WHY CARNOT CYCLE IS NOT PRACTICABLE FOR A STEAM POWER PLANT
Theoretically, a carnot cycle is most efficient, however, the following difficulties are associated with it when steam is the working fluid.
Just for an idea,
This is how the classical Carnot Heat Engine Looks...
Theoretically, a carnot cycle is most efficient, however, the following difficulties are associated with it when steam is the working fluid.
- Steam condensation is not allowed to proceed to completion. The condensation process is controlled one.
- The working fluid after condensation process is both in the liquid and vapour state, and these do not form a homogeneous mixture. It is rather difficult to compress the two phase mixture isentropically.
- The vapour has a large specific volume and to accomodate greater volumes, the size of the compressor becomes quite big.
- For running a large sized compressor more powder is required and that results in a poor plant efficiency.
- Carnot cycle has high specific steam consumption, large back work ratio and low work ratio.
- The steam at exhaust from the turbine is of low quality i.e., high moisture content. The liquid water droplets cause pitting and hence erosion of the turbine blades.
This is how the classical Carnot Heat Engine Looks...
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