2. Benchmark solution#
2.1. Calculation method#
2.1.1. Calculating vapour pressure from temperature#
We assume the linear saturation curve. So it is written:
eq 2.1.1-1
The equation [éq 2.2.3.3-2] from the reference document [R7.01.11] then gives:
Eq 2.1.1-2
We write that the total mass of water and the total mass of air are preserved (because there is no water or gas flow at the edge) and we get:
Eq 2.1.1-3
Eq 2.1.1-4
[R7.01.11] [éq 4.1.4-1] also gives:
Eq 2.1.1-5
The coupling of equations [éq 2.1.1-3], [éq 2.1.1-4] and [éq 2.1.1-5], to which must be added the ideal gas equation for steam, dry air and dissolved air as well as Henry’s law is a highly non-linear system that we will solve in small disturbances, which allows it to be linearized.
All calculations done, we get:
Eq 2.1.1-6
2.1.2. Temperature calculation#
Equation [éq 3.2.4.3-1] from the reference document [R7.01.11] gives:
Eq 2.1.2-1
(since the other expansion coefficients are zero).
Equation [éq 3.2.4.3-2] gives:
eq 2.1.2-2
So we get:
Eq 2.1.2-3
In this problem,
is nothing but the heat provided per unit volume.
By calling
the total volume of the room and
its lateral surface and
the application time of the flows:
Eq 2.1.2-4
2.1.3. System to be solved#
Eq 2.1.3-1
(calculated) |
||||||
5,00E-01 |
-1,00E-12 |
3,00E+02 |
3,70E+03 |
2.50E+06 |
2,67E-02 |
1.00E+03 |
(calculated) |
l |
(calculated) |
||||
2.20E+03 |
3,00E-01 |
2,93E+03 |
1.05E+03 |
4,18E+03 |
1.90E+03 |
2.78E+06 |
1.00E+06 |
10 |
6,00E+04 |
1.00E+06 |
The following results are obtained:
After solving this system, we obtain:
This gives in terms of Aster result (increment):
\(\mathrm{PRE1}\) |
|
|
|
1.49E5 |
113 |
0.216 |
44 |
2.2. Uncertainties#
The uncertainties are quite large because the analytical solution is an approximate solution due to the linearization of the equations.