Mechanical Engineering Exam > Mechanical Engineering Questions > A simple Rankine cycle operates the Boiler at...
Start Learning for Free
A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.
At 0.5 bar: hf = 340.5 kJ/kg, hg = 2646 kJ/kg
At 30 bar: hf = 1008 kJ/kg, hg = 2804 kJ/kg
- a)7
- b)17
- c)21
- d)37
Correct answer is option 'B'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Verified Answer
A simple Rankine cycle operates the Boiler at 3 MPa with an outlet tem...
The efficiency of the Rankine cycle is then given by:
Most Upvoted Answer
A simple Rankine cycle operates the Boiler at 3 MPa with an outlet tem...
°C and 3500 kJ/kg, respectively. The steam is then expanded in a turbine to a pressure of 0.5 MPa. The condenser pressure is 10 kPa. Determine the following:
a) The quality of the steam at the turbine exit.
b) The thermal efficiency of the cycle.
c) The specific work output of the turbine.
To solve this problem, we will use the properties of water and steam provided in the steam tables. The given values are:
- Boiler outlet pressure (P1) = 3 MPa
- Boiler outlet temperature (T1) = 350 °C
- Boiler outlet enthalpy (h1) = 3500 kJ/kg
- Turbine outlet pressure (P2) = 0.5 MPa
- Condenser pressure (P3) = 10 kPa
First, let's determine the state of the steam at the turbine exit (state 2):
Using the steam tables, we can find the saturation temperature corresponding to the turbine outlet pressure:
Saturation temperature at P2 = Tsat(P2) ≈ 151.85 °C
Comparing this with the given turbine outlet temperature (T2 = 350 °C), we can conclude that the steam is superheated at the turbine exit.
Next, let's determine the quality of the steam at the turbine exit (state 2):
Using the steam tables, we can find the enthalpy at the saturation temperature:
hf2 = h(P2, sf2) ≈ 797.12 kJ/kg
hg2 = h(P2, sg2) ≈ 2765.35 kJ/kg
The quality (x2) can be calculated using the equation:
x2 = (h2 - hf2) / (hg2 - hf2)
x2 = (3500 - 797.12) / (2765.35 - 797.12) ≈ 0.901
a) The quality of the steam at the turbine exit is approximately 0.901.
Next, let's calculate the thermal efficiency of the cycle:
The thermal efficiency (η) of a Rankine cycle is given by the equation:
η = 1 - (Qout / Qin)
First, let's determine the heat input (Qin) to the cycle:
Using the steam tables, we can find the enthalpy at the boiler inlet (state 1):
h1 = 3500 kJ/kg
The heat input is given by the equation:
Qin = m * (h1 - h3)
Next, let's determine the heat output (Qout) from the cycle:
Using the steam tables, we can find the enthalpy at the condenser outlet (state 4):
h4 = hf(P3) ≈ 191.81 kJ/kg
The heat output is given by the equation:
Qout = m * (h2 - h4)
Now, let's calculate the thermal efficiency:
η = 1 - (Qout / Qin)
η = 1 - [(h2 - h4) / (h1 - h3)]
Using the given values and the calculated quality (x2), we can substitute the enthalpy values:
η = 1 - [(3500 - 191.81) / (3500 - h3)]
To find h3, we can use
a) The quality of the steam at the turbine exit.
b) The thermal efficiency of the cycle.
c) The specific work output of the turbine.
To solve this problem, we will use the properties of water and steam provided in the steam tables. The given values are:
- Boiler outlet pressure (P1) = 3 MPa
- Boiler outlet temperature (T1) = 350 °C
- Boiler outlet enthalpy (h1) = 3500 kJ/kg
- Turbine outlet pressure (P2) = 0.5 MPa
- Condenser pressure (P3) = 10 kPa
First, let's determine the state of the steam at the turbine exit (state 2):
Using the steam tables, we can find the saturation temperature corresponding to the turbine outlet pressure:
Saturation temperature at P2 = Tsat(P2) ≈ 151.85 °C
Comparing this with the given turbine outlet temperature (T2 = 350 °C), we can conclude that the steam is superheated at the turbine exit.
Next, let's determine the quality of the steam at the turbine exit (state 2):
Using the steam tables, we can find the enthalpy at the saturation temperature:
hf2 = h(P2, sf2) ≈ 797.12 kJ/kg
hg2 = h(P2, sg2) ≈ 2765.35 kJ/kg
The quality (x2) can be calculated using the equation:
x2 = (h2 - hf2) / (hg2 - hf2)
x2 = (3500 - 797.12) / (2765.35 - 797.12) ≈ 0.901
a) The quality of the steam at the turbine exit is approximately 0.901.
Next, let's calculate the thermal efficiency of the cycle:
The thermal efficiency (η) of a Rankine cycle is given by the equation:
η = 1 - (Qout / Qin)
First, let's determine the heat input (Qin) to the cycle:
Using the steam tables, we can find the enthalpy at the boiler inlet (state 1):
h1 = 3500 kJ/kg
The heat input is given by the equation:
Qin = m * (h1 - h3)
Next, let's determine the heat output (Qout) from the cycle:
Using the steam tables, we can find the enthalpy at the condenser outlet (state 4):
h4 = hf(P3) ≈ 191.81 kJ/kg
The heat output is given by the equation:
Qout = m * (h2 - h4)
Now, let's calculate the thermal efficiency:
η = 1 - (Qout / Qin)
η = 1 - [(h2 - h4) / (h1 - h3)]
Using the given values and the calculated quality (x2), we can substitute the enthalpy values:
η = 1 - [(3500 - 191.81) / (3500 - h3)]
To find h3, we can use
Attention Mechanical Engineering Students!
To make sure you are not studying endlessly, EduRev has designed Mechanical Engineering study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Mechanical Engineering.
|
Explore Courses for Mechanical Engineering exam
|
|
Top Courses for Mechanical EngineeringView all
A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer?
Question Description
A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer?.
A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer?.
Solutions for A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for Mechanical Engineering.
Download more important topics, notes, lectures and mock test series for Mechanical Engineering Exam by signing up for free.
Here you can find the meaning of A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer?, a detailed solution for A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer? has been provided alongside types of A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice A simple Rankine cycle operates the Boiler at 3 MPa with an outlet temperature and enthalpy of 350°C and 3115.3 kJ/kg respectively and the condenser at 50 kPa. Assuming ideal operation and processes, what is the thermal efficiency of this cycle? Neglect the pump work. Assume exhaust from the turbine is dry saturated steam.At 0.5 bar: hf= 340.5 kJ/kg, hg= 2646 kJ/kgAt 30 bar: hf= 1008 kJ/kg, hg= 2804 kJ/kga)7b)17c)21d)37Correct answer is option 'B'. Can you explain this answer? tests, examples and also practice Mechanical Engineering tests.
|
|
Explore Courses for Mechanical Engineering exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup