Operational Advantages of Tri-Fuel Diesel Electric Propulsion (TFDE) Over Diesel Engine Propulsion
This article throws light on LNG ships in general. The two most famous designs of Q-flex and TFDE LNG ships are being compared. Readers can also easily compare the difference in operation on an electrically propelled ship and a conventional diesel propelled ship. Tri-Fuel diesel Electric Propulsion Ships (TFDE) Operations. TFDE stands for Tri-Fuel diesel electric propulsion ships specifically for LNG carriers. Let us now see the general operational advantages from an Engineering point of view.
- These ships have no Main propulsion diesel engine. They just have two small electrical motors. Thus less space and weight which can be used for cargo carrying.
- Almost “zero” maintenance on electrical motors when compared to main diesel engines.
- The bottom platform is almost empty without main diesel engines. Thus greater flexibility for locating machineries.
- No scavenge space waste oil production. No cylinder oil and main lube oil Usage.
- The ship can be constructed without any main engine sump space for lube oil and thus associated cofferdams.
- No starting air pipelines and starting air compressors for main engine.
- No HFO/MDO purifiers will be running as in diesel ship and thus less maintenance and cost.
- Sludge production is very minimal and condensate from main engine, its associated tank can be neglected.
- Easier watch keeping as parameters are less to monitor in the absence of main propulsion engine.
- No vibrations and noise as compared to diesel engines.
- The electrical motors can run even at 1 or 2 RPMs. Thus adding greater navigational advantages.
- No limitations in number of starts on diesel engine.
- Departure or arrival port, notice time required is very less when compared to a diesel engine propelled ship.
- Complex electrical, electronic circuits and transformers for propulsion motor and speed control devices are required.
- Sea water piping and cooling circuits are comparatively smaller.
- Regular transfer of fuel is not required as the ships generator runs on gas.
- The ship is generally classed as high voltage as the operating voltage may be of the order of 6600 Volts to 11kV.
- Electric motor starting problems are very less when compared to diesel engine reversing and starting problems.
- Electrical braking of the propulsion shaft is very much effective when compared to mechanical breaking in case of diesel engines.
- The total operational cost of the ship is very less when compared to a diesel engine propelled ship.
These are some of the operational advantages of an electrically propelled ship over a diesel engine propelled ship. More of automation and engines which run on gas offer engineers a real peace of life on board a ship. http://www.marineinsight.com/


