Device for recovering hot air of dry type slag removal machine and reducing disorganized air leakage of bottom of hearth and application thereof

Abstract

The invention provides a device for recovering hot air of a dry type slag removal machine and reducing disorganized air leakage of the bottom of a hearth. The device comprises a suction pipeline, a cyclone separator, a suction fan, a control device, a ventilation bypass, a first control damper, a first isolation valve, a second control damper, a second isolation valve, a third control damper and a third isolation valve. The cyclone separator, the first control damper, the first isolation valve, the suction fan, the ventilation bypass, the second isolation valve and the second control damper are sequentially arranged on the suction pipeline from the inlet to the outlet. The third isolation valve and the third control damper are sequentially arranged on the ventilation bypass from the inlet to the outlet. A slag gate box is arranged at the bottom of the cyclone separator. By means of the device, the disorganized air leakage of the bottom of a furnace is changed to organized air supply, and the thermal efficiency of the furnace is improved to close to the optimum value; the flame center height of the hearth is controlled, temperature reduction water quantity of a superheater and a reheater is reduced, cocking which may happen to the platen superheater is reduced, NOx emission concentration is lowered, and remarkable comprehensive benefits to the unit are achieved.

Description

technical field [0001] The invention belongs to the field of electric equipment, and particularly relates to a device for recovering hot air from a dry slag remover to reduce fugitive air leakage at the bottom of a furnace, and also relates to a device for recovering hot air from a dry slag remover to reduce fugitive air leakage at the bottom of a furnace. Background technique [0002] Dry-type slag removal machine has been valued by the power industry for its energy-saving, water-saving, environmental protection and good comprehensive benefits. At present, hundreds of units have been put into operation with dry-type slag removal machine. Working process of dry slag removal machine: high temperature slag falls on the conveyor belt of slag discharge machine through the furnace bottom slag discharge door, and uses the negative pressure of the furnace to cool the slag by sucking in ambient air. The cold air absorbs the physical sensible heat of the hot slag and the slag is combu...

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Problems solved by technology

[0004] At present, the dry slag remover generally has the problem of high air leakage rate, and it greatly deviates from the design value of 1% air leakage rate. The air leakage rate of some units exceeds 10%, or even higher. The secondary air volume of the air preheater is further reduced, making the thermal efficiency of the boiler farther away from the optimum value, which affects the economical operation of the unit; the air leakage rate at the bottom of the furnace is higher, which makes the boiler generate nitrogen oxides under high and medium load conditions The increase in the amount of nitrogen oxides will affect the emission control of nitrogen oxides and greatly increase the operating cost; at the same time, because most of the units are mixed with economical coal, the quality of the coal used deviates from the design coal quality, resulting in the amount of slag deviation from the design value, which affects The air leakage rate control at the bottom of the furnace is artificially increased, which affects the reduction of the thermal efficiency of the boiler

The increase of the air leakage rate at the bottom of the furnace will not only affect the deviation of the boiler thermal efficiency from the optimal boiler thermal efficiency value, but also affect the rise of the furnace flame center, resulting in an increase in the smoke temperature at the furnace outlet, an increase in the desuperheating water volume of the superheater and reheater, and the panel superheater The possibility of coking increases, which affects the safety and economy of unit operation

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