SU1143929A1 - Method of burning solid fuel in fluidized bed - Google Patents

Abstract

A SOLUTION FOR SOLID FUEL IN A DRINKED LIQUID LAYER by feeding an oxidant under the bed, burning the fuel and entering the water burning zone, characterized in that, in order to improve efficiency, water is introduced in one or more jets that direct the oxidizer. (L 4ib CO QD tc CO

Description

The invention relates to the field of energy and can be used when burning solid fuels in fluidized bed furnaces. The known method of using igani solid fuel in a fluidized bed by igniting the fuel and cooling it with a coolant in heating surfaces with regulation by changing the height of the Ct 3 layer. The closest to the invention in technical terms is the method of burning solid fuel in the frozen layer by feeding an oxidizer, igniting the fuel, and entering the water combustion zone under the bed. A disadvantage of the known methods is low efficiency. The aim of the invention is to improve the economy. This goal is achieved in that according to the method of burning solid fuel in a fluidized bed by supplying an oxidant sublayer, igniting the fuel and entering water into a mountain zone, water is introduced in the form of one or more psi, which direct the oxidant. The drawing shows a device that implements the proposed method. The device contains a fuel supply unit 1 and a combustion chamber 2 with a gas distribution grid 3, a gold outlet pipe 4, a gas duct 5 and a node 6 for removing a dip. For the water supply, there is a movable tank. At the top of the chamber 2, nozzles 9 are installed for supplying the oxidizing agent, and fluidized c is located in its lower part. oh 10 fuel. When the device is operated, a solid fuel is supplied to the chamber 2 through the node. From the bottom of the apparatus, through the gas distribution grid 3, a pseudo-liquefying gas, such as air, is supplied, while the ash is discharged through the booster 4, the combustion products are removed through the duct 5, and the failure is removed by the knot 6, Water for cooling the bed to a predetermined temperature is supplied from the reservoir 7 through the inclined tube 8. At the top of the apparatus, oxygen-containing gas, such as air, is fed through the nozzles 9 for the after-burning of products of incomplete combustion AND dust. Water is fed to the zone adjacent to the upper face of the layer 10. The height of the zone is 0.3-0.4 of the height of the layer 10 in the state of fluidization. The speed of the jet of water while 0.1-1.5 m / s. Example 1. In a furnace with a fluidized bed with a capacity of up to 0.8 Gkap / h, coal enrichment wastes are burned — the middling coal of the grade K RP of Karagandinsk with a heat of combustion varying from kcal / kg to Q j3950 kcal / kg. The height of the fluidized bed is 850 mm. The water supply is carried out on the boundary layer, i.e. The water outlet from the tube is located at the height of the overflow threshold, through which excess ash is removed from the layer. A stream of water is directed against the fluidizing air supplied from below the apparatus. The results of combustion, in which the flow rate of water varies from 1.3 to 1.5 m / s, are presented in the table. The completeness of the combustion of fuel 92.8%, the maximum particle size of coal 25 mm. Example 2. In the combustion device of Example 1, grade D coal is burned with heat of combustion Q / 4485-5083 kcal / kg. The height of the fluidized bed of inert material is 470 mm. The bed is cooled by a stream of water directed oppositely to the stream of fluidizing air. The flow rate of water is 0.9-1 m / s. The flow of water is directed to the boundary of the fluidized bed and read the ash content of focal residues, gas analysis, temperature values for three hours. Further, the water flow is directed to the zone adjacent to the bottom of the layer, i.e. The water supply pipe is installed in such a way that the water outlet is below the layer boundary by 70-94 mm. The duration of operation in this mode is 2 hours. After that, the coal is burned with the flow of water into the zone above the layer boundary, i.e. when installing the water outlet at a distance of 90-94 mm above the layer boundary. The duration of the apparatus operation in this mode is 1.5 hours. The results of the experiment in Example 2 are presented in the table in average values, since the difference in performance for the three modes does not go beyond the limits of measurement errors. The completeness of the combustion of fuel is 99.1%, the maximum particle size of fuel is 13 mm. Prima rz. In the combustion device of Example 1, coal near Moscow (Belkovsk mine) is burned with heat of combustion Q 2130-23SO kcal / kg. The height of the fluidized bed is 850 mm. The layer is cooled with a stream of water directed against the fluidizing air. The flow rate of water is 0.10, 3 m / s. Water is fed to the boundary of the layer as well as to the lower and upper boundaries of the zone with a height of 340 mm (from the height of the fluidized bed) adjacent symmetrically from above and below to the free surface of the layer - its upper boundary. Reducing the flow rate of water below 0.1 m / s (when measuring the tube 1 9 for supplying water) leads to instability of the combustion mode and ultimately to an increase in the temperature of the bed. The results of the experiment are presented in average values in the table. Completeness of combustion 93.7%. The proposed method, by supplying water in the form of one or several jets directed opposite to the oxidizer, improves the uniformity of temperature distribution over the bed volume and, as a result, significantly improves the efficiency of coal ash burning at 40% at temperatures excluding slagging and also increases heat transfer. fluidized bed, reduce the consumption of oxidant supplied from the top of the device, and thereby reduce its consumption of materials.

Indicator

Example 1

Fuel consumption, kg / m. h1800.0

Fuel class, mm0-25

Air flow:

under the grid, nm / m h78w &, 0

over the layer,% 13,4

Water consumption in the layer

kg / kg fuel 0.7

Actual excess air ratio of 1.13

Layer temperature, С

1030

Carbon content:

in ablation,% 9.0-17.2

in the material discharged from the layer,% Heat loss with chemical underburning,%

Heat loss with mechanical underburning,%:

in ash

The value of the indicator in the experience

Example 4

Example 3

Example 2 (known)

656.02310.0370-1000

0-13 0-253-5.0

4380,08920,01100-1600

24.45,560-70

0.40

0.12

1.28 1.1-1.18 850 1000-1100

3.9-11.0 3.7-6.6 15.0-50.0

1.4-1.7 5.0-15.0

0.00 Not determined

5.5 Separately not Indicator,

Example 1

in the material discharged from the layer,%

Completeness of combustion,%

(efficiency

burning)

Heat localization pseudo-,

the freezing bed

Gcal / mh

Example 4

Example 3

Example 2 known

0.8 determined

93.7 45.0-70.0

5.8 2.2-3.3 11439296 and E239 ™ §CN§13. The value of the indicator in the experience

Claims (1)

METHOD FOR BURNING SOLID FUEL IN A PSEUDO-LIQUIDED LAYER by applying an oxidizing layer under the layer, firing the fuel and introducing water into the combustion zone, with the exception of Ito, in order to increase efficiency, water is introduced in the form of one or several jets that are directed counter to the oxidizing agent. SU _p „1143929