Showing papers on "Secondary air injection published in 2005"

Control method for an exhaust gas purification system and an exhaust gas purification system

Abstract: An exhaust gas purification system (1) comprising a continuous regeneration-type DPF (13) and a DPF control means (30C) is composed to perform an exhaust gas temperature raising control by multi-injection in the case where the collecting quantity (ΔPm) exceeds a predetermined first temperature rising judgment collecting quantity (ΔP01) lower than a predetermined collecting quantity (ΔP1) and, thereafter, to stop the exhaust gas temperature raising control by multi-injection in the case where the collecting quantity (ΔPm) becomes lower than a predetermined second temperature rising judgment collecting quantity (ΔP02) lower than the predetermined first temperature rising judgment collecting quantity (ΔP01). Thereby, frequency of the manual regeneration switch operation can be reduced remarkably, and the operability for a driver can be improved, in the exhaust gas purification system (1) prompting the driver to stop the vehicle and perform the forced regeneration by the manual regeneration switch, in the case of detecting that the detected collecting quantity (ΔPm) is higher than the predetermined judgment collecting quantity (ΔP1), concerning the regeneration of the continuous regeneration-type diesel particulate filter device (13) .

Exhaust gas purification device of internal combustion engine

Abstract: A catalyst (22) suitable for reduction of the NOx in an exhaust gas by ammonia in the presence of excess oxygen is arranged in the exhaust passage (18, 21) of an internal combustion engine. An aqueous urea solution is fed through a flow control valve (33) to the inside of the exhaust passage (21) upstream of the catalyst (22). When the temperature of the catalyst (22) is low, a large amount of the aqueous urea solution is fed to make the urea contained in the aqueous urea solution be stored in the catalyst (22). When the engine is accelerated and the temperature of the catalyst (22) rises, ammonia is released at a little at a time from the inside of the catalyst (22) and the NOx in the exhaust gas is reduced by the released ammonia.

Achieving Lower Exhaust Emissions and Better Performance in an HSDI Diesel Engine with Multiple Injection

Abstract: The effects of multiple-injection on exhaust emissions and performance in a small HSDI (High Speed Direct Injection) Diesel engine were examined The causes for the improvement were investigated using both in-cylinder observation and three-dimensional numerical analysis methods It is possible to increase the maximum torque, which is limited by the exhaust smoke number, while decreasing the combustion noise under low speed and full load conditions by advancing the timing of the pilot injection Dividing this early-timed pilot injection into two with a small fuel amount is effective for further decreasing the noise while suppressing the increase in HC emission and fuel consumption This is realized by the reduced amount of adhered fuel to the cylinder wall At light loads, the amount of pilot injection fuel must be reduced, and the injection must be timed just prior to the main injection in order to suppress a possible increase in smoke and HC After-injection, which injects a small amount of fuel immediately after the end of the main injection, reduces smoke, HC and fuel consumption This is because the jet flame of the after-injection carries the remaining soot of the main injection to the squish area, and then oxidizes that together with the soot which previously existed in the squish area by promoted atmospheric temperature and enhanced mixing with fresh air

Exhaust gas purification system of internal combustion engine

Abstract: An electronic control unit of an internal combustion engine calculates a basic post-injection quantity of temperature increasing means if a deposition quantity of particulate matters deposited on a diesel particulate filter (DPF) exceeds a predetermined value. Then, a final post-injection quantity is calculated by correcting the basic post-injection quantity based on a temperature correction value, which is calculated by multiplying a deviation between DPF upstream exhaust gas temperature and target temperature and past temperature correction values by feedback gains. The feedback gains are switched in accordance with a delay in an exhaust gas temperature change in a present operating state, based on an intake air quantity sensed by an air flow meter. Thus, response can be improved, while maintaining stability.

