Experimental study of influence of Liquefied Petroleum Gas addition in Hydrotreated Vegetable Oil fuel on ignition delay, flame lift off length and soot emission under diesel-like conditions

[EN] The fundamental behaviour on ignition and combustion characteristics of blends of Hydrotreated Vegetable Oil and Liquid Petroleum Gas was investigated in a constant high pressure, high temperature combustion chamber, using a prototype lab-scale injection system adapted from a conventional common-rail system to conduct the injection events, ensuring that fuel was liquid at any point of the injection system and avoiding the formation of fuel vapour bubbles that could alter the injected fuel behaviour. The ignition delay, flame lift-off length and the soot formation were studied by means of high-speed imaging techniques, for different operating conditions. The aim of the work is to characterize the effect of Hydrotreated Vegetable Oil-Liquid Petroleum Gas blend ratios on the previously mentioned parameters. Experimental results show that the behaviour of the fuel blends follow the expected trends of conventional diesel type fuels when varying ambient temperature, density and injection pressure. Hydrotreated Vegetable Oil, being the highest reactivity fraction, controls auto ignition of the blend. However, Liquid Petroleum Gas acts as combustion inhibitor increasing both ignition delay and lift-off length as its ratio in the blend increases. As a consequence, the differences observed in terms of flame radiation suggest that increasing Liquid Petroleum Gas fraction reduces soot formation as it promotes a higher air/mixture.The authors acknowledge that this research work has been partly funded by the Government of Spain and FEDER under TRANCO project (TRA2017-87694-R) and by Universitat Politècnica de València through the Programa de Ayudas de Investigación y Desarrollo (PAID01-18) program.Pastor, JV.; García Martínez, A.; Mico Reche, C.; Garcia-Carrero, AA. (2020). Experimental study of influence of Liquefied Petroleum Gas addition in Hydrotreated Vegetable Oil fuel on ignition delay, flame lift off length and soot emission under diesel-like conditions. Fuel. 260:1-11. https://doi.org/10.1016/j.fuel.2019.116377S111260Roadmap to a Single European Transport Area – Towards a competitive and resource efficient. Transport System, White Paper COM(2011):144–final.Sheehan J, Camobreco V, Duffield J, Graboski M, Shapouri H. An Overview of Biodiesel and Petroleum Diesel Life Cycles, NREL/TP-580-24772.Hasan, M. M., & Rahman, M. M. (2017). Performance and emission characteristics of biodiesel–diesel blend and environmental and economic impacts of biodiesel production: A review. Renewable and Sustainable Energy Reviews, 74, 938-948. doi:10.1016/j.rser.2017.03.045Bhardwaj, O. P., Kolbeck, A. F., Kkoerfer, T., & Honkanen, M. (2013). Potential of Hydrogenated Vegetable Oil (HVO) in Future High Efficiency Combustion System. SAE International Journal of Fuels and Lubricants, 6(1), 157-169. doi:10.4271/2013-01-1677Chakraborty, A., Roy, S., & Banerjee, R. (2016). An experimental based ANN approach in mapping performance-emission characteristics of a diesel engine operating in dual-fuel mode with LPG. Journal of Natural Gas Science and Engineering, 28, 15-30. doi:10.1016/j.jngse.2015.11.024Aatola, H., Larmi, M., Sarjovaara, T., & Mikkonen, S. (2008). Hydrotreated Vegetable Oil (HVO) as a Renewable Diesel Fuel: Trade-off between NOx, Particulate Emission, and Fuel Consumption of a Heavy Duty Engine. SAE International Journal of Engines, 1(1), 1251-1262. doi:10.4271/2008-01-2500Neste Oil, Hydrotreated vegetable oil, premium renewable biofuel for diesel engines, 