JPH09257248A - Fuel leakage detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit easy and sure detection of whether fuel is leaked out of a fuel injection pipe into a pressure vessel or not. SOLUTION: A fluidized bed boiler main body 2, in which bed material 6 is stored so as to be fluidized by pressurized air A from an air diffusion pipe 4, is stored in a pressure vessel 1 and a pressure air introducing pipe 7 for supplying the pressure air A, supplied into the pressure vessel 1, into the air diffusion pipe 4 is stored in the pressure vessel 1 while a CO2 gas concentration detector 23 is connected to the pressurized air introducing pipe 7 so as to be positioned at the outside of the pressure vessel 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel leak detection device capable of detecting whether fuel is leaking from a fuel pipe in a pressure vessel in which a fluidized bed boiler main body is housed.

[0002]

2. Description of the Related Art In recent years, a pressurized fluidized bed boiler has come to be used for effective use of energy during power generation, and an example of such a pressurized fluidized bed boiler is shown in FIG. ing.

That is, a fluidized bed boiler main body 2 having an ashing hopper 3 at the bottom is housed in a pressure vessel 1 whose inside can be made into a pressurized atmosphere.
An air diffuser 4 is arranged in the lower part of the above so as to be located above the ashing hopper 3.

As shown in FIG. 4, for example, the air diffuser tubes 4 extend in the left-right direction and are arranged in a plurality of rows at required intervals in a direction orthogonal to the paper surface. A large number of pressurized air jet nozzles 5 are arranged upward so as to jet air into the fluidized-bed boiler body 2.

A pressurized air introducing pipe 7 is connected to the lower end of the air diffusing pipe 4 via a wind box, and the pressurized air introducing pipe 7 penetrates the inclined plate 3a of the ashing hopper 3 and the fluidized bed boiler main body. 2 extends outward and upward in the pressure vessel 1, and its upper end opens in the vicinity of the lower portion of the upper end plate 1a in the pressure vessel 1.

The upper end of the pressurized air introduction pipe 7 is opened near the lower end of the upper end plate 1a in the pressure vessel 1 so that the pressurized air A having a high temperature in the pressure vessel 1 is supplied into the fluidized bed boiler body 2. This is because.

At the upper part of the air diffuser 4 in the fluidized bed boiler body 2, a fuel slurry F such as coal slurry in a fuel slurry tank 8 is passed through a fuel slurry supply pipe 9 to a fuel slurry pump 10.
A fuel slurry injection pipe 11 supplied by

In the fluidized bed boiler main body 2, a heat transfer tube 12 constituting an evaporator, a heater, a reheater, etc. is housed, and a desulfurizing agent such as limestone forming a fluidized bed, coal ash, etc. The mixed bed material 6 is stored.

Thus, the bed material 6 is introduced from the pressure vessel 1 through the upper end of the pressurized air introduction pipe 7 and is ejected into the fluidized bed boiler main body 2 through the air diffuser pipe 4 and the pressurized air ejection nozzle 5. And the fuel slurry F injected from the fuel slurry injection pipe 11 is mixed and burned to generate the combustion gas GB, and the combustion gas GB and the heat of the fluidized bed material 6 cause the fluidization. Heat transfer tube 1 in the heat transfer tube forming the wall surface of the bed boiler body 2 or in the fluidized bed boiler body 2
The fluid flowing in 2 can be heated to generate steam V.

A vertically oriented exhaust gas duct 13 is connected to the upper end of the fluidized bed boiler body 2 so that the combustion gas GB discharged from the fluidized bed boiler body 2 can be raised as the boiler exhaust gas GE. At the upper end of the duct 13, a horizontally oriented exhaust gas duct 15 for supplying the boiler exhaust gas GE to the cyclone 14 stored in the pressure vessel 1 is connected. Thus, the cyclone 14 can separate the bed material and ash in the boiler exhaust gas GE.

A turbine drive gas supply pipe 16 for sending the cleaned boiler exhaust gas GE to the rear as a turbine drive gas GD is connected to the upper end of the cyclone 14, and the turbine drive gas supply pipe 16 connects the pressure vessel 1 to the turbine. It penetrates and its tip is connected to a gas turbine 17 arranged outside the pressure vessel 1. The generator 18 and the compressor 19 are connected to the gas turbine 17, and the generator 18 and the compressor 19 can be driven by driving the gas turbine 17.

