Consider a hot working operation in which there is no work hardening, but the flow stress is sensitive to the strain rate. Calcu
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Answer:
YES
Explanation:
Entropy is an extensive property of the system entropy change that value of entropy change can be determined for any process between the states whether reversible or not. i have attached the formula to calculate entropy change which is independent of whether the system is reversible or not and can be determined for any process.
Answer:
ηa=0.349
ηb=0.345
Explanation:
The enthalpy and entropy at state 3 are determined from the given pressure and temperature with data from table:
The quality at state 4 is determined from the condition and the entropies of the components at the condenser pressure taken from table:
The enthalpy at state 4 then is:
Part A
In the case when the water is in a saturated liquid state at the entrance of the pump the enthalpy and specific volume are determined from A-5 for the given pressure:
The enthalpy at state 2 is determined from an energy balance on the pump:
=346.67 kJ/kg
The thermal efficiency is then determined from the heat input and output in the cycle:
Part B
In the case when the water is at a lower temperature than the saturation temperature at the condenser pressure we look into table and see the water is in a compressed liquid state. Then we take the enthalpy and specific volume for that temperature with data from and the saturated liquid values:
The enthalpy at state 2 is then determined from an energy balance on the pump:
=299.79 kJ/kg
The thermal efficiency in this case then is: