JPH07119419B2 - Abnormality detection method for coke dry fire extinguishing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention uses high-temperature red hot coke discharged from a coke oven with a circulating gas such as an inert gas in a cooling tower when producing coke for iron making and the like. Regarding the coke dry type fire extinguishing equipment that cools and uses the exhaust heat to generate steam in the boiler and uses it for power generation, etc., relates to the abnormality detection method of the coke dry type equipment that detects the leakage of the boiler tube installed in the boiler It is a thing.

[Prior Art] A general coke dry fire extinguishing system will be described with reference to FIG.

In the figure, 1 is a cooling tower which cools the red hot coke c with a circulating gas such as an inert gas. Further, 2 is a boiler, which generates steam by using the circulating gas after cooling in the cooling tower 1 as a heat source.

The circulating gas that has entered the boiler 2 from the cooling tower 1 heats the boiler tube 3 in the boiler 2 to about 180 ° C., and coke powder in the gas is removed by a cyclone 4 provided on the downstream side of the boiler 2. After that, the pressure is increased by the circulation fan 5 and is blown into the coke c from the lower portion of the cooling tower 1 through the circulation duct 6. The circulating gas blown into the coke c cools the reddish coke c while rising in the tower 1, absorbs the heat, and returns to the boiler 2 through the flue 7 connected to the cooling tower 1.

The components of this circulating gas are H ₂ 5%, CO 10%, CO ₂ 12%, H ₂ O10
%, N ₂ 65%, but this composition ratio varies greatly depending on operating conditions. Therefore, the combustible components of the circulating gas such as H ₂ , C
A dilution air supply fan 8 and a dilution air adjusting valve 9 are connected to the flue 7 for controlling O, and the dilution air is blown into the circulating gas flowing in the flue 7 for combustion. In addition, in order to collect excess gas and use it as fuel, the circulation duct 6
Further, a gas recovery pipe 10 and a gas flow rate control valve 11 for adjusting the recovered gas flow rate are provided to appropriately recover the gas.

By the way, in addition to the main components described above, the circulating gas contains corrosive component gases such as hydrogen sulfide (H ₂ S) and coke powder. Then, the boiler tube 3 provided in the boiler 2 is repeatedly corroded and worn by the corrosive gas and the coke powder, and the wall thickness is reduced. Then, when the wall thickness of the tube 3 becomes thinner than the limit capable of withstanding the internal pressure, a rupture hole occurs and the boiler water is ejected. The jetted water becomes steam due to the heat of the circulating gas, is introduced into the cooling pipe 1, and reacts with the coke c. Therefore, C + H ₂ O → H ₂ + CO or C + 2H ₂ O → 2H ₂ + CO
Component ratio of H _2, CO is increased by ₂ reactions. Then, this H ₂ could not be released from the excess gas recovery pipe 10 and the cooling tower 1
There was a case where the charging device (not shown) was blown out from the charging port 12 provided in the upper part of the container and burned in the atmosphere to damage the charging device (not shown).

Therefore, in order to prevent water leakage of the boiler tube 3, a material resistant to corrosion is selected, and measures are taken to protect the tube 3 with a protect plate (not shown) to avoid wear, but it is not enough. There wasn't.

Therefore, in order to detect the water leakage of the boiler tube 3 early and to treat it before the flame is generated on the charging port 12, the conventional method is used.
H ₂ , C, CO ₂ , and O ₂ gas components were automatically measured by a gas analyzer (not shown), and H ₂ , C displayed on the chart
The O value was artificially judged by the operator. The criterion was such that if H ₂ % exceeds a predetermined value, it is considered as tube damage.

[Problems to be Solved by the Invention] By the way, the following problems have been encountered in this type of countermeasure.

Since the gas component varies as shown in FIGS. 4 and 5 by operating conditions, or H ₂ is increased by the tube damage, it has been a problem that H ₂ is difficult to do determination increased in normal operation .

Therefore, there has been a problem that the rupture of the tube abruptly expands before H ₂ reaches a predetermined value and it is determined that the tube is damaged, and the above-mentioned accident due to water leakage occurs.

