Tightening requirements for emissions reductions highlight the turbocharger’s role in engine efficiency
In June 2019, PBS Turbo and the MAN Turbocharger division combined under a new brand, PBST, to offer a wide range of technologies for turbocharging and exhaust-gas treatment for applications in the shipping, energy, rail transport, industrial, construction and mining sectors.
“Our ambition was to position ourselves as an even stronger turbocharger supplier for engine builders and shipyards, while increasing internal synergies and simplifying external communication and handling,” explains PBST marketing and communications manager Denis Pissarski.
He points out that the move allowed PBST to integrate exhaust gas after-treatment systems and turbochargers in one comprehensive portfolio to provide smart and synchronised air-management systems for many applications, not only in the maritime sector.
Besides broadening its customer base beyond its traditional markets, the rebranding enabled PBST to more easily work with other OEMs to support their turbocharger needs. “We had been approached by many other OEMs to extend our turbocharging portfolio to (support) them – even though some of them might be in competition with our engine division,” says Mr Pissarski.
PBST offers customers all standard turbocharger sizes for two- and four-stroke engines, including the TCR series that is designed specifically for the requirements of liquid-fuel and gas engines. The recently launched TCT series can also increase the overall efficiency of four-stroke engines up to 80% as part of a two-stage application.
Mr Pissarski says the rebranding effort has boosted the company’s engineering efforts. “For instance, we are currently developing an updated radial turbocharger series, which will be available to high-speed engine manufacturers very soon – this is a huge step for us. It will also increase our footprint in the locomotive and construction sectors.”
In the marine sector, shipowners continue to focus on increasing engine efficiency and emissions reductions – both of which can be addressed by two-stage turbocharging. “In terms of two-stage turbocharging, we are considered as a market leader with more than 35M operating hours with our current applications available in the market,” notes Mr Pissarski.
The company’s Ecocharge two-stage turbocharging combines low- and high-pressure stages with intercooling that improves engine performance, reducing fuel costs and emissions.
“We are developing an updated radial turbocharger series, which will be available to high-speed engine manufacturers very soon”
The Ecocharge principle optimally combines a low-pressure turbocharger – usually a TCA or TCR – with a high-pressure stage for which the newly developed TCX series was designed.
The increase in turbocharging efficiencies, in comparison to a single-stage turbochargers, is mainly related to the intercooler – positioned between the low-pressure-stage and high-pressure-stage turbochargers – which significantly reduces the energy required to compress the intake air to high pressure. The resulting efficiencies have an instantaneous impact on the engine by advantageously increasing the air pressure over the cylinder during the scavenging process. Additionally, greater turbocharging efficiency fosters the reduction of NOx emissions through the Miller cycle, while the improved scavenging efficiencies provided by the Ecocharge system make the engine more fuel efficient.
The higher power-density generated by the Ecocharge technology presents the opportunity to choose between significantly boosting an engine’s power output or reducing engine size. The Ecocharge system’s increased efficiencies and higher cylinder rating facilitate the use of a smaller engine with the same power output of a larger unit, which employs traditional, single-stage turbocharging.
New TCT series
PBST’s new TCT series is suitable for conventional and dual-fuel two-stroke engines, ranging from 2,100 kW to 25,000 kW output per turbocharger. With a maximum pressure ratio of 5.0, the compact TCT design is optimised for IMO Tier III two-stroke engines. PBST reports that there are a number of key benefits to engine builders, shipyards and shipowners. Highlights of the TCT series are its lighter weight, more compact design, projected 30% lower operational costs and extended component life.
New additions to the TCT series in 2021 will be TCT50 and TCT70.
SCR-HP for two-stroke engines
Just as turbochargers are a critical tool in the reduction of GHG emissions, exhaust-gas treatment is indispensable for engines. A selective catalytic reduction (SCR) system can reduce an engine’s NOx emissions by up to 90% without any loss of efficiency.
In terms of exhaust gas treatment systems, PBST has sold about 20 of its high-pressure SCR-HP solutions in the first two years after its launch, most of them for its cluster-3 concept, according to Mr Pissarski. The first 13 systems have been delivered to customers, one of which passed through sea trials.
Confidence in the solution was reinforced when the cluster-3 SCR-HP passed a ClassNK approval test in February 2020 at the Makita Works in Japan. Tests were performed on the first of four SCR systems ordered in 2018 and 2019 for vessels with two-stroke MAN B&W 6S46ME-B8.5 engines. Fitted with the SCR-HP system makes each vessel Tier III-compatible. The first engine was ordered by Kanax Corporation and installed in a newly developed 39,000-dwt bulk carrier built at Shin Kurushima Toyohashi Shipbuilding Co, Ltd.
PBST is also developing a low-pressure SCR-LPH system for high-speed engines. “Two of the most important OEMs in the medium-speed area are currently testing our two-stage turbocharging solutions for their new gas engine series,” notes Mr Pissarski.
Some of MAN Energy Solutions’ two-stroke customers that prefer exhaust gas recirculation (EGR) solutions have opted for the electrical turbo blowers (ETBs), says Mr Pissarski. He says PBST has sold about 30 ETB 40 units.
The EGR blower ETB is suitable for engines of all fuel types in all application ranges.
Specifically designed for EGR systems, the ETB´s active control plays an important role in enabling these systems to reach IMO Tier III emission standards and ensure compliance with Emission Control Areas (ECAs). The required EGR operating conditions are achieved by using a high-speed electric motor directly coupled to the compressor wheel and controlled by a frequency converter.
Additionally, the ETB features a highly efficient blower wheel, optimised for low pressure ratios.
Smart glasses support turbomachinery repair
As a way of supporting customers remotely, MAN Energy Solutions began testing Eyetech technology, an assisted reality application with smart glasses, in December 2019. The remote support tool enables mobile video conferences to be set up via data glasses, providing the customer’s perspective to allow remotely located technicians to troubleshoot maintenance issues. EyeTech technology combines a safety helmet with a camera, micro screen, microphone and headphones. The camera mounted on the helmet enables a remotely located expert to see on screen what the technician sees on site and to guide the technician visually and acoustically through maintenance processes. Additional information is provided to the customer via a helmet display.
For the turbocharger sector, Mr Pissarski says PBST handles Eyetech support itself, as opposed to through its service partner MAN PrimeServ, with single field applications in Japan, South Korea, China and two in Europe.
“With this tool,” adds Mr Pissarski, “we can now support customers fully digitally during commissioning, testing and service jobs – requiring no manpower from us on site.”
When additional manpower is required for technical service, PBST can also count on MAN PrimeServ, with 120 locations in the Americas, Europe, Africa, the Middle East, Asia and Australia.
PBST is investing about €50M (US$56M) in its R&D facility Turbocharger Performance Centre, which is nearing completion in Augsburg, Germany. “This is the biggest investment ever done in Augsburg, says to Mr Pissarski. “It also proves that we see a bright future in turbocharging.”