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Full-Text Articles in Mechanical Engineering

Evaluation And Forecast Of Energy Consumption In Different Sectors Of The United States Using Artificial Neural Networks, Arash Kialashaki Dec 2014

Evaluation And Forecast Of Energy Consumption In Different Sectors Of The United States Using Artificial Neural Networks, Arash Kialashaki

Theses and Dissertations

The United States is a country which consumes a vast amount of energy. In order to keep the development of the United States sustainable (diverse and productive over the time) energy planning should be carried out comprehensively and precisely. This dissertation presents a specific mathematical modeling approach towards energy demand modeling of the United States and forecast future energy demand. To generate more detailed and accurate results, this dissertation investigates the energy demand of each sector separately using the analysis of trend for unique set of independent parameters which affect the energy demand in that sector.

In solving a forecast …


Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson Dec 2014

Methane Production By A Packed-Bed Anaerobic Digester Fed Dairy Barn Flush Water, Sean Richard Thomson

Master's Theses

Packed-bed digesters are an alternative to covered lagoon digesters for methane production and anaerobic treatment of dilute wastewaters such as dairy barn flush water. The physical media of packed-beds retain biofilms, often allowing increased treatment rates. Previous studies have evaluated several types of media for digestion of dilute wastewaters, but cost and media fouling have setback commercial development. A major operational cost has been effluent recirculation pumping.

In the present effort, a novel approach to anaerobic digestion of flush dairy water was developed at pilot-scale: broken walnut shells were used as a low-cost packed-bed medium and effluent recirculation was replaced …


Waste Heat Recovery Options In A Large Gas-Turbine Combined Power Plant, Ularee Upathumchard Oct 2014

Waste Heat Recovery Options In A Large Gas-Turbine Combined Power Plant, Ularee Upathumchard

Open Access Theses

This study focuses on power plant heat loss and how to utilize the waste heat in energy recovery systems in order to increase the overall power plant efficiency. The case study of this research is a 700-MW natural gas combined cycle power plant, located in a suburban area of Thailand. An analysis of the heat loss of the combustion process, power generation process, lubrication system, and cooling system has been conducted to evaluate waste heat recovery options. The design of the waste heat recovery options depends to the amount of heat loss from each system and its temperature. Feasible waste …


High Voltage Rear Electric Drivetrain Design For A Parallelthrough-The-Road Plug-In Hybrid Electric Vehicle, Adam Garrett Fogarty Oct 2014

High Voltage Rear Electric Drivetrain Design For A Parallelthrough-The-Road Plug-In Hybrid Electric Vehicle, Adam Garrett Fogarty

Open Access Theses

Purdue University was selected as one of 15 universities to participate in a three year Advanced Vehicle Technology Competition (AVTC) called EcoCar2: Plugging Into the Future. The vehicle built by the Purdue team was a Parallel-Through-The-Road Plug-in Hybrid Electric Vehicle (PTTR PHEV). The vehicle utilized a B20 diesel powertrain to power the front wheels, as well as a custom electric drivetrain to power the rear wheels. Using this vehicle during the final year of the competition, the team was successful in placing 4th overall as well as 2nd in the category of Well-To-Wheel (WTW) Greenhouse Gas Emissions. A stock 2013 …


Investigation Of Concurrent Energy Harvesting From Ambient Vibrations And Wind, Amin Bibo Aug 2014

Investigation Of Concurrent Energy Harvesting From Ambient Vibrations And Wind, Amin Bibo

All Dissertations

In recent years, many new concepts for micro-power generation have been introduced to harness wasted energy from the environment and maintain low-power electronics including wireless sensors, data transmitters, controllers, and medical implants. Generally, such systems aim to provide a cheap and compact alternative energy source for applications where battery charging or replacement is expensive, time consuming, and/or cumbersome. Within the vast field of micro-power generation, utilizing the piezoelectric effect to generate an electric potential in response to mechanical stimuli has recently flourished as a major thrust area. Based on the nature of the ambient excitation, piezoelectric energy harvesters are divided …


