Unformatted text preview: 1. A 1000-MW electric power plant has an efFciency of 33 percent with 15 percent waste heat being released to the atmosphere as stack heat and the other 85% taken away in cooling water drawn from a nearby river (used to cool and condense down the hot steam exiting the generator turbines). To eliminate heating the bodies of water surrounding the power plant, the evaporation of the coolant water is what cools the steam; the water vapor generated by this evaporation is released to the atmosphere. At what rate must we supply 15°C water from the river to make up for the water lost by evaporation in the ? 2. Suppose the total world energy consumption of fossil fuels, equal to 3 × 10 17 kJ/yr, were to be obtained entirely by combustion of petroleum with the approximate chemical formula C 2 H 3 . Combustion of this petroleum releases about 43 × 10 3 kJ/kg. a. Estimate the emissions of carbon dioxide per year....
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- Fall '08
- percent waste heat, stack heat