CN104153853A - Tail gas heating and urea hydrolysis system applied to vehicular SCR (selective catalytic reduction) - Google Patents
Tail gas heating and urea hydrolysis system applied to vehicular SCR (selective catalytic reduction) Download PDFInfo
- Publication number
- CN104153853A CN104153853A CN201410337973.4A CN201410337973A CN104153853A CN 104153853 A CN104153853 A CN 104153853A CN 201410337973 A CN201410337973 A CN 201410337973A CN 104153853 A CN104153853 A CN 104153853A
- Authority
- CN
- China
- Prior art keywords
- tail gas
- urea
- gas heating
- reactor
- gas
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- 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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
Abstract
The invention discloses a tail gas heating and urea hydrolysis system applied to vehicular SCR (selective catalytic reduction). The tail gas heating and urea hydrolysis system comprises a reactor barrel. A tail gas heating corrugated pipe is arranged in the reactor barrel, a gas and liquid separator is arranged on the upper side of the reactor barrel and is connected with a pressure stabilizing cavity, a product gas outlet is formed in the upper end of the pressure stabilizing cavity, and staggered oblique barriers are arranged inside the gas and liquid separator and are arranged on the inner wall of the gas and liquid separator. A series of physical and chemical change procedures of heating, pressurization, hydrolysis reaction, gaseous product precipitation, gas and liquid separation, flow stabilization and the like can be carried out on urea solution in a hydrolysis reactor. The tail gas heating and urea hydrolysis system has the advantages that a closed-loop SCR control system without NOX sensors can be formed, accordingly, the NOX sensors, urea tank cooling systems and vehicular compressed air sources can be omitted as compared with the conventional reactors, and equipment materials and cost can be saved; the circular tail gas heating corrugated pipe is of a corrugated heat exchange pipe structure, accordingly, heat transfer can be intensified, and the heat transfer efficiency can be improved.
Description
Technical field
The present invention relates to a kind of hydrolysis of urea system, particularly relate to a kind of tail gas heating hydrolysis of urea system that is applied to vehicle-mounted SCR.
Background technique
Vehicle-mounted SCR refers to and is arranged in automobile exhaust system, and the NOx in motor discharge is catalysed and reduced into N
2and O
2catalytic reduction device, select aqueous solution of urea as reducing agent.Aqueous solution of urea is ejected in the outlet pipe of catalyzer upstream, and under the effect of exhaust gas temperature and air-flow, pyrolysis is produced as CO
2and ammonia, ammonia is reduced into free of contamination nitrogen G&W as reducing agent by NOx.The mature technology that urea liquid generates NH3 has pyrolysis and is hydrolyzed two kinds.Existing pyrolytic technique system flow complexity, generates sediments and crystallization under low temperature, affect system effectiveness.
Summary of the invention
Technical problem to be solved by this invention is that by hydrolysis of urea system applies, on vehicle-mounted SCR, this hydrolysis of urea system is utilized using waste heat from tail gas heating urea, without NO
xsensor just can form closed loop control, can simplify SCR system flow, improves system effectiveness and reduces system user cost.
The present invention requires the technical problem solving to be achieved through the following technical solutions: a kind of tail gas heating hydrolysis of urea system that is applied to vehicle-mounted SCR, and utilize tail gas heating urea to be hydrolyzed and realize the closed loop control of SCR system.This system comprises reactor, tail gas heating line pipe, gas-liquid separator, pressure stabilizing cavity, gas product output pipeline, one-way valve and corresponding connecting pipeline.Tail gas heating line pipe is located in reactor, two ends are connected with offgas duct and vehicle-mounted SCR catalyst converter respectively, reactor is provided with urea liquid import and urea liquid outlet, reactor top arranges gas-liquid separator, the inwall of gas-liquid separator is provided with staggered sloping baffle, the excessive urea droplet that sloping baffle carries in the process of shifting out for blocking the gaseous product that overflows.Gas-liquid separator is connected with pressure stabilizing cavity, and the upper end of pressure stabilizing cavity is provided with gas product output pipeline, and gas product output pipeline is connected with one-way valve, and one-way valve lower end is connected with product gas outlet pipe, and product gas outlet stretches into the blowdown piping of tail gas heating line pipe.Far transmission level meter and teletransmission thermometer are installed in reactor, and tail gas heating line pipe adopts ripple type heat exchange tube structure, and its cross section is circular, and product gas outlet is used one-way valve to control.Utilize tail gas heating urea to be hydrolyzed and realize the closed loop control of SCR system.
