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
julia-pushkina [17]
3 years ago
5

Steam enters a two-stage adiabatic turbine at 8 MPa and 5008C. It expands in the first stage to a state of 2 MPa and 3508C. Stea

m is then reheated at constant pressure to a temperature of 5008C before it is routed to the second stage, where it exits at 30 kPa and a quality of 97 percent. The work output of the turbine is 5 MW. Assuming the surroundings to be at 258C, determine the reversible power output and the rate of exergy destruction within this turbine.
Engineering
1 answer:
Nataly [62]3 years ago
6 0

Answer:

1) The exergy of destruction is approximately 456.93 kW

2) The reversible power output is approximately 5456.93 kW

Explanation:

1) The given parameters are;

P₁ = 8 MPa

T₁ = 500°C

From which we have;

s₁ = 6.727 kJ/(kg·K)

h₁ = 3399 kJ/kg

P₂ = 2 MPa

T₂ = 350°C

From which we have;

s₂ = 6.958 kJ/(kg·K)

h₂ = 3138 kJ/kg

P₃ = 2 MPa

T₃ = 500°C

From which we have;

s₃ = 7.434 kJ/(kg·K)

h₃ = 3468 kJ/kg

P₄ = 30 KPa

T₄ = 69.09 C (saturation temperature)

From which we have;

h₄ = h_{f4} + x₄×h_{fg} = 289.229 + 0.97*2335.32 = 2554.49 kJ/kg

s₄ =  s_{f4} + x₄×s_{fg} = 0.94394 + 0.97*6.8235 ≈ 7.563 kJ/(kg·K)

The exergy of destruction, \dot X_{dest}, is given as follows;

\dot X_{dest} = T₀ × \dot S_{gen} = T₀ × \dot m × (s₄ + s₂ - s₁ - s₃)

\dot X_{dest} = T₀ × \dot W×(s₄ + s₂ - s₁ - s₃)/(h₁ + h₃ - h₂ - h₄)

∴ \dot X_{dest} = 298.15 × 5000 × (7.563 + 6.958 - 6.727 - 7.434)/(3399 + 3468 - 3138  - 2554.49) ≈ 456.93 kW

The exergy of destruction ≈ 456.93 kW

2) The reversible power output, \dot W_{rev} = \dot W_{} + \dot X_{dest} ≈ 5000 + 456.93 kW = 5456.93 kW

The reversible power output ≈ 5456.93 kW.

You might be interested in
Re armature of a 4 pole DC generator is required to generate an emf of 520v on open circuit when revolving at a speed of 660rpm.
bija089 [108]

Since the armature is wave wound, the magnetic flux per pole is 0.0274 Weber.

<u>Given the following data:</u>

  • Emf = 520 Volts
  • Speed = 660 r.p.m
  • Number of armature conductors = 144 slots
  • Number of poles = 4 poles
  • Number of parallel paths = 2

To find the magnetic flux per pole:

Mathematically, the emf generated by a DC generator is given by the formula;

E = \frac{\theta ZN}{60} × \frac{P}{A}

<u>Where:</u>

  • E is the electromotive force in the DC generator.
  • Z is the total number of armature conductors.
  • N is the speed or armature rotation in r.p.m.
  • P is the number of poles.
  • A is the number of parallel paths in armature.
  • Ф is the magnetic flux.

First of all, we would determine the total number of armature conductors:

Z = 144 × 2 × 3

Z = 864

Substituting the given parameters into the formula, we have;

520 = \frac{\theta (864)(660)}{60} × \frac{4}{2}

520 = \theta (864)(11) × 2

520 = 19008 \theta \\\\\Theta = \frac{520}{19008}

<em>Magnetic flux </em><em>=</em><em> 0.0274 Weber.</em>

Therefore, the magnetic flux per pole is 0.0274 Weber.

Read more: brainly.com/question/15449812?referrer=searchResults

5 0
2 years ago
9. Calculate the total resistance and current in a parallel cir-
Taya2010 [7]

Answer:

  d. 2.3 ohms (5.3 amperes)

Explanation:

The calculator's 1/x key makes it convenient to calculate parallel resistance.

