A numerical study of ultra-high efficiency combustion of a hydrogen-oxygen-argon mixture in HCCI engines

S. Saxena, V. H. Rapp, J. Y. Chen, Robert Dibble

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review

1 Scopus citations

Abstract

Ultra-high efficiency combustion of hydrogen-in-oxygen, comparable with fuel cell efficiency, can be achieved by using Argon rather than atmospheric Nitrogen as a working fluid. Otto-cycle thermal efficiency is influenced by compression ratio and the ratio of specific heats. The use of Argon as a working fluid increases the specific heat ratio, allowing for higher achievable thermal efficiency. Previous research has identified that the undesirable side-effect of using Argon, however, is that engine knocking occurs more readily. As a result, gains in efficiency are yet to be realized because the compression ratio is reduced to avoid knocking. The purpose of this study is the numerical determination of whether engine knocking in H2-O2-Ar HCCI combustion can be mitigated using reduced equivalence ratios, and delayed combustion timing allowing for higher compression ratios and thereby higher thermal efficiency. The results show that the relationship between indicated efficiency and compression ratio is parabolic, and there is a maximum point beyond which further increases in compression ratio actually decrease efficiency. The study also explores the effects of other parameters such as combustion timing, boost pressure, equivalence ratio and %Argon upon indicated efficiency. The results identify the maximum indicated efficiency point surpassing 48% can be achieved using a compression ratio of 11, intake pressure of 2.0 atm, Argon fraction of 80% and highly delayed combustion timings.

Original languageEnglish (US)
Title of host publicationWestern States Section of the Combustion Institute Spring Technical Meeting 2010
PublisherWestern States Section/Combustion Institute
Pages101-113
Number of pages13
ISBN (Electronic)9781617384196
StatePublished - Jan 1 2010
EventWestern States Section of the Combustion Institute Spring Technical Meeting 2010 - Boulder, United States
Duration: Mar 22 2010Mar 23 2010

Publication series

NameWestern States Section of the Combustion Institute Spring Technical Meeting 2010

Other

OtherWestern States Section of the Combustion Institute Spring Technical Meeting 2010
CountryUnited States
CityBoulder
Period03/22/1003/23/10

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Physical and Theoretical Chemistry
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'A numerical study of ultra-high efficiency combustion of a hydrogen-oxygen-argon mixture in HCCI engines'. Together they form a unique fingerprint.

Cite this