Job step of the present invention is: urea liquid is by urea liquid import injecting reactor, tail gas enters reactor through tail gas heating line pipe, heat is conducted to the urea liquid outside housing interior conduit, in uniform temperature, pressure range, through certain reaction time, (reaction time is different and different with tail gas flow velocity
,
τfor the reaction time;
lfor the offgas duct length in urea box;
vfor exhaust velocity), generate product: ammonia, carbon dioxide and water vapor, the formula of reaction is CO (NH
2)
2+ H
2o → 2NH
3+ CO
2.
Reactor heating steam pressure between 0.8MPa～1.8MPa, reactor operating pressure 0.4MPa～0.8MPa, 100 DEG C～230 DEG C of running temperatures.
The invention has the beneficial effects as follows: the present invention can form without NO
xthe closed loop SCR control system of sensor, compared with popular response device, has saved NO
xsensor, urea box cooling system, vehicle-mounted source of compressed air, saved equipment and materials and cost.Circular tail gas heating line pipe adopts ripple type heat exchange tube structure, not only can augmentation of heat transfer, and improve heat transfer efficiency.
brief description of the drawings:
Fig. 1 is the apparatus structure perspective diagram of the embodiment of the present invention.
Fig. 2 is Fig. 1 side-looking perspective structure schematic diagram.
In figure: 1, urea liquid outlet, 2, reactor, 3, tail gas heating line pipe, 4, product gas outlet 4,5, far transmission level meter, 6, urea liquid import, 7, gas-liquid separator, 8, pressure stabilizing cavity, 9, one-way valve, 10, teletransmission thermometer.
Embodiment
Below in conjunction with drawings and Examples, the present invention is entered to be described further.
Fig. 1, Fig. 2 are depicted as a kind of tail gas heating hydrolysis of urea system that is applied to vehicle-mounted SCR, utilize tail gas heating urea to be hydrolyzed and realize the closed loop control of SCR system.This system comprises reactor 2, tail gas heating line pipe 3, gas-liquid separator 7, pressure stabilizing cavity 8, product gas outlet 4, one-way valve 9 and corresponding connecting pipeline.Tail gas heating line pipe 3 is located in reactor 2, two ends are connected with offgas duct and vehicle-mounted SCR catalyst converter respectively, reactor is provided with urea liquid import 6 and urea liquid outlet 1, reactor top arranges gas-liquid separator 7, the inwall of gas-liquid separator is provided with staggered sloping baffle, the excessive urea droplet that sloping baffle carries in the process of shifting out for blocking the gaseous product that overflows.Gas-liquid separator is connected with pressure stabilizing cavity 8, and the upper end of pressure stabilizing cavity is provided with gas product output pipeline, and gas product output pipeline is connected with one-way valve 9, and one-way valve lower end is connected with product gas outlet 4, and product gas outlet stretches into the blowdown piping of tail gas heating line pipe.Far transmission level meter and teletransmission thermometer are installed in reactor, and tail gas heating line pipe adopts ripple type heat exchange tube structure, and its cross section is circular, and product gas outlet is used one-way valve to control.
Specific works process is: the reaction site that has certain density urea liquid and enter by urea liquid import 6 hydrolysis of urea reactor 2.Urea liquid is further heated to hydrolysising reacting temperature in this region from the heat of tail gas heating line pipe 3, urea liquid is hydrolyzed into gas overflowing liquid phase, the gas overflowing from urea liquid after hydrolysis reaction rises and enters into pressure stabilizing cavity 8 through gas-liquid separator 7, in gas-liquid separator 7, sloping baffle is set, fine droplet in gas constantly gathers herein, form stable liquid film on surface, rely on surface tension constantly to absorb the drop in gas, liquid film reaches certain thickness and relies on gravity to flow into by the wall of gas separator 7 to continue to be hydrolyzed in the liquid phase urea liquid of reactor 2 reaction, gas enters pressure stabilizing cavity 8 after by gas-liquid separator 7, in the full and uniform distribution of this gas, form stable source of the gas, by the gas outlet on pressure stabilizing cavity 8 tops, discharge along product gas outlet 4 along pipeline.
