JPH1183638A - Thermometer for pressurized fluidized-bed boiler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable early detection of abrasion generated in a thermometer by forming the thermometer in a double pipe structure and setting an apparatus which detects inflow of a high-temperature gas at a gap between the outside and inside of the structure. SOLUTION: This thermometer is constituted of an outer pipe 15 and an inner pipe 16. A coil 17 for detection of abrasion is wound at the circumference of the inner pipe 16 tightly without a gap. When the outer pipe 15 is abraded and penetrated because of collision of ash particles 13 included in a high- temperature gas 5, the high-temperature gas 5 enters the interior of the thermometer. If driving is continued in this state, the ash particles 13 in the high- temperature gas 5 abrade the coil 17 and finally break the coil. The break of the coil 17 shuts a current flowing in the coil 17, when a detection apparatus 18 detects the abrasion by an abnormal signal. The generation of abrasion can be easily detected before a wall face of the thermometer is abraded and penetrated to cause a leak of the high-temperature gas 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a steam turbine which is operated by using a high-temperature gas generated in a fluidized-bed boiler to generate steam in a heat transfer tube installed in the boiler. The present invention relates to a fluidized-bed boiler combined cycle cycle plant that drives a gas turbine by transporting it to a gas turbine, and particularly relates to a thermometer structure installed in the high-temperature pipe.

[0002]

2. Description of the Related Art A system diagram of a combined cycle plant using a fluidized bed boiler is shown in FIG. In the fluidized bed boiler 1, pulverized coal 4 is supplied by air 3 supplied from an air compressor 2.
Is burned. The hot gas 5 generated by combustion is
The heat is transmitted to the heat transfer tube 6 installed in the boiler 1, and steam is generated in the heat transfer tube 6. The steam is guided to a steam turbine 7 and drives a generator 8. After removing the ash particles by the cyclone 9, the high-temperature gas 5 is transported to the gas turbine 12 via the header 11 by the high-temperature pipe 10. At that time, the high-temperature gas 5 has a maximum of 10
About 0 (μmm) of ash particles of about a few (μmm) which cannot be completely removed even after passing through the cyclone 9 remain.

In the high temperature pipe 10, a thermometer as shown in FIGS. 3 (a) and 3 (b) is installed in order to measure a high temperature gas temperature. The thermometer comprises a single tube structure 16 and a thermocouple 14. If the plant is operated for a long time, ash particles 13
Of the thermometer installed on the high-temperature pipe 10 countlessly, causing serious wear on the thermometer wall 16. Conventionally, only the presence or absence of wear was inspected by periodic inspection or the like.

[0004]

As described above, the ash particles 13 countlessly collide with the thermometer installed in the high-temperature pipe 10 and cause serious wear on the thermometer wall 16. As shown in FIG. 3, the conventional thermometer is constituted by a single pipe, so that the inside of the thermometer is directly connected to the outside of the pipe. When the thermometer wall is worn by the particles, the high-temperature gas 5 flows into the thermometer. Further, the high-temperature gas 5 leaks to the outside of the pipe 10 through a thermometer damaged by abrasion. The high-temperature gas is a gas having a pressure of about 10.0 atm and a temperature of about 850 ° C. If leaked, it may seriously damage equipment and piping.

An object of the present invention is to provide a means for early detecting abrasion generated in a thermometer installed in a high-temperature pipe of a pressurized fluidized-bed boiler.

[0006]

A first thermometer for a pressurized fluidized bed boiler according to the present invention has a double structure, and detects the inflow of the high-temperature gas into the gap between the outside and inside of the double pipe. It is configured by installing a device that performs

A second thermometer structure for a pressurized fluidized-bed boiler according to the present invention is the thermometer for a pressurized fluidized-bed boiler of the first configuration, which detects inflow of a high-temperature gas into the double-pipe structure. The apparatus is configured to use a coil energized around the inner tube.

A third thermometer structure for a pressurized fluidized bed boiler according to the present invention is the thermometer structure for a pressurized fluidized bed boiler of the first configuration, wherein a pressure sensor is used in a gap between the outer and inner pipes. It is configured in.

That is, according to the first thermometer of the present invention, when abrasion occurs and progresses in the thermometer due to particles in the high-temperature gas, the particle abrasion penetrates the outer wall surface of the thermometer double pipe, and the high-temperature Gas flows into the gap between the outer and inner tubes. By detecting the leakage of the high-temperature gas, it is possible to easily detect the wear generated on the thermometer under the operating conditions of the fluidized-bed boiler. At the same time, since there is a double pipe inner structure, high temperature gas does not leak to the outside of the pipe.

