water supply / drainage system, and the flow rate integrated value by this flow meter is compared with the flow rate integrated value at a normal time. , It is known that a warning is issued when the difference exceeds a certain level (Japanese Patent Publication No.
No. 6008).

[0004]

According to the conventional method for detecting the leakage of water in the blower tuyere from the difference in the flow rate of the water supply and drainage, it is necessary to use two flowmeters per tuyere, which leads to a high equipment cost. There's a problem. In other words, in a large blast furnace, the typical number of tuyere is about 40. Therefore, installing two flowmeters for each of the many tuyere in this way includes the construction cost. There is a problem that equipment costs will rise.

The water leakage detection method disclosed in Japanese Patent Publication No. 51-6008 is quite effective when the cooling water supply system for the tuyere is stable because it is a dedicated water supply system. . However, it is common that the cooling water supply system for the tuyere is also used as the water supply system for other locations.For example, the amount of water supply to the tuyere changes depending on the presence or absence of water sprinkling on the top of the furnace, resulting in frequent false alarms. Problems such as doing are expected.

Further, the conventional method disclosed in Japanese Patent Publication No. 51-6008 has a problem that the water supply amount between the tuyere is unbalanced due to the tuyere exchange at the time of rest, and the water supply amount once collapsed is stabilized. However, there is a problem in that it is difficult to determine the integrated value under normal conditions. Furthermore, this conventional method
Since the integrated value of the water supply is used, there are inherent problems such as a delay in response and the inability to detect an intermittent small amount of water leakage. Therefore, an object of the present invention is to provide a low-cost and highly reliable method for detecting leakage of tuyere water.

[0007]

According to the water leakage detection method of the present invention, the discharge amount of cooling water supplied to each of a plurality of blower tuyeres installed in a furnace body is measured by a flow meter, and each measured value is measured. And whether or not the difference between a predetermined reference value that has been set in advance for the amount of water discharged from each blower tuyere has changed by a predetermined value or more,
When the number of blast tuyere that fluctuates by a predetermined value or more simultaneously occurs, it is configured to detect the occurrence of water leakage in such a predetermined number or less of blast tuyere.

[0008]

In the present invention, attention is paid to the fact that there is a very rare probability that water leakage will occur simultaneously in a plurality of blast tuyeres, and a predetermined number or less of blast tuyeres (for example, only one or two blast tuyeres). In (1), the fact that the differential flow rate fluctuates by a predetermined value or more detects the occurrence of water leakage at the blower tuyere.
In other words, if there are fluctuations in the differential flow rate that are greater than or equal to the specified value with more than the specified number of blower tuyeres, it is determined that the fluctuation is not due to water leakage but due to the operation of another cooling water system. To be done. An appropriate method can be considered as a method for detecting that the fluctuation of the differential flow rate above the predetermined value has not occurred in a predetermined number or less of the blower tuyeres. A method of detecting from the fact that the difference between the added value and a predetermined reference value for this added value is less than a predetermined value is also conceivable.

Further, as described above, the flow rate of the water supply / drainage system of the blower tuyere fluctuates with the fluctuation of the flow rate of the other water supply / drainage system, or the tuyere is exchanged between the tuyere due to the exchange of the tuyere at the time of rest. It is not easy to obtain a stable actual measurement value of the flow rate or to set a reference value as a normal reference, because the flow rate distribution collapses or it takes time to stabilize the flow rate distribution once collapsed. . Therefore, in a preferred embodiment of the present invention, the actual measurement of the amount of cooling water discharged in each of the blower tuyeres is performed by collecting sampling values over a predetermined number from a flow meter at a predetermined period, and further, each sampling The average value of each sampling value when the variation of the value is less than or equal to a predetermined value is set as a reference value of the amount of drainage at each air blowing tuyere. Hereinafter, the present invention will be described in more detail with reference to Examples.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 3 is a block diagram showing the structure of a water leakage detecting device to which the water leakage detecting method of one embodiment of the present invention is applied, together with the blower tuyere to be monitored. In the furnace body A of the blast furnace, a plurality of blast tuyeres T1, T2 ... Tk to be monitored are installed. Each of the tuyere T1 to Tk has a water supply pipe C10 and C2.
0, the cooling water is supplied, and each tuyere is drained through the drain pipes C91 to C9k and C90. In addition to the cooling water supply pipe C10 for the tuyere, other cooling water supply pipes C30 and C40 for, for example, the above-mentioned top water sprinkler are connected to the water supply pipe C10.

