ATMOsphere Europe selects technology case studies

The ATMOsphere Review Panel has selected the first and the second round of case studies to be presented at ATMO Europe 2018, taking place in Lago di Garda, Italy (19-21 November 2018).

More case studies will be selected and announced in the coming weeks.

Click here to see the conference programme.

The selected case studies with CO₂–based technologies are:

Carrier Commercial Refrigeration | High efficiency solutions with CO₂ for warm & hot climates

Mostly based on ejectors, the full CO₂ solutions necessary to tackle the "CO₂Equator" have been introduced in the last past years. A second generation of advanced CO₂ systems, based on a combination of ejectors and other means to be tailored to the applications, is now available to deliver increased efficiency all year long, achieving significant annual energy consumption savings in warm and hot climates, when facing ambient temperature up to or even greater than 40°C. These systems will help to reach the Kigali HFC phase-down objectives anywhere in the world, including Middle East and Asia, by providing full CO₂ performance greater than the non-natural solutions used so far.

Tewis | Integration of refrigeration & air conditioning with CO₂ in supermarkets

Both the refrigeration and air conditioning industry are currently being driven by the EU’s F-Gas Regulation, taxes based on GWP refrigerants value, reduced supply of HFC refrigerants and the increases in prices to phase down HFCs. This scenario gives us the possibility to develop solutions based on natural refrigerants such as CO₂ to cover the needs of refrigeration and air conditioning in retail and supermarkets without forgoing the energy efficiency of the systems thanks to the synergies with complementary technologies.

These technical solutions require a deep knowledge of the refrigeration systems, an adequate risk analysis in the facilities and the implementation of new and specific controllers. The object solution is based on a CO₂ transcritical booster cycle machine with climate aspiration, parallel compressor and liquid economizer for freezing services. In addition to this integration, we propose to raise the evaporation pressure for freezing, cooling and AC controlling electronically the evaporators with an SH value between 2 and 0.

Enex | Water and brine chillers using CO₂ as a refrigerant 

Several water and brine chillers have been designed and installed in the last four years by Enex. The design of CO₂ chillers, originally similar to conventional HFC racks with dry expansion evaporators, evolved in a completely new design. This latest solution proved its advantage in terms of efficiency, reliability and simplicity. The experience gained allowed the optimisation of the product, which now can compete with state of the art products based on HFCs or HFOs. A further innovation is now available. A further step for efficiency improvement was done in 2017, following the adoption of ejectors for energy recovery. The result is an increase of efficiency such as to bring the new chillers at the same or better efficiency level than state of the art conventional HFC products.

The presentation will focus on some installations during the last two years, presenting measurements of efficiency and efficiency analysis compared with existing products.  

MITA | Energy optimisation in the food cold storage: MITA Alchemist solution

Electricity consumption for food cold storage is very high and represent a major obstacle to achieve NZEB qualification for buildings such as supermarkets. The operating temperature is too low to take advantage of any free cooling technology. Therefore it is necessary to optimise the energy efficiency of the systems, looking for synergies with the HVAC system. This case study illustrates a simpler and cost effective way to reduce electricity consumption for new R744 supermarkets with or without HVAC interfacing. This solution consists in installing an Adiabatic Extra Cooler (ALCHEMIST) piped downstream from the gas cooler.