The farther north, the closer to nature

Many new trends are coming from the north of Europe. The city of Vejle in southern Denmark has nearly 60,000 residents and is known, in particular, for its wave-shaped housing complex Bølgen. A recently completed project in the city is less obvious, yet just as indispensable: discount food retailer REMA 1000 built a new warehouse for the delivery of goods to its shops in western Denmark. The discount chain supports more than 800 subsidiaries in Denmark and Norway. REMA 1000 joined forces with system manufacturer Advansor and long-standing partner BITZER.

Advansor’s biggest compound system to date

The project kicked off in summer 2018. Working with ICS Industrial Cooling Systems, Advansor assumed responsibility for planning and implementing the new refrigeration system. ‘The warehouse was set up in an old dry-storage warehouse, though the system itself was new,’ says Business Development Manager Kenneth Madsen of Advansor. ‘A system like this is standard for us. But for this project we built the biggest compound system in company history.’

The refrigeration system has a total capacity of 940 kW at –4°C evaporation temperature and 32°C ambient temperature. And it is quite large, too, at 10.8 metres long. Six BITZER ECOLINE+ compressors ensure the medium temperature application, while two additional ECOLINE+ compressors provide for even greater efficiency in parallel compounding. The system is run in transcritical operation – and with CO₂ as a refrigerant, which has a GWP of 1, making it virtually climate-neutral.

Energy efficiency increased by more than ten per cent

Kenneth Madsen continues: ‘We’ve been working very closely with BITZER for a long time and source around 95 per cent of our compressors from the company. For this project, we opted for ECOLINE+ for the first time – because the best efficiency possible plays an important role with this system. This is also our first experience with LSPM.’ A BITZER LSPM motor is a line start permanent magnet motor. Kenneth Madsen knows the advantages of this technology very well: ‘Very few other technologies would be suitable for this system. They simply can’t handle the cold climate here. LSPM is a good technology because it works in any climate.’ In combination with Advansor’s system design, LSPM enables new increases in energy efficiency – by more than ten per cent.

With stringent limitations applied to fill volumes for synthetic refrigerants in Denmark in 2007, system designers and manufacturers will inevitably need to turn to natural refrigerants. At Advansor, however, this is not only a requirement, but also a choice: the OEM specialises in CO₂ solutions. Kenneth Madsen explains: ‘In Denmark, it’s probably easier than in other countries for these systems to gain a foothold.’ While hydrocarbons wouldn’t be an option, ammonia would. But most distribution centres and smaller businesses rely on CO₂, as it’s more affordable to purchase and operate with. ‘Five or ten years ago, this project would have opted for an ammonia system – but now the focus is on CO₂ for such cases. Everywhere in Europe.’

Further-developed CO₂ technology

Generally speaking, the regulations supporting the use of CO₂ in refrigeration are stringent in Scandinavia. BITZER compressors can offer effective solutions: ECOLINE+ is a further development of the proven ECOLINE reciprocating compressor series and is designed for supermarket applications in particular. One of its most important new features: the LSPM increases annual performance figures by more than ten per cent. The motors can be connected directly to networks with 50 and 60 Hz and offer a whole new level of efficiency in full and part load operation. The permanent magnet motors are also extremely robust and simple to use. In addition to direct operation in the network, the motors can also be used in the well-known speed range with frequency inverters.