JPS6026241Y2 - Structure of bulkhead heat transfer surface of fluidized bed boiler - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a bulkhead heat transfer surface structure for a fluidized bed boiler having a main combustion chamber and a pre-carphone combustion chamber.

A fluidized bed boiler uses silica sand above the air distribution plate at the bottom of the furnace.
A solid particle layer is formed from limestone etc. in a state as if it were boiling.This solid particle layer, in other words a fluidized bed, is made by inserting wood pipes into it, and has extremely good combustibility and heat transfer properties. It has the advantages of being able to burn low-quality fuels, whether liquid or gas, desulfurizing the furnace by adding limestone, and making the boiler more compact.For this reason, research is currently being carried out to put it into practical use. be.

Conventionally, in order to efficiently combust unburned carbon generated in a fluidized bed boiler, a fluidized bed boiler has a structure in which a partition is provided in the combustion chamber (foury board section) to divide it into a main combustion chamber and an unburned carbon combustion chamber. has already been proposed, but in order to have a structure that can withstand the pressure caused by the difference in pressure inside the furnace between the main combustion chamber and the unburned carbon combustion chamber, it is made of molded steel, etc., in the same way as the walls of the water-cooled pipes around the combustion chamber. It is necessary to provide a pack stay for reinforcement.

Furthermore, unlike the water-cooled pipe walls surrounding the combustion chamber, both sides of this partition wall are exposed to high-temperature combustion gas, so the pack steel used for this partition wall must be made of expensive materials such as heat-resistant alloys, which is costly. There is a problem in that it increases.

As mentioned above, in the fluidized bed section of a fluidized bed boiler, high wind pressure is applied to the surrounding walls (furnace bottom, side walls), and therefore it is necessary to reinforce the surrounding walls.

The object of the present invention is to prevent the partition wall, which is difficult to reinforce, from being deformed when a high wind pressure (1000 to 200 o7ra1tAq) is applied in the lateral direction.

The present invention was developed in view of the above points, and the partition wall is formed by a water-cooled pipe wall formed by arranging a large number of wooden pipes, and two pipes are arranged perpendicularly or almost perpendicularly to the water-cooled pipe wall. By connecting the above-mentioned reinforcing water pipes through fins or directly in multiple stages, the main combustion chamber and the unburnt carbon combustion chamber can be connected to each other by providing sufficient rigidity to the bulkhead without installing a pack stay. The purpose of the present invention is to provide a bulkhead heat transfer surface structure that can withstand the force caused by the difference in pressure within the furnace.

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

FIG. 1 shows an example of a fluidized bed boiler having a partition wall heat transfer surface structure according to the present invention.

Reference numeral 1 denotes an air distribution plate provided at the bottom of the furnace, and water-cooled pipe walls 2 and 3 each having a large number of wood pipes arranged in a vertical direction are provided on the inside surface of the furnace from the side to the upper side of this air distribution plate 1. A fluidized bed 4 made of silica sand and/or limestone is placed above the air distribution plate 1.
is formed.

A partition wall 6 formed by vertically arranging a large number of water pipes 5 is provided in the combustion chamber (freeboard section) above the fluidized bed 4 to divide it into a main combustion chamber 7 and an unburned carphone combustion chamber 8. There is.

As shown in FIG. 2, this partition wall 6 is formed of a water-cooled pipe wall formed by arranging a large number of water pipes 5 in a line in the vertical direction and connecting them with fins 10, and is oriented perpendicularly or approximately to the water-cooled pipe wall. It is formed by connecting two or more reinforcing water pipes 11 in a right angle direction.

The reinforcing water pipe 11 may be made to protrude toward the main combustion chamber 7 side, or may be made to protrude toward the unburned carphone combustion chamber 8 side.

This reinforcing water pipe may be constructed by connecting the wood pipes 11 with fins 12, as shown in FIG. 3, or by connecting the finned wood pipes 13 so that their fins are in contact with each other, as shown in FIG. Furthermore, as shown in FIG. 5, the woodwinds 11 may be directly connected to each other by welding or the like.

In FIG. 1, 14 and 15 are wind boxes, 16 and 17 are air inlets, 18 is an evaporation pipe installed in the fluidized bed of the main combustion chamber,
20 is a superheated steam pipe installed in the flue above the main combustion chamber;
1 is a slag remover installed on the upper part of the partition wall 6 that divides the flue above the main combustion chamber into two, 22 is a preheating pipe installed in the flue downstream of the slag remover, and 23 is a combustion chamber in the main combustion chamber. The exhaust gas outlet 24 is a combustion exhaust gas outlet of the unburned carbon combustion chamber.

The combustion exhaust gas discharged from the combustion exhaust gas outlet 23 of the main combustion chamber is introduced into a dust separator (not shown) such as a multi-cyclone to separate unburned carbon, and this unburnt carbon is transferred to the unburned carbon combustion chamber. 8 and incinerated at high temperature.

Since combustion of unburned carbon requires a high temperature, an evaporation tube or the like is usually not provided in the fluidized bed of the unburned carbon combustion chamber 8.

Although not shown, the water cooling pipe wall 2 around the combustion chamber,
The outer surface of No. 3 is covered with a heat insulating material and an exterior material.

Since the bulkhead heat transfer surface structure of the present invention is constructed as described above, two or more wood pipes can be connected through fins or Sufficient strength can be given to the partition wall by connecting and reinforcing directly connected wood pipes in multiple stages.Moreover, since the reinforcing material is made by connecting wood pipes together through fins or directly, the transmission strength increases accordingly. This has the effect of increasing the thermal area.

[Brief explanation of the drawing]

FIG. 1 is an explanatory elevational view showing an example of a fluidized bed boiler having a partition wall heat transfer surface structure of the present invention, FIG. 2 is a plan sectional view showing an embodiment of the partition wall heat transfer surface structure of the present invention, and FIG. Figures 5 to 5 are cross-sectional views showing an example of a reinforcing water pipe. 1...Air distribution plate, 2, 3...Water cooling pipe wall, 4...Fluidized bed, 5...Water pipe, 6.
...Bulkhead, 7...Main combustion chamber, 8...
...Unburned carbon combustion chamber, 10...Fin, 1
1... Reinforcement water pipe, 12... Fin,
13...Finned woodwind, 14,15...
・Wind box, 18... Evaporation pipe, 20... Superheated steam pipe, 22... Preheating pipe, 23.24...
...Combustion exhaust gas outlet.

Claims (1)

[Scope of utility model registration request] An air distribution plate is provided at the bottom of the furnace, a fluidized bed is formed above the air distribution plate, and a partition is provided in the combustion chamber above the fluidized bed to divide it into a main combustion chamber and an unburned carbon combustion chamber. In a fluidized bed, the partition wall is formed by a water-cooled pipe wall formed by arranging a large number of wooden pipes, and two or more reinforcing water pipes are finned in a direction perpendicular or almost perpendicular to the water-cooled pipe wall. A partition wall heat transfer surface structure for a fluidized bed boiler, characterized in that it is formed by connecting multiple stages through or directly.