US20130145749A1 - Fluid manifold for use in an scr dosing system - Google Patents

Fluid manifold for use in an scr dosing system Download PDF

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Publication number
US20130145749A1
US20130145749A1 US13/316,996 US201113316996A US2013145749A1 US 20130145749 A1 US20130145749 A1 US 20130145749A1 US 201113316996 A US201113316996 A US 201113316996A US 2013145749 A1 US2013145749 A1 US 2013145749A1
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Prior art keywords
reductant
passage
fluid
manifold
coolant
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US13/316,996
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Jack A. Merchant
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Caterpillar Inc
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Caterpillar Inc
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Priority to US13/316,996 priority Critical patent/US20130145749A1/en
Assigned to CATERPILLAR INC. reassignment CATERPILLAR INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: MERCHANT, JACK A.
Publication of US20130145749A1 publication Critical patent/US20130145749A1/en
Abandoned legal-status Critical Current

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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2066Selective catalytic reduction [SCR]
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2590/00Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines
    • F01N2590/08Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for heavy duty applications, e.g. trucks, buses, tractors, locomotives
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00Adding substances to exhaust gases
    • F01N2610/02Adding substances to exhaust gases the substance being ammonia or urea
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00Adding substances to exhaust gases
    • F01N2610/10Adding substances to exhaust gases the substance being heated, e.g. by heating tank or supply line of the added substance
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00Adding substances to exhaust gases
    • F01N2610/11Adding substances to exhaust gases the substance or part of the dosing system being cooled
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00Adding substances to exhaust gases
    • F01N2610/14Arrangements for the supply of substances, e.g. conduits
    • F01N2610/1406Storage means for substances, e.g. tanks or reservoirs
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/12Improving ICE efficiencies

Definitions

  • the present disclosure relates generally to exhaust aftertreatment systems and methods and, more particularly, to systems and methods for supplying a reductant to an exhaust stream.
  • a selective catalytic reduction (SCR) system may be included in an exhaust treatment or aftertreatment system for a power system to remove or reduce nitrous oxide (NOx or NO) emissions coming from the exhaust of an engine.
  • SCR systems use reductants, such as urea, that are introduced into the exhaust stream to significantly reduce the amount of nitrous oxides (NOx) in the exhaust.
  • SCR system The construction and installation of the SCR system can be a considerable component of the overall power system cost.
  • components of the SCR system are typically designed to meet basic design requirements without additional flexibility or modularity. That is, once designed, most SCR systems are static in that additional capability can not easily be accommodated using the existing components.
  • U.S. Pat. No. 7,895,829 discloses an aftertreatment system including an SCR system.
  • the '829 patent SCR system includes a urea solution tank.
  • a urea solution pump is provided within the urea solution tank.
  • such a configuration may be problematic if the pump needs maintenance or replacement.
  • a reductant dosing system manifold includes: a body, a first passage in the body configured to receive a first fluid from a first separately disposed component of a reductant dosing system, and a second passage in the body configured to receive the first fluid from a second separately disposed component of the reductant dosing system, wherein the first passage and the second passage are fluidly isolated from each other within the body, and wherein a positional relationship of the first passage and the second passage is fixed by the body.
  • a reductant supply assembly includes: a reductant tank, a reductant pump in fluid communication with the reductant tank, and a fluid manifold including: a body, a first passage in the body configured to receive a first fluid from a first separately disposed component of the reductant supply assembly; and a second passage in the body configured to receive the first fluid from a second separately disposed component of the reductant supply assembly, wherein the first passage and the second passage are fluidly isolated from each other within the body, wherein a positional relationship of the first passage and the second passage are fixed by the body, and wherein the fluid manifold provides the fluid communication between the reductant tank and the reductant pump.
  • FIG. 1 is a diagrammatic view of a machine including a power system with an engine and an aftertreatment system.
  • FIG. 2 is a diagrammatic view of the aftertreatment system including a reductant supply system including a pump electronics and tank unit (PETU) including a fluid manifold according to the present disclosure.
  • PETU pump electronics and tank unit
  • FIG. 3 is an isometric view of a PETU including a fluid manifold according to the present disclosure.
  • FIG. 4 is an isometric view of a fluid manifold according to the present disclosure.
  • FIG. 1 is a diagrammatic view of a machine 1 including a cab 2 where an operator 3 sits and a power system 10 .
  • the machine 1 might be a track type tractor (as illustrated), on-highway truck, car, vehicle, off-highway truck, earth moving equipment, material handler, logging machine, compactor, construction equipment, stationary power generator, pump, aerospace application, locomotive application, marine application, or any other device or application requiring a power system 10 .
  • the power system 10 includes an engine 12 and an aftertreatment system 14 to treat an exhaust stream 16 produced by the engine 12 .
  • the engine 12 may include other features not shown, such as controllers, fuel systems, air systems, cooling systems, peripheries, drivetrain components, turbochargers, exhaust gas recirculation systems, etc.
  • the engine 12 may be any type of engine (internal combustion, gas, diesel, gaseous fuel, natural gas, propane, etc.), may be of any size, with any number of cylinders, any type of combustion chamber (cylindrical, rotary spark ignition, compression ignition, 4-stroke and 2-stroke, etc.), and in any configuration (“V,” in-line, radial, etc.).
  • the aftertreatment system 14 includes an exhaust conduit 18 for delivering the exhaust stream 16 and a Selective Catalytic Reduction (SCR) system 20 .
  • the SCR system 20 includes an SCR catalyst 22 , and a reductant supply assembly 24 .
  • the aftertreatment system 14 may also include a diesel oxidation catalyst (DOC) 26 , a diesel particulate filter (DPF) 28 , and/or a clean-up catalyst 30 .
  • DOC diesel oxidation catalyst
  • DPF diesel particulate filter
  • the DOC 26 , DPF 28 , SCR catalyst 22 , and clean-up catalyst 30 may include the appropriate catalyst or other material, respective of their intended functions, disposed on a substrate.
  • the substrate may consist of cordierite, silicon carbide, other ceramic, a metal structure or other configurations of similar materials.
  • the substrates may form a honeycomb structure with a plurality of longitudinal channels or cells for the exhaust stream 16 to pass through.
  • the DOC 26 , DPF 28 , SCR catalyst 22 , and clean-up catalyst 30 substrates may be housed in canisters, as shown, or may be integrated into the exhaust conduit 18 .
  • the DOC 26 and DPF 28 may be in the same canister, as shown, or may be separately disposed.
