8th Edition

ISBN: 9780073398174

Author: Yunus A. Cengel Dr., Michael A. Boles

Publisher: McGraw-Hill Education

See similar textbooks

Videos

Textbook Question

Chapter 10.9, Problem 112RP

Show that the thermal efficiency of a combined gas–steam power plant ηcc can be expressed as

η ∞ = η g + η s − η g η s

where ηg = Wg /Qin and η_s = W_s/Q_g_,out are the thermal efficiencies of the gas and steam cycles, respectively. Using this relation, determine the thermal efficiency of a combined power cycle that consists of a topping gas-turbine cycle with an efficiency of 40 percent and a bottoming steam-turbine cycle with an efficiency of 30 percent.

Expert Solution & Answer

Want to see the full answer?

Check out a sample textbook solution

See solution

Chapter 10.9, Problem 107RP

Chapter 10.9, Problem 113RP

Students have asked these similar questions

You are an operating engineer in a steam power plant which is working on a regenerative Rankine cycle and you are requested to find the thermal efficiency of this cycle. You read the following data from the measuring devices used in the power plant: The pressure and temperature of the steam at the inlet of the turbine are 7000kPa and 550 °C, respectively. The pressure at the inlet of the condenser is 22 kPa. The extracted steam from the turbine is at 500 kPa and it is used to heat the feed water in an open feed water heater. The pumps and turbine efficiencies are 80% and 85%, respectively. Don't forget to show the evele on a T-s diagram.

A medium size power station is used to produce 30 MW net power for a refinery. The station uses steam as the operating fluid and operates according to the Carnot cycle between the pressure limits of 0.4 bar and 35 bar. Steam enters the boiler as a saturated liquid and leaves it as a dry saturated vapour. (x) State the name of the cycle that is used in practice in power stations, along with three key benefits over the Carnot cycle.

A power cycle operates between two thermal reservoirs at 300 K and 800 K. The working fluid of the cycle is air, which can be considered to be an ideal gas. Specific heats are not assumed to be constant. An inventor claims that for a heat input of 250 kJ, the net work from the cycle is 80 kJ. The work generating component in the cycle is a reversible, steady state turbine. The inlet pressure and temperature are 1000 kPa and 600 K and the exit temperature is 550 K. The turbine receives 150 kJ/kg of heat from the high temperature reservoir and loses 10 kJ/kg of heat to the ambient at 298 K. (a) Prove whether or not the overall cycle is possible using second law arguments. (b) determine the work done by the turbine [kJ/kg]

Chapter 10 Solutions

Thermodynamics: An Engineering Approach

Ch. 10.9 - Why is the Carnot cycle not a realistic model for...Ch. 10.9 - Prob. 2P Ch. 10.9 - A steady-flow Carnot cycle uses water as the...Ch. 10.9 - A steady-flow Carnot cycle uses water as the...Ch. 10.9 - Consider a steady-flow Carnot cycle with water as...Ch. 10.9 - Consider a simple ideal Rankine cycle with fixed...Ch. 10.9 - Consider a simple ideal Rankine cycle with fixed...Ch. 10.9 - Consider a simple ideal Rankine cycle with fixed...Ch. 10.9 - How do actual vapor power cycles differ from...Ch. 10.9 - The entropy of steam increases in actual steam...

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.

Solution Summary: The author explains that the expression for the thermal efficiency of a combined gas-steam power plant is 58%.

Videos

Want to see the full answer?

Chapter 10 Solutions