The present disclosure relates generally to engine exhaust systems, and more particularly, to exhaust aftertreatment systems including a ground level access point for introducing reductant to a machine for storage in, and delivery from, a tank positioned at a higher elevation than, or more generally, a substantial distance from, a supply port which is accessible from a ground level.
Various systems for removing or converting exhaust constituents, such as Selective Catalytic Reduction (SCR) systems, for example, have been incorporated into exhaust aftertreatment systems to control emissions of regulated exhaust constituents. These exhaust aftertreatment systems may use a pump electronics and tank unit (PETU), for example, to deliver a reductant to a flow of exhaust upstream of a catalyst. Some reductants may be susceptible to freezing due to their respective compositions, e.g., aqueous ammonia, an environment where a machine incorporating the exhaust aftertreatment system is operated, a frequency of operation of the machine wherein the reductant is stored, and/or a configuration for supplying the reductant. As a result, reductant being delivered to, stored in, and delivered from a tank of a PETU or other type of reductant delivery system, can be at risk of freezing.
U.S. Patent Application Publication No. 2013/0000729 (the 729 publication), entitled “DEF Pump and Tank Thawing System and Method,” relates to technology for an exhaust aftertreatment system that prevents freezing of reductant in a reductant storage tank and a reductant pump. The '729 publication describes a tank and a pump of the exhaust aftertreatment system being in thermal communication with a first coolant circuit and a second coolant circuit, respectively. Coolant from an engine is routed by the first coolant circuit and second coolant circuit to respective coolant loops inside the tank and the pump, to heat reductant in the tank and the pump.
While the '729 publication is focused on reductant that is stored in a tank or delivered from the tank to a flow of exhaust, reductant in other components of a reductant storage and delivery system may be susceptible to freezing. Therefore, there is a need for reductant storage and delivery systems and methods that address other freezing modes and/or other problems in the art.
According to an aspect of the present disclosure, a reductant filling assembly comprises a first end and a second end, the first end adapted to connect from an interior side of a machine to a supply port attached to a receiver extending to an exterior side of the machine; a housing extending between the first end and the second end of the reductant filling assembly, the housing extending from a first housing end to a second housing end; a reductant supply conduit extending through the housing from the first end to the second end; a first circulating conduit extending through the housing from the first end to the second end; and a second circulating conduit extending through the housing from the first end to the second end. At least the first circulating conduit is in thermal communication with a wall of the reductant supply conduit, such that a heating fluid flowing through the first circulating conduit in a first direction transfers heat to a reductant fluid in the reductant supply conduit.
According to another aspect of the disclosure, a machine comprises an engine including an internal fluid circuit; an exhaust conduit connected to the engine that receives exhaust gas from the engine; a heating fluid circuit including a fluid supply conduit connected to an outlet of the internal fluid circuit and a fluid return conduit connected to an inlet of the internal fluid circuit; a receiver that extends to an exterior side of the machine; and a supply port on an interior side of the machine and fluidly connected to the receiver. The machine may further comprise an exhaust aftertreatment system including a tank that stores a reductant fluid to be delivered, a reductant output conduit in fluid communication with a portion of the exhaust conduit, and a pump in fluid communication with the reductant fluid to be delivered in the tank and the reductant output conduit. The machine may further comprise a reductant filling assembly including a first end and a second end, the first end adapted to connect from the interior side of the machine to the supply port, a housing extending between the first end and the second end of the reductant filling assembly, the housing extending from a first housing end to a second housing end, a reductant supply conduit extending through the housing from the first end to the second end, a first circulating conduit extending through the housing from the first end to the second end, and a second circulating conduit extending through the housing from the first end to the second end. The first circulating conduit and the second circulating conduit are fluidly connected to the heating fluid circuit downstream of the outlet of the internal fluid circuit and upstream of a section of the heating fluid circuit disposed in the tank. At least the first circulating conduit is positioned in thermal communication with a wall of the reductant supply conduit, such that a heating fluid flowing through the first circulating conduit in a first direction transfers heat to a reductant fluid in the reductant supply conduit.
