The evaporator of a water chiller has 15 stainless tubes of outer diameter 20mm and length 0.5 m through which water flows at a total flow rate of 0.05 kgsí1 . Water enters the evaporator at 18°C....

The evaporator of a water chiller has 15 stainless tubes of outer diameter 20mm and length 0.5 m through which water flows at a total flow rate of 0.05 kgsí1 . Water enters the evaporator at 18°C. Refrigerant 134a at 6°C undergoes pool boiling on the outer surface of the tubes. Assume that the outer surface of the tubes is at a uniform temperature of 9°C. Calculate (i) the pool boiling heat transfer coefficient, and (ii) the outlet temperature of the water. Outline a procedure to check whether the assumed tube surface temperature is accurate.