According to the second thermometer of the present invention, when abrasion occurs and progresses in the thermometer due to particles in the high-temperature gas, the particle abrasion penetrates the outer wall surface of the thermometer and further forms a coil in the inner wall surface of the thermometer. Break the wire wound around. The current is interrupted by this disconnection, and it is possible to easily detect under the operating condition that excessive wear has occurred on the thermometer.
Similarly to the first temperature, since the inside wall surface is inside the coil, the hot gas does not leak to the outside of the pipe.

According to the third high-temperature pipe of the present invention, when particles in the high-temperature gas cause wear and progress on the thermometer,
Particle wear penetrates the thermometer outer wall. In that case, the hot gas is pressurized to approximately 8 atm,
If the pressure in the gap is set appropriately in advance, the pressure change inside the gap can be easily measured. By measuring the pressure in this gap, it is possible to easily detect under the operating condition that excessive wear has occurred on the thermometer. Like the first and second thermometers, there is an inner wall surface of the thermometer, so that the hot gas does not leak to the outside of the pipe.

[0012]

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

FIGS. 1A and 1B show a first embodiment of a thermometer according to the present invention. In FIG. 1, 5 is a hot gas,
10 is a high-temperature pipe, and 13 is ash particles. As shown in the figure, in this embodiment, the thermometer includes an outer tube 15 and an inner tube 16. A coil 17 for detecting wear is provided around the inner tube 16.
However, it is preferably wound without a gap. When the outer tube 15 penetrates due to wear, the hot gas 5 enters the inside of the thermometer. If the operation is continued in that state, the particles 15 in the high-temperature gas 5 wear the coil 17 and eventually break. When the coil is broken, the current flowing through the coil is cut off, and the detection device 18 can detect wear as an abnormal signal. 4A and 4B show a second embodiment of the high-temperature pipe according to the present invention. In FIG. 4, 5 is a high-temperature gas, 10 is a high-temperature pipe, and 13 is ash particles. As shown in the drawing, in the present embodiment, as in the first embodiment, the thermometer includes an outer pipe 15 and an inner pipe 16, and uses a pressure gauge 19 as a wear detecting device. The signal from the pressure gauge 19 is sent to the detecting device 18 and compared with the normal pressure level. When the outer tube 15 penetrates due to wear, the hot gas 5 enters the inside of the thermometer. Since the high temperature gas has a pressure of about 10 atm, the high temperature gas 5
However, when the gas enters the gap between the outer pipe 15 and the inner pipe 16, the pressure in the gap greatly changes. By detecting the change in pressure, wear can be detected.

[0014]

According to the first embodiment of the present invention, the wall of the thermometer is worn due to the collision of the ash particles contained in the high-temperature gas, and before the wall penetrates and the high-temperature gas leaks, The occurrence of wear can be easily detected.

According to the second embodiment of the present invention, as in the first embodiment, the collision of the ash particles contained in the hot gas causes
It is possible to easily detect the occurrence of abrasion before the thermometer wall is worn, and furthermore, before the wall penetrates and the high-temperature gas leaks.

[Brief description of the drawings]

FIG. 1 is a diagram showing a thermometer according to the present invention.

FIG. 2 is a system diagram of a combined cycle plant using a fluidized bed.

FIG. 3 is a diagram showing a structure of a conventional thermometer.

FIG. 4 is a diagram showing a thermometer according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fluidized bed boiler, 2 ... Air compressor, 3 ... Air, 4 ...
Pulverized coal, 5 ... High temperature gas, 6 ... Heat transfer tube, 7 ... Steam turbine, 8 ... Generator, 9 ... Cyclone, 10 ... High temperature pipe, 1
DESCRIPTION OF SYMBOLS 1 ... Header, 12 ... Gas turbine, 13 ... Ash particles, 1
4 thermocouple, 15 outer tube, 16 inner tube, 17 coil, 18 detector, 19 pressure gauge.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Narika Kobayashi 7-2-1, Omika-cho, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Power & Electricity Development Division

Claims (3)

[Claims] 1. A high-temperature gas generated in a fluidized-bed boiler generates steam in a heat transfer tube installed in the boiler to drive a steam turbine, and further transports the high-temperature gas to the gas turbine through a high-temperature pipe. In the fluidized-bed boiler combined cycle cycle plant that drives the gas turbine, a thermometer installed in the high-temperature pipe has a double-pipe structure, and the inflow of the high-temperature gas into gaps outside and inside the double pipe. A thermometer for a fluidized-bed boiler, comprising a device for detecting. 2. A thermometer for a fluidized-bed boiler according to claim 1, wherein a coil energized around the inner pipe is used as a device for detecting the inflow of high-temperature gas into the double pipe structure. Thermometer for fluidized bed boiler. 3. The high-temperature pipe according to claim 1, wherein the apparatus for detecting the inflow of high-temperature gas into the double-pipe structure includes:
A thermometer for a fluidized-bed boiler, wherein a pressure sensor is used in a gap between the outer and inner pipes.