thermal modelling for the implementation of an energetic ...€¦ · thermal modelling for the...

Thermal modelling for the implementation of an energetic efficiency control system in a room of

meetings of singular geometry

Manuel José Martínez B.Instituto Tecnológico de la Energía

Presented at the COMSOL Conference 2010 Paris

http://www.comsol.com/conf_cd_2011_eu

Introduction & objectives

• Introduction & objectives.

• Construction details.

• Irradiance data.

• Simulation scenarios.

• Irradiance curve fitting.

• Restrictions and b. c. approach.

• Finite Element mesh.

• Results.

• Conclusions

0

5

10

15

20

25

30

35

Modelling thermal losses

LIMITS of the main variables: temperature,

speed of inlet air

Number of persons

Irradiance (W/m2)

Information to control system

Energy savings

Introduction & objectives

Collect irradiance data from weather station for 1 year.

Fit the irradiance data to a mathematical model.

Approach the Finite Element model and impose the corresponding boundary conditions.

Estimate the spatial and temporary temperature evolution of the model and analize different scenarios.








• Results.

• Conclusions

Enclosure construction details

Enclosure features

9.55 m

2.60

m

13.5 m

N

SE

W

9.55 m

2.60

m

13.5 m

N

SE

W

Enclosure volume: 118.46 m3








• Results.

• Conclusions


Enclosure features

9.55 m

2.60

m

13.5 m

N

SE

W

9.55 m

2.60

m

13.5 m

N

SE

W

glass windows (1 cm. thickness)

brick wall

concrete ceiling

concrete floor









• Results.

• Conclusions


Enclosure features and sun trajectory

9.55 m

2.60

m

13.5 m

N

SE

W

9.55 m

2.60

m

13.5 m

N

SE

W

glass windows (1 cm. thickness)

brick wall

concrete ceiling

concrete floor

sun trajectory

6.00 am8.30 am

2.00 pm3.00 pm

8.30 pm5.30 pm









• Results.

• Conclusions

Irradiance data

Irradiance data from weather station• Introduction & objectives.







• Results.

• Conclusions

Irradiance data

Irradiance data from weather station

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

9 10 11 12 13 14 15 16 17 18 19

IRR

AD

IAN

CE

(W/m

2)

Summer irradiance








• Results.

• Conclusions

Irradiance data


0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

9 10 11 12 13 14 15 16 17 18 19

IRR

AD

IAN

CE

(W/m

2)

Summer irradiance

West facade

East facade








• Results.

• Conclusions

Irradiance data


0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

9 10 11 12 13 14 15 16 17 18 19

IRR

AD

IAN

CE

(W/m

2)

Summer irradiance

Winter irradiance

West facade

East facade

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

9 10 11 12 13 14 15 16 17 18 19

IRR

AD

IAN

CE

(W/m

2)

West facade

East facade








• Results.

• Conclusions

Simulation scenarios

Modelling taking into account:• Introduction & objectives.







• Results.

• Conclusions


Modelling taking into account:• Time of the day

• Morning (9.00 am to 12.00 m)

• Noon (12.00 m to 4.00 pm)

• Later (4.00 pm to 7.00 pm)








• Results.

• Conclusions




• Noon (12.00 m to 4.00 pm)

• Later (4.00 pm to 7.00 pm)

• Weather season

• Summer

• Winter








• Results.

• Conclusions




• Noon (12.00 m to 4.00 pm)

• Later (4.00 pm to 7.00 pm)

• Weather season

• Summer

• Winter

• Existence or not of air conditioning

• Number of persons

• 1,2,5 and 10 persons.








• Results.

• Conclusions

Irradiance curve fitting








• Results.

• Conclusions


Mathematical model fitted to the initial data in order to be introduced in Comsol.Polynomial curves.








• Results.

• Conclusions


Mathematical model fitted to the initial data in order to be introduced in Comsol.Polynomial curves.Summer irradiance

East facade5 9 3 8 7 6 5 4

3 2

5.74 10 2.11 10 0.027 0.13 0.0894 2.817811.4836 19.675 68.0458 106.835

x x x x x xx x x

− −⋅ − ⋅ + − − +

− + + +

West facade4 9 8 7 6 5 4

3 2

2.467 10 0.0115 0.219 2.146 11.227 28.55318.761 44.859 38.910 23.081

x x x x x xx x x

−⋅ − + − + −

+ + + +








• Results.

