November 15, 2007
Type approval for MAN 1,000 kW/cyl dual fuel engine
MAN Diesel's new 51/60 DF, four stroke, medium speed dual-fuel engine has passed another milestone.
Targeted at LNG carriers and stationary electrical power generation applications, the engine offers a 1,000 kW/cylinder output in both gaseous and liquid fuel operating modes
It has now received type approval from classification societies American Bureau of Shipping (ABS), Bureau Veritas (BV), Det Norske Veritas (DNV), Germanischer Lloyd (GL), Lloyd's Register of Shipping (LR), Nippon Kaiji Kyokai, Registro Italiano Navale and the Russian Maritime Register of Shipping.
The type approval process begins early in the overall test program of an engine with the submission of drawings and other data, including a thermal imaging camera scan to ensure surface temperatures are in compliance with the appropriate SOLAS regulations.
In the case of the 51/60 DF dual fuel engine, type approval testing in the presence of all the relevant classification societies was preceded by special testing specified by individual Societies. These were the extreme condition test specified by DNV and emergency operation testing without the turbocharger witnessed by ABS, BV, DNV, GL, LR. In the extreme condition test the engine is run for one hour at both 100% MCR and idling condition with its lube oil temperature and pressure close to their respective high and low alarm trigger limits.
The type approval procedure itself included two days of engine test runs in both gaseous and liquid fuels modes according to a comprehensive set of pre-defined load profiles and including the extreme conditions 106% of rated speed and 110% of maximum continuous rating (MCR).
The 51/60 DF demonstrated operation in the 110% MCR condition in both the gaseous fuel and liquid fuel modes.
On the first day of the type approval tests, the program demonstrated the comprehensiveness of the MAN Diesel dual fuel safety concept, including operation at over 25 alarm conditions in the gas mode, emergency engine shut downs and rapid gas to diesel switchovers under conditions such as heavy combustion knocking.
The third and final day of the type approval process saw the inspection of one complete cylinder unit (cylinder head, liner, connecting rod and big-end bearing shell) and a crankshaft main bearing shell, both chosen by the classification societies on the basis of operating data. Injection tests were carried out on simulation rigs to ensure that both the micro-pilot and main fuel injectors from the cylinder unit were still injecting cleanly.
In total, the seven cylinder 7L 51/60 DF test engine has now achieved over 1,000 operating hours at MAN Diesel's Augsburg test facilities.
With Type Approval achieved on schedule, the engine's development and test program is on target for the engine to provide propulsion and onboard electrical power for LNG carriers presently at the project stage.
Announced in 2006, the 51/60 DF diesel fuel engine is based on the well-proven 48/60B heavy fuel engine. It will be offered in inline versions with 6, 7, 8 and 9 cylinders and vee configuration versions with 12, 14, 16, and 18 cylinders.