  • the SCR catalyst 22 and clean-up catalyst 30 may also be in the same canister, as shown, or may be separately disposed.
  • the aftertreatment system 14 is configured to remove, collect, or convert undesired constituents from the exhaust stream 16 .
  • the DOC 26 oxidizes carbon monoxide (CO) and unburnt hydrocarbons (HC) into carbon dioxide (CO 2 ) and water (H 2 O).
  • the DPF 28 collects particulate matter or soot.
  • the SCR catalyst 22 is configured to reduce an amount of nitrous oxides (NOx) in the exhaust stream 16 in the presence of a reductant.
  • the clean-up catalyst 30 may embody an ammonia oxidation catalyst (AMOX).
  • AMOX ammonia oxidation catalyst
  • the clean-up catalyst 30 is configured to capture, store, oxidize, reduce, and/or convert reductant that may slip past or break through the SCR catalyst 22 .
  • the clean-up catalyst 30 may also be configured to capture, store, oxidize, reduce, and/or convert other constituents present in the exhaust stream.
  • the exhaust stream 16 is configured to exit the engine 12 , pass through the DOC 26 and DPF 28 , pass through the SCR catalyst 22 , and then pass through the clean-up catalyst 30 via the exhaust conduit 18 .
  • the SCR system 20 is downstream of the DPF 28 and the DOC 26 is upstream of the DPF 28 .
  • the clean-up catalyst 30 is downstream of the SCR system 20 .
  • these devices may be arranged in a variety of orders and may be combined together.
  • the SCR catalyst 22 may be combined with the DPF 28 with the catalyst material for the SCR deposited on the DPF 28 .
  • Other exhaust treatment devices may also be located upstream, downstream, or within the SCR system 20 .
  • FIG. 2 is a diagrammatic view of the aftertreatment system 14 wherein the reductant supply assembly 24 is configured to introduce the reductant into the exhaust stream 16 upstream of the SCR catalyst 22 .
  • the reductant supply assembly 24 may include a pump electronics and tank unit (PETU) 32 , a reductant line 34 , and an injector 36 .
  • the PETU 32 generally includes several separately disposed components; specifically the PETU 32 includes a tank 110 including a header 120 , a fluid manifold 130 , a pump 140 and associated electronics (not shown). Embodiments of the PETU 32 will be described in more detail below.
  • the tank 110 may include a cap and associated filling passage 111 to introduce reductant into the tank 110 .
  • the tank 110 may also be configured to include at least one drain 114 disposed along the bottom thereof in order to easily drain the tank 110 , e.g., to drain the tank 110 to remove sludge, to prevent freezing of the reductant within the tank 110 , or to correct a misfilling event.
  • the tank 110 includes a header 120 integrated therewith.
  • Embodiments include configurations wherein the tank 110 and header 120 are a single, unitary component, and alternative embodiments include configurations wherein the tank 110 and header 120 are separately disposed divisible components.
  • the header 120 includes a plurality of ports disposed therein.
  • the header 120 includes a reductant outlet port 121 , a first coolant inlet port 123 and a first coolant outlet port 124 .
  • the header 120 may also include a reductant return port (not shown) for returning reductant to the tank 110 during a purge event.
  • the header 120 may also include an electrical connection which may be connected to a level sensor (not shown), a temperature sensor (not shown), or various other sensors for detecting conditions within the tank 110 . As illustrated in FIG. 2 , the header 120 may be connected to a coolant loop 126 within the tank 110 . The function of the coolant within the PETU 32 will be described in more detail below.
  • the header 120 may also be connected to a reductant pickup line 127 which extends in proximity to a bottom of the tank 110 .
  • the header 120 may also include a coolant flow valve 150 which fluidly connects the header 120 and the fluid manifold 130 as will be described in more detail below.
  • the coolant flow valve 150 may include a coolant outlet 151 and a coolant inlet 152 , although alternative embodiments may include configurations wherein the coolant inlet 152 is disposed elsewhere on the header 120 , within the PETU 32 or within the reductant supply assembly.
  • the coolant flow valve 150 is omitted, such that coolant flows continuously through the tank 110 and pump 140 , the coolant inlet 152 may be directly coupled to the engine 12 .
  • Alternative embodiments include configurations wherein one or more of the ports, lines, sensors and/or connections described above may be omitted or wherein additional ports, lines, sensors and/or connections may be added.
  • coolant flow valve 150 may be connected to the pump 140 or on a bracket (not shown) coupled to the tank 110 .
  • the coolant flow valve 150 may include an electronic control capability as discussed in more detail below.
  • the fluid manifold 130 includes a manifold body 131 , a first passage 132 in the manifold body 131 , a second passage 133 in the manifold body 131 and a third passage 134 in the manifold body 131 .
  • the coolant outlet 151 from the coolant flow valve 150 is in fluid communication with the first passage 132 such that first passage 132 may receive coolant from the header 120 .
  • the manifold body 131 is configured such that coolant may then flow through the first passage 132 in the manifold body 131 and into the pump 140 .
  • the first passage 132 may extend within the manifold body 131 such that thermal energy from coolant in the first passage 132 may be transferred to other components of the fluid manifold 130 , e.g., the first passage 132 may run horizontally along a longitudinal axis of the manifold body 131 before connecting to the pump 140 .
  • the second passage 133 in the manifold body 131 is configured to receive the coolant from the pump 140 . That is, the second passage 133 is configured such that coolant that has flowed through the manifold body 131 and into the pump 140 via the first passage 132 may circulate within the pump 140 and may exchange thermal energy with the pump 140 in order to thaw reductant in the pump 140 . The second passage 133 is configured such that after the coolant circulates within the pump 140 , the coolant may flow to the second passage 133 in the manifold body 131 .
  • the first passage 132 and the second passage 133 are not in fluid communication within the manifold body 131 ; that is, they are fluidly isolated from one another within the manifold body 131 .
  • a positional relationship of the first passage 132 and the second passage 133 is fixed by the manifold body 131 .
  • the fluid manifold 130 includes a third passage 134 in the manifold body 131 configured to receive the reductant from the reductant outlet port 121 .
  • the third passage 134 is not in fluid communication with the first passage 132 or the second passage 133 ; that is, they are fluidly isolated from one another within the manifold body 131 .
  • a positional relationship of the first passage 132 , the second passage 133 and the third passage 134 is fixed by the manifold body 131 .
  • the fluid manifold 130 may further include an additional passage (not shown) for returning reductant from the pump 140 to the tank 110 during a purge event, e.g., such as may occur when engine 12 is shut-down.