• Conclusions


Mathematical model fitted to the initial data in order to be introduced in Comsol.Polynomial curves.Summer irradiance

East facade5 9 3 8 7 6 5 4

3 2

5.74 10 2.11 10 0.027 0.13 0.0894 2.817811.4836 19.675 68.0458 106.835

x x x x x xx x x

− −⋅ − ⋅ + − − +

− + + +

West facade4 9 8 7 6 5 4

3 2

2.467 10 0.0115 0.219 2.146 11.227 28.55318.761 44.859 38.910 23.081

x x x x x xx x x

−⋅ − + − + −

+ + + +( )

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

9 10 11 12 13 14 15 16 17 18 19

IRR

AD

IAN

CE

(W/m

2)

West facade

East facade








• Results.

• Conclusions

( )

0.00

100.00

200.00

300.00

400.00

500.00

600.00

700.00

9 10 11 12 13 14 15 16 17 18 19

IRR

AD

IAN

CE

(W/m

2)


Mathematical model fitted to the initial data in order to be introduced in Comsol.Polynomial curves.Winter irradiance

East facade

West facade

West facade

East facade

4 9 8 7 6 5 4

3 2

1.598 10 0.008 0.177 1.965 11.912 36.57133.981 54.017 23.841 14.832

x x x x x xx x x

−⋅ − + − + −

+ + + −

5 9 4 8 7 6 5 4

3 2

6.39 10 8.99 10 0.026 0.762 6.463 24.77230.239 37.999 5.974 30.031

x x x x x xx x x

− −− ⋅ + ⋅ + − + −

+ + − −








• Results.

• Conclusions

Restrictions and boundary conditions approach

Comsol approach

• Heat transfer module (3D)• Fluid-thermal interaction

• Turbulent Non-isothermal Flow, k - ε

• General heat transfer (htgh)

• k - ε

Turbulence Model (chns)








• Results.

• Conclusions


Comsol approach

• Subdomain settings, (chns and htgh)








• Results.

• Conclusions


Comsol approach


Air (library material)rho (p0[1/Pa], Tf[1/K]) [kg/m3] (density)eta (Tf[1/K]) [Pa·s] (dynamic viscosity)








• Results.

• Conclusions


Comsol approach


Air (library material)rho (p0[1/Pa], Tf[1/K]) [kg/m3] (density)eta (Tf[1/K]) [Pa·s] (dynamic viscosity)

chnsStabilization

htghConvectionInit. Value Tf(t0 )








• Results.

• Conclusions


Comsol approach

• Boundary settings, chns

Boundary type:Inlet

Boundary cond.:VelocityU0 , LT , IT








• Results.

• Conclusions


Comsol approach

• Boundary settings, chns

Boundary type:Inlet

Boundary cond.:VelocityU0 , LT , IT

Boundary type:Outlet

Boundary cond.:Pressure, P0








• Results.

• Conclusions


Comsol approach

• Boundary settings, htgh








• Results.

• Conclusions


Comsol approach


Boundary cond.:Heat fluxq0 = fitted curves








• Results.

• Conclusions


Comsol approach



Boundary cond.:Temperature, T0

Boundary cond.:Convective flux








• Results.

• Conclusions


Comsol approach



Boundary cond.:Temperature, T0

Boundary cond.:

q0 , T0

Boundary cond.:

Convective flux








• Results.

• Conclusions


Comsol approach

• Differential equations

( ) ( ) ( )ρu ρv ρwρt x y z

∂ ∂ ∂∂+ + +

∂ ∂ ∂ ∂

22 u3

Tx x

p uρa ρF μ ζ μx x xu v u wμ μ

y y x z z x

∂ ∂ ∂⎛ ⎞⎛ ⎞= − + + − ∇ +⎜ ⎟⎜ ⎟∂ ∂ ∂ ⎝ ⎠⎝ ⎠⎛ ⎞∂ ∂ ∂ ∂ ∂ ∂⎛ ⎞ ⎛ ⎞⎛ ⎞+ + +⎜ ⎟⎜ ⎟⎜ ⎟⎜ ⎟∂ ∂ ∂ ∂ ∂ ∂⎝ ⎠⎝ ⎠⎝ ⎠⎝ ⎠

