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 12 of 12 for “"HVAC&R"”.
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PLATE HEAT EXCHANGER IMPROVEMENTS WITH SHAPE OPTIMIZATION
… Air-Conditioning, and Refrigeration (HVAC&R). PHXs are favored by the HVAC&R industry due to their compactness, flexible sizing, close approach temperature, and good heat transfer performance. PHXs are increasingly utilized and becoming very competitive in two-phase flow applications …
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Impact of heat exchanger surface wettability on condensation, frosting, and defrosting performance under practical testing conditions
… air conditioning, and refrigeration (HVAC&R) systems. Both phenomena increase thermal resistance and airflow restriction, which diminish heat transfer, lower system capacity, and drive up energy consumption. In air-source heat pumps (ASHPs) and electric vehicle heat pumps (EV HPs), …
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Development of capacitive sensor to determine void fraction in horizontal and vertical tubes
… To apply this sensor to more applications in HVAC&R systems, electrodes with different axial lengths are built together to be compared. The comparison of signals from them show the signals are independent on axial length. Due to the non-uniformity of the electric field between the electrodes …
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Cop and capacity improvement through work and heat recovery by using vortex tube
… experimental validation of vortex tubes in HVAC&R systems are far less optimistic, which is often caused by the selection of cycle architectures that seem inappropriate for vortex tubes. This thesis takes a fresh look at performance of commercially available vortex tubes with refrigerant and …
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Enhanced phase change heat transfer through advanced fabrication techniques
… power generation, filtration, desalination, and HVAC&R (Heating, Ventilation, Air Conditioning and Refrigeration) systems utilize water as the working fluid. As a result, these industrial applications are susceptible to water phase change during operations. Heat transfer during vapor to liquid …
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Vortex-enhanced heat transfer by a new delta-winglet array
… low Reynolds numbers, representative of many HVAC&R applications and compact heat exchanger designs.
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Instability of flow boiling in parallel microchannels
… of energy conversion systems, including HVAC&R equipment. The compact microchannel design of a heat exchanger (MCHX) allows for significant reduction of its volume, weight, and raw material, in comparison to conventional fin-and-tube heat exchangers in HVAC&R systems. The current …
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The void fraction in headers of microchannel heat exchangers
In HVAC&R systems, microchannel heat exchangers (MCHEs) are commonly used with the advantages of compactness, the potential for reduction of charge, and improvement of heat transfer performance compared to other traditional heat exchangers. The void fraction in the headers affects the thermal …
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Study of transient oil migration at compressor and improved oil return
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-05-01
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Structured surfaces at the extremes of heat transfer
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-08-01
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Flow distribution in brazed plate heat exchangers
… air conditioning, and refrigeration (HVAC&R) industry for their compactness and high heat transfer coefficient. However, they suffer from the flow maldistribution among parallel plate channels. Especially when they are used as evaporators, the non-uniform distribution of two-phase …
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Design, build-up, and commissioning of R410A chiller facility for experimental investigation into the effect of compressor capacity modulation strategies on seasonal performance
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2024-05-01