  • a reductant quality sensor 135 may be disposed in fluid communication with reductant in the third passage 134 , e.g., through a port 136 in the manifold body 131 .
  • the reductant quality sensor 135 may determine a quality of reductant flowing through the third passage 134 and into the pump 140 .
  • Reductant quality may refer to a concentration of active ingredients in the reductant or other characteristics of the reductant.
  • Various techniques may be used for determining reductant quality.
  • the reductant quality sensor 135 may measure an electrical resistance of the reductant in order to determine the urea-concentration of the reductant.
  • the reductant quality sensor 135 may electrically communicate a reductant quality signal with an electronics unit as discussed in more detail below.
  • the manifold body 131 may include various additional ports to accommodate additional fluid paths and components as will be discussed in more detail below.
  • the fluid manifold 130 may include at least one expansion plug 137 in fluid configuration with any of the first passage 132 , the second passage 133 , the third passage 134 or combinations thereof.
  • the expansion plug 137 may prevent damage due to freezing of fluids within the manifold body 131 .
  • the fluid manifold 130 may also include at least one through-hole 138 for coupling the fluid manifold 130 to another component of the PETU 32 .
  • the fluid manifold 130 is coupled to the pump 140 via a series of through-holes 138 and a corresponding series of bolts 141 .
  • the bolts 141 are configured to be passed through the through-holes 138 and received in threaded receptacles (not shown) in the pump 140 .
  • the present disclosure is not limited to such a configuration and alternative means for coupling the fluid manifold 130 and the pump 140 are within the scope of this disclosure, e.g., clamps, adhesives, welding, snap fittings, and various other coupling mechanisms, alone or in combination, may be used.
  • the fluid manifold 130 may be configured to include at least a portion thereof which has a lower resistance to expansion than at least one of the tank 110 and the pump 140 . That is, the fluid manifold 130 may function as a pressure relief point such that a buildup of pressure may be released from the fluid manifold 130 before damage occurs in the tank 110 and/or the pump 140 .
  • the fluid manifold 130 may also be fluidly coupled to fluid channels (not shown) in the pump 140 via non-threaded jumper connections 139 .
  • the present disclosure is not limited to such a configuration and alternative methods for fluidly coupling the fluid manifold 130 to the fluid channels in the pump 140 are within the scope of this disclosure.
  • a PETU electronics unit supplies control signals to the pump 140 , injector 36 and coolant flow valve 150 .
  • the PETU electronics unit receives signals from a level sensor (not shown) and a temperature sensor (not shown) located within the tank 110 and relays those signals to a main electronics unit (not shown), such as an electronics control unit associated with the main power system 10 or an independent electronics unit located in proximity to the tank 110 .
  • the PETU electronics unit may also receive signals from at least one NOx sensor (not shown) in the exhaust stream 16 and relay signals from that at least one NOx sensor to the main electronics unit.
  • the PETU electronics unit, or the main electronics unit may use the NOx sensor, engine maps, or both, to control the introduction of reductant from the reductant supply assembly 24 to achieve the desired level of NOx reduction while controlling reductant slip through the clean-up catalyst 30 .
  • Alternative embodiments include configurations wherein the electronics unit is omitted from the PETU 32 and disposed in an alternative location, e.g., separate from the tank 110 , header 120 , fluid manifold 130 and pump 140 .
  • the electronics unit is omitted altogether; in such an alternative embodiment, electronic control signals may alternatively be sent from, and received by, the independent electronics unit.
  • signals from the level sensor (not shown), the temperature sensor (not shown), soot sensors (not shown) and NOx sensor (not shown) may be sent directly to the independent electronics unit. Combinations of the two configurations are also possible within the scope of this disclosure.
  • the injector 36 injects reductant into a mixing section 40 of the exhaust conduit 18 where the reductant may be mixed with the exhaust stream 16 .
  • a mixer (not shown) may also be included in the mixing section 40 to assist the mixing of reductant with the exhaust stream 16 . While other reductants are possible, urea is the most common reductant.
  • a heat source may also be included to remove soot from the DPF 28 in a process referred to as regeneration.
  • the heat source may also thermally manage the SCR catalyst 22 , DOC 26 , or clean-up catalyst 30 , to remove sulfur from the DOC 26 , DPF 28 , SCR catalyst 22 or clean-up catalyst 30 , or to remove deposits of reductant that may have formed in any of those components or along the exhaust conduit 18 .
  • the heat source may embody a burner, hydrocarbon dosing system to create an exothermic reaction on the DOC 26 , electric heating element, microwave device, or other heat source.
  • the heat could also be applied by operating the engine 12 under conditions to generate elevated exhaust stream 16 temperatures.
  • a backpressure valve or another restriction in the exhaust conduit 18 could also be used to elevate the temperature of exhaust stream 16 .
  • Prior art SCR systems utilize reductant supply systems that independently connect a tank and a pump in order to supply reductant to the pump. Such systems also independently output reductant from the pump to a reductant injector and then into the exhaust stream. In addition, when such systems include a system for thawing the pump, coolant lines are independently connected to the pump from the tank. Thus, there may be numerals individual connections between the various components of the system, and those connections may be located throughout the system without a centralized, common connection point.
  • the independently connected systems may not include fluid connections for accommodating sensors, such as urea quality sensors, which may not have been required at the time the system was originally designed.
  • the prior art systems may need to undergo redesigning of major components, e.g., the tank, header or pump, in order to receive the newly required element.
  • redesigns of these components may be time consuming and expensive, leading to decreased parts availability and increased production costs.
  • the prior art systems may attempt to splice the additional components into existing fluid passages.
  • such splicing may require additional testing for robustness, e.g., vibration testing.
  • splicing may not provide adequate physical support for, or thermal transfer to, the additional component.
  • the present disclosure is presented to alleviate such difficulties.
  • the power system 10 in operation, the power system 10 generates the exhaust stream 16 .
  • the exhaust stream 16 flows along the exhaust conduit 18 and is received by the DOC 26 , when included, and the DPF 28 .
  • the DOC 26 and DPF 28 modify the exhaust stream 16 to remove particulate matter and oxidizes carbon monoxide (CO) and unburnt hydrocarbons (HC) into carbon dioxide (CO 2 ) and water (H 2 O) as discussed above.
  • Alternative embodiments include configurations wherein both the DOC 26 and DPF 28 are omitted.
  • the modified exhaust stream 16 then flows downstream to be treated by the SCR system 20 .
