The Chemistry Controlling the Homogeneous Charge Compression Ignition (HCCI) Combustion Process

Drexel University, Philadelphia PA

Investigators

Abstract

This is a study of reaction mechanisms and chemical pathways relevant to the homogeneous charge compression ignition (HCCI) process. Single-component fuels and mixtures of 2 to 5 species of unsaturated hydrocarbons are investigated using the Drexel Pressurized Flow Reactor Facility and associated instrumentation for gas analysis. A suite of analytical techniques is used to identify and quantify the stable reaction intermediates and product species. Specific objectives include the production of detailed chemical species evolution profiles as functions of fuel size and structure, oxygen concentration, temperature, and pressure; the isolation of relevant pathways and mechanisms; the development of detailed and reduced chemical kinetic models; and the exploration of possible chemical methods for controlling the HCCI process. The homogeneous charge compression ignition (HCCI) engine, proposed 20 years ago by Japanese engineers, is under active consideration for next generation vehicles. It offers the potential for both high efficiency (high gas mileage) and clean burning (low NOx and particulates). However, the process is not well understood and real systems have problems of stability and fuel optimization.