JPS58164914A - Starting method for fluidized-bed combustion apparatus - Google Patents

Abstract

PURPOSE:To start the fluidized-bed combustion apparatus economically without preventing the combustion of a starting cell, to reduce the capacity and number of facilities largely, to lighten the heat-resistant property of an air box and to cut down the manufacturing cost by adjusting the speed of heat exchange by the quantity of air supplied to the small air box of an ignition cell. CONSTITUTION:The air box 2 is formed to the bottom of a main body 1, a fluid bed 4 consisting of silica sand, limestone, ash, etc. is formed on the upper side of the air box 2 through an air dispersing plate 3, and the air box 2 is divided into a plurality of the small air boxes 2a-2e each provided with independent air regulating functions by partition walls 6. A hot stove 7 is installed to the side section of the small air box 2a, and an in-layer burner 8 is mounted to the side section of a small fluidized bed 4a. When the small fluidized bed 4a is used as the starting cell and a small fluidized bed 4b as the ignition cell on operation, a clear boundary 14a on which grains do not move is generated between the small fluidized bed 4a on the small air box 2a and the small fluidized bed 4b on the small air box 2b when the small fluidized bed 4b is supplied with air at the flow rate less than the fluidization starting speed. The upper section of the small fluidized bed 4b is heated by the scattering of the grains of the small fluidized bed 4a, only a section in the vicinity of the surface is fluidized, the small fludized bed 4a and grains are mixed, and the boundary of fluidizing sections is moved slowly to the lower section of the small fluidized bed 4b.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention consists of an air distribution plate, a wind box, and a fluidized bed, each of which is independent of the other. The fluidized bed is divided into multiple small air boxes with an air flow rate adjustment function, and there is a partition wall inside the fluidized bed on the air distribution plate connected to the air box. The present invention relates to a method for starting a combustion device.

In a fluidized bed combustion device, a layer of solid particles made of silica sand, limestone, etc. is placed above the air dispersion plate at the bottom of the device as if it were boiling.
A heat transfer tube is inserted into this solid particle layer, that is, a fluidized bed.It has extremely good combustibility and heat transfer characteristics, and can be used regardless of whether it is dust, solid-liquid, or gas. It has the advantages of being able to burn low-quality fuel, desulfurizing the furnace by adding limestone, and making the equipment more compact.For this reason, efforts are being made to put it into practical use. .

Conventionally, a fuel such as coal, oil, or industrial waste is supplied into a fluidized bed formed by solid particles such as silica sand, sulfur, ash, etc. to perform a combustion reaction, and then inserted into the fluidized bed.
Fluidized bed boilers that recover heat using heat transfer tubes and heat exchangers that utilize the high heat transfer properties of fluidized beds made of solid particles such as catalysts have already been proposed, but these fluidized bed boilers and In a fluidized bed heat exchanger (hereinafter referred to as a fluidized bed combustion device), if the device is larger, the capacity of the auxiliary combustion equipment for startup will be larger, which will increase the cost.
``If the fluidized bed is divided into a plurality of fluidized beds, each small fluidized bed requires combustion equipment for startup, which also raises the problem of increased costs. In order to solve these problems, a method has been proposed in the past in which startup cells are provided to perform split startup, but rapid mixing
When I try to start it up.

darkness.

Fluidized bed misfire 1 - When starting a small heat capacity fluidized bed from a large heat capacity fluidized bed - problems such as impracticability were encountered.

The present invention was developed in view of the above-mentioned points, and since the mixing speed changes depending on the flow state of the large cell, the heat exchange speed is adjusted by the flow rate of air supplied to the small air box of the ignition cell. An object of the present invention is to provide a method that can economically start up a fluidized bed combustion apparatus without inhibiting the combustion of fuel.