  • the injector 36 injects a reductant into the exhaust stream 16 upstream of the SCR catalyst 22 . While other reductants are possible, urea is the most common reductant.
  • the urea reductant converts, decomposes, or hydrolyzes into ammonia (NH 3 ) and is then adsorbed or otherwise stored in the SCR catalyst 22 .
  • the NH 3 is then consumed in the SCR catalyst 22 through a reduction of NOx into nitrogen gas (N2) and water (H 2 O).
  • N2 nitrogen gas
  • H 2 O water
  • the injector 36 receives the reductant from the pump 140 , which in turn draws the reductant from the tank 110 along the reductant pickup line 127 and via the header 120 and fluid manifold 130 .
  • the reductant may undergo filtering within the tank 110 , at the injector 36 , or substantially anywhere in between.
  • the PETU 32 includes the tank 110 having sufficient capacity for supplying reductant to the exhaust stream 16 during operation of the power system 10 . That is, if the power system 10 typically undergoes a work period of 8 hours between shut-down events, the tank 110 may be sized to provide enough reductant for operation of the power system 10 under typical operating conditions during the 8 hour work period.
  • the PETU 32 includes a thermal management system utilizing coolant from the engine 12 in order to thaw, or prevent freezing of, the reductant within the tank 110 , header 120 , fluid manifold 130 and pump 140 .
  • the thermal management system helps to ensure that the engine 12 may operate in an emissions compliant mode, even in extremely cold operating environments.
  • a temperature reading sensed by the temperature sensor in the tank 110 may be sent to the electronics unit.
  • a determination about the condition of the reductant contained in the tank 110 may then be made based on the temperature reading and appropriate actions may be taken based on the determination, e.g., if the temperature reading is below a predetermined threshold, the electronics unit initiates a reductant thawing event.
  • One embodiment of the thawing event may include opening the coolant flow valve 150 to allow coolant from the engine 12 , which has a relatively high temperature compared to the frozen reductant, to flow therethrough into the header 120 and then through the coolant loop 126 of the tank 110 .
  • the coolant after flowing through the coolant loop 126 , the coolant then flows back out through the header 120 and back to the coolant flow valve 150 .
  • the coolant may then be transferred to the fluid manifold 130 to transfer thermal energy to the pump 140 before flowing back to the engine 12 .
  • the electronics unit determines the reductant to be in a thawed state and terminates the thawing event, e.g., by closing the coolant flow valve 150 .
  • the coolant flow valve 150 may stop coolant flow to the fluid manifold 130 prior to stopping coolant flow through the tank 110 , e.g., coolant flow to the fluid manifold 130 may be independent of coolant flow through the tank 110 .
  • the reductant line 34 may be heated by electrical heaters (not shown) or by water jackets (not shown) heated by engine coolant in order to thaw, or prevent freezing of, reductant contained therein.
  • the SCR system 20 is more easily adaptable.
  • the fluid manifold 130 may include ports therein allowing access to fluids entering and exiting various components of the SCR system 20 .
  • the fluid manifold 130 may include a port 136 to accommodate a reductant quality sensor 135 , which may not readily be accommodated elsewhere in the SCR system 20 .
  • the present disclosure is readily adaptable to new requirements. That is, in the disclosed system, newly required additional components, e.g., sensors, may be added to ports on the fluid manifold 130 without redesigning any components. Even if the number of newly required additional components exceeds the number of available ports on the fluid manifold 130 , only the fluid manifold 130 would need to be redesigned. This is in direct contrast to prior art designs where complicated, expensive structures having moving parts may need to be redesigned.
  • the present disclosure provides a fluid manifold 130 which may be stably mounted to other components of the SCR system 20 .
  • additional components may be added thereto without the need for extensive additional testing, if any additional testing is required at all.
  • the fluid manifold 130 also provides a common location for many fluid connections, i.e., the fluid manifold 130 includes the first passage 132 , the second passage 133 and the third passage 134 through which coolant is transferred to and away from the pump 140 and through which reductant is transferred to the pump 140 and to the reductant quality sensor 135 .
  • the fluid manifold 130 may allow for a more rapid assembly process due to the fluid connections being co-located along a single component in proximity to one another.
  • the fluid manifold may also facilitate repair or replacement of the pump 140 . That is, rather than having to remove a plurality of individual fittings in order to disconnect the pump 140 from the other components of the system, a repair technician would simply need to disconnect the fluid manifold 130 from the pump 140 .
  • the fluid manifold 130 may be configured to include at least a portion thereof which has a lower resistance to expansion than at least one of the tank 110 and the pump 140 , the fluid manifold 130 may function as a pressure relief point. That is, in such a configuration the fluid manifold 130 may structurally fail and release pressure prior to the same pressure damaging one of the tank 110 and the pump 140 .

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust Gas After Treatment (AREA)

Abstract

A reductant dosing system manifold includes: a body, a first passage in the body configured to receive a first fluid from a first separately disposed component of a reductant dosing system, and a second passage in the body configured to receive the first fluid from a second separately disposed component of the reductant dosing system, wherein the first passage and the second passage are fluidly isolated from each other within the body, and wherein a positional relationship of the first passage and the second passage is fixed by the body.

Description

    TECHNICAL FIELD
  • The present disclosure relates generally to exhaust aftertreatment systems and methods and, more particularly, to systems and methods for supplying a reductant to an exhaust stream.
  • BACKGROUND
  • A selective catalytic reduction (SCR) system may be included in an exhaust treatment or aftertreatment system for a power system to remove or reduce nitrous oxide (NOx or NO) emissions coming from the exhaust of an engine. SCR systems use reductants, such as urea, that are introduced into the exhaust stream to significantly reduce the amount of nitrous oxides (NOx) in the exhaust.
  • The construction and installation of the SCR system can be a considerable component of the overall power system cost. In an attempt to reduce costs, components of the SCR system are typically designed to meet basic design requirements without additional flexibility or modularity. That is, once designed, most SCR systems are static in that additional capability can not easily be accommodated using the existing components.
  • U.S. Pat. No. 7,895,829 (the '829 patent) discloses an aftertreatment system including an SCR system. The '829 patent SCR system includes a urea solution tank. A urea solution pump is provided within the urea solution tank. However, such a configuration may be problematic if the pump needs maintenance or replacement.
