Question

Air enters a counterflow heat exchanger operating at steady state at 22°C, 0.1 MPa and exits at 7°C. Refrigerant 134a enters at 0.2 MPa, a quality of 0.21, and a mass flow rate of 30 kg/h. Refrigerant exits at 0°C. There is no significant change in pressure for either stream. (a) For the Refrigerant 134a stream, determine the rate of heat transfer, in kJ/h (b) For the refrigerant stream evaluate the change in flow exergy rate, in kJ/h. (c) For the air stream evaluate the change in flow exergy rate, in kJ/h. Let T0 = 22°C, p0 = 0.1 MPa, and ignore the effects of motion and gravity. Round your answers to 3 significant digits.

Answer 1