A flowmeter Dn (n = 1 to k) of an appropriate type such as an electromagnetic flowmeter is attached to the drain pipe C9n (n = 1 to k) of an arbitrary blower tuyere Tn (n = 1 to k). is set up. The detected value of each flow meter Dn is transferred to the computer COM in the form of an electric signal. The computer COM reads the measured value of the flow rate of the cooling water transferred from each flow meter at a predetermined sampling cycle, processes the measured value, and when a leak is detected at any of the air blowing tuyeres, a leak detection signal is output to the monitoring device VD.
Send to T. The monitoring device VDT is a computer COM
When a water leak detection signal is received from the water leak detection device, a water leak warning sound is emitted and the screen is displayed to notify the operating operator of the water leak detection.

Next, the water leak detection process performed by the computer COM will be described with reference to the flowchart of FIG.

The computer COM has the first step 1
In 1, the predetermined reference value Fno that is predetermined for the drainage amount of each tuyere Tn and the threshold value α that is predetermined for the difference between the reference value Fno and the actual measured value Fn of the drainage amount are read. Furthermore, the computer COM also reads a predetermined threshold value β that is predetermined with respect to the difference between the total sum of the measured drainage amounts of all tuyere and the sum total of the reference values of the drainage amounts of all tuyere.
It should be noted that this threshold value β does not necessarily match the value obtained by adding the above-described threshold value α for each tuyere Tn for all tuyere.

The computer COM executes the next step 12
Then, the measured value Fn of the drainage amount by the flowmeter Dn installed in the drainage pipe of each blower tuyere Tn is read. The computer COM proceeds to the next step 13 to calculate the difference flow rate ΔFn for each tuyere by subtracting a predetermined reference value Fno from the measured value Fn of the drainage amount. In the following step 14, the added value of the differential flow rate obtained by adding the differential flow rate calculated for each tuyere for all tuyere Σ _{n = 1} ^k ΔFn = Σ
_{n = 1} ^k (Fn-Fno) is calculated.

In the next step 15, it is determined whether or not the absolute value of the differential flow rate ΔFn calculated in step 13 is greater than or equal to a predetermined threshold value α for all tuyere Tn. If the absolute value of the differential flow rate ΔFn is less than the threshold value α, it is determined that there is no risk of water leakage for all tuyere, and the process returns to step 12 and the above-described processing from step 12 to determination step 15 is performed. Repeated.

At the decision step 15, if the absolute value of the differential flow rate ΔFn for any tuyere is greater than or equal to the threshold value α, the process proceeds to step 16. That is, the added value of the differential flow rate calculated in step 14 Σ _{n = 1} ^k
It is determined whether the absolute value of ΔFn is greater than or equal to a predetermined threshold β. When the computer COM determines in step 16 that the absolute value of the added value of the differential flow rates is less than the threshold value β, water leakage occurs in the tuyere Tn that is determined in step 15 that the absolute value of the differential flow rate ΔFn is equal to or greater than the threshold value α. It is determined that it has occurred, and a water leak alarm is issued via the monitoring device VDT.

On the other hand, in step 16, the computer COM determines that the absolute value of the added value of the differential flow rates is the threshold value β.
If it is determined that the above is the case, the tuyere Tn determined in step 15 that the absolute value of the differential flow rate ΔFn is greater than or equal to the threshold value α
It is determined that no water leakage has occurred, and the flow returns to step 12 without generating a water leakage alarm, and the above-described processing is repeated.

In this embodiment, the total number of blast tuyere is 29, and the reference value Fno of the discharge amount of each blast tuyere Tn is 400 per minute.
Liter, the threshold value α of the differential flow rate of each tuyere is 10 liters per minute,
The differential flow threshold β for all tuyere was set to 150 liters per minute.

Next, a method of calculating the reference value Fno of the drainage amount of each tuyere by the computer COM, which is set by the computer COM in step 11 of FIG. 1, will be described with reference to the flowchart of FIG.

The computer COM executes the first step 2
1, the predetermined data sampling period T, the predetermined sampling data number L, the predetermined upper limit value γ of the variation of the sampling data and the predetermined upper limit value δ of the number of calculation iterations are read, and then the number of calculation iterations N. Is set to an initial value 0 (step 22).

Next, for each of the blast tuyeres Tn,
The actual measured value Fnm (m = 1 to L) of the drainage amount is read in a sampling cycle of T seconds (step 23), and the average value X and the variation σ of the measured value Fnm of L for each tuyere Tn are calculated. (Step 24). Subsequently, it is determined whether or not the calculated variation σ for each tuyere Tn is less than a predetermined upper limit value γ (step 2
5) If the variation σ is less than the threshold value γ, the drainage amount is regarded as normal, and the average value X of the calculated actual measurement data is the reference value Fn.
is set as o (step 26).

