JP4260649B2 - Combined power generation facility having a chimney of an exhaust heat recovery boiler and a chimney of the exhaust heat recovery boiler - Google Patents

Description

  The present invention relates to prevention of sulfur oxide and rust scattering in a combined power generation facility using an oil-fired gas turbine, an exhaust heat recovery boiler, and a denitration device.

The equipment block diagram of the conventional power generation equipment is shown in FIG.
Exhaust gas from the gas turbine 1 is guided to the exhaust heat recovery boiler 2. The exhaust heat recovery boiler 2 recovers heat from the exhaust gas and generates steam. The steam is superheated by the superheater 5, and the steam is used in a factory or the like through the main steam pipe 8, or is supplied to a steam turbine and used for power generation.

Further, since the exhaust gas contains nitrogen oxides (hereinafter abbreviated as NOx), a denitration device 6 is incorporated in the exhaust heat recovery boiler 2 and ammonia (NH ₃ ) is injected into the exhaust gas. NOx removal is performed. When oils such as A heavy oil are used as the fuel for the gas turbine 1, the exhaust gas of the gas turbine 1 contains sulfurized compounds (hereinafter abbreviated as SOx) due to the sulfur content in the fuel. In this case, acidic ammonium sulfate is generated in the region where the gas temperature is 220 ° C. to 150 ° C. (corresponding to the region of the economizer 3 in FIG. 8) due to the chemical reaction between ammonia and SOx injected for NOx removal, It adheres to the heat transfer tube group. This acidic ammonium sulfate is corrosive and rusts the heat transfer tube group. Further, the acidic ammonium sulfate becomes powdery when cooled, but when the exhaust heat recovery boiler 2 is stopped and cooled, the acidic ammonium sulfate becomes powdery in the exhaust heat recovery boiler 2. When the gas turbine 1 is started in such a state, rust and acidic ammonium sulfate are conveyed to the gas and scattered from the chimney 9 (height is about 50 to 80 m) at the outlet of the exhaust heat recovery boiler 2, or rust and There is a risk of contaminating and corroding surrounding equipment with acidic ammonium sulfate.

  Therefore, conventionally, as shown in FIG. 9, a temporary net 17 is installed in the chimney 9 before the gas turbine 1 is started in order to prevent scattering of rust and acidic ammonium sulfate. Further, when rust or acidic ammonium sulfate adheres to the mesh 17, the gas differential pressure inside the chimney 9 increases from the location where the mesh 17 is installed, which hinders the operation of the gas turbine 1. Therefore, after operating for a specified time, the net 17 is taken out from the chimney 9 using the heavy machine 16, rust and acid ammonium sulfate adhering to the net 17 are removed by air blow or the like, and then installed in the chimney 9 again with the heavy machine 16. Had to be carried out.

Further, as disclosed in Patent Document 1 below, the atmosphere inside the exhaust heat recovery boiler 2 is heated when the gas turbine 1 is stopped so that rust does not occur in the heat transfer tube, and rust and acid ammonium sulfate outside from the chimney are removed. Some inventions have been made so as not to discharge to the outside.
JP 2002-98301 A

In the method of installing the temporary net 17 in the chimney 9 before starting the gas turbine 1 of the above-described prior art, since the net 17 is cleaned several times until the normal operation state is started after the gas turbine 1 starts, There are problems that it takes time for the recovery boiler 2 to enter normal normal operation and that construction costs such as installation and removal of the temporary net 17 inside the chimney 9 are required.
Further, in the invention described in Japanese Patent Application Laid-Open No. 2002-98301, it is necessary to arrange a heating tube for heating the entire area inside the exhaust heat recovery boiler 2, which requires a large equipment cost.

  An object of the present invention is to provide a waste heat recovery boiler (chimney) in which solid materials such as rust, acidic ammonium sulfate and dust are not discharged from the chimney to the outside without relatively increasing the equipment cost, and a combined power generation including the boiler Is to provide facilities.

  An object of the present invention is to provide an exhaust heat recovery boiler (chimney) that can easily remove rust, acidic ammonium sulfate and dust in a short time and a combined power generation facility including the boiler.

In order to solve the above problems, the present invention uses the following means.
The invention according to claim 1 is used in a combined power generation facility including one or more gas turbines, a heat exchange unit that introduces exhaust gas from the gas turbines to generate steam, and an exhaust heat recovery boiler having a denitration device. In the chimney of the exhaust heat recovery boiler that discharges the purified exhaust gas, a first damper that has the function of closing the gas flow path and stopping the gas flow is arranged below the gas flow path, and rust, acid ammonium sulfate, and soot dust are disposed above it. It is a chimney of a waste heat recovery boiler provided with the 2nd damper which has a passage hole of the size which collects the solid matter containing .