A compressed air supply pipe 20 is connected to the discharge side of the compressor 19, and the tip of the compressed air supply pipe 20 can supply the compressed air A into the pressure vessel 1. , Connected to the body of the pressure vessel 1.

In the figure, reference numeral 21 is an ash cutting valve for cutting out the ash in the ash discharging hopper 3.

In the above equipment, the compressed air A discharged from the compressor 19 and supplied into the pressure vessel 1 through the compressed air supply pipe 20 is supplied from the upper end of the compressed air introduction pipe 7 to the compressed air introduction pipe 7. 7 is supplied into the air diffuser pipe 4 through the pressurized air introduction pipe 7, and is jetted from the pressurized air jet nozzle 5 on the upper surface of the diffuser pipe 4 into the fluidized bed boiler main body 2. As a result, the bed material 6
Fluidize and a fluidized bed is formed.

Further, the fuel slurry F in the fuel slurry tank 8
Is supplied to the fuel slurry injection pipe 11 through the fuel slurry supply pipe 9 by the fuel slurry pump 10, and is injected from the fuel slurry injection pipe 11 into the bed material 6 fluidized in the fluidized bed boiler main body 2.

Thus, the heat of the bed material 6 burns the combustion components in the fuel slurry F to generate the combustion gas GB, and the bed material 6 also absorbs heat. Therefore, the combustion gas GB
The fluid flowing in the heat transfer tube forming the wall surface of the fluidized bed boiler body 2 or the heat transfer tube 12 in the fluidized bed boiler body 2 is heated by the heat of the bed material 6 and steam V is generated.

The generated steam V is supplied to a steam turbine (not shown) to drive the steam turbine, and the steam turbine drives a generator to generate electric power.

On the other hand, the combustion gas GB is discharged from the fluidized bed boiler main body 2 to the exhaust gas duct 13, and the boiler exhaust gas GE is discharged.
Is introduced into the cyclone 14 through the exhaust gas ducts 13 and 15, and in the cyclone 14, the bed material 6, ash, and solid unburned components of the fuel that are entrained in the boiler exhaust gas GE are removed, and the boiler exhaust gas GE becomes clean. .

Thus, the cleaned boiler exhaust gas GE
Is sent from the cyclone 14 to the turbine driving gas supply pipe 16, is introduced from the turbine driving gas supply pipe 16 to the gas turbine 17, and the gas turbine 17 is driven. The gas after driving the gas turbine 17 is the gas turbine 1
It is discharged from 7 and sent to the subsequent process.

The generator 1 is driven by driving the gas turbine 17.
8 is driven to generate electric power, and the compressor 19 is driven to generate the compressed air A. The generated compressed air A
Is sent to the pressure vessel 1 via the pressurized air supply pipe 20.

[0021]

Since the pressure vessel 1 has a high temperature (about 300 ° C.), a high pressure (10 to 15 kg / cm ² G), and a high O ₂ partial pressure, the pressure vessel of the fuel slurry injection pipe 11 is high. If the fuel slurry F leaks into the pressure vessel 1 from a part located inside the pressure vessel 1 for some reason, the fuel may be ignited and burned at a high temperature to damage the equipment in the pressure vessel 1. Not preferable.

In view of the above-mentioned circumstances, the present invention is to make it possible to easily and surely detect a leak of fuel such as fuel slurry used in a pressurized fluidized bed boiler into the pressure vessel. It was done as a purpose.

[0023]

According to the present invention, a fluidized bed boiler main body in which a bed material is housed so as to be fluidized by pressurized air ejected from an air diffuser disposed inside is housed in a pressure vessel, and A pressurized air introduction pipe for supplying the pressurized air supplied into the pressure vessel to the air diffuser is stored in the pressure vessel, and the pressure vessel is provided above the air diffuser in the fluidized bed boiler body. In a pressurized fluidized bed boiler in which a fuel pipe is arranged so as to allow the fuel to be supplied from the outside to the inside of the fluidized bed boiler main body, whether the fuel leaks into the pressure vessel to the pressurized air introduction pipe Is connected to the means for detecting.

In the present invention, means for issuing an alarm can be provided when fuel leaks into the pressure vessel.

