The first IMO exhaust emissions certificate for a Sulzer diesel engine has been awarded. Issued by the classification society Nippon Kaiji Kyokai, it is for a Sulzer 7RTA52U engine which was tested at the Aioi works of the Wärtsilä NSD licensee Diesel United Ltd, Japan. The engine with 10,920 kW (14,840 bhp) output at 135 rev/min will propel a 1618 TEU Uniglory container ship being built at Evergreen H.I. in Japan.
The regulation for limiting NOX emissions from ships was established by the International Maritime Organization (IMO) in 1997 and will come into effect on 1 January 2000, even though it has not yet been ratified by sufficient number of member countries.
All Sulzer RTA-series engines available in today's programme have been prepared to comply with the NOX limits prescribed in the IMO regulation. New engines, such as the recently-introduced RTA60C are designed to comply with the IMO regulation from the beginning. After many years of intensive research and testing, the detailed specifications of the measures necessary to reduce NOX emissions were defined in 1998. The company has adopted the "Low NOX Tuning" concept for reduced emissions. In this concept, a careful combination of adapted compression ratio, injection timing and exhaust valve timing, and different fuel nozzles is applied so as to achieve the best results. Low NOX Tuning is simple and effective yet assures the high reliability of Sulzer RTA engines and also keeps the fuel consumption at the lowest possible level.
The Technical Code associated with the IMO NOX regulation requires that each engine certified as complying with the regulation is provided with a Technical File documenting the technical details of compliance. This file includes the testbed results, defines the relevant components and settings, and states the procedure for checking these components and settings by surveyors who will be inspecting the vessel in future. In this respect, Wärtsilä NSD has established a clearly-defined system of identification numbering for the components relevant to NOX emissions. Beyond being used for the simple checking procedure, this numbering system also guarantees the world-wide availability of the correct spare components to ensure that customers can maintain compliance of their Sulzer engines.
More information: Wartsila