CN206868015U - SCR denitration system SO can be reduced2/SO3The urea pyrolysis ammonia structure of conversion ratio - Google Patents
SCR denitration system SO can be reduced2/SO3The urea pyrolysis ammonia structure of conversion ratio Download PDFInfo
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- CN206868015U CN206868015U CN201720274660.8U CN201720274660U CN206868015U CN 206868015 U CN206868015 U CN 206868015U CN 201720274660 U CN201720274660 U CN 201720274660U CN 206868015 U CN206868015 U CN 206868015U
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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/129—Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
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Abstract
The utility model, which provides one kind, can reduce SCR denitration system SO2/SO3The urea pyrolysis ammonia structure of conversion ratio.Atomizing lance is arranged in pyrolysis chamber；Pyrolysis chamber's gas vent connects with ammonia-spraying grid；Flue gas heat-exchange unit is arranged between first floor catalyst and second layer catalyst, and the smoke inlet of flue gas heat-exchange unit communicates with first floor catalyst exhanst gas outlet, and exhanst gas outlet communicates with second layer catalyst smoke inlet；The outlet of flue gas heat-exchange unit heat transferring medium connects with pyrolysis chamber gas access, heat transferring medium entrance and dilution air outlet；Electric heater is arranged between the outlet of flue gas heat-exchange unit heat transferring medium and pyrolysis chamber gas access.The utility model make use of fume afterheat, reduce conventional urea pyrolysis cost, is lowered into the flue-gas temperature of second layer catalyst, reduces second layer catalyst and below catalytic unit SO2/SO3Conversion ratio, reduce SO3Growing amount, effectively alleviate the deposition problems of upstream device ammonium sulfate and ammonium hydrogen sulfate.
Description
Technical field
The utility model is related to one kind can reduce SCR denitration system SO2/SO3The urea pyrolysis ammonia structure of conversion ratio, category
In coal fired power plant SCR denitrating flue gas field.
Background technology
SCR（Selective Catalytic Reduction, SCR）Gas denitrifying technology is because of its denitration
Efficiency high, technology maturation, it has also become the one preferred technique of Large-scale fire-electricity unit denitration.Its technical principle is that reduction is sprayed into flue gas
Agent NH3, harmless N is generated with the NOx reactions in flue gas under catalyst action2And H2O.SCR gas denitrifying technology engineer applieds
One of key be reducing agent preparation, such as the Chinese patent of Application No. 201310542654.2, present domestic and international application
Reducing agent mainly has liquefied ammonia, ammoniacal liquor, three kinds of urea, but no matter which kind of reducing agent is required to using outside heat by liquid or with it
Ammonia existing for his compound form changes into ammonia, how to reduce the consumption of this portion of energy as reducing agent Study on Preparation
Hot issue.
SCR denitration system is also in the prevalence of ammonium hydrogen sulfate（ABS）The problem of deposition, ABS are not complete by reactor outlet
The NH of full response3(the escaping of ammonia) and the SO in flue gas3With generating under certain condition, ABS under liquid has corrosivity and viscous
Property, endanger catalyst, air preheater and follow-up equipment.As coal unit SCR equipment for denitrifying flue gas puts into operation the increase of time and super
The implementation of low emission transformation, ABS deposition problems progressively highlight, are mainly manifested in air preheater resistance and are significantly increased, seriously
Influence the safe and stable operation of unit.
Meanwhile catalyst also has certain scope and requirement to running temperature in coal unit SCR denitration system, cigarette temperature is low
In minimum continuous running temperature（MOT）NH4HSO can be caused4Simultaneously blocking catalyst internal-response micropore is generated, causes catalyst to lose
It is living.Therefore, in actual denitration operation, in order to ensure the activity of catalyst, denitrification apparatus should operate in minimum company steadily in the long term
It is more than reforwarding row cigarette temperature；However, current domestic unit generally existing rate of load condensate is low, denitrification apparatus entrance flue gas temperature is low, low negative
The denitrification apparatus problem that puts into operation is also more prominent under lotus operating condition.
Correlative study shows：The minimum continuous running temperature of SCR equipment for denitrifying flue gas mainly with inlet flue gas condition
NH3Concentration and SO3Concentration is relevant, with SO3And NH3The increase of concentration and raise, but first floor catalyst after due to major part
NH3It is consumed, for the second layer and with rear catalyst, required minimum continuous running temperature significantly reduces, and fits
When the reduction second layer and later layer catalyst inlet flue-gas temperature will not have an impact to denitrification apparatus full load operation；Separately
Outside, SO2/SO3Conversion mainly by reaction temperature and NH3The influence of concentration.Flue-gas temperature is higher, SO2/SO3Conversion ratio get over
It is high；NH3 concentration is higher, SO2/SO3Conversion ratio it is lower.For SCR flue gas denitrification systems, due to first floor catalyst inlet NH3It is dense
Spend higher, the SO of generation2/SO3Conversion lack, but after first floor catalyst, most NH3It is consumed, the second level and below
The NH3 concentration of catalyst is relatively low, is SO2/SO3The main generation area of conversion, if SCR equipment for denitrifying flue gas can be controlled rationally
Flue-gas temperature after first floor catalyst, for reducing SO3Generation have important influence.
Therefore, how SCR multi-layer catalysts SO is correctly utilized2/SO3Transformation rule and denitration rule, will reduce SO3Generation,
The preparation for reducing the escaping of ammonia and reducing agent is joined together, and while reduction ammonia cost, further alleviates SCR upstream devices
ABS phenomenons, turn into a new focus of reducing agent preparation field research.
Utility model content
The purpose of this utility model is to overcome above shortcomings in the prior art, and provides a kind of structure design and close
Reason reduces SCR denitration system SO2/SO3The urea pyrolysis ammonia structure of conversion ratio, ensureing denitrating system Effec-tive Function
Meanwhile cost of energy prepared by reducing agent is reduced, reduce SO2/SO3Conversion ratio, mitigate ABS depositional phenomenons.
The technical scheme in the invention for solving the above technical problem is：One kind can reduce SCR denitration system SO2/SO3
The urea pyrolysis ammonia structure of conversion ratio, including urea liquid dissolving tank, filter, urea liquid transfer pump, metering distribution
Device, atomizing lance, pyrolysis chamber and SCR reactors；Urea liquid dissolving tank, filter, urea liquid transfer pump, metering point
It is sequentially communicated with device, atomizing lance；Atomizing lance is arranged in pyrolysis chamber；Be disposed with SCR reactors ammonia-spraying grid,
Static mixer, flow straightening grid, first floor catalyst, second layer catalyst and third layer catalyst；The gas vent of pyrolysis chamber with
Ammonia-spraying grid connects；It is characterized in that：Also include flue gas heat-exchange unit, electric heater and dilution air；Flue gas heat-exchange unit is arranged on
Between first floor catalyst and second layer catalyst, the smoke inlet of flue gas heat-exchange unit communicates with the exhanst gas outlet of first floor catalyst,
The exhanst gas outlet of flue gas heat-exchange unit communicates with the smoke inlet of second layer catalyst；Heat transferring medium outlet and the heat of flue gas heat-exchange unit
Solve the outlet of the connection of room gas access, heat transferring medium entrance and dilution air；Electric heater is arranged on flue gas heat-exchange unit and changed
Between thermal medium outlet and pyrolysis chamber gas access.
Dilution air described in the utility model is two, and two dilution airs are arranged in parallel.
Flue gas heat-exchange unit described in the utility model uses pipe heat exchanger, and heat exchanger tube uses finned tube.
Filter described in the utility model is two, and two filters are arranged in parallel.
Urea liquid transfer pump described in the utility model is two, and two urea liquid transfer pumps are arranged in parallel.
The utility model compared with prior art, has advantages below and effect：Because the utility model in SCR by taking off
Flue gas heat-exchange unit is set between nitre device first floor catalyst and second layer catalyst, make use of fume afterheat, reduces traditional urine
Element pyrolysis cost；The flue-gas temperature of second layer catalyst is lowered into simultaneously, reduces second layer catalyst and below catalytic unit
SO2/SO3Conversion ratio, reduce SO3Growing amount, effectively alleviate the deposition problems of upstream device ammonium sulfate and ammonium hydrogen sulfate.
Brief description of the drawings
Fig. 1 is that the utility model embodiment can reduce SCR denitration system SO2/SO3The urea pyrolysis ammonia structure of conversion ratio
Structural representation.
Embodiment
Below in conjunction with the accompanying drawings and the utility model is described in further detail by embodiment.
