The Water System


The pressure of a city's main water line is much higher than the pressure in the water line of apartments. It is suggested that a hydraulic turbine be installed to utilize the water pressure to run an electric motor which can be supplied to the lighting system of the apartments. Is the power generated by the turbine enough to light the apartments?

What is known:

  • Water at room temperature ( 300 K) enters the turbine at P1 = 750 kPa
  • Water at at room temperature ( 300 K) leaves the turbine at P2 = 170 kPa
  • One apartment uses 10,000 kg water per hour
  • Each apartment needs 500 W power for illumination

  Determine the power that could be produced by this hydraulic turbine.

Control Volume


Consider the turbine as a control volume. It is a one-inlet-one-exit system. The flow is steady. The energy balance is: