JP3433990B2 - Ash treatment equipment for pressurized fluidized-bed boiler - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cyclone, a cyclone, a combustion gas of a pressurized fluidized bed boiler in which fluidized bed combustion is performed under high pressure using coal as fuel and limestone as a desulfurizing agent. The present invention relates to an ash treatment device for reducing the temperature of ash collected by an ash collection device such as a filter and discharging the ash to the outside of the system. 2. Description of the Related Art FIG. 4 is an overall configuration diagram showing one example of a conventional gas turbine / steam turbine combined cycle power plant having a pressurized fluidized bed boiler, and FIG. 5 is a diagram showing one example of a conventional ash treatment device. is there. In these figures, (7) is a decompression hopper, (1)
0) is a normal pressure ash transfer line, (15) is an ash / gas suction unit, (19) is a reduced pressure release line, (20) is pressurized air, (22) is an airtight valve, and (25) contains ash. High pressure high temperature combustion gas, (26) is high pressure high temperature combustion gas after dust removal, (3)
1) is a pressurized fluidized bed boiler, (32) is a coal / limestone feeder, (33) is an air compressor, (34) is a high-temperature gas pipe,
(35) is a cyclone separator, (36) is a ceramic filter, (37) is a gas turbine / generator, (38) is a gas turbine outlet flue, (39) is a denitration device, and (40).
Is a waste heat recovery feed water heater, (41) is a chimney, (43) is a steam turbine / generator, (44) is a condenser, (45) is a feed water heater, (51) is a water-cooled jacket type screw feeder, (52) shows high-pressure ash storage tanks, respectively. First, in a pressurized fluidized bed boiler (31) in FIG. 4, coal and limestone are supplied to a furnace from a coal / limestone supply device (32), and fluidized bed is supplied by air supplied from an air compressor (33). Burn. The generated high-pressure and high-temperature combustion exhaust gas passes through a high-temperature gas pipe (34), is subjected to dust removal by a cyclone separator (35) and a ceramic filter (36), and is then introduced into a gas turbine / generator (37) to drive it. I do. The gas turbine outlet gas passes through a flue (38) and is discharged from a chimney (41) to the atmosphere via a denitration device (39) and an exhaust heat recovery feedwater heater (40). The ash collected by the cyclone separator (35) and the ceramic filter (36) is sent from the ash / gas suction part (15) to the ash treatment device shown in FIG. That is, in this example, as means for collecting and discharging high-pressure and high-temperature ash contained in the combustion gas of the pressurized fluidized-bed boiler (31), a centrifugal cyclone separator (35) for removing coarse particles is provided. A ceramic filter (36) for removing fine particles is used, and the collected ash is cooled by a water-cooled jacket-type screw feeder (51) shown in FIG. 5, and further reduced in pressure by a reduced-pressure hopper (7). It is discharged out of the system via the line (10). Next, FIG. 6 is a view showing another example of a conventional ash processing apparatus. In this example, the ash particles are transported as a gas-particle mixture from the cyclone separator (35), and the pressure is reduced by the bend loss of a special transport conduit (61) that repeatedly changes the flow direction, and at the same time, the transport conduit is cooled by a coolant ( (Combustion air) (62). In FIG. 6,
(63) is a throttle, (64) is a normal pressure cyclone, (65)
Indicates a gas cooler, (66) indicates a bag filter, (67) indicates an ash discharge line, and (68) indicates an air input line. [0007] The pressurized fluidized bed boiler (31) shown in FIG. 4 includes gas turbines (37) and (3).
