DE112016003787T5 - Exhaust aftertreatment system with ammonia gas generator - Google Patents

Abstract

An exhaust aftertreatment system may include a reductant tank, an ammonia gas source, an injector, a first conduit, and a second conduit. The injector may receive the liquid reducing agent from the reducing agent tank and the ammonia gas from the ammonia gas source and inject the liquid reducing agent into an exhaust gas stream in a first mode, the ammonia gas into the exhaust gas stream in a second mode and both the liquid reducing agent and the third in a third mode Ammonia gas to the exhaust gas feed. The first conduit may carry liquid reductant from the reductant tank to the injector. The second line may carry ammonia gas from the ammonia gas source to the injector.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the priority of filed on November 3, 2015 U.S. Patent Application No. 14 / 931,039 , The present application also claims priority from August 20, 2015 filed German Patent Application No. 102015113835.2 , The disclosures of the aforementioned applications are hereby incorporated by reference in their entirety.

TERRITORY

The present disclosure relates to an exhaust aftertreatment system having an ammonia gas generator.

BACKGROUND

This section provides background information for the present disclosure and is not necessarily prior art.

In an attempt to reduce the amounts of nitrogen oxides (NO _x ) and particulates emitted into the atmosphere during operation of an internal combustion engine, a number of exhaust aftertreatment devices have been developed. Exhaust aftertreatment systems are needed especially when using diesel fuel burning processes. Typical diesel engine exhaust aftertreatment systems may include a diesel particulate filter (DPF), a selective catalytic reduction (SCR) system, a hydrocarbon (HC) injector, and / or a diesel oxidation catalyst (DOC). Typical SCR systems include a reductant delivery system that allows a reductant (eg, urea) to be injected upstream of an SCR catalyst.

More recently, reactors have been provided which produce gaseous ammonia from a liquid reductant. Ammonia gas is more reactive compared to liquid urea, is more easily distributed evenly in the exhaust stream and is more active within a wider temperature range. The use of gaseous ammonia in an SCR system can therefore improve both the efficiency and the effectiveness of the SCR system.

Gaseous ammonia reactors are most effective when operating within a certain temperature range. For this reason, the generation of gaseous ammonia may be delayed and / or inhibited after a cold start of an engine. Accordingly, it may be desirable to provide an aftertreatment system that can effectively deliver gaseous ammonia to an SCR catalyst immediately after a cold start of an engine.

SUMMARY

This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

In one form, the present disclosure provides an exhaust aftertreatment system that may include a reductant tank, an ammonia gas source, an injector, a first conduit, and a second conduit. The injector may receive the liquid reducing agent from the reducing agent tank and the ammonia gas from the ammonia gas source. In a first mode, the injector can inject the liquid reducing agent into an exhaust gas stream and, in a second mode, introduce the ammonia gas into an exhaust gas stream. The first conduit may carry liquid reductant from the reductant tank to the injector. The second conduit may direct ammonia gas from the ammonia gas source to the injector.

In some configurations, in a third mode, the injector may simultaneously introduce the liquid reductant and the ammonia gas into the exhaust stream.

In some configurations, the injector is fluidly connected to an exhaust pipe at a location upstream of a catalyst in the exhaust stream.

In some configurations, the injector includes a liquid reductant inlet for receiving the liquid reductant and an ammonia gas inlet for receiving the ammonia gas.

In some configurations, an air tank facilitates the injection of both the liquid reductant and the ammonia gas into the exhaust stream.

In some configurations, the air reservoir is fluidly connected to an injector via a third conduit, with air flow through a passage in the injector cooling the injector.

In some configurations, along the third conduit a first control valve is arranged which controls the flow of the medium through this conduit.

In some configurations, a pump pumps the fluid from the air tank to the exhaust flow.

In some configurations, the liquid reductant from the reductant tank and the ammonia gas from the ammonia gas source are mixed in a chamber within the injector.

In some configurations, an electrical heating element is in a heat transfer relationship with the air tank.

In some configurations, the first conduit includes a second valve for preventing backflow of the liquid reductant.

In some configurations, a control module controls the positioning of the first valve and the rate of injection of the reductant-ammonia gas mixture.

In another form, the present disclosure provides an exhaust aftertreatment system that includes a reductant tank that includes a liquid reductant, an ammonia gas source, an air tank, a first conduit, a second conduit, and a third conduit. The air tank facilitates the injection of the liquid reducing agent and / or the ammonia gas into an exhaust gas stream. The first line carries the liquid reducing agent from the reducing agent tank to the exhaust gas stream. The second line carries the ammonia gas from the ammonia gas source to the exhaust stream. The third line carries a medium from the air tank to the exhaust stream.

In some configurations, the exhaust aftertreatment system includes an injector that receives the ammonia gas from the second conduit and the air from the third conduit. The second and third lines may be connected to each other upstream of the injector.

In some configurations, a pump pumps the fluid from the air tank to the exhaust flow.

In some configurations, an injector receives the liquid reductant from the reductant tank via the first conduit and the ammonia gas from the ammonia gas source via the second conduit and introduces both the reductant and the ammonia gas into the exhaust stream in a third mode.

In some configurations, the reductant liquid reducing agent and the ammonia gas from the ammonia gas source are mixed in a chamber within the injector.

In another form, the present disclosure provides a delivery device for feeding an additive into a mixing device of an exhaust system, wherein at least a first supply channel, at least a second supply channel and a heating element are included. The at least one first supply channel contains at least one first supply opening and the at least one second supply channel contains at least one second supply opening. The heating element is coupled to the at least one first supply channel and / or the at least one second supply channel in order to evaporate at least part of the additive supplied through this supply channel. The second supply channel may be free of heating elements serving for evaporation.

In some configurations, the at least one first supply channel is arranged in a first supply unit and the at least one second supply channel is arranged in a second supply unit.

In some configurations, the first and second feed units are assembled together in a housing or the first and second feed units are each housed in a separate housing.

In some configurations, the conveyor includes an exhaust system.

In some configurations, the exhaust system includes a mixer.

In another form, the present disclosure provides a method of introducing an additive into an exhaust system using a conveyor. The method comprises feeding the additive through a first feed channel having a first feed opening and / or a second feed channel having a second feed opening, the additive evaporating at least partially when it is fed to the exhaust system via the first feed channel and being supplied via the second feed channel Channel is initiated in the liquid state.

In some configurations, the additive is evaporated at least partially upstream of the first supply passage and / or in the first supply passage.

In some configurations, at least a portion of 50 to 80% or 70% of the mass of the additive passed through the first feed passage or directed into the first feed port is vaporized.

In some configurations, between 60 g / h and 600 g / h of additive is supplied to the exhaust gas through the first supply passage.

In some configurations, a urea-water solution or a water-ammonia solution is used as an additive.

In another form, the present disclosure provides an exhaust aftertreatment system that may include a reductant tank, a reactor system, a storage tank, a first conduit, and a second conduit. The reactor system may receive reducing agent from the reducing agent tank and may output ammonia gas. The storage tank may receive ammonia gas from the reactor system and store an ammonia gas volume. The first line may carry ammonia gas from the reactor system to an exhaust stream. The first line can bypass the storage tank. The second line may carry ammonia gas from the storage tank to the exhaust stream.

For example, in some configurations, the reactor system could be an electrolysis reactor system.

In some configurations, the first and second conduits are fluidly connected to an exhaust pipe at a location upstream of a catalyst in the exhaust stream.

In some configurations, the catalyst is an SCR catalyst for selective catalytic reduction.

In some configurations, the exhaust aftertreatment system includes a particulate filter and an oxidation catalyst. The particulate filter may be located upstream of the site and the SCR catalyst. The oxidation catalyst may be disposed upstream of the particulate filter.

In some configurations, the exhaust aftertreatment system includes a first heat exchanger that is in a heat transfer relationship with the reactor system. The first heat exchanger can transfer heat from the exhaust to the reactor system.

In some configurations, the exhaust aftertreatment system includes an exhaust gas supply passage that fluidly connects the exhaust gas flow to the first heat exchanger such that exhaust gas from the exhaust flow may flow through the first heat exchanger.

In some configurations, the exhaust feed passage includes a valve that controls the flow of fluid therethrough.

In some configurations, the exhaust aftertreatment system also includes an exhaust gas recirculation passage that fluidly connects the exhaust flow and the first heat exchanger. The exhaust gas supply and return passages may be connected to the exhaust gas stream upstream of a catalyst in the exhaust gas stream.

In some configurations, the exhaust aftertreatment system includes an electrical heating element that is in a heat transfer relationship with the reactor system.

In some configurations, the exhaust aftertreatment system includes a second heat exchanger in which heat is transferred from the exhaust stream to a working fluid. The first and second heat exchangers may be fluidly connected to each other so as to allow a first flow of the working fluid therebetween.

In some configurations, the second heat exchanger is fluidly connected to a motor to allow a second flow of the working fluid therebetween.

In some configurations, the exhaust aftertreatment system includes a valve controlling the first and second streams of the working fluid.

In some configurations, the exhaust after-treatment system for heat transfer from the exhaust gas to the working fluid includes a Rankine cycle. The first heat exchanger may receive the working fluid and transfer heat from the working fluid to the reactor system.

In some configurations, the exhaust aftertreatment system includes a first heat exchanger that is in a heat transfer relationship with the reactor system. The first heat exchanger may be fluidly connected to a motor to permit transfer of a working fluid therebetween. The first heat exchanger can transfer heat from the working fluid to the reactor system.

