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Description
Wind measurements are fundamental inputs for the evaluation of potential energy yield and performance of wind farms. Three-dimensional scanning coherent Doppler lidar (CDL) may provide a new basis for wind farm site selection, design, and control. In this research, CDL measurements obtained from multiple wind energy developments are analyzed and a novel wind farm control approach has been modeled. The possibility of using lidar measurements to more fully characterize the wind field is discussed, specifically, terrain effects, spatial variation of winds, power density, and the effect of shear at different layers within the rotor swept area. Various vector retrieval methods have been applied to the lidar data, and results are presented on an elevated terrain-following surface at hub height. The vector retrieval estimates are compared with tower measurements, after interpolation to the appropriate level. CDL data is used to estimate the spatial power density at hub height. Since CDL can measure winds at different vertical levels, an approach for estimating wind power density over the wind turbine rotor-swept area is explored. Sample optimized layouts of wind farm using lidar data and global optimization algorithms, accounting for wake interaction effects, have been explored. An approach to evaluate spatial wind speed and direction estimates from a standard nested Coupled Ocean and Atmosphere Mesoscale Prediction System (COAMPS) model and CDL is presented. The magnitude of spatial difference between observations and simulation for wind energy assessment is researched. Diurnal effects and ramp events as estimated by CDL and COAMPS were inter-compared. Novel wind farm control based on incoming winds and direction input from CDL's is developed. Both yaw and pitch control using scanning CDL for efficient wind farm control is analyzed. The wind farm control optimizes power production and reduces loads on wind turbines for various lidar wind speed and direction inputs, accounting for wind farm wake losses and wind speed evolution. Several wind farm control configurations were developed, for enhanced integrability into the electrical grid. Finally, the value proposition of CDL for a wind farm development, based on uncertainty reduction and return of investment is analyzed.
ContributorsKrishnamurthy, Raghavendra (Author) / Calhoun, Ronald J (Thesis advisor) / Chen, Kangping (Committee member) / Huang, Huei-Ping (Committee member) / Fraser, Matthew (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2013
Description
An eco-industrial park (EIP) is an industrial ecosystem in which a group of co-located firms are involved in collective resource optimization with each other and with the local community through physical exchanges of energy, water, materials, byproducts and services - referenced in the industrial ecology literature as "industrial symbiosis". EIPs, when compared with standard industrial resource sharing networks, prove to be of greater public advantage as they offer improved environmental and economic benefits, and higher operational efficiencies both upstream and downstream in their supply chain.
Although there have been many attempts to adapt EIP methodology to existing industrial sharing networks, most of them have failed for various factors: geographic restrictions by governmental organizations on use of technology, cost of technology, the inability of industries to effectively communicate their upstream and downstream resource usage, and to diminishing natural resources such as water, land and non-renewable energy (NRE) sources for energy production.
This paper presents a feasibility study conducted to evaluate the comparative environmental, economic, and geographic impacts arising from the use of renewable energy (RE) and NRE to power EIPs. Life Cycle Assessment (LCA) methodology, which is used in a variety of sectors to evaluate the environmental merits and demerits of different kinds of products and processes, was employed for comparison between these two energy production methods based on factors such as greenhouse gas emission, acidification potential, eutrophication potential, human toxicity potential, fresh water usage and land usage. To complement the environmental LCA analysis, levelized cost of electricity was used to evaluate the economic impact. This model was analyzed for two different geographic locations; United States and Europe, for 12 different energy production technologies.
The outcome of this study points out the environmental, economic and geographic superiority of one energy source over the other, including the total carbon dioxide equivalent emissions, which can then be related to the total number of carbon credits that can be earned or used to mitigate the overall carbon emission and move closer towards a net zero carbon footprint goal thus making the EIPs truly sustainable.
Although there have been many attempts to adapt EIP methodology to existing industrial sharing networks, most of them have failed for various factors: geographic restrictions by governmental organizations on use of technology, cost of technology, the inability of industries to effectively communicate their upstream and downstream resource usage, and to diminishing natural resources such as water, land and non-renewable energy (NRE) sources for energy production.