With the comparison of existing vehicle-mounted SCR system schema:
1) existing SCR system is directly injected to urea in tail pipe, to carry out pyrolysis, and the present invention adopts hydrolysis of urea technology, generates after ammonia, then is drained in tail gas and reacts.
2) the present invention adopts using waste heat from tail gas heating urea to be hydrolyzed, and forms the closed loop control of system, without complicated control loop, nozzle and expensive sensor device, can reduce system user cost.
3) the present invention need to coordinate catalyst converter to use that (this reactor is connected with catalyst converter by cylinder back-end flange, and abundant mixed ammonia and tail gas mixed gas enter catalyst converter, under the effect of catalyzer, NOx are reduced to N
2).
More than show and described basic principle of the present invention, major character and advantage of the present invention.The technician of the industry should understand; the present invention is not restricted to the described embodiments; that in above-described embodiment and specification, describes just illustrates principle of the present invention; the present invention also has various changes and modifications without departing from the spirit and scope of the present invention, and these changes and improvements all fall in the claimed scope of the invention.The claimed scope of the present invention is defined by appending claims and equivalent thereof.
Claims (4)
1. one kind is applied to the tail gas heating hydrolysis of urea system of vehicle-mounted SCR, it is characterized in that, this system is utilized tail gas heating urea to be hydrolyzed and is realized the closed loop control of SCR system, this system comprises reactor (2), tail gas heating line pipe (3), gas-liquid separator (7), pressure stabilizing cavity (8), product gas outlet (4), one-way valve (9) and corresponding connecting pipeline, tail gas heating line pipe (3) is located in reactor (2), reactor (2) is provided with urea liquid import (6) and urea liquid outlet (1), reactor (2) top arranges gas-liquid separator (7), gas-liquid separator (7) is connected with pressure stabilizing cavity (8), the inwall of gas-liquid separator (7) is provided with staggered sloping baffle, the upper end of pressure stabilizing cavity (8) is provided with gas product output pipeline, gas product output pipeline is connected with one-way valve (9), one-way valve lower end is connected with product gas outlet (4), product gas outlet (4) stretches into the blowdown piping of tail gas heating line pipe (3), mix with the even of tail gas to reach ammonia, one end of tail gas heating line pipe (3) is connected with automobile tail gas pipe, can directly be placed in any position of offgas duct, the other end of tail gas heating line pipe (3) is connected with SCR catalyst converter, can directly be placed in SCR catalyst converter front end and be used in conjunction with, the job step of native system is: urea liquid is by urea liquid import injecting reactor (2), tail gas enters reactor (2) through tail gas heating line pipe (3), reactor (2) heating steam pressure is between 0.8MPa～1.8MPa, reactor (2) operating pressure 0.4MPa～0.8MPa, 100 DEG C～230 DEG C of running temperatures, heat is conducted in reactor (2), urea liquid outside tail gas heating line pipe (3) pipeline, through certain reaction time, reaction time is different and different with tail gas flow velocity,
,
τfor the reaction time,
lfor the offgas duct length in urea box,
vfor exhaust velocity, generate ammonia, carbon dioxide and water vapor,
CO(NH
2)
2+H
2O → 2NH
3+ CO
2 。
2. according to a kind of tail gas heating hydrolysis of urea system that is applied to vehicle-mounted SCR described in claim 1, it is characterized in that, far transmission level meter (5) and teletransmission thermometer (10) are installed in described reactor (2).
3. according to a kind of tail gas heating hydrolysis of urea system that is applied to vehicle-mounted SCR described in claim 1, it is characterized in that, described tail gas heating line pipe (3) adopts ripple type heat exchange tube structure, and its cross section is circular.
