RU2066810C1 - Convective heating surface - Google Patents

Abstract

FIELD: thermal engineering; manufacture of steam generators. SUBSTANCE: convective heating surface has inlet header 1, outlet header 2, vertical heated tubes 3, spacer tubes 4 arranged in horizontal tiers 5 on straight vertical sections of heated tubes 4 and crosswise rigidly fixed together over convective surface periphery; pair of spacing tubes 4 embraces only one row of heated tubes 3. EFFECT: facilitated installation and repair operations. 4 dwg

Description

 The invention relates to a power system and can be used in steam generation.

 During the operation of the steam generator, especially on slagging fuel or high sulfur fuel oil, on the vertical heating surfaces, usually located in a horizontal gas duct, a large amount of slag is deposited. The foci for intense slagging are places where the transverse steps between the vertical pipes are reduced due to their exit from the project plane (from the ranking). In these places, the consumption and speed of flue gases decreases sharply and this further contributes to the slagging of heating surfaces. In addition, external pipe rankings, especially in the transverse direction of the movement of heating gases, worsen the cleaning conditions by blowing or other devices. Currently used various uncooled devices made of heat-resistant materials quickly burn out under the influence of high temperatures and aggressive components (sulfur, vanadium) of heating gases.

 Using your own, i.e. connected in parallel with the heated pipes heating surfaces, the distance of the heated pipes leads to uneven conditions of their work, because distance pipes necessarily differ in length and configuration from the main pipes, which reduces the reliability of the heating surface.

A known design of the convective heating surface, in which the spacing of the heated pipes is carried out by uncooled spacer bars of heat-resistant cast iron. For example, on a boiler TGMP-204 [1]
The disadvantage of this design is the fragility of the spacer bars, since under high temperature gases and aggressive components of the fuel combustion products they quickly burn and collapse, which leads to a violation of the distance between the heated pipes of the heating surface, contributes to the drift of their ash and slag, poor heat transfer and reduced reliability steam generator operation.

Closest to the claimed one is the design of the convective heating surface, containing inlet and outlet headers, vertically located heated pipes and horizontal tiers installed spacing pipes, cooled by the working environment and equipped with spikes that form cells, each of which contains one vertical pipe. In general, all the distance pipes connected by spikes form a horizontal rigid lattice through which heated pipes of the heating surface are passed [2]
A disadvantage of the known design is the complexity of installation and low maintainability, consisting in the fact that if it is necessary to replace a damaged heated pipe located in the middle of the vertical heating surface, it is completely impossible to push the heated vertical pipes to facilitate access to the damaged place. This applies equally to the spacer tubes themselves, equipped with spikes. To access the damaged place, it is necessary to cut a large number of undamaged pipes in accessible places for this with their subsequent restoration. The operating experience of the indicated surface on the TGMP-204 boilers confirms the above.

 The aim of the invention is to remedy these disadvantages, as well as improving installation and repair manufacturability.

 This goal is achieved by the fact that in the convective heating surface containing the inlet and outlet collectors, vertically mounted heated pipes and spacing pipes arranged in horizontal tiers, spacing pipes in the form of horizontal tiers are placed on straight vertical sections of heated pipes, pairwise rigidly interconnected around the periphery convective surface, with each mentioned pair covering only one row of heated pipes.

The invention is illustrated by drawings, which depict:
in FIG. 1 General view of the convective heating surface,
in FIG. 2 is a section along AA of FIG. 1,
in FIG. 3 a section along BB in FIG. 2
in FIG. 4 is a section along BB of FIG. 2.

 The convective heating surface contains inlet 1 and outlet 2 collectors, vertically mounted heated pipes 3, spacer pipes 4 made in the form of horizontal tiers 5 placed on straight sections of pipes 3 along the surface height parallel to the movement of heating gases and pairwise covering each row of these pipes. The pipes 4 are rigidly interconnected by welding 6 along the periphery of the heating surface.

 Convective heating surface works as follows.

 When the thermal state of the steam generator changes, the spacer pipes 4 hold in one plane each row of heated pipes 3, which tend to leave the ranking due to uneven heating. Maintaining the ranking of the pipes 3 ensures uniform gas velocities over the entire width of the gas duct, reduces the possibility of ash entering its individual sections, and also improves the cleaning conditions using blowing or other devices. The retention of the heated pipes 3 in the ranking significantly improves the conditions for their inspection and repair.

Claims (1)

 A convective heating surface comprising input and output collectors, vertically mounted heated pipes and spacer pipes arranged in horizontal tiers, characterized in that the spacer pipes are placed in horizontal tiers in straight vertical sections of the heated pipes and are pairwise rigidly bonded to each other along the periphery of the convective surface, each a pair of spacer tubes covers only one row of heated tubes.

Images