JP5153810B2 - Flue cleaning method for thermal power generation facilities - Google Patents

Description

  The present invention relates to a flue cleaning method for a thermal power generation facility.

  The thermal power generation facility removes sulfur oxide from the boiler that burns fossil fuel, the electric dust collector that removes the ash generated by combustion from the combustion gas after combustion, and the combustion gas that has passed through this electric dust collector A flue gas desulfurization device and a chimney that discharges the gas from which sulfur oxides have been removed by the flue gas desulfurization device to the outside air are provided, and the respective devices are connected by a pipe serving as a flue (see Patent Document 1). .

JP 2001-25626 A

  Thermal power generation facilities need to be cleaned and inspected by periodically stopping the operation of each device in the facilities in order to ensure safety. At this time, the remaining combustion ash that is generated by the combustion of the boiler and remains without being burned is accumulated in the flue connecting the devices in the facility downstream of the boiler, and the flue is also cleaned. There is a need. In order to remove the accumulated residual combustion ash, it was necessary to clean it manually, which required a lot of labor.

  Therefore, an object of this invention is to provide the cleaning method which can reduce or abbreviate | omit the operation | work which cleans the ash deposited in the flue downstream from a boiler at the time of cleaning of an installation.

  (1) A flue cleaning method for a thermal power generation facility according to the present invention includes a boiler for burning fossil fuel, an electric dust collector connected to the boiler via a first flue, and the electric dust collector. In a thermal power generation facility comprising a flue gas desulfurization device connected through a second flue and a chimney connected to the flue gas desulfurization device through a third flue, the boiler is stopped In this state, the operation of the flue gas desulfurization device is started in advance, and the first flue and the second flue are vented to clean the residual combustion ash adhering to both flues, and the exhaust flue gas. The exhaust gas is discharged from the chimney after the residual combustion ash is removed by a smoke desulfurization apparatus.

  (2) It is preferable that a push ventilator for sending combustion air to the boiler is connected to the boiler, and the ventilation process is performed by operating the push ventilator.

  (3) It is preferable that the operation of the push ventilator also serves as an operation check of the push ventilator in the thermal power generation facility.

  (4) It is preferable to further comprise a fourth flue branched from the first flue or the second flue and connected to the third flue or the chimney.

  ADVANTAGE OF THE INVENTION According to this invention, the cleaning method which can reduce or abbreviate | omit the operation | work which cleans the ash deposited in the flue downstream from a boiler at the time of cleaning of an installation can be provided.

It is the schematic of the thermal power generation equipment which concerns on embodiment of this invention. It is the schematic at the time of the cleaning by the flue cleaning method of the thermal power generation equipment which concerns on embodiment of this invention. It is the schematic of the thermal power generation equipment before performing the cleaning by the flue cleaning method of the thermal power generation equipment which concerns on embodiment of this invention.

  Hereinafter, a preferred embodiment according to a flue cleaning method for a thermal power generation facility of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic view of a thermal power generation facility 1 according to an embodiment of the present invention.
The thermal power generation facility 1 is a facility that generates power by burning fossil fuel. The thermal power generation facility 1 includes a boiler 10 that burns fossil fuel, an electric dust collector 20 that removes soot from the gas generated by the combustion, and a flue gas desulfurization device 30 that removes sulfur oxide from the gas from which soot has been removed. And a chimney 40 and a forced air blower 50 that sends combustion air to the boiler 10. Note that a denitration device (not shown) is disposed between the normal boiler 10 and the electrostatic precipitator 20.

  The thermal power generation facility 1 includes a first flue 11 provided between the boiler 10 and the electric dust collector 20, a second flue 12 provided between the electric dust collector 20 and the flue gas desulfurization device 30, and an exhaust gas. Provided between the third flue 13 provided between the smoke desulfurization device 30 and the chimney 40, the fourth flue 14 provided between the second flue 12 and the chimney 40, and the boiler 10 and the forced air blower 50. The air supply path 15 is provided.

  The flue and air supply path 15 are constituted by hollow pipes. The first flue 11 has one end connected to the boiler 10 and the other end connected to the electric dust collector 20, and the electric dust collector 20 is connected to the boiler 10 via the first flue 11. . One end of the second flue 12 is connected to the electric dust collector 20 and the other end is connected to the flue gas desulfurization device 30. The flue gas desulfurization device 30 is connected to the electric dust collector 20 via the second flue 12. Are connected. The third flue 13 has one end connected to the flue gas desulfurization device 30 and the other end connected to the chimney 40, and the chimney 40 is connected to the flue gas desulfurization device 30 via the third flue 13. . The fourth flue 14 has one end branched from the second flue 12 and the other end connected to the chimney 40. The fourth flue 14 is provided as a bypass flue for preventing the exhaust gas having heat from flowing into the flue gas desulfurization device 30 at the time of emergency stop of the flue gas desulfurization device 30. The boiler 10, the forced air blower 50, the electrostatic precipitator 20, the flue gas desulfurization device 30, and the chimney 40 include the first flue 11, the second flue 12, and the third flue 13. Then, the air flows through the fourth flue 14 and the air supply path 15.

The boiler 10 generates power by burning fossil fuel inside. The boiler 10 is connected to a forced air blower 50 that sends combustion air to the boiler 10 and an induction ventilator (not shown) that sucks gas generated by combustion from the boiler 10.
The forced draft fan 50 includes a fan that is rotated by a motor, and supplies air to the boiler 10 via the air supply path 15.

  The electric dust collector 20 is disposed downstream of the first flue 11. The electrostatic precipitator 20 has a plurality of electrodes therein. When the gas generated by the combustion flows in the electric dust collector 20, the electric dust collector 20 charges the dust contained in the gas generated by the combustion and collects it with the electrode. Thereby, the electrostatic precipitator 20 removes the dust contained in the gas generated by burning the fossil fuel in the boiler 10.

The flue gas desulfurization device 30 is disposed downstream of the second flue 12. The flue gas desulfurization apparatus 30 includes a water absorption tower 31 filled with a water absorption liquid that absorbs and removes sulfur oxides contained in gas, a desulfurization fan 32 that sends gas from the second flue 12 to the water absorption tower 31, and the water absorption tower 31. A water absorption tower circulation pump 33 for circulating the water absorption liquid inside the water absorption tower 31, and a sprayer 34 for spraying the water absorption liquid of the water absorption tower 31 circulated by the water absorption tower circulation pump 33 onto the gas fed from the desulfurization fan 32. And comprising.
In the flue gas desulfurization apparatus 30, gas is sent from the second flue to the water absorption tower 31 by the desulfurization fan 32, and the absorption liquid is sprayed on the gas to bring the alkaline water absorption liquid and gas into contact with each other in the water absorption tower 31. Absorbs and removes sulfur oxides in the gas. The absorption liquid is a slurry containing calcium carbonate, and the sulfur oxide absorbed in the water absorption liquid is oxidized and combined with calcium to be changed to gypsum.

  The chimney 40 is disposed downstream of the third flue 13. The gas from which the sulfur oxide has been removed by the flue gas desulfurization device 30 is discharged from the chimney 40 to the outside air.

Drawing 2 is a schematic diagram at the time of cleaning by the cleaning method of thermal power generation equipment 1 concerning the embodiment of the present invention. With reference to FIG. 2, the cleaning method of the thermal power generation equipment 1 which concerns on embodiment of this invention is demonstrated.
When inspecting the thermal power generation facility 1, the operation of the boiler 10, the electric dust collector 20, the flue gas desulfurization device 30, and the forced air blower 50 is stopped. And each of these boilers 10, the electrostatic precipitator 20, the flue gas desulfurization apparatus 30, and the forced air blower 50 (henceforth the apparatus in equipment) is inspected.
At this time, the residual combustion ash generated during the operation of the thermal power generation facility 1 and not removed by the electric dust collector 20 gradually adheres to the inside of the first flue 11 and the second flue 12. It is deposited. Similarly, residual combustion ash circulated from the first flue 11 or the second flue 12 also adheres and accumulates on the fourth flue 14.

