Secondary air injection

About: Secondary air injection is a research topic. Over the lifetime, 11452 publications have been published within this topic receiving 112147 citations.

The Effect of Oil Layers on the Hydrocarbon Emissions from Spark-Ignited Engines

Abstract: Measured amounts of oil were added to the engine cylinder of a single-cylinder CFR engine to determine the effect of oil layers on exhaust hydrocarbon emissions. The exhaust hydrocarbon concentration increased in proportion to the amount of oil added when the engine was fueled on isooctane. Addition of 0·6 cm3 of oil produced an increase of 1000 ppmC in exhaust hydrocarbon emissions at a coolant temperature of 320°K. Gas chromatographic analysis of the exhaust determined that fuel and fuel oxidation species, not oil oxidation products, were responsible for most of the increase. Similar experiments performed with propane fuel showed no increase in exhaust emissions when oil was added to the cylinder. These measurements have determined that the increase in tailpipe hydrocarbon concentration consists of fuel related species and is proportional to both the amount of oil added and the solubility of the fuel in the oil. Thus, we believe that the principal source of this increase in exhaust hydrocarbon ...

Turbocharged engine system and method of operation

Abstract: A system (10) is provided. The system includes an internal combustion engine having an intake manifold (16) and an exhaust manifold (18) . The system also includes a high pressure turbocharger (20) having a variable geometry high pressure turbine (22) drivingly coupled to a high pressure compressor (24) , wherein the variable geometry high pressure turbine (22) is driven by a first portion of exhaust gases from the exhaust manifold (18) / wherein the high pressure compressor (24) is configured to compress an intake air and to provide the compressed intake air to the intake manifold (16) . The system also includes a low pressure turbocharger (28) having a variable geometry low pressure turbine (30) drivingly coupled to a low pressure compressor, (32) wherein the variable geometry low pressure turbine (30) is driven by a second portion of the exhaust gases from the exhaust manifold.

Exhaust gas recirculation system for diesel engine

Abstract: An exhaust gas recirculation (EGR) system for a diesel engine comprising an EGR control valve for regulating the flow of exhaust gases to be recirculated from an engine exhaust system back to an engine air intake system. When the exhaust gas recirculation is to be interrupted, the EGR control valve is closed a predetermined time after the opening of a throttle valve used in the air intake system for regulating the flow of air towards the engine. For this purpose, delay valves are utilized in association with the throttle valve and the EGR control valve.

Air/fuel control system for an internal combustion engine

Abstract: An air/fuel control system having a feedback variable generated by modulating fuel flow into the engine, generating an error signal from a difference between the average of an exhaust gas oxygen sensor output and a reference value correlated with a desired air/fuel ratio, and integrating the error signal. The reference value is periodically offset in both lean and rich air/fuel directions. A biasing signal is generated from an exhaust gas oxygen sensor position downstream of the converter in response to the air/fuel offset. After removing the offset from the reference value, the bias signal is applied thereto for centering engine air/fuel operation within the peak efficiency window of a catalytic converter.