A counterflow, concentric tube heat exchanger used for enginecooling has been in service for an extended period of time. Theheat transfer surface area of the exchanger is 5 m2, andthe design value of the overall convection coefficient (without anyfouling) is 38 W/m2K. During a test run, engine oilflowing at 0.1 kg/s is cooled from 110oC to66oC by water supplied at a temperature of25oC and a flow rate of 0.18 kg/s. Determine whetherfouling has occurred during the service period. If so, calculatethe fouling factor, Râ€f (m2K/W).Specific heat of engine oil is 2166 J/kgK, and water is 4178J/kgK.
What is Râ€f = x 10-3m2K/W?
