Thermodynamic and entropy generation analyses of Telsa-valve structured meso-scale combustors fuelled with hydrogen for thermophotovoltaic applications

Energy, Journal Year: 2024, Volume and Issue: 307, P. 132788 - 132788

Published: Aug. 10, 2024

The present work numerically examed the effects of hydrogen volume flow rates (Qv) and equivalence ratios (Φ) on thermal performances meso-scale combustors structured with Tesla-vale type channels. Four distinct Tesla-valve configurations are implemented then subsequently compared. reverse-flow Tesla valve counter-flow combustor (RC) structure shows a remarkable improvement 72.6 % to wall temperature at Qv = 100 mL/min. diodicity (Di) is found be increased higher Qv, lower Φ contributes Di. Besides, Di decreased when goes up, stabilizing 0.9. exhibits more uniform pressure distribution entropy production than forward-flow valve. At 0.9, hydrogen-to-air ratio maximized heat release, producing highest entropy. demonstrate near complete combustion before reaching efficiency (ηcombustion) gradually after getting 1.0. RC construction achieved maximum under conditions insufficient oxygen. This study demonstrates feasibility enhancing overall channels, revealing key parameters characteristics in these combustors.

Language: Английский

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Thermodynamic and emission analysis of an ammonia fueled micro-combustor with double-channel reverse flow structure

International Journal of Hydrogen Energy, Journal Year: 2023, Volume and Issue: 49, P. 1303 - 1314

Published: Nov. 17, 2023

This study proposes a novel micro-combustor fueled by ammonia and oxygen, employing double-channel inlet outlet (DIDO) configuration with the reverse flow structure. The investigation delves into parameters of volumetric rate (Qv), pressure (Pin), equivalence ratio (Φ), baffle length (d) on both nitrogen oxide emissions thermal performance micro-combustor. It is observed that, in comparison to conventional systems, DIDO combustor capable generating vortex at outlet, thereby reducing NOx emissions. Specifically, Qv 900 mL/min, NO concentration can be curtailed 29.23 %. Furthermore, exhibit gradual decline increase Φ Pin. Notably, yields substantial enhancement performance, achieving 51 % reduction standard deviation outer wall temperature (ST,W) when set 500 mL/min which significantly enhances uniformity temperature. peak maximum radiation efficiency (ηradiation) reached = 0.9. analysis entropy production indicates that it increases augmentation Qv, while elongating d augments exergy (ηexergy).

Language: Английский

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Combustion and exergy performance optimization investigations on premixed methane/hydrogen mixtures by tuning fuel injection strategies

International Journal of Hydrogen Energy, Journal Year: 2025, Volume and Issue: 105, P. 80 - 89

Published: Jan. 20, 2025

Language: Английский

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Numerical Analyses of Entropy Production and Thermodynamics Exergy on a Hydrogen-Fueled Micro Combustor Featuring a Diamond-Shaped Bifurcated Inner-Tube Structure for Thermophotovoltaic Applications

Entropy, Journal Year: 2025, Volume and Issue: 27(2), P. 114 - 114

Published: Jan. 24, 2025

To improve the heat transfer mechanisms from thermal energy to walls, current work presents a new structure for micro combustor fueled by hydrogen featuring diamond-shaped bifurcated inner-tube configuration. For this purpose, series of three-dimensional (3D) numerical analyses are conducted investigate effects length structure, width inner flame channels, inlet equivalence ratio, and volume flow rate on key performance thermodynamic parameters. In comparison conventional design, outcomes reveal that proposed configuration exhibits remarkable improvements in conversion efficiency, as it reduces mean exhaust gas temperature 585.98 K boosts exergy radiation efficiencies 7.78% 14.08%, respectively. The parametric study design parameters indicates elongating widening channels enhance dynamics consequently rates absorption walls. increase feeds system with additional and, therefore, advances average wall its uniformity across external surface. Nevertheless, also efficiency due limited capacity utilize large input along high magnitude entropy production resulting particularly mechanism chemical generation. Operating under stoichiometric condition balances oxygen premixed charge, achieving optimal combustor.

