Energy Efficiency Improvement of Diesel Aftertreatment With Flow Reversal and Central Fuelling

2007 ◽  
Author(s):  
Ming Zheng ◽  
Siddhartha Banerjee ◽  
Xiaohong Xu ◽  
Usman Asad ◽  
Xiaoye Han ◽  
...  
Keyword(s):  
Gas Flow ◽  
Flow Reversal ◽  
Regeneration Rate ◽  
Exhaust Temperature ◽  
Energy Efficiency Improvement ◽  
Unidirectional Flow ◽  
Central Heating ◽  
Fuel Delivery ◽  
Delivery Technique ◽  
Substrate Properties

Empirical and theoretical studies are made between the inlet and central heating schemes in a flow reversal embedment of diesel aftertreatment converters in order to investigate the influences of gas flow, heat transfer, chemical reaction, oxygen concentration, and substrate properties. The periodic flow reversal converter is found effective to treat engine exhausts that are difficult to cope with conventional unidirectional flow converters. However, the previous work indicates that the exhaust temperature from modern diesel engines is commonly insufficient to sustain a high conversion or regeneration rate and thus supplemental heating techniques are commonly applied. A technique of fuelling at the central region of a flow-reversal embedment is found more energy-efficient to raise the temperature of the catalytic flow-bed and therefore to drastically reduce the supplemental heating to the substrate. An effective fuel delivery technique has been tested to improve the fuel dispersion of the central fuel delivery strategy at various engine-out exhaust temperatures, compositions, and flow rates.

Rapid Non-Intrusive Gas Turbine Exhaust Temperature Measurement

2000 ◽  
Author(s):  
Michael. A. Welch ◽  
Moira Hilton ◽  
Chris W. Wilson
Keyword(s):  
Gas Turbine ◽  
Infrared Radiation ◽  
Gas Flow ◽  
Beam Steering ◽  
Black Body ◽  
Exhaust Temperature ◽  
Steering Mechanism ◽  
Ftir Spectrometer ◽  
Gas Turbine Exhaust ◽  
Analysis System

An integrated data collection and rapid analysis system was developed which produces temperature maps of gas turbine efflux using Fourier Transform Infrared (FTIR) spectroscopy. The system is purely passive, collecting the infrared radiation from the hot plume gases and requiring no contact with the plume or additional source of infrared radiation. A remotely controlled infrared beam steering mechanism traverses in 2 dimensions, parallel to the direction of exhaust gas flow, positioning the line of sight of a FTIR spectrometer across the plume. Project-specific software integrates the collection of infrared spectra by the FTIR spectrometer (interfacing with the commercial spectrometer software) and analysis of the data utilising a single PC. The plume gas temperatures are calculated by comparison of specific CO2 bands with the radiance of a black body source.

The Numerical Simulation Research on Thermal Flow-Reversal Reactor of Mine Ventilation Gas

2014 ◽  
Vol 926-930 ◽  
pp. 1627-1631
Author(s):  
Wei Feng Zou ◽  
Bo Lan
Keyword(s):  
Numerical Simulation ◽  
Gas Flow ◽  
Single Channel ◽  
Volume Fraction ◽  
Mine Ventilation ◽  
Optimal Operation ◽  
Flow Reversal ◽  
Thermal Flow ◽  
Reactor Performance ◽  
Operation Condition

The paper uses computational fluid dynamics software FLUENT to build a single-channel numerical simulation model of the mine ventilation gas Thermal Flow-Reversal Reactor (TFRR). Combining with the analysis of orthogonal test, the influences that four factors (Initial temperature distribution, Ventilation gas flow velocity, Volume fraction of methane, Exchange period) act on reactor performance is investigated. An optimal operation condition is proposed by the establishment of the priority sequence of these four factors.

