Thermodynamics: An Engineering Approach
9th Edition
ISBN: 9781259822674
Author: Yunus A. Cengel Dr., Michael A. Boles
Publisher: McGraw-Hill Education
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Textbook Question
Chapter 10.9, Problem 47P
How do the following quantities change when the simple ideal Rankine cycle is modified with regeneration? Assume the mass flow rate through the boiler is the same.
Turbine work output: (a) increases, (b) decreases, (c) remains the same
Heat supplied: (a) increases, (b) decreases, (c) remains the same
Heat rejected: (a) increases, (b) decreases, (c) remains the same
Moisture content at turbine exit: (a) increases, (b) decreases, (c) remains the same
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Students have asked these similar questions
(a) What is the working fluid for Rankine cycle?
(b) Describe the main characteristics of a Rankine cycle.
(c) Draw the four components of a Rankine cycle.
(d) Draw the "temperature-entropy" diagram that represents the cycle.
(e) The maximal temperature in a Rankine cycle is limited now by metallurgical conditions,
presently the highest steam temperature at the turbine is around 620 °C. Calculate the upper
limit of a heat engine i.e. Carnot efficiency (%) if the environment temperature is 20 °C.
* The system diagram and a number of the state properties are given below for a
regenerative Rankine cycle. The isentropic efficiency of both turbines is 85% and the isentropic efficiency
of the pump is 90%. Using the provided state data below, detemine the:
(a) Percent of diverted flow after the first turbine, y
(b) The thermal efficiency of the cycle, ncyc
(c) The entropy production rate at the closed feedwater heater per mass flow of steam entering the
first turbine "FWH, in [kJ/kg-K]
State T ("C) p (kPa) h (kJ/kg)
s (kJ/kg-K)
480
10000
3323
6.531
172.4
700
2781
6.749
2s
164.9
2686
6.531
|3[a -»
3
36.16
6.
2183
7.09
(y)
3s
36.16
2078
6.749
Steam
4
36.16
151.5
0.5208
Condenser
generator
5
36.69
162.6
0.5244
(1)
0.5208
1.98
5s
36.43
161.5
Pump
6.
164.9
702.3
7
164.9
697
1.992
|t
8
36.16
697
2.285
Closed
feedwater
heater
Trap
(y)
(v)
Known: The data provided at the principal states of a thermal power plant. Assume an Ideal Rankine Cycle.
(a) Explain about the general theory about the thermal power plant?
(b) Formulate to determine the work done by the pump, and also formulate the work done by the turbine?
(c) Evaluate the amount of heat supplied to the steam, and also determine the thermal efficiency of the cycle?
Conditions: The steam enters into the turbine at a Pressure of 24 bar & 400°C and the exhaust steam is enter
into the condenser at a pressure of 0.1 bar.
