JPH0791646A - Fuel supplying apparatus - Google Patents

Abstract

PURPOSE:To stop supply of fuel by rapidly sensing, when clogging of fuel occurs in a fuel supply tube, it in a fuel supplying apparatus for a fluidized-bed boiler, etc. CONSTITUTION:Pressure pickup ports 13 are provided at two positions in each fuel supply tube 2, and its differential pressure is detected. When a malfunction such as clogging, a reverse flow, etc., occurs in the tube 2, the pressure becomes an abnormal value, and hence the malfunction in the tube is sensed to automatically close a shut-off valve 4. Accordingly, a response is early conducted as compared with a conventional system for detecting a metal temperature rise of the tube 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply pipe applied to a fuel supply device such as a fluidized bed boiler.
It is also applied to powder conveying devices in general.

[0002]

2. Description of the Related Art FIG. 3 is a system diagram showing an example of a conventional fuel supply device for a fluidized bed boiler. When the fuel is introduced from the bottom of the fluidized bed furnace of the fluidized bed boiler by air flow, the mixed gas of fuel and air is distributed to the plurality of fuel supply pipes (2) by the distributor (1), and is fed to the fluidized bed boiler (8). It is supplied to the bottom of the fluidized bed furnace (7) through the installed fuel supply nozzle (6).

A thermometer (9) is installed in the vicinity of the fluidized bed bottom (7) of the fuel supply pipe (2) to detect clogging and backflow of fuel. That is, the temperature is constant when the fuel is smoothly supplied to the fuel supply pipe (2) by the carrier air, but when clogging or backflow occurs, the fuel supply pipe is not cooled and is not cooled. (2) This is detected by utilizing the temperature rise in the inside. When such a behavior of the thermometer (9) is detected, the worker visually detects it and shuts off the shutoff valve (3).
Was manually closed to shut off the distributor (1) and the fluidized bed boiler (8).

[0004]

As described above, in the conventional fuel supply system, the thermometer (9) is used to detect clogging or backflow of the fuel due to a change in the temperature and cope with the abnormality. Since a highly abrasive mixed fluid of fuel and air flows inside the supply pipe (2), the temperature sensing part of the thermometer (9) cannot be installed inside the fuel supply pipe (2). Therefore, the metal temperature of the fuel supply pipe (2) must be measured, not the temperature of the mixed fluid itself in the pipe. as a result,
The trackability of temperature measurement is poor, and the time constant is at least several tens of seconds. Then, a considerable amount of time is required for the recovery operation including purging of the fuel supply pipe (2), and as a result, the operating condition of the fluidized bed boiler (8) is disturbed, which is a problem.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides a fuel supply system in which a fuel is carried by an air flow and is introduced into a fluidized bed furnace from the bottom of a furnace, and a fuel supply pipe is provided with a constant amount. A differential pressure detection device having a pressure outlet with a long distance is provided, and when the differential pressure detected by the differential pressure detection device becomes an abnormal value, a shutoff provided in the fuel supply pipe near the bottom of the furnace A fuel supply device characterized in that the valve is automatically closed; and, in addition to the above requirements, a temperature sensor is provided in the fuel supply pipe near the bottom of the furnace, and the temperature detected by the temperature sensor is A fuel supply device characterized in that a signal for closing the shutoff valve is issued when the set value is exceeded.

[0006]

[Action]

1) In the first solution means, when the differential pressure in a certain section of the fuel supply pipe is measured, it shows a constant value during normal operation, but when the fuel supply pipe is clogged, the differential pressure is Or the differential pressure itself between the fluidized bed boiler and the distributor appears. When the fluid flows from the bottom of the fluidized bed furnace back into the fuel supply pipe, the differential pressure becomes negative.

When such a behavior of the differential pressure indicates a value at which it is judged that clogging or backflow has occurred in the fuel supply pipe, an automatic shutoff valve provided in the fuel supply pipe near the bottom of the furnace automatically Close and stop fuel supply. Then, you can quickly start the recovery operation such as purging.
Disturbances to the operating conditions of the fluidized bed boiler can be minimized.

2) As described above, in addition to detecting the abnormal differential pressure and automatically closing the shut-off valve for early recovery from an abnormal situation, in the second solving means, the fuel near the bottom of the furnace is used. A temperature sensor is provided in the supply pipe, and when the detected temperature exceeds a set value due to backflow of high temperature combustion gas from the fluidized bed furnace, a signal for closing the shutoff valve is issued,
Make sure that the shut-off valve that has already been closed due to an abnormal differential pressure is confirmed to be fully closed.

