Energy efficiency analysis of multi-event injections

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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.