Patent ID: 7114485

Claim:
An over expanded, two-stroke HCCI cycle for operating an HCCI engine comprising: a compression process 1 - 2 - 3 , said compression process 1 - 2 - 3 further comprising: a first compression process 1 - 2 carried out via an external compressor; and a second compression process 2 - 3 carried out by changing the volume of a cylinder of said engine; a multi-stage fuel injection process 1 - 2 - 3 - 4 - 5 , said fuel injection process further comprising: a first stage fuel injection taking place during said first compression process 1 - 2 , which enters the cylinder via an intake manifold as a homogeneous charge; a second stage fuel injection taking place towards the end of said second compression process 2 - 3 ; and a third stage fuel injection taking place at the start of an expansion process 4 - 5 ; a heat addition process 3 - 4 - 5 , said heat addition process 3 - 4 - 5 further comprising: a first heat addition process 3 - 4 carried out via said second stage fuel injection triggering autoignition of the compressed homogenous charge; a second heat addition via combustion of the homogeneous charge; and a third heat addition process 4 - 5 carried out via injection and combustion of said fuel in said cylinder while maintaining a constant, limiting temperature; an adiabatic expansion process 5 - 6 ; a heat removal process 6 - 7 - 1 , said heat removal process 6 - 7 - 1 further comprising: a first heat removal process 6 - 7 under a constant volume; and a second heat removal process 7 - 1 under constant pressure; wherein said compression process, said heat addition process, said adiabatic expansion process, and said heat removal process combine to form an over expanded, HCCI cycle 1 - 2 - 3 - 4 - 5 - 6 - 7 - 1 .