JPH08200654A - Incinerator of waste - Google Patents

Abstract

PURPOSE: To enable attainment of high-temperature steam without accelerating corrosion of a heat transfer tube and to enhance the efficiency of generation of electric power of a refuse incinerating power generation system by providing a steam piping inside a furnace wall constituting an incinerator. CONSTITUTION: Refuse 20 thrown in a hopper 2 is burnt by air supplied from an air supply pipe 9, while it is transferred to stokers 3 to 5. Combustion gas 10 passes through a combustion space 6 and gives heat to a boiler 11. The temperature of steam generated in the boiler 11 is maintained at 300 deg.C or below at which the speed of high temperature corrosion in a boiler heat transfer tube does not become so large. The temperature of the steam of 300 deg.C or below is raised to about 400 deg.C with its flow through a steam piping 12 piercing the inside of a furnace wall 7 of which the temperature exceeds 300 deg.C. The steam of which the temperature is raised to about 400 deg.C is supplied to a steam turbine 16 through a high pressure steam piping 14 and drives the steam turbine 16 and thereby a generator 15 is rotated. According to this constitution, high temperature steam is obtained without accelerating corrosion of the heat transfer tube and the efficiency of power generation of a refuse incinerating power generation system can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to combustible waste (hereinafter referred to as
We call it a waste incinerator that burns waste)
In particular, the present invention relates to a waste incinerator suitable for use in a system that utilizes the heat of an incinerator for steam generation, for example, a waste power generation system.

[0002]

2. Description of the Related Art Conventionally, a system for driving a steam turbine to generate electricity by using steam generated by utilizing heat of a waste incinerator,
That is, in the waste power generation system, steam was generated by the boiler installed at the combustion gas outlet of the incinerator (see I. Waste incineration power generation in the presentation material "The latest trends in high temperature corrosion countermeasures for waste incineration facilities and waste power generation"). Status and future issues: Issued by KNOWHOW SUPPORT CENTER, PI-6 (1993)
(December 15, 2012)). Moreover, when the boiler heat transfer tube comes into contact with the combustion gas containing corrosive gas, high temperature corrosion occurs at a temperature exceeding 320 ° C., so that the generated steam is suppressed to a low temperature of 300 ° C. or less. As a result, the power generation efficiency of the waste power generation system remained at a low value of at most about 15%.

[0003]

The most effective means for increasing the power generation efficiency of a waste power generation system is to raise the steam temperature at the steam turbine inlet. In other words, it is necessary to solve the problem of how to take out high temperature steam without promoting the corrosion of the heat transfer tube.

An object of the present invention is to provide a waste incinerator capable of obtaining high temperature steam without promoting corrosion of heat transfer tubes.

[0005]

[Means for Solving the Problems] The waste incinerator is constructed of refractory bricks, and has a structure that insulates the inside and outside of the incinerator. The combustion gas temperature is set in consideration of the life of the incinerator. Normal combustion gas has a relatively low temperature of 800 to 900 ° C.
It is suppressed to some extent.

At the same time, the inner wall temperature of the incinerator is 80
It also means 0 to 900 ° C. That is, 3
Combustion containing a corrosive gas by embedding a heat transfer tube serving as a steam flow path in a refractory brick having a temperature exceeding 00 ° C or by bringing the high temperature refractory brick and the heat transfer tube into contact with each other so as to obtain a good heat transfer 30 without direct contact between gas and heat transfer tubes
It becomes possible to obtain high temperature steam of 0 ° C. or higher.

The waste incinerator of the present invention has a structure in which a steam pipe is provided inside a furnace wall which constitutes the incinerator.

[0008]

According to the above structure, the heat transfer tube can perform heat exchange in a state surrounded by refractory bricks, so that the heat transfer tube is not directly contacted with the combustion gas containing corrosive gas.
That is, high temperature steam of 300 ° C. or higher can be obtained without promoting high temperature corrosion. As a result, higher temperature steam can be supplied to the steam turbine and power generation efficiency can be improved.

[0009]

Embodiments of the waste incinerator according to the present invention will be described below with reference to the drawings, taking a stoker furnace type as an example.

