What is the typical overall thermal efficiency range for a standard thermal power plant___________________?
Show answer Hide answer
Answer: C. 30%
Explanation
Standard thermal power plants convert chemical energy of fuel into electrical energy efficiently. Thermodynamic losses in boilers, turbines, and condensers limit overall plant efficiency. Real-world operational data confirms standard steam power plants achieve roughly thirty percent efficiency. Rankine cycles govern the thermodynamic operation of vapor-based thermal power stations. Condenser heat rejection accounts for the largest energy loss in steam power generation. Thermal efficiency is the ratio of net electrical energy output to fuel energy input.
Electric utility companies strive to improve plant efficiency to reduce fossil fuel consumption. Supercritical power plants achieve higher efficiencies by operating at elevated steam pressures. Environmental regulations encourage cogeneration and combined cycle plants to exceed thirty percent. Fifteen percent is too low and represents inefficient or obsolete older steam engines. Twenty percent is characteristic of smaller or poorly optimized thermal generation units. Forty-five percent or sixty percent require advanced combined cycle gas turbine configurations.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. What thermodynamic cycle consists of two adiabatic and two constant-pressure processes___________________?
Show answer Hide answer
Answer: C. Joule cycle
The Joule cycle, commonly known as the Brayton cycle, consists of two adiabatic and two constant pressure processes. This thermodynamic cycle forms the ideal theoretical basis for gas turbine engines and jet propulsion s...
Q2. A gas in a cylinder is compressed by a movable piston to half its initial volume, rejecting 300 kJ of heat while internal energy remains constant. What is the work done on the gas in N·m___________________?
Show answer Hide answer
Answer: B. 300,000 Nm
For an isothermal process with constant internal energy, work done equals the heat rejected. Heat rejected of 300 kJ converts directly to 300,000 Joules or N·m of work. Mathematical conversion from kilojoules to newton-m...
Q3. How is a closed thermodynamic system defined_________________________?
Show answer Hide answer
Answer: A. mass does not cross boundaries of the system, though energy may do so
In a closed thermodynamic system, mass does not cross boundaries of the system. However, energy in the form of heat or work may freely cross the system boundaries. This distinction separates closed systems from open syst...
Q4. According to Avogadro’s Hypothesis, what is true regarding gas molecules ______________________?
Show answer Hide answer
Answer: A. the molecular weights of all the perfect gases occupy the same volume under same conditions of pressure and temperature
Avogadro hypothesis states that equal volumes of all perfect gases under identical pressure and temperature contain equal molecules. This fundamental gas law establishes that molecular weights of perfect gases occupy ide...
Q5. What weather condition does a sudden drop in barometric pressure indicate________________?
Show answer Hide answer
Answer: C. storm
Atmospheric pressure falls rapidly when low-pressure weather disturbances approach an area. Barometers detect these pressure drops, serving as reliable early warning indicators for severe wind and rain. A sudden barometr...
Q6. How does the Clausius statement of the second law of thermodynamics express heat transfer___________________?
Show answer Hide answer
Answer: D. heat can’t be transferred from low temperature to high temperature source without the aid of external energy
The Clausius statement asserts that heat cannot transfer from cold to hot without external work. Refrigeration cycles require external energy input to pump thermal energy uphill against gradients. Without external power,...