Air Permeability of Waste in a Municipal Solid Waste Landfill

Abstract: The permeability of compacted municipal solid waste in a landfill with respect to air (or gas) flow was estimated using a short-term air injection test. Air was added to 134 vertical wells installed at three different depths at flow rates in the range of 0.14 –1.4 m3 min−1 and the corresponding steady state pressures were recorded. The permeability of the waste with respect to airflow (described here as the air permeability) was estimated for different anisotropy ratios ( kr ∕ kz =1 , 10, and 100) using a steady state, two-dimensional, axisymmetric analytical fluid flow model in conjunction with the measured flow and pressure data. The air permeability of landfilled municipal solid waste modeled as an isotropic medium was found to range from 1.6× 10−13 to 3.2× 10−11 m2 . The estimated air permeability results were on the low end of values previously applied to model landfill gas flow. Estimated air permeability decreased significantly with increasing waste depth. The lower permeability encountered in the ...

The Effects of High-Pressure Injection on a Compression–Ignition, Direct Injection of Natural Gas Engine

Abstract: This study investigated the effects of injection pressure on the performance and emissions of a pilot-ignited, late-cycle direct-injected natural gas fueled heavy-duty engine. The experiments, conducted on a single-cylinder engine, covered a wide range of engine speeds, loads, and exhaust gas recirculation fractions. The injection pressure was varied at each operating condition while all other parameters were held constant. At high loads, increasing the injection pressure substantially reduced particulate matter and CO emissions, with small increases in NOx and no significant effect on hydrocarbon emissions or fuel consumption. At low loads, injection pressure had no significant impact on either emissions or performance. At high loads, higher injection pressures consistently reduced both the number density and the size of particles in the exhaust stream. Injection pressure had reduced effects at increased engine speeds.

Injection controller for internal combustion engine

Abstract: An injection controller for an internal combustion engine that suppresses the accumulation of deposits on a nozzle hole of a direct injection valve. The injection controller (50) includes the direct injection valve (21), which injects fuel into a cylinder, and an intake passage injection valve (22), which injects fuel into an intake passage. An ECU (31), which is connected to the direct injection and intake passage injection valves, executes a first fuel injection mode for injecting fuel with the direct injection valve and a second fuel injection mode for injecting fuel with the intake passage injection valve. The ECU switches fuel injection modes from the second fuel injection mode to the first fuel injection mode for a predetermined period when fuel is to be injected in the second fuel injection mode.

Exhaust Gas Recirculation in Gas Turbines for Reduction of CO2 Emissions; Combustion Testing with Focus on Stability and Emissions

Abstract: Exhaust gas recirculation can be applied with the intention of reducing CO2 emissions. When a fraction of the exhaust gas is injected in the entry of a gas turbine, the amount of CO2 in the exhaust gas not being recirculated will be higher and less complicated to capture. However, with this change in combustion air composition, especially the reduced concentration of oxygen, the combustion process will be affected. The lower oxygen concentration decreases the stability and the increased amount of CO2, H2O and N2 will decrease the combustion temperature and thus, the NOx emissions. Testing has been performed on a 65 kW gas turbine combustor, to investigate the effect of adding N2, CO2 and O2 in the combustion process, with focus on stability and emissions of NOx. Results show that adding N2 and CO2 decreases the NOx emissions, whereas O2 addition increases the NOx emissions. The tests have been performed both in a diffusion flame (pilot burner) and a premixed flame (main burner), and for additives being injected with the fuel or with the air stream. Addition into the fuel stream is proven to affect the NOx emissions the most. The stability limits of the flames are indicated with respect to mass-based additive-to-fuel ratios.

Stability and emissions control using air injection and H2 addition in premixed combustion

Abstract: We experimentally study lean premixed combustion stabilized behind a backward-facing step. For a propane–air mixture, the lean blowout limit is associated with strong pressure fluctuation arising simultaneously with strong flame–vortex interactions, which have been shown to constitute the mechanism of heat release dynamics in this flow. A high-speed air jet, issuing from a small slot and injected perpendicular to the main flow near the step, is used to disrupt this mechanism. For momentum ratio of jet to main flow below unity, the jet dilutes the mixture, further destabilizing the flame or leading to complete blowout. Above unity, the flame becomes more stable, and the pressure oscillations are suppressed. Flow visualization and OH*/CH* chemiluminescence measurements show that a strong jet produces a more compact flame that is less driven by the wake vortex, anchored closer to the step, and deflected upwards away from the lower wall of the channel. This renders the flame less vulnerable to heat loss and strong strains, which improves its stability and extends the flammability limit. Adding hydrogen to the main fuel improves the flame stability over the entire range of the air jet mass flow, with better results for momentum ratio larger than 1; H 2 pulls the flame further upstream, away from the shear zone and the unsteady vortex. NO x emission benefits from the air jet, while, with H 2 addition, NO x concentration is higher in the products as the overall burning temperature rises. However, hydrogen addition enables extending the flammability limit further by increasing air supply in the primary stream, hence achieving lower NO x . The study suggests a simpler, almost passive, multi-objective combustion control technique and indicates that hydrogen addition can be a successful in situ approach for NO x reduction.

