A pump in a chilled water system draws 8 kW to pump of 15 kg/s of water at 5 C through a system. The pressure entering the pump is 250 kPa absolute and that leaving is 700 kPa absolute. Determine the pump efficiency and the temperature rise of the water through the pump.

Estimate the change in specific internal energy au and specific enthalpy h from inlet to outlet for ethylene glycol (a liquid) flowing through each of the following devices: (a) a heat exchanger where the glycol temperature increases from 20 °c to 80 °c; (b) a pump operating at about 25 °c and increasing the glycol pressure from 100 kpa to 8 mpa.