Reduction Of Cyclic Variations By Using Advanced Ignition Systems In A Lean-Burn Stationary Natural Gas Engine Operating At 10 Bar Bmep And 1800 Rpm

Keywords

Cyclic variability; Laser ignition; Natural gas engine; Power generation

Abstract

In stationary natural gas engines, lean-burn combustion offers higher engine efficiencies with simultaneous compliance with emission regulations. A prominent problem that one encounters with lean operation is cyclic variations. Advanced ignition systems offer a potential solution as they suppress cyclic variations in addition to extending the lean ignition limit. In this article, the performance of three ignition systems-conventional spark ignition (SI), single-point laser ignition (LI), and prechamber equipped laser ignition (PCLI)-in a single-cylinder natural gas engine is presented. First, a thorough discussion regarding the efficacy of several metrics, besides coefficient of variation of indicated mean effective pressure (COV_IMEP), in representing combustion instability is presented. This is followed by a discussion about the performance of the three ignition systems at a single operational condition, that is, same excess air ratio (λ) and ignition timing (IT). Next, these metrics are compared at the most optimal operational points for each ignition system, that is, at points where λ and IT are optimized to achieve highest efficiency. From these observations, it is noted that PCLI achieves the highest increase in engine efficiency, Δη = 2.1% points, and outperforms the other two methods of ignition. A closer look reveals that the coefficient of variation in ignition delay (COV_ID) was negligible, whereas that in coefficient of variation in combustion duration (COV_CD) was significantly lower by 2.2% points. However, the metrics COV_ID and COV_CD are not well correlated with COV_IMEP.

Publication Date

12-14-2018

Publication Title

SAE International Journal of Engines

Volume

12

Issue

1

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.4271/03-12-01-0005

Socpus ID

85063696272 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/85063696272

This document is currently not available here.

Share

COinS