New absorption chillers for high efficient solar cooling ... - AHK ZAKK

New absorption chillers for high efficient solar cooling systems

New absorption chillers for high efficient solar cooling systems Dipl.-Ing. Stefan Petersen & Dipl.-Ing. Jan Albers

Foto: TU Berlin

Foto: TU Berlin

1. 2. 3. 4.

General Technology Overview Operating data Solar cooling system layout Showcase results

Technische Universität Berlin • Institut für Energietechnik

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Solar air-conditioning technologies electrical systems - PV + Vapor compression chiller -…

thermal systems

heat transformation processes

thermomechanical processes - steam jet cycles

closed cycles

open cycles

- rankine cycle + vapor compression chiller -…

liquid sorbent

solid sorbent

absorption chiller

adsorption chiller

liquid sorbent

solid sorbent

desiccant and evaporative cooling (DEC)


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Basics –compression chiller inner cycle condenser

steam

cooling water refrigerant throttle

compressor electric power

chilled water evaporator

steam

water-cooled vapor compression chiller [1] liquid refrigerant

vaporous refrigerant

[1] Carrier


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Basics – absorption chiller inner cycle condenser

steam

desorber hot water

cooling water

refrigerant throttle

Chilled water evaporator

steam

absorber cooling water

10 kW Phönix-absorption chillerTU Berlin

refrigerant


diluted solution

concentrated solution

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Short general characteristic 70

0.9 0 , 8

Cooling Capacity [kW]

60

New 50 kW Chiller

0.8

0 , 7

0.7

50

0.6 High efficient10 kW

40

0 , 5

0.5

0 , 4

0.4

30

0 , 3

0.3

20

0 , 2

Nominal load

0.2

10

0.1

0

0.0 24

29

34 39 44 Reject Heat Inlet Temperature [°C]


49

5

COP [-]

0 , 6


System setup – thermal system configuration Heat transformation process

Basic system configuration Storage almost inevitable Technische Universität Berlin • Institut für Energietechnik

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Variability Driving Heat Source I @ t_RH=30°C, V_RH=3,8kg/s, t_CW=21/16°C

Cooling Capacity [kW]

70 0,9 l/s 0,6 l/s

60 50

dT@40kW 13K

40

40K 0,3 l/s

30 0,1 l/s

20 10 0 50

60

70 80 90 Heat Source Inlet temperature [°C]


100

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Variability Driving Heat Source II @ t_RH=30°C, V_RH=3,8kg/s, t_CW=21/16°C

0.9 0.8 0.7

dt in/out < 13K@77/64 ….. to.. ≈ 40K@97/57

COP [-]

0.6 0.5 0.4

Volume flow 0.9 l/s Volumenstrom

0.3

Volume flow 0.6 l/s Volumenstrom Volume flow 0.3 l/s Volumenstrom

0.2 0.1 0.0 0

10

20

30

40

Cooling capacity [kW]


50

60

70 8


Variability Reject Heat Sink I @ t_DH=90°C, V_DH=0,9kg/s, t_CW=21/16°C

60 3,8 l/s Cooling Capacity [kW]

50 2,0 l/s 40

1,5 l/s

30

Phydraulic = nominal =100%

1,0 l/s

20

Phydraulic = 1/64*nominal = 1.5%

10 0 25

30 35 40 Reject Heat Inlet Temperature [°C]


45 9


Energetic comparison including auxiliaries 2

auxiliary power demand pa=0



pa=1%

1,5 pa=10% break even

1

0,5

0 0

0,2

0,4

0,6

0,8

1

Solar fraction Technische Universität Berlin • Institut für Energietechnik

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SAC-System UBA Dessau

image source: Busse


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Concept for solar cooling system

(Dry) reject heat device

KKM

Compression chiller

District heating

AKA

Solar Collectors

Hot water storage

Absorptionschiller


Cold Chilled water consumer storage

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SAC-System UBA Dessau

Temperature collector outlet Temperature top of storage

Solar driving temperature


Chilled water outlet

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Operating data and control Temperatur / °C, Volumenstrom / (m³/h), Strahlung / (10 W/m²)

100 solar Solar Antriebstemperatur driving temperature

90 80 70

Temperatur Kollektoraustritt Temperature at collector outlet

Temperature Temperatur at Speicher 1 oben top of storage Solarstrahlung Horizontal horizontal

60

irradiation

50 40 30

Flow rate in collector circuit Volumenstrom Kollektorkreis

20 10 0 04:00

Entladevolumenstrom Driving flow rate to chiller 08:00

12:00 16:00 Uhrzeit am 03.09.2011


20:00

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Regelung und Betriebsergebnisse 100 Temperatur / °C, Leistung / kW

90 80

Driving temperature Antriebstemperatur

70

Reject heat inlet temperature Temperatur Kühlwasser Eintritt

60 Antriebstemperatur Driving temperature (Sollwert) (set point

50 40

Cooling load(Sollwert) (set value) Kälteleistung

30 20 10

Cooling load Kälteleistung Reject heat inlet temp.(Sollwert) (set value) Temperatur Kühlwasser

0 04:00

08:00

Temperatur Kaltwasser Austritt Chilled water temperature

12:00 16:00 Uhrzeit am 03.09.2011


20:00

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Results of first year Previous year with adsorption chiller Aug. 2010 – Jul. 2011

Change First year with new absorption chiller Aug. 2011 – Jul. 2012

Cold generation

104 MWh0

59 MWh0

Driving heat

221 MWhth

80 MWhth

Thermal efficiency

0,47 MWh0/MWhth

0,76 MWh0/MWhth

+62%

Electrical efficiency

2,9 MWh0/MWhel

4,5 MWh0/MWhel

+55%

Water consumption

4,0 m³/MWh0

1,3 m³/MWh0

68%


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Control Issues: Parasitic electricity consumption

Control Strategy

SEERel

SEERth

Classic

12,4

0,76

+Reject heat, vol.flow

17,8

0,75

+Hot Water, vol.flow

13,6

0,76

+vol.flows +reject heat temp.

20,1

0,75

SEER = Seasonal Energy Efficiency Ratio Technische Universität Berlin • Institut für Energietechnik

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Conclusion  Development started in 2008 with case studies and optimization: - Thermodynamic design - Manufacturing process - Cost efficiency  Final chiller concept fixed in 2009  Starting of pre-industrial manufacturing and laboratory measurements in 2010  Installation of first prototypes in Berlin and Dessau in 2011  Commercial launch in 2013: - high energy efficiency (COP > 0,75) - high energy density and compactness - high cooling water temperatures > 45°C - low driving temperatures (tstart < 60°C) - low investment (~300 €/kW) Technische Universität Berlin • Institut für Energietechnik

Foto: TU Berlin

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