Problem 2: A cartridge electrical heater is shaped as a cylinder of length L = 300...

Transcribed Image Text:

Problem 2: A cartridge electrical heater is shaped as a cylinder of length L = 300 mm and outer diameter D= 30 mm. Under normal operating conditions, the heater dissipates 2 kW while submerged in a water flow that is at 20C and provides a convection heat transfer coefficient of h = 5000 W/mK. At some point the heater is accidentally removed from the water while still running and its surface is exposed to air that is also at 20C but for which h = 50 W/mK. Neglecting heat transfer from the ends of the heater and radiation heat transfer, determine its surface temperature Ts and the thermal resistance due to convection in the two cases. What are the consequences of such an accidental event of removing the heater from the water while still running? Problem 2: A cartridge electrical heater is shaped as a cylinder of length L = 300 mm and outer diameter D= 30 mm. Under normal operating conditions, the heater dissipates 2 kW while submerged in a water flow that is at 20C and provides a convection heat transfer coefficient of h = 5000 W/mK. At some point the heater is accidentally removed from the water while still running and its surface is exposed to air that is also at 20C but for which h = 50 W/mK. Neglecting heat transfer from the ends of the heater and radiation heat transfer, determine its surface temperature Ts and the thermal resistance due to convection in the two cases. What are the consequences of such an accidental event of removing the heater from the water while still running?