JPH06265135A - Air supply tube for fluidized-bed boiler - Google Patents

Abstract

PURPOSE:To facilitate piping of a flue around a boiler and to simplify a boiler housing by sufficiently shortening the length of a channel of an air duct of an inlet of each wind box. CONSTITUTION:A secondary air duct 1 is extended to be formed in parallel direction of cells along a wind box 36. The dust 1 is so axially partitioned to a plurality of channels 2 by a partition plate 3 that sectional areas of the channels 2 become equal. The channels 2 respectively feed the air to wind box inlet air ducts 7. Each channel 2 has an airtight damper 6 provided heretofore for each duct 7 to supply and stop the air, a control damper 4 for regulating an air flow rate, and a flowmeter 5 for detecting a flow rate of the air.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention can sufficiently reduce the flow path length of each wind box inlet air passage, and thus the piping of the air passage around the boiler can be facilitated and the boiler building can be made compact. Blast tube for fluidized bed boiler.

[0002]

2. Description of the Related Art In a large fluidized bed boiler such as a commercial boiler, one bed is divided into a plurality of cells (generally about 8 to 10 cells) to perform slumping load control. In this slumping load control, the wind box is partitioned into cells so that the total amount of coal and the amount of air in each cell can be adjusted for each cell, and each operating cell is started and stopped according to the load demand. ing.

An example of such a blower tube for a fluidized bed boiler is shown in FIG. FIG. 3 is a plan view showing an example of the arrangement of a ventilation pipe for a fluidized bed boiler used in a conventional fluidized bed boiler used for thermal power generation. Referring to the figure, the wind box 36 arranged at the lower part of the fluidized bed of a fluidized bed boiler (not shown) is partitioned by the partition plate 32 into cells. Reference numeral 35 is a hot air stove that supplies hot air to a startup cell (not shown), and 8 is a hot air duct for starting air that is blown to the hot air oven 35. An airtight damper 11 for supplying and stopping air to and from the hot-air stove 35 for starting and stopping the operation of an unillustrated start-up cell in the hot air passage 8 for start-up, and the amount of air supplied to the hot-air stove 35 are adjusted. The control damper 4 and the flow meter 10 for detecting the amount of air flowing through the hot air passage 8 for startup are provided.

Reference numeral 1 denotes a secondary air passage through which the air supplied to the wind box 36 circulates, which is formed along the wind box 36 so as to extend in the parallel direction of the cells. From this secondary air passage 1, air is distributed and supplied to each cell via a wind box inlet air passage 7. Further, in order to adjust the air amount of each cell for each cell, an airtight damper 6 that supplies and stops the supply of air and a control damper 4 that adjusts the air amount for each wind box inlet air passage 7.
And a flow meter 5 for detecting the amount of air flowing through the wind box inlet wind passage 1. When these are provided in the wind box inlet wind passage 7, a straight portion of the wind box inlet wind passage 7 is required before and after the flow meter 5, and for example,
For a 350 MW class fluidized bed boiler for thermal power generation, 15 m or more is required.

[0005]

However, in the fluidized bed boiler, in order to keep the superficial velocity low, the boiler cross section is larger than that of the pulverized coal burning boiler, and the wind box inlet air passage 7 is provided as described above. Since it has to be formed relatively long, it becomes difficult to arrange the secondary air passage 1 and the wind box inlet air passage 7, and the spacing between the pillars 41 and 42 of the boiler building 40 that houses the fluidized bed boiler must be large. However, the boiler building 40 becomes large in size, which is difficult to apply to a large capacity boiler.

On the other hand, for example, in Japanese Unexamined Patent Publication No. 2-36738, a flow path downstream of a venturi meter for measuring the total air volume installed in the flow path of a duct is equally divided into a plurality of stages by a horizontal partition plate. , A pair of throats are arranged opposite to each other on the inner side surfaces of each of the equally divided flows to form a Bencheri meter for partial air volume measurement, and the equally divided flow paths are connected to burners that communicate with the respective burners. Of combustion air supply ducts are shown. Further, a damper for adjusting the air volume provided in each of the divided flow paths is also shown.

According to this structure, the flow passages that are adjacent to each other on the left and right with the vertical partition plate can share the Venturi meter for measuring the partial air volume, the total number can be halved, and the entire duct can be made compact. It may be possible to say that it will be possible to some extent to alleviate the restrictions on the equipment layout around the boiler, but the flow path downstream of the venturi meter for measuring the total air flow installed in the flow path of the duct is the flow bed boiler If it is a wind box inlet air passage, the wind box inlet air passage must still be formed to be relatively long, and the fluidized bed boiler must be installed in each wind box inlet to start and stop the operation of each cell. Since air supply means such as an airtight damper for supplying and stopping air to the wind passage is also necessary, in order to shorten the wind box inlet wind passage, Arrangement Cal air supply means also need to be considered.

The present invention is for a fluidized bed boiler, in which the flow path length of each wind box inlet air passage can be sufficiently shortened, so that the air passage around the boiler can be easily piped and the boiler building can be made compact. The purpose is to provide a blower pipe.

[0009]

Means for Solving the Problems The gist of the present invention for achieving such an object is to arrange a windbox in parallel with each other along the windbox of a fluidized-bed boiler for partitioning and slamping load control of each cell. A secondary air passage through which air to be supplied to the wind box that is formed to extend, and a plurality of wind box inlet air passages that distribute and supply the air flowing through the secondary air passage to each of the cells are provided. In a blower pipe for a fluidized bed boiler, the secondary air passage is divided into a plurality of flow passages in the axial direction of the air passage, and each of the flow passages blows air to the wind box inlet air passage, Air supply means for supplying and stopping air to and from the wind box inlet air passages for starting and stopping the operation of each cell, and air to be supplied to the wind box inlet air passages. There is an air quantity adjusting means for adjusting the air quantity detecting means and an air quantity detecting means for detecting the quantity of air flowing in the air passage in the air flow pipe for a fluidized bed boiler, which is provided for each of the flow paths. .

