JPH10141016A - Waste power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce dioxine by forming a high temperature flue in a multiplex pipe structure to guide high temperature combustion gas generated by a combustor as a heat source for an superheater to the superheater so that a turbine can be driven with steam superheated by an superheating system to superheat steam generated by an incineration system for power generation. SOLUTION: Wastes are incinerated by an incinerator 1 and obtained combustion gas 2 is supplied as oxidizing agent for a combustor 5. Dioxine contained in the combustion gas 2 is decomposed while staying in a high temperature atmosphere (at about 800 deg.C) for a certain time (about one second) when passing through the combustor 5 and a high temperature flue 8. The high temperature flue 8 is formed in a multiplex pipe structure, or into a triple pipe, to reduce the dioxine, which can stay in a high temperature atmosphere for a long time. Steam 3 generated with waste combustion gas 2 is superheated by an superheater 4 to drive a steam turbine 11 for operating a power generator 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a waste power generation system.

[0002]

2. Description of the Related Art A waste power generation system having a steam turbine system is used to obtain steam for driving a steam turbine.
Steam is generated by the heat of the combustion gas obtained by incinerating waste in an incinerator. However, the operating temperature of the boiler is usually about 30 due to corrosive substances contained in the combustion gas of the incinerator.
Limited to 0 ° C, low power generation efficiency. Therefore, materials for lectures on the development and development of high-efficiency waste power generation, hosted by the Industrial Technology Association, October 7, 1994, and Industrial Pollution, Vol.
9, No. 8 (1993), III-13, and a steam superheater installed to burn fuel such as natural gas There has been proposed a system for increasing the temperature of steam by using the heat energy of the combustion gas.

[0003] On the other hand, in the combustion gas from incineration of waste,
It contains dioxins that are harmful to the human body, and their reduction is required. Until now, a method has been adopted in which the operating conditions of the incinerator are adjusted to suppress the generation of dioxin.
However, when the temperature in the furnace is increased to suppress the generation of dioxins, there are many problems in a trade-off relationship, such as an increase in NOx emissions and a shortened life of the furnace. It was not found.

[0004]

It is generally known that dioxin decomposes when exposed to a high temperature for a certain period of time. Therefore, a system is considered in which waste combustion gas is supplied as an oxidizing agent for a combustor, which is a heat source of a steam superheater, and dioxin is reduced by a high-temperature atmosphere generated by combustion.

In a system for reducing dioxin by supplying waste combustion gas to a combustor, a sufficient length of a flue from the combustor to a boiler is ensured, and dioxin is retained in a high-temperature gas generated by combustion for a certain period of time. is required.

For example, in the case of a waste power generation system having a waste disposal rate of 300 t / day, a high-temperature flue having a diameter of 1 m needs to be about 10 m long to keep dioxin for 1 second. Therefore, there is a problem that the occupied area of the high-temperature flue is large and disadvantageous in terms of space, and the thermal expansion is increased.

An object of the present invention is to provide a highly reliable waste power generation system in which a high-temperature flue for reducing dioxin generated in a waste incinerator has a compact structure with a small thermal expansion.

[0008]

A waste power generation system according to the present invention which achieves the above object comprises an incinerator for burning waste, and a boiler for generating steam by a first combustion gas generated in the incinerator. A superheater that superheats the steam generated by the boiler, and a steam turbine that drives a turbine with the superheated steam to generate power, and generates high-temperature combustion generated from a combustor serving as a heat source of the superheater. The high-temperature flue for introducing gas to the superheater is constituted by adopting a multi-tube structure or a structure having a guide plate inside.

The high-temperature flue for waste power generation of the present invention has a structure having multiple tubes or a guide plate inside. Therefore, the overall length is reduced and the space can be saved as compared with the case where the same flow path length is secured. In addition, since the elongation of the high-temperature flue due to heat is considered to increase in proportion to the overall length, the thermal elongation can be reduced as compared with a normal single tube.

[0010]

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

FIG. 1 shows a first embodiment of the present invention. The waste power generation system according to the present invention includes an incinerator for incinerating waste 1, a boiler 4 for generating steam 3 by waste combustion gas 2, a superheater 4 for heating the steam 3 obtained by the boiler 4,
A combustor 5 serving as a heat source of the superheater 4, fuel 6 of the combustor 5, a high-temperature flue 8 for guiding the combustion gas 7 generated in the combustor 5 to the superheater 4, and exhaust gas 9 passing through the superheater 4 are discharged. Chimney 1
The steam turbine 11 includes a steam turbine 11 driven by steam superheated by the superheater 5 and a generator 12 connected to the steam turbine 11 to generate power.