3) A combined cycle power plant combined with a steam turbine (43). Since a large amount of combustion gas is generated, a plurality of cyclone separators (35) and ceramic filters (36) for collecting ash in the combustion gas are provided. Will be installed. As a means for reducing the temperature of the ash collected by the cyclone separator (35) and the ceramic filter (36), the water-cooled jacket type screw feeder (51) shown in FIG. 5 includes a cyclone separator (35) and a ceramic filter (36). ) Is required for each tower, or one for connecting each tower is required, which makes the system complicated and impractical. Further, the collected ash is fine particles of several μm to several tens of μm, so that it is easily compacted, and the cooling performance of the screw feeder (51) is reduced. Further, in the pressurized fluidized-bed boiler (31), since the combustion air is supplied from the gas turbines (37) and (33) and the pressure of the gas system fluctuates depending on the load, the ash consolidation and the ash consolidation in the screw feeder (51) are performed. Ash flushing is likely to occur. In the ash treatment apparatus shown in FIG. 6, the cooling and decompression of the ash are reduced by the bend loss of a special transport conduit (61) for repeatedly changing the flow direction and the constriction (63) of the conveying pipe. Is cooled by air or coolant, and the flow rate of the carrier gas is not controlled. Therefore, a high-pressure, high-temperature gas, which is a driving source of the gas turbine, is excessively discharged out of the system. SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides a combustion gas of a pressurized fluidized-bed boiler in which coal is used as fuel, limestone is used as a desulfurizing agent, and fluidized-bed combustion is performed under high pressure. An ash collector that collects the ash contained therein, an ash transport pipe that transports the high-temperature, high-pressure ash discharged downward from the ash collector, and an ash cooler that cools the ash in the ash transport pipe And a high-pressure ash storage tank for receiving the ash transported by the ash transport pipe, and means for separating ash from the carrier gas in the high-pressure ash storage tank;
In ash treatment apparatus provided with a pressure reducing device to pull the gas in the high-pressure ash storage tank, the high-pressure ash tank 1 above the ash collecting device relative group, a plurality of sets against the ash conveying pipe and the ash cooler
The above ash can be transported in parallel, and the above ash is stored in the high-pressure ash storage tank.
A decompression device is connected and provided, and the ash collection device has means for stirring high-temperature and high-pressure ash falling and flowing into the ash transport pipe, and the means for stirring is provided at a lower portion of the ash collection device. An ash treatment device for a pressurized fluidized-bed boiler, comprising a stirring nozzle for jetting pressurized air in a horizontal direction orthogonal to a center line, is proposed. In the present invention, a plurality of ash collecting devices, ash transport pipes and ash cooling devices are connected to one high-pressure ash storage tank.
Parallel transportation is possible, and the same high-pressure ash storage tank
The ash is transported by the decompression device provided in the
Although it is equipped with a collecting device, ash transport pipe and ash cooling device,
And the centralization of high-pressure ash storage tanks and decompression equipment
As a body, installation space and equipment costs can be significantly reduced. That is, in general, when powder is conveyed in parallel through a plurality of conduits, the pressure loss also fluctuates with the fluctuation of the concentration, and the flow rate becomes unbalanced, which tends to induce clogging. However, in the present invention, the ash collecting device has means for stirring the high-temperature and high-pressure ash that falls and flows into the ash conveying pipe, and the stirring means is provided at a lower portion of the ash collecting device and perpendicular to its center line. It is composed of a stirring nozzle that blows out pressurized air in the horizontal direction. The ash mass is loosened by ejecting the ash, the ash flowing into the ash transport pipe is quantified, and the ash concentration in the ash transport pipe is stabilized. This will enable parallel transportation as described above.
And high-pressure ash tank and decompression equipment corresponding to the high-pressure ash tank
To reduce the installation space and equipment costs described above.
Can be achieved. FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG.
FIG. 2 is an enlarged longitudinal sectional view showing a lower end portion of the ash collecting device in FIG. 1. In these figures, the same parts as those of the related art described with reference to FIGS. 4 to 6 are denoted by the same reference numerals to avoid redundancy, and detailed description is omitted. Here, as codes newly used, (1a),
(1b) is an ash collector, (2) is an ash transport pipe, (3) is an ash cooler, (4) is a high-pressure ash storage tank, (5) is a filter with a built-in high-pressure ash storage tank, and (6) is a decompression device ( (8) an atmospheric ash hopper, (9) an atmospheric air suction unit, (11) a stirring nozzle, (12) an ash transport pipe mounting seat, and (13) water cooling. Jacket, (14) blind plate, (1
6) cooling water, (17) purge air, (18) filter backwash line, (21) bridge breaker air,
(23) shows ash discharge valves, respectively. First, in general, in this embodiment, a plurality of ash collecting devices (1) such as a cyclone or a filter are used.
An ash cooler (3) having a built-in ash transport pipe (2) is provided between each of the ash collection devices (1) between (a) and (1b) and the high-pressure ash storage tank (4).
a) and (1b). The high-pressure ash storage tank (4) is provided with a built-in filter (5) and a pressure reducing device (6) which is a means for exhausting gas. The exhaust gas is discharged to a gas turbine outlet flue (38), and a heat exchanger (not shown) (exhaust heat recovery feedwater heater (40) in FIG. 4).
Etc.) to perform heat recovery. Below the high pressure ash storage tank (4), a high pressure ash decompression hopper (7) and a normal pressure hopper (8)
After the ash is decompressed to the atmospheric pressure, the ash is pneumatically conveyed to an ash silo (not shown) by a normal pressure ash transfer line (10). As shown in FIG. 2, a stirring nozzle (11) for injecting pressurized air is provided below each of the ash collecting devices (1a) and (1b). That is, in FIG.
In the lower part of the ash collecting device (1a),
Spouts compressed air in a horizontal direction perpendicular to the center line of a)
The stirring nozzle (11) is provided for
The stirring nozzle (11) moves downward from above in the ash collector (1a).
Spouts air without fear of being blocked by ash falling
The ash agitated by the air flow ejected from the agitating nozzle (11) flows into the ash / gas suction unit (15) almost every time, and the ash using the cooling water (16) as a coolant is used. The temperature is reduced while flowing in the ash transport pipe (2) passing through the cooler (3), and transported to the high-pressure ash storage tank (4). The purge air (17) is used for recovery from blockage of the ash transfer pipe (2) and for warming at the time of startup. The gas from which the ash is gravity-separated in the high-pressure ash storage tank (4) is subjected to a filter (5) installed in the upper part of the high-pressure ash storage tank (4) to remove accompanying fine ash, and then to a pressure control valve or the like. Through the pressure reducing device (6) of the gas turbine and the flue (3
8). A backwash line (18) is installed in the filter (5) to enable continuous operation while suppressing an increase in pressure loss. On the other hand, the fine ash and gravity separated ash accumulate on the bottom of the high-pressure ash storage tank (4) and are discharged to the reduced-pressure hopper (7). Further, the pressure inside the reduced-pressure hopper (7) is reduced to atmospheric pressure by a reduced-pressure discharge line (19), then discharged to a normal-pressure ash hopper (8), and sent to an ash silo (not shown) by a normal-pressure ash transport line (10). The decompression hopper (7)
After dispensing the ash, repressurize with pressurized air (20),
Prepare to receive ash from high pressure ash storage tank (4). In the present embodiment, the gas in the high-pressure ash storage tank (4) is continuously exhausted by the pressure reducing device (6) according to the plant load, so that the plurality of ash collecting devices (1) are removed.
An appropriate pressure difference is generated between a) and (1b) and the high-pressure ash storage tank (4), and the high-temperature ash is continuously conveyed and deposited in the high-pressure ash storage tank (4) by the gas flow generated for this purpose. The gas flow rate can be controlled by the decompression device (6), the gas flow rate required for ash conveyance can be minimized, a low-speed and high-concentration ash flow can be realized, and the loss of high-pressure and high-temperature gas can be minimized. . Since the ash having a high concentration is conveyed at a low speed in this manner, wear of the ash conveying pipe (2) is suppressed, and the reliability and durability of the device are improved. In the present embodiment, the ash and gas are cooled during the ash transfer process, and the design temperature of the downstream equipment can be lowered. Therefore, the reliability and durability of the airtight valve (22), the ash discharge valve (23), and the like are reduced. improves. Furthermore, since the dust contained in the high-pressure ash storage tank (4) can be precisely removed by the built-in filter, the durability of the pressure reducing device (6) is also improved. In addition, in the present embodiment, a plurality of ash collecting devices (1a) and (1b) and a plurality of ash transport pipes (2) are connected to one high-pressure ash storage tank (4), so that installation space and space are reduced. Equipment costs can be significantly reduced. Generally, when powder is conveyed in parallel through a plurality of conduits, the pressure loss fluctuates with the fluctuation of the concentration, the flow rate becomes unbalanced, and clogging is likely to occur. In this embodiment, the ash collecting device (1a) is used. ) And (1b), a stir nozzle (11) is installed at the lower part to inject pressurized air, so that ash transport in the ash transport pipe (2) is stabilized, and parallel transport by a plurality of ash transport pipes becomes possible. . That is, for ash falling continuously and in large quantities from the cyclone separator (35) or ash falling intermittently from the ceramic filter (36) at every backwash, the ash collectors (1a) and (1b) are provided. Since the jet of air or the like injected from the stirring nozzle (11) attached to the lower part of the ash serves to loosen the ash mass, the ash falling and flowing into the ash / gas suction part (15) is quantified, and the ash is conveyed. The concentration in the tube (2) stabilizes. In FIG. 3, the horizontal axis represents time, and the vertical axis represents the pressure loss A in the horizontal part and the pressure loss B in the vertical part of the ash transport pipe (2).
FIG. 6 is a diagram showing the change with time in the lower stage (b) when the stirring nozzle (11) is used, and the upper stage (a) shows the stirring nozzle (1).
1) is not used. In this figure, when the stirring nozzle (11) is not used, the pressure losses A and B pulsate greatly due to the concentration change. On the other hand, when the stirring nozzle (11) is used, the ash transfer pipe (2) is used. Since the ash concentration in the parentheses is stable, the horizontal part pressure loss A and the vertical part pressure loss B
It can also be seen that is also much more stable. From the above, it can be said that smoothing of the amount of ash flowing into the ash transport pipe is a point that enables parallel operation. According to the present invention, the high-temperature and high-pressure ash falling and flowing from the ash collecting device into the ash conveying pipe is provided under the ash collecting device.
Than it stirred by the stirring nozzle section, the mass of ash disentangled
Quantified Te, ash transport ash conveying pipe is stabilized, it is possible to parallel transport of a plurality of ash conveying pipe. That is, this
By became possible urchin parallel transport, plural sets of the ash collecting device, high independently for each set of ash conveying pipe and ash cooler
Multiple sets of ash collectors and ash transporters without installing a pressurized ash storage tank
It is connected in parallel flue and ash cooling device to a high pressure ash storage tank of 1 group
It becomes possible. Moreover, this one high pressure ash storage tank
The plurality of sets of ash traps are connected by a pressure reducing device
Conveys ash via collector, ash transfer pipe and ash cooling device
Therefore, each set of the ash collection device, the ash transport pipe and the ash cooling device
There is no need to separately provide a decompression device for each. Therefore, the present invention
According to the ash collection device, ash transport pipe and ash cooling device
High pressure ash storage tank and decompression device
As a result, the installation space and equipment costs of the entire apparatus can be significantly reduced. Also, as described above,
Gas flow required for ash transportation due to ash transportation by device
It is easy to realize low speed and high concentration ash flow by minimizing the amount.
Ash transport pipe etc.
Wear of the equipment is reduced and the reliability and durability of the equipment are improved.
Fruits can be played together. And also said high pressure ash
Ash cooling, which cools the ash in the ash transport pipe, along the path leading to the storage tank
Ash and gas are cooled during the ash transfer process.