  Req = 1/(1/4 +1/8 +1/16) = 1/(7/16) = 16/7 ≈ 2.3 ohms

This corresponds to answer choice D.

__

<em>Additional comment</em>

This problem statement does not tell the applied voltage. The answer choices suggest that it is 12 V. If so, the current is 12/(16/7) = 21/4 = 5.25 amperes.

5 0
3 years ago
A horse pulls a cart along a road with a force of 550 lbs. If the horse does 2,674,100 ftlbs of work by the time it stops, how f
BartSMP [9]

Answer:

When a horse pull a cart the action is on?

A horse is harnessed to a cart. If the horse tries to pull the cart, the horse must exert a force on the cart. By Newton's third law the cart must then exert an equal and opposite force on the horse. Newton's second law tells us that acceleration is equal to the net force divided by the mass of the system.

Explanation:

5 0
3 years ago
Read 2 more answers
What are three common hazardous
Delicious77 [7]

Answer:

  1. SNOW SQUALLS - Squalls are substantial snow showers that cause white-out conditions. A couple of squalls are conceivable at the beginning of today through mid-evening. The most elevated possibility is north of the expressway.
  2. COLD - Because of away from and a new cover of day off, have plunged to the youngsters and 20s. There are frigid untreated surfaces.
  3. WINDS – One can expect supported breezes 15-25 mph this evening, with blasts to 40 mph. Solid breezes, alongside temperatures during the 30s, will create wind chills during the 20s.
  4. FOG - Perceivability is improving, however parts of Lancaster, Lebanon, Schuylkill, Berks, and Dauphin Provinces have decreased perceivability. With temperatures beneath freezing, mist can stick to the streets and produce frigid conditions.

Explanation:

An effect day in Pennsylvania is a day that highlights climate that will probably upset your typical every day calendar or schedule. At the point when the News 8 Tempest Group accept climate arrives at this limit, a yellow triangle with a shout imprint will show up on the figure demonstrating the climate will cause an effect. You may likewise observe the symbol utilized during a day-part figure when the News 8 Tempest Group accepts certain times may have a greater amount of an effect than others. An effect day's climate isn't viewed as outrageous or serious, perilous climate.  

Light downpour, day off, ice during a morning or night drive would be instances of effect climate. Most Pennsylvania workers can deal with driving in light downpour, day off, ice, however light downpour, day off, ice at the pinnacle of busy time can upset travel or cause mishaps because of the high volume of drivers. Thick mist over the Valley which could likewise modify a drive would be delegated an effect day.  

Moderate cold throughout the fall, winter, spring months, or warmth in the mid year months that may constrain open air presentation to the components would get this assignment.  

The Susquehanna Valley is a significant agrarian community for the locale. Pre-summer or late-summer ice or freezes that could harm or murder vegetation would fit into this class.  

Days that component consume bans from delayed droughts combined with solid breeze blasts likewise would be considered to conceivably make an effect a day ahead.

4 0
3 years ago
Light duty scaffolds are to be used for loads up to 25 lbs./sq. ft.<br> True<br> False
11Alexandr11 [23.1K]

Answer:

The answer is true

Explanation:

Light duty scaffolds are to be used for loads up to 25 lbs./sq. ft.

6 0
2 years ago
Other questions:
  • A student is using a 12.9 ft ramp to raise an object 6 ft above the ground.
    5·1 answer
  • Air enters a well-insulated turbine operating at steady, state with negligible velocity at 4 MPa, 300°C. The air expands to an e
    10·1 answer
  • # 17
    13·2 answers
  • A city emergency management agency and a construction company have formed a public-private partnership. The construction company
    15·1 answer
  • Which one of the following activities is not an example of incident coordination
    15·1 answer
  • A two-phase mixture of water and steam with a quality of 0.63 and T = 300F expands isothermally until only saturated vapor rema
    7·1 answer
  • - If you overload the rear portion of you vehicle &amp; it's raining out, your car could easily:
    14·1 answer
  • The bulk density of a compacted soil specimen (Gs = 2.70) and its water content are 2060 kg/m^3 and 15.3%, respectively. If the
    5·1 answer
  • Find all the words, Figure out my puzzle!
    14·2 answers
  • "Transformer is used to change the voltage".
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!