This paper presents a feasibility study conducted to evaluate the comparative environmental, economic, and geographic impacts arising from the use of renewable energy (RE) and NRE to power EIPs. Life Cycle Assessment (LCA) methodology, which is used in a variety of sectors to evaluate the environmental merits and demerits of different kinds of products and processes, was employed for comparison between these two energy production methods based on factors such as greenhouse gas emission, acidification potential, eutrophication potential, human toxicity potential, fresh water usage and land usage. To complement the environmental LCA analysis, levelized cost of electricity was used to evaluate the economic impact. This model was analyzed for two different geographic locations; United States and Europe, for 12 different energy production technologies.
The outcome of this study points out the environmental, economic and geographic superiority of one energy source over the other, including the total carbon dioxide equivalent emissions, which can then be related to the total number of carbon credits that can be earned or used to mitigate the overall carbon emission and move closer towards a net zero carbon footprint goal thus making the EIPs truly sustainable.
ContributorsGupta, Vaibhav (Author) / Calhoun, Ronald J (Thesis advisor) / Dooley, Kevin (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2014
Description
Among the various end-use sectors, the commercial sector is expected to have the second-largest increase in total primary energy consump¬tion from 2009 to 2035 (5.8 quadrillion Btu) with a growth rate of 1.1% per year, it is the fastest growing end-use sectors. In order to make major gains in reducing U.S. building energy use commercial sector buildings must be improved. Energy benchmarking of buildings gives the facility manager or the building owner a quick evaluation of energy use and the potential for energy savings. It is the process of comparing the energy performance of a building to standards and codes, to a set target performance or to a range of energy performance values of similar buildings in order to help assess opportunities for improvement. Commissioning of buildings is the process of ensuring that systems are designed, installed, functionally tested and capable of being operated and maintained according to the owner's operational needs. It is the first stage in the building upgrade process after it has been assessed using benchmarking tools. The staged approach accounts for the interactions among all the energy flows in a building and produces a systematic method for planning upgrades that increase energy savings. This research compares and analyzes selected benchmarking and retrocommissioning tools to validate their accuracy such that they could be used in the initial audit process of a building. The benchmarking study analyzes the Energy Use Intensities (EUIs) and Ratings assigned by Portfolio Manager and Oak Ridge National Laboratory (ORNL) Spreadsheets. The 90.1 Prototype models and Commercial Reference Building model for Large Office building type were used for this comparative analysis. A case-study building from the DOE - funded Energize Phoenix program was also benchmarked for its EUI and rating. The retrocommissioning study was conducted by modeling these prototype models and the case-study building in the Facility Energy Decision System (FEDS) tool to simulate their energy consumption and analyze the retrofits suggested by the tool. The results of the benchmarking study proved that a benchmarking tool could be used as a first step in the audit process, encouraging the building owner to conduct an energy audit and realize the energy savings potential. The retrocommissioning study established the validity of FEDS as an accurate tool to simulate a building for its energy performance using basic inputs and to accurately predict the energy savings achieved by the retrofits recommended on the basis of maximum LCC savings.
ContributorsAgnihotri, Shreya Prabodhkumar (Author) / Reddy, T Agami (Thesis advisor) / Bryan, Harvey (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2011
Description
Nanoparticles are ubiquitous in various fields due to their unique properties not seen in similar bulk materials. Among them, core-shell composite nanoparticles are an important class of materials which are attractive for their applications in catalysis, sensing, electromagnetic shielding, drug delivery, and environmental remediation. This dissertation focuses on the study of core-shell type of nanoparticles where a polymer serves as the core and inorganic nanoparticles are the shell. This is an interesting class of supramolecular building blocks and can "exhibit unusual, possibly unique, properties which cannot be obtained simply by co-mixing polymer and inorganic particles". The one-step Pickering emulsion polymerization method was successfully developed and applied to synthesize polystyrene-silica core-shell composite particles. Possible mechanisms of the Pickering emulsion polymerization were also explored. The silica nanoparticles were thermodynamically favorable to self-assemble at liquid-liquid interfaces at the initial stage of polymerization and remained at the interface to finally form the shells of the composite particles. More importantly, Pickering emulsion polymerization was employed to synthesize polystyrene/poly(N-isopropylacrylamide) (PNIPAAm)-silica core-shell nanoparticles with N-isopropylacrylamide incorporated into the core as a co-monomer. The composite nanoparticles were temperature sensitive and could be up-taken by human prostate cancer cells and demonstrated effectiveness in drug delivery and cancer therapy. Similarly, by incorporating poly-2-(N,N)-dimethylamino)ethyl methacrylate (PDMA) into the core, pH sensitive core-shell composite nanoparticles were synthesized and applied as effective carriers to release a rheological modifier upon a pH change. Finally, the research focuses on facile approaches to engineer the transition of the temperature-sensitive particles and develop composite core-shell nanoparticles with a metallic shell.
