Showing papers on "Secondary air injection published in 2010"

System and method for waste heat recovery in exhaust gas recirculation

Abstract: A system and method for waste heat recovery in exhaust gas recirculation is disclosed. The system includes an engine having an intake manifold and an exhaust manifold, an exhaust conduit connected to the exhaust manifold, and a turbocharger having a turbine and a compressor, the turbine being connected to the exhaust conduit to receive a portion of the exhaust gas from the exhaust manifold. The system also includes an EGR system connected to the exhaust conduit to receive a portion of the exhaust gas, with the EGR system including an EGR conduit that is connected to the exhaust conduit to receive a portion of the exhaust gas, a heat exchanger connected to the EGR conduit and being configured to extract heat from the exhaust gas, and a waste heat recovery system connected to the heat exchanger and configured to capture the heat extracted by the heat exchanger.

Low temperature selective catalytic reduction catalyst and associated systems and methods

Abstract: According to one embodiment, described herein is an exhaust gas after-treatment system that is coupleable in exhaust gas stream receiving communication with an internal combustion engine. The exhaust gas after-treatment system includes a low temperature SCR catalyst configured to reduce NO x in exhaust gas having a temperature below a temperature threshold. The system also includes a normal-to-high temperature SCR catalyst configured to reduce NO x in exhaust gas having a temperature above the temperature threshold.

Pocketed air and fuel mixing tube

Abstract: An improved mixing tube design and fuel nozzle that allows for a more uniform and thorough mixing of fuel and air being fed to the combustor of a gas turbine engine, wherein each of a plurality of mixing tubes comprises a pair of concentric hollow cylinders that define a ring-like, annular path for the flow of fuel between the two hollow cylinders in each mixing tube, a plurality of air injection slots formed in the concentric hollow cylinders defining corresponding air flow paths from the outside into the interior of each mixing tube, and one or more fuel injection ports formed in selected ones of the plurality of air injection slots that allow for the flow of fuel from the annular path formed by the hollow cylinders into the air flow path, resulting in significantly better mixing and improved thermodynamic behavior of the fuel and air mixture downstream of the nozzle and upstream of the combustor.

Exhaust emission purifying apparatus for internal combustion engine

Abstract: In an exhaust emission purifying apparatus for an internal combustion engine, for adding a reducing agent for NOx to the exhaust gas to thereby purify NOx in the exhaust gas, the mixing of the reducing agent injected by an injection nozzle with the exhaust gas is accelerated. To this end, in the apparatus of the present invention, the injection nozzle for the urea water is disposed to be opposite to the flow of the exhaust gas, or to face upward in a vertical direction.

Integrated pump and injector for exhaust after treatment

Abstract: A urea solution injection system and an injector with which urea solution or other exhaust treatment liquid from a source tank can be injected as an atomized spray into an exhaust pipe. A metering pump with integrated injection nozzle are contained in a common housing mounted directly to the exhaust pipe, thereby eliminating the separate electric motor driven pump, line between pump, and injector in conventional systems.

Reductant decomposition system

Abstract: Described herein are various embodiments of a reductant decomposition system. According to one representative embodiment, the reductant decomposition system includes an exhaust gas chamber including an inlet and outlet. The system also includes a first exhaust gas distribution component positioned within the chamber and communicable in exhaust gas receiving communication with the outlet. The first exhaust gas distribution component causes swirling exhaust gas flow patterns within the exhaust gas chamber. Additionally, the system includes a second exhaust gas distribution component positioned within the chamber and communicable in exhaust gas providing communication with the inlet. The second exhaust gas distribution component includes features that cause a swirling exhaust gas flow pattern within a space defined by the second exhaust gas distribution component. Further, the system includes a reductant injector coupled to the exhaust gas chamber. The reductant injector is communicable in reductant injecting communication with exhaust gas within the chamber.

Unit for recovering and converting thermal energy from the exhaust gases of an internal combustion engine of a vehicle

Abstract: A unit (1, 1') for recovering and converting thermal energy from the exhaust gases of an internal combustion engine (14) of a vehicle comprises a heat exchanger (2, 2') to be traversed by exhaust gases flowing along a by-pass path (5,5') branching out from an exhaust gas main line (4) of said internal combustion engine (14) and valve means (12) for controlling the flow of the exhaust gases through said path, said valve means (12) being driven by an actuator device (12A). The by-pass path (5, 5') is a U-shaped path defined entirely within the heat exchanger (2, 2'),starting from an inlet section (6, 6') and ending at an outlet section of the heat exchanger, the inlet and outlet sections (7,7') being located on a same side of the heat exchanger (2) and both opening on an interface conduit portion (3) interposed in said exhaust gas main line (4). The heat exchanger (2, 2') is arranged so that said U-shaped path is oriented transversely to the direction of the exhaust gas main line (4), in such a manner that the exhaust gases traversing the heat exchanger flow firstly in the transverse direction away from the exhaust gas main line (4) and then back in the transverse direction towards the exhaust gas main line (4), The valve means (12) are arranged within said interface conduit portion (3),between merging points of the inlet and outlet portions (6,7) of the heat exchanger (2,2').

