History of a New Technology - Part 5
The consolidation of the business and the ejector
1. The consolidation of business
Between 2009 and 2013, transcritical CO2 technology was still considered a niche, nevertheless it started to attract large companies. The first consequence was the acquisition, or the partnership, of large companies with the 3 companies specialized in CO2 and founded between 2004 and 2007. Dover group took over Advansor, Carrier took over Green&Cool and Huurre, a Finnish group, acquired a minority stake in Enex. It was the first signal of the interest of the market, even before a real significant increase in sales.
2. The Ejector Revolution: An Unexpected Discovery
The ejector was an almost “mysterious” object in refrigeration. Invented in France around 1850 for other purposes, it remained a theoretical concept in refrigeration until it was revisited by SINTEF in Trondheim around 2010. It is a static device that uses expansion energy to reduce the work required by compressors.
The real breakthrough happened at Enex, from an intuition born during a test gone wrong:
- The Unexpected: While testing an ejector on a heat pump, we noticed it wasn’t performing according to the calculations, but it was behaving as an excellent “liquid pump.”
- The Intuition: “What if we used it to recirculate refrigerant in the evaporators?” Thus, the concept of the overfed (or semi-flooded) evaporator was born.
- The Result: The first real plant, installed by Enex in Lahti, Finland, showed an average efficiency increase of 20-25%. This technological leap, protected by a series of patents, changed the rules of cooling in 2010.
3. Switzerland: A Permanent Laboratory
Switzerland was a source of excellence. Enex, together with partners like Frigo Consulting and Kaeltering, perfected the integration of the ejector and the economizer circuit between 2011 and 2012. After the first experiments in Finland by Enex, some very interesting field tests were done. First of all one installation in Bulle, near Gruyere, then one installation near Luzern (Schwitz) followed. After that many others.
Initially Enex produced directly the ejectors based on a design made by Sintef. More solutions became soon available. Starting 2015 Danfoss developed the “multiejector”, an industrial breakthrough. Carrier and Carel developed the step-motor controlling mechanism for their ejector.
The configurations developed solved a limitation: it allowed the ejector to operate continuously and stably in all environmental conditions, without the need for complex control devices.
In Switzerland the cooperation between Frigoconsulting, Kaeltering and Enex allowed to make preliminary tests with other devices, like for example with an expander. However the ejector, theoretically less efficient, was superior due to intrinsic simplicity and the intrinsic reliability.
4. 2013: Expansion of CO2 to eastern countries
Thanks to the prestige earned through Swiss and Scandinavian installations, the Eastern European market unexpectedly opened up. Some large retailers decided to use CO2 in Romania and Poland for some hypermarkets. Enex and Green&Cool (Carrier) were initially the competing suppliers for these installations.