CN101548074A - 内燃机的排气净化装置 - Google Patents
内燃机的排气净化装置 Download PDFInfo
- Publication number
- CN101548074A CN101548074A CNA2008800008909A CN200880000890A CN101548074A CN 101548074 A CN101548074 A CN 101548074A CN A2008800008909 A CNA2008800008909 A CN A2008800008909A CN 200880000890 A CN200880000890 A CN 200880000890A CN 101548074 A CN101548074 A CN 101548074A
- Authority
- CN
- China
- Prior art keywords
- selective reduction
- ammonia
- adsorption
- sensor
- combustion engine
- 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
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 37
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 162
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 84
- 239000003054 catalyst Substances 0.000 claims abstract description 23
- 239000004202 carbamide Substances 0.000 claims abstract description 22
- 239000000446 fuel Substances 0.000 claims abstract description 22
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 19
- 229920006395 saturated elastomer Polymers 0.000 claims abstract description 18
- 238000001179 sorption measurement Methods 0.000 claims description 52
- 238000010521 absorption reaction Methods 0.000 claims description 5
- 150000003672 ureas Chemical class 0.000 claims description 3
- 230000002829 reductive effect Effects 0.000 abstract description 6
- 239000007789 gas Substances 0.000 description 15
- 230000003647 oxidation Effects 0.000 description 12
- 238000007254 oxidation reaction Methods 0.000 description 12
- 238000000746 purification Methods 0.000 description 8
- WTHDKMILWLGDKL-UHFFFAOYSA-N urea;hydrate Chemical compound O.NC(N)=O WTHDKMILWLGDKL-UHFFFAOYSA-N 0.000 description 7
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 6
- 230000000881 depressing effect Effects 0.000 description 5
- 230000006870 function Effects 0.000 description 5
- RZCJYMOBWVJQGV-UHFFFAOYSA-N 2-naphthyloxyacetic acid Chemical compound C1=CC=CC2=CC(OCC(=O)O)=CC=C21 RZCJYMOBWVJQGV-UHFFFAOYSA-N 0.000 description 4
- 238000001816 cooling Methods 0.000 description 4
- 239000000498 cooling water Substances 0.000 description 4
- 238000007599 discharging Methods 0.000 description 4
- 231100001143 noxa Toxicity 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 229910000510 noble metal Inorganic materials 0.000 description 3
- 229910052697 platinum Inorganic materials 0.000 description 3
