JPS58148304A - Marine fluidized bed boiler - Google Patents

Abstract

PURPOSE:To stabilize a combustibility and a thermal conductivity, and to maintain uniform characteristics in a boiler, by forming a uniformly fluidized bed area even if the boiler is tilted due to the oscillation of a ship, by fluidizing unfluidized medium in the bed, by providing fluidizing air diffuser pipes to the part of a combustion chamber where an unfluidized bed is liable to be formed or in its vicinity. CONSTITUTION:Air diffuser pipes 6 are disposed near the confronting side-walls which are in parallel with the longitudinal direction of a ship. A part of fluidizing air feed pipe to feeds the fluidizing air into a wind box is branched off and is connected to air diffuser pipes 6 from an air diffuser pipes header 7 by the intermediary of stop valves 8. The air diffuser pipes 6 having air diffuser ports 9 are arranged along the confronting side-walls of a combustion chamber 1 in the transverse direction of a ship, so as to be covered with a fluidized bed. Conditions are repeated by changed from/to (A) and (B) in the combustion chamber 1 if the ship is rolled when the fluidizing air is fed into the fluidized bed from the wind box to burn combustible substance such as coal, a heat transfer pipe 5 is heated, and heat-exchange is taken place. At that time, the stop valves 8 and 8' for air diffuser pipes 6 are opened, the fluidizing air is injected from the air diffuser ports 9 to fluidize the medium, in order to prevent the fluidized medium from forming an unfluidized part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a fluidized bed boiler that is tilted and oscillated when used for ships, etc., in which the entire fluidized bed boiler is fixed in a part of the fluidized bed. This invention relates to a fixed bed prevention device that actively fluidizes the bed and attempts to maintain uniform combustion characteristics and heat transfer characteristics within the fluidized bed regardless of tilting or agitation.

In a fluidized bed boiler, a combustion chamber is filled with a fluidized medium made of inert granular material such as sand, and fluidizing air is injected into the combustion chamber from the bottom of the M combustion chamber, so that the fluidized medium is heated as if the liquid were boiling. Coal or other combustible material is supplied into the fluidized bed formation area and burned, and the generated heat is transferred to heat exchanger tubes placed within the fluidized bed formation area. Heat is exchanged and a fluid is passed through the heat transfer tube to generate hot fluid or steam.

In this type of boiler, it is important to uniformly fluidize the fluidized medium in order to maintain good combustion characteristics, heat transfer coefficient, and stable boiler load factor.

However, for example, in a fluidized bed boiler mounted on a ship, that is, a fluidized bed boiler that involves tilting and shaking of the ship, there are parts in the combustion chamber fluidized bed where the fluidization of the fluidized medium is inhibited.
Immediately, a fixed layer is generated, which adversely affects combustion characteristics, heat transfer, boiler load factor, etc.

Therefore, the present invention is concerned with the generation of the fixed layer.

Alternatively, by arranging a fluidizing diffuser pipe near it, the fluidized medium in the fixed bed is fluidized, and even when the boiler is tilted or shaken, a uniform fluidized bed region is formed, improving combustion characteristics and heat transfer. The aim is to stabilize the boiler rate and maintain uniform boiler characteristics.

Embodiments of the present invention will be described below with reference to the drawings.

For example, when installing a fluidized bed boiler as a marine boiler, the fluidized bed moves from the state shown in Figure 1 to the state 8 as the ship rolls, and changes to the state shown in Figure 1 A or B at intervals of 10 to 20 seconds, for example. becomes.

1 is the combustion chamber of the fluidized bed boiler, 2 is the fluidized bed, 3 is the wind box,
Fluidizing air is blown up from below the fluidized bed to fluidize and agitate the fluidized medium, such as sand and fuel. There is heat transfer in the fluidized bed 2! F5 is installed to exchange heat with the water in the heat transfer tube.

The fluidized bed 2 forms a fixed bed 4, which is a non-fluidized portion, due to the inclination of the fluidized bed boiler as the ship moves. The air supplied from the wind box 3 to the bottom of the fluidized bed moves straight upwards and has the effect of lifting this fluidized medium, but when the fluidized bed boiler is shaken, the air that is supplied to the bottom of the fluidized bed moves straight up, but when the fluidized bed boiler is shaken, the air that is supplied to the bottom of the fluidized bed moves directly to the bottom of the fluidized bed. This is unfavorable in terms of boiler characteristics. To deal with this situation, in the present invention, the air diffuser 6 is disposed near opposing enclosure walls parallel to the bow and stern of the ship. A part of the flowing air pipe sent to the wind box is branched to the diffuser pipe 6 and connected to the diffuser pipe 6 via the stop valve 8 from the diffuser header 7. Diffuse! 6 has an air diffuser port 9 as shown in FIG. Diffuser pipe 6
are arranged along the surrounding walls of the combustion chambers 1 that face each other in the left and right chord directions of the ship, and are hidden within the fluidized bed.

Therefore, when the ship lists to starboard, the starboard stop valve 8 opens and the port stop valve 8'' closes, and when the ship lists to port, the port stop valve 8' opens and the starboard side stops. If an inclined opening/closing device is provided so that the stop valve 8 is closed, the operation becomes extremely difficult.

Next, the operation of the present invention will be explained. Heat transfer using a fluidized bed boiler as a marine boiler! ! 5 to generate steam for the main engine or auxiliary engine.

That is, when fluidizing air is supplied from the wind box to the fluidized bed to burn combustible materials such as coal, heat the heat transfer tubes 5, and perform heat exchange, if the ship is shaken, the phenomena shown in Figure 1 A and B will be repeated. becomes. In this case, aeration 9 is used to prevent the formation of fixed layer 4.
When the 16 stop valves 8.8' are opened, fluidizing air is ejected from the aeration port 9 against the fixed bed 4, causing the fluidizing medium to flow. The stop valve 8.8' is an automatic stop valve that automatically opens and closes depending on the tilt, and when the fluidized bed boiler tilts to starboard, only the stop valve 8 on the starboard side opens, and the stop valve 8' on the port side closes. Flowing air is supplied to the fixed bed 4 generated in the starboard direction, so that no fixed bed is formed. Also, if the ship lists to port, the port side stop valve 8' opens, and the starboard side stop valve 8' opens.
is blocked, and fluidizing air is sent to the fixed layer 4 that occurs near the wall of the combustion chamber in the port direction, so that fixation (2) does not occur. Even if the surface of the fluidized bed on the side where the stop valve is closed drops due to the movement of the ship and the diffuser pipe 6 is exposed from the flow (2), no air is diffused, so no fluidizing air is wasted.

As described above, the present invention provides a fluidized bed boiler for a ship, etc. with a diffuser pipe having a diffuser port for supplying fluidizing air to the side wall in the inclined direction. The fluidizing air does not flow through the fluidizing medium along the side walls in the inclined direction when air is fed, and a fixed layer is formed. However, the present invention eliminates this problem and reduces the amount of time required. Flowing air is supplied from the diffuser port on the side wall surface in the diagonal direction.) 1. Tilt, oscillation, and so on.
The combustion characteristics, heat transfer coefficient, boiler load, etc. of the bed boiler do not deteriorate. In addition, the air supplied to the diffuser pipe is controlled by a stop valve, and the stop valve is configured such that the stop valve for the diffuser pipe on the side wall in the inclined direction opens and the stop valve for the diffuser pipe on the opposite side closes. By using this method, there is no waste of fluidizing air, there is no fixed bed in the fluidized bed, and there is no deterioration in boiler characteristics due to tilting or oscillation.

[Brief explanation of the drawings] Figure 1 shows fluidized bed boilers A, B, and 2 in a tilted state.
m! FIG. 2 is a cross-sectional view of a fluidized bed boiler for explaining the present invention, and FIG. 3 is a perspective view of parts applied to the present invention. 1...Fluidized bed boiler, 2...Fluidized bed, 3...
III. 4...Fixed layer, 5...Heat transfer tube, 6...Aeration pipe, 7...Aeration pipe header, 8.8'...Stop valve, 9...Aeration port. (A) 1 Bait 211 False (B) , 7--- Value 311

Claims (2)

[Claims] (1) A fluidized bed boiler for a ship or the like, which is provided with a diffuser pipe having a diffuser port for supplying fluidized air along the inside of opposing surrounding walls parallel to the bow and aft direction. (2) A fluidized bed boiler for a ship or the like as set forth in claim 1, wherein an automatic stop valve is connected to the diffuser pipe to set #11WI by inclination.