THERMODYNAMICS: ENG APPROACH LOOSELEAF
9th Edition
ISBN: 9781266084584
Author: CENGEL
Publisher: MCG
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Chapter 10.9, Problem 44P
To determine
How to justify the following action:
During a regeneration process, some steam is extracted from the turbine and is used to heat the liquid water leaving the pump. This does not seem like a smart thing to do since the extracted steam could produce some more work in the turbine.
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Students have asked these similar questions
A steam power plant operates on the cycle shown in Fig. 10-5. If the isen-
tropic efficiency of the turbine is 87 percent and the isentropic efficiency of
the pump is 85 percent, determine (a) the thermal efficiency of the cycle
and (bi the net power output of the plant for a mass flow rate of 15 kg's.
15.9 MPa
15.2 MPa
35°C
625 C
Boiler
1S MPa
600 C
O 16 MPa
Wihat
Turbine
= 087
Pump
Of 10 kPa
9 AP
38°C
Condenser
A steam power plant operates on the cycle shown in Fig. 10-5. If the isen-
tropic efficiency of the turbine is 87 percent and the isentropic efficiency of
the pump is 85 percent, determine (a) the thermal efficiency of the cycle
and (b) the net power output of the plant for a mass flow rate of 15 kg's.
15.9 MPa
35 C
15.2 MPa
625 C
Beiler
15 MPa
16 MPa
Turbine
y= 087
Pump
t0 kPa
9 APa
38C
Condenser
Steam enters the turbine of a cogeneration plant at 6 MPa and 550 degrees * C . One-third of the steam is extracted from the turbine at 1400 kPa pressure for process heating. The remaining steam continues to expand to 20 kPa. The extracted steam is then condensed and mixed with feedwater at constant pressure and the mixture is pumped to the boiler pressure of 6 MPaThe mass flow rate of steam through the boiler is 30 kg/s. Disregarding any pressure drops and heat losses in the piping, and assuming the turbine and the pump to be isentropic, determine (a) the net power produced(b) the utilization factor of the plant, (c) the exergy destruction associated with the process heating, and (d ) the entropy generation associated with the process in the boiler. Assuming a source temperature of 1000 K and a sink temperature of 298 K
Chapter 10 Solutions
THERMODYNAMICS: ENG APPROACH LOOSELEAF
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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