In the present invention, means for detecting whether fuel is leaking into the pressure vessel is provided outside the pressure vessel for detecting the concentration of CO ₂ gas in the pressurized air flowing in the pressurized air introducing pipe. The CO ₂ gas concentration detector provided can be used.

In the present invention, means for detecting whether fuel is leaking into the pressure vessel is provided outside the pressure vessel for detecting the O ₂ gas concentration in the pressurized air flowing in the pressurized air introducing pipe. It can be an installed O ₂ gas concentration detector.

In the present invention, the means for detecting whether or not the fuel leaks into the pressure vessel may be means for sampling and analyzing the pressurized air flowing in the pressurized air introducing pipe.

In the present invention, if fuel leaks into the pressure vessel,
If there is a CO_TwoGas concentration detection
CO connected to the detector and detected_TwoGas concentration is set
CO _TwoOutputs a command when the gas concentration exceeds the preset level.
Arithmetic control device, and connected to the arithmetic control device and detected
CO_TwoGas concentration is CO_TwoIf the gas concentration exceeds
It can be an alarm device that issues an alarm based on
You.

According to the present invention, means for issuing an alarm when fuel leaks into the pressure vessel is connected to an O ₂ gas concentration detector, and the detected O ₂ gas concentration is set to O ₂
An arithmetic and control unit that outputs a command when the gas concentration is less than or equal to, and an alarm that is connected to the arithmetic and control unit and that issues an alarm based on the command when the detected O ₂ gas concentration is less than or equal to the O ₂ gas set concentration It can be a device.

According to the present invention, it is possible to easily and surely detect the leakage of the fuel into the pressure vessel, so that the equipment in the pressure vessel can be prevented from being damaged due to the combustion of the fuel, and if necessary. Accordingly, it is possible to automatically detect that the fuel has leaked and issue an alarm.

[0031]

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

FIG. 1 is a first example of an embodiment of the fuel leakage detection apparatus of the present invention, and the basic structure of the pressurized fluidized bed boiler is the same as that shown in FIG. Thus, in the present embodiment, the conduit 22 extending outside the pressure vessel 1 is connected to the middle portion of the pressurized air introduction pipe 7, and the CO ₂ gas concentration at the outer end of the pressure vessel 1 of the conduit 22. The detector 23 is connected.

The CO ₂ gas concentration detector 23 is connected to the pressurized air introducing pipe 7 because the pressurized air A always flows in the pressurized air introducing pipe 7 and therefore the fuel in the pressure vessel 1 This is because the CO ₂ gas concentration can be detected easily and reliably when the CO ₂ gas is generated by combustion.

Therefore, in this embodiment, C
By visually observing the meter of the O ₂ gas concentration detector 23, the CO ₂ gas concentration in the pressure vessel 1 can be known, and the fuel slurry injection pipe 11
Therefore, it can be determined whether the fuel slurry F is leaking into the pressure vessel 1. Therefore, it is possible to prevent damage to the device due to combustion of fuel in the pressure vessel 1.

[0035] Figure 2 is a second example embodiment of a fuel leak detection system of the present invention, in the present embodiment calculates the CO ₂ gas concentration X1 detected by the CO ₂ gas concentration sensor 23 as a signal The difference between the detected CO ₂ gas concentration X1 and the preset CO ₂ gas set concentration X2 is taken by the controller 24, and when X1 ≧ X2, the calculation controller 24 The command Y is given to the alarm device 25 to issue an alarm.

With such a configuration, it is possible to automatically detect whether or not the fuel slurry F is leaking into the pressure vessel 1 without visually observing the CO ₂ gas concentration detector 23.

FIG. 3 is a third example of the embodiment of the fuel leakage detection apparatus of the present invention. In this embodiment, the pressurized air A flowing in the pressurized air introducing pipe 7 is passed through the conduit 22. This is an example in which the CO ₂ gas concentration or the O ₂ gas concentration can be detected by appropriately sampling in the container 26 and analyzing the gas sampled in the container 26. In the figure, 27 is an opening / closing valve provided in the middle of the conduit 22.

Even with such a configuration, the same operational effects as those of the above-described respective embodiments can be obtained.