2014.Singh, D., Subramanian, K. A., Bal, R., Singh, S. P., & Badola, R. (2018). Combustion and emission characteristics of a light duty diesel engine fueled with hydro-processed renewable diesel. Energy, 154, 498-507. doi:10.1016/j.energy.2018.04.139Zhong, W., Pachiannan, T., He, Z., Xuan, T., & Wang, Q. (2019). Experimental study of ignition, lift-off length and emission characteristics of diesel/hydrogenated catalytic biodiesel blends. Applied Energy, 235, 641-652. doi:10.1016/j.apenergy.2018.10.115Tira, H. S., Herreros, J. M., Tsolakis, A., & Wyszynski, M. L. (2014). Influence of the addition of LPG-reformate and H2 on an engine dually fuelled with LPG–diesel, –RME and –GTL Fuels. Fuel, 118, 73-82. doi:10.1016/j.fuel.2013.10.065Goto, S., Lee, D., Shakal, J., Harayama, N., Honjyo, F., & Ueno, H. (1999). Performance and Emissions of an LPG Lean-Burn Engine for Heavy Duty Vehicles. SAE Technical Paper Series. doi:10.4271/1999-01-1513Musthafa, M. M. (2019). A comparative study on coated and uncoated diesel engine performance and emissions running on dual fuel (LPG – biodiesel) with and without additive. Industrial Crops and Products, 128, 194-198. doi:10.1016/j.indcrop.2018.11.012Hashimoto, K., Ohta, H., Hirasawa, T., Arai, M., & Tamura, M. (2002). Evaluation of Ignition Quality of LPG with Cetane Number Improver. SAE Technical Paper Series. doi:10.4271/2002-01-0870Benajes, J., Molina, S., García, A., & Monsalve-Serrano, J. (2015). Effects of low reactivity fuel characteristics and blending ratio on low load RCCI (reactivity controlled compression ignition) performance and emissions in a heavy-duty diesel engine. Energy, 90, 1261-1271. doi:10.1016/j.energy.2015.06.088Benajes, J., García, A., Monsalve-Serrano, J., & Boronat, V. (2016). Dual-Fuel Combustion for Future Clean and Efficient Compression Ignition Engines. Applied Sciences, 7(1), 36. doi:10.3390/app7010036Benajes, J., García, A., Monsalve-Serrano, J., & Boronat, V. (2017). Achieving clean and efficient engine operation up to full load by combining optimized RCCI and dual-fuel diesel-gasoline combustion strategies. Energy Conversion and Management, 136, 142-151. doi:10.1016/j.enconman.2017.01.010Kokjohn, S. L., Hanson, R. M., Splitter, D. A., & Reitz, R. D. (2011). Fuel reactivity controlled compression ignition (RCCI): a pathway to controlled high-efficiency clean combustion. International Journal of Engine Research, 12(3), 209-226. doi:10.1177/1468087411401548Payri, R., Gimeno, J., Bardi, M., & Plazas, A. H. (2013). Study liquid length penetration results obtained with a direct acting piezo electric injector. Applied Energy, 106, 152-162. doi:10.1016/j.apenergy.2013.01.027Gimeno, J., Martí-Aldaraví, P., Carreres, M., & Peraza, J. E. (2018). Effect of the nozzle holder on injected fuel temperature for experimental test rigs and its influence on diesel sprays. International Journal of Engine Research, 19(3), 374-389. doi:10.1177/1468087417751531Pastor, J. V., García-Oliver, J. M., García, A., Micó, C., & Möller, S. (2016). Application of optical diagnostics to the quantification of soot in n-alkane flames under diesel conditions. Combustion and Flame, 164, 212-223. doi:10.1016/j.combustflame.2015.11.018Pastor, J., Garcia-Oliver, J. M., Garcia, A., & Nareddy, V. R. (2017). Characterization of Spray Evaporation and Mixing Using Blends of Commercial Gasoline and Diesel Fuels in Engine-Like Conditions. SAE Technical Paper Series. doi:10.4271/2017-01-0843Pastor, J. V., Payri, R., Garcia-Oliver, J. M., & Briceño, F. J. (2013). Schlieren Methodology for the Analysis of Transient Diesel Flame Evolution. SAE International Journal of Engines, 6(3), 1661-1676. doi:10.4271/2013-24-0041Siebers, D. L. (1998). Liquid-Phase Fuel Penetration in Diesel