  According to a second aspect of the present invention, a gas pressure detector is installed in a gas flow path between the first damper and the second damper, and the second damper is opened and closed by a detection signal of the gas pressure detector. The chimney of the exhaust heat recovery boiler according to claim 1, further comprising a control device that controls operation and shutdown of the gas turbine.

  The invention according to claim 3 is the chimney of the exhaust heat recovery boiler according to claim 1, wherein the first damper has a funnel shape capable of recovering the solid matter collected by the second damper. .

  The invention according to claim 4 is the chimney of the exhaust heat recovery boiler according to claim 3, wherein the second damper is provided with a scaffold for knocking off the solid matter collected by the worker.

  The invention according to claim 5 is the chimney of the exhaust heat recovery boiler according to claim 3, wherein a blower device for blowing off the solid matter collected by the second damper is provided above the second damper. .

  A sixth aspect of the present invention is the chimney of the exhaust heat recovery boiler according to the third aspect, wherein a printing pipe for discharging the collected solid matter to the outside of the chimney is connected below the funnel shape of the first damper. is there.

  According to a seventh aspect of the present invention, a partition plate for partitioning the gas flow path into two or more along the gas flow direction is provided, and the first damper and the second damper are provided in each gas flow path. It is a chimney of the described exhaust heat recovery boiler.

  According to an eighth aspect of the present invention, the first damper is rotatable about a rotation shaft provided on the partition plate, and the partition plate has the same or substantially the same size as the first damper. 8. A chimney of an exhaust heat recovery boiler according to claim 7, wherein an opening is provided.

  The invention according to claim 9 is a combined power generation facility comprising a gas turbine provided with the chimney of the exhaust heat recovery boiler according to claim 1 and an exhaust heat recovery boiler.

  According to the invention described in claim 1, after the solid matter is sufficiently collected by the second damper having a function of collecting solid matter such as rust, acidic ammonium sulfate and dust in the chimney of the exhaust heat recovery boiler, By temporarily closing the gas flow path with the first damper and removing the solid matter collected by the second damper, temporary trapping of solid matter such as rust, acidic ammonium sulfate, and dust that has been performed in the past has been carried out. It is possible to remove gathering materials (nets, etc.) every time the differential pressure increases, and to significantly reduce the time and cost spent after installation and after installation (1/5 to 1/10).

  According to the second aspect of the present invention, when the gas pressure in the gas flow path between the first damper and the second damper exceeds the predetermined value, the operation of the gas turbine is stopped. The first damper can close the gas flow path to remove the solid matter collected by the second damper, and the work efficiency is good.

  According to the third aspect of the invention, since the solid matter collected by the second damper is collected at the bottom of the funnel-shaped first damper, the work of collecting the solid matter can be omitted.

  According to invention of Claim 4, since the solid substance which the worker collected on the scaffold provided in the 2nd damper can be knocked off, collection | recovery of solid substance can be performed efficiently.

  According to the fifth aspect of the present invention, the dust collected by the second damper can be blown off by the blower device above the second damper, so that the worker does not enter the chimney and directly remove it. The solids can be collected easily.

  According to the sixth aspect of the present invention, the dust collected by the funnel-shaped first damper can be discharged from the printing pipe to the outside of the chimney, so that the solid matter in which the worker enters the chimney There is no need to perform the collection work.

  According to the seventh aspect of the present invention, since the first damper and the second damper are provided in each of the two or more gas flow paths partitioned by the partition plate, at least one gas flow path side plant is stopped. The chimney can be cleaned without letting it go.

  According to the invention described in claim 8, it is possible to flow from one gas flow path partitioned by the partition plate in the invention according to claim 7 to the other gas flow path through an opening provided in the partition plate. The second damper can be cleaned without stopping the plant connected to the gas flow path in the chimney where the gas flow path is opened.

  According to the ninth aspect of the invention, the combined power generation facility can be operated without harming the environment.

