When a train in a subway approaches the station, it releases heat
to its surrounding air when it brakes to stop. The heated air is exhausted
through the vents under the station island. An ideal to reuse
this waste heat is to design a waste
recovery system. In this system, cold water is heated by the exhausted
air. To evaluate the recovery system, exergy analysis of this system
should be done.
What is known:
- 200 kg/s air at 60oC enters the heat recovery system.
- Air leaves the heat recovery system at 35oC.
- Cold water at 25oC is sent to the heat recovery system
and leaves at 50oC.
- Ambient temperature is 25oC.