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.

Exhaust gas purifying equipment for a diesel engine

Abstract: An exhaust gas purifying equipment for a diesel engine having a first continuous regeneration type DPF ( 12 ) in an exhaust passage ( 7 ) of an engine ( 2 ), a second continuous regeneration type DPF ( 13 ) in a bypass passage ( 101 ), a switching valve ( 102 ) for switching the flow path of an exhaust gas, an exhaust temperature raising means, an exhaust temperature area detector, and a controller controlling the exhaust temperature raising means and the switching valve ( 102 ), wherein the controller operates the exhaust temperature raising means and at the same time executes the post-injection, and, furthermore, controls the switching valve ( 102 ) so that the exhaust gas passes through the second continuous regeneration type DPF ( 13 ), in the case where the exhaust temperature area of an engine ( 2 ) detected by the exhaust temperature area detector is in an extremely low temperature area (Z 2 ) of which the exhaust temperature is lower than that of a predetermined temperature area. Thereby, even under an environment such as a very cold land, the PM collected by the DPF can be made burn steadily and continuously over the whole operating range of an in-vehicle diesel engine.

Engine exhaust gas recirculation particle trap

Abstract: An exhaust gas recirculation system for an internal combustion engine includes intake and exhaust manifolds that respectively receive ambient air and expel exhaust gas. A recirculation line fluidly connects the exhaust and intake manifolds. An exhaust gas recirculation valve is included in the recirculation line and is controlled to distribute exhaust gas into the intake manifold. A particle trap is arranged to receive all of the exhaust gases from the exhaust manifold and includes a particle collection chamber therein. A stagnation region is provided within the particle trap such that all the exhaust gas passed through the exhaust gas particle trap is directed toward the stagnation region therein and at least a portion of debris carried with the exhaust gas is retained within the particle collection chamber.

Modeling the impact of early exhaust valve opening on exhaust aftertreatment thermal management and efficiency for compression ignition engines

Abstract: In response to strict emissions regulations, engine manufacturers have implemented aftertreatment technologies to reduce the tailpipe emissions from diesel engines. The effectiveness of most of these systems is limited when exhaust temperatures are below 250°C. This is problematic during cold start and at low-load engine operation when the exhaust gas temperature is too low to keep the aftertreatment working effectively. The implementation of variable valve actuation strategies, including early exhaust valve opening, has been proposed as a means to elevate exhaust temperatures. Early exhaust valve opening results in hotter exhaust gas; however, more fueling is needed to maintain brake power output. This article outlines an analysis of the impact of early exhaust valve opening on exhaust temperature (measured at the turbine outlet) and the required fueling. An experimentally validated model is developed, which relates fueling increase with the timing of exhaust valve opening. This model is used to generate...

Centrifugal study of zone of influence during air-sparging

Abstract: Air sparging (AS) is one of the groundwater remediation techniques for remediating volatile organic compounds (VOCs) in saturated soil. However, in spite of the success of air sparging as a remediation technique for the cleanup of contaminated soils, to date, the fundamental mechanisms or the physics of air flow through porous media is not well understood. In this study, centrifugal modeling tests were performed to investigate air flow rates and the evolution of the zone of influence during the air sparging under various g-levels. The test results show that with the increase in sparging pressure the mass flow rate of the air sparging volume increases. The air mass flow rate increases linearly with the effective sparging pressure ratio, which is the difference between sparging pressure and hydrostatic pressure normalized with respect to the effective overburden pressure at the sparging point. Also the slope of mass flow rate with effective sparging pressure ratio increases with higher g-levels. This variation of the slope of mass flow rate of air sparging volume versus effective sparging pressure ratio, M, is linear with g-level confirming that the air flow through soil for a given effective sparging pressure ratio only depends on the g-level. The test results also show that with increasing sparging pressure, the zone of influence (ZOI), which consists of the width at the tip of the cone or lateral intrusion and the cone angle, will lead to an increase in both lateral intrusion and the cone angle. With a further increase in air injection pressure, the cone angle reaches a constant value while the lateral intrusion becomes the main contributor to the enlargement of the ZOI. However, beyond a certain value of effective sparging pressure ratio, there is no further enlargement of the ZOI.