ALL - CO2 SUPERMARKET REFRIGERATION SYSTEMS

CO2 REFRIGERATING UNITS

Kyoto protocol and its consequences

Why CO2

State of the art

EU proposal: evolution of regulation 2037/2000

Obligation to perform regular leak test

Reporting duties regarding greenhouse gas emission

Logbooks for control and recharging operations

Phase out R134a in automotive air conditioners from 2014 (probably replaced by CO2)

Several North European countries are moving to natural refrigerants

Danish government applies a 100€ for 1 kg of HFCS in taxes

Kyoto protocol

Came into force from February 16th 2005, Over 160 nations involved

Greenhouse gas emission reduction

Strong influence on refrigeration and air conditioning

EU banishes HFCS, HCFCS, restricts the use of HFCS

Many important nations, such as Australia, Canada and Japan, set funds for HFCS emission reduction

Russia ratified Kyoto protocol on 2004

KYOTO PROTOCOL AND EU

Natural refrigerants: Why CO2

•Ammonia NH3

Know how available

Toxic/Flammable

Indirect system required

Water condensation

•Hydrocarbons HC

Know how available

Flammable/Explosive

Indirect system required

Reliable for domestic refrigeration

Largely available in nature (GWP=1)

Very low cost respect to traditional refrigerants

High refrigerating capacity

Not toxic/Not flammable

Direct expansion system with heat recovery

Redesign components required

EPTA CHOICE

Carbon Dioxide CO2

ALTERNATIVES

OUR CONCLUSIONS

Secondary systems aren’t economical choices, especially in LT. A DX concept is needed

The only natural fluid that can be used without harm is CO2

PLANT SOLUTIONS

2 Direct expansion

CO2 LT in cascade

with R404A or NH3

MT

3 Direct expansion

CO2 LT and MT with

heat realised

directly into the

atmosphere

1 MT and LT pack

with R404A or NH3

and CO2 as a

secondary

refrigerant subject

to phase change

Secondary fluid

system

Centralised CO2

system

SECONDARY FLUID SYSTEM

ADVANTAGES

Low pressure in piping High evaporator efficiency

DISADVANTAGES

Two refrigerants are used Pump energy consumption Plant complexity Installation costs

HFC, NH3

or HC

CO2

CO2 pump

HYCOOL®

• Product specification Following data is at 20°CComposition: Potassium formate 30-50%, deionised water and corrosion inhibitor

• Appearance: Clear fluid, insignificant smell

• Freezing point: -20 to -50°C• Density: 1194 – 1348 kg/m³• Dynamic viscosity: 1,8 – 2,6

mPas (cP)• Thermal conductivity: 0,50 –

0,56 W/mK• Specific heat capacity: 2,5 –

3,0 kJ/kgK

• Boiling point: 105 – 115°C at atmospheric pressure

• pH: 10,6 – 11,4• Refractive index: 1,364 – 1,385• Surface tension: 78,5 mN/m

för HYCOOL 20• Thermal expension coefficient:

3-4 • 10 -4 1/K• Vapour pressure: 1,3 – 2,0 kPa

Electrical conductivity: 210 – 240 mS/cm

• Flashpoint: Non-flammable• Miscibility with water:

Complete

CASCADE SYSTEM

ADVANTAGES

Consolidated know-how Low pressure in piping

DISADVANTAGES

Three fluids used LT not autonomous Plant complexity High installation costs

HFC, NH3

or HC

CO2

Secondary Fluid

(Propylene,etc..)