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

In FIG. 1, the schematic block diagram of the waste heat recovery boiler 2 of a present Example is shown.
When the exhaust gas from the gas turbine 1 is introduced into the exhaust heat recovery boiler 2, steam is generated from the water flowing inside the heat transfer tube of the heat exchange section including the economizer 3, the evaporator 4, the superheater 5, and the like. . Water is separated from steam by the drum 7, and the obtained steam is superheated by the superheater 5, and the steam is used in a factory or the like through the main steam pipe 8 or supplied to a steam turbine (not shown) to generate power. Used. At this time, ammonia (NH ₃ ) injected by the denitration device 6 reacts with SOx in the exhaust gas to produce acidic ammonium sulfate and adhere to the heat transfer tube group, and the acidic ammonium sulfate rusts the heat transfer tube group. As already mentioned, the powdered acidic ammonium sulfate and rust cooled by the shutdown of the exhaust heat recovery boiler 2 may be scattered from the chimney 9 at the outlet of the exhaust heat recovery boiler 2 when the gas turbine 1 is restarted. is there.

  In this embodiment, in order to prevent powdered acidic ammonium sulfate and rust from scattering from the chimney 9 at the outlet of the exhaust heat recovery boiler 2 when the gas turbine 1 is restarted, a net-like damper 11 (second A damper) and a plate-like damper 10 (first damper) are installed. A perspective view of the first damper is shown in FIG. 1 (b), and a perspective view of the second damper is shown in FIG. 1 (c).

  In order to capture acidic ammonium sulfate and rust that are scattered when the gas turbine 1 is started after the exhaust heat recovery boiler 2 is stopped, the chimney 9 is closed by a net-like damper 11. After operating the combined power plant for the specified time, the gas turbine 1 is stopped to remove the acidic ammonium sulfate and rust adhering to the mesh damper 11, but in this case, it was installed on the gas upstream side (lower chimney in FIG. 1). As shown in FIG. 3, the plate-shaped damper 10 is closed, and an operator enters the chimney 9 from the man door 15 of the chimney 9, and uses the damper 10 instead of the scaffold to clean the mesh damper 11. Is. Moreover, the plate-like damper 10 can also prevent acid ammonium sulfate and rust removed when the mesh damper 11 is cleaned from dropping to the exhaust heat recovery boiler 2 side.

In addition, the usage method of both the dampers 10 and 11 is as follows.
During operation of the normal gas turbine 1, the dampers 10 and 11 are naturally fully opened. The gas turbine 1 stops and the exhaust heat recovery boiler 2 is warmed up until the next start-up (about 10 to 50 hours) (the time from the start of the gas turbine 1 until the rated load is reached in this state) In other words, the plate-like damper 10 remains in the fully closed state and the mesh damper 11 remains in the fully open state. When the gas turbine 1 is stopped for a long time and started after a periodic inspection of the exhaust heat recovery boiler 2 (removal of acid ammonium sulfate and rust), the plate-like damper 10 is fully opened, The damper 11 is in a fully closed state to capture scattered acidic ammonium sulfate and rust.

  After the net damper 10 is fully closed for a specified time, the gas turbine 1 is stopped, the plate damper 10 is fully closed, the damper 10 is used as a scaffold, and acid ammonium sulfate and rust adhering to the net damper 11 are removed. Remove. After cleaning the mesh damper 11, the mesh damper 11 is fully closed, the plate damper 10 is fully opened, and the gas turbine 1 is started. Thereafter, the process is repeated until there is almost no adhesion to the net damper 11. In addition, since a chimney diameter is about 3-5 m, since both dampers 10 and 11 can be installed 2-3 m apart, it is possible to clean using the plate damper 10 instead of a scaffold.

  FIG. 2 is a schematic view of a combined power plant showing a second embodiment of the present invention. In the chimney 9 at the outlet of the exhaust heat recovery boiler 2, a net-like 11 and a plate-like 10 damper are installed, and a gas pressure detector 12 is installed between them. When acidic ammonium sulfate or rust adheres to the mesh damper 11 and the amount of adhesion increases, the gas differential pressure of the mesh damper 11 increases, and as a result, the exhaust pressure of the gas turbine 1 also increases. Therefore, the gas pressure is monitored by the gas pressure detector 12.

When the gas pressure detector 12 detects the operating gas pressure and the pressure is likely to exceed a preset allowable pressure of the mesh damper 10 or an allowable exhaust pressure of the gas turbine 1, a signal of the gas pressure detector 12 is received. A command to stop the gas turbine 1 is issued to the gas turbine operation control device 14, and at the same time, a command to open the mesh damper 10 is issued to the damper opening / closing control device 13. Thereafter, the plate-like damper 10 is closed, and the net-like damper 11 is cleaned.
By such an operation, the differential pressure of the mesh damper 11 and the exhaust pressure of the gas turbine 1 can be suppressed to a specified value or less.

Note that the plate-like damper 10 (first damper) in the above embodiment does not necessarily have a plate-like shape as long as the gas flow is stopped in the closed state.
Further, the net-like damper 11 (second damper) may not necessarily be a net-like one as long as it can collect dust and the like in the gas in a closed state and distribute the gas.