In some configurations, the exhaust aftertreatment system includes a second heat exchanger that communicates with the reductant tank in a heat transfer relationship, the second heat exchanger transfers heat from the exhaust gas to the reductant tank, and a valve that controls the flows of a heat transfer medium through the first and second heat exchangers.

In some configurations, the reactor system includes an electrolysis reactor unit and a deposition unit (eg, depositing water or electrolyte) downstream of the electrolysis reactor unit.

In some configurations, the exhaust aftertreatment system includes a heat exchanger in a heat transfer relationship with the electrolysis reactor unit and another heat exchanger in a heat transfer relationship with the water separator. The heat exchangers can transfer heat from the exhaust gas to the electrolysis reactor unit and to the water separator.

In another form, the present disclosure provides an exhaust aftertreatment system that may include a reductant tank, a reactor system, a conduit, a first heat exchanger, a second heat exchanger, and a valve. The reactor system may receive reducing agent from the reducing agent tank and may output ammonia gas. The line may carry ammonia gas from the reactor system to an exhaust stream. The first heat exchanger may be in a heat transfer relationship with the reactor system. The first heat exchanger can transfer heat from the exhaust to the reactor system. The second heat exchanger may be in a heat transfer relationship with the reducing agent tank. The second heat exchanger can transfer heat from the exhaust gas to the reducing agent tank. The valve may control the flows of a heat transfer medium through the first and second heat exchangers.

In some configurations, the exhaust aftertreatment system includes a storage tank receiving ammonia gas from the reactor system and storing an ammonia gas volume, a first conduit bypassing the storage tank carrying ammonia gas from the reactor system to an exhaust gas stream, and a second conduit carrying ammonia gas from the storage tank to the exhaust gas flow, the first and second the second conduit is fluidly connected to an injector mounted upstream of a catalyst in the exhaust stream.

In some configurations, the exhaust aftertreatment system includes an exhaust passage that fluidly connects the exhaust flow to the first and second heat exchangers so that exhaust from the exhaust flow may flow through the first and second heat exchangers.

In some configurations, the exhaust aftertreatment system includes a third heat exchanger in which heat is transferred from the exhaust stream to a working fluid. The first and second heat exchangers may be fluidly connected to the third heat exchanger so that the working fluid may flow between both the first and third heat exchangers and between the second and third heat exchangers.

In some configurations, the third heat exchanger is fluidly connected to a motor so that the working fluid can flow therebetween.

In some configurations, the exhaust aftertreatment system includes an electrical heating element that is in heat transfer relationship with the reactor system.

In another form, the present disclosure provides a method of treating the exhaust gas emitted from an internal combustion engine. The method may include generating ammonia gas from a reductant, wherein a first portion of the ammonia gas is stored in a vessel, a second portion of the ammonia gas fluidly separated from the vessel is directed into an exhaust stream, and ammonia gas is passed from the vessel into the exhaust during a cold start of the internal combustion engine Exhaust gas flow is initiated.

In some configurations, the second portion of the ammonia gas is introduced into the exhaust stream through an orifice (eg, an injector, a nozzle, a hole, etc.) and ammonia gas from the tank is supplied to the exhaust stream through the same opening.

In some configurations, the method includes heat transfer from the exhaust gas to a reactor system that generates the ammonia gas.

In some configurations, the method provides a first heat exchanger in a heat transfer relationship with the reactor system, and a Rankine cycle for transferring heat from the exhaust gas to the working fluid. The first heat exchanger can receive the working fluid and transfer heat from the working fluid to the reactor system.

In some configurations, the method provides a first heat exchanger in a heat transfer relationship with the reactor system. The first heat exchanger may be fluidly connected to the internal combustion engine and thus allow transfer of a working fluid therebetween. The first heat exchanger can transfer heat from the working fluid to the reactor system.

In some configurations, the method provides a first heat exchanger in a heat transfer relationship with the reactor system. The heat transfer from the exhaust gas to a reactor system may include the diversion of exhaust gas through the first heat exchanger.

In some configurations, heat transfer from the exhaust gas to the reactor system includes heat transfer from the exhaust gas to a working fluid with subsequent heat transfer from the working fluid to the reactor system.

In some configurations, the method provides a first heat exchanger in heat transfer relationship with the reactor system and a second heat exchanger in which heat is transferred from the exhaust stream to the working fluid. The first and second heat exchangers are fluidly connected to each other to allow a first flow of the working fluid therebetween.

In some configurations, the second heat exchanger is fluidly connected to the internal combustion engine to allow a second flow of the working fluid therebetween.

In some configurations, the method includes controlling, based on operating parameters of the internal combustion engine, the first and second streams of the working fluid.

In some configurations, the method includes heating the reactor system with an electrical heating element.

In another form, the present disclosure provides an injector for an exhaust aftertreatment system. The injector may include an injector body having first, second, third, fourth and fifth ports. The first port may be fluidly connected to the third and fifth ports. The second port may be fluidly connected to the fourth port. The second and fourth ports may be fluidly separated from the first, third and fifth ports. The injector body may include a pin which is movable between a closed position preventing fluid flow through the fifth port and an open position allowing fluid flow through the fifth port.

In some configurations, the first port is fluidly connected to a conduit of liquid reductant and the second port is fluidly connected to a gaseous ammonia carrying conduit.

In some configurations, the third port forms a liquid reductant outlet to which is fluidly connected a return line to a tank of liquid reductant.

In some configurations, the fourth port is defined by an outer ring collar surrounding the fifth port.

In some configurations, the injector includes an intermediate collar extending from the injector body. The intermediate annular collar is surrounded by the outer annular collar and, cooperating with the outer annular collar, defines the fourth port.

In some configurations, the injector includes a tubular inner body that the intermediate collar surrounds. The tubular inner body may cooperatively form, with the intermediate collar, an annular passageway fluidly connected to the first port. The tubular inner body may form an inner, fluidly connected to the third port inner passage.

In some configurations, the pin is disposed within the inner passage.

In another form, the present disclosure provides another injector for an exhaust aftertreatment system. The injector may include an outer body and a pin. The outer body may include a liquid introduction port for receiving liquid reducing agent, a gas introduction port for receiving ammonia gas, a liquid outlet port through which the liquid reducing agent leaves the injector, and a gas outlet port through which the ammonia gas exits the injector , The spigot is disposed within the outer body and may be moved between an open position that allows fluid flow through the fluid outlet port and a closed position that prevents fluid flow through the fluid outlet port.

In some configurations, the gas outlet port is in the form of a collar surrounding the fluid outlet port.

In some configurations, the gas outlet port is an annular port surrounding the fluid outlet port.

In some configurations, the collar includes an annular recess partially surrounding the pin, which communicates with the gas inlet port and the gas outlet port in fluid communication. The annular recess may be axially spaced from the liquid outlet port.

In some configurations, the outer body includes a liquid return port.

In some configurations, the liquid return port is fluidly connected to the inner passage disposed in the outer body.

In some configurations, the pin is at least partially disposed in the inner passageway.

In some configurations, the outer body includes a first annular collar that defines a first annular passage that at least partially surrounds a portion of the inner passageway. The first annular passage may fluidly connect the fluid supply port to the fluid outlet port.

In some configurations, the outer body includes a second annular collar that defines the gas outlet port in cooperation with the first annular collar.

In some configurations, the gas outlet port is a second annular passage that at least partially surrounds at least a portion of the first annular passageway.

Further areas of application emerge from the description provided here. The description and specific examples of this summary are by way of illustration only and are not intended to limit the scope of the present disclosure in any way.

list of figures

• ist eine schematische Darstellung eines Abgasnachbehandlungssystems, das ein Elektrolyse-Reaktorsystem und einen Ammoniakgas-Speichertank nach den Prinzipien der vorliegenden Offenbarung enthält.
• ist eine schematische Darstellung eines anderen Abgasnachbehandlungssystems, das ein Elektrolyse-Reaktorsystem und einen Ammoniakgas-Speichertank nach den Prinzipien der vorliegenden Offenbarung enthält.
• ist eine schematische Darstellung eines weiteren Abgasnachbehandlungssystems, das ein Elektrolyse-Reaktorsystem und einen Ammoniakgas-Speichertank nach den Prinzipien der vorliegenden Offenbarung enthält.
• ist eine schematische Darstellung eines weiteren Abgasnachbehandlungssystems, das ein Elektrolyse-Reaktorsystem und einen Ammoniakgas-Speichertank nach den Prinzipien der vorliegenden Offenbarung enthält.
• ist eine schematische Darstellung eines weiteren Abgasnachbehandlungssystems, das ein Elektrolyse-Reaktorsystem und einen Ammoniakgas-Speichertank nach den Prinzipien der vorliegenden Offenbarung enthält.
• ist eine schematische Darstellung eines weiteren Abgasnachbehandlungssystems, das ein SCR-System nach den Prinzipien der vorliegenden Offenbarung enthält.
• ist eine räumliche Darstellung eines Injektors, welcher im Abgasnachbehandlungssystem von eingebaut werden kann.
• zeigt eine Schnittzeichnung des Injektors von .
• ist eine schematische Darstellung einer anderen Konfiguration des Injektors der und .
• zeigt eine Schnittzeichnung eines anderen Injektors, der im Abgasnachbehandlungssystem von eingebaut werden kann.
• zeigt eine schematische Darstellung eines weiteren Abgasnachbehandlungssystems mit einer Einspritzvorrichtung nach den Prinzipien der vorliegenden Offenbarung.
• zeigt eine schematische Darstellung eines weiteren Abgasnachbehandlungssystem mit einer abwechselnd arbeitenden Einspritzvorrichtung.

