Showing papers on "Secondary air injection published in 2000"

Low emission, diesel-cycle engine

Abstract: A diesel-cycle engine (22) with a unique exhaust gas recirculation system includes a plurality of cylinders with fuel feed for each of the cylinders and an intake manifold (21) for distributing intake air to each of the cylinders for combustion of the fuel charges therein with generation of exhaust gas. The exhaust gas is discharged to ambient atmosphere through an exhaust line (15) with a gas turbine (27) therein. The gas turbine drives an intake compressor (19) which serves to compress the intake air. An engine controller controls a valve (14) regulating the amount of exhaust gas recirculation responsive to sensed concentration of an exhaust gas component.

Combustion engine having exhaust gas recirculation

Abstract: A combustion engine having an exhaust-gas-driven turbo compressor (6) is provided with a device (20) for recirculating exhaust gases to the engine, this device being connected to the exhaust system of the engine upstream of the turbo compressor (6) and being provided with a cooling device (17) for the recirculated exhaust gases The engine is provided with at least two exhaust valves (2, 3) per cylinder and has divided exhaust-gas flow, each cylinder being connected by a first exhaust valve (2) to a first exhaust collector (4), which leads to the turbine (7) in the turbo compressor, and each cylinder being connected by a second exhaust valve (3) to a second exhaust collector (5), which is connected to the exhaust system of the engine downstream of the turbine (7) The second exhaust collector (5) forms part of the device (20) for recirculating exhaust gases to the engine and is also connected to the inlet (12) of the engine

Process for removing nox and sox from exhaust gas

Abstract: Exhaust gases containing oxides of nitrogen and sulfur from a fired process heater, a fossil fuel fired boiler, or a chemical process are diverted from a stack prior to admission to the atmosphere through a duct system containing heat exchangers that reduce the exhaust gas from an elevated temperature, if any, to about ambient temperature. Any heat extracted from the exhaust gas may be transferred to the boiler feed water which would serve to reduce the energy cost of operating a boiler. Once the exhaust gas is cooled to about ambient temperature, the gas is then mixed with an oxidant, such as ozone, at a preselected molar ratio to transform the oxides to higher orders of nitrogen and sulfur oxides to increase the absorbability of the nitrogen and sulfur oxides in a reagent solution. The reagent absorbs the oxidized contaminants from the exhaust gas. The oxides are transformed to dilute acids which are then neutralized to form salts that are acceptable for discharge to a municipal waste water treatment plant. The treated exhaust gas is then emitted from an exhaust stack containing contaminants at a level meeting air quality standards. Additionally any heat recovered from the exhaust gas can be used to lower operating costs.

Film cooling downstream of a row of discrete holes with compound angle

Abstract: A special naphthalene sublimation technique is used to study the film cooling performance downstream of one row of holes of 35° inclination angle and 45° compound angle with 3 diameter hole spacing and relatively small hole length to diameter ratio (63) Both film cooling effectiveness and mass/heat transfer coefficients are determined for blowing rates from 05 to 20 with density ratio of unity The mass transfer coefficient is measured using pure air film injection, while the film cooling effectiveness is derived from comparison of mass transfer coefficients obtained following injection of naphthalene-vapor-saturated air with that of pure air injection This technique enables one to obtain detailed local information on film cooling performance General agreement is found in local film cooling effectiveness when compared with previous experiments The laterally-averaged effectiveness with compound angle injection is higher than that with inclined holes immediately downstream of injection at a blowing rate of 05 and is higher at all locations downstream of injection at larger blowing rates A large variation of mass transfer coefficients in the lateral direction is observed in the present study At low blowing rates of 05 and 10, the laterally-averaged mass transfer coefficient is close to that of injection without compound angle At the highest blowing rate used (20), the asymmetrical vortex motion under the jets increases the mass transfer coefficient drastically ten diameters downstream of injectionCopyright © 2000 by ASME

Method for controlling an exhaust gas temperature of an engine for improved performance of exhaust aftertreatment systems

Abstract: A method for regenerating a particulate filter communicating with exhaust gases of an internal combustion engine 12 is provided. The method includes indicating that the particulate filter 48 needs to be regenerated. The method further includes adjusting the throttle valve 18 to decrease an amount of air inducted into one of the engine cylinders to increase a temperature of the exhaust gases while maintaining an engine speed above a predetermined engine speed. The method further includes increasing the speed of the engine 12 and injecting a predetermined amount of fuel into one of said cylinders late in a power stroke of the cylinder to further increase the temperature of the exhaust gases to regenerate the filter 48.

