Application of High Energy Multi-Striking Ignition to Large Bore Engines, Including Effects on Combustion Stability and Ignition of Lean Mixtures
The development and testing of a high energy multi-striking digital ignition system with variable energy is described, including five case histories of laboratory and field testing on large bore slow speed gas engines. The system, in its multi-striking mode, was found to benefit combustion stability at existing air/fuel ratios by reducing the evidence of misfires and improving the uniformity of cylinder peak pressures. The ability to ignite extra lean mixtures created by field turbocharging engines which previously operated at much richer levels was also demonstrated. NOx emissions of engines in this category were reduced as much as 88%, to levels below 2 grams/BHP-hr. (2.68 gm/kW-hr). Other capabilities of the system, such as serial data link to automation computers, individual cylinder timing control, control of spark characteristics, display of critical data, and self-diagnostics, were found to be of benefit to engines operating in gas compression service.