solar coolingand air-conditioning air conditioning.pdf · solar coolingand air-conditioning....
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Renewable Energy Week, Brussels, Jan/Feb 2007 1
Hans-Martin Henning
Fraunhofer-Institut für Solare Energie-
systeme ISE, Freiburg/GERMANY
Solar Cooling and
Air-Conditioning
Renewable Energy Week, Brussels, Jan/Feb 2007 2
Overview
• Introduction
• Technologies
• Status, Examples
• Outlook
Renewable Energy Week, Brussels, Jan/Feb 2007 3
Introduction
• Introduction
• Technologies
• Status, Examples
• Outlook
Renewable Energy Week, Brussels, Jan/Feb 2007 4
World market for air-conditioning
0.000
10.000
20.000
30.000
40.000
50.000
1998 1999 2000 2001 2002 2003 2004 2005 2006
RA
C u
nit s
ales
(in
Mio
. uni
ts)
Japan
Asia (excl.Japan)
Middle East
Europe
North America
Central & SouthAmerica
Africa
Oceania
Renewable Energy Week, Brussels, Jan/Feb 2007 5
Resulting increase in electric capacity
0
100
200
300
400
500
1998 1999 2000 2001 2002 2003 2004 2005 2006
tota
l ins
talle
d el
ectri
c ca
paci
ty in
GW
Japan
Asia (excl.Japan)
Middle East
Europe
North America
Central & SouthAmerica
Africa
Oceania
Renewable Energy Week, Brussels, Jan/Feb 2007 6
Why solar heat for cooling / air-conditioning?
• Coincidence of solar
gains and cooling
loads
• Reduce electric
peak loads created
by air-conditioning
• High use of solar
gains during the
entire year
• Reduce summer
surplus solar gains in
solar systems
designed for heating
application (solar
combi-systems)
1 2 3 4 5 6 7 8 9 10 11 12
Heating Cooling
DHW Solar
Renewable Energy Week, Brussels, Jan/Feb 2007 7
Why solar heat for cooling / air-conditioning?
• Coincidence of solar
gains and cooling
loads
• Reduce electric
peak loads created
by air-conditioning
• High use of solar
gains during the
entire year
• Reduce summer
surplus solar gains in
solar systems
designed for heating
application (solar
combi-systems)
7.0heatdriving
coolingusefulCOP ========
1 2 3 4 5 6 7 8 9 10 11 12
Heating CoolingDHW TotalSolar
Renewable Energy Week, Brussels, Jan/Feb 2007 8
Basic system scheme
Thermal driven cooling process
heat
chilled water
conditioned air
Thermallydriven coolingprocess
Renewable Energy Week, Brussels, Jan/Feb 2007 9
• Introduction
• Technologies
• Status, Examples
• Outlook
Technologies
Renewable Energy Week, Brussels, Jan/Feb 2007 10
heat storage cold productionso
lar
colle
ctor
fiel
d
air handling unit
hot w
ater
cold distr. building, loadheat cold storage
chill
ed w
ater
cond
. air
othe
r he
at s
ourc
esheat distr.
chilledceiling
fancoils
heating
heat drivenchiller
desiccant air handling unit
solar collector
Renewable Energy Week, Brussels, Jan/Feb 2007 11
single-effect absorption
double-effectabsorption
adsorption
steam jet cycle
many products for cooling power > 100 kW; few products <100 kW; refrigerant/sorption pair either water/LiBr or ammonia/water
several manufacturers; often direct firedsystems; no products <100 kW; refrigerant/ sorption pair in most cases water/LiBr
a few commercially available systems (Asia); refrigerant/sorption pair water/silica gel
tailor-made sytems for large capacities; refrigerant water
water chillers produce chilled water which can supply any type of air-conditioning equipment (e.g. air handling units, fan-coils, chilled ceilings,....)
