Effects of charged air temperature and pressure on NOx emissions of marine medium speed engines

This paper uses operational data to examine the impact of onboard marine engine installation has NOx emissions under actual operating conditions. The results suggest the need to perform emission measurements in the commissioning phase of the engines to meet NOx emission regulations. The analysis also indicates that direct measurements are better carried out onboard rather then limiting them to a parent engine on the test bench, especially if the diesel engines are on delivery trials.

Research highlights
► Engine test modifying charge air temperature and pressure were done on test bench.
► NOx emissions were analyzed in test bench under modified operating conditions.
► Engine emission tests were done onboard ships in real operating conditions.
► Installation aspects have a direct impact in NOx emissions.
► The NOx emissions onboard could be higher than IMO emission threshold.