  • SUMMARY
  • According to an embodiment, a reductant dosing system manifold includes: a body, a first passage in the body configured to receive a first fluid from a first separately disposed component of a reductant dosing system, and a second passage in the body configured to receive the first fluid from a second separately disposed component of the reductant dosing system, wherein the first passage and the second passage are fluidly isolated from each other within the body, and wherein a positional relationship of the first passage and the second passage is fixed by the body.
  • According to an embodiment, a reductant supply assembly includes: a reductant tank, a reductant pump in fluid communication with the reductant tank, and a fluid manifold including: a body, a first passage in the body configured to receive a first fluid from a first separately disposed component of the reductant supply assembly; and a second passage in the body configured to receive the first fluid from a second separately disposed component of the reductant supply assembly, wherein the first passage and the second passage are fluidly isolated from each other within the body, wherein a positional relationship of the first passage and the second passage are fixed by the body, and wherein the fluid manifold provides the fluid communication between the reductant tank and the reductant pump.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a diagrammatic view of a machine including a power system with an engine and an aftertreatment system.
  • FIG. 2 is a diagrammatic view of the aftertreatment system including a reductant supply system including a pump electronics and tank unit (PETU) including a fluid manifold according to the present disclosure.
  • FIG. 3 is an isometric view of a PETU including a fluid manifold according to the present disclosure.
  • FIG. 4 is an isometric view of a fluid manifold according to the present disclosure.
  • DETAILED DESCRIPTION
  • FIG. 1 is a diagrammatic view of a machine 1 including a cab 2 where an operator 3 sits and a power system 10. The machine 1 might be a track type tractor (as illustrated), on-highway truck, car, vehicle, off-highway truck, earth moving equipment, material handler, logging machine, compactor, construction equipment, stationary power generator, pump, aerospace application, locomotive application, marine application, or any other device or application requiring a power system 10.
  • The power system 10 includes an engine 12 and an aftertreatment system 14 to treat an exhaust stream 16 produced by the engine 12. The engine 12 may include other features not shown, such as controllers, fuel systems, air systems, cooling systems, peripheries, drivetrain components, turbochargers, exhaust gas recirculation systems, etc. The engine 12 may be any type of engine (internal combustion, gas, diesel, gaseous fuel, natural gas, propane, etc.), may be of any size, with any number of cylinders, any type of combustion chamber (cylindrical, rotary spark ignition, compression ignition, 4-stroke and 2-stroke, etc.), and in any configuration (“V,” in-line, radial, etc.).
  • The aftertreatment system 14 includes an exhaust conduit 18 for delivering the exhaust stream 16 and a Selective Catalytic Reduction (SCR) system 20. The SCR system 20 includes an SCR catalyst 22, and a reductant supply assembly 24.
  • In some embodiments, the aftertreatment system 14 may also include a diesel oxidation catalyst (DOC) 26, a diesel particulate filter (DPF) 28, and/or a clean-up catalyst 30. The DOC 26, DPF 28, SCR catalyst 22, and clean-up catalyst 30 may include the appropriate catalyst or other material, respective of their intended functions, disposed on a substrate. The substrate may consist of cordierite, silicon carbide, other ceramic, a metal structure or other configurations of similar materials. In one embodiment, the substrates may form a honeycomb structure with a plurality of longitudinal channels or cells for the exhaust stream 16 to pass through. The DOC 26, DPF 28, SCR catalyst 22, and clean-up catalyst 30 substrates may be housed in canisters, as shown, or may be integrated into the exhaust conduit 18. The DOC 26 and DPF 28 may be in the same canister, as shown, or may be separately disposed. Similarly, the SCR catalyst 22 and clean-up catalyst 30 may also be in the same canister, as shown, or may be separately disposed.
  • The aftertreatment system 14 is configured to remove, collect, or convert undesired constituents from the exhaust stream 16. The DOC 26 oxidizes carbon monoxide (CO) and unburnt hydrocarbons (HC) into carbon dioxide (CO2) and water (H2O). The DPF 28 collects particulate matter or soot. The SCR catalyst 22 is configured to reduce an amount of nitrous oxides (NOx) in the exhaust stream 16 in the presence of a reductant.
  • The clean-up catalyst 30 may embody an ammonia oxidation catalyst (AMOX). The clean-up catalyst 30 is configured to capture, store, oxidize, reduce, and/or convert reductant that may slip past or break through the SCR catalyst 22. The clean-up catalyst 30 may also be configured to capture, store, oxidize, reduce, and/or convert other constituents present in the exhaust stream.
  • In the illustrated embodiment, the exhaust stream 16 is configured to exit the engine 12, pass through the DOC 26 and DPF 28, pass through the SCR catalyst 22, and then pass through the clean-up catalyst 30 via the exhaust conduit 18. In the illustrated exemplary embodiment, the SCR system 20 is downstream of the DPF 28 and the DOC 26 is upstream of the DPF 28. In embodiments where it is included, the clean-up catalyst 30 is downstream of the SCR system 20. In other embodiments, these devices may be arranged in a variety of orders and may be combined together. In one alternative embodiment, the SCR catalyst 22 may be combined with the DPF 28 with the catalyst material for the SCR deposited on the DPF 28. Other exhaust treatment devices may also be located upstream, downstream, or within the SCR system 20.
  • FIG. 2 is a diagrammatic view of the aftertreatment system 14 wherein the reductant supply assembly 24 is configured to introduce the reductant into the exhaust stream 16 upstream of the SCR catalyst 22. The reductant supply assembly 24 may include a pump electronics and tank unit (PETU) 32, a reductant line 34, and an injector 36. In the embodiment illustrated in FIGS. 1 and 2, the PETU 32 generally includes several separately disposed components; specifically the PETU 32 includes a tank 110 including a header 120, a fluid manifold 130, a pump 140 and associated electronics (not shown). Embodiments of the PETU 32 will be described in more detail below.
  • As illustrated in FIGS. 2-4, the tank 110 may include a cap and associated filling passage 111 to introduce reductant into the tank 110. The tank 110 may also be configured to include at least one drain 114 disposed along the bottom thereof in order to easily drain the tank 110, e.g., to drain the tank 110 to remove sludge, to prevent freezing of the reductant within the tank 110, or to correct a misfilling event.
