Mechanical Engineering Commons^™

Performance Analysis Of Coal-Fired Boiler And Natural Gas Fired Boiler At Morehead State University, Devender Banne

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Devender Banne on May 4, 2009.

An On-Sun Parametric Study Of Solar Hydrogen Production Using Wo3 Photoanodes, Christopher K. Halford

UNLV Theses, Dissertations, Professional Papers, and Capstones

The solar production of hydrogen using photoactive electrodes is a topic receiving much attention in recent years. The use of thin metal oxide films as photoanodes allows the water splitting reaction to occur at a much lower applied voltage than would be necessary with a straight electrolysis process. Researchers have reported up to 18% solar to hydrogen efficiencies over short periods. The University of Nevada Las Vegas in conjunction with the UK based firm Hydrogen Solar have developed a prototype of this type of cell using a WO3 photoanode. An on-sun test facility has been constructed by the UNLV Center …

Temperature Influence And Heat Management Requirements Of Microalgae Cultivation In Photobioreactors, Thomas Hagen Mehlitz

Master's Theses

Microalgae are considered one of the most promising feedstocks for biofuel production for the future. The most efficient way to produce vast amounts of algal biomass is the use of closed tubular photobioreactors (PBR). The heat requirement for a given system is a major concern since the best algae growth rates are obtained between 25-30 °C, depending on the specific strain. A procedure to determine temperature influence on algal growth rates was developed for a lab-scale PBR system using the species Chlorella. A maximum growth rate of 1.44 doublings per day at 29 °C (optimal temperature) was determined. In addition, …

Assessment Of Alternative Maritime Power (Cold Ironing) And Its Impact On Port Management And Operations., Richard Fiadomor

World Maritime University Dissertations

No abstract provided.

Harvesting Human Exercise Power At The Cal Poly Rec Center: Exercise Bike Power Generator Ii, Jared Rounsevell, Claire M. Shubert, Matthew Snitowsky, Andrew Wong

Mechanical Engineering

The overall goal of this project is to create a workable system to harvest the power generated on exercise bikes at the Cal Poly Rec Center so that the electricity produced can eventually be sent to the power grid. Our part of the project will focus on the mechanical harvesting of this power with the goal of using the product to run the Morningstar ProStar 12V 30 amp charge controller available from the 2007 project. Eventually, the power produced could be fed to the grid in the appropriate form. The finished result of this project should be marketable to exercise …

Two-Tank Indirect Thermal Storage Designs For Solar Parabolic Trough Power Plants, Joseph E. Kopp

UNLV Theses, Dissertations, Professional Papers, and Capstones

The performance of a solar thermal parabolic trough plant with thermal storage is dependent upon the arrangement of the heat exchangers that ultimately transfer energy from the sun into steam. The steam is utilized in a traditional Rankine cycle power plant. The most commercially accepted thermal storage design is an indirect two-tank molten salt storage system where molten salt interacts with the solar field heat transfer fluid (HTF) through a heat exchanger. The molten salt remains in a closed loop with the HTF and the HTF is the heat source for steam generation. An alternate indirect two tank molten salt …

Carbon-Free Compressed Air Energy Storage, Dustin Andrew Shively

Boise State University Theses and Dissertations

The inherent intermittency of the two fastest growing renewable energy sources, wind and solar, presents a significant barrier to widespread penetration and replacement of fossil-fuel sourced baseload generation. These intermittencies range from short term ramp events experienced by wind farms to the diurnal fluctuation of solar installations. Traditionally, grid operators have had very little control over demand and full control over supply. With the increase in wind and solar based generation onto an electric grid comes a decrease in control of supply. Grid operators are required to have a certain amount of spinning reserve ready to respond when wind or …

Empirically Derived Formulas To Predict Indoor Maximum, Average, And Minimum Temperatures In Roofpond Buildings Using Minimum Climatic Information, Ibrahim Kivarkis Kako

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis introduces an empirically developed formula to predict the comfort conditions and thermal performance of a Skytherm(TM) Southwest Roofpond placed over a light-weight un-insulated structure built at the School of Architecture at the University of Nevada, Las Vegas.

The predictive formula introduced in this study may be used in different parts of the world (particularly developing nations where insulation and air-conditioning are rarely used) to predict the performance of a Skytherm(TM) Southwest Roofpond using minimal climate data.

The data collected in the experimental setup at the Natural Energies Advanced Technologies Laboratory included outside and inside temperatures of various surfaces …

Optimization Of Channel Geometry In A Proton Exchange Membrane (Pem) Fuel Cell, Jephanya Kasukurthi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bipolar plates are the important components of the PEM fuel cell. The flow distribution inside the bipolar plate should be uniform. Non-uniform flow distribution inside the bipolar leads to poor performance of the fuel cell and wastage of expensive catalyst. A single channel PEM fuel cell is taken and electrochemical analysis is carried out on it. The results are compared with the available published experimental data obtained by other research group, and they are found to be in good agreement. A baseline design of the bipolar plate is taken and numerical analysis is carried out. The results show that the …

