A counterflow heat exchanger operates at steady state with negligible kinetic and potential energy effects. In one stream, liquid water enters at 17°C and exits at 25°C with a negligible change in pressure. In the other stream, Refrigerant 134a enters at 14 bar, 80°C with a mass flow rate of 5 kg/min and exits as saturated liquid at 52°C. Heat transfer from the outer surface of the heat exchanger can be ignored. Determine
(a) the mass flow rate of the liquid water stream, in kg/min.
(b) the rate of entropy production within the heat exchanger, in kW/K.