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

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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

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1. Introduction and Scopes

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Green Kitchen ProjectEuropean funded project

IAPP (Industry-Academia Partnerships and Pathways)

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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

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2. NORMATIVE OVEN

ENERGY CLASS TEST

EN 50304

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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

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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)

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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

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3. NUMERICAL MODEL(COMSOL Multiphysics®)

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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

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Modeling a domestic oven with a 3-glasses door

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“Transport of Dilute Species” Module

“Heat and Mass Transfer” Module

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Boundary conditions:

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Experimental transient temperature of the

oven parts.

Broil

Bake

Ring

Air cavity

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Brick surface

Boundary conditions:

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Hot wire anemometers

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α

Validation:

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Experimental transient temperature of the

oven parts.

Brick

Bottom surface

Walls

Glass

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4. RESULTS

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• Oven Temperature (t=50min)

Results: Evolution of the Temperature

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Broil Bake

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• Evolution of the Brick Temperature (transient)

Results: Evolution of the Temperature

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Results: concentration of the water

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EVAPORATED WATER (BRICK)

166g (Predicted) vs 171 g (Experimental)

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• 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

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Thanks

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More info: john_doyle@Whirlpool.com

nelsongarciapolanco@gmail.com