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.
Results
Showing 1 to 20 of 48 for “"Coefficient of Performance"”.
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Integrated heat pump options for heat upgrading in Cu-Cl cycle for hydrogen production
… for hydrogen. The Cu-Cl cycle has a number of endothermic reactions that take place at high temperature level. One of the highest temperature demanding components in the Cu-Cl cycle is the copper oxychloride decomposition reactor. This thesis proposes two potential methods to address this …
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Thermoelectric cooler design
Thermoelectric Cooler Design is a Microsoft Windows program to be used as an aid in the design of thermoelectric cooler devices. This program was written to be used to quickly model and compare alternative designs. A couple's optimum coefficient of performance and maximum heat pumping can be …
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Design of a residential air source heat pump for extremely cold climates
… for space heating applications, however, their performance drastically degrades in low ambient temperatures. An innovative design is proposed in this thesis that can switch operating modes to allow efficient heating operation in an ambient temperature range of -50 °C to +20 °C. The proposed …
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Design and development of a novel liquid desiccant air-conditioning system
… rapidly and incumbent direct-expansion system performance is poor. Unlike other LDAC systems, DECAL is modular. This allows the indoor hardware to remain small and non-intrusive, and offers increased flexibility to install the system in existing building stock without costly changes to the …
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Potentials for COP increase in vapor compression systems
… presents an experimental and numerical study of three different opportunities for COP increase in vapor compression systems: work recovery ejectors, condenser subcooling and increase of relative size of heat exchangers (HXs). Regarding work recovery ejectors, experimental results showed that …
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Design and analysis of the power electronics system for the Lean Operation Rotary Adsorption Cooling System
… sustainable space cooling systems in the face of the growing threat of global warming. While traditional cooling systems rely on large amounts of grid electricity and a suite of environmentally harmful chemicals, the LORACS instead leverages thermal properties of water and desiccants to create …
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Nanoscale thermal systems in subcritical region
The behavior of a nanoscale fluid system in the subcritical region is investigated using molecular simulation. The fluid used is argon and the intermolecular forces are represented by the Lennard-Jones potential. The simulations show that the phase change in a nanoscale system becomes continuous as …
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Processes Involving Acid Gas Solubility In Room Temperature Ionic Liquids (RTILs)
The literature contains a number of thermodynamic studies involving the solubility of acid gases in RTILs. This thesis looks at using these studies in the context of two processes: membrane separation and absorption refrigeration cycles. The first part of this study investigated the separation of a …
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Refrigerant charge reduction in small commercial refrigeration systems
This paper presents analysis of location of refrigerant inventory and numerical results of charge reduction in a typical bottle cooler. The original unit was first characterized by determining its capacity, the coefficient of performance (COP), pull-down characteristics, and total charge using …
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Exploring the Performance of Active Thermal Tiles for Space Applications
… 88 different conditions over a temperature range of 280K to 310K. The power supplied to the electronic component was varied between 5W and 40W, and the current running through the ATTs was varied between 0.0A and 3.0A. Conductance and the coefficient of performance were measured, and a performance …
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A THERMO-ECONOMIC STUDY OF SOLAR COOLING/HOT WATER SYSTEMS
… requirements for absorption cooling. The performance could be improved by incorporating a water heating loop in the basic cooling system so that the collectors could be utilised for hot water production during such "idle" periods. Commercial applications for such hybrid systems exist in …
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Theoretical and Experimental Analysis of Liquid Flooded Compression in Scroll Compressors
… large temperature lifts, the increase in system coefficient of performance can be greater than 50%. In order to better understand the liquid-flooded working process, a detailed scroll compressor model has been developed which comprises a geometric model and an overall compressor model. The …
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Improvements on performance of a heat pump water heater system
… friendly nature with low energy consumption. The Coefficient of Performance (COP) of the HPWH can be influenced by multiple factors: ambient temperature, relative humidity, hot water usage profile, the size and shape of heat exchangers (evaporator and condenser), type and shape of compressor, …
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Proposed Design for a Coupled Ground-Source Heat Pump/Energy Recovery Ventilator System to Reduce Building Energy Demand
… thesis focuses on reducing the energy demand of a residential building by using a coupled ground-source heat pump/energy recovery ventilation (GSHP-ERV) system to present a novel approach to space condition and domestic hot water supply for a residence. The proposed system is capable of …
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Investigations into solar powered diffusion-absorption cooling machines
… airconditioning in domestic housing as well as office and hotel buildings. Presently there are no thermally driven absorption cooling machines available on the market that can provide a smaller cooling capacity than 10kW for cooling buildings. For this reason, two single-effect solar heated …
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Flow modelling of scroll compressors and expanders
The use of scroll compressors in refrigeration systems is becoming increasing popular. However the development and use of a scroll machine as an expander to replace a throttle valve has never been reported. This thesis describes the work carried out to develop a two phase scroll expander for use in …
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Field Testing the Effects of Low Reynolds Number on the Power Performance of the Cal Poly Wind Power Research Center Small Wind Turbine
<p>This thesis report investigates the effects of low Reynolds number on the power performance of a 3.74 m diameter horizontal axis wind turbine. The small wind turbine was field tested at the Cal Poly Wind Power Research Center to acquire its coefficient of performance, <em>C<sub>p</sub></em>, …
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Examining the feasibility of a novel ground-storage cooling system
… needed to maintain occupant comfort in summer is often provided by condensing the excess moisture onto surfaces cooled by cold water. The systems currently used to provide the cold water have limited efficiencies, so alternative systems must be sought in order to achieve reductions in building …
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Modeling and design of a power boosted turbo-compression cooling system
… challenges through the modeling and design of a volume optimized turbo-compression cooling system (TCCS). The TCCS is driven by low-grade waste heat in the shipboard diesel generator set jacket water and lubrication oil and was designed to be a drop-in replacement of electric chiller …
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A comprehensive model of electric-field-enhanced jumping-droplet condensation on superhydrophobic surfaces
… due to their potential to enhance heat transfer performance by shedding positively charged water droplets via coalescence-induced droplet jumping at length scales below the capillary length, and allowing the use of external electric fields to enhance droplet removal and heat transfer, in what has …
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