CS248486B1

CS248486B1 - Steam boiler with two-stage liquid focal point

Info

Publication number: CS248486B1
Application number: CS783084A
Authority: CS
Inventors: Marian Kosnac; Pavel Novotny
Original assignee: Marian Kosnac; Pavel Novotny
Priority date: 1984-10-15
Filing date: 1984-10-15
Publication date: 1987-02-12

Abstract

Riešenie sa týká parného kotlá s dvojstupňovým íluidným ohniskom a rieši přednostně problematiku ak spal'ovacieho procesu, tak i udržanie projektového prehriatia páry pri spalovaní menejhodnotného uhlia s nízkou výhrevnosťou a velkou variabilitou akosti. Jeho podstatou je, že strop i steny fluidného reaktora sú převedené vo formě plynotesných membrán, ktoré sú zapojené ako diel prehrievača páry.The solution concerns a steam boiler with a two-stage fluidized bed and primarily addresses the issue of both the combustion process and maintaining the design superheat of steam when burning inferior coal with low calorific value and high variability of quality. Its essence is that the ceiling and walls of the fluidized bed reactor are made in the form of gas-tight membranes, which are connected as part of the steam superheater.

Description

The solution relates to a steam boiler with a two-stage fluidized focus and solves preferentially the problems and to the sputtering process, as well as maintaining the project superheat of the steam in the combustion of low-value coal with low calorific value and high quality variability.

The essence of this is that both the ceiling and the walls of the fluidized bed reactor are transferred in the form of gas-tight membranes that are connected as part of a steam superheater.

> QOQ <248486 3 '248486

BACKGROUND OF THE INVENTION The present invention relates to a steam boiler with a two-stage fluidized bed and this apparatus addresses the issue of viewing low-grade coal while maintaining the prescribed superheated steam. The current solution of a steam boiler with a two-stage fluidized focus solves the problem of viewing low-grade coal only from the viewpoint of the sputtering process, because in simplified coal preparation, a stable sputtering process is achieved without any stabilization in a wide range of power control without slagging and the like. However, compliance with the prescribed steam overheating temperature is not solved when the coal calorific value decreases, when the flame temperature changes substantially with the change in coal quality. Another disadvantage of the present two-stage fluidized bed steam boiler solution is the large weight of the slipper, particularly the fluidized bed ceiling.

These disadvantages are eliminated by the steam boiler according to the invention, the principle of which is that the ceiling, possibly the walls of the associated fluidized bed reactor, are transferred in the form of gas-tight membranes, which are either bare or sealed on the inner side, and the ceiling membrane is also circumferential. it is connected as one part of the steam superheater. An advantage of the steam boiler according to the invention is the fact that in the inner space of the fluidized bed reactor there is a temperature which does not change depending on the quality of the coal and therefore the heat transfer to the membranes connected as a steam superheater part is constant. In this way, lower heat transfers to the steam superheater in the downstream chamber and the boiler tensions are compensated. Another advantage is that, compared to the cooling of the membranes by the boiler water, it is not necessary to install a circulation pump and that the weight of the whole boiler is reduced while the total heat exchange surfaces of the boiler are increased, which will enable the waste gas temperature to be lowered and the boiler to be more efficient. An example of an embodiment of a two-stage fluidized bed steam boiler according to the invention is shown in the accompanying drawing.

A fluidized-bed reactor 2 with a fuel inlet 3 is connected to the boiler chamber 1. Fluidization air is fed through the air chamber 4, secondary air through nozzles 5. The rigid residual spots left in the boiler chamber are drained off 6, the flue gas is discharged through the neck 7. Convector part of the superheater 8 of the steam is connected by a steam pipe 9 to the membranes in the machine 10 and the walls 11 of the fluidized bed reactor therefrom are steam exhausted by the steam pipe 12.

When operating the boilers, coal of different quality is burned, so that the flame in the boiling chamber of boiler 1 has a temperature. Therefore, the convection superheater 8 also achieves steam overheating. In contrast, the temperature of the fluidized bed reactor 2 is constant and therefore the proportion of heat transferred to the membranes will also depend on the quality of the coal. In the combustion of higher quality fuel and possibly higher heat transfer to the superheater 8, superheating of the steam can be reduced by notorious methods - injection control.

The invention can be used both for newly built boiler units and for reconstruction! existing boilers, fumigated by floods with powder or grate foci, for heating with a two-stage fluidized bed.

Claims

Two-stage fluidized-bed steam boiler consisting of a steam boiler and an associated fluidized bed reactor in which the ceiling and / or walls are converted in the form of gas-tight membranes which are either single or wall-mounted on the inner side. the membrane of the ceiling (10) or even of the peripheral walls (11i) is connected as part of the superheater (8).