QUESTION $1(27$ Marks$)$

$1\mathrm{.}1.$An absorption type refrigerator of $25$ R papacity is operating with generator, condenser,

absorber$,$ and evaporator temperatures of $90C,48C,34C$ and $-16C$ respectively. $100\%$ pure

ammonia saturated vapour at $48C$ leaves the generator. The ammonia concentration in solution at

the absorber exit is $0\mathrm{.}42$ with an enthalpy of $26\mathrm{.}7k\frac{J}{k}g$ while, at generator exit the concentration

weak solution is $0\mathrm{.}13$ with an enthalpy of $758k\frac{J}{k}g.$ Draw a diagram for this refrigerator and

determine the mass flow rate of ammonia in the evaporator and the mass flow rates of the week and

strong solutions. What amounts of heat is rejected from the absorber and condenser and added in the

generator?

$1\mathrm{.}2.$ Compare the COP of the above refrigerator with the maximum COP achievable for the same

operating temperatures.