Language: Английский

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Experimental Studies on Droplet-Size Distribution in a Reverse-Flow Combustor of a Two-Staged Fuel Injector

Journal of Aerospace Engineering, Journal Year: 2025, Volume and Issue: 38(4)

Published: March 28, 2025

Language: Английский

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A CFD Study of Thermodynamics and Efficiency Metrics in a Hydrogen-Fueled Micro Planar Combustor Housing Dual Heat-Recirculating Cylindrical Combustors for MTPV Applications

Processes, Journal Year: 2025, Volume and Issue: 13(4), P. 1142 - 1142

Published: April 10, 2025

The micro combustor is the energy source of micro-thermophotovoltaic systems; thus, optimizing its design one key parameters that lead to an increase in output energy. Therefore, enhance system’s overall efficiency, this numerical work introduces a new configuration for parallel-flow (PF) and counter-flow (CF) hydrogen-fueled cylindrical combustors integrated into planar combustor. To overcome short residence time applications causing high heat dissipation, house heat-recirculating channels allow more transfer external walls. In pursuit target, simulations are carried out analyze thermodynamic system efficiency parameters. addition, different initial operating conditions varied optimize system, including inlet velocity equivalence ratio. results reveal PF CF structures result significantly higher wall temperatures uniform temperature variations than conventional (CD). Despite entropy generations, exhaust gas 591 K 580 lower CD, respectively, both 14% increases radiation efficiency. Increasing improves thermal designs; however, experiences drastic reduction. power density highlights unity ratio as optimal. designs yield roughly identical findings, but exhibits most cases due equal from opposite sides.

Language: Английский

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Thermodynamic and Heat Transfer Analysis of Hydrogen-Fueled Meso-Scale Combustors with Tear-Drop Structures for Thermophotovoltaic Applications

Energy, Journal Year: 2025, Volume and Issue: unknown, P. 136143 - 136143

Published: April 1, 2025

Language: Английский

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Numerical investigation of blended hydrogen/ammonia combustion in a bluff-body and swirl stabilized micro combustor for micropower applications

International Journal of Hydrogen Energy, Journal Year: 2024, Volume and Issue: 98, P. 957 - 984

Published: Dec. 13, 2024

Language: Английский

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Numerical identifications of T-shaped rod effect on thermal performance and exergy efficiency in methane/air combustion

Applied Thermal Engineering, Journal Year: 2023, Volume and Issue: 239, P. 122143 - 122143

Published: Dec. 4, 2023

Language: Английский

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A Numerical Study on Key Thermal Parameters and NOx Emissions of a Hydrogen-Fueled Double-Channel Outlet Micro Cylindrical Combustor Employing a Heat-Recirculating Configuration for Thermophotovoltaic Applications

Processes, Journal Year: 2024, Volume and Issue: 12(9), P. 1848 - 1848

Published: Aug. 29, 2024

The current study proposes a novel design configuration of hydrogen-fueled micro cylindrical combustor. newly developed consists single-channel inlet and double-channel outlet with heat-recirculating structure aimed at enhancing the heat transfer mechanism from combustion to walls. Investigations are conducted using three-dimensional numerical simulation means, emphasis is placed on assessing effects key thermal parameters nitrogen oxide (NOx) emissions. modeling approach first validated against experimental data available in literature. A parametric then by means varying length width channel, velocity, equivalence ratio. findings revealed that significantly improves performance curtails NOx emissions comparison those conventional structure. For example, proposed leads radiation efficiency increase roughly 10%. preheating channel yields further optimization boosting process flame Elevating velocity exhibits pronounced mean wall temperature more uniform distribution temperature. However, exhaust gas increases increasing leading reduction exergy efficiencies. ratio unity optimizes parameters, as lean rich conditions suffer low hydrogen oxygen contents, respectively.

Language: Английский

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