Energy efficiency analysis of multi-event injections

为了满足当前和未来的柴油发动机排放标准，必须能够以整体的电子方式控制发动机的运行、燃料进入发动机的方法(喷射技术)和任何废气后处理装置。作为这一总体要求的一部分，这项研究将集中在加油和加油控制方法如何影响发动机性能和排放。多脉冲喷射技术被认为是减少氮氧化物(NOx)和颗粒物(PM)排放的有效方法。然而，与低NOx和低PM要求相关的热释放速率会导致偏离发动机条件，而发动机条件通常会使燃烧过程的能量效率最大化。需要有效地平衡排放和能源使用效率。因此，主要目的将是开发一种分析模型来评估现代柴油机多脉冲燃油喷射的性能。为了校准和验证该模型，将在一台原型共轨柴油机上对发动机循环的瞬时热和燃烧特性进行经验检验，该原型发动机由一个集成了嵌入式控制器和复杂的可编程功率驱动器的基于现场可编程门阵列(FPGA)的复杂系统控制。将使用钢瓶压力传感器、快速响应温度传感器和气缸内直接气体采样分析仪测量钢瓶气体压力、温度和成分的详细时间分布。这样，就有可能研究超低排放燃烧时能源效率与燃油喷射计划之间的基本权衡。

To meet the current and future emissions standards for Diesel Engines it is necessary to able to electonically control in an holistic manner the operation of the engine, the methods of getting the fuel into the engine (injection techniques) and any exhaust aftertreatment device. As part of this overall requirement this research will concentrate on how the methods of fuelling and fuelling control effects the engine performance and emissions. The technique of multi-pulse injection has been identified as an effective way to reduce nitrogen oxides (NOx) and particulate matter (PM) emissions. However, the heat release rates associated with low NOx and low PM requirments cause departures from engine conditions which normally maximize the energy efficiency of the combustion process. There is a need to balance in an effective manner emissions with energy-use efficency. Thus, the main aim will be to develop an analytic model to assess the performance of multi-pulse fuel injection in modern diesel engines. To calibrate and validate this model the transient thermal and combustion characteristics of the engine cycle will be examined empirically on a prototype common-rail diesel engine controlled by a sophisticated a field programmable gate array (FPGA) based system integrated with an embedded controller and a sophisticated programmable power drive. The detailed temporal profiles of cylinder gas pressure, temperature, and composition will be measured with cylinder pressure transducers, fast-response temperature sensors, and in-cylinder direct gas sampling analyzers. In this way it will be possible to investigate the fundamental trade-offs of the energy efficiency versus the fuel injection schedule when ultra low emission combustion is targeted.