Showing papers on "Secondary air injection published in 2001"

Air-fuel ratio control apparatus of internal combustion engine

Abstract: An air-fuel ratio control apparatus of an internal combustion engine according to the present invention is provided with oxygen storage amount estimating means, downstream exhaust air-fuel ratio detecting means, maximum oxygen storage amount estimating means, and air-fuel ratio target setting means. The oxygen storage amount estimating means estimates an oxygen storage amount of an exhaust purifying catalyst, based on a history of an oxygen adsorption/desorption amount of the exhaust purifying catalyst located on an exhaust path. The downstream exhaust air-fuel ratio detecting means is located downstream of the exhaust purifying catalyst and detects an exhaust air-fuel ratio downstream of the exhaust purifying catalyst. The maximum oxygen storage amount estimating means estimates a maximum oxygen storage amount, based on an oxygen storage amount estimate when the exhaust air-fuel ratio detected is a predetermined air-fuel ratio. This permits effective utilization of oxygen occlusion capability of the exhaust purifying catalyst and improvement in exhaust purification performance.

Diesel engine control

Abstract: A control unit (41) controls an opening of an exhaust recirculation valve (6) according to a running condition of a diesel engine (1). The control unit (41) calculates an equivalence ratio of the gas mixture supplied to the engine (1) and a target intake fresh air amount taking account of the air amount in the exhaust gas recirculated by the exhaust gas circulation valve (6), based on the opening of the valve (6) and a target excess air factor of the engine (1) set according to the running condition. By controlling a turbocharger (50) according to the target intake fresh air amount, and by controlling the fuel supply mechanism according to a fuel injection amount calculated from the equivalence ratio, the excess air factor of the engine (1) and an exhaust gas recirculation rate of the exhaust gas recirculation valve (6) are respectively controlled to optimum values.

Turbocharged engine with exhaust gas recirculation

Abstract: A turbocharged internal combustion engine assembly with exhaust gas recirculation (EGR) includes an air compressor driven by an exhaust turbine, an EGR line that diverts exhaust gases from an exhaust line leading from the engine to an air intake line leading to the engine from the compressor, and a combustion bypass line that conveys compressed air from the compressor to the exhaust turbine without combustion. A pressure adjusting feature disposed along at least one of the air intake line and the exhaust line maintains the pressure at the turbine inlet below the pressure at the compressor outlet and above the pressure at the air inlet of the engine. Examples of suitable pressure adjusting features include a venturi placed in the air intake line at the second point, a power turbine located along the exhaust line downstream of the exhaust turbine, a split exhaust manifold feeding unequal turbine inlets, and an orifice located along the exhaust line between the EGR line and the bypass line.

Fuel injection controlling system for a diesel engine

Abstract: A fuel injection controller for a diesel engine to be mounted on an engine-operated vehicle, having a control unit which conducts computation to determine a total amount of fresh intake air per an engine cylinder through the computation of the sum of a residue amount of fresh air that remains in the computed amount of exhaust gas entering the engine cylinder and the computed amount of intake air, to obtain an amount of fuel injection under the total amount of fresh intake air, which defines a smoke generation limit as a basic limitative smoke generating fuel injection amount, to store the basic limitative smoke generating fuel injection amount as a stored basic limitative smoke generating fuel injection amount upon judging whether or not the engine comes into either accelerating or decelerating operation, to compare the stored basic limitative amount of fuel injection and the basic amount of fuel injection computed during the accelerating or decelerating operation to thereby determine a larger or smaller one of the compared basic amounts of fuel injection as a desired limitative smoke generating fuel injection amount from the time of judgment of the accelerating or decelerating operation of the engine, and to prevent an objective amount of fuel injection from exceeding the desired limitative smoke generating fuel injection amount from the time of the judgment of the accelerating or decelerating operation of the engine so that the objective amount of fuel injection is supplied to the engine.

Catalyst activation control system for engines

Abstract: An engine has variable timing mechanisms, which are controlled in starting an engine to set valve opening overlap of an intake valve and an exhaust valve around 30° CA. In this case, internal EGR is actively conducted and fuel burning velocity within a cylinder becomes relatively slow and unburned fuel within the cylinder is emitted to an exhaust pipe to be post-burned by itself. Temperature of exhaust gas is maintained high and catalyst converters in the cold state may be activated quickly by actively implementing the post-burning within the exhaust pipe. Further, ignition timing is retarded, an air-fuel ratio is controlled at a slightly lean ratio and the exhaust valve is advanced. The effect of raising the temperature of exhaust gas by the post-burning may be realized more reliably by combining each of these controls.