EFFECT OF GAS FLOW REVERSAL THROUGH ANESTHESIA VAPORIZERS

1994 ◽  
Vol 81 (SUPPLEMENT) ◽  
pp. A576
Author(s):  
J. B. Eisenkraft ◽  
M. Abel
Keyword(s):  
Gas Flow ◽  
Flow Reversal

scholarly journals Research into properties of dust from domestic central heating boiler fired with coal and solid biofuels

2017 ◽  
Vol 43 (2) ◽  
pp. 20-27 ◽  
Author(s):  
Jan Konieczyński ◽  
Bogusław Komosiński ◽  
Ewelina Cieślik ◽  
Tomasz Konieczny ◽  
Barbara Mathews ◽  
...  
Keyword(s):  
Flue Gas ◽  
Bituminous Coal ◽  
Barley Grain ◽  
Flue Gases ◽  
Tree Bark ◽  
Central Heating ◽  
Fuel Delivery ◽  
Solid Biofuels ◽  
Coniferous Wood ◽  
Heating Boiler

Abstract The aim of this research was to assess the content and composition of the pollutants emitted by domestic central heating boilers equipped with an automatic underfeed fuel delivery system for the combustion chamber. The comparative research was conducted. It concerned fuel properties, flue gas parameters, contents of dust (fl y ash) and gaseous substances polluting the air in the flue gases emitted from a domestic CH boiler burning bituminous coal, pellets from coniferous wood, cereal straw, miscanthus, and sunflower husks, coniferous tree bark, and oats and barley grain. The emission factors for dust and gaseous air pollutants were established as they are helpful to assess the contribution of such boilers in the atmospheric air pollution. When assessing the researched boiler, it was found out that despite the development in design and construction, flue gases contained fly ash with a significant EC content, which affected the air quality.

Numerical Simulation of Thermodynamic Parameters during Diffusion Combustion for Vehicle Air Heater

2011 ◽  
Vol 80-81 ◽  
pp. 783-787
Author(s):  
Pei Yong Ni ◽  
Xiang Li Wang ◽  
Sheng Li Wei
Keyword(s):  
Heat Flux ◽  
Turbulence Intensity ◽  
Gas Flow ◽  
Diffusion Combustion ◽  
Operation Condition ◽  
Radial Temperature ◽  
Air Heater ◽  
Exhaust Temperature ◽  
Excess Air ◽  
Excess Air Coefficient

The diffusion combustion of the air heater was numerically simulated at different excess air coefficient using Fluent software. The distributions of the temperature, gas flow velocity, and turbulence intensity were present. And the heat flux was calculated. The result showed that the excess air coefficient had a little effect on the maximum combustion temperature distribution. As the excess air coefficient increased, the axial temperature at first increased and then decreased, and in contrast both the total heat flux and radiation heat flux decreased. The radial temperature, velocity and turbulence intensity increased firstly and then decreased at the same operation condition. The measured exhaust temperature increased with time. At 90 second, it was about 250 °C, which showed good agreement with simulation result. This provides theory basis for the reform of the heater.

scholarly journals Generalized Predictive Controller Design for Compressed Air Distribution

2019 ◽  
Vol 8 (9) ◽  
pp. 18-22
Keyword(s):  
Distribution System ◽  
Associate Degree ◽  
Gas Flow ◽  
Controller Design ◽  
Compressed Air ◽  
Air Distribution ◽  
Unidirectional Flow ◽  
Electrical Analogy ◽  
Area Unit ◽  
World Organization

Compressed air distribution system is a major source of industrial power as it is safe, reduces cost of labour and easily transmitted. A well designed system should transport compressed air from the point of production to the point of application. However certain factors like type of compressor, air quality, layout and flow rate are major attributes to a well-designed system. Air ducts area unit the foremost vital elements of such reasonably systems, they outline the most important dynamic characteristics. The unidirectional flow is sometimes assumed once modelling the gas flow through associate degree duct. The work utilization of the electrical analogy methodology by change of integrity opposition with the hypothetically determined models of capacitance and inductance that prompts loads of first-request customary differential conditions for transient investigation of equal gas streams in pipeline network. Understanding the projected order standard equation is actually loads a lot of simple than world organization ravelling the arrangement of incomplete differential conditions. The process focal points of this strategy are shown by different them and therefore the ancient techniques once connected to a scope of pipe network simulation.

