Fill an empty bottle with R-134a

[stoky]

Homework Statement

We want to fill a bottle with R-134a. The fluid comes from a fluid line.

1. The bottle is initially empty, the bottle volume is 12 litres, the bottle is insulated (adiabatic filling).
2. The fluid line contains R-134a at 20 bar, saturated steam.

Homework Equations

Using the second equation of energy balance.

The Attempt at a Solution

From the bottle perspective:
Qcv=0
Wcv=0
dEcv/dt=m•ui
me=0
hi=428.2 kJ/Kg

Then:
mi•ui=mi•hi
Then
ui=428.2 kJ/Kg
Which reading R134a tables results in superheated steam: P2=2000 kPa, u2=428.2 kJ/Kg.

Results in m2 (bottle)=1.11 Kg
Specific volume=0.01081 m^3/Kg
Temperature=83.18 celsius

My concern is if the calculations are correct.

 

[Chestermiller]

Homework Statement

We want to fill a bottle with R-134a. The fluid comes from a fluid line.

1. The bottle is initially empty, the bottle volume is 12 litres, the bottle is insulated (adiabatic filling).
2. The fluid line contains R-134a at 20 bar, saturated steam.

Homework Equations

View attachment 235368
Using the second equation of energy balance.

The Attempt at a Solution

From the bottle perspective:
Qcv=0
Wcv=0
dEcv/dt=m•ui
me=0
hi=428.2 kJ/Kg

Then:
mi•ui=mi•hi
Then
ui=428.2 kJ/Kg
Which reading R134a tables results in superheated steam: P2=2000 kPa, u2=428.2 kJ/Kg.

Results in m2 (bottle)=1.11 Kg
Specific volume=0.01081 m^3/Kg
Temperature=83.18 celsius

My concern is if the calculations are correct.

I'm not sure whether you did it right or not because your notation is all screwy. The differential equation should be
$$\frac{dE_{dv}}{dt}=\dot{m}_i h_i$$
so that $$u_{final}=h_i$$
If that's what you did, then it is correct.