In view of the problems as described above, the present invention is a coke dry fire extinguishing equipment capable of suppressing damage to a minimum by detecting a water leak of a boiler tube provided in a boiler at an initial stage and operating a safety device. It is an object of the present invention to provide an abnormality detection device.

[Means for Solving Problems] In order to solve the problems in the prior art, the first invention method is to measure the component ratios of H ₂ , CO, CO ₂ , and O ₂ by a gas analyzer, Obtain the component ratio of H ₂ O determined from the measured value and the mass balance of the gas circulation system, and if the calculated value of this H ₂ O is negative or falls below a specified value, it is judged that the boiler tube is leaking water. It is designed to activate the safety device.

In addition, the second invention method uses H ₂ , CO, CO ₂ , O ₂ by an analyzer.
And measuring the component ratio of H ₂ O, the H _2, CO, CO _2, and the measured value of the O _2, H ₂ O, which is determined from the mass balance of the gas circulation system
Calculated by the calculator using the formula to calculate the component ratio of
Seeking component ratio of H ₂ O, it determines the calculated values of H ₂ O, and leakage of boiler tubes when the difference between the measured values of the H ₂ O measured by the gas analyzer becomes equal to or larger than a predetermined value Then, the safety device is activated.

[Operation] In the first invention method performed as described above, the gas analyzer automatically and continuously measures the component ratios of H ₂ , CO, CO ₂ , and O ₂ , and sequentially determines these values. Let αH ₂ , αCO, αCO ₂ , and αO ₂ .

Further, the following formula for calculating the component ratio of H ₂ O is determined from the mass balance of the gas circulation system.

The αH _2, αCO, αCO _2, and the value of .alpha.0 ₂ Request component ratio × of H ₂ O of H ₂ O on the calculation by substituting this expression.

Then, when this x H ₂ O becomes negative or becomes less than a predetermined value, it is judged by the calculator that the boiler tube is leaking water, and an alarm signal is displayed, and the charging device of the cooling tower is interlocked. It activates the safety device.

Next, in the second invention method, H ₂ , C
O, CO _2, O ₂ and H ₂ O ratio of components automatically measured continuously, and these values turn αH _2, αCO, αCO _2, and .alpha.0 ₂ and alpha H ₂ O.

Further, the following formula for calculating the component ratio of H ₂ O is determined from the mass balance of the gas circulation system.

By substituting the values of αH ₂ , αCO, αCO ₂ and αO ₂ into this equation, the calculated H ₂ O component ratio × H ₂ O is obtained.

Then, when the value obtained by subtracting this x H ₂ O from the measured value of α ₃ H ₃ O above becomes a predetermined value or more, the calculator judges that the boiler tube is leaking water, displays an alarm signal, and cools down. It operates safety devices such as interlocking the charging equipment of the tower.

[Embodiment] Hereinafter, a method for detecting an abnormality in a coke dry fire extinguishing facility according to the present invention will be described in detail with reference to the accompanying drawings.

First, an example of an apparatus adopted to carry out the present invention will be described.

As shown in FIG. 1, the coke dry fire extinguishing equipment mainly comprises a cooling tower 1 and a boiler 2. The cooling tower 1 contains red hot coke c therein and is cooled with a circulating gas such as an inert gas. The boiler 2 produces steam in the cooling tower 1 as a heat source of the circulating gas after cooling. The upper part of the cooling tower 1 and the upper part of the boiler 2 are connected by a flue 7, and the circulation boss in the cooling tower 1 is transferred to the boiler 2. The lower part of the boiler 2 and the lower part of the cooling tower 1 are connected by a circulation duct 6, and the circulating gas introduced into the boiler 2 is transferred to the cooling tower 1 again. A dilution air supply fan 8 and a dilution air flow adjusting valve 9 are connected to the flue 7,
Diluting air is blown into the circulating gas flowing in the flue 7 for combustion. Further, the circulation duct 6 is provided with a cyclone 4 for removing coke powder in the gas and a circulation fan 5 for increasing the pressure in order from the upstream side. Further, a gas recovery pipe 10 is connected to a circulation duct 6 between the circulation fan 5 and the cooling tower 1. This gas recovery pipe
A gas flow rate control valve 11 for controlling the flow rate of the recovered gas is provided at 10 and appropriately recovers the excess gas and uses it as fuel.

