Furnace processes in boilers with inversion furnace

Аuthors

Puzyrev E. M.¹, Surin D. E.², Maslov K. V.¹, Khutornenko S. N.²

1. Proenergomash-Project LLC, 17a Yuzhny Ave., Barnaul, Altai Territory, 656006
2. Inter RAO-Engineering LLC, 119435, Moscow, Bolshaya Pirogovskaya str., 27, building 4

Abstract

The layout of the boiler unit and its individual elements, especially the combustion chamber, implies the mutual arrangement of gas ducts and the placement of individual heating surfaces in them. There are several types of layouts known today, for example, two pass, T, U, N, tower and half-tower, and other types of boiler gas duct arrangement, each of which has a number of advantages and disadvantages.

For example, the two pass layout is the most popular. This allows you to get around the boiler's relatively small height. As a result, it is a simpler and cheaper boiler frame than the T – shaped layout.

The disadvantages of the two-pass arrangement are threefold rotation of combustion products: in the area of burner devices, as well as at the exit from the furnace and from the rotary gas duct.

The U – shaped boiler layout with an inversion furnace layout has a number of advantages over the two pass layout. U – shaped boilers have a low height. They differ favourably from other layouts in that the superheater is located at a low height, close to the height of the steam turbine, which also improves the installation and maintenance of the superheater. An additional advantage of this superheater is that in the event of slagging, the fall of slag deposits from the low-lying superheater tubes will not damage the heating surfaces.

The U – shaped boilers have another significant advantage, which is the minimum boiler area, as many elements are located on the top. This advantage makes it possible to increase the boiler output in comparison with the two pass, T – shaped layout with a comparable constructional area or, on the contrary, to reduce it with the same output.

When the burners are located on the furnace ceiling in the U – shaped arrangement, due to buoyancy forces, the burner jets, especially the twisted ones, suck a large amount of flue medium into the flame root, which reduces nitrogen oxide emissions.

An additional effect of the ceiling burner arrangement is that the furnace screens are better protected from flame buildup and, as a consequence, from slagging, with the accompanying stable heat perception of the furnace screens.

Keywords:

U – shaped arrangement, furnace process, inversion arrangement, nitrogen oxides, ash

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