Problem # p018

Efficiency, fuel and cooling water needs of a power plant

A 600 MW power plant has an efficiency (benefits/costs) of 0.41.
  1. It is cooled by a nearby river. The cooling water enters the plant with a temperature of 20 °C and is returned to the river at 23 °C. How much water [kg or tons] per second do we need ?
    At these temperatures the specific heat of water is c=4.22 kJ/(kg K)
  2. Heat is supplied by burning coal. How many trains of coal do we need daily ? Assume that each train has 20 cars , each car carries 100 tons of coal and each kg of coal produces 20 MJ (average value for coal) of heat. Please, write out the equation you use to get to your answer.
Note : 1 ton = 1000 kg  ;  1 MW = 1000 kJ/s