The combustion gas 2 obtained by incinerating the waste is supplied as an oxidizing agent for the combustor 5. Dioxin contained in the combustion gas 2 is decomposed by staying in a high-temperature atmosphere (about 800 ° C.) for a certain time (about 1 second) when passing through the inside of the combustor 5 and the high-temperature flue 8. Therefore, the harmless gas is discharged from the chimney 10.

The waste power generation system of this embodiment is characterized in that the high temperature flue 8 has a multi-tube structure.
In the example of FIG. 1, a triple tube is used. Since it is effective to stay in a high-temperature atmosphere for a long time to reduce dioxin, the longer the high-temperature flue, the more advantageous it is. However, in this embodiment, the high-temperature flue is compared with a single-tube structure having the same flow path length. Becomes about 1/3, and the thermal elongation becomes smaller.

FIG. 2 shows a second embodiment of the present invention.
In this figure, parts different from those of the embodiment are mainly shown. FIG.
Only the differences between the embodiment of FIG. 1 and the embodiment of FIG. The embodiment of FIG.
Is characterized in that it has a structure in which a number of guide plates 13 are provided therein. By the guide plate 13, a flow path longer than the entire length is formed inside the high-temperature flue 8. Therefore, in the present embodiment, the length of the high-temperature flue is shortened and the thermal elongation is further reduced as compared with a single pipe having the same channel length.

FIG. 3 shows a third embodiment of the present invention.
In this figure, parts different from those of the embodiment are mainly shown. FIG.
In this embodiment, only the parts different from the embodiment of FIG.
The features will be described. The embodiment of FIG. 3 is characterized in that a spiral guide plate 14 is provided inside a high-temperature flue.
The guide plate 14 forms a flow path inside the high-temperature flue 8 that is longer than the entire length thereof. Therefore, in the present embodiment, the length of the high-temperature flue is shortened and the thermal elongation is further reduced as compared with a single pipe having the same channel length.

[0016]

According to the present invention, a waste power generation system having a high-temperature flue structure suitable for reducing dioxins generated in a waste incinerator can be provided.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a waste power generation system using a high-temperature flue structure according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a high-temperature flue according to a second embodiment of the present invention.

FIG. 3 is a sectional view of a high-temperature flue according to a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Incinerator, 2, 7 ... Combustion gas, 3 ... Steam, 4 ... Superheater, 5 ... Combustor, 6 ... Fuel, 8 ... Hot flue, 9 ... Exhaust gas, 10 ... Chimney, 11 ... Steam turbine, 12 ... generator.

Continued on the front page (72) Inventor Shigeo Hatamiya 7-2-1, Omika-cho, Hitachi City, Ibaraki Pref. Hitachi, Ltd. Power and Electricity Development Division (72) Inventor Yasuko Yashiro 7-chome, Omika-cho, Hitachi City, Ibaraki Prefecture No. 2 Hitachi Power Systems, Ltd. Electric Power Development Division (72) Inventor Megumi Suno 3-1-1 Sakaicho, Hitachi City, Ibaraki Prefecture Inside Hitachi Works, Ltd. Hitachi Plant

Claims (3)

[Claims] 1. An incineration system for generating steam by a first combustion gas obtained by burning waste, a superheating system for superheating steam generated in the incineration system, and a turbine using steam superheated by the superheating system. A waste power generation system having a steam turbine system that drives and generates electric power, wherein the superheating system burns a hydrocarbon-based raw fuel using a first combustion gas as an oxidant and generates a second combustion gas. And a high-temperature flue that guides the second combustion gas generated in the combustor to a superheater that superheats the steam generated in the incineration system, wherein the high-temperature flue has a multi-tube structure. Characteristic waste power generation system. 2. The waste power generation system according to claim 1, wherein said high-temperature flue having a plurality of guide plates therein is provided. 3. The waste power generation system according to claim 1, wherein a high-temperature flue in which a spiral flow path is formed by a guide plate in the interior is provided.