Thermal management of exhaust systems

An exhaust emissions reduction system for diesel engines, the diesel engine producing an exhaust stream containing particulate matter and emissions, the exhaust emissions reduction system comprising:

• an emissions oxidation device;
• a heat exchanger downstream from said emissions oxidation device, said heat exchanger adapted to change a temperature of the exhaust stream;
• a selective catalytic reduction device adapted to chemically alter emissions in the temperature adjusted exhaust stream, said selective catalytic reduction device placed downstream from said heat exchanger;
• a filter to remove particulate matter from the exhaust stream;
• heater placed downstream from said selective catalytic reduction device and upstream from said filter for regenerating said filter;
• at least one sensor disposed in the exhaust stream and sensing the temperature of the exhaust stream;
• and
• a controller coupled to said heat exchanger and said heater, said controller adapted to control operations of said heat exchanger and said heater based upon the temperature sensed by said sensor.