Case Study Detail
Carrefour Galati (RO)
The CO2-Booster-Refrigeration system in Galati sets new standards
The Carrefour hypermarket opened its doors in the new "Galati Shopping City" on 22nd of November, 2013. It is the first hypermarket in Romania to use a CO2-booster-refrigeration-system to supply all medium and low temperature consumers and sets new energy-efficiency standards. A 30% energy efficiency and a 70% reduction in CO2-footprint in comparison to refrigeration systems using synthetic refrigerants can now be achieved in Romania.
The continental climate in Romania, the transfer of know-how and the supply of technical CO2-refrigerating parts were the biggest chal-lenges faced by implementing the full CO2-systems to Romania, now this project is honoured as a sustainable success story.
The continental climate in Romania, the transfer of know-how and the supply of technical CO2-refrigerating parts were the biggest chal-lenges faced by implementing the full CO2-systems to Romania, now this project is honoured as a sustainable success story.
"Full" CO2-refrigeration-systems are now the most sustainable and energy-efficient solution in both the commercial and industrial sectors and were rediscovered exactly one decade ago. Prompted by the tightening of laws and increase of taxes on synthetic refrigerants, countries such as Denmark, Scandinavia and Switzerland now regard "full" CO2-refrigeration systems as the most advanced technology. Yet other countries were slower off the mark. The reasons ranged from cost aspects to use in countries with warmer climates. It is understandable that it would take a lot to con-vince sceptics before this almost extinct technology could be implemented on a large scale again. It took the driving inno-vative force and developments of a small team of engineers using refined system technology and synergies between energy efficiency and financial viability to correctly inform and convince operators and finally set aside the scepticism. Carrefour Europe has not only leveraged this enormous yet untapped potential to save operating costs and reduce the CO2-footprint, the hypermarket giants also recognised that the CO2-footprint of a refrigeration system could also be significantly reduced. For this reason, Carrefour Europe decided to introduce CO2-refrigeration systems into all its hypermarkets.
Situated on the Danube river shortly before it enters the Black Sea and close to the border with Moldova, the climate in Galati is dominated by extreme temperature differences ranging from -20°C in winter to +40°C in summer. The solution to this climate challenge was to design a system with parallel compression in combination with an air-cooled subcooler that also uses the natural refrigerant propane. A booster control unit with integrated parallel compression management was used to facilitate control, increase energy efficiency while also reducing investment and operating costs.
By integrating a CO2-subcooler, the gas cooler outlet temperature can be reduced to +26°C all year round and the flash gas is aspirated directly from the receiver 9K higher than the medium temperature evaporating level thanks to the parallel compression technology. Both energy efficiency and occupational safety were incorporated into the design that generates energy savings of 30% with 265 kW of medium and low temperature cooling capacity and results in annual electricity savings of over 100,000 kWh.Whereas only a percentage of the waste heat was previously converted or otherwise emitted into the environment in Romania, now 100% of it is used in Galati to heat on aver-age 4,000 litres of water each day for domestic use and to heat the warehouse, social rooms and offices at the Carre-four hypermarket. This helps to significantly reduce the use of fossil fuels, which in turn reduces the carbon footprint. This has yet to be considered in the comparison of refrigera-tion technologies and the reduced CO2-emissions of 3.6 million kilograms.
"Full" CO2-refrigeration-systems are now the most sustainable and energy-efficient solution in both the commercial and industrial sectors and were rediscovered exactly one decade ago. Prompted by the tightening of laws and increase of taxes on synthetic refrigerants, countries such as Denmark, Scandinavia and Switzerland now regard "full" CO2-refrigeration systems as the most advanced technology. Yet other countries were slower off the mark. The reasons ranged from cost aspects to use in countries with warmer climates. It is understandable that it would take a lot to con-vince sceptics before this almost extinct technology could be implemented on a large scale again. It took the driving inno-vative force and developments of a small team of engineers using refined system technology and synergies between energy efficiency and financial viability to correctly inform and convince operators and finally set aside the scepticism. Carrefour Europe has not only leveraged this enormous yet untapped potential to save operating costs and reduce the CO2-footprint, the hypermarket giants also recognised that the CO2-footprint of a refrigeration system could also be significantly reduced. For this reason, Carrefour Europe decided to introduce CO2-refrigeration systems into all its hypermarkets.
Situated on the Danube river shortly before it enters the Black Sea and close to the border with Moldova, the climate in Galati is dominated by extreme temperature differences ranging from -20°C in winter to +40°C in summer. The solution to this climate challenge was to design a system with parallel compression in combination with an air-cooled subcooler that also uses the natural refrigerant propane. A booster control unit with integrated parallel compression management was used to facilitate control, increase energy efficiency while also reducing investment and operating costs.
By integrating a CO2-subcooler, the gas cooler outlet temperature can be reduced to +26°C all year round and the flash gas is aspirated directly from the receiver 9K higher than the medium temperature evaporating level thanks to the parallel compression technology. Both energy efficiency and occupational safety were incorporated into the design that generates energy savings of 30% with 265 kW of medium and low temperature cooling capacity and results in annual electricity savings of over 100,000 kWh.Whereas only a percentage of the waste heat was previously converted or otherwise emitted into the environment in Romania, now 100% of it is used in Galati to heat on aver-age 4,000 litres of water each day for domestic use and to heat the warehouse, social rooms and offices at the Carre-four hypermarket. This helps to significantly reduce the use of fossil fuels, which in turn reduces the carbon footprint. This has yet to be considered in the comparison of refrigera-tion technologies and the reduced CO2-emissions of 3.6 million kilograms.
Extremely optimistic outlook
The entire refrigeration industry has now also woken up to the potential and benefits of “full” CO2-refrigeration systems, and no other industrial sector has witnessed such a high number of innovations and developments for any other refrigerant. This opens up diverse and, above all, sustaina-ble benefits for operators, manufacturers and system engineers; costs are constantly being driven down due to the high level of industrial production, standard processes and lower stock levels. As a result, the decision to invest in "full" CO2-technology today makes obvious sense, the CO2-footprint will continue to decrease despite higher investment costs and ensure decisively lower operating costs for the operator.
Diagram of the "full" CO2-booster system with integrated parallel compression and external subcooler, with the natural refrigerant R290 propane used in the new Carrefour hypermarket in Galati.
The diagram compares the environmental impact of CO2-emissions from a standard refrigeration system with synthetic refrigerants to the "full" CO2-refrigeration-system from one Carrefour hypermarket in Galati. The reduction of 3.6 million kilograms of CO2-emissions over a 15-year period is the equivalent of exhaust emis-sions from 1,800 mid-range cars
CO2-gas cooler in the background in combination with the subcooler above the machinery room & CO2-booster-refrigeration-system from Carrefour Galati.
In cooperation with:
January 2014
Project leader:
Marcus Hoepfl