Question

A) Steam enters a horizontal pipe operating at steady state with a specific enthalpy of 2,663 kJ/kg and a mass flow rate of 0.1 kg/s. At the exit, the specific enthalpy is 1,531 kJ/kg. If there is no significant change in kinetic energy from inlet to exit, determine the rate of heat transfer between the pipe and its surroundings, in kW.

B) Refrigerant 134a enters a horizontal pipe operating at steady state at 40°C, 3.1 bar and a velocity of 58 m/s. At the exit, the temperature is 50 °C and the pressure is 240 kPa. The pipe diameter is 0.04 m. Determine the velocity at the exit in m/s.

C) Water vapor enters an insulated nozzle operating at steady state at 500°C, 50 bar, with a velocity of 112 m/s, and exits at 400°C, 25 bar. Determine the velocity at the exit, in m/s?

D) Steam enters a nozzle operating at steady state at 20 bar, 262°C, with a velocity of 41 m/s. The exit pressure and temperature are 8 bar and 161°C, respectively. The mass flow rate is 1.1 kg/s. Neglecting heat transfer and potential energy, determine the inlet area in cm².

E) Refrigerant 134a enters a horizontal pipe operating at steady state at 50°C, 450 kPa and a velocity of 23.2 m/s. At the exit, the temperature is 60 °C and the pressure is 220 kPa. The pipe diameter is 0.02 m. Determine the rate of heat transfer between the pipe and its surroundings, in kW.

Answer 1

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