In a concurrent flow tubular heat exchanger, a liquid food, flowing in the inner pipe, is heated from 20 to 40°C.In the outer pipe the heating medium (water) cools from 90 to 50°C.
The overall heat transfer coefficient based on the inside diameter is 2000 W/(m2°C). The inside diameter is 5 cm and length of the heat exchanger is 10 m. The average specific heat of water is 4.181 kJ/(kg°C). Calculate the mass flow rate of water in the outer pipe.