REVERSED CARNOT AND PRODUCT LOAD CALCULATION

Описание: Problems:
What is the coefficient of performance of a reversed Carnot engine operating between -12ºF and -182ºF?
A refrigeration system operates in a reversed Carnot cycle, with a refrigerant higher temperature of 60ºC, COP of 4 and a capacity of 52 tons. Determine the change in entropy.
A Carnot refrigerator absorbs heat at -15ºC and rejects heat at 40ºC. Calculate:
COP
If the cycle is absorbing 15 kW at -15ºC, how much work input is required?
If a Carnot heat pump operate at the same temperature limits as Carnot refrigerator, what is the COP?
What is the rate of heat rejection at 40ºC if the heat absorbed is 15 kW?
A refrigeration system is designed have a capacity of 120 tons. Its actual COP is 6 and 30% of the power supplied to the compressor is lost in the form of friction. Determine the motor power in kW.
Find the tons of refrigeration needed to convert 1 metric ton of water at 50ºC to ice at -20ºC in one day.
Find the tons of refrigeration required to transform water at 40ºF to ice at -10ºF in 36 hrs if the mass of water is 2 tons. Assume 20% losses for the chilling and freezing load.
Nestle Fresh Milk plant must cool 4000 gallons of fresh milk received from the farm from an initial temperature of 80ºF to a temperature of 40ºF in 5 hrs. If the density of milk is 8.6 lb/gal, specific gravity is 1.03 and specific heat is 0.935 Btu/lb-R, how much brine must be circulated, if the change in temperature of brine is 15ºF, sg=1.182 and cp=0.72 BTU/lb-R?
Fish weighing 11,000 kg with a temperature of 20ºC is brought to a cold storage and which shall be cooled to -10ºC in 11 hours. Find the required plant refrigerating capacity in tons of refrigeration if the specific heat of fish is 0.7 kcal/kg-ºC above freezing point and 0.3 kcal/kg-ºC below freezing point which is -3ºC. The latent heat of freezing is 55.5 kcal/kg.