A Generalized Approach for Verifying the Emission Benefits of Off-Road Hybrid Mobile Sources

Autor: Kent C. Johnson, Varalakshmi Jayaram, M. Yusuf Khan, David R. Cocker, William A. Welch, J. Wayne Miller
Rok vydání: 2016
Předmět:
Zdroj: Emission Control Science and Technology. 2:89-98
ISSN: 2199-3637
2199-3629
DOI: 10.1007/s40825-015-0032-9
Popis: More off-road mobile sources are using hybrid technology, and this research outlines a generalized approach for calculating the differences in emissions between conventional and the complex hybrid designs. The basic approach requires simultaneous measurement of activity and emissions for both designs. The case study for this research was a marine vessel, requiring simultaneously measurement of four diesel engines on both vessels and an additional 126 batteries on the hybrid vessel. Analysis of logged data showed both tugs performed the same five activities and the fraction of time at each load for the main propulsion engines was up to 83 % lower than EPA factors. The in-use emissions were measured at operating loads and total emissions from both vessels were calculated using the new weighting factors. Comparative results showed the hybrid tug had significant reductions: 73 % for PM2.5, 51 % for NOx and 27 % for CO2. Interestingly, most benefits occurred during the transit mode and not the standby mode as was the initial hypothesis. During the transit mode, the hybrid energy management system shut down both large propulsion engines and relied on power from batteries and the auxiliary engines now coupled to the propellers. The basic model developed in this research can be applied to other off-road sources and to estimate various scenarios, including retrofits of existing marine vessels or new designs.
Databáze: OpenAIRE
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