MAN targets Q3 2019 for Mk10 shop tests

Senior Manager Susanne Kindt of the Large-Bore Design Dept. noted that the three models are due to undergo shop tests at MAN Energy System’s licensees in South Korea in Q3, 2019.

In terms of the next models that are the focus of the development programme, Kindt confirmed that design work on Mk10.5 models of its 800mm bore and 600mm bore G-type ME engines was continuing.

There was no clarity about the time-to-market for the models, as the development time depended upon commercial demand from customers.

One platform – two approaches

Kindt noted that the engine designer was taking two different approaches to the upgrading of engines to the Mark 10 platform.

All of the engines were benefiting from an increase in the maximum pressure and lower fuel consumption. However, MAN was applying a “lighter touch” upgrade for some engines, such as the G60 and G95 models, retaining the overall outline for the existing engine model.

The G60 upgrade included replacement of the previous model’s two-stud exhaust valve with a slim design exhaust valve with multi-studs. The new exhaust valve uses heat-resistant alloy pieces to withstand the higher heat emitted from the combustion process, where combustion temperatures and pressures have increased.

“We remodelled the exhaust valve to create more space on the cylinder cover as the LPG fuel injection well needs more room.”

Applying a platform upgrade without changing the outline substantially offered substantial operational benefits, Kindt explained. The new engine would be compatible with existing shipyard designs using Mark 9.5 models with only minor modifications. The continuity of design also offers advantages for engine manufacturers who will be able to continue to manufacture the new engine model.

“The choice between keeping the outline and developing a new outline is dependent on different factors, such as time to market as well as the requirements of the individual engine type,” Kindt said.

“Demand varies from engine type to engine type. We have seen very fast pick up for some engine models, such as the G95, where we have gone from the G95ME-C10.5 model in January 2018 to a shop test within 18 months, which is incredibly fast,” Kindt said.

A new outline

For other engine models, such as the S60/70, G70, G80 and G90, the engine design was being overhauled.

All are designed with the flex-rod connecting rod and the flexible main bearing support, which are the main contributors in achieving the reduced cylinder distance, despite the increase in maximum firing pressure which will have a tendency to make the structure parts grow.

The cylinder frame size has been optimised and reduced in weight – up to 37% for the S60ME-C10.5.The piston crown top, cylinder cover and exhaust valve have been remodelled to withstand the increased heat from the higher maximum cylinder pressure and consequentially reduced combustion volume on combustion chamber components.

Process of optimisation

The optimisation of engine components, such as the replacement of the HCU and actuators with the top controlled exhaust valve (TCEV) and fuel booster injection valves (FBIV), has helped improve hydraulic performance while contributing to a reduction in overall engine size and weight.

The engine designer noted that combining the fuel booster injection valve and the top controlled exhaust valve with the G/S60 Mk10.5 slim design of exhaust valve housing with a weight reduction of up to 50%, could be a combination for future engines, Kindt said.

“It was important that we focus on weight reduction,” said Kindt, “as we are continuing to receive requests for lower fuel consumption and thereby increased engine pressures. Engine components will have a tendency to increase in size and weight in line with combustion temperatures unless optimised, so it was important that we looked to lower the engine weight.”

Reference overview for Mk10