A) Liquid sodium flowing a 100 kg/s, enters a heat exchanger at 450 C and exits at 350 C. The specific heat of sodium is 1.25 kJ/kg.K. Water enters at 5000 kPa and 20 C.
Determine the minimum mass flow rate (kg/s) of the water so that the water not completley vaporize. Neglect the pressure drop through the exchanger and assume a saturated vapor state for the exiting steam to obtain the maximum allowable exiting enthlapy. Also, calculate the rate of heat transfer (kW) to the water.
b) A family has a natural hot spring on their property. They wish to use the hot groundwater to power heat engine and generate electricity. If the groundwater is 95 C and a mass flow rate of 0.2 kg/s is possible, estimate the maximum power output (kW). you may assume a constant specific heat for water during the process.