Bavarian Center of Applied Energy Research Solar Air Conditioning - Research and Development Activities at the ZAE Bayern Astrid Hublitz ZAE Bayern, Munich, Germany Division: Technology for Energy Systems and Renewable Energy hublitz@muc.zae-bayern.de
Outline Introduction Thermal Driven Air Conditioning Systems Liquid Desiccant Cooling Systems for Dehumidification Demonstration Project ZAE Bayern & L-DCS Technology GmbH: Installation of the Plant and First Operational Experience
Methods of Solar Air-Conditioning solar radiation collector PV-cell thermal energy Mechanical Energy electrical energy open cycle desiccant cooling closed absorption chiller liquid desiccant cooling Vapor Compression Cooling Steam Jet Cooling Peltier element vapor compression chiller
Configuration Electric Vapor Compression System the electric chiller produces 6 C chilled water dehumidification is made by condensation in air handling unit incoming air 32 C 8 C 22 C 24 18 C
Closed Cycle Absorption Water Chiller (AWC) LiBr/Water system cooling power 10 kw driven by hot water of 75/65 C produces cold water 18/15 C heat Wärmetauscher exchanger solar collector absorption Sorptionskältemaschine chiller Solarkollektor cooling Kühlturm tower heat Wärmespeicher storage fan coils z.b. Kühldecken
Closed Cycle Absorption Chiller Performance LiBr-chiller 120 110 100 90 80 70 60 50 40 0,1 0,0 0 5 10 15 Cooling Kälteleistung power [kw] [kw] 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 Temperature Heisswassertemp. of heat [ C] supply [ C] Kältezahl (COP) Coefficient of Performance [-] COP inlet temperature outlet temperature
SolarCool + PCM Solar heating and cooling system with latent heat storage absorption cooling system based on water/libr solution dry cooling system replaces wet cooling tower latent heat storage supports the reject heat sink
SolarCool + PCM: Cooling Mode Day-Time Operation: Charging of PCM- Storage 15 C 18 C CHILLER Absorptionswärmepumpe bzw. Kältemaschine 90 C 85 C Wärme- Speicher AUX. Heizkessel BOILER 40 C 32 C Luftwärmetauscher 32 C DRY AIR COOLER 40 C PCM- Speicher 36 C NT- Kühl-/Heizsystem COOLING SYSTEM LATENT HEAT STORAGE 32 C Solarkollektoranlage SOLAR SYSTEM
SolarCool + PCM: Cooling Mode Night-Time Operation: Discharging of PCM- Storage CHILLER Absorptionswärmepumpe bzw. Kältemaschine Wärme- Speicher AUX. Heizkessel BOILER Luftwärmetauscher 18 C DRY AIR COOLER PCM- Speicher 22 C NT- Kühl-/Heizsystem COOLING SYSTEM LATENT HEAT STORAGE 25 C Solarkollektoranlage SOLAR SYSTEM
SolarCool + PCM: Heating Mode Surplus Solar Heat: Charging of PCM- Storage CHILLER Absorptionswärmepumpe bzw. Kältemaschine Wärme- Speicher AUX. Heizkessel BOILER Solarkollektoranlage SOLAR SYSTEM Luftwärmetauscher 32 C 35 C NT- Kühl-/Heizsystem COOLING SYSTEM LATENT HEAT STORAGE PCM- Speicher
SolarCool + PCM: Heating Mode Low Solar Gain: Discharging of PCM- Storage CHILLER Absorptionswärmepumpe bzw. Kältemaschine Luftwärmetauscher Wärme- Speicher AUX. Heizkessel BOILER Solarkollektoranlage SOLAR SYSTEM 32 C 35 C NT- Kühl-/Heizsystem COOLING SYSTEM LATENT HEAT STORAGE PCM- Speicher
Desiccant Cooling System DCS open cycle DCS system, Munters Corporation COP 0.5 exhausted air incoming air
Liquid Desiccant Cooling System = L-DCS high density thermochemical storage: storage is free of losses Regenerator built in energy recovery: high COP th 0.8-1.2 flat plate collector low driving temperatures higher collector Collector efficiency Array& lower costs collector array Energy Storage incoming air Absorber Air Cooler exhausted air Indirect Evaporative Cooling Systems
Comparison of Storage Capacity for Dehumidification cold water storage: 6-12 C hot water storage for AHP: 75-100 C, COP = 0.7 ice & water: 0-12 C, f vol = 0.7 salt solution: LiCl-H20, energy density = 200-250 kwh/m³ 200 specific volume [m³/mwh] specific cost [ /MWh] 40000 150 100 50 0 140 cold water 50 13 ice & water 5 hotwater LiCl- H 2 0 30,000 cold water 20,000 21,000 ice & water 15,000 hotwater LiCl- H 2 0 30000 20000 10000 0
Comparison of Primary Energy Balance Compression Chiller L-DCS Technology 100 kw cooling
Demonstration Project in Singapore L-DCS Technology GmbH and ZAE Bayern Ambient Conditions Munich & Singapore comfort zone
Optimized Configuration L-DCS combined with compression chiller conventional chiller cools the building L-DCS using salt solution for dehumidification indirect evaporative cooler for cooling of the absorption process 32 25 C 20 10 g/kg 30 25 C energy storage up to 250 kwh/m³ 24 18 C
Scheme of Solar Dehumidification System 350 kw drying 550 m² 300 kw 12 m³ storage 32 25 C 20 10 g/kg for 12 h 13,000 m³/h 3000 m²
L-DCS combined with compression chiller Solar Insolation and Dehumidification Demand Thermal Power [kw] 500 400 300 200 100 0 Cooling Demand q1_fresh Insolation Q_CollectorArray 0 24 48 72 96 120 144 168 192 216 240 Hour of the year [h]
Summary of the Demonstration Project in Singapore L-DCS Technology GmbH & ZAE Bayern has installed a first solar dehumidification plant in Singapore in 2006 with 550 m² flat plate collector and 12 m³ storage volume. It has a power of about 200 kw. First tests are done: The absorber showed ca. 90% of the dehumidification expected. A coefficient of performance of 0.7 was evaluated in the first test. A specific energy storage capacity of about 225 kwh/m³ (90% of predicted) was evaluated experimentally.
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