# B how many watts would be delivered if the element is

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Unformatted text preview: would be delivered if the element is supplied with 208 V instead of 240 V? c. Neglecting any losses from the tank, how long would it take for 4800 W to heat the 52 gallons of water from 60◦ F to 120◦ F? The conversion between kilowatts of electricity and Btu/hr of heat is given by 3412 Btu/hr = 1 kW. Also, one Btu heats 1 lb of water by 1◦ F and 1 gallon of water weighs 8.34 lbs. 3. (Masters 3.4) A combined-cycle, natural-gas, power plant has an efficiency of 52%. Natural gas has an energy density of 55,340 kJ/kg and about 77% of the fuel is carbon. a. What is the heat rate of this plant expressed as kJ/kWh and Btu/kWh? b. Find the emission rate of carbon (kgC/kWh) and carbon dioxide (kgCO2/kWh). 4. (Masters 3.5) A new coal-fired power plant with a heat rate of 9000 Btu/kWh burns coal with an energy content of 24,000 kJ/kg. The coal content includes 62% carbon, 2% sulfur and 10% unburnable minerals called ash. a. What will be the carbon emission rate (g C/kWh)? b. What will...
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## This document was uploaded on 03/25/2014.

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