September 16, 2010
MAN Diesel & Turbo introduces the Diesel Switch
Could changing fuel grades become as easy as flipping a switch?
MAN Diesel & Turbo SE has introduced the Diesel Switch, designed to eliminate fuel changeover problems
Shipowners and operators now have to operate their MAN B&W two-stroke main engines on ultra-low sulfur fuels in defined marine zones. In addition, since July 1, 2009, CARB (the Californian Air Resource Board) has enforced the use of diesel oils (MDO) or gas oils (MGO) in Californian waters with European harbors introducing similar requirements at the start of 2010. All this adds up to more frequent, running changeovers of fuel type.
The very small clearances within fuel pumps means that the changeover from preheated HFO to cold MDO/MGO, or vice versa, presents a risk for fuel-pump sticking or seizure if not performed properly.
MAN Diesel & Turbo has developed the Diesel Switch, building on its own patent, to handle the fuel changeover in a controlled way and avoid rapid temperature deviations and fuel-pump seizures.
The Diesel Switch is offered in two variants: for retrofits and newbuildings.
While MAN Diesel & Turbo currently recommends vessels to reduce loads to 25-40 percent before changing fuel type, the Diesel Switch retrofit enables a controlled and safe changeover independent of engine load. It does this through continuously checking temperature versus time. If the fuel temperature at the engine inlet exceeds 2 degrees/minute, the Diesel Switch emits an alarm and automatically halts the changeover process.
The Diesel Switch also logs the entire changeover process for subsequent use as official documentation for port authorities if required.
The Diesel Switch hardware is controlled by a touch-screen control panel and has software to operate an MGO cooler to adjust fuel temperatures. The changeover valve uses magnetic couples that dispense with mechanical seals and are 100 percent leak-proof. It also has integrated sensors for detecting current and end positions. As a back-up, the entire system has a manual override.