Another aspect of the disclosure provides a method for heating a reductant fluid in a reductant filling assembly including a first end and a second end, the first end connected from an interior side of a machine to a supply port attached to a receiver extending to an exterior side of the machine, and the second end connected to a tank. The method for heating the reductant fluid may comprise supplying the reductant fluid from the exterior side through the supply port into a reductant supply conduit positioned within the reductant filling assembly and into the tank; supplying a flow of heating fluid to a heating fluid circuit fluidly coupled to the reductant filling assembly; supplying the flow of heating fluid from the heating fluid circuit to the second end of the reductant filling assembly and directing the flow of heating fluid in a first direction from the second end to the first end in a first circulating conduit positioned within the reductant filling assembly; transferring heat from a portion of the flow of heating fluid within the first circulating conduit to the reductant fluid in the reductant supply conduit; directing the flow of heating fluid from the first circulating conduit into a manifold at the first end and from the manifold into a second circulating conduit positioned within the reductant filling assembly; and directing the flow of heating fluid through the second circulating in a second direction from the first end to the second end and into the heating fluid circuit, the second direction being opposite to the first direction.
Aspects of the disclosure will now be described in detail with reference to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, unless specified otherwise.
Exhaust may flow in the exhaust conduit 11 to the aftertreatment system 30. Either the exhaust conduit 11 or the aftertreatment system 30 may include elements not shown, such as a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF), through which the exhaust may flow through prior to entering, for example, an SCR system provided in the aftertreatment system 30. A reductant delivery system 50 may supply reductant to the aftertreatment system 30 to promote conversion of exhaust constituents in the aftertreatment system 30. In a non-limiting aspect of the disclosure, the reductant may consist of or contain a diesel exhaust fluid (DEF) including urea, which may thermally decompose into ammonia (NH3) in admixture with the exhaust stream, and react with nitrogen oxides (collectively “NOx”) in the presence of a catalyst to produce nitrogen (N2) and water (H2O). However, the reductant may be any fluid known in the art that is capable of a reducing reaction with an exhaust constituent, whether or not in the presence of a catalyst.
The reductant may be supplied to the reductant delivery system 50 through a filling assembly 100 of a filling system from a source of reductant 3 located on a ground level G. The filling assembly 100 may be attached to a receiver 121, described in detail later, from an interior side 5 of the machine 1. The receiver 121 may be accessible from an exterior side 7 of the machine 1 by an operator on the ground level G (e.g., a ground level access point). For example, the receiver 121 may be attached to an arm 9, or other type of panel or access door, that the operator may lower to the ground level G to fluidly couple the filling assembly 100 with the source of reductant 3 through the receiver 121.
As illustrated in
Combined with a location and frequency of use of the machine 1, after a filling operation, reductant remaining in a conduit that supplies the reductant may be at risk of freezing. As described in further detail below, aspects of the filling assembly 100 according to the present disclosure enable the filling assembly 100 to be integrated with a heating fluid circuit 200 to prevent freezing of reductant contained therein, or to thaw the filling assembly 100 should freezing occur.
Aspects of the heating fluid circuit 200 will now be described with reference to
As illustrated in
A pump circulating conduit 213 positioned within the pump 55 is in fluid communication with the pump heating fluid supply conduit 207. The pump circulating conduit 213 may be looped, or otherwise routed within the pump 55, to effect a desired heat transfer from the heating fluid flowing within the pump circulating conduit 213 to the reductant in the pump 55. As illustrated in
The pump circulating conduit 213 is fluidly connected to an injector heating fluid supply conduit 209, which is fluidly connected to an injector circulating conduit 215 positioned within the injector 31. The injector circulating conduit 215 may be looped, or otherwise routed within the injector 31 and around the injector reductant output conduit 59, to effect a desired heat transfer from the heating fluid flowing within the injector circulating conduit 215 to the reductant flowing from the injector 31 through the injector reductant output conduit 59. Heating fluid flowing through the injector circulating conduit 215 heats the reductant supplied to and from the injector 31, and flows into to the heating fluid return conduit 203. It will be appreciated that other series or parallel arrangements of the first assembly circulating conduit 105, the second assembly circulating conduit 107, the tank circulating conduit 211, the pump circulating conduit 213, and the injector circulating conduit 215 are contemplated to be within the scope of the present disclosure.
