Romania’s first CO2 transcritical store with parallel compression system by Advansor

By Silvia Scaldaferri, Mar 04, 2014, 16:12 2 minute reading

In November 2013, the first transcritical Carrefour hypermarket was installed in Galati, Romania. Frigo-Consulting Ltd. was responsible for engineering, designing and the execution consulting of the project, whilst Frigotehnica comissioned, installed and will maintain the entire installation over the next decade. The system, supplied by Advansor, uses parallel compression that allows for better energy performance in high ambient region of Romania. 2014 will see several other CO2 tran

Whilst already over 2,880 stores have been equipped with CO2 transcritical systems across Europe, in November 2013, the first of its kind was installed in a Carrefour hypermarket in Romania.

This project was a success for Frigotehnica. For the first-time ever in Romania transcritical technology was used, and the complete design and installation was performed by our team,” commented Razvan Voicu, Operations Manager of Frigotehnica.

Carrefour is currently the only retailer focused on both transcritical and hybrid technology in Romania, noted Voicu of Frigotehnica, and expressed his hopes for some future projects with the retailer in the region.

For Advansor, the supplier of the system, this project was its first high ambient installation. Torben M. Hansen, Advansor’s Director, gave a preview of the company’s plans for the near future:

Presently we are planning more jobs in Romania, Italy and Spain, expecting at least ten warm climate solutions this year in Europe. In addition our American colleagues are planning quite a few hot ambient projects.”

Parallel compression improves efficiency in high ambient

Advansor has supplied a full CO2 system for LT and MT operation, with 2-stage heat recovery to water. “The system has a so called 'parallel compression' feature to enhance the energy performance of the system during warm ambient and also during winter heat-recovery operation,” explained Hansen.

“In traditional DX systems, the flash gas is generated and removed on the MT and LT stages. In a parallel compression system, the majority of flash gas is removed at a higher pressure by the parallel compressor and hence, the energy penalty from the flash gas is less.

In this way the parallel compression is quite similar to an economiser system in an NH3 plant. When the CO2 systems are operated in warm climates, the flash gas generation is particularly high and hence the parallel compression is justified in warm ambient regions,” he added.

The system allows for improved energy efficiency to HFC, however, the real benefit is the lower direct emission due to the refrigerant R744.

Key features and specifications of the system

The system has 4 normal MT compressors [Bitzer] plus one parallel compressor for the upper stage. The low stage has 3 LT compressors,” described Hansen.

The Advansor booster unit compSUPER XL 4+1x4B installed in this project has the following specifications:

  • The capacities are approximately 200 kW MT and 45 kW LT loads.
  • 25 kW hot water produce at 60°C
  • 240 kW building heat to water, 27°C -42°C

Other key components of the refrigeration system include:

  • Kimessa AG CO2 detection system consisting of 27 CO2 sensors and complete monitoring, alarm
  • Euroklimat chiller (propane as refrigerant, ethylenglycol as brine) for CO2 gas sub cooling
  • Danfoss complete control and monitoring solution both for booster unit and refrigerating plant, with 24 hours remote monitoring
  • Danfoss electronic expansion valves for cold rooms and cabinets
  • LU-VE CO2 evaporators including 2 special units in stainless steel construction


By Silvia Scaldaferri

Mar 04, 2014, 16:12

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