Liquid hydrogen is flowing through an insulated pipe ( k = 23 W/m .K, D i =3 cm, D o =4 cm and L= 20 m) . The pipe is situated in a chemical plant, where the average air temperature is 40°C. The convection heat transfer coefficients of the liquid hydrogen and the ambient air are 200 W/m 2 K and 50 W/m 2 .K, respectively. If the oilier surface temperature of the insulated pipe is 5°C, determine the thickness of the pipe insulation ( k = 0.6 W/m .K) and in order to keep the liquid hydrogen flowing at an average temperature of -300°C.
Liquid hydrogen is flowing through an insulated pipe ( k = 23 W/m .K, D i =3 cm, D o =4 cm and L= 20 m) . The pipe is situated in a chemical plant, where the average air temperature is 40°C. The convection heat transfer coefficients of the liquid hydrogen and the ambient air are 200 W/m 2 K and 50 W/m 2 .K, respectively. If the oilier surface temperature of the insulated pipe is 5°C, determine the thickness of the pipe insulation ( k = 0.6 W/m .K) and in order to keep the liquid hydrogen flowing at an average temperature of -300°C.
Solution Summary: The author explains the thickness of the pipe insulation in order to keep the liquid hydrogen flowing at an average temperature of -300 o C.
Liquid hydrogen is flowing through an insulated pipe
(
k
=
23
W/m
.K,
D
i
=3 cm, D
o
=4 cm and L= 20 m)
. The pipe is situated in a chemical plant, where the average air temperature is 40°C. The convection heat transfer coefficients of the liquid hydrogen and the ambient air are 200 W/m2 K and 50 W/m2 .K, respectively. If the oilier surface temperature of the insulated pipe is 5°C, determine the thickness of the pipe insulation
(
k
=
0.6
W/m
.K)
and in order to keep the liquid hydrogen flowing at an average temperature of -300°C.
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A steel duct whose internal diameter is 5.0 cm, and external diameter is 7.6 cm and thermal conductivity is: k = 15.0 (W/(m ºC)) is covered with an insulating material whose thickness is 2.0 cm and of thermal conductivity k = 0.2 (W/(m ºC)). A hot gas flows through the interior of the duct at a temperature of 330.0 ºC that generates a heat transfer coefficient by forced convection h=400.0 (W/(m^2 · ºC)). The outer surface of the insulating layer is exposed to air whose temperature is 30.0 ºC with forced convection heat transfer surface h = 60.0 (W/(m^2 · °C)).
As a process engineer and in charge of company operations, you have been asked to:
i. Determine the heat loss experienced by the pipe along 10.0 m.ii. The temperature drops that are generated in the different thermal resistances of the system. That is, on the air side, the duct wall and on the hot gas side.
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