JPH07119915A - Malfunction sensing method for coke dry type fire extinguishing facility - Google Patents

Abstract

PURPOSE:To easily sense a malfunction of a waste heat boiler by predging a boiler tube to be damaged when an instantaneous value of a flow rate difference between a water supply amount and generated steam amount to the boiler or an average value of an integrated value within a predetermined value exceeds a predetermined set value. CONSTITUTION:A flow rate difference operator 29 operates a flow rate difference from a water supply amount and generated steam amount to a waste heat boiler 13 to be input from a water supply amount detecting sensor 27 and a generated steam amount detecting sensor 28 of the boiler 13. It obtains an instantaneous value of the difference and an average value of an integral value for a predetermined value of the instantaneous value. Further, the value is compared with a predetermined set instantaneous value (e.g. 10.0t/hr) and an average value (e.g., 5.0t/hr) of a set integrated value, and when the instantaneous value or the average value of the integrated value for the predetermined time exceeds the set instantaneous value or the average value of the set integrated value, it is output to a boiler tube damage sensor 26.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting abnormality such as breakage of a boiler tube of a waste heat boiler during the operation of coke dry fire extinguishing equipment.

[0002]

2. Description of the Related Art Conventionally, for extinguishing red hot coke discharged from a coke oven, a fire extinguisher loaded with red hot coke is moved to a fire extinguisher tower, and a large amount of water is sprinkled from the upper part to extinguish the wet type of fire. Was there. However, wet-type extinguishing of red hot coke not only causes the enormous amount of heat of red hot coke to escape into the atmosphere as steam, but it also accompanies the generated steam and scatters powder coke to the surrounding suburbs, causing pollution problems. It will cause it. For this reason, as for the recent extinguishing of the red hot coke, the mainstream is the coke dry extinguishing which can effectively use the enormous amount of heat of the red hot coke, improve the quality of the coke, and solve or reduce the problem of dust pollution.

Coke dry fire extinguishing equipment receives red hot coke that has been carbonized in a coke oven in a coke bucket mounted on a bucket car, and hoists the coke bucket at the top of a cooling tower consisting of a prechamber and a cooling chamber. After the charging lid at the top is opened and charged, the heat is exchanged with the circulating inert gas introduced from the circulating inert gas inlet provided in the lower portion of the cooling chamber below the pre-chamber, and the temperature is cooled to around 200 ° C. Then, the coke cutting device at the bottom cuts out a fixed amount one by one and conveys it to the blast furnace. The inert gas that has exchanged heat with the red hot coke and has risen to a temperature near 800 ° C smoke from the small flue provided around the boundary between the pre-chamber and the cooling chamber through the circular flue in the outer wall of the pre-chamber. After reaching the road, the primary dust remover made of dust-removing grid bricks installed in the flue is used for primary dust removal, and then introduced into a waste heat boiler to recover heat.
Secondary dust is removed with a cyclone, etc., and then blown again by the circulating blower from the circulating inert gas inlet provided in the lower part of the cooling chamber.

Most of the circulating inert gas in the coke dry fire extinguishing equipment is nitrogen gas and carbon dioxide gas, and also contains combustible hydrogen gas and carbon monoxide gas generated from red hot coke. Therefore, the circulating inert gas burns the combustible hydrogen gas and carbon monoxide gas by the dilution air blown into the flue gas so as not to enter the explosion limit. Furthermore, the waste heat boiler of coke dry fire extinguishing equipment is required to be inspected regularly by the Industrial Safety and Health Law.