Scheme and given data:
Boiler
24 bar
& 400°C
Turbine
0.1 bar
Condenser
Chapter 10 Solutions
Thermodynamics: An Engineering Approach
Ch. 10.9 - Why is the Carnot cycle not a realistic model for...Ch. 10.9 - Why is excessive moisture in steam undesirable in...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 - Water enters the boiler of a steady-flow Carnot...Ch. 10.9 - What four processes make up the simple ideal...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 - Compare the pressures at the inlet and the exit of...Ch. 10.9 - The entropy of steam increases in actual steam...Ch. 10.9 - Is it possible to maintain a pressure of 10 kPa in...Ch. 10.9 - A simple ideal Rankine cycle with water as the...Ch. 10.9 - A simple ideal Rankine cycle with water as the...Ch. 10.9 - A simple ideal Rankine cycle which uses water as...Ch. 10.9 - Consider a solar-pond power plant that operates on...Ch. 10.9 - Consider a 210-MW steam power plant that operates...Ch. 10.9 - Consider a 210-MW steam power plant that operates...Ch. 10.9 - A simple ideal Rankine cycle with water as the...Ch. 10.9 - A simple ideal Rankine cycle with water as the...Ch. 10.9 - A steam Rankine cycle operates between the...Ch. 10.9 - A steam Rankine cycle operates between the...Ch. 10.9 - A simple Rankine cycle uses water as the working...Ch. 10.9 - The net work output and the thermal efficiency for...Ch. 10.9 - A binary geothermal power plant uses geothermal...Ch. 10.9 - Consider a coal-fired steam power plant that...Ch. 10.9 - Show the ideal Rankine cycle with three stages of...Ch. 10.9 - Is there an optimal pressure for reheating the...Ch. 10.9 - How do the following quantities change when a...Ch. 10.9 - Consider a simple ideal Rankine cycle and an ideal...Ch. 10.9 - Consider a steam power plant that operates on the...Ch. 10.9 - Consider a steam power plant that operates on the...Ch. 10.9 - An ideal reheat Rankine cycle with water as the...Ch. 10.9 - Steam enters the high-pressure turbine of a steam...Ch. 10.9 - An ideal reheat Rankine cycle with water as the...Ch. 10.9 - A steam power plant operates on an ideal reheat...Ch. 10.9 - Consider a steam power plant that operates on a...Ch. 10.9 - Repeat Prob. 1041 assuming both the pump and the...Ch. 10.9 - Prob. 43PCh. 10.9 - Prob. 44PCh. 10.9 - How do open feedwater heaters differ from closed...Ch. 10.9 - How do the following quantities change when the...Ch. 10.9 - Cold feedwater enters a 200-kPa open feedwater...Ch. 10.9 - In a regenerative Rankine cycle. the closed...Ch. 10.9 - A steam power plant operates on an ideal...Ch. 10.9 - A steam power plant operates on an ideal...Ch. 10.9 - A steam power plant operates on an ideal...Ch. 10.9 - Consider an ideal steam regenerative Rankine cycle...Ch. 10.9 - Consider a steam power plant that operates on the...Ch. 10.9 - Consider a steam power plant that operates on the...Ch. 10.9 - Consider a steam power plant that operates on the...Ch. 10.9 - A steam power plant operates on an ideal...Ch. 10.9 - Repeat Prob. 1060, but replace the open feedwater...Ch. 10.9 - A steam power plant operates on an ideal...Ch. 10.9 - A simple ideal Rankine cycle with water as the...Ch. 10.9 - Prob. 64PCh. 10.9 - An ideal reheat Rankine cycle with water as the...Ch. 10.9 - Consider a steam power plant that operates on a...Ch. 10.9 - Prob. 67PCh. 10.9 - A steam power plant operates on an ideal...Ch. 10.9 - The schematic of a single-flash geothermal power...Ch. 10.9 - What is the difference between cogeneration and...Ch. 10.9 - Prob. 71PCh. 10.9 - Prob. 72PCh. 10.9 - Consider a cogeneration plant for which the...Ch. 10.9 - Steam is generated in the boiler of a cogeneration...Ch. 10.9 - A large food-processing plant requires 1.5 lbm/s...Ch. 10.9 - An ideal cogeneration steam plant is to generate...Ch. 10.9 - Steam is generated in the boiler of a cogeneration...Ch. 10.9 - Consider a cogeneration power plant modified with...Ch. 10.9 - Prob. 80PCh. 10.9 - Why is the combined gassteam cycle more efficient...Ch. 10.9 - The gas-turbine portion of a combined gassteam...Ch. 10.9 - A combined gassteam