  FIG. 4 shows a chimney internal structure diagram of a combined power plant according to a third embodiment of the present invention. The second damper 11 may have a scaffold member 20 as shown in FIG. An operator rides on the scaffold member 20 in the second damper 11 and beats dust or the like adhering to the second damper 11 or drops it to the lower first damper 10 by a blower or the like and collects it. . As a result, the worker does not have to be covered with the falling dust. The arrangement interval, the shape configuration, and the like of the scaffold member 20 are not particularly limited.

Further, the blower device 25 may be provided so as to extend from the wall surface of the chimney 9 to above the second damper 11 without depending on human power, and dust or the like may be dropped by blowing air or the like. The blower device 25 may be of any type, number, etc., such as a movable type, a fixed type, and a pluggable type.
Further, dust or the like may be dropped by applying impact or vibration to the second damper 11 by a striking means or a vibration means (not shown).
Dropped dust or the like may be collected easily by means such as a funnel shape in which the central portion of the first damper 10 is depressed as shown in FIG. 4, for example.

  Furthermore, an opening 23 may be provided at the lowermost end of the depressed funnel portion of the first damper 10 so that dust or the like is printed out of the chimney 9 through the printing means. Specifically, as shown in the view from the direction of arrow A in FIG. 4 of FIG. 5, an insertion / removal type printing pipe 22 is passed through the opening 24 of the wall surface of the chimney 9 and provided at the end thereof. What is necessary is just to connect an opening part and the said opening part 23 provided in the 1st damper 10, and to suck | inhal dust etc. from the printing piping 22. FIG.

  As a result, it is possible to work without the person entering the chimney 9, and even if conditions such as gas or temperature inside the chimney 9 are not suitable for human work, dust removal can be performed, so that the operation of the plant is possible. Efficiency is improved.

  FIG. 6 shows the internal structure of the chimney part of the combined power plant according to the fourth embodiment of the present invention. This embodiment shows an example in which the inside of the chimney 9 is divided in the gas flow direction by the partition plate 26 and a plurality of exhaust gas flow paths from a plurality of adjacent exhaust heat recovery boilers are formed. The partition plate 26 inside the chimney 9 divides the gas flow into two or more according to the number of exhaust gas flow paths of the exhaust heat recovery boiler 2.

  The first dampers 10A and 10B and the second dampers 11A and 11B respectively arranged in the gas flow paths inside the chimney divided by the partition plate 26 are individually opened and closed for each gas flow path with the shafts 21A and 21B as axes. The movable range may be either above or below the height of the shaft 21 portion that is the rotation axis of the damper.

  The partition plate 26 is provided with a bypass opening 27. The bypass opening 27 has substantially the same shape as the first dampers 10A and 10B, and is opened below the shaft 21 portion that is the rotation shaft of the first dampers 10A and 10B. 10B has an opening shape that rotates around the shafts 21A and 21B and is flush with the partition plate 26.

Therefore, when the first dampers 10A and 10B are rotated downward as substantially the same shape as the first dampers 10A and 10B, the bypass opening 27 is closed.
In the present embodiment, one of the first dampers 10A and 10B has shown a form in which the bypass opening 27 is closed, but a closing member may be provided independently for opening and closing.

  FIG. 7 (FIG. 7A is a perspective view and FIG. 7B is a longitudinal sectional view) is an example in which the same printing means as in FIG. 5 is provided in the form of FIG. The shape of the bottom plates 29A and 29B of 10B is inclined from the shafts 21A and 21B toward one end in the circumferential direction, and the opening 23 is provided at the lowest position. Note that the side plates 30A and 30B of the first dampers 10A and 10B may be shaped to be inclined inward so as not to interfere with the chimney wall.

With the above configuration, in the gas flow path (hereinafter referred to as the gas flow path A) in which the first damper 10A and the second damper 11A are provided, the second damper 11A is closed during plant operation. When the amount of dust or the like adhering to the second damper 11A increases, the first damper 10A is closed, and the first damper 10B rotates upward about the shaft 21B and flows through the gas flow path A. Can be induced to flow in a gas flow path (hereinafter referred to as gas flow path B) provided with the first damper 10B and the second damper 11B.
Thereby, dust etc. adhering to the second damper 11A on the gas flow path A side can be removed without stopping the power plant on the gas flow path A side.

