JPH03217488A - Method for detecting abnormality of boiler tube of coke dry type cooler - Google Patents

Abstract

PURPOSE:To prevent reduction of thickness of heating tube and breakage of hole thereof and carry out safe operation of coke furnace by detecting abnormality of boiler tube by difference of circulating gas pressure of inlet and outlet of boiler. CONSTITUTION:A number of pressure measuring devices 20-23 are provided in inlet and outlet of a boiler 11, preferably in the direction of height of the boiler 11 and pressure loss between prescribed positions in the boiler 11 is operated from the difference of pressure of circulating gas measured thereby and deposited amount of small mass coke and powder coke is estimated. When the estimated amount reaches prescribed value or above, feed of circulating gas to the boiler 11 is stopped and the deposited small mass coke and powder coke are removed to prevent abnormality of each pipe line of heating tube groups SH1 to SH5 of the boiler 11.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention detects abnormalities in heat transfer tubes called boiler tubes of dry cooling equipment that cools scorching coke extruded from coke ovens, and detects thinning of the heat transfer tubes. and a method for preventing hole breakage.

[Prior Art] As a device for extinguishing and cooling scorching hot coke extruded from a coke oven, in recent years, from the viewpoint of energy saving, a dry cooling device as shown in Japanese Patent Publication No. 56-45860, for example, has been used.

The structure of this dry cooling device will be explained below based on FIG. 5.

The cooling tower 1 of the dry cooling system is charged with scorching coke extruded from a coke oven through an inlet 2 provided at the top of the cooling tower 1, and low-temperature coke is charged through a cooling gas inlet 4 provided at the bottom of the cooling tower 1. Circulating gas is injected.

On the way down the cooling tower 1, the scorching coke is sequentially cooled by the circulating gas rising from the lower part of the cooling tower 1 to the body, and is discharged from the lower part of the cooling tower 1.

On the other hand, as described above, the circulating gas blown from the cooling gas inlet 4 of the cooling tower 1 absorbs heat from the scorching coke while rising in the cooling tower 1, reaches a high temperature of about 900 to 1000°C, and becomes a sloping flue. -5 and passes through a duct 10 with a dust catcher -9 to a boiler 11
flows into.

This boiler 11 pumps high-temperature circulating gas at 160~180℃.
℃, the next stage cyclone 12, blower 13,
The cooled gas is sequentially passed through the cooler 14 and is again blown in from the cooling gas inlet 4 of the cooling tower 1 as a low-temperature circulating gas.

[Problems to be Solved by the Invention] The boiler 11 has heat transfer tube groups SH, -SH5 through which cooling water flows in the high-temperature circulating gas flow path 15, and in particular, the heat transfer tube groups SH. , S.H. In order to increase the heat recovery efficiency, the pipes 3 are arranged closely, and fins 6 are provided around the outer circumference of the pipes 3 as shown in Fig. 2 to increase the heat transfer area (hereinafter referred to as fins 3). , this conduit is called a finned heat exchanger tube).

On the other hand, small coke and coke breeze in the cooling tower 1 are flown from the throbbing flue 5 along with high temperature circulating gas.

The flown small coke and powder coke damage the pipelines of the heat exchanger tube groups SH, -SHs, causing holes and leaking cooling water. When a hole breaks in this pipe, cooling of the scorching coke in the cooling tower 1 must be immediately stopped and the pipe with the hole must be repaired, which requires a great deal of time and effort. Especially in coke ovens operating with a single dry cooling device, the scorching coke cannot be cooled during that time, which is a serious problem.

The present invention prevents the above problem by predicting a hole in the pipeline of the heat transfer tube group SHI to SHS while the dry cooling device is in operation, and removing the cause of the hole based on the prediction. The challenge is to ensure stable operation without any problems.

