UMD Theses and Dissertations

Permanent URI for this collectionhttp://hdl.handle.net/1903/3

New submissions to the thesis/dissertation collections are added automatically as they are received from the Graduate School. Currently, the Graduate School deposits all theses and dissertations from a given semester after the official graduation date. This means that there may be up to a 4 month delay in the appearance of a given thesis/dissertation in DRUM.

More information is available at Theses and Dissertations at University of Maryland Libraries.

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    MODELING AND OPTIMIZATION OF MICROGRID ENERGY SYSTEM FOR SHIP APPLICATIONS
    (2016) Cao, Tao; Radermacher, Reinhard; Mechanical Engineering; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)
    Microgrid energy systems are widely used in remote communities and off-grid sites, where primary energy supplies are dominated by fuels. Limited attentions have been paid to ship applications, which require thorough and in-depth research to address their unique challenges and increasing pressure on reducing fuel consumptions. This dissertation presents comprehensive microgrid system studies for ship applications in four aspects: component modeling and study, dynamic system modeling on novel designs, novel optimization based system design framework development and investigations on two enhancement options: integrating with separate sensible and latent cooling systems, maximizing heat recovery through pinch analysis. Comprehensive component studies consist of new component models addressing unique features of ship applications. Desiccant wheels with new materials were investigated experimentally, especially under high humidity conditions for ship applications. Dynamic system modeling was conducted on several novel solar energy and waste heat powered systems, with a focus on their capabilities to reduce fuel consumptions and CO2 emissions. Results were validated against experimental data. Payload and economic studies were conducted to evaluate feasibilities of applying the designs to ship applications. A novel optimization based design framework was then developed. The framework is capable of conducting both system configuration and control strategy optimization under transient weather and load profiles, differentiating itself with current control strategy focused energy system optimization studies (Jradi and Riffat, 2014). It also extends Buoro et al. (2012)’s study on system configuration optimization to complete design from scratch with comprehensive equipment selections and integrating options. The design framework was demonstrated through a case study on container ships. Optimized systems and control strategies were found from three different scenarios: single-objective optimization, bi-objective optimization and optimization under uncertainty. Finally, two previously listed options were investigated to enhance microgrid system performance regarding thermal comfort and fuel savings. This research fills current research gaps on microgrid energy system for ship applications. It also serves as the basis for advanced microgrid system analysis framework for any applications. The dynamic system modeling platform, optimization based design framework and enhancement methods can help engineers develop and evaluate ultra-high efficiency designs, aiming to reduce energy consumptions and CO2 emissions.