As a method for detecting an abnormality such as a tube breakage of a waste heat boiler of the above-mentioned coke dry fire extinguishing equipment, small coke and powder coke into the boiler due to a pressure difference between a boiler inlet / outlet and a pressure gauge measurement value installed inside the boiler. When the estimated deposition amount of deposits exceeds a predetermined value, the deposit deposition coke breaks and flows down with the circulating inert gas inside the boiler, and the coke collides with the boiler tube and friction causes the boiler. A method for predicting tube breakage (Japanese Patent Laid-Open No. 3-217)
No. 488), abnormalities such as water leakage due to breakage of the boiler tube are analyzed by analyzing the gas components of the gas circulation system to measure the component ratios of hydrogen, carbon monoxide, carbon dioxide, and oxygen. Obtain the water component ratio determined from the mass balance, and when the calculated water component ratio value is negative or lower than a specified value, and the actual water component ratio value is measured to determine the water component ratio. There has been proposed a method (Japanese Patent Laid-Open No. 64-51490) of determining water leakage in a boiler tube when the difference between the calculated value and the actual value is larger than a predetermined value.

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The method disclosed in Japanese Patent No. 488 has a tendency that the boiler tube frequently breaks when the amount of adhered and deposited coke increases in the early stage coke dry fire extinguishing equipment. In recent years, therefore, wear countermeasures such as installing a cover on the boiler tube are sufficient. In addition, measures have been taken to reduce the adhesion and deposition of coke in the boiler, reducing the frequency of boiler tube damage that occurs due to abrasion of the adhered deposition coke on the boiler tube and friction. There is. Therefore, recently, the frequency of boiler tube breakage due to disturbance factors other than the adhered and deposited coke has increased, and the error in estimation accuracy has increased, making it difficult to maintain estimation accuracy. Further, the method disclosed in JP-A-64-51490 requires analysis of hydrogen, carbon monoxide, carbon dioxide, oxygen, water and a large number of gas components, and continuously measures these components. Is technically difficult, and it usually takes several minutes to analyze such a number of gas components with one analyzer, so to detect water leakage immediately due to changes in gas components, for example, (Analysis It is necessary to install a considerable number of gas analyzers such as (the number of target gas components to be processed) × (the number of measurement points). On the other hand, gas analyzers are large, such as gas dust removers, dehumidifiers, and gas component analyzers, and their equipment costs are also quite large.Installing several of these equipment would require too much capital investment. It is not suitable as an anomaly detection system.

An object of the present invention is to provide a coke dry fire extinguishing equipment which can detect an abnormality of a waste heat boiler at an early stage by utilizing a sensor conventionally installed in a normal coke dry extinguishing equipment without newly installing a sensor. It is to provide an abnormality detection method.

[0008]

[Means for Solving the Problems] The present inventors have conducted various test studies in order to achieve the above object. As a result, water leakage from the boiler tube is caused by minute damage to the boiler tube, which is often overlooked by the instantaneous value only, by monitoring the instantaneous value and integrated value of the difference between the amount of water supplied to the boiler and the amount of steam generated from the boiler. It is also possible to detect the amount of water leakage, and when steam flows out into the cooling tower due to breakage of the boiler tube, the pressure inside the pre-chamber rises due to contact reaction with red hot coke, so the pre-chamber pressure is monitored. It was confirmed that it is possible to detect breakage of the boiler tube by comparing with a normal pressure control state, and the present invention has been reached.

That is, the first invention of the present application is a method for detecting an abnormality of a waste heat boiler of a coke dry fire extinguishing system, in which an instantaneous value of the flow rate difference is calculated by calculating a flow rate difference between the amount of water supplied to the waste heat boiler and the amount of steam generated. Then, the average value of the integrated values within a predetermined time is determined, and the instantaneous value of the flow rate difference or the average value of the integrated values within the predetermined time is compared with the respective preset values to determine the instantaneous value of the flow rate difference. A method for detecting an abnormality in a coke dry fire extinguisher facility, characterized in that it is determined that the boiler tube is broken when either the value or the average value of integrated values within a predetermined time exceeds respective preset values.