scholarly journals Observation of Axial Neutral-Gas Flow Reversal in an ECR Plasma

2019 ◽  
Vol 14 (0) ◽  
pp. 1201066-1201066
Author(s):  
Emika ABE ◽  
Kenichiro TERASAKA ◽  
Shinji YOSHIMURA ◽  
Mitsutoshi ARAMAKI ◽  
Masayoshi Y. TANAKA
Keyword(s):  
Gas Flow ◽  
Flow Reversal ◽  
Ecr Plasma ◽  
Neutral Gas

Solar Internal Rotation and Dynamo Waves: A Two-Dimensional Asymptotic Solution in the Convection Zone

2000 ◽  
Vol 179 ◽  
pp. 379-380
Author(s):  
Gaetano Belvedere ◽  
Kirill Kuzanyan ◽  
Dmitry Sokoloff
Keyword(s):  
Magnetic Field ◽  
Asymptotic Solution ◽  
Internal Rotation ◽  
Convection Zone ◽  
General Idea ◽  
Dynamo Model ◽  
Axially Symmetric ◽  
Dynamo Action ◽  
Regeneration Rate ◽  
Dynamo Waves

Extended abstractHere we outline how asymptotic models may contribute to the investigation of mean field dynamos applied to the solar convective zone. We calculate here a spatial 2-D structure of the mean magnetic field, adopting real profiles of the solar internal rotation (the Ω-effect) and an extended prescription of the turbulent α-effect. In our model assumptions we do not prescribe any meridional flow that might seriously affect the resulting generated magnetic fields. We do not assume apriori any region or layer as a preferred site for the dynamo action (such as the overshoot zone), but the location of the α- and Ω-effects results in the propagation of dynamo waves deep in the convection zone. We consider an axially symmetric magnetic field dynamo model in a differentially rotating spherical shell. The main assumption, when using asymptotic WKB methods, is that the absolute value of the dynamo number (regeneration rate) |D| is large, i.e., the spatial scale of the solution is small. Following the general idea of an asymptotic solution for dynamo waves (e.g., Kuzanyan & Sokoloff 1995), we search for a solution in the form of a power series with respect to the small parameter |D|–1/3(short wavelength scale). This solution is of the order of magnitude of exp(i|D|1/3S), where S is a scalar function of position.

TEM evaluation of graded SixGe1-x heterolayers

1991 ◽  
Vol 49 ◽  
pp. 894-895
Author(s):  
N. David Theodore ◽  
Mamoru Tomozane ◽  
Ming Liaw
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Gas Flow ◽  
Field Effect Transistors ◽  
Chemical Vapor ◽  
Dark Field ◽  
Bipolar Transistors ◽  
Structural Quality ◽  
Weak Beam ◽  
Transmission Electron ◽  
And Behavior

There is extensive interest in SiGe for use in heterojunction bipolar transistors. SiGe/Si superlattices are also of interest because of their potential for use in infrared detectors and field-effect transistors. The processing required for these materials is quite compatible with existing silicon technology. However, before SiGe can be used extensively for devices, there is a need to understand and then control the origin and behavior of defects in the materials. The present study was aimed at investigating the structural quality of, and the behavior of defects in, graded SiGe layers grown by chemical vapor deposition (CVD).The structures investigated in this study consisted of Si1-xGex[x=0.16]/Si1-xGex[x= 0.14, 0.13, 0.12, 0.10, 0.09, 0.07, 0.05, 0.04, 0.005, 0]/epi-Si/substrate heterolayers grown by CVD. The Si1-xGex layers were isochronally grown [t = 0.4 minutes per layer], with gas-flow rates being adjusted to control composition. Cross-section TEM specimens were prepared in the 110 geometry. These were then analyzed using two-beam bright-field, dark-field and weak-beam images. A JEOL JEM 200CX transmission electron microscope was used, operating at 200 kV.

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