(a) Explanation The T − s diagram with given state is shown below. Figure-(1) Write the expression for the isentropic efficiency for the 1 st stage turbine. η T I = h 1 − h 2 h 1 − h 2 s (I) Here, the enthalpy at point 1 is h 1 and the enthalpy at point 2 is h 2 . Write the expression for the isentropic efficiency for the 2 nd stage turbine. η T I I = h 2 − h 3 h 2 − h 3 s (II) Here, the enthalpy at point 1 is h 1 and the enthalpy at point 2 is h 2 . Write the expression for the enthalpy at point 5. h 5 = h 4 + v 4 ( p 5 − p 4 ) η p I (III) Here, the isentropic efficiency of the 1 st pump is η p I the pressure at the point 5 is p 5 , the pressure at the point 4 is p 4 , the specific volume at point 4 is v 4 , the specific enthalpy at state 5 is h 5 and the specific enthalpy at state 4 is h 4 . Write the expression for the enthalpy at point 7. h 7 = h 6 + v 6 ( p 7 − p 6 ) η p I I (IV) Here, the isentropic efficiency of the 2 nd pump is η p I I ,the pressure at the point 7 is p 7 , the pressure at the point 6 is p 6 , the specific volume at point 6 is v 6 , the specific enthalpy at state 7 is h 7 and the specific enthalpy at state 6 is h 6 . Write the expression for the fraction of the mass of steam entering in to feed water heater before entering into second stage turbine. y = ( h 6 − h 5 ) ( h 2 − h 5 ) (V) Write the expression for te turbine work. W T m ˙ = ( h 1 − h 2 ) + ( 1 − y ) ( h 2 − h 3 ) (VI) Write the expression for the pump work. W P m ˙ = ( h 7 − h 6 ) + ( 1 − y ) ( h 5 − h 4 ) (VII) Write the expression for the heat addition for 1 st stage turbine. Q ˙ 1 st m ˙ = h 1 − h 7 (VIII) Here, the enthalpy at point 1 is h 1 . Write the expression for thermal efficiency. η t h = W T m ˙ − W P m ˙ Q ˙ 1 st m ˙ (IX) Conclusion: Refer to Superheated steam table to obtain specific enthalpy as 3506.2 kJ / kg and the specific entropy 6.6840 kJ / kg ⋅ K at temperature 560 ° C and pressure 12 MPa and specific enthalpy as 2823.3 kJ / kg , at pressure 1 MPa and the specific entropy as 6.9174 kJ / kg ⋅ K at pressure 1 MPa , specific enthalpy of the liquid as 152.74 kJ / kg at 1 MPa and the specific entropy of the liquid as 0.5249 kJ / kg ⋅ K at pressure 1 MPa . Refer to saturated steam table to obtain specific enthalpy of liquid as 151.53 kJ / kg , specific enthalpy of vaporization 2415.9 kJ / kg , and the specific entropy of liquid 0.521 kJ / kg ⋅ K and specific entropy of vaporization as 7.8094 kJ / kg ⋅ K and specific volume of liquid 1.0064 × 10 − 3 m 3 / kg and dryness fractions as 0.8191 and 0.8760 and specific enthalpies as 2130.4 kJ / kg and 2267.9 kJ / kg , and specific entropy as 7.3620 kJ / kg ⋅ K at pressure 6 kPa , the specific enthalpy of the liquid as 762.81 kJ / kg , the specific entropy as 2.1387 kJ / kg ⋅ K and the specific volume of the saturate liquid as 1.1273 × 10 − 3 m 3 / kg . Substitute 3506.2 kJ / kg for h 1 , 0.83 for η T 1 , 2823.3 kJ / kg for h 2 s in Equation (I). 0.83 = 3506.2 kJ / kg − h 2 3506.2 kJ / kg − 2823.3 kJ / kg h 2 = 3506.2 kJ / kg − 583.40 kJ / kg h 2 = 2923 kJ / kg Substitute 2923 kJ / kg for h 2 , 0.83 for η T I I , 2130.4 kJ / kg for h 3 s in Equation (II). 0.83 = 2923 kJ / kg − h 3 2923 kJ / kg − 2130.4 kJ / kg h 3 = 2923 kJ / kg − 657 (b) To determine The mass flow rate into the first turbine stage. (c) To determine The rate of entropy production in the open feedwater heater.