ContributorsSanyal, Sriya (Author) / Dai, Lenore L. (Thesis advisor) / Jiang, Hanqing (Committee member) / Lind, Mary L. (Committee member) / Phelan, Patrick (Committee member) / Rege, Kaushal (Committee member) / Arizona State University (Publisher)
Created2012
Description
Pavement surface temperature is calculated using a fundamental energy balance model developed previously. It can be studied using a one-dimensional mathematical model. The input to the model is changed, to study the effect of different properties of pavement on its diurnal surface temperatures. It is observed that the pavement surface temperature has a microclimatic effect on the air temperature above it. A major increase in local air temperature is caused by heating of solid surfaces in that locality. A case study was done and correlations have been established to calculate the air temperature above a paved surface. Validation with in-situ pavement surface and air temperatures were made. Experimental measurement for the city of Phoenix shows the difference between the ambient air temperature of the city and the microclimatic air temperature above the pavement is approximately 10 degrees Fahrenheit. One mitigation strategy that has been explored is increasing the albedo of the paved surface. Although it will reduce the pavement surface temperature, leading to a reduction in air temperature close to the surface, the increased pavement albedo will also result in greater reflected solar radiation directed towards the building, thus increasing the building solar load. The first effect will imply a reduction in the building energy consumption, while the second effect will imply an increase in the building energy consumption. Simulation is done using the EnergyPlus tool, to find the microclimatic effect of pavement on the building energy performance. The results indicate the cooling energy savings of an office building for different types of pavements can be variable as much as 30%.
ContributorsSengupta, Shawli (Author) / Phelan, Patrick (Thesis advisor) / Kaloush, Kamil (Committee member) / Calhoun, Ronald (Committee member) / Arizona State University (Publisher)
Created2015
Description
In recent years, 40% of the total world energy consumption and greenhouse gas emissions is because of buildings. Out of that 60% of building energy consumption is due to HVAC systems. Under current trends these values will increase in coming years. So, it is important to identify passive cooling or heating technologies to meet this need. The concept of thermal energy storage (TES), as noted by many authors, is a promising way to rectify indoor temperature fluctuations. Due to its high energy density and the use of latent energy, Phase Change Materials (PCMs) are an efficient choice to use as TES. A question that has not satisfactorily been addressed, however, is the optimum location of PCM. In other words, given a constant PCM mass, where is the best location for it in a building? This thesis addresses this question by positioning PCM to obtain maximum energy savings and peak time delay. This study is divided into three parts. The first part is to understand the thermal behavior of building surfaces, using EnergyPlus software. For analysis, a commercial prototype building model for a small office in Phoenix, provided by the U.S. Department of Energy, is applied and the weather location file for Phoenix, Arizona is also used. The second part is to justify the best location, which is obtained from EnergyPlus, using a transient grey box building model. For that we have developed a Resistance-Capacitance (RC) thermal network and studied the thermal profile of a building in Phoenix. The final part is to find the best location for PCMs in buildings using EnergyPlus software. In this part, the mass of PCM used in each location remains unchanged. This part also includes the impact of the PCM mass on the optimized location and how the peak shift varies. From the analysis, it is observed that the ceiling is the best location to install PCM for yielding the maximum reduction in HVAC energy consumption for a hot, arid climate like Phoenix.
