Influence of EGR compounds on the oxidation of an HCCI-diesel surrogate

TL;DR

This study investigates how different additives like NO, ethylene, and methanol affect the oxidation process of a surrogate fuel blend in conditions similar to HCCI engine pre-ignition, using experiments and simulations.

Contribution

It provides new insights into the effects of specific EGR compounds on surrogate fuel oxidation under HCCI-like conditions through combined experimental and numerical analysis.

Findings

Additives significantly influence oxidation behavior in the NTC zone.

Experimental and numerical results show variations in ignition delay times.

EGR compounds alter the oxidation pathways of the surrogate fuel.

Abstract

This paper presents an experimental and numerical study of the impact of various additives on the oxidation of a typical automotive surrogate fuel blend, i.e. n-heptane and toluene. It examines the impact of engine re-cycled exhaust has compounds on the control of an Homogeneous Charge Compression-Ignition (HCCI) engine. Series of experiments were performed in a hihly diluted Jet-Stirred Reactor (JDR) at pressures of 1 and 10 atm (1 atm = 101,325 Pa). The chosen thermo-chemical conditions were close to those characteristices of the pre-ignition period in an HCCI engine. The influence of various additives, namely nitric oxide (NO), ethylene (C2H4) and methanol (CH3OH), on the oxidation of a n-heptane/toluene blend was studied over a wide range of temperatures (550-1100 K), including the zone of the Negative Temperature Coefficient (NTC).