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Browsing by Author "Alrebei, Odi Fawwaz"

Now showing 1 - 3 of 3
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    Parametric Enhancement of a Window-Windcatcher for Enhanced Thermal Comfort and Natural Ventilation
    Obeidat, Laith M.; Alrebei, Odi Fawwaz; Nouh Ma’bdeh, Shouib; Al-Radaideh, Tamer; Amhamed, Abdulkarem I. (MDPI, 2023-05-09)
    Window-windcatchers, a passive ventilation method, have been shown to improve ventilation and enhance thermal comfort. Preliminary characterization of a novel window-windcatcher has been undertaken in a previous work, but no relationship had been identified between the actual ventilation rate (Qact), the wind velocity (VTw) and crucial design parameters such as the fins angle (ϴ)). In this paper, the relationship that quantifies how the window-windcatcher’s performance depends on VTw and ϴ was determined. Additionally, for the first time, the ventilation performance of the window-windcatcher was optimized by studying the effects of ϴ and the fins-wall distance (DW−f) through a Computational Fluid Dynamics parametric study (ANSYS)|. In this optimization approach, the angle ϴ and the distance DW−f corresponding to the maximum actual-to-required ventilation rate were found to be 80° and 45 cm, respectively. The actual ventilation rate increased by approximately 13.2% compared with the baseline design of the windcatcher (ϴ and DW−f equal to 40° and 45 cm, respectively); this corresponds to an increase of approximately 8.6% in the actual-to-required ventilation rate, according to the ASHRAE standards.
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    Quantifying CO2 Emissions and Energy Production from Power Plants to Run HVAC Systems in ASHRAE-Based Buildings
    Alrebei, Odi Fawwaz; Obeidat, Bushra; Al-Radaideh, Tamer; Le Page, Laurent M.; Hewlett, Sally; Al Assaf, Anwar H.; Amhamed, Abdulkarem I. (MDPI, 2022-11-22)
    Recent evidence available in the literature has highlighted that the high-energy consumption rate associated with air conditioning leads to the undesired “overcooling” condition in arid-climate regions. To this end, this study quantified the effects of increasing the cooling setpoint temperature on reducing energy consumption and CO2 emissions to mitigate overcooling. DesignBuilder software was used to simulate the performance of a generic building operating under the currently adopted ASHRAE HVAC criteria. It was found that increasing the cooling setpoint temperature by 1 °C will increase the operative temperature by approximately 0.25 °C and reduce the annual cooling electricity consumption required for each 1 m2 of an occupied area by approximately 8 kWh/year. This accounts for a reduction of 8% in cooling energy consumption compared to the ASHRAE cooling setpoint (i.e., t_s = 26 °C) and a reduction in the annual CO2 emission rate to roughly 4.8 kg/m2 °C. The largest reduction in cooling energy consumption and CO2 emissions was found to occur in October, with reduced rates of approximately–1.3 kWh/m2 °C and −0.8 kg/m2 °C, respectively.
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    State of the Art in Separation Processes for Alternative Working Fluids in Clean and Efficient Power Generation
    Alrebei, Odi Fawwaz; Amhamed, Abdulkarem I.; El-Naas, Muftah H.; Hayajnh, Mahmoud; Orabi, Yasmeen A.; Fawaz, Ward; Al-tawaha, Ahmad S.; Medina, Agustin Valera (MDPI, 2022-01)
    Gas turbines must now comply with much stricter emission control regulations. In fact, to combat the greenhouse effect, regulatory authorities have drastically reduced allowable emission levels. For example, in less than 12 years, the United States' Clean Air Act issued the New Source Performance Standards (NSPS), which tightened the NOx emission margin of natural gas combustion (from 75 ppm to 10 ppm). On the other hand, despite those efforts, the high demand for energy produced by fossil-fueled gas turbines in power plants has resulted in dramatic increases in anthropogenic CO2 and NOx emitted by gas combustors. Most systems responsible for these undesirable emissions are directly linked to power generation, with gas turbines playing a pivotal role. Yet, gas turbines are still widely used in power plants and will continue to meet the growing demand. Therefore, sequestration and separation techniques such as Carbon Capture and Storage (CCS) and Air Separation Units (ASU) are essential to reduce CO2 and NOx emissions while allowing large amounts of power to be generated from these systems. This paper provides an in-depth examination of the current state of the art in alternative working fluids utilized in the power generation industry (i.e., gas turbines, combustion). In addition, this paper highlights the recent contribution of integrating separation techniques, such as air separation, steam methane reforming, and water-gas shifting, to the power generation industry to facilitate a continuous and adequate supply of alternative working fluids.