22 u3

Ty y

p vρa ρF μ ζ μy y y

v w v uμ μz z y x x y

∂ ∂ ∂⎛ ⎞⎛ ⎞= − + + − ∇ +⎜ ⎟⎜ ⎟∂ ∂ ∂ ⎝ ⎠⎝ ⎠⎛ ⎞ ⎛ ⎞∂ ∂ ∂ ∂ ∂ ∂⎛ ⎞ ⎛ ⎞+ + +⎜ ⎟ ⎜ ⎟⎜ ⎟ ⎜ ⎟∂ ∂ ∂ ∂ ∂ ∂⎝ ⎠ ⎝ ⎠⎝ ⎠ ⎝ ⎠

22 u3

Tz z

p wρa ρF μ ζ μz z zw u w vμ μ

x x z y y z

∂ ∂ ∂⎛ ⎞⎛ ⎞= − + + − ∇ +⎜ ⎟⎜ ⎟∂ ∂ ∂ ⎝ ⎠⎝ ⎠⎛ ⎞∂ ∂ ∂ ∂ ∂ ∂⎛ ⎞⎛ ⎞⎛ ⎞+ + +⎜ ⎟⎜ ⎟ ⎜ ⎟⎜ ⎟∂ ∂ ∂ ∂ ∂ ∂⎝ ⎠⎝ ⎠ ⎝ ⎠⎝ ⎠

( ) ( ) ( ) ( )2 2 2

Td r

T T T Qk k k qx x y y z z t

ρ D DEρu ρv ρw u v w ρx y z Dt Dt

∂ ∂ ∂ ∂ ∂ ∂ ∂⎛ ⎞⎛ ⎞ ⎛ ⎞+ + + +Φ −∇ =⎜ ⎟ ⎜ ⎟⎜ ⎟∂ ∂ ∂ ∂ ∂ ∂ ∂⎝ ⎠ ⎝ ⎠⎝ ⎠∂ ∂ ∂

+ + + + + +∂ ∂ ∂ 2








• Results.

• Conclusions

Finite Element mesh

Enclosure’s Finite Elements mesh

Tetrahedral elements60883 elements99069 dof








• Results.

• Conclusions

Results. Experimental validation

Temperature comparissons at reference points.• Introduction & objectives.







• Results.

• Conclusions


Temperature comparissons at reference points.

13.5 m

9.55 m

6.75 m

N

S

E W

145 6 7

89 10

13.5 m

9.55 m

6.75 m

N

S

E W

145 6 7

89 10








• Results.

• Conclusions



13.5 m

9.55 m

6.75 m

N

S

E W

145 6 7

89 10

13.5 m

9.55 m

6.75 m

N

S

E W

145 6 7

89 10

280

285

290

295

300

305

9 10 11 12 13 14 15 16 17 18 19

TIME

TEM

PER

ATU

RE

(K

point 10

experimental

FEM








• Results.

• Conclusions



13.5 m

9.55 m

6.75 m

N

S

E W

145 6 7

89 10

13.5 m

9.55 m

6.75 m

N

S

E W

145 6 7

89 10

280

285

290

295

300

305

9 10 11 12 13 14 15 16 17 18 19

TIME

TEM

PER

ATU

RE

(K

280

285

290

295

300

305

9 10 11 12 13 14 15 16 17 18 19

TIME

TEM

PER

ATU

RE

(K

point 7

point 10

Good approximation between experimental results and FEM

experimental

FEM

experimentalFEM








• Results.

• Conclusions

Results. Temperature evolution

Temperature distribution of the enclosure. Ten people








• Results.

• Conclusions


Temperature evolution. Summer.• Introduction & objectives.







• Results.

• Conclusions


Temperature evolution. Summer.

Air conditioning








• Results.

• Conclusions



Air conditioning

0 people 10 people

No air conditioning








• Results.

• Conclusions



Air conditioning

0 people 10 people

No air conditioning

• Enclosure’s temperature 10 people > enclosure’s temp. 0 people• The trend of the temperature evolution is similar to the irradiance curve.• With air conditioning the temperature remains within the comfort range.








• Results.

• Conclusions


Temperature evolution. Winter.

Air conditioning No air conditioning

0 people 10 people

• The trend of the temperature evolution is similar to the irradiance curve.• With air conditioning the temperature remains within the comfort range.








• Results.

• Conclusions

Conclusions

Influence of the irradiance in the temperature evolution into the enclosure.

Setting the irradiance curves to assign a heat source to modelling in Comsol.

Good approximation between experimental and numerical results.

Trend of the temperature evolution similar to the irradiance curve.








• Results.

• Conclusions

Thermal modelling for the implementation of an energetic efficiency control system in a room of

meetings of singular geometry

Thanks !

thermal modelling for the implementation of an energetic ...€¦ · thermal modelling for the...

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