The European Union (EU) has recently adopted new directives to reduce the level of pollutant emissions from non-road mobile machinery engines. The main scope of project RIVER for which this study is relating is to develop possible solutions to achieve nitrogen-free combustion and zero-carbon emissions in diesel engines. RIVER aims to apply oxy-fuel combustion with Carbon Capture and Storage (CCS) technology to eliminate NOx emissions and to capture and store carbon emissions. As part of this project, a computational fluid dynamic (CFD) analysis has been performed to investigate the effects of oxy-fuel combustion on combustion characteristics and engine operating conditions in a diesel engine under Homogenous Charge Compression Ignition (HCCI) mode. A reduced chemical n-heptane-n-butanol-PAH mechanism which consists of 76 species and 349 reactions has been applied for oxy-fuel HCCI combustion modeling. Different diluent strategies based on the volume fraction of oxygen and a diluent gas has been considered over a wide range of air-fuel equivalence ratios. Variation in the diluent ratio has been achieved by adding different percentages of carbon dioxide for a range from 77 to 83 vol.% in the intake charge. Results show that indicated thermal efficiency (ITE) has reduced from 32.7% to 20.9% as the CO₂ concentration has increased from 77% to 83% at low engine loads while it doesn’t bring any remarkable change at high engine loads. It has also found that this technology has brought CO and PM emissions to a very ultra-low level (near zero) while NOx emissions have been completely eliminated.

欧盟（EU）最近通过了新指令，以减少非道路移动机械引擎的污染物排放水平。这项研究涉及的RIVER项目的主要范围是开发可能的解决方案，以实现柴油发动机的无氮燃烧和零碳排放。RIVER的目标是将氧燃料燃烧与碳捕集与封存（CCS）技术结合使用，以消除NOx排放并捕获和储存碳排放。作为该项目的一部分，已进行了计算流体动力学（CFD）分析，以研究均质充量压缩点火（HCCI）模式下含氧燃料燃烧对柴油机燃烧特性和发动机工况的影响。还原化学正庚烷-正丁醇-PAH机理由76种物质和349个反应组成，已应用于氧燃料HCCI燃烧建模。在广泛的空燃当量比范围内，已经考虑了基于氧气和稀释气体体积分数的不同稀释策略。通过添加不同百分比的二氧化碳以达到进气费用的77％至83％（体积），可以实现稀释剂比例的变化。结果表明，随着CO的使用，指示的热效率（ITE）从32.7％降低至20.9％通过添加不同百分比的二氧化碳以达到进气费用的77％至83％（体积），可以实现稀释剂比例的变化。结果表明，随着CO的使用，指示的热效率（ITE）从32.7％降低至20.9％通过添加不同百分比的二氧化碳以达到进气费用的77至83％（体积），可以实现稀释剂比例的变化。结果表明，随着CO的使用，指示的热效率（ITE）从32.7％降低至20.9％₂浓度在低发动机负荷下已从77％增加到83％，而在高发动机负荷下并没有带来任何显着变化。还发现，该技术使CO和PM排放量达到了非常低的水平（接近零），而NOx排放量已被完全消除。