CO₂ systems in warmer climates and for heat recovery, hot topics at ATMOsphere

Taking place from 5-7 November in Brussels, ATMOsphere Europe 2012 will bring together around 200 experts from Europe and beyond to discuss latest trends and developments for natural refrigerants. Two case study sessions will include innovative projects and present latest efficiency and cost results and comparisons for CO₂ systems. Below we have prepared a short summary of the presentation abstracts. For further details, please go to www.ATMO.org.

• Field trial results of efficient container refrigeration applications using CO₂ by J. Michael Griffin, Carrier Transicold: Last November Carrier introduced the world’s first natural refrigerant container unit, the NaturaLINE™, which uses carbon dioxide refrigerant. The units have successfully operated over a full range of ambient temperature settings and conditions, maintaining frozen and perishable set points -35º C (-31° F) to 30º C (86° F), on routes crossing the Atlantic and Pacific oceans, on trips ranging from 4- to 28-days. Carrier will provide a case study overview and field trial results of an actual shipment. Overall performance characteristics, such as energy and CO₂ emissions savings will also be discussed

• Transcritical CO₂ cooling system for Norwegian ice cream manufacturer by Torben Hansen, Advansor: The case study will present a project with Norway’s leading ice cream manufacturer, Diplom-Is AS, who wanted to install an environmental and cost efficient refrigeration system in a newly built cold storage warehouse in Trondheim, Norway. Advansor delivered a CO₂ transcritical booster system. Heat recovery with capacity of 150kW and hot gas defrost options were specially designed and added. Expected yearly energy savings as well as first results and efficiency figures will be presented.

• Heat recovery with CO₂ Systems in Food Retail by Torben Funder-Kristensen, Danfoss: Two case studies will be presented, one involving a middle sized and one involving a small supermarket. Instead of rejecting heat into the ambient, heat is reclaimed to warm up sanitary water and water for space heating. CO₂ shows splendid characteristics for this application because it is easy to control the discharge temperature. Very good overall COP improvements are seen and a short pay back on investment are shown.

• Large scale NH₃/CO₂ system for warmer climates by Alexander Cohr Pachai, Johnson Controls: Considering the Montreal Protocol and the coming phase-out of CFCs and HCFCs in article 5 countries, Jordan Poultry has chosen to invest in a CAFP cascade unit using ammonia for the high temperature stage and CO₂ for cooling and freezing applications. JCI will present the project that was installed and commissioned in August 2012, a system that is perfectly suitable for warmer climates like the Mediterranean regions.

• Transport refrigeration system using CO₂ by Bart Ezendam, Thermo King: The case study will summarise the developments by Thermo King of cryogenic solutions over the last 15 years, which reduce the carbon footprint of refrigerated vehicle fleets. Being the only open cycle transport refrigeration system using CO₂ that is currently commercially available, the concept is based on the use of liquid CO₂ to provide refrigeration effect. An analysis of the actual refrigerant consumption, based on a typical life of the units will be also presented.

• Sustainable CO₂ technology and the role of control systems by Diego Malimpensa, CAREL: Based on knowledge of real systems and experiences developed together with our technological partners, this report will illustrate how continual innovation of control systems can have a key role in facilitating the introduction of CO₂ into the market, through:

1. Worldwide training and dissemination of knowledge through local support network
2. Design of specific, integrated solutions that simplify the development and commissioning of intrinsically complex systems such as CO₂ (R744)

• Efficiency analysis and comparison of innovative CO₂ refrigeration systems by Jonas Schönenberger, Frigo Consulting: In an ongoing research project commissioned by the Swiss Federal Office of Energy, the company is investigating the efficiency of existing, innovative CO₂ refrigeration systems and developing additional innovative proposals to further increase the efficiency of transcritical CO₂ refrigeration systems. In the project that will be presented, the operation of existing CO₂ refrigeration systems with an expansion‐compression‐unit, with an adsorption chiller as well as with parallel compression will be analysed in detail and compared in efficiency, life cycle costs, market potential and lessons learned.

• Efficiency improvement in commercial refrigeration for warmer climates with CO₂ by Sergio Girotto, enEX: A new system design, based on a liquid recirculation method using an ejector for liquid pumping with a saving potential of 15% during the whole year as well as experimental data will be presented by Sergio Girotto. The ejector design can be easily combined with the so-called parallel compression techniques suitable for increasing efficiency in warm climates. Lessons learned will be presented, as well as an energy and economic analysis. The overall energy efficiency increase compared to simple CO₂ systems now in use can be as high as 25%.

• Field measurements of supermarket refrigeration systems: CO₂ transcritical vs. HFC conventional by Samer Sawalha, KTH: The case study will present experiences in applying CO₂ in supermarket refrigeration and in ice rinks. Computer simulation modelling, laboratory experimental work and actual field measurements were used to investigate CO₂ in indirect, cascade and transcritical refrigeration systems. In this case study the cooling demands and the COP of five CO₂ transcritical and three conventional supermarket installations will be presented.

• Presentation focused on other refrigerants: Natural Refrigerants in Different Industrial Heat Pump plants in Norway by Jan Boone, Mayekawa

About ATMOsphere Europe 2012

NATURAL REFRIGERANTS - SOLUTIONS FOR EUROPE: Already in its fourth year, this interactive workshop and conference on Natural Refrigerants (CO₂, ammonia, hydrocarbons, water, air) will be organised in Brussels from Tuesday to Wednesday, 6-7 November, with a pre-event on 5 November. This year the emphasis will be on case studies, experiences, and discussions - meaning solutions - to how natural refrigerants can be viable alternatives to f-gases across Europe.