  • As illustrated in FIGS. 2-4, the tank 110 includes a header 120 integrated therewith. Embodiments include configurations wherein the tank 110 and header 120 are a single, unitary component, and alternative embodiments include configurations wherein the tank 110 and header 120 are separately disposed divisible components. The header 120 includes a plurality of ports disposed therein. According to one exemplary embodiment, the header 120 includes a reductant outlet port 121, a first coolant inlet port 123 and a first coolant outlet port 124. In another embodiment, the header 120 may also include a reductant return port (not shown) for returning reductant to the tank 110 during a purge event. The header 120 may also include an electrical connection which may be connected to a level sensor (not shown), a temperature sensor (not shown), or various other sensors for detecting conditions within the tank 110. As illustrated in FIG. 2, the header 120 may be connected to a coolant loop 126 within the tank 110. The function of the coolant within the PETU 32 will be described in more detail below.
  • The header 120 may also be connected to a reductant pickup line 127 which extends in proximity to a bottom of the tank 110. The header 120 may also include a coolant flow valve 150 which fluidly connects the header 120 and the fluid manifold 130 as will be described in more detail below. In one embodiment, the coolant flow valve 150 may include a coolant outlet 151 and a coolant inlet 152, although alternative embodiments may include configurations wherein the coolant inlet 152 is disposed elsewhere on the header 120, within the PETU 32 or within the reductant supply assembly. In an alternative embodiment wherein the coolant flow valve 150 is omitted, such that coolant flows continuously through the tank 110 and pump 140, the coolant inlet 152 may be directly coupled to the engine 12. Alternative embodiments include configurations wherein one or more of the ports, lines, sensors and/or connections described above may be omitted or wherein additional ports, lines, sensors and/or connections may be added.
  • Alternative embodiments include configurations wherein the coolant flow valve 150 may be connected to the pump 140 or on a bracket (not shown) coupled to the tank 110. In at least one embodiment, the coolant flow valve 150 may include an electronic control capability as discussed in more detail below.
  • As illustrated in FIGS. 3 and 4, the fluid manifold 130 includes a manifold body 131, a first passage 132 in the manifold body 131, a second passage 133 in the manifold body 131 and a third passage 134 in the manifold body 131. In the present embodiment, the coolant outlet 151 from the coolant flow valve 150 is in fluid communication with the first passage 132 such that first passage 132 may receive coolant from the header 120. The manifold body 131 is configured such that coolant may then flow through the first passage 132 in the manifold body 131 and into the pump 140. The first passage 132 may extend within the manifold body 131 such that thermal energy from coolant in the first passage 132 may be transferred to other components of the fluid manifold 130, e.g., the first passage 132 may run horizontally along a longitudinal axis of the manifold body 131 before connecting to the pump 140.
  • As shown in FIGS. 3 and 4, the second passage 133 in the manifold body 131 is configured to receive the coolant from the pump 140. That is, the second passage 133 is configured such that coolant that has flowed through the manifold body 131 and into the pump 140 via the first passage 132 may circulate within the pump 140 and may exchange thermal energy with the pump 140 in order to thaw reductant in the pump 140. The second passage 133 is configured such that after the coolant circulates within the pump 140, the coolant may flow to the second passage 133 in the manifold body 131. The first passage 132 and the second passage 133 are not in fluid communication within the manifold body 131; that is, they are fluidly isolated from one another within the manifold body 131. A positional relationship of the first passage 132 and the second passage 133 is fixed by the manifold body 131.
  • The fluid manifold 130 includes a third passage 134 in the manifold body 131 configured to receive the reductant from the reductant outlet port 121. The third passage 134 is not in fluid communication with the first passage 132 or the second passage 133; that is, they are fluidly isolated from one another within the manifold body 131. A positional relationship of the first passage 132, the second passage 133 and the third passage 134 is fixed by the manifold body 131. In an alternative embodiment, the fluid manifold 130 may further include an additional passage (not shown) for returning reductant from the pump 140 to the tank 110 during a purge event, e.g., such as may occur when engine 12 is shut-down.
  • A reductant quality sensor 135 may be disposed in fluid communication with reductant in the third passage 134, e.g., through a port 136 in the manifold body 131. The reductant quality sensor 135 may determine a quality of reductant flowing through the third passage 134 and into the pump 140. Reductant quality may refer to a concentration of active ingredients in the reductant or other characteristics of the reductant. Various techniques may be used for determining reductant quality. When the reductant is a urea-based reductant, the reductant quality sensor 135 may measure an electrical resistance of the reductant in order to determine the urea-concentration of the reductant. The reductant quality sensor 135 may electrically communicate a reductant quality signal with an electronics unit as discussed in more detail below. The manifold body 131 may include various additional ports to accommodate additional fluid paths and components as will be discussed in more detail below.
  • The fluid manifold 130 may include at least one expansion plug 137 in fluid configuration with any of the first passage 132, the second passage 133, the third passage 134 or combinations thereof. The expansion plug 137 may prevent damage due to freezing of fluids within the manifold body 131.
  • The fluid manifold 130 may also include at least one through-hole 138 for coupling the fluid manifold 130 to another component of the PETU 32. In the embodiment illustrated in FIGS. 2-4, the fluid manifold 130 is coupled to the pump 140 via a series of through-holes 138 and a corresponding series of bolts 141. The bolts 141 are configured to be passed through the through-holes 138 and received in threaded receptacles (not shown) in the pump 140. However, the present disclosure is not limited to such a configuration and alternative means for coupling the fluid manifold 130 and the pump 140 are within the scope of this disclosure, e.g., clamps, adhesives, welding, snap fittings, and various other coupling mechanisms, alone or in combination, may be used.
  • The fluid manifold 130 may be configured to include at least a portion thereof which has a lower resistance to expansion than at least one of the tank 110 and the pump 140. That is, the fluid manifold 130 may function as a pressure relief point such that a buildup of pressure may be released from the fluid manifold 130 before damage occurs in the tank 110 and/or the pump 140.
  • In one embodiment, the fluid manifold 130 may also be fluidly coupled to fluid channels (not shown) in the pump 140 via non-threaded jumper connections 139. However, the present disclosure is not limited to such a configuration and alternative methods for fluidly coupling the fluid manifold 130 to the fluid channels in the pump 140 are within the scope of this disclosure.
  • According to one exemplary embodiment, a PETU electronics unit supplies control signals to the pump 140, injector 36 and coolant flow valve 150. In the present embodiment, the PETU electronics unit receives signals from a level sensor (not shown) and a temperature sensor (not shown) located within the tank 110 and relays those signals to a main electronics unit (not shown), such as an electronics control unit associated with the main power system 10 or an independent electronics unit located in proximity to the tank 110. The PETU electronics unit may also receive signals from at least one NOx sensor (not shown) in the exhaust stream 16 and relay signals from that at least one NOx sensor to the main electronics unit. The PETU electronics unit, or the main electronics unit, may use the NOx sensor, engine maps, or both, to control the introduction of reductant from the reductant supply assembly 24 to achieve the desired level of NOx reduction while controlling reductant slip through the clean-up catalyst 30.