Further, a gas analyzer 20 is connected to the circulation duct 6 between the cooling tower 1 and the gas recovery pipe 10 of the coke dry fire extinguishing facility thus configured. The gas analyzer 20 employs one capable of measuring the component ratio of H ₂ , CO, CO ₂ , O ₂ and H ₂ O. Further, the gas analyzer 20 is connected to the input side of a calculator 21. This calculator 21 is determined from the measured values of H ₂ , CO, CO ₂ , and O ₂ measured by the gas analyzer 20 and the mass balance of the gas circulation system. The component ratio of H ₂ O is calculated from the formula for calculating the component ratio of H ₂ O. The formula for calculating the component ratio of H ₂ O is H ₂ , CO, CO ₂ , and O ₂
Value respectively .alpha.H ₂ components ratio, αCO, αCO _2, and as .alpha.0 ₂ And is input to the calculator 21 in advance. A safety device 22 operated by the output signal of the calculator 21 is connected to the output side of the calculator 21. This safety device
When the calculator 21 judges that the boiler tube 3 is leaking water, 22 indicates an alarm by the output signal, and the cooling tower 1
It is designed to interlock.

Incidentally, the gas analyzer 20 is, for convenience, a cooling tower 1 and a gas recovery pipe.
Although it is connected to the circulation damper 6 between 10 and 10, it may be connected to any portion in the circulation system.

The abnormality detection method of the coke dry fire extinguishing equipment of the present invention, which is performed by using the above apparatus, will be described.

First, the gas analyzer 20 continuously and automatically measures the component ratios of H ₂ , CO, CO ₂ , O ₂ and H ₂ O. Then, each of these measurements s αH _2, αCO, αCO _2, and .alpha.0 ₂ and alpha H ₂ O.

Here, the circulation system of coke dry fire extinguishing equipment is modeled as shown in FIG. Assuming that the total volume of the circulating gas is Qx (Nm ³ / H), the gas component ratios of Q ₃ , Qw, Ql, Qc and Qp in the figure are as follows.

Qa: dilution air _{O 2 -21%, N 2 -79} % Qw: leakage during boiler tube damage vapor H ₂ O-100% Ql: lower stripped gas _{H 2 -αH 2, CO-αCO} , CO 2 -αCO 2 _{H 2 O-αH 2 O,} N 2 -αN 2, O 2 -αO 2 → circulation gas component _{αH 2 + αCO + αCO 2 +} αH 2 O + αN 2 + αO 2
= 1 Qc: generated gas H ₂ O-0% by reaction with _{coke, O 2 -0%, N 2} -0% QP: in Purichanba mass balance of gas H ₂ -100% circulatory system generated from coke Of which, the N ₂ balance is Also, the O ₂ balance is From expressions and expressions Here, the component ratio of α H ₂ O is αH ₂ O = 1-αH ₂ −αCO−αCO ₂ −αN ₂ −αO ₂ ... Therefore, the component ratio of α H ₂ O is Here, when there is no water leakage from the boiler tube, Qw = 0, so the calculated H ₂ O component ratio is Thus, H ₂ determined from the mass balance of the gas circulation system
An equation for calculating the O component ratio is input to the calculator 21 in advance. Then, continuously measuring the calculator 21 by the gas analyzer 20 αH _{2, αCO,} inputs constantly value of ArufaCO ₂ and .alpha.0 _2. Then, determined with these measurements, the ratio of components of H ₂ O on the calculation by the calculator 21 and a formula for calculating the ratio of components H ₂ O which is determined from the mass balance of the gas circulation system. This calculation is sequentially performed according to the change in the measured value input from the gas analyzer 20.

XH ₂ O in the above equation is positive (XH ₂ O ≧
0), and when Qw is greater than a certain value due to water leakage, it is negative (XH ₂ O <0).

Therefore, it is possible to determine that the water leaks when the predetermined value C ₁ is determined from the operation data and XH ₂ O ≦ C ₁ (C ₁ ≧ 0). That is, when the calculated value of H ₂ O is negative or becomes a predetermined value C ₁ or less, it is judged that the boiler tube is leaking water. When the calculator 21 determines that there is water leakage, the safety device 22 is activated by the output signal. As the safety device 22, for example, an alarm is displayed and the circulation fan 5 and a charging device (not shown) are interlocked.

