Development and control of homogenous charge compression ignition engines: a preliminary study

Abstract For many years, researchers have been trying to develop internal combustion engines with increased efficiency, while striving to satisfy stricter environmental regulations that limit the constituents of harmful emissions being produced. Homogenous charge compression ignition (HCCI) engines have provided a window of opportunity to make this happen since they incorporate the most ‘attractive’ features from both the standard spark-ignition engine and the compression-ignition engine, resulting in higher efficiencies and cleaner emissions. The main challenge of HCCI combustion is that it is triggered by the auto-ignition of the air-fuel mixture during compression, therefore, making it difficult to control while ensuring maximum efficiency. This research project aims to apply HCCI technology in an attempt to improve the performance of stationary power generation systems in Qatar by developing a low emission – high efficiency natural gas engine. In this poster, we will demonstrate the experimental setup that has been installed and the control strategy that will be used to control ignition timing. The test bench is made up of a single-cylinder engine with intake and exhaust piping system, as well as sensory equipment. The engine is controlled and monitored by a data acquisition (DAQ) computer system. We will show that initial performance data, obtained under full load and at different engine speeds, are in accordance with the performance data from the manufacturer. In addition, a mathematical pressure model has been developed and compared with experimental data, which will be used as the primary input for the feedback control mechanism. We will explain the process in which engine control algorithms use instantaneous cylinder pressure measurements and appropriate thermodynamic relationships to determine the rate of heat release (ROHR). Measured ROHR will then be compared with acceptable rates and controlled using exhaust gas recirculation (EGR) and intake and exhaust manifold pressures and temperatures. Finally, further work to implement HCCI natural gas fueled engine will be discussed.