The second invention of the present application is a method for detecting an abnormality in a waste heat boiler of a coke dry fire extinguisher, wherein the prechamber internal pressure is controlled while the prechamber internal pressure is controlled during operation of the coke dry fire extinguishing equipment. And the opening / closing of the charging lid are detected and compared with a preset pressure setting value when the charging lid is opened or closed, and when each detected value exceeds the set value, or when the charging lid is closed A method for detecting an abnormality in a coke dry fire extinguishing facility, characterized in that it is determined that a boiler tube is damaged when the value continuously exceeds a predetermined set value for a predetermined time.

Further, a third invention of the present application is a method for detecting an abnormality of a waste heat boiler of a coke dry fire extinguishing facility, in which the difference in flow rate between the amount of water supplied to the waste heat boiler and the amount of generated steam is calculated to determine the instantaneous difference in flow rate. Obtain an average value of the integrated value within a predetermined time and a predetermined value, and compare the instantaneous value of the flow rate difference or the average value of the integrated value within a predetermined time with each of the preset setting values,
Whether any of the instantaneous value of the flow rate difference or the average value of the integrated values within a predetermined time exceeds each preset setting value,
Alternatively, the pre-chamber pressure and the opening / closing of the charging lid are detected while the pre-chamber pressure is controlled during the operation of the coke dry fire extinguishing equipment, and the preset pressure setting value when the charging lid is opened or closed. If the detected value exceeds the preset value, or if the preset value is continuously exceeded for a predetermined time when the charging lid is closed, it is judged that the boiler tube is damaged. This is a characteristic method for detecting abnormalities in coke dry fire extinguishing equipment.

[0012]

In the present invention, a sensor for detecting the amount of water supplied to the waste heat boiler, the amount of generated steam, the pressure in the pre-chamber, and the opening / closing of the charging lid is installed in the ordinary coke dry fire extinguishing equipment for operation monitoring. Utilizing this, each of these sensors is connected to a computing unit, and the computation result is input to the boiler tube breakage detection device. In the first invention, the flow rate difference between the amount of water supplied to the waste heat boiler and the amount of generated steam is calculated to obtain the average value of the instantaneous value of the flow rate difference and the integrated value of the instantaneous values within a predetermined time. When the boiler tube is damaged, there is a difference in flow rate between the amount of steam supplied to the boiler and the amount of steam generated due to water leakage and steam leakage from the damaged part. The instantaneous value of the flow rate difference and the average value of the integrated values within a predetermined time period are compared with the respective preset values, and either the instantaneous value of the flow rate difference or the average value of the integrated values within the predetermined time period is compared. If it exceeds each preset value, it is judged that the boiler tube is broken, and it is possible to detect even a small amount of water leakage due to the breakage of the boiler tube, which is often overlooked only by the instantaneous value of the flow rate difference between the water supply amount and the generated steam amount. It becomes possible. In addition, the average value of the integrated value of the instantaneous value within the predetermined time is
Even if the average value of the integrated values of the instantaneous values for a predetermined time period is updated at regular time intervals, or if it is the average value of the moving integrated values within the predetermined time period for the instantaneous value Good.

During normal coke dry fire extinguishing equipment operation, the pressure inside the pre-chamber is controlled to be constant by adjusting the on-off valves installed in the upper and lower diffusion pipes. In the second aspect of the present invention, the pre-chamber internal pressure and the opening / closing of the charging lid are detected while the pre-chamber internal pressure is controlled during the operation of the coke dry fire extinguishing equipment.
If the boiler tube is damaged, if water or steam leaking from the damaged part travels through the system and flows into the cooling chamber and comes into contact with red hot coke, an abnormal gas will be generated due to the aqueous reaction between water and red hot coke. Then, the pressure in the pre-chamber rises. On the other hand, when operating the coke dry fire extinguishing equipment, the charging lid is opened and closed.Therefore, set the pressure setting value when the charging lid is opened or closed, and when the charging lid is opened. Or, when the charging lid is closed, it is compared with a preset setting value when the charging lid is opened or closed, and when each detected value exceeds the setting value, or when the charging lid is closed, the preset value is set for a predetermined time If it exceeds continuously, it is judged that the boiler tube is damaged.

