1. In a set-up of Brayton cycle , I know that the turbine has to give a greater magnitude of work output than the magnitude of the work done by the compressor (because the turbine has to run the compressor)....but the turbine and compressor are at the ends of the same shaft, then how how we make the turbine do more work?
2. The whole idea of reheat in Brayton cycle is to increase the efficiency of the cycle-- but efficiency = Wout/ Qin (Heat going in)....so the reheater, which provides extra heat energy increases drastically the value of the denominator, Qin...then how does the efficiency increase?
3. Lastly, In Brayton cycle, I know that reheat has the effect of reducing the efficiency of the cycle if not combined with regeneration...whereas in the Rankine, reheat doesn't need to be accompanied by regernartion...what is the basic reason for this difference?
The Attempt at a Solution
2. I asked my prof about this...he said that the reheater forms a different system, so we don't consider the heat from the reheater while calculating efficiency of the cycle....but this doesn't make sense.
3. Both the Brayton and Rankine cycle are vapour cycles, so I don't understand why the difference exists.