[0010]

According to such means, the secondary air passage has a sufficient length because it is formed so as to extend in the parallel direction of the cells along the wind box. Therefore, the secondary air passage is divided into a plurality of flow passages in the axial direction of the air passage, and each of the flow passages is configured to blow air to each wind box inlet air passage, and each flow passage has an air supply means and an air By providing the amount adjusting means and the air amount detecting means, the secondary air passage will have the role of the conventional wind box inlet air passage, and the air supply means, the air amount adjusting means, the air It is not necessary to provide a quantity detecting means, and the flow path length of the wind box inlet wind passage can be sufficiently shortened.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing a blast pipe for a fluidized bed boiler used in a fluidized bed boiler for thermal power generation according to an embodiment of the present invention, and FIG. 2 is a side view of the same. Since the members having the same reference numerals as those in FIG. 3 are the same members as the conventional blower pipes for fluidized bed boilers described with reference to FIG.

An in-layer heat transfer tube 34 is provided in the fluidized bed 30 of the fluidized bed boiler 37, and a wind box 36 for supplying combustion air is provided in the lower portion of the fluidized bed 30 by the partition plate 32 for each cell. Is divided into eight. In this partitioned wind box 36, from the secondary wind passage 1,
Each for combustion through the wind box inlet wind passage 7,
Fluidizing air is supplied.

It is necessary to supply hot air to the starting cell 15 of the fluidized bed boiler 37, and the starting combustion air is supplied from the starting hot air passage 8 to the hot stove 35. If the fluidized bed boiler 37 of the 350 MW class is a huge one with an outer diameter of 3 m and a length of 7 m, the arrangement of the hot air duct 8 for starting is also restricted. Therefore, the secondary air duct 1 and the hot air stove 35 are separately arranged on both sides of the fluidized bed boiler 37.

The secondary air passage 1 is formed along the wind box 36 so as to extend in the parallel direction of the cells. The inside of the secondary air passage 1 is divided into a plurality of flow passages 2 in the axial direction by a partition plate 3 so that the cross-sectional areas of the respective flow passages 2 are equally divided.
The respective flow paths 2 blow air to the respective wind box inlet air passages 7. Each wind box inlet air passage 7 is formed to have the same cross-sectional area as the cross-sectional area of each flow path 2, and except for the portion corresponding to the starting cell 33, it is divided into seven cells of the partitioned wind box 36. Guide the air from the secondary wind passage 1.

An airtight damper 6 for supplying and stopping the air, which has been conventionally provided for each wind box inlet 7 in each flow path 2, a control damper 4 for adjusting the amount of air, and an air flow rate are detected. And a flow meter 5 for each.

Next, the operation of the fluidized-bed boiler blow tube according to this embodiment will be described. The secondary wind passage 1 has a sufficient length because it is formed so as to extend in the parallel direction of the cells along the wind box 36. Therefore, as described above, the secondary air passage 1 is divided into a plurality of flow passages 2 in the axial direction of the air passage 1,
If each flow path 2 is configured to send air to each wind box inlet air passage 7, and each flow path 2 is provided with an airtight damper 6, a control damper 4, and a flow meter 5, the secondary air passage 1 will be With the role of the wind box inlet air passage, it is no longer necessary to provide the airtight damper 6, the control damper 5, and the flow meter 5 in the wind box inlet air passage 7.
The wind box inlet air passage 7 only needs to have a function of supplying the air from the secondary air passage 1 to each cell, and the wind box inlet air passage 7 can be shortened. Thereby, the interval between the pillars 41 and 42 of the boiler building 40 is, for example,
In the 350 MW class fluidized bed boiler for thermal power generation, it was possible to reduce the length to 5.5 m, which is about one half of the conventional one.

[0017]

As described above, according to the present invention, as described above, the wind box inlet air passage can be made sufficiently short, so that the air passage around the boiler can be easily piped and the boiler building can be made compact. be able to.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of an arrangement of a ventilation pipe for a fluidized bed boiler according to an embodiment of the present invention.

FIG. 2 is a side view showing an example of the arrangement of the ventilation pipes for a fluidized bed boiler according to an embodiment of the present invention.

FIG. 3 is a plan view showing an example of a conventional arrangement of a blower tube for a fluidized bed boiler.

[Explanation of symbols]

 1 Secondary wind passage 2 Flow path 3 Partition plate 4 Control damper 5 Flow meter 6 Airtight damper 7 Wind box Inlet wind passage 36 Wind box

Claims (1)

[Claims] 1. A windbox is partitioned for each cell, and the air supplied to the windbox is formed along the windbox of the fluidized bed boiler for controlling the slumping load and extending in the parallel direction of the cells. In a blower pipe for a fluidized bed boiler, which comprises a secondary air duct and a plurality of wind box inlet air ducts that distribute and supply the air circulating in the secondary air duct for each cell, the secondary air duct is It is divided into a plurality of flow passages in the axial direction of the wind passage, and each of the flow passages sends air to the wind box inlet wind passage,
Air supply means for supplying and stopping supply of air to the wind box inlet air passages for starting and stopping the operation of the cells, and air amount adjustment for adjusting the amount of air supplied to the wind box inlet air passages. A blower tube for a fluidized bed boiler, characterized in that the means and the air amount detecting means for detecting the amount of air flowing in the air passage are provided in each flow path for each flow path.