[Thousand Steps to Solve the Problem] The present inventors have developed heat exchanger tube groups SH, ~SHs in the boiler 11.
The present invention was developed based on the knowledge that the pressure drop inside the boiler 11 increases when a hole breaks in the pipe line of the boiler 11. A cooling tower is installed in which coke is charged from the top and the cooled coke is cut out from the bottom, and heat transfer tubes are installed to circulate cooling medium through the high-temperature gas passage, and the heat of the high-temperature circulating gas flowing through the high-temperature gas passage is recovered. a boiler that supplies high-temperature circulating gas led out from the body of the cooling tower to the boiler, and circulates and supplies low-temperature circulating gas that has been stripped of heat in the boiler and flows out from the lower part of the cooling tower into the cooling tower. In a coke dry cooling system having a gas path, a pressure measuring device is installed at the entrance and exit of the boiler, and a pressure difference is calculated from the circulating gas pressure value of the boiler ratio population measured by both pressure measuring devices, and the pressure difference is used to transmit information. There is a device that detects abnormalities in heat pipes.

In addition to the circulating gas pressure measuring device at the boiler inlet and outlet of the means (1), means (2-) is provided with a plurality of pressure measuring devices in the circulating gas flow direction within the boiler, and the circulating gas pressure measuring device at each position measured by each pressure measuring device is provided. The pressure difference between each position is calculated from the gas pressure value, and abnormalities in the heat exchanger tube are detected based on the pressure difference.

[Made for production] The operation of the present invention will be explained with reference to FIGS. 1 to 4.

The present inventors have developed a heat exchanger tube group SH in a boiler. After conducting various investigations into the causes of holes in the ~SH5 pipelines, we found that, as shown in Figure 3, ■When holes occur in the heat exchanger tube groups SH and ~SH5 pipelines, pressure loss within the boiler 11 is the cause. increases rapidly.

■ When repairing the holes in the pipes of the heat exchanger tube groups SH, -SH5, the heat exchanger tube groups SH, %SH. It was found that the pressure drop inside the boiler 11 was low when the operation was started after removing small coke particles and coke powder that had accumulated in the pipes.

As a result of further study on this issue, we found that the heat transfer tube groups SH, ~sH3 in the upper region of the boiler have pipes arranged with an interval of 40 mm to 50 mm, whereas the heat transfer tubes in the lower region of the boiler Pipe line 3 of heat tube groups SH4 and SH5 is 10+nm
The fins 6 are arranged at intervals of ~20 mm, and the fins 6 are attached around the conduit 3 as described above, and the fins 6 overlap each other as shown in FIG. 2 when viewed from above. be.

Therefore, the small coke that has flowed in from the cooling tower 1 along with the high temperature circulating gas is transferred to the lower heat exchanger tube group SH4 of the boiler 11.
, Powder that is caught between the fins 6 of the finned heat exchanger tube 3 of the SHS, or between the fins 6 and the heat exchanger tube 3, causing clogging, and furthermore, powder that has flowed in with the high temperature circulating gas as above. Coke adheres and accumulates.

However, due to some reason, the gap between the fins 6 or
If the small coke sandwiched between the heat exchanger tube 3 and the heat transfer tube 3 escapes, or if the piled up height of the amount of coke powder becomes too high, the small coke and the accumulated layer of coke powder will break and the boiler 11 It flows down with the circulating gas flowing inside.

This large amount of coke powder and small coke flowing down hits the finned heat exchanger tube 3 below, but this is because a large amount of coke powder and small coke are locally blown onto the heat exchanger tube 3. Similarly, it was found that the heat exchanger tube 3 and the fins 6 were sequentially worn away and thinned, and finally the heat exchanger tube 3 became ruptured.

From now on, in order for the finned heat exchanger tubes 3 in the lower part of the boiler 11 to reach a hole, the amount of lump coke and fine coke deposited on the heat exchanger tubes 3 is proportional to the amount of coke inside the boiler 11 as shown in FIG. We obtained the knowledge that the pressure drop increases.