Optimization Of Solid Oxide Fuel Cell Interconnect Design, Krishna C. Pulagam

UNLV Theses, Dissertations, Professional Papers, and Capstones

Performance of solid oxide fuel cells (SOFC) is dependent of a set of complex physical and chemical processes occurring simultaneously. Interconnect for SOFC is important as it provides electrical connection between anode of one individual cell to the cathode of neighboring one. It also acts as a physical barrier to protect the air electrode material from the reducing environment of the fuel on the fuel electrode side, and it equally prevents the fuel electrode material from contacting with oxidizing atmosphere of the oxidant electrode side. A three-dimensional numerical model has been developed to evaluate the SOFC including the current collector, …

Benefits Of Leed Designs In Arkansas K-12 Schools, Philip Thrift

Mechanical Engineering Undergraduate Honors Theses

This paper provides and evaluation of an existing LEED certified sustainable green building for energy-efficiency, environmental impact, economic value, and occupant health. The new Bethel Middle School located in Bryant, Arkansas was the first LEED (Leadership in Energy and Environmental Design) certified public school building in the state. Based on actual building specifications and validated with the first year's utility bills, a simulation model was used to evaluate various design aspects of the school building. The building's baseline energy usage was compared with numerous energy and environmental scenarios. Results include both environmental and economic assessments. Overall, the study found that …

Using Building Energy Simulation And Geospatial Modeling Techniques In Determine High Resolution Building Sector Energy Consumption Profiles, Shem C. Heiple

Dissertations and Theses

A technique is presented for estimating hourly and seasonal energy consumption profiles in the building sector at spatial scales down to the individual taxlot or parcel. The method combines annual building energy simulations for cityspecific prototypical buildings and commonly available geospatial data in a Geographical Information System (GIS) framework. Hourly results can be extracted for any day and exported as a raster output at spatial scales as fine as an individual parcel (

Coupled Thermal Fluid Modelling Of A Low Embedded Energy Solar Thermal Collector, Myrrha Corcoran

Theses

Flat-plate collectors are the most economical and are popular in solar domestic heating water system since they are usually permanently fixed in position, have simple construction, and require little maintenance. The design of a solar energy system is generally concerned with obtaining maximum efficiency at minimum cost. The aim of this thesis was to develop a mathematical model, for a forced convection solar heated water system. The solar collector in this study incorporated a honeycombed extruded polycarbonate structure, for both the cover and water channels.

A very detailed thermal analysis of the flat-plate solar collector was carried out to predict …

Optimisation Of Heat Transfer And Fluid Flow In The Cooling Of Building Integrated Photovoltaic Facades., Eoin Patrick Hodge

Theses

The aim of this research was to explore the effects of mature and developing technologies from aeronautical industries such as impingement and film cooling, and electronic cooling techniques, in the setting up of different laminar and turbulent flow regimes on PV cooling duct heat transfer rates, with air flow as that brought about with natural buoyancy effects in a vertical building facade. The problem of efficiency losses in PV panels, due to overheating, is one of the factors restricting the development and use of this renewable power source. PV panels can experience very high temperatures, due to the heat input …

Thermal Assessment Of Silicon-Based Composite Materials Used In Photovoltaics, Pavlos K. Bataglannis

Theses

Photovoltaics are devices that convert sunlight directly to electricity. It is well established that the conversion efficiency of mono and poly-crystalline silicon-based photovoltaic modules is inversely related to their temperature. Substantial improvements in operational performance can thus be achieved if the thermal energy accumulating in the material can be effectively dissipated.

Accurate modelling of modules would allow possible methods of thermal dissipation to be evaluated, and as a crucial component of the model, the thermal properties of the constituent materials of PV modules needed to be known. Special consideration needed to be given to the interfaces between dissimilar materials and …

Reduced Small Engine Emissions With Perforated Plates, Derek S. Lindsay

Honors Capstone Projects and Theses

No abstract provided.

A Performance Comparison Of Solar Radiation Predictive Models For Both Fixed And Tracking Surfaces, William F. Marion

Retrospective Theses and Dissertations

Accurate performance prediction for a system utilizing solar energy requires accurate estimates of the solar radiation received by the collector surface. This thesis compares the performance of five different diffuse solar radiation models in estimating the diffuse radiation received by a tilted surface in the warm, humid climate of Central Florida.

The following models were studied: Isotropic Model, Temps and Coulson Model, Klucher Model, Hay Model, and Perez Model. The models were evaluated for both a fixed south facing surface and for three different tracking schemes suitable for photovoltaic applications. Model estimates were then compared to the solar radiation data …

A Cavity Absorber For A Focusing Solar Collector, Andrew W. Crapo

Retrospective Theses and Dissertations

The concept of a cavity absorber for use with a focusing parabolic trough is developed in this paper. A mathematical model is formulated and used to compare different absorber geometries. Limitations of the model are discussed and within the range of materials and fabrication methods available, the choice of a cylindrical cavity is substantiated. Relative sizes of the gap and cylinder are chosen for a given mirror arc length, focal length, and alignment error. The model is used to optimize these parameters and predict absorber and collector efficiency. The processes of building and testing the absorber are detailed, and test …

Development Of An Integrated Program Of Water Reuse In A Pulp And Paper Mill, Zafar M. Chaudhri

Masters Theses

No abstract provided.

The Design Of A Solar Powered Air Conditioning System For An Albuquerque Office Building, Kuo S. Lee

Mechanical Engineering ETDs

The purpose of this investigation is to predict the performance of a solar powered jet refrigeration system for summer air conditioning, to measure the performance of the solar heat collector at the Bridgers and Paxton building in Albuquerque, and to design a Freon-12 ejector and generator for collection to that collector.