Development Of A Black-Box Transient Thermal Model For Residential Buildings, Andrew Cross Aug 2014

Development Of A Black-Box Transient Thermal Model For Residential Buildings, Andrew Cross

UNLV Theses, Dissertations, Professional Papers, and Capstones

Heavily populated metropolitan areas located in cooling-dominated climates, as are found in the Desert Southwest, pose a challenge to electrical utilities that service these areas. During the late afternoons of the summer months, residents of these metropolitan areas require larger than normal amounts of power to run their homes' air conditioning systems, at significant expense to the utilities. In the study reported here, interior temperature and power consumption data, accumulated over the course of a year and a half from seven houses within a Las Vegas neighborhood, are used to develop a predictive black-box statistical model for residential thermal transience. …


Experimental Study Of Unsteady Heat Release In An Unstable Single Element Lean Direct Injection (Ldi) Gas Turbine Combustor, Varun S. Lakshmanan Jul 2014

Experimental Study Of Unsteady Heat Release In An Unstable Single Element Lean Direct Injection (Ldi) Gas Turbine Combustor, Varun S. Lakshmanan

Open Access Theses

In an effort to curb emissions from gas turbine engines, many low emission engine concepts have been developed. Among the most promising of these is the LDI (Lean Direct Injection). These systems operate at relatively low equivalence ratios close to blowout and are prone to instabilities. Combustion instabilities can reduce the life of the combustor by causing large pressure fluctuations and enhanced heat release to the walls of the combustor and reduce the efficiency of the engines. The understanding of combustion instabilities is vital to the implementation of such systems. Combustion instabilities are studied in an self-excited single element gas …


A Novel Microgrid Demand-Side Management System For Manufacturing Facilities, Terance Jerome Harper Jul 2014

A Novel Microgrid Demand-Side Management System For Manufacturing Facilities, Terance Jerome Harper

Open Access Theses

Thirty-one percent of annual energy consumption in the United States occurs within the industrial sector, where manufacturing processes account for the largest amount of energy consumption and carbon emissions. For this reason, energy efficiency in manufacturing facilities is increasingly important for reducing operating costs and improving profits. Using microgrids to generate local sustainable power should reduce energy consumption from the main utility grid along with energy costs and carbon emissions. Also, microgrids have the potential to serve as reliable energy generators in international locations where the utility grid is often unstable.

For this research, a manufacturing process that had approximately …


High Temperature Flooded Expansion For Solar Thermal Power Generation, Nelson Alexander James Jul 2014

High Temperature Flooded Expansion For Solar Thermal Power Generation, Nelson Alexander James

Open Access Theses

Even though solar power usage has seen rapid growth over the past decade, fossil fuel generation sources are still generally a less expensive means of producing power. The Liquid-Flooded Ericsson Cycle (LFEC) was investigated as a high efficiency power cycle for reducing the cost of concentrated solar power (CSP) plants and helping to address this cost disparity. High temperature flooded expansion was identified as one of the main challenges in regards to utilizing the LFEC as a power cycle. Thermodynamic models were developed to help assess the performance of the LFEC and a load stand was constructed to test a …


Looking For Small Changes In Heat Capacity Using A Differential Scanning Calorimeter, Will Linthicum Jun 2014

Looking For Small Changes In Heat Capacity Using A Differential Scanning Calorimeter, Will Linthicum

Honors Theses

One of the major difficulties in development of renewable energy is the lack of an adequate and economical means of energy storage. In the case of concentrated solar power a large mass of thermal fluid is required to store a reasonable amount of energy. This is primarily because the fluids tend to have a low specific heat capacity. Formulating composites of these fluids can enhance their specific heat capacity and avails opportunities to make concentrated solar power more attractive. In most cases, the specific heat capacity of composite materials is a weighted average of the individual component heat capacities. This, …


Study Of Water Transport Phenomena On Cathode Of Pemfcs Using Monte Carlo Simulation, Karn Soontrapa May 2014

