KBB has improved the capacity and efficiency of its ST27-EP range of turbochargers (image: KBB)
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.
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.”
His remarks reinforced some that he had made last June at the CIMAC World Congress in Vancouver where he spoke of the advantages of having a turbocharger monitoring unit separate from the engine control unit but went on to say that “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.”
At present, however, data transfer can be time-consuming and the response time may not be quick enough to prevent some turbocharger damage, although he suggested in his paper that this could be solved by suitable upgrades to the engine and turbocharger control hardware and software.
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 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.