Hydraulically powered exhaust gas recirculation system

Abstract: A hydraulically powered exhaust gas recirculation system for an internal combustion engine includes a hydraulically driven turbine ( 71 ) that powers a compressor ( 72 ). The compressor ( 72 ) pressurizes a portion of the exhaust gas from an internal combustion engine ( 10 ) and supplies it to a mixer ( 40 ). Another portion of the exhaust gas drives the turbine ( 21 ) of a turbocharger ( 20 ), which in turn powers a compressor ( 23 ) that delivers intake air to the mixer ( 40 ). The mixer ( 40 ) combines the air and the recirculated exhaust gas and delivers the mixture to the intake manifold ( 11 ) of the engine ( 10 ). The hydraulically powered turbine ( 71 ) may be driven by any of a number of systems, such as the power steering system of an automobile, high pressure oil from a diesel fuel injection system or an auxiliary hydraulic system. The flow of recirculated exhaust gas may be regulated in any number of manners, such as by controlling the pressure and displacement of the hydraulic pump ( 82 ) or by a valve ( 50 ).

Emissions diagnostic system

Abstract: An emissions diagnostic system (10) is used with a compression ignition engine having an exhaust gas stream (36) directed into an SCR catalyst (60) capable of reducing NOx in the exhaust gas stream (36). The system (10) comprises a tank (12) for storing a solution of urea, a pump (24) in fluid communication with the tank (12) for drawing the solution of urea from the tank (12), a valve 30 in fluid communication with the pump (24) and the exhaust gas stream (36) for receiving the solution of urea from the pump (24), an air pump (32) connected to the valve (30) for providing air into the valve (30) for mixing with the solution of urea, the valve (30) for spraying the solution of urea into the exhaust gas stream (36), a sensor (56) for sensing the level of NOx emissions emitted by the SCR catalyst (60), and a control module (42) connected to the sensor (56) for determining whether the level of NOx emissions is at an acceptable level.

Real-time exhaust gas modular flowmeter and emissions reporting system for mobile apparatus

Abstract: A real-time emissions reporting system includes an instrument module adapted to be detachably connected to the exhaust pipe of a combustion engine to provide for flow of exhaust gas therethrough. The instrument module includes a differential pressure probe which allows for determination of flow rate of the exhaust gas and a gas sampling tube for continuously feeding a sample of the exhaust gas to a gas analyzer or a mounting location for a non-sampling gas analyzer. In addition to the module, the emissions reporting system also includes an elastomeric boot for detachably connecting the module to the exhaust pipe of the combustion engine, a gas analyzer for receiving and analyzing gases sampled within the module and a computer for calculating pollutant mass flow rates based on concentrations detected by the gas analyzer and the detected flowrate of the exhaust gas. The system may also include a particulate matter detector with a second gas sampling tube feeding same mounted within the instrument module.

Reduction of exhaust smoke emissions following extended diesel engine idling

Abstract: A diesel engine equipped with an exhaust gas particulate filter includes a control system that reduces exhaust gas smoke emissions normally resulting from an extended period of engine idling. The control method periodically raises the exhaust gas temperature in order to purge the particulate filter of water and hydrocarbons that build up during extended engine idling and cause exhaust smoke. A timer records the elapsed period during which the engine remains at idle and the exhaust temperature is below a threshold level. When the recorded time period exceeds a preselected value, the filter is purged by elevating the exhaust gas temperature to a level sufficient to oxidize the gaseous hydrocarbons and evaporate any water that may have accumulated in the filter.

