Assuming the tube surface to have a uniform temperature corresponding to that of the phase change.Ī shell-and-tube heat exchanger consisting of one shell pass and two tube passes is used to transfer heat from an ethylene glycol-water solution (shell side) supplied from a rooftop solar collector to pure water (tube side) used for household purposes. The latent heat of fusion and density of ice are hsf = 334000 J/kg and p = 917 kg/m3,respectively. As ethylene glycol flows through the center tube, heat is transferred to the ice between inner and outer tubes,converting it from the solid ice at OC) to liquid state (ice-cold water at 0C at the phase change temperature of 0C. The diameter of the center tube Di = 0.3 m, the diameter of the outer tube D, = 0.8 m.
In a de-icing test, hot ethylene glycol is flowing at 10 kg/s and an inlet temperature of 350 C in the center tube in a horizontal concentric tube heat exchanger (tube in tube). Using internal flow, answer the following questions: (1) What is the Reynolds number (Rep) for the hot ethylene glycol? (2) What is the heat transfer coefficient (h) for the hot ethylene glycol? (3) What is the the exiting temperatures for the ethylene glycol? (4) How long would it take to completely liquefy the ice? The thermophysical properties of ethylene glycol:ĭensity p is 1079 kg/m3 Kinematic viscosity v is 3.17x10-6 m2/s Prandtl Number Pr is 34.6 Dynamic viscosity is 0.00342 kg/m*s Thermal conductivity K is 0.261 W/mK Specific heat Cp is 2637 J/kgK Assuming the tube surface to have a uniform temperature corresponding to that of the phase change.
SOLVED: In a de-icing test, hot ethylene glycol is flowing at 10 kg/s and an inlet temperature of 350 C in the center tube in a horizontal concentric tube heat exchanger (tube in tube).
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