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:

_images/Object_7.svg

eq 2.1.1-1

The equation [éq 2.2.3.3-2] from the reference document [R7.01.11] then gives:

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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:

_images/Object_9.svg _images/Object_10.svg

Eq 2.1.1-3

_images/Object_11.svg _images/Object_12.svg

Eq 2.1.1-4

[R7.01.11] [éq 4.1.4-1] also gives:

_images/Object_13.svg

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:

_images/Object_14.svg

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:

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Eq 2.1.2-1

(since the other expansion coefficients are zero).

Equation [éq 3.2.4.3-2] gives:

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eq 2.1.2-2

So we get:

_images/Object_17.svg

Eq 2.1.2-3

In this problem,

_images/Object_18.svg

is nothing but the heat provided per unit volume.

By calling

_images/Object_19.svg

the total volume of the room and

_images/Object_20.svg

its lateral surface and

_images/Object_21.svg

the application time of the flows:

_images/Object_22.svg

Eq 2.1.2-4

2.1.3. System to be solved#

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Eq 2.1.3-1

_images/Object_24.svg _images/Object_25.svg _images/Object_26.svg _images/Object_27.svg _images/Object_28.svg _images/Object_29.svg

(calculated)

_images/Object_30.svg

5,00E-01

-1,00E-12

3,00E+02

3,70E+03

2.50E+06

2,67E-02

1.00E+03

_images/Object_31.svg _images/Object_32.svg _images/Object_33.svg

(calculated)

_images/Object_34.svg _images/Object_35.svg

l

_images/Object_36.svg _images/Object_37.svg

(calculated)

2.20E+03

3,00E-01

2,93E+03

1.05E+03

4,18E+03

1.90E+03

2.78E+06

_images/Object_38.svg _images/Object_39.svg _images/Object_40.svg _images/Object_41.svg

1.00E+06

10

6,00E+04

1.00E+06

The following results are obtained:

After solving this system, we obtain:

_images/Object_42.svg

This gives in terms of Aster result (increment):

\(\mathrm{PRE1}\)

\(\mathrm{PRE2}\)

\(\mathrm{DT}\)

\(\mathrm{PVP}\) (\(\mathrm{V3}\))

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.