Answer:
Part a: <em>The temperature of the mixture at 160kPA is 257.68K.</em>
Part b<em>:The specific enthalpy of the mixture as it exits the system is 237.97 kJ/kg.</em>
Part c:<em>The entropy change for the mixture is 0.6999kJ/K</em>
Part d: <em>The total entropy change is 0.027 kJ/K</em>
Explanation:
Part a
The temperature is as viewed from the the table of Saturated properties for the Refrigerant 134a for Pressure of 160kPa.
![T_{sat\rightarrow 160kPa}=-15.62^o C\\T_{sat\rightarrow 160kPa}=-15.62+273K\\T_{sat\rightarrow 160kPa}=-15.62^o C\,\, or \,\, 257.28 K](https://tex.z-dn.net/?f=T_%7Bsat%5Crightarrow%20160kPa%7D%3D-15.62%5Eo%20C%5C%5CT_%7Bsat%5Crightarrow%20160kPa%7D%3D-15.62%2B273K%5C%5CT_%7Bsat%5Crightarrow%20160kPa%7D%3D-15.62%5Eo%20C%5C%2C%5C%2C%20or%20%5C%2C%5C%2C%20257.28%20K)
<em>The temperature of the mixture at 160kPA is 257.68K</em>
Part b
For specific enthalpy from the same table of Saturated properties for the Refrigerant 134a for Pressure of 160kPa for the vapour phase which is given as
![h_g=237.97 kJ/kg](https://tex.z-dn.net/?f=h_g%3D237.97%20kJ%2Fkg)
<em>The specific enthalpy of the mixture as it exits the system is 237.97 kJ/kg.</em>
Part c
The entropy change for the mixture is given as
![s=\frac{\Delta Q}{T}](https://tex.z-dn.net/?f=s%3D%5Cfrac%7B%5CDelta%20Q%7D%7BT%7D)
Here
ΔQ is the heat in which is given as 180kJ
T is the temperature of the mixture which is calculated in part a as 257.28K
so the equation becomes.
![s_1=\frac{Q_{in}}{T}\\s_1=\frac{180 kJ}{257.28K}\\s_1=0.6999 kJ/K](https://tex.z-dn.net/?f=s_1%3D%5Cfrac%7BQ_%7Bin%7D%7D%7BT%7D%5C%5Cs_1%3D%5Cfrac%7B180%20kJ%7D%7B257.28K%7D%5C%5Cs_1%3D0.6999%20kJ%2FK)
<em>The entropy change for the mixture is 0.6999kJ/K</em>
Part d
For overall entropy change, the entropy change in the cooled space is also to be calculated such that
Q is the heat in which is given as 180kJ
T is the temperature of the cooled space which is given as -5°C or 268K
so the equation becomes.
![s_2=-\frac{ Qout}{T}\\s_2=-\frac{180 kJ}{268K}\\s_2=-0.672 kJ/K](https://tex.z-dn.net/?f=s_2%3D-%5Cfrac%7B%20Qout%7D%7BT%7D%5C%5Cs_2%3D-%5Cfrac%7B180%20kJ%7D%7B268K%7D%5C%5Cs_2%3D-0.672%20kJ%2FK)
So the total entropy change is
![\Delta s=\Delta s_1+\Delta s_2\\\Delta s_{gen} =0.699-0.672\\\Delta s_{gen} =0.027 kJ/K](https://tex.z-dn.net/?f=%5CDelta%20s%3D%5CDelta%20s_1%2B%5CDelta%20s_2%5C%5C%5CDelta%20s_%7Bgen%7D%20%3D0.699-0.672%5C%5C%5CDelta%20s_%7Bgen%7D%20%3D0.027%20kJ%2FK)
<em>The total entropy change is 0.027 kJ/K</em>