ATMOsphere Europe presents first round of CO2 case studies

The four case studies will be presented at the 8th edition of ATMOsphere Europe, which takes place in Berlin, Germany, on 25-27 September. Over 350 industry experts will attend the three-day conference (two half-days and one full day) to discuss the latest policy and market trends and technological innovations in the natural refrigerants world. A session dedicated to the German market is among this year’s highlights. The presentations are: Dorin | CO₂ Against Ammonia: New Trends in the European Market by Giacomo Pisano CO₂ has been identified as one of the best alternatives to HFCs in many sectors, including commercial refrigeration. However, due to some lack of components, ammonia has so far been the preferred choice for larger applications, even if it brings several drawbacks; in particular, currently available CO₂ compressor displacements made it too expensive to compete with ammonia systems. This work deals with and describes a performance and cost comparison for large systems (capacity of around 1.5 MW) made with ammonia and CO₂. The system layouts are described as well as the very many efficiency advantages that have been possible to achieve thanks to the deployment of these new technologies. GEA | Highly efficient ammonia heat pump installed in central London by Kenneth Hoffmann In 2017, Islington Council has installed a 1,000 kW, two-stage, highly efficient heat pump which is turning the waste heat from a London Underground ventilation shaft into useable heat for the area’s high-rise apartment block in an extension to a district heating network. Up to 80⁰C hot water is required from the heat pump for the current district-heating network. By using two- stage piston compressors it has been possible to achieve a heating COP of above 3.5. This ensures significant local environmental benefit. As the project is next to a residential building the installation includes an ammonia absorber, which filtrates the air from the emergency extract fan to ensure that the extracted air is ammonia-free. This was an essential part of the installation as more high-rise buildings are planned in the area. University of Braunschweig – Institute of Technology | Energy assessment of water-loop systems for supermarket refrigeration by Nicolas Fidorra Water-loop systems with self-contained display cabinets are an alternative to centralised CO₂ booster refrigeration systems for supermarkets. They allow higher flexibility for rearranging the display cabinets and require little refrigerant charge inside the cabinets. This case study shows results from a simulation-based systematic investigation of different water-loop systems, using chiller, dry coolers and heat pumps for heat rejection or heat recovery. Furthermore, it looks at options to integrate cold thermal energy storage. The utilisation of different refrigerants in the display cabinets as well as in the chillers and heat pumps is assessed. The results are an energy assessment of different concepts of water-loop systems for supermarkets and indications of which concept runs efficiently under certain climatic conditions. Advansor | Small supermarkets with CO₂ remote systems – Mini-booster by Kim G. Christensen During the last 10 years CO₂ as a refrigerant has been evolving from test studies to mainstream usage in supermarkets. Medium and large supermarkets have already been adopting the technology for years. But smaller stores below 800m² have been a challenge: mainly due to price and complexity. Now, as the deadlines of the EU F-Gas Regulation move closer, these smaller stores must also make up their minds and go for natural refrigerants. So far, due to cost, the main choice has been plug-in or semi-plug-in solutions for small stores and solutions with CO₂ have been the second choice. This priority will change in the coming years due to better performance-cost ratio of a newly developed CO₂ system (Mini-booster) for this segment. This case study tells the story of a big discounter converting directly from R404A systems to CO₂. The conversion to CO₂ brought significant energy savings and reduced cost of ownership, but also increased the quality of the installations. Finally, the challenges of education and training will covered and the extensive programme used in this project will be explained. Read More