In the embodiment of the present invention,
Although the case of using a coal slurry as the fuel has been described, the fuel is not limited to the slurry-like one, and it can be applied to a liquid or powdered granular material to be air-fed. There it has been described may be detected by the amount of O ₂ gas concentration in the case of detecting whether or not the leak by CO ₂ gas concentration (provided that the O ₂ gas concentration detected in this case in advance Detects whether it is lower than the set O ₂ gas set concentration,
If it is low, give an alarm. ) And other various modifications can be made without departing from the scope of the present invention.

[0040]

According to the fuel leakage detection apparatus of the present invention, in any of the claims, it is possible to easily and surely detect the leakage of the fuel into the pressure vessel. It is possible to prevent damage to the equipment in the pressure vessel, and in the second, sixth and seventh aspects, it is possible to obtain various excellent effects such as automatic detection of leakage of fuel into the pressure vessel.

[Brief description of drawings]

FIG. 1 is a schematic diagram including a pressurized fluidized bed boiler showing a first example of an embodiment of a fuel leakage detection device of the present invention.

FIG. 2 is a schematic diagram including a pressurized fluidized bed boiler showing a second example of the embodiment of the fuel leakage detection apparatus of the present invention.

FIG. 3 is a schematic diagram including a pressurized fluidized bed boiler showing a third example of the embodiment of the fuel leakage detection apparatus of the present invention.

FIG. 4 is a schematic diagram of a general pressurized fluidized bed boiler.

[Explanation of symbols]

1 Pressure Vessel 2 Fluidized Bed Boiler Main Body 4 Diffuser Pipe 6 Bed Material 7 Pressurized Air Introducing Pipe 11 Fuel Slurry Injection Pipe (Fuel Pipe) 23 CO ₂ Gas Concentration Detector 24 Calculation Control Device 25 Alarm Device 26 Container A Pressurized Air F Fuel slurry (fuel) X1 CO ₂ gas concentration X2 CO ₂ gas set concentration Y command

Claims (7)

[Claims] 1. A fluidized bed boiler main body, in which a bed material is housed so as to be fluidized by pressurized air ejected from an air diffuser arranged inside, is housed in a pressure vessel and supplied to the pressure vessel. A pressurized air introduction pipe for supplying pressurized air to the diffuser pipe is stored in the pressure vessel, and the fuel flows from the outside through the pressure vessel above the diffuser tube in the fluidized bed boiler body. In a pressurized fluidized bed boiler in which a fuel pipe is arranged so as to be able to supply into the bed boiler main body, a means for detecting whether fuel is leaking into the pressure vessel is connected to the pressurized air introduction pipe. A fuel leakage detection device. 2. The fuel leakage detection device according to claim 1, further comprising means for issuing an alarm when fuel leaks into the pressure vessel. 3. A means for detecting whether fuel is leaking into the pressure vessel is provided outside the pressure vessel for detecting the concentration of CO ₂ gas in the pressurized air flowing in the pressurized air introducing pipe. The fuel leakage detection device according to claim 1, which is a CO ₂ gas concentration detector. 4. A means for detecting whether fuel is leaking into the pressure vessel is provided outside the pressure vessel for detecting the O ₂ gas concentration in the pressurized air flowing in the pressurized air introducing pipe. O ₂
The fuel leakage detection device according to claim 1, which is a gas concentration detector. 5. The fuel leak detection according to claim 1, wherein the means for detecting whether or not the fuel leaks into the pressure vessel is means for sampling and analyzing the pressurized air flowing in the pressurized air introducing pipe. apparatus. 6. A CO ₂ gas set concentration in which a means for issuing an alarm when the fuel leaks into the pressure vessel is connected to a CO ₂ gas concentration detector and the detected CO ₂ gas concentration is set. In the above cases, an arithmetic control device that outputs a command, and an alarm device that is connected to the arithmetic control device and that issues an alarm based on the command when the detected CO ₂ gas concentration is equal to or higher than the CO ₂ gas set concentration The fuel leakage detection device according to claim 2. 7. A means for issuing an alarm when fuel leaks into the pressure vessel is connected to an O ₂ gas concentration detector, and the detected O ₂ gas concentration is below a set O ₂ gas concentration. In the case of, an arithmetic and control unit that outputs a command, and an alarm device that is connected to the arithmetic and control unit and issues an alarm based on the command when the detected O ₂ gas concentration is less than or equal to the O ₂ gas set concentration The fuel leakage detection device according to claim 2.