Crankcase ventilation systems are coming into new focus due to safety concerns associated with alternative fuels such as ammonia and hydrogen. In addition, innovation is being driven by increasingly stringent legislation that plays an important role in limiting crankcase emissions. This study characterizes aerosol separation and pressure control of a modern crankcase ventilation system, which is referred to as “smart” due to enabling monitoring, diagnostics, and predictive maintenance. Experiments were conducted on custom-built and commercial test rigs that mimic the physical conditions to which crankcase ventilation systems are subjected. The main findings were that the pressure drop of the filter media followed the profile described by the “jump-and-channel model”, also indicating the presence of an oil film. However, such an oil film was not detected on the full-size element, which had a positive effect on the pressure drop. Excellent separation efficiencies around 99.9% were achieved for all flow rates and filter conditions. In addition, re-entrainment of oil was not detected. The electronic pressure regulator (EPR) was found to accurately (± 1 mbar) adjust the crankcase pressure to the required level. Moreover, the fully open EPR featured a low differential pressure of about 1 mbar, which effectively reduces crankcase peak pressure during engine startup. These features exceed those of conventional pressure control valves. In addition, only the electronic regulator enables “smart” features.

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