Showing papers on "Secondary air injection published in 2007"

Exhaust gas purification system for hybrid vehicle

Abstract: An exhaust gas purification system for a hybrid vehicle is disclosed. An internal combustion engine and an electric motor are each arranged for providing power output for the vehicle. An exhaust gas purification device is provided in an exhaust gas passage of the engine to treat exhaust gas components contained in the exhaust gas from the engine. A controller is arranged and configured to selectively perform a regeneration operation of the exhaust gas purification device to burn and remove deposits accumulated in the exhaust gas purification device. The controller is further arranged and configured to control the internal combustion engine and the electric motor such that the exhaust gas purification device is restrained from reaching an excessive temperature during the regeneration operation of the exhaust gas purification device.

Low emission turbine system and method

Abstract: A turbine system is provided. The turbine system includes a compressor configured to compress ambient air and a combustor configured to receive compressed air from the compressor, and to combust a fuel stream to generate an exhaust gas. The turbine system also includes a turbine for receiving the exhaust gas from the combustor to generate electricity; wherein a first portion of the exhaust gas is mixed with the ambient air to form a low-oxygen air stream, and wherein the low-oxygen air stream is compressed using the compressor, and is directed to the combustor for combusting the fuel stream to generate a low-NOx exhaust gas.

Approach for Delivering a Liquid Reductant into an Exhaust Flow of a Fuel Burning Engine

Abstract: An exhaust system for an internal combustion engine for a vehicle is provided. The system comprises an exhaust passage for transporting exhaust gases from the engine; an injector coupled to a wall of the exhaust passage, said injector including an injection axis that is angled relative to a longitudinal axis of a mixing region of the exhaust passage; and a first mixing device arranged within the exhaust passage downstream of the injector within the mixing region, said first mixing device including a plurality of flaps, wherein said plurality of flaps are inclined relative to the longitudinal axis; a second mixing device arranged within the exhaust passage downstream of the first mixing device; wherein the injection axis of the injector intersects the first mixing device.

System for recirculating the exhaust of a turbomachine

Abstract: A portion of the exhaust generated by a turbomachine is recirculated through an inlet portion by an exhaust gas recirculation system. The system reduces the level of harmful constituents within the exhaust before the exhaust is recirculated.

Exhaust gas post treatment system

Abstract: Exhaust gas post treatment system for nitrogen oxide and particle reduction of an internal combustion engines operated with excess air. An oxidation catalytic converter is disposed in the exhaust gas stream of the engine for converting at least a portion of the nitric oxide of the exhaust gas into nitrogen dioxide. A metering device adds reduction agent to the exhaust gas stream downstream of the oxidation catalytic converter and/or to a partial exhaust gas stream branched off upstream of the oxidation catalytic converter and returned to the exhaust gas stream downstream thereof. The reduction agent is ammonia or a material that releases ammonia downstream of the supply location due to the hot exhaust gas. A particle separator or filter is disposed in the exhaust gas stream downstream of the oxidation catalytic converter and of the supply location, and converts carbon particles accumulated in the separator or filter into carbon monoxide, carbon dioxide, nitrogen and nitric oxide with the aid of nitrogen dioxide in the exhaust gas stream. An SCR catalytic converter is disposed downstream of the separator or filter for reducing nitrogen oxides in the exhaust gas stream into nitrogen and water vapor with the aid of ammonia or released ammonia by selective catalytic reduction.

The Local Geometry of Gas Injection into Saturated Homogeneous Porous Media

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.

Method and apparatus for estimating exhaust pressure of an internal combustion engine

Abstract: A method and apparatus are provided, comprising an internal combustion engine equipped with a variable geometry intake air compressing device and a control module operative to estimate exhaust gas pressure during ongoing engine operation. The control module is adapted to monitor sensing devices of the internal combustion engine, and is adapted to execute algorithms. The method comprises monitoring signal inputs from the sensing devices, and determining operating parameters for exhaust flow and an exhaust pressure of the intake air compressing device. An exhaust pressure ratio is determined based upon the parameters for exhaust flow and the exhaust pressure of the intake air compressing device. An exhaust pressure is determined based upon the exhaust pressure ratio.

Internal combustion engine having an exhaust gas turbocharge and an exhaust gas recirculation system

Abstract: In a supercharged internal combustion engine having an intake duct and an exhaust gas recirculation system and comprising an exhaust gas turbine with two separate flow passages of different flow cross-sections arranged upstream of a turbine rotor of the exhaust gas turbine, each flow passage being in communication with a respective engine exhaust line for supplying it with exhaust gas and an exhaust gas recirculation line extending from one of the engine exhaust lines to the engine intake duct, a bypass line bypassing the exhaust gas turbine is provided and a common control element is arranged in the recirculation line of the exhaust gas recirculation system and in the bypass line for controlling the exhaust gas flow from the recirculation line selectively to none or any of the intake duct and the turbine bypass line.

