A pipe with 8 cm internal diameter, 9 cm outer diameter, 2 meter long, thermal conductivity 30W/mK is insulated by glass wool material with which thermal conductivity 0,05W/mK, thickness 4 cm. Internal surface temperature of the pipe T₁ is 80°C, surrounding temperature where pipe is located is 20°C, convection heat transfer constant on outer surface of insulation is 25W/m2K. K30W/mK T. = 20°C h. = 25W/m²K 4cm -0,05W/mK a. Determine the heat loss from the pipe to surrounding (W)? b. What is temperature of the surface between glass wooden and pipe (T₂)? c. What is critical insulation radius for pipe? Is insulation on the pipe succesful? Explain

A pipe with 8 cm internal diameter, 9 cm outer diameter, 2 meter long, thermal conductivity 30W/mK is insulated by glass wool material with which thermal conductivity 0,05W/mK, thickness 4 cm. Internal surface temperature of the pipe T₁ is 80°C, surrounding temperature where pipe is located is 20°C, convection heat transfer constant on outer surface of insulation is 25W/m2K. K30W/mK T. = 20°C h. = 25W/m²K 4cm -0,05W/mK a. Determine the heat loss from the pipe to surrounding (W)? b. What is temperature of the surface between glass wooden and pipe (T₂)? c. What is critical insulation radius for pipe? Is insulation on the pipe succesful? Explain

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter3: Transient Heat Conduction

Section: Chapter Questions

Problem 3.10P: 3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the...

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3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the atmosphere from outer space. If its original temperature is 38°C, the effective average temperature of the atmosphere is 1093°C, and the effective heat transfer coefficient is , estimate the temperature of the shell after reentry, assuming the time of reentry is 10 min and the interior of the shell is evacuated.
An electronic device that internally generates 600 mW of heat has a maximum permissible operating temperature of 70C. It is to be cooled in 25C air by attaching aluminum fins with a total surface area of 12cm2. The convection heat transfer coefficient between the fins and the air is 20W/m2K. Estimate the operating temperature when the fins are attached in such a way that (a) there is a contact resistance of approximately 50 K/W between the surface of the device and the fin array and (b) there is no contact resistance (in this case, the construction of the device is more expensive). Comment on the design options.
1.10 A heat flux meter at the outer (cold) wall of a concrete building indicates that the heat loss through a wall of 10-cm thickness is . If a thermocouple at the inner surface of the wall indicates a temperature of 22°C while another at the outer surface shows 6°C, calculate the thermal conductivity of the concrete and compare your result with the value in Appendix 2, Table 11.
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A pipe with 8 cm internal diameter, 9 cm outer diameter, 2 meter long, thermal conductivity 30W/mK is insulated by glass wool material with which thermal conductivity 0,05W/mK, thickness 4 cm. Internal surface temperature of the pipe T1 is 80°C, surrounding temperature where pipe is located is 20°C, convection heat transfer constant on outer surface of insulation is 25W/m2K. Kppe 30W/mk T. 20°C h. = 25W/mK 4cm K=0,05W/mk a. Detemine the heat loss from the pipe to surrounding (W)? b. What is temperature of the surface between glass wooden and pipe (T2)? c. What is critical insulation radius for pipe? Is insulation on the pipe succesful? Explain
* Question A pipe with 8 cm intemal diameter, 9 cm outer diameter, 2 meter long, thermal conductivity 30Wimk is insulated by glass wool material wilth which thermal conductivity 0,0SW/MK, thickness 4 cm. Internal surface temperature of the pipe T1 is 80'C, surrounding temperature where pipe is located is 20°C, convection heat transfer constant on outer surface of insulation is 25Wim?k. K30Wimk T. 20°C h. = 25WimK K0.05Wimk a. Detemino the heat loss rom the pipe to surrounding (W)? b. What is tomperature of the surface between glass wooden and pipe (T2? e. What is critical insulation radius for pipe? is insulation on the pipe succeshul? Explain
A pipe with 8 cm internal diameter, 9 cm outer diameter, 2 meter long, thermal conductivity 30W/mK is insulated by glass wool material with which thermal conductivity 0,05W/mK, thickness 4 cm. Internal surface temperature of the pipe T1 is 80°C, surrounding temperature where pipe is located is 20°C, convection heat transfer constant on outer surface of insulation is 25W/m?K. K 30WimK T. 20°C h. = 25W/MK 4cm 0,05W/mK a. Detemine the heat loss from the pipe to surrounding (W)? b. What is temperature of the surface between glass wooden and pipe (T2)? c. What is critical insulation radius for pipe? Is insulation on the pipe succesful? Explain
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A pipe with 8 cm internal diameter, 9 cm outer diameter, 2 meter long, thermal conductivity 30W/mK is insulated by glass wool material with which thermal conductivity 0,05W/mK, thickness 4 cm. Internal surface temperature of the pipe T1 is 80°C, surrounding temperature where pipe is located is 20°C, convection heat transfer constant on outer surface of insulation is 25W/m?K. Kpo 30W/mk T.= 20°C h. = 25W/MK 4cm K= 0,05W/mK a. Detemine the heat loss from the pipe to surrounding (W)? b. What is temperature of the surface between glass wooden and pipe (T2)? c. What is critical insulation radius for pipe? Is insulation on the pipe succesful? Explain