Fundamentals of Engineering Thermodynamics

8th Edition

ISBN: 9781118832318

Author: MORAN

Publisher: WILEY

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Chapter 8.6, Problem 43P

(a)

To determine

The cycle efficiency.

(b)

To determine

The mass flow rate into the first turbine stage.

(c)

To determine

The rate of entropy production in the open feedwater heater.

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Chapter 8.6, Problem 42P

Chapter 8.6, Problem 44P

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Chapter 8 Solutions

Fundamentals of Engineering Thermodynamics

Ch. 8.6 - Prob. 1E Ch. 8.6 - Prob. 2E Ch. 8.6 - Prob. 3E Ch. 8.6 - Prob. 4E Ch. 8.6 - Prob. 5E Ch. 8.6 - Prob. 6E Ch. 8.6 - Prob. 7E Ch. 8.6 - 8. What is the relationship between global climate...Ch. 8.6 - Prob. 9E Ch. 8.6 - Prob. 10E

Ch. 8.6 - Prob. 11E Ch. 8.6 - Prob. 12E Ch. 8.6 - Prob. 13E Ch. 8.6 - Prob. 1CU Ch. 8.6 - Prob. 2CU Ch. 8.6 - 3. The component of the Rankine cycle in which the...Ch. 8.6 - 4. A cycle that couples two vapor cycles so the...Ch. 8.6 - 5. The ratio of the pump work input to the work...Ch. 8.6 - 6. A shell-and-tube-type recuperator in which the...Ch. 8.6 - Prob. 7CU Ch. 8.6 - Prob. 8CU Ch. 8.6 - Prob. 9CU Ch. 8.6 - Prob. 10CU Ch. 8.6 - 11. An example of an external irreversibility...Ch. 8.6 - Prob. 12CU Ch. 8.6 - Prob. 13CU Ch. 8.6 - Prob. 14CU Ch. 8.6 - 15. A direct-contact–type heat exchanger found in...Ch. 8.6 - 16. The component of a regenerative vapor power...Ch. 8.6 - Prob. 17CU Ch. 8.6 - 18. A Rankine cycle that employs an organic...Ch. 8.6 - Prob. 19CU Ch. 8.6 - Prob. 20CU Ch. 8.6 - Prob. 21CU Ch. 8.6 - Prob. 22CU Ch. 8.6 - Prob. 23CU Ch. 8.6 - 24. The purpose of deaeration is ______________. Ch. 8.6 - Prob. 25CU Ch. 8.6 - Prob. 26CU Ch. 8.6 - Prob. 27CU Ch. 8.6 - Prob. 28CU Ch. 8.6 - 29. The total cost associated with a power plant...Ch. 8.6 - Prob. 30CU Ch. 8.6 - Prob. 31CU Ch. 8.6 - Prob. 32CU Ch. 8.6 - Prob. 33CU Ch. 8.6 - Prob. 34CU Ch. 8.6 - Prob. 35CU Ch. 8.6 - Prob. 36CU Ch. 8.6 - Prob. 37CU Ch. 8.6 - Prob. 38CU Ch. 8.6 - Prob. 39CU Ch. 8.6 - 40. For a vapor power cycle with and , the...Ch. 8.6 - Prob. 41CU Ch. 8.6 - Prob. 42CU Ch. 8.6 - Prob. 43CU Ch. 8.6 - Prob. 44CU Ch. 8.6 - Prob. 45CU Ch. 8.6 - Prob. 46CU Ch. 8.6 - Prob. 47CU Ch. 8.6 - Prob. 48CU Ch. 8.6 - Prob. 49CU Ch. 8.6 - 50. In a binary cycle, energy discharged by heat...Ch. 8.6 - Prob. 1P Ch. 8.6 - Prob. 2P Ch. 8.6 - Prob. 3P Ch. 8.6 - Prob. 6P Ch. 8.6 - 8.7 Water is the working fluid in an ideal Rankine...Ch. 8.6 - Prob. 8P Ch. 8.6 - 8.10 Water is the working fluid in an ideal...Ch. 8.6 - Prob. 12P Ch. 8.6 - Prob. 13P Ch. 8.6 - 8.14 On the south coast of the island of Hawaii,...Ch. 8.6 - Prob. 15P Ch. 8.6 - 8.17. Water is the working fluid in a Rankine...Ch. 8.6 - 8.19 Water is the working fluid in a Rankine...Ch. 8.6 - Prob. 20P Ch. 8.6 - Prob. 21P Ch. 8.6 - 8.22 Superheated steam at 8 MPa and 480°C leaves...Ch. 8.6 - Prob. 23P Ch. 8.6 - Prob. 25P Ch. 8.6 - Prob. 26P Ch. 8.6 - 8.27 Steam is the working fluid in the ideal...Ch. 8.6 - Prob. 28P Ch. 8.6 - Prob. 29P Ch. 8.6 - Prob. 30P Ch. 8.6 - Prob. 31P Ch. 8.6 - 8.32 An ideal Rankine cycle with reheat uses water...Ch. 8.6 - Prob. 33P Ch. 8.6 - 8.34 Steam at 4800 lbf/in.2, 1000℉ enters the...Ch. 8.6 - Prob. 35P Ch. 8.6 - Prob. 37P Ch. 8.6 - 8.38 For the cycle of Problem 8.37, reconsider the...Ch. 8.6 - Prob. 39P Ch. 8.6 - Prob. 40P Ch. 8.6 - Prob. 41P Ch. 8.6 - Prob. 42P Ch. 8.6 - Prob. 43P Ch. 8.6 - Prob. 44P Ch. 8.6 - Prob. 45P Ch. 8.6 - Prob. 46P Ch. 8.6 - Prob. 47P Ch. 8.6 - 8.48 For the cycle of Problem 8.47, investigate...Ch. 8.6 - Prob. 49P Ch. 8.6 - Prob. 50P Ch. 8.6 - Prob. 51P Ch. 8.6 - 8.52 As indicated in Fig. P8.52, a power plant...Ch. 8.6 - Prob. 53P Ch. 8.6 - Prob. 54P Ch. 8.6 - Prob. 55P Ch. 8.6 - Prob. 56P Ch. 8.6 - Prob. 57P Ch. 8.6 - Prob. 58P Ch. 8.6 - Prob. 59P Ch. 8.6 - Prob. 60P Ch. 8.6 - Prob. 61P Ch. 8.6 - Prob. 63P Ch. 8.6 - Prob. 64P Ch. 8.6 - Prob. 65P Ch. 8.6 - Prob. 66P Ch. 8.6 - 8.67 Water is the working fluid in a Rankine cycle...Ch. 8.6 - Prob. 68P Ch. 8.6 - Prob. 69P Ch. 8.6 - Prob. 70P Ch. 8.6 - 8.72 Water is the working fluid in a...Ch. 8.6 - Prob. 73P Ch. 8.6 - Prob. 74P Ch. 8.6 - Prob. 75P Ch. 8.6 - 8.76 A binary vapor power cycle consists of two...Ch. 8.6 - A binary vapor cycle consists of two Rankine...Ch. 8.6 - Prob. 78P Ch. 8.6 - Prob. 79P Ch. 8.6 - Prob. 80P Ch. 8.6 - 8.81 Figure P8.81 shows a combined heat and power...Ch. 8.6 - 8.82 Figure P8.82 shows a cogeneration cycle that...Ch. 8.6 - Prob. 83P Ch. 8.6 - 8.84 The steam generator of a vapor power plant...Ch. 8.6 - 8.85 Determine the exergy input, in kJ per kg of...Ch. 8.6 - 8.86 In the steam generator of the cycle of...Ch. 8.6 - Prob. 87P Ch. 8.6 - 8.88 Determine the rate of exergy input, in Btu/h,...Ch. 8.6 - Prob. 89P Ch. 8.6 - Prob. 90P Ch. 8.6 - Prob. 91P Ch. 8.6 - 8.92 Figure P8.92 provides steady-state operating...Ch. 8.6 - 8.93 Steam enters the turbine of a simple vapor...

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