Browsing by Author "Bazooyar, Bahamin"

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    Comparative analysis of ammonia combustion for domestic applications
    (Elsevier, 2022-12-02) Bazooyar, Bahamin; Coomson, George; Manovic, Vasilije; Nabavi, Seyed Ali
    This article explores whether ammonia is a reliable fuel for heat and electricity generation in domestic applications. First, the ammonia combustion characteristics, including adiabatic flame temperature, ignition delay time, and laminar flame speed are analysed and compared with the conventional fuels such as natural gas, dimethyl ether, hydrogen, and syngas, under 12 kWe turbine and 45kWth boiler conditions. Furthermore, the combustion of ammonia at a conventional boiler and turbine combustor was numerically modelled, analysed, and compared with the available fuels. The finding demonstrates that ammonia provides inferior combustion characteristics in combustion heat releases, stability region, and ignition characteristics. The ammonia combustion characteristics including, laminar flame speed and ignition delay time, were comparable to those of methane. The flame temperature and exhaust gas composition of ammonia are rather different than those of methane which may vary the heat transfer during the operation of gas turbines and boilers. The combustion of ammonia in boilers may produce the required heat for heating purposes; however, it needs further modification to achieve better NOX control. In a gas turbine, on the other hand, combustion ammonia leads to remarkably higher temperatures if the same turbine inlet temperature is needed compared to other fuels, however, at the cost of significant NOX formation, which may go beyond 100 ppm with thermal NO formation on par of fuel NO.
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    Data supporting: 'Comparative analysis of ammonia combustion for domestic applications'
    (Cranfield University, 2022-10-28 15:38) Bazooyar, Bahamin; Manovic, Vasilije; ali Nabavi, Seyed
    The research of ammonia combustion in Gas Turbines and Boilers
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    Direct numerical simulation of packed and monolith syngas catalytic combustors for micro electrical mechanical systems
    (Elsevier, 2023-08-19) Bazooyar, Bahamin; Zhu, Mingming; Manovic, Vasilije; Nabavi, Seyed Ali
    In this work, a catalytic combustor for micro electrical mechanical system for syngas was designed and analysed using Direct Numerical Simulation (DNS) in conjunction with finite rate chemistry. The effect of catalyst (platinum (Pt), palladium (Pd), palladium oxide (PdO), and rhodium (Rh)), bed type (packed with twelve catalyst shapes and four catalyst monolith), shapes (packed: cylinder, hollow cylinder, four cylinder, single cylinder, single cylinder, cross-webb, grooved, pall-ring, hexagonal, berl-saddle, cube, intalox-saddle, and sphere, monolith: triangular, rectangular, hexagonal, and circular), and operating conditions (inlet temperature and velocity, fuel/air ratio, different concentrations CH4-H2-CO) on combustion efficiency and pressure drop were studied using different parameters (combustion efficiency (η), pressure drop, effectiveness factor (Ψ), and fuel conversions (H2 and CH4 conversions)). Analysis under different operating conditions reveals that the designed combustor can operate effectively with syngas of varying compositions with a high combustion efficiency of over 85%. Combustion mainly takes place on the surface of the catalyst without gas phase reaction with pressure drops between 18 Pa and 155 Pa. The intalox saddle shape catalysts resulted in the bed effectiveness factor 0.93.1 The Damköhler for hydroxyl radicals (OH) over the entire length of the reactor is uniformly distributed and well below 3, suggesting uniform combustion.
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    The effect of hydrogen fuel on the performance and emissions of 3 kWe natural gas fuelled microturbine
    (Elsevier, 2024-11-15) Jomekian, Abolfazl; Alhasnawi, Bilal Naji; Bazooyar, Bahamin; Nabavi, Ali; Varasteh, Hirbod
    Hydrogen is an alternative fuel to power microturbines. In this work, the application of H2 in a 3 kWe microturbine combustor is investigated. First, the combustor is tested with different molar concentrations of hydrogen in methane fuel (XH2= 5%, 10% and 20%). Afterward, the operation of the microturbine is verified using thermodynamic analysis of the microturbine cycle. The combustion of the fuels is investigated using CFD analysis. The level of gaseous emissions including (CO2, CO, and NOX) and the microturbine overall operability in terms of turbomachine mechanical and thermal efficiencies are compared in each case to find out the influence of hydrogen addition on the natural gas combustion in the microturbine (MT). Findings show that the application of hydrogen in the MT combustor decreases the level of CO2 and CO emissions while increasing NOX emissions. Despite the improvement in combustion, hydrogen could deteriorate the MT effectiveness and overall efficiency. The findings demonstrate that if the hydrogen mole percent in the fuel rises from 0 to 10, the cycle efficiency decreases from 4.73% to 4.7% and if it increases to 20 percent, the efficiency of the cycle increases from 4.7% to 4.92%.