JPH0590105U - Fluidized bed boiler tube inner tube corrosion wear monitoring device - Google Patents

Abstract

(57) [Abstract] [Purpose] To detect the decrease in wall thickness of in-layer heat transfer tubes. [Structure] A sheath type thermocouple 16 is embedded in the wall of the in-layer heat transfer tube 7 provided in the fluidized bed of the fluidized bed boiler along the extending direction of the in-layer heat transfer tube 7, and is drawn out of the furnace 1. An ammeter 17 is connected to the end of the sheath type thermocouple 16. [Effect] When the thickness of the in-layer heat transfer tube 7 is reduced and the sheath thermocouple 16 is cut, the ammeter 17 detects the abnormality.
Since it is formed to display, the progress of corrosion and wear of the in-layer heat transfer tube 7 can be constantly monitored by monitoring the ammeter 17.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a corrosive wear monitoring device for a fluidized bed boiler inner tube.

[0002]

[Prior Art]

 FIG. 6 is a schematic diagram showing an outline of an example of a conventional fluidized bed boiler. Reference numeral 1 denotes a furnace. An air diffusing tube 2 is provided at the bottom of the furnace 1, an air box 3 is formed above the air diffusing tube 2, and an air distribution plate 4 having a large number of small air holes in the upper part of the air box 3. A fluidized medium 5 made of inert particles (eg, silica sand, limestone, etc.) is deposited on the air dispersion plate 4 to form a fluidized bed 6, and an intralayer heat transfer tube 7 is formed in the fluidized bed 6. Plumb. Reference numeral 8 is a header for distributing the flow to the in-layer heat transfer tube 7.

Further, a combustion gas duct 10 communicating with the dust collector 9 provided at the rear of the furnace 1 is provided, and the combustion exhaust gas dedusted and purified by the dust collector 9 is supplied to the gas turbine 11 a of the gas turbine generator 11. An exhaust gas duct 12 for feeding is provided between the dust collector 9 and the gas turbine 11a, and an air duct 13 for feeding air discharged from a compressor 11b directly connected to the gas turbine 11a is provided for discharging the compressor 11b. It is connected to a diffuser pipe 2 which extends from the outlet and is provided at the bottom of the furnace 1. Reference numeral 14 is a fluid medium duct for supplying the fluidized medium 5 into the fluidized bed 6, and 15 is a coal duct for supplying coal into the fluidized bed 6.

Then, the fluidized medium 5 is heated to a temperature higher than the ignition temperature of coal and fed into the fluidized bed 6 through the fluidized medium duct 14 by a blower for transportation (not shown), and pulverized coal and high-temperature primary air are also fed. When and are fed into the fluidized bed 6 through the coal duct 15, the air and the pulverized coal are mixed by the vigorous movement of the fluidized medium 5 due to the synergistic effect with the action of secondary air, which will be described later, and a continuous combustion state occurs. The heat generated by combustion is transmitted to the in-layer heat transfer tube 7 arranged there.

Further, the combustion gas generated in the furnace 1 is discharged to the dust collector 9 through the combustion gas duct 10, dedusted and purified by the dust collector 9, and the gas turbine generator 11 through the exhaust gas duct 12. The gas turbine 11a is driven to drive the gas turbine 11a. When the gas turbine 11a is driven, the gas turbine generator 11 directly connected to the gas turbine 11a operates to generate electric power, and the compressor 11b operates to compress the air and disperse as secondary air through the air duct 13. Deliver to trachea 2.

[0006]

[Problems to be solved by the device]

 However, in the above-mentioned fluidized bed boiler inner tube, the fluid medium 5 that moves violently collides with the inner layer heat transfer tube 7, so that there is a case where the wall thickness of the inner layer heat transfer tube 7 decreases due to wear and corrosion. In particular, the in-layer heat transfer tube 7 provided close to the air distribution plate 4 and the in-layer heat transfer tube 7 provided in the slush zone of the fluidized bed 6 in the upper part of the fluidized bed 6 can be moved even more violently. Since it is exposed, it is experienced that the pipe wall thickness decreases drastically. However, in the past, during the operation of the boiler, the decrease in the pipe wall thickness due to corrosion and wear of the in-layer heat transfer pipe 7 was detected, and the safety of the plant was improved. There is no effective means or device to secure it. Therefore, it is necessary to measure the wall thickness of the in-layer heat transfer tube 7 to manage the remaining life of the in-layer heat transfer tube 7 at the time of regular inspection, which requires a great deal of time and labor. There was a problem that required.

In view of the above-mentioned circumstances, the present invention has an object to provide a fluidized bed boiler inner layer tube corrosion wear monitoring device capable of detecting a decrease in the wall thickness of the inner layer heat transfer tube even during boiler operation. It is what you have done.

[0008]

[Means for Solving the Problems]

 According to the present invention, a current circuit is embedded in a wall of an in-layer heat transfer tube provided in a fluidized bed of a fluidized bed boiler along an extension direction of the in-layer heat transfer tube, and a portion outside the furnace where the current circuit is drawn out. A display instrument is connected to the minute.

