A liquid food (specifi c heat 4.0 kJ/[kg °C]) fl ows in the inner pipe of a doublepipe
heat exchanger. The liquid food enters the heat exchanger at 20°C
and exits at 60°C ( Fig. E4.16 ). The fl ow rate of the liquid food is 0.5 kg/s. In
the annular section, hot water at 90°C enters the heat exchanger and fl ows
countercurrently at a fl ow rate of 1 kg/s. The average specifi c heat of water is
4.18 kJ/(kg °C). Assume steady-state conditions.