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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.


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Patent
20 Jan 2001
TL;DR: In this article, a system and method for using an engine's exhaust back pressure (1210) to control a variable geometry turbocharger is presented, where the difference value (1215) is used to determine the duty cycle (1220).
Abstract: There is provided a system and method for using an engine's exhaust back pressure (1210) to control a variable geometry turbocharger. The control system determines a desired exhaust back pressure (1205) based on engine parameters. The desired exhaust back pressure (1205) is then compared with a measured exhaust back pressure (1210) to determine the difference (1215) between the measured (1210) and desired (1205) exhaust back pressures. The difference value (1215) is used to determine the duty cycle (1220). In an alternate embodiment, the exhaust gas pressure (1615) is used to adjust the duty cycle (1605) determined based on the engine parameters. The difference (1620) between the measured (1615) and desired (1610) exhaust back pressures is used to determine an exhaust pressure control duty cycle (1625). The base duty cycle (1605) is then adjusted by the exhaust pressure control duty cycle (1625) to give a turbocharger duty cycle (1630).

52 citations

Journal ArticleDOI
TL;DR: In this paper, the performance of air sparging systems, as measured by the predicted region of airflow, was investigated by conducting numerical simulations with a multiphase modeling program (TETRAD).
Abstract: The performance of air sparging systems, as measured by the predicted region of airflow, was investigated by conducting numerical simulations with a multiphase modeling program (TETRAD). The simulations employed standard two-phase flow theory, and included pressure-dependent calculations of the compressibility of water and air. Simulations tested the response of air sparging systems to variations in geological properties. Three stages of flow behavior are predicted following initiation of air injection. These are: (1) an initial transient period of growth in the lateral and vertical limits of airflow (expansion stage); (2) a second transient period of reduction in the lateral limits of airflow (collapse stage); and (3) a steady-state stage, during which the system remains static as long as injection parameters do not change. In homogeneous media the geometry of the region of airflow changes from a teardrop- or bell-shaped configuration to a shape that is roughly conical during the expansion stage. During the collapse stage, air is preferentially diverted to established regions of high effective air permeability, and ground water resaturates the remainder of the original region of influence. For pilot testing it is important to realize that measurements of the lateral extent of airflow expansion and collapse stages can bemore » misleading because they will differ from the limits established at steady-state. The time required for a particular system to progress through the transient stages and establish steady-state behavior can vary from hours to years, and is dependent on the permeability structure of the aquifer, injection depth, and injection rate. Under homogeneous conditions the maximum width of the region of airflow attained during the transient expansion stage was substantially greater than the width attached at steady-state.« less

52 citations

Patent
16 Jul 2001
TL;DR: In this article, a gas turbine unit has a compressor for compressing ambient air and producing compressed air, a combustion chamber to which the compressed air is supplied, a source of relatively high grade fuel for burning in the combustion chamber and producing combustion gases, and an organic working fluid responsive to exhaust gases for converting heat in the exhaust gases to electricity.
Abstract: Apparatus for generating power includes a gas turbine unit having a compressor for compressing ambient air and producing compressed air, a combustion chamber to which the compressed air is supplied, a source of relatively high grade fuel for burning in the combustion chamber and producing combustion gases, and a gas turbine connected to generator and to the compressor for expanding the combustion gases and producing exhaust gases. The apparatus further includes a combustor that burns relatively low grade fuel, and produces combustion products, and an indirect contact heat exchanger responsive to the combustion products for heating the compressed air before the latter is applied to the combustion chamber, and for producing cooled combustion products. In addition, an energy converter is provided having an organic working fluid responsive to the exhaust gases for converting heat in the exhaust gases to electricity. Finally, the apparatus of the invention serves to minimize the consumption of high grade fuel in the presence of changes in the heating value of the low grade fuel.

52 citations

Patent
22 Apr 2005
TL;DR: In this article, an estimate of the intake manifold oxygen concentration is derived from the air fraction within the manifold, which is determined from an engine system model that provides interdependent air mass fractions at various locations within the engine system.
Abstract: An internal combustion engine system includes an intake manifold, a combustion chamber, an exhaust manifold and exhaust gas recirculation apparatus for recirculating a portion of the exhausted gases from the exhaust manifold to the intake manifold. An estimate intake manifold oxygen concentration is determined from the air fraction within the intake manifold which is determined from an engine system model that provides interdependent air mass fractions at various locations within the engine system.

52 citations

Patent
15 Feb 2002
TL;DR: In this article, the authors describe an apparatus and a process for supplying recirculated exhaust gases to incoming air to a piston-type internal combustion engine. But their work is limited to the case where the feed pipe opens out into an outlet section comprising a t least one outlet for the supply of the exhaust gases.
Abstract: The invention relates to an apparatus and a process for supplying recirculated exhaust gases to incoming air to a piston-type internal combustion engine. The apparatus comprises a duct (2) for incoming air and a feed pipe (1) for said exhaust gases and is especially well characterized in that the feed pipe (1) opens out into an outlet section (3) comprising a t least one outlet (4) for the supply of the exhaust gases, which outlet section constitutes an outlet path (a) extended in the longitudinal direction of the duct.

52 citations


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