The drawings described herein are merely illustrative of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure in any way.

• FIG. 10 is a schematic illustration of an exhaust aftertreatment system including an electrolysis reactor system and an ammonia gas storage tank in accordance with the principles of the present disclosure.
• FIG. 12 is a schematic representation of another exhaust after-treatment system including an electrolysis reactor system and an ammonia gas storage tank in accordance with the principles of the present disclosure. FIG.
• FIG. 10 is a schematic representation of another exhaust aftertreatment system including an electrolysis reactor system and an ammonia gas storage tank in accordance with the principles of the present disclosure. FIG.
• FIG. 10 is a schematic representation of another exhaust aftertreatment system including an electrolysis reactor system and an ammonia gas storage tank in accordance with the principles of the present disclosure. FIG.
• FIG. 10 is a schematic representation of another exhaust aftertreatment system including an electrolysis reactor system and an ammonia gas storage tank in accordance with the principles of the present disclosure. FIG.
• FIG. 12 is a schematic illustration of another exhaust after-treatment system incorporating an SCR system in accordance with the principles of the present disclosure. FIG.
• is a perspective view of an injector, which in the exhaust aftertreatment system of can be installed.
• shows a sectional drawing of the injector of ,
• is a schematic representation of another configuration of the injector of and ,
• shows a sectional view of another injector, the exhaust aftertreatment system of can be installed.
• FIG. 12 is a schematic illustration of another exhaust after-treatment system having an injector according to the principles of the present disclosure. FIG.
• shows a schematic representation of another exhaust aftertreatment system with an alternately operating injection device.

Corresponding reference numbers show corresponding parts in the various views of the drawings.

DETAILED DESCRIPTION

Embodiments will now be described in more detail with reference to the accompanying drawings.

Exemplary embodiments are provided so that this disclosure will be thorough and fully convey the scope of protection to those skilled in the art. Numerous special details are given, such as: B. Examples of specific components, devices, and methods to provide a thorough understanding of the embodiments of the present disclosure. It will be obvious to those skilled in the art that the specific details are not to be employed, that exemplary embodiments may be embodied in many different forms, and that neither should be construed as limiting the scope of the disclosure. In some embodiments, well-known methods, well-known device structures, and well-known technologies are not described in detail.

The terminology used herein is for the purpose of describing particular Embodiments and should not be construed as limiting. As used herein, the singular forms "a,""an," and "the" should also include the plural forms unless the context expressly indicates otherwise. The terms "comprising", "comprising (d)", "containing (d)" and "having (d)" are meant to be inclusive and therefore indicate the presence of cited features, integers, steps, operations, elements and / or components but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The process steps, procedures and operations described herein should not be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically indicated as the order of performance. It is further understood that other or alternative steps may be used.

When an element or layer is described as being "on," "engaged with," "connected to," or "coupled with" another element or layer, it may be directly attached to the other element or layer in engagement with, connected to, or coupled to, or intervening elements or layers may be present. Conversely, when an element is described as being "directly on," "directly engaged with," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. Another wording used to describe the relationship between elements should be interpreted in a similar manner (eg, "between" versus "directly between," "beside" versus "directly next to", etc.). As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed objects.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms can only be used to distinguish one element, component, region, layer, or section from another section, layer, or section. Terms such as "first," "second," and any other numerical terms used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, a first component, a first region, a first layer, or a first portion discussed below may be referred to as a second element, a second component, a second region, a second layer, or a second region. without departing from the teachings of the exemplary embodiments.

Spatial terms such as "inner," "outer," "below," "below," "lower," "above," "upper," and the like may be used herein to simplify the description to describe the relationship of an element or feature to describe one or more other elements or features as illustrated in the figures. By spatially referenced terms, it may be intended to encompass various orientations of the device in use or operation in addition to the orientation shown in the figures. For example, if the device in the figures is turned over, elements described as "below" or "below" other elements or features would then be aligned "above" the other elements or features. Thus, the exemplary term "under" may include both an over and under orientation. The device may also be otherwise oriented (rotated 90 degrees or in other orientations) and the spatially related descriptive terms used herein interpreted accordingly.

With reference to becomes an exhaust aftertreatment system 10 provided, which is an exhaust pipe 12 and an SCR system 14 may contain. An exhaust gas flow from an internal combustion engine 16 can the exhaust pipe 12 flow through. For example, the engine can 16 , the exhaust pipe 12 and the SCR system 14 be installed in a vehicle (not shown). The SCR system 14 can be a reducing agent tank 18 , a reactor system 20 , a storage tank 22 , an injector or a conveyor 24 and an SCR catalyst 26 contain. One in the reducing agent tank 18 contained reducing agent and / or from the reactor system 20 generated ammonia gas (eg, a gas with a high percentage of ammonia) may be in the exhaust gas flow in the exhaust pipe 12 through the injector 24 upstream of the exhaust pipe 12 located SCR catalyst 26 be injected. In some configurations, the exhaust aftertreatment system 10 also an oxidation catalyst 28 and a particle filter 30 included in the exhaust pipe 12 upstream of the injector 24 are installed. It is understood that the injector 24 through a nozzle, a hole or any other opening to the exhaust stream in the exhaust pipe 12 could be replaced. An ammonia slip catalyst 31 may be downstream of the SCR catalyst 26 be arranged. In some configurations, it may be particulate Filter 30 to handle a diesel particulate filter with SCR coating and the injector 24 could be between the oxidation catalyst 28 and the filter 30 be arranged.

The reactor system 20 can be a reactor unit 32 and a deposition unit 34 contain. For example, the reactor system 20 consist of or contain an electrolysis reactor, which may be a similar or identical device to the SCR GreenBox ™ available from E3 Clean Technologies, or any other ammonia gas generating device. The separation unit 34 could precipitate water or electrolyte. Deposited electrolyte can go to the reactor 32 to be led back. Secluded water could pass through the outlet 36 directed, released to the atmosphere or into the engine 16 be injected. The separation unit 34 could contain several separators for separating gases from gases or gases from liquids. The separation unit 34 could separate water from ammonia, remove electrolyte and / or return to the reactor, separate CO ₂ and NH ₃ , and / or purify NH ₃ . In some configurations, the reactor system could 20 the separation unit 34 not included.

The reactor system 20 may include reducing agent (for example, a urea-containing liquid) from the reducing agent tank 18 and ammonia gas (and the gases carbon dioxide, carbon monoxide, hydrogen, etc.) through the outlet 36 submit. The outlet 36 is fluid with a first line 38 and an inlet 40 the storage tank 22 connected. The first line 38 is fluid with the injector 24 connected so that at least part of the reactor system 20 discharged ammonia gas into the exhaust stream upstream of the SCR catalyst 26 in the exhaust pipe 12 can be injected. A control valve 43 could be the fluid flow through the first conduit 38 Taxes.

Another part of the reactor system 20 discharged gas can through the inlet 40 in the storage tank 22 stream. The storage tank 22 can store an ammonia gas volume, as desired via a second line 42 to the injector 24 can be directed. The second line 42 can be a first control valve 44 for controlling the flow of ammonia gas through the second conduit 42 contain. In some configurations, a pump (not shown) may be provided which removes fluid from the storage tank 22 to the injector 24 promotes. The first control valve 44 can with a control module 46 For example, based on operating parameters of the engine 16 or the reactor system 20 and / or the flow rate through the outlet 36 from the reactor system 20 discharged ammonia gas, the first control valve 44 opens and closes. The control module 46 can be the first control valve 44 open in response to a cold start of the engine 16 Ammonia gas from the storage tank 22 to the injector 24 to flow. In this way, ammonia gas can be removed from the storage tank 22 be available immediately after the cold start for introduction into the exhaust stream. This is advantageous because the production of ammonia gas in the reactor system 20 at low ambient temperatures can be prevented or prevented if the vehicle in which the aftertreatment system 10 was installed, had not been operated for an extended period of time and had been exposed to low temperatures. Once the reactor system 20 is able to produce the required amount of ammonia gas, the control module 46 the first control valve 44 Close completely or partially.

The aftertreatment system 10 For example, a heating system may be used to promote the efficient production of ammonia gas 48 include, for heating the reducing agent tank 18 and / or the reactor system 20 can be used. The heating system 48 can have one or more heating elements 50 in a heat transfer permitting relationship with the reactor system 20 and / or the reducing agent tank 18 contain. The control module 46 can the operation of electric heating elements 50 in such a way that control the reactor system 20 and / or the reducing agent tank 18 be kept at or above a desired minimum temperature.

The heating system 48 can also have one or more first heat exchangers 52 contained in a heat transfer relationship with the reactor system 20 stand, and / or one or more, in a heat transfer relationship with the reducing agent tank 18 standing second heat exchanger 54 , The first and second heat exchangers 52 . 54 can flow with the exhaust pipe 12 via an exhaust gas supply passage 56 be connected. In this way, heat can be removed from that through the first and second heat exchangers 52 . 54 flowing exhaust gas to the reactor system 20 , or the reducing agent tank 18 be transmitted. After flowing through the / the first heat exchanger 52 the exhaust gas may pass through a first return passage 57 to the exhaust pipe 12 be returned. Similarly, the exhaust gas after flowing through the second heat exchanger 54 through a second return passage 59 to the exhaust pipe 12 to be led back. The feed and return passages 56 . 57 . 59 can on the exhaust pipe 12 be connected at any suitable locations (for example, upstream or downstream of the oxidation catalyst 28 and / or the particulate filter 30 and / or the SCR catalyst 26 ).

A second control valve 58 can along the exhaust passage 56 be arranged and adjusted between several positions, to a fluid connection between the exhaust pipe 12 and the first and second heat exchangers 52 . 54 to prevent and a fluid connection between the exhaust pipe 12 and the first and / or the second heat exchanger 52 . 54 to enable. The control module 46 can with the second control valve 58 be connected and so on the position of the second control valve 58 acting on the exhaust gas flow through the first and second heat exchangers 52 . 54 is controlled. The control module 46 may be the second control valve 58 for example, based on temperatures of the reactor system 20 , the reducing agent tank 18 and / or in the reactor system 20 or reducing agent tank 18 control fluid contained. Additionally or alternatively, the control module could 46 the second control valve 58 for example, based on engine temperature, engine runtime and / or ambient temperature control.

Further referring to becomes the operation of the aftertreatment system 10 described in more detail. In response to a cold start of the engine 16 can the control module 46 the first control valve 44 open to ammonia gas from the storage tank 22 through the second line 42 and the injector 24 to the exhaust gas flow in the exhaust pipe 12 initiate. As the reactor system 20 after the cold start with the production of ammonia gas begins, and this ammonia gas through the first line 38 to the injector 24 be directed. After the gas generation rate of the reactor system 20 has been increased to a level which corresponds to at least one requested amount of ammonia gas, the control module 46 the first control valve 44 close to the flow of ammonia gas through the second conduit 42 to prevent.

After the cold start of the engine 16 may be heating the reactor system 20 to enable the reactions occurring therein to produce ammonia gas. In such cases, the control module 46 the second control valve 58 so put that exhaust the exhaust pipe 12 through the exhaust gas supply passage 56 leave and the first heat exchanger (s) 52 flow through and thus the reactor system 20 can warm up. After sufficient heating of the reactor system 20 can the control module 46 the second control valve 58 set so that the flow of exhaust gas to the / the first heat exchangers 52 is blocked and exhaust gas through the second heat exchanger 54 flow and the reducing agent tank 18 can warm up. After sufficient heating of the reducing agent tank 18 can the control module 46 the second control valve 58 the flow of exhaust gas to the second heat exchanger 54 lock. It can be seen that the control module 46 the second control valve 58 so could put that exhaust gas as desired the first and second heat exchangers 52 . 54 can flow simultaneously or separately. Additionally or alternatively, the control module 46 also at any time, as desired, the electric heating elements 50 enable or disable.

It is understood that the system 14 in some configurations, a bypass line 39 could contain the tank 18 upstream of the SCR catalyst 26 directly with the injector 24 combines. A control valve 45 can control the fluid flow through the bypass line 39 To control this, to selectively allow that reducing agent from the tank 18 the reactor 32 and the separation unit 34 bypasses and upstream of the SCR catalyst 26 is introduced into the exhaust stream. In some configurations, a mixing device could be used with the injector 24 or upstream of the injector 24 be arranged in the liquid reducing agent from the bypass line 39 and ammonia gas from the second conduit 42 before her through a common outlet of the injector 24 taking place injection into the exhaust pipe 12 can be mixed.

In some configurations, the second control valve 58 immediately after a cold start, the exhaust gas partially or completely to the second heat exchanger 54 lead to first in the tank 18 Thaw liquid. During this time, reducing agent can be removed from the tank 18 be introduced through the bypass line described above directly into the exhaust stream (for example, bypassing the reactor 32 and the separation unit 34 ). After warming, heat is diverted to promote conversion to the gaseous state. After warming up the reducing agent in the tank 18 may be the second control valve 58 Exhaust gas in the first heat exchanger 52 let in.

In some configurations, the tank can 18 a pressure compensating valve, which in response to the generation of high-pressure ammonia in the tank 18 during the heating of the tank 18 the tank 18 can vent. For example, excess ammonia could come out of the tank 18 to a point of low pressure upstream of the injector 24 be vented. In some configurations, the storage tank 22 a pressure compensation valve containing the storage tank 22 in response to the generation of high ammonia pressure in the storage tank 22 can vent. For example, excess ammonia gas could be at a location on the exhaust pipe 12 upstream of the ammonia slip catalyst 31 or vented to the atmosphere.

With reference to will be another exhaust aftertreatment system 110 provided, which is an exhaust pipe 112 , an SCR system 114 and a heating system 148 included and from an internal combustion engine 116 can treat discharged exhaust gas. The exhaust pipe 112 , the SCR system 114 and the heating system 148 can each be structured in a similar or identical manner and work as the exhaust pipe 12 , SCR system 14 and heating system 48 , with the exception of some deviations described below. Similar properties will therefore not be described again in detail.

Like the SCR system 14 can the SCR system 114 a reducing agent tank 118 , a reactor system 120 and a storage tank 122 contain. The SCR system 114 can generate and store ammonia gas and the exhaust gas flow in the exhaust pipe 112 Feed ammonia gas. Like the heating system 48 can also use the heating system 148 one or more first heat exchangers 152 in a heat transfer relationship with the reactor system 120 and a second heat exchanger 154 in a heat transfer relationship with the reducing agent tank 118 contain.

The first and second heat exchangers 152 . 154 can flow with a third heat exchanger 155 be connected. The third heat exchanger 155 can in the exhaust pipe 112 or be arranged adjacent to this, so that a third heat exchanger 155 flowing working fluid (for example, a coolant) heat from that through the exhaust pipe 112 can absorb flowing exhaust gas. A feed passage 156 and first and second return passages 157 . 159 can the third heat exchanger 155 with the first and second heat exchangers 152 . 154 fluidly to form a closed circuit between them. A pump (not shown) may supply the working fluid between the first, second and third heat exchangers 152 . 154 . 155 let it circulate.

A control valve 158 can along the feed passage 156 can be arranged and can be adjusted between several positions to a fluid connection between the third heat exchanger 155 and the first and second heat exchangers 152 . 154 to lock and between the third heat exchanger 155 and either the first or the second heat exchanger 152 . 154 or both at the same time. A control module 146 can with the control valve 158 and its position for controlling the flow of the working fluid through the first and second heat exchangers 152 . 154 Taxes. The control module 146 can the control valve 158 for example, based on the temperatures of the reactor system 120 , the reducing agent tank 118 and / or in the reactor system 120 or in the reducing agent tank 118 control located fluid. Additionally or alternatively, the control module could 146 the control valve 158 for example, based on the engine temperature, the engine run time, and / or the outside ambient temperature. Additionally or alternatively, the control module 146 at any time on request, the electric heating elements 150 for heating the reactor system 120 enable or disable.

With reference to will be another exhaust aftertreatment system 210 provided, which is an exhaust pipe 212 , an SCR system 214 and a heating system 248 included and from an internal combustion engine 216 can treat discharged exhaust gas. The exhaust pipe 212 , the SCR system 214 and the heating system 248 can each be structured in a similar or identical manner and work as the exhaust pipe 12 . 112 , SCR system 14 . 114 and heating system 48 . 148 , with the exception of some deviations described below. Similar properties will therefore not be described again in detail.

Like the SCR system 14 can also use the SCR system 214 a reducing agent tank 218 , a reactor system 220 and a storage tank 222 contain. The SCR system 214 can generate and store ammonia gas and the exhaust gas flow in the exhaust pipe 212 Feed ammonia gas. Like the heating systems 48 . 148 can the heating system 248 one or more first heat exchangers 252 in a heat transfer relationship with the reactor system 220 and a second heat exchanger 254 in a heat transfer relationship with the reducing agent tank 218 contain.

The first and the second heat exchanger 252 . 254 can flow with a third heat exchanger 255 be connected. The third heat exchanger 255 can in the exhaust pipe 212 or be arranged adjacent to this, so that a through the third heat exchanger 255 flowing working fluid (eg, a coolant) from the exhaust pipe 212 flowing exhaust gas can absorb heat. The third heat exchanger 255 Can also be fluid with cooling channels in the engine 216 be connected so that the engine 216 can be heated by the coolant after a cold start.

The first and second feed passages 256 . 260 and a first return passage 262 can the third heat exchanger 255 fluidly with the first and second heat exchangers 252 . 254 connect. The first feed passage 256 , a third feed passage 264 and a second return passage 266 can the third heat exchanger 255 fluidly with the engine 216 connect. A pump (not shown) may circulate the working fluid between the first, second and third heat exchangers 252 . 254 . 255 and the engine 216 to back up. It can a bypass line and a bypass valve are arranged, which selectively the working fluid at the reducing agent tank 218 can bypass if the reducing agent tank 218 is heated too much. While in the feed passage 260 and the return passage 262 are configured so that the working fluid before the reducing agent tank 218 through the reactor system 220 flows, the passages could 260 . 262 be configured in some configurations so that the working fluid upstream of the reactor system 220 to the reducing agent tank 218 flows.

A control valve 258 can along the first feed passage 256 arranged and displaced between a plurality of positions to a fluid connection between the first, second and third heat exchangers 252 . 254 . 255 and between the third heat exchanger 255 and the engine 216 to control. A control module 246 can with the control valve 258 communicate and the control valve 258 to passage or blocking of a flow of the working fluid through the first and second heat exchangers 152 . 154 and / or by the engine 216 put. The control module 246 can the control valve 258 for example, based on the temperatures of the reactor system 220 , the reducing agent tank 218 and / or in the reactor system 220 or in the reducing agent tank 218 control fluid contained. Additionally or alternatively, the control module could 246 the control valve 258 for example, based on the engine temperature, the engine run time, and / or the outside ambient temperature. Additionally or alternatively, the control module 246 at any time, as desired, to heat the reactor system 220 the electric heating elements 250 enable or disable.

