ACTIVE BUILDING ELEMENTS WITH PCMGRADUATION PROJECT: THERMAL SIMULATION OF AN ENERGY

NEUTRAL BUILDING CONCEPT.

IR. BART KOLKMAN

Introduction

Concept design

Model development

Development of simulation software

Optimizations and results

Conclusions

8-June-2012Active building elements with pcm

CONTENT

Reduction of energy consumption of buildings

Smart energy storage and release

Using PCM materials

8-June-2012Active building elements with pcm

INTRODUCTION

Stored heat

Te

mpera

ture

PCM

Material without phase

change

Heat of fusion

Reduction of energy consumption of buildings

Smart energy storage and release

Using PCM materials

Simulation of buildings using PCM in walls

8-June-2012Active building elements with pcm

INTRODUCTION

8-June-2012Active building elements with pcm

CONCEPT DESIGN OF BUILDING

Module

Basin

Window with

shutter

+ -

Battery

Ventilation box

Internal heat

Walls (Thermal

or PV)

Heat flows

Module

Basin

Window with

shutter

+ -Battery

Ventilation box

Internal heat

Walls (Thermal or PV)

Heat flows

8-June-2012Active building elements with pcm

WALL DESIGN

Internal

air

PCM/water

layer IsolationAluminum plate

with water

channels

Photo-

voltaic

material

External

air

Thermal collectorCombined thermal + PV collector

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ENVIRONMENTAL VARIABLES

Solar irradiance

Internal solar irradiance

External air

temperature, wi

nd speed and

direction

Ground

temperature

Dutch weather conditions

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MODEL DEVELOPMENTWALL 1D FINITE ELEMENT MODEL

Thermal masses

Resistances

DynamicWallModel

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MODEL DEVELOPMENTWALL 1D FINITE ELEMENT MODEL

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MODEL DEVELOPMENTWALL 1D FINITE ELEMENT MODEL

Composition of:

1. Thermal model

Thermal state of walls and internal volume, based on previous state

2. Shape model

Defines the shape en position of walls, window, etc.

Calculation of external influences on the model (wind, solar irradiance)

Calculation of shined areas through window

3. Controller

Heating and cooling of thermal masses, functioning of the ventilation

box and window shutter

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SIMULATION SOFTWARE

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RESULTS

Optimization of design for:

Heat collection

Passive heating of the interior

Heat storage

Electricity storage

Fine-tuning of model by various simulations

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RESULTS

Optimization parameters:

Choice of:

black anodized aluminum or

selective absorber surface material

Optional glass cover

Efficient collectors are essential to have enough heat generation in the

spring and autumn, minimizing the need for thermal storage.

Uncovered collectors have too low efficiencies at low external

temperatures

Selective absorber material is performing better, especially at lower

irradiation levels

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OPTIMIZATIONS OF HEAT COLLECTION

Optimization parameters:

Window area. [1 m2, 2 m2, 4 m2]

PCM thickness of inner wall. [10 mm, 20 mm, 30 mm]

Increased window area and PCM thickness gives lower heating

requirements and reduced maximal temperatures

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OPTIMIZATION OF PASSIVE HEATING

Optimization parameters:

Basin height. [0.1 m, 0.3 m, 0.5 m]

Basin isolation thickness. [200 mm, 100 mm]

Basin internal material. [Water, PCM]

Small water basin can be used but results in high storage

temperatures and thereby high losses.

Use of 3 cm PCM is sufficient, and also reduces the conduction losses

due to the lower storage temperatures.

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OPTIMIZATION OF HEAT STORAGE

Variables:

Battery capacity

Battery efficiency

Inclination of the roof [0°, 17°,35°]

The production per month exceeds the consumption.

An efficient storage system is essential.

Inclination of the roof increases the electric yield, but reduces the

thermal performance of the building and is therefore not ideal.

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OPTIMIZATION OF ELECTRICITY STORAGE

Simulation over a longer period (multiple years)

More thermal and electric capacity is sometimes required.

Replacement of PCM/water layer by pure PCM for some sides.

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FINE-TUNING OF MODELLONGER SIMULATION PERIOD AND FINE-TUNING

Both practical and theoretical approach

Satisfying results for inside temperature

PCM in basin and walls gives good opportunities for energy reduction

Integrated solution with:

Control system

Different energy resources

Smart storage and release of energy

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CONCLUSIONS

Development of simulations for various applications

Obtain integrated solutions for multi-variable problems

THANK YOU FOR YOUR ATTENTION

8-June-2012Active building elements with pcm

CURRENT WORK AREA