Sprays. SAE Technical Paper Series. doi:10.4271/980809ECN. Engine Combustion Network. https://ecn.sandia.gov/.Desantes, J. M., Pastor, J. V., García-Oliver, J. M., & Briceño, F. J. (2014). An experimental analysis on the evolution of the transient tip penetration in reacting Diesel sprays. Combustion and Flame, 161(8), 2137-2150. doi:10.1016/j.combustflame.2014.01.022Payri, R., Viera, J. P., Pei, Y., & Som, S. (2015). Experimental and numerical study of lift-off length and ignition delay of a two-component diesel surrogate. Fuel, 158, 957-967. doi:10.1016/j.fuel.2014.11.072Reyes, M., Tinaut, F. V., Giménez, B., & Pastor, J. V. (2018). Effect of hydrogen addition on the OH* and CH* chemiluminescence emissions of premixed combustion of methane-air mixtures. International Journal of Hydrogen Energy, 43(42), 19778-19791. doi:10.1016/j.ijhydene.2018.09.005Siebers, D. L., & Higgins, B. (2001). Flame Lift-Off on Direct-Injection Diesel Sprays Under Quiescent Conditions. SAE Technical Paper Series. doi:10.4271/2001-01-0530Benajes, J., Payri, R., Bardi, M., & Martí-Aldaraví, P. (2013). Experimental characterization of diesel ignition and lift-off length using a single-hole ECN injector. Applied Thermal Engineering, 58(1-2), 554-563. doi:10.1016/j.applthermaleng.2013.04.044Payri, R., Salvador, F. J., Manin, J., & Viera, A. (2016). Diesel ignition delay and lift-off length through different methodologies using a multi-hole injector. Applied Energy, 162, 541-550. doi:10.1016/j.apenergy.2015.10.118Kook, S., & Pickett, L. M. (2012). Liquid length and vapor penetration of conventional, Fischer–Tropsch, coal-derived, and surrogate fuel sprays at high-temperature and high-pressure ambient conditions. Fuel, 93, 539-548. doi:10.1016/j.fuel.2011.10.004Payri, R., García-Oliver, J. M., Xuan, T., & Bardi, M. (2015). A study on diesel spray tip penetration and radial expansion under reacting conditions. Applied Thermal Engineering, 90, 619-629. doi:10.1016/j.applthermaleng.2015.07.042Payri, R., Viera, J. P., Gopalakrishnan, V., & Szymkowicz, P. G. (2017). The effect of nozzle geometry over ignition delay and flame lift-off of reacting direct-injection sprays for three different fuels. Fuel, 199, 76-90. doi:10.1016/j.fuel.2017.02.075Pickett, L. M., Siebers, D. L., & Idicheria, C. A. (2005). Relationship Between Ignition Processes and the Lift-Off Length of Diesel Fuel Jets. SAE Technical Paper Series. doi:10.4271/2005-01-3843Xuan, T., Desantes, J. M., Pastor, J. V., & Garcia-Oliver, J. M. (2019). Soot temperature characterization of spray a flames by combined extinction and radiation methodology. Combustion and Flame, 204, 290-303. doi:10.1016/j.combustflame.2019.03.023Desantes, J. M., Pastor, J. V., García-Oliver, J. M., & Pastor, J. M. (2009). A 1D model for the description of mixing-controlled reacting diesel sprays. Combustion and Flame, 156(1), 234-249. doi:10.1016/j.combustflame.2008.10.00

Experimental Study of the Influence of Gasoline-Diesel Blends on the Combustion Process and Soot Formation under Diesel Engine-Like Conditions

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Energy & Fuels, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.energyfuels.0c00091.