With reference to will be another exhaust aftertreatment system 310 provided, which is an exhaust pipe 312 , an SCR system 314 and a heating system 348 included and from an internal combustion engine 316 can treat discharged exhaust gas. The exhaust pipe 312 , the SCR system 314 and the heating system 348 can each be structured in a similar or identical manner and work as the exhaust pipe 12 , SCR system 14 and heating system 48 , with the exception of some deviations described below. Similar properties will therefore not be described again in detail.

Like the SCR system 14 can also use the SCR system 314 a reducing agent tank 318 , a reactor system 320 and a storage tank 322 contain. The SCR system 314 can generate and store ammonia gas and the exhaust gas flow in the exhaust pipe 312 Feed ammonia gas. Like the heating systems 48 . 148 . 248 can the heating system 348 one or more first heat exchangers 352 contained in a heat transfer relationship with the reactor system 320 stand.

The first heat exchanger (s) 352 may flow through a coolant supply passage 356 and a return passage 357 with cooling channels in the engine 316 be connected. A pump 358 can the working fluid between the first heat exchangers 352 and the engine 316 let it circulate. A control module 346 can with the pump 358 communicate and operate the pump 358 control a flow of working fluid through the first heat exchangers 352 and the engine 316 to set in motion and be able to interrupt. The control module 346 can the pump 358 for example, based on a temperature of the reactor system 320 and / or in the reactor system 320 control fluid contained. Additionally or alternatively, the control module could 346 the pump 358 for example, based on the engine temperature, the engine run time, and / or the outside ambient temperature. In addition or as an alternative, the control module 346 at any time as desired for heating the reactor system 320 the electric heating elements 350 enable or disable. In some configurations, the pump can 358 Working fluid can also flow through another heat exchanger, the reducing agent tank 318 heated.

With reference to will be another exhaust aftertreatment system 410 provided, which is an exhaust pipe 412 , an SCR system 414 and a heating system 448 included and from an internal combustion engine 416 can treat discharged exhaust gas. The exhaust pipe 412 , the SCR system 414 and the heating system 448 can each be structured in a similar or identical manner and work as the exhaust pipe 12 , SCR system 14 and heating system 48 , with the exception of some deviations described below. Similar properties will therefore not be described again in detail.

Like the SCR system 14 can the SCR system 414 a reducing agent tank 418 , a reactor system 420 and a storage tank 422 contain. The SCR system 414 can generate and store ammonia gas and ammonia gas the exhaust stream in the exhaust pipe 412 respectively. Like the heating systems 48 . 148 . 248 and 348 can also use the heating system 448 one or more first heat exchangers 452 contained in a heat transfer relationship with the reactor system 420 stand.

The first heat exchanger (s) 452 may be in a heat transfer relationship with a waste heat recovery system, for example a Rankine cycle 455 , stand. In the Rankine circle 455 can circulate a first working fluid, that of the engine 416 emitted exhaust heat receives. The first heat exchanger (s) 452 can flow with a heat exchanger of the Rankine circle 455 via a feed passage 456 and a return passage 457 communicate so that the first heat exchanger (s) 452 take a second working fluid in the heat exchanger of the Rankine circle 455 Absorbs heat from the first working fluid. It is understood that the first and second working fluids could be the same or different types.

A pump 458 can the working fluid between the first heat exchangers 452 and the Rankine Circle 455 let it circulate. A control module 446 can with the pump 458 in communication and to initiate and interrupt a flow of the working fluid through the first heat exchangers 452 the operation of the pump 458 Taxes. The control module 446 can the pump 458 for example, based on a temperature of the reactor system 420 and / or in the reactor system 420 control fluid contained. Additionally or alternatively, the control module could 446 the pump 458 for example, based on the engine temperature, the engine run time, and / or the outside ambient temperature. In addition or as an alternative, the control module 446 at any time the electric heating elements 450 as desired, for heating the reactor system 420 enable or disable. In some configurations, the pump can 458 The working fluid can also circulate through another heat exchanger, the reducing agent tank 418 heated.

With reference to will be another exhaust aftertreatment system 510 provided, which is an exhaust pipe 512 , a reductant delivery system 514 and a heating system 548 included and from an internal combustion engine 516 can treat discharged exhaust gas.

The reductant delivery system 514 can be a tank of liquid reducing agent 518 , an ammonia source 520 , an injector or a conveyor 524 , a compressed air source 523 (which an air tank 525 and / or a pump 540 may contain) and an SCR catalyst 526 includes. That in the reducing agent tank 518 contained liquid reducing agent may in a first mode via a first line 528 the injector 524 be supplied. A first pump 530 the liquid reducing agent can be from the reducing agent tank 518 to the injector 524 promote. Along the first line 528 can be a check valve 532 are arranged to prevent the return flow of the reducing agent.

The ammonia source 520 can be an ammonia generator (eg the one in shown reactor system 20 or any other reactor system or apparatus that generates ammonia gas and / or a device for storing ammonia gas (for example, those described in U.S. Pat shown storage tank 22 ), which stores gaseous ammonia. The gaseous ammonia may in a second mode via a second conduit 534 to the injector 524 be guided. A second pump 536 can the gaseous ammonia from the source of ammonia 520 to the injector 524 promote. In becomes the second pump 536 along the second line 534 shown, however, the second pump can 536 in some configurations also from the second line 534 be discontinued and the source of ammonia 520 put under pressure.

The injector 524 is fluid with the exhaust pipe 512 at a point upstream of the SCR catalyst 526 connected. The injector 524 the liquid reducing agent can be from the reducing agent tank 518 and the gaseous ammonia from the ammonia source 520 via a reducing agent inlet (not shown) or via an ammonia gas inlet (not shown) and the liquid reducing agent and / or the gaseous ammonia supply the exhaust gas stream. If both the liquid reducing agent and the ammonia gas are introduced into the exhaust gas stream in a third mode, the liquid reducing agent and the gaseous ammonia may be in a chamber (not shown) within the injector 524 be mixed prior to their introduction into the exhaust stream. In some configurations, the liquid reductant and the gaseous ammonia may be present in a mixing device (not shown) upstream of the injector 524 be mixed. The injector 524 can with a control module 546 communicating the injection and rate of injection of the liquid reductant and / or gaseous ammonia into the exhaust stream, for example, based on operating parameters of the engine 516 and / or a flow rate of the ammonia source 520 leaving ammonia gas controls.

The air tank 525 contains a pressurized fluid (eg, compressed air) and is in fluid communication with the exhaust stream via a third conduit 538 and the injector 524 in connection, whereby the injection of the liquid reducing agent and / or the gaseous ammonia is made possible in the exhaust gas stream. A third pump 540 can the fluid from the air tank 525 to promote exhaust flow and a control valve 542 controls the flow of fluid through the third conduit 538 , In some configurations, a mixing device (not shown) could be upstream of the injector 524 and downstream of the control valve 542 and the second pump 534 be arranged, in which compressed air and ammonia gas can mix. Although the third pump 540 in as along the third management 538 however, in some configurations, the third pump may be shown 540 from the third line 538 be set down and the air tank 525 put under pressure. In configurations of the compressed air source 523 without air tank 525 can the third pump 540 Aspirate air from the environment or any other volume of air. In addition, the control valve 542 , this in upstream of the junction of the second and third lines 534 . 538 shown in some configurations between the injector 524 and the intersection of the second and third lines 534 . 538 be located. The control module 546 can with the control valve 542 communicate with the control valve 542 for example, based on operating parameters of the engine 516 and / or a flow rate of the ammonia source 520 leaving ammonia gas to open and close. Additionally or alternatively, the control module could 546 the control valve 542 For example, based on the engine temperature, the engine runtime and / or the ambient temperature control.

The aftertreatment system 510 can the heating system 548 for heating the reducing agent tank 518 , the air tank 525 and the source of ammonia 520 operate. The heating system 548 can electrical heating elements 550 . 552 . 554 in a heat transfer relationship with the reducing agent tank 518 , the air tank 525 or the source of ammonia 520 contain. The control module 546 can the operation of electric heating elements 550 . 552 . 554 control to the reducing agent tank 518 , the air tank 525 and the source of ammonia 520 each at or above a desired minimum temperature.

Further referring to becomes the operation of the aftertreatment system 10 described in more detail. In response to a cold start of the engine 516 (which can be done in circumstances where that of the engine 516 emitted exhaust gas warmer than the activation temperature of the SCR 526 is, but colder than the temperature at which liquid reducing agent can go into the gas state) that in the source of ammonia 520 stored ammonia gas the exhaust stream in the exhaust pipe 512 through the second line 534 and the injector 524 be supplied. After the cold start of the engine 516 may be heating the ammonia source 520 be required to allow the necessary for the production of the ammonia gas reactions in this. Under such conditions, the control module 546 the electric heating element 554 activate.

Immediately after a cold start, the control module 546 the electric heating element 550 activate to in the tank 518 Thaw liquid. During this time, the liquid reducing agent from the tank 518 through the first line 528 to the injector 524 be delivered and the control module 546 can be operated to the exhaust gas flow in the exhaust pipe 512 to inject the liquid reducing agent instead of the ammonia gas.

