Abstract: In an exhaust aftertreatment system comprising a NOx adsorber-catalyst followed by an SCR catalyst, means are provided for preventing the SCR catalyst from becoming heated to near the same peak temperatures as the NOx adsorber-catalyst during desulfation. In one embodiment, the means is a thermal mass between the NOx adsorber-catalyst and the SCR catalyst. In another embodiment, the means is a valve configured to selectively divert exhaust leaving the NOx adsorber-catalyst from the SCR catalyst. In a method of the invention, the NOx adsorber-catalyst temperature is cycled during desulfation. The peaks of the cycles are within an appropriate temperature range for desulfating the NOx adsorber-catalyst, but the average temperature is below the temperature range at which the SCR catalyst is damaged. The temperature peaks are damped as they travel from the NOx adsorber-catalyst to the SCR, whereby the SCR experiences much lower peak temperatures than the NOx adsorber-catalyst.

Abstract: A power generation system comprising a LNT for exhaust aftertreatment. The LNT has an effective operating temperature range. When the LNT is near a limit of its effective operating temperature range, the transmission is used to select operating points that increase the LNT's effectiveness. Generally, these operating points reduce the exhaust flow rate, although other factors such as the exhaust temperature may also be taken into account in selecting the operating points. Preferably, the LNT's effective operating temperature-range includes exhaust temperatures produced by the engine at its point of peak power output, whereby the LNT does not approach the limits of its effective operating temperature range except when the engine is at less than peak power. At lower power levels, it is generally possible to select operating points that provide lower exhaust flow rates than the flow rate occurring at the peak power level.

Abstract: A power generation system having a fuel reformer positioned inline with an engine exhaust stream. A transmission controller selects torque ratios and thereby operating points for the engine in order to facilitate start-up or operation of the fuel reformer. In one embodiment, the controller selects operating points to heat the exhaust and thus the reformer prior to starting the reformer. In another embodiment, the controller selects operating points to reduce or limit the oxygen concentration in the exhaust during denitration or desulfation of a LNT. In a further embodiment, the controller selects operating points to reduce a fuel penalty for a regeneration. The fuel penalty includes at least a contribution associated with consuming excess oxygen in the exhaust.

Abstract: One aspect of the invention relates an exhaust treatment system having an SCR reactor following a NOx adsorber. Syn gas is used to regenerate the NOx adsorber. Another aspect relates to an LNT/SCR provided with an ammonia source separate from the LNT. A further aspect relates to a system comprising first and second LNTs and one or more SCRs downstream of the LNTs. A still further aspect relates to a device comprising first and second NOx adsorbers contained in a single housing. Another aspect relates to coating a surface of a moving part in an exhaust system with an oxidation catalyst to mitigate fouling. Additional aspects of the invention relate to strategies for controlling one or more of the time to initiate a regeneration cycle, the time to terminate a regeneration cycle, and the reductant injection rate during regeneration of LNT/SCR exhaust treatment systems.

Abstract: An exhaust aftertreatment system is provided with a first SCR catalyst, a NOx adsorber-catalyst, and an ammonia-SCR catalyst. The first catalyst is generally a hydrocarbon-SCR catalyst, but can be a carbon monoxide-SCR catalyst or a hydrogen-SCR catalyst. The first catalyst is functional to reduce NOx in lean exhaust using the corresponding reductant. The NOx adsorbant-catalyst is functional to adsorb NOx and to produce ammonia during regeneration. The ammonia SCR catalyst is configured to adsorb ammonia so produced and is functional to subsequently use that ammonia to reduce NOx in lean exhaust. The first SCR catalyst is useful to reduce the frequency with which the NOx adsorber-catalyst needs to be regenerated, and can thereby extends the life of that catalyst. In one embodiment, reductant for the first SCR catalyst is stored during regeneration of the NOx adsorber-catalyst and is used to convert additional NOx in a subsequent lean phase.

Abstract: In an exhaust aftertreatment system comprising a NOx adsorber-catalyst followed by an SCR catalyst, means are provided for preventing the SCR catalyst from becoming heated to near the same peak temperatures as the NOx adsorber-catalyst during desulfation. In one embodiment, the means is a thermal mass between the NOx adsorber-catalyst and the SCR catalyst. In another embodiment, the means is a valve configured to selectively divert exhaust leaving the NOx adsorber-catalyst from the SCR catalyst. In a method of the invention, the NOx adsorber-catalyst temperature is cycled during desulfation. The peaks of the cycles are within an appropriate temperature range for desulfating the NOx adsorber-catalyst, but the average temperature is below the temperature range at which the SCR catalyst is damaged. The temperature peaks are damped as they travel from the NOx adsorber-catalyst to the SCR, whereby the SCR experiences much lower peak temperatures than the NOx adsorber-catalyst.

