JPH0861015A - Refuse power generating system - Google Patents

Abstract

PURPOSE: To provide an economical refuse power generating system by effectively utilizing the energy sustained substantially by refuse itself. CONSTITUTION: A refuse power generating system comprises a waste heat boiler 2 set in a refuse incinerator 1, a combustion type superheater 3 to superheat the steam generated in the waste heat boiler 2, and a power generator 4 to generate power by the superheated steam from the combustion type superheater 3. Also it is provided with a fermenting device 5 to generate fermentation gas with a main component of hydrocarbon from semi-fluid organic matter such as dust, sludge, etc. Then a desulfurizing device 4 to remove sulfate from the fermentation gas produced in the fermenting device 5 is installed to supply the fermentation gas passed through the desulfurizing device 4 as a fuel for a combustion type superheater.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses a waste heat boiler installed in a refuse incinerator, a fermentation tank for fermenting organic matter with methane, and methane produced from this fermentation tank, and steam produced by the waste heat boiler. The present invention relates to a waste power generation system including a combustion type superheater that superheats a fuel and a power generation device that generates electric power with superheated steam by the combustion type superheater.

[0002]

2. Description of the Related Art In recent years, attention has been paid to a garbage power generation system that effectively uses heat generated in a garbage incinerator to generate electricity. However, sulfides (sulfur oxides) and chlorination contained in exhaust gas from the garbage incinerator are attracting attention. In order to prevent high temperature corrosion of heat exchange parts such as heat transfer tubes due to substances (hydrogen chloride, etc.), the steam generated by the waste heat boiler cannot be superheated to a high temperature. Therefore, conventionally, in order to raise the steam temperature and improve power generation efficiency, a combustion type superheater using city gas as a supply fuel is provided outside the refuse incinerator, and the waste heat is used by using the combustion type superheater. The steam produced in the boiler was overheating.

On the other hand, water-containing organic matter such as sewage sludge is dehydrated by a dehydrator separate from the municipal waste incinerator, or dried by a dryer utilizing the waste heat of the incinerator, and then an incinerator for sludge or the like. Had been incinerated at.

[0004]

However, in the conventional waste power generation system, if the steam temperature is raised in order to raise the power generation efficiency, a separate fossil fuel must be used for the combustion type superheater, There was an economic problem that the power generation cost was high, and there was room for further improvement in terms of effectively utilizing the energy originally possessed by the waste itself.

An object of the present invention is to provide a waste power generation system which is rich in economic efficiency by converting the energy originally possessed by the waste itself into exergy and utilizing it.

[0006]

To achieve this object, a garbage power generation system according to the present invention is characterized in that it is a fermentation apparatus for producing a fermentation gas containing hydrocarbon as a main component from water-containing organic matter such as kitchen waste or sludge. And a desulfurization device for removing sulfides from the fermentation gas generated by the fermentation device,
The fermentation gas that has passed through the desulfurizer is supplied as fuel for the combustion type superheater.

Further, in the above structure, a steam flow path for guiding at least a part of hot water or steam generated at 60 ° C. or higher generated from the refuse incinerator to the fermentation apparatus is formed so as to supply a heat quantity for fermentation. There is a point that is configured.

[0008]

In other words, organic substances in a water-containing state such as kitchen waste or sludge originally have hydrocarbon as a main component, and these are treated by microorganisms (methane bacteria, etc.) in a fermenter using a high temperature method, for example. When decomposed using a biochemical reaction, a fermentation gas containing methane as a main component is obtained. Fermentation gas produced by the fermenter, which removes sulfur as a component that corrodes metals etc. in a desulfurizer, can be used as a fuel for the combustion type superheater to reduce the risk of corrosion and use the heater at high temperature. You can do it.

Further, 60 generated in the refuse incinerator
By forming a steam flow path for guiding hot water or steam at a temperature of not less than 0 ° C. to the fermentation device, the surplus heat released to the atmosphere can be effectively used as heat retention heat for fermentation in the fermentation device.

[0010]

As described above, according to the present invention, it is possible to provide a highly economical garbage power generation system by making the energy originally possessed by the garbage itself into exergy and effectively utilizing it. .

[0011]

EXAMPLES Examples will be described below. As shown in FIG. 1, the waste power generation system includes a waste heat boiler 2 installed in a waste incinerator 1, a combustion type superheater 3 that superheats steam generated in the waste heat boiler 2, and the combustion type superheater. 3 is provided with a power generation device 4 for generating electric power with superheated steam, and a fermentation device 5 for generating a fermentation gas containing hydrocarbons as a main component from a water-containing organic substance such as garbage or sludge, and the fermentation device 5 A desulfurization device 6 for removing sulfides from the fermentation gas is provided, and the fermentation gas passing through the desulfurization device 6 is supplied as fuel for the combustion type superheater 3.