That is, as in the present invention, a large number of pressure measuring instruments 2 are provided at the entrance and exit of the boiler 11, preferably in the height direction of the boiler 11.
0 to 23 are provided, and the pressure difference between predetermined positions in the boiler 11, that is, the pressure loss, is calculated from the pressure difference of the circulating gas measured by the pressure measuring devices 20 to 23. The amount of coke deposited is estimated, and when the estimated amount of deposited coke exceeds a predetermined value, the supply of circulating gas to the boiler 11 is stopped, and the small coke particles that have been deposited are removed.
By removing the coke powder, thinning of the pipes or holes in the heat transfer tube groups SHI to SHS of the boiler 11 are prevented.

[Example] An embodiment of the present invention will be described below with reference to FIG.

In the figure, SH, to SH5 are heat exchanger tube groups provided in the boiler 11, SH4, SH are finned heat exchanger tube groups, SH,
~SH3 is simply a group of heat exchanger tubes (bare tubes) without fins or the like.

20 to 23 are pressure gauges provided inside the boiler 11, and the pressure gauge 20 is provided on the inlet side of the boiler 11 to measure the pressure P1. A pressure gauge 23 is provided on the outlet side of the boiler 11 and measures its pressure P4. Pressure gauge 2
1 is provided between the heat exchanger tube group SH3 and the finned heat exchanger tube group SH4, and measures the pressure P2. Pressure gauge 2
2 is a finned heat exchanger tube group SH. and finned heat exchanger tube group SHs
The pressure P3 is measured. 24
is a circulating gas flow meter installed on the outlet side of the boiler 11, which measures the circulating gas flow rate Q passing through the boiler 11.

25 is each pressure difference ΔP l1+ ΔP21, ΔP between the pressures P1 to P4 in the boiler 11 measured by the pressure gauges 20 to 23
26 is a pressure correction coefficient calculating section which calculates 3+, and 26 is a pressure correction coefficient calculating section. Since the pressure inside the boiler 11 changes when the amount of gas flowing inside the boiler 11 changes, the circulation measured by the circulating gas flow meter 24 Comparing the gas flow ftQ and the reference gas flow rate Q0 from the setting device 27, each pressure difference ΔPI 1
+ΔP2, , ΔP31 correction coefficient α is calculated. 28
is the pressure difference ΔP]1, ΔP21, ΔP3l between each position in the boiler 11 calculated by the pressure difference calculation unit 25? A pressure correction calculation unit 29 performs a correction calculation using the correction coefficient α calculated by the rti positive coefficient calculation unit 26;
Corrected pressure difference ΔP12, ΔP22, ΔP32 calculated in 8
and the reference pressure difference ΔPOO from the setting device 30,
Each corrected pressure difference ΔP12, ΔP22, ΔP32 is the reference pressure difference ΔP0. This is a comparison unit that outputs an abnormality alarm signal to the alarm device 31 when the alarm becomes larger. This alarm device 31 issues an alarm in response to an abnormality alarm signal from the comparator 29.

In other words, when red-hot coke pressed from a coke oven (not shown) is cooled by a dry cooling device, the small lumps and coke breeze flow into the boiler 11 along with the circulating gas and flow into the heat transfer tube groups SH, to SH5. In particular, the finned heat exchanger tube group SH4. SH5 has a large amount of small lumps and coke powder that adhere and accumulate.

This circulating gas in the boiler 11 is sucked up by the blower 13 installed downstream of the boiler 11 as shown in FIG. Negative pressure is low.

For this reason, as small lumps and coke breeze accumulate on the heat exchanger tube groups SH, ~SHS as described above, the circulation of the circulating gas deteriorates, and the negative pressure measured by the pressure gauges 20 to 23 becomes small (in other words, the positive (in the pressure direction). For example, the finned heat exchanger tube group SH. When small lumps and coke powder start to adhere to the pressure; the pressure measurements P3 and P4 at d22 and 23 hardly change, or is the pressure at the pressure gauge 20 and 21? Fixed value P,,P2
The negative pressure gradually decreases.

