Visual Study of In-Situ EGR Cooler Fouling Layer Evolution

2014 ◽  
Author(s):  
Haochi Li ◽  
John Hoard ◽  
Daniel Styles ◽  
Ashwin Salvi ◽  
Akshay Kini ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Gas Flow ◽  
Nox Reduction ◽  
Time Lapse ◽  
Layer Growth ◽  
Future Emission ◽  
Egr Cooler ◽  
Gas Recirculation ◽  
Deposit Layer

Exhaust gas recirculation (EGR) is a major technology to reduce NOx from diesel engines for future emission standards. The implementation of EGR coolers has been a common methodology to provide engine in-cylinder NOx reduction. However, EGR cooler fouling is a common problem. The particulate matter in exhaust tends to form a deposit layer on the wall of the heat exchangers. This effect leads to a reduction of thermal effectiveness of the heat exchangers resulting in insufficient EGR cooling and subsequently higher engine NOx emission. This paper utilized a unique test rig offering visible and infrared optical access to the deposit layer in a simulated diesel EGR cooler to study the evolution of the layer from fresh to heavy deposit. A 460μm thick deposit layer was built during a 37 hour exposure. Time lapse videos were taken provide visual in-situ evidence for the investigation of the layer thickness development and morphology change during the deposition. The layer growth tended to stabilize from about 22 hours of deposition. The shear force exerted by the gas flow moves surface particles of 20μm in diameter or larger. This could contribute to the stabilization phenomenon.

Effect of Volatiles on Soot Based Deposit Layers

2013 ◽  
Author(s):  
Ashwin Salvi ◽  
John Hoard ◽  
Mitchell Bieniek ◽  
Mehdi Abarham ◽  
Dan Styles ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Nox Reduction ◽  
Infrared Camera ◽  
Optical Microscope ◽  
Exhaust Gas ◽  
Thermogravimetric Analyzer ◽  
Gas Recirculation ◽  
Thermo Physical Properties ◽  
Deposit Layer

The implementation of exhaust gas recirculation (EGR) coolers has recently been a widespread methodology for engine in-cylinder NOX reduction. A common problem with the use of EGR coolers is the tendency for a deposit, or fouling layer to form through thermophoresis. These deposit layers consist of soot and volatiles and reduce the effectiveness of heat exchangers at decreasing exhaust gas outlet temperatures, subsequently increasing engine out NOX emission. This paper presents results from a novel visualization rig that allows for the development of a deposit layer while providing optical and infrared access. A 24-hour, 379 micron thick deposit layer was developed and characterized with an optical microscope, an infrared camera, and a thermogravimetric analyzer. The in-situ thermal conductivity of the deposit layer was calculated to be 0.047 W/mK. Volatiles from the layer were then evaporated off and the layer reanalyzed. Results suggest that volatile bake-out can significantly alter the thermo-physical properties of the deposit layer and hypotheses are presented as to how.

Effect of Volatiles on Soot Based Deposit Layers

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Ashwin Salvi ◽  
John Hoard ◽  
Mitchell Bieniek ◽  
Mehdi Abarham ◽  
Dan Styles ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Nox Reduction ◽  
Infrared Camera ◽  
Optical Microscope ◽  
Volatile Components ◽  
Exhaust Gas ◽  
Thermogravimetric Analyzer ◽  
Gas Recirculation ◽  
Deposit Layer

The implementation of exhaust gas recirculation (EGR) coolers has recently been a widespread methodology for engine in-cylinder NOx reduction. A common problem with the use of EGR coolers is the tendency for a deposit, or fouling layer to form through thermophoresis. These deposit layers consist of soot and volatiles and reduce the effectiveness of heat exchangers at decreasing exhaust gas outlet temperatures, subsequently increasing engine out NOx emission. This paper presents results from a novel visualization rig that allows for the development of a deposit layer while providing optical and infrared access. A 24 h, 379-micron-thick deposit layer was developed and characterized with an optical microscope, an infrared camera, and a thermogravimetric analyzer. The in situ thermal conductivity of the deposit layer was calculated to be 0.047 W/mK. Volatiles from the layer were then evaporated off and the layer reanalyzed. Results suggest that the removal of volatile components affect the thermophysical properties of the deposit. Hypotheses supporting these results are presented.

In-Situ Thermophysical Properties of an Evolving Carbon Nanoparticle Based Deposit Layer Utilizing a Novel Infrared and Optical Methodology

2015 ◽  
Author(s):  
Ashwin A. Salvi ◽  
John Hoard ◽  
Dan Styles ◽  
Dennis Assanis
Keyword(s):  
Thermal Conductivity ◽  
Internal Combustion Engines ◽  
Linear Increase ◽  
Outlet Temperature ◽  
Combustion Engines ◽  
Deposit Thickness ◽  
Exhaust Gases ◽  
Gas Recirculation ◽  
Deposit Layer

The use of exhaust gas recirculation (EGR) in internal combustion engines has significant impacts on engine combustion and emissions. EGR can be used to reduce in-cylinder NOx production, reduce fuel consumption, and enable advanced forms of combustion. To maximize the benefits of EGR, the exhaust gases are often cooled with liquid to gas heat exchangers. However, the build up of a fouling deposit layer from exhaust particulates and volatiles result in the decrease of heat exchanger efficiency, and increase the outlet temperature of the exhaust gases, and decrease the advantages of EGR. This paper presents experimental data from a novel in-situ measurement technique in a visualization rig during the development of a 378 micron thick deposit layer. Measurements were performed every 6 hours for up to 24 hours. Results show a non-linear increase in deposit thickness with an increase in layer surface area as deposition continued. Deposit surface temperature and temperature difference across the thickness of the layer was shown to increase with deposit thickness while heat transfer decreased. The provided measurements combine to produce deposit thermal conductivity. A thorough uncertainty analysis of the in-situ technique is presented and suggests higher measurement accuracy at thicker deposit layers and with larger temperature differences across the layer. The interface and wall temperature measurements are identified as the strongest contributors to the measurement uncertainty. Due to instrument uncertainty, the influence of deposit thickness and temperature could not be determined. At an average deposit thickness of 378 microns and at a temperature of 100°C, the deposit thermal conductivity was determined to be 0.044 ± 0.0062 W/mK at a 90% confidence interval based on instrument accuracy.

In Situ Thermophysical Properties of an Evolving Carbon Nanoparticle Based Deposit Layer Utilizing a Novel Infrared and Optical Methodology

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Ashwin A. Salvi ◽  
John Hoard ◽  
Dan Styles ◽  
Dennis Assanis
Keyword(s):  
Thermal Conductivity ◽  
Internal Combustion Engines ◽  
Outlet Temperature ◽  
Combustion Engines ◽  
Deposit Thickness ◽  
Exhaust Gases ◽  
Engine Combustion ◽  
Gas Recirculation ◽  
Deposit Layer

The use of exhaust gas recirculation (EGR) in internal combustion engines has significant impacts on engine combustion and emissions. EGR can be used to reduce in-cylinder NOx production, reduce fuel consumption, and enable advanced forms of combustion. To maximize the benefits of EGR, the exhaust gases are often cooled with liquid to gas heat exchangers. However, the build up of a fouling deposit layer from exhaust particulates and volatiles results in the decrease of heat exchanger efficiency, increasing the outlet temperature of the exhaust gases and decreasing the advantages of EGR. This paper presents an experimental data from a novel in situ measurement technique in a visualization rig during the development of a 378 μm thick deposit layer. Measurements were performed every 6 hrs for up to 24 hrs. The results show a nonlinear increase in deposit thickness with an increase in layer surface area as deposition continued. Deposit surface temperature and temperature difference across the thickness of the layer was shown to increase with deposit thickness while heat transfer decreased. The provided measurements combine to produce deposit thermal conductivity. A thorough uncertainty analysis of the in situ technique is presented and suggests higher measurement accuracy at thicker deposit layers and with larger temperature differences across the layer. The interface and wall temperature measurements are identified as the strongest contributors to the measurement uncertainty. Due to instrument uncertainty, the influence of deposit thickness and temperature could not be determined. At an average deposit thickness of 378 μm and at a temperature of 100 °C, the deposit thermal conductivity was determined to be 0.044 ± 0.0062 W/m K at a 90% confidence interval based on instrument accuracy.

In situ time-lapse synchrotron radiation X-ray diffraction of silver corrosion

2015 ◽  
Vol 30 (3) ◽  
pp. 694-701 ◽  
Author(s):  
Rita Wiesinger ◽  
Rosie Grayburn ◽  
Mark Dowsett ◽  
Pieter-Jan Sabbe ◽  
Paul Thompson ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Gas Flow ◽  
Time Lapse ◽  
X Ray Diffraction ◽  
X Ray ◽  
Environmental Cell ◽  
Temperature And Pressure ◽  
Set Up ◽  
Gaseous Corrosion

In order to study the initial corrosion processes of silver in the presence of corrosive gases in situ time-lapse XRD experiments were performed. The data collected using a newly combined environmental cell/gas flow set up introduces a set of highly useful tools for scientists to study time-lapse gaseous corrosion at ambient temperature and pressure.

scholarly journals Investigation of In Situ Boron-Doping in SiGe Source/Drain Layer Growth for PMOS Devices

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Min Zhong ◽  
Shou Mian Chen ◽  
David Wei Zhang
Keyword(s):  
Gas Flow ◽  
Semiconductor Industry ◽  
Boron Doping ◽  
Sige Layer ◽  
Layer Growth ◽  
Experimental Conditions ◽  
Transmission Electron ◽  
Diffraction Mode ◽  
Secondary Ion

Embedded SiGe (eSiGe) source/drain (S/D) was studied to enhance PMOS performance. Detailed investigations concerning the effect of GeH4and B2H6gas flow rate on the resultant Boron-doping of the SiGe layer (on a 40 nm patterned wafer) were carried out. Various SiGeB epitaxial growth experiments were realized under systematically varying experimental conditions. Key structural and chemical characteristics of the SiGeB layers were investigated using Secondary Ion Mass Spectroscopy (SIMS), nanobeam diffraction mode (NBD), and Transmission Electron Microscopy (TEM) itself. Furthermore,Ion/Ioffperformances of 40 nm PMOS transistors are also measured by the Parametric Test Systems for the semiconductor industry. The results indicate that the ratio between GeH4and B2H6gas flow rates influences not only the Ge and Boron content of the SiGeB layer, but also the PMOS channel strain and the morphology of the eSiGe S/D regions which directly affect PMOS performance. In addition, the mechanism of Boron-doping during SiGe layer growth on the pattern wafer is briefly discussed. The results and discussion presented within this paper are expected to contribute to the optimization of eSiGe stressor, aimed for advanced CMOS devices.

Oblique-incidence Reflectivity Difference (OI-RD) and Leed Studies of Adsorption and Growth of Xe on Nb(110)

2003 ◽  
Vol 780 ◽  
Author(s):  
P. Thomas ◽  
E. Nabighian ◽  
M.C. Bartelt ◽  
C.Y. Fong ◽  
X.D. Zhu
Keyword(s):  
Transition Layer ◽  
Layer Growth ◽  
Flow Mode ◽  
Layer By Layer ◽  
Zeroth Order ◽  
Step Flow ◽  
Low Energy Electron Diffraction ◽  
Oriented Film ◽  
Low Energy Electron

AbstractWe studied adsorption, growth and desorption of Xe on Nb(110) using an in-situ obliqueincidence reflectivity difference (OI-RD) technique and low energy electron diffraction (LEED) from 32 K to 100 K. The results show that Xe grows a (111)-oriented film after a transition layer is formed on Nb(110). The transition layer consists of three layers. The first two layers are disordered with Xe-Xe separation significantly larger than the bulk value. The third monolayer forms a close packed (111) structure on top of the tensile-strained double layer and serves as a template for subsequent homoepitaxy. The adsorption of the first and the second layers are zeroth order with sticking coefficient close to one. Growth of the Xe(111) film on the transition layer proceeds in a step flow mode from 54K to 40K. At 40K, an incomplete layer-by-layer growth is observed while below 35K the growth proceeds in a multilayer mode.

NbC and VC Nanoparticles Reinforced Fe-Si-Mn Matrix Composite In Situ Synthesized by Plasma Jet

2011 ◽  
Vol 415-417 ◽  
pp. 71-75
Author(s):  
Chun Xiang Cui ◽  
Yan Chun Li ◽  
Tie Bao Wang ◽  
Shuang Jin Liu ◽  
Suek Bong Kang
Keyword(s):  
Matrix Composite ◽  
Hybrid Composite ◽  
Gas Flow ◽  
Plasma Jet ◽  
Homogeneous Distribution ◽  
Active Nitrogen ◽  
Ceramic Particles ◽  
Nanometer Range ◽  
Short Time

In situ NbC and VC nanoparticles reinforced Fe-Si-Mn-Nb-V matrix composite was carried out using a plasma jet with a plasma gas flow of (Ar + CH4) for very short time. The process involve improving the efficiency of the reaction in terms of consumption of the available active nitrogen atoms as well as the production of very fine and homogeneous distribution of all reinforcing phases of ceramic particles, preferable in the nanometer range. The nanoreinforcements synthesized by in situ reaction in this hybrid composite are NbC and VC ceramic particles.

scholarly journals In-situ diffraction experiments at the Photon Factory MX beamlines

2014 ◽  
Vol 70 (a1) ◽  
pp. C500-C500
Author(s):  
Yusuke Yamada ◽  
Naohiro Matsugaki ◽  
Masahiko Hiraki ◽  
Ryuichi Kato ◽  
Toshiya Senda
Keyword(s):  
Gas Flow ◽  
Active Area ◽  
Array Detector ◽  
Data Sets ◽  
Diffraction Experiment ◽  
X Ray ◽  
Photon Factory ◽  
Large Active Area ◽  
In Situ Diffraction

Crystallization trial is one of the most important but time-consuming steps in macromolecular crystallography. Once a crystal appears in a certain crystallization condition, the crystal is typically harvested from the crystallization drop, soaked into a cryoprotection buffer, flash-cooled with a liquid nitrogen or cold gas flow and finally evaluated its diffraction quality by an X-ray beam. During these long process, crystal may be damaged and the result from the diffraction experiment does not necessarily reflect a nature of the crystal. On in-situ diffraction experiment, where a crystal in a crystallization drop is directly irradiated to an X-ray beam, a diffraction image from a crystal without any external factors such as harvesting and cryoprotection and, as a result, a nature of crystal can be evaluated quickly. In the Photon Factory, a new table-top diffractometer for in-situ diffraction experiments has been developed. It consists of XYZ translation stages with a plate handler, on-axis viewing system with a large numeric aperture and a plate rack where ten crystallization plates can be placed. These components sit on a common plate and it is placed on the existing diffractometer table in the beamline endstation. The CCD detector with a large active area and a pixel array detector with a small active area are used for acquiring diffraction images from crystals. Dedicated control software and user interface were also developed. Since 2014, user operation of the new diffractometer was started and in-situ diffraction experiments were mainly performed for evaluations of crystallization plates from a large crystallization screening project in our facility. BL-17A [1], one of micro-focus beamlines at the Photon Factory, is planned to be upgraded in March 2015. With this upgrade, a new diffractometer, which has a capability to handle a crystallization plate, will be installed so that diffraction data sets from crystals in crystallization drop can be collected.

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