Exhaust gas recirculation air handling system for an internal combustion engine

Abstract: A variable geometry turbine and active wastegate are provided in combination along with independent control of the variable geometry turbine and wastegate valve so as to independently control exhaust gas recirculation flow and air flow in an internal combustion engine. Such independent control of exhaust gas recirculation flow and air flow in an internal combustion engine is achieved by providing a system for exhaust gas recirculation including an intake air manifold, an exhaust manifold, an exhaust gas recirculation passage providing fluid communication between the exhaust manifold and the intake air manifold, a variable geometry turbine positioned downstream of the exhaust manifold, and a waste gate passage providing fluid communication between the exhaust gas manifold and a point downstream of the variable geometry turbine. A control system is provided for controlling exhaust gas recirculation through the exhaust gas recirculation passage by independently controlling a geometry of the variable geometry turbine and thus the casing size of the turbine to control air flow and passage of exhaust gas through a waste gate passage in order to control compressor power which delivers the pressure ratio to the compressor and intake manifold. In doing so, both flow and power are independently controlled in order to maximize efficiency of the system.

Internal combustion engine with exhaust gas turbocharger and compound power 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

Device and method for reduction of a gas component in an exhaust gas flow of a combustion engine

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.

Method and apparatus for using hydroxyl to reduce pollutants in the exhaust gases from the combustion of a fuel

Abstract: A method and apparatus are provided for reducing pollutants in the exhaust gases produced from the combustion of a fuel by introducing hydroxyl and associated radicals and oxidizers into at least one of the precombustion and postcombustion gas stream of the combustion engine upstream of the catalytic converter and treating the exhaust gases with the catalytic converter.

Exhaust gas purifying system and method

Abstract: An exhaust gas purifying system for an automotive internal combustion engine. The exhaust gas purifying system comprises a flow-through monolithic catalyst disposed in an exhaust gas passageway through which exhaust gas flows. The monolithic catalyst functions to adsorb and oxidize a soluble organic fraction in exhaust gas, to adsorb nitrogen oxides in exhaust gas in a condition in which a temperature of exhaust gas is not higher than 200° C. and to allow carbon particle in exhaust gas to pass through the monolithic catalyst. Additionally, a filter catalyst is disposed in the exhaust gas passageway downstream of the flow-through monolithic catalyst. The filter catalyst functions to trap the carbon particle and to oxidize hydrocarbons, carbon monoxide and nitrogen monoxide in exhaust gas.

Exhaust emission control device and method of controlling exhaust emission

Abstract: A method of controlling exhaust emission, comprising the steps of providing a first heat resistant filter medium in the exhaust emission passage of an internal combustion engine to collect hydrocarbon compounds and carbon-containing suspended particles contained in the exhaust emission distributedly so as to be brought into contact with the oxygen contained in the exhaust emission, burning the collected hydrocarbon compounds and carbon-containing suspended particles by using the exhaust emission with an inflow temperature lower than the inflammable temperature of the carbon-containing suspended particles, and providing a second heat resistant filter medium on the downstream side of the first heat resistant filter medium to collect the carbon-containing suspended particles passed through the heat resistant filter medium without being collected by the first filter medium, whereby the purification rate of the particles can be increased and, because most particles are filtrated by the first filter medium, the second filter medium can maintain a high purification rate over a long period of time.

Bypass air injection method and apparatus for gas turbines

Abstract: A bypass air injection scheme for a combustor of a gas turbine. Combustor includes a body with an inner liner and a casing enclosing the body with a passageway defined therebetween. A predetermined amount of the compressor discharge air passing through the passageway is extracted through a manifold. A conduit feeds the extracted air into an injection manifold having a plurality of injection tubes for injecting the extracted air into the combustor bypassing the reactor. The injection tubes and the injection manifold are disposed in a substantially common axial plane.

Exhaust gas purification apparatus and method

Abstract: An exhaust gas purification apparatus and method is applied to an internal combustion engine. The internal combustion engine generates an exhaust gas to be introduced to an exhaust system thereof. There is provided a reformer and controller. The reformer introduces a fuel and a part of the exhaust gas and generates a reformed gas including at least hydrogen and the controller is programmed to control a fuel supply amount of the fuel introduced to the reformer and an exhaust gas introduction amount of the exhaust gas introduced to the reformer in accordance with a demanded hydrogen amount of the reformer and operating conditions of the internal combustion engine. The exhaust gas is purified while controlling the fuel supply amount and the exhaust gas introduction amount.

Fuel control apparatus for an engine

Abstract: In the case that an engine is operated in a state where an in-cylinder air/fuel ratio is lean in a stratified combustion region and a fuel cut control is performed under a predetermined condition, when catalysts are in a low temperature state where a purification performance is deteriorated or when a NOx absorptive amount of the lean NOx catalyst, a control procedure for exhaust air/fuel state at a recovery timing from the fuel cut control so that a driving sensation is improved while maintaining the exhaust purification performance by the catalysts. When the fuel cut control is terminated and the engine shifts into the stratified combustion region, if a catalyst temperature is at or below a set temperature or a NOx absorptive amount is at or above a set amount, the in-cylinder air/fuel ratio of the engine is correctively enriched and the exhaust air/fuel state is enriched.

