Ignition System Design And Experimental Study Of A Natual Gas Engine

In the context of worldwide oil energy shortages and stringent emissions regulations, naturalgas is considered to be one of the most promising alternative fuel for engine, because of its richresource storage and excellent emissions performance. With the acceleration of promoting naturalgas engines used, as well as the development of electronic control technology, the gas engineignition system with high performance is becoming a hot research focus.In this paper, a natural gas engine experimental table was constructed with a2135G-type dieselengine. And s new ignition control system was developed for meeting requirements of this gasengine. The system can accurately judge the engine operating conditions according to sensor signals,can achieve flexible switching and closed-loop control of the ignition parameters. The ignitioncontrol parameters can be modified online through the serial port.The discharge performance of single-coil ignition was studied, by direct test and simulated loadtest. The influence of charging time on primary energy storage, Ignition energy and energyconversion efficiency was studied. In order to improve discharge characteristics and achieve flexibleswitching, a dual-coil ignition was designed. And the influence of discharge time interval andenergy distribution method on discharge characteristics of the dual-coil ignition was studied throughsimulation and experimental study. Compared with single-coil ignition, the results show that thedual-coil ignition can produce higher secondary voltage and ignition energy, improve energyconversion efficiency, extend spark duration, and achieve multiple ignition. In conclusion, a totalIgnition control program was designed to meet the requirements of different operating conditions ofthe engine.The effects of ignition advance angle and ignition energy on Lean combustion characteristics ofCNG engine was studied. The results show that ignition advance angle has significant effects oncombustion parameters. Engine combustion performance can be optimized through controllingignition advance angle flexibly. Ignition energy has little effects on combustion parameters. Enginecombustion performance can’t be optimized by improving ignition energy under the condition ofsuccessful ignition.