A steam plant operates on a thermodynamic cycle based on two isothermal

processes and two isentropic processes. Pure water enters the plant at a rate of

$100kg{s}^{-1}$ at $75$ bar and the saturation temperature, and is isothermally heated and

fully vaporised. The stream is then isentropically expanded through a turbine to

$0\mathrm{.}5$ bar. After that, it is cooled to the same entropy as the inlet water before being

compressed back to the inlet conditions.

$($a$)$ Find the following by using the Steam Tables provided in Tables Q$4\mathrm{.}1$ and

Q$4\mathrm{.}2$:

$($i$)$ the state and properties of the stream after each process step

$($ii$)$ the heat transfer rates

$(8$ marks$)$

$($iii$)$ the net work transferred

$(4$ marks$)$

$($iv$)$ the process thermal efficiency.

$(4$ marks$)$

$(4$ marks$)$

$($b$)$ Comment on the process in terms of process thermal efficiency and

practical operability and propose your design to improve it$.$

$(5$ marks$)$