SU1673784A1 - Burning of fuel at thermal power station - Google Patents

Abstract

The invention relates to the technique and technology of co-combustion of pulverized and gaseous fuels and can be used in thermal power plants. The purpose of the invention is the reduction of nitrogen oxides in combustion products. For this, the vertical tetrahedral furnace 1 contains pulverized coal 2 located at different levels and gas burners 5 located below them, the first are placed on the front wall 3 of the firebox 1, and the second on its side walls at the level (0.55 - 2.1) D from the level of pulverized coal, and on the back wall 6 above the level of the burners 2 at a distance of (0.05-0.2) D air nozzles 7 are additionally placed, where D is the diameter of the burner embrasure 2, m. To increase the burnout rate of the air through the burner 5 is supported equal to 0.35 - 0.45, and through pulverized coal equal to 0.45 - 0.55 of the total air flow introduced into the furnace through the burners 2 and 5 and the nozzle 7. 2 sec. f-ly, 3 ill.

Description

one

(21) 4728804/06 (22) 09.08.89 (46) 08.30.91. Bul №32

(71) Kyrgyz Research Department of Energy

(72) B.V. Osintsev, A.K. Dzhundubaev, A.P. Lysov, G.N. Kirichenko, V.V. Urobushkin, V.P. Martynov, V.A. Lakeev and G.V. Ligunov (53) 662951.2 (088.8)

(56) USSR Author's Certificate N; 1163089. class. F23 From 1/12, 1985.

(54) VERTICAL FOUR-HEADED FOOT FOR JOINT BURNING OF GASEOUS AND DUSTY TOP THERMAL AND ITS WAYS

(57) The invention relates to the technique and technology of co-combustion of pulverized and gaseous fuels and can be used in thermal power plants. The purpose of the invention is the reduction of nitrogen oxides in combustion products. For this, the vertical tetrahedral firebox 1 contains pulverized coal 2 located at different levels and gas burners 5 located below them, the first are placed on the front wall 3 of the firebox 1, and the second - on its side walls at the level (0.55-2.1) D from the level of pulverized coal, and on the rear wall 6 above the level of the burners 2 at a distance of (0.05–0.2) D air nozzles 7 are additionally placed; where D is the diameter of the embrasure of the burners 2, m. To increase the degree of fuel burnout, the air flow through the burners 5 is maintained at 0.35-0.45, and through the pulverized coal, equal to 0.45-0.55 of the total air flow introduced into the furnace through the burners 2 and 5 and the nozzles 7. 2 s ffl, 3 ill.

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The invention relates to the combustion of fuels and can be used in thermal power plants.

The aim of the invention is to reduce the concentration of nitrogen oxides in the combustion products.

FIG. 1 schematically depicts the proposed furnace, a longitudinal section; in fig. 2 - cross-section of the furnace, 1 option; in fig. 3 - the same, 2 option.

The vertical tetrahedral furnace 1 contains pulverized coal burners 2 mounted on the front wall 3. Gas burners 5 are mounted on the side walls 4, and air nozzles 7 are located on the back wall b, and gas burners 5 are lowered relative to pulverized coal burners 2 by distance D (0, 55-2.1) D, and the air nozzles 7 are lifted relative to the same burners 2 at a distance of B (0.05-0.2) D, where D is the diameter of the embrasure of the pulverized coal burners, m.

The furnace works as follows. The operation of the furnace 1 is carried out by introducing dust and air through the burners 2, gas and air through the burners 5, and only air through the nozzles 7, with the air flow through the burners 2 and 5 being equal respectively (0.45-0.55) and (0.35-0.45) of the total air flow introduced into the furnace. Heat of combustible fuels is transferred through heating surfaces (not shown) to water and steam, and cooled products of combustion are emitted into the atmosphere,

When the fuel is supplied through the burners 2 and 5 thus arranged, and the air through the nozzles 7, the concentration of nitrogen oxides in flue gases decreases by 35–40%. Maintaining the flow of air through gas and pulverized coal burners 5 and 2 within the specified limits allows to reduce the mechanical and chemical underburning of fuel and maintain the degree of fuel burnout at a level not worse than 0.999. Outside the specified distance ranges for the placement of the burners 2 and 5 and the air nozzles 7, as well as the flow ratio ranges

air through them, the amount of nitrogen oxides in the combustion products increases dramatically and the burnout of the fuel decreases. Thus, if, while maintaining the indicated ratios of V / D and G / D, the relative level of nitrogen oxides in gases is maintained within 0.6-0.65, then with a slight deviation from them the level of nitrogen oxides changes abruptly and reaches a value of 0.95 -1.0 (as compared with the values obtained for V / D 0 and G / D 0). The same is observed with the degree of fuel burnout when the air flow rate deviates from the burners and

air nozzles beyond specified limits.

Claims (1)

1. Vertical four-sided furnace for co-combustion of gaseous and pulverized fuels containing pulverized coal and gas burners located at different levels, the latter being placed below the first, characterized in that, in order to reduce the concentration of nitrogen oxides in the combustion products, bullet-type burners are placed only on the front wall of the furnace, and gas burners on its side walls at the level of (0.55-2.1) 0 from the level of pulverized coal burners, above which at the level of (0.05-0.2) 6 from it are additionally placed air nozzles, where D is the diameter of the embrasure of the pulverized coal burners. 2, A method of operating a vertical four-sided furnace for co-combustion of gaseous and pulverized fuels by feeding gas-air mixture into it through gas burners, air mixture through pulverized coal burners and additional air through air nozzles, characterized in that Air flow Cr through gas burners is maintained equal to (0.35-0.45). And through pulverized coal 5 Cp equal to (0.45-0.55) of the total air flow introduced into the furnace through the burners and nozzles. Vlrivnt i 7 five VyR # lchg2. /