科创中国

       The future of engines 发动机的未来

       Bengt Johansson本·约翰逊

       Chalmers University of Technology查尔默斯理工大学

       个人简介

       Prof Johansson was director of the engine research centerKFPat Lund University Sweden.2003-2015 before leaving for KAUST in Saudi Arabia 2016-2020.He has now moved back to to Sweden and the engine center CERC at Chalmers University since 2021.Prof Johansson been most active with low temperature combustion modes like HCCI and PPC and the interaction of fuel properties and combustion modes.The narrow throat prechamber was developed at KAUST and more recentlythe Double Compression ExpansionDCEE engine has been the focus ofhis interest.He is SAE fellow and was until recently chairman of Powertrain Fuels and Lubricants executive committee.He published more than 400 papers on laser diagnostics, engine performance and closed loop combustion control.

        约翰逊教授于2003-2015年担任瑞典kfpat Lund大学发动机研究中心主任，2016-2020年前往沙特阿拉伯KAUST。从2021年开始，他回到了瑞典查尔默斯大学的发动机中心CERC。约翰逊教授最活跃的领域是低温燃烧模式，如HCCI和PPC，以及燃料特性和燃烧模式的相互作用。窄喉预室是KAUST开发的，而最近双压缩扩张型dcee发动机一直是他感兴趣的焦点。他是SAE会员，直到最近还担任动力总成燃料和润滑油执行委员会主席。他在激光诊断、发动机性能和闭环燃烧控制方面发表了400多篇论文。

       报告摘要

      This presentation will start with showing that the engine efficiency could reach 80% if we can get a best possible thermodynamic cycle in place.The practical limits will then be discussed and the trade-off between thermodynamic and mechanical efficiency highlighted The temperature of the charge before combustion will be shown to be important with high efficiency thermodynamics and the implications on the possible combustion modes will discussed.A concept showing a great potential.called Double Compression Expansion Engine. DCEE, is shown.

      Then combustion of hydrogen is discussed. The very high temperature before combustion in the DCEE enables compression ignition of hydrogen, something that is not possible with normal compression ratios. The resulting diffusion combustion is shown to be quite different to conventional diesel combustion, CDC, and thus also should be optimized in a totally different way. Evolution of combustion and gas exchange optimization ofthe H2 DCEE shows a gradual improvement of brake thermal efficiency from 51all the way to 60.3%.

       这个演讲将从展示发动机效率可以达到80%开始如果我们能得到一个最好的热力学循环。然后将讨论实际的极限，并强调热力学和机械效率之间的权衡。燃烧前的电荷温度将被证明是重要的，与高效热力学和可能的燃烧模式的影响将被讨论。一个显示出巨大潜力的概念。叫做双压缩膨胀引擎。如图所示。

       然后讨论了氢的燃烧。DCEE燃烧前的高温使氢气能够压缩点火，这在正常的压缩比下是不可能的。由此产生的扩散燃烧与传统的柴油燃烧CDC有很大的不同，因此也应该以完全不同的方式进行优化。H2 DCEE的燃烧和气体交换优化过程表明，制动热效率从51一路提高到60.3%。