Rapid Pulse Discharges: A New Approach to Particulate Filter Regeneration

该项目将研究一种全新的清洁表面的方法，使用脉冲放电来有效地再生发动机排气颗粒过滤器。内燃机是世界上主要的动力来源，预计这一事实将持续到本世纪。虽然柴油发动机排放低CO2排放，并且具有良好的燃油经济性和良好的耐久性，但它们排放大量的潜在有害的颗粒物（PM）排放物。欧盟、美国和亚洲的发动机和车辆法规规定，只有使用柴油颗粒过滤器（DPF）才能实现，并计划在2013年进一步减少。如果没有定期清洁（再生），DPF在车辆运行约150英里后会堵塞，导致发动机上的高排气背压，从而导致性能和燃油经济性较差。虽然目前的DPF通过迫使气流通过多孔陶瓷壁而产生>95%的PM减少，但是迄今为止的再生系统遭受高功耗、不可靠性、不可接受的高成本和有限的材料选择，或者仅仅是太庞大和复杂。本文提出的再生技术的阶跃变化将实现更理想的系统，并且可以使DPF更广泛地应用于更多的发动机和应用。本文提出的研究将实现非热非氧化再生系统的优点，而不对过滤器几何形状和孔结构敏感，也不具有过高的功率消耗，体积庞大，沉重和噪音大的再生系统。该新概念使用脉冲放电来快速且非常有效地从过滤器表面去除PM而不氧化。初步结果表明，冲击波产生的过滤器内的脉冲放电克服表面力，以打破的PM与过滤器表面使用低至10 W的电功率为整个过滤器的债券。过滤器内的压力波和伴随放电的电场的组合效应使聚集的颗粒破碎，并且允许使用小的反向流从过滤器有效地去除PM。然后，PM被捕获在容器中，随后可以通过坚固且易于控制的电加热器将其销毁，或者压缩和储存，从而减少碳排放。其结果是柴油颗粒过滤器的快速、低功率、耐用、有效和低成本再生，而没有灰分积累。放电的一个非常重要的额外优势是它们被吸引到过滤器内最导电的位置，即一旦放电清洁了一个区域，它将自动选择一个具有较高PM负载的区域。该研究得到了关键合作伙伴Caterpillar和3DX-Ray Ltd.的大力支持，世卫组织将在现金、设备、工作人员时间和开发途径方面提供大量支持。这将提高研究的影响力，预计在新的科学和技术知识、商业价值和对环境的社会效益方面将产生很大的影响。

The project will research a radically new approach to cleaning surfaces that uses pulsed electric discharges to efficiently regenerate engine exhaust particulate filters. It has class-leading features that make it potentially both commercially and technically very attractive.IC engines are the major source of motive power in the world, a fact that is expected to continue well into this century. Whilst diesel engines emit low CO2 emissions, and have good fuel economy and good durability, they emit significant amounts of particulate matter (PM) emissions that are potentially harmful. Engine and vehicle legislation introduced in the EU, US and Asia can only be achieved with the use of diesel particulate filters (DPFs) with further reductions proposed for 2013. Without regular cleaning (regeneration) DPFs become clogged after about 150 miles of vehicle operation leading to a high exhaust back-pressure on the engine, resulting in poor performance and fuel economy. Whilst current DPFs yield >95% reductions in PM by forcing the gas stream through a porous ceramic wall, to-date the regeneration systems suffer from high power consumption, unreliability, unacceptably high cost and limited choice of materials, or are simply too bulky and complex. The step-change in regeneration technology proposed here will achieve a more ideal system and could enable wider application of DPFs to a greater number of engines and applications.The research proposed here will achieve the advantages of a non-thermal non-oxidative regeneration system without either the sensitivity to filter geometry and pore structure or a prohibitively high power consumption, bulky, heavy and noisy regeneration system. The new concept uses pulsed electric discharges to rapidly and very efficiently remove the PM from the filter surface without oxidation. Preliminary results suggest that shock waves produced by pulsed electric discharges within the filter overcome surface forces to break the bond of the PM with the filter surface using as little as 10 W electrical power for a whole filter. The combined effect of the pressure waves within the filter and the electric field accompanying the discharge break up the agglomerated particulates and allow efficient removal of the PM from the filter using a small reverse flow. The PM is then captured in a container, from where it can be subsequently destroyed, e.g. by a robust and easily controlled electric heater, or compacted and stored, reducing carbon emissions. The result is the rapid, low power, durable, effective and low cost regeneration of diesel particulate filters without ash accumulation. A very significant additional advantage of electrical discharges are that they are attracted to the most electrically conducting sites within the filter, i.e. once the discharge has cleaned one region it will self select a region with higher PM loadings.The research is strongly supported by key partners Caterpillar and 3DX-Ray Ltd., who will be providing substantial support in terms of cash, equipment, staff time and exploitation paths. This will enhance the impact of the research, which is expected to be high in terms of new scientific and technical knowledge, commercial value and societal benefits to the environment.