- 238000011144 upstream manufacturing Methods 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 229910021536 Zeolite Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- HNPSIPDUKPIQMN-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Al]O[Al]=O HNPSIPDUKPIQMN-UHFFFAOYSA-N 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
- 239000010457 zeolite Substances 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/18—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
- F01N3/20—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
- F01N3/2066—Selective catalytic reduction [SCR]
- F01N3/208—Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9404—Removing only nitrogen compounds
- B01D53/9409—Nitrogen oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9495—Controlling the catalytic process
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/009—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more separate purifying devices arranged in series
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
- F01N3/105—General auxiliary catalysts, e.g. upstream or downstream of the main catalyst
- F01N3/106—Auxiliary oxidation catalysts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2067—Urea
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
- F01N2560/02—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor
- F01N2560/021—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor for measuring or detecting ammonia NH3
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2560/00—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics
- F01N2560/02—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor
- F01N2560/026—Exhaust systems with means for detecting or measuring exhaust gas components or characteristics the means being an exhaust gas sensor for measuring or detecting NOx
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
- F01N2570/18—Ammonia
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/02—Adding substances to exhaust gases the substance being ammonia or urea
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2610/00—Adding substances to exhaust gases
- F01N2610/14—Arrangements for the supply of substances, e.g. conduits
- F01N2610/1453—Sprayers or atomisers; Arrangement thereof in the exhaust apparatus
- F01N2610/146—Control thereof, e.g. control of injectors or injection valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/04—Methods of control or diagnosing
- F01N2900/0412—Methods of control or diagnosing using pre-calibrated maps, tables or charts
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/06—Parameters used for exhaust control or diagnosing