Exhaust gas recirculation system for a turbocharged engine

Abstract: Exhaust gas recirculation is provided in a turbocharged diesel engine by adding a separate EGR manifold and a secondary exhaust valve for each combustion chamber that permits passage of exhaust gas from the combustion chamber to the EGR manifold The secondary exhaust valve is opened during the expansion stroke of the engine cycle and sometime after the combustion process has been completed while the pressure in the combustion chamber is still greater than the pressure in the intake manifold One or two EGR valves can be opened to admit the high pressure exhaust gas from the EGR manifold into the intake manifold Decompression braking can be provided by an additional valve between the EGR manifold and the exhaust manifold that is opened to dump the gas from the EGR manifold to the exhaust manifold while the secondary exhaust valve in the cylinder head is opened at the beginning of the expansion stroke of the piston whereby the compressed air in the cylinder escapes before performing work on the piston

Turbocharger incorporating an integral pump for exhaust gas recirculation

Abstract: A turbocharger with an integral Exhaust Gas Recirculation system for an internal combustion engine having a compressor rotor with two sets of vanes on opposite sides of the rotor disk for compression of charge air and recirculated exhaust gas. The charge air and recirculated exhaust gas streams are segregated in the turbocharger and an inlet and an outlet volute for the recirculated exhaust gas is integral with the turbocharger center housing. A variable geometry turbine inlet is provided for exhaust backpressure and fuel air mixture control and an integral exhaust gas bypass for recirculating EGR is controlled by an integral valve mounted with the turbine housing.

Dual flow turbine housing for a turbocharger in a divided manifold exhaust system having E.G.R. flow

Abstract: An internal combustion engine, particularly suitable for a vehicle, is provided with a plurality of combustion cylinders, a first exhaust manifold, a second exhaust manifold and an intake manifold. Each exhaust manifold is coupled with a plurality of the combustion cylinders. An EGR system is disposed in fluid flow communication between the first exhaust manifold and the intake manifold. A turbocharger includes a compressor having an inlet receiving combustion gas and an outlet in fluid flow communication with the intake manifold. A turbine is drivingly coupled to the compressor, and has a turbine casing and a turbine wheel. The turbine casing defines separate first and second inlet paths for exhaust gas flow from the first and second exhaust manifolds. Efficiency and performance are improved by preserving pulse energy in one exhaust manifold flow, and increasing back pressure in the manifold providing EGR flow.

Electricity generation from air conditioning exhaust

Abstract: An electricity generator powered by air conditioner exhaust having a wind turbine and a bracket to hold the wind turbine in a relatively fixed position, to an air conditioner exhaust. The wind turbine has a propeller with two or more blades, a shaft and a generator. The bracket holds the wind turbine so the blades are turned by exhaust air from the air conditioner. The bracket can be a shroud. The invention includes the method of generating electricity from air conditioning exhaust by holding a wind turbine in a relatively fixed proximity to an air conditioning exhaust port.