The determination of water leakage by the above formula does not require actual measurement of the H ₂ O component, so the equipment can be simplified, but its detection accuracy is not very good.

Therefore, the measurement value α of H ₂ O measured by the gas analyzer 20
Uses H ₂ O. If there is leakage of the boiler tubes since the last term on the right side of the equation is reduced, the difference between the alpha H ₂ O increases XH ₂ O increases.

That is, Transform Left side is Y Qa is positive (Qa ≧ 0), so put D in parentheses It turns out that there is a leak in the boiler tube. Considering the instrumental error, the water leak is judged when the following equation is satisfied.

The above C ₂ is a predetermined value determined from normal operation data.

Thus, the calculated XH ₂ O value and the gas analyzer 20
When the difference between the measured value of α H ₂ O measured by and the measured value exceeds a predetermined value C ₂ , it is judged that the boiler tube is leaking water. When the calculator 21 determines that there is water leakage, the safety device 22 is activated by the output signal.

Considering the above criteria on the safety side, the calculated XH ₂ O
Is negative or becomes less than or equal to the specified value C ₁ , or the difference between the calculated XH ₂ O value and the measured value α H ₂ O is the specified value C ₂
The safety device 22 is actuated when any of the above conditions is met.

In addition, in the water blow-in type coke dry fire extinguishing equipment in which a water blow-in pipe (not shown) is provided in the circulation damper 6 to improve the cooling performance and increase the amount of recovered steam, the above-mentioned formula is used. The method of the present invention can be applied by preliminarily incorporating the blowing amount into Qw.

Also, the reason why the measured value α H ₂ O of the gas analyzer 20 is not used as it is as the criterion for judging the leakage of water in the boiler tube is the component ratio of H ₂ O such as H ₂ and CO shown in FIGS. 4 and 5 above. This is because variations occur.

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are exhibited.

(1) Since the standard for judging the leakage of the boiler tube was set and the calculator was made to judge this, it was judged mechanically and uniformly compared to the conventional artificial judgment, and immediately after the tube damage occurred. Can be detected.

(2) Since the leakage of the boiler tube is detected early and the safety device is activated, the plant can be safely stopped before the flame injection from the inlet of the cooling tower becomes large. It is possible to prevent damage to equipment such as a charging device (hoisting machine) around the device.

[Brief description of drawings]

FIG. 1 is a schematic view showing a coke dry fire extinguisher equipped with an abnormality detection device for carrying out the method of the present invention, and FIG. 2 is an explanatory view modeling a circulation system of the coke dry fire extinguishing equipment, and FIG.
Figure is a schematic diagram showing conventional general coke dry fire extinguishing equipment, Figure 4 is a graph showing changes in H ₂ component ratio, and Figure 5 is
It is a graph which shows the change of the component ratio of CO. In the figure, 20 is a gas analyzer, 21 is a calculator, and 22 is a safety device.

Claims (2)

[Claims] 1. A H ₂ Gas analyzer, CO, CO _2, and measuring the ratio of components O _2, and these measurements, the component ratio of H ₂ O which is determined from the mass balance of the gas circulation system seeking of H ₂ O ratio of components of the calculation by the calculator with a calculating formula, the H ₂ O
An abnormality detection method for coke dry fire extinguishing equipment, characterized in that the safety device is activated by determining that the boiler tube is leaking water when the calculated value of is negative or below a predetermined value. 2. A gas analyzer for measuring H ₂ , CO, CO ₂ , O ₂ and H ₂ O.
The component ratio of is measured, and the above H ₂ , CO, CO ₂ , and O ₂ measured values,
Seeking of H ₂ O ratio of components of the calculation by the calculator by using the equation for calculating the component ratio of H ₂ O which is determined from the mass balance of the gas circulation system, and the calculated value of the H ₂ O, the gas When the difference between the measured value of H ₂ O measured by the analyzer exceeds a specified value, it is judged that the boiler tube is leaking water, and the safety device is activated. Anomaly detection method.