According to an aspect of the present disclosure, where the first end 100a of the filling assembly 100 is connected to the first manifold 111, the reductant supply conduit 103 may be connected to the first manifold 111 outside of the intake end 101a of the housing 101 by a reductant supply connection 113. The reductant supply connection 113 is in fluid communication with the receiver 121. According to an aspect of the present disclosure, the receiver 121 may be connected or mounted to the arm 9, or other type of panel or access door, of the machine 1 illustrated in
According to an aspect of the present disclosure, where the second end 100b is connected to the second manifold 131, the reductant supply conduit 103 may be connected to the second manifold 131 outside of the outlet end 101b of the housing 101 by a reductant outlet connection 133. The reductant outlet connection 133 is in fluid communication with a fill valve 141 that is positioned within the tank 51. The fill valve 141 controls a flow of reductant into the tank 51. According to one aspect of the present disclosure, the fill valve 141 may be mounted on an inner surface of a side wall of the tank 51. In another aspect of the present disclosure, the fill valve 141 may perform an automatic closing operation in response to a level of reductant in the tank 51 rising to a level such that a portion or all of the fill valve 141 is covered by the reductant.
Next, an integration of the heating fluid circuit 200 and the filling assembly 100 will be described. The heating fluid supply conduit 201 is in fluid communication with the first assembly circulating conduit 105 by a first inlet port 137a and a first outlet port 137b of the second manifold 131. As illustrated in
According to the present disclosure, “thermal communication” refers to an orientation, position, or configuration of elements or materials that one of ordinary skill in the art would recognize as facilitating a degree of heat transfer from one element or material to another element or material that may not occur with a different orientation, position, or configuration of the elements or materials. For example, two elements or materials may be considered in thermal communication if heat is transferred more efficiently therebetween than if each element was thermally isolated or thermally insulated. An orientation, position, or configuration in which elements are in thermal communication may result in the elements approaching thermal equilibrium or thermal steady state. According to the present disclosure, elements in thermal communication may be separated by a space or gap, or a heat transfer material, or a component. Further, elements in thermal communication may also be provided in physical contact according to the present disclosure. Thermal communication may be limited according to the present disclosure to thermal communication via conduction and/or convection.
At the first end 100a, heating fluid may flow from the first assembly circulating conduit 105 to the second assembly circulating conduit 107 via the manifold circulation channel 119. Accordingly, heat from the heating fluid in the manifold circulation channel 119 is transferred to (1) the reductant supply connection 113, and (2) an end of the reductant supply conduit 103 that may be connected to the reductant supply connection 113 outside of the intake end 101a of the housing 101. At the second end 100b, the heating fluid flows through the second manifold 131 twice so that heat may be transferred to (1) an end of the reductant supply conduit 103 that may be connected to the reductant outlet connection 133 outside of the outlet end 101b of the housing 101, and (2) the reductant outlet connection 133. Thus, the first manifold 111 and the second manifold 131 are in thermal communication with, and function to heat portions of a combined reductant supply conduit (103, 113, 133) at connection points for the first end 100a and the second end 100b of the filling assembly 100 that may not be covered by the housing 101, and help prevent freezing of reductant being supplied to the reductant delivery system 50, or to thaw frozen reductant contained within the reductant delivery system 50.
According to one aspect of the disclosure, heat is transferred from both the first and second assembly circulating conduits (105, 107) along the length of the reductant supply conduit 103 in the filling assembly 100. The housing 101 is formed with a layer of insulation 101c that insulates the filling assembly 100, and helps facilitate heat transfer from both the first and second assembly circulating conduits (105, 107) to the reductant flowing in the reductant supply conduit 103. According to another aspect of the present disclosure, a thermal conductivity of the heat transfer material is greater than a thermal conductivity of the layer of insulation 101c. For example, the layer of insulation 101c could be formed of rubber, fiberglass, or other insulating materials known in the art, and the heat transfer material may be formed of a material having a relatively high thermal conductivity, such as a metal, including aluminum, steel, and copper alloys that may be adhered (e.g. via welding or other type of adhesion) to the outer surfaces of the reductant supply conduit 103 and the circulating conduits (105, 107).
The layer of insulation 101c may be wrapped around a combination of the reductant supply conduit 103, first assembly circulating conduit 105, and the second assembly circulating conduit 107. Alternatively, the housing 101 may be formed as a sleeve including a slit along a longitudinal axis that may be opened to place the combination of the reductant supply conduit 103, first assembly circulating conduit 105, and the second assembly circulating conduit 107 within the sleeve.