Similarly, when the amount of dust or the like adhering to the second damper 11B increases, the first damper 10B is closed, and the first damper 10A rotates upward about the shaft 21A, and the gas The exhaust gas flowing through the flow path B can be made to flow through the flow path A.
Therefore, dust removal can be performed without stopping any of the plants on the gas flow path A side and the gas flow path B side, so that the operation efficiency of the power plant is significantly improved.

  In the above embodiment, the first dampers 10A and 10B and the second dampers 11A and 11B are shown as examples in which the gas flow paths A and B are opened and closed by rotating around the shafts 21A and 21B. These are simple components with few components, but the configuration and the form are not limited as long as the opening and closing functions of the gas flow paths A and B are realized.

  INDUSTRIAL APPLICABILITY The present invention can be used for an exhaust heat recovery boiler (a chimney) having a countermeasure for preventing sulfur oxide and rust from being scattered in a combined power generation facility using an oil-fired gas turbine, an exhaust heat recovery boiler, and a denitration apparatus.

1 is a schematic configuration diagram of an exhaust heat recovery boiler according to an embodiment of the present invention (FIG. 1A), a perspective view of a first damper (FIG. 1B), and a perspective view of a second damper (FIG. 1C). It is. It is a schematic block diagram of the combined power plant equipment of one Example of this invention. It is a figure which shows the mode at the time of cleaning of the damper of the chimney of the waste heat recovery boiler of one Example of this invention. It is a perspective view which shows the damper part of the chimney of the waste heat recovery boiler of one Example of this invention. It is a top view which shows the 1st damper part of the chimney of FIG. It is a perspective view which shows the damper part of the chimney of the waste heat recovery boiler of one Example of this invention. They are a perspective view (Drawing 7 (a)) and a longitudinal section (Drawing 7 (b)) which show the 1st damper part of a chimney of Drawing 6. It is an arrangement block diagram of the conventional combined power plant equipment. It is a conceptual diagram of the installation point of the temporary net | network in the chimney of the conventional waste heat recovery boiler.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas turbine 2 Waste heat recovery boiler 3 Carbon-saving device 4 Evaporator 5 Superheater 6 Denitration device 7 Drum 8 Main steam pipe 9 Chimney 10 First damper 11 Second damper 12 Gas pressure detector 13 Damper opening / closing control device 14 Gas turbine operation control device 15 Mandoor 16 Heavy machine 17 Temporary network 20 Scaffolding member 21 Shaft 22 Printing pipe 23 Opening portion 24 Opening portion of chimney wall 25 Blower device 26 Partition plate 27 Bypass opening 29 Bottom plate 30 Side plate A, B Gas flow path

Claims (9)

Exhaust heat recovery for exhausting purified exhaust gas used in a combined power generation facility comprising one or more gas turbines, a heat exchange section that introduces exhaust gas from the gas turbine to generate steam, and an exhaust heat recovery boiler having a denitration device In the boiler chimney,
A first damper having a function of closing the gas flow path to stop the gas flow is disposed below the gas flow path, and a passage hole having a size for collecting solid matter including rust, acidic ammonium sulfate, and soot dust on the first damper. A waste heat recovery boiler chimney comprising a second damper having   A gas pressure detector is installed in the gas flow path between the first damper and the second damper, and the opening and closing of the second damper and the operation and operation of the gas turbine are detected by a detection signal of the gas pressure detector. The chimney of the exhaust heat recovery boiler according to claim 1, further comprising a control device for controlling the stop.   The chimney of the exhaust heat recovery boiler according to claim 1, wherein the first damper has a funnel shape capable of recovering the solid matter collected by the second damper.   4. A chimney of an exhaust heat recovery boiler according to claim 3, wherein said second damper is provided with a scaffold for knocking off solid matter collected by an operator.   4. A chimney of an exhaust heat recovery boiler according to claim 3, wherein a blower device for blowing off solid matter collected by the second damper is provided above the second damper.   4. A chimney of an exhaust heat recovery boiler according to claim 3, wherein a printing pipe for discharging the collected solid matter to the outside of the chimney is connected below the funnel shape of the first damper.   2. The exhaust according to claim 1, wherein a partition plate for partitioning the gas flow path into two or more along the gas flow direction is provided, and the first damper and the second damper are provided in each gas flow path. The chimney of the heat recovery boiler.   The first damper is rotatable about a rotation shaft provided on the partition plate, and the partition plate is provided with an opening having the same or almost the same size as the first damper. A chimney of an exhaust heat recovery boiler according to claim 7 characterized by the above.   A combined power generation facility comprising a gas turbine and an exhaust heat recovery boiler, comprising the chimney of the exhaust heat recovery boiler according to claim 1.

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