RU1776343C - Boiler circulation loop - Google Patents

Abstract

Usage: in the devices of steam boilers. SUMMARY OF THE INVENTION: The boiler circulation circuit contains evaporation tubes 1, connected by lower and upper collectors 2 and 3, and a horizontal pipe 6 connected to the latter, to the lower part of which recirculation pipes 4 are connected, and to the upper part, between the collector 3 and the recirculation connection zone pipes 4 - steam exhaust pipes 5. The circuit is provided with an additional water-cooled surface 11, introduced into the upper part of the recirculation pipes 4, and the second end of the mentioned pipe 6 is muffled. When the boiler is operating, cooling medium is supplied to surface 11. Condensation of the vapor reduces the capture of the latter in the recirculation pipes 4. 2 il.

Description

The invention relates to boiler building.

A boiler circulation loop is known, which contains evaporation pipes combined by a lower distributing and upper collecting manifold, as well as steam and recirculating pipes. Moreover, the latter are made unheated and, in order to reduce them, the steam is again connected to the upper collector in the region of its lower generatrix.

In the case of connecting to the upper collector in the region of its lower generatrix a large number of evaporation pipes, which is most often used in boiler technology, it is not possible to connect recirculation pipes according to the known scheme.

It is also known to connect recirculation pipes to the upper collector radially above its lower generatrix. Such a connection scheme makes it possible to connect the evaporator pipes to the upper collector in the region of its lower generatrix. However, such a circuit has a reduced reliability of circulation due to the possibility of steam again in the recirculation pipes. At the same time, the weight of the medium column in the pipes decreases and their resistance increases, which leads to a decrease in the amount of water circulating along the circuit.

In addition, when the upper collector is located inside the gas duct with both recirculation pipe connection schemes

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difficulties arise when the latter are brought into the unheated zone.

An object of the invention is to increase the reliability of circulation in a circuit.

This goal is achieved by the fact that in the circulating circuit of the boiler containing evaporation pipes combined by the lower distribution and upper collecting manifolds, as well as recirculation and steam pipes, the evaporation pipes are connected to the upper manifold in the region of its lower generatrix, recirculating pipes with their upper ends connected to the lower generatrix of the nozzle, horizontally connected by one end to the upper collector in the region of its lateral generatrix and plugged from the other end, and steam vent pipes would be connected to the upper generatrix of this pipe in the area between the upper collector and recirculation pipes. A heat exchange surface, for example, such as a pipe in a pipe, can be introduced into the cavity of the upper end of the recirculation pipes.

Figure 1 shows a general view of the circulation circuit located in the convective gas duct of the boiler; figure 2 - option with additional heat transfer surface.

The boiler circulation circuit contains evaporation pipes 1, united by the lower distribution pipes 2 and the upper collecting 3 collectors, as well as recirculation 4 and steam exhaust pipes 5. Evaporation tubes 1 are connected to the upper collector 3 in the region of its lower generatrix. The recirculation pipes 4 with their upper ends are connected to the lower generatrix of the nozzles 6, horizontally connected with one end to the upper manifold 3 in the region of its lateral generatrix and plugged from the other end, and the lower ones to the lower manifold 2 and taken out of the flue 7. The dust extraction pipes 5 are connected to the upper generatrix of the nozzles 6 in the area between the upper collector 3 and the recirculation pipes 4 and, for example, to the steam volume of the cyclone separator 8, the water volume of which is connected through the discharge pipes 9 to the lower in collector cavity 2. The upper end of the recirculation pipe 4 through the connector 10 introduced heat exchange surface 11 of the tube in tube type, the outer tube 12

which is plugged at the ends and connected by a pipe 13 to the feed water line to the economizer (not shown in the drawing). Inner pipe 14 open

end coaxially inserted into the cavity of the pipe 13, and the other end is connected to the feed water line from the economizer to the drum (not shown).

The circulation circuit operates as follows.

Hot gases enter the gas duct 7 and, moving from top to bottom, give off heat to the water circulating in the evaporator tubes 1. Formed with the last steam train on

the mixture enters the upper collector 3 and from it to the nozzles 6. In the latter, the steam-water mixture is stratified into steam and water. Steam is discharged through steam pipes 5 to a cyclone separator 8, from which

The drained steam is discharged into the boiler drum, and the separated water through the downpipes is returned through the lower manifold 2 to the circulation circuit. Water and the remaining steam in it from the nozzles 6 come

to recirculation pipes 4, in the upper ends of which steam is condensed upon contact with the heat exchange surface 11 through which the feed water flows. Heated in a heat exchanger

11, feed water is sent to the drum of the boiler. Water from recirculation pipes 4 through the lower collector 2 again enters the evaporation pipes 1.

The claimed design allows

Claims (1)

prevent the drift of steam into the recirculation pipes, thereby increasing the weight of the column of medium in them and reduce their resistance. which increases the reliability of circulation. The claims The boiler circulation circuit, the evaporation pipes combined by the lower and upper collectors, and a horizontal pipe connected to the last end, to the lower part of which are recirculation pipes, and to the upper between the collector and the recirculation pipe connection zone, steam pipes, which differs in order to increase reliability by reducing the likelihood of steam being trapped in the recirculation pipes, it is equipped with an additional water-cooled surface introduced into the upper part of the recirculation pipes Ub, and the second end of the mentioned pipe executed muffled. f3 eleven