CN2676041Y

CN2676041Y - Hypothermal gas recirculation equipment for boiler of large capacity power station

Info

Publication number: CN2676041Y
Application number: CNU2003201228455U
Authority: CN
Inventors: 乐长义
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-12-25
Filing date: 2003-12-25
Publication date: 2005-02-02
Anticipated expiration: 2013-12-25

Abstract

The utility model relates to hypothermal gas recirculation equipment for a boiler of a large capacity power station, comprising an inlet smoke flue, a recirculation fan, a coupler, an electric motor, and an outlet smoke flue. The electric motor drives the recirculation fan by the coupler, the inlet of the inlet smoke flue is connected in parallel with an outlet pipe of a large capacity electric dust collector provided with a reheat coal boiler in the middle, and the outlet of the inlet smoke flue is connected with the recirculation fan whose outlet is connected with the inlet of the outlet smoke flue. The outlet of the outlet smoke flue is fixed to the lower part of a bottom ash hopper of the furnace cavity of the fire coal. The utility model which adopts the hypothermal gas recirculation technology raises the steam temperature of the superheater and the reheater in a low-load operation, improving an economical efficiency of the operation of the motor-generator set.

Description

Big Capacity Power Plant Boilers low-temperature flue gas EGR

(1) technical field

The utility model relates to the flue gas recirculation device of big Capacity Power Plant Boilers, relates in particular to the low-temperature flue gas EGR of 125MW, 200MW, 300MW and 600MW station boiler.

(2) background technology

The flue gas flow of existing big Capacity Power Plant Boilers is: coal dust and secondary wind enter the burner hearth burning through burner and produce high-temperature flue gas, flue gas drains into atmosphere through chimney again through upper furnace, high temperature superheater, high temperature reheater, low-temperature reheater, low temperature superheater, economizer, air preheater, electric precipitator, air-introduced machine.Big Capacity Power Plant Boilers is when rated load, and parameters such as steam pressure, overheating steam temperature, reheat steam temperature can reach design load.In order to satisfy the peak load regulation network requirement, often require night generating set in underrun, general in 40% to 60% of rated load, or lower, overheating steam temperature and reheat steam temperature often are lower than the steam temperature rated value more than 20 ℃, influence the economy of unit operation.Steam temperature during for the underrun of raising station boiler, once adopted the high temperature flue gas recirculating technique, the flue gas that is about to the boiler tail economizer exit is extracted out, through a high temperature centrifugal blower, partial fume is sent into furnace hopper position under the fire box, to increase the caloric receptivity of superheater, reheater, improve superheater, the vapor (steam) temperature of reheater when underrun.But because high-temperature blower is to use under 360～370 ℃ of high temperature and under the environment of high dustiness, cause the high-temperature blower blade wear to damage easily, stop using already.

(3) summary of the invention

It is on the low side that the utility model has overcome existing big Capacity Power Plant Boilers reheat steam temperature when underrun, influences the defective of economy, and a kind of big Capacity Power Plant Boilers low-temperature flue gas EGR is provided.This big Capacity Power Plant Boilers low-temperature flue gas EGR adopts the low-temperature flue gas recirculating technique, improves superheater, the vapor (steam) temperature of reheater when underrun, has improved the economy of generating set operation.

The utility model is achieved in that a kind of big Capacity Power Plant Boilers low-temperature flue gas EGR, comprise inlet flue duct, recirculation blower, shaft coupling, motor, exhaust pass, motor drives recirculation blower through shaft coupling, the inlet flue duct import also connects the electric precipitator outlet of big capacity resuperheat coal-burning boiler, the inlet flue duct outlet connects recirculation blower, recirculation blower outlet exit chimney intake, the exhaust pass outlet is connected to coal-fired furnace cavity furnace hopper bottom.

Above-mentioned big Capacity Power Plant Boilers low-temperature flue gas EGR, the described controllable register that between inlet flue duct, is equipped with, controllable register is by the remote control actuating mechanism controls.

Above-mentioned big Capacity Power Plant Boilers low-temperature flue gas EGR, described inlet flue duct and exhaust pass comprise suspension and support and expansion joint.

