CN103706241A - SNCR flue gas denitration method suitable for full load conditions of circulating fluidized bed boiler - Google Patents
SNCR flue gas denitration method suitable for full load conditions of circulating fluidized bed boiler Download PDFInfo
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- CN103706241A CN103706241A CN201310620062.8A CN201310620062A CN103706241A CN 103706241 A CN103706241 A CN 103706241A CN 201310620062 A CN201310620062 A CN 201310620062A CN 103706241 A CN103706241 A CN 103706241A
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Abstract
The invention discloses a SNCR flue gas denitration method suitable for full load conditions of a circulating fluidized bed boiler and belongs to the field of SNCR flue gas denitration. According to the SNCR flue gas denitration method, a reduction agent is injected into flue gas and the reduction agent and NOx in the flue gas undergo a reaction so that denitration is realized. When a furnace box temperature is above 850 DEG C or boiler load is higher than 50%, reducing agent jet points are necessarily arranged at a cyclone separator inlet horizontal flue, and other selectable jet points can also be used; when a furnace box temperature is greater than 800 DEG C and less than 850 DEG C or boiler load is in a range of 30-50%, reducing agent jet points are necessarily arranged at a furnace wall, and other selectable jet points can also be used; and when a furnace box temperature is less than 800 DEG C or boiler load is below 30%, reducing agent jet points are necessarily arranged at a secondary air duct, and other selectable jet points can also be used. The SNCR flue gas denitration method realizes denitration under the full load conditions of a CFB boiler so that SNCR flue gas denitration efficiency is above 85%.
Description
Technical field
The invention belongs to SNCR denitrating flue gas field.
Background technology
SNCR (SNCR) denitrating flue gas is a kind of full-fledged NOx control technology.SNCR cardinal principle is not have under catalyst action, in 850～1170 ℃ of high-temperature flue gas, injects reducing agent, and reducing agent reacts with NOx in flue gas and generates N
2.Compare with SCR (SCR) denitrating technique, SNCR has that technique is simple, investment and the low feature of operating cost, is particularly suitable for recirculating fluidized bed (CFB) boiler that furnace outlet NOx relative concentration is lower.
Existing CFB-SNCR technology is mainly to spray into reducing agent at CFB boiler cyclone inlet horizontal flue place, reducing agent in cyclone separator, mix with flue gas and with flue gas in NOx react.Although flue gas mixes with reducing agent acutely in cyclone separator, but because reducing agent time of staying in separator is short, be difficult to guarantee that reducing agent and flue gas are full and uniform mixes, the enough reaction time can not be provided for the reduction reaction of NOx, make the denitration efficiency of existing CFB-SNCR technology only can reach 50% under 100% load condition, under optimal conditions, also only can reach 70% denitration efficiency, can not meet more high efficiency denitration requirement; And when CFB boiler at low load operation, as 30-70% boiler load operating mode, fire box temperature is during lower than 850 ℃, SNCR denitration efficiency is very low or to no effect, can not meet boiler full load denitration requirement.Therefore, when CFB boiler furnace outlet NOx concentration surpasses 300mg/Nm
3time, existing CFB-SNCR technology can not be controlled at 100mg/Nm by CFB emission of NOx of boiler concentration
3(GB13223-2011) and lower below.Therefore, must further promote CFB-SNCR technology, improve CFB-SNCR technology denitration efficiency and the adaptability to boiler load, to guarantee that CFB boiler meets NOx emission compliance under full load mode, and keep the advantage of CFB boiler aspect pollutant control.
In prior art, there is the arrangement of various reducing agents injections, but all can not meet the SNCR denitrating flue gas requirement of boiler full load mode.The inventor finds by the research to prior art, such as, in burner hearth, bottom carries out SNCR denitration by wind of boiler or/and Secondary Air sprays into reducing agent: when reducing agent sprays into burner hearth by a wind, because CFBB bottom concentration of solid particles is larger, reducing agent is the active component Fe in solid particle more easily
2o
3, be oxidized to NOx under the catalytic action such as CaO, do not reach the object of NO_x removal, can cause on the contrary furnace outlet NOx concentration to increase; And only spray into reducing agent by Secondary Air, carry out SNCR denitration reaction, be also difficult to realize the denitration efficiency that surpasses 70%.Therefore,, if adopt the method, be difficult to reach the object of efficient NO_x removal.
