Rankine Cycle

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lly returns to the initial state. In introducing the 2nd law of thermodynamics, we consider the cyclic heat engines consisting of four separate processes. We noted there that it is possible to have these engines operate at steady-state, steady-flow (SSSF devices involving shaft work or as cylinder /piston involving boundary-movement work.
RANKINE CYCLE
The Rankine cycle is common cycle used in all steam power plants. In Rankine cycle, the working fluid undergoes a change of phase during the cycle. As in this cycle phase change occurs. The properties of the particular working substance must be taken in account, while analyzing the cycle.
Rankine cycle is a modified Carnot Cycle in order to make it practical and economical.
The simple Rankine cycle is the common cycle used in all steam power plants. The Rankine Cycle was devised to make use of the characteristics of water as working fluid and to handle the phase change between liquid and vapor. Of course, many other materials can be chosen instead of water as working fluid. The choice depends on many factors, including the need to accommodate the temperatures of heat transfer to and from the vapor and liquid states while maintaining low vapor pressures in the system.
In Carnot Cycle, it would be difficult to control the condensation process (heat rejections from fluid) so that it stopped as state 1. Further more, it also would be difficult to carry out the compression of the very wet vapor efficiency. During the compression, the liquid tends to separate from the vapor and the compressor would have to deal with a non-homogeneous mixture.
Because of the high volume of vapor, the size of the compressor could be very big as well as costly. On the other hand, it is quite easy to condense th...