Operation principle of the present utility model is to adopt the low-temperature flue gas recirculating technique, the flue gas intake of recirculation blower is moved to the electric precipitator outlet, partial fume is sent to the furnace hopper bottom of boiler furnace burner hearth through the low temperature recirculation blower, improve superheater, the vapor (steam) temperature of reheater when underrun, improved the economy of generating set operation.Because the flue-gas temperature behind the electric precipitator is lower, at 130～150 ℃, and also lower through the dust content behind the deduster, wearing and tearing are lacked to fan blade, make that recirculation blower can long-term normal use under low flue-gas temperature.Simultaneously flue gas makes fire box temperature descend to some extent after entering the furnace hopper of lower furnace portion, can reduce the growing amount of nitrogen oxide, helps environmental protection.

(4) description of drawings

Fig. 1 is the schematic diagram of the big Capacity Power Plant Boilers low-temperature flue gas of the utility model EGR in flue gas flow figure, and Fig. 2 is big Capacity Power Plant Boilers low-temperature flue gas EGR structural representation.

Among the figure: 1 furnace hopper, 2 burners, 3 burner hearths, 4 high temperature superheaters, 5 high temperature reheaters, 6 low-temperature reheaters, 7 low temperature superheaters, 8 economizers, 9 air preheaters, 10 electric precipitators, 11 air-introduced machines, 12 chimneys, 13 low-temperature flue gas EGRs, 15 inlet flue ducts, 16 controllable registers, 17 recirculation blowers, 18 shaft couplings, 19 motor, 20 exhaust pass.

(5) specific embodiment

Provide embodiment of the present utility model below in conjunction with accompanying drawing.

Referring to Fig. 1, Fig. 2, a kind of big Capacity Power Plant Boilers low-temperature flue gas EGR comprises inlet flue duct 15, recirculation blower 17, shaft coupling 18, motor 19, exhaust pass 20.Motor 19 drives recirculation blower 17 through shaft coupling 18.Inlet flue duct 15 imports also connect electric precipitator 10 outlets of big capacity resuperheat coal-burning boiler, 15 of inlet flue ducts controllable register 16 are housed, and controllable register 16 is by the remote control actuating mechanism controls, and inlet flue duct 15 outlets connect recirculation blower 17.Recirculation blower 17 outlet exit flue 20 imports, exhaust pass 20 outlets are connected to coal-fired furnace cavity furnace hopper 1 bottom or are connected to the combustion chamber, and the combustion chamber is the combustion space in the burner hearth.Inlet flue duct 15 and exhaust pass 20 comprise suspension and support and expansion joint.

The flue gas flow direction of low-temperature flue gas recirculation is: extract out in the flue of 20%～30% boiler smoke by electric precipitator 10 outlets, enter the recirculation blower 17 of big Capacity Power Plant Boilers low-temperature flue gas EGR 13 through inlet flue duct 15, recirculation blower 17 outputs enter boiler furnace furnace hopper 1 bottom through exhaust pass 20, the flue gas of burning is through burner hearth 3 tops, high temperature superheater 4, high temperature reheater 5, low-temperature reheater 6, low temperature superheater 7, economizer 8, air preheater 9, electric precipitator 10, low-temperature flue gas recirculation blower 17, boiler furnace furnace hopper 1 bottom, flue gas constantly circulates.

Claims

1. one kind big Capacity Power Plant Boilers low-temperature flue gas EGR, its feature comprises inlet flue duct, recirculation blower, shaft coupling, motor, exhaust pass, motor drives recirculation blower through shaft coupling, the inlet flue duct import also connects the electric precipitator outlet of big capacity resuperheat coal-burning boiler, the inlet flue duct outlet connects recirculation blower, recirculation blower outlet exit chimney intake, the exhaust pass outlet is connected to coal-fired furnace cavity furnace hopper bottom or is connected to the combustion chamber.

2. big Capacity Power Plant Boilers low-temperature flue gas EGR according to claim 1 is characterized in that being equipped with controllable register between inlet flue duct, controllable register is by the remote control actuating mechanism controls.

3. big Capacity Power Plant Boilers low-temperature flue gas EGR according to claim 1 and 2 is characterized in that inlet flue duct and exhaust pass comprise suspension and support and expansion joint.