4. according to a kind of tail gas heating hydrolysis of urea system that is applied to vehicle-mounted SCR described in claim 1, it is characterized in that, described product gas outlet (4) is used one-way valve (9) to control.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410337973.4A CN104153853B (en) | 2014-07-16 | Tail gas heating urea hydrolysis system applied to vehicle-mounted SCR |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410337973.4A CN104153853B (en) | 2014-07-16 | Tail gas heating urea hydrolysis system applied to vehicle-mounted SCR |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN104153853A true CN104153853A (en) | 2014-11-19 |
| CN104153853B CN104153853B (en) | 2017-01-04 |
Family
ID=
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104989502A (en) * | 2015-07-13 | 2015-10-21 | 大连大学 | SCR urea hydrolyzing reactor for vehicle |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000054828A (en) * | 1998-06-04 | 2000-02-22 | Toyota Motor Corp | Exhaust emission control device for internal combustion engine |
| US20110258991A1 (en) * | 2009-09-18 | 2011-10-27 | Kwang Sung Co., Ltd. | Selective catalyst reduction system with bypass system |
| KR20130024079A (en) * | 2011-08-30 | 2013-03-08 | 현대자동차주식회사 | Solid scr system and heating method of solid reductant using the same |
| CN203685356U (en) * | 2013-10-17 | 2014-07-02 | 刘观柏 | Ammonium bicarbonate wet-method-ammonia-production and metered-injection system for engine SCR (Selective Catalytic Reduction) |
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000054828A (en) * | 1998-06-04 | 2000-02-22 | Toyota Motor Corp | Exhaust emission control device for internal combustion engine |
| US20110258991A1 (en) * | 2009-09-18 | 2011-10-27 | Kwang Sung Co., Ltd. | Selective catalyst reduction system with bypass system |
| KR20130024079A (en) * | 2011-08-30 | 2013-03-08 | 현대자동차주식회사 | Solid scr system and heating method of solid reductant using the same |
| CN203685356U (en) * | 2013-10-17 | 2014-07-02 | 刘观柏 | Ammonium bicarbonate wet-method-ammonia-production and metered-injection system for engine SCR (Selective Catalytic Reduction) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104989502A (en) * | 2015-07-13 | 2015-10-21 | 大连大学 | SCR urea hydrolyzing reactor for vehicle |
| CN104989502B (en) * | 2015-07-13 | 2017-06-30 | 大连大学 | A kind of automobile-used SCR hydrolysis of urea reactor |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106474904B (en) | A kind of CO of hydrate joint chemical absorption method2Gas fractionation unit and method | |
| CN105457451A (en) | Ammonia gas absorption device | |
| CN102320588B (en) | Lithium hexafluorophosphate synthesizer | |
| CN202609956U (en) | Flue gas denitration steady-flow urea hydrolysis ammonia preparation reactor | |
| CN205164443U (en) | Efficiency of absorb on urea device low pressure absorption tower is improved device | |
| CN203715292U (en) | System for producing ammonia gas by evaporation of ammonium hydroxide | |
| CN104153853A (en) | Tail gas heating and urea hydrolysis system applied to vehicular SCR (selective catalytic reduction) | |
| CN104153853B (en) | Tail gas heating urea hydrolysis system applied to vehicle-mounted SCR | |
| CN103482649B (en) | Urea solution hydrolysis reactor | |
| CN104003417B (en) | A kind of reverse-flow urea pyrolysis ammonia-preparing device and method | |
| CN103723743A (en) | Reactor for urea pyrolysis to produce ammonia for flue gas denitration | |
| CN209254435U (en) | A kind of novel carbon dioxide Jet absorber | |
| CN106631907A (en) | Synthetic rubber accelerator system and technique | |
| CN106582287B (en) | A ammonium bicarbonate solution pyrolysis rectification purification system of making ammonia for SCR reaction | |
| CN206604395U (en) | A kind of gas mixer produced for methacrylaldehyde | |
| CN204827613U (en) | Automobile -used SCR urea hydrolysis reactor | |
| CN204251349U (en) | U-shaped streaming urea pyrolysis reactor | |
| WO2018041754A1 (en) | System and method for increasing the urea concentration of an aqueous solution on-board a vehicle | |
| CN104959006B (en) | Treatment tower for flue gas from boilers | |
| CN202430017U (en) | Urea hydrolyzer applied to flue gas denitrification | |
| CN203558864U (en) | Reactor for producing ammonium by performing pyrolysis on urea obtained by flue gas denitrification | |
| CN203448100U (en) | Residue circulating reaction device for preparing glyoxylic acid by oxygen oxidization method | |
| CN202542882U (en) | Pyrolysis device for producing ammonia by urea solution | |
| CN202339122U (en) | Gas cooling device | |
| CN104989502B (en) | A kind of automobile-used SCR hydrolysis of urea reactor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |