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A metal pipe with an outside diameter (OD) of 12cm is covered with an insulation material [k-0.07W/m.°C] of 2.5cm thick. If the outer pipe wall is at 100°C and the outer surface of the insulation is at 20°C, find the heat loss from the pipe per meter length

Respuesta :

Answer:

Q= 65.57 W

Explanation:

Given that

Outer diameter=12 cm

Thickness = 2.5 cm

So inner diameter = 7 cm

Outer wall temperature =100° C

Outer surface of insulation = 20 °C

As we know that thermal resistance of cylinder pipe is given as follows

[tex]R_{th}=\dfrac{ln\frac{r_2}{r_1}}{2\pi Kl}[/tex]

Now by putting the values

Lets put l = 1 m because given that find heat loss per unit length

[tex]R_{th}=\dfrac{ln\frac{6}{3.5}}{2\pi \times 0.07\times 1}[/tex]

So

[tex]R_{th}=1.22 \frac{W}{m-K}[/tex]

now heat loss Q

[tex]Q=\dfrac{\Delta T}{R_{th}}[/tex]

[tex]Q=\dfrac{100-20}{1.22}[/tex]

Q= 65.57 W

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