ers a heat exchanger operating at steady state at 5 bar with a specific enthalpy of 2298 kJ/kg and exits at the same sa saturated liquid. The steam mass flow rate is 1.29 kg/min. stream of air with a mass flow rate of 48.3 kg/min enters at 38.4 °C and exits at 76.7 °C. as model with c, = 1.005 kJ/kg.K can be assumed for air. Kinetic and potential energy effects are negligible. ne the quality of the entering steam:

Air enters a diffuser operating at steady state at 540°R, 15 Ilbf/in.?, with a velocity of 600 ft/s, and exits with a velocity of 60 ft/s. The ratio of the exit area to the inlet area is 6. Assuming the ideal gas model for the air and ignoring heat transfer, determine the temperature, in °R, and pressure, in Ibf/in.?, at the exit.

Chapter 6 9.

Figure shows data for a portion of the ducting in ventilation system operating at steady state. The ducts are well insulated and the pressure is very nearly 1 bar throughout. Assuming the ideal gas model for air with Cp  = 1 kJ/kg · K. and ignoring kinetic and potential energy effects, determine: (a) the temperature of the air at the exit, in °C. (b) the exit diameter, in m. (c) the rate of entropy production within the duct, in kJ/min.

Expert Q&A A counterflow heat exchanger operates at steady state while being well-insulated from the surroundings with air and ammonia flowing in separate streams. Ammonia enters at state 1 with -20°C and a quality of 20% and exits at state 2 as saturated vapor at -20°C. Air enters at state 3 with pressure 1 bar and temperature 295 K and exits at state 4 with pressure 1 bar and temperature 265 K. The flow rate of air is 10 kg/s. Ignore kinetic and potential energy effects, and take the dead state as 1 bar and 300 K. a. Sketch states 1 and 2 on a T-s diagram, including the liquid-vapor dome. b. Describe the heat transfer inside the heat exchanger (what is transferring heat to what?) c. Determine the specific enthalpy of each state, in kJ/kg. d. Determine the mass flow rate of ammonia, in kg/s. e. Determine the rate of exergy destruction within the heat exchanger, in kW. f. Devise and evaluate an exergetic efficiency for the heat exchanger. Done