JP2702636B2 - Garbage incineration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a waste heat recovery boiler for exhaust gas from an incinerator having a secondary combustion chamber, and a steam supply passage for supplying generated steam from the waste heat recovery boiler to a steam turbine for power generation. The present invention relates to a refuse incineration apparatus provided with a heat exchange section of a combustion type superheater in a steam supply path.

[0002]

2. Description of the Related Art In a steam cycle having such a superheat process, in addition to waste heat recovered by a waste heat recovery boiler, heat is given to steam by a combustion type superheater to generate higher temperature superheated steam. It has been proposed to achieve high power generation efficiency by supplying power to a power generation steam turbine. That is, the heat exchange part of the combustion type superheater is provided in the steam supply path of the waste heat recovery boiler, and the steam is reheated in this part. Conventionally, the flue gas after the heat exchange has been directly discharged into the atmosphere and discarded. On the other hand, in this type of refuse incinerator, a secondary combustion chamber is provided on the lower side of the primary combustion chamber, and complete combustion of unburned gas is achieved in this portion. In this secondary combustion chamber,
Conventionally, ambient temperature air has been supplied as it is as secondary air.

[0003]

However, in an incinerator as an example of such a garbage incinerator, the municipal garbage to be charged has various contents, and there is no municipal garbage which is easily burnable or hardly burnable. Discrimination is mixed. Furthermore, the amount of municipal garbage to be processed per unit time varies. Therefore, the combustion temperature in the furnace will vary considerably, and according to the change in the combustion temperature,
The temperature of the secondary combustion chamber also changes, and a complete combustion state in this portion is not ensured. If the combustion temperature decreases, dioxin, CO, and the like may be directly discharged to the exhaust path side. When the atmosphere is supplied as secondary air to the secondary combustion chamber in such a state, the temperature of the secondary combustion air is relatively low, so that the combustion temperature is guided to a lower side and a predetermined complete combustion state is stabilized. There was a problem with maintaining. Therefore, an object of the present invention is to maintain the combustion in the secondary combustion chamber in a stable and complete combustion state, and to minimize the amount of pollutants contained in the exhaust gas discharged. To obtain a garbage incinerator capable of performing the above.

[0004]

The refuse incinerator according to the present invention for achieving this object is characterized in that the combustion exhaust gas generated in the superheater burner of the combustion type superheater is produced by increasing the oxygen concentration of the combustion exhaust gas. A first secondary air supply passage leading to the secondary combustion chamber via the heat exchange unit; and a second secondary air supply passage leading directly to the secondary combustion chamber without passing through the heat exchange unit. The configuration is such that the ratio of the amount of secondary air supplied from each of the second secondary air supply paths can be changed.

[0005]

That is, this refuse incinerator is configured to guide the combustion exhaust gas of the combustion type superheater to the secondary combustion chamber through the first secondary air supply path and the second secondary air supply path. here,
The air supplied from the first secondary air supply passage is at a relatively low temperature due to the heat exchange section (however, considerably higher than room temperature), and that from the second secondary air supply passage is relatively hot. It has become something. And the supply ratio of these secondary air is made variable. As a result, it is possible to appropriately supply the secondary air to the secondary combustion chamber by changing the ratio of the secondary air having different temperatures supplied from these two systems according to the combustion state in the secondary combustion chamber. In addition, the combustion state of the secondary combustion chamber can be favorably maintained. Accordingly, it is possible to maintain a stable complete combustion state and suppress the generation of pollutants and the like.

[0006]

According to the present invention, a refuse incinerator capable of maintaining the combustion state of the secondary combustion chamber in a complete combustion state by effectively utilizing the combustion exhaust gas from the combustion type superheater which has been discharged directly into the atmosphere. Could be provided. Therefore, in the garbage incinerator, since generation of unburned gas can be prevented, generation of carbon monoxide and dioxin can be suppressed,
Further, the amount of generated dust can be suppressed.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a refuse incinerator according to the present invention will be described with reference to the drawings. As shown in FIG. 1, 450 t / d
A stoker-type incinerator 1 for incineration of municipal garbage, an exhaust gas treatment device 2 for treating 11.4 × 10 ⁴ Nm ³ / h of exhaust gas generated from the incinerator 1, and heat of the exhaust gas A garbage incinerator is constituted by the power generator 3 that generates electric power.

