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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.


Papers
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Journal ArticleDOI
TL;DR: In this paper, the influence of the rate of gas delivery and the vertical distance from the source on the vertical radius of the gas flow is analyzed and compared with published and experimental data of air injection into slabs consisting of saturated sands.
Abstract: The injection of gases into liquid saturated porous media is of theoretical and practical interest (e.g., air sparging for the removal of volatile organic compounds from contaminated aquifer sediments). The influence of the rate of gas delivery and the vertical distance from the source are developed. The concept of a “near-injection region” is presented in which the pressure gradients exceed buoyant gradients and thus exhibits largely radial flow. The near-injection size is shown to have an area required to carry the injected gas flow under unit gradient. The parabolic movement of gas outside of this area which has often been observed is explained as reflecting the sum of many realizations of gas channels following random lateral movements as they precede upward independent of flux. These concepts are confirmed through comparison with published and experimental data of air injection into slabs consisting of saturated sands of a range of textures.

73 citations

Patent
10 Oct 2001
TL;DR: In this article, an internal combustion engine including an exhaust gas turbocharger and a compound power turbine connected to the crankshaft of the engine and a recirculation system extending between the engine exhaust duct upstream of the exhaust gas turbine and the intake duct downstream of the compressor of the turbine.
Abstract: In an internal combustion engine including an exhaust gas turbocharger and a compound power turbine connected to the crankshaft of the engine and an exhaust gas recirculation system extending between the engine exhaust duct upstream of the exhaust gas turbine and the intake duct downstream of the compressor of the exhaust gas turbocharger, the exhaust gas turbine and the compound power turbine have a size relationship determined by the power absorption capability φ of each turbine such that: φ = m  T p wherein: {dot over (m)} is the exhaust gas mass flow rate through the turbine, T is the exhaust gas temperature at the turbine inlet, and p is the exhaust gas pressure at the turbine outlet and the maximal compound power turbine absorption capability exceeds the maximal absorption capability of the exhaust gas turbine

73 citations

Patent
19 Feb 2008
TL;DR: In this paper, inlet air at an input of a compressor was used to generate compressed air at the compressor using the received inlet-air, and the compressed air from the compressor to a combustor, where the combustor produces combustion involving compressed air and fuel, and at least a portion of the exhaust gases were sent to the intake section via a recirculation line.
Abstract: Systems and methods may be provided for exhaust gas recirculation The systems and methods may include receiving, via an intake section, inlet air at an input of a compressor, generating compressed air at the compressor using the received inlet air, and providing the compressed air from the compressor to a combustor, where the combustor produces combustion involving the compressed air and fuel The systems and methods may also include receiving combustion products associated with the combustion at a turbine component, where the turbine component releases exhaust gases, and recirculating at least a portion of the exhaust gases to the intake section via a recirculation line, where the recirculated exhaust gases raise a temperature of the inlet air

72 citations

Patent
30 Apr 2001
TL;DR: In this article, an improved reduction of NOx compounds from a so-called "lean-burn" engine is provided. But this reduction is based on a selective passage of a gas component before other gas components in the exhaust gas flow.
Abstract: The invention relates to a device for reduction of a gas component in an exhaust gas flow of a combustion engine (1) which is adapted for operation by a lean air/fuel mixture, comprising an exhaust pipe (21) for transport of said exhaust gas flow from the engine (1). The invention is characterized in that it comprises a separation unit (22) which is arranged along the exhaust pipe (21), which separation unit (22) comprises a wall structure (32) of a material which provides separation of said gas component from said exhaust gas flow by means of a selective passage of said gas component before other gas components in the exhaust gas flow. The invention also relates to a method for such a reduction and a separation unit which is intended to be utilized during such a reduction. By means of the invention, an improved reduction of in particular NOx compounds from a so-called 'lean-burn' engine is provided.

72 citations

Patent
15 Apr 1993
TL;DR: In this paper, a monolith carrier, at least one first catalyst layer having a three-way catalytic activity, provided on the carrier, and a second catalyst layer with a hydrocarbon purification activity provided by the first layer.
Abstract: A catalyst for exhaust gas purification has at least one monolith carrier, at least one first catalyst layer having a three-way catalytic activity, provided on the carrier, and a second catalyst layer having a hydrocarbon purification activity, provided on the first catalyst layer. In a gasoline engine automobile provided with the above catalyst for exhaust gas purification in the exhaust gas system, the hydrocarbons present in the exhaust gas can be converted at a high efficiency by introducing secondary air into the exhaust gas in front of the catalyst to make the exhaust gas lean, at the engine start when a large amount of unburnt hydrocarbons are present in the exhaust gas. Further, the engine warm-up property of the automobile can be improved by the heat generated by the catalytic reaction of the hydrocarbons. The catalyst further exhibits a three-way catalytic activity even during the steady state engine operation after warm-up.

72 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202327
202277
202160
2020146
2019173
2018159