- F01N2900/14—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust gas
- F01N2900/1402—Exhaust gas composition
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2900/00—Details of electrical control or of the monitoring of the exhaust gas treating apparatus
- F01N2900/06—Parameters used for exhaust control or diagnosing
- F01N2900/16—Parameters used for exhaust control or diagnosing said parameters being related to the exhaust apparatus, e.g. particulate filter or catalyst
- F01N2900/1622—Catalyst reducing agent absorption capacity or consumption amount
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02D—CONTROLLING COMBUSTION ENGINES
- F02D41/00—Electrical control of supply of combustible mixture or its constituents
- F02D41/02—Circuit arrangements for generating control signals
- F02D41/04—Introducing corrections for particular operating conditions
- F02D41/12—Introducing corrections for particular operating conditions for deceleration
- F02D41/123—Introducing corrections for particular operating conditions for deceleration the fuel injection being cut-off
-
- 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
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Toxicology (AREA)
- Materials Engineering (AREA)
- Biomedical Technology (AREA)
- Environmental & Geological Engineering (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Exhaust Gas After Treatment (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
在内燃机的内燃机排气通路内配置有NOx选择还原催化剂(15)。向NOx选择还原催化剂(15)供给尿素,由该尿素产生的氨被NOx选择还原催化剂(15)吸附,主要利用该吸附的氨选择性地还原排气中所含有的NOx。在NOx选择还原催化剂(15)下游的内燃机排气通路内配置有能够检测排气中含有的NOx和氨的NOx传感器(29),基于减速运转时向内燃机的燃料供给被停止时的NOx传感器(29)的检测值,判断NOx选择还原催化剂(15)上的氨吸附量是否饱和。
Description
技术领域
本发明涉及内燃机的排气净化装置。
背景技术
已公知在内燃机排气通路内配置NOx选择还原催化剂,向NOx选择还原催化剂供给尿素,使由该尿素产生的氨吸附在NOx选择还原催化剂上,主要利用该吸附的氨选择性地还原排气(废气)中所含有的NOx的内燃机(例如参照日本特开2005-127256号公报)。在利用这样地被NOx选择还原催化剂吸附的氨选择性地还原排气中所含有的NOx的场合,若使吸附在NOx选择还原催化剂上的氨量为饱和状态,则能够得到最大的NOx净化率。
因此,对于上述的内燃机而言,在NOx选择还原催化剂的上游侧和下游侧分别配置NOx传感器,由这些NOx传感器的检测值求出NOx选择还原催化剂的NOx净化率,由该NOx净化率和从内燃机排出的NOx量算出在NOx选择还原催化剂中为还原NOx而被消耗的吸附氨量,由该吸附氨的消耗量和尿素的供给量算出被NOx选择催化剂吸附的吸附氨量,控制尿素的供给使得该吸附氨量为饱和状态。
然而,NOx传感器不仅检测排气中所含有的NOx,还检测排气中所含有的氨,因此并不知道NOx传感器的输出值是表示排气中所含有NOx量还是表示氨量。所以,若基于NOx传感器的输出值控制尿素的供给量,则存在不能够将吸附氨量准确地控制为目标量的问题。
发明内容
本发明的目的在于,提供能够准确地判断NOx选择还原催化剂上的氨吸附量是否饱和的内燃机的排气净化装置。
根据本发明,提供一种内燃机的排气净化装置,其是在内燃机排气通路内配置NOx选择还原催化剂,向NOx选择还原催化剂供给尿素,使由该尿素产生的氨吸附于NOx选择还原催化剂上,并主要利用该吸附的氨选择性地还原排气中所含有的NOx的内燃机的排气净化装置,在NOx选择还原催化剂下游的内燃机排气通路内,配置能够检测排气中所含有的NOx和氨的NOx传感器,基于减速运转时向内燃机的燃料供给被停止时的NOx传感器的检测值,判断NOx选择还原催化剂上的氨吸附量是否饱和。
