A Carnot heat engine receives heat from a reservoir at 1700 degrees Farenheit at a rate of 700 Btu/min and rejects the waste heat to the ambient air at 80 degrees Farenheit. The entire work output of the heat engine is used to drive a refrigerator that removes heat from the refrigerated space at 20 degrees Farenheit and transfers it to the same ambient air at 80 degrees Farenheit. Determine:
a) the maximum rate of heat removal from the refrigerated space
b) the total rate of heat rejection to the ambient air
a) 4200 Btu/min
b) 4900 Btu/min
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Calculating Temperature, Water Evaporation, and Heat in a Power Plant Cooling Situation
In a nuclear power plant the cooling tower system must be run on a closed cycle. That is, the air exiting the tower passes over cooling coils to return it to its initial condition prior to reentering the tower. Air at 20 degrees C and 40% relative humidity enters the tower at a rate of 1.3 x 106 kg/sec. Water enters the tower at 50C and leaves at 25C. The water flow rate is 750,000 kg/sec. Saturated air exists the tower and passes over cooling coils which returns it to 20C and 40% relative humidity. Water at 22C condenses out of the air. Determine:
A) The temperature of air leaving the tower
B) Amount of water evaporating in kg/sec.
C) The heat removed by the cooling coils in kW