FIG. 1 is a sectional view showing an embodiment of a waste incinerator in a refuse power generation system. Waste incinerator 1
Is the part surrounded by the broken line in FIG.
And a stoker 3, a combustor stoker 4, a post-combustor stoker 5, which are provided at the bottom of the dust input hopper 2, in a stepwise manner, and a furnace wall 7 forming a combustion space 6 above these stokers. Further, an air supply pipe 9 is connected to each stoker via the pushing fan 8.

Regarding the structure of the steam system, the combustion gas 10
A boiler 11 is installed at the outlet of the waste incinerator 1 from which the steam is discharged. From the boiler 11, a steam pipe 12 penetrates the inside of the furnace wall 7 and is then connected to a high-pressure steam sump 13.
The high-pressure steam reservoir 13 is connected by a high-pressure steam pipe 14 to a steam turbine 16 coupled with a generator 15. A low-pressure steam pipe 17 is connected to the condenser 18 from the steam turbine 16, and a water pipe 19 is connected to the boiler 11 from the condenser 18.

Next, the operation of this embodiment will be described.

Waste 20 thrown into the waste throw hopper 2
Is transferred by the drying stoker 3, the combustion stoker 4, and the post-combustion stoker 5 in this order, and is combusted by the air supplied from the air supply pipe 9 to each stoker by the pushing fan 8. The combustion gas 10 passes through the combustion space 6 formed by the furnace wall 7 and gives heat to the boiler 11 installed at the outlet of the furnace wall 7. The steam generated in the boiler 11 has a high-temperature corrosion rate in the boiler heat transfer tube that does not increase so much.
It is kept at a temperature below ℃. Steam below 300 ℃ is 3
By passing through the steam pipe 12 provided so as to penetrate the inside of the furnace wall 7 having a temperature exceeding 00 ° C., 400 ° C.
The temperature is raised to a certain degree. The steam heated to about 400 ° C. is sent to the high-pressure steam reservoir 13 and then supplied to the steam turbine 16 via the high-pressure steam pipe 14, and the steam turbine 16
To drive the generator 15. The steam after the power is recovered by the steam turbine 16 is guided to the condenser 18 by the low pressure steam pipe 17 and becomes condensed water. The condensed water is returned to the boiler 11 by the water pipe 19 and is used again as steam.

According to this embodiment, since the temperature of the furnace wall of the incinerator can be lowered by recovering the heat by the steam,
It is possible to provide a waste incinerator with a long life.

FIG. 2 is a longitudinal sectional view of the waste incinerator of the present invention, and FIG. 3 is an example of the structure of refractory bricks.

FIG. 2 shows a state in which the steam pipe 12 is provided so as to penetrate the inside of the furnace wall 7. As shown in FIG. 3, the steam piping 12 is provided on the refractory bricks 21 forming the furnace wall 7.
Is provided with a space 22. The space 22 is formed when the refractory bricks 21 are combined. In the space between the fire brick 21 and the steam pipe 12 formed after the steam pipe 12 is laid in the space 22,
The heat transfer accelerator 23, for example, a mixture of metal powder and cement is filled. With these configurations, the steam flowing in the steam pipe 12 passes through the high-temperature refractory brick 21 and the combustion gas 10
It is given more heat and heated to a temperature of 300 ° C. or higher.

According to this embodiment, since the mixture of metal powder and cement is filled between the refractory bricks, the refractory bricks constituting the waste incinerator can be reinforced.

[0018]

According to the present invention, it is possible to provide a waste incinerator capable of obtaining high temperature steam without promoting corrosion of the heat transfer tube.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a waste incinerator of the present invention in a refuse power generation system.

FIG. 2 is a sectional view of a waste incinerator showing an embodiment of the present invention.

FIG. 3 is an explanatory view of the structure of a refractory brick in a waste incinerator showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Waste incinerator, 2 ... Waste input hopper, 6 ... Combustion space, 7 ... Furnace wall, 10 ... Combustion gas, 11 ... Boiler, 12 ...
Steam piping, 13 ... High-pressure steam reservoir, 15 ... Generator, 16 ...
Steam turbine, 18 ... Condenser.

Claims (3)

[Claims] 1. An incinerator for burning waste, characterized in that a steam pipe is provided inside a furnace wall constituting the incinerator. 2. The waste incinerator according to claim 1, wherein the outer surface of the steam pipe is coated with a heat transfer accelerator. 3. The waste incinerator according to claim 2, wherein the heat transfer accelerator is a mixture of metal powder and cement.