[EN] Recent research has demonstrated that a reduction in pollutant emissions of diesel engines can be achieved by using high octane fuels such as gasoline, methane, or liquefied petroleum gas. Therefore, in this study, the focus was to investigate the influence of blends of diesel and gasoline on combustion characteristics such as ignition delay, rate of heat release, and lift-off length as well as the influence on soot formation. The experiments were carried out in a test rig with optical access which mimics a single-cylinder diesel engine. Four blends were tested: one blend with 100% diesel and then three diesel-gasoline blends with 30%, 50%, and70% gasoline. The blends were made in volumetric proportions and injected using a common rail injection system without any kind of modification. The ignition delay and the apparent heat release were obtained by means of the in-cylinder pressure signal. Furthermore, the combustion development and soot formation were studied using three optical techniques: OH* chemiluminescence, natural luminosity, and diffused back-illumination extinction imaging (DBI). Different engine operating conditions were analyzed. Results showed that ID increases with the gasoline content in the blend. Similarly, as the reacting time increased, the lift-off length was longer. On the other hand, the apparent rate of heat release decreased due to a reduction of the fuel injection rate, which depends on the density of the blend. In addition, differences in the flame radiation were also observed. Gasoline-diesel blends had less luminosity, which is related to less soot formation. To confirm this, the KL factor obtained from the DBI technique was determined, and it was concluded that increasing the gasoline fraction in the blend reduces soot formation.This research work has been partly funded by the Government of Spain and FEDER under TRANCO project (TRA2017-87694-R) and by Universitat Politecnica de Valencia through the Programa de Ayudas de Investigacion y Desarrollo (PAID-01-18 and PAID-06-18) program.Pastor, JV.; García Martínez, A.; Mico Reche, C.; Garcia-Carrero, AA. (2020). Experimental Study of the Influence of Gasoline-Diesel Blends on the Combustion Process and Soot Formation under Diesel Engine-Like Conditions. Energy & Fuels. 34(5):5589-5598. https://doi.org/10.1021/acs.energyfuels.0c00091S55895598345Murugesa Pandian, M., & Anand, K. (2018). Comparison of different low temperature combustion strategies in a light duty air cooled diesel engine. Applied Thermal Engineering, 142, 380-390. doi:10.1016/j.applthermaleng.2018.07.047Kokjohn, S. L., Hanson, R. M., Splitter, D. A., & Reitz, R. D. (2011). Fuel reactivity controlled compression ignition (RCCI): a pathway to controlled high-efficiency clean combustion. International Journal of Engine Research, 12(3), 209-226. doi:10.1177/1468087411401548Kokjohn, S. L., Hanson, R. M., Splitter, D. A., & Reitz, R. D. (2009). Experiments and Modeling of Dual-Fuel HCCI and PCCI Combustion Using In-Cylinder Fuel Blending. SAE International Journal of Engines, 2(2), 24-39. doi:10.4271/2009-01-2647Benajes, J., García, A., Monsalve-Serrano, J., & Boronat, V. (2016). Dual-Fuel Combustion for Future Clean and Efficient Compression Ignition Engines. Applied Sciences, 7(1), 36. doi:10.3390/app7010036Benajes, J., García, A., Monsalve-Serrano, J., & Boronat, V. (2017). Achieving clean and efficient engine operation up to full load by combining optimized RCCI and dual-fuel diesel-gasoline combustion strategies. Energy Conversion and Management, 136, 142-151. doi:10.1016/j.enconman.2017.01.010Benajes, J., García, A., Monsalve-Serrano, J., & Boronat, V. (2017). An investigation on the particulate number and size distributions over the whole engine map from an optimized combustion strategy combining RCCI and dual-fuel diesel-gasoline. Energy Conversion and Management, 140, 98-108. doi:10.1016/j.enconman.2017.02.073Benajes, J., García, A., Monsalve-Serrano, J., & Boronat, V. (2017). Gaseous emissions and particle size distribution of dual-mode dual-fuel diesel-gasoline concept from low to full load. Applied Thermal Engineering, 120, 138-149. doi:10.1016/j.applthermaleng.2017.04.005Dempsey, A. B., Curran, S., & Reitz, R. D. (2015). Characterization