multiphysicsapproach to improve the performance of a...

Authors: Nelson Garcia-Polanco, Joaquín Capablo and John Doyle

Whirlpool R&D, Italy.

Multiphysics Approach to Improve thePerformance of a Domestic Oven

17-19 September 2014 Cambridge – UK

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Whirlpool EMEA, Italy J. Capablo, J. Doyle and N. Garcia-Polanco

Summary

1. Introduction and scopes

2. Normative Oven Energy Class Test, EN 50304

3. Numerical Model (COMSOL Multiphysics®)

4. Results

5. Conclusions


1. Introduction and Scopes


Green Kitchen ProjectEuropean funded project

IAPP (Industry-Academia Partnerships and Pathways)


Reduction of the energy and water

consumption of home appliances.

Partners:

www.iapp-greenkitchen.eu

• Reduction of the Energy

Consumption of Electrical Ovens.

• Set up an accurate digital model to

test our new solutions.

• Improve the performance of our

products in cooking performance

and energy consumption.

Specific Objectives


2. NORMATIVE OVEN

ENERGY CLASS TEST

EN 50304


Oven model

Energy

Consumption

(kWh)

Energy

consumption

label

Heating

function

Usable

Volume (l)

MINERVA 0.90 A Static 73

OVEN MODEL

WHIRLPOOL MODEL: MINERVA OVEN


Brick Test (CEI EN 50304)

BRICK (Food Load Simulator)

-Dimensions: 230mm x 114mm x 64mm

-Material: Hypor

Cp=0.80 J/g°C

ρ=550 ± 40 kg/m3

Porosity=77%

-Weight:

Winitial ≈ 920g (brick) + 1050 g (water)

≈ 1050 g water absorved after 8h in chilled water

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Representing

similar food matrix

behavior inside the

oven cavity

BRICK

-Tfinal: Tinitial + ∆T (55 °C)


EXPERIMENTAL STUDY

Thermocouples type J (iron/constatan)

Heating elements

Walls

Glass

Brick

Temperature monitoration:

Data logger: Yokogawa MV100

Frequence: Every second

Range: −40 to +750 °C

Precision: 0.1 °C

Tair out: 1 measurement

Tcavity: 2 measurements

Tbrick: 2 measurements


3. NUMERICAL MODEL(COMSOL Multiphysics®)


Numerical Model

• It is important to model the transient behavior of the oven to be able to reduce the energy consumption.

• For example, advanced design can be developed by performing some parametric analyses:

– Emissivity of the glass

– Dimensions of the cavity walls

– Material properties of the cavity walls

– Heating elements design


Modeling a domestic oven with a 3-glasses door

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“Transport of Dilute Species” Module

“Heat and Mass Transfer” Module


Boundary conditions:

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Experimental transient temperature of the

oven parts.

Broil

Bake

Ring

Air cavity


Brick surface

Boundary conditions:

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Hot wire anemometers


α

Validation:

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Experimental transient temperature of the

oven parts.

Brick

Bottom surface

Walls

Glass


4. RESULTS


• Oven Temperature (t=50min)

Results: Evolution of the Temperature

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Broil Bake


• Evolution of the Brick Temperature (transient)

Results: Evolution of the Temperature


Results: concentration of the water

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EVAPORATED WATER (BRICK)

166g (Predicted) vs 171 g (Experimental)


• Experimental Study Information:

– Standard test for energy consumption, EN 50304.

• Temperature Evolution obtained in the test:

– Similar to the predictions of evolution of the temperature obtained in the theoretical model.

• Experimental Validation of the Model:

– Make possible to further study innovative strategies to obtain an optimized oven performance

• Parametric study

• Design optimization

Conclusions


Thanks


More info: [email protected]

[email protected]

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