Abstract: One concept of the inventors relates to a system and method in which a particulate filter comprises at least about 40% by weight of an NOx adsorbant. The filter can be used as both an NOx trap and a particulate filter. By constructing the filter elements using a substantial amount of NOx adsorbant, a large volume of NOx adsorbant can be incorporated into the particulate filter, which substantially reduces the volume and expense of an exhaust system that includes both a catalytic diesel particulate filter and an NOx trap having a large quantity of NOx adsorbant. In a preferred embodiment, the filter also oxidizes NO to NO2. In another preferred embodiment, an SCR catalyst is position downstream of the filter elements.

Abstract: The invention relates to a power generation system with a continuously operating fuel reformer. Preferably, the fuel reformer is either off, warming up, or operating with an essentially constant fueling rate. Some of the reformed fuel is intermittently used to regenerate a NOx trap that treats the exhaust of an internal combustion engine. Any reformed fuel not used for other purposes is supplied to a fuel cell. The fuel reformer does not shut down between NOx trap regeneration cycles except when the engine is also shut down. The invention substantially eliminates issues of reformer response time as they relate to NOx trap regeneration.

Abstract: One or more parameters for denitration or desulfations of a LNT is varied, whereby the saturation of NOx and/or SOx in the LNT is reduced to a lower level when an operating state makes the LNT otherwise less effective or places a greater demand for conversion efficiency on the LNT. The operating state can relate to whether the LNT is at the limit of its effective operating temperature range, a degree of poisoning, or an engine operating state. Selectively tolerating high degrees of sulfur poisoning or NOx saturation during periods of low exhaust flow allows the efficiency of denitrations and/or desulfations to be increased over a large portion of a vehicle's operating cycle, particularly when the engine uses a CVT. Another concept relates to a power generation system comprising an engine tuned to efficiently operate in a narrow speed range for all levels of power output.

Abstract: One aspect of the invention relates to a particulate filter useful in treating exhaust from a diesel-power vehicle. The particulate filter comprises filter elements for removing particulate matter and an ammonia SCR catalyst. Ammonia can be produced during regeneration of an NOx adsorbant. The adsorbant can be contained in a separate device upstream of the particulate filter or be incorporated within the particulate filter. Another aspect of the invention relates to a method of cleaning exhaust comprising passing the exhaust over an NOx adsorber to adsorb a portion of NOx from the exhaust; passing the exhaust through a particulate filter to remove particulate matter from the exhaust; and removing a further portion of NOx from the exhaust by reducing it with ammonia over an ammonia SCR catalyst. Preferably, a catalyst contained within the adsorbant provides NO2 for continuously regenerating the particulate filter.

Abstract: A hybrid power train and method for operating same in which the operation of the engine is modified to effect an improvement in the fuel economy and/or emissions performance of the hybrid power train. In one embodiment, the battery of the power train is employed to provide auxiliary heat to an engine aftertreatment system to thereby improve the effectiveness of the aftertreatment system. In another embodiment, various components of the engine, such as a water pump, are wholly or partly operated by electric motors that receive power from the battery of the power train. In another embodiment, engine braking can be employed in situations where regenerative braking does not provide sufficient braking torque. In a further embodiment, the engine valves may be selectively opened to reduce pumping losses associated with the back-driving of the engine.

Abstract: A hybrid powertrain and method for operating same in which the operation of the engine is modified to effect an improvement in the fuel economy and/or emissions performance of the hybrid powertrain. In one embodiment, the battery of the powertrain is employed to provide auxiliary heat to an engine aftertreatment system to thereby improve the effectiveness of the aftertreatment system. In another embodiment, various components of the engine, such as a water pump, are wholly or partly operated by electric motors that receive power from the battery of the powertrain. In another embodiment, engine braking can be employed in situations where regenerative braking does not provide sufficient braking torque. In a further embodiment, the engine valves may be selectively opened to reduce pumping losses associated with the back-driving of the engine.

Abstract: One aspect of the invention relates to a power generation system comprising an internal combustion engine that operates, generally by limiting the adiabatic flame temperature, to produce an engine exhaust that is low in NOx and particulate matter. The exhaust is treated by a fuel cell to remove organic compounds and CO while producing useful power. Another aspect of the invention relates to controlling the adiabatic flame temperature by EGR drawing from upstream of the fuel cell. A further aspect of the invention relates to treating engine exhaust with a reducing catalyst and then with a fuel cell. A still further aspect of the invention relates to treating exhaust with an intermediate temperature solid oxide fuel cell. A further aspect of the invention relates to a system equipped with a valve allowing exhaust to selectively bypass a fuel cell.

Abstract: One aspect of the invention relates to a clean power generation system in which an internal combustion engine is operated to produce shaft power and an exhaust stream. The exhaust stream is processed by a fuel cell. Fluctuations in power demand are met, at least in part, by increasing or decreasing power output from the fuel cell and/or power uptake or output from a power storage device. The engine can operate at a relatively constant rate, providing a steady exhaust stream, which facilitates pollution control and fuel cell operation. According to another aspect of the invention, the exhaust of an engine is treated with a fuel cell having an electrolyte that conducts protons. In addition to removing pollutants from the exhaust while generating useful power, the fuel cell can provide a supply of low acidity water. The water can be used in the fuel reformer.

Abstract: The invention relates to a fuel reforming system in which an intensifier is used to pressurize the fuel. An intensifier is a simple device that can be used to step up the pressure provided by a conventional fuel pump. The fuel at increased pressure is passed through a nozzle. As the fuel leaves the nozzle, it atomizes and partially vaporizes. Optionally, the nozzle entrains air through the Venturi effect. Treating the fuel in this manner promotes mixing, increase reformer efficiency, and reduces the formation of byproducts. The invention is particularly suited to vehicle-mounted fuel reformer systems.

Abstract: An exhaust aftertreatment system comprising two or more branches, at least one of which contains a NOx adsorber-catalyst. The branches unite downstream into a trailing conduit that contains an ammonia-SCR catalyst. Ammonia generated by the NOx adsorber-catalyst during regeneration is stored for later use by the SCR catalyst. One advantage of this configuration is a continuous or near continuous presence of oxygen within the trailing exhaust conduit. The continuous presence of improves the efficiency of the SCR catalyst. Another concept is to configure a multi-branch exhaust aftertreatment system without valves, dampers, or other electronically controlled devices adapted to selectively alter the distribution of the exhaust between the branches. The absence of such devices generally results in a comparatively balanced division of exhaust between the branches. One benefit of this configuration is improved reliability as compared to systems that use valves.

Abstract: One aspect of the invention relates an exhaust treatment system having an SCR reactor following a NOx adsorber. Syn gas is used to regenerate the NOx adsorber. Another aspect relates to an LNT/SCR provided with an ammonia source separate from the LNT. A further aspect relates to a system comprising first and second LNTs and one or more SCRs downstream of the LNTs. A still further aspect relates to a device comprising first and second NOx adsorbers contained in a single housing. Another aspect relates to coating a surface of a moving part in an exhaust system with an oxidation catalyst to mitigate fouling. Additional aspects of the invention relate to strategies for controlling one or more of the time to initiate a regeneration cycle, the time to terminate a regeneration cycle, and the reductant injection rate during regeneration of LNT/SCR exhaust treatment systems.

Abstract: One aspect of the invention relates to cooled internal EGR. Cooled internal EGR is achieved by selectively admitting exhaust to an intake manifold. A heat exchanger is used to cool the exhaust within the intake manifold. Another aspect of the invention related to an intake manifold adapted for internal EGR cooling. The manifold has a bulge to retain exhaust, whereby the exhaust admitted to the intake side for internal EGR generally does not flow past the intake manifold and significantly heat or foul any upstream portion of the system. The manifold further includes a heat exchanger for cooling the exhaust. A further aspect of the invention relates to a method of reducing the response time of an EGR system. The method comprises providing a temporary increase in an internal EGR rate during a transition from a first to a second external EGR rate.

Abstract: A high-pressure connector for a fuel injection system including an elongated body having an inlet that is in fluid communication with a source of high-pressure fuel, an outlet in fluid communication with the inlet of a fuel injector and a fuel passage extending therebetween. A filter is supported within the fuel passage and acts to filter particulates from the high-pressure fuel. A fuel flow limiter is supported within the fuel passage and is operable to provide predetermined quantities of fuel to pass between the inlet and the outlet at each injection event during normal operation of the combustion chamber serviced by the injector and to automatically terminate fuel flow through the connector in the event of a malfunction at the combustion chamber.

Abstract: A pump includes a pump housing, a rotating shaft extending through the pump housing, a plurality of pistons, and a plurality of control sleeves. Each piston may be at least partially, slidably contained within a respective piston sleeve. The pistons may also be be operably coupled to the rotating shaft such that rotation of the shaft rotates and reciprocates the pistons. Each control sleeve may be slidably disposed on a respective one of said piston sleeves and operable to selectively vary the amount of fluid delivered by the pump.