Micro-explosion of Fuel Blends in Low Carbon Diesel Engines: Experimental and Modelling Study

低碳柴油发动机中混合燃料的微爆炸：实验和建模研究

• 批准号: EP/J018023/1
• 负责人: Thanos Megaritis
• 金额: $ 66.52万
• 依托单位: Brunel University London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FJ018023%2F1
• 关键词: Micro; explosion; Fuel; Blends; Low

The transport sector accounts for a significant part of carbon emissions worldwide and in the UK about 20% of CO2 emissions are attributed to road transportation. Consequently, the need to mitigate the greenhouse effect of CO2 and reduce vehicle exhaust emissions has provided the driving force for developing cleaner more efficient vehicle powertrains and environmentally friendly fuels. Reducing consumption of petroleum-derived fuels has become one of the top priorities in the 21st century. As substitutes of the internal combustion engine have yet to overcome technical challenges to attain significant utilisation in the transport sector, the compression ignition diesel engine remains a very attractive powertrain option due to its high thermal efficiency. The International Energy Agency estimates that biofuels can grow to as much as 30% of the world's road transport fuel mix by 2050. Such fuels will include biodiesel and synthetic diesel fuels. In the same frame, alcohols such as bio-ethanol produced from non-food sources with reduced production costs and low CO2 emissions have been proposed as alternative fuels for direct blending with diesel, biodiesel or synthetic diesel. According to Shell, our industrial partner, ethanol made from Brazilian sugar cane produces around 70% lower CO2 emissions from production to use compared to gasoline. Therefore, the potential of ethanol-diesel blends (e-diesel) as alternative fuel for low carbon advanced diesel engines of today and tomorrow has become very important. The use of bio-derived fuel blends such as e-diesel also offers the benefit of compatibility with existing infrastructure.On the other hand, as the complexity of the properties of fuel blends increases, new phenomena that affect engine performance occur in the engine combustion chamber. Thus, improved scientific understanding is essential to overcome potential issues and/or gain potential benefits. One key phenomenon is the micro-explosion of multi-component fuels that is exceedingly possible to occur during spray atomisation and combustion in the case of fuel blends with difference of physical properties among the different fuels in the mixture. The micro-explosion of a miscible multi-component fuel droplet is due to the difference of volatility and boiling point among the different components. For an immiscible multi-component fuel droplet (emulsion droplet as routinely termed), the likelihood of micro-explosion will considerably increase if the lower-boiling-point component cannot dissolve in the mixture and disperse as micro-droplets inside the fuel droplet, such as in the case of e-diesel as the volume fraction of bioethanol increases.Micro-explosion in diesel engines has potentially significant implications on engine performance, combustion and emissions. The phenomenon offers a unique potential in optimising charge preparation in spray combustion systems, making the demands and design of fuel atomisation devices potentially more flexible.However, despite the potentially significant impact, fundamental understanding of the micro-explosion of fuel blends in diesel engines is still lacking. In the present study, we propose for the first time to carry out frontier research using both experimental and modelling techniques to investigate systematically the micro-explosion phenomenon and its effects on spray atomisation and combustion and emissions under realistic diesel engine conditions. The proposed research exploits the creativity that is highly likely to occur at the active interfaces and with the close collaboration between the experimental and modelling researchers with support from Shell which is one of the world's biggest distributors of biofuels. The research outcomes will be disseminated at top international conferences and journals. Development of this science base is vital for the UK to lead the world in advanced technologies of clean, efficient engines and sustainable low CO2 fuels today and tomorrow.

