Effect of preheated air temperature on a liquid ammonia flash spray in a swirl combustor

Abstract

Ammonia is a suitable carbon-free alternative fuel for power equipment. Direct combustion of liquid ammonia has the potential to reduce system costs and heat loss of gas turbine (GT). However, its tendency to flash and the high latent heat of vaporization can lead to combustion deterioration. Previous research suggests that stabilizing a liquid ammonia flame requires swirling and preheated air. So far, the influencemechanism of preheated air on liquid ammonia swirl spray remains inadequately explored. To fill this research gap, this study conducted a large eddy simulation (LES) to investigate the effect of preheated air temperature (T_a) on a liquid ammonia flash spray in a swirl combustor. The influence of T_a on the spray morphology and the axial velocity, diameter, and temperature distributions of the droplets were investigated to understand the spray characteristics. Besides, the effects of T_a on the evaporation characteristics, the properties, and the possible ignition performance of themixture were studied. The results show that with the increase of T_a, the heating capacity of air is enhanced, leading to a greater proportion of droplets reaching flash boiling conditions. This greatly optimizes the evaporation process, resulting in more complete evaporation and significantly smaller volume. The bulk air flow velocity is increased, causing the expansion of the inner recirculation zone (IRZ), and the gaseous temperature and mixture concentration distribution are optimized. In addition, the low gaseous ammonia concentration makes ignition difficulty at T_a = 300 K. The high |τ| value (τ is the shear stress) and large inner recirculation zone area lead to a larger RegionM and a smaller RegionL at T_a = 300 K compared to the case of T_a = 500 K.

References

[1] Valera-Medina A, Xiao H, Owen-Jones M, David WI, Bowen P. Ammonia for power. Prog Energy Combust Sci. 2018;69:63-102.

[2] Elbaz AM, Wang S, Guiberti TF, Roberts WL. Review on the recent advances on ammonia combustion from the fundamentals to the applications. Fuel Commun. 2022:10;100053.

[3] Kobayashi H, Hayakawa A, Somarathne KKA, Okafor EC. Science and technology of ammonia combustion. Proc Combust Inst. 2019;37:109-133.

[4] Zhang M, An Z, Wang L, et al. The regulation effect of methane and hydrogen on the emission characteristics of ammonia/air combustion in a model combustor. Int J Hydrogen Energy. 2021;46:21013-21025.

[5] An Z, Zhang M, Zhang W, et al. Emission prediction and analysis on CH₄ CH₃/air swirl flames with LES-FGM method. Fuel. 2021;304:121370.

[6] Wei X, Zhang M, An Z, Wang J, Huang Z, Tan H. Large eddy simulation on flame topologies and the blow-off characteristics of ammonia/air flame in a model gas turbine combustor. Fuel. 2021;298:120846.

[7] Zhang M, Wei X, Wang J, Huang Z, Tan H. The blow-off and transient characteristics of co-firing ammonia/methane fuels in a swirl combustor. Proc Combust Inst. 2021;38:5181-5190.

[8] Okafor EC, Somarathne KKA, Hayakawa A, et al. Towards the development of an efficient low-NO_x ammonia combustor for a micro gas turbine. Proc Combust Inst. 2019;37:4597-4606.

[9] Okafor EC, Yamashita H, Hayakawa A, et al. Flame stability and emissions characteristics of liquid ammonia spray co-fired with methane in a single stage swirl combustor. Fuel. 2021;287:119433.

[10] Li T, Zhou X, Wang N, et al. A comparison between low-and high-pressure injection dual-fuel modes of diesel-pilot-ignition ammonia combustion engines. J Energy Inst. 2022;102:362-373.

[11] Pelé R, Mounaïm-Rousselle C, Bréquigny P, Hespel C, Bellettre J. First study on ammonia spray characteristics with a current GDI engine injector. Fuels. 2021;2:253-271.

[12] Li S, Li T, Wang N, Zhou X, Chen R, Yi P. An investigation on near-field and far-field characteristics of superheated ammonia spray. Fuel. 2022;324:124683.

[13] Liu X, Yao X, Wang Z, Tang C. Single hole ammonia spray macroscopic and microscopic characteristics at flare and transition flash boiling regions. Appl Therm Eng. 2023;235:121443.

[14] Fang Y, Ma X, Zhang Y, et al. Experimental investigation of high-pressure liquid ammonia injection under non-flash boiling and flash boiling conditions. Energies. 2023;16:2843.

[15] Cheng Q, Ojanen K, Diao Y, Kaario O, Larmi M. Dynamics of the ammonia spray using high-speed schlieren imaging. SAE Int J Adv Curr Pract Mobility. 2022;4:1138-1153.

[16] Scharl V, Lackovic T, Sattelmayer T. Characterization of ammonia spray combustion and mixture formation under high-pressure, direct injection conditions. Fuel. 2023;333:126454.

[17] Ichikawa Y, Niki Y, Takasaki K, Kobayashi H, Miyanagi A. NH₃ combustion using three-layer stratified fuel injection for a large two-stroke marine engine: experimental verification of the concept. Appl Energy Combust Sci. 2022;10:100071.

[18] Ichikawa Y, Niki Y, Takasaki K, Kobayashi H, Miyanagi A. Experimental study of combustion process of NH₃ stratified spray using imaging methods for NH₃ fueled large two-stroke marine engine. Appl Energy Combust Sci. 2023;13:100119.

[19] An Z, Xing J, Kurose R. Numerical study on the phase change and spray characteristics of liquid ammonia flash spray. Fuel. 2023;345:128229.

[20] Zhang Y, Xu L, Zhu Y, Xu S, Bai X-S. Numerical study on liquid ammonia direct injection spray characteristics under engine-relevant conditions. Appl Energy. 2023;334:120680.

[21] Shin J, Park S. An ammonia flash break-up model based on bubble dynamics with force and energy analysis on droplet. Fuel. 2023;342:127841.

[22] Okafor EC, Kurata O, Yamashita H, et al. Liquid ammonia spray combustion in two-stage micro gas turbine combustors at 0.25 MPa;relevance of combustion enhancement to flame stability and NO_x control. Appl Energy Combust Sci. 2021;7:100038.

[23] Somarathne KDKA, Yamashita H, Colson S, et al. Liquid ammonia spray combustion and emission characteristics with gaseous hydrogen/air co-firing. Proceedings of the 13th Asia Pacific Conference on Combustion, Abu Dhabi, UAE, 2021: W6-15 n.d.

[24] Angelilli L, Pérez FEH, Im HG, Ciottoli PP, Valorani M. Evaporation and clustering of ammonia droplets in a hot environment. Phys Rev Fluids. 2022;7:114301.

[25] Yamashita H, Okafor EC, Colson S, et al. Optical measurements under non-reacting condition and investigation of combustion characteristics in a swirling flow for liquid ammonia spray combustion. The 59th Japanese Symposium on Combustion, Gifu, Japan, 2021: B311.

[26] Shin J, Kim D, Seo J, Park S. Effects of the physical properties of fuel on spray characteristics from a gas turbine nozzle. Energy. 2020;205:118090.

[27] Schiller L. A drag coefficient correlation. Z Ver Deutsch Ing. 1933;77:318-320.

[28] Bird RB. Transport phenomena. Appl Mech Rev. 2002;55: R1-R4.

[29] Zhang P, Li W, Zhang T, Yan Y, Li J, Tang H. Multiscale modeling of liquid jet breakup in crossflow using an Eulerian/Lagrangian approach. Phys Fluids. 2023;35:125146.

[30] Ranz W. Evaporation from drops-I and-II. Chem Eng Prog. 1952;48:141-146.

[31] Sánchez AL, Urzay J, Liñán A. The role of separation of scales in the description of spray combustion. Proc Combust Inst. 2015;35:1549-1577.

[32] Giusti A, Kotzagianni M, Mastorakos E. LES/CMC simulations of swirl-stabilised ethanol spray flames approaching blow-off. Flow Turbul Combust. 2016;97:1165-1184.

[33] Abedinejad MS. Analysis of spray evaporation in a model evaporating chamber: effect of air swirl. J Therm Sci. 2023;32:837-853.

[34] Zhou Z-F, Yin J, Chen B, Liu B, Thrassos P. Liquid phase model and its coupling interaction with the ambient gas for the droplet heating and evaporation of highly volatile R134a. Int J Heat Mass Transfer. 2021;166:120740.

[35] Zhou Z-F, Lu G-Y. Chen B. Numerical study on the spray and thermal characteristics of R404A flashing spray using OpenFOAM. Int J Heat Mass Transfer. 2018;117:1312-1321.

[36] Cen K, Li Y, Wei L, Li W, Wang Y, Dai M. Evaporation of single moving liquid nitrogen droplet: experimental study and numerical simulation. Int J Heat Mass Transfer. 2023;201:123584.

[37] Hu W, Zhao Y, Zhou X, et al. Experimental and numerical investigations on flash evaporation of a sessile droplet under reduced pressure. Phys Fluids. 2023;35:112119.

[38] Zuo B, Gomes A, Rutland C. Modelling superheated fuel sprays and vaporization. Int J Engine Res. 2000;1:321-336.

[39] Adachi M, McDonell VG, Tanaka D, Senda J, Fujimoto H. Characterization of Fuel Vapor Concentration Inside a Flash Boiling Spray. Tech. Rep., SAE Technical Paper; 1997.

[40] Lu Y, Li Y, Liu W, Tang J, Yan J, Liu Q. Characteristics and mechanism of spray deviation of ethanol and its blended fuel in multi-hole spray. Phys Fluids. 2023;35:123332.

[41] Xu M, Zhang Y, Zeng W, Zhang G, Zhang M. Flash boiling: easy and better way to generate ideal sprays than the high injection pressure. SAE Int J Fuels Lubr. 2013;6:137-148.

[42] Huang Z, Wang H, Luo K, Fan J. Large eddy simulation investigation of ammonia spray characteristics under flash and non-flash boiling conditions. Appl Energy Combust Sci. 2023;16:100220.

[43] Yang S, Zhang C, Lin Y, Xue X, Gan X. Experimental investigation of the ignition process in a separated dual-swirl spray flame. Combust Flame. 2020;219:161-177.

[44] Abdel-Gayed RG, Bradley D, Lung FK-K. Combustion regimes and the straining of turbulent premixed flames. Combust Flame. 1989;76:213-218.

[45] Collin-Bastiani F, Marrero-Santiago J, Riber E, Cabot G, Renou B, Cuenot B. A joint experimental and numerical study of ignition in a spray burner. Proc Combust Inst. 2019;37:5047-5055.

[46] Marchione T, Ahmed SF, Mastorakos E. Ignition of turbulent swirling n-heptane spray flames using single and multiple sparks. Combust Flame. 2009;156:166-180.

RIGHTS & PERMISSIONS

2025 2025 The Author(s). Droplet published by Jilin University and John Wiley & Sons Australia, Ltd.