In Situ Treatment Technology

Abstract: LIMITATIONS OF PUMP-AND-TREAT REMEDIATION METHODS, E.K. Nyer Water as a Carrier The Contamination Plume Plume Movement Advection Dispersion Retardation Chemical Precipitation and Biotransformation Non-Aqueous Phase Liquids - NAPL Pump and Treat Air as the Carrier Limitations Conclusion LIFE CYCLE DESIGN, E.K. Nyer Life Cycle Design for Pump and Treat Systems Concentration Changes with Time Capital Costs Operator Expenses Using Life Cycle Design to Describe the End of the Project What is Clean? Retardation vs. Biochemical Activity Active Management Life Cycle Design for in Situ Treatment Methods Determining the Time Required to Complete a Life Cycle in Groundwater Remediation IN SITU BIOREMEDIATION, E.K. Nyer, T.L. Crossman, and G. Boettcher Introduction Biochemical Reactions Microorganisms Distribution and Occurrence of Microorganisms in the Environment Soil Ground Water Biochemical Reactions of Microorganisms Inorganic Nutrients Environmental Factors Microbial Biodegradation of Xenobiotic Organic Compounds Gratuitous Biodegradation Cometabolism Microbial Communities Halogenated Hydrocarbons Degradation Rate In Situ Bioremediation Biogeochemical Characterization Modeling Support for Intrinsic Bioattenuation Risk/Biomodeling Approach Case Histories of Intrinsic Bioattenuation Enhanced Bioremediation Existing Reactions Change of Environment Delivery of Required Enhancements Summary VAPOR EXTRACTION AND BIOVENTING, S. Fam Introduction Contaminant Partitioning in the Subsurface Air Flow Requirements and Capabilities Air Flow Capability Air Flow Requirements Evaluation of Conditions Where VES is Applicable Contaminant Properties Vapor Pressure Solubility Henry's Law Other Molecular Properties Summary Properties of the Soil Bulk Density/Soil Porosity Soil Adsorption Soil Moisture Site Surface Topography Depth to Water Table Site Homogeneity Modeling Tools for Vapor Extraction System Design Engineering Design Model Flow Models Multiphase Transport Models Pilot Studies Laboratory Studies Field Pilot Studies Vapor Extraction Testing Well Vapor Extraction Monitoring Well System Design Bioventing Introduction Advantages of Vapor Phase Biotreatment Performance Criteria/Bioventing Plan Protocols Laboratory Testing Field Respirometry Testing Soil Gas Permeability Testing Bioventing System Configurations Clean Up Goals and Costs Case Study VACUUM-ENHANCED RECOVERY, P.L. Palmer Introduction Mass Balance Approach to Site Remediation Groundwater Recovery Enhancement Applicability Enhanced Effectiveness - LNAPLs Enhanced Effectiveness - Dissolved Phase Enhanced Effectiveness - Air Phase Types of Systems Preliminary Evaluation of Applicability Pilot Test Procedures Test and Monitoring Wells Test Method Monitoring Mass Removal Estimation System Design Well Design Well Spacing Fluid Flow Rate Vacuum Pressure Air Flow Rate Off-Gas Treatment Equipment Selection Mass Removal and Reaching Cleanup Goals Enhanced Effectiveness - LNAPLs Enhanced Effectiveness - Dissolved Phase Enhanced Effectiveness - Dewatering IN SITU AIR SPARGING, S.S. Suthersan Introduction Governing Phenomena In Situ Air Stripping Direct Volatilization Biodegradation Applicability Examples of Contaminant Applicability Geological Considerations Description of the Process Air Injection into Water-Saturated Soils Mounding of Water Table Distribution of Air Flow Pathways System Design Parameters Air Distribution (Zone of Influence) Depth of Air Injection Air Injection Pressure and Flow Rate Injection Mode (Pulsing) Injection Wells Contaminant Type and Distribution Pilot Testing Limitations Modifications to Conventional Air Sparging Application Horizontal Trench Sparging In Well Air Sparging Biosparging Clean-Up Rates AIR TREATMENT FOR IN SITU TECHNOLOGIES, S. Sam Introduction Design Criteria Regulatory Requirements Mass of Contaminants Life Cycle Emission Concentration Citing and Utility Considerations Treatment Technologies Adsorption-Based Treatment Technologies Oxidation-Based Technologies Biological Technologies Technology Selection Summary FRACTURING, D.F. Kidd Introduction Applicability Geologic Conditions Technology Description Hydraulic Fracturing Pneumatic Fracturing Screening Tools Geologic Characterization Geotechnical Evaluations Pilot Testing Proppants Full-Scale Design Case Histories Pneumatic Fracturing Air Phase Effectiveness - Hydraulic Fracturing Air Phase REACTIVE WALLS, P.L. Palmer Introduction General Reactive Wall Designs Installation Methodologies Types of in Situ Reactors Transformation Processes Physical Removal Modify pH or Eh Conditions Precipitation of Metals Contaminant Removal via Sorption or Ion Exchange Biological Degradation Design Considerations Case Study: Reactive Wall Design Background Funnel and Gate Modeling Study Gradient Control Underflow of Barrier Gate Design MISCELLANEOUS IN SITU TREATMENT TECHNOLOGIES, F.J. Johns, II and E.K. Nyer Introduction Contaminant Removal Technologies Steam Flushing Hot Air Flushing Resistance Heating Radio Frequency Heating Chemically-Enhanced Flushing Electrochemical Remediation In-Well Air Stripping Phytoremediation Contaminant Fixation Technologies Stabilization and Solidification Vitrification In Situ Biochemical Precipitation Index

