MAN Diesel Sells 3,000th TCA Turbocharger
Milestone Contract Features New VTA Technology
Only a few years since the introduction of its TCA range of axial turbochargers, MAN Diesel has announced receipt of the order for number 3000.
The order covers a mid range TCA66V being built by MAN Diesel’s Business Unit Turbocharger at its works in Augsburg, Germany. The TCA66V will turbocharge a six cylinder MAN B&W brand low speed 6S50ME-B engine built by licensee Dalian Marine Diesel in China. The engine is rated 8,864 kW at 124 rpm and will power a 50,500 dwt chemical carrier on order at the Chinese Guangzhou Shipyard International from Danish shipping company Torm.
In fact, MAN Diesel notes, the 3000th TCA turbocharger is part of a series for a total of six identical vessels ordered by Torm, all to be powered by a 6S50ME-B engine with TCA66V turbocharger.
Interestingly – and emphasising the pace of continuous development at the Business Unit Turbocharger – the TCA66V is one of the first turbochargers to be equipped with MAN Diesel’s advanced air management system. The “V” suffix denotes that the TCA66V is equipped with a “VTA” variable turbine area nozzle ring with adjustable axial vanes. Adjusting vane pitch regulates the pressure of the exhaust gases impinging on the turbine to vary compressor output. The quantity of charge air can thus be precisely matched to the quantity of injected fuel, allowing the engine’s fuel consumption, emissions and dynamic behaviour to be optimised to power demand across the complete load and speed profile.
In this way MAN Diesel’s VTA technology provides entirely new turbocharging possibilities for marine diesel engines at a time when flexibility of air and fuel management are key factors. They are increasingly important in meeting not only tightening emissions limits but also new demands from operators regarding the interrelated topics of engine flexibility and fuel consumption.
Slow Steaming Solution
For example, at fuel prices of 600 USD per tonne and higher, savings due to VTA technology are considerable. Against a background of decreasing vessel speeds to reduce fuel consumption – “slow steaming“– field tests prior to sales release demonstrated that VTA technology can reduce specific fuel oil consumption (SFOC) by 2 g/kWh at engine loads below 75%. Extrapolated over 6,000 operating hours per year, the annual savings are some 85 tonnes of fuel or 51,000 US Dollars. Savings of this order mean a very short pay-back time for the additional investment in the VTA versions of new turbochargers or a VTA retrofit on existing MAN Diesel turbochargers.
Likewise for slow steaming, in the engine load range 25% to 50%, MAN Diesel offers a lay-out with SFOC savings as high as 3g/kWh.
VTA technology is offered on MAN Diesel’s ranges of both axial TCA and radial TCR turbochargers. Trials on a marine engine started in September 2007 and since then over 5,000 hours of successful operation have been logged, demonstrating welcome fuel savings and proving the VTA system mechanisms in HFO operation.