FOCAS® Hot Gas Test Rig (FOCAS HGTR™)
 

The FOCAS® Hot Gas Test Rig (HGTR™) is a high-flow, diesel-fueled, burner-based catalyst aging system which expands on the capabilities of the Southwest Research Institute® (SwRI®) FOCAS aging system. FOCAS is a computer-controlled, gasoline-fueled burner system designed to simulate the aging conditions of an engine with or without the presence of lubricating oil-poisoning effects. SwRI designed the rig to accommodate full-sized catalyst systems and provide user-designed programmable aging cycles, allowing users to create aging cycles to meet specific needs.

 

Schematic diagram of FOCAS HGTR™ with a diesel DPF–SCR emissions system installed.

FOCAS HGTR™ Features

• Diesel-fueled exhaust
• Independent control of NOx concentration (100–1200 ppm)
• Temperature control (200–1000°C)
• Flow control (up to 2700 kg/hr)
• Wide-range, closed-loop air/fuel ratio control (0.7 < <1.3)
• Capable of continuous operation at stoichiometric ratios
• Heat recovery, minimized heat loss and dilution for reduced fuel consumption
• Separate burner and dilution air controls
• Full FMEA (failure modes and effects analysis) safety monitoring and response
• Ability to add oil component to aging
• Ability to add water vapor

Measured NOx and CO concentration data as a function of NOx control signal on FOCAS HGTR™.

Advantages of Burner-Based Diesel Aging

Because most current diesel emission systems involve NOx control technology, simulating diesel engine NOx levels is an important part of an aging test stand. Since NOx formation is closely linked to peak combustion temperatures (which are lower at lower pressures), burner-based aging systems produce lower NOx levels than engine-based systems. The FOCAS HGTR™ uses a patent-pending method to control the exhaust gas NOx from burner baseline levels to levels higher than 1200 ppm.

The system uses closed-loop control based on NOx sensor feedback. Varying NOx concentration set points can be added to aging cycles, independent of temperature and flow setpoints.

Examples of the impact of burner dilution, heat recovery, and heat loss on fuel savings. The FOCAS HGTR™ will utilize heat recovery and dilution for fuel cost savings compared to engine aging. The real fuel savings will be directly related to real burner outlet temperature (which is affected by heat loss) and the level of dilution that can be utilized (which will be affected by required catalyst inlet temperature, efficiency of heat loss recovery, and burner heat loss efficiency).

This flyer was published in April 2007.  For more information about FOCAS® Hot Gas Test Rig (FOCAS HGTR™), contact Cynthia Webb, Phone (210) 522-5873, or Bruce Bykowski, Phone (210) 522-2937, Engine, Emissions and Vehicle Research Division, Southwest Research Institute, Fax (210) 522- 3950, P.O. Drawer 28510, San Antonio, Texas 78228-0510.

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