Eaton Corporation

International Engine Intellectual Property Company, LLC

Johannes Walter Reuter

James Edward McCarthy, Jr

Christian Thomas Chimner

Karen Evelyn Bevan

Subbaraya Radhamohan

Dmitry Arie Shamis

Haoran Hu

Vishal Singh

Matthew Richard Busdiecker

Jiyang Yan

Desulfation methods for an exhaust treatment system having a fuel reformer configured upstream of a LNT. Reductant is injected upstream of the fuel reformer. The reductant reacts within the reformer to generate heat, but the system is configured for some reductant to breakthrough and react in the LNT to generate further heat. This configuration allows the LNT to operate at temperatures higher the than first device and facilitates independent control of the LNT and first device temperatures.

LNT desulfation strategy with reformer temperature management

Discontinuous torque ratio shifts by a transmission can result in complex transient exhaust conditions that can adversely affect exhaust air-fuel ratio control, which can result in ineffective regeneration. In extreme cases, the result can be irreversible damage to exhaust system components. The inventors' concept is to alter either regeneration scheduling or shift scheduling to avoid shifting while regenerating.

Transmission shift signal for aftertreatment device control

A lean NOtrap is a diesel exhaust aftertreatment system is selectively denitrated based on a measure relating to the state and/or the performance of the exhaust aftertreatment system, or a portion thereof comprising the lean NOtrap, reaching a critical value. The critical value is varied according to the demands currently being place on the exhaust aftertreatment system. In one embodiment, the critical value is set based on engine speed-load information. The method regenerates more frequently when exhaust aftertreatment demands are high and less frequently when demands are low. The method improves aftertreatment performance while reducing aftertreatment fuel penalty.

Algorithm incorporating driving conditions into LNT regeneration scheduling

The inventors' concept relates to controlling a power generation system having an exhaust aftertreatment system comprising a fuel reformer and an LNT in series. Over the course of a desulfation, a fuel injection upstream of the fuel reformer is pulsed to create alternating lean and rich phases and control the LNT temperature. The LNT temperature is controlled by manipulating a minimum temperature for the fuel reformer at the end of the lean phase, a length of the lean phase, or a pulse frequency. Preferably, the rich phases end when the fuel reformer reaches a predetermined maximum temperature. The method is effective in regulating the fuel reformer temperature while accurately controlling the LNT temperature.

Desulfation control strategy

Desulfation methods for an exhaust treatment system having a fuel reformer configured upstream of a LNT. Reductant is injected upstream of the fuel reformer. The reductant reacts within the reformer to generate heat, but the system is configured for some reductant to breakthrough and react in the LNT to generate further heat. This configuration allows the LNT to operate at temperatures higher the than first device and facilitates independent control of the LNT and first device temperatures. An outer loop controls the LNT temperature by issuing instructions to an inner loop that controls the reformer. Typically, the inner loop will pulse the reductant injection rate in order to limit the reformer temperature. The outer loop can pulses the loop on a longer time scale, resulting in two pulse periods. Through timing, a reformate peak from one period is made to overlap a temperature peak from a previous period.

A method is provided for regenerating a LNT in a diesel engine exhaust aftertreatment system. Typically, the aftertreatment system comprises a fuel reformer, a LNT, and a SCR catalyst in that order. Over the course of the regeneration, the concentration or flow rate of syn gas is increased, peaked, and then reduced. Preferably, the syn gas concentration or flow rate and the fuel reformer temperature are simultaneously controlled using at least a fuel injector and an engine intake air throttle. The pattern of increasing the syn gas concentration or flow rate during a first part of the regeneration and decreasing the syn gas concentration of flow rate in a latter part of the regeneration reduces the fuel penalty for the regeneration and improves the ammonia production rate as compared to a system in which the syn gas concentration or flow rate is essentially constant throughout the regeneration.

Optimal fuel profiles

A fuel reformer is configured in an exhaust line upstream of a LNT. To desulfate the LNT, over a first period, fuel is provided to the exhaust to make the exhaust rich. While producing reformate, the reformer is allowed to heat to a relatively large extent, typically at least about 75&#xb0; C. Before the reformer overheats, the provision of fuel is reduced and typically stopped entirely for a second period, over which the reformer cools. The heating and cooling periods are repeated to complete the desulfation process. The reduced efficiency of operating the reformer over an extended temperature range is more than compensated for by the benefits of extending the rich pulse.

LNT desulfation strategy

The invention relates to systems and methods of detecting faults in an exhaust line fuel injection system. An expected relationship between a temperature within the exhaust system and a commanded fuel injection rate or amount is compared to an actual relationship in order to detect faults. The temperature is preferably a temperature of, within, or downstream of an exhaust system device that catalyzes an oxidation or partial oxidation reaction of the fuel, such as an oxidation catalyst or a fuel reformer. The expected relationship may be defined in terms of a thermal model of a system comprising the catalytic device. The invention can be used to detect spray quality faults or to detect fuel injector faults without the use of flow meter.

Model based diagnostics of an aftertreatment fuel dosing system

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.

Mechanism and method of combined fuel reformer and dosing system for exhaust aftertreatment and anti-idle SOFC APU

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 NOfor continuously regenerating the particulate filter.

Growing community of inventors

Ypsilanti, MI, United States of America

Johannes Walter Reuter