SupermarketRefrigeration Systems in Germany

25. August 2007

Prof. Dr.-Ing. Michael Kauffeld

Institute of Refrigeration, Air Conditioning and Environmental EngineeringKarlsruhe University of Applied Sciences

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

2 / 30© Prof. Dr.-Ing. Michael Kauffeld

Content

Objectives of different German projectsStructure of German supermarket areaEnvironmental measures in German supermarkets

Reduce refrigerant chargeReduce direct GWPReduce energy consumptionUse regenerative energy

Data baseConclusion

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

3 / 30© Prof. Dr.-Ing. Michael Kauffeld

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

4 / 30© Prof. Dr.-Ing. Michael Kauffeld

Number of Grocery Stores per Person in EU

0,00 1,00 2,00 3,00 4,00 5,00 6,00

GriechenlandZypern

MaltaPortugal

BulgarienSpanien

RumänienItalienPolen

UngarnEU 25 gesamt

BelgienIrland

Norw egenSchw edenFrankreich

LitauenDänemark

LettlandLuxemburgÖsterreich

GroßbritannieEstland

FinnlandSlow enien

NiederlandeDeutschland

LEH/1000 Einwohner

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

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Grocery Stores in Germany

/Information Resources Inc.:Perspektiven 2007 –Die Herausforderungen für den LEH/

Grocery Store: up to 400 m2

Discounter: 400 to 800 m2

over 80% food

Supermarket: 600 to 1,500 m2

Hypermarket: 1,500 to 5,000 m2

and over 5,000 m2

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

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Grocery Stores in Germany

• Changes in refrigeration system:every 7 to 10 years

• Entirely new system:every 14 years

7 to 10,000 remodelings and4 to 5,000 entirely new systems every year

Mainly focus on installation costBut more recently also on running cost and environment

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

7 / 30© Prof. Dr.-Ing. Michael Kauffeld

Environmental Focus in German Supermarkets

Reduce emissions of greenhouse gasesHermetically tight systems with control scheme

EU F-Gas regulationReduce refrigerant chargeRefrigerants without or with negligible GWP

Reduce energy consumptionUse regenerative energy

… but so far only minority of new systems utilizing one or more of the above– examples on following slides

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

8 / 30© Prof. Dr.-Ing. Michael Kauffeld

Reduce Refrigerant Charge

Minichannel heat exchangerscan reduce refrigerant chargein heat exchanger by up to 90 %.While at the same timeincreasing efficiency

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

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Refrigerants without or with negligible GWP

0 1.000 2.000 3.000 4.000

R22

R134a

R404A

R407C

R410A

R507

R600a

R290

R1270

R717

R744

GWP

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

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Typical German Supermarket (except Discounter)

Central Multiplex System

Discounter use plug-in freezers, i.e. no LT multiplex system

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

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Central Multiplex Systems

Melting secondary refrigerant

Evaporating secondary refrigerant

Liquid secondary refrigerant, single phase

Direct expansion (only HFC and R744)

Cold Distribution LT

R744R717Hydrocarbon(R290 or R1270)

HFC(R404A, R507)Refrigerant LT

Melting secondary refrigerant

Evaporating secondary refrigerant

Liquid secondary refrigerant, single phase

Direct expansion (only HFC and R744)

Cold Distribution MT

R744R717Hydrocarbon(R290 or R1270)

HFC(R134a, R404A, R410A or R507)

Refrigerant MT

water cooled; water cooling in ambient air cooled heat exchanger

water cooled; heating tab water or store (heat recovery)

air cooled; heating store air (heat recovery)

air cooled; ambientCondenser

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

12 / 30© Prof. Dr.-Ing. Michael Kauffeld

Example 1: Central Multiplex System with CO2

OptionalHeatRecovery

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

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Example 1: Transcritical CO2-System

/Heinbokel, B.; Gernemann, A.: Eine neuentwickelte CO2-Kälteanlage für den Normal- und Tiefkühlbereich in einem Schweizer Hypermarkt. DKV 2005, Würzburg /

Energy consumption in North and Central Europe approx. 5 to 10 %lower than comparable R404A-System (R744 annual mean COP = 3.4)Investment cost (objective) approx. 10 to 20 % higher depending on size

Transcriticaloperation

Ambient temperature in °C

CO2 betterthan R404A

Ann

ual a

mbi

ent

degr

ee h

ours

hours

Spra

y sy

stem

cut

-in

CO2 gas cooler with spray system

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

14 / 30© Prof. Dr.-Ing. Michael Kauffeld

Example 1: Additional Energy Savings

… in a transcritical CO2-system :

Water spray on condenserExpansion machine instead of valveEjector as expansion device

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

15 / 30© Prof. Dr.-Ing. Michael Kauffeld

Example 2: Central Multiplex System with R404A and CO2

• Energy efficient application of CO2-system for LT working sub-critical• All components available; pressure below 40 bar• R744 LT system for larger supermarkets cheaper than R404A due to smaller

pipe size• Easy heat recovery

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

16 / 30© Prof. Dr.-Ing. Michael Kauffeld

Example 3: Plug-in Chest Freezers

Change from R404A to R290GWP reduced from 3.900 to approximately 2010 to 15 % energy savings