Summary of the invention
The object of the invention is to: the defect and the deficiency that for existing CFB-SNCR denitration technology, exist, the present invention is based on experimental study, according to the temperature window under CFB boiler different load, choose denitrification reducing agent at the different jeting areas of boiler and in boiler zones of different, implement the combinations of injections of denitrification reducing agent, strengthening denitrification reducing agent is mixed with the full and uniform of flue gas, extend reducing agent and NOx reaction time, provide a kind of can be under CFB boiler full load mode denitration and make SNCR gas denitrifying technology denitration efficiency reach more than 85% method.
The inventor by the research of prior art and the CFB-SNCR injection of reducing agent exit point screening test of carrying out on CFBC experimental rig, obtains as drawn a conclusion:
1, in fire box temperature, be from a wind, to spray into reducing agent all without denitration effect within the scope of 700-930 ℃, and NOx concentration have certain increase;
When 2, fire box temperature is changed to 700 ℃ from 930 ℃, best injection of reducing agent exit point position moves forward to furnace wall by cyclone inlet gradually, then moves forward to Secondary Air pipeline by furnace wall;
3, from positions such as separator outlet, fluidized wind pipeline, material returning device, external bed, spray into reducing agent and there is certain denitration effect, but be not best injection of reducing agent exit point.
Thus, the object of the invention realizes by following technical proposals:
For a SNCR denitration method for flue gas for CFBB full load mode, it by injecting reducing agent in flue gas, and reducing agent reacts and denitration with NOx in flue gas, comprising:
1) when fire box temperature is more than 850 ℃, or boiler load is higher than 50% time, injection of reducing agent exit point is chosen as: essential cyclone inlet horizontal flue, and one or more in optional cyclone separator outlet, secondary air duct, furnace wall, fluidisation air channel, material returning device, external bed;
2) when being greater than 800 ℃, fire box temperature is less than 850 ℃, or boiler load is when 30-50%, injection of reducing agent exit point is chosen as: essential furnace wall, and one or more in optional cyclone inlet horizontal flue, cyclone separator outlet, secondary air duct, fluidisation air channel, material returning device, external bed;
3) when fire box temperature is below 800 ℃, or boiler load is lower than 30% time, injection of reducing agent exit point is chosen as: essential secondary air duct, and one or more in optional cyclone inlet horizontal flue, cyclone separator outlet, furnace wall, fluidisation air channel, material returning device, external bed.
As selection, when injection of reducing agent exit point comprises secondary air duct, in described secondary air duct, mixing arrangement is set.
As selection, when injection of reducing agent exit point comprises fluidisation air channel, in described fluidisation air channel, mixing arrangement is set.
In such scheme, can strengthen the mixture homogeneity of reducing agent and Secondary Air/fluidized wind.
The main scheme of aforementioned the present invention and each further selection scheme thereof can independent assortment to form a plurality of schemes, be that the present invention can adopt and claimed scheme.In the present invention, each selects to get final product and main scheme and other selection any combination, and those skilled in the art can understand there is multiple combination according to prior art and common practise after understanding the present invention program, at this, do not do exhaustive.
Beneficial effect of the present invention: the present invention can generate level according to the fire box temperature window under CFB boiler different load and NOx, for providing different SNCR denitrification reducing agent, CFB boiler sprays arrangement and the strategy that puts into operation, guarantee that CFB-SNCR denitration efficiency all can meet or exceed 85% under CFB boiler full load operating condition.The invention enables in CFB boiler NOx generation concentration and reach 400mg/Nm
3level time, still can only adopt SNCR denitration technology just can meet NOx concentration of emission limit value <100 mg/Nm
3requirement (GB13223-2011), and even lower 50 mg/Nm that reach
3below.
Accompanying drawing explanation
Fig. 1 is the technology arrangement schematic flow sheet of the embodiment of the present invention;
Wherein 1 for cyclone inlet horizontal flue, 2 for cyclone separator outlet, 3 for secondary air duct, 4 for furnace wall, 5 for fluidisation air channel, 6 for material returning device, 7 for external bed, 8 for burner hearth, 9 for cyclone separator, 10 for back-end ductwork, 11 for external bed, 12 for fluidized air blower, 13 be wind preheater, 14 for primary air fan, 15 for Secondary Air preheater, 16 be overfire air fan.
The specific embodiment
Following non-limiting examples is used for illustrating the present invention.
embodiment 1:
On certain 300MWCFB boiler, adopt CFB boiler full-power SNCR high effective flue gas denitration technology to fall low NOx drainage, specifically take measures as follows:
1, as shown in Figure 1, at cyclone inlet horizontal flue 1, cyclone separator outlet 2, secondary air duct 3, furnace wall 4, fluidisation air channel 5, material returning device 6 and external bed 7 places, be provided with reducing agent injection;
When 2, spray gun/jet pipe is arranged on secondary air duct 3 or fluidisation air channel 5, guarantee that reducing agent mixes with Secondary Air or fluidized wind as far as possible, mixing arrangement can be set and strengthen mixing; Spray gun/jet pipe be arranged on cyclone inlet horizontal flue 1 or/and cyclone separator outlet 2 or/and furnace wall 4 or/and during external bed 7, must insert cyclone separator horizontal flue 1 or/and cyclone separator outlet 2 or/and furnace wall 4 or/and the interior 0.05-0.5m injection of external bed 7, to avoid refractory material in cyclone separator or/and furnace wall cooling pipe or/and the corrosion of external bed heat-transfer surface;
3, when fire box temperature is more than 850 ℃, or boiler load is higher than 50% time, injection of reducing agent exit point is chosen as: essential cyclone inlet horizontal flue, and one or more in optional cyclone separator outlet, secondary air duct, furnace wall, fluidisation air channel, material returning device, external bed; When being greater than 800 ℃, fire box temperature is less than 850 ℃, or boiler load is when 30-50%, injection of reducing agent exit point is chosen as: essential furnace wall, and one or more in optional cyclone inlet horizontal flue, cyclone separator outlet, secondary air duct, fluidisation air channel, material returning device, external bed; When fire box temperature is below 800 ℃, or boiler load is lower than 30% time, injection of reducing agent exit point is chosen as: essential secondary air duct, and one or more in optional cyclone inlet horizontal flue, cyclone separator outlet, furnace wall, fluidisation air channel, material returning device, external bed.
Adopt aforementioned schemes, under CFB boiler full load operating condition, CFB-SNCR denitration efficiency all can meet or exceed 85%.When CFB boiler NOx generation concentration reaches the level of 400mg/Nm3, it still can meet the requirement (GB13223-2011) of NOx concentration of emission limit value <100 mg/Nm3, and even lower reaching below 50 mg/Nm3.
comparative example 1:
Fire box temperature 880-900 ℃, load is at 90-100%, and when injection of reducing agent exit point is arranged in cyclone inlet horizontal flue, its denitration efficiency is 76.4%.
comparative example 2:
Fire box temperature 880-900 ℃, load is at 90-100%, and when injection of reducing agent exit point is arranged in furnace wall, its denitration efficiency is 71.9%.
comparative example 3:
Fire box temperature 880-900 ℃, load is at 90-100%, and when injection of reducing agent exit point is arranged in cyclone separator outlet, its denitration efficiency is 52.1%.
comparative example 4:
Fire box temperature 880-900 ℃, load is at 90-100%, and when injection of reducing agent exit point is arranged in material returning device, its denitration efficiency is 33.1%.
