Exhaust Gas Recirculation (EGR) in marine engines is intended to

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Exhaust Gas Recirculation (EGR) in marine engines is intended to

Exhaust Gas Recirculation lowers the peak combustion temperature by mixing a portion of exhaust gas back into the intake charge, diluting the fresh air with inert gases like CO2 and H2O. That heat-absorbing effect and reduced oxygen concentration drop the flame temperature, which in turn significantly lowers NOx formation since NOx grows rapidly with temperature. In practice, this cooling and dilution can slow combustion and slightly reduce available oxygen for the fuel, so there’s often a tradeoff with engine efficiency or power. EGR does not raise NOx, and it does alter emissions by reducing NOx rather than having no effect, so the best description is reducing combustion temperatures and NOx formation, sometimes at a cost to efficiency. In marine applications, EGR is used to meet NOx limits and is commonly part of an overall emissions-control strategy.

Exhaust Gas Recirculation lowers the peak combustion temperature by mixing a portion of exhaust gas back into the intake charge, diluting the fresh air with inert gases like CO2 and H2O. That heat-absorbing effect and reduced oxygen concentration drop the flame temperature, which in turn significantly lowers NOx formation since NOx grows rapidly with temperature. In practice, this cooling and dilution can slow combustion and slightly reduce available oxygen for the fuel, so there’s often a tradeoff with engine efficiency or power. EGR does not raise NOx, and it does alter emissions by reducing NOx rather than having no effect, so the best description is reducing combustion temperatures and NOx formation, sometimes at a cost to efficiency. In marine applications, EGR is used to meet NOx limits and is commonly part of an overall emissions-control strategy.

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