Analysis of Exhaust Pollutants from Four-Stroke Marine Diesel Engines Based on Bench Tests

Implementation of new emissions regulations calls for a reassessment of the emissions levels of newly built ships sailing in Chinese regions. In this paper, marine diesel engines are subjected to emissions bench tests using high-precision testing equipment. A total of 135 marine diesel engines meeting the Limits and Measurement Methods for Exhaust Pollutants from Marine Engines (CHINA I/II) were first systematically analyzed. The emission factors of marine main engines (ME) and auxiliary engines (AE) were obtained under different displacements. The results show that the fuel-based emission factors for NOX + HC and CO meeting CHINA I/II are 25.80 similar to 44.87/16.47 similar to 46.35 and 2.47 similar to 13.22/1.64 similar to 5.62 kg/t-fuel, respectively. The energy-based emission factors for NOX + HC, CO, CO2, and PM satisfying CHINA I/II are 5.70 similar to 9.24/3.70 similar to 9.07, 0.49 similar to 2.30/0.36 similar to 0.99, 620 similar to 683/612 similar to 718, and 0.05 similar to 0.36/0.05 similar to 0.27 g/kWh, respectively. Additionally, the specific emission of NOx rises with the increase in single-cylinder displacement, so the CO emission limit of pure diesel fuel is recommended to be lower than 5 g/kWh. The results in this paper provide valuable basic data for research on and estimation of ship emissions in waterway transportation and for understanding the emission characteristics of marine diesel engines.

Automated summary

The implementation of new emissions regulations in China requires a reassessment of emissions levels in newly built ships. This study conducted emissions bench tests on marine diesel engines using high-precision testing equipment. The results provide valuable data on emission factors and characteristics of marine diesel engines, contributing to research on ship emissions and understanding of the impact of waterway transportation.