在本发明中,由于在减速运转时向内燃机的燃料供给被停止时,即排气中不含有NOx时基于NOx传感器的检测值判断NOx选择还原催化剂上的氨吸附量是否饱和,因此能够准确地判断NOx选择还原催化剂上的氨吸附量是否饱和。
附图说明
图1是压缩点火式内燃机的总体图;图2是表示压缩点火式内燃机的另一实施例的总体图;图3是表示NOx传感器的输出值的图;图4是表示目标氨吸附量Qt及其修正量△Qtijk、KQT等的图;图5是表示NOx传感器的输出值变化的时间图;图6是用于控制内燃机运转的流程图;图7是表示排出NOx量NOXA的图谱等的图。
具体实施方式
图1表示压缩点火式内燃机的总体图。
参照图1,图中标号分别表示如下:1-内燃机主体、2-各气缸的燃烧室、3-用于向各燃烧室2内分别喷射燃料的电子控制式燃料喷射阀、4-吸气岐管、5-排气岐管。吸气岐管4通过吸气导管6与排气涡轮增压器7的压缩机7a的出口连接,压缩机7a的入口通过吸入空气量检测器8与空气滤清器9连接。在吸气导管6内配置有由步进电动机驱动的节气门10,而且在吸气导管6周围配置有用于将在吸气导管6内流动的吸入空气冷却的冷却装置11。在图1所示的实施例中,内燃机冷却水被导入到冷却装置11内,吸入空气被内燃机冷却水冷却。
另一方面,排气岐管5与排气涡轮增压器7的排气涡轮7b的入口连接,排气涡轮7b的出口与氧化催化剂12的入口连接。在该氧化催化剂12的下游,与氧化催化剂12邻接地配置有用于捕集排气中所含有的粒子状物质的微粒过滤器13,该微粒过滤器13的出口通过排气管14与NOx选择还原催化剂15的入口连接。在该NOx选择还原催化剂15的出口连接有氧化催化剂16。
在NOx选择还原催化剂15上游的排气管14内配置有尿素水供给阀17,该尿素水供给阀17通过供给管18、供给泵19与尿素水罐20连接。贮藏在尿素水罐20内的尿素水,由供给泵19从尿素水供给阀17喷射到在排气管14内流动的排气中,排气中含有的NOx在NOx选择还原催化剂中被由尿素产生的氨((NH2)2CO+H2O→2NH3+CO2)还原。
排气岐管5和吸气岐管4,通过排气再循环(以下称为EGR)通路21相互连接,在EGR通路21内配置有电子控制式EGR控制阀22。并且,在EGR通路21周围配置有用于将在EGR通路21内流动的EGR气体冷却的冷却装置23。在图1所示的实施例中,内燃机冷却水被导入到冷却装置23内,EGR气体被内燃机冷却水冷却。另一方面,各燃料喷射阀3通过燃料供给管24与共轨25连接,该共轨25通过电子控制式的喷出量可变的燃料泵26与燃料罐27连接。燃料罐27内所贮藏的燃料,由燃料泵26向共轨25内供给,供给到共轨25内的燃料经由各燃料供给管24供给到燃料喷射阀3。
电子控制单元30包括数字计算机,具有由双向性总线31相互连接的ROM(只读存储器)32、RAM(随机存储器)33、CPU(微处理器)34、输入端口35和输出端口36。在NOx选择还原催化剂15的上游侧和下游侧分别配置有温度传感器28a、28b,而且在NOx选择还原催化剂15的下游侧配置有NOx传感器29。这些温度传感器28a、28b、NOx传感器29和吸入空气量检测器8的输出信号分别通过相对应的AD转换器37输入到输入端口35。
另一方面,在油门踏板40上连接有产生与油门踏板40的踏下量L成比例的输出电压的负荷传感器41,负荷传感器41的输出电压通过相对应的AD转换器37输入到输入端口35。而且,在输入端口35上连接有每当曲轴旋转例如15°就产生输出脉冲的曲轴转角传感器42。另一方面,输出端口36通过相对应的驱动电路38与燃料喷射泵3、节气门10的驱动用步进电动机、尿素水供给阀17、供给泵19、EGR控制阀22以及燃料泵26连接。
氧化催化剂12担载有例如铂之类的贵金属催化剂,该氧化催化剂12发挥将排气中含有的NO转换成NO2的作用和使排气中含有的HC氧化的作用。另一方面,作为微粒过滤器13,可以使用不担载催化剂的微粒过滤器,也可以使用担载了例如铂之类的贵金属催化剂的微粒过滤器。另外,NOx选择还原催化剂15由在低温下具有较高的NOx净化率的氨吸附型的Fe沸石构成。氧化催化剂16担载有例如包含铂的贵金属催化剂,该氧化催化剂16发挥将从NOx选择还原催化剂15漏出的氨进行氧化的作用。
图2表示压缩点火式内燃机的另一实施例。在该实施例中,在氧化催化剂16的下游配置有微粒过滤器13,因此在该实施例中,氧化催化剂12的出口通过排气管14与NOx选择还原催化剂15的入口连接。
另外,NOx传感器29本来是用于检测排气中的NOx的传感器。然而,排气中含有的氨NH3也在NOx传感器29中被氧化成NOx,这样一来NOx传感器29会检测排气中所含有的NOx以及氨。图3表示NOx传感器29的输出电压V与排气中的NOx浓度以及NH3浓度的关系。由图3可知,NOx传感器29的输出电压V与排气中的NOx浓度以及NH3浓度成比例。
在图4(A)中,Qt表示处于饱和状态的NOx选择还原催化剂15上的氨吸附量,即饱和吸附量,在本发明的实施例中,该氨的饱和吸附量Qt被作为目标氨吸附量。如图4(A)所示,该目标氨吸附量Qt是NOx选择还原催化剂15的床温TC的函数,床温TC越高该目标氨吸附量Qt越低。在本发明的实施例中,在开始使用内燃机的当初,控制尿素的供给使得NOx选择还原催化剂15上的氨吸附量变为目标氨吸附量Qt。
然而,氨的饱和吸附量根据NOx选择还原催化剂15而不同,并且该氨的饱和吸附量随着使用期间经过而变化。因此,发生目标氨吸附量Qt超过氨的饱和吸附量的情况,该情况下,没有吸附完的大量的氨从NOx选择还原催化剂15中排出。该场合下,为了阻止氨从NOx选择还原催化剂15中排出,必须使目标氨吸附量Qt降低。因此在本发明中,由NOx传感器29检测氨从NOx选择还原催化剂15中的排出,相应于该NOx传感器29的检测值向减少的方向修正目标氨吸附量Qt。