comparative example 5:
Fire box temperature 880-900 ℃, load is at 90-100%, and when injection of reducing agent exit point is arranged in cyclone inlet horizontal flue and furnace wall, its denitration efficiency is 91.8%.
comparative example 6:
Fire box temperature 810-830 ℃, load is 50%, and when injection of reducing agent exit point is arranged in furnace wall and cyclone inlet horizontal flue, its denitration efficiency is 89.9%.
comparative example 7:
760 ℃ of fire box temperatures, load is 30%, and when injection of reducing agent exit point is arranged in secondary air duct, its denitration efficiency is 67.2%.
comparative example 8:
760 ℃ of fire box temperatures, load is 30%, and when injection of reducing agent exit point is arranged in fluidisation air channel, its denitration efficiency is 36.2%.
comparative example 9:
760 ℃ of fire box temperatures, load is 30%, and when injection of reducing agent exit point is arranged in secondary air duct, cyclone inlet horizontal flue and fluidisation air channel, its denitration efficiency is 86.5%.
The foregoing is only preferred embodiment of the present invention, not in order to limit the present invention, all any modifications of doing within the spirit and principles in the present invention, be equal to and replace and improvement etc., within all should being included in protection scope of the present invention.
Claims (3)
1. for a SNCR denitration method for flue gas for CFBB full load mode, it by injecting reducing agent in flue gas, and reducing agent reacts and denitration with NOx in flue gas, it is characterized in that comprising:
1) when fire box temperature is more than 850 ℃, or boiler load is higher than 50% time, injection of reducing agent exit point is chosen as: essential cyclone inlet horizontal flue, and one or more in optional cyclone separator outlet, secondary air duct, furnace wall, fluidisation air channel, material returning device, external bed;
2) when being greater than 800 ℃, fire box temperature is less than 850 ℃, or boiler load is when 30-50%, injection of reducing agent exit point is chosen as: essential furnace wall, and one or more in optional cyclone inlet horizontal flue, cyclone separator outlet, secondary air duct, fluidisation air channel, material returning device, external bed;
3) when fire box temperature is below 800 ℃, or boiler load is lower than 30% time, injection of reducing agent exit point is chosen as: essential secondary air duct, and one or more in optional cyclone inlet horizontal flue, cyclone separator outlet, furnace wall, fluidisation air channel, material returning device, external bed.
2. the SNCR denitration method for flue gas for CFBB full load mode as claimed in claim 1, is characterized in that: when injection of reducing agent exit point comprises secondary air duct, in described secondary air duct, mixing arrangement is set.
3. the SNCR denitration method for flue gas for CFBB full load mode as claimed in claim 1, is characterized in that: when injection of reducing agent exit point comprises fluidisation air channel, in described fluidisation air channel, mixing arrangement is set.
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106051751A (en) * | 2016-06-27 | 2016-10-26 | 东方电气集团东方锅炉股份有限公司 | Circulating fluidized bed boiler capable of cooperatively controlling pollutant emission |
| CN106268261A (en) * | 2016-10-10 | 2017-01-04 | 福建龙净环保股份有限公司 | A kind of method of SNCR denitrating flue gas |
| CN108905568A (en) * | 2018-08-20 | 2018-11-30 | 山东省建设高压容器有限公司 | A kind of circulating fluidized bed boiler flue gas desulfuration and denitrification system and its remodeling method |
| CN109058979A (en) * | 2018-08-13 | 2018-12-21 | 中国华能集团有限公司 | Cyclone furnace denitrating system and method |
