Increased Efficiency in SI Engine with Air Replaced by Oxygen in Argon Mixture

PDF Version Also Available for Download.

Description

Basic engine thermodynamics predicts that spark ignited engine efficiency is a function of both the compression ratio of the engine and the specific heat ratio of the working fluid. In practice the compression ratio of the engine is often limited due to knock. Both higher specific heat ratio and higher compression ratio lead to higher end gas temperatures and increase the likelihood of knock. In actual engine cycles, heat transfer losses increase at higher compression ratios and limit efficiency even when the knock limit is not reached. In this paper we investigate the role of both the compression ratio and ... continued below

Physical Description

PDF-file: 25 pages; size: 0.3 Mbytes

Creation Information

Killingsworth, N J; Rapp, V H; Flowers, D L; Aceves, S M; Chen, J & Dibble, R January 13, 2010.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

Basic engine thermodynamics predicts that spark ignited engine efficiency is a function of both the compression ratio of the engine and the specific heat ratio of the working fluid. In practice the compression ratio of the engine is often limited due to knock. Both higher specific heat ratio and higher compression ratio lead to higher end gas temperatures and increase the likelihood of knock. In actual engine cycles, heat transfer losses increase at higher compression ratios and limit efficiency even when the knock limit is not reached. In this paper we investigate the role of both the compression ratio and the specific heat ratio on engine efficiency by conducting experiments comparing operation of a single-cylinder variable-compression-ratio engine with both hydrogen-air and hydrogen-oxygen-argon mixtures. For low load operation it is found that the hydrogen-oxygen-argon mixtures result in higher indicated thermal efficiencies. Peak efficiency for the hydrogen-oxygen-argon mixtures is found at compression ratio 5.5 whereas for the hydrogen-air mixture with an equivalence ratio of 0.24 the peak efficiency is found at compression ratio 13. We apply a three-zone model to help explain the effects of specific heat ratio and compression ratio on efficiency. Operation with hydrogen-oxygen-argon mixtures at low loads is more efficient because the lower compression ratio results in a substantially larger portion of the gas to reside in the adiabatic core rather than in the boundary layer and in the crevices, leading to less heat transfer and more complete combustion.

Physical Description

PDF-file: 25 pages; size: 0.3 Mbytes

Source

  • Presented at: 33rd International Symposium on Combustion, Beijing, China, Aug 01 - Aug 06, 2010

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: LLNL-CONF-422515
  • Grant Number: W-7405-ENG-48
  • Office of Scientific & Technical Information Report Number: 988947
  • Archival Resource Key: ark:/67531/metadc1013048

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • January 13, 2010

Added to The UNT Digital Library

  • Oct. 14, 2017, 8:36 a.m.

Description Last Updated

  • Oct. 27, 2017, 5:36 p.m.

Usage Statistics

When was this article last used?

Yesterday: 1
Past 30 days: 2
Total Uses: 9

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Killingsworth, N J; Rapp, V H; Flowers, D L; Aceves, S M; Chen, J & Dibble, R. Increased Efficiency in SI Engine with Air Replaced by Oxygen in Argon Mixture, article, January 13, 2010; Livermore, California. (digital.library.unt.edu/ark:/67531/metadc1013048/: accessed November 15, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.