Control of a variable geometry turbocharger by sensing exhaust pressure

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).

Method of and apparatus for generating power

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.

Exhaust gas heat exchanger

Abstract: An exhaust gas heat exchanger comprising an external shell (20) extending between two tube plates (30, 31) and defining a coolant chamber; internal tubes (38) forming exhaust gas passages which extend between the tube plates (30, 31); an exhaust gas manifold divided by a baffle plate (29) into first and second chambers (26, 28) with an exhaust gas inlet (25) and outlet (27) respectively. The baffle plate (29) is provided with a valve (51) which can be operated between an open position, in which exhaust gas flows along the cooling tubes (38), and a closed position, in which exhaust gas is diverted directly from the first chamber (26) to the second chamber (28).

Exhaust purifying apparatus and method for internal combustion engine

Abstract: An exhaust purifying apparatus for an internal combustion engine includes a catalyst that purifies exhaust gas from the engine, a first passage that allows exhaust gas to flow from the engine to the catalyst, and a second passage that allows exhaust gas to flow from the engine to the catalyst. The first passage includes an accelerated cooling portion whose cross section is designed so that a relatively large quantity of heat is released from the exhaust gas in the first passage, and the second passage has a cross section designed so that a relatively small quantity of heat is released from the exhaust gas in the second passage. The apparatus further includes a flow amount controller that controls amounts of exhaust gas flowing through the first and second passages, such that the amount of exhaust gas flow through the first passage is made larger than that through the second passage when the temperature of exhaust gas emitted from the engine is to be lowered by a relatively large degree before reaching the catalyst, and such that the amount of exhaust gas flow through the second passage is made larger than that through the first passage when the temperature of exhaust gas emitted from the engine is to be lowered by a relatively small degree before reaching the catalyst.

Post injections during cold operation

Abstract: An exhaust gas heating system and method of a direct injection compression ignition internal combustion engine which has a plurality of combustion chambers, an exhaust passage, and one or more direct fuel injection devices, each operable to inject fuel directly into a corresponding one of the combustion chambers. The system also includes a fuel injection controller which is operable to provide to at least one of the direct fuel injection devices, a post fuel injection signal during a corresponding cylinder cycle of the corresponding one of the plurality of combustion chambers. The post fuel injection signal is timed so as to provide exhaust gas heating from a resultant post fuel injection, and the fuel injection controller dynamically determines the particular one or more of the plurality of direct fuel injection devices to which the post fuel injection signal will be applied based on a temperature related engine operating parameter such as a desired amount of exhaust gas heating. The post fuel injection may also be timed and/or shaped such that it does not produce a substantial amount of mechanical energy but instead produces heated exhaust gasses.

An internal-combustion engine provided with an exhaust gas recirculation system, in particular for a vehicle

Abstract: An internal-combustion engine, in particular for a vehicle, is provided with a plurality of cylinders and a cylinder head which defines, for each cylinder, at least one exhaust duct and at least one intake duct; the engine is further provided with an exhaust manifold communicating with the exhaust ducts, and a system for recirculating exhaust gas from the exhaust manifold to the intake ducts; the system comprises a further manifold which distributes the recirculated exhaust gases to the intake ducts and communicates with the exhaust manifold through a recirculation duct provided at least partly directly in the cylinder head which is provided with a heat exchanger for cooling the recirculated exhaust gases.

Joint-cycle high-efficiency fuel cell system with power generating turbine

Abstract: The efficiency of a combination reformer/fuel cell system is significantly improved by recapturing the energy value of heat generated in the fuel cell and producing additional power. The cooling water (40) from the fuel (44) cell is mixed, entirely or in part, with sufficient or excess compressed air, and at least partially evaporates in the compressed air. The air is at least sufficient to support the oxidative reactions in the fuel cell and also to serve as oxidant in a burner (10) that provides heat to reform fuel/steam mixtures into hydrogen-containing reformate. This air/steam mixture, after leaving the fuel cell (70), is further heated by heat exchange with the reformate stream and reformate-producing modules, and with the exhaust stream (50) of the burner (10). The steam/air mixture (12) is injected into the burner optionally after superheating in the burner exhaust, and is reacted with fuel (14) in the burner. The burner exhaust may be used to provide heat to a fuel reforming reaction. The high-temperature burner exhaust may also be used to drive an expander, preferably a turbine, at a location in the system which is downstream of the burner, but in which the exhaust is at a high temperature so as to run the turbine efficiently. The turbine recovers heat energy from the fuel cell as mechanical energy, typically in excess of the energy required to run a compressor, because of the addition of steam to the compressed air. Moreover, system heat removal elements, such as radiators, as well as overall system size and cost, can be markedly reduced for a given level of output.