The first assembly circulating conduit 1105 and the second assembly circulating conduit 1107 are wrapped around the reductant supply conduit 1103, and along with the reductant supply conduit 1103, extend through an intake end 1101a and an outlet end 1101b of the housing 1101. As illustrated in
Vertical sections (119a, 119c) of the manifold circulation channel 119 may be connected to the inlet port 117a and the outlet port 117b of the first manifold 111. In addition, a connecting section 119b of the manifold circulation channel 119 that fluidly couples the vertical sections (119a, 119c), may extend to an additional port 119d formed in the first manifold 111. The additional port 119d may receive a plug 119e or be connected to a conduit, such as the assembly circulating conduits (105, 107, 1105,1107). According to one aspect of the disclosure, the plug 119e is placed in the additional port 119d, and can be removed to drain the manifold circulation channel 119, as well as the first and second assembly circulating conduits (105, 107, 1105, 1107).
A second coupling 125 is provided at an end of the first assembly circulating conduit (105, 1105) and the second assembly circulating conduit (107, 1107). A reducer 125a of the second coupling 125 is connected to a respective heating assembly conduit, and a fitting 125b is attached the inlet port 117a and the outlet port 117b of the first manifold 111. To avoid heating fluid leaking from the heating fluid circuit 200, the inlet port 117a, outlet port 117b, and fitting 125b may include corresponding threaded sections to provide threaded connections between the first and second assembly circulating conduits (105, 107, 1105, 1107) and the first manifold 111.
The first outlet port 137b and the second inlet port 139a of the second manifold 131 are respectively attached by second couplings 125 to ends of the first assembly circulating conduit (105, 1105) and the second assembly circulating conduit (107, 1107) that extend through the outlet end (101b, 1101b) of the housing (101, 1101). The first outlet port 137b is provided at an end of a first sub-manifold channel 137c. The first sub-manifold channel 137c is in fluid communication with the heating fluid supply conduit 201 through the first inlet port 137a. The second inlet port 139a is provided at an end of a second sub-manifold channel 139c. The second sub-manifold channel 139c is in fluid communication with the tank heating fluid supply conduit 205 through the second outlet port 139b.
Each of the sub-manifolds (137, 139) may be formed of material having a relatively high thermal conductivity, such as metals, including aluminum, steel, and copper alloys, for example. Thus, heat may be absorbed by portions of a sub-manifold surrounding a respective channel, and transferred via convection, conduction, or both, from a respective external wall to an area around the end of the reductant supply conduit (103, 1103) connected to the reductant outlet connection 133. In the non-limiting embodiment illustrated in
Heating fluid flows within the first assembly heating conduit 2105 from the second manifold 2131 to a first manifold 2111 in direct contact with an outer wall of the reductant supply conduit 2103. Alternatively, the first assembly circulating conduit 2105 may include two concentric tubes, a smaller concentric tube engaging the outer wall of the reductant supply conduit 2103 by an interference fit, a sliding fit, or a slip fit, for example. In these configurations, an outer surface of the reductant supply conduit 2103 is in contact with heating fluid, or a wall in contact with heating fluid, flowing in the first assembly circulating conduit 2105 for a substantially entire length of the reductant supply conduit 2103.
Heating fluid in the first assembly circulating conduit 2105 flows through a manifold circulation channel 2119 of the second manifold 2131, and into a second assembly circulating conduit 2107. As illustrated in
The controller 301 operates the purge control valve 303 to be normally open, i.e., the purge control valve 303 is open in a default state. During a filling operation in which reductant is supplied to the reductant delivery system 50 through the receiver 121 and the filling assembly 2100, the controller 301 monitors the parameter associated with the amount or level of reductant entering the tank 51 with the tank reductant sensor 305. In response to the reductant reaching a certain amount or level within the tank 51 (e.g., when the tank 51 is substantially full), the controller 301 may receive a signal from the tank reductant sensor 305, close the receiver 121, and close the purge control valve 303.
The reductant supply conduit 2103 of the filling assembly 2100, or any other filling assembly described herein, may be formed of a flexible material such as rubber, a rubber/nylon composite, or any other flexible material that is resistant to corrosion. According to an aspect of the present disclosure, the reductant supply conduit 2103 is sufficiently flexible to be compressed and become substantially flat under pressure applied by the heating fluid according to an operation of the purge control valve 303.
