Risk Assessment of Mildly Flammable Refrigerants 2012 Progress Report The Japan Society of Refrigerating and Air-Conditi

1. Collaboration of JSRAE and SAME Okinawa Chapter Risk Assessment of Mildly Flammable Refrigerants 2012 Progress Report The Japan Society of Refrigerating and Air-Conditioning (JSRAE) November 22, 2013 Akio MIYARA Saga University Department of Mechanical Engineering

2. Contents of the report 1 Introduction 2 Legal issues with mildly flammable refrigerant 2-1 Explanation of high pressure gas safety law and legal issues with mildly flammable refrigerant 2-2 Current international trends regarding refrigerant 3 Research on safety of mildly flammable refrigerants3-1 Progress of the University of Tokyo 3-2 Research and development of low-GWP refrigerants suited to heat pump systems 3-3 Physical hazard evaluation of A2L-class refrigerants using several types of conceivable accident scenarios 3-4 Progress report by research Institute for Innovation in Sustainable Chemistry, AIST 3-5 Physical hazard evaluation on explosion and combustion of A2L class refrigerants 4 Progress of the Japan Refrigeration and Air Conditioning Industry Association (JRAIA) 4-1 Mini-split air-conditioner risk assessment SWG: The risk assessment result of the residential air-conditioner, and the study of the mini-split air-conditioner for small business use 4-2 VRFrisk assessment SWG: The 1st risk assessment of VRFsystem with A2L refrigerant and future 4-3 Chiller risk assessment SWG: Risk assessments policy of the chiller and guideline planning taking IEC60079 into consideration 5 Deregulation activities in Japan for the introduction of mobile air conditioning refrigerant R1234yf File can be downloaded from “ http://www.jsrae.or.jp/info/2012progress_report_e.pdf ”

3. Background Necessary & Indispensable Technology Comfortable life Refrigerating Sustainable society Survive Cold storage Freezing Cold chain Refrigerator car 1 Vapor compression system Food supply Food processing Absorption system Medical & Biological fields Refrigerator Industrial process Data center Industrial fields Drying Clean room House Hot water Automobile Office Hospital Heat Pump Building Adsorption system Air-Conditioning Combustion Cooling Heating

4. Background Need to Build Low-Carbon Society • Montreal Protocol (1987) • Phase out of ozone depletion gasses, CFCs, HCFCs, etc. • Developed countries • CFC: 1995 (Phase out was completed in Japan) • HCFC: 2020 (Production is being reduced) • Developing countries • CFC: Phase out in 2010 (start from 1999) • HCFC: Phase out in 2040 (start from 2016) • Alternative refrigerants: HFCs (R134a, R410A, etc. ) • Successful replacement • Kyoto Protocol (1997) • Reduction of greenhouse gases, CO2, HFCs(R32, R410A, etc.), etc. • Developed countries • Average reduction of 5.2% reduction from 1990 level by the year 2012 • 6% reduction for Japan, F-gas regulation in Europe • IPCC Fifth Assessment Report: Sep. 2013 ~ Oct. 2014

5. Motivation Next Generation Refrigerants • Natural refrigerants • HC in refrigerator, CO2 in HP water heater, NH3 in industrial … • Tentative continuous use of HFCs for midway • Refrigerant management • Refrigerant leakage, Refrigerant tracking, Engineers skill, … • R32is now being promoted. • Low GWP synthetic refrigerants: HFOs • R1234yf for mobile AC, R1234ze(E) for turbo chiller,R1234ze(Z) for heat pump in high temperature range …other HFOs, R1234ye, R1233zd, R1243zf, R1225 • Study on Properties, Heat transfer , Drop-in test, … • Refrigerant mixtures • Limitation of pure refrigerant properties • Suitable properties such as pressure, flammability, … • Property measurements, Cycle simulation, Drop-in test, …

6. Introduction by EijiHIHARA, University of Tokyo Summary of the proposed regulation of HFCs • EU protocol on mobile air-conditioning refrigerants • GWP < 150 from January 1, 2011 • Revise the Montreal Protocol (US, Canada, Mexico) • Restriction of production and sales of HFCs • F-gas Regulation for stationary air-conditioners • Reducing leakage,Proper management, Instruction courses, Labeling, Report by producers/importers/exporters

7. Proposed phasedown schedule of HFCs Proposal by US, Canada, Mexico Developing countries Developed countries Proposal by EU Commission

8. Emissions of HFCs in Japan -present situation- Total CO2 emission of HFCs[million-t] others Ref. & AC million-t CO2 Small refrigerator Large refrigerator Medium refrigerator Package AC for building Other business use Room AC Show case (split-type) In dispose In use Leakage

9. Trend in mildly flammable refrigerants • Environment-friendly refrigerants • Zero ODP (ozone depletion potential) • Low GWP (global warming potential) Refrigerants for room and package air-conditioners • HFOs • R1234fy ODP=0, GWP=4 • R1234ze(E)ODP=0, GWP=6 • HFCs • R32 ODP=0, GWP=675(note: most of other HFCs: GWP>1000) Mildly flammable rank 2L on ASHRAE Standard 34 Requirement of risk assessment

10. Methodology of risk assessment Burning characteristics of flammable refrigerants Mechanism of ignition Probability of ignition = (Leakage) X (High concentration) X (Ignition source) X (Low air velocity)

11. Research on safety of mildly flammable refrigerants By EijiHIHARA, Tatsuhito HATTORI, Makoto ITO University of Tokyo • Leakage of mildly flammable refrigerants

12. Simulation conditions of leakage of refrigerants Leakage scenarios Variable refrigerant flow air conditioning systems for building (VRF) Room air conditioners (RAC)

13. Simulation results of leakage of refrigerants Leak of R32 from wall-mounted indoor unit of RAC Simulation model Simulation result isosurface of concentration at LFL (13.3 vol%) Leakage scenario Combustion does not occur if the ignition source does not exist inside the indoor unit.

14. Simulation results of leakage of refrigerants Leak of R32 from floor-mounted indoor unit of RAC Simulation model Simulation result isosurface of concentration at LFL (13.3 vol%) Leakage scenario The leakage of flammable refrigerants from a floor-mounted indoor unit has a high risk of combustion.

15. Simulation results of leakage of refrigerants Leak of R32 from outdoor unit of RACin balcony Simulation model Simulation result isosurface of concentration at LFL (13.3 vol%) Leakage scenario The leakage of flammable refrigerants from an outdoor unit has a high risk of combustion. Note: Drains and under cuts shorten the presence of the gas.

16. Simulation results of leakage of refrigerants Leak of R32 from ceiling-mounted indoor unit of VRF Simulation model Simulation result isosurface of concentration at LFL (13.3 vol%) Leakage scenario A combustion gas region only exists just below the air outlet and the suction of the VRF, even if the entire quantity of refrigerant is discharged.

17. Simulation results of leakage of refrigerants Time variation of concentration of R32

18. Research and development of low-GWP refrigerants suitable for heat pump system By Shigeru KOYAMA, Kyushu University Yukihiro HIGASHI, Iwaki Meisei University Akio MIYARA, Saga University Ryo AKASAKA, Kyushu Sangyo University • Flammability • Toxicity • Thermodynamic properties • Transport properties • Heat transfer • Heat pump cycle

19. Drop-in experiments of pure HFO and HFO+HFC

20. Drop-in experiments of pure HFO and HFO+HFC

21. Drop-in experiments of pure HFO and HFO+HFC