Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 157 for “"working fluid"”.
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Nitrous oxide as working fluid in enhanced geothermal systems (EGS)
… tesis doctoral presenta un estudio sobre los fluidos de trabajo que pueden usarse en un Sistema Geotérmico Mejorado (EGS), como una forma de hacer un uso eficiente y a gran escala de los enormes recursos que ofrece la energía geotérmica. En primer lugar, investigamos los dos fluidos de trabajo …
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Evaluation of ethane as a power conversion system working fluid for fast reactors
A supercritical ethane working fluid Brayton power conversion system is evaluated as an alternative to carbon dioxide. The HSC® chemical kinetics code was used to study thermal dissociation and chemical interactions for ethane and other coolants under a variety of conditions. The NIST database was …
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Analysis of hydraulic power transduction in regenerative rotary shock absorbers as function of working fluid kinematic viscosity
… to investigate the relationship of kinematic fluid viscosity to the effective power transduction seen by a hydraulic motor. Applications of this research specifically relate to energy recovery from a vehicle suspension system through the shock absorbers. A regenerative, hydraulic-based, rotary …
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The efficient collection and long term storage of solar energy in the UK, using air as the working fluid
This thesis describes the results of four years work on the design, construction, testing and evaluation of a high performance air heating collector designed to supply heat to a communal interseasonal store, which could heat many houses all the year round in the U.K. Interseasonal storage utilizing …
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Transient heat transfer analysis of heat exchangers in a Marnoch Heat Engine
… is modelled. The temperature variations of the working fluid, the heating fluid and the wall, are calculated. The temperature distribution of the fluids and the wall over the length of the heat exchanger is also calculated. It is found that the temperature of the working fluid rises sharply to a …
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MITIGATION OF GEAR MESH-FREQUENCY VIBRATIONS UTILIZING A HYDROSTATIC BEARING
… drive.</p><p>Hydrostatic bearings are a class of fluid bearings consisting of externally pressurized fluid trapped in a recess to provide the necessary bearing support. Previous research has assumed the incompressibility of the working fluid in a hydrostatic bearing. In practice, the working fluid …
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Design considerations of a 15kW heat exchanger for the CSPonD Project
… salt receiver is proposed. Using an intermediate working fluid to shuttle heat energy between the receiver and a power cycle working fluid, thermal loads in the heat exchanger are reduced when compared to a similar alternative heat extraction system without a buffer-like intermediate working …
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Low temperature glide cycles for energy storage applications: Thermodynamic and capital cost analysis
… differs by employing a zeotropic mixture for the working fluid. As a result, evaporation and condensation occur non-isothermally over a temperature “glide”, making this cycle a good match for sensible heat storage. The mixture used for the working fluid must be chosen carefully. Its effective heat …
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OPTIMIZATION OF A PIEZOELECTRIC ACOUSTICAL COMPRESSOR
… linear finite element model describing a fluid interacting with a piezoelectric actuator is developed. This system is used to generate finite amplitude standing waves in an acoustic cavity with rigid walls. The model includes the effects of viscous and thermal damping of the fluid at the …
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Second law analysis of a waste heat recovery combined power cycle using transcritical carbon dioxide
… heat exchanger effectiveness, a transcritical working fluid is used in the Rankine bottoming cycle to better match the heating curve of the sensible heat source. Carbon dioxide is selected as the working fluid because it possesses a relatively low critical temperature which makes it attractive …
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Analysis of required supporting systems for the supercritical CO₂ power conversion system
… been drawn to the viability of using S-CO₂ as a working fluid in modem reactor designs. Near the critical point, CO₂ has a rapid rise in density allowing a significant reduction in the compressor work of a closed Brayton Cycle. Therefore > 45% efficiency can be achieved at much more moderate …
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Dual-temperature Kalina cycle for geothermal-solar hybrid power systems
… of power generation, a plant design where the working fluid is heated (and partially vaporized) by low- to medium-temperature geothermal brine, before being further vaporized by solar heat, presents an opportunity for efficient operation of the power plant. Given a set of design parameters and …
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Design And Optimization Of Organic Rankine Cycle For Low Temperature Geothermal Power Plant
… observed between the critical temperature of the working fluid and the efficiency for the cycle. Exergy analysis of the cycle revealed that the highest exergy destruction occurs in evaporator followed by condenser, turbine and working fluid pump for the base case scenarios.</p> <p>Performance of …
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The Acoustic Expander: A New Expansion Machine for Use in Cryogenic Refrigeration
… mechanical energy from the expansion of a working fluid from high-pressure to low-pressure thereby cooling the low-pressure fluid for use in refrigeration. The novelty of the acoustic expander is that the mechanical energy is transferred through a gaseous acoustic wave, as opposed to a …
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Surface Patterning and Rotordynamic Response of Annular Pressure Seals Used in Turbomachinery
… instability risk in rotor dynamic components as fluids-structure interactions take place. In addition, critical damage of rotordynamic components can result from high level vibrations of supporting bearing system, where the reduced rotor speed can lead to system operating near the rotor critical …
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Design, Fabrication, and Experimental Investigation of an Additively Manufactured Flat Plate Heat Pipe
… are passive heat transfer devices in which a working fluid is sealed inside a metal enclosure. Properly designed wick structures on the inner surface of the heat pipe are critical as the wick aids in the return of the condensed liquid from the cold end back to the hot end where the …
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Full-scale operation of a tubular ultrafiltration system in the treatment of oily waste
… in West Virginia uses an oil-water (metal working fluid) in their rolling mill process for lubrication. In the past, the company collected the oily-waste into two lined waste ponds with a combined holding capacity of 5 million gallons. Separation of the oil-water mixture occurred as …
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Flat-Plate Solar Collectors for Water Heating with Improved Heat Transfer for Application in Climatic Conditions of the Mediterranean Region
… of energy conversion from the collector to the working fluid. This is accomplished by employing an aluminium grid placed in the channels of a collector to induce a gradient of heat capacitance. This novel technique is tested both theoretically by means of simplistic designs using Computational …
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Tools for supercritical carbon dioxide cycle analysis and the cycle's applicability to sodium fast reactors
… including the choice of steam or C0₂ as the working fluid. This work has developed some of the tools necessary for evaluating different design core and balance of plant options. Much of it has concentrated on the S-C0₂ Recompression cycle. S-C0₂ promises to be useful as a working fluid in …
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