  • Alternative embodiments include configurations wherein the electronics unit is omitted from the PETU 32 and disposed in an alternative location, e.g., separate from the tank 110, header 120, fluid manifold 130 and pump 140. According to one exemplary embodiment, the electronics unit is omitted altogether; in such an alternative embodiment, electronic control signals may alternatively be sent from, and received by, the independent electronics unit. In such an alternative exemplary embodiment, signals from the level sensor (not shown), the temperature sensor (not shown), soot sensors (not shown) and NOx sensor (not shown) may be sent directly to the independent electronics unit. Combinations of the two configurations are also possible within the scope of this disclosure.
  • The injector 36 injects reductant into a mixing section 40 of the exhaust conduit 18 where the reductant may be mixed with the exhaust stream 16. A mixer (not shown) may also be included in the mixing section 40 to assist the mixing of reductant with the exhaust stream 16. While other reductants are possible, urea is the most common reductant.
  • A heat source (not shown) may also be included to remove soot from the DPF 28 in a process referred to as regeneration. The heat source may also thermally manage the SCR catalyst 22, DOC 26, or clean-up catalyst 30, to remove sulfur from the DOC 26, DPF 28, SCR catalyst 22 or clean-up catalyst 30, or to remove deposits of reductant that may have formed in any of those components or along the exhaust conduit 18. The heat source may embody a burner, hydrocarbon dosing system to create an exothermic reaction on the DOC 26, electric heating element, microwave device, or other heat source. The heat could also be applied by operating the engine 12 under conditions to generate elevated exhaust stream 16 temperatures. A backpressure valve or another restriction in the exhaust conduit 18 could also be used to elevate the temperature of exhaust stream 16.
  • INDUSTRIAL APPLICABILITY
  • Prior art SCR systems utilize reductant supply systems that independently connect a tank and a pump in order to supply reductant to the pump. Such systems also independently output reductant from the pump to a reductant injector and then into the exhaust stream. In addition, when such systems include a system for thawing the pump, coolant lines are independently connected to the pump from the tank. Thus, there may be numerals individual connections between the various components of the system, and those connections may be located throughout the system without a centralized, common connection point.
  • These prior art systems lack the ability to easily expand to include additional components as may be required by changing regulations. For example, the independently connected systems may not include fluid connections for accommodating sensors, such as urea quality sensors, which may not have been required at the time the system was originally designed. In order to accommodate the additional components imposed by changing regulations, the prior art systems may need to undergo redesigning of major components, e.g., the tank, header or pump, in order to receive the newly required element. However, redesigns of these components may be time consuming and expensive, leading to decreased parts availability and increased production costs. Alternatively, the prior art systems may attempt to splice the additional components into existing fluid passages. However, such splicing may require additional testing for robustness, e.g., vibration testing. Furthermore, splicing may not provide adequate physical support for, or thermal transfer to, the additional component. The present disclosure is presented to alleviate such difficulties.
  • Referring again to FIGS. 1 and 2, in operation, the power system 10 generates the exhaust stream 16. The exhaust stream 16 flows along the exhaust conduit 18 and is received by the DOC 26, when included, and the DPF 28. The DOC 26 and DPF 28 modify the exhaust stream 16 to remove particulate matter and oxidizes carbon monoxide (CO) and unburnt hydrocarbons (HC) into carbon dioxide (CO2) and water (H2O) as discussed above. Alternative embodiments include configurations wherein both the DOC 26 and DPF 28 are omitted.
  • The modified exhaust stream 16 then flows downstream to be treated by the SCR system 20. The injector 36 injects a reductant into the exhaust stream 16 upstream of the SCR catalyst 22. While other reductants are possible, urea is the most common reductant. The urea reductant converts, decomposes, or hydrolyzes into ammonia (NH3) and is then adsorbed or otherwise stored in the SCR catalyst 22. The NH3 is then consumed in the SCR catalyst 22 through a reduction of NOx into nitrogen gas (N2) and water (H2O). Thus, the level of NOx in the exhaust stream 16 is reduced after exiting the SCR catalyst 22.
  • The injector 36 receives the reductant from the pump 140, which in turn draws the reductant from the tank 110 along the reductant pickup line 127 and via the header 120 and fluid manifold 130. The reductant may undergo filtering within the tank 110, at the injector 36, or substantially anywhere in between.
  • As illustrated in FIGS. 2-4, the PETU 32 includes the tank 110 having sufficient capacity for supplying reductant to the exhaust stream 16 during operation of the power system 10. That is, if the power system 10 typically undergoes a work period of 8 hours between shut-down events, the tank 110 may be sized to provide enough reductant for operation of the power system 10 under typical operating conditions during the 8 hour work period.
  • As discussed above, the PETU 32 includes a thermal management system utilizing coolant from the engine 12 in order to thaw, or prevent freezing of, the reductant within the tank 110, header 120, fluid manifold 130 and pump 140. The thermal management system helps to ensure that the engine 12 may operate in an emissions compliant mode, even in extremely cold operating environments.
  • In operation, a temperature reading sensed by the temperature sensor in the tank 110 may be sent to the electronics unit. A determination about the condition of the reductant contained in the tank 110 may then be made based on the temperature reading and appropriate actions may be taken based on the determination, e.g., if the temperature reading is below a predetermined threshold, the electronics unit initiates a reductant thawing event.
  • One embodiment of the thawing event may include opening the coolant flow valve 150 to allow coolant from the engine 12, which has a relatively high temperature compared to the frozen reductant, to flow therethrough into the header 120 and then through the coolant loop 126 of the tank 110. In the present embodiment, after flowing through the coolant loop 126, the coolant then flows back out through the header 120 and back to the coolant flow valve 150. The coolant may then be transferred to the fluid manifold 130 to transfer thermal energy to the pump 140 before flowing back to the engine 12. Once the temperature reading from the tank 110 is above the predetermined threshold, the electronics unit determines the reductant to be in a thawed state and terminates the thawing event, e.g., by closing the coolant flow valve 150. In another embodiment, the coolant flow valve 150 may stop coolant flow to the fluid manifold 130 prior to stopping coolant flow through the tank 110, e.g., coolant flow to the fluid manifold 130 may be independent of coolant flow through the tank 110.
  • According to various alternative embodiments, the reductant line 34 may be heated by electrical heaters (not shown) or by water jackets (not shown) heated by engine coolant in order to thaw, or prevent freezing of, reductant contained therein.
  • While one embodiment of a method for thawing the tank 110, header 120, fluid manifold 130 and pump 140 has been described above, the present disclosure is not limited thereto and various other control schemes may alternatively be used to thermally manage the SCR system 20.
  • By including a fluid manifold 130 in the SCR system 20, the SCR system 20 is more easily adaptable. Specifically, the fluid manifold 130 may include ports therein allowing access to fluids entering and exiting various components of the SCR system 20. For example, the fluid manifold 130 may include a port 136 to accommodate a reductant quality sensor 135, which may not readily be accommodated elsewhere in the SCR system 20.
  • In contrast to prior art systems wherein major components, such as the tank, header or pump, must be redesigned in order to accommodate additional sensors, the present disclosure is readily adaptable to new requirements. That is, in the disclosed system, newly required additional components, e.g., sensors, may be added to ports on the fluid manifold 130 without redesigning any components. Even if the number of newly required additional components exceeds the number of available ports on the fluid manifold 130, only the fluid manifold 130 would need to be redesigned. This is in direct contrast to prior art designs where complicated, expensive structures having moving parts may need to be redesigned.
  • Furthermore, the present disclosure provides a fluid manifold 130 which may be stably mounted to other components of the SCR system 20. Thus, once the fluid manifold 130 has been tested for robustness, e.g., against vibration, additional components may be added thereto without the need for extensive additional testing, if any additional testing is required at all.
  • The fluid manifold 130 also provides a common location for many fluid connections, i.e., the fluid manifold 130 includes the first passage 132, the second passage 133 and the third passage 134 through which coolant is transferred to and away from the pump 140 and through which reductant is transferred to the pump 140 and to the reductant quality sensor 135. Thus, the fluid manifold 130 may allow for a more rapid assembly process due to the fluid connections being co-located along a single component in proximity to one another.
  • The fluid manifold may also facilitate repair or replacement of the pump 140. That is, rather than having to remove a plurality of individual fittings in order to disconnect the pump 140 from the other components of the system, a repair technician would simply need to disconnect the fluid manifold 130 from the pump 140.
  • In addition, because the fluid manifold 130 may be configured to include at least a portion thereof which has a lower resistance to expansion than at least one of the tank 110 and the pump 140, the fluid manifold 130 may function as a pressure relief point. That is, in such a configuration the fluid manifold 130 may structurally fail and release pressure prior to the same pressure damaging one of the tank 110 and the pump 140.
  • Although the embodiments of this disclosure as described herein may be incorporated without departing from the scope of the following claims, it will be apparent to those skilled in the art that various modifications and variations can be made. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.

Claims (20)

What is claimed is:
1. A reductant dosing system manifold comprising:
a body;
a first passage in the body configured to receive a first fluid from a first separately disposed component of a reductant dosing system; and
a second passage in the body configured to receive the first fluid from a second separately disposed component of the reductant dosing system,
wherein the first passage and the second passage are fluidly isolated from each other within the body, and wherein a positional relationship of the first passage and the second passage is fixed by the body.
2. The reductant dosing system manifold of claim 1, wherein the first fluid is a coolant.
3. The reductant dosing system manifold of claim 2, wherein the first separately disposed component is a reductant tank, and the second separately disposed component is a reductant pump.
4. The reductant dosing system manifold of claim 3, wherein the first passage receives the coolant from the reductant tank and transmits the coolant to the reductant pump, and wherein the second passage receives the coolant from the reductant pump and transmits the coolant away from the reductant pump.
5. The reductant dosing system manifold of claim 1, further including a third passage in the body configured to receive a second fluid,
wherein the third passage is fluidly isolated from both the first passage and the second passage within the body, and wherein a positional relationship of the first passage, the second passage and the third passage is fixed by the body.
6. The reductant dosing system manifold of claim 5, wherein the first fluid is coolant and the second fluid is reductant
7. The reductant dosing system manifold of claim 6, wherein the reductant includes urea.
8. The reductant dosing system manifold of claim 6, further including a reductant quality sensor disposed in fluid communication with the third passage.
9. The reductant dosing system manifold of claim 6, further including a reductant quality sensor disposed in thermal communication with the coolant.
10. The reductant dosing system manifold of claim 5, wherein the body includes:
a first component including the first passage disposed therein;
a second component including the second passage disposed therein; and
a third component including the third passage disposed therein.
11. The reductant dosing system manifold of claim 10, wherein the first component, the second component and the third component are a single, unitary and indivisible component.
12. The reductant dosing system manifold of claim 10, wherein at least two of the first component, the second component and the third component are divisible components.
13. A reductant supply assembly comprising:
a reductant tank;
a reductant pump in fluid communication with the reductant tank; and
a fluid manifold including:
a body;
a first passage in the body configured to receive a first fluid from a first separately disposed component of the reductant supply assembly; and
a second passage in the body configured to receive the first fluid from a second separately disposed component of the reductant supply assembly,
wherein the first passage and the second passage are fluidly isolated from each other within the body, wherein a positional relationship of the first passage and the second passage are fixed by the body, and wherein the fluid manifold provides the fluid communication between the reductant tank and the reductant pump.
14. The reductant supply assembly of claim 13, wherein the first fluid is a coolant and the first passage transmits the coolant to the reductant pump and the second passage transmits the coolant away from the reductant pump.
15. The reductant supply assembly of claim 13, wherein the fluid manifold includes a third passage in the body configured to receive a second fluid,
wherein the third passage is fluidly isolated from both the first passage and the second passage within the body, and wherein a positional relationship of the first passage, the second passage and the third passage is fixed by the body.
16. The reductant supply assembly of claim 15, wherein the second fluid includes reductant including urea.
17. The reductant supply assembly of claim 16, wherein the fluid manifold further includes a reductant quality sensor in fluid communication with the reductant.
18. The reductant supply assembly of claim 17, wherein the first fluid is a coolant and the reductant quality sensor is in thermal communication with the coolant.
19. The reductant supply assembly of claim 15, wherein the fluid manifold further comprises an expansion device in fluid communication with at least one of the first passage, second passage or third passage and configured to expand with freezing of fluid in the at least one of the first passage, second passage or third passage.
20. The reductant supply assembly of claim 13, wherein the fluid manifold is configured to include at least a portion thereof which has a lower resistance to expansion than at least one of the reductant tank and the reductant pump.
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