Question 11.CSGP.180c: Consider an ideal refrigeration cycle that has a condenser t......

Fundamentals of Thermodynamics – Solution Manual [1477300]

Consider an ideal refrigeration cycle that has a condenser temperature of 45°C and an evaporator temperature of −15°C. Determine the coefficient of performance of this refrigerator for the working fluid R-22.

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Ideal refrigeration cycle

$\begin{aligned}T _{\text {cond }} & =45^{\circ} C = T _3 \\T _{\text {evap }} & =-15^{\circ} C = T _1\end{aligned}$

The value of $h_2$ is taken from the computer program as it otherwise will be a double interpolation due to the value of $P_2$ .

R-22	Property for:
244.13	$h _1, kJ / kg$	Compressor
0.9505	$s _2= s _1, kJ / kg K$
1.729	$P _2, MPa$
74.4	$T _2,{ }^{\circ} C$
289.26	$h _2, kJ / kg$
45.13	$w _{ C }= h _2- h _1$
100.98	$h _3= h _4, kJ / kg$	Exp. valve
143.15	$q _{ L }= h _1- h _4$	Evaporator
3.172	$\beta= q _{ L } / w _{ C }$

102

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