In an operational mode in which the purge control valve 303 is closed, the heating fluid will not flow within the heating fluid circuit 200 past the purge control valve 303. Pressure applied to the outer wall of the reductant supply conduit 2103 will increase as the heating fluid continues to flow into the filling assembly 2100 without subsequently passing through the purge control valve 303. Due to the flexibility of the reductant supply conduit 2103, an outer wall thereof will begin compressing under the increase in pressure applied by an increasing volume of heating fluid flowing into the first assembly circulating conduit 2105. During this mode, it may be preferable that reductant is not supplied to the filling assembly 2100 through the receiver 121 from an external source.
As illustrated in
At step 1707, the controller 301 closes the receiver 121, and a supply of reductant to reductant supply conduit 2103 is stopped. Next, at step 1709, the controller 301 closes the purge control valve 303. At this point in the method 1700, the controller 301 may start to track a time that the purge control valve 303 is closed or initiate a counter. With respect to step 1711, a monitored variable t may represent an elapsed time or a current value of the counter. At step 1711, the controller 301 may check the time or increment a value of the counter until the monitored variable t is equal to a reference value s representing a predetermined threshold for an elapsed time or count value.
When the monitored variable t is greater than or equal to the reference value s the method 1700 moves on to step 1713 and the controller 301 opens the purge control valve 303. Thus, the reductant supply conduit 2103 will expand and the heating fluid will again flow through the filling assembly 2100, past the purge control valve 303, and in to the tank 51 and heat the reductant fluid stored in the tank 51. If the machine 1 continues to operate, reductant remaining in the reductant supply conduit 2103 may receive heat transferred from the heating fluid flowing though the filling assembly 2100 and past the purge control valve 303.
At step 1715 the method 1700 ends with the purge control valve 303 in an open state and the heating fluid flowing in series from the engine 10, through the filling assembly 2100, past the purge control valve 303 into the tank heating fluid supply conduit 205, and into the tank circulating conduit 211.
In addition to the method 1700 of
For example, the purge control valve 303 may be closed according to a shutdown operation, or other type of operation, of the engine 10 being requested or initiated. Thus, in response to the request or the initiation of a particular operation of the engine, the controller 301 may estimate a first time to complete the operation, or a portion of a shutdown operation, of the engine 10, and monitor an elapsed time after the first time is estimated. When the first time is estimated, the controller 301 may also estimate a second time to complete a purging operation, or a combination of operations including the purging operation.
In response to the elapsed time being equal to the first time, either the controller 301, or a central controller (not shown) for the machine 1 receiving a signal from the controller 301, may operate the engine 10 in an idle state or a predetermined operating condition for the second time following a point when the elapsed time is equal to the first time. In response to a start, or an elapsing of a predetermined period of time after the start of the engine 10 operating in the idle state or the predetermined operating condition, the controller 301 may close the purge control valve 303. The controller 301 may continue to monitor the elapsed time. In response to the elapsed time being equal to the first time plus the second time, the controller 301 can open the purge control valve 303 and either stop, or send a signal to the central controller to stop the engine 10 operating in the idle state or the predetermined operating condition.
Accordingly, the engine 10 may be operated in the idle state or the predetermined operating condition so that heating fluid is circulated in the heating fluid circuit 200 for a period of time sufficient to close the purge control valve 303 and substantially compress the reductant supply conduit 2103 and purge reductant in the reductant supply conduit 2103 into the tank 51. As such, the reductant supply conduit 2103 may be purged at a time corresponding to immediately before an end of an operating session of the machine 1, reducing the amount of reductant in the reductant supply conduit 2103 that may be at risk of freezing when the machine 1 is not in use.
In another operation responsive to a state of the engine 10, a filling operation may be delayed based on a temperature of the engine. According to an aspect of the present disclosure, when the engine 10 operates during a filling operation, reductant in the reductant supply conduit 2103 is heated by the heating fluid in the fluid heating circuit 200 which may be heated by the engine 10 (e.g., when the heating fluid is engine coolant). In a situation where the engine 10 has just been started or is otherwise in a cold state, and a filling operation is attempted, signals indicating (1) a temperature of the engine and/or of the heating fluid in the heating fluid circuit 200, and (2) an attempt to perform the filling operation, may be sent to the controller 301. As a result, the controller 301 may close the shut-off mechanism in the receiver 121 and operate the engine 10 at a higher than normal idle so the temperature of the heating fluid reaches a predetermined temperature in a shorter period of time. Subsequently, the controller 301 may open the receiver 121 and a filling operation may be performed.
