World first Hybrid Turbocharger with Electric-Assist function and Variable Turbine Inlet (VTI) verified its performance at Sea Trial Reducing the ship power consumption at slow steaming
The car carrier that mounts the world first Hybrid Turbocharger with Electric Assist function and Variable Turbine Inlet (VTI) ran its sea trial from April 17-22 and proved the world's first electric-assist turbocharger function on actual ship. The turbocharger was manufactured by Mitsubishi Heavy Industries Marine Machinery & Engine Co., Ltd. (MHI-MME). By using the electric-assist function, the ship will be able to save energy consumption substantially at slow steaming by reducing the amount of time of auxiliary blower operation. The turbocharger combines the function of electric generation as a hybrid turbocharger and that of VTI in addition to the electric assist function.
This ship is a car carrier built by Shin Kurushima Dockyard Co., Ltd. and it is deceided that the same turbocharger (MET66MAG-VTI) will be installed in its next two car carriers. In addition, three more MET66MAG-VTIs are decided to adopt, as the result, MHI-MME has received six units orders of the turbocharger in total. MHI-MME will pursue a goal of creating fuel-saving and environment-friendly products.
Hybrid Turbocharger, which incorporates high-speed generators, utilizes exhaust gas waste energy and provides up to 5% of the main engine output. Consequently that makes it possible to significantly reduce ship fuel consumption without the use of auxiliary diesel power generation.
During slow steaming, separate auxiliary blower was necessary for assisting the turbocharger rotation, in general. Electric-assist turbocharger which is used in place of auxiliary blower incorporates an electric motor that assists the driving of the turbocharger and reduces the operation cost for low load operation of Engine.
Variable Turbine Inlet (VTI) features a special nozzle ring which is cylindrically divided into outer and inner part. The gas passage to the inner part has a control valve which shuts off gas flow into it. This unique system is integrated with the gas inlet casing which enables two-step variation of the turbine capacity. It is simple and reliable solution of flexible turbocharger operation, especially at low load. Retrofit is also available with minimum modification on the turbocharger.
MHI-MME has three major high functionally MET turbochargers: Hybrid turbochargers incorporating generator, Electric-assist turbochargers that reduce the operation cost by its motor running under slow steaming, and VTI turbochargers which are equipped with the variable turbine inlet to increase its scavenging air pressure at slow steaming. The turbocharger which we introduce in this article has all the above three functions.