Solar Cooling Technologies & Applications Christodoulaki Rosie PhD cand. Mech. Eng. MSc Environmental design & engineering BSc Physics

Solar Cooling Technologies 1.

Closed Cycle i. ii.

2.

Absorption Chillers Adsorption Chillers

Open Cycle i. ii.

Solid Desiccant Evaporative Cooling Liquid Desiccant Evaporative Cooling

chilled water

heat

Thermal driven cooling process conditioned air Source : Fraunhofer ISE, Solarnext

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Closed Cycle Systems - Absorption/Adsorption - Refrigerant medium: Water - Production of chilled water - Possible use of existing fan coils, chilled ceilings, underfloor heating.

~18°C

Driving temperature > 60°C

Chilled ceiling

Supply air system

Fresh air 15 - 18°C (< 12°C)

Absorption / Adsorption Chiller

Fan coil

6 - 9°C

(thermally driven)

Conditioned area

Chilled water temperature

Source : Fraunhofer ISE

Single effect absorption process driving heat (e.g. solar collector)

pressure

heat rejection (cooling tower) condenser

throttle

useful cold

generator

solution pump solution heat exchanger

vapour evaporator

vapour

absorber

heat rejection (cooling tower) temperature

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Open Cycle Systems -

Driving temperature > 50°C

Liquid/Solid DEC Refrigerant medium: Water Production of conditioned air Possible use of existing fan coils.

Return air

Supply air

Conditioned area

Desiccant Evaporative Cooling (DEC)

Source : Fraunhofer ISE

Thermodynamic Processes driving heat high temperature, TH environment, e.g. cooling tower

solar collector heat rejection intermediate temperature, TM air-conditioning system

Coefficient of useful cooling low temperature, TC

Performance (COPthermal) = useful cooling driving heat Source : Fraunhofer ISE

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Solar Cooling Systems Overview

Source : EU Altener Project Climasol

Efficiency – Operational temperature, 2007 Open systems Liquid DEC: Τ = 60C, COP = 0.7 Solid DEC: T = 80C, COP = 0.5 Closed systems Absorption: Τ = 75C, COP = 0.7 Adsorption: T = 55C, COP = 0.5

Initial cost – Collector area needed, 2007. Open systems Liquid DEC: 4500 €/kW, 5 m2/kW Solid DEC: 3500 €/kW, 0.5 m2/kW Closed systems Absorption: 2000 €/kW, 4 m2/kW Adsorption: 5500 €/kW, 2.5 m2/kW

Source : CA Balaras, G Grossman, HM Henning, Solar Air-Conditioning in Europe - an overview, Renewable Energy & Sustainable Energy Reviews, 11, 2007, 299-314

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Solar Cooling Systems installed in Europe - Absorption: 58% - Solid DEC: 23% - Adsorption: 12% - Liquid DEC: 4%

collector area

0.6%

desiccant, liquid

cooling capacity

1.5%

number of systems

4.4%

8.7%

desiccant, rotor

14.1% 23.5%

32.7%

adsorption

26.3% 11.8%

57.8%

absorption

57.9% 58.8%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

Source : HM Henning, Solar Assisted air conditioning of buildings – an overview, Applied Thermal Engineering, 27, 2007, 1734-1749.

Solar Cooling Applications

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PENA, CRES technological park, Athens, El PENA, Lavrio Solar cooling Solid DEC system Demo & research application for CRES In operation since

2007

Air conditioned area

84m²

Collector type

10 m2, Calpak flat-plate

Collector fluid

water-glycol 60°C

Operation temperature

1100 m3/h

Nominal air flow rate Min. air volume flow rate Desiccant cooling system Brand of desiccant unit

373 m3/h solid LiCl Klingenburg

Sarantis, Cosmetics industry, Inofita Viotias, El Operation 1999 - One of the largest installations in the world - 2,700 m2 flat plate collectors (SOLE) - 2 adsorption cooling machines, 350 kW cooling each - 3 compression cooling machines, 350 kW

Cost

Solar

Others sonstiges 6% 6%

Sub-structure for collectors Unterbau für 5% Kollektoren 5%

Solarkollektoren collectors 28% 28%

AdsorptionsAdsorption kältemaschinen cooling 20% machine

20%

Rückkühlwerke Cooling tower 6%

6%

Regelung, control Monitoring Monitoring 5% 5%

Installations-

Installation kosten Costs 20% 20%

Öl befeuerte Oil-driven Kessel als boiler Back-Upas back-up 10%

10%

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GICB wine cellar Banyuls/mer, Fr

-130 m² evacuated tube collectors - 52 kWcooling - Investment cost: 1,6 MF (1991)

Source : TECSOL

DIREN Guadeloupe, Fr - Chilled surface: 570 m² - 61 m² evacuated tube collectors - 35 kWcooling - Absorption chiller

Source : TECSOL

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Collectors 57%

Technical room 4%

Solar collectors Technical room Cold production Condensation Electricity Monitoring Startup Total HT: €. HT / kWf

Collectors (€ / m²)

€. HT 89 314 6 065 32 263 9 920 13 108 8 422 610 159 701 4 563

1 441

Cold production 20%

Startup 0% Condensation 6% Monitoring 5%

Electricity 8%

Source : TECSOL

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Cosmetic laboratory, Sophia Antipolis, Fr

- 570 m² evacuated tube collectors - 210 kW cooling - Investment cost: 2500 € / kWf

Academic Hospital of Freiburg, De

-

-

-

Adsorption cooling: 70 kWcooling Evacuated tube collectors direct flow: initially 90 m2, then increased at 170 m2 (2001) Air flow: 8000 m3/h

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Thank you for your attention!

Centre for Renewable Energy Sources Solar Thermal Department 19klm. Marathonos av., 19009, Pikermi tel. 00302106603300, fax. 00302106603301 www.cres.gr Rosa Christodoulaki [email protected]

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