At step 1907, the controller 301 closes the receiver 121, and a supply of reductant to reductant supply conduit 2103 is stopped. Next, at step 1909, the controller 301 opens the bypass control valve 309 and closes the purge control valve 303. As a result, heating fluid flows through the bypass conduit 307 to the tank circulating conduit 211 so reductant in the tank 51 continues to be heated while the reductant supply conduit 2103 is purged. The controller 301 may start to track a time that the purge control valve 303 is closed, or initiate a counter. Similar to method 1700, at step 1911 of the method 1900, the controller 301 may check the time or increment a value of a counter until a monitored variable t is equal to a reference value s. When the monitored variable t is greater than or equal to the reference value s, the method 1900 moves to step 1913.
At step 1913, the controller 301 opens the purge control valve 303 and closes the bypass control valve 309. According to another aspect of the present disclosure, additional sensors that detect a presence of reductant in the reductant supply conduit 2103 may communicate with controller 301. In response, the controller 301 may close the purge control valve 303 at other times which do not correspond to a filling operation. Thus, the controller 301 may perform a purge operation during different times of operation of the machine 1 in which the heating fluid flows through the filling assembly 2100, based on different monitored parameters of operation and reductant delivery. Alternatively, the purge control valve 303 could remain closed and the bypass control valve 309 could remain open while the machine 1 is operating. This may avoid reductant flowing back into the reductant supply conduit 2103 from the tank 51, while continuing to heat the reductant in the tank 51, the pump 55, and the injector 31.
At step 1915 the method 1900 ends with the purge control valve 303 in an open state and the heating fluid flowing in series from the engine 10, through the filling assembly 2100, past the purge control valve 303 in to the tank heating fluid supply conduit 205, and into the tank circulating conduit 211.
Any of the methods or functions described herein may be performed by or controlled by the controller 301. Further, any of the methods or functions described herein may be embodied in a computer-readable non-transitory medium for causing the controller 301 to perform the methods or functions described herein. Such computer-readable non-transitory media may include magnetic disks, optical discs, solid state disk drives, combinations thereof, or any other computer-readable non-transitory medium known in the art. Moreover, it will be appreciated that the methods and functions described herein may be incorporated into larger control schemes for an engine, a machine, or combinations thereof, including other methods and functions not described herein.
Heat provided by assembly circulating conduits and first and second manifolds described herein may be supplemented by heat generated by other heating devices. According to an aspect of the present disclosure, an electrically powered heating device may be incorporated with any filling assembly described herein. For example, an electrical heating wire or wrap (e.g., heat tape) may be wrapped around a portion, or substantially all, of a reductant supply conduit prior to being assembled in a filling assembly. Ends of the electrical heating wire or wrap (e.g., leads) may extend through an intake end or an outlet end of a housing so as to be able to connect, disconnect, or reconnect to a power source that supplies a current passing through the electrical heating wire or wrap.
An amount of current required for the electrical heating wire or wrap to generate a desired heat output is proportional to a length of the electrical heating wire or wrap. A current required for a length for an electrical heating wire or wrap provided along an entire length of a reductant supply conduit may be large and could require an additional alternator as a power source. Accordingly, a system that relies solely on an electrical heating wire or wrap (i.e., a system without assembly circulating conduits as described herein) to heat a conduit carrying reductant to a PETU, for example, may require an alternator not provided for in an original design of a machine. According to one aspect of the present disclosure, only a portion of a reductant supply conduit may be provided with the electrical heating wire or wrap, such that a length of the portion corresponds to a length of an electrical heating wire or wrap that requires an amount of current which can be supplied by an existing power source of a machine. The existing power source preferably not being generally dedicated to supplying power to electrical heating wires or wraps in the machine.
An electrical heating wire or wrap that is incorporated, preferably without an additional alternator, in a filling assembly according the present disclosure may be utilized at different times to heat a reductant supply conduit to a desired extent in combination with operations utilizing heating fluid flowing in a filling assembly. For example, the electrical heating wire or wrap may be used to preheat, but not necessarily completely thaw, a reductant supply conduit during a cold start of an engine or just before a filling operation begins. Any method or function employing an electrical heating device described herein may be performed by or controlled by the controller 301, and/or incorporated into larger control schemes for an engine, a machine, or combinations thereof, including other methods and functions not described herein.
