Question

4: Refrigerant-134a at 1 MPa and 90°C is to be cooled to 1 MPa and 40°C in a condenser by air. The air enters at 100 kPa and 27 C with a volume flow rate of 600 m3/min and leaves at 95 kPa and 65°C Determine the mass flow rate of the refrigerant. 5: The hot- water needs of a household are to be met by heating water at 55°F to 180°F by solar collector at a rate of 5 lbm/s. Water flows through a 1.5-in-diameter thin aluminum tube whose outer surface is black-anodized in order to maximize its solar absorption ability. The centerline of the tube coincides with the focal line of the collector, and a glass sleeve is placed outside the tube to minimize the heat losses. If solar energy is transferred to water at a net rate of 400 Btu/hr per ft length of the tube, determine the required length of the parabolic collector to meet the hot-water requirements of this house. parabolic a 6: An adiabatic air compressor is to be powered by driving a generator. Steam enters the turbine at 10 MPa and 500°C at a rate of 25 kg/s and exits at 10 kPa and a quality of 0.85. Air enters the compressor at 98 kPa and 295 K at a rate of 10 kg/s and exits at 1 MPa and 620 K. Determine the net power delivered to the generator by the turbine direct-coupled adiabatic steam turbine that is also a I MPa 620 K 10MPA 500 C Steam turbine Air compressor 10kPa 98 kPa 295 K

Answer 1