A refrigeration system cools a brine stream (Cp = 3.6 kJ. kg-1.K -1 ) from 25 C to -20 C at a rate of 18 kg. s -1 . Heat is discarded to the atmosphere at a temperature of 32 C. What is the power requirement (= real work) if the thermodynamic efficiency of the system is 30%?

Adouble-strand no. 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and a 52-tooth driven sprocket. a) what is the allowable horsepower of this drive? b) estimate the center-to-center distance if the chain length is 82 pitches. c) estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power.