T&T SHIPBUILDER & REPAIR NEWS ISSUE #036 – SEPTEMBER 2010.
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SCR and 32/44 emission techniques With the SCR method, exhaust gas is treated with ammonia or urea and fed through a catalytic converter at a temperature of 300 to 400 degrees Celsius to reduce NOx emissions by up to 98%. However, while the SCR is essential for meeting Tier-III limits, the SMM engine, as previously mentioned, satisfies IMO Tier-II alone through its ultra-modern design. As such, the 32/44CR engine represents the latest technologies in the area of medium-speed, industrial diesel engines and is a synthesis of the most advanced large engine technologies available. These include: a higher compression ratio that gives a faster reduction in temperature after the ignition of the fuel, reducing NOx formation and the associated increase in SFOC, Miller valve timing that reduces the temperature peaks that promote NOx formation MAN Diesel & Turbo turbochargers equipped with the latest high-efficiency compressor wheels to alleviate the NOx-SFOC trade off. The higher pressure ratio increases engine efficiency, compensating for the increase in SFOC normally associated with lower NOx emissions, variable valve timing to compensate for the increase in SFOC associated with lower NOx emissions a common-rail injection system that allows flexible setting of injection timing, duration and pressure for each cylinder, facilitating the optimisation of the fuel consumption and emissions and the latest generation of SaCoSone, MAN Diesel & Turbo’s proven engine-management system. That offers integrated self-diagnosis, maximum reliability and availability, simple userinterface, quick exchange of modules (plug in), and trouble-free commissioning ********************
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