CN103511040A - System for preparing ammonia through ammonium bicarbonate according to dry method and conducting injection in measured mode and for engine SCR - Google Patents
System for preparing ammonia through ammonium bicarbonate according to dry method and conducting injection in measured mode and for engine SCR Download PDFInfo
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- CN103511040A CN103511040A CN201310486810.8A CN201310486810A CN103511040A CN 103511040 A CN103511040 A CN 103511040A CN 201310486810 A CN201310486810 A CN 201310486810A CN 103511040 A CN103511040 A CN 103511040A
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- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
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Abstract
The invention relates to a system for preparing ammonia through ammonium bicarbonate according to a dry method and conducting injection in a measured mode and for an engine SCR and belongs to the technical field of the engine SCR. The system comprises an SCR postprocessor, an ammonia gas generator, a control unit, an electric heater, an electromagnetic switch valve, a heating coil, an ammonia gas generator temperature and pressure sensor, a feeding port, a flow control valve, an ammonia delivery pipe and an ammonia gas nozzle. Pyrolysis is conducted on solid ammonium bicarbonate in the ammonia gas generator so that mixed gas of ammonia gas, steam and carbon dioxide can be released. The mixed gas is injected into a gas exhaust pipe of an engine in a measured mode through the flow control valve and NOx is reduced to N2 through the ammonia gas under the action of a catalyst. According to the system for preparing the ammonia through the ammonium bicarbonate according to the dry method and conducting injection in the measured mode and for the engine SCR, the ammonium bicarbonate is delivered and stored conveniently and safely, the economical performance is better than that of a urea reducing agent, the ammonium bicarbonate serves as the reducing agent for oxygen generation through dry method pyrolysis, the use amount of the ammonium bicarbonate is easy to control, and ammonia gas is generated stably, and the whole system is simple, efficient and simple in structure. The system for preparing the ammonia and conducting injection in the measured mode for the engine SCR is low in cost and good in safety.
Description
Technical field
The invention belongs to I. C. engine exhaust SCR purification system technique field.Be particularly related to a kind of ammonium bicarbonate dry method ammonia processed and metering injection system.
Background technique
The flue gas that motor gives off contains NOx serious environment pollution.The environmental regulation of increasingly stringent requires cluster engine must configure Exhaust gas purifying device.Conventional engine exhaust post-processing technology is generally that a certain amount of urea liquid is sprayed in engine exhaust pipe, and release ammonia is decomposed in urea atomization in engine exhaust pipe.Under the effect of catalyzer, NOx is reduced into N by ammonia
2.
SCR, refers to selective catalytic reduction; SCR reaction is usingd ammonia as reducing agent, in the exhaust passageway of motor, configure SCR catalyzer, by supplying with ammonia to SCR catalyzer, make the NOx(nitrogen oxide in ammonia and exhaust) generation reduction generation, form water vapour (H2O) and nitrogen (N2), thereby can effectively reduce diesel engine NO
xdischarge, purified exhaust.For ammonia is supplied with to SCR catalyzer, conventionally to supplying with in exhaust passageway to compare with ammonia, process easier urea water, therefore need to use urea water injection device by aqueous solution of urea process finer atomization metered injection intake and exhaust pipeline, make vaporific urea water utilize the heat of exhaust to decompose and generate ammonia, thereby the ammonia of generation is adsorbed on SCR catalyzer, makes NOx and ammonia react resolve into water vapour (H2O) and nitrogen (N2) and discharge.How in outlet pipe, spraying the core technology that quantitative wellatomized urea liquid is SCR system, current technology generally adopts metering pump to pressurize to urea liquid.Owing to all need to being powered to this metering pump by storage battery in automobile and other car and boat, and metering pump needs elevated pressures, is beneficial to the atomization of urea, the loss that has therefore strengthened storage battery electric energy; Meanwhile, metering pump is mainly controlled by external producer at present, can't realize domestic, and price is more expensive, and metering pump belongs to precision equipment, is also one of the easiest out of order equipment in SCR system, after being out of order, can only change, so equipment later maintenance upkeep cost is also very high.
Under carbonic hydroammonium normal temperature and pressure, with solid-state, exist, ammonium hydrogencarbonate, not having safety problem aspect storage and transportation, is compared with urea, carbonic hydroammonium low price, and decomposition temperature is low, and system economy is better.Therefore, from Security and Economy angle, consider, carbonic hydroammonium is suitable as the reducing agent of diesel SCR exhaust after treatment system.