of Reactivity Controlled Compression Ignition (RCCI) Using Premixed Gasoline and Direct-Injected Gasoline with a Cetane Improver on a Multi-Cylinder Engine. SAE International Journal of Engines, 8(2), 859-877. doi:10.4271/2015-01-0855Bendu, H., & Murugan, S. (2014). Homogeneous charge compression ignition (HCCI) combustion: Mixture preparation and control strategies in diesel engines. Renewable and Sustainable Energy Reviews, 38, 732-746. doi:10.1016/j.rser.2014.07.019Bermúdez, V., García, J. M., Juliá, E., & Martínez, S. (2003). Engine with Optically Accessible Cylinder Head: A Research Tool for Injection and Combustion Processes. SAE Technical Paper Series. doi:10.4271/2003-01-1110Pastor, J. V., García-Oliver, J. M., García, A., Micó, C., & Möller, S. (2016). Application of optical diagnostics to the quantification of soot in n-alkane flames under diesel conditions. Combustion and Flame, 164, 212-223. doi:10.1016/j.combustflame.2015.11.018Pastor, J., Garcia-Oliver, J. M., Garcia, A., & Nareddy, V. R. (2017). Characterization of Spray Evaporation and Mixing Using Blends of Commercial Gasoline and Diesel Fuels in Engine-Like Conditions. SAE Technical Paper Series. doi:10.4271/2017-01-0843Pastor, J. V., García-Oliver, J. M., García, A., & Pinotti, M. (2017). Effect of laser induced plasma ignition timing and location on Diesel spray combustion. Energy Conversion and Management, 133, 41-55. doi:10.1016/j.enconman.2016.11.054Pastor, J. V., García-Oliver, J. M., García, A., & Pinotti, M. (2016). Laser induced plasma methodology for ignition control in direct injection sprays. Energy Conversion and Management, 120, 144-156. doi:10.1016/j.enconman.2016.04.086Pastor, J. V., Payri, R., Gimeno, J., & Nerva, J. G. (2009). Experimental Study on RME Blends: Liquid-Phase Fuel Penetration, Chemiluminescence, and Soot Luminosity in Diesel-Like Conditions. Energy & Fuels, 23(12), 5899-5915. doi:10.1021/ef9007328Pastor, J. V., García-Oliver, J. M., Nerva, J.-G., & Giménez, B. (2011). Fuel effect on the liquid-phase penetration of an evaporating spray under transient diesel-like conditions. Fuel, 90(11), 3369-3381. doi:10.1016/j.fuel.2011.05.006Reyes, M., Tinaut, F. V., Giménez, B., & Pastor, J. V. (2018). Effect of hydrogen addition on the OH* and CH* chemiluminescence emissions of premixed combustion of methane-air mixtures. International Journal of Hydrogen Energy, 43(42), 19778-19791. doi:10.1016/j.ijhydene.2018.09.005Siebers, D. L., & Higgins, B. (2001). Flame Lift-Off on Direct-Injection Diesel Sprays Under Quiescent Conditions. SAE Technical Paper Series. doi:10.4271/2001-01-0530Pastor, J. V., Garcia-Oliver, J. M., Garcia, A., & Pinotti, M. (2017). Soot Characterization of Diesel/Gasoline Blends Injected through a Single Injection System in CI engines. SAE Technical Paper Series. doi:10.4271/2017-24-0048Pastor, J. V., García, J. M., Pastor, J. M., & Buitrago, J. E. (2005). Analysis Methodology of Diesel Combustion by Using Flame Luminosity, Two-Colour Method and Laser-Induced Incandescence. SAE Technical Paper Series. doi:10.4271/2005-24-012Xuan, T., Pastor, J. V., García-Oliver, J. M., García, A., He, Z., Wang, Q., & Reyes, M. (2019). In-flame soot quantification of diesel sprays under sooting/non-sooting critical conditions in an optical engine. Applied Thermal Engineering, 149, 1-10. doi:10.1016/j.applthermaleng.2018.11.112Xuan, T., Desantes, J. M., Pastor, J. V., & Garcia-Oliver, J. M. (2019). Soot temperature characterization of spray a flames by combined extinction and radiation methodology. Combustion and Flame, 204, 290-303. doi:10.1016/j.combustflame.2019.03.023Wang, J., Yang, F., & Ouyang, M. (2015). Dieseline fueled flexible fuel compression