交通运输部门占全球碳排放量的很大一部分，在英国，约20%的二氧化碳排放量归因于道路运输。因此，缓解CO2的温室效应和减少车辆废气排放的需求为开发更清洁、更高效的车辆动力系统和环境友好型燃料提供了驱动力。减少石油衍生燃料的消耗已成为21世纪的首要任务之一。由于内燃机的替代品尚未克服技术挑战以在运输部门获得显著利用，压缩点火柴油发动机由于其高热效率而仍然是非常有吸引力的动力系统选择。国际能源署估计，到2050年，生物燃料将占世界公路运输燃料组合的30%。这些燃料将包括生物柴油和合成柴油。在同一框架内，已经提出了从非粮食来源生产的生物乙醇等醇类，其生产成本降低，二氧化碳排放量低，可作为替代燃料，与柴油、生物柴油或合成柴油直接混合。根据壳牌公司的工业合作伙伴，从巴西甘蔗生产的乙醇从生产到使用的二氧化碳排放量比汽油低约70%。因此，乙醇-柴油混合物（e-diesel）作为低碳先进柴油发动机的替代燃料的潜力变得非常重要。使用生物衍生燃料混合物（如电子柴油）还具有与现有基础设施兼容的优点。另一方面，随着混合燃料性质复杂性的增加，发动机燃烧室中会出现影响发动机性能的新现象。因此，提高科学认识对于克服潜在问题和/或获得潜在利益至关重要。一个关键现象是多组分燃料的微爆炸，在混合物中不同燃料之间具有不同物理性质的燃料混合物的情况下，在喷雾雾化和燃烧期间极有可能发生微爆炸。多组分混溶燃料液滴的微爆炸是由于不同组分之间挥发性和沸点的差异造成的。对于不混溶的多组分燃料液滴由于柴油机中的微爆炸（如通常所称的乳化液滴），如果低沸点组分不能溶解在混合物中并作为微滴分散在燃料液滴内，则微爆炸的可能性将显著增加，例如在电子柴油的情况下，随着生物乙醇的体积分数增加。柴油发动机中的微爆炸对发动机性能具有潜在的重大影响，燃烧和排放。该现象为优化喷雾燃烧系统中的装料准备提供了独特的潜力，使燃料雾化装置的需求和设计可能更加灵活。然而，尽管可能产生重大影响，但对柴油发动机中混合燃料微爆炸的基本了解仍然缺乏。在本研究中，我们首次提出了使用实验和建模技术进行前沿研究，系统地研究微爆炸现象及其对喷雾雾化和燃烧的影响，并在现实的柴油机条件下的排放。拟议的研究利用了活跃界面极有可能出现的创造力，并与实验和建模研究人员之间的密切合作，并得到世界上最大的生物燃料分销商之一壳牌公司的支持。研究成果将在顶级国际会议和期刊上传播。这一科学基础的发展对于英国在当今和未来引领世界清洁、高效发动机和可持续低二氧化碳燃料的先进技术至关重要。

项目成果

Effect of Spray Bulging on Ignition of High Pressure Diesel Sprays

喷雾鼓胀对高压柴油喷雾点火的影响

• 发表时间: 2019
• 作者: Avulapati M.M.

Modeling temperature distribution inside an emulsion fuel droplet under convective heating: A key to predicting microexplosion and puffing

• DOI: 10.1615/atomizspr.2015013302
• 发表时间: 2016
• 期刊: Atomization and Sprays
• 影响因子: 1.2
• 作者: J. Shinjo;J. Xia;A. Megaritis;L. Ganippa;R. Cracknell

Combustion characteristics of a single decane/ethanol emulsion droplet and a droplet group under puffing conditions

• DOI: 10.1016/j.proci.2016.06.191
• 发表时间: 2017
• 作者: J. Shinjo;J. Xia

Experimental understanding on the dynamics of micro-explosion and puffing in ternary emulsion droplets

• DOI: 10.1016/j.fuel.2018.11.112
• 发表时间: 2019-03
• 期刊: Fuel
• 影响因子: 7.4
• 作者: Madan Mohan Avulapati;T. Megaritis;J. Xia;L. Ganippa

Insights into near nozzle spray evolution, ignition and air/flame entrainment in high pressure spray flames

• DOI: 10.1016/j.fuel.2021.120383
• 发表时间: 2021-06
• 期刊: Fuel
• 影响因子: 7.4
• 作者: Madan Mohan Avulapati;R. Pos;T. Megaritis;L. Ganippa