power cycle uses a simple gas...Ch. 10.9 - Reconsider Prob. 1083. An ideal regenerator is...Ch. 10.9 - Reconsider Prob. 1083. Determine which components...Ch. 10.9 - Consider a combined gassteam power plant that has...Ch. 10.9 - Prob. 89PCh. 10.9 - What is the difference between the binary vapor...Ch. 10.9 - Why is mercury a suitable working fluid for the...Ch. 10.9 - Why is steam not an ideal working fluid for vapor...Ch. 10.9 - By writing an energy balance on the heat exchanger...Ch. 10.9 - Prob. 94RPCh. 10.9 - Steam enters the turbine of a steam power plant...Ch. 10.9 - Consider a steam power plant operating on the...Ch. 10.9 - A steam power plant operates on an ideal Rankine...Ch. 10.9 - Consider a steam power plant that operates on a...Ch. 10.9 - Repeat Prob. 1098 assuming both the pump and the...Ch. 10.9 - Consider an ideal reheatregenerative Rankine cycle...Ch. 10.9 - Prob. 101RPCh. 10.9 - A textile plant requires 4 kg/s of saturated steam...Ch. 10.9 - Consider a cogeneration power plant that is...Ch. 10.9 - Prob. 104RPCh. 10.9 - Prob. 105RPCh. 10.9 - Reconsider Prob. 10105E. It has been suggested...Ch. 10.9 - Reconsider Prob. 10106E. During winter, the system...Ch. 10.9 - Prob. 108RPCh. 10.9 - Prob. 109RPCh. 10.9 - A steam power plant operates on an ideal...Ch. 10.9 - A Rankine steam cycle modified for reheat, a...Ch. 10.9 - Show that the thermal efficiency of a combined...Ch. 10.9 - Prob. 118RPCh. 10.9 - A solar collector system delivers heat to a power...Ch. 10.9 - Starting with Eq. 1020, show that the exergy...Ch. 10.9 - Consider a simple ideal Rankine cycle with fixed...Ch. 10.9 - Consider a simple ideal Rankine cycle. If the...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 steady-flow Carnot cycle with water as...Ch. 10.9 - Prob. 126FEPCh. 10.9 - Prob. 127FEPCh. 10.9 - A simple ideal Rankine cycle operates between the...Ch. 10.9 - Pressurized feedwater in a steam power plant is to...Ch. 10.9 - Consider a steam power plant that operates on the...Ch. 10.9 - Consider a combined gas-steam power plant. Water...
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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.Similar questions
- Ideal Rankine Cycle with Regeneration: After having investigated the Rankine cycle in detail, we can begin to augment the cycle with modifications beyond a theoretical model toward what might be practical in real life. In an effort to increase the thermal efficiency of the cycle, a small portion of hot steam is extracted from the turbine and sent to a mixing box to "preheat" the cold liquid before it enters the steam generator. The mixing box is often referred to as an open feedwater heater and the process that results is referred to as a regeneration process. The Rankine cycle with regeneration operates with water as the working fluid and has the following conditions: P: = 75 kPa, xI = 0, P: = 2000 kPa, T; = 700 °C, P; = Ps = 1200 kPa, x3 = 0, m = 2.0 kg/s, m3= 0.5 kg/s Determine hi, ha, hs, ha, hs, hs, hr, hs, Wp1, Wa2: Q2. Qa. W,, and na We1 5 OFHarrow_forwardThe single-stage expansion process of an ideal Brayton cycle without regeneration is replaced by a multistage expansion process with reheating between the same pressure limits. As a result of this modification, (a) Does the turbine work increase, decrease, or remain the same? (b) Does the back work ratio increase, decrease, or remain the same? (c) Does the thermal efficiency increase, decrease, or remain the same?arrow_forward2) A steam power plant operates according to the simple ideal Rankine cycle. The pressure limits of the cycle are 9 MPa and 10 kPa, and the flow of water eirculating in the cycle is 60 kg/s. It is required that the moisture content of the steam at the turbine outlet does not fall below 90 percent. Accordingly, calculate (a) the lowest possible turbine inlet temperature, (b) the heat supplied to the cycle, and (c) the thermal efficiency of the cycle by showing the cycle on a T-s diagram with saturated vapor and saturated liquid curves,.arrow_forward
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