A New Instrument for Diesel Particulate Filter Functional Tests in Development and Quality Control Applications 2010-01-0809

A new Diesel Particulate Generator (DPG) has been developed and commercialized for the automated testing of full-size, light duty Diesel Particulate Filters (DPFs). The system was optimized for filter development testing with a wide parameter range of relevant functional tests, and quality assurance testing where repeatability and rapid testing is important. A carefully designed Diesel-fuelled burner is combined with blowers to produce flows, temperatures and particulate matter (PM) that are representative of Diesel engines. The burner operates with continuous combustion of a Diesel fuel spray, with three-stage introduction of controlled airflows. Variation of these flows allows control of particulate generation independently of total gas flow and temperature (over a temperature and flow range). The system can generate stable PM at more than 20 g/h, or operate without PM formation so permitting preheating of a test filter. To ensure stability of PM generation, gas is drawn through the filter by a vacuum blower on the filter's exhaust side, such that the operating pressure of the burner which generates the PM is unaffected by changing backpressure across the filter as it is loaded with PM.

Data are presented that characterize the reliable performance of the DPG system (stability, repeatability etc), and various comparisons between DPG and Diesel engine PM are made. Results are presented demonstrating capability for standard backpressure versus flow-rate measurements under “cold” conditions. In addition to measuring backpressure as a function of PM load under typical engine operating conditions, the DPG can also achieve conditions for filter regeneration. Regeneration behavior can be studied by adjusting fuel and air flows to simulate engine “Maximum Soot Load” (MSL) tests. Data are presented comparing regenerations of a DPF with identical engine and DPG PM loadings of 8 g/litre. Real-time filtration efficiency is shown during the loading of a “clean” regenerated DPF. The importance of ‘DPF pre-conditioning’ in the Euro 5/6 PMP solid particle number protocol is clearly demonstrated.