عنوان مقاله [English]
In this research, the effect of electrode’s configuration on the required voltage and performance of a
natural gas fuel base engine is investigated using three types of spark plugs with the same heat range and
different electrode’s configuration. Then, durability of spark plugs is investigated in durability tests. Scanning
electron microscope (SEM) is used to study mechanisms of electrode erosion. Also, sparking quality
of spark plugs has been investigated by spark plug test rig. Finally, the effects of electrode erosion on the
required voltage, performance and fuel consumption of engine will be investigated during combustion test.
According to the results of new spark plugs, groove in ground electrode causes to 21% decline in required
voltage. Considering results of durability tests, after 200 hours test, average of gap growth for nickel based
electrodes seven times higher than platinum electrodes. SEM analysis of electrode’s surface indicates many
cracks and craters on the surface of nickel based electrodes. Initiation and growth of cracks and intrude of
calcium oxide could lead to accelerate erosion of nickel based electrodes. Results of combustion test shows
that if ignition coil could supply required voltage, electrode’s erosion would not considerable effect on the
amount of torque and brake specific fuel consumption (BSFC) of engine in operation with CNG.