A Review of Low Temperature Combustion Techniques and the Evolution of Combustion Strategies

The challenges offered by the conventional gasoline engines and diesel engines, the energy security, and the rigorous emission rules have led the research into the direction of advanced combustion techniques. The low temperature combustion (LTC) technique is an advanced combustion strategy that enables combustion at low temperature and offers a way to realize ultra-low NOx and PM emissions with higher thermal efficiency. Homogeneous charge compression ignition (HCCI), premixed charge compression ignition (PCCI), partially premixed compression ignition (PPCI), reactivity controlled compression ignition (RCCI), and dual direct injection (DDI) are the different forms of LTC. It is noted that all forms of LTC have the potential to control emissions and improve thermal efficiency. However, in the absence of a combustion controlling mechanism unlike conventional engines, control over combustion is highly challenging. The increased level of CO and UHC is also the problem with LTC. It is also reported that as compared to HCCI, the PPCI, RCCI, and DDI provide better control over the combustion by offering stratifications. This paper covers the detailed concepts, positive aspects, and limitations of different forms of LTC.