A-) For this case, by drawing the T-s diagram, Rankine Find the thermal efficiency of the cycle.
To solve this problem, we need to use the Rankine cycle with water vapor as the working fluid. The given parameters are:
- Condenser pressure: 10 kPa
- Boiler pressure: 2 MPa
- Inlet temperature of steam to the turbine: 360 °C
- Working fluid enters the pump as a saturated liquid
Using the steam tables, we can find the properties of steam at different pressures and temperatures. The following steps can be used to solve the problem:
1. The pump process is isentropic, so the specific entropy of the working fluid remains constant. We can find the specific entropy of the working fluid at the condenser pressure of 10 kPa from the steam tables. The value is:
s1 = 0.1919 kJ/kg·K
2. The working fluid enters the pump as a saturated liquid, so its specific entropy remains constant during the pump process. We can find the specific volume of the saturated liquid at the condenser pressure from the steam tables. The value is:
v2 = 0.001044 m³/kg
3. The boiler process is isobaric, so the pressure remains constant. We can find the specific enthalpy of the working fluid at the boiler pressure of 2 MPa and the inlet temperature of 360 °C from the steam tables. The value is:
h3 = 3272.8 kJ/kg
4. The turbine process is isentropic, so the specific entropy of the working fluid remains constant. We can find the specific entropy of the working fluid at the boiler pressure of 2 MPa and the inlet temperature of 360 °C from the steam tables. The value is:
s4 = 6.9246 kJ/kg·K
5. The working fluid leaves the turbine as a mixture of saturated liquid and vapor. We can find the quality of the steam at the turbine outlet using the following formula:
x4 = (s4 - s5) / (s4 - s5s)
where s5 is the specific entropy of the saturated liquid at the condenser pressure and s5s is the specific entropy of the saturated vapor at the condenser pressure. We can find these values from the steam tables. The values are:
s5 = 0.6492 kJ/kg·K
s5s = 7.2964 kJ