Global experts discuss R744 in all applications

Gathering at the c-dig meeting in Tokyo last week, experts discussed the use of CO₂ in refrigeration, heating, and air conditioning systems.

From 27-29 August, around 40 global experts from leading component and system suppliers, research institutes, and universities met in Japan to discuss latest developments in CO₂ Technology. Subjects covered a whole range of applications, from hot water heat pumps to climate control systems in army vehicles and cold storage plants. The three day event also included several visits to suppliers and research institutes specialized on CO₂ systems, among them the Nikkiso Pumps factory, the Waseda University, and the Mycom plant.

CO₂ success stories Klaas Visser from KAV Consulting explained the benefits of CO₂ in domestic hot water heating, building air conditioning, and industrial refrigeration. Test results presented by him showed that applying direct CO₂ cooling to water heating will reduce the total energy use significantly, as well as retrofitting CO₂ cooling systems to already existing building air conditioning systems does. In food processing operations, where simultaneous cooling and heating is required, transcritical CO₂ refrigeration coupled with subcritical systems offered a significant potential for energy reduction.

Pega Hrnjak from Creative Thermal Solutions presented his project of converting an U.S. Army 15 kW ECU unit working with R-134a to a CO₂ unit. The results proved that using the same unit, evaporator and fans, the converted CO₂ unit achieved a 12% higher efficiency and a 66% higher capacity at 52°C outside temperature compared to the baseline system. Other presentations Other interventions covered:

• Latest studies on CO₂ heat pump developments (Kiyoshi Saito, Waseda University)
• CO₂ Eco Cute Heat Pump Developments in Sweden (Yang Chen, Royal Institute of Technology, Sweden)
• CO₂/NH3 plant operation from the end-user perspective – The 1st large-scale installation in Japan (Atsushi Ishii, Nestlé)
• CO₂ compressor development (Nick Kawamura, Mycom Compressors) – see the image gallery below
• Latest trends and developments in Eco Cute heat pumps (CRIEPI) – see the image gallery below
• R744.com – Your Market Place for CO₂ Technology, News & Policy (Marc Chasserot, Shecco) - see the presentation below

Background The carbon dioxide interest group (c-dig) promotes CO₂ as a refrigerant in cost-effective and energy-efficient systems through a regular exchange of information, technical presentations, and research support. At present, it counts 138 members from the academia, manufacturers, contractors, and the media from all around the world.