In support of the Daimler SuperTruck I team’s 55% brake thermal efficiency (BTE) pathway goal, researchers at Oak Ridge National Laboratory performed an experimental investigation of the potential efficiency and emissions benefits of dual-fuel advanced combustion approaches on a modified heavy-duty 15-L Detroit™ DD15 engine. For this work, a natural gas port fuel injection system with an independent injection control for each cylinder was added to the DD15 engine. For the dual-fuel strategies investigated, 65%–90% of the total fuel energy was supplied through the added port fuel injection natural gas (NG) fueling system. The remaining fuel energy was supplied by one or more direct injections of diesel fuel using the production high pressure diesel fueling system. The production DD15 air handling system and combustion geometry were unmodified for this study. Efficiency and emissions with dual-fuel strategies including both low temperature combustion (LTC) and non-LTC approaches such as dual fuel direct-injection were investigated along with control authority over combustion phasing. Parametric studies of dual-fuel NG/diesel advanced combustion were conducted in order to experimentally investigate the potential of high-efficiency, dual-fuel combustion strategies to improve BTE in a multi-cylinder engine, understand the potential reductions in engine-out emissions, and characterize the range of combustion phasing controllability. Characterization of mode transitions from mixing-controlled diesel pilot ignition to kinetically controlled ignition is presented. Key findings from this study included a reproducible demonstration of BTE approaching 48% at up to a 13-bar brake mean effective pressure with significant reductions in engine-out NOx and soot emissions. Additional results from investigating load transients in dual-fuel mode and initial characterization of particle size distribution during dual-fuel operation are presented.

为了支持戴姆勒SuperTruck I小组55％的制动热效率（BTE）路径目标，橡树岭国家实验室的研究人员对改进型重载15双燃料先进燃烧方法的潜在效率和排放效益进行了实验研究。 -L底特律DD15发动机。对于这项工作，在DD15发动机上增加了具有每个气缸独立喷射控制的天然气进气口燃料喷射系统。对于所研究的双燃料策略，总燃料能量的65％–90％是通过增加的端口燃料喷射天然气（NG）燃料系统提供的。剩余的燃料能量是使用生产的高压柴油加油系统通过一次或多次直接注入柴油来提供的。这项研究未更改生产的DD15空气处理系统和燃烧几何形状。研究了包括低温燃烧（LTC）和非LTC方法（例如双重燃料直接喷射）在内的双重燃料策略的效率和排放，以及对燃烧定相的控制权。进行了双燃料NG /柴油高级燃烧的参数研究，目的是通过实验研究高效的双燃料燃烧策略，以改善多缸发动机的BTE，了解可能减少的发动机尾气排放，并描述了燃烧定相可控性的范围。提出了从混合控制的柴油引燃到动力控制的点火模式转换的特征。这项研究的主要发现包括在高达13巴的制动平均有效压力下BTE接近48％的可重复性证明，并显着降低了发动机排出的NOx和烟尘排放量。给出了通过研究双燃料模式下的负载瞬变以及双燃料运行过程中粒度分布的初始表征获得的其他结果。