JP2740095B2 - Garbage incineration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION In recent years, in order to effectively use the heat energy generated in a refuse incinerator, a generator that generates heat by exchanging heat contained in exhaust gas generated from the incinerator with a waste heat boiler has been developed. Municipal garbage incinerators equipped have been attracting attention.
The present invention provides an incinerator provided with a drying zone for drying while transporting dust by a stoker-type transport unit, a combustion zone for burning while transporting the dried dust, and waste gas generated in the incinerator. A waste heat boiler that generates steam by recovering heat, a power generation device that drives a turbine with the generated steam to generate power, and a combustion type that overheats steam in a road to a steam supply path from the waste heat boiler to the power generation device The present invention relates to a garbage incinerator equipped with a superheater.

[0002]

2. Description of the Related Art The above-mentioned combustion type superheater is used to improve the power generation efficiency by superheating steam generated in a waste heat boiler. The quality of the garbage fluctuates drastically due to the
The combustion state in the combustion chamber fluctuates and the generated steam amount usually fluctuates, and when the generated steam amount in the waste heat boiler decreases,
In the combustion type superheater, the amount of insufficient steam is supplemented by water spray, and when the amount of generated steam increases, the amount of steam generated is limited by limiting the input steam to the turbine, and the amount of steam is discharged from the combustion type superheater. It has been considered that complete combustion is promoted by supplying a high-temperature exhaust gas having a high residual oxygen concentration as a secondary combustion gas to the incinerator. In addition, when the garbage quality is high and contains a large amount of water, the combustion in the combustion zone is promoted by using an auxiliary burner used at the time of ignition, or high-temperature outside air heat-exchanged with steam generated by the waste heat boiler is used as primary combustion air. Had supplied.

[0003]

However, when the above-described auxiliary burner is used, the fuel for the auxiliary burner is further required, which is not economical. When heat is exchanged with the exhaust gas passing through the waste heat boiler, Since the temperature of the exhaust gas decreases accordingly, there is a disadvantage that it becomes difficult to preheat the water supplied from the steam turbine and cooled water. An object of the present invention is to solve the above-mentioned conventional drawbacks and to make effective use of the heat energy of the exhaust gas of the combustion type superheater to immediately reduce the amount of steam generated when the incinerator waste is deteriorated. It is an object of the present invention to provide a garbage incinerator having a specific measure.

[0004]

In order to achieve this object, a characteristic structure of a refuse incinerator according to the present invention is to provide a heat exchanger using exhaust gas from the combustion type superheater as a heat source, and to use the heat exchanger. Providing a combustion air supply path that supplies the superheated air as the primary combustion air to the drying zone or the combustion zone, and the supply amount of the heated air supplied to the drying zone or the combustion zone, The point is that an adjusting means for adjusting according to the combustion state in the incinerator is provided.

[0005]

By using a heat exchanger utilizing the heat energy of the exhaust gas from the combustion type superheater, the heated air is supplied as primary combustion air of the incinerator through a combustion air supply passage. Prevent lowering of combustion temperature in furnace. At this time, when the quality of the refuse is extremely deteriorated and the amount of generated steam is greatly reduced, the control means is operated to supply the heated air to the combustion zone, so that the combustion state in the furnace is rapidly increased. Otherwise, by operating the adjusting means and supplying the heated air to the drying zone, it is possible to avoid abnormal high-temperature combustion in the combustion zone and obtain a stable combustion state. It promotes the drying of garbage in the garbage.

[0006]

According to the present invention, a quick-acting measure for avoiding a decrease in the amount of steam generated when the quality of refuse in an incinerator is deteriorated by effectively utilizing the heat energy of the exhaust gas of the combustion type superheater. It has become possible to provide a garbage incinerator having the following.

[0007]

Embodiments will be described below. Garbage incineration equipment
As shown in FIG. 1, a stoker-type incinerator 1 for incineration of municipal garbage, an exhaust gas treatment device 2 for purifying exhaust gas generated from the incinerator 1, and a power generation device 3 for generating electricity using heat of the exhaust gas And so on.

