Recalculate P3.2 assuming that the pump efficiency \(\eta_{\mathrm{P}}=0.8\), and the turbine efficiency \(\eta_{\mathrm{T}}=\) 0.9. Comment on the effect on the thermal efficiency of the plant, and also the back work ratio. [21.81\%;0.47\%]

P3.2 

A steam power plant operating on a basic Rankine cycle has the following parameters: maximum (boiler) pressure 20 bar; minimum (condenser) pressure 0.5 bar. Calculate the thermal efficiency of the cycle, and compare it to that of a Carnot cycle operating between the same temperature limits (see P3.1). Calculate the specific power output and the back work ratio (defined as \(\dot{w}_{\mathrm{P}} / \dot{w}_{\mathrm{T}}\) ) for the cycle in this question and that in P3.1. Comment on the results obtained.

(Assume the pump and turbine operate isentropically.)

[24.26\%;27.0\%;598.5 kW/(kg/s); 0.34\%; 14.7\%]