| CN109794149A (en) * | 2019-03-20 | 2019-05-24 | 中国华能集团清洁能源技术研究院有限公司 | A kind of CFB boiler denitrating flue gas autocontrol method and system |
| CN110064285A (en) * | 2019-04-12 | 2019-07-30 | 华电电力科学研究院有限公司 | A kind of high temperature resistant and the efficient SNCR injection apparatus and its working method for strengthening mixing |
| CN114832589A (en) * | 2022-04-01 | 2022-08-02 | 清华大学山西清洁能源研究院 | SNCR (selective non-catalytic reduction) denitration optimization control method of circulating fluidized bed and cyclone separator |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3626039A1 (en) * | 1986-08-01 | 1988-02-11 | Hoelter Heinz | NOx reduction by ammonia in a fluidised-bed furnace |
| JP2000279751A (en) * | 1999-03-29 | 2000-10-10 | Electric Power Dev Co Ltd | Method and device for denitrating pressure fluidized bed boiler |
| EP2522417A1 (en) * | 2011-05-13 | 2012-11-14 | Hitachi Power Europe GmbH | Flue gas conduit jetting device |
| CN103252163A (en) * | 2013-04-24 | 2013-08-21 | 浙江富春江环保热电股份有限公司 | Device for removing NOX from smoke by combining ammonia agent spraying and built-in catalytic reaction |
-
2013
- 2013-11-29 CN CN201310620062.8A patent/CN103706241B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3626039A1 (en) * | 1986-08-01 | 1988-02-11 | Hoelter Heinz | NOx reduction by ammonia in a fluidised-bed furnace |
| JP2000279751A (en) * | 1999-03-29 | 2000-10-10 | Electric Power Dev Co Ltd | Method and device for denitrating pressure fluidized bed boiler |
| EP2522417A1 (en) * | 2011-05-13 | 2012-11-14 | Hitachi Power Europe GmbH | Flue gas conduit jetting device |
| CN103252163A (en) * | 2013-04-24 | 2013-08-21 | 浙江富春江环保热电股份有限公司 | Device for removing NOX from smoke by combining ammonia agent spraying and built-in catalytic reaction |
Non-Patent Citations (1)
| Title |
|---|
| 陈慧等: "中温条件下烟气De-NOx技术的研究现状与发展", 《中国电机工程学报》 * |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106051751A (en) * | 2016-06-27 | 2016-10-26 | 东方电气集团东方锅炉股份有限公司 | Circulating fluidized bed boiler capable of cooperatively controlling pollutant emission |
| CN106051751B (en) * | 2016-06-27 | 2018-04-06 | 东方电气集团东方锅炉股份有限公司 | The CFBB of Collaborative Control pollutant emission |
| CN106268261A (en) * | 2016-10-10 | 2017-01-04 | 福建龙净环保股份有限公司 | A kind of method of SNCR denitrating flue gas |
| CN109058979A (en) * | 2018-08-13 | 2018-12-21 | 中国华能集团有限公司 | Cyclone furnace denitrating system and method |
| CN109058979B (en) * | 2018-08-13 | 2023-11-03 | 中国华能集团有限公司 | Cyclone furnace denitration system and method |
| CN108905568A (en) * | 2018-08-20 | 2018-11-30 | 山东省建设高压容器有限公司 | A kind of circulating fluidized bed boiler flue gas desulfuration and denitrification system and its remodeling method |
| CN109794149A (en) * | 2019-03-20 | 2019-05-24 | 中国华能集团清洁能源技术研究院有限公司 | A kind of CFB boiler denitrating flue gas autocontrol method and system |
| CN109794149B (en) * | 2019-03-20 | 2021-09-21 | 中国华能集团清洁能源技术研究院有限公司 | Automatic control method and system for flue gas denitration of CFB boiler |
| CN110064285A (en) * | 2019-04-12 | 2019-07-30 | 华电电力科学研究院有限公司 | A kind of high temperature resistant and the efficient SNCR injection apparatus and its working method for strengthening mixing |
| CN110064285B (en) * | 2019-04-12 | 2023-07-14 | 华电电力科学研究院有限公司 | High-temperature-resistant and intensified-mixing high-efficiency SNCR (selective non-catalytic reduction) injection device and working method thereof |
| CN114832589A (en) * | 2022-04-01 | 2022-08-02 | 清华大学山西清洁能源研究院 | SNCR (selective non-catalytic reduction) denitration optimization control method of circulating fluidized bed and cyclone separator |
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