In some configurations, the control module may 546 the injector 524 to operate a mixture of the liquid reducing agent from the reducing agent tank 518 and the ammonia gas from the ammonia source 520 to inject into the exhaust stream. The air tank 525 can the fluid contained in it via the third line 538 to the injector 524 injecting the mixture of the liquid reducing agent and the ammonia gas into the exhaust gas stream. The control module 546 can be operated to the position of the control valve 542 to control that from the air tank 525 an optimum amount of the fluid is provided at a given time to allow the injection of the mixture of the liquid reducing agent and the ammonia gas into the exhaust gas stream. It is understood that the air tank 525 Also, the injection of the liquid reducing agent and ammonia gas in the exhaust stream can independently allow each other.

The control module 546 can the heating element 552 for preheating the in the air tank 525 activated fluid so that the system reaches the desired efficacy. That along the first line 528 arranged check valve 532 prevents that from the air tank 525 escaping fluid in the first conduit 528 generates a return current.

The control module 546 can also with the first pump 530 , the second pump 536 and the third pump 540 communicate and control their operation.

In some configurations, the injector 524 fluidly with a return line 529 be connected, through which of the injector 524 over the first line 528 obtained liquid reducing agent to the tank of liquid reducing agent 518 can be returned. That from the injector 524 to the tank of liquid reducing agent 518 through the return 529 Returned liquid tank liquid reducing agent can help to better cool the injector 524 serve. In some configurations, air may be from the air tank 525 and / or gas from the source of ammonia 520 for cooling the injector 524 can be used in which they or heat-sensitive components of the injector 524 around flows.

With reference to the and becomes an injector 624 made available instead of the injector 524 in the exhaust aftertreatment system 510 can be installed. The injector 624 may be an outer injector body 626 , a first inner injector body 628 , a second inner injector body 630 , a cone 632 , a pen head 634 and a perforated plate 636 contain. The outer injector body 626 can have an internal cavity 638 contained, in which the inner injector body 628 . 630 , the cone 632 , the pencil head 634 and the perforated plate 636 are arranged. The outer injector body 626 may also include a first port (eg, a liquid reductant inlet) 640, a second port (eg, an ammonia gas inlet) 642, a third port (eg, a return port) 644, a fourth port (eg, an ammonia gas outlet ) 646 and a fifth port (for example, a liquid reductant outlet) 648. The first, third and fifth port 640 . 644 . 648 can flow with the cavity 638 be connected. The second and the fourth port 642 . 646 are fluidly interconnected and can from the cavity 638 be separated in terms of flow.

The first and second inner injector bodies 628 . 630 may generally be tubular bodies, each having first and second internal passages 650 . 652 which are fluid with each other and with the third port 644 are connected. The first and second inner injector bodies 628 . 630 can share an annular outer passage 654 form, which the inner passages 650 . 652 encloses. The second inner injector body 630 is axially between the first inner injector body 628 and the perforated plate 636 arranged. One end of the second inner injector body 630 can have one or more openings 657 having a fluid connection between the annular outer passage 654 and the second inner passage 652 enable.

The pin 632 and the pen head 634 are attached to each other and within the second inner injector body 630 arranged. The pen head 634 is at one end of the pen 632 attached and the other end of the pen 632 sits selectively on the perforated plate 636 , The pen head 634 can have one or more culverts 655 having a fluid connection between the first and second inner passage 654 deliver.

A feather 656 is inside the first inner injector body 628 arranged and clamped the pin head 634 from the first inner injector body 628 anticipated, causing the pin 632 against one, one outlet 658 in the perforated plate 636 is biased forming valve seat. A magnet 660 can the pen head 634 enclose and operate so that it is the pen head 634 and the pin 632 against the first inner injector body 628 pushes to the pin 632 from the outlet 658 to separate and fluid from the annular outer passage 654 through the outlet 658 in the perforated plate 636 and from the injector 624 through the fifth port 648 to let escape.

The second port 642 may be fluid with a through the outer injector body 626 extending passage 670 be connected. The outer injector body 626 can a ring collar 672 containing a portion of the second inner injector body 630 and the fifth port 648 encloses. An annular recess 674 can be in one axial end of the waistband 672 be formed and a fluid connection between the passage 670 and the fourth port 646 enable.

As described above, the injector 624 instead of the injector 524 in the shown system 510 be installed. That is, the first port 640 can flow with the first line 528 be connected, the second port 642 can flow with the second line 534 and the third line 538 be connected and the third port 644 can flow with the return line 529 be connected.

Liquid reducing agent can be added to the injector 624 through the first port 640 enter and enter the outer annular passageway 654 at the first inner injector body 628 is present, inflow. The liquid reducing agent may pass axially through the outer annular passage 654 (that is, parallel to a longitudinal axis of the outer annular passage 654 ) to the perforated plate 636 flow. The control module 546 can with the magnet 660 communicate and the magnet 660 the pin 632 from a sealing engagement with the perforated plate 636 let slide so that the liquid reducing agent in the outer annular passage 654 through the outlet 658 and the fifth port 648 flow and into the exhaust stream in the exhaust pipe 512 can occur.

If the pin 632 in a sealing engagement with the perforated plate 636 (and hereby a current through the fifth port 648 prevents), the liquid reducing agent in the outer annular passage 654 through the one or more passages 657 in the second inner injector body 630 and in the second inner passage 652 stream. Liquid reducing agent in the second internal passage 652 can be axial to the pin head 634 and through the one or more passages 655 in the pen head 634 in the first inner passage 650 flow. From the first inner passage 650 can the liquid reducing agent from the injector 624 through the third port 644 and in the return 529 back to the tank of liquid reducing agent 518 flow. That by the internal passages 650 . 652 flowing liquid reducing agent may be the magnet 660 and / or other heat-sensitive components of the injector 624 cool.

Gaseous ammonia (and optionally air) can enter the injector 624 through the second port 642 enter and into the passage 670 stream. From the passage 670 can gaseous ammonia (and air) to the annular recess 674 and through the fourth port 646 in the exhaust gas flow in the exhaust pipe 512 stream. In some configurations, the flow of gaseous ammonia and / or air through the second and fourth ports 642 . 646 the magnet 660 and / or other heat-sensitive components of the injector 624 cool.

In some configurations (for example, the in shown configuration) contains the injector 624 possibly no second port 642 and fourth port 646 , In such configurations the system will close 510 possibly no return 529 one, the third port 644 can flow with the second line 534 and the third line 538 be connected and the first port 640 can be fluid, as in shown with the first lead 528 be connected. As described above, liquid reductant may be from the first conduit 528 through the first port 640 , the annular outer passage 654 and the fifth port 648 flow when the pin 632 from a sealing engagement with the perforated plate 636 pushed.

Gaseous ammonia (and optionally air) can pass through the third port 644 in the injector 624 enter. From the third port 644 can gaseous ammonia (and air) through the first internal passage 650 and in the second inner passage 652 stream. From the second inner passage 652 The gaseous ammonia (and air) can pass through the one or more passages 657 in the second inner injector body 630 and through the fifth port 648 (and into the exhaust pipe 512 ) flow when the pin 632 from a sealing engagement with the perforated plate 636 pushed. The gaseous ammonia (and air) may be in the annular outer passage 654 mix with the liquid reducing agent, which before, during and / or after the outflow of the liquid reducing agent and the ammonia gas through the outlet 658 and the fifth port 648 can be done.

In the above configuration of the injector 624 ( ), which is the second port 642 and the fourth port 646 not containing, could be the injector 624 also in any of the systems described above 10 . 110 . 210 . 310 . 410 be installed.

In reference to will now be another injector 724 provided instead of the injector 524 in the system 510 can be installed. Structure and function of the injector 724 can generally be similar to the injector described above 624 Its and similar properties may therefore not be described repeatedly in detail. The injector 724 may be an outer injector body 726 which includes a first port (eg, a liquid reductant inlet) 740, a second port (eg, an ammonia gas inlet) 742, a third port (eg, a return port) 744, a fourth port Port (eg, an ammonia gas outlet) 746 and a fifth port (eg, a liquid reductant outlet) 748. The fifth injector port 748 can through a perforated plate 736 To be defined.

A tubular inner body 728 can be axial on the third port 744 be aligned and an internal passage 752 in fluid communication with the third port 744 define. A cone 732 can through the inner passage 752 run and selectively a valve seat on the fifth port 748 forming perforated plate 736 sealingly into sealing engagement. A first ring collar 760 may be from the outer injector body 726 extend and at least a portion of the tubular inner body 728 enclose. The first ring collar 760 and the tubular inner body 728 can together form an annular intermediate passage 754 form, in fluid communication with the first port 740 stands. The annular intermediate passage 754 is fluid with the first port 740 and the fifth port 748 connected when the pin 748 in an open position (that is, from the magnet 760 from a sealing engagement with the perforated plate 736 is moved). The annular intermediate passage 754 is also in fluid communication with the internal passageway 752 What about one or more culverts 762 in a lower on the tubular inner body 728 and the first ring collar 760 attached guide member 764 he follows. The tubular inner body 728 and the first ring collar 760 can form a cartridge assembly that resembles the cartridge assembly used in its own U.S. Patent No. 8,978,364 of the assignee, the disclosure of which is incorporated herein by reference.

A second ring collar 770 may be from the outer injector body 726 extend and at least a portion of the first ring collar 760 and the tubular inner body 728 enclose. The second ring collar 770 and the first ring collar 760 can together form a ring shape of the fourth port 746 define so that the fourth port 746 the fifth port 748 encloses and radially outside the fifth port 748 is located. The fifth port 748 is fluid with the second port 742 connected. Due to the ring shape of the second ring collar 770 and the positioning of the second annular collar 770 around the first ring collar 760 and the pin 732 may be the gaseous ammonia and / or the air through the second annular collar 770 flow and heat sensitive components of the injector 724 cool. While the fourth port 746 represents as open ring-shaped port, the fourth port 746 in some configurations, spacers (ie, supporting members) having the second annular collar 770 partly with respect to the first ring collar 760 support and partially block the fluid flow therethrough.

