Wärtsilä and Mitsubishi Heavy Industries Marine Machinery & Equipment (MHI-MME) have signed a Memorandum of Understanding (MoU) for the commercial marketing of a new energy solution to increase power generation capacity and propulsion from ships.
The solution combines MHI-MME’s waste heat recovery and energy saving power generation system (WHRS) with Wärtsilä’s operational control technology for shaft generator systems. The result is a solution that increases the energy efficiency design index (EEDI) of ships and gives a greater energy efficiency in ship navigation.
The solution combines a power take off/take in (PTO/PTI) shaft generator system with the WHRS, increasing the stability of the WHRS. Extra electrical energy produced by the WHRS can be used by the PTO/PTI generator to drive the propeller shaft.
At full load, the surplus energy can be used to assist the ship’s drive by being applied directly to the propeller shaft. At low main engine load, the WHRS can be operated in parallel with a diesel generator set. Parallel operation with a shaft generator via PTO operation is also easily implemented.
The patented design connects the WHRS generator into the DC link circuit of the PTO/PTI shaft generator rather than directly into the mains. This allows operation of the WHRS at reduced speed to create higher efficiency of the turbine system at part load. This means that no speed regulation valves are required, which cause throttle or bypass losses.