Solutions for a Sustainable Future
In recent years, protection of the environment and energy efficiency have become major concerns for society as a whole. Being part of the global Auchan Group, which insists on making a sustainable development a daily reality, the Alcampa Management looked for a green refrigeration solution for the new hypermarket in Toledo.
From the outset, Danfoss took part in designing the solution, thanks to the experience it has gained in the over 1500 sub-critical and trans-critical installations throughout the world.
To ensure optimum performance and the lowest carbon footprint, contractor Maxfri Costa S.L, chose a cascade R134a/CO2 system together with Danfoss. Choosing this system, Alcampo’s annual CO2 emission from the refrigeration system will be reduced by up to 65%.
Combined with a lesser load of refrigerant needed, the hypermarket will gain substantial savings by shifting to the less expensive CO2 compared to HFC refrigerants.
The maintenance of a Danfoss CO2 refrigerating system is the same as for an HFC system.
A sustainable CO2
refrigeration system with heat recovery is an excellent solution for retailers as it generates cold and heat at the same time.
is a natural refrigerant with a low impact on ozone layer degradation and a GWP index of 1. CO2
has an excellent volumetric efficiency, which entails smaller diameters in the piping (a sizeable advantage as the price of copper soars) and a lesser load of refrigerant. CO2
offers a high energy output and is still less expensive than other HFC refrigerants.
Normally, the heat generated by a refrigeration system is released straight out into the fresh air. This is avoided, when the refrigeration system uses CO2
as a refrigerant.
Although the CO2
-refrigerant is very attractive, it appears to be difficult to handle at first glance. The major difficulties stem from the need to use higher working pressures than usual, and the fact that algorithms for the electronic controllers must be adapted to the specific properties of this refrigerant. With a complete range of both electronic controllers and line components that make it possible to overcome these difficulties, together with ample experience and knowledge in the field, Danfoss could guide Maxfri Costa in selecting the components and optimizing the system parameters.
The Alcampa Solution in Details
The R134a circuit cools the refrigerated services (refrigerator cabinets and cold storage rooms), expanding directly via AKV electronic valves. Besides performing the refrigeration cooling, the R134a circuit is also used to remove heat from the CO2
circuit by condensation of CO2
in a plate heat exchanger in which the R 134a expansion is carried out directly via ETS electronic valves.
In the same manner, the CO2
cools the freezer services (freezer units and walk-in freezers), expanding directly via AKV electronic valves. The CO2
is then compressed in a CO2
compressor and condensed in the R134/CO2
Reduction of CO
Refrigerant R134a was chosen instead of R404A due to its excellent thermodynamic properties and its low Global Warming Potential (GWP). As regards the CO2
, it meets the technical specifications perfectly. It is a natural refrigerant that has little impact on the deterioration of the Ozone layer and has a Global Warming Potential (GWP) index of 1.
In terms of GWP, if we compare the traditional R404A installation with the new R134a/CO2
installation, assuming the level of leaks remains the same each year, the environmental impact measured in the equivalent of kg of CO2
will be reduced by up to 65%.
Reduction of Energy Consumption
From an energy saving point of view, another of the participants in the project (Fergasa), using a simulation tool that looks at all possible action areas relating to the Danfoss ADAP-KOOL® electronic controller, estimated the additional energy saving of the installation, comparing two versions of the same installation:
- The traditional version featuring two R404A central units with AKV electronic expansion valves on all services, etc.
- The new suggested R134a/CO2 version, also with AKV electronic expansion valves on all services, etc.
Facts About the Auchan Group
Alcampo is a hypermarket chain in the French Auchan Group. In 2014, the group operated in 16 countries, employed 302 500 people and generated in 2013 €62.1 in revenue including taxes for the chains. The group operates within banking, real estate, e-commerce, and hyper-/supermarkets among other businesses.
What Is a Hypermarket?
> 2,500to 22,000 m²
of sales area
> 150 to 900
> 5,000 to 30,000
customers a day
> 30,000 to 100,000
food and non-food products
> 20 to 90
> 1,000 to 5,000