Exhaust emission control system

Abstract: An exhaust emission control system (1) comprising a continuous regenerating DPF (13) and a DPF controlling means (30C), wherein control is so performed as to accept the operation of a forced regenerating means (34C) at an operation request by a driver when it is judged a traveling distance (ΔMc) after starting collection detected by a traveling distance detecting means (33C) has reached a specified judging traveling distance (ΔM1) even when the DPF controlling means (30C) detects a collection amount (ΔPm) detected by a collection amount detecting means (32C) is smaller than a specified judging collection amount (ΔP1). Accordingly, in a continuous regenerating DPF (13) capable of manual regenerating, the number of warnings such as a blinking regeneration button prompting a manual regeneration is reduced to relieve a driver of trouble.

Adaptive intake oxygen estimation in a diesel engine

Abstract: A method for estimating an oxygen concentration in an intake manifold of a diesel engine utilizing exhaust gas recirculation includes monitoring engine operation, monitoring an exhaust gas recirculation valve, and monitoring an exhaust air fuel ratio. When the engine operates in steady state with the exhaust gas recirculation valve in the closed position, a volumetric efficiency for the engine is updated. A partial pressure due to exhaust gas recirculation within the intake manifold based upon the updated volumetric efficiency is determined, and an estimated oxygen concentration within the intake manifold based upon the partial pressure due to exhaust gas recirculation within the intake manifold and the exhaust air fuel ratio is determined. Operation of the engine is controlled based upon the estimated oxygen concentration within the intake manifold.

Exhaust heat recovery for engine heating and exhaust cooling

Abstract: Various systems and method for heating an engine in a vehicle are described. In one example, intake air flowing in a first direction may be heated via a gas-to-gas heat exchange with exhaust gases. The heated intake air may then be used in a subsequent gas-to-liquid heat exchange to heat a fluid circulating through the engine. In another example, intake air flowing in a second direction may be heated via a heat exchange with exhaust gases in order to cool an exhaust catalyst.

Effects of secondary air injection during cold start of SI engines

Abstract: The paucity of exhaust oxygen during cold start of automobile SI engines limits the extent of exothermic chemical reactions in the exhaust port, manifold, and catalyst. The injection of air into the exhaust system therefore could be an effective way to utilize additional thermal and chemical energy available in the exhaust gas. This study investigates the thermal and chemical processes associated with secondary air injection (SAI) inside the exhaust system in order to fully exploit the simultaneous benefits of reducing converter-in emissions and improving catalyst lightoff performance during cold start. An experimental study was performed to develop a more fundamental understanding of the effects of SAI on exhaust gas emissions and catalyst light-off characteristics during cold start of a modern SI engine. The effects of several design and operating parameters such as spark retardation, fuel enrichment, secondary air flow rate and air injection location were investigated to understand the mixing, heat loss, and thermal and catalytic oxidation processes associated with SAI. Timeresolved HC, CO and CO2 concentrations were tracked from the cylinder exit to the catalytic converter outlet and converted to mass flow rates by applying an instantaneous exhaust mass flow rate model. A phenomenological model of exhaust heat transfer combined with the gas composition analysis was also developed to define the thermal and chemical energy state of the exhaust gas with SAI. The study found that significant emissions reduction can be achieved with SAI by the thermal oxidation process prior to the catalyst, which results in enhancing the chemical process inside the catalyst by faster catalyst light-off. The engine operation, with a relative air/fuel ratio 20% rich of stoichiometric and 100% secondary air, yielded the fastest catalyst light-off (4.2 sec). The SAI system reduced HC emissions by 46% to 88% and CO emissions by 37% to 93% compared with the normal operating conditions. The analysis showed that the post-catalyst HC emissions levels were optimized with secondary air flow rates corresponding to an overall exhaust lambda of 1.3. Thesis Supervisor: John B. Heywood Title: Professor of Mechanical Engineering

SCR exhaust gas aftertreatment device

Abstract: An SCR exhaust gas aftertreatment device in which a urea-water solution is injected into an exhaust gas line is provided. At least one component of the device (e.g., a filter element) lies in an area of an internal space, and is bounded by an elastomer membrane that is embedded in a frost equalization foam. This prevents freezing damage even over a very long period of time and a large number of freezing cycles.

Effect of Two-Stage Injection on Unburned Hydrocarbon and Carbon Monoxide Emissions in Smokeless Low-Temperature Diesel Combustion with Ultra-High Exhaust Gas Recirculation

Abstract: The unburned hydrocarbon (UHC) and carbon monoxide (CO) emissions from smokeless low-temperature diesel combustion (LTC) with ultra-high exhaust gas recirculation (EGR) can be attributed to lowered...