Referring to Fig. 1, the utility model embodiment can reduce SCR denitration system SO2/SO3The urea pyrolysis ammonia knot of conversion ratio
Structure includes urea liquid dissolving tank 1, filter 2, urea liquid transfer pump 3, metered dispensing unit 4, atomizing lance 5, pyrolysis
Room 6, SCR reactors, flue gas heat-exchange unit 11, dilution air 14 and electric heater.
Urea liquid dissolving tank 1, filter 2, urea liquid transfer pump 3, metered dispensing unit 4, atomizing lance 5 are successively
Connection.
Atomizing lance 5 is arranged in pyrolysis chamber 6.
The gas vent at the top of pyrolysis chamber 6 connects with ammonia-spraying grid 7.
Ammonia-spraying grid 7, static mixer 8, flow straightening grid 9, first floor catalyst 10, are disposed with SCR reactors
Two layers of catalyst 12 and third layer catalyst 13, ammonia-spraying grid 7 is close to the smoke inlet of SCR reactors, third layer catalyst 13
Close to the exhanst gas outlet of SCR reactors.
Filter 2 is two, and two filters 2 are arranged in parallel.
Urea liquid transfer pump 3 is two, and two urea liquid transfer pumps 3 are arranged in parallel.
The outlet of dilution air 14 connects with the heat transferring medium entrance of flue gas heat-exchange unit 11.Dilution air 14 is two, two
Dilution air 14 is arranged in parallel.
Flue gas heat-exchange unit 11 is arranged between first floor catalyst 10 and second layer catalyst 12, the flue gas of flue gas heat-exchange unit 11
Entrance communicates with the exhanst gas outlet of first floor catalyst 10, the exhanst gas outlet of flue gas heat-exchange unit 11 and the flue gas of second layer catalyst 12
Entrance communicates
The outlet of the heat transferring medium of flue gas heat-exchange unit 11 connects with the gas access of the bottom of pyrolysis chamber 6.
The heat transferring medium of flue gas heat-exchange unit 11 exports and electric heater is provided between the gas access of pyrolysis chamber 6, and advantage is real
In existing routine use based on high-temperature flue gas heat exchanger supplemented by electric heater（Fine setting and quick response）Occupation mode, it is necessary
When both it is standby each other, be advantageous to the reliability of raising system.
Flue gas heat-exchange unit 11 uses pipe heat exchanger, and heat exchanger tube uses finned tube, and advantage is can to optimize first floor catalyst
Flue gas flow field between 10 and second layer catalyst 12, the Effec-tive Function of SCR equipment for denitrifying flue gas is further ensured that, reduces ammonia and escape
Ease amount, the generation of ammonium hydrogen sulfate can be also reduced to a certain extent.Flue gas heat-exchange unit 11 is one or more levels.
Metered dispensing unit 4 needs to automatically control the urea amount for spraying into pyrolysis chamber 6 according to system.
Flue gas enters from the smoke inlet of SCR reactors；Mass concentration is 30%~50% urea in urea liquid storage tank 1
After the filtered device 2 of solution filters, metered dispensing unit 4 is sent into by urea liquid transfer pump 3 and carries out metering distribution, is then sent
Enter atomizing lance 5, atomizing lance 5 is injected urea solution into pyrolysis chamber 6, is sufficiently mixed, is pyrolyzed with high-temperature evaporation gas, forms ammonia
The mixed gas of the ammonia of mass concentration 5%, air and vapor；Mixed gas enters spray ammonia by the gas vent at the top of pyrolysis chamber 6
Mixed gas is injected in the flue gas of SCR reactors by grid 7, ammonia-spraying grid 7, and mixed gas passes through static mixer with flue gas
Enter first floor catalyst 10 after 8 mixing and carry out reduction reaction；Flue gas after reduction reaction is reduced by the temperature of flue gas heat-exchange unit 11
Second layer catalyst 12 is sequentially entered after 20~50 DEG C and third layer catalyst 13 carries out reduction reaction, finally from SCR reactors
Exhanst gas outlet discharge.Because flue-gas temperature reduces, the SO of second layer catalyst 12 and third layer catalyst 132/SO3Conversion ratio
Reduce, SO3Growing amount reduce, effectively alleviate catalyst and below in equipment ABS deposition, and do not influence denitrating flue gas dress
Full load is put to put into operation.