With reference to and will be another conveyor 1 and exhaust system 2 delivered. The conveyor 1 may be similar or identical to the conveyors or injectors described above 24 . 524 . 624 . 724 be structured and functioning, with the exception of some deviations described below. Similar properties will therefore not be described again in detail.

The conveyor 1 may be an additive in a mixing device 2.1 an exhaust system 2 upstream of an exhaust aftertreatment device 7 (eg, an SCR catalyst, oxidation catalyst, particulate filter, etc.), the delivery device 1 at least a first Zuleitkanal 1.1 with at least one first feed opening 1.2 and a heating element 3 to evaporate at least a portion of the additive passing through the first supply channel 1.1 can be introduced.

In the vaporized state, the additive is present as a gas. At an evaporation rate below 100%, the remaining part is liquid, usually in the form of an unvaporised liquid film or droplets. The size of the droplets can be very different depending on the environmental conditions. Also, an originally vaporous medium can condense by cooling and become liquid again in the form of droplets.

The present disclosure also provides a method of introducing the additive into the exhaust system 2 by means of the conveyor 1 of this type.

The additive may be a substrate designed to be supplied alone by itself. Alternatively, the additive may be a carrier solution containing the desired substrate. In the described embodiment, in particular, a reducing agent such as ammonia can be considered as a possible substrate. The present disclosure also provides a mixer 2.1 with the conveyor 1 and the exhaust system 2 with the mixing device 2.1 of this type.

A dosing unit for an additive is already from the US Patent 2008/0073558 A1 known. This contains a surrounded by a heat storage system capillary channel to promote the liquid additive. By means of the heat storage system, the additive can be heated briefly or continuously until it reaches an evaporation temperature.

A similar dosing unit for an additive, e.g. As an ammonia solution or a hydrocarbon, is from the WO 2014/070516 A1 known. This contains a circulation channel for the additive, so that it can serve as a coolant for the metering unit. In addition, one or more capillary channels are provided in which the additive for introduction into the flow of the exhaust gas is evaporated. The heat energy required for this purpose can optionally be generated by a heating element, especially during the starting phase.

An object of the present disclosure is the design and arrangement of a conveyor 1 for supplying the additive and a method for introducing the additive so that an improved introduction rate and a faster provision of the additive can be achieved.

The goal may be achieved, in one aspect of the present disclosure, by having at least one second supply channel 1.3 with at least one second feed opening 1.4 is provided, wherein the second supply channel 1.3 the heating element used for evaporation 3 does not contain.

The objective may also be achieved, in one aspect of the present disclosure, by selectively passing the additive through the first delivery channel 1.1 and the first feed opening 1.2 and / or through the second supply channel 1.3 and the second feed opening 1.4 is introduced, wherein at the supply line through the first supply channel 1.1 the additive is at least partially vaporized and at least partially vaporized from the first supply port 1.2 to the exhaust system 2 is guided, and the additive via the second supply channel 1.3 and the second feed opening 1.4 is supplied in liquid form.

This makes it possible, depending on the operating condition of the engine optimally additives in different states of matter the exhaust gas on the conveyor 1 supply. The corresponding feed openings 1.2 . 1.4 or supply channels 1.1 . 1.3 can be designed in accordance with the respective state of aggregation to be supplied so that optimum flow conditions can be obtained on the one hand for the liquid medium and on the other hand for the at least partially gaseous medium. By using the second channel 1.3 the supply can also take place simultaneously in two different states of aggregation (for example in liquid form and in at least partially vaporized form).

While at low loads and during the cold start phase, a purely gaseous feed is advantageous, at a high metering required operating point, for example, at medium and full load, a complementary liquid supply. In such operating conditions, there is normally a correspondingly higher exhaust gas temperature level. If the exhaust gas temperatures are sufficiently high, a restriction solely to liquid supply can be advantageous. In this way, the risk of deposits, such as occur in pure liquid supply at low exhaust gas temperatures can be reduced. At the same time energy savings can be achieved because not all supplied additives must be evaporated.

However, the liquid to be introduced additive may be in the conveyor 1 or in the second supply channel 1.3 preheated, so that after its exit from the Zuleitkanal 1.3 a faster evaporation in the exhaust gas is ensured. Exclusive evaporation in the second supply channel 1.3 will not be delivered.

It may also be advantageous for this purpose if a first feed unit 4.1 and a second feeding unit 4.2 be supplied, wherein the at least one first Zuleitkanal 1.1 in the first feeder unit 4.1 and the at least one second Zuleitkanal 1.3 in the second feed unit 4.2 are arranged. When two different feed units are used, the respective supply channel is divided with regard to the provision of additive on the one hand and of heat on the other hand. This can prove to be advantageous, especially in view of the different amounts of heat to be transferred.

Furthermore, it may be advantageous if the first feed unit 4.1 and the second feed unit 4.2 in a housing 5 ( ) or when the first feeder unit 4.1 and the second feed unit 4.2 each in separate housings 5.1 . 5.2 , are housed ( ). Both variants have their advantages. At one in the two housings 5.1 . 5.2 divided structure is each independent positioning on or in the exhaust system 2 possible. Hereby, on the one hand, the desired discharge points and on the other hand, the outside of the exhaust system 2 existing structural conditions. When using a single case 5 manufacturing and assembly are facilitated.

It can be advantageously set up here so that the additive upstream of the first Zuleitkanals 1.1 and / or within the first supply channel 1.1 at least partially evaporated. If the evaporation is carried out as late as possible (for example, shortly before the feed opening), then the further feed path to be heated is up to the feed opening 1.2 correspondingly short. Thus, less heating power is needed. It may be particularly important that at least a share of 50 to 80% or 70% of that through the first supply channel 1.1 guided or to the first feed opening 1.2 passed additive amount is evaporated. On the one hand, the above-mentioned evaporation rate results in an optimum ratio of the introduction rate and, on the other hand, the required heat input. A higher evaporation rate may be beneficial. However, this requires a larger heat input. In view of deposits of residual additive to be avoided, lower evaporation rates must be avoided, especially in internal combustion engines with lower operating temperatures.

In connection with the design and arrangement according to one aspect of the present disclosure, it may be advantageous if the exhaust gas has between 60 g / h and 600 g / h of additive through the first supply channel 1.1 be supplied. The flow rate of the at least partially vaporized additive automatically leads to a corresponding heat, at least in the case of constant evaporation rate. However, at a lower evaporation rate with the same heat input, a higher flow rate can be supplied.

In addition, the use of a reducing agent, such as a urea-water solution or a water-ammonia solution, may be advantageous as an additive.

In the present application, including the definitions below, the term "module" or "controller" may be replaced by the term "circuit". The term "module" may refer to, form part of, or include: an application specific integrated circuit (ASIC); a digital, analog or mixed analog / digital discrete circuit; a digital, analog or mixed analog / digital integrated circuit; a logic gate circuit; a field programmable gate array (FPGA); a processor circuit (shared, dedicated or grouped) that executes code; a memory circuit (shared, dedicated or grouped) which stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above as in a system on chip.

The module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the Internet, a wide area network (WAN), or combinations thereof. The functionality of a given module of the present disclosure may be distributed over a plurality of modules connected via interface circuits. For example, multiple modules may allow for load balancing. In another example, a server (also known as a remote device or cloud) may perform some functionality on behalf of a client module.

The term code, as used above, may include software, firmware, and / or microcode, and may refer to programs, routines, functions, classes, data structures, and / or objects. The term shared processor circuit includes a single processor circuit that executes some or all of the code from multiple modules. The term grouped processor circuit includes a processor circuit that, in combination with additional processor circuits, executes some or all of the code from one or more modules. References to multiple processor circuits include multiple discrete-die processor circuits, multiple single-chip processor circuits, multiple cores of a single processor circuit, multiple threads of a single processor circuit, or a combination of the foregoing. The term shared memory circuit comprises a single memory circuit which stores some or all of the code from several modules. The term grouped memory circuit includes a memory circuit which, in combination with additional memories, stores some or all of the code from one or more modules.

The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium as used herein includes nonvolatile electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); The term computer-readable medium can therefore be regarded as tangible and non-volatile. Non-limiting examples of a nonvolatile, tangible computer readable medium include nonvolatile memory circuits (such as a flash memory circuit, an erasable programmable read only memory circuit or a mask read only memory circuit), volatile memory circuits (such as a static random access memory circuit or a dynamic random access memory circuit). , magnetic storage media (such as an analog or digital magnetic tape or hard disk drive), and optical storage media (such as a CD, DVD, or Blu-ray Disc).

The apparatus and methods described in this application may be partially or fully implemented by a specialized computer created by configuring a general purpose computer to perform one or more particular functions embedded in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into the computer programs through the routine work of a trained technician or programmer.

The computer programs include processor executable instructions stored on at least one non-transitory, tangible computer-readable medium. The computer programs may also include or rely on stored data. The computer programs may include a basic input / output system (BIOS) that interacts with special computer hardware, device drivers that interact with particular devices of the special purpose computer, one or more operating systems, user applications, background services, background applications, and so on.

