System for recovering exhaust gas energy
The invention relates to a system ( 12 ) for the recovery of energy from exhaust gases from at least one turboshaft engine, comprising a turbine ( 34 ) fitted rotatably around a recovery shaft ( 40 ), adapted to bleed off at least a part ( 14 ) of the exhaust gases, known as bleed gases ( 14 ), and to expand said bleed gases ( 14 ) to become expanded gases ( 42 ) at a pressure below atmospheric pressure, a first heat exchanger ( 44 ), adapted to use a cold source ( 45 ) to cool said expanded gases ( 42 ) to become cooled gases ( 46 ), and a compressor ( 36 ) fitted rotatably around said recovery shaft ( 40 ), adapted to compress said cooled gases ( 46 ) to atmospheric pressure.
1. A turboshaft engine, fitted with a system for the recovery of energy from exhaust gases from the turboshaft engine, comprising:
a turbine fitted rotatably around a recovery shaft, adapted to bleed off at least a part of the exhaust gases, known as bleed gases, and to expand said bleed gases to become expanded gases at a pressure below atmospheric pressure;
a first heat exchanger, adapted to use a cold source to cool said expanded gases to become cooled gases;
a compressor fitted rotatably around said recovery shaft, adapted to compress said cooled gases to atmospheric pressure;
a fan configured to bring the cold source to the first heat exchanger, the fan being driven in rotation by the recovery shaft;
a turbine driving in rotation a turbine shaft, the recovery shaft being connected to the turbine shaft.
2. The turboshaft engine according to claim 1 , wherein the energy recovery system comprises a second heat exchanger, adapted to perform a preliminary cooling of the expanded gases, before they pass into the first heat exchanger.
3. The turboshaft engine according to claim 1 , wherein the energy recovery system comprises an air intake, adapted to perform a preliminary cooling of the expanded gases, before they pass into the first heat exchanger.
4. The turboshaft engine according to claim 1 , wherein the energy recovery system comprises a plurality of ducts connecting the turbine to a plurality of exhaust pipes for bleeding off exhaust gases originating from a plurality of turboshaft engines.
5. A helicopter comprising a turboshaft engine according to claim 1 .
6. The helicopter according to claim 5 , further comprising a tail rotor driven by a rear shaft, wherein the recovery shaft is connected to said rear shaft.