The EU Stage IIIB approval for SISU engines over 130 kW was granted already earlier in the autumn of 2010. The corresponding EPA Tier 4 interim approval was granted on December 14th, 2010. This approval is one of the first the EPA has granted for non road engines utilizing SCR technology. The Stage IIIB and Tier 4 interim requirements will be applied in production for ratings above 130 kW starting January 1st, 2011. The production of these engines has already started at AGCO SISU POWER Nokia factory for non road engine customers in Europe and the U.S.
The SISU engines with SCR technology offer the best fuel economy in the world for non road applications because with SCR, the combustion can be set to optimum temperature and Air/Fuel - ratio. The nitrous oxides which form at high combustion temperatures are reduced in the exhaust line with the maintenance-free SCR technology. Depending on load, the consumption of AdBlue fluid (a mixture of urea and water) is only 2 to 6 percent of fuel consumption. SISU engines do not need the problematic EGR technology to reduce combustion temperatures and formation of nitrous oxides. Thus, there is no need for expensive and problematic variable geometry turbochargers to control EGR. The particulate level is controlled already in the cylinder by using high A/F ratios and combustion temperatures. That makes the use of the expensive Diesel Particulate Filter and its regeneration unnecessary. As EGR technology is not needed, there is also no need for the cooling of re-circulated exhaust. The cooling capacity of the Stage IIIB / Tier 4i SISU engines does not have to be increased from Stage IIIA / Tier 3. Also the efficiency improvement of 7 to 10 percent with SCR technology helps with cooling system design. The fan power and the size and cost of the cooling system are reduced. The EGR & DPF technology adopted by some competitors to reduce emissions requires an increase of 20 to 40 percent in the capacity of the cooling system due to the cooling of re-circulated exhaust and poor efficiency.
The SCR technology, which the SISU non road engines utilize to reduce nitrous oxides in the exhaust line, has already been used in Europe for more than five years in trucks and buses. The combustion efficiency in the cylinder can be optimized really well without the use of EGR, DPF or VGT technology and without an increase in cooling power. The fuel economy of SISU engines is improved up to 10 percent due to the use of SCR technology. The competitors who use EGR, DPF and larger fans suffer from lower fuel economy. The difference is about 7 to 10 percent in favour of SCR technology. The competitive advantage of SISU non road engines is improved regarding economy, reliability and durability, in spite of reduced exhaust emissions.
Information: Juha Tervala Marketing Director Tel. +358 40 5088727 juha.tervala@agcosisupower.com
Mauno Ylivakeri R&D Director Tel. +358 40 5088718 mauno.ylivakeri@agcosisupower.com
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