Water chillers - market available systems
Renewable Energy Week, Brussels, Jan/Feb 2007 12
Europe is leading in development of
small thermally driven chillers
SK SonnenKlima GmbHSK SonnenKlima GmbHSK SonnenKlima GmbHSK SonnenKlima GmbHEAW
Renewable Energy Week, Brussels, Jan/Feb 2007 13
Desiccant systems - market available equipment
• desiccant systems are used for direct air treatment
• they consist of a combination of
sorptive air dehumidification and evaporative cooling
• two major technologies exist
– systems with desiccant rotors
• desiccant rotors available in a broad range of sizes from several manufacturers
• sorption material either silica gel or lithium-
chloride
• cycle adjustable to different climatic
conditions
– systems using liquid desiccants
• few systems in pilot plant operation
• LiCl as desiccant material
Renewable Energy Week, Brussels, Jan/Feb 2007 14
humidifier coolingloads
supply
backupheater
return
desiccant rotor heat recovery
am-bient
ex-haust
Desiccant system schematic
Renewable Energy Week, Brussels, Jan/Feb 2007 15
Temperature needs
• Desiccant systems: 50 – 80°C
– Solar air collectors, flat plate collectors
• Adsorption: 65 – 85°C
– Flat plate collectors, evacuated tubes
• Single-effect absorption (comfort air-conditioning): 70 – 100°C
– Flat plate collectors, evacuated tubes,
optical concentration without tracking
• Double-effect absorption: 130-160°C
– High efficient evacuated tubes, optical
concentration with tracking
Glasabdeckung
Isolierung Kollektorrahmen
Absorber mit Luftkanälen
Glasabdeckung
Isolierung KollektorrahmenAbsorber mit Fluidkanälen
IsolierungKollektorrahmen
Glasabdeckung
Absorber mit Fluidkanal
Reflektor
Folie
Renewable Energy Week, Brussels, Jan/Feb 2007 16
• Introduction
• Technologies
• Status, Examples
• Outlook
Status, Examples
Renewable Energy Week, Brussels, Jan/Feb 2007 17
Status in Europe
• Approx. 120 installations
• Approx. 20
MWcold installed
• Specificcollector area
– 3 m2/kWcold for
chilled water
production
– 10 m2 per 1000
m3/h for
sorptive air
handling units
39.1%
8.7%
27.5%
4.3%
4.3%2.9%5.8%
2.9%1.4%1.4%
1.4%
Germany
Greece
Spain
Portugal
Italy
Austria
France
Netherlands
Israel
Turkey
Serbia (Kosovo)
(2004-values)
Renewable Energy Week, Brussels, Jan/Feb 2007 18
Air-conditioning of a factory
• flat plat collector field: 2700 m2
• 2 adsorptions chillerswith 350 kW cooling capacity each
• 3 compression chillers with 350 kW each
• air conditioning of the production facilities of a cosmetics factory
• site: Inofita Viotias (appr. 50 km north-east of Athens)
• largest system today
� interesting system concept: electricity saving by solar cooling
Renewable Energy Week, Brussels, Jan/Feb 2007 19
Wine store cooling
• evacuated tube collector field: 130 m2
• single-effect absorption chillerwith 52 kWcooling capacity
• no back-up system
• cooling of a wine store (about 3 million bottles) with 3 air handling units (25.000 m3/h air flow)
• site: Banyuls (south France)
• one of the oldest systems; operates more than 12 years without problems
� solar autonomous and not buffer storage ==> storage on load side
Renewable Energy Week, Brussels, Jan/Feb 2007 20
Air-conditioning of a seminar room
• solar air collector as only heat source: 100 m2
• desiccant cooling system (10.200 m3 per hour) with silica gel rotor
• no back-up system
• air-conditioning of the seminar room and the cafeteria in the building of the chamber for trade & commerce in Freiburg/ Germany
• simple solar system with simple integration into the air-conditioning plant
• no back-up, no storage
� promising concept for buildings with a high similarity of cooling loads and solar gains
Renewable Energy Week, Brussels, Jan/Feb 2007 21
Hotel air-conditioning
• parabolic trough collector produces heat
at 180°C: 180 m2 aperture area
• double effect absorption chiller (cooling capacity 116 kW, 4 bar saturated steam; COP > 1.2)
• air-conditioning of a hotel and steam supply for the hotel laundry
• LPG-fired back-up steam boiler
• site: Dalaman (mediterranean coast Turkey)
� first system with double effect chiller
� high overall conversion efficiency
� interesting concept for sites with high direct radiation
Renewable Energy Week, Brussels, Jan/Feb 2007 22
• Introduction
• Technologies
• Status, Examples
• Outlook
Outlook
Renewable Energy Week, Brussels, Jan/Feb 2007 23
Status
• Energy saving
– Primary energy saving for properly designed chilled water systems 40 – 60 %
– Primary energy saving for properly designed open cycles 20 – 50 %
• First cost
– 2 – 2.5 times higher compared to conventional reference systems
• Overall annual cost
– 1.2 – 1.5 times higher compared to conventional reference systems
– Close to break-even with funds in the range of 100 € per m2 of collector
• Large potential, in particular in mediterranean countries
• Potential for cost reduction
– Higher standardization
– Less effort in planning and design
– Lower component cost
Renewable Energy Week, Brussels, Jan/Feb 2007 24
Main future needs
• standardized systems
• small capacity systems
• advanced operation & control
• transfer to professionals
… thank you for your attentionTask 38Solar Air-Conditioningand Refr igeration
Renewable Energy Week, Brussels, Jan/Feb 2007 25
Cooling with low driving tempertature
• Small commercial applications: offices, surgeries etc.
• Residential: single-family, multi-family
Renewable Energy Week, Brussels, Jan/Feb 2007 26
Fan-coil system – single-effect absorption chiller
buffer storage
backup heater
absorpt.chiller
fancoils
• Mainly commercial buildings: medium to large offices, hotels
• Production facilities
Renewable Energy Week, Brussels, Jan/Feb 2007 27
Fan-coil system – double-effect absorption chiller
buffer storage
backup heater
absorpt.chiller
fancoils
• Mainly commercial buildings or cooling networks
• High fraction of direct solar radiation necessary