Characteristics of low temperature and low oxygen diesel combustion with ultra-high exhaust gas recirculation:

Abstract: Ultra-low NOx and smokeless operation at higher loads up to half of the rated torque is attempted with large rates of cold exhaust gas recirculation (EGR). NOx decreases below 6 ppm (0.05 g/kW h) and soot significantly increases when first decreasing the oxygen concentration to 16 per cent with cold EGR. However, after peaking at 12–14 per cent oxygen, soot then decreases sharply to essentially zero at 9–10 per cent oxygen while maintaining ultra-low NOx, regardless of fuel injection quantity and injection pressure. However, at higher loads, with the oxygen concentration below 9–10 per cent, the air-fuel ratio has to be over-rich to exceed half of the rated torque, and thermal efficiency, CO, and THC deteriorate significantly. As the EGR rate increases, exhaust gas emissions and thermal efficiency vary with the intake oxygen content rather than with the excess air ratio. Longer ignition delays due to either advancing or retarding the injection timing reduced the smoke emissions, but advancing the ...

Control method of exhaust gas purification system and exhaust gas purification system

Abstract: An exhaust gas purification system has an exhaust gas purification device (12) for purifying components in exhaust gas from an internal combustion engine (10) such as a diesel engine. In order to recover the purification ability of the exhaust gas purification device (12), and in order to prevent oil dilution occurring when post injection is conducted as part of an in-cylinder fuel injection control during an exhaust gas temperature raising control that raises the temperature of exhaust gas, the system performs the following. In a regenerative control for recovering purification ability of the exhaust gas purification device (12), injection quantities (Qp) of post injections are calculated based on previously set map data (Mp), accumulated to calculate a post injection accumulated injection amount (ΣQp), and, when the accumulated injection amount (ΣQp) exceeds a predetermined determination value (Cp), the post injection is stopped to cease the regenerative control.

Control of rotor tip leakage and secondary flow by casing air injection in unshrouded axial turbines

Abstract: The objective of this work is to study control mechanisms for rotor tip leakage and secondary flows in unshrouded high-pressure axial turbines to improve turbine aerodynamic efficiency. This thesis presents the results of a detailed experimental study on a one-and-1/2-stage, unshrouded, axial turbine test rig. The turbine was especially designed for this investigation to model a highly loaded, high pressure, multi-stage turbine environment. The design of the blade rows, the mechanical turbine design, as well as instrumentation and commissioning of the turbine represent a substantial part of this work. For the evaluation of the time-resolved turbine flow, the unsteady flow fields at inlet and exit of all blade rows are measured with a high spatial resolution with a 2sensor fast-response aerodynamic probe technique. Due to the low aspect ratio and the high loading of the turbine profiles secondary flow structures dominate up to 50% of the blade span at the exit of the first stage. The unsteady interaction of secondary flow vortices of the stator with the secondary flow and the tip leakage flow of the rotor is one major source of losses in the first turbine stage. At the exit of the first rotor the interaction region of stator and rotor secondary flows appears periodically with the rotor blade passing frequency at a fixed location in the stationary frame of reference. By changing the circumferential position of the first stator row relative to the second one, the location of this interaction region can be adjusted relative to the leading edge of the second stator. The high threedimensionality of the flow induced by secondary vortex interaction causes local changes of total pressure loss in the second stator with clocking, whereas the overall change is found to be only marginal. Stator clocking in high pressure turbine is therefore seen as a tool to control the radial distribution of massflow and loss in a downstream stator. The potential of loss reduction is judged to be limited. This finding also implies that the wake model commonly used to describe the effect of clocking on performance is not applicable in high-pressure turbines due to the dominance of secondary flow structures. In this work a novel method is investigated that aims to reduce the rotor tip leakage flow and hence the losses associated to the interaction of the tip leakage vortex with the main passage flow. Cooling air is injected through an array of holes in the rotor casing that are inclined in circumferential direction, such that the injected fluid counteracts the motion of the tip leakage flow. Injection massflows representing 0.7% and 1.0% of the turbine massflow were tested at the axial injection locations at 30% and 50% rotor axial chord. The

Exhaust system for an internal combustion engine

Abstract: The present invention relates to an exhaust system for an internal combustion engine, having an exhaust line for removing exhaust gas from the internal combustion engine and having a secondary fuel supply for introducing secondary fuel into the exhaust gas of the internal combustion engine. To improve the introduction of the secondary fuel into the exhaust, a recirculation device is connected to the exhaust line and to the secondary fuel supply so that the introduction of secondary fuel into the exhaust is accomplished via or through the recirculation device. The recirculation device has a circulation space which receives an exhaust substream from the exhaust line in which the secondary fuel is introduced into the exhaust substream and from which the modified exhaust substream is returned to the exhaust line.