That is, one method of the present invention is to supply fluidized air only to a specific divided small air box to form a small fluidized bed only above the specific divided small air box. Heating outside temperature 1 using a starting device such as a single layer inner bar attached to the hot air stove.
．． After that, start up the small fluidized bed with fuel supply 1- to the rated temperature, and use the small fluidized bed that has reached this rating as the initial cell, and start another adjacent small fluidized bed that has already reached the rated temperature. To the small air box adjacent to the small air box of the small fluidized bed containing the starting cell and 1, □,.

Starting a new crab 1. Yo□Uto1. The heat capacity between the small fluidized bed and the small fluidized bed is 11. The heat capacity between the small fluidized bed and the small fluidized bed is The present invention is characterized by raising the temperature of one adjacent small fluidized bed and starting it without inhibiting the combustion of the starting cell while adjusting the amount of exchange.

Hereinafter, the configuration of the present invention will be explained based on the drawings.

FIG. 1 shows an example of a fluidized bed combustion apparatus for carrying out the method of the present invention. Reference numeral 1 designates the main body of the device. A wind box 2 is provided at the bottom of the main body 1 of the device, and an air dispersion plate 3 is installed above the wind box 2.
[2] A fluidized bed 4 made of silica sand, a desulfurizing agent such as limestone, dolomite, ash, etc. is formed, and a heat transfer tube 5 is disposed within this fluidized bed 4, and the wind boxes 2 are separated from each other by a partition wall A. Multiple small wind boxes 2a~2 with independent air conditioning function
It is divided into θ. Although FIG. 1 shows, as an example, a case where the wind box is divided into five pieces, the number is not limited to five pieces, and it may be two or more pieces. These small wind boxes 2
The small fluidized beds above a to 2e are designated as 4a to 4e, respectively. A hot air stove 7 is provided on the side of the small air box 2a, and an in-bed burner 8 is provided on the side of the small fluidized bed 4a. Air supply pipes 12 each equipped with dampers 9b to 94, 10, and 11 are connected to the shrunk small air boxes 2b to 2e and the inner bar 8 of the hot air stove 7. 16 is a forced fan.

A first embodiment of the present invention will be described in a fluidized bed combustion apparatus configured as described above.

In this embodiment, when the small fluidized bed 4b is ignited using one small fluidized bed 4a as the starting cell, the temperature difference between the two-handed fluidized bed 4a=4b is small or the volume of the small fluidized bed 4b which is the ignition cell is small. This is the startup method.

That is, the temperature of the small fluidized bed 4b is high and the small fluidized bed 4a=
4b is completely mixed and the fuel can be ignited at a temperature of -500°C or higher, open the damper 9b and fill the small air box 2b with air at a flow rate higher than the fluidization start speed of the small fluidized bed 4b. Stream 1-1 small fluidized bed 4a=4b are mixed and fuel is supplied to both small fluidized beds 4a-4b. The fuel supply means shown in the figure is G. For example, when coal is supplied, it is dropped from above the fluidized bed.7 Reference numeral 14 in FIG. 1 is the boundary between the fluidized section and the stationary section. The temperature curves of the small fluidized beds 4a and 4b are shown in FIG.

Next, based on FIG. 3, we will discuss the second embodiment of the present invention.
I will explain. In this embodiment, when the small fluidized bed 4a is used as the starting cell and the small fluidized bed 4b is ignited, the two-handed fluidized bed 4a-
4b I7') Start-up method when the temperature difference is large or the ignition cell volume is large. In this case, since the mixing temperature of the small fluidized beds 4a-4b is below the fuel ignition temperature,
The damper 9b is opened intermittently to fluidize the small fluidized bed 4b intermittently, and the small fluidized beds 4a-4b are mixed intermittently for a short period of time, and the bed temperature of the small fluidized bed 4a is adjusted until the small fluidized bed 4a misfires. When the temperature of the small fluidized bed 4a-4b reaches a temperature at which ignition is possible even with complete mixing (1-1), the process is repeated (1-1), and when the constant temperature is reached, the process of the first embodiment is carried out.