The incinerator 1 includes a hopper 4 for receiving an incinerated material, a pusher Pu for injecting municipal garbage, which is an incinerated material in the hopper 4, from a lower end into the incinerator, and an incinerator input by the pusher Pu. A stoker S including a drying zone S1 for drying, a combustion zone S2 for burning, and a post-combustion zone S3 for ashing is provided while stirring and transporting the material, and the stoker S is used to complete the combustion of the unburned gas. A secondary combustion space 7 is formed in the upper space, and a secondary combustion air supply unit 9 for supplying secondary combustion air to the space 7 is provided facing the space 7, and a secondary combustion air supply unit 9 is provided downstream of the space 7. In space 8,
A waste heat boiler 6 for recovering the thermal energy of the combustion exhaust gas is provided.

The exhaust gas treatment device 2 comprises a bag filter 12, a smoke washing device 13 and the like provided in the middle of a flow path from an exhaust gas passage 10 provided downstream of the space 8 to a chimney 11.

The power generator 3 comprises a steam turbine 14 and a generator 15 connected to its output shaft.
About 100 kgf / c generated from the waste heat boiler 6
High-pressure steam of m ² , 310 ° C. is led to a combustion type superheater 17 via a steam supply line 16 which is a main steam path, and after being superheated to about 500 ° C. by the combustion type superheater 17, is supplied to the steam turbine 14. I do. The steam supplied to the steam turbine 14 and used for generating all the energy is cooled by a cooler 18 through an exhaust path 14c and collected, and the waste heat boiler 6
Circulated through a condensate channel 25 circulating through A part of the steam supplied to the steam turbine 14 is extracted from the extraction passages 14 a and 14 b after a part of the energy is supplied to the power generation, and is supplied to the feed water preheater 19 provided in the condensate passage 25.
It is led to.

A branch 20 is provided in the steam supply path 16, and a pressure reducing mechanism 20a comprising a pressure reducing valve for reducing a part of the steam generated in the waste heat boiler 6 to 40 kgf / cm ² is provided in the branch 20. , An accumulator A for accumulating depressurized steam, an air passage 21 for venting the steam from the accumulator A, and a bleed passage 14 a for the turbine 14.
And are connected.

In the waste heat boiler 6, not only does the steam amount of several percent fluctuate frequently in a cycle of several seconds, but also,
When the incineration condition in the incinerator 1 is good (flammable garbage is stably supplied), the amount of steam generated in the waste heat boiler 6 increases as a whole, and the incineration condition deteriorates (moisture content). (A large amount of unburnable refuse is supplied), the amount of steam generated in the waste heat boiler 6 is reduced as a whole, and the steam amount fluctuates by several tens of percent due to a period of tens of minutes. Therefore, when surplus steam is generated in response to a change in the steam amount of several tens percent due to a period of tens of minutes, the surplus steam is adjusted by adjusting the flow control valve 22 provided in the steam supply path 16 to the accumulator. If the generated steam is insufficient in the waste heat boiler 6, the accumulation of the steam in the accumulator A is stopped, and the extraction amount adjusting valve 23 provided in the extraction passage 14 a of the turbine 14 is operated. The amount of heat supplied to the turbine 14 is squeezed to effectively use the power for power generation, and the ventilation amount adjustment valve 24 provided in the ventilation path 21 is opened to release the steam (24 kgf / cm ² ) accumulated in the accumulator A. The air is supplied to the bleed passage 14a.

The combustion type superheater 17 includes a gas burner 17
a from the combustion flow of the fuel gas supplied from
d, which superheats the steam from the waste heat boiler 6 passing therethrough. A water spraying mechanism 17f for adjusting the steam flow rate is provided, and one of the exhaust gas is used as a cooling gas to protect the side wall of the heat exchange section. The portion is circulated and supplied through a cooling circuit 17c provided with a flow rate adjusting damper 17e, and the remaining exhaust gas is supplied as secondary combustion air of the incinerator 1 through a combustion air supply channel 30. By branching the combustion air supply passage 30 and guiding a part of the exhaust gas to the heat exchanger 31, the room temperature air is heated to about 250 ° C. and supplied as combustion air to the combustion type superheater 17. A combustion air supply path 32 is provided to increase the combustion efficiency of the combustion type superheater 17 and supply a part of the air heated by the heat exchanger 31 as primary combustion air of the incinerator 1.

The combustion air supply path 32 is provided with a damper 33 for adjusting the flow rate. The damper 33 is provided based on the value of a steam amount sensor 17b provided at the inlet of the steam to the combustion type superheater 17. Control means 34 is provided for controlling the opening degree of 33 so as to promptly avoid deterioration of the combustion state in the combustion zone S2 and stabilize the combustion state.
In other words, when the decrease in the amount of generated steam is detected by the steam amount sensor 17b, it is determined that the quality of the dust is reduced or the combustion state is deteriorated due to the reduced amount of the dust, and the opening of the damper 33 for adjusting the flow rate is largely adjusted. In addition, the supply amount of dust is increased by transport control means (not shown), the amount of fuel supplied to the gas burner 17a is increased in the combustion type superheater 17, and the variable steam amount is corrected and stabilized by water spray, When the increase in the generated steam amount is detected by the steam amount sensor 17b, it is determined that the combustion state is good, and the opening degree of the damper 33 for adjusting the flow rate is maintained or adjusted to a small value, and the flow rate to the gas burner 17a is controlled. Aim for low fuel consumption combustion by reducing supply fuel by supplying high-temperature combustion air.

Further, the combustion air supply passage 32 includes:
A damper 35 for adjusting the supply amount of the primary combustion air to the drying zone S1 or the combustion zone S2 is provided, and the control unit 34 sets the steam flow rate based on the value of the steam amount sensor 17b. If you judge that it is less than the amount,
By operating the damper 35 in synchronization with the damper 33 and supplying it mainly to the combustion zone S2, deterioration of the combustion state in the combustion zone S2 is quickly avoided, otherwise the drying zone It is mainly supplied to S1 and is controlled so that the combustion state is stabilized by stabilizing the waste. That is, the control means 34, the damper 35, and the steam amount sensor 17b constitute an adjusting means.

Although the case where a part of the air heated by the heat exchanger 31 is used as the primary combustion air of the incinerator 1 has been described, in this case, in addition to the above-described primary combustion air,
The primary combustion air at normal temperature is supplied to the drying zone S1, the combustion zone S2,
A supply path 35 for supplying each to the post-combustion zone S3 is provided.

Another embodiment will be described below. The damper 3
5 is operated to switch only to either the drying zone S1 or the combustion zone S2, the supply amount of the heated air supplied to the drying zone S1 and the combustion zone S2 is changed to the steam amount. The adjustment may be made based on the value of the sensor 17b. Further, although the detection of the combustion state of the incinerator 1 is described by providing a flow rate detection sensor for detecting the amount of steam generated in the waste heat boiler 6 and making a determination based on the value, the present invention is not limited to this. Instead, a temperature sensor for detecting the furnace temperature may be provided, and the determination may be made based on the value.

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 a schematic configuration diagram of a garbage incinerator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Incinerator 3 Power generator 6 Waste heat boiler 14 Turbine 16 Steam supply path 17 Combustion type superheater 31 Heat exchanger 32 Combustion air supply path C control means S1 Drying zone S2 Combustion zone

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-55-56514 (JP, A) JP-A-54-35422 (JP, A) JP-A-59-180212 (JP, A) JP-A-2- 115610 (JP, A) JP-A-52-106045 (JP, A)

Claims (1)

(57) [Claims] An incinerator (1) having a drying zone (S1) for drying while transporting dust by a stalker type transport means, and a combustion zone (S2) for burning while transporting the dried dust. A waste heat boiler (6) for recovering waste heat from exhaust gas generated in the incinerator (1) and generating steam, and a power generating device (3) for generating electricity by driving a turbine (14) using the generated steam. A refuse incinerator comprising a combustion type superheater (17) for superheating steam in a steam supply path (16) from the waste heat boiler (6) to the power generation device (3), wherein the combustion type superheating is provided. A heat exchanger (31) using exhaust gas from the heat exchanger (17) as a heat source, and using the air superheated by the heat exchanger (31) as primary combustion air in the drying zone (S1) or the combustion zone. Providing a combustion air supply path (32) to be supplied to (S2); Together, the drying zone (S1)
Alternatively, a refuse incinerator provided with an adjusting means (C) for adjusting the supply amount of the heated air supplied to the combustion zone (S2) according to the combustion state in the incinerator (1).