Physics, 10.03.2020 07:16, manywonders

⦁ A gas-turbine power plant operating on an ideal Brayton cycle has a pressure ratio of 8. The gas temperature is 300 K at the compressor inlet and 1400 K at the turbine inlet. Utilizing the air-standard assumptions, determine (a) the gas temperature at the exits of the compressor and the turbine, (b) the back work ratio, and (c) the thermal efficiency.

Answers: 2

Show answers

Answers

answered: jessejames48

The value of temperature at compressor outlet = 543.43 K

The temperature at turbine outlet = 773.04 K

Back work ratio = 0.388

The value of efficiency of the Ideal Brayton cycle =0.448

Explanation:

Pressure ratio ( $r_{p}$ )= 8 And specific heat ratio ( $\gamma$ ) = 1.4

Compressor inlet temperature ( $T_{1}$ ) = 300 K

Turbine inlet temperature ( $T_{3}$ ) = 1400 K

(a). Temperature ratio inside the compressor is given by

$\frac{T_{2} }{T_{1} }$ = $r_{p}\frac{\gamma - 1}{\gamma}$

Where $T_{1}$ & $T_{2}$ represents the compressor inlet and outlet temperature.

Put all the values in the given formula we get

⇒ $\frac{T_{2} }{300}$ = $8^{\frac{1.4 - 1}{1.4} }$

⇒ $\frac{T_{2} }{300}$ = 1.811

⇒ $T_{2}$ = 543.43 K

This is the value of temperature at compressor outlet.

The temperature ratio inside the turbine is given by

$\frac{T_{3} }{T_{4} }$ = $r_{p}\frac{\gamma - 1}{\gamma}$

Where $T_{3}$ & $T_{4}$ represents the turbine inlet & outlet temperatures.

Put all the values in the given formula we get

⇒ $\frac{1400}{T_{4} }$ = $8^{\frac{1.4 - 1}{1.4} }$

⇒ $T_{4}$ = 773.05 K

This is the temperature at turbine outlet.

(b). The work done by the turbine is given by the formula ( $W_{T}$ ) = $C_{p}$ ( $T_{3}$ - $T_{4}$ )

Put all the values in the above formula we get $W_{T}$ = 1.005 × (1400 - 773.05)

$W_{T}$ = 630.08 $\frac{KJ}{Kg}$

And work done inside the pump is given by $W_{c}$ = $C_{p}$ ( $T_{2}$ - $T_{1}$ )

Put all the values in the above formula we get $W_{c}$ = 1.005 × (543.43 - 300)

$W_{c}$ = 244.65 $\frac{KJ}{Kg}$

Back work ratio is given by $r_{b}$ = $\frac{W_{C} }{W_{}T}$

Put the values of $W_{c}$ & $W_{T}$ in above formula we get

⇒ $r_{b}$ = $\frac{244.65}{630.08}$

⇒ $r_{b}$ = 0.388

This is the value of back work ratio.

(C). Thermal Efficiency is given by E = 1 - $\frac{1}{r_{p} ^{\frac{\gamma - 1}{\gamma} } }$

⇒ E = 1 - $\frac{1}{8 ^{\frac{1.4 - 1}{1.4} } }$

⇒ E = 0.448

This is the value of efficiency of the Ideal Brayton cycle.

answered: Guest

Because they're in different places for this the temperature varies.

answered: Guest

Each student aligns the edge of the object with the left edge of the ruler as shown above. all four students read the ruler with a measurement of 4.6 cm. which statement describes the data they collect? i believe the answer is: the data have poor precision and poor accuracy because of a systematic error.

Other questions on the subject: Physics

Physics, 22.06.2019 06:30, bradleydb222

5submission this assignment is worth 20 points total. you are required to submit the following by next lab: 1. (3 points) determine the equation for the output angular velocity ω2 = θ˙ 2 as a function of θ1, ω1 = θ˙ 1 and α. you must show all your work to receive credit. 2. (2 points) use the result of problem#1 to plot ω2 over 0 ≤ θ1 ≤ 360deg with ω1 = 360deg/sec. do this for α = {10,30}deg. show the results on the same plot and properly label the axes, title, legend. for this you can use matlab or ms excel. 3. (3 points) determine the equation for the output angular acceleration ω˙ 2 and create a plot similar to the one in problem#2. 4. (10 points) submit plots of the results (ω2 and ω˙ 2) obtained from creo/mechanism and compare them to results of problem#2 and problem#3. note that you should do these comparisons for the two cases with α = {10,30}deg. 5. (2 points) provide a brief explanation of the results. did they match? what are the implications as misalignment angle increases?

Answers: 3

continue

Physics, 22.06.2019 08:00, olejlund8073

If the force applied to an object remains constant, is more power needed for the object to move faster ? explain

Answers: 3

continue

Physics, 22.06.2019 10:00, nayellisoto15

Asap and show ! a 14 kg rock starting from rest free falls through a distance of 5.0 m with no air resistance. find the momentum change of the rock caused by its fall and the resulting change in the magnitude of earths velocity. earth mass is 6.0 * 10^24 kg. show your work assuming the rock earth system is closed.

Answers: 2

continue

Physics, 22.06.2019 14:00, astigall4272

What is the force that opposes motion and works against the downward pull? a) friction b) gravity c) weight d) acceleration

Answers: 1

continue

Do you know the correct answer?

⦁ A gas-turbine power plant operating on an ideal Brayton cycle has a pressure ratio of 8. The gas t...