  When the equipment in the facility is inspected, first, the operation of the boiler is stopped, and the operation of the flue gas desulfurization device 30 is started with the electric dust collector 20 activated. When the operation of the flue gas desulfurization apparatus 30 is started, the desulfurization fan 32 is activated. When the desulfurization fan 32 is activated, the air flowing through the first flue 11 and the second flue 12 is drawn into the flue gas desulfurization device 30 by the desulfurization fan 32.

Next, the operation of the forced air blower 50 is started and air is supplied to the boiler 10. Since the boiler 10 is not operated, the boiler 10 does not burn fossil fuel even if air is supplied from the forced air blower 50. For this reason, the air supplied from the forced air blower 50 flows through the first flue 11.
Similarly, the electrostatic precipitator 20 is operated, and the air that has circulated through the first flue 11 passes through the electric precipitator 20 and circulates through the second flue 12. Thus, the ventilation process of the 1st flue 11 and the 2nd flue 12 is performed by the driving | operation of the forced air blower 50. FIG.

  It is necessary to check the operation of the pushing ventilator 50 to determine whether or not it normally operates after cleaning. Therefore, after the operation of the flue gas desulfurization apparatus 30 is started, the operation of the forced air blower 50 is performed before the operation of the boiler 10 is started. The operation of the push ventilator 50 also serves as an operation check of the push ventilator 50 in the thermal power generation facility 1. Since the boiler 10 is not operated, the check is made by changing the ventilation rate and speed of the forced draft fan 50 to a desired size without affecting the combustion of the fossil fuel.

  When air is supplied from the forced air blower 50 to the boiler 10 via the air supply path 15, residual combustion ash adhering to the inside of the first flue 11 and the second flue 12 is blown off by the air. By performing the ventilation process of the first flue 11 and the second flue 12, the residual combustion ash adhering to both the flues is cleaned.

  Downstream of the second flue 12 is connected to a desulfurization fan 32 of the flue gas desulfurization device 30 that has been in operation prior to the forced air blower 50, and the first flue 11 and the second flue 12 are connected to each other. It draws in air that circulates. For this reason, the residual combustion ash blown off by the ventilation process of the first flue 11 and the second flue 12 is drawn into the flue gas desulfurization apparatus 30.

  Drawing 3 is a figure showing thermal power generation equipment 1 before performing flue cleaning by a flue cleaning method of thermal power generation equipment 1 concerning this embodiment. As shown in FIG. 3, since the fourth flue 14 as a bypass is connected to the first flue 11 and the second flue 12, the residual combustion ash from the first flue 11 and the second flue 12. Is flowing in and depositing.

  However, since the fourth flue 14 is connected to the second flue 12, the fourth flue 14 is affected by the air flow generated by the desulfurization fan 32 connected to the second flue 12. For this reason, the residual combustion ash adhering or accumulating inside the fourth flue 14 is drawn in by the desulfurization fan 32 and flows to the second flue 12.

  As described above, after the operation of the flue gas desulfurization apparatus 30 is started, when the ventilation fan 50 is operated and the ventilation process is performed, the first flue 11 and the second flue are formed in the second flue 12. The residual combustion ash blown off by the aeration process 12 and the residual combustion ash circulated from the fourth flue 14 merge and circulate. The residual combustion ash flowing through the second flue 12 is drawn into the flue gas desulfurization device 30. The water absorption tower 31 of the operated flue gas desulfurization apparatus 30 is filled with the water absorption liquid, and the absorption liquid is sprayed by the sprayer 34. For this reason, residual combustion ash contained in the air flowing through the second flue 12 is collected and removed as solid matter inside the water absorption tower 31. Further, the sulfur oxide contained in the residual combustion ash is combined with the alkaline component in the absorbent and changed to gypsum and removed. As described above, the residual combustion ash contained in the air flowing through the first flue 11 and the second flue 12 together with the residual combustion ash contained in the air drawn from the fourth flue 14 is flue gas desulfurization. Removal processing is performed by the apparatus 30.

  The air flowing through the first flue 11 and the second flue 12 is passed through the third flue 13 to the chimney 40 after the residual combustion ash is removed by the flue gas desulfurization device 30. And it is discharged | emitted from the chimney 40 to the open air as ventilation gas.

According to the above-described method for cleaning a flue of a thermal power generation facility, the following effects can be obtained.
With the boiler 10 stopped, the operation of the flue gas desulfurization device 30 is started in advance, and the first flue 11 and the second flue 12 are ventilated to clean the residual combustion ash adhering to both flues. The exhaust gas was discharged from the chimney 40 after the residual combustion ash was removed by the flue gas desulfurization apparatus 30.
By starting the operation of the flue gas desulfurization device 30 in advance, a flow of drawing air flowing through the first flue 11 and the second flue 12 from the flue gas desulfurization device 30 is generated. And if ventilation processing is performed to the 1st flue 11 and the 2nd flue 12, since the cleaning of the residual combustion ash adhering in both flues blows away, the inside of the 1st flue 11 and the 2nd flue 12 by human power It is no longer necessary to clean the residual combustion ash adhering to the surface.

  Moreover, it decided to perform an aeration process by connecting the pressing ventilator 50 to the boiler 10, and operating the pressing ventilator 50. FIG. For this reason, cleaning can be performed only by changing the operation method of the apparatus in the facility using the apparatus in the existing facility.

  In addition, the operation of the push ventilator 50 also serves as an operation check of the push ventilator 50 in the thermal power generation facility. As a result, the operation of the push ventilator 50 can be checked and the flue can be cleaned at the same time. This eliminates the need for a separate cleaning process and further reduces the labor required for cleaning.

Moreover, in the case of the aspect provided with the 4th flue 14 branched from the 1st flue 11 or the 2nd flue 12, and connected to the 3rd flue 13 or the chimney 40, the desulfurization fan 32 is drive | operated previously. Since the air flowing through the first flue 11 or the second flue 12 is drawn in, the residual combustion ash flows from the first flue 11 or the second flue 12 into the fourth flue 14 at the time of cleaning. Can be prevented.
Moreover, since the 4th flue 14 is connected to the 2nd flue 12, the residual combustion ash deposited on the 4th flue 14 receives the influence of the air flow by the desulfurization fan 32, and the 1st flue. 11 or the second flue 12 is merged with the air and then circulated to the flue gas desulfurization apparatus 30. Therefore, it is not necessary to clean the fourth flue 14 manually.

  As mentioned above, although embodiment of this invention was described, this invention is not restricted to embodiment mentioned above. The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

  For example, in the present embodiment, the fourth flue 14 is branched from the second flue, but may be branched from the first flue. Further, the fourth flue 14 is connected to the chimney 40, but may be connected to the third flue 13.

DESCRIPTION OF SYMBOLS 1 Thermal power generation equipment 10 Boiler 11 1st flue 12 2nd flue 13 3rd flue 14 4th flue 15 Air supply path 20 Electric dust collector 30 Flue gas desulfurization device 40 Chimney 50 Pushing ventilator

Claims (4)

A boiler that burns fossil fuels;
An electric dust collector connected to the boiler via a first flue;
A flue gas desulfurization device connected to the electric dust collector via a second flue;
A thermal power generation facility comprising a chimney connected to the flue gas desulfurization device via a third flue,
In the state where the boiler is stopped, the operation of the flue gas desulfurization device is started in advance,
The residual flue ash adhering to both flues is cleaned by performing ventilation treatment on the first flue and the second flue, and after the residual flue ash is removed by the flue gas desulfurization device, A method for cleaning a flue of a thermal power generation facility, characterized by exhausting aeration gas from a chimney.   The flue cleaning method for a thermal power generation facility according to claim 1, wherein the boiler is connected to a forced draft fan for sending combustion air to the boiler, and the ventilation process is performed by operating the forced draft fan.   The method for cleaning a flue of a thermal power generation facility according to claim 2, wherein the operation of the forced draft fan also serves as an operation check of the forced draft fan in the thermal power generation facility.   The flue of the thermal power generation facility according to any one of claims 1 to 3, further comprising a fourth flue branched from the first flue or the second flue and connected to the third flue or the chimney. Cleaning method.

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