Steam in a heating system flows through tubes whose outer diameter is 5 cm and whose walls are maintained at a temperature of 180°C. Circular aluminum alloy 2024-T6 fins (k = 186 W/m·K) of outer diameter 6 cm and constant thickness 1 mm are attached to the tube. The space between the fins is 3 mm, and thus there are 250 fins per meter length of the tube. Heat is transferred to the surrounding air at T_ˆž= 25°C, with a heat transfer coefficient of 40 W/m²·K. Determine the increase in heat transfer from the tube per meter of its length as a result of adding fins.

Transcribed Image Text:

2.5 cm 3 ст т - 25°C 180°C 1 mm 3 mm