ContributorsPrem Anand Jayaprabha, Jyothis Anand (Author) / Phelan, Patrick (Thesis advisor) / Wang, Robert (Committee member) / Parrish, Kristen (Committee member) / Arizona State University (Publisher)
Created2018
Description
Hydrogel polymers have been the subject of many studies, due to their fascinating ability to alternate between being hydrophilic and hydrophobic, upon the application of appropriate stimuli. In particular, thermo-responsive hydrogels such as N-Isopropylacrylamide (NIPAM), which possess a unique lower critical solution temperature (LCST) of 32°C, have been leveraged for membrane-based processes such as using NIPAM as a draw agent for forward osmosis (FO) desalination. The low LCST temperature of NIPAM ensures that fresh water can be recovered, at a modest energy cost as compared to other thermally based desalination processes which require water recovery at higher temperatures. This work studies by experimentation, key process parameters involved in desalination by FO using NIPAM and a copolymer of NIPAM and Sodium Acrylate (NIPAM-SA). It encompasses synthesis of the hydrogels, development of experiments to effectively characterize synthesized products, and the measuring of FO performance for the individual hydrogels. FO performance was measured using single layers of NIPAM and NIPAM-SA respectively. The values of permeation flux obtained were compared to relevant published literature and it was found to be within reasonable range. Furthermore, a conceptual design for future large-scale implementation of this technology is proposed. It is proposed that perhaps more effort should focus on physical processes that have the ability to increase the low permeation flux of hydrogel driven FO desalination systems, rather than development of novel classes of hydrogels
ContributorsAbdullahi, Adnan None (Author) / Phelan, Patrick (Thesis advisor) / Wang, Robert (Committee member) / Dai, Lenore (Committee member) / Arizona State University (Publisher)
Created2019
Description
One of the key infrastructures of any community or facility is the energy system which consists of utility power plants, distributed generation technologies, and building heating and cooling systems. In general, there are two dimensions to “sustainability” as it applies to an engineered system. It needs to be designed, operated, and managed such that its environmental impacts and costs are minimal (energy efficient design and operation), and also be designed and configured in a way that it is resilient in confronting disruptions posed by natural, manmade, or random events. In this regard, development of quantitative sustainability metrics in support of decision-making relevant to design, future growth planning, and day-to-day operation of such systems would be of great value. In this study, a pragmatic performance-based sustainability assessment framework and quantitative indices are developed towards this end whereby sustainability goals and concepts can be translated and integrated into engineering practices.
New quantitative sustainability indices are proposed to capture the energy system environmental impacts, economic performance, and resilience attributes, characterized by normalized environmental/health externalities, energy costs, and penalty costs respectively. A comprehensive Life Cycle Assessment is proposed which includes externalities due to emissions from different supply and demand-side energy systems specific to the regional power generation energy portfolio mix. An approach based on external costs, i.e. the monetized health and environmental impacts, was used to quantify adverse consequences associated with different energy system components.
Further, this thesis also proposes a new performance-based method for characterizing and assessing resilience of multi-functional demand-side engineered systems. Through modeling of system response to potential internal and external failures during different operational temporal periods reflective of diurnal variation in loads and services, the proposed methodology quantifies resilience of the system based on imposed penalty costs to the system stakeholders due to undelivered or interrupted services and/or non-optimal system performance.
A conceptual diagram called “Sustainability Compass” is also proposed which facilitates communicating the assessment results and allow better decision-analysis through illustration of different system attributes and trade-offs between different alternatives. The proposed methodologies have been illustrated using end-use monitored data for whole year operation of a university campus energy system.
New quantitative sustainability indices are proposed to capture the energy system environmental impacts, economic performance, and resilience attributes, characterized by normalized environmental/health externalities, energy costs, and penalty costs respectively. A comprehensive Life Cycle Assessment is proposed which includes externalities due to emissions from different supply and demand-side energy systems specific to the regional power generation energy portfolio mix. An approach based on external costs, i.e. the monetized health and environmental impacts, was used to quantify adverse consequences associated with different energy system components.
Further, this thesis also proposes a new performance-based method for characterizing and assessing resilience of multi-functional demand-side engineered systems. Through modeling of system response to potential internal and external failures during different operational temporal periods reflective of diurnal variation in loads and services, the proposed methodology quantifies resilience of the system based on imposed penalty costs to the system stakeholders due to undelivered or interrupted services and/or non-optimal system performance.
A conceptual diagram called “Sustainability Compass” is also proposed which facilitates communicating the assessment results and allow better decision-analysis through illustration of different system attributes and trade-offs between different alternatives. The proposed methodologies have been illustrated using end-use monitored data for whole year operation of a university campus energy system.
ContributorsMoslehi, Salim (Author) / Reddy, T. Agami (Thesis advisor) / Lackner, Klaus S (Committee member) / Parrish, Kristen (Committee member) / Pendyala, Ram M. (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2018
Description
Soft polymer composites with improved thermal conductivity are needed for the thermal management of electronics. Interfacial thermal boundary resistance, however, prevents the efficient use of many high thermal conductivity fill materials. Magnetic alignment of ferrous fill material enforces percolation of the high thermal conductivity fill, thereby shifting the governing boundary resistance to the particle- particle interfaces and increasing the directional thermal conductivity of the polymer composite. Magnetic alignment maximizes the thermal conductivity while minimizing composite stiffening at a fill fraction of half the maximum packing factor. The directional thermal conductivity of the composite is improved by more than 2-fold. Particle-particle contact engineering is then introduced to decrease the particle- particle boundary resistance and further improve the thermal conductivity of the composite.
