Operation of Spark Plugs in a Landfill Gas-Fueled Piston Engine

This paper analyzes the operation of a spark-ignition reciprocating engine fueled by purified landfill gas (LFG). The engine serves as the prime mover for an electric generator and a heat source within a Combined Heat and Power (CHP) unit. Experimental data is retrieved from the Engine Control Unit (ECU). The findings encompass 3000 operating hours (September–December), a period characterized by evolving spark plug conditions, during which various adjustments and service tasks are performed. This study primarily addresses operational strategies for spark plug maintenance to guarantee CHP system reliability, with a specific focus on electrode degradation and its subsequent effect on engine performance. A significant portion of the research analyzes the wear of eight OEM spark plugs installed during the observation period. Utilizing data from a specific interval (4044 to 4797 h), the study calculates the wear rates for both center and ground electrodes based on volume loss measurements obtained via digital microscopy. The results indicate varied electrode wear across the set. Furthermore, the correlation between spark plug condition, misfire counts, emergency shutdowns, and service intervals is examined. The misfires counter is proposed as a parameter for predicting emergency shutdowns and as an indicator for spark plug adjustment or replacement. Lastly, the paper describes potential causes of accelerated ground electrode wear and suggests probable methods for enhancing component longevity.