Development and testing of a multiplexing system for laser ignition of large bore natural gas engines

Abstract

Conventional electric spark plugs present a hindrance to the continuing goals of higher efficiency and reduced emissions for large-bore natural gas engines. In order to achieve these goals, higher compression ratios and higher air-to-fuel ratios must be achieved relative to those currently allowed by conventional spark plugs. Laser ignition has been shown to work farther into the lean limit, and contrary to conventional electric spark plugs, laser sparks are easier to produce at higher pressures. Laser ignition has also been shown to reduce NOx emissions. This work presents efforts to design, build, and test a single-laser-to-multiple-cylinders multiplexed laser ignition system for use with a large bore natural gas engine. A fiber based laser delivery system was found to work for laser ignition on the bench-top. Results of bench top tests are presented.