A system for heating water from an inlet temperature of Tm-20C to an outlet temperature of...

 

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A system for heating water from an inlet temperature of Tm-20°C to an outlet temperature of Tmo-60°C involves passing the water through a thick-walled tube having inner and outer diameters of 20 and 40 mm. The outer surface of the tube is well insulated and electrical heating within the wall provides for a uniform generation rate of à = 10°W /m. Given that the Cp = 4179 J/kg.K at Tm. (i) For water mass flow rate of 0.1 kg/s, how long must the tube be to achieve the desired outlet temperature? [5 marks] If the inner surface temperature of the tube T, =70°C at the outlet, what is the local (ii) convection heat transfer coefficient at the outlet? [5 marks] A system for heating water from an inlet temperature of Tm-20°C to an outlet temperature of Tmo-60°C involves passing the water through a thick-walled tube having inner and outer diameters of 20 and 40 mm. The outer surface of the tube is well insulated and electrical heating within the wall provides for a uniform generation rate of à = 10°W /m. Given that the Cp = 4179 J/kg.K at Tm. (i) For water mass flow rate of 0.1 kg/s, how long must the tube be to achieve the desired outlet temperature? [5 marks] If the inner surface temperature of the tube T, =70°C at the outlet, what is the local (ii) convection heat transfer coefficient at the outlet? [5 marks]

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Ts70C Di20mm Tmo 60c 3D TMi20C Imsulation Laimlet outlet Ass... View the full answer