Cummins engines to meet Tier 4 and Stage IIIB standards
Cummins have announced plans to develop key integrated technologies to comply with the forthcoming US EPA Tier 4 and EU Stage IIIB emission standards in the 130–560kW (174–75hp) power category.
According to the company, there are many ways to meet the stringent emissions regulations and, given the range of engines to which regulations apply, it is critical to match the right solution with the right application.
The solutions include: controlling the by-products of combustion in cylinder; recirculation of exhaust gas to the combustion chamber; cooled exhaust gas recirculation (EGR); and various forms of treatment systems, such as lean-NOx catalysts and active particulate filters.
In their bid to reduce engine emissions, Cummins are concentrating on developing EGR and particulate filter solutions, together with engine enhancements such as variable-geometry turbochargers, advanced electronic controls and high-pressure common-rail fuel systems.
The company will achieve Tier 4/Stage IIIB interim emissions levels by producing an integrated engine and after-treatment solution, whereby the engine combustion recipe works with the after-treatment filter to reduce particulate matter (PM) emissions by as much as 90%. The particulate matter is collected in the filter and oxidized gradually by catalytic passive regeneration, exiting the filter as clean exhaust gas.
Combining with this solution will be a cooled EGR sub-system, developed to provide a 45% reduction in levels of nitrogen oxide. EGR works by re-circulating a varying proportion of the exhaust gas back into the cylinder, which reduces the oxygen content to lower combustion temperatures.
It can be used in tandem with the Cummins variable-geometry turbo system, offering superior engine response by varying airflow boost to suit engine speed, load demands and exhaust gas recirculation rates. In addition, fuel consumption, say the company, can be reduced by up to 5% depending on the engine rating and duty cycle. Both Stage IIIB and Tier 4 power systems will be driven by upgraded electronic engine control modules.
Hugh Foden, Cummins executive director – engine business, said: ‘Our Stage IIIB solution is being developed by the need to deliver the most productive engines with the lowest cost of ownership. Common sub-system architecture will extend from the 6.7 litre QSB to the QSX engines.’
Meanwhile, common architecture for Tier 4 will expand from the QSB to the heavy-duty QSX engines. Cummins say equipment manufacturers will be able to take advantage of specifying either a single-source Stage IIIB or Tier 4 power system from the company.
Susan Harrison, executive director, Cummins Industrial Engineering, commented: ‘Minimizing installation complexity is a key focus of Cummins’ Stage IIIB/Tier 4 development programme, and this is made possible by being able to design and pre-engineer all the key sub-systems in house.’
Cummins UK, 40-44 Rutherford Drive, Park Farm Industrial Estate, Wellingborough, Northants NN8 6AN; tel: (01933) 334200; fax: (01933) 334198.
