A long thin-walled double-pipe heat exchanger with tube and shell diameters of 1.0 and 2.5 cm, respectively, is used to condense refrigerant 134a by water at 20°C. refrigerant flows through the tube, with a convection heat transfer coefficient =5000 W/m².°C. Water flows through the shell at a rate of 0.3 kg/s. determine overall heat transfer coefficient of this heat exchanger. p = 998 kg/m³, Pr = 7.01, 0.598 W/m.°C and v = 1.004 x10-6 m²/s.