A Primer on HFOs Hydrofluoro-olefins Low-GWP Refrigerants Brett Van Horn, PhD Arkema Inc. January 30, 2011 2011 ASHRAE Winter Conference Las Vegas, NV
Learning Objectives for this Session Describe the climate change issue and associated with high GWP refrigerants and the leading low GWP options available Explain the refrigerant thermophysical property requirements needed for new low GWP refrigerants and how property data may be used Be able to explain the challenges with measuring the flammability properties of refrigerants that are only marginally flammable and options to make these measurements Explain the development history of hydrofluoro-olefin low GWP refrigerants such as HFO-1234yf Describe the codes and regulations in the US, Europe and Japan that govern the use of low GWP refrigerants such as CO 2, ammonia, hydrocarbons and HFOs and the barriers in current standards for their potential use Apply learnings from this seminar to begin selecting low GWP refrigerants for specific applications and begin designing new HVAC&R systems with these refrigerants ASHRAE is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to ASHRAE Records for AIA members. Certificates of Completion for non-aia members are available on request. This program is registered with the AIA/ASHRAE for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
Drivers for Refrigerant Selection Environmental Sustainability ODP, GWP, LCCP NASA-GSFC, 2002 Safety Flammability Toxicity Performance Efficiency Capacity Supply Cost, Availability
Refrigerant Timeline Feasibility Ethyl Ether NH 3 CO 2 CH 3 Cl SO 2 CCl 4 Etc. 1930 1950 1970 1990 2010 1748: William Cullen: mechanical refrigeration 1805: Oliver Evans : concepts of mechanical refrigeration 1824: Nicolas Léonard Sadi Carnot: Carnot Cycle 1834: Jacob Perkins: refrigerating device 1844: John Gorrie: first practical refrigerator 1857: James Harrison: refrigerator U.S. Patent 8,080
Refrigerant Timeline Feasibility Safety & Efficiency Ethyl Ether NH 3 CO 2 CH 3 Cl SO 2 CCl 4 Etc. 1930 1950 1970 1990 2010 CFCs HCFCs 1928: Midgley, Henne, McNary (GM): CFC refrigerants 1931: R-12 1932: R-11 1933: R-114 1934: R-113 1936: R-22
Refrigerant Timeline Feasibility Safety & Efficiency Ozone Protection Ethyl Ether NH 3 CO 2 CH 3 Cl SO 2 CCl 4 Etc. 1930 1950 1970 1990 2010 CFCs HCFCs HFCs 1985: Vienna Convention 1987: Montreal Protocol 1996: CFC phase-out NASA-GSFC, 2002
Refrigerant Timeline Feasibility Safety & Efficiency Ozone Protection Climate Change Ethyl Ether NH 3 CO 2 CH 3 Cl SO 2 CCl 4 Etc. 1930 1950 1970 1990 2010 CFCs HCFCs HFCs HFOs Next Generation: HFO Refrigerants Can offer balance among: Environmental profile Safety and Durability Performance
HFO: Nomenclature Hydro-Fluoro-Olefin 2,3,3,3-tetrafluoroprop-1-ene HFO 1 2 3 4 y f # of fluorine atoms # of hydrogen atoms + 1 # of carbon atoms - 1 # of unsaturated bonds Propene Series Substitution on terminal methylene carbon: a: =CCl 2 c: =CF 2 e: =CHF b: =CClF d: =CHCl f: =CH 2 Substitution on central carbon: x: -Cl, y: -F, z: -H
Propylene Series: examples R-1270 R-1243zf R-1234yf R-1234ze(E) R-1216 T b = -48 C T b = -22 C T b = -29 C T b = -19 C T b = -29 C Flammability 3 #F = 0 2 * #F = 3 2L #F = 4 2L ^ #F = 4 1 * #F = 6 Toxicity A nc A A ^ nc *: estimated. ^: as submitted to ASHRAE. nc: not classified by ASHRAE
Refrigerant Timeline: Introduction of Propenes Ethyl Ether NH 3 CO 2 CH 3 Cl SO 2 CCl 4 Etc. 1930 1950 1970 1990 2010 CFCs HCFCs HFCs HFOs
Refrigerant Timeline: Introduction of Propenes Ethyl Ether NH 3 CO 2 CH 3 Cl SO 2 CCl 4 Etc. 1930 1950 1970 1990 2010 CFCs HCFCs HFCs HFOs R-1270
Refrigerant Timeline: Introduction of Propenes R-1243zf Ethyl Ether NH 3 CO 2 CH 3 Cl SO 2 CCl 4 Etc. 1930 1950 1970 1990 2010 CFCs HCFCs HFOs HFCs R-1270
Refrigerant Timeline: Introduction of Propenes R-1243zf R-1216 Ethyl Ether NH 3 CO 2 CH 3 Cl SO 2 CCl 4 Etc. 1930 1950 1970 1990 2010 CFCs HCFCs HFOs HFCs R-1270 Fluoropropenes (1243zf, 1234yf, 1234ze, 1216...)
