Thermodynamics Commons^™

Solution To Exide Technologies Inbatec Inefficiency, Shixuan Hou, Reagan Gilker, Mary Fairley, Spencer Christian, Covenson Latouche

Chemical Engineering Undergraduate Honors Theses

The inefficiency of the battery charging time in Inbatec Units 1 and 2 in the Exide Technologies Fort Smith was initially investigated by a student team in Fall 2019, and the investigation was continued into Spring 2020. The Exide Technologies facility in Fort Smith, Arkansas utilizes 13 Inbatec units to charge the lead-acid batteries. The Inbatec systems circulate the sulfuric acid solution through a cooling tower to maintain to optimal charging temperature. Previous analysis of the charging process for Inbatec Units 1 and 2 show the cooling tower have the capacity to quickly remove the excess heat in the sulfuric …

Improving Pv Module Efficiency Through Cooling, Blake Bradley

Chemical Engineering Undergraduate Honors Theses

The Solarbacks researched and designed a variety of cooling methods that could be used to improve the efficiency of photovoltaics. These cooling methods can be separated into two categories: active and passive methods. The active cooling method of hydraulic cooling and the passive cooling methods of heat sinks (fins), optical coatings, thermosyphons, phase change materials, and thermoelectric generators were all taken into consideration as potential cooling methods. Passive cooling methods were preferred because the use of electricity required for the cooling mechanism would reduce the net electricity and subsequent profit from the panels.

Two variations of hydraulic cooling were researched: …

Solution To Exide Technologies Inbatec Inefficiency, Spencer Christian, Shixuan Hou, Mary Fairley, Reagan Gilker, Covenson Latouche

Chemical Engineering Undergraduate Honors Theses

The inefficiency of the battery charging time in Inbatec Units 1 and 2 in the Exide Technologies Fort Smith was initially investigated by a student team in Fall 2019, and the investigation was continued into Spring 2020. The Exide Technologies facility in Fort Smith, Arkansas utilizes 13 Inbatec units to charge the lead-acid batteries. The Inbatec systems circulate the sulfuric acid solution through a cooling tower to maintain to optimal charging temperature. Previous analysis of the charging process for Inbatec Units 1 and 2 show the cooling tower have the capacity to quickly remove the excess heat in the sulfuric …

Numerical And Experimental Analysis Of Air-Cooled Condensers, Kaipo Kekaula

UNLV Theses, Dissertations, Professional Papers, and Capstones

The scope of this project is to numerically and experimentally dry cooling process in air-cooled condensers (ACCs) designed for concentrated solar power (CSP) applications. This effort is driven by the growing economic and political pressure to reduce water consumption during power generation due to limited water resources in the arid geographic climate of the southwestern United States. A computational approach is used in conjunction with experimental validation to gain a more complete understanding of these systems.

Traditionally research into ACCs have been largely limited to air-side heat transfer modelling as it accounts for a large portion of the total thermal …

The Effect Of Oxygen On Properties Of Zirconium Metal, Jie Zhao

Doctoral Dissertations

The influence of oxygen on the thermophysical properties of zirconium has been investigated using MSL-EML (Material Science Laboratory Electromagnetic Levitator) on ISS (International Space Station) in collaboration with NASA (National Aeronautics and Space Administration), ESA (European Space Agency), and DLR (German Aerospace Center). Zirconium samples with different oxygen concentrations was subjected to multiple melt cycles during which the thermophysical properties, such as density, viscosity and surface tension, have been measured at various undercooled and superheated temperatures. Also, there are melt cycles for verifying the solidification mechanism. Similar samples were found to show anomalous nucleation of the solid for certain ranges …

Rational Interface Design For High-Performance All-Solid-State Lithium Batteries, Changhong Wang

Electronic Thesis and Dissertation Repository

All-solid-state lithium batteries (ASSLBs) have gained substantial attention owing to their excellent safety and high energy density. However, the development of ASSLBs has been hindered by large interfacial resistance originating from the detrimental interfacial reactions, poor solid-solid contact, and lithium dendrite growth. The research in this thesis aims at achieving high-performance ASSLBs via rational interface design and understanding the interfacial reaction mechanisms.

At the cathode interface, an ideal dual core-shell nanostructure was first designed. Moreover, single-crystal LiNi_0.5Mn_0.3Co_0.2O₂ (SC-NMC532) cathode was compared with polycrystalline NMC532, the former exhibits much enhanced Li⁺ diffusion kinetics …

Desarrollo De Un Esquema De Gestión Hídrica En El Sistema Acuífero Sap 3.1 Apoyado De La Tipificación De Suelos Y El Modelo Conceptual De Thöt, Maria Camila Soriano Espinosa, Camilo José Rodríguez Carvajal

