Cooling water at a steady rate of 0.5 kg/s flows through an inner tube having inner diameter of 25 mm and length of 10 m of a tube – in – tube condenser. The mean inlet temperature of cooling water is 100C. Saturated steam condenses in the annulus at a uniform rate such that the inner surface temperature of the tube is constant throughout the length of the tube at 400C. The average condensing side heat transfer coefficient is 10000 W/m2 – K. Neglect the thickness of the heat exchanger tube. Calculate the effectiveness of the heat exchanger and the exit water temperature.
Properties of water are given below :
Specific heat = 4180 J/kg – K,
Density = 990 kg/m3,
Dynamic viscosity=0.8 $\times$ 10-3 Pa.sec
Thermal conductivity = 0.57 W/m – K.
You may use the relation