This reduces the design temperature of downstream equipment,
Reliability and durability are improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram showing one embodiment of the present invention. FIG. 2 is an enlarged longitudinal sectional view showing a lower end portion of the ash collecting device in FIG. 1; FIG. 3 is a diagram showing an effect of a stirring nozzle in the embodiment. FIG. 4 is an overall configuration diagram showing an example of a conventional combined gas / steam turbine power plant having a pressurized fluidized bed boiler. FIG. 5 is a diagram showing an example of a conventional ash treatment device. FIG. 6 is a diagram showing another example of a conventional ash treatment device. [Description of Signs] (1a), (1b) Ash collection device (2) Ash transport pipe (3) Ash cooler (4) High pressure ash storage tank (5) High pressure ash storage tank built-in filter (6) Decompression device (ash transport) (7) Vacuum hopper (8) Atmospheric pressure ash hopper (9) Atmospheric pressure air suction section (10) Atmospheric pressure ash transport line (11) Stirring nozzle (12) Ash transport pipe mounting seat (13) ) Water cooling jacket (14) Blind plate (15) Ash / gas suction part (16) Cooling water (17) Purge air (18) Filter backwash line (19) Vacuum release line (20) Air for pressurization (21) Bridge breaker Air (22) Airtight valve (23) Ash discharge valve (25) High pressure high temperature combustion gas containing ash (26) High pressure high temperature combustion gas after dust removal (31) Pressurized fluidized bed boiler (32) Coal / limestone supply device (33) ) Air compressor (34) Hot gas pipe (35) Cyclone separator (36) Ceramic filter (37) Gas turbine / generator (38) Gas turbine outlet flue (39) Denitration equipment (40) Waste heat recovery feedwater heater (41) Chimney (43) Steam turbine / generator (44) Condenser (45) Feedwater heater (51) Water-cooled jacket type screw feeder (52) High-pressure ash storage tank (61) Ash transport conduit (62) Combustion air (coolant) (63) Restrictor (64) Cyclone (65) Gas cooler (66) Bag filter (67) Ash discharge line (68) Air inlet line

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Ichiro Amano 1-1-1, Akunouramachi, Nagasaki-shi, Nagasaki Shipyard, Mitsubishi Heavy Industries, Ltd. (56) References JP-A-59-86511 (JP, A) JP-A-57 JP-A-164216 (JP, A) JP-A-63-207906 (JP, A) JP-A-1-310219 (JP, A) JP-A-57-70315 (JP, A) JP-A-5-264013 (JP, A) JP-A-60-238609 (JP, A) JP-A-60-89616 (JP, A) JP-A-3-129201 (JP, A) Fully open sho 59-103031 (JP, U) Really open sho 62- 18512 (JP, U) Shokai Sho 56-52131 (JP, U) Shokai Sho 56-75538 (JP, U) Tokuhyo Hei 3-505777 (JP, A) (58) Fields surveyed (Int. Cl. ⁷ , DB name) F23J 1/02 F23C 11/02 B65G 53/04

Claims (1)

(57) [Claims 1] Ash collection for collecting ash contained in the combustion gas of a pressurized fluidized bed boiler in which fluidized bed combustion is performed under high pressure using coal as fuel and limestone as a desulfurizing agent The apparatus, an ash transport pipe for transporting high-temperature and high-pressure ash discharged downward from the ash collection apparatus, an ash cooler for cooling ash in the ash transport pipe, and an ash transported by the ash transport pipe. A high-pressure ash storage tank for receiving, a means for separating ash from a carrier gas in the high-pressure ash storage tank, and a decompression device for removing gas from the high-pressure ash storage tank; The ash collecting device, the ash transport pipe and the ash cooling device are connected in plural sets.
The above ash can be transported in parallel.
Provided by connecting the device, and the ash collecting device has a means for stirring the ash at high temperature and high pressure to drop or flow into the ash conveying pipe, means for the agitating its center at the bottom of the ash collecting device An ash treatment device for a pressurized fluidized-bed boiler, comprising a stirring nozzle for jetting pressurized air in a horizontal direction orthogonal to a line.