2. Reference 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_5.svg

eq 2.1.1-1

[R7.01.11 éq 3.2.1-2] then give:

_images/Object_6.svg

Eq 2.1.1-2

We write that the total mass of water is preserved (because there is no water flow at the edge) and we get:

_images/Object_7.svg

Eq 2.1.1-3

[R7.01.11 éq 4.4-1] also gives

_images/Object_8.svg

Eq 2.1.1-4

The coupling of equations [éq 2.1.1-3] and [éq 2.1.1-4], to which must be added the ideal gas equation for steam, is a highly non-linear system that we will solve in a small disturbance, which allows it to be linearized.

All calculations done, we get:

_images/Object_9.svg

Eq 2.1.1-5

2.1.2. Temperature calculation#

[R7.01.11 éq 3.2.4.3-1] gives:

_images/Object_10.svg

Eq 2.1.2-1

(since the other expansion coefficients are zero).

[éq 3.2.4.3-2] gives:

_images/Object_11.svg

eq 2.1.2-2

So we get:

_images/Object_12.svg

Eq 2.1.2-3

In this problem,

_images/Object_13.svg

is nothing but the heat provided per unit volume.

By calling

_images/Object_14.svg

the total volume of the room and

_images/Object_15.svg

its lateral surface and

_images/Object_16.svg

the application time of the flows:

_images/Object_17.svg

Eq 2.1.2-4

2.1.3. System to be solved#

_images/Object_18.svg

Eq 2.1.3-1

2.2. Benchmark results#

We give the value of the temperature, liquid pressure and vapor pressure, solution of the system [éq 2.1.3-1] with the data summarized in paragraphs [§1.2] and recalled below. To calculate the calorific capacities, the following relationships are used:

_images/Object_19.svg _images/Object_20.svg _images/Object_21.svg

, the latter relationship being true because the grain expansion coefficient is zero.

_images/Object_22.svg _images/Object_23.svg _images/Object_24.svg _images/Object_25.svg _images/Object_26.svg _images/Object_27.svg

(calculated)

_images/Object_28.svg

5,00E-01

-1,00E-12

3,00E+02

3,70E+03

2.50E+06

2,67E-02

1.00E+03

_images/Object_29.svg _images/Object_30.svg _images/Object_31.svg

(calculated)

_images/Object_32.svg _images/Object_33.svg

l

_images/Object_34.svg _images/Object_35.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_36.svg _images/Object_37.svg _images/Object_38.svg _images/Object_39.svg

1.00E+06

1000

400

1.00E+04

After resolution, the following results are obtained:

_images/Object_40.svg

3.E+03

_images/Object_41.svg

-1E+07

_images/Object_42.svg

14

2.3. Uncertainties#

The uncertainties are quite large because the analytical solution is an approximate solution due to the linearization of the equations.