Dilution air 14 provides enough diluent gas, and diluent gas is used as heat transferring medium into flue gas heat-exchange unit 11, with
Flue gas in SCR reactors carries out heat exchange, heats diluent gas using fume afterheat, heated diluent gas is again by electricity
Heater is further heated to 350~650 DEG C, subsequently into pyrolysis chamber 6, turns into the boil-off gas for being pyrolyzed urea liquid, with atomization
The urea liquid particle that spray gun 5 sprays into is sufficiently mixed, and urea is decomposed, is prepared reducing agent NH3。
Diluent gas is surrounding air.
Above content described in this specification is only to the utility model structure example explanation；Moreover,
The title that the utility model each several part is taken can also be different, it is all according to the utility model patent conceive described construction, feature and
The equivalent or simple change that principle is done, is included in the protection domain of the utility model patent.
Claims (5)
1. one kind can reduce SCR denitration system SO2/SO3The urea pyrolysis ammonia structure of conversion ratio, including urea liquid dissolving tank,
Filter, urea liquid transfer pump, metered dispensing unit, atomizing lance, pyrolysis chamber and SCR reactors；Urea liquid dissolves
Tank, filter, urea liquid transfer pump, metered dispensing unit, atomizing lance are sequentially communicated；Atomizing lance is arranged on pyrolysis chamber
In；Ammonia-spraying grid, static mixer, flow straightening grid, first floor catalyst, second layer catalyst are disposed with SCR reactors
With third layer catalyst；The gas vent of pyrolysis chamber connects with ammonia-spraying grid；It is characterized in that：Also include flue gas heat-exchange unit, electricity
Heater and dilution air；Flue gas heat-exchange unit is arranged between first floor catalyst and second layer catalyst, the cigarette of flue gas heat-exchange unit
Gas entrance communicates with the exhanst gas outlet of first floor catalyst, the exhanst gas outlet of flue gas heat-exchange unit and the smoke inlet of second layer catalyst
Communicate；The heat transferring medium outlet of flue gas heat-exchange unit connects with pyrolysis chamber gas access, and heat transferring medium entrance and dilution air go out
Mouth connection；Electric heater is arranged between the outlet of flue gas heat-exchange unit heat transferring medium and pyrolysis chamber gas access.
2. according to claim 1 reduce SCR denitration system SO2/SO3The urea pyrolysis ammonia structure of conversion ratio, it is special
Sign is：Described dilution air is two, and two dilution airs are arranged in parallel.
3. according to claim 1 reduce SCR denitration system SO2/SO3The urea pyrolysis ammonia structure of conversion ratio, it is special
Sign is：Described flue gas heat-exchange unit uses pipe heat exchanger, and heat exchanger tube uses finned tube.
4. according to claim 1 reduce SCR denitration system SO2/SO3The urea pyrolysis ammonia structure of conversion ratio, it is special
Sign is：Described filter is two, and two filters are arranged in parallel.
5. according to claim 1 reduce SCR denitration system SO2/SO3The urea pyrolysis ammonia structure of conversion ratio, it is special
Sign is：Described urea liquid transfer pump is two, and two urea liquid transfer pumps are arranged in parallel.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720274660.8U CN206868015U (en) | 2017-03-21 | 2017-03-21 | SCR denitration system SO can be reduced2/SO3The urea pyrolysis ammonia structure of conversion ratio |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201720274660.8U CN206868015U (en) | 2017-03-21 | 2017-03-21 | SCR denitration system SO can be reduced2/SO3The urea pyrolysis ammonia structure of conversion ratio |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106955592A (en) * | 2017-03-21 | 2017-07-18 | 华电电力科学研究院 | The urea pyrolysis ammonia structures and methods of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate can be reduced |
| CN110508132A (en) * | 2019-09-19 | 2019-11-29 | 山东电力工程咨询院有限公司 | A kind of denitrating system and method for denitration of the denitration of gas turbine unit SCR efficient |
-
2017
- 2017-03-21 CN CN201720274660.8U patent/CN206868015U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106955592A (en) * | 2017-03-21 | 2017-07-18 | 华电电力科学研究院 | The urea pyrolysis ammonia structures and methods of SCR denitration system sulfur dioxide/sulphur trioxide conversion rate can be reduced |
| CN110508132A (en) * | 2019-09-19 | 2019-11-29 | 山东电力工程咨询院有限公司 | A kind of denitrating system and method for denitration of the denitration of gas turbine unit SCR efficient |
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