Supermarket Refrigeration Systems in Germany

25. August 2007 Prof. Dr.-Ing. Michael Kauffeld Institute of Refrigeration, Air Conditioning and Environmental Engineering Karlsruhe University of Applied Sciences

Content † Objectives of different German projects † Structure of German supermarket area † Environmental measures in German supermarkets „ „ „ „

Reduce refrigerant charge Reduce direct GWP Reduce energy consumption Use regenerative energy

† Data base † Conclusion

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Number of Grocery Stores per Person in EU Deutschland Niederlande Slow enien Finnland Estland Großbritannie Österreich Luxemburg Lettland Dänemark Litauen Frankreich Schw eden Norw egen Irland Belgien EU 25 gesamt Ungarn Polen Italien Rumänien Spanien Bulgarien Portugal Malta Zypern Griechenland

0,00

1,00

2,00

3,00

4,00

5,00

6,00

LEH/1000 Einwohner Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Grocery Stores in Germany

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

/Information Resources Inc.: Perspektiven 2007 – Die Herausforderungen für den LEH/ Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

5 / 30 © Prof. Dr.-Ing. Michael Kauffeld

Grocery Stores in Germany • Changes in refrigeration system: every 7 to 10 years • Entirely new system: every 14 years Æ 7 to 10,000 remodelings and 4 to 5,000 entirely new systems every year Mainly focus on installation cost But more recently also on running cost and environment

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

6 / 30 © Prof. Dr.-Ing. Michael Kauffeld

Environmental Focus in German Supermarkets † Reduce emissions of greenhouse gases „ Hermetically tight systems with control scheme Æ EU F-Gas regulation „ Reduce refrigerant charge „ Refrigerants without or with negligible GWP

† Reduce energy consumption † Use 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 Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Reduce Refrigerant Charge

Minichannel heat exchangers can reduce refrigerant charge in heat exchanger by up to 90 %. While at the same time increasing efficiency

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Refrigerants without or with negligible GWP R744 R717 R1270 R290 R600a R507 R410A R407C R404A R134a R22 0

1.000

2.000

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

3.000

4.000

GWP

9 / 30 © Prof. Dr.-Ing. Michael Kauffeld

Typical German Supermarket (except Discounter) Central Multiplex System

Discounter use plug-in freezers, i.e. no LT multiplex system Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

10 / 30 © Prof. Dr.-Ing. Michael Kauffeld

Central Multiplex Systems Condenser

air cooled; ambient

HFC Refrigerant MT

(R134a, R404A, R410A or R507)

Cold Distribution MT

Direct expansion

Refrigerant LT

HFC

Cold Distribution LT

Direct expansion

(only HFC and R744)

(R404A, R507)

(only HFC and R744)

air cooled; heating store air (heat recovery)

water cooled;

water cooled;

heating tab water or store (heat recovery)

water cooling in ambient air cooled heat exchanger

Hydrocarbon (R290 or R1270)

R717

R744

Liquid secondary refrigerant, single phase

Evaporating secondary refrigerant

Melting secondary refrigerant

Hydrocarbon (R290 or R1270)

R717

R744

Liquid secondary refrigerant, single phase

Evaporating secondary refrigerant

Melting secondary refrigerant

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

11 / 30 © Prof. Dr.-Ing. Michael Kauffeld

Example 1:

Central Multiplex System with CO2

Optional Heat Recovery

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Example 1:

Transcritical CO2-System hours CO2 gas cooler with spray system

Spray system cut-in

Annual ambient degree hours

Transcritical operation

CO2 better than R404A Ambient temperature in °C

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

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

13 / 30 © Prof. Dr.-Ing. Michael Kauffeld

Example 1:

Additional Energy Savings

… in a transcritical CO2-system : † Water spray on condenser † Expansion machine instead of valve † Ejector as expansion device

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

14 / 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 Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Example 3:

Plug-in Chest Freezers

† Change from R404A to R290 Æ GWP reduced from 3.900 to approximately 20 Æ 10 to 15 % energy savings

† Speed controlled compressor Æ 10 to 15 % energy savings

Æ 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 % higher † Charge limit at 150 g for HC Æ 1 kW maximum refrigeration capacity entire range could be covered with 500 g HC charge Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Example 3:

Additional Energy Savings

Additional water cooled condenser inside freezer

all inside freezer

Water cooling loop for removal of condenser heat during non-heating periods Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Reduce Energy Consumption (1/5) Consumption of Electricity in a typical Supermarket large machines 6% small machines 9% Office machines 11%

Refrigeration 48%

Lights 26%

… in addition use of fossil fuel for space heating and hot water Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Reduce Energy Consumption (2/5) During design / installation „ „ „ „ „ „ „ „ „ „ „ „

Glass door or lid Improved insulation Fan motor outside cabinet Improved evaporator fan and/or fan motor Improved air flow in open multidecks Infrared reflecting shades or baldachines Improved antisweat heaters / dew point control Siphon in defrost drain Hot gas defrost Speed control of compressors, pumps, fans Improved expansion valve Expansion machine

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

19 / 30 © Prof. Dr.-Ing. Michael Kauffeld

Reduce Energy Consumption (3/5) During design / installation „ „ „ „ „

Improved evaporator Flooded evaporator Defrost on demand Improved lights Reduced condensation temperature † Outside air temperature adjusted condensing temperature † Evaporative cooling of condenser † Condenser heat to soil

„ Free cooling „ Heat recovery „ Cold storage

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Reduce Energy Consumption (4/5) During operation „ Correct loading of products „ Air humidity in shop area „ Evaporator and condenser cleaning

Reduction of energy consumption is important due to : „ Reduction of global warming through indirect emissions depending 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 profit refrigeration 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 Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Potential of selected measures (5/5) air humidity in shop area proper loading of products adjusted condensation temp. decresed cond. temp. by 3 K improved lights defrost on demand flooded evaporator increased evap. temp. 3 Kelvin improved expansion valve two stage compression speed control of compressor improved antisweat heaters baldachin efficient evaporator fan fan motor outside cabinet glass doors / lids

0%

5%

10%

15%

20%

25%

30%

35%

40%

… many of them can be combined Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Use regenerative energy † Solar 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 Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Summary † Energy 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 Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Comments, Questions ?

Contact:

Prof. Dr.-Ing. Michael Kauffeld Karlsruhe University of Applied Sciences Mechanical Engineering and Mechatronics Department

Institute of Refrigeration, Air Conditioning and Environmental Engineering Moltkestr. 30 76133 Karlsruhe Germany Tel.: +49 (0) 721 925 1843 Fax: +49 (0) 721 925 1915 E-Mail: [email protected] Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

30 / 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 Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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

Scatter in Energy Consumption

Energiebedarf pro Laufmeter Kühlmöbel in Schweizer Supermärkten. Messwerte: COOP Basel, LKS Schweiz AG [Hei2006] Karlsruhe University of Applied Sciences Institute of Refrigeration, Air Conditioning and Environmental Engineering

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