Superheated steam enters a turbine (10 MPa, 480 C) of an ideal Rankine cycle with reheat...

 

Transcribed Image Text:

Superheated steam enters a turbine (10 MPa, 480 C) of an ideal Rankine cycle with reheat and exits at 6 kPa. Steam expands through the first-stage turbine to 0.7 MPa and then is reheated to 480 C. Express all answers with 3 significant digits. Without using special software (Excel and calculators are acceptable), perform the following tasks: 1. Calculate the total heat addition, net work of the cycle, heat extraction through condenser, and thermal efficiency of this ideal Rankine cycle with reheat. [20] 2. From scratch, calculate the same quantities assuming that the pump and each turbine stage have an isentropic efficiency of 80%. [20] 3. Draw the T-s diagrams for both cycles on the same plot. [20] 4. Draw the p-v diagrams for both cycles on the same plot. [19] 5. For a pressure of 7 bar right after the first stage turbine in the ideal Rame cycle, create two plots: thermal efficiency as a function of the reheat temperature from 200 C to 500 C; and the net work, heat addition, and heat extraction on the same graph as a function of the reheat temperature from 200 C to 500 C. [14] 6. Is there a local maximum or minimum thermal efficiency for 200 C Superheated steam enters a turbine (10 MPa, 480 C) of an ideal Rankine cycle with reheat and exits at 6 kPa. Steam expands through the first-stage turbine to 0.7 MPa and then is reheated to 480 C. Express all answers with 3 significant digits. Without using special software (Excel and calculators are acceptable), perform the following tasks: 1. Calculate the total heat addition, net work of the cycle, heat extraction through condenser, and thermal efficiency of this ideal Rankine cycle with reheat. [20] 2. From scratch, calculate the same quantities assuming that the pump and each turbine stage have an isentropic efficiency of 80%. [20] 3. Draw the T-s diagrams for both cycles on the same plot. [20] 4. Draw the p-v diagrams for both cycles on the same plot. [19] 5. For a pressure of 7 bar right after the first stage turbine in the ideal Rame cycle, create two plots: thermal efficiency as a function of the reheat temperature from 200 C to 500 C; and the net work, heat addition, and heat extraction on the same graph as a function of the reheat temperature from 200 C to 500 C. [14] 6. Is there a local maximum or minimum thermal efficiency for 200 C