Exhaust gas purification device used for post-treating IC engine exhaust gases comprises post-treatment unit, unit for introducing auxiliary agent into post-treatment unit, and unit for mixing exhaust gas with agent

Abstract: An exhaust gas purification device comprises a post-treatment unit (50); a unit (45) for introducing an auxiliary agent into the post-treatment unit; and a unit (30) for mixing the exhaust gas with the agent. Preferred Features: The mixing unit contains a screen suitable for producing inhomogeneities in the exhaust gas stream. The screen has a deviating blade through which the exhaust gas flows and by which the gas can be deviated from its flow direction. The blade is arranged to rotate about a conical central region. The post-treatment unit contains a catalyst for the selective catalytic reduction of nitrogen oxides in the exhaust gas. The auxiliary agent is a reductant made from a urea-water solution.

Air injection into light and medium heavy oil reservoirs : combustion tube studies on west of Shetlands Clair oil and light Australian oil

Abstract: Four combustion tube tests were performed at a high initial water saturation using Bath University's High Pressure Combustion Tube Facility. Two tests were conducted on Clair medium heavy oil (19.8°API) at 75 and 100 bar pressure, with initial oil saturations of 48% and 60%, at 80°C initial bed temperature. Maximum combustion temperatures exceeded 600°C during the early period, settling down to around 400°C. The combusted zone extended over about 30% of the sandpack length. Oil recovery was mainly affected by the large steam flood generated ahead of the combustion front, due to in situ vapourization of the original water in place, reducing the oil residual down to 21%. The thermal cracking reactions taking place ahead of combustion front converted part of the residual oil to lighter components, which were displaced with the gas flow, at the same time producing about 10% coke (fuel) for the combustion process. Two tests were carried out on a light Australian oil (38.8°API), starting at low initial oil residuals of So = 41 and 45%, at an operating pressure of 70 bar and initial bed temperature of 63°C. The combustion temperature was about 250°C in both tests. The axial temperature profile in the sand pack was similar to that normally associated with a moving combustion front, but at a relatively low temperature. Also, there was no steam plateau condition, which was very observable in the Clair oil tests. High combustion front velocities were achieved in all four tests, varying from 0.15 to 0.31m h–1. Fuel consumption, air requirement and oxygen utilization were generally favourable as regards improved oil recovery.

Influence of Porous Media, Airflow Rate, and Air Channel Spacing on Benzene NAPL Removal during Air Sparging

Abstract: To study the effects of porous media type, airflow rate, and air channel spacing on NAPL removal, air sparging of a benzene NAPL was performed in a lab-scale reactor with two isolated vertical air channels on either side of the NAPL. Experimental conditions included three discrete air channel distances, three types of saturated porous media, and five airflow rates. Benzene NAPL removal efficiency was shown to increase from 7.5% to 16.2% with increasing porous media mean particle size over the 168 h of operation. Initial change in the airflow rate had an effect on contaminant removal rate, but further change in the airflow rate had little effect. Benzene NAPL removal efficiency was shown to decrease with increasing channel spacing, but the mere presence of air channels was shown to suppress lateral contaminant migration. Benzene removal efficiency was shown to be highly correlated with the mean particle diameter, the square root of the uniformity coefficient, and the inverse of the square of the distance between the NAPL and the air channel.

Exhaust gas purifier and method of purifying exhaust gas for a hybrid vehicle

Abstract: A hybrid vehicle driven using power from an internal combustion engine and power from an auxiliary power source, includes an exhaust gas purification catalyst disposed in an exhaust passage of the engine. The catalyst stores oxygen and a power controller causes the engine to discharge exhaust gas including excess oxygen and causes the auxiliary power source to assist the engine in driving the vehicle when oxygen is to be stored in the exhaust gas purification catalyst. It is possible to supply the catalyst with exhaust gas containing excess oxygen while inhibiting the driveability from being adversely affected.