Thus, the pressure difference ΔP2■ between the pressure gauges 21 and 22 gradually increases. As a result, the corrected pressure difference ΔP22 after correction in the pressure correction calculating section 28 becomes larger sequentially, and the reference pressure difference ΔPOO
When the value exceeds this value, the comparator 29 issues an abnormality alarm signal and the alarm device 31 issues an alarm.

This alarm 31 alerts the operator to the boiler 11.
The supply of circulating gas to the boiler 11 is stopped and the boiler 11 is retired.

After this boiler 11 has been cooled, the small lumps and coke powder that have adhered and accumulated on the finned heat exchanger tube group SH4 are removed, and the operation of the boiler 11 is resumed.

Incidentally, in this embodiment, abnormalities in the boiler 11 are automatically detected, but the present invention is not limited to this, and each pressure difference ΔPI1. ΔP2■,
An operator may directly monitor ΔP3+ and detect any abnormality based on this pressure difference.

In addition, only pressure gauges 20 and 23 are installed, and with these, abnormalities in the entire boiler 11 can be detected. The operator may detect this and remove the accumulated small lumps and coke powder, but in this case, it will take some time to restart the operation, but it will not pose a major problem in terms of operation.

[Effects] The present invention detects abnormalities before the heat exchanger tubes in the boiler break down and removes small lumps and coke powder that cause the heat exchanger tubes to break. Since water does not leak outside and there is no need to repair damage, it is possible to restart the boiler in a short time.
It is particularly effective in coke ovens where red-hot coke is extinguished and cooled using a single dry cooling device, and its effects in this field are significant.

4.

[Brief explanation of drawings]

Fig. 3 is a diagram showing the pressure drop value inside the boiler during operation of the dry cooling system, Fig. 4 is a diagram showing the relationship between the small coke deposited on the heat transfer tubes in the boiler, the amount of fine coke and the pressure drop, Figure 'j85 is a diagram showing a conventional example. 1...Cooling tower 2...Inlet 3...Pipeline 4...Blowing port 5...Throwing flue 6...Fin 9...Dust catcher 10...Tact 11...・Boiler 12・
...Cyclone 13...Blower 14...Cooler 15...Circulating gas flow passages 20-23...
Pressure measuring device 24...flow meter 25...pressure calculation section 26.
...Pressure correction coefficient calculation section 27...Setter 28...Pressure difference calculation section 29
... Comparison section 3 1 ... Alarm device 3 0 ... Setting device S H ... Heat exchanger tube group and 4 others

Claims (1)

[Claims] 1. A cooling tower into which scorching coke is charged from the upper part and cooled coke is cut from the lower part, and a boiler tube through which a cooling medium flows through the high-temperature gas passage, and the high-temperature gas passage is A boiler that recovers the heat of the circulating high-temperature circulating gas, and a boiler that supplies the high-temperature circulating gas led out from the body of the cooling tower to the boiler, and collects the low-temperature circulating gas that has taken heat in the boiler and flows out to the lower part of the cooling tower. In a coke dry cooling system having a circulating gas path that circulates and supplies from the boiler to the cooling tower, a pressure measuring device is provided at the inlet and outlet of the boiler, and the pressure difference is calculated from the circulating gas pressure value at the boiler inlet and outlet measured by both pressure measuring devices. 1. A method for detecting an abnormality in a boiler tube of a coke dry cooling system, comprising calculating and detecting an abnormality in the boiler tube based on the pressure difference. 2 In addition to the cooling gas pressure measuring device at the boiler entrance and exit,
Multiple pressure measuring instruments are installed in the circulating gas flow direction within the boiler, and the pressure difference between each position is calculated from the circulating gas pressure value at each position measured by each pressure measuring instrument, and the abnormality of the boiler tube is detected based on the pressure difference. 2. The method for detecting abnormality in a boiler tube of a coke dry cooling system according to claim 1, further comprising detecting an abnormality in a boiler tube of a coke dry cooling system.