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
Leviafan [203]
3 years ago
10

Steam at 20 bars is in the saturated vapor state (call this state 1) and contained in a pistoncylinderdevice with a volume of 0.

03 m3. Assume the steam is cooled at constantvolume (i.e. the piston is held fixed in place) until the temperature reaches 200 C (callthis state 2). Then the steam is expanded isothermally until its volume is three times theinitial value (state 3).
Required:
a. Determine the pressures at state 2 and 3. ans. 15.5 bar, ~10 bar
b. Determine the change in specific internal energy, u, for each of the two processes.
-389 kJ/kg, 410 kJ/kg
c. Make qualitatively correct sketches of the processes on a T-v plot.

Engineering
1 answer:
saul85 [17]3 years ago
3 0

Answer:

Explanation:

Given that:

<u>At state 1:</u>

Pressure P₁ = 20 bar

Volume V₁ = 0.03 \mathbf{m^{3}}

From the tables at saturated vapour;

Temperature T₁ = 212.4⁰ C  ; v_1 = vg_1 = 0.0996 \mathbf{m^{3}} / kg

The mass inside the cylinder is m = 0.3 kg, which is constant.

The specific internal energy u₁ = ug₁ = 2599.2 kJ/kg

<u>At state 2:</u>

Temperature T₂ = 200⁰ C

Since the 1 - 2 occurs in an isochoric process v₂ = v₁ = 0.099 \mathbf{m^{3}} / kg

From temperature T₂ = 200⁰ C

v_f_2 = 0.0016 \ m^3/kg  

vg_2 = 0.127 \ m^3/kg  

Since  vf_2 < v_2 , the saturated pressure at state 2 i.e. P₂ = 15.5 bar

Mixture quality x_2 = \dfrac{v_2-vf_2}{vg_2 -vf_2}

x_2 = \dfrac{(0.099-0.0016)m^3/kg}{(0.127 -0.0016) m^3/kg}

x_2 = \dfrac{(0.0974)m^3/kg}{(0.1254) m^3/kg}

\mathsf{x_2 =0.78}

At temperature T₂, the specific internal energy u_f_2 = 850.6 \ kJ/kg , also ug_2 = 2594.3 \ kJ/kg

Thus,

u_2 = uf_2 + x_2 (ug_2 -uf_2)

u_2 =850.6  +0.78 (2594.3 -850.6)

u_2 =850.6  +1360.086

u_2 =2210.686 \ kJ/kg

<u>At state 3:</u>

Temperature T_3=T_2 = 200 ^0 C ,

V_3 = 2V_1 = 0.06 \ m^3

Specific volume v_3 = 0.2  \ m^3/kg

Thus; vg_3 =vg_2 = 0.127 \ m^3/kg ,

SInce v_3 > vg_3, therefore, the phase is in a superheated vapour state.

From the tables of superheated vapour tables; at v_3 = 0.2  \ m^3/kg and T₃ = 200⁰ C

The pressure = 10 bar and v =0.206 \ m^3/kg

The specific internal energy u_3 at the pressure of 10 bar = 2622.3 kJ/kg

The changes in the specific internal energy is:

u_2-u_1

= (2210.686 - 2599.2) kJ/kg

= -388.514 kJ/kg

≅ - 389 kJ/kg

u_3-u_2

= (2622.3 - 2210.686)  kJ/kg

= 411.614 kJ/kg

≅ 410 kJ/kg  

We can see the correct sketches of the T-v plot showing the diagrammatic expression in the image attached below.

You might be interested in
Wireless technology has made communicating
emmainna [20.7K]

Answer:

Taking as a basis of calculation 100 mol of gas leaving the conversion reactor, draw andcompletely label a flowchart of this process. Then calculate the moles of fresh methanol feed,formaldehyde product solution, recycled methanol, and absorber off-gas, the kg of steamgenerated in the waste-heat boiler, and the kg of cooling water fed to the heat exchangerbetween the waste-heat boiler and the absorber. Finally, calculate the heat (kJ) that must beremoved in the distillation column overhead condenser, assuming that methanol enters as asaturated vapor at 1 atm and leaves as a saturated liquid at the same pressure.

1

SEE ANSWER

Explanation:

6 0
3 years ago
Can you solve this question​
Alecsey [184]

Answer:

eojcjksjsososisjsiisisiiaodbjspbcpjsphcpjajosjjs ahahhahahahahahahahahahahahahhhahahahaahahhahahahahaahahahahaha

6 0
2 years ago
Read 2 more answers
The basic barometer can be used to measure the height of a building. If the barometric readings at the top and at the bottom of
bixtya [17]

Answer:

h = 287.1 m

Explanation:

the density of mercury \rho =13570 kg/m3

the atmospheric pressure at the top of the building is

p_t = \rho gh  = 13570*908*0.73 = 97.08 kPa

the atmospheric pressure at bottom

p_b = \rho gh  = 13570*908*0.75 = 100.4 kPa

\frac{w_{air}}{A} =p_b -p_t

we have also

(\rho gh)_{air} = p_b - p_t

1.18*9.81*h = (100.4 -97.08)*10^3

h = 287.1 m

7 0
3 years ago
Which of the following is NOT associated with Urban Sprawl?
pochemuha

The option that is not associated with the given term called urban sprawl is; Option A: Blocking high views

What is Urban Sprawl?

Urban sprawl is defined as the rapid expansion of the geographic boundaries of towns and cities which is often accompanied by low-density residential housing and increased reliance on the private automobilefor movement.

Looking at the given options, "blocking high views" is the option that is not typically a problem associated with urban sprawl because urbanization usually takes place on relatively flat levels.

The missing options are;

a. blocking high views

b. destroying animal habitats

c. overrunning farmland

d. reducing green space

Read more about urban sprawl at; brainly.com/question/504389

8 0
2 years ago
HOW TO CALCULATE MARGINAL RATE
Basile [38]

Answer:

Divide the difference in tax by the amount of income from the investment, and you'll get the economic marginal tax rate from investing. Most people refer to marginal tax rates as being identical to tax brackets.

hope this helps

have a good day :)

Explanation:

8 0
2 years ago
Other questions:
  • A 356 cast aluminum test bar is tested in tension. The initial gage length as marked on the sample is 50mm and the initial diame
    9·1 answer
  • Light energy produces the only voltage in a solar cell. (a)-True(T) (b)- false(F)
    9·1 answer
  • Block B starts from rest, block A moves with a constant acceleration, and slider block C moves to the right with a constant acce
    11·1 answer
  • Consider a pipe with an inner radius of 5cm and an outer radius of 7cm.The inner surface is kept at 100C, and the outer surface
    11·1 answer
  • The price of a single item within a group of items is
    8·1 answer
  • In the following scenario, what could the engineers have done to keep the bridge from collapsing?
    8·1 answer
  • Which of the following is not a relationship set between elements in a sketch​
    7·1 answer
  • Why is recycling important
    9·2 answers
  • If an internally piloted DCV does not shift, you should use a gauge to _____. A.check the pilot line pressure b. check the inlet
    15·1 answer
  • when discussing valve train components, technician a says stamped rocker arms are very strong and may be used in high-horsepower
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!