29.4 bro I hope that helps
Answer:
solution in the picture attached
Explanation:
Answer:
4.6 mm
Explanation:
Given data includes:
thin-walled pipe diameter = 100-mm =0.1 m
Temperature of pipe
= -15° C = (-15 +273)K =258 K
Temperature of water
= 3° C = (3 + 273)K = 276 K
Temperature of ice
= 0° C = (0 +273)K =273 K
Thermal conductivity (k) from the ice table = 1.94 W/m.K ; R = 0.05
convection coefficient
=2000 W/m².K
The energy balance can be expressed as:
![q_{conduction} =q_{convention}](https://tex.z-dn.net/?f=q_%7Bconduction%7D%20%3Dq_%7Bconvention%7D)
where;
------------- equation (1)
------------ equation(2)
Equating both equation (1) and (2); we have;
![= \pi DLh_l(T_w-T_i)](https://tex.z-dn.net/?f=%3D%20%5Cpi%20DLh_l%28T_w-T_i%29)
Replacing the given data; we have:
![= \pi (0.1)*2000(276-273)](https://tex.z-dn.net/?f=%3D%20%5Cpi%20%280.1%29%2A2000%28276-273%29)
![\frac{182.84}{In(\frac{0.05}{r}) } = 1884.96](https://tex.z-dn.net/?f=%5Cfrac%7B182.84%7D%7BIn%28%5Cfrac%7B0.05%7D%7Br%7D%29%20%7D%20%3D%201884.96)
![In(\frac{0.05}{r})*1884.96 = 182.84](https://tex.z-dn.net/?f=In%28%5Cfrac%7B0.05%7D%7Br%7D%29%2A1884.96%20%3D%20182.84)
![In(\frac{0.05}{r}) = \frac{182.84}{1884.96}](https://tex.z-dn.net/?f=In%28%5Cfrac%7B0.05%7D%7Br%7D%29%20%3D%20%5Cfrac%7B182.84%7D%7B1884.96%7D)
![In(\frac{0.05}{r}) =0.0970](https://tex.z-dn.net/?f=In%28%5Cfrac%7B0.05%7D%7Br%7D%29%20%3D0.0970)
![\frac {0.05}{r} =e^{0.0970}](https://tex.z-dn.net/?f=%5Cfrac%20%7B0.05%7D%7Br%7D%20%3De%5E%7B0.0970%7D)
![\frac {0.05}{r} =1.102](https://tex.z-dn.net/?f=%5Cfrac%20%7B0.05%7D%7Br%7D%20%3D1.102)
![r=\frac{0.05}{1.102}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B0.05%7D%7B1.102%7D)
r = 0.0454
The thickness (t) of the ice layer can now be calculated as:
t = (R - r)
t = (0.05 - 0.0454)
t = 0.0046 m
t = 4.6 mm