Energy-based closed-loop control of turbine outlet temperature in a vehicle

A control system for use aboard a vehicle having an internal combustion engine, the control system comprising:

• a first temperature sensor adapted for measuring an inlet temperature of intake air entering an air compressor of the vehicle, wherein the air compressor is energized within an air compressor intake assembly by a turbine to thereby generate compressed intake air;
• a second temperature sensor adapted for measuring an outlet temperature of exhaust gas exiting the turbine;
• a mass flow sensor positioned to measure a mass flow rate of the compressed intake air entering the engine from the air compressor;
• and
• a host machine operable for calculating an engine thermal efficiency value as a function of the inlet temperature, the outlet temperature, and the mass flow rate;
• wherein the host machine maintains a temperature of the exhaust gas exiting the turbine above a calibrated threshold temperature using the engine thermal efficiency value.

A method for maintaining a temperature of an exhaust gas in a vehicle having an engine, a turbine which energizes an air compressor, and an exhaust system having fuel injectors adapted to inject fuel into a stream of exhaust gas, wherein the exhaust system is operable for purifying the exhaust gas by selectively igniting the fuel in the exhaust gas, the method comprising:

• measuring an inlet temperature of intake air entering the air compressor and an outlet temperature of the exhaust gas exiting the turbine;
• measuring a mass flow rate of compressed intake air entering the engine from the air compressor;
• using a host machine to calculate an engine thermal efficiency value as a function of the inlet temperature, the outlet temperature, and the mass flow rate of the compressed air;
• and
• using the engine thermal efficiency value to automatically maintain a temperature of the exhaust gas at the outlet of the turbine above a calibrated threshold temperature.