JPS609521Y2 - Fluidized bed boiler equipment - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fluidized bed boiler device, and in particular to a boiler structure that improves thermal efficiency and reduces the accumulation of ash.

The fluidized bed has good combustion efficiency and has a high ash content (for example, ash content of 5
(0% or more) It is also possible to burn fuel with a low calorific value.

However, in the case of a fluidized bed boiler that recovers the heat generated in the fluidized bed, the generation of a large amount of ash has the problem of reducing the thermal efficiency of the boiler.

In other words, as a result of the fluidized bed's good combustion efficiency, when using fuel with a low calorific value, combustion can be sustained when the bed temperature is below the melting temperature of ash (e.g. 8°C to 900'C). Therefore, a large amount of the generated ash will be scattered along with the combustion gas.

FIG. 1 shows an example of a conventional fluidized bed boiler, in which a heat recovery section IIa consisting of evaporative water pipes 8 is arranged above a combustion chamber Ia having a fluidized bed 1.

In this type of boiler, the flow rate of the combustion gas G is slow and the heat transfer coefficient is poor, so the evaporative water pipe 8 is provided with fins in order to widen the heat transfer area.

However, by attaching these fins, the ash content in the combustion gas adheres, and as a result, the heat transfer coefficient hardly increases.

FIG. 2 shows another boiler device in which a heat recovery section nb is arranged next to a combustion chamber Ib formed by a water-cooled pipe 3 to ensure a combustion gas flow rate.

This combustion device uses high-temperature combustion gas G generated in the combustion chamber Ib.
flows into the evaporative wood pipe 8 side by the baffle plate 9a,
Furthermore, another baffle plate 9 formed inside the evaporative wood pipe 8
The structure is such that heat exchange is performed by passing through a space formed in the direction of b.

This combustion device has a baffle plate that stands upright, so only a small amount of ash adheres, but the combustion gas G flows parallel to the evaporation water pipe 8, resulting in poor thermal efficiency, and a heat recovery section is also installed next to the combustion chamber. This has the disadvantage of increasing the size of the device.

The purpose of this invention is to eliminate the above-mentioned drawbacks of the prior art, and to provide a fluidized bed boiler device that has good thermal efficiency, does not cause ash accumulation, and is compact.

In short, this idea supports the steam drum of the heat recovery section by a combustion chamber composed of water-cooled walls, fixes this heat recovery section at an angle to the combustion chamber, and then attaches the heat recovery section at an angle to the horizontal. Regarding the structure of a fluidized bed boiler with baffle plates installed so that

Examples of this invention will be described below with reference to the drawings.

In FIG. 3, the combustion chamber Ic formed by the water-cooled wall 3
supports the steam drum 6 of the heat recovery section IIc.

On the other hand, the water barrel 7 disposed at the lower part via the evaporative water pipe 8 is disposed outside the combustion chamber Ic, and the heat recovery section Inc as a whole is installed at an angle with respect to the combustion chamber Ic.

Reference numeral 10 denotes a connecting pipe that connects this water barrel 7 and the lower header 4 for the intralayer heat exchanger tubes 2.

Next, the combustion chamber Ic and the evaporative water pipe 8 of the heat recovery section IIc are partially separated by a partition wall 15.

Also, for the evaporative water pipe 8, there are multiple sheets (the one shown is two sheets).
The baffle plate 9C is installed so as to be substantially perpendicular to the evaporation water pipe 8.

In the above apparatus, the air A that has flowed into the wind box 11 fluidizes the fluidized bed 1 that has flowed into the combustion chamber Ic via the air distribution plate 5, and burns the incinerated material.

The heat in the bed is recovered by the bed transfer pipe 2 while the fluidized bed 1
The combustion gas G that has exited the steam drum 6 flows into the evaporating wood pipe group of the heat recovery section 2C through the opening between the partition wall 15 and the steam drum 6.

Here, the combustion gas G flows through the baffle plate 9C almost perpendicularly to each evaporative water pipe 8 to exchange heat.
Finally, it is discharged from the flue 14 to the outside of the device.

At this time, ash adheres to the baffle plate 9c, but since the baffle plate 9c is installed obliquely with respect to the horizontal ground surface, the ash gradually falls and is discharged to the outside by the ash hopper 13 provided at the bottom. Ru.

Furthermore, in this embodiment, the baffle plate is disposed perpendicular to the evaporator wood pipe, so that the combustion gas flows almost perpendicularly to the evaporator wood pipe, thereby improving heat transfer.

According to this invention, there is almost no adhesion of ash from the incinerated materials, and the adhering ash can easily fall off and be removed because the baffle plate is arranged diagonally to the ground surface.

In addition, since the heat recovery section is arranged diagonally with respect to the combustion chamber, the device can be made smaller, and even in the steam drum, heat can be recovered from the radiant heat of the combustion chamber and the flow of combustion gas, resulting in good thermal efficiency.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a conventional fluidized bed boiler, FIG. 2 is a side sectional view of another type of conventional fluidized bed boiler, and FIG. 3 is a side sectional view of a fluidized bed boiler according to this invention. Ia, Ib, Ic=combustion chamber, IIa,
I[b, IIC...Heat recovery section, 1...
・Fluidized bed, 3... Water cooling wall, 6... Steam drum, 7... Water barrel, 8... Evaporation water pipe, 9a, 9b, 9c. ...Baffle plate.

Claims (1)

[Scope of utility model registration request] In a boiler device consisting of a combustion chamber with a fluidized bed and a heat recovery section composed of a steam drum, a water barrel, and an evaporator wood tube, the heat recovery section is arranged diagonally with respect to the combustion chamber by supporting the steam drum in the combustion chamber. A fluidized bed boiler device in which the heat recovery section is provided with one or more baffle plates that are diagonal to the horizontal.