Design and Implementation of a Retrofit Solar-Assisted HVAC System for Residential Applications Prof Paul Cooper Director, Sustainable Buildings Research Centre University of Wollongong
Summary Overview of Solar Decathlon Competition The Journey to Datong The Team UOW Illawarra Flame House Photovoltaic Thermal System and Phase Change Energy Storage systems Solar Assisted HVAC System Design Modelling Initial results
THE SOLAR DECATHLON A competition for University students to design, build and operate sustainable, net-zero energy, attractive and affordable homes. Objective: accelerate the development and adoption of advanced building technologies. Since 2002: 8 competitions 5 in US 2 in Europe 1 in China Total of 164 teams SOLAR DECATHLON 2009 WASHINGTON MALL
THE SOLAR DECATHLON CHINA 2013 COMPETITION US Department of Energy and Chinese National Energy Administration held the first SD China in 2013. Team UOW was a collaboration between UOW and TAFE NSW Illawarra Institute. Team UOW the first ever team from Australia to win entry to a Solar Decathlon. 270,000 people attended the competition site. SOLAR DECATHLON CHINA 2013 DATONG 35,000 people were toured through the Illawarra Flame House throughout the competition week one every 8 seconds!
SUB-COMPETITIONS
TRANSFORMING OUR HOUSES...
The Base Plan
INTO SUSTAINABLE HOMES
ILLAWARRA FLAME HOUSE FEATURES State of the art photovoltaic panels Greywater treatment system Natural ventilation and automated high level windows Innovative HVAC system featuring Photovoltaic-Thermal solar system and Phase Change Material (PCM) Thermal Store Innovative Building Management System ILLAWARRA FLAME HOUSE IN DATONG 2013
PHOTOVOLTAIC THERMAL SYSTEM Daytime generation Night time radiant cooling
PVT AND PCM PVT ROOF ILLAWARRA FLAME HOUSE DATONG 2013 BLUESCOPE LYSAGHT TRIMDEK
PVT AND PCM For optimization it was necessary to develop: Thermal Model Mechanical Model (Fan Consumption) Electrical Model (electrical generation efficiency is a function of PV temperature) THERMAL NETWORK MODEL
PHASE CHANGE MATERIAL THERMAL STORE There is generally a significant offset between the thermal generation and the house demand Thermal energy storage has been included in the design, through the latent heat of Phase Change Material (PCM). Melting temperature has been identified at 22 C 180 160 UA value [W/K] 140 120 The PCM store acts as a heat exchanger. 100 80 60 PLUS ICE PCM BRICKS 20 40 60 80 100 120 140 Airflow rate [L/s]
SOLAR ASSISTED HVAC SYSTEM
ILLAWARRA FLAME HOUSE 4X First build at TAFE Dress rehearsal at UOW Innovation Campus Under (Re)Construction Final build at SBRC 3 rd build at competition site
Construction in China
PVT AND PCM INITIAL RESULTS ELECTRICAL MODEL VALIDATION 3500 3000 PV Generation, Model, South side PV Generation, Model, North side PV Generation, Model, Total PV Generation, Measured 2500 Power [W] 2000 1500 1000 500 0 0 50 100 150 200 250 300 350 400 450 500 Time [min]
PVT AND PCM THERMAL MODEL VALIDATION 80 900 Temperature [ C] 70 60 50 40 30 20 10 800 700 600 500 400 300 200 100 Radiation [W/m 2 ] - Airflow rate [L/s] 0 1 9 17 25 33 41 49 57 65 73 81 89 97 105 113 121 129 137 145 153 161 169 177 185 193 201 209 217 225 233 241 249 Time [mins] 0 Tambient [degc] Tpvt_Model [degc] Tpvt_Measured [degc] Ghr [W/m2] Vflow [L/s]
SOLAR ASSISTED HVAC SYSTEM HVAC System Managed by a Residential type of control system. Customized logic and nonstandard use of devices to automate the system and control the subcomponents ILLAWARRA FLAME BMS
SOLAR ASSISTED HVAC SYSTEM 2 PCM Charging with PVT Optimization Example Heat Transfer, 750 W/m2 Electrical Power Consumption Increased Electrical Generation 2500 2000 550 W/m2 650 W/m2 750 W/m2 850 W/m2 Power [kw] 1.5 1 Cost Function [W] 1500 1000 0.5 500 0 0 50 100 150 200 250 300 350 400 450 500 Airflow [L/s] 0 50 100 150 200 250 300 350 400 Airflow [L/s] C = P tt + α( P e,geg P e,ccgc )
SOLAR ASSISTED HVAC SYSTEM 5000 25000 4000 20000 3000 15000 Power [W] 2000 1000 10000 5000 Energy stored [Wh] 0 0-1000 -5000-2000 1 17 33 49 65 81 97 113 129 145 161 177 193 209 225 241 257 273 289 305 321 337 353 369 385 401 417 433 449 465 481 497 513 529 545 561 577 593 609 625 641 657 673 689 705 721 737 Time [h] -10000 Heating Load Charging Hmiss Discharge Charge
SOLAR ASSISTED HVAC SYSTEM Simulated Performance Results Winter July (Heating) Summer February (Cooling) Total demand, Thermal (kwh) 206 165 Thermal Energy supplied through PV-T/PCM (kwh) Electrical Energy for Discharging (kwh) 139 116 6.1 9.6 COP Discharging 22.8 12.1 Thermal Energy Charged 131.4 163.6 (kwh) Electrical Energy for Charging (kwh) 5.0 10.1 COP Charging 26.4 16.2 COP Overall 12.3 6.9
Team UOW Win! Overall winner of Solar Decathlon China 2013 Highest overall score in the history of Solar Decathlon Competitions (957.6/1000) Placed first in five out of the 10 competitions: Architecture Engineering Solar Application Hot Water Energy Balances Second by one point in: Communications Market Appeal >35,000 people toured through house (1 person every 8 seconds!) >270,000 members of the public attended competition site
Illawarra Flame and SBRC at UOW
Summary Team UOW first: Australian Team to win entry to a Solar Decathlon Team ever to demonstrate a retrofit of an existing building Place at SD China 2013, with highest ever overall score Air-based PVT system linked with PCM store and conventional heat pump. The Team UOW/BlueScope Solar Assisted HVAC system winner of the 2013 Denis Joseph competition. Illawarra Flame house now reconstructed and will be a long-term test bed for solar and HVAC technologies at the SBRC@UOW.
Acknowledgements Thank you to all Team UOW members, but especially for key members of the PVT/PCM/HVAC system team: Massimo Fiorentini Lloyd Niccol Michael Whitehouse Laia Ledo Rui Yan Eva Guo Dr Zhenjun Ma Vincent Tannahil All our sponsors, especially BlueScope Energy Matters Clipsal Schneider Electric Partnership Northrop