Speed controlled compressor10 to 15 % energy savings

In total approx. 25 % lower energy consumption while at the same time reducing the direct greenhouse gas emissions to almost Zero

Investment cost currently approx. 15 % higherCharge limit at 150 g for HC

1 kW maximum refrigeration capacityentire range could be covered with 500 g HC charge

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

17 / 30© Prof. Dr.-Ing. Michael Kauffeld

Example 3: Additional Energy Savings

Water cooling loop for removal of condenser heatduring non-heating periods

all inside freezer

Additional water cooledcondenser inside freezer

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

18 / 30© Prof. Dr.-Ing. Michael Kauffeld

Refrigeration48%

Lights26%

Office machines11%

small machines9%

large machines6%

Reduce Energy Consumption (1/5)

Consumption of Electricity in a typical Supermarket

… in addition use of fossil fuel for space heating and hot water

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

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Reduce Energy Consumption (2/5)

During design / installationGlass door or lidImproved insulationFan motor outside cabinetImproved evaporator fan and/or fan motorImproved air flow in open multidecksInfrared reflecting shades or baldachinesImproved antisweat heaters / dew point controlSiphon in defrost drainHot gas defrostSpeed control of compressors, pumps, fansImproved expansion valveExpansion machine

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

20 / 30© Prof. Dr.-Ing. Michael Kauffeld

Reduce Energy Consumption (3/5)

During design / installationImproved evaporatorFlooded evaporatorDefrost on demandImproved lightsReduced condensation temperature

Outside air temperature adjusted condensing temperature Evaporative cooling of condenserCondenser heat to soil

Free coolingHeat recoveryCold storage

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

21 / 30© Prof. Dr.-Ing. Michael Kauffeld

Reduce Energy Consumption (4/5)

During operationCorrect loading of productsAir humidity in shop areaEvaporator and condenser cleaning

Reduction of energy consumption is important due to :Reduction of global warming through indirect emissionsdepending on refrigerant, leakage rate and refrigeration system,energy related global warming contribution varies from 50 % for a R404A multiplex system with 300 kg refrigerant charge, 10 % leakage rate and almost 100 % for a R290 plug-in freezer or a R744 central system.

Reduction of running cost – increase of profitrefrigeration accounts for 40 to 60 % of store energy consumption; energy costs some times in the same order of magnitude as profit (1 to 2 % of turnover).

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

22 / 30© Prof. Dr.-Ing. Michael Kauffeld

0% 5% 10% 15% 20% 25% 30% 35% 40%

glass doors / lids

fan motor outside cabinet

efficient evaporator fan

baldachin

improved antisweat heaters

speed control of compressor

two stage compression

improved expansion valve

increased evap. temp. 3 Kelvin

flooded evaporator

defrost on demand

improved lights

decresed cond. temp. by 3 K

adjusted condensation temp.

proper loading of products

air humidity in shop area

Potential of selected measures (5/5)

… many of them can be combined

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

23 / 30© Prof. Dr.-Ing. Michael Kauffeld

Use regenerative energySolar photovoltaic panels on roof

Ground source heat under parking lot

Wind generator

Ground source concrete foundations

Bio-fuel co-generation power/heating plant

… so far only demonstration character projects by few supermarket chains

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

24 / 30© Prof. Dr.-Ing. Michael Kauffeld

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

25 / 30© Prof. Dr.-Ing. Michael Kauffeld

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

26 / 30© Prof. Dr.-Ing. Michael Kauffeld

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

27 / 30© Prof. Dr.-Ing. Michael Kauffeld

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

28 / 30© Prof. Dr.-Ing. Michael Kauffeld

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

29 / 30© Prof. Dr.-Ing. Michael Kauffeld

SummaryEnergy savings potential in supermarket refrigeration systems up to 50 % and more at moderate costs

HFC can be replaced at acceptable cost in all applications

In countries with adequate laws, e.g. Denmark, Norway and Sweden, many HFC-free or HFC-reduced systems are built with good energy efficiency

In Germany so far only few “demonstration” sites

HFC-free plug-in units with better energy efficiency are available up to approximately 1 kW capacity

Energy consumption data available from 25 stores

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

30 / 30© Prof. Dr.-Ing. Michael Kauffeld

Comments, Questions ?

Contact:

Prof. Dr.-Ing. Michael Kauffeld

Karlsruhe University of Applied SciencesMechanical Engineering and Mechatronics DepartmentInstitute of Refrigeration, Air Conditioning and Environmental Engineering

Moltkestr. 3076133 KarlsruheGermany

Tel.: +49 (0) 721 925 1843Fax: +49 (0) 721 925 1915E-Mail: michael.kauffeld@hs-karlsruhe.de

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

31 / 30© Prof. Dr.-Ing. Michael Kauffeld

Scatter in Energy Consumption

Auf laufende Meter Kühlmöbel normierte tägliche Stromverbräuche für die Kälteerzeugung in 226 Penny-Märkten im Jahre 2001 [Ecofys2003]

Karlsruhe University of Applied SciencesInstitute of Refrigeration, Air Conditioning and Environmental Engineering

32 / 30© Prof. Dr.-Ing. Michael Kauffeld

Scatter in Energy Consumption

Energiebedarf pro Laufmeter Kühlmöbel in Schweizer Supermärkten. Messwerte: COOP Basel, LKS Schweiz AG [Hei2006]