The computer programs may comprise: (i) descriptive text to be dissected, such as HTML (hypertext markup language) or XML (extensible markup language), (ii) assembly code, (iii) object code generated by a compiler from source code, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a use-synchronous compiler, etc. Source code may, by way of example only, be construed using syntax from languages including C, C ++, C #, Objective C, Haskell, Go , SQL, R, Lisp, Java ^®, Fortran, Perl, Pascal, Curl, OCaml, Javascript ^®, HTML5, Ada, ASP (active server pages), PHP, Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash ^®, Visual Basic ^® , Lua and Python ^{® are} written.

None of the elements recited in the claims are intended to constitute a mean-plus-function element as defined by 35 U.S.C. §112 (f), except where an element is expressly cited using the phrase "means for" or, in the case of a method claim, using the phrase "operation for" or "step for".

The foregoing description of the embodiments has been provided for purposes of illustration and description. It should not be exhaustive or limit the revelation. Individual elements or features of a In particular, particular embodiments are not limited to this particular embodiment but, where applicable, interchangeable and may be used in a selected embodiment, even if not specifically shown or described. This can also be changed in different ways. Such variants are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 14931039 [0001]
• DE 102015113835 [0001]
• US 8978364 [0149]
• US 2008/0073558 A1 [0156]
• WO 2014/070516 A1 [0157]

Claims (42)

Exhaust after-treatment system with: a reducing agent tank, an ammonia gas source, an injector which receives liquid reducing agent from the reducing agent tank and ammonia gas from the ammonia gas source and in a first mode injects the liquid reducing agent into an exhaust gas stream and in a second mode introduces the ammonia gas into the exhaust gas stream, a first conduit, the liquid reducing agent from the reducing agent tank leads to the injector and a second conduit that carries ammonia gas from the ammonia gas source to the injector. Exhaust after-treatment system according to Claim 1 wherein the injector simultaneously introduces both the liquid reducing agent and the ammonia gas into the exhaust stream in a third mode. Exhaust after-treatment system according to Claim 2 wherein the injector has an outlet port through which a mixture of liquid reducing agent and ammonia gas is injected into the exhaust gas stream. Exhaust after-treatment system according to Claim 3 wherein the injector has a pair of inlet ports that fluidly connect the first and second conduits to the outlet port. Exhaust after-treatment system according to Claim 1 wherein the injector is fluidly connected to an exhaust pipe at a location upstream of a catalyst in the exhaust stream. Exhaust after-treatment system according to Claim 5 wherein the injector includes an inlet for liquid reducing agent for receiving the liquid reducing agent and an ammonia inlet for receiving the ammonia gas. Exhaust after-treatment system according to Claim 6 wherein the catalyst is an SCR catalyst. Exhaust after-treatment system according to Claim 1 which further includes an air source to facilitate the injection of the liquid reductant and the ammonia gas into the exhaust gas stream. Exhaust after-treatment system according to Claim 8 wherein the air source is fluidly connected to the injector via a third conduit, and wherein the airflow cools the injector through a passage in the injector. Exhaust after-treatment system according to Claim 9 which also includes a first valve disposed along the third conduit which controls the flow of fluid therethrough. Exhaust after-treatment system according to Claim 10 wherein the injector includes a liquid reductant outlet fluidly connected to a return conduit coupled to a tank of liquid reductant. Exhaust after-treatment system according to Claim 11 wherein the liquid reducing agent coming from the reducing agent tank and the ammonia gas coming from the ammonia gas source are mixed in a chamber inside the injector. Exhaust after-treatment system according to Claim 12 additionally including an electrical heating element in heat transfer relationship with the air tank. Exhaust after-treatment system according to Claim 13 wherein the first conduit includes a second valve for preventing backflow of the liquid reducing agent. Exhaust after-treatment system according to Claim 14 additionally including a control module that controls a position of the first valve and an injection rate of a mixture of liquid reducing agent and the ammonia gas. Exhaust after-treatment system with: a reducing agent tank containing a liquid reducing agent, an ammonia gas containing ammonia gas source, a compressed air source facilitating the injection of the liquid reducing agent and / or the ammonia gas into an exhaust gas stream, a first conduit that carries liquid reductant from the reductant tank to the exhaust stream, a second conduit which carries ammonia gas from the ammonia gas source to the exhaust gas flow, and a third line that carries compressed air from the compressed air source to the exhaust stream. Exhaust after-treatment system according to Claim 16 which additionally includes an injector receiving the ammonia gas from the second conduit and the pressurized air from the third conduit, the second and third conduits communicating with each other upstream of the injector. Exhaust after-treatment system according to Claim 16 which additionally includes an electrical heating element in heat transfer relationship with the compressed air source. Exhaust after-treatment system according to Claim 16 additionally including an injector in fluid communication with the first, second, and third conduits, and wherein the injector includes a liquid reductant outlet fluidly connected to a return conduit coupled to the tank of liquid reductant. Exhaust after-treatment system according to Claim 16 wherein a first valve is disposed along the first conduit for preventing backflow of the liquid reducing agent. Exhaust after-treatment system according to Claim 20 wherein a second valve is disposed along the third conduit for controlling fluid flow therethrough. Exhaust after-treatment system according to Claim 16 additionally containing an injector which receives the liquid reducing agent from the reducing agent tank via the first line and the ammonia gas from the ammonia gas source via the second line and introduces both the reducing agent and the ammonia gas into the exhaust gas stream. Exhaust after-treatment system according to Claim 22 wherein the liquid reducing agent coming from the reducing agent tank and the ammonia gas coming from the ammonia gas source are mixed in a chamber inside the injector. An injector for an exhaust aftertreatment system, comprising an injector body including a first port, a second port, a third port, a fourth port, and a fifth port, the first port in fluid communication with the third port and the fifth port, and the second port Port is fluidly connected to the fourth port, the second and the fourth port are fluidly separated from the first, third and fifth ports, the injector body supports a pin which is locked between a closed position in which the fluid flow through the fifth port, and an open position, which allows the fluid flow through the fifth port, can be moved. Injector after Claim 24 wherein the first port is fluidly connected to a conduit of liquid reductant and the second port is fluidly connected to a conduit of gaseous ammonia. Injector after Claim 25 wherein the third port forms a liquid reductant outlet fluidly connected to a return conduit coupled to a tank of liquid reductant. Injector after Claim 25 wherein the fourth port is defined by an outer annular collar surrounding the fifth port. Injector after Claim 27 additionally including an intermediate collar extending from the injector body, the intermediate collar being surrounded by the outer collar and cooperatively defining, with the outer collar, the fourth port. Injector after Claim 28 in addition comprising a tubular intermediate ring surrounded by the inner body defining cooperatively with the Zwischenringbund an annular passage, which is fluidly connected to the first port, and wherein the tubular inner body has an inner passage which is fluidly connected to the third port. Injector after Claim 29 wherein the pin is disposed within the inner passage. An injector for an exhaust aftertreatment system, wherein the injector includes: an outer body including a liquid reducing agent receiving liquid inlet port, an ammonia gas receiving gas introduction port, a liquid outlet port through which the liquid reducing agent leaves the injector, and a gas outlet port through which the ammonia gas exits the injector, and a spigot disposed within the outer body that is movable between an open position permitting fluid flow through the fluid outlet port and a closed position blocking fluid flow through the fluid outlet port. Injector after Claim 31 wherein the gas outlet port is in the form of an annular collar at least partially surrounding the fluid outlet port. Injector after Claim 32 wherein the gas outlet port is an annular port at least partially surrounding the fluid outlet port. Injector after Claim 32 wherein the annular collar has an annular recess which encloses a portion of the pin and is fluidly connected to the gas inlet port and the gas outlet port, and wherein the annular recess is axially spaced from the liquid outlet port. Injector after Claim 31 wherein the outer body comprises a liquid return port. Injector after Claim 35 wherein the liquid return port is fluidly connected to the inner passage disposed in the outer body, the pin being at least partially in wherein the outer body includes a first annular collar defining a first annular passageway surrounding a portion of the inner passageway, the first annular passageway fluidly communicating the fluid introduction port with the fluid outlet port, the outer body defining a second annular collar which defines, together with the first annular collar, the gas outlet port and wherein the gas outlet port is a second annular passage which encloses at least a portion of the first annular passage. Exhaust after-treatment system with: a reducing agent tank, a reactor system receiving reducing agent from the reducing agent tank and discharging ammonia-containing gas, a storage tank receiving ammonia-containing gas from the reactor system and storing a volume of ammonia-containing gas, a first conduit which carries ammonia-containing gas from the reactor system to an exhaust gas stream, the first conduit bypassing the storage tank, a second conduit, the ammonia-containing gas from the storage tank leads to the exhaust stream and a third conduit which carries the ammonia-containing gas from the reactor system to the storage tank. Exhaust after-treatment system according to Claim 37 additionally comprising a first heat exchanger in a heat transfer relationship with the reactor system, the first heat exchanger transferring heat from the exhaust gas to the reactor system. Exhaust after-treatment system according to Claim 38 additionally comprising an exhaust gas supply passage which fluidly connects the exhaust gas flow to the first heat exchanger so that exhaust gas from the exhaust gas flow can flow through the first heat exchanger. Exhaust after-treatment system according to Claim 39 wherein the exhaust gas feed passage includes a valve controlling the fluid flow therethrough. Exhaust after-treatment system according to Claim 38 in addition comprising a second heat exchanger in which heat is transferred from the exhaust stream to a working fluid, the first and second heat exchangers being fluidly connected to one another to allow a first flow of the working fluid therebetween. Exhaust after-treatment system according to Claim 37 additionally containing an electrical heating element in a heat transfer relationship with the reactor system.

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