JPS5933801B2 - fluidized bed boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluidized bed boiler that can prevent burnout of a superheater and/or reheater at the time of starting the boiler.

BACKGROUND ART Fluidized bed boilers that use heavy oil, coal, etc. as fuel have already been proposed.

The temperature inside the fluidized bed of this fluidized bed boiler is usually 800 to 90.
Although the temperature is 0℃, if a superheater or (and) reheater is installed in the fluidized bed, the superheater or (and) reheater will be empty for a certain period of time after the boiler starts. However, boiler tubes commonly used in the past would burn out. In order to prevent this burnout, auxiliary steam must be injected into the superheater and/or reheater in advance when starting the boiler, or materials that can withstand high temperatures must be used for the boiler tube. However, these methods have the disadvantage of complicating the boiler system and increasing costs. The present invention has been made to solve the above-mentioned drawbacks, and includes a partition wall provided in the fluidized bed combustion chamber to divide the chamber into a plurality of small fluidized bed combustion chambers, and an evaporator, superheater or By installing a reheater and configuring it so that each small fluidized bed combustion chamber can be operated and adjusted independently, when the boiler is started, the fluidized bed in the evaporator system is operated first, and when self-steam is generated, the fluidized bed is operated first. The purpose is to provide a fluidized bed boiler in which the superheater or (and) reheater system is operated in a fluidized bed, so that no special consideration is required for the superheater or (and) reheater. be.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below based on embodiments shown in the drawings. In FIG. 1, 1 is a boiler main body, and a partition wall 3 is provided in a fluidized bed combustion chamber having a fluidized bed 2 in the boiler main body parallel or almost parallel to the combustion gas flow to form two fluidized bed combustion chambers. The combustion chamber is divided into small fluidized bed combustion chambers 4 and 5. In this case, the partition wall 3 may partition only the fluidized bed, but it is preferable that the partition wall 3 partitions down to the bottom of the distributor 6 as shown in the figure. An evaporator T made of a boiler tube is installed in one small fluidized bed combustion chamber 4, and a superheater 8 made of a boiler tube is placed in the other small fluidized bed combustion chamber 5. An economizer 11 with a boiler water supply pipe 10 connected to one end is installed in the upper part of the boiler body 1. This economizer 1
The outlet of drum 1 is connected to a drum (or steam/water separator) 12, the lower part of this drum 12 is connected to the lower end of evaporator T via a circulation pump 13, and the upper end of this evaporator □ is connected to drum 1
Connected to 2. The upper end of the drum 12 is connected to the lower end of the superheater 8, and the upper end of the superheater 8 is connected to the steam outlet pipe 14. In the boiler body 1 below the distributor 6,
Combustion air supply ducts 15 and 16 are independently connected to the small fluidized bed combustion chambers 4 and 5, respectively. 17,18
20 is an air conditioning damper, and 20 is a combustion exhaust gas outlet.

Although not shown in the figure, combustion burners are installed in the lower portions of the small fluidized bed combustion chambers 4 and 5, respectively. In the fluidized bed boiler configured as described above, when starting the boiler, firstly, air is supplied only to one combustion air supply tag port 5, and while adjusting the amount of combustion air, the air is supplied to the small fluidized bed combustion chamber of the evaporator system. 4 independently. After the boiler feed water is heated by the economizer 11, it passes through the drum 12, the circulation pump 13, and the evaporator 7, and then enters the drum 12 again. When steam is generated in the drum, air is also supplied to the other combustion air supply tag port 6, and the small fluidized bed combustion chamber 5 of the superheater system is activated while adjusting the amount of fuel. drum 12
The steam therein is superheated in the superheater 8 and sent out from the steam outlet pipe 14 as turbine steam or process steam. The fuel is combusted in the fluidized bed 2, and the combustion exhaust gas is discharged from the combustion exhaust gas outlet 20 after heating the boiler feed water.
Next, another embodiment of the present invention will be described based on FIG.

This embodiment is a case of a fluidized bed boiler having a reheater, and there are partition walls 21 and 2 at two locations in the fluidized bed combustion chamber in the boiler body 1.
2 is provided, and the fluidized bed combustion chamber is divided into three small fluidized bed combustion chambers 23.
, 24, 25, each small fluidized bed combustion chamber 23
, 24, 25 include an evaporator 26, a superheater 27, and a reheater 28.
evaporator system when starting the boiler. , then the superheater system, and then the reheater system, which can be operated and adjusted in sequence at different timings. The other configurations are the same as in the previous embodiment.
As explained above, in the fluidized bed boiler of the present invention, a partition wall is provided in the fluidized bed combustion chamber, and an evaporator, superheater, or reheater is installed inside each partition, and the combustion chamber of each partition is separated. Since it is configured to be able to start, stop, or adjust the amount of fuel independently, and to operate by staggering the start timing of the combustion chamber for each partition, it is different from conventional fluidized bed boilers. It is possible to prevent the superheater or (and) reheater from running dry when the boiler is started.
and) there is no need to inject auxiliary steam into the reheater;
It also has the effect of eliminating the need to use expensive heat-resistant materials for the boiler tube.

[Brief explanation of the drawing]

Fig. 1 is a schematic system diagram showing one embodiment of the fluidized bed boiler of the present invention, and Fig. 2 shows another embodiment of the fluidized bed boiler of the present invention, in which a reheater is installed in the fluidized bed combustion chamber. This is a schematic diagram of the system when added/installed. 1...Boiler body, 2...Fluidized bed, 3
......Partition wall, 4,5...Small fluidized bed combustion chamber, 6...Distributor, 7...
・Evaporator, 8... Superheater, 10... Boiler water supply pipe, 11... Economizer, 12...
...Drum, 13...Circulation pump, 14.
... Steam outlet pipe, 15, 16 ... Combustion air supply duct, 17, 18 ... Air conditioning damper, 20 ... Combustion exhaust gas outlet, 21 ,22・
...Partition wall, 23, 24, 25...Small fluidized bed combustion chamber, 26...Evaporator, 27...
・Superheater, 28...Reheater.

Claims (1)

[Claims] 1 A partition wall is provided in the fluidized bed combustion chamber to divide it into a plurality of small fluidized bed combustion chambers, and an evaporator,
A fluidized bed boiler characterized by installing a superheater or a reheater so that each small fluidized bed combustion chamber can be operated and adjusted independently.