Assessment of condensable pm measured by legislative methods US EPA 5b/202 wet impengers and US EPA 5i/202 dry impingers when used for ultra-low pm level produced by gas turbine engine

With the development of gas turbine engine technology, the Particulate Matter emission levels have been reduced significantly. This has imposed a great challenge when measuring them using the legislative methods. Historically those methods have been developed for much higher level of PM produced by coal burning power stations. When used on a modern gas turbine those methods have been pushed to, or below, their limit of detection.

In this paper, a series of tests using Legislative methods USA EPA 5B/202 and US EPA 5I/202 have been tested on Dry Low Emission DLE gasturbine engine.

The two methods US EPA 5B/202 (Wet Method) and US EPA 5I/202 both showed good agreement in the total condensables levels, However, in general, the wet method showed increment in the inorganic portion compared to the dry method. This could partially due to the gaseous contaminants (such as NOx and SOx) which can partially absorb in the water and chemically oxidize to form material counted as inorganic condensables.

The organic condensable fraction of the PM10s appeared to consist mainly of siloxanes. This is not originated from the engine or the ducting (intake and exhaust). It was concluded that the siloxane is present in the ambient air or from the test method itself.