[0009]

Therefore, in the present invention, when the intra-layer heat transfer tube is corroded or abraded due to the collision of the fluid medium, and the inner wall of the intra-layer heat transfer tube is worn out, the current circuit is exposed and the current circuit is disconnected. An abnormality occurs in the current, and the display meter indicates the abnormality.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of a fluidized bed boiler inner layer tube corrosion / wear monitoring apparatus according to the present invention, FIG. 2 is a sectional view of an inner layer heat transfer tube related to FIG. 1, and FIG. 3 is an inner layer transfer related to FIG. FIG. 4 is a cross-sectional view of another example of the heat pipe, FIG. 4 is a detailed view of embedding the sheath-type thermocouple of the in-layer heat transfer tube related to FIG. 1, and FIG. 5 is a sheath-type thermoelectric device embedded in the in-layer heat transfer tube related to FIG. It is a sectional view of a pair. In the figure, the same parts as those in FIG. 6 are designated by the same reference numerals.

In the embodiment of the present invention, as shown in FIG. 2 to FIG. 4, in the inner wall of the in-layer heat transfer tube 7 provided in the fluidized bed 6, along the extending direction of the in-layer heat transfer tube 7. A sheath type thermocouple 16 is embedded, and an ammeter 17 is connected to the end of the lead wire of the sheath type thermocouple 16 drawn out of the furnace 1.

Normally, when the tip contact of the sheath type thermocouple 16 is heated by the heat generated by combustion in the fluidized bed 6, a heat current is passed through the lead wire of the sheath type thermocouple 16 and the current is displayed in the ammeter 17. Although the elephant is displayed, the intra-layer heat transfer tube 7 is corroded and abraded due to the collision of the fluidized medium 5, the inner wall of the intra-layer heat transfer tube 7 is worn, and the wall thickness is reduced to reduce the sheath type thermocouple 16 When the sheath type thermocouple 16 is exposed, the exposed sheath type thermocouple 16 is exposed to the collision of the fluid medium 5 that moves violently, so that the conductor wire of the sheath type thermocouple 16 is eventually broken and the heat flowing through the conductor line is lost. The current is cut off, and the abnormality is detected and displayed by the ammeter 17.

According to the above, the sheath type thermocouple 16 embedded with the reduced thickness of the intralayer heat transfer tube 7 is exposed, and the conductor wire of the sheath type thermocouple 16 is broken and flows in the conductor wire. When the thermoelectric current is cut off, the ammeter 17 is designed to detect and display the abnormality. Therefore, by monitoring the ammeter 17, the progress of corrosion and wear of the in-layer heat transfer tube 7 can be constantly monitored. The safety of the plant can be secured.

It should be noted that the present invention is not limited to the above-described embodiment, but in the above-mentioned embodiment, the case where the sheath type thermocouple 16 is embedded in the tube meat of the in-layer heat transfer tube 7 has been described. Needless to say, various modifications may be made within the scope not departing from the gist of the present invention, such as embedding a current circuit through which a weak current flows instead of the sheath type thermocouple 16.

[0016]

[Effect of the device]

 According to the fluidized-bed boiler in-layer pipe corrosion wear monitoring apparatus of the present invention, the current circuit is embedded in the in-layer heat transfer pipe, and the thickness of the in-layer heat transfer pipe 7 is reduced to expose the current circuit. When the current flowing through the current circuit is cut off, the display instrument detects and displays the abnormality.By monitoring the display instrument, corrosion and wear of the heat transfer tube in the layer can be monitored. The progress of the plant can be monitored at all times, and thus the safety of the plant can be ensured very easily, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a side view of a fluidized bed boiler bed inner tube corrosion / wear monitoring apparatus according to the present invention.

FIG. 2 is a cross-sectional view of the intra-layer heat transfer tube related to FIG.

FIG. 3 is a cross-sectional view of another example of the intra-layer heat transfer tube related to FIG.

FIG. 4 is a detailed view of embedding a sheath type thermocouple of the in-layer heat transfer tube related to FIG. 1.

5 is a cross-sectional view of a sheath-type thermocouple embedded in the intra-layer heat transfer tube related to FIG.

FIG. 6 is a schematic diagram showing an outline of an example of a conventional fluidized bed boiler.

[Explanation of symbols]

 1 Furnace 6 Fluidized bed 7 In-layer heat transfer tube 16 Sheath type thermocouple (current circuit) 17 Ammeter (display instrument)

Claims (1)

[Scope of utility model registration request] 1. A current circuit is embedded in a wall of an in-layer heat transfer tube provided in a fluidized bed of a fluidized bed boiler along an extension direction of the in-layer heat transfer tube, and a portion of the current circuit drawn out from a furnace. A corrosive wear monitoring system for fluidized-bed boiler layer pipes characterized in that a display instrument is connected to.