During the past year Mitsui Engineering & Shipbuilding (MES) has continued its work with MAN Energy Solutions and the companies are cooperating closely on turbocharging issues. MES engine scavenging pressure requirements have increased significantly in recent years and the company acknowledges that the use single-stage turbocharging is now very close to its limit. Despite the adoption of two-stage turbocharging for four-stroke engines, however, MES plans to retain single-stage configurations for two-stroke in the immediate future.
With the continued drive towards better performance, this could limit efficiencies, particularly in the smaller capacity range, but MES is now paying increased attention to optimising selection and matching of turbochargers to engines and applications. As part of this drive, MES has begun testing MAN TCT type turbochargers, with the first TCT40 product having been successfully shop-tested on an engine in MES’ Tamano factory.
Designed for engine outputs from 2,100 kW to 25,000 kW per turbocharger, the TCT product is optimised for two-stroke application and can boost to a pressure ratio of up to 5.0:1. It also offers a 10% higher specific airflow for 40% cent less weight than a MAN TCA model.
MES also sees good EEDI performance as significant to the industry. “Better EEDI figures will become more important and one of the ways to improve these is to use a waste heat recovery system,” said MES associate director Masaki Ohtsu. “In our case, we have applied a Turbo Hydraulic System (THS) to the turbocharger rotor shaft.” Installed at the compressor end, the THS enables excess energy to be taken from the shaft for use as hydraulic power. Although application numbers are low, MES expects them to grow in the future.
MES and MAN Energy Solutions are committed to further cooperation. This includes R&D into integrating engine and turbocharging developments to achieve maximum engine efficiencies and operational flexibility.