以下参照图5对采用该NOx传感器29进行的氨排出的检测方法进行说明。图5表示内燃机运转时燃料向内燃机的供给被停止的时候。即,在油门踏板40的踏下量L为零、开始减速时,在内燃机转速N比复位转速NZ例如800rpm高时,燃料的供给被停止,接着当内燃机转速N降低到复位转速NZ时,再开始燃料的供给。
另外,在NOx选择还原催化剂15上的氨吸附量超过饱和吸附量时,在减速运转时,即使燃料的供给被停止时,氨也从NOx选择还原催化剂15中排出。另一方面,在燃料的供给被停止时,不从内燃机中排出NOx,所以此时能够由NOx传感器29检测是否从NOx选择还原催化剂15中排出氨。因此,在本发明中,基于减速运转时向内燃机的燃料供给被停止时的NOx传感器29的检测值,判断NOx选择还原催化剂15上的氨吸附量是否饱和。
在NOx选择还原催化剂15上的氨吸附量超过饱和吸附量时,即使在减速运转开始前也从NOx选择还原催化剂15中排出氨。可是,由于此时氨被用于还原排气中含有的NOx,因此从NOx选择还原催化剂15中排出的氨量为少量。并且,此时从NOx选择还原催化剂15中排出的NOx量也为少量。因此如图5所示,通常,减速运转开始前的NOx传感器29的输出值V低,当开始减速运转、燃料的供给被停止时,由于不存在应该还原的NOx,因此NOx传感器29的输出值V增大。
在减速运转时,在燃料的供给被停止时,尿素的供给也被停止,因此,此时从NOx选择还原催化剂15中排出的氨量先上升,然后,随着相对于饱和吸附量剩余的吸附氨量减少而减少。可以认为,此时相对于饱和吸附量剩余的氨量与NOx传感器29的检测值V的最大值Vmax成比例,或者与NOx传感器29的检测值V的积分值∑V成比例。然而,在本发明的实施例中,减速运转开始后,经过直到稳定的等待时间△t后,开始NOx传感器29的检测作用。因此,最大值Vmax是经过等待时间△t后的NOx传感器29的检测值V的最大值,积分值∑V是经过等待时间△t后,直到经过tx时间的NOx传感器29的检测值V的累积值。
另外,在本发明中,在基于NOx传感器29的检测值判断出NOx选择还原催化剂15上的氨吸附量饱和时,目标氨吸附量Qt向减少方向修正。该场合下,在本发明中,预先存储NOx传感器29的输出值与目标氨吸附量Qt的修正量△Qt的关系,基于该关系由NOx传感器29的输出值算出目标氨吸附量Qt的修正量△Qt。
具体地讲,在本发明的实施例中,目标氨吸附量Qt的修正值△Qtijk,作为与排气量即吸入空气量Ga和NOx选择还原催化剂15的床温TC以及NOx传感器29的输出值V的最大值Vmax或积分值∑V的函数,以图4(B)所示的三维图的形式预先存储在ROM32内。该场合下,如图4(C)所示,目标氨吸附量Qt的修正值△Qtijk与最大值Vmax或积分值∑V成正比。
求出目标氨吸附量Qt的修正量△Qtijk,由目标氨吸附量Qt减去修正量△Qtijk的减算结果(Qt-△Qtijk)被作为新的目标氨吸附量,控制尿素的供给,使得NOx选择还原催化剂15上的氨吸附量为该新的目标氨吸附量(Qt-△Qtijk)。接着,在这样的状态下进行减速运转时,在从NOx选择还原催化剂15中再次排出氨时,由NOx传感器29的检测值再次算出修正量△Qtijk,该修正量被加到此前所使用的修正量中,被作为新的修正量KQt。
求出新的修正量KQt,如图4(A)所示,由目标氨吸附量Qt减去修正量KQt的减算结果(Qt-KQt)被作为新的目标氨吸附量,控制尿素的供给,使得NOx选择还原催化剂15上的氨吸附量为该新的目标氨吸附量(Qt-KQt)。由图4(B)可知,修正量△Qtijk,即KQt相应于吸入空气量Ga和NOx选择还原催化剂15的床温TC而变化,因此新的目标氨吸附量(Qt-KQt)不仅相应于NOx选择还原催化剂15的床温TC而变化,而且相应于吸入空气量Ga而变化。
图6表示用于控制内燃机运转的程序。再者,该程序通过每隔一定时间的插入来执行。
参照图6,首先在步骤50中判别油门踏板40的踏下量L是否为零。在油门踏板40的踏下量L不为零时进入到步骤51中进行燃料喷射控制。接着,在步骤52中算出每单位时间从燃烧室2排出的排出NOx量NOXA。该排出NOx量NOXA,如图7(A)所示那样作为要求扭矩TQ和内燃机转速N的函数以图谱的形式预选存储在ROM32内。
接着,在步骤53中,算出NOx选择还原催化剂15的NOx净化率R。该NOx净化率R如图7(B)所示那样是NOx选择还原催化剂15的床温TC的函数,而且相应于排气量即吸入空气量Ga而变化,该NOx净化率R,如图7(C)所示作为吸入空气量Ga和NOx选择还原催化剂15的床温TC的函数以图谱的形式预先存储在ROM32内。
接着,在步骤54中,由排出NOx量NOXA和NOx净化率R算出为了还原NOx每单位时间所消耗的吸附氨量ND。接着在步骤55中,算出以尿素的形式每单位时间所供给的供给氨量NI。接着在步骤56中,算出NOx选择还原催化剂15的氨吸附量∑NH3(∑NH3+NI-ND)。接着在步骤57中,判别该氨吸附量∑NH3是否比目标氨吸附量(Qt-KQt)大。∑NH3<(Qt-KQt)时进入步骤58中供给尿素,∑NH3≥(Qt-KQt)时进入步骤59中停止尿素的供给。
另一方面,在步骤50中油门踏板40的踏下量L为零时进入步骤60中,判别内燃机转速N是否比复位转速NZ(图5)低。N>NZ时进入步骤61中停止燃料的供给,接着在步骤62中停止尿素的供给。接着在步骤63中判别是否经过了等待时间△t,经过了等待时间△t时进入步骤64中由一对温度传感器28a、28b的输出值的平均值检测NOx选择还原催化剂15的床温TC,而且检测吸入空气量Ga和NOx传感器29的输出值V。
接着在步骤60中判别出N≤NZ时,进入步骤65中判别在上次的处理循环中是否N>NE。在N>NE时,即在由N>NE变为N≤NE时进入步骤66算出时间tx(图5)内的床温TC和吸入空气量Ga的平均值。接着在步骤67中算出NOx传感器29的输出值V的最大值Vmax或积分值∑V。
