Patent ID: 7748976

Claim:
A burner-based system for generating exhaust gas that simulates exhaust gas from an internal combustion engine, and for delivering the exhaust gas to an emissions control device for testing, comprising: a main flow line; a forced air device for forcing air along the main flow line; a burner downstream the forced air device; a fuel injector for delivering fuel to the burner; wherein the burner combusts a mixture of air and fuel in a combustion region, thereby providing fresh exhaust gas as output from the combustion region; a recirculation flow line for diverting at least a portion of the exhaust gas from the main flow line at a point downstream the emissions control device and for delivering the diverted exhaust gas back to the main flow line at a point downstream the burner's combustion region; a main flow heat exchanger that receives the fresh exhaust directly from the burner, and also receives the diverted exhaust gas, and delivers a cooled mixture of exhaust gas directly to the emissions control device; and a compressor on the recirculation flow line configured to receive only recirculated exhaust and to boost the flow of the recirculated exhaust through the recirculation flow line and into the main flow line; a turbine on the main flow line, the turbine configured to drive the compressor, and the turbine directly receiving the output of the main flow heat exchanger and directly exhausting into the emissions control device; a mass air flow sensor on the recirculation line; and a control unit for receiving a measurement signal from the mass air flow sensor and for controlling the fuel delivered to the burner at least partly in response to the measurement signal.