sign in sign up
<<
Home , Solar air conditioning

Solar Cooling and Air-Conditioning

Hans-Martin Henning Fraunhofer-Institut für Solare Energie- systeme ISE, Freiburg/GERMANY

Renewable Energy Week, Brussels, Jan/Feb 2007 1 Overview

• Introduction

• Technologies

• Status, Examples

• Outlook

Renewable Energy Week, Brussels, Jan/Feb 2007 2 Introduction

• Introduction

• Technologies

• Status, Examples

• Outlook

Renewable Energy Week, Brussels, Jan/Feb 2007 3 World market for air-conditioning

50.000 Japan

Asia (excl. 40.000 Japan)

Middle East

30.000 Europe

North America 20.000

Central & South America 10.000

RAC unit sales (in Mio. units) sales(inunit RAC Mio. Africa

0.000 Oceania 1998 1999 2000 2001 2002 2003 2004 2005 2006

Renewable Energy Week, Brussels, Jan/Feb 2007 4 Resulting increase in electric capacity

500 Japan

Asia (excl. 400 Japan)

Middle East

300 Europe

North America 200

Central & South America 100 Africa total installed electric totalinstalledGW electric capacity in

0 Oceania 1998 1999 2000 2001 2002 2003 2004 2005 2006

Renewable Energy Week, Brussels, Jan/Feb 2007 5 Why solar heat for cooling / air-conditioning?

• Coincidence of solar gains and cooling loads

• Reduce Cooling peak loads created DHW Solar 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 1011 12

Renewable Energy Week, Brussels, Jan/Feb 2007 6 Why solar heat for cooling / air-conditioning?

• Coincidence of solar useful cooling gains and cooling COP ======7.0 loads driving heat

• Reduce electric Heating Cooling peak loads created DHW Total by air-conditioning Solar • 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 1011 12

Renewable Energy Week, Brussels, Jan/Feb 2007 7 Basic system scheme

ThermallyThermal driven cooling heat driven cooling processprocess

conditioned air

Renewable Energy Week, Brussels, Jan/Feb 2007 8 Technologies

• Introduction

• Technologies

• Status, Examples

• Outlook

Renewable Energy Week, Brussels, Jan/Feb 2007 9 heat heat storage heat distr. cold production cold storage cold distr. building, load

solar collector

heat driven chilled ceiling solarcollector field chilledwater

coils

air handling unit heating hotwater otherheat sources cond.air

desiccant air handling unit

Renewable Energy Week, Brussels, Jan/Feb 2007 10 Water - market available systems water chillers produce chilled water which can supply any type of air- conditioning equipment (e.g. air handling units, fan-coils, chilled ceilings,....)

single-effect absorption many products for cooling power > 100 kW; few products <100 kW; refrigerant/sorption pair either water/LiBr or /water

double-effect several manufacturers; often direct fired absorption systems; no products <100 kW; refrigerant/ sorption pair in most cases water/LiBr

adsorption a few commercially available systems (Asia); refrigerant/sorption pair water/silica gel

steam jet cycle tailor-made sytems for large capacities; refrigerant water

Renewable Energy Week, Brussels, Jan/Feb 2007 11 Europe is leading in development of small thermally driven chillers

SK SonnenKlima GmbH EAW

Renewable Energy Week, Brussels, Jan/Feb 2007 12 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 - 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 13 Desiccant system schematic

backup heater

return ex- haust

cooling loads am- bient supply

desiccant rotor heat recovery

Renewable Energy Week, Brussels, Jan/Feb 2007 14 Temperature needs

• Desiccant systems: 50 – 80°C Glasabdeckung

Isolierung Kollektorrahmen – Solar air collectors, flat plate collectors Absorber mit Luftkanälen

• Adsorption: 65 – 85°C

Glasabdeckung – Flat plate collectors, evacuated tubes

Isolierung Kollektorrahmen Absorber mit Fluidkanälen • Single-effect absorption (comfort air- conditioning): 70 – 100°C

Glasabdeckung Folie – Flat plate collectors, evacuated tubes,

Isolierung Reflektor Kollektorrahmen optical concentration without tracking Absorber mit Fluidkanal

• Double-effect absorption: 130-160°C – High efficient evacuated tubes, optical concentration with tracking

Renewable Energy Week, Brussels, Jan/Feb 2007 15 Status, Examples

• Introduction

• Technologies

• Status, Examples

• Outlook

Renewable Energy Week, Brussels, Jan/Feb 2007 16 Status in Europe

• Approx. 120 installations 8.7%

• Approx. 20 Germany Greece MW cold installed Spain 27.5% • Specific Portugal 39.1% collector area Italy Austria – 3 m 2/kW for cold France chilled water Netherlands production Israel – 10 m 2 per 1000 Turkey 3 Serbia (Kosovo) m /h for 4.3% sorptive air (2004-values) 1.4% 4.3% 2.9% handling units 5.8% 1.4% 1.4% 2.9%

Renewable Energy Week, Brussels, Jan/Feb 2007 17 Air-conditioning of a factory

• flat plat collector field: 2700 m 2 • 2 adsorptions chillers with 350 kW cooling capacity each • 3 compression chillers with 350 kW each • 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 18 Wine store cooling

• evacuated tube collector field: 130 m 2 • single-effect absorption chiller with 52 kW cooling 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 19 Air-conditioning of a seminar room

• solar air collector as only heat source: 100 m 2 • desiccant cooling system (10.200 m 3 per ) 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 20 Hotel air-conditioning

• parabolic trough collector produces heat at 180°C: 180 m 2 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 • 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 21 Outlook

• Introduction

• Technologies

• Status, Examples

• Outlook

Renewable Energy Week, Brussels, Jan/Feb 2007 22 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 m 2 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 23 Main future needs

• standardized systems

• small capacity systems

• advanced operation & control

• transfer to professionals

Task 38 … thank you forSolar your Air-Conditioning attention and

Renewable Energy Week, Brussels, Jan/Feb 2007 24 Cooling with low driving tempertature

• Small commercial applications: offices, surgeries etc. • Residential: single-family, multi-family

Renewable Energy Week, Brussels, Jan/Feb 2007 25 Fan-coil system – single-effect absorption chiller

fan coils

backup heater

buffer storage absorpt. chiller

• Mainly commercial buildings: medium to large offices, hotels • Production facilities

Renewable Energy Week, Brussels, Jan/Feb 2007 26 Fan-coil system – double-effect absorption chiller

fan coils

backup heater

buffer storage absorpt. chiller

• Mainly commercial buildings or cooling networks • High fraction of direct solar radiation necessary

Renewable Energy Week, Brussels, Jan/Feb 2007 27 System for hot climate

fan dry coils cooling

absorpt. chiller

ice storage

• Ice storage, food production • High fraction of direct solar radiation necessary

Renewable Energy Week, Brussels, Jan/Feb 2007 28