Venturi bypass exhaust gas recirculation system

Abstract: An internal combustion engine is provided with a combustion air supply, an intake manifold, an exhaust manifold, and an exhaust gas recirculation system having a venturi assembly. The venturi assembly includes an outlet, a combustion air inlet connected and in communication with the combustion air supply, and an exhaust gas inlet connected and in communication with the exhaust manifold. A bypass fluid line and a bypass valve in the nature of a check valve are provided to bypass the venturi assembly. The check valve is responsive to changes in pressure drop across the venturi assembly, to open and close the bypass fluid line and limit the pressure drop across the venturi assembly.

High-Efficiency NOx and PM Exhaust Emission Control for Heavy-Duty On-Highway Diesel Engines

Abstract: A diesel exhaust emission control system consisting of catalyzed diesel particulate filters and NOx adsorber catalysts arranged in a dual-path configuration was developed and evaluated using a 1999-specification 5.9 liter medium-heavy-duty diesel engine. NOx adsorber regeneration was accomplished via a secondary exhaust fuel injection system. An alternating restriction of the exhaust flow between the two flow paths allowed injection and adsorber regeneration to occur under very low space velocity conditions. NOx and PM reductions in excess of 90% were observed over a broad range of steady-state operating conditions and over the hot-start HDDE-FTP transient cycle.

Device for purifying the exhaust gas of an internal combustion engine

Abstract: A device for purifying the exhaust gas of an internal combustion engine is disclosed The device comprises a particulate trap disposed in the engine exhaust system, an exhaust gas recirculation passage communicating the upstream of the particulate trap in the engine exhaust system with the engine intake system, a control valve for controlling the amount of exhaust gas recirculated through the exhaust gas recirculation passage to be an optimum amount in accordance with an engine operating condition In the device, an amount of the fresh air introduced into the engine intake system during a fuel-cut is detected, and an amount of particulate trapped by the particulate trap is estimated on the basis of the amount of fresh air detected after the control valve is opened to a predetermined opening degree

Effects of system parameters on the physical characteristics of bubbles produced through air sparging.

Abstract: Air sparging is a relatively new, cost-effective technology for the remediation of soil and groundwater contaminated with volatile organic compounds (VOCs). While the method has met with reasonable success at a large number of field sites, implementation of the technique is restricted to relatively coarse-grained soils with large values of air permeability, which significantly limits its applicability. An understanding of the fundamental parameters that control the formation and distribution of air in the sparging process is useful for optimizing the system implementation and extending its range of applicability. This work presents the results of an experimental investigation into the effect of process control parameters on the size and size distribution of air bubbles produced in aqueous and idealized saturated porous media systems. The experiments used digital image analysis to image and quantify the physical characteristics of the bubbles generated in a bench scale test cell. Results demonstrated that the average bubble size and range of size distribution increased as the injection pressure and size of the injection orifice were increased. Larger diameter bubbles with wider size distributions were produced in the presence of particles when compared to aqueous systems. As the particle size was decreased, the size of bubbles produced increased. Finally, the presence of trace quantities of the surfactant Triton X100 led to uniformly small diameter bubbles under all experimental conditions. The presence of the surfactant coating produced bubbles with physical characteristics that are more suited to in situ stripping of VOCs than the bubbles produced in the absence of a surfactant.

Method and device for the control of an exhaust treatment system

Abstract: A method and device for the control of an exhaust treatment system, in particular on an internal combustion engine are disclosed. A special operation is periodically carried out, whereby the control and/or monitoring of the special operation is carried out depending upon a first parameter (01), characterising the oxygen concentration in the exhaust gases before the exhaust treatment system and a second parameter (02), characterising the oxygen concentration in the exhaust gases after the exhaust treatment system.

Electronic flow control for a stratified EGR system

Abstract: A stratified exhaust gas re-circulation (EGR) engine uses an exhaust port per cylinder for exhausting exhaust gases and to re-circulate exhaust gas. The EGR valve may be phased from the exhaust stroke to the intake stroke. The EGR valves that control the exhaust gas re-circulation ports may be on a separate camshaft from the other valves. The EGR ports and an intake port for each of the cylinders may be helical or tangential ports that stratified the exhaust gas and the air in the cylinder. The engine may be a direct injection or a port fuel injection engine with one or more exhaust manifolds. The exhaust gas re-circulation ports may be controlled by a single flow valve or each port may have a separate flow valve. The intake ports may be controlled by a single flow valve or each intake port may have a separate flow valve.