System and method for boosted direct injection engine

Abstract: An engine system, comprising of a combustion chamber selectively communicating with an intake manifold via at least an intake valve and an exhaust manifold via at least an exhaust valve, a turbocharger including a compressor operatively coupled to the intake manifold and a turbine operatively coupled to the exhaust manifold, wherein the turbocharger is configured to selectively boost intake manifold pressure greater than exhaust manifold pressure during at least one operating condition, a direct fuel injector configured to inject fuel directly into the combustion chamber, a spark plug configured to provide an ignition spark to the combustion chamber, a valve actuation system coupled to the intake valve and the exhaust valve configured to vary a relative timing of the intake valve and the exhaust valve and a control system communicatively coupled to the valve actuation system, the direct fuel injector, and the spark plug wherein during said at least one operating condition, the control system is configured to operate the valve actuation system to increase an overlap between exhaust valve opening and intake valve opening to increase an amount of air flowing through the combustion chamber from the intake manifold via the opened intake valve to the exhaust manifold via the opened exhaust valve, initiate an injection of fuel directly into the combustion chamber via the direct fuel injector after the exhaust valve has closed, and ignite said injected fuel by operating the spark plug to provide an ignition spark.

Air-fuel ratio control system for internal combustion engine

Abstract: An air-fuel ratio control system for an internal combustion engine provided with a NOx trap catalyst which is disposed in an exhaust gas passageway and arranged to trap NOx when the air-fuel ratio of exhaust gas flowing to the NOx trap catalyst is lean and to release and reduce trapped NOx when the air-fuel ratio is rich. The air-fuel ratio control system comprises a sensor for detecting an air-fuel ratio of exhaust gas in the exhaust gas passageway downstream of the NOx trap catalyst. Additionally, a control circuit is provided and configured to cause the engine to operate at a rich air-fuel ratio to accomplish a rich air-fuel ratio engine operation after an engine operation at a lean air-fuel ratio, and continue the rich air-fuel ratio engine operation for a duration even after the sensor has detected that the air-fuel ratio of exhaust gas is rich.

Engine exhaust systems with secondary air injection systems

Abstract: A variety of embodiments of exhaust systems for engines including small off-road engines, and related methods of operation, are disclosed. In at least some embodiments, the exhaust system includes a first conduit that receives exhaust emissions from a first engine cylinder, and a second conduit that communicates air to a first port on the first conduit. The air mixes with the exhaust emissions within the first conduit so as to produce a chemical reaction, and a level of at least one undesirable component of the exhaust emissions is reduced. Further, the exhaust system does not include any catalytic converter. In some embodiments, the exhaust system further comprises a crankcase ventilation system.

Exhaust gas recirculation device of internal combustion engine, and control method thereof

Abstract: An exhaust gas recirculation device includes a turbocharger (5) having a turbine (5b) on an exhaust pipe (4) and a compressor (5a) on an intake pipe (3), a low-pressure EGR passage (31) connecting the exhaust pipe (4) downstream of the turbine (5b) and the intake pipe (3) upstream of the compressor (5a), and a filter (13) provided on the exhaust pipe (4) downstream of the turbine (5b). In the device, an exhaust throttle valve (19) is disposed on the exhaust pipe (4) that is downstream of the filter (13) and that is upstream of a site of connection with the low-pressure EGR passage (31).

Vehicle control method and vehicle control apparatus

Abstract: A vehicle control apparatus and methodology relate to an exhaust gas sensor and sensor heater associated with an exhaust passage of a vehicle engine. The exhaust gas sensor is selectively heated to an applicable activation temperature by the heater so that the sensor may output a normal and accurate sensing signal. The heating must take place, however, without causing damage to the sensor such as that resulting from condensation that may occur within the exhaust passage as a result of engine operation and environmental conditions.

Method and device for monitoring the regeneration of a pollution-removal system

Abstract: Method for monitoring the regeneration of a pollution-removal system (8), relying on the introduction of fuel into the exhaust gases by delayed injections of fuel into certain combustion chambers of the engine and/or direct injections into the exhaust system upstream of the filter depending on the inlet temperature of the system, characterized in that the fuel delivery (Qred) introduced is assigned to direct injections into the exhaust system and/or to delayed injections into the combustion chamber according to the value of the wall temperature (Tparoi) of the exhaust system.