接着在步骤68中基于这些床温TC的平均值、吸入空气量Ga的平均值以及最大值Vmax或积分值∑V,由图4(B)所示的三维图谱算出修正量△Qijk。接着在步骤69中更新修正量KQt(←KQt+△Qijk)。另一方面,在步骤65中判断出不是N>NZ时,进入步骤51中再开始燃料喷射。
Claims (3)
1、一种内燃机的排气净化装置,是在内燃机排气通路内配置NOx选择还原催化剂,向该NOx选择还原催化剂供给尿素,使由该尿素产生的氨吸附于NOx选择还原催化剂上,并主要利用该吸附的氨选择性地还原排气中所含有的NOx的内燃机排气净化装置,在NOx选择还原催化剂下游的内燃机排气通路内,配置能够检测排气中所含有的NOx和氨的NOx传感器,基于减速运转时向内燃机的燃料供给被停止时的NOx传感器的检测值,判断NOx选择还原催化剂上的氨吸附量是否饱和。
2、根据权利要求1所述的内燃机的排气净化装置,其具备控制尿素的供给量使得NOx选择还原催化剂上的氨吸附量为目标氨吸附量的尿素供给量控制单元,在基于NOx传感器的检测值判断出NOx选择还原催化剂上的氨吸附量饱和时,将所述目标氨吸附量向减少方向修正。
3、根据权利要求2所述的内燃机的排气净化装置,其中,预先存储所述NOx传感器的输出值与所述目标氨吸附量的修正量的关系,基于该关系由NOx传感器的输出值算出目标氨吸附量的修正量。
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP086481/2007 | 2007-03-29 | ||
JP2007086481A JP4661814B2 (ja) | 2007-03-29 | 2007-03-29 | 内燃機関の排気浄化装置 |
PCT/JP2008/055797 WO2008120649A1 (ja) | 2007-03-29 | 2008-03-19 | 内燃機関の排気浄化装置 |
Publications (2)
Publication Number | Publication Date |
---|---|
CN101548074A true CN101548074A (zh) | 2009-09-30 |
CN101548074B CN101548074B (zh) | 2011-07-06 |
Family
ID=39808231
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN2008800008909A Expired - Fee Related CN101548074B (zh) | 2007-03-29 | 2008-03-19 | 内燃机的排气净化装置 |
Country Status (7)
Country | Link |
---|---|
US (1) | US8359830B2 (zh) |
EP (1) | EP2133524B1 (zh) |
JP (1) | JP4661814B2 (zh) |
CN (1) | CN101548074B (zh) |
AT (1) | ATE541113T1 (zh) |
ES (1) | ES2376789T3 (zh) |
WO (1) | WO2008120649A1 (zh) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102971502A (zh) * | 2010-07-07 | 2013-03-13 | 丰田自动车株式会社 | 用于内燃发动机的排气净化设备和还原剂分配方法 |
CN103038488A (zh) * | 2010-05-10 | 2013-04-10 | 丰田自动车株式会社 | 车辆控制装置 |
Families Citing this family (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP5177413B2 (ja) * | 2008-09-24 | 2013-04-03 | マツダ株式会社 | エンジンの排気浄化装置 |
US20110083429A1 (en) * | 2009-01-09 | 2011-04-14 | Masaaki Sato | Catalyst passing component determining apparatus and exhaust purification apparatus for internal combustion engine |
WO2010095221A1 (ja) * | 2009-02-18 | 2010-08-26 | 本田技研工業株式会社 | 内燃機関の排気浄化システム |
JP5398372B2 (ja) * | 2009-06-18 | 2014-01-29 | Udトラックス株式会社 | エンジンの排気浄化装置 |
JP5553629B2 (ja) * | 2010-02-09 | 2014-07-16 | 本田技研工業株式会社 | 内燃機関の排気浄化装置 |
SE535748C2 (sv) | 2010-04-08 | 2012-12-04 | Scania Cv Ab | Anordning och förfarande för att detektera ett tillstånd hos en NOx-sensor hos ett motorfordon |
US9528413B2 (en) * | 2010-07-30 | 2016-12-27 | Ford Global Technologies, Llc | Synergistic SCR/DOC configurations for lowering diesel emissions |
