Mechanical Engineering Commons^™

Applications Of Thermal Energy Storage With Electrified Heating And Cooling, Erich Ryan

Masters Theses

With a clear correlation between climate change and rising CO₂ emissions, decarbonization has garnered serious interest in many sectors to limit the adverse effects of global warming. Heating and cooling systems have been a focus of decarbonization efforts, with heat pumps becoming more popular in the United States and abroad. In fact, heating, ventilation, and air conditioning accounts for nearly 27% of total energy use in the United States [1]. Ground source heat pumps (GSHP) utilizing borehole heat exchangers (BHE) have been shown to be an effective method of electrifying heating and cooling systems, maintaining some of the best …

Development Of Phase Change Thermal Storage Medium: Cooking With More Power And Versatility, Martin Osei

Masters Theses

With an Insulated Solar Electric Cooker (ISEC), a 100 W solar panel directly cooks food while providing 5W off-grid electricity access; but it cooks slowly. Storing the day’s energy with phase change thermal storage allows ISEC to cook more rapidly as well as cook after sunset. The ISEC is made by sticking a 3ohm resistive to an aluminum pot (inner phase change assembly PCA) where another cooking pot fits. The resistive heater is surrounded by a bigger pot (outer PCA) that contains the PCM and is tightly sealed. The solar panel is connected to the resistive heater with a thermal …

Characterization Of Near Isothermal Compression And Expansion For Energy Storage, Saiid Kassaee

Doctoral Dissertations

As the global share of electricity generation from intermittent renewable energy sources increases, developing efficient and scalable electricity storage technologies becomes critical to modernizing the grid, matching the supply and demand, and raising the capacity factor of renewable generation. The Ground-Level Integrated Diverse Energy Storage (GLIDES) is an efficient energy storage technology invented at Oak Ridge National Laboratory (ORNL). GLIDES stores energy by compressing gas using a liquid piston in pressure vessels benefiting from employing hydraulic turbomachinery which are more efficient than gas turbomachinery. Therefore, GLIDES has higher round-trip efficiency (RTE) than Compressed Air Energy Storage (CAES). Since GLIDES employs …

Experimental Investigation Of Spray Cooling/Heating Of A Near-Isothermal Hydro-Pneumatic Energy Storage System, Saiid Kassaee

Masters Theses

Proposing experimental investigation of spray cooling/heating of a near-isothermal, scalable, efficient, high density, hydro-pneumatic integrated energy storage system; capable of spray cooling/heating during gas compression/expansion and capable of excess heat integration. The invented Ground-Level Integrated Diverse Energy Storage (GLIDES) is an energy storage technology capable of storing energy in high-pressure vessel using hydro-pneumatic concept. Indicated roundtrip efficiencies of 98% can be reached using the proposed technology marking an isothermal compression/expansion energy storage.

Optimization Of Titanium Liquid/Gas Diffusion Layers In Proton Exchange Membrane Electrolyzer Cells, Stuart Mccoy Steen

Masters Theses

Polymer electrolyte membrane electrolyzer cells (PEMECs), which are reverse PEM fuel cells (PEMFCs), are effective energy storage medium by producing hydrogen/oxygen from water using electricity from renewable energy sources. This is due in part because of its efficiency, high energy density, compact design, and large capacity. In a PEMEC, a liquid/gas diffusion layer (LGDL) is located between the catalyst layer and the current distributing flow field. The LGDL is expected to transport electrons, heat, and reactants/products to and from the catalyst layer with minimum voltage, current, thermal, interfacial, and fluidic losses. Carbon materials (carbon paper or carbon cloth), typically used …

Investigation Of Compressed Air Energy Storage Efficiency, James W. Keeney

Master's Theses

This study investigates Compressed Air Energy Storage (CAES) application in the

electrical power and transportation industries. Information concerning current CAES projects is

presented. A thorough thermodynamic analysis of the CAES process is completed; including

theoretical efficiency determination for several variants of the compression and expansion

processes. Industry claimed efficiencies ranging from 26% to 82% are presented and explained.

Isothermal and Isentropic efficiency baselines are developed. Energy density of compressed air

on both a mass and volume basis is compared to other energy storage methods. Best expected

efficiency of a hypothetical CAES system is determined to be 34% using currently achievable …

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 …