Fuel-saving turbocharger technology 'Stena President', sistership of 'Stena Progress' Concordia Maritime and French energy company Total have jointly taken the decision to install MAN Diesel turbochargers with the VTA variable turbine area technology aboard a new tanker. The turbochargers with VTA technology will equip the MAN B&W brand type 6S46MC-C low-speed engines aboard the new tanker 'Stena Progress'. On the basis of earlier trials, they are expected to reduce fuel consumption by around two to three percent, with parallel reductions in exhaust emissions. "We are always interested in new energy saving technologies," noted Hans Norén, President, Concordia Maritime. "When approached by MAN Diesel about employing VTA we decided right away that this was something we wanted to participate in." 'Stena Progress' is a 65,200DWT shallow-draught ice class tanker of the P-MAX type under construction for Concordia Maritime at the Brodosplit shipyard in Split, Croatia, where the main engines will also be built under licence. The tanker is due for delivery in June 2009 and will be chartered to Total for 5 years. In MAN Diesel-type TCA55V turbochargers, the "V" suffix denotes the inclusion of variable turbine area technology, which will be used on both the six-cylinder 6S46MC-C low-speed main engines aboard the 'Stena Progress' and other P-MAXs. MAN Diesel noted that the results of field testing aboard the 'Stena President' were closely monitored and exceeded expectations. "These tankers' routes include arctic waters, which means varying ice conditions and thus highly variable load profiles," stated Jacob Norrby, Naval Architect, at Stena Teknik. "By allowing charge-air delivery to be optimised at all engine loads, the TCA55V turbochargers give the engines better response to load changes, improved emissions at part load and, most importantly, the two to three percent reduction in fuel consumption. "So as well as low noxious emissions, we are also reducing emissions of greenhouse gases to the atmosphere." MAN Diesel VTA Technology In MAN Diesel TCA axial and TCR radial turbochargers with VTA technology, fixed-vane nozzle rings are substituted by nozzle rings with adjustable vanes. Under electronic control, vane pitch is adjusted to regulate the pressure of the exhaust gases on the turbocharger turbine and so vary the output of the turbocharger compressor. The quantity of charge air entering the cylinder can be more precisely matched to the quantity of fuel injected, allowing combustion to be optimised over the complete engine-operating profile. According to turbocharger type, VTA technology can also be retrofitted to turbochargers already in service. For further information contact: MAN Diesel, Germany Email: mandiesel-de@mandiesel.com Web: www.manbw.com