Ingeniería Ambiental y Sanitaria

El presente proyecto tiene como objetivo principal desarrollar un esquema de gestión hídrica (EGH) en el sistema acuífero SAP 3.1, provincia llanos orientales, con base en la tipificación de suelos y el modelo conceptual de Tӧth, partiendo de que las aguas subterráneas se consideran una fuente alternativa de abastecimiento por su mejor calidad y el bajo costo de manejo en comparación al agua superficial, y teniendo en cuenta que el Departamento del Meta conoce la riqueza hídrica que está en su jurisdicción, no cuenta con una regulación adecuada en pro de una gestión hídrica a nivel subterráneo. La metodología empleada …

Experimental And Computational Characterization Of Sodium Nitrate @ Silica Nano Capsules For Thermal Energy Storage Applications, Wataru Hashimoto

Graduate Research Theses & Dissertations

In this investigation, a nanocapsule composed of a sodium nitrate core and a silicon dioxide shell is synthesized, characterized, and analyzed utilizing a mixture of analytical and computational tools. The sol-gel method was selected as the process of nanoencapsulation. Analytical characterization techniques employed in this investigation include differential scanning calorimetry (DSC) to measure melting temperatures and enthalpies of fusion, dynamic light scattering (DLS) to calculate particle size distributions, scanning electron microscopy (SEM) to analyze surface characteristics, transmission electron microscopy (TEM) to perform shell characterization, and energy dispersive X-ray spectroscopy (EDS) to determine chemical composition. Preliminary results indicated a decrease in …

Process Modeling And Techno-Economic Analysis Of Thermo-Catalytic Dimethyl Ether Synthesis And Microwave-Based Aromatics Production Technologies From Shale Gas, Chirag Mevawala

Graduate Theses, Dissertations, and Problem Reports

Production of dimethyl ether (DME) and direct non-oxidative methane dehydroaromatization (DHA) to aromatics via conventional and microwave (MW)-assisted processes are investigated in this research. Plant-wide models of the shale gas to DME process with integrated CO₂ capture via direct and indirect synthesis routes have been developed. Optimal parameter estimation, and model validation are undertaken for various sections of the process including the pre-reforming reactor, auto-thermal reforming reactor, DME synthesis reactors, CO₂ capture units and separation sections. A novel DME separation process has been developed for efficient separation of DME, syngas, and CO₂. Plant-wide techno-economic optimization is …

Thermal / Structural Analysis Of The Hb 650 Thermal Shield, Gerald J. Smith

Graduate Research Theses & Dissertations

Fermilab’s PIP-II project’s superconducting linear accelerator (Linac) will drive the next generation of particle accelerators through a revolution in beam intensity. Key to beam intensification are the high efficiencies of niobium-tin superconducting radiofrequency (SRF) cavities operating at cryogenic temperatures near 5 Kelvin. A multifaceted approach is employed to achieve and maintain the extreme temperature. Vacuum provides the first barrier to thermal convection. Physical thermal intercept zones further isolate the exterior shell vacuum vessel at 300 Kelvin from the supercooled beamline. The first thermal intercept lies just inside the exterior vacuum vessel forming the 40 Kelvin zone. This 40K thermal shield …

Coarse-Grained Dynamically Accurate Simulations Of Ionic Liquids At Vacuum-Interface, Tyler D. Stoffel

Theses and Dissertations--Mechanical Engineering

Ionic liquids, possessing improved properties in many areas of technical application, are excellent candidates as components in development of next-generation technology, including ultra-high energy batteries. If they are thus applied, however, extensive interfacial analysis of any selected ionic configuration will likely be required. Molecular dynamics (MD) provides an advantageous route by which this may be accomplished, but can fall short in observing some phenomena only present at larger time/length scales than it can simulate. Often times this is approached by coarse-graining (CG), with which scope of simulation can be significantly increased. However, coarse-grained MD systems are generally known to produce …

Investigation Of Asphaltene Adsorption At Liquid-Liquid And Liquid-Solid Interfaces, Fang Liu

Dissertations and Theses

Asphaltenes, as indigenous components in crude oils, are believed to play an important role in the petroleum production and processing industry. For example, asphaltene molecules can adsorb onto the water / oil interface like the amphiphiles and hinder water droplet coalescence, resulting in the stabilization of water-in-oil emulsions. Also, in the upstream production, depending on the temperature and pressure, asphaltenes can precipitate and deposit onto the reservoir rocks, the wellbores and the pipelines, leading to the change in reservoir rocks’ surface wettability and the blockage of the production facilities. Hence, it is crucial to understand the mechanism of asphaltenes adsorption …

Capillary Forces And Wetting Dynamics By Diffuse-Interface Modeling, Fanny Thomas

Dissertations and Theses

Wetting phenomena underlie many natural and industrial processes, from the proper functioning of the lungs to the thin coating of surfaces. The three-phase interactions involved at microscopic scales play a critical role. Adding solid particles to an emulsion, for example, can drastically change the flow behavior due to capillary bridging between the particles. The study of these three-phase systems is especially relevant to the petroleum industry, where gas hydrates forming large clusters in subsea pipelines during crude oil transportation is a major concern. The dynamics of such systems is also of great interest from a fundamental perspective. Indeed describing non-equilibrium …

Energy Conservation And Heat Transfer Enhancement For Mixed Convection On The Vertical Galvanizing Furnace, Dan Mei, Yuzheng Zhu, Xuemei Xu, Futang Xing

Mechanical & Aerospace Engineering Faculty Publications

The alloying temperature is an important parameter that affects the properties of galvanized products. The objective of this study is to explore the mechanism of conjugate mixed convection in the vertical galvanizing furnace and propose a novel energy conservation method to improve the soaking zone temperature based on the flow pattern and heat transfer characteristics. Herein, the present study applied the k-ε two-equation turbulence model to enclose the Navier-Stokes fluid dynamic and energy conservation equations, and the temperature distributions of the steel plate and air-flow field in the furnace were obtained for six Richardson numbers between 1.91 ⋅ 10^{5 …}

Process Development Of Shale Gas Assisted Lignin And Biomass Reforming Through Novel Reaction Pathway And Catalyst Design To Produce Hydrogen Rich Syngas For Fuels And Value Added Chemicals, Amoolya D. Lalsare

Graduate Theses, Dissertations, and Problem Reports

Novel biomass reforming strategy through synergistic co-processing with flare gas (methane and carbon dioxide) was developed at West Virginia University. Hardwood biomass comprised of lignin, hemicellulose, and cellulose is abundant in the US and potentially a sustainable source of hydrogen through extensive reforming and gasification. Ever-increasing shale gas production in the US occasionally leads to flaring owing to stranded production across the US. Achieving biomass co-processing with natural gas about to be flared in such stranded shale plays is the underlying motivation here. A novel reaction pathway was discovered wherein methane and carbon dioxide assisted reforming of biomass could be …

Electrification Of Domestic Hot Water To Aid The Integration Of Renewable Energy In The California Grid, Alejandro Cervantes

Cal Poly Humboldt theses and projects

Water heating in residential buildings, also known as domestic hot water (DHW), is the third largest use of energy after appliances and space conditioning. About 90% of the residential buildings in the state use natural gas fueled water heaters, 6% use electricity, and a small percent use liquefied petroleum gas (LPG) or solar water heaters. The current energy use associated with residential water heating is small relative to the total amount of energy consumption in the residential building sector, but it is still a contributor of greenhouse gas (GHG) emissions. Improving hot water systems can be beneficial for bill customer …

Customized Boron And Magnesium-Based Reactive Materials Prepared By High Energy Mechanical Milling, Xinhang Liu

Dissertations

New reactive materials need to be developed having biocidal combustion products. When ignited, such material can add chemical biocidal effects to the common effects of high temperature and pressure. Biocidal combustion products are capable of deactivating harmful spores or bacteria, which can be released by targets containing biological weapons of mass destruction. Research showed that halogens, especially iodine, are effective as biocidal components of reactive material formulations. Recently, magnesium combustion product MgO is also found to have a biocidal effect. Thus, advanced formulations containing both magnesium and iodine are of interest; such formulations are prepared and investigated here.

Reactive materials …

Coulombic And Non-Coulombic Effects Of Single And Overlapping Electric Double Layers With Surface Charge Regulation, Raviteja Vangara

Chemical and Biological Engineering ETDs

The physical origin of charged interfaces involving electrolyte solutions is in the thermodynamic equilibrium between the surface reactive groups and certain dissolved ionic species in the bulk. This equilibrium is very strongly dependent on the precise local density of these species, also known as potential determining ions in the solution. The latter, however, is determined by the overall solution structure, which is dominated by the large number of solvent molecules relative to all solutes. Hence, the solvent contribution to the molecular structure is a crucial factor that determines the properties of electric double layers. Models that explicitly account for the …

Cfd Simulation Investigating The Effects Of Groove Geometry On Heat Transfer For Internally Grooved Tubes, Richard Zaven Saroukhanoff

UNLV Theses, Dissertations, Professional Papers, and Capstones

This numerical study investigates the thermal performance of internally grooved tubes used in heat exchangers. In order to enhance the performance of heat exchangers, turbulence promoters are inserted along the streamwise flow. The use of inserts, grooves, and augmentations along the axial length of the tube creates disturbances that improve the overall heat transfer due to enhanced fluid mixing and greater surface contact boundary walls. However, the implementation of tube wall augmentations creates an increase in pressure drop across the tube which must be compensated for with additional pumping power for the working fluid. Therefore, in order to analyze the …

Performance Modeling Of Supercritical Carbon Dioxide Zigzag-Channel Printed Circuit Heat Exchangers, Katrine Birgitte Bennett

UNLV Theses, Dissertations, Professional Papers, and Capstones

Supercritical carbon dioxide (sCO2) is currently being studied as the working fluid in power producing Brayton cycles due to its excellent physical and thermodynamic properties, especially near the critical point. Printed circuit heat exchangers (PCHEs) are being considered for use as condensers and recuperators for this purpose due to their high strength and compact designs. Many experimental and numerical studies are being conducted to characterize and optimize sCO2 PCHE operation and develop correlations to describe their thermal-hydraulic performance. Additionally, a few experimental and numerical structural assessments of these PCHEs have been conducted, but all have been somewhat limited due to …