Effect of air inlet hole diameter of venturi tube on air injection rate

Abstract: The oxygen concentration in water is a prime indicator of the water quality for human use as well as for the aquatic biota. The physical process of oxygen transfer or oxygen absorption from the atmosphere acts to replenish the used oxygen. This process is termed re-aeration or aeration. Venturi aeration is a method of aeration that has become popular in recent years. A venturi tube allows air bubbles to be inserted into flowing water from air inlet holes and so increases oxygen levels in the water. In the present study, a series of experiments on venturi tubes were conducted to investigate the effect of air inlet hole diameter on air injection. It was observed from the results that air inlet hole diameter on venturi tube played a significant role in air injection and there was an optimal diameter that maximizes air injection. Moreover, a multiple non-linear regression equation was obtained for venturi tubes relating air flow and water flow to Reynolds number, inlet diameter and air inlet hole diameter.

Intake air heating and exhaust cooling

Abstract: Intake air heating and exhaust cooling is provided by a double wall exhaust system serving as an exhaust-to-air heat exchanger, sourcing hot air to the intake manifold for intake stroke pumping benefit and cooling the exhaust system during high load operation by routing excess boost air through an interstitial space of the double wall.

On-vehicle nitrogen oxide aftertreatment system

Abstract: An emissions system for reducing nitrogen oxides in engine exhaust includes an emissions catalyst having an inlet adapted to receive an exhaust from the engine. A fuel tank is adapted to provide fuel for combustion within the engine. A first injector is operable to inject fuel into the exhaust upstream of the catalyst. A second injector is operable to inject supplemental reductant from a supplemental reductant tank into the exhaust upstream of the catalyst. A controller is operable to control the first and second injectors and vary the supply of fuel and supplemental reductant into the exhaust to reduce nitrogen oxides within the exhaust.

Diesel engine system and control method for a diesel engine system

Abstract: A diesel engine system includes a cylinder, an exhaust manifold, an exhaust gas recirculation (EGR) manifold, and a valve. The exhaust manifold is fluidly coupled with the cylinder and directs exhaust generated in the cylinder to an exhaust outlet that delivers the exhaust to an external atmosphere. The EGR manifold is fluidly coupled with the cylinder and recirculates the exhaust generated in the cylinder back to the cylinder as at least part of intake air that is received by the cylinder. The valve is disposed between the cylinder and the exhaust manifold and between the cylinder and the EGR manifold. The valve has a donating mode and a non-donating mode. The valve fluidly couples the cylinder with the EGR manifold when the valve is in the donating mode and fluidly couples the cylinder with the exhaust manifold when the valve is in the non-donating mode.

Emissions control systems and methods

Abstract: Methods and systems are provided related to an emissions control system. The emissions control system has an exhaust after-treatment system defining a plurality of distinct exhaust flow passages through which at least a portion of an exhaust stream can flow, e.g., the exhaust stream is produced by an engine. The emissions control system also includes a controller for controlling injection of reductant into the exhaust stream flowing through each of the flow passages. In one example, the emissions control system is configured for use in a vehicle, such as a locomotive or other rail vehicle.

Experimental investigation of cold start emissions using electrically heated catalysts in a spark ignition engine

Abstract: The population of spark-ignition vehicles in urban areas is very high and is increasing rapidly due to their convenience for short distance transportation. These vehicles are major sources of urban air pollution compared to vehicles with diesel engines. Catalytic converters are used to control their emissions but they attain their maximum conversion rates of about 80%–90% under optimum operating conditions and are not effective during cold start conditions. The objective of the present work is to demonstrate that an electrically heated catalyst (EHC) in combination with a traditional converter can achieve the Low and Ultra Low Emission Vehicle (LEV, ULEV) standards. Experiments were conducted to investigate the impact of various metal oxides in EHC and design parameters to reduce cold-start emissions of a multi-cylinder SI engine. It is observed that EHC reduces cold-start hydrocarbon and carbon monoxide emissions when used with an existing catalytic converter. The maximum CO and HC reductions were achieved with copper oxide as the catalyst in EHC with air injection of 80 lpm for 40 sec after cold start of the engine.

Controlling exhaust temperatures

Abstract: An exhaust manifold cooling jacket has internal passages for the circulation of liquid coolant and encloses an exhaust manifold such that a gap is created between the exhaust manifold and cooling jacket. Flowing coolant through the jacket regulates outer jacket temperature while enabling high intra-manifold exhaust gas temperatures for thorough intra-manifold combustion and improved emissions. A liquid-cooled exhaust system includes a turbocharger disposed between manifold and elbow, with liquid coolant flowing from manifold to elbow through the turbocharger. Another liquid-cooled exhaust manifold contains an internal exhaust combustion catalyst wrapped in an insulating blanket. In some marine applications, seawater or fresh water coolant is discharged into the exhaust gas stream at an attached exhaust elbow.