CN104061571A - Banking fire method for circulating fluidized bed coal-fired boiler - Google Patents

Abstract

The invention discloses a banking fire method for a circulating fluidized bed coal-fired boiler. According to the banking fire method for the circulating fluidized bed coal-fired boiler, the heat storage capacity of a fluidized bed coal layer is improved, the method is convenient and rapid to use and flexible, the boiler banking fire maintenance time is greatly prolonged, the phenomenon that fire in the boiler burns up for the second time, or even boiler starting operation through original ignition is carried out is avoided, and cost and energy sources are greatly saved.

Description

A kind of circulating fluidized bed combustion coal boiler pressuring fire method

Technical field

The present invention relates to a kind of coal-burning boiler banking fire method, relate in particular to a kind of banking fire method of circulating fluidized bed combustion coal boiler.

Background technology

The fault of the aspects such as coal-burning boiler, in production run process, often there will be some thermal technologies, equipment, electric, at this time just needs banking fire blowing out maintenance conventionally, after fixing a breakdown, more again raises fiery furnace lifting.Holding time of banking fire blowing out is most important, if still cannot handle trouble point well within the time maintaining, generally can only operate by the program of original igniting furnace lifting, not only down time long, and various energy resource consumption waste is large.Even thermal technology conditions permit, maintenance period secondary is raised fire, holds time with prolonged boiler, also will cause a large amount of fire coal wastes.

For grate type boiler, before banking fire, can suitably reduce boiler load, then according to the length of furnace outage time, coal seam is thickeied, suitably accelerate fire grate speed, in the time that the coal seam of thickening approaches to eagle iron, stop fire grate and rotate, stop induced draft, the adjustable plate gear and the damper that turn down in right amount air zoning, rely on gravity-flow ventilation to maintain the faint burning of coal, reaches the object maintaining.During this time, can hold time by the mode proper extension that manually spreads coal.And circulating fluidized bed combustion coal boiler, wanting to extend banking fire holds time, before common way is banking fire, suitably improve boiler load, be with high bed bed material thickness, stop after coal supply, stop successively immediately wind one time, Secondary Air and air inducing, and close all air doors, stop boiler feedwater steam off output valve simultaneously, enter banking fire and maintain state.But this method of operating is held time and generally can only be controlled in 6 hours, the failed risk of fire is raised in just existence to exceed 6 hours, and raising boiler load needs the regular hour, particularly process conditions do not allow or quantity of steam cannot the situation of balance under, operating space can be more difficult, and boiler pressuring fire is held time and can be as short as in 2 hours.If the maintenance work of boiler pressuring fire maintenance period is not smooth or occur other unexpected factor, will directly cause boiler raise fire failure and stop working, cause larger property loss and energy waste.

Summary of the invention

The present invention is in order to solve the circulating fluidized bed combustion coal boiler pressuring fire short problem of holding time.Want prolonged boiler banking fire and hold time, Main Means is nothing more than two kinds, and a kind of is the heat storage capacity that improves fluid bed coal seam, and the 2nd, reduce as far as possible maintenance period thermal loss.The present invention, by improving the heat storage capacity in fluid bed coal seam, has extended significantly boiler pressuring fire and has held time, and even reaches more than 16 hours.

The present invention includes following steps:

(1) connect after boiler pressuring fire instruction, first stop successively Secondary Air and air inducing, after time delay certain hour, stop again wind and coal supply simultaneously;

(2) boiler pressuring fire flow operations routinely again, stops boiler feedwater, steam off output valve, closes each air door of fan, enters banking fire and maintains state.

Wherein, the described boiler of step (1) refers to that evaporability is lower than 130 tons/hour, particularly the medium temperature and medium pressure CFBB of 35～75 tons/hour.

Time delay certain hour described in step (1) is according to the CFBB of various different sizes and supporting feeder thereof, and the bonded boiler banking fire demand of holding time is determined, generally be set between 15～60 seconds, overlong time one is there is no need, the 2nd, fluid bed coal seam carbon residue is too high, the risk firing while existing boiler to raise fire.Meanwhile, must raise fiery operating provision by strict implement boiler, first open air inducing, the issuable flammable explosive gas of coal seam carbon residue imperfect combustion of finding time, more slowly open wind one time, and enter and raise fiery state, stop boiler blast accident.

Compared with the present invention raises ignition technique with existing CFBB, do not need to be with for a long time high bed bed material thickness, can facilitate more rapidly, carry out flexibly and comfortably banking fire operation; Hold time owing to significantly having extended circulating fluidized bed combustion coal boiler pressuring fire, make Maintenance of Boiler time, repair quality obtain sufficient guarantee, avoided boiler secondary to raise the even original igniting furnace lifting operation of fire, saved a large amount of properties and the energy.

Claims (3)

1. a banking fire method for circulating fluidized bed combustion coal boiler, is characterized in that comprising the following steps:

(1) connect after boiler pressuring fire instruction, first stop successively Secondary Air and air inducing, after time delay certain hour, stop again wind and coal supply simultaneously;

(2) boiler pressuring fire flow operations routinely again, stops boiler feedwater, steam off output valve, closes each air door of fan, enters banking fire and maintains state.

2. a method according to claim 1, wherein the described boiler of step (1) is the medium temperature and medium pressure circulating fluidized bed combustion coal boiler of 35～75 tons/hour.

3. a method according to claim 1 and 2, wherein described in step (1), time delay certain hour is 15～60 seconds.