Further, in the third invention, the flow rate difference between the amount of water supplied to the waste heat boiler and the amount of generated steam is calculated to obtain the instantaneous value of the flow rate difference and the average value of the integrated values within a predetermined time. Comparing the instantaneous value of the flow rate difference and the average value of the integrated values within a predetermined time period with each of the preset setting values, whichever of the instantaneous value of the flow rate difference or the average value of the integrated values within the predetermined time period. When the pressure exceeds each preset value, or when the pre-chamber pressure is controlled while the coke dry fire extinguisher is operating, the pre-chamber pressure and the opening / closing of the charging lid are detected, and charging is performed. When the lid is opened or closed, it is compared with a preset pressure set value when the charging lid is opened or closed, and when each detected value exceeds the set value, or when the charging lid is closed, it is determined in advance. When the set value is continuously exceeded for a predetermined time When one, by determining the boiler tube failure, which improves the accuracy of the boiler tube breakage detection.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the method of the present invention will be described below with reference to FIGS. FIG. 1 is an explanatory view of a device configuration of a sensor, a computing unit, etc. in a coke dry fire extinguisher for carrying out the method of the present invention, and FIG. In FIG. 1, 1 is a cooling tower composed of a pre-chamber 2 and a cooling chamber 3, 4 is a coke bucket for loading red hot coke discharged from a coke oven, 5 is a bucket truck for carrying the coke bucket 4, and 6 is a hoist. Then, the coke bucket 4 loaded with the red hot coke is rolled up and traversed right above the cooling tower 1, the charging lid 7 of the pre-chamber 2 is opened, and the red hot coke is charged.

Reference numeral 8 is a circulating inert gas inlet provided in the lower portion of the cooling chamber 3, and the red hot coke descending in the cooling tower 1 is
It is cooled to about 200 ° C. by exchanging heat with the circulating inert gas blown from the circulating inert gas blowing port 8, sequentially cut by the coke cutting device 9 at the bottom of the cooling chamber 3, and then conveyed by the conveyor 10 to the next step. Be transported to. The circulating inert gas that has exchanged heat with the red hot coke and has been heated to about 800 ° C. reaches the flue 12 via the annular flue 11 at the outer periphery of the pre-chamber 2 and is subjected to primary dust removal by a not-shown primary dust remover. The waste heat boiler 13 recovers heat, the cyclone 14 further removes dust, and the circulating blower 15 blows the inert gas through the circulation inert gas inlet 8.

Reference numeral 21 is a pressure detecting sensor provided in the pre-chamber 2, and outputs the detected pressure to the pre-chamber pressure control device 22 and the pre-chamber pressure monitoring device 23. The pre-chamber pressure control device 22 compares the internal pressure of the pre-chamber 2 input from the sensor 21 with a predetermined pressure set value, and when the internal pressure of the pre-chamber 2 exceeds the set value, the upper diffusion valve 24 or the lower diffusion valve 24 is released. Valve 25
To release the gas and control the pressure inside the pre-chamber 2 to a set value. The pre-chamber pressure monitoring device 23 detects the pressure inside the pre-chamber 2 input from the sensor 21,
Based on a separately input signal for opening or closing the charging lid 7, the pressure inside the pre-chamber 2 is compared with a preset pressure when the charging lid 7 is opened or closed (for example, 20 mmAq or 100 mmAq). Is exceeded, or when the charging lid 7 is closed, a preset pressure (for example, 50 mmA)
When q) is continuously exceeded for a predetermined time, it is configured to output to the boiler tube breakage detection device 26.

