In 2007, certification standards for heavy duty diesel particulate matter (PM) emissions were reduced from 0.1g/bhp-hr to 0.01g/bhp-hr, representing an order of magnitude reduction in pollutant level. Coincident with these standards revisions are refinements to test procedures that target reductions in measurement uncertainties. The 2007 U.S. Environmental Protection Agency (US EPA) specifications, as defined in 40 CFR parts 86, and US EPA 2010 specifications, as defined in CFR 1065, require significant updates to established laboratory measurement systems and test procedures. Moreover, additional regulatory standards pertaining to in-use compliance of heavy duty diesel engines will significantly impact the future of heavy duty diesel emissions measurement. As a result of the reduced emission production levels, demand for ‘real-world’ emissions measurements, and subsequent development and evaluation of on-board emissions measurement systems, West Virginia University’s Center for Alternative Fuels, Engines, and Emissions (CAFEE) has designed and constructed, with support from the U.S. Department of Energy (DOE), the ‘next level’ transportable dual primary full-flow dilution tunnel emissions measurement laboratory. The objective of this project was to build a mobile emissions measurement laboratory, of engine test cell quality, that is capable of measuring regulated and non-regulated emissions, and meets US EPA 2007 and 2010 specifications. A thirty-foot long cargo container was constructed to house a portable emissions measurement facility, comprised of a High Efficiency Particulate Air (HEPA) primary dilution unit, two primary full-flow dilution tunnels, a subsonic venturi, a secondary particulate matter sampling system, a gaseous emissions analytical bench instrumentation system, a computer based data acquisition (DAQ) and control system, full air conditioning and ventilation system, and chassis dynamometer control systems. Dual tunnels, of 18 inches ID and 20 feet long provide dedicated measurement capability for both lower PM vehicles, as well as legacy diesel fueled vehicles. This provision reduces tunnel history effects between test programs which address differing exhaust composition and PM loading. The laboratory grade analytical system can be transported to virtually any location with a demand for emissions testing, either with or without WVU’s transportable medium or heavy duty chassis dynamometers. Alternatively, the system can be loaded onto a flatbed trailer in order to test emissions while a vehicle is operated over the road. This paper describes each sub-system of this transportable laboratory in the aspect of specifications and design considerations, and presents results of qualification tests on the laboratory.
Characterization of particulate matter and hydrocarbon emissions from in-use heavy-duty diesel engines