When it is determined in step 25 that the calculated variation σ is greater than or equal to the threshold value γ, the number of operation iterations is increased by 1 (step 27), and the increased number of operation iterations is less than the predetermined threshold value δ. It is determined whether or not there is (step 28), and if less than, step 23 to step 25
The actual measurement and calculation processes up to are repeated. Computer C
When the OM determines in step 28 that the number of repetitions of the actual measurement of the above data and the calculation of the average value and the variation has reached the predetermined value δ, it sends an alarm to the monitoring device VDT that the calculation of the management value is impossible. Then, the arithmetic processing ends.

As described above, since the difference between the added value of the measured values of the drainage amount of all the blower tuyeres and the reference value set in advance with respect to this added value is less than the predetermined value, the difference in flow rate of any blower tuyere The configuration in which it is determined that only one has changed by a predetermined value or more has been illustrated. However, since the differential flow rate is measured for each blast tuyere, the number of blast tuyere where the differential flow rate fluctuates by a predetermined value or more is counted, and there is only one, so water leakage occurs at that tuyere. It is possible to adopt a configuration in which it is determined that it has done.

The case has been exemplified above in which the threshold value of the differential flow rate of each blast tuyere Tn is set to the same value α for all blast tuyere. However, a different value αn may be set according to the difference in the standard drainage amount of each air blowing tuyere.

[0025]

As described above in detail, the water leakage detection method of the present invention is configured to determine that water leakage has occurred because the differential flow rate has changed by a predetermined value or more in a predetermined number or less of blower tuyeres. It is possible to effectively solve the problem of the conventional method that it is easy to erroneously detect a change in the amount of drainage caused by another water supply / drainage system as the occurrence of leakage.

Further, according to the water leakage detection method of the present invention, since it is sufficient to install one flow meter for each blowing tuyere, there is an effect that equipment cost including installation work can be reduced.

Further, according to a preferred embodiment of the present invention, the actual measurement of the drainage amount of each tuyere collects a sampling value over a predetermined number in a predetermined cycle, and an average value when the variation is less than a predetermined value is used as a reference. Since it is set as a value, the flow rate of the air supply / drainage system of the blower tuyere fluctuates with the fluctuation of the flow rate of other water supply / drainage systems, and the flow rate between the tuyere with the replacement of the tuyere at rest. There is an advantage that an appropriate reference value can be set even if the distribution of the flow rate is broken or it takes time until the distribution of the flow rate once broken is stabilized.

[Brief description of drawings]

FIG. 1 is a flowchart for explaining the contents of a water leakage detection method according to an embodiment of the present invention.

FIG. 2 is a flow chart for explaining an example of a method of setting a reference value of drainage amount for each blower tuyere in the above embodiment.

FIG. 3 is a conceptual diagram for explaining the configuration of each blower tuyere to which the embodiment of FIG. 1 is applied together with the furnace body of the blast furnace.

[Explanation of symbols]

T1 ~ Tk Blower tuyeres D1 ~ Dk Flow meter for measuring the amount of drainage of each blast tuyer C20 Water supply pipe to each blast tuyer C90 ~ C9k Drain pipe of each blast tuyer COM Computer VDT monitoring device

Claims (4)

[Claims] 1. The discharge amount of cooling water supplied to each of a plurality of blower tuyeres installed in a furnace body is measured by a flow meter, and each measured value and the discharge amount of each blower tuyere are set in advance. It is determined whether or not the difference from the predetermined reference value has changed by a predetermined value or more, and if the number of blower tuyere that has changed by the predetermined value or more occurs at the same time by a predetermined number or less, the blower tuyere of such a predetermined number or less A method for detecting water leakage in a blower tuyere, comprising detecting that water leakage has occurred. 2. The predetermined number according to claim 1, wherein the difference between the added value of the measured values of the drainage amount of all the blower tuyeres and a reference value set in advance for the added value is less than a predetermined value. A method for detecting water leakage in a blower tuyere, comprising determining that the differential flow rate has changed by a predetermined value or more in the blower tuyere. 3. The drainage amount of cooling water at each of the blower tuyeres according to claim 1 or 2, wherein actual measurement is performed by collecting a sampling value from a corresponding flow meter over a predetermined number at a predetermined cycle. A method for detecting water leakage in the blast tuyere. 4. The air blower according to claim 3, wherein an average value of the sampling values when the variation of the sampling values is less than or equal to a predetermined value is set as a reference value of the drainage amount at each of the air blowing tuyere. Tuyere leak detection method.