Problem#$2$

A simple ideal vapor$-$compression refrigeration cycle has working temperatures of $-25C$ and $40C.$ If it operates with R$134$a as a working fluid:

$1-$ Plot the cycle on the T$-$s diagram.

$2-$ Plot the cycle on the P$-$h diagram, and calculate:

$3-$ the work of isentropic compression and

$4-$ refrigeration effect,

$5-$ heat rejected per kg of refrigerant, and

$6-$ COP.

Problem#$3$

An ideal vapor$-$compression cycle developing $50$ kW of refrigeration using R $22$ operates with a condensing temperature of $35C$ and an evaporating temperature of $-10C.$ Calculate:

$($a$)$ the refrigerating effect in kilojoules per kilogram,

$($b$)$ the circulation rate of refrigerant in kilograms per second,

$($c$)$ the power required by the compressor in kilowatts,

$($d$)$ the coefficient of performance,

$($e$)$ the volume flow rate measured at the compressor suction,

$($f$)$ the power per kilowatt of refrigeration, and

$($g$)$ the compressor discharge temperature.