The present disclosure is applicable to diesel emission treatment systems that enable engine exhaust systems to meet international emission standards (e.g., Tier 4 Final/EU Stage IV emission standards). In particular, the present disclosure is applicable to diesel emission treatment systems that incorporate Selective Catalytic Reduction (SCR), which targets nitrogen oxides (NOx) in diesel exhaust for reduction to nitrogen (N2) and water vapor (H2O).
The present disclosure is particularly applicable to situations where a reductant delivery system is supplied with reductant conveyed through a fluid carrying conduit attached to a receiver positioned on a machine at a significantly lower elevation than the reductant delivery system. Issues of the reductant freezing in the conduit may arise for several reasons. First, since the conduit is long, a surface area exposed to a temperature of an environment surrounding the conduit is large. Thus, if a path of the conduit in a particular application exposes the conduit to low ambient temperatures or other components that may absorb heat, the reductant in the conduit may also be exposed to these temperature lowering factors across a large surface area due to a length of the conduit. Second, when reductant is not being supplied, since an elevation of the reductant delivery system is higher than a receiver through which reductant is initially supplied, reductant in the conduit remains in the conduit; it does not flow to the reductant delivery system and is not drained to another location. Thus, reductant in the conduit during these periods remains stagnate and exposed to the temperature of the environment and heat absorbing characteristics of the components surrounding the conduit.
According to one aspect of the present disclosure, an existing heat source (e.g., engine 10) in the machine 1 may be used to heat a reductant supply conduit (103, 1103, 2103, 3103). This provides certain benefits over adding an additional heat source, such as electrically heating the supply conduit (103, 1103, 2103, 3102); for instance there is no requirement for additional electrical power generation.
Referring to
According to one aspect of the present disclosure, heat is transferred to reductant prior to being received by the tank 51 of the reductant delivery system 50, over substantially an entire respective path between the tank 51 and the receiver 121.
Referring to
Referring to
According to an aspect of the present disclosure, the method (1700, 1900) may be performed to reduce a risk of reductant freezing during periods when reductant is not supplied through a filling assembly, when a machine is operating, and when a machine is about to stop operating.
In the method (1700, 1900), reductant in the reductant supply conduit 2103 being supplied to the reductant delivery system 50 may be discharged from the reductant supply conduit 2103 at the end of a filling operation. The controller 301 may monitor the tank reductant sensor 305 and close the purge control valve 303 at the end of the filling operation when a monitored parameter related to an amount of reductant in the tank 51 is equal to or greater than a predetermined threshold. Heating fluid continues to be supplied to the first assembly circulating conduit 2105, but does not flow beyond the purge control valve 303. The flexible material of the reductant supply conduit 2103 enables the reductant supply conduit 2103 to elastically compress under the increased pressure applied by the heating fluid still flowing into the first assembly circulating conduit 2105.
As portions of a wall of the reductant supply conduit 2103 move together under increasing pressure, the reductant is forced out of the reductant supply conduit 2103 and into the tank 51. This may continue for a period of time controlled by the controller 301, until only a very small amount of reductant remains between small spaces between the flattened portions of the wall of the reductant supply conduit 2103, as illustrated in
The controller 301 may open the purge control valve 303 after the purge operation, and heating fluid may flow past the purge control valve 303 into the tank 51 and heat the reductant stored in the tank 51. Alternatively, reductant in the tank 51 may be heated while the reductant supply conduit 2103 is purged. The bypass control valve 309 may be provided in the bypass conduit 307, and operated by the controller 301 to open when the purge control valve 303 is closed. The heating fluid may then flow through the bypass conduit 307 into the tank 51 to heat the reductant therein while the reductant supply conduit 2103 is purged.
According to an aspect of the present disclosure, the filling assembly (100, 1100, 2100, 3100) can be easily installed or removed as a single assembly.
Referring to
It will be appreciated that the foregoing description provides examples of the disclosed systems and techniques. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.
It is noted that as used in the specification and the appending claims the singular forms “a,” “an,” and “the” can include plural references unless the context clearly dictates otherwise.
Unless specified otherwise, the terms “substantial” or “substantially” as used herein mean “considerable in extent,” or “largely but not necessarily wholly that which is specified.”
Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.