I'd been having difficulty with a problem from Cengel and Boles, Thermodynamics An engineering approach. The problem is about the deviated Rankine cycle from Idealised ones.
The question I would like to ask is how to obtain the enthalpy at state 3 and at state 6. The image attached shows the data for the problem.
I would also like to know is there a need to use the T-S diagram in obtaining the enthalpies in state 3 and state 6.
This is what I got so far:
The enthalpy at state 1 is obtained from the steam table and is h1 = 182.586 kJ/kg.
The actual work done by the pump is calculated using the isentropic efficiency value for pump and the value is w(pump, actual) = 18.986 kJ/kg
To calculate the heat input, the enthalpy at state 3 and state 4 must be known. The problem is I do not know how to get the enthalpy at state 3.
Similarly for the work done by the turbine, w(turbine,actual) the enthalpy at state 5 and 6 needs to be know. The problem is that I do not know how to obtain for enthalpy at state 6.
I managed to obtain the work done by actual turbine with the method described by @algo.
The problem that I still have is how to obtain the enthalpy at state 3. I need it to obtain the heat input to the boiler. Can considering irreversibilities in the pipes (State 2 to 3) actually help in obtaining the enthalpy at state 3? Currently, I have no clue on how to start.
Any helpful reply would be appreciated.