eml 3100 efficiencies 2

eml 3100 efficiencies 2 - Thermodynamics Efficiencies A...

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1 Thermodynamics Efficiencies A boiler consumes 400 therms of natural gas per hour (1 therm of natural gas = 100,000 btu lower heating value). This boiler generates 33,000 pounds per hour of steam. The make-up water to the boiler is liquid water at 100 psia and 190 deg F. The steam leaves as superheated vapor, 100 psia and 400 deg F.
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2 Thermodynamics Steam Output Natural Gas Input Make-up water Input Gas Fired Steam Boiler Exhaust Gases Out Heat Losses from Boiler Casing
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3 Thermodynamics input gas of value heating h h m steam steam _ _ _ _ ) ( 1 2 - = η Efficiencies What is the efficiency of the boiler? η = output/input 88 . 0 000 , 100 * 400 ) 03 . 158 5 . 1227 ( 000 , 33 = - = or 88%
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4 Thermodynamics Efficiencies An air conditioner provides cooling for a three bedroom house with an area of 1500 sq. ft. This requires 3 tons of cooling. A ton of cooling is equivalent to 12,000 btu/h heat extraction. This air conditioner consumes electricity at the rate of 2.7kW when providing this cooling. What is the COP for this unit?
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5 Thermodynamics Condensing unit (compressor, condenser and controls) Air Handling Unit (blower and cooling coil) Refrigerant Piping Electrical Input Cooling Effect Cool, Dry Air Warm, moist air Heat and Moisture Gains to the Home Heat Rejection 98 deg F 75 deg F
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Thermodynamics kWh btu kW hton
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This note was uploaded on 08/03/2011 for the course EML 3100 taught by Professor Sherif during the Summer '08 term at University of Florida.

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eml 3100 efficiencies 2 - Thermodynamics Efficiencies A...

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