The incinerator 1 has a receiving hopper 4 for receiving an object to be treated as municipal waste and a stoker 5 for transporting the object to be treated received from the receiving hopper 4 in the furnace main body, and the receiving hopper 4 is provided. A burner 6 for assisting and igniting is provided on the wall surface opposite to the side, so that the objects to be processed received from the receiving hopper 4 are sequentially transferred, and are burned while being dried. In order to complete the combustion of the unburned gas, a secondary combustion chamber 7 is formed in the upper space,
A secondary combustion air supply unit 8 for supplying a total amount of secondary air of about 400 ° C. and about 1000 ° C. of about 2.0 × 10 ⁴ Nm ³ / h is provided facing the secondary combustion chamber 7. On the downstream side of the next combustion chamber 7, a waste heat recovery boiler 9 for recovering a part of the heat amount of the combustion exhaust gas is provided.

The exhaust gas treatment device 2 has a flue gas passage 10 whose exhaust gas inlet is connected to the downstream side of the waste heat recovery boiler 9, and a chimney 11 of the flue gas passage 10.
, A bag filter 12, a smoke washing device 13, a white smoke prevention device 14, and the like are arranged.

The power generating device 3 includes a power generating steam turbine 15.
And a generator 16 driven thereby, and a steam supply path 17 for supplying 310 ° C. steam generated from the waste heat recovery boiler 9 to the power generation steam turbine 15. In the middle of the steam supply path 17, the waste heat recovery boiler 9
Is provided with a heat exchange section 19 of a combustion type superheater 18 for raising the temperature of 310 ° C. steam generated from the steam to 500 ° C.
The combustion type superheater 18 is provided with a superheat burner section 20 for burning fuel. The heat exchange section 19 described above is provided downstream of the superheat burner section 20. Further, the flow path is the same as that described above. It is connected to the secondary combustion air supply section 8. This flow path is referred to as a first secondary air supply path 21. on the other hand,
A second secondary air supply passage 22 is provided that is directly connected to the secondary combustion air supply unit 8 without passing through the heat exchange unit 19 from the superheat burner unit 20. A control device 23 is provided for changing the ratio of the respective secondary air supplied from the first secondary air supply passage 21 and the second secondary air supply passage 22 depending on the temperature of the secondary combustion chamber 7. When the temperature is low, the supply of the secondary air from the second secondary air supply passage 22 is increased, and when the temperature is low, the supply of the secondary air is increased so that the supply ratio from the first secondary air supply passage 21 is increased. Is adjusted. Here, the combustion type superheater 18 maintains the air ratio at 2,
Combustion with high oxygen concentration. This overheating burner part 2
At 0, exhaust gas of 1000 ° C. or higher is obtained, and the temperature of the secondary air that has passed through the heat exchange section 19 is reduced to about 400 ° C. The total amount of secondary air is 2.0 × 1
0 ⁴ Nm ³ / h is led to the secondary combustion chamber 7. The secondary combustion chamber 7 is maintained at about 1000 ° C. by the operation of supplying the secondary air, thereby preventing the generation of dioxin, CO, and the like.

Next, the state downstream of the steam turbine 15 will be described.
Is heated to 300 ° C. by heat exchange with the exhaust gas of the incinerator 1 and supplied to the waste heat recovery boiler 9. That is, a heat exchange pipe 24 passing through the flue gas passage 10 of the incinerator 1 is provided, and a part of the steam is also taken in from the intermediate stage of the turbine 15.
The steam pressure water is heated.

On the other hand, regarding the exhaust gas generated from the furnace,
Heat is applied to the waste heat recovery boiler 9 to reach 300 ° C., and is discharged from the chimney 11 to the atmosphere via the bag filter 12, the smoke washer 13, and the white smoke prevention device 14.

In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a garbage incinerator according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 incinerator 7 secondary combustion chamber 9 waste heat recovery boiler 15 steam turbine 17 steam supply path 18 combustion type superheater 19 heat exchanger 20 superheater burner section 21 first secondary air supply path 22 second secondary air supply path

Claims (1)

(57) [Claims] An incinerator (1) having a secondary combustion chamber (7)
A waste heat recovery boiler (9) for exhaust gas from the steam generator; a steam supply path (17) for supplying generated steam from the waste heat recovery boiler (9) to a power generation steam turbine (15); 17) A refuse incinerator provided with a heat exchange section (19) of a combustion type superheater (18) in the combustion exhaust gas generated in a superheating burner section (20) of the combustion type superheater (18). In the state where the pressure is raised, the first gas is guided to the secondary combustion chamber (7) through the heat exchange section (19).
A secondary air supply path (21); a second secondary air supply path (22) for directly leading to the secondary combustion chamber (7) without passing through the heat exchange section (19); And a garbage incinerator configured to change the ratio of the amount of secondary air supplied from each of the second secondary air supply paths (21) and (22).