Background technology
The cleaning of coal is the great technical task in energy and environment protection field, the world today with efficient the utilization, also is one of gordian technique of Chinese national economy and social sustainable development.Coal Gasification Technology is the key of clean coal technology as the frontier technology of coal deep processing, conversion.Gasification is meant throws in coal in vapourizing furnace, and under certain temperature and pressure condition, organic matter with vaporized chemical (as steam/air or oxygen etc.) series of chemical takes place in the coal, the solid coal is converted into contains CO, H
2, CH
4Deng inflammable gas and CO
2, N
2Process Deng incombustible gas.The coal gasification technology is very extensive in sector applications such as combined cycle (IGCC) power generation assembly, synthetic ammonia and synthesizing methanols, and vapourizing furnace then is the key equipment of gasification.Therefore, the scientific and technical personnel of countries in the world have researched and developed out various types of vapourizing furnaces.Wherein, air flow bed is compared with fixed bed, fluidized-bed, and air flow bed has coal and granularity adaptability and better technical feature preferably, is coal-based large vol, high effect cleaning, reliable combustion gas and the one preferred technique of synthesis gas preparation device.
At present, adopt in the technology that air flow bed gasifies, representational major technique school has: the employing coal water slurry is a raw material, the U.S. Texaco vapourizing furnace of slag tap and be raw material with the dry coal powder, the Dutch Shell vapourizing furnace of slag tap.
U.S. Texaco vapourizing furnace, coal water slurry is sprayed into downwards by the vapourizing furnace furnace roof, carries out the slag gasification in stove.Because the residence time wider distribution of material in this vapourizing furnace, the residence time of partial material in stove is very short, does not reach mean residence time and just overflows outside the stove, and therefore, efficiency of carbon conversion generally is lower than 95%.The gasification operation temperature of U.S. Texaco vapourizing furnace is 1400~1500 ℃, and gasification operation pressure is 2.5~8.5Mpa.The worldwide commercialization of U.S.'s Texaco vapourizing furnace market occupancy volume is big, technology maturation, it because of coal slurry preparation, metering, carry, control is simple, safe and reliable, the working pressure height can reach the low technical characterstic that waits of 6.5MPa and investment and be used widely.
Holland Shell vapourizing furnace belongs to pressurization to spray formula fine coal slag tap vapourizing furnace.The dry coal powder is with pressurization locking-type coal bunker, by nitrogen or CO
2Gas delivery mixes to spray in the stove with oxygen and a small amount of water vapor, gasifier temperature maintains 1400~1600 ℃, and the slag of formation is discharged at the central bottom slag-drip opening, and returned cold coal gas Quench mode is adopted in the coal gas back of coming out of the stove.This stove is equipped with four coal burners, and the installing water wall, will produce saturation steam in water wall.
Holland's Shell vapourizing furnace is compared with U.S. Texaco vapourizing furnace, and cold gas efficiency is high 6~8 percentage points, descends significantly than coal consumption with than the oxygen consumption, and coal adaptability is wider, and the foundation of investment of gasification system is suitable.
In China, surplus the commercialization of coal and the socialization existing so far 100 year, but form can with the autonomous property right Coal Gasification Technology of the commercialization that contends with in the world.Play Xibei Chemical Inst the seventies in 20th century and researched and developed the coal water slurry gasification technology and built pilot plant, provide rich experience for 4 tame factories after this introduce Texaco coal water slurry gasification technology.
The nineties later stage, along with applying of clean coal power generation technology such as IGCC, under the subsidy of State Power Corporation, Xi'an hot working research institute has set up domestic first cover dry coal powder pressure gasifying characteristic test apparatus and dry coal powder pressurization concentrated phase feed device, it is 700kg that day is handled the coal amount, vapor pressure is 2.0~3.0MPa, and has carried out the research of dry coal powder gasification characteristic and dry coal powder concentrated phase pressurization feeder system.
Tenth Five-Year Plan Period, Yankuang Group Ltd., East China University of Science bore " 863 " problem---novel water-coal-slurry gasification technology, had built the opposed coal slurry gasifier of the four nozzles commercial demonstration unit (4.0MPa) of day handling the 1000t coal.
Tenth Five-Year Plan Period, Xi'an hot working research institute is responsible for having finished the research of national high-tech research evolutionary operation(EVOP) (863 Program) problem " dry coal powder pressure gasifying technology " pilot plant test, utility model the double-section dry coal powder pressurized-gasification furnace of band water wall and gas cooler, the scale of having built up is the pilot plant of 36t/d.Vapourizing furnace working pressure 3.4MPa, 1400~1600 ℃ of service temperatures, the close phase charging of dry coal powder, slag tap has carried out tens kinds of coal gasification tests, and has passed through national acceptance.