DIRECT EXPANSION SYSTEM/1

CO2

High pressure CO2 compressors

CO2

NT LT

DIRECT EXPANSION SYSTEM/2

ADVANTAGES

Completely “green”, only CO2

Simple system Competitive energy efficiency especially in cold climates Reduced CO2 charge

DISADVANTAGES

CO2 Relatively high pressure in piping Efficiency somewhat lower than conventional dx systems in hot climates without special arrangements

DESIGN CONCEPTS

With CO2 systems the following design concepts should be used:

To operate at the lowest discharge pressure permitted by ambient temperature (or cooling medium available) to operate in subcritical conditions when ambient temperature is < 20°

To use subcooling when operating at subcritical conditions

To use hybrid cooling when operating with high ambient temperature (> 30° C), the mass flow of water needed is very low

To use a 2 stage concept in low temperature (- 35°C) discharging the heat directly to ambient

COP - MEDIUM TEMPERATURE

CONDITIONS

Evap. temp. -10°C

Temp. evap. out -5°C

Subcooling 3 K in subcritical

Approach 3 K in transcritical

Calculation based on the monthly medium-day temperature

Minimum condensing temperature +25°C (R404A), +15°C (CO2)

HER based on indoor temperature

24

1 24

1

i iinmonth W

HERCOP

MT AIR COOLED

Ambient temperature

COP - LOW TEMPERATURE

CONDITIONS

Evap. temp. -35°C

Temp. evap. out -30°C

Efficiency of S/L HX 60%

Subcooling 3 K in subcritical

Approach 3 K in transcritical

Minimum condensing temperature +25°C (R404A), +15°C (CO2)

Calculation based on the monthly medium-day temperature

HER based on indoor temperature

24

1 24

1

i iinmonth W

HERCOP

LT AIR COOLED

Ambient temperature

ENERGY CONSUMPTION

CONDITIONS

MT 120kW

LT 20kW

Based on Bruxelles TRY

HER weighted upon internal thermal load

Minimum condensing temperature +25°C (R404A), +15°C(CO2)

COP of MT and LT CO2 unit as a function of ambient temperature

0

1

2

3

4

5

6

7

8

0 5 10 15 20 25 30

External temperature [°C]

CO

P

COP MT -10°C

COP LT -35°C

Customization required to gain efficiency in hot climate countries

Medium Temperature

EPTA RANGE

EPTA RANGE

Low Temperature

EPTA RANGE

Dimensions of 2 compressors units

EPTA RANGE

Three-compressors NT cooling pack, water gas cooling

EPTA RANGE

AIR GAS COOLER

SAFETY: PRESSURE/1

Design pressure of units is 120 bar high side and 60 bar low side Units are CE marked Evaporators of cabinets and cold rooms are designed for 60 bar Multipipe distribution system allows the use of small piping: 18 mm OD for about 20 kW at - 10°C, with pressure drop less than 100 kPa ( 1,5 K) in suction line for 40 m run Max working pressure of annealed copper pipe up to 18 mm is about 60 bar. Hard copper and joints can withstand even higher pressure Relief valves on unit manifolds and vessels protect piping and evaporators in the event of power supply failure for an extended period (typically many hours)

Opportunity: only main manufacturers and customers

PED compliance: new components by commercial refrigeration usual suppliers and industry suppliers are specifically designed (vessels, manifolds, filters,…)

Reliability: there are no technical reasons in the medium term for substantial differences between HFCs plants and carbon dioxide plants

Industrialization: high quality level over the whole supply and production chain

SAFETY: PRESSURE/2

Carbon dioxide concentration in the market area (600 sm)

0

2000

4000

6000

8000

10000

0 200 400 600 800Time to release the whole CO2

charge[min]

Concentr

ati

on

[ppm

]

15 min30 min60 min120 min240 min480 min

TOXICITY

Potential risks only in the machine room (leak detector)