The interface between rigid fill particles is a point contact with very little interfacial area connecting them. Silver and gallium-based liquid metal (LM) coatings provide soft interfaces that, under pressure, increase the interfacial area between particles and decrease the particle-particle boundary resistance. These engineered contacts are investigated both in and out of the polymer matrix and with and without magnetic alignment of the fill. Magnetically aligned in the polymer matrix, 350nm- thick silver coatings on nickel particles produce a 1.8-fold increase in composite thermal conductivity over the aligned bare-nickel composites. The LM coatings provide similar enhancements, but require higher volumes of LM to do so. This is due to the rapid formation of gallium oxide, which introduces additional thermal boundaries and decreases the benefit of the LM coatings.
The oxide shell of LM droplets (LMDs) can be ruptured using pressure. The pressure needed to rupture LMDs matches closely to thin-walled pressure vessel theory. Furthermore, the addition of tungsten particles stabilizes the mixture for use at higher pressures. Finally, thiols and hydrochloric acid weaken the oxide shell and boost the thermal performance of the beds of LMDs by 50% at pressures much lower than 1 megapascal (MPa) to make them more suitable for use in TIMs.
The interface between rigid fill particles is a point contact with very little interfacial area connecting them. Silver and gallium-based liquid metal (LM) coatings provide soft interfaces that, under pressure, increase the interfacial area between particles and decrease the particle-particle boundary resistance. These engineered contacts are investigated both in and out of the polymer matrix and with and without magnetic alignment of the fill. Magnetically aligned in the polymer matrix, 350nm- thick silver coatings on nickel particles produce a 1.8-fold increase in composite thermal conductivity over the aligned bare-nickel composites. The LM coatings provide similar enhancements, but require higher volumes of LM to do so. This is due to the rapid formation of gallium oxide, which introduces additional thermal boundaries and decreases the benefit of the LM coatings.
The oxide shell of LM droplets (LMDs) can be ruptured using pressure. The pressure needed to rupture LMDs matches closely to thin-walled pressure vessel theory. Furthermore, the addition of tungsten particles stabilizes the mixture for use at higher pressures. Finally, thiols and hydrochloric acid weaken the oxide shell and boost the thermal performance of the beds of LMDs by 50% at pressures much lower than 1 megapascal (MPa) to make them more suitable for use in TIMs.
ContributorsRalphs, Matthew (Author) / Rykaczewski, Konrad (Thesis advisor) / Wang, Robert Y (Thesis advisor) / Phelan, Patrick (Committee member) / Wang, Liping (Committee member) / Devasenathipathy, Shankar (Committee member) / Arizona State University (Publisher)
Created2019
Description
The research analyzes the transformation of wasted thermal energy into a usable form through thermogalvanic devices. This technology helps mitigate international growing energy demands. Building energy efficiency is a critical research topic, since the loads account for 40% of all energy demand in developed nations, and 30% in less developed nations. A significant portion of the energy consumed for heating and cooling, where a majority is dissipated to the ambient as waste heat. This research answers how much power output (µW·cm-2) can the thermogalvanic brick experimentally produce from an induced temperature gradient? While there are multiple avenues for the initial and optimized prototype design, one key area of interest relating to thermogalvanic devices is the effective surface area of the electrodes. This report highlights the experimental power output measurements of a Cu/Cu2+ thermogalvanic brick by manipulating the effective surface area of the electrodes. Across three meshes, the maximum power output normalized for temperature was found to be between 2.13-2.87 x 10-3 μWcm-2K-2. The highest normalized power output corresponded to the mesh with the highest effective surface area, which was classified as the fine mesh. This intuitively aligned with the theoretical understanding of surface area and maximum power output, where decreasing the activation resistance also reduces the internal resistance, which increases the theoretical maximum power.
ContributorsKiracofe, Ryan Moore (Author) / Phelan, Patrick (Thesis director) / El Asmar, Mounir (Committee member) / Mechanical and Aerospace Engineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2019-05