Browsing by Author "Al-Mutawa, Nawaf"

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    Energetic and exergetic analysis of combined cycle power plant: Part-1 operation and performance
    (MDPI, 2015-12-14) Almutairi, Abdulrahman S.; Pilidis, Pericles; Al-Mutawa, Nawaf
    Energetic and exergetic analyses are conducted using operating data for Sabiya, a combined cycle power plant (CCPP) with an advanced triple pressure reheat heat recovery steam generator (HRSG). Furthermore, a sensitivity analysis is carried out on the HRSG using a recent approach to differentiate between the sources of irreversibility. The proposed system was modelled using the IPSEpro software and further validated by the manufacturer’s data. The performance of the Sabiya CCPP was examined for different climatic conditions, pressure ratios, pinch point temperatures, high-pressure steam, and condenser pressure values. The results confirmed that 60.9% of the total exergy destruction occurs in the combustion chamber, which constitutes the main source of irreversibilities within a system. The exergy destruction was significantly affected by both the pressure ratio and the high-pressure steam, where the relation between them was seen to be inversely proportional. The high-pressure stage contributes about 50% of the exergy destruction within the HRSG compared to other stages and the reheat system, due to the high temperature difference between the streams and the large number of components, which leads to high energy loss to the surroundings. Numerous possibilities for improving the CCPP’s performance are introduced, based on the obtained results.
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    Exergetic and sustainability analysis of an intercooled gas turbine cogeneration plant with reverse osmosis desalination system
    (American Society of Civil Engineers, 2017-03-14) Almutairi, Abdulrahman; Pilidis, Pericles; Al-Mutawa, Nawaf; Al-Weshahi, Mohammed
    In this study, an advanced cogeneration plant based on a 100-MW aeroderivative intercooled gas turbine (ICGT) engine and large two-pass reverse osmosis (RO) desalination system is analyzed thermodynamically. The proposed model has been developed using specialized software and validated with manufacturers’ published data. Saline water is simulated using the latest physical properties available in the literature and treated as a real mixture. Combined energetic and exergetic performance criteria for the design of a cogeneration plant is presented as being, today, the most efficient method for accurate assessment of performance, which also permits quantification of system deficiencies. The performance of the proposed plant was investigated using different loads, ambient temperatures, pressure ratios, and feed water temperatures. The results show an intercooler system improves cogeneration plant performance despite having a negative impact on the combustion chamber performance because of its reduction of compressed air temperature. The ICGT engine is considered the best available choice to integrate with a RO unit because of its high pressure ratio and low power consumption in the compressors. From an operational perspective, full load and low ambient and high feed-water temperatures are highly recommended. The exergetic efficiency of the ICGT engine, RO system, and cogeneration plant are shown to be 44.3, 32.83, and 47.6%, respectively. From a sustainability perspective, the exergetic-environmental efficiency is slightly affected by ambient temperature, whereas it is highly affected by load variation. Based upon the obtained results, numerous possibilities are presented to improve the performance of cogeneration plants.
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    Exergetic, exergoeconomic and exergoenvironmental analysis of intercooled gas turbine engine
    (American Institute of Aeronautics and Astronautics, 2016-07-01) Almutairi, Abdulrahman S.; Pilidis, Pericles; Al-Mutawa, Nawaf
    Exergetic and exergoeconomic and exergoenvironmental analyses have been performed for an advanced aero-derivative intercooled gas turbine engine. The proposed system was modelled using the IPSEpro software package and validated using manufacturer’s published data. The exergoeconomic model evaluates the cost-effectiveness of the gas turbine engine based on the Specific Exergy Costing [SPECO] method. The CO2 emissions per KWh were estimated using a generic combustor model, HEPHAESTUS, developed at Cranfield University. It is well known that the exergetic analysis can determine the magnitudes, locations and types of losses within an energy system. The effect of load and ambient temperature variations on gas turbine performance were investigated for two different configurations. The first system, Case-I, was a simple gas turbine (SCGT) engine, and the second, Case-II, an intercooling gas turbine (ICGT) system. The latter enhances gas turbine efficiency but, at the same time, has an adverse effect on the combustion chamber due to reduced compressed air temperature. It was confirmed that full load and low ambient temperature are preferable due to the low waste exergy. The unit exergy cost rate for both SCGT and ICGT have been calculated as 8.59 and 8.32 US$/GJ respectively. The exergoenvironmental results show the ICGT achieved lower emission levels and is more environmentally friendly than the SCGT.