Cylinder Balancing Algorithms: Enabling the Transition to Future Fuels in Large-Bore Spark-Ignited Engines

Large-bore spark-ignited engines equipped with individual cylinder injection systems require advanced balancing strategies to achieve optimal combustion performance and mitigate risks associated with abnormal combustion phenomena. The integration of highly reactive fuels, such as hydrogen, introduces additional challenges for high-power-density, low-speed engines. This study investigates closed-loop cylinder balancing strategies utilizing real-time cylinder pressure feedback to optimize engine operation. Key performance metrics were evaluated on a 20-cylinder medium speed stationary gas engine (8.5 MW electrical power) under eight different control strategies. The results indicate that the tested balancing methods reduce average knock intensity and variation of combustion peak pressure across all cylinders compared with original manufacturer control strategy. Furthermore, the study demonstrates that a well-balanced engine offers significant advantages, including enhanced power output, a 0.5% improvement in thermal efficiency, and a 20% reduction in NO_x emissions. These findings highlight the critical role of cylinder pressure-based balancing algorithms in improving the performance, efficiency, and environmental sustainability of engines operating on natural gas and hydrogen blends. This research provides a unique experimental campaign with valuable insights into the development of next-generation combustion control systems in large-scale industrial and power generation applications.