Investigations of the scaling criteria for a mild combustion burner

Abstract: In this paper, a new strategy for scaling burners based on "mild combustion" is evolved and adopted to scaling a burner from 3 to a 150 kW burner at a high heat release Late of 5 MW/m(3) Existing scaling methods (constant velocity, constant residence time, and Cole's procedure [Proc. Combust. Inst. 28 (2000) 1297]) are found to be inadequate for mild combustion burners. Constant velocity approach leads to reduced heat release rates at large sizes and constant residence time approach in unacceptable levels of pressure drop across the system. To achieve mild combustion at high heat release rates at all scales, a modified approach with high recirculation is adopted in the present studies. Major geometrical dimensions are scaled as D similar to Q(1/3) with an air injection velocity of similar to 100 m/s (Delta p similar to 600 mm water gauge). Using CFD support, the position of air injection holes is selected to enhance the recirculation rates. The precise role of secondary air is to increase the recirculation rates and burn LIP the residual CO in the downstream. Measurements of temperature and oxidizer concentrations inside 3 kW, 150 kW burner and a jet flame are used to distinguish the combustion process in these burners. The burner can be used for a wide range of fuels from LPG to producer gas as extremes. Up to 8 dB of noise level reduction is observed in comparison to the conventional combustion mode. Exhaust NO emissions below 26 and 3 ppm and temperatures 1710 and 1520 K were measured for LPG and producer gas when the burner is operated at stoichiometry. (c) 2004 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Method for controlling injection of reducing agent in exhaust gas from a combustion engine

Abstract: The invention relates to a method for controlling injection of a reductant into a NO x containing exhaust gas stream from a combustion engine, where combustion of a known fuel takes place and where the NO x is reduced by selective cata- lytic reduction, SCR, in the presence of a SCR catalyst, comprising establishing signals related to exhaust gas flow, NO x concentration in the exhaust gas stream upstream of the catalyst, exhaust gas temperature upstream of the SCR catalyst, exhaust gas temperature downstream of the SCR catalyst and to input data for catalyst characteristics. From the signals an adjusted amount of the reductant is calculated by using a calculated amount of reductant and a value d(E*T)/dt, where E is the exhaust gas flow, T is the exhaust gas temperature upstream of the catalyst and t is time.

Air-cooled exhaust gas heat exchanger, in particular exhaust gas cooler for motor vehicles

Abstract: The invention relates to an air-cooled exhaust gas heat exchanger, in particular exhaust gas cooler ( 1 ) for motor vehicles comprising channels (exhaust gas channels) which can be cross-flown by the exhaust gas of an internal combustion engine, between which ribs ( 4 ) for air cooling are arranged According to the invention, the exhaust gas channels are embodied as tubes, in particular as flat tubes ( 3 ), which form the ribs ( 4 ) of a rib tube block ( 2 ) and the tube ( 3 ) has tube ends ( 3 a ) which are received in the collecting vessels ( 5 ) for the exhaust gas

Exhaust system for an internal combustion engine and a respective operating method

Abstract: The present invention relates to an exhaust system for an internal combustion engine, in particular in a motor vehicle, with an exhaust line in which an oxidation catalyst is provided for treatment of the exhaust gases coming from the internal combustion engine. To be able to heat the oxidation catalyst more rapidly in a cold start of the internal combustion engine, a pre-oxidation unit may be provided in the exhaust line upstream from the oxidation catalyst and connected to a secondary fuel supply and adapted so that it partially oxidizes the secondary fuel supplied in combination with an oxidizer in a catalyst heating operation and the partially oxidized intermediate products are supplied to the oxidation catalyst for complete oxidation.

