Although introduced by Volvo Penta in 2006, the SCR technology is still a matter of novelty. Intended to meet the emission legislation of 2011, the SCR system has more than lived up to the expectations of making the Volvo Penta industrial engines a particularly good choice from an environmental point of view.
In fact, Volvo Penta’s SCR technology has been so successful that it forms the basis for the company’s strategy to meet the highly stringent demands of Tier 4 Final/Stage 4 that will take effect in 2014.
The SCR (Selective Catalytic Reduction) system is based on high-efficiency combustion which reduces the fuel consumption and results in extremely low levels of particulate matter (PM), but also in high levels of nitrogen oxides (NOx). Here, the smartness of the system is revealed: the exhaust NOx is converted into harmless nitrogen gas and water vapour.
This is made possible thanks to the SCR system which automatically injects up to 5% AdBlue®, a diesel exhaust fluid, to the exhaust gases. The gases are then passed through a catalytic converter before it is emitted to the environment. The extremely low levels of particulate matter in the emissions also make exhaust gas filtration (DPF) unnecessary.
Environmental targets met
The introduction of the SCR system on Volvo Penta engines primarily meant that the Tier 4 Interim/Stage 3B emission standards of 2011 were fulfilled – and in good time. It was, and still is, a palpable competitive quality, but also a matter of course for Volvo Penta and the Volvo Group – environmental care is one of their three core values.
Users gained lower fuel consumption
When the Volvo Penta SCR engines were introduced, the benefits for the users were increased power and lower fuel consumption, by 5-10% compared with corresponding engines. And since the catalytic converter was designed to last the life of the engine, the Volvo Penta SCR systems didn’t demand any increase in service intervals, or cause any additional downtime.
Easier installation and more for equipment builders
Equipment builders saw preserved – or even lowered – demand for cooling, which, in turn, meant that noise levels and the cost of the radiator package could be minimised. A smaller radiator allowed OEMs greater flexibility for accommodating the cooling system in installations where space is scarce.
The fact that more energy could be turned into mechanical power (less heat rejection) meant that the power output could be maximised for a given engine displacement, resulting in smaller engine sizes, reduced costs and simplified installations.
Tier 4 Final/Stage 4 – the next step for SCR
Though being a well-established technology for several years, today, the SCR is in the limelight once again. And the reason for this is of course the coming Tier 4 Final/Stage 4 emission legislation to be effective in 2014. Compared with Tier 4 Interim/Stage 3B, the NOx emissions is to be reduced by as much as 80%.
The solution Volvo Penta put forward in 2011 was based on SCR, optimizing fuel consumption, same cooling-package size and no re-generation. In 2014, Volvo Penta will achieve the same objectives again, no re-generation and limited installation challenges for OEMs and low operating costs – again, based on SCR technology.
Volvo Penta will be unveiling its Tier 4 Final/Stage 4 product range at the Intermat exhibition in Paris, in April, 2012.
For further information, please contact Åke Edman, AB Volvo Penta:
phone: +46 (0) 31 322 51 90, e-mail: ake.edman@volvo.com
Picture: The SCR Technology – how it works.
AdBlue® is a registered trademark of the Verband der Automobilindustrie e.V. (VDA )