Conférence HFO de l'IIF : l'efficacité énergétique et la sécurité à l'honneur (en anglais)
For the first time, the IIR organised an international conference on HFOs. It took place on September 2-5, 2018 in Birmingham, UK. 175 people attended and 68 papers were presented, dealing mostly with safety, energy efficiency and environmental issues. It was a success and a second IIR Conference on HFOs will be organised.
A workshop on the European Project “Real Alternatives for Life” on training on low GWP refrigerants, including HFOs, was organised.
Energy efficiency and safety were at the heart of the conference. Of the 68 papers presented, 38 addressed the energy efficiency issue through performance evaluation of refrigerating systems using HFOs and HFO blends in various applications and 22 raised the safety issue linked to the use of these A2L (mildly flammable) refrigerants.
All papers from this conference can be downloaded through the IIR Fridoc database.
- Regarding energy efficiency, C. Allgood and A. Pansulla1, from Chemours, compared the total (direct + indirect) carbon emissions of a commercial refrigeration system for various system configurations and various refrigerants through a TEWI-based modelling.
The following refrigerants and system set ups were studied as part of the TEWI analysis: R-404A Centralized, R-449A Centralized/Distributed, R-454A Centralized, R-454C Centralized, CO2/R-134a Cascade, CO2/R-513A Cascade, CO2/R-454C Secondary Loop, CO2/R-1234yf Secondary Loop, and CO2 Transcritical Booster. Two climate profiles in the USA were considered: San Diego, CA and Syracuse, NY. In both the warmer climate of San Diego and the cooler climate of Syracuse, the R-1234yf/CO2 secondary loop, the R-454C/CO2 secondary loop and the R-513A/CO2 cascade configurations showed promising CO2 eq savings, relative to the R-404A baseline. The cooler temperature of Syracuse also allowed for the CO2 transcritical booster system to have relatively low carbon emissions. When considering the cost of systems, a case can also be made for R-449A, providing very favorable carbon emission savings at a relatively low cost.
- Regarding safety issues, X. Wang2 presented the results of AHRI research activities aimed at accelerating the safe use of flammable refrigerants in air conditioning and refrigeration equipment.
Extensive ignition testing for A2L refrigerants R-32 (HFC), R-1234yf, R-1234ze (HFOs) and R-452B (HFC-HFO blend) with ignition sources commonly seen inside residential dwellings was conducted in an experimental apparatus. Testing results indicated that lubricant, room temperature and humidity had no effect or reduced event severity. High charge, high leak rate and low release height and furniture obstruction increase event severity. When employing fan circulation as a mitigation method, fans must be activated quickly before ignition occurs. Majority of tested potential ignition sources commonly seen in homes were unable to ignite the A2L refrigerants/air mixtures. The tested sources resulting in ignition are open flame (lighter, match and candle) and hot nichrome wire. Refrigerants R-32, R-452B and R-1234ze were not ignited when in contact with a hot plate having surface temperatures up to 850°C. None of them with 3% oil was ignited with the hot plate temperatures up to 800°C.