Intake oxygen estimator for internal combustion engine

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.

Control of exhaust to a turbo of internal combustion engine

Abstract: An internal combustion engine has a plurality of cylinders, and each cylinder has at least one first and one second exhaust port with associated respective first and second exhaust valves. At least one first and one second exhaust manifold are flow-connected to the respective first and second exhaust ports. A turbo unit for supercharging the charge air delivered to the cylinders comprises at least one first and one second exhaust gas turbine respectively flow connected to the first and the second exhaust manifolds. An exhaust gas chamber flow-connects the first and the second exhaust manifolds upstream of the exhaust gas turbines. The first and second exhaust valves can be deactivated/activated during operation. A throttle valve in the exhaust gas chamber may assume a closed position in order to separate the first and the second exhaust manifolds. A method of operating includes opening and closing different valves at different engine speeds.

Clean power system

Abstract: One aspect of the invention relates to a clean power generation system in which an internal combustion engine is operated to produce shaft power and an exhaust stream. The exhaust stream is processed by a fuel cell. Fluctuations in power demand are met, at least in part, by increasing or decreasing power output from the fuel cell and/or power uptake or output from a power storage device. The engine can operate at a relatively constant rate, providing a steady exhaust stream, which facilitates pollution control and fuel cell operation. According to another aspect of the invention, the exhaust of an engine is treated with a fuel cell having an electrolyte that conducts protons. In addition to removing pollutants from the exhaust while generating useful power, the fuel cell can provide a supply of low acidity water. The water can be used in the fuel reformer.

Engine shut-down for engine having adjustable valve timing

Abstract: A method for operating at least an intake and exhaust valve in a cylinder with a piston of an engine in a vehicle, comprising during conditions of an engine shut-down, maintaining at least one of the intake and exhaust valves in a closed position, and during conditions where said at least one valve is in said closed position operating with the other of the intake and exhaust valve open, then closing the other of the intake and exhaust valve, and then opening the other of the intake and exhaust valve to generate braking torque to slow the engine.

Engine and method of maintaining engine exhaust temperature

Abstract: In a method of maintaining temperature of engine exhaust gas from cylinders of a multi-cylinder engine (23) with a desired range, exhaust gas from a first group of cylinders (25) including at least one cylinder is routed to at least one of an EGR system (53) and an exhaust system (41). Exhaust gas from a second group of cylinders (27) including at least one of the cylinders is routed to the exhaust system (41). Routing of the exhaust gas from the first group of cylinders between the EGR system and the exhaust system is controlled to maintain a temperature of engine exhaust gas within a desired range. An engine (23), a control system (69), and a controller (71), as well as an exhaust gas mixture, are also disclosed.

Bypass for exhaust gas cooler

Abstract: An exhaust gas recirculation cooler (100, 300), typically of the drawn cup design, with a bypass (9, 301) and control valve (6, 342) is disclosed. The control valve (6, 342) can direct a proportion of the exhaust gas to the cooler (80) and a proportion to bypass the cooler depending on the input temperature of the exhaust gas and the required temperature of the exhaust gas. The proportion of the exhaust gas directed to the cooler (80)/bypassing the cooler (80) can be varied as required and so the temperature of the exhaust gas can be controlled. One benefit of certain embodiments of the invention is that engine damaging chemicals, such as sulphuric acid, which result from over-cooling the exhaust gas are reduced.

Method and system for treating exhaust gas, and method and apparatus for separating carbon dioxide

Abstract: A method for treating an exhaust gas, which comprises passing an exhaust gas discharged from a boiler using coal or LNG as a fuel through a cooling medium, to cool the exhaust gas to a first temperature at which carbon dioxide is not solidified and a nitrogen oxide or a sulfur oxide is liquefied or solidified, to thereby liquefy or solidify a nitrogen oxide or a sulfur oxide contained in the above exhaust gas as a harmful gas component and separate it from the exhaust gas and simultaneously remove the moisture contained in the exhaust gas, and then cool the resultant exhaust gas to a second temperature at which carbon dioxide is solidified, to thereby solidify the carbon dioxide contained in the exhaust gas and separate the carbon dioxide from the exhaust gas.

Fuel cell anode exhaust fuel recovery by adsorption

Abstract: A method of operating a fuel cell system includes providing a fuel inlet stream into a fuel cell stack, operating the fuel cell stack to generate electricity and a hydrogen containing fuel exhaust stream, separating at least a portion of hydrogen contained in the fuel exhaust stream using partial pressure swing adsorption, and providing the hydrogen separated from the fuel exhaust stream into the fuel inlet stream.

Device for introducing fuel into an exhaust gas line

Abstract: The device has a fuel injector (2) for injecting fuel under an injection pressure into an exhaust line (4) through a radial opening (5) in a pipe section. The injector is connected indirectly through an injector mount to a coolant circulation system (7) to transfer heat. An injector receptacle (10) passes radially through an injector mount and opens into the radial opening of the pipe section (3).

Regeneration controller for exhaust purification apparatus of internal combustion engine

Abstract: A regeneration controller that prevents overheating when performing burn-up heating for completely burning particulate matter by intermittent fuel addition to an exhaust system or intermittent increase of fuel addition to the exhaust system The regeneration controller includes first and second exhaust temperature sensors (44, 46), each detecting the exhaust temperature at a location downstream from the exhaust purification apparatus An ECU (70) determines the timing for stopping fuel addition to the exhaust system or increase of fuel addition to the exhaust system based on the elapsed time of fuel addition to the exhaust system or increase of fuel addition to the exhaust system

Vehicle exhaust systems

Abstract: A vehicle exhaust assembly (100) for improved evacuation of exhaust gases from an internal combustion engine. The system comprises a modular replacement exhaust system having a novel header pipe (102) and muffler (104). The present invention readily adapts to a range of vehicle applications including automobiles, motorcycles, and all terrain vehicles.

Real-time control of exhaust flow

Abstract: A flow control system for controlling exhaust flow can measure effluent escaping from the exhaust hood at a given flow rate. An interferometric detector can measure fluctuations in fluid properties external to and/or in the vicinity of the exhaust hood. The flow control system may vary a flow rate of the exhaust hood and/or control exhaust hood structures responsive to the measurements to contain the effluent while minimizing the exhaust of air from the occupied space.

Exhaust gas-driven generator system and method of controlling electrical system

Abstract: An amount of electric power generatable by an exhaust gas-driven rotating electric machine is determined corresponding to an operating point, so that an increment amount of fuel by the exhaust gas-driven electric power generation is smaller than engine-driven alternator power generation. The power generation can be thereby performed by effectively utilizing exhaust energy of the engine.

Supercharging system for internal combustion engine

Abstract: A supercharging system for an internal combustion engine includes an exhaust introduction passage for introducing exhaust gas from an internal combustion engine; an exhaust discharge passage for introducing the exhaust gas from the exhaust introduction passage and exhausting the exhaust gas to an exterior; a mixture part arranged between the exhaust introduction passage and the exhaust discharge passage, for changing internal pressure into negative pressure upon accelerating flowing velocity of the exhaust gas with a narrowed flowing passage set to have a smaller diameter than the exhaust introduction pipe; an absorption passage for mixing outside air and the exhaust gas inside the mixture part upon introducing the outside air with use of negative pressure into an inside of the mixture part; and an intake passage for taking out and returning a part of mixed gas mixed inside the mixture part to a side of the internal combustion engine.

System and method for reducing surge

Abstract: A method for controlling an engine having an intake manifold and an exhaust manifold, where an exhaust gas recirculation path with a valve is provided between said intake and exhaust manifold, and the engine has a turbocharger; the method comprising during at least one decreased engine output condition, increasing opening of the exhaust gas recirculation valve and adjusting exhaust expansion through a turbine of the turbocharger to decrease expansion through the turbocharger and thereby reduce a likelihood of turbocharger surge.