Study Of Water Transport Phenomena On Cathode Of Pemfcs Using Monte Carlo Simulation, Karn Soontrapa

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation deals with the development of a three-dimensional computational model of water transport phenomena in the cathode catalyst layer (CCL) of PEMFCs. The catalyst layer in the numerical simulation was developed using the optimized sphere packing algorithm. The optimization technique named the adaptive random search technique (ARSET) was employed in this packing algorithm. The ARSET algorithm will generate the initial location of spheres and allow them to move in the random direction with the variable moving distance, randomly selected from the sampling range, based on the Lennard-jones potential of the current and new configuration. The solid fraction values obtained …


Improving Indoor Air Quality Through Botanical Air Filtration In Energy Efficient Residences, Daniel William Newkirk Apr 2014

Improving Indoor Air Quality Through Botanical Air Filtration In Energy Efficient Residences, Daniel William Newkirk

Open Access Theses

According to the U.S. EPA, the average American spends 90% of their time indoors where pollutants are two to five times more prevalent than outside. The consequences of these pollutants are estimated to cost the U.S. 125 billion dollars in lost health and productivity. Background literature suggests botanical air filtration may be able to solve this problem by leveraging the natural ability of plants to purify indoor air. By improving indoor air quality, energy consumption can also be reduced by bringing in less outside air to dilute contaminants within the space. A botanical air filter, called the Biowall, was designed …


A Metaevaluation Of Energy Efficiency Evaluations, Brandy Brown Apr 2014

A Metaevaluation Of Energy Efficiency Evaluations, Brandy Brown

Dissertations

This study systematically reviews the methodological characteristics of energy efficiency evaluations and uses metaevaluation to assess its quality. Metaevaluation is used to systematically assess the quality of evaluation products, confirm that evaluations deliver sound findings and conclusions, are useful to the client, are credible, are ethically conducted, and are done as cost-effective as possible. The results of this study show that the ability to accurately assess evaluation for methodological quality using evaluations reports as a primary data source depends on the presence of detailed descriptions of evaluation methods. Furthermore, the study suggests that methodological variations of energy efficiency evaluations coalesce …


Design And Evaluation Of A High Temperature/Pressure Supercritical Carbon Dioxide Direct Tubular Receiver For Concentrating Solar Power Applications, Jesus Daniel Ortega Jan 2014

Design And Evaluation Of A High Temperature/Pressure Supercritical Carbon Dioxide Direct Tubular Receiver For Concentrating Solar Power Applications, Jesus Daniel Ortega

Open Access Theses & Dissertations

This work focuses on the development of a solar power thermal receiver for a supercritical-carbon dioxide (sCO2), Brayton power-cycle to produce ~1 MWe. Closed-loop sCO2 Brayton cycles are being evaluated in combination with concentrating solar power to provide higher thermal-to-electric conversion efficiencies relative to conventional steam Rankine cycles. High temperatures (923 - 973 K) and pressures (20 - 25 MPa) are required in the solar receiver to achieve thermal efficiencies of ~50%, making concentrating solar power (CSP) technologies a competitive alternative to current power generation methods. In this study, the CSP receiver is required to achieve an outlet temperature of …


Design And Development Of Scalable Solar Powered Water Purification Systems For Developing Nations, Shavin Pinto Jan 2014

Design And Development Of Scalable Solar Powered Water Purification Systems For Developing Nations, Shavin Pinto

Doctoral Dissertations and Master's Theses

This thesis presents the design and development of solar powered water purification systems. The systems were designed to meet specific customer requirements that were established from the experiences gained after the installation of five water purification systems in various Haitian communities. The systems are scalable and are able to supply 10,000-20,000 gallons of clean drinking water per day. The design consists of a three-stage filtration system with a disc-type sediment filter, a 0.1 micron ultrafiltration membrane, and an ultraviolet light for disinfection. The backwash cycle extends the life of the ultrafiltration membrane to 4-7 years before a new filter is …