Summary of the invention
The object of the invention is to needs metering pump to make cost higher or make the problems such as storage battery energy consumption Stability and veracity too high and urea solution jet amount is poor for existing SCR reaction reductant metering ejecting system, and a kind of ammonium bicarbonate dry method ammonia processed and metering injection system for SCR reaction is provided.
For achieving the above object, the step of described a kind of ammonium bicarbonate dry method ammonia processed and metering injection system is: 1) ammonium hydrogencarbonate solid is added to ammonia generator, in ammonia generator, introduce and utilize the heating coil of engine exhaust or adopt electric heating to heat carbonic hydroammonium, carbonic hydroammonium high-temperature heating is decomposed into ammonia, carbon dioxide and water vapour mixed gas; Mixed gas enters engine exhaust pipe through flow control valve and ammonia nozzle subsequently, mixes, and under catalyst action, in SCR preprocessor, NOx is reduced to N in outlet pipe with engine exhaust
2.
Beneficial effect of the present invention is:
1. the present invention adopts carbonic hydroammonium as reducing agent, because carbonic hydroammonium is nontoxic, and is heated and easily decomposes, and ammonia-preparing process is easily controlled, and ammonia generating rate is stable.Transportation stores convenient and safe.System operation is fool proof.
2. the present invention adopts carbonic hydroammonium as reducing agent, by SCR, reacts required ammonia amount conversion, and it is more cheap than adopting urea that reducing agent adopts carbonic hydroammonium, good economy performance.Carbonic hydroammonium oxygen content is 21. 5%, and urea oxygen content is 56.7%.The average price of domestic carbonic hydroammonium is about 480 yuan/ton of left and right, and the average selling price of urea is 1800 yuan/ton of left and right.1 kilogram of ammonia of every generation, adopts bicarbonate to connect as reducing agent, need to spend 2.23 yuan; And adopt urea as reducing agent, need to spend 3.17 yuan.Obviously, carbonic hydroammonium is more more economical than urea as reducing agent.
3, the present invention adopts gas or flow adjusting valve for steam to control the amount that sprays into the reducing agent ammonia in engine exhaust pipe, do not need to manufacture accurate and expensive urea solution metering pump, thereby can reduce widely product cost and maintenance cost, break away from the dependence to imported product; Simultaneously owing to adopting gas flow control valve metering to spray into the ammonia amount in outlet pipe, measuring accuracy is very high, low price can domesticize, equipment and technology is ripe, with low cost, all devices all can be selected production domesticization equipment, easily relies on Domestic Resources to realize industrial applications, is conducive to large-scale promotion and application.
4. the mixed gas that carbonic hydroammonium decomposes adopts gaseous state to spray into engine exhaust pipe, thereby more easily evenly mixes with the waste gas of outlet pipe, is conducive to the carrying out of reaction, and can not has the problems such as urea liquid crystallization and obstruction.
Accompanying drawing explanation
Fig. 1 is described a kind of ammonium bicarbonate by using wet process for motor SCR ammonia processed and metering injection system structural representation.
Number in the figure: 1:SCR preprocessor, 2: the anti-raw device of ammonia, 3: control unit, 4: electric heater, 5: electromagnetic switch valve, 6: heating coil, 7: ammonia generator pressure and temp, pressure transducer, 8: charging hole, 9: flow control valve, 10: defeated ammonia pipe, 11: ammonia nozzle.
Embodiment
The invention provides a kind of ammonium bicarbonate dry method for motor SCR ammonia processed and metering injection system, below in conjunction with accompanying drawing explanation and embodiment, the present invention is described in further detail.
As shown in Figure 1, a kind of ammonium bicarbonate dry method for motor SCR ammonia processed and metering injection system, comprise 1:SCR preprocessor, 2: the anti-raw device of ammonia, 3: control unit, 4: electric heater, 5: electromagnetic switch valve, 6: heating coil, 7: ammonia generator pressure and temp, pressure transducer, 8: charging hole, 9: flow control valve, 10: defeated ammonia pipe, 11: ammonia nozzle.
