 |
| 1 | |
A Carnot vapor power cycle operates its boiler at 3.0 MPa and its condenser at 50 kPa. What is the thermal efficiency of this cycle? |
| | A) | 20% |
| | B) | 30% |
| | C) | 40% |
| | D) | 50% |
|
|
|
| 2 | |
A simple Rankine cycle operates the boiler at 3 MPa with an outlet temperature of 350°C and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? |
| | A) | 7.7% |
| | B) | 17.7% |
| | C) | 27.7% |
| | D) | 37.7% |
|
|
|
| 3 | |
A simple Rankine cycle operates its boiler at 3 MPa with an outlet temperature of 350°C and its condenser at 50 kPa. The turbine has an isentropic efficiency of 0.9 while all other operating conditions and process are ideal. What is the thermal efficiency of this cycle? |
| | A) | 25.0% |
| | B) | 30.9% |
| | C) | 35.9% |
| | D) | 40.9% |
|
|
|
| 4 | |
A simple, ideal Rankine cycle operates the boiler at 3 MPa and the condenser at 50 kPa. The temperature at the boiler outlet is 400°C. What is the rate at which heat must be supplied to the water in the boiler for a power production of 100 MW? |
| | A) | 157 MW |
| | B) | 218 MW |
| | C) | 273 MW |
| | D) | 352 MW |
|
|
|
| 5 | |
An ideal Rankine cycle with reheat operates the boiler at 3 MPa, the reheater at 1 MPa, and the condenser at 50 kPa. The temperature at the boiler and reheater outlets is 350°C. What is the thermal efficiency of this cycle? |
| | A) | 24.5% |
| | B) | 26.5% |
| | C) | 28.5% |
| | D) | 30.5% |
|
|
|
| 6 | |
An ideal Rankine cycle with reheat operates the boiler at 3 MPa, the reheater at 1 MPa, and the condenser at 50 kPa. The temperature at the boiler and reheater outlets is 350°C. The boiler and reheater are fired with a fuel that releases 9,000 kJ/kg of heat as it is burned. What is the mass flow rate of the fuel for such a cycle when sized to produce 50 MW of net work? |
| | A) | 40 Mg/hr |
| | B) | 50 Mg/hr |
| | C) | 60 Mg/hr |
| | D) | 70 Mg/hr |
|
|
|
| 7 | |
An ideal Rankine cycle with an open-feedwater-heater regenerator operates the boiler at 3 MPa, the regenerator at 125 kPa, and the condenser at 50 kPa. At the boiler outlet, the temperature is 350°C. What percentage of the mass flow rate passing through the boiler is bled from the turbine for the regenerator? |
| | A) | 4.85% |
| | B) | 7.31% |
| | C) | 10.6% |
| | D) | 13.2% |
|
|
|
| 8 | |
An ideal Rankine cycle with an open-feedwater-heater regenerator operates the boiler at 3 MPa, the regenerator at 125 kPa, and the condenser at 50 kPa. At the boiler outlet, the temperature is 350°C. What is the thermal efficiency of this cycle? |
| | A) | 24.6% |
| | B) | 28.6% |
| | C) | 32.6% |
| | D) | 36.6% |
|
|
|
| 9 | |
A simple Rankine cycle operates the boiler at 3 MPa and the condenser at 50 kPa. The temperature at the boiler outlet is 350°C. The energy source is at 400°C and the energy sink is at 27°C. What is the irreversibility of this cycle per unit of mass passing through the boiler? |
| | A) | 561.2 kJ/kg |
| | B) | 613.4 kJ/kg |
| | C) | 694.2 kJ/kg |
| | D) | 767.8 kJ/kg |
|
|
|
| 10 | |
A simple Rankine cycle produces 40 MW of power, 50 MW of process heat and rejects 60 MW of heat to the surroundings. What is the utilization factor of this cogeneration cycle neglecting the pump work? |
| | A) | 50% |
| | B) | 60% |
| | C) | 70% |
| | D) | 80% |
|
|
.