1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Shkiper50 [21]
3 years ago
7

An air-standard Carnot cycle is executed in a closed system between the temperature limits of 350 and 1200 K. The pressures befo

re and after the isothermal compression are 150 and 300 kPa, respectively. If the net work output per cycle isPage 529 0.5 kJ, determine (a) the maximum pressure in the cycle, (b) the heat transfer to air, and (c) the mass of air. Assume variable specific heats for air.
Engineering
1 answer:
SVEN [57.7K]3 years ago
5 0

This question is incomplete, the complete question is;

An air-standard Carnot cycle is executed in a closed system between the temperature limits of 350 and 1200 K. The pressures before and after the isothermal compression are 150 and 300 kPa, respectively. If the net work output per cycle is 0.5 kJ, determine (a) the maximum pressure in the cycle, (b) the heat transfer to air, and (c) the mass of air. Assume variable specific heats for air.

Answer:

a) the maximum pressure in the cycle is 30.01 Mpa

b) the heat transfer to air is 0.7058 KJ

c) mass of Air is 0.002957 kg

Explanation:

Given the data in the question;

We find the relative pressure of air at 1200 K (T1) and 350 K ( T4)

so from the "ideal gas properties of air table"

Pr1 = 238

Pr4 = 2.379

we know that Pressure P1 is only maximum at the beginning of the expansion process,

so

now we express the relative pressure and pressure relation for the process 4-1

P1 = (Pr2/Pr4)P4

so we substitute

P1 = (238/2.379)300 kPa

P1 = 30012.6 kPa = 30.01 Mpa

Therefore the maximum pressure in the cycle is 30.01 Mpa

b)

the Thermal heat efficiency of the Carnot cycle is expressed as;

ηth = 1 - (TL/TH)

we substitute

ηth = 1 - (350K/1200K)

ηth = 1 - 0.2916

ηth = 0.7084

now we find the heat transferred

Qin = W_net.out / ηth

given that the net work output per cycle is 0.5 kJ

we substitute

Qin = 0.5 / 0.7084

Qin = 0.7058 KJ

Therefore, the heat transfer to air is 0.7058 KJ

c)

first lets express the change in entropy for process 3 - 4

S4 - S3 = (S°4 - S°3) - R.In(P4/P3)

S4 - S3 = - (0.287 kJ/Kg.K) In(300/150)kPa

= -0.1989 Kj/Kg.K = S1 - S2

so that; S2 - S1 = 0.1989 Kj/Kg.K

Next we find the net work output per unit mass for the Carnot cycle

W"_netout = (S2 - S1)(TH - TL)

we substitute

W"_netout = ( 0.1989 Kj/Kg.K )( 1200 - 350)K

= 169.065 kJ/kg

Finally we find the mass

mass m = W_ net.out /  W"_netout

we substitute

m = 0.5 / 169.065

m = 0.002957 kg

Therefore, mass of Air is 0.002957 kg

You might be interested in
3. When performing overhead work on scaffolding, what protective measures must be taken to prevent objects
hjlf

Answer:

Toeboards, debris nets, or canopies

Explanation:

7 0
3 years ago
Most equipment is cooled by bringing cold air in the front and ducting the heat out of the back. What is the term for where the
vitfil [10]

Answer: Hot aisle

Explanation:

6 0
2 years ago
Im passed due someone help meeeeeee
vovangra [49]

Answer:

how are supposed to help when you can't do anything?

8 0
3 years ago
Read 2 more answers
Which Finance jobs can someone pursue with only a high school diploma? Check all that apply.
Zolol [24]

Answer:

Teller, Loan Officer, and Tax Preparer

Explanation:

3 0
3 years ago
Read 2 more answers
What does an engineer do? List as many types of engineers as you can.
BARSIC [14]

Answer:

Mechanical Engineering

Chemical Engineering

Civil Engineering

Explanation:

I got it from my old homework And I learn those at school ( Thank You For The Points)

7 0
3 years ago
Other questions:
  • Thermal energy storage systems commonly involve a packed bed of solid spheres, through which a hot gas flows if the system is be
    13·1 answer
  • Air at 20 C and 1 atm flows over a flat plate at 35 m/s. The plate is 75 cm long and is maintained at 60 с. Assuming unit depth
    8·1 answer
  • Define the hydraulic diameter for a rectangular duct
    7·1 answer
  • Create a document that includes a constructor function named Company in the document head area. Include four properties in the C
    7·1 answer
  • You are given that kc = 10-1 kg eq-1 min-1, ku = 10-3 kg2 eq-2 min-1 and [A]0 = 10 eq kg-1, where kc is the rate constant for a
    15·1 answer
  • Hi plz delete this question i had to edit it cuz it was wrong question
    5·1 answer
  • What are probiotic bacteria and how did Danino and his team use this type of bacteria to detect liver cancer?
    15·1 answer
  • Best budget freestyle drone?
    6·1 answer
  • What is it that makes a battery rechargeable? How is it different from a regular battery?
    14·2 answers
  • The irreversible losses in the penstock of a hydroelectric dam are estimated to be 7 m. The elevation difference between the res
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!