Methods and systems for reducing hydrocarbon emissions
AssigneeFord Global Technologies, LLC
InventorsXiaogang Zhang, Daniel Styles
Life of this patent
Estimating the term…
Abstract
Methods and systems for heating an emission control device are provided. In one example, a method for a vehicle comprises during an engine cold start, heating an emission control device of the engine using a dual heat exchanger to heat secondary air and cool exhaust gas, and further heat secondary air with an electric heater. The method further comprises directing the heated secondary air to each exhaust runner of the engine via individual air injectors to mix with exhaust gas. In this way, an improved mixture of air and exhaust reduces catalyst light-off time and increases conversion efficiency, thereby reducing hydrocarbon emissions during engine cold start.
Claims20
A method for a vehicle, comprising:
- during an engine cold start,
- heating an emission control device of the engine using a dual heat exchanger to heat secondary air and cool exhaust gas, and further heat the secondary air with an electric heater.
A system for a vehicle, comprising:
- an engine having a secondary air injection passage and an EGR passage;
- a dual heat exchanger coupled to the secondary air injection passage and to the EGR passage;
- an electric heater coupled to the secondary air injection passage downstream of the dual heat exchanger;
- and
- a controller storing instructions in non-transitory memory that, when executed, cause the controller to:
- responsive to a cold start of the engine, heat an emission control device of the engine using the dual heat exchanger to heat air flowing through the secondary air injection passage and cool exhaust gas flowing through the EGR passage, and further heat the air with the electric heater.
A method for an engine, comprising;
- responsive to a cold start of the engine, opening an EGR valve positioned in an EGR passage to flow exhaust gas through the EGR passage, and activating a PETA air pump positioned in a secondary air injection passage to flow secondary air through the secondary air injection passage;
- heating the secondary air and cooling the exhaust gas using a dual heat exchanger, the dual heat exchanger being coupled to the EGR passage and the secondary air injection passage downstream of the EGR valve and the PETA air pump;
- heating the secondary air further with an electric heater coupled to the secondary air injection passage downstream of the dual heat exchanger;
- and
- directing the secondary air to a plurality of exhaust runners via a plurality of air injectors to mix the secondary air with the exhaust gas.
Dependencies are inferred from the claim text.