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
8-June-2012Active building elements with pcm
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
8-June-2012Active building elements with pcm
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