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lord [1]
3 years ago
10

A 2 in. diameter pipe supplying steam at 300°F is enclosed in a 1 ft square duct at 70°F. The outside of the duct is perfectly i

nsulated. Assume the emissivity of pipe surface and duct surfaces as 0.79 and 0.276, respectively. Estimate the radiation heat transfer per foot length.
Engineering
1 answer:
Shkiper50 [21]3 years ago
4 0

Answer:

The value of heat transferred watt per foot length Q = 54.78 Watt per foot length.

Explanation:

Diameter of pipe = 2 in = 0.0508 m

Steam temperature T_{1} = 300 F  = 422.04 K

Duct temperature T_{2} = 70 F = 294.26 K

Emmisivity of surface 1 = 0.79

Emmisivity of surface 2 = 0.276

Net emmisivity of both surfaces ∈ = 0.25

Stefan volazman constant \sigma = 5.67 × 10^{-8} \frac{W}{m^{2} K^{4}  }

Heat transfer  per foot length is given by

Q = ∈ \sigma A ( T_{1}^{4} - T_{2} ^{4} ) ------ (1)

Put all the values in equation (1) , we get

Q = 0.25 × 5.67 × 10^{-8} × 3.14 × 0.0508 × 1 × ( 422.04^{4} - 294.26^{4} )

Q = 54.78 Watt per foot.

This is the value of heat transferred watt per foot length.

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kolbaska11 [484]

Answer:

  5 microhenries

Explanation:

The effective value of inductors in parallel "add" in the same way that resistors in parallel do. The value is the reciprocal of the sum of the reciprocals of the inductances that are in parallel.

  10 uH ║ 10 uH = 5 uH

The effective inductance is 5 uH.

6 0
3 years ago
A fuel gas containing 45.00 mole% methane and the balance ethane is burned completely with pure oxygen at 25.00 degree C, and th
Dennis_Churaev [7]

Answer:

A)

- Q ( kw ) for vapor =  -1258.05 kw

- Q ( kw ) for liquid = -1146.3 kw

B )

- Q ( kj ) for vapor  = -1258.05 kJ

- Q ( KJ ) for liquid = - 1146.3 KJ

Explanation:

Given data :

45.00 % mole of methane

55.00 % of ethane

attached below is a detailed solution

A) calculate - Q(kw)

- Q ( kw ) for vapor =  -1258.05 kw

- Q ( kw ) for liquid = -1146.3 kw

B ) calculate  - Q ( KJ )

- Q ( kj ) for vapor  = -1258.05 kJ

- Q ( KJ ) for liquid = - 1146.3 KJ

since combustion takes place in a constant-volume batch reactor

7 0
3 years ago
Polylines are made up of:____________
Drupady [299]

Answer:

2. are connected sequences of lines and arcs

Explanation:

A polyline is an object that is compound in nature as it includes one or more linear or curved segments. It is made up of connected sequence of lines and arcs that are created as a single object rather than individual objects.

Polylines are useful in the following;

i. Easy creation of rectangles and polygons as a single entity.

ii. In AUTOCAD, they allow for easy extrusion for 3D solids.

8 0
3 years ago
A 2-m3 rigid tank initially contains air at 100 kPa and 22°C. The tank is connected to a supply line through a valve. Air is flo
Finger [1]

Answer:

9.58 Kg of air has entered the tank.

heat entered=3483.76 Kilo.Joule

Explanation:

(A) R=287 Kilo.J/Kg.K

as per initial conditions P=100 Kilo.Pa ,V=2 cubic meter, T=22 C=295.15 K,

using the relation P*V=m*R*T

m=(100*1000*2)/(287*295.15)=2.36 Kg this is the mass that is already present in tank.

after filling tank at 600 Kilo.Pa.

P=600 Kilo Pa T=77 C=350.15 K

P*V=m*R*T

m=(600*1000*2)/(287*350.15)=11.94 Kg

mass that has entered=11.94-2.36=9.58 Kg

(b) using air psychometric  property table

specific heat content initial  100 KILO Pa and 22 C=295.576 Kilo.Joule/Kg

specific heat content final  600 Kilo Pa and 77 C=350.194 Kilo.Joule/Kg

heat at initial stage=295.576*2.36=697.56 Kilo.Joule

heat at final stage=350.194*11.94=4181.32 Kilo.Joule

heat entered=4181.32-697.56=3483.76 Kilo.Joule

3 0
3 years ago
Which statement best describes the lower vc-turbo engine compression ratios?.
kobusy [5.1K]

The statement that best describes the lower vc-turbo engine compression ratios is that its generate an increased amount of power with the average fuel consumption.

<h3>Vc-turbo engine</h3>

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Hence, the turbo engines run lower static compression ratios to increase the amount of power they can reliable generate on pump gas.

Therefore, the statement that best describes the lower vc-turbo engine compression ratios is that its generate an increased amount of power with the average fuel consumption.

Read more about turbo engines

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7 0
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