Urea injection system treating exhaust gases from lean burn engine, comprises air-cooling jacket surrounding injector valve to keep it cool, so that a petrol injection valve may be used

Abstract: The dosing unit has an injection valve (14). This has a double-walled valve casing (17) connected to an air compressor (19) for cooling. It blows into the gap (144) between outer- (173) and inner- (172) walls of the casing, cooling at least that section close to the exhaust pipe. An Independent claim is included for the corresponding method of secondary treatment for exhaust gases. Preferred Features: Mounting design in the double-walled casing brings the injection valve outlet close to the passage into the exhaust system. The mounting is funnel-shaped so that the tip of the injector valve (143) is surrounded by an air gap (144). The outer wall of the valve mounting casing is fixed to the wall (41) of the exhaust pipe. The valve axis is normal to the exhaust pipe wall, or is at an acute angle. The mounting is metallic, ceramic or temperature-resistant plastic. The air compressor is an electrically-controlled pump (19), or is driven mechanically from the engine. An air reservoir (20) and non-return valve (21) is included in the air line.

Exhaust and intake rocker arm assemblies for modifying valve lift and timing during positive power

Abstract: The present invention is directed to an apparatus for operating at least one intake valve and at least one exhaust valve in an engine cylinder. The apparatus includes an exhaust valve operating assembly (510) for operating the at least one exhaust valve of the engine cylinder, wherein the exhaust valve operating assembly is capable of producing an exhaust gas recirculation event. The apparatus also includes an intake valve operating assembly (520) for operating the at least one intake valve of the engine cylinder. The apparatus further includes an exhaust modifying assembly for modifying the operation of the exhaust valve operating assembly during a predetermined engine operating condition and an intake modifying assembly for modifying the operation of the intake valve operating assembly during a predetermined engine operating condition.

Removal of dissolved- and free-phase benzene pools from ground water using in situ air sparging

Abstract: This paper presents the results of a laboratory investigation performed to study the use of air sparging to remediate dissolved-phase and free-phase [or non-aqueous-phase liquid (NAPL)-phase] benzene pools from ground water. The specific objectives of the study were (1) to assess how air injection rate affects the mass transfer and transport of dissolved- and NAPL-phase pools; and (2) to determine the effect of ground-water flow on the removal of dissolved- and NAPL-phase pools during the application of air sparging. A total of five 2D physical model tests were performed in a homogeneous coarse sand profile subjected to both static ground water and ground-water flow conditions. Three different air injection rates were used in a static ground-water condition, and two different air flow rates were used in soil profiles subjected to ground-water flow (hydraulic gradient = 0.011). All tests were performed with similar initial dissolved- and NAPL-phase benzene conditions. Injected air traveled within a parabol...

Exhaust emission control system for the exhaust gas of a diesel engine

Abstract: An injection device for a reducing agent, a mixing device and a catalyst device are provided in an exhaust pipe. The mixing device is disposed upstream of the injection device as seen in the direction of flow of the exhaust gas. An exhaust gas inlet pipe is connected to the exhaust pipe along the main axis of the exhaust pipe. A first level of the catalyst device may advantageously be a hydrolysis-catalyst module, while the other levels may be SCR catalyst modules.

Combustion and emissions in a methane di stratified charge engine with hydrogen pre-mixing.

Abstract: Characteristics of combustion and emissions in a methane direct injection stratified charge engine premixed with hydrogen lean mixture were analyzed. Results showed the combustion system achieved a higher thermal efficiency due to higher flame propagation velocity and lower exhaust emissions. An increase in the amount of premixed hydrogen stabilizes the combustion to reduce HC and CO exhaust emission, and increases the degree of constant volume combustion and NOx exhaust emission. The increase in NOx emission can be maintained at a lower level with retarded ignition timing without deteriorating the improved thermal efficiency.

Direct Injection Systems for Spark-Ignition and Compression-Ignition Engines

Abstract: The topics covered in this book include direct ignition systems for spark ignition engines (direct injection as an element of the mixture formation concept, the physical possibilities of direct injection methods, the Mitsubishi method, the Common Rail method, the ZWICKAU Pressure Pulse system, the IFP method and the Orbital method) and direct injection systems for compression ignition engines (injection rate modulation, injection systems with speed dependent injection rate, injection systems with accumulated fuel high-pressure (Common Rail), injection systems with speed dependent pressure wave and variable flow passage, injection systems with speed dependent modulation of the pressure wave - the diesel pressure pulse system, and injection systems for alternative fuels (liquid gases)).

Compression self-ignition type gasoline engine

Abstract: PROBLEM TO BE SOLVED: To provide a compressed self-ignition type gasoline engine wherein the discharge of unburnt fuel is reduce din the case of compressed self-ignition and combustion and its fuel efficiency is improved. SOLUTION: A tumble control valve 14 is disposed at the front eng part of a partition plate 18 partitioning the inside of an intake port 5 into upper and lower parts. In the case of compressed ignition and combustion, an upper intake passage is closed by the valve 14 for the purpose of causing reverse tumble flow within combustion chamber and densely distributing the fuel injected from a fuel injection valve 19 on the exhaust side of the inside of a cylinder, and open/close timing-variable means 16, 17 are controlled in order to get the timing of intake/exhaust valves 6, 8 into a minus-overlapped condition and internal ERG(exhaust gas recirculation) gas is distributed on the exhaust side of the inside of the cylinder for the temperature on the exhaust side of the inside of the cylinder to be higher than that on the intake side thereof in temperature distribution. Accordingly, compressed ignition is caused on the exhaust side and the exhaust valve 8 is closed in the process of an exhaust stroke. Consequently, the unburnt fuel on the intake side is carried over with the EGR gas to the next cycle. COPYRIGHT: (C)2001,JPO

Numerical and Experimental Study of Large Steam-Air Bubbles Injected in a Water Pool

Abstract: In certain passive, future boiling water reactor concepts, during emergency cooling conditions, mixtures of steam and nitrogen are blown into a pool of water via a downward-facing open pipe; at its end, large gas bubbles form, break up, and rise in the water. We have developed a computer simulation program for the hydrodynamics of the process using an isothermal piecewise linear interface construction-volume of fluid method and carried out an experiment with flow rates up to 50 l/s into a tank of 1 m3 volume. Bubble frequencies and volumes can be predicted fairly well for the case of air injection. The experiments show that most of the condensation takes place before the bubble detaches from the pipe exit. The phenomena depend mainly on the volumetric flow rate of the gas and on a parameter measuring the shrinkage due to condensation. The rates of condensation were estimated to be very high.

Exhaust temperature raising apparatus and method for internal combustion engine

Abstract: An exhaust temperature raising apparatus has an exhaust throttle valve that adjusts the engine exhaust amount based on the amount of throttling, and an injector that performs main injection and a sub-injection directly into a cylinder, a combination of an ECU, the injection and the exhaust throttle valve as exhaust gas temperature increase apparatus for, during an engine warm-up, performing and controlling the exhaust throttling by the exhaust valve and performing and controlling an exhaust gas temperature increase through combustion attributed to the main injection performed in an excess-air condition and combustion attributed to the sub-injection, an exhaust gas temperature sensor that monitors a state of temperature increase of the exhaust gas caused by performance of the exhaust gas temperature increase apparatus, and the ECU as monitor abnormality detection apparatus for determining whether the exhaust gas temperature sensor has an abnormality, and the ECU as exhaust gas temperature increase stop apparatus for stopping the operation of the exhaust gas temperature increase apparatus when the ECU determines that the exhaust gas temperature sensor has an abnormality.

Flow and Heat Transfer at the Hub Endwall of Inlet Vane Passages — Experiments and Simulations

Abstract: The heat transfer distribution on the hub endwall of a model turbine vane passage was studied experimentally and by numerical simulation. The experiments were carried out in a low speed wind tunnel featuring a linear cascade of scaled-up inlet vanes. Measurements were made both without and with secondary air injection through slots located upstream of the vane leading edge using the transient liquid crystal technique. Results are presented for ReCax, in = 6.76 × 104 and blowing ratios of zero (no secondary air injection) and 1.3. Simulations were performed on unstructured grids using Fluent. A near-wall description of the flow field was employed. Turbulent stresses in the momentum equations were closed using the Spalart-Almaras model, and the turbulent heat flux in the thermal energy equation was closed using a constant turbulent Prandtl number. The agreement between the measurements and the simulations is generally good.Copyright © 2000 by ASME