Very low risks in the market area

Over two times lower than the value that causes a breathing acceleration

CASE HISTORY/1

DISTRIBUTOR / CONTRACTOR

CUSTOMER/ FIRM

COUNTRY PLACEINSTALLED

ONTYPE

COOP I LESTANS December-01TRANSCRITICAL,

WATER CONDENSED

AVESANI I VERONA May-02TRANSCRITICAL,

WATER CONDENSED

DE BASTIANI I SEDICO May-02TRANSCRITICAL,

WATER CONDENSED

TESAB COOP S KRISTINEHAMN September-02AMMONIA-CARBON DIOXIDE CASCADE

SYSTEM

GOETZ COOP CH BURGDORF August-03AMMONIA-CARBON DIOXIDE CASCADE

SYSTEM

SABCOBEL GB LUX MARNACH J uly-04CHILLER - GLYCOL AS

SECONDARY FLUID

TESAB ICA MAXI S TORSLANDA October-04AMMONIA-CARBON DIOXIDE CASCADE

SYSTEM

SABCOBEL LUX LUXEMBURG

CHILLER - TRANSCRITICAL, AIR CONDENSED, GLYCOL AS SECONDARY FLUID

ODENSE SUPER BEST DK STRANDBERG February-05TRANSCRITICAL, AIR

CONDENSED

ODENSE SPAR DK SOHUSTRANSCRITICAL, AIR

CONDENSEDTRANSCRITICAL, AIR

CONDENSEDFebruary-05NORREGADE

TESAB ICA FLODA

ODENSE DKTEGNING

S GOTEBORG February-05 TRANSCRITICAL, AIR CONDENSED

ODENSE TRANSCRITICAL, WATER CONDENSED

March-03DK BELLINGESUPER BEST

TRANSCRITICAL, WATER CONDENSED

J anuary-04VARBERGS

TRANSCRITICAL, WATER CONDENSED

TESAB COOP FORUM S LULEA August-04

S

ICA KVANTUMTESAB

COOP KONSUMTESAB

TRANSCRITICAL, WATER CONDENSED

HAKON-RIMI TEMPE

TESAB - TRONDHEIM

TRANSCRITICAL, WATER CONDENSED

October-04

TRANSCRITICAL, WATER CONDENSED

October-04TRONDHEIMN

LILLANGE - OSTERSUND

December-02BINGO I CORNUDA

2002: First supermarket

Chillers

Heat recovery

Transcritical air condensed

Transcritical water condensed

Cascade

CASE HISTORY/2

2002: First supermarket, 50 kw MT + 38 kw LT

Reliability: LT and MT refrigerating units are indipendent

2004: 180kw MT + 76kw LT

COSTAN:

2004: 160kw + 34kw

Transcritical MT + cascade subcritical LT

LINDE:

Complexity, criticity, reliability

DI STRI BUTOR / CONTRACTOR

CUSTOMER/ FI RM

COOLI NG PACKS

COOLI NG CAPACI TY

COOP 1 X MT 17 kW

AVESANI 2 X MT 40 kw

DE BASTIANI 1 X MT 18 kW

2 X MT 50 kW1 X LT 38 kW

TESAB COOP 2 X LT 40 kW

2 X MT 80 kW1 X LT 24 kW

GOETZ COOP 1 X LT 36 kW

2 X MT 150 kW2 X LT 76 kW

SABCOBEL GB 1 X MT 50 kW

2 X MT 180 kW2 X LT 76 kW

TESAB ICA MAXI 2 X LT 40 kW

2 X MT 180 kW2 X LT 76 kW1 X MT 75 kW1 X LT 38 kW2 X MT 100 kW1 X LT 38 kW

SABCOBEL 1 X MT 75 kW

TESAB ICA MAXI

TESAB ICA HYPER

ODENSE SUPER BEST 1 X LT 57 kW

ODENSE SPAR 1 X LT 45 kW

1 X MT 40 kW1 X LT 24 kW

BINGO

HAKON-RIMI TEMPE

TESAB - TRONDHEIM

ICA KVANTUMTESAB

COOP KONSUMTESAB

TESAB COOP FORUM

ODENSE SUPER BEST

TESAB ICA FLODA

ODENSE TEGNING

CONCLUSIONS

CO2 is a natural fluid, non toxic and non flammable

A single “green” fluid for all the refrigeration

system

Simple system

Energy efficient, especially in cold climates

Reduced CO2 charge

Reduced pipe diameters, low installation cost

Technically the best solution available today,

with further improvements under development

ALL - CO2 SUPERMARKET REFRIGERATION SYSTEMS