Fuel injectors for exhaust heaters

#The present disclosure relates emissions control systems, and more particularly exhaust heaters for emissions control systems employing catalytic reactors.

#Internal combustion engines commonly include pollution systems to limit engine emissions. For example, catalytic converters are routinely used in pollution control systems to convert toxic and harmful gases and pollutants in exhaust gases from an internal combustion engine into less-toxic pollutants by catalyzing a redox reaction, i.e. an oxidation and a reduction reaction. Since redox reactions can be sensitive to temperature it can be necessary to heat the engine exhaust prior to introduction into the catalytic converter. Heating exhaust gases prior to introduction to the catalytic converter can extend emission control to operation intervals when the catalytic converter is cold, such as during starting and/or in cold weather.

#Exhaust heaters can employ heat exchangers, electrical heating elements, or combustors. Heat exchangers, such as those employing a flow of heated coolant from the engine, require that the engine coolant be heated and therefore can be of limited use to limit emissions immediately after starting. Electric heating elements can generally provide heat quickly but complicate the engine electrical system. Combustors typically divert pressurized fuel from the engine fuel system, reducing fuel efficiency or requiring valves and control schemes for selective operation.

#So that those skilled in the art to which the subject disclosure appertains will readily understand how to make and use the devices and methods of the subject disclosure without undue experimentation, embodiments thereof will be described in detail herein below with reference to certain figures, wherein:

#FIG. 1 is a schematic view of an exemplary embodiment of a vehicle constructed in accordance with the present disclosure, showing an exhaust heater with a fuel injector;

#FIG. 2 is cross-sectional view of the exhaust heater of FIG. 1, showing the fuel injector fastened to a combustor with a combustor liner fixed between the cover and the combustor;

#Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a partial view of an exemplary embodiment of an exhaust heater with a fuel injector in accordance with the disclosure is shown in FIG. 1 and is designated generally by reference character 100. Other embodiments of exhaust heaters, fuel injectors for exhaust heaters, and methods of making fuel injectors for exhaust heaters in accordance with the disclosure, or aspects thereof, are provided in FIGS. 2-10, as will be described. The systems and methods described herein can be used for heating combustion products generated by diesel engines for reduction in catalytic reactors when the catalytic reactor may otherwise be unable to support reduction, such as during cold weather and/or during engine starting, though the present disclosure is not limited to cold weather operation and/or starting or to diesel engines in general.

#Referring to FIG. 1, a vehicle 10 is shown. Vehicle 10 includes an engine 12, an exhaust conduit 14, a catalytic reactor 16, and an exhaust heater 100. Engine 12 is configured and adapted for providing motive power to vehicle 10 and can be, in certain embodiments, a diesel engine for an automotive application. Exhaust conduit 14 connects engine 12 to catalytic reactor 16 to convey thereto combustion products 18 generated by engine 12 to catalytic reactor 16 for reduction prior to emission into the ambient environment 20 as reduced combustion products 22. Catalytic reactor 16 is configured and adapted for supporting a redox reaction of combustion products 18 communicated thereto by engine 12 through exhaust conduit 14. Exhaust heater 100 is configured and adapted to communicate heat H to combustion products 18 as combustion products 18 flow between engine 12 and catalytic reactor 16 to promote the reduction of combustion products 18 by catalytic reactor 16. While described herein in the context of a diesel engine it is to be understood and appreciated that other types of engines can benefit from the present disclosure, such gas-type internal combustion engines by way of non-limiting example.

#As will be appreciated by those of skill in the art in view of the present disclosure, the efficiency of catalytic reactor 16 can be affected by temperature of combustion products 18 arriving at catalytic reactor 16. In particular, when the temperature of combustion products 18 is relatively low catalytic reactor 16 can have difficulty initiating and/or sustaining the redox reaction necessary to render combustion products 18 less toxic than as emitted from engine 12. This can be the case, for example, during engine operation in cold weather and/or during engine starting. To promote the redox reaction in catalytic reactor 16 when combustion products 18 are relatively cool exhaust heater 100 is in thermal communication with exhaust conduit 14 to heat combustion products 18 prior to entry to catalytic reactor 16.