The refuse incinerator 1 is an urban refuse incinerator having an incineration zone 1a for drying, burning, and post-burning while transporting dust by a stoker mechanism, and a flue 1b reaching a space above the combustion zone. The waste heat boiler 2 is installed on the downstream side of the. Since the exhaust gas of the refuse incinerator 1 contains corrosive gases such as chlorides and sulfides, the waste heat boiler 2 has a temperature of 800 ° C. to 950 ° C. from the viewpoint of high temperature corrosion prevention. Then, the steam can be heated to about 300 ° C.

Therefore, a combustion type superheater 3 is provided outside the refuse incinerator 1, and the steam generated in the waste heat boiler 2 is heated to, for example, 500 ° C. and supplied to the power generator 4. .

As shown in FIGS. 1 and 2, the fermenter 5 inputs kitchen waste, sludge or the like, or a water-containing organic substance composed of these into a fermentation tank 5a covered with a heat insulating material from an input port 5c above. Then, it decomposes using biochemical reaction by microorganisms in a tank adjusted to a temperature of about 60 ° C to 52 ° C to generate hydrocarbon gas containing methane as a main component.
In order to circulate methane gas, carbon dioxide gas, etc. generated in the fermentation tank 5a for stirring in the tank using the blower fan mechanism 5b etc., sludge etc. after fermentation is discharged from the lower discharge port. Configured.

The generated gas is subjected to removal of sulfides (hydrogen sulfide, etc.) by a well-known wet or dry desulfurization device 6, and a clean heat amount of about 5500 kcal / Nm ³ consisting of about 60% methane and 40% carbon dioxide. The fuel is generated, the clean fuel is supplied from the burner 3a of the combustion type superheater 3 and burned, and the sludge and the like after fermentation are dehydrated and then incinerated by the garbage incinerator 1 and the like. The desulfurization device may be omitted if the sulfide concentration in the fermentation gas is low.

The power generator 4 is composed of a steam turbine 4a and a generator 4b, and a part of the steam supplied to the steam turbine 4a is formed around the fermentation tank 5a and in an inflow path. A steam flow path 7 leading to the heat pipes 5d and 10 is provided so as to supply heat and heat retention to the above-mentioned optimum temperature for fermentation of about 50 ° C to 52 ° C. That is, the calorific value of the steam after being used for power generation is reused to secure a predetermined fermentation temperature in the fermentation tank 5a and then returned to the waste heat boiler 2.

Another embodiment will be described below. The structure of the fermenter is not limited to the above-mentioned one, but can be appropriately constituted. For example, in order to agitate the contents (sludge, etc.) in the fermentation tank, the above-mentioned air flow circulation method of circulating the generated gas from below to above is used, and the contents themselves are taken out from below the fermentation tank using a pump. It may be configured so as to inject from above. The desulfurization device is not particularly limited and can be appropriately configured by using a known mechanism. The exhaust gas of the combustion type superheater 3 is the flue 1b which is the secondary combustion region of the refuse incinerator.
And is used for stable production of steam by the waste heat boiler 2 while promoting secondary combustion. Also,
Garbage is not limited to municipal waste, and may be broadly considered as flammable waste or flammable coal. Further, the fermentation residue such as sludge generated from the fermentation tank is incinerated together with garbage in the incinerator after reducing water content such as dehydration.

Although the stoker type incinerator is used as the refuse incinerator 1 in the above description, other types such as a fluidized bed type incinerator can be used.

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 drawings]

FIG. 1 is a schematic configuration diagram of a garbage power generation system.

FIG. 2 is a configuration diagram of a main part.

[Explanation of symbols]

 1 Waste Incinerator 2 Waste Heat Boiler 3 Combustion Type Superheater 4 Power Generation Device 5 Fermentation Device 6 Desulfurization Device 8 Condenser 9 Economizer 10 Heat Exchanger

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F23G 5/00 ZAB Z

Claims (2)

[Claims] 1. A waste heat boiler (2) installed in a refuse incinerator (1), a combustion type superheater (3) for heating steam generated in the waste heat boiler (2), and the combustion type superheater. Bowl (3)
A waste power generation system comprising a power generation device (4) for generating electric power with superheated steam by means of a fermentation device for generating a fermentation gas containing hydrocarbon as a main component from organic matter having a large amount of water such as garbage or sludge ( 5) and a desulfurization device (6) for removing sulfides from the fermentation gas generated in the fermentation device (5) are provided, and the fermentation gas passed through the desulfurization device (6) is used in the combustion type superheater ( Waste power generation system that supplies as fuel of 3). 2. A steam flow path (7) for guiding a part of the steam supplied to the power generator (4) or the steam from the waste heat boiler (2) to the fermentation device (5) is provided. A structure for supplying a quantity of heat for the fermentation device (5).
The refuse power generation system described.