27 is a sensor for detecting the amount of water supplied to the waste heat boiler 13, 28 is a sensor for detecting the amount of steam generated by the waste heat boiler 13, and the amount of water supplied and the amount of steam generated by the sensors 27, 28 are It is output to the flow rate difference calculator 29. The flow rate difference calculator 29 calculates a flow rate difference from the amount of water supplied to the waste heat boiler 13 and the amount of steam generated, which are input from the sensors 27 and 28, and averages the instantaneous value and the integrated value of the instantaneous values for a predetermined time. The value is calculated and compared with a preset set instantaneous value (for example, 10.0 t / h) and an average value of set integrated values (for example, 5.0 t / h) to determine whether it is an instantaneous value or an average value of integrated values for a predetermined time. When the value exceeds the set instantaneous value or the average of the set integrated values, the boiler tube breakage detection device 26
To output to. As shown in FIG. 2, the boiler tube damage detection device 26 outputs a signal indicating that the pressure inside the pre-chamber 2 exceeds a set value, which is input from the pre-chamber pressure monitoring device 23, or a set value that is set in advance when the charging lid 7 is closed. For a predetermined time continuously, and a signal for which either the instantaneous value input from the flow rate difference calculator 29 or the average value of the integrated values for the predetermined time exceeds the set instantaneous value or the average value of the set integrated values. On the basis of the above, the boiler tube is judged to be broken, and an alarm is issued, and a command is issued to stop the combustion air fan (not shown), stop coke cutting out, stop coke charging, open system gas release valve, and system nitrogen gas purge. In FIG. 2, 30 is an OR circuit and 31 is an AND circuit.

With the above construction, when the boiler tube is damaged, the sensor 27 for detecting the amount of water supplied to the boiler due to water leakage and steam leakage from the damaged portion.
And a flow rate difference occurs between the sensor 28 for detecting the amount of generated steam. The flow rate calculator 29 calculates a flow rate difference between the water supply amount and the generated steam amount, obtains an instantaneous value of the flow amount difference and an average value of integrated values of the instantaneous values within a predetermined time, and preset settings are input. An instantaneous value (for example, 10.0 t / h) and an average value of set integrated values (for example, 5.0 t / h) are compared to set either the instantaneous value of the flow rate difference or the average value of integrated values within a predetermined time. When the average value of the instantaneous value and the set integrated value is exceeded,
The signal is output to the boiler tube breakage detection device 26.

On the other hand, when water and steam leaking from the damaged portion of the boiler tube flow through the system into the cooling chamber 3 and come into contact with the red hot coke, an abnormal gas is generated due to an aqueous reaction between water and the red hot coke. , The pressure in the pre-chamber 2 rises. The pre-chamber pressure monitoring device 23 detects the pressure inside the pre-chamber 2 input from the sensor 21,
Based on a separately input signal of opening or closing of the charging lid 7, a predetermined set value when the charging lid is opened or closed (20 mmA
q or 100 mmAq), if any of the detected values exceeds the set value, or if the set value (50 mmAq) previously set when the charging lid is closed exceeds the set value continuously for a predetermined time, the signal is sent to the boiler. Output to the tube breakage detection device 26.

In the boiler tube breakage detection device 26, either the instantaneous value of the flow rate difference input from the flow rate calculator 29 or the average value of the integrated values within a predetermined time exceeds the set instantaneous value and the average value of the set integrated values. Pre-chamber 2 that is input from the signal and the pre-chamber pressure monitoring device 23
A signal that the internal pressure exceeds a preset value (20 mmAq or 100 mmAq) when the charging lid is opened or closed, and a preset value (5 when the charging lid is closed).
0 mmAq) is continuously exceeded for a predetermined time based on a signal that the boiler tube is judged to be broken by the judgment circuit shown in FIG. 2 and necessary measures are instructed. As a result, in the present invention, it is possible to detect even a small amount of water leakage due to the breakage of the boiler tube that is often overlooked by the instantaneous value of the flow rate difference between the water supply amount and the generated steam amount. Since it monitors the boiler tube damage by monitoring, even in the case of equipment failure such as sensor failure,
Boiler tube damage determination accuracy can be improved.