DE102011003599A1 (de) * | 2011-02-03 | 2012-08-09 | Robert Bosch Gmbh | Verfahren zum Dosieren eines Reduktionsmittels |
FR3006371B1 (fr) * | 2013-05-28 | 2017-04-28 | Renault Sas | Procede et systeme de controle de la qualite d'un agent de reduction catalytique selective d'oxydes d'azote, injecte dans une ligne d'echappement d'un vehicule automobile |
Family Cites Families (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4087914B2 (ja) | 1996-07-25 | 2008-05-21 | 日本碍子株式会社 | 脱硝システム及び脱硝方法 |
JP2001303934A (ja) | 1998-06-23 | 2001-10-31 | Toyota Motor Corp | 内燃機関の排気浄化装置 |
JP4292633B2 (ja) * | 1999-07-16 | 2009-07-08 | トヨタ自動車株式会社 | 内燃機関の排気浄化装置 |
US6427439B1 (en) * | 2000-07-13 | 2002-08-06 | Ford Global Technologies, Inc. | Method and system for NOx reduction |
US6546720B2 (en) * | 2001-09-04 | 2003-04-15 | Ford Global Technologies, Inc. | Method and apparatus for controlling the amount of reactant to be added to a substance using a sensor which is responsive to both the reactant and the substance |
JP3979153B2 (ja) * | 2002-04-03 | 2007-09-19 | 三菱ふそうトラック・バス株式会社 | 内燃機関のNOx浄化装置 |
JP4114389B2 (ja) * | 2002-04-22 | 2008-07-09 | 三菱ふそうトラック・バス株式会社 | 排気浄化装置 |
US6941746B2 (en) | 2002-11-21 | 2005-09-13 | Combustion Components Associates, Inc. | Mobile diesel selective catalytic reduction systems and methods |
JP4305643B2 (ja) * | 2003-10-24 | 2009-07-29 | 三菱ふそうトラック・バス株式会社 | 内燃機関の排気浄化装置 |
DE102004031624A1 (de) * | 2004-06-30 | 2006-02-02 | Robert Bosch Gmbh | Verfahren zum Betreiben eines zur Reinigung des Abgases einer Brennkraftmaschine verwendeten Katalysators und Vorrichtung zur Durchführung des Verfahrens |
US7213395B2 (en) * | 2004-07-14 | 2007-05-08 | Eaton Corporation | Hybrid catalyst system for exhaust emissions reduction |
DE102005042489A1 (de) * | 2005-09-07 | 2007-03-08 | Robert Bosch Gmbh | Verfahren zum Betreiben einer Brennkraftmaschine und Vorrichtung zur Durchführung des Verfahrens |
DE102005042488A1 (de) * | 2005-09-07 | 2007-03-08 | Robert Bosch Gmbh | Verfahren zum Betreiben einer Brennkraftmaschine und Vorrichtung zur Durchführung des Verfahrens |
DE102007009824A1 (de) * | 2006-03-03 | 2007-09-27 | Ford Global Technologies, LLC, Dearborn | System und Verfahren zum Erfassen von Reduktionsmittelspeicherung |
JP2009221992A (ja) * | 2008-03-17 | 2009-10-01 | Denso Corp | 排出ガスセンサの異常診断装置 |
JP4692911B2 (ja) * | 2008-09-18 | 2011-06-01 | トヨタ自動車株式会社 | NOxセンサの出力較正装置及び出力較正方法 |
US8256205B2 (en) * | 2009-04-14 | 2012-09-04 | Ford Global Technologies, Llc | Exhaust system with a NOx sensor |