ignition engine control based on in-cylinder pressure sensor. Applied Energy, 159, 87-96. doi:10.1016/j.apenergy.2015.08.101Han, M. (2013). The effects of synthetically designed diesel fuel properties – cetane number, aromatic content, distillation temperature, on low-temperature diesel combustion. Fuel, 109, 512-519. doi:10.1016/j.fuel.2013.03.039Benajes, J., Payri, R., Bardi, M., & Martí-Aldaraví, P. (2013). Experimental characterization of diesel ignition and lift-off length using a single-hole ECN injector. Applied Thermal Engineering, 58(1-2), 554-563. doi:10.1016/j.applthermaleng.2013.04.044Pickett, L. M., Siebers, D. L., & Idicheria, C. A. (2005). Relationship Between Ignition Processes and the Lift-Off Length of Diesel Fuel Jets. SAE Technical Paper Series. doi:10.4271/2005-01-3843Payri, R., Salvador, F. J., Manin, J., & Viera, A. (2016). Diesel ignition delay and lift-off length through different methodologies using a multi-hole injector. Applied Energy, 162, 541-550. doi:10.1016/j.apenergy.2015.10.11

Experimental Study of the Effect of Hydrotreated Vegetable Oil and Oxymethylene Ethers on Main Spray and Combustion Characteristics under Engine Combustion Network Spray A Conditions

[EN] Featured Application This work contributes to the understanding of the macroscopic characteristics of the spray as well as to the evolution of the combustion process for alternative fuels. All these fuels have been studied under the same operating conditions than diesel therefore the comparison can be made directly, leaving in evidence that some fuels can achieve a similar behavior to diesel in terms of auto ignition but avoiding one of the biggest disadvantages of diesel such as the soot formation. Moreover, the quantification of characteristic parameters such as ignition delay, liquid length, vapor penetration and flame lift-off length represent the most important data to adjust and subsequently validate the computational models that simulate the spray evolution and combustion development of these alternative fuels inside the combustion chamber. The stringent emission regulations have motivated the development of cleaner fuels as diesel surrogates. However, their different physical-chemical properties make the study of their behavior in compression ignition engines essential. In this sense, optical techniques are a very effective tool for determining the spray evolution and combustion characteristics occurring in the combustion chamber. In this work, quantitative parameters describing the evolution of diesel-like sprays such as liquid length, spray penetration, ignition delay, lift-off length and flame penetration as well as the soot formation were tested in a constant high pressure and high temperature installation using schlieren, OH* chemiluminescence and diffused back-illumination extinction imaging techniques. Boundary conditions such as rail pressure, chamber density and temperature were defined using guidelines from the Engine Combustion Network (ECN). Two paraffinic fuels (dodecane and a renewable hydrotreated vegetable oil (HVO)) and two oxygenated fuels (methylal identified as OME(1)and a blend of oxymethylene ethers, identified as OMEx) were tested and compared to a conventional diesel fuel used as reference. Results showed that paraffinic fuels and OME(x)sprays have similar behavior in terms of global combustion metrics. In the case of OME1, a shorter liquid length, but longer ignition delay time and flame lift-off length were observed. However, in terms of soot formation, a big difference between paraffinic and oxygenated fuels could be appreciated. While paraffinic fuels did not show any significant decrease of soot formation when compared to diesel