TURBOCHARGERS
CUSTOMERS WANT T/C PERFORMANCE DATA, SAYS KBB End-users want to use this data for performance analysis, for condition-based maintenance (CBM) and to predict a turbocharger’s lifetime, he said. Most of the partners it works with have their own CBM strategy and are monitoring or controlling hardware, but there is no standardisation, he said. Nonetheless, “most of our partners are open to working with third-party algorithms [such as] a blackbox in their engine controller hardware.” Separating the turbocharger monitoring unit from the ECU was an advantage, Risse said, adding “the potential offered by offline analysis is significantly larger. By transferring measurement data from the turbocharger and the engine to the cloud it can be stored and evaluated “extensively and locally with suitable computer technology at the same time or later.” Data latency means response times may not be quick enough to prevent some turbocharger damage, although suitable upgrades to the engine and turbocharger control hardware and software offer potential solutions. Speaking to The Motorship for this report, he said that including “a proved third-party blackbox algorithm is much easier and safer than an additional hardware box on an engine.” And there is no shortage of data available from modern engines, his comments suggested. A lot of engines have OEM-provided monitoring systems and performance analysis “is easy for these engines because no additional sensors or hardware are required,” he said. Meanwhile, KBB has been working on improvements to some of its models and Dr Risse particularly mentioned its established single-stage ST27-EP range of turbochargers, which offer a pressure ratio of 6:1, saying that new designs have been released that incorporate improved capacity and efficiency. He also drew attention to its two-stage K2B series, which has an overall pressure ratio of 10:1 and now features
Credit: KB
Customer demands for more turbocharger performance data to be made accessible online are intensifying, head of turbocharging technology at KBB, Dr Silvio Risse, told The Motorship
new impeller designs that increased compressor flow capacity. Some of these changes were outlined in his CIMAC paper and Dr Risse summarised them for The Motorship, explaining that the capacity improvements are based mainly on blade design optimisation of the compressor and turbine wheels. This is supported by CFD-led flow optimisation for diffusers, nozzle rings and inserts to achieve best performance in combination with new wheel designs. “These modifications are beneficial for thermodynamic efficiency and reduced inertia,” he said. Despite these changes, the turbochargers’ external dimensions have been kept the same, which means that the improved units can be supplied for retrofit installations to improve performance of existing installations, as well for new projects. KBB is currently working on further improvement to both its single- and two-stage turbochargers - mainly involving their components - to extend their service intervals and lifetime, Dr Risse said.
8 KBB has improved the capacity and efficiency of its ST27-EP range of turbochargers
MES wins first order for its latest THS concept What is believed to be the first order for Mitsui Engineering & Shipbuilding’s (MES) latest version of its turbo hydraulic system (THS2) was placed in February for installation on a Mitsui-MAN B&W 7S65ME-C8.5 engine for a 208,000dwt bulk carrier. This technology has its roots in a concept first developed in 2008 that took excess turbocharger energy via a hydraulic pump and matching hydraulic motor to provide additional propulsion power. It has been fitted to 19 ships and gone through a number of iterations over the years. MES said in a statement in February that THS2 improves fuel efficiency by up to 2% on a single engine at 50% load operation or
more when the hydraulic energy recovered from the turbocharger is also used to open and close the exhaust valves and fuel injection of an electronically-controlled engine. It is a refinement that has been under development since 2016. An earlier modification had made it possible to operate the system in ‘turbocharger assist’ mode when the engine is operating at low load. Instead of using the auxiliary blower to supplement the turbocharger, the hydraulic pump and motor can be operated in reverse to deliver engine power to support its turbocharger “and contribute to the reduction of greenhouse gases,” MES said.
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In its statement, MES also noted that among THS’s benefits is that it requires fewer parts to be fitted to an engine than other waste heat recovery technologies, reducing cost and space.
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