-
2007
- 2007-03-29 JP JP2007086481A patent/JP4661814B2/ja not_active Expired - Fee Related
-
2008
- 2008-03-19 CN CN2008800008909A patent/CN101548074B/zh not_active Expired - Fee Related
- 2008-03-19 ES ES08738964T patent/ES2376789T3/es active Active
- 2008-03-19 AT AT08738964T patent/ATE541113T1/de active
- 2008-03-19 EP EP08738964A patent/EP2133524B1/en not_active Not-in-force
- 2008-03-19 WO PCT/JP2008/055797 patent/WO2008120649A1/ja active Application Filing
- 2008-03-19 US US12/308,251 patent/US8359830B2/en not_active Expired - Fee Related
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN103038488A (zh) * | 2010-05-10 | 2013-04-10 | 丰田自动车株式会社 | 车辆控制装置 |
CN102971502A (zh) * | 2010-07-07 | 2013-03-13 | 丰田自动车株式会社 | 用于内燃发动机的排气净化设备和还原剂分配方法 |
CN102971502B (zh) * | 2010-07-07 | 2015-04-29 | 丰田自动车株式会社 | 用于内燃发动机的排气净化设备和还原剂分配方法 |
Also Published As
Publication number | Publication date |
---|---|
CN101548074B (zh) | 2011-07-06 |
EP2133524A1 (en) | 2009-12-16 |
ATE541113T1 (de) | 2012-01-15 |
US8359830B2 (en) | 2013-01-29 |
US20100043405A1 (en) | 2010-02-25 |
JP4661814B2 (ja) | 2011-03-30 |
EP2133524B1 (en) | 2012-01-11 |
WO2008120649A1 (ja) | 2008-10-09 |
EP2133524A4 (en) | 2010-09-08 |
JP2008240716A (ja) | 2008-10-09 |
ES2376789T3 (es) | 2012-03-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN101548074B (zh) | 内燃机的排气净化装置 | |
CN101548077B (zh) | 内燃机的排气净化装置 | |
US8516808B2 (en) | Exhaust purification device of internal combustion engine | |
EP2141332B1 (en) | Exhaust purification device of internal combustion engine | |
CN101725392B (zh) | 尿素水喷射量控制器和尿素水喷射控制系统 | |
CN101646846B (zh) | 氨氧化催化剂中的n2o生成量推定方法以及内燃机的排气净化系统 | |
US8371106B2 (en) | Exhaust gas purification system of internal combustion engine | |
CN101600864A (zh) | 内燃机的排气净化装置 | |
CN101646852A (zh) | 内燃机的排气净化装置 | |
CN101600862A (zh) | 压缩点火式内燃机的排气净化装置 | |
EP3073083B1 (en) | Exhaust gas control apparatus | |
JP5834831B2 (ja) | 内燃機関の排気浄化装置 | |
EP2264291B1 (en) | Exhaust gas purification system for internal combustion engine | |
JP4595926B2 (ja) | 内燃機関の排気浄化装置 | |
JP2013104346A (ja) | 内燃機関の排気浄化装置 | |
JP2009167940A (ja) | 内燃機関の排気浄化装置 | |
CN104685175A (zh) | 内燃机的排气净化装置 | |
JP2018173048A (ja) | 内燃機関の制御装置 | |
CN103097684A (zh) | 内燃机的排气净化装置 | |
JP2008255942A (ja) | 内燃機関の排気浄化装置 |
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 | ||
CF01 | Termination of patent right due to non-payment of annual fee | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110706 Termination date: 20200319 |