fuel, soot formed by OME(1)and OME(x)was below the detection threshold in all tested conditions.This research has been partly funded by the European Union's Horizon 2020 Programme through the ENERXICO project, grant agreement no 828947, and from the Mexican Department of Energy, CONACYT-SENER Hidrocarburos grant agreement no B-S-69926 and by Universitat Politecnica de Valencia through the Programa de Ayudas de Investigacion y Desarrollo (PAID-01-18).Pastor, JV.; García-Oliver, JM.; Mico Reche, C.; Garcia-Carrero, AA.; Gómez, A. (2020). Experimental Study of the Effect of Hydrotreated Vegetable Oil and Oxymethylene Ethers on Main Spray and Combustion Characteristics under Engine Combustion Network Spray A Conditions. Applied Sciences. 10(16):1-20. https://doi.org/10.3390/app10165460S1201016Reşitoğlu, İ. A., Altinişik, K., & Keskin, A. (2014). The pollutant emissions from diesel-engine vehicles and exhaust aftertreatment systems. Clean Technologies and Environmental Policy, 17(1), 15-27. doi:10.1007/s10098-014-0793-9Mohan, B., Yang, W., & Chou, S. kiang. (2013). Fuel injection strategies for performance improvement and emissions reduction in compression ignition engines—A review. Renewable and Sustainable Energy Reviews, 28, 664-676. doi:10.1016/j.rser.2013.08.051Leach, F., Kalghatgi, G., Stone, R., & Miles, P. (2020). The scope for improving the efficiency and environmental impact of internal combustion engines. Transportation Engineering, 1, 100005. doi:10.1016/j.treng.2020.100005Kim, H., Ge, J., & Choi, N. (2018). Application of Palm Oil Biodiesel Blends under Idle Operating Conditions in a Common-Rail Direct-Injection Diesel Engine. Applied Sciences, 8(12), 2665. doi:10.3390/app8122665Tziourtzioumis, D., & Stamatelos, A. (2017). Experimental Investigation of the Effect of Biodiesel Blends on a DI Diesel Engine’s Injection and Combustion. Energies, 10(7), 970. doi:10.3390/en10070970Merola, S. S., Tornatore, C., Iannuzzi, S. E., Marchitto, L., & Valentino, G. (2014). Combustion process investigation in a high speed diesel engine fuelled with n-butanol diesel blend by conventional methods and optical diagnostics. Renewable Energy, 64, 225-237. doi:10.1016/j.renene.2013.11.017Choi, K., Park, S., Roh, H. G., & Lee, C. S. (2019). Combustion and Emission Reduction Characteristics of GTL-Biodiesel Fuel in a Single-Cylinder Diesel Engine. Energies, 12(11), 2201. doi:10.3390/en12112201Dimitriadis, A., Seljak, T., Vihar, R., Žvar Baškovič, U., Dimaratos, A., Bezergianni, S., … Katrašnik, T. (2020). Improving PM-NOx trade-off with paraffinic fuels: A study towards diesel engine optimization with HVO. Fuel, 265, 116921. doi:10.1016/j.fuel.2019.116921Pastor, J. V., García, A., Micó, C., & Lewiski, F. (2020). An optical investigation of Fischer-Tropsch diesel and Oxymethylene dimethyl ether impact on combustion process for CI engines. Applied Energy, 260, 114238. doi:10.1016/j.apenergy.2019.114238Bergthorson, J. M., & Thomson, M. J. (2015). A review of the combustion and emissions properties of advanced transportation biofuels and their impact on existing and future engines. Renewable and Sustainable Energy Reviews, 42, 1393-1417. doi:10.1016/j.rser.2014.10.034Yehliu, K., Boehman, A. L., & Armas, O. (2010). Emissions from different alternative diesel fuels operating with single and split fuel injection. Fuel, 89(2), 423-437. doi:10.1016/j.fuel.2009.08.025Gómez, A., Soriano, J. A., & Armas, O. (2016). Evaluation of sooting tendency of different oxygenated and paraffinic fuels blended with diesel fuel. Fuel, 184, 536-543. doi:10.1016/j.fuel.2016.07.049Benajes, J., García, A., Monsalve-Serrano, J., & Martínez-Boggio, S. (2020). Potential of using OMEx as substitute of diesel