[0022]

As described above, according to the method of the present invention, damage to the boiler tube of the coke dry fire extinguishing equipment can be prevented.
Highly accurate detection is possible, and because existing sensors are used, there is no need to install sensors, and equipment costs can be reduced.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a device configuration such as a sensor and a computing unit in a coke dry fire extinguisher device for carrying out the method of the present invention.

FIG. 2 is a sequence diagram of the boiler abnormality detection system of the method of the present invention.

[Explanation of symbols]

 1 Cooling Tower 2 Pre-chamber 3 Cooling Chamber 4 Coke Bucket 5 Bucket Cart 6 Hoisting Machine 7 Charging Lid 8 Circulating Inert Gas Blow-in Port 9 Coke Cutting Device 10 Transport Conveyor 11 Circular Flue 12 Flue 13 Waste Heat Boiler 14 Cyclone 15 Circulation blower 21, 27, 28 Sensor 22 Pre-chamber pressure control device 23 Pre-chamber pressure monitoring device 24 Upper diffusion valve 25 Lower diffusion valve 26 Boiler tube breakage detection device 29 Flow rate difference calculator 30 OR circuit 31 AND circuit

Front page continuation (72) Inventor Shizuyoshi Matsunami 1850 Minato, Wakayama, Wakayama Sumitomo Metal Industries, Ltd. Wakayama Steel Works (72) Inventor Shuji Saeki 4-53, Kitahama, Chuo-ku, Osaka, Osaka Sumitomo Metals Industrial Co., Ltd. (72) Inventor Yutaka Hirata 4-53-3 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture Sumitomo Metal Industries, Ltd.

Claims (3)

[Claims] 1. A method for detecting an abnormality in a waste heat boiler of a coke dry fire extinguishing system, wherein a flow rate difference between the amount of water supplied to the waste heat boiler and the amount of generated steam is calculated to determine an instantaneous value of the flow rate difference within a predetermined time. The average value of the integrated values of the flow rate difference is calculated, and the average value of the integrated values of the flow rate difference or the integrated value within a predetermined time is compared with each preset setting value, and the instantaneous value of the flow rate difference or the integrated value within the predetermined time is calculated. A method for detecting abnormality in a coke dry fire extinguishing facility, characterized in that if any one of the average values exceeds a predetermined set value, it is determined that the boiler tube is damaged. 2. A method for detecting an abnormality in a waste heat boiler of a coke dry fire extinguisher, wherein the prechamber pressure and the opening / closing of the charging lid are detected while the prechamber pressure is controlled during the operation of the coke dry fire extinguisher. Then, compare with the preset pressure setting value when the charging lid is opened or closed, and if each detected value exceeds the set value, or if the detected value when the charging lid is closed is set to the preset value. A method for detecting an abnormality in a coke dry fire extinguishing facility, characterized in that it is determined that a boiler tube has been damaged when a predetermined time has been exceeded continuously. 3. An abnormality detection method for a waste heat boiler of a coke dry fire extinguishing facility, wherein a flow rate difference between the amount of water supplied to the waste heat boiler and the amount of steam generated is calculated to determine an instantaneous value of the flow rate difference within a predetermined time. The average value of the integrated values of the flow rate difference is calculated, and the instantaneous value of the flow rate difference or the average value of the integrated values within a predetermined time is compared with the respective preset values, and the instantaneous value of the flow rate difference or the integrated value within the predetermined time is compared. If either of the average values of the pre-chamber exceeds the respective preset values or the pre-chamber pressure is controlled during the operation of the coke dry fire extinguishing equipment, the pre-chamber pressure and the opening / closing of the charging lid are detected. Then, compare with the preset pressure setting value when the charging lid is opened or closed, and if each detected value exceeds the set value, or if the charging lid is closed, keep the preset setting value for a predetermined time. At any time if exceeded , Coke dry fire extinguishing equipment abnormality detection method characterized by determining that the boiler tube is damaged.