4 and 5 show the case of the third embodiment of the present invention 1-. This embodiment is a starting method when the small fluidized bed 48 is used as the starting cell and the small fluidized bed 4b is used as the ignition cell, and the temperature difference between the two fluidized beds is large or the ignition cell volume is large. When air is supplied to the small fluidized bed 4b at a flow rate lower than the fluidization start speed, there is no movement of particles between the small fluidized bed 4a of the small air box 2a and the small fluidized bed 4b above the small air box 2b. A boundary 14a is generated. Due to the scattering of particles in the small fluidized bed 4a, the upper part of the small fluidized bed 4b is heated and becomes fluidized near one surface.The small fluidized bed 4a and the particles are mixed, and the boundary of the fluidized part gradually becomes the lower part of the small fluidized bed 4b. move to. That is, from the boundary 14a to the boundary 1 through the boundary 14b
Move to 4C. Increase the amount of air supplied to the small air box 2b in step b. 1- Fluidize the entire small fluidized bed 4b to supply fuel. 9
A is a damper installed in the air supply pipe to the small air box 2a.

Further, in the fourth embodiment of the present invention, there is a method in which an appropriate amount of fuel is mixed in advance in the 1° ignition cell when carrying out each of the starting methods of the first to third embodiments. . This is particularly effective in the case of the third embodiment. As explained above, according to the method of the present invention.

Wow,,t,,meeeei. □-□Yaka, 1-O, and in cells with and without starting equipment, the required heat resistance of the wind box is reduced, so it is advantageous in terms of structure and has the effect of reducing manufacturing costs. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a fluidized bed combustion apparatus for implementing the method of the present invention; FIG. 2 is a temperature curve diagram of small fluidized beds 4a-4b in the first embodiment of the present invention; The figure is a temperature curve diagram in the second embodiment, FIG. 4 is an explanatory diagram of main parts of the fluidized bed combustion apparatus in the third embodiment, and FIG. 5 is a temperature curve diagram in the third embodiment. 1. Device main body, 2. Wind box + 2a to 2e... Small wind box. 6...Air distribution plate-4...Fluidized bed-4a~4e...Small fluidized bed-5...Heat transfer tube, 6...-Partition wall-7...Hot stove-8...In-bed burner 98~ 9e...Damper-10
-11... Damper -12... Air supply pipe -16.
- Push-in fan. 1114a, 14b-, j 4Q ... Boundary patent applicant Tsukiichi Saki Heavy Industries Co., Ltd. Figure 2 Figure 5 Opening Figure 4 Figure 5 Figure 68-

Claims (1)

[Claims] 1 With a wind box at the bottom 1-1 A fluidized bed is formed above this wind box through an air distribution plate 1-1, heat transfer tubes are placed in this fluidized bed, and each wind box is made independent. When starting up a fluidized bed combustion equipment consisting of 5 (divided into multiple small air boxes with air flow rate adjustment function) 1. - Supply fluidizing air only to the divided small wind boxes of Tokuyu 1. After forming a small fluidized bed only above the divided small air box of the special electricity and raising the temperature using a starting device such as a hot blast furnace or an in-bed burner attached to this small air box,
Supply fuel 1- to start up to the rated temperature, use the small fluidized bed as a starting cell when the rated temperature is reached, and use it as a starting cell to start another adjacent small fluidized bed when the rated temperature has already been reached 1-. The heat capacity ratio, wetness difference, mutual cross-sectional area, and new start-up cell between the small wind box adjacent to the small wind box of the small fluidized bed that is currently in use, and the small fluidized bed that is about to be started up again. Adjust the amount of heat exchange between one small fluidized bed by supplying fluidizing air at an appropriate flow rate according to the fluidized bed volume ratio of the cell, etc.1. 1. A method for starting a fluidized bed combustion apparatus, characterized in that, at the same time, one adjacent new small fluidized bed is heated and started without inhibiting combustion in the starting cell.