[0009]

1 is a system diagram showing a first embodiment of the present invention. When the fuel is injected from the fluidized bed bottom (7) of the fluidized bed boiler (8) by air flow transfer, the mixed fluid of fuel and air is distributed by the distributor (1) to the plurality of fuel supply pipes (2), It is supplied to the fluidized bed furnace bottom (7) from a fuel supply nozzle (6) installed in the fluidized bed boiler (8) via the fuel supply pipe (2).

In this embodiment, the fuel supply pipe (2) extending from the distributor (1) to the fuel supply nozzle (6) in the bottom (8) of the fluidized bed furnace is pressured at regular intervals. Provide two outlets (13) each. In that case, one is provided near the distributor (1) and the other is provided near the fluidized bed furnace bottom (8),
Make sure that a sufficient differential pressure is obtained. Then, a differential pressure detecting device (5) for measuring the differential pressure therebetween is connected by a pressure take-out pipe. Furthermore, a differential pressure contact (12) which operates depending on some set differential pressure is connected to this detection signal system.
Further, an automatic shutoff valve (4) which operates by receiving a signal from the differential pressure contact (12) is installed near the inlet of the fluidized bed boiler (8) of the fuel supply pipe (2).

In the above structure, the differential pressure detecting device (5) constantly measures the differential pressure during the operation of the fluidized bed boiler (8). When the supply pipe (2) is clogged, or when a backflow from the fluidized bed furnace bottom (7) to the fuel supply pipe (2) occurs, the value becomes abnormal. When such a behavior of the differential pressure indicates a value at which it is determined that clogging or backflow has occurred in the fuel supply pipe (2), the differential pressure contact (12) is detected by the detection signal from the differential pressure detection device (5). Is activated, the signal is transmitted to the automatic shutoff valve (4), and the automatic shutoff valve (4) is fully closed automatically to shut off between the distributor (1) and the fluidized bed boiler (8).

Next, FIG. 2 is a system diagram showing a second embodiment of the present invention. In this embodiment, a temperature sensor (10) is provided in each of the fuel supply pipes (2) near the bottom (7) of the fluidized bed furnace. When the detection signal exceeds a preset temperature, an activation signal is emitted from the temperature contact (11) and transmitted to the automatic shutoff valve (4), which is supposed to have been shut off by the differential pressure. Make sure that the valve (4) is fully closed to ensure safety.

In the first or second embodiment described above, it is also possible to give an alarm to the driver's cab by instructing the driver from the information from the sensor in which the pressure difference or the temperature is added to the pressure difference.

[0014]

EFFECTS OF THE INVENTION In a fuel supply system in which fuel is introduced from the bottom of a fluidized bed furnace by air flow, clogging of a fuel supply pipe or reverse flow is detected by an abnormality in a value detected by a differential pressure detection device to supply fuel. By automatically closing the shutoff valve installed in the pipe, it is possible to shut off the fuel supply in a short time. As a result, recovery operations such as purging can be performed without delay, and disturbance to the operating state of the fluidized bed furnace can be minimized.

Further, a temperature sensor is provided in the fuel supply pipe near the bottom of the fluidized bed furnace, and when the detected temperature becomes abnormally high and exceeds the set value, a signal for closing the shut-off valve is issued to make the differential pressure difference. You can additionally confirm that the shut-off valve is fully closed due to an abnormality, and take precautions to prevent an accident.

[Brief description of drawings]

FIG. 1 is a system diagram showing a first embodiment of the present invention.

FIG. 2 is a system diagram showing a second embodiment of the present invention.

FIG. 3 is a system diagram showing an example of a conventional fuel supply device.

[Explanation of symbols]

 (1) Distributor (2) Fuel supply pipe (3) Shutoff valve (4) Automatic shutoff valve (5) Differential pressure detector (6) Fuel supply nozzle (7) Fluidized bed bottom (8) Fluidized bed boiler (9) ) Thermometer (10) Temperature sensor (11) Temperature contact (12) Differential pressure contact (13) Differential pressure outlet

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshishige Uematsu 1-1, Atsunoura-machi, Nagasaki-shi Nagasaki Shipyard Co., Ltd.

Claims (2)

[Claims] 1. A fuel supply device for transporting fuel by an air flow and charging it into a fluidized bed furnace from the bottom of a furnace, wherein a differential pressure detection device having a pressure outlet at a certain distance is provided in a fuel supply pipe, and the same difference is provided. A fuel supply device characterized in that when a differential pressure detected by a pressure detection device becomes an abnormal value, a shutoff valve provided in the fuel supply pipe near the furnace bottom is automatically closed. 2. A temperature sensor is provided in the fuel supply pipe near the bottom of the furnace, and a signal for closing the shutoff valve is issued when the temperature detected by the temperature sensor exceeds a set value. The fuel supply device according to claim 1.