in the dual-fuel combustion mode to reduce the global CO2 emissions. Transportation Engineering, 1, 100001. doi:10.1016/j.treng.2020.01.001Burger, J., Siegert, M., Ströfer, E., & Hasse, H. (2010). Poly(oxymethylene) dimethyl ethers as components of tailored diesel fuel: Properties, synthesis and purification concepts. Fuel, 89(11), 3315-3319. doi:10.1016/j.fuel.2010.05.014Iannuzzi, S. E., Barro, C., Boulouchos, K., & Burger, J. (2017). POMDME-diesel blends: Evaluation of performance and exhaust emissions in a single cylinder heavy-duty diesel engine. Fuel, 203, 57-67. doi:10.1016/j.fuel.2017.04.089Omari, A., Heuser, B., & Pischinger, S. (2017). Potential of oxymethylenether-diesel blends for ultra-low emission engines. Fuel, 209, 232-237. doi:10.1016/j.fuel.2017.07.107Bjørgen, K. O. P., Emberson, D. R., & Løvås, T. (2020). Combustion and soot characteristics of hydrotreated vegetable oil compression-ignited spray flames. 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An experimental study with renewable fuels using ECN Spray A and D nozzles

This is the author¿s version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/14680874211031200.[EN] The decarbonization process of the automotive industry and the road transport sector has raised the interest on the development of cleaner fuels. A proper characterization of their properties and behavior under different operating conditions is mandatory to achieve an effective implementation in commercial engines. With this objective, the current work presents a comparison of two injectors from the Engine Combustion Network (ECN), namely Spray A and Spray D injectors, in terms of spray characteristics and combustion behavior for different fuels: diesel, dodecane, Hydrotreated Vegetable Oil (HVO), and two types of oxymethylene ethers (OME1 and OME x ). The aim is to analyze how differences in nozzle geometry affect the behavior of different types of fuels. The experiments were carried out in a High Temperature and High Pressure test rig and operating conditions were chosen following ECN guidelines. Visualization techniques such as high speed schlieren imaging, OH* chemiluminescence and diffused back illumination were implemented to analyze the differences in liquid length, vapor penetration, auto ignition, flame lift-off length, and soot formation for both nozzles. In general, results showed the same trend for all the fuels tested: longer liquid length and faster vapor penetration for Spray D, as well as higher ignition delay and longer lift-off length. However, it was found that these parameters were less sensitive to the nozzle diameter for the oxygenated fuels tested. Furthermore, a different trend was observed for OME1, in terms of ignition behavior, in comparison to the other fuels. In terms of soot production, the Spray D nozzle increases its formation with the non-oxygenated fuels. In contrast, no soot was observed with the oxygenated ones under any operating conditions.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors acknowledge that this research work has been partly funded by the European Union's Horizon 2020 Programme, grant agreement no. 828947, and from the Mexican Department of Energy, CONACYT-SENER Hidrocarburos grant agreement no. B-S-69926 and by Universitat Politecnica de Valencia through the Programa de Ayudas de Investigacion y Desarrollo (PAID-01-18). Part of the equipment used in this work was funded by FEDER and GVA through contract IDIFEDER/2018/037.Pastor, JV.; García-Oliver, JM.; Micó, C.; Garcia-Carrero, AA. (2021). An experimental study with renewable fuels using ECN Spray A and D nozzles. International Journal of Engine Research. 1-12. https://doi.org/10.1177/1468087421103120011