Summary of the invention
The purpose of this utility model is to provide a kind of solid slag discharging gasifying furnace of multistage powdered coal carrying bed, and it is more even that this vapourizing furnace distributes the flow field of gasification reactor chamber and temperature field, and the gasification operation temperature is between 1300~1500 ℃.With the dry coal powder is raw material, and air, oxygen enrichment or pure oxygen are vaporized chemical.For the coal of ash-rich and high ash melting point, the lime-ash that its gasification produces is discharged from the vapourizing furnace bottom with solid-state form, and flying dust is sent into gasification reactor chamber through flying dust recirculation unit and first step nozzle feeder system after then separating, collect through cyclonic separator.
For achieving the above object, the technical solution adopted in the utility model is: comprise the vapourizing furnace housing and the gasification reactor chamber that offer pneumatic outlet and slag-drip opening, be furnished with a group or more the multistage nozzle that is connected with gasification reactor chamber symmetrically and evenly at the different level place of vapourizing furnace housing, the lime-ash that gasification reactor chamber produces is discharged through slag-drip opening with solid-state form, the pneumatic outlet of gasification reactor chamber is connected with cyclonic separator by pipeline, the upper end outlet of cyclonic separator is connected with gas cooler by pipeline, and the lower end of cyclonic separator is connected with the first step nozzle of minimum absolute altitude by the flying dust recirculation unit.
Be provided with the water wall that constitutes gasification reactor chamber in the vapourizing furnace housing of the present utility model; Multistage nozzle comprises first step nozzle, second stage nozzle and the third stage nozzle that is arranged on vapourizing furnace housing different level place from bottom to top.
Because the utility model is provided with multistage nozzle, every grade of nozzle drops into the material difference, and amount is also different, by regulating the difference of every grade of nozzle input inventory, not only adjusted the interior gasification reaction of temperature field, flow field and stove of gasification reactor chamber, and the varying load ability is strengthened greatly.
Embodiment
Below in conjunction with accompanying drawing the utility model is described in further detail.
Referring to accompanying drawing 1, the utility model comprises vapourizing furnace housing 1, gasification reactor chamber 2, water wall 3, multistage nozzle, cyclonic separator 7, flying dust recirculation unit 8 and gas cooler 9.Symmetric arrangement has first step nozzle 6, second stage nozzle 5 and third stage nozzle 4 from bottom to top at the different level place of vapourizing furnace housing 1, the pneumatic outlet of gasification reactor chamber 2 is connected with cyclonic separator 7 by pipeline, and cyclonic separator 7 is connected with gas cooler 9.Flying dust is delivered to first step nozzle feeder system through flying dust recirculation unit 8 after cyclonic separator separates, collects.Raw gas enters follow-up system after cooling off through gas cooler 9.Flying dust is then sent into the feeder system of first step nozzle 6 through flying dust recirculation unit 8.The lime-ash that gasification reactor chamber 2 produces is then discharged through the hearth deslagging mouth with solid-state form.
The utility model process implementing step:
Initial period, 1300 ℃~1500 ℃ of vapourizing furnace service temperatures, under the condition of working pressure 3.0MPa, at first the dry coal powder (contains nitrogen or CO
2) and vaporized chemical (air, oxygen enrichment or pure oxygen) and water vapor enter in the gasification reactor chamber 2 from the first step nozzle 6 of vapourizing furnace bottom lowest bid eminence symmetric arrangement and gasify.After gasification was stablized 10 minutes, vaporized chemical and water vapor began to enter in the gasification reactor chamber 2 from the second stage nozzle 5 of the middle absolute altitude symmetric arrangement of vapourizing furnace, and the dry coal powder (contains nitrogen or CO simultaneously
2) and water vapor drop into gasification reactor chambers from the third stage nozzle 4 of vapourizing furnace top absolute altitude symmetric arrangement.In gasification reactor chamber 2, generate with CO and H
2Be main raw gas, the temperature of the raw gas of generation is about 1500 ℃, and raw gas flows in vapourizing furnace from bottom to top, is exported to cyclonic separator 7 through vapourizing furnace and carries out entering gas cooler 9 and cooling off after flying dust separates, and enters follow-up system at last.Flying dust is sent into first step nozzle 6 feeder systems through flying dust recirculation unit 8, enter then in the gasification reactor chamber 2, and the lime-ash that gasification reactor chamber 2 produces is discharged through slag-drip opening with solid-state form.
The utility model has proposed solid slag discharging gasifying furnace of multistage powdered coal carrying bed first, and the flow field of gasification reactor chamber and temperature field distribute more even, and efficiency of carbon conversion is up to more than 98%.This gasification furnace structure is reasonable, and is lower than the oxygen consumption, and supporting oxygenerator investment is less, and the varying load ability is strong, and service life of equipment is long, the reliability height.The gasification operation temperature is suitable for high ash, high ash melting point coal gasification between 1300~1500 ℃.