Described carbonic hydroammonium is stored in ammonia generator, and carbonic hydroammonium is heated to decompose and produces ammonia, carbon dioxide, water vapour mixed gas in ammonia generator; On ammonia generator 2, be provided with temperature, pressure transducer 7, described temperature, pressure transducer 7 are electrically connected to controller 3 or vehicle-mounted ECU, and temperature, pressure transducer 7 all feed back to ECU (Electrical Control Unit) 3 or vehicle-mounted ECU by the temperature of the anti-generator 2 of ammonia and pressure and other parameters.Ammonia generator 2 can utilize the heating coil 6 of introducing engine exhaust to heat, and whether heating coil 6 heating control heating by the introducing of electromagnetic switch valve 5 control engine exhausts, and the switch of electromagnetic switch valve is controlled by ECU (Electrical Control Unit) 3 or vehicle-mounted ECU; Also can adopt the other forms of mode of heatings such as electric heater 4.Its object is all to provide heat for the carbonic hydroammonium reaction in ammonia generator 2.Ammonia generator 2 is connected with ammonia nozzle 11 by defeated ammonia pipe 10, on described defeated ammonia pipe 10, flow control valve 9 is set; Described flow control valve 9 is electrically connected to control unit 3 or vehicle-mounted ECU, thereby control unit 3 or vehicle-mounted ECU are controlled the quantity delivered that the unlatching size of flow control valve 9 is controlled ammonia, carbon dioxide and steam mixture, realize thus flow control valve 9 and accurately control and spray into outlet pipe air-fuel mixture amount.SCR preprocessor 1 is arranged on ammonia nozzle 11 downstreams, mainly carrier and catalyzer, consists of, and its effect is under the effect of catalyzer, and the ammonia gas react of the NOx in engine exhaust and injection is generated to harmless nitrogen G&W, reaches NO in reduction, purifying exhaust gas<sub TranNum="69">x</sub>effect.
Referring to Fig. 1, working procedure specifically comprises as follows: one, startup system: during engine start, should will start for ammonium bicarbonate dry method ammonia processed and the metering injection system of motor SCR, ECU (Electrical Control Unit) 3 is by ammonia generator temperature, the temperature and pressure parameter that pressure transducer 7 detects in ammonia generator 2, when the pressure drop of ammonia generator 2 is during to the working pressure minimum value of flow control valve 9, ECU (Electrical Control Unit) 3 sends instruction and pumps into a certain amount of ammonium bicarbonate soln to ammonia generator 2, when the working pressure of ammonia generator 2 reaches the working pressure maximum value of flow control valve 9, time-out is to ammonia generator 2 pumping ammonium bicarbonate solns, when flow control valve 9 herein guarantees normal metering gas, it has a range of working pressure conventionally, in this range of working pressure, flow control valve 9 can be realized correct function of measuring, and the maximum value of flow control valve 9 working pressures and minimum value are determined by its design.Two, ammonium bicarbonate soln decomposes: ammonium bicarbonate soln is decomposed into ammonia, carbon dioxide and water vapour mixed gas in ammonia generator 2 under the effect of outlet pipe or electric heater heating, and mixed gas makes ammonia generator 2 pressure be elevated to the range of working pressure of flow control valve 9.Three, ammonia sprays: when ammonia generator 2 pressure are elevated to after the range of working pressure of flow control valve 9, the mixed gas of ammonia, carbon dioxide and water vapour is transported to ammonia nozzle 11 by defeated ammonia pipe 10, then the mixed gas of ammonia and water vapour is sprayed in outlet pipe, flow control valve 9 sprays into the amount in outlet pipe according to control unit 3 or vehicle-mounted ECU instruction accurate control ammonia, carbon dioxide and water vapour mixed gas, in SCR preprocessor 1, the ammonia in mixed gas under catalyst action by the NO in exhaust
xdischarge is reduced to nitrogen, reaches and reduces NO in exhaust
xeffect; Four, the ammonium bicarbonate soln of again annotating: when ammonia generator 2 internal pressures drop to flow control valve 9 working pressure minimum value, ECU (Electrical Control Unit) 3 sends instruction and again to ammonia generator 2, pumps into a certain amount of ammonium bicarbonate soln, ammonium bicarbonate soln generates ammonia, carbon dioxide and water vapour mixed gas in the interior reaction of ammonia generator 2, make to reach and be raised to flow control valve 9 working pressure maximum values in ammonia generator 2 internal pressures, then suspend pumping ammonium bicarbonate soln, so periodic duty.In the present invention, owing to adopting, directly in outlet pipe, spray into ammonia, do not need expensive accurate urea metering pump, with low cost, all devices all can be selected production domesticization equipment, is conducive to large-scale promotion and application; And ammonia more easily mixes with NOx and reacts, and NOx transformation efficiency is higher.
Above content is in conjunction with concrete preferred implementation further description made for the present invention, can not assert that specific embodiment of the invention is confined to these explanations.For general technical staff of the technical field of the invention, without departing from the inventive concept of the premise, can also make some simple deduction or replace, said structure all should be considered as belonging to protection scope of the present invention.
Claims (6)
1. for ammonium bicarbonate dry method ammonia processed and a metering injection system of motor SCR, comprising: 1.SCR preprocessor, 2: the anti-raw device of ammonia, 3. control unit, 4. electric heater, 5. electromagnetic switch valve, 6. heating coil, 7. ammonia generator pressure and temp, pressure transducer, 8. charging hole, 9. flow control valve, 10: defeated ammonia pipe, 11: ammonia nozzle.
2. a kind of ammonium bicarbonate dry method for motor SCR according to claim 1 ammonia processed and metering injection system, it is characterized in that: on described ammonia generator (2), be provided with temperature, pressure transducer (7), described temperature, pressure transducer (7) are electrically connected to control unit (3) or vehicle-mounted ECU.
3. a kind of ammonium bicarbonate dry method for motor SCR according to claim 1 ammonia processed and metering injection system, it is characterized in that: described carbonic hydroammonium decomposition reaction institute calorific requirement can be adopted by electric heating, also can be heated by engine exhaust, and other mode of heatings.
4. a kind of ammonium bicarbonate dry method for motor SCR according to claim 1 ammonia processed and metering injection system, is characterized in that: described ammonia generator is the reservoir vessel of carbonic hydroammonium, is also the reactor of carbonic hydroammonium decomposition reaction.
5. a kind of ammonium bicarbonate dry method for motor SCR according to claim 1 ammonia processed and metering injection system, it is characterized in that: described defeated ammonia pipe and engine exhaust pipe are arranged in parallel in order to gathering around outlet pipe companion heat, to avoid the raw reverse reaction of ammonia and carbon dioxide occurs at low temperatures to generate carbaminate blocking pipe.
6. a kind of ammonium bicarbonate dry method for motor SCR according to claim 1 ammonia processed and metering injection system, it is characterized in that: described flow control valve can be gas or steam Proportional valve, throttle valve, gas nozzle etc. can accurately be controlled the flow control device of mixed gas.
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| CN201310486810.8A CN103511040A (en) | 2013-10-17 | 2013-10-17 | System for preparing ammonia through ammonium bicarbonate according to dry method and conducting injection in measured mode and for engine SCR |
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| CN201310486810.8A CN103511040A (en) | 2013-10-17 | 2013-10-17 | System for preparing ammonia through ammonium bicarbonate according to dry method and conducting injection in measured mode and for engine SCR |
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Cited By (4)
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| CN103912348A (en) * | 2014-04-08 | 2014-07-09 | 刘观柏 | Electric heating ammonium bicarbonate dry ammonium preparation and measured spraying system |
| CN110741141A (en) * | 2017-06-16 | 2020-01-31 | 沃特洛电气制造公司 | Temperature-based control of reagent distribution |
| CN111577503A (en) * | 2020-04-24 | 2020-08-25 | 中国第一汽车股份有限公司 | Temperature control device |
| CN113090361A (en) * | 2019-12-23 | 2021-07-09 | 中国船舶重工集团公司第七一一研究所 | SCR supply injection system using solid ammonium as reducing agent |
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Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103912348A (en) * | 2014-04-08 | 2014-07-09 | 刘观柏 | Electric heating ammonium bicarbonate dry ammonium preparation and measured spraying system |
| CN110741141A (en) * | 2017-06-16 | 2020-01-31 | 沃特洛电气制造公司 | Temperature-based control of reagent distribution |
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| CN113090361A (en) * | 2019-12-23 | 2021-07-09 | 中国船舶重工集团公司第七一一研究所 | SCR supply injection system using solid ammonium as reducing agent |
| CN113090361B (en) * | 2019-12-23 | 2024-06-28 | 中国船舶集团有限公司第七一一研究所 | SCR (selective catalytic reduction) supply injection system taking solid ammonium as reducing agent |
| CN111577503A (en) * | 2020-04-24 | 2020-08-25 | 中国第一汽车股份有限公司 | Temperature control device |
| CN111577503B (en) * | 2020-04-24 | 2022-04-01 | 中国第一汽车股份有限公司 | Temperature control device |
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Application publication date: 20140115 |