$5($d$)\_$#$2$: A vapor$-$compression refrigeration system circulates Refrigerant $22$ at a rate of $12$lb$/$min$.$ The refrigerant enters the compressor at $-40$ oF$,15$ lbf$/$in$^2,$ and exits at $80$ lbf$/$in$^2.$ The isentropic compressor efficiency is $67\%.$ There are no appreciable pressure drops as the refrigerant flows through the condenser and evaporator. The refrigerant leaves the condenser at $80$ lbf$/$in$^2,30$ oF$.$ Ignoring heat transfer between the compressor and its surroundings, determine

a$)$ the compressor power, in Btu$/$min$,$ and the refrigeration capacity, in tons. Ans: $(4\mathrm{.}89$ tons$)$

b$)$ the coefficient of performance. Ans: $(3\mathrm{.}1)$

c$)$ draw a T$-$s diagram of the cycle