Simultaneous EGR correction and individual cylinder combustion phase balancing

Abstract: An internal combustion engine is configured with combustion chamber pressure sensing and exhaust gas recirculation apparatus. Fuel injection timing is adjusted based on combustion phasing and exhaust gas recirculation is controlled based on average fuel injection timing adjustments.

Cooling device for high temperature exhaust

Abstract: A cooling system for cooling exhaust gases includes a section of pipe adapted to receive exhaust gases having a first temperature. The cooling system further includes an air amplifier with a passage extending therethrough. The air amplifier receives a flow of compressed air and directs the flow of the compressed air through the passageway. The compressed air entrains ambient air into one end of the passageway so that discharge air, which includes compressed air and ambient air, is discharged from the other end of the passageway. A conduit is connected to the air amplifier and extends through a wall of the section of pipe. Discharge air from the air amplifier passes through the conduit into the interior portion of the pipe and mixes with the exhaust gases. The mixture of discharge air and exhaust gases has a second temperature that is less than the first temperature.

Exhaust emission control device and method for internal combustion engine, and engine control unit

Abstract: An exhaust emission control device for an internal combustion engine, which is capable of properly regenerating a NOx catalyst, while properly controlling NOx catalyst temperature and ensuring excellent drivability. As a regeneration operation, the exhaust emission control device feedback-controls a detected reducing condition of exhaust gases to a predetermined reducing condition, by controlling the amount of main fuel injected by main injection or feedback-controls the same to the predetermined reducing condition by controlling the amount of auxiliary fuel injected by auxiliary injection. The device determines whether the regeneration operation should be executed in a catalyst temperature control mode for controlling the NOx catalyst temperature. If, as a result of the determination, the regeneration operation should be executed in the catalyst temperature control mode, the device selects the feedback control of the main fuel amount, and otherwise selects the feedback control of the auxiliary fuel amount.

Treatment Systems and Methods for Internal Combustion Engine Exhaust Streams

Abstract: Emissions treatment systems and methods are disclosed, which reduce the carbon monoxide, unburned hydrocarbons, and nitrogen oxides content in the exhaust stream of an internal combustion engine adjusted to a rich combustion ratio. One embodiment of a system comprises an ammonia oxidation catalyst, a supplemental air supply for providing a lean combustion ratio, and at least one three-way catalyst. Another embodiment further comprises a second three-way catalyst located in the exhaust stream.

Exhaust system utilizing a low-temperature oxidation catalyst

Abstract: An exhaust treatment system is provided having a first exhaust passageway fluidly connected to an engine. A particulate filter and a selective catalytic reduction catalyst are situated within the first exhaust passageway. In addition, the system has a first oxidation catalyst located within the first exhaust passageway upstream of the particulate filter and the selective catalytic reduction catalyst. The system also has a second exhaust passageway fluidly connected to the first exhaust passageway upstream and downstream of the first oxidation catalyst. The exhaust treatment system further has a sensor configured to sense a parameter indicative of an exhaust gas temperature. Furthermore, the system has a controller configured to direct exhaust gas through the first oxidation catalyst when the exhaust gas temperature is below a threshold temperature and direct the exhaust gas through the second exhaust passageway when the exhaust gas temperature is above the threshold temperature.

Arrangement for the dosed injection of a reducing medium into the exhaust tract of an internal combustion engine

Abstract: In an arrangement for the dosed injection of a reducing agent into the exhaust tract of an internal combustion engine, comprising a pump for the pulsed pumping of the reducing agent and an atomizing injection nozzle disposed in the exhaust tract of the internal combustion engine, the injection nozzle includes a valve element which opens and closes the injection nozzle depending on the pressure generated by the pump and permits the injection of the reducing agent into the exhaust tract only when the pressure of the reducing agent is in excess of a certain value in order to ensure proper atomization of any reducing agent injected into the exhaust tract.

METHOD AND APPARATUS FOR A NON-CATALYTIC NOx REDUCTION

Abstract: A method of reducing NOx in exhaust gases generated by an internal combustion engine includes advancing the exhaust gases along an exhaust path to a selective catalytic reduction (SCR) catalyst positioned downstream from the internal combustion engine. The method further includes activating a heat source if the exhaust gases are below a predetermined temperature, such that the exhaust gases along a segment of the exhaust path are heated to a temperature of 700-1000° C. The method further includes injecting a reductant into the segment of the exhaust path upstream of the SCR catalyst to react in the segment with NOx in the exhaust gases. The method further includes deactivating the heat source if the temperature of the exhaust gases at the catalyst rises above the first predetermined temperature. An emission abatement assembly is also disclosed.