Refrigerant Timeline: Introduction of Propenes R-1243zf R-1216 Ethyl Ether NH 3 CO 2 CH 3 Cl SO 2 CCl 4 Etc. 1930 1950 1970 1990 2010 CFCs HCFCs HFOs HFCs R-1270 R-1234yf Fluoropropenes (1243zf, 1234yf, 1234ze, 1216...)
Refrigerant Selection Durability Stability Material Compatibility Physical Properties Density, Thermal Conductivity, Pressure, Viscosity,... Environmental Ozone Depletion Global Warming Refrigerant Selection Performance Efficiency, Capacity Flow Rate, Pressure Ratio, Many factors are important for selecting a refrigerant for any particular application Safety Flammability Toxicity, Pressure Thermodynamics Boiling Point, Critical Point P-H, T-S,... The approach is to find the best balance between refrigerant properties, system architecture, and application environment. Advances in refrigeration technology can affect refrigerant selection.
Refrigerant Volumetric Capacities (CAP) Relative Volumetric Capacity (%) 1000 100 10 Water R-410A R-12 R-32 R-22 R-134a R-152a R-125 R-114 R-404A R-123 R-290 R-113 R-245fa R-11 R-600a R-365mfc 1 0.01 0.1 1 10 Evaporator Pressure (bar)
Refrigerant Volumetric Capacities (CAP) Relative Volumetric Capacity (%) 1000 100 10 Water R-12 R-134a R-152a R-114 R-123 R-113 R-245fa R-11 R-365mfc 1 0.01 0.1 1 10 Evaporator Pressure (bar) R-410A R-32 R-22 R-125 R-404A R-1234yf R-290 R-1243zf R-1234ze R-600a R-1234yf is a close match to R-134a
R-1234yf Properties Summary R-1234yf R-134a CF3-CF=CH2 Formula CF3-CFH2 0 ODP 0 4 GWP 1430 11 days Atm. Lifetime 13.8 years 114 mw (g/mol) 102-29 Bp ( C) -26 95 Tc ( C) 102 A Toxicity A Low Toxicity Low Flammability Performance similar to R-134a Pure component, no glide Similar coefficient of performance and capacity Good thermal stability and material compatibility Atmospheric chemistry is published Same breakdown products as R-134a No high-gwp breakdown products LCCP R-1234yf < LCCP R-134a 2 L Flammability 1 6.5% / 12.3% LFL/UFL (v/v) none
R-1234yf Flammability Class LFL (kg/m 3 ) (v%) 0.35 18 ΔFL (v%) 0 MIE (mj) HoC (MJ/kg) 0 BV (cm/s) 0 1 R-134a No flame propagation 1000 100 10 10 more flammable 2L 2 R-1234yf R-32, NH 3 BV 10cm/s BV > 10cm/s R-152a LFL > 0.1 kg/m 3 and HOC < 19 MJ/kg 1 0 0 18 0.1 50 50 3 R-290 LFL 0.1 kg/m 3 or HOC 19 MJ/kg R-1234yf Low Flammable Range High LFL Narrow flammable window Difficult to ignite High Min. Ignition Energy Low impact of ignition Low Burning Velocity Low Heat of Combustion
HVAC / R Perspective on HFO Blends Blend R-1234yf with other refrigerants to reduce the GWP and adjust refrigerant properties for market segments Tailor blend compositions for target applications & system architectures
Refrigerant Blends: Volumetric Capacities 1000 Relative Volumetric Capacity (%) 100 R-12 R-152a R-134a HFO-1234yf R-407C R-22 R-410A R-32 R-404A 10 1.0 Evaporator Pressure (bar) 10.0
Refrigerant Blends: Volumetric Capacities 1000 Relative Volumetric Capacity (%) 100 R-407C ARM06 R-12 R-152a R-134a HFO-1234yf ARM04 R-22 ARM05 ARM01 R-410A R-32 ARM03 ARM02 R-404A ARM Blends GWP < 1000 10 1.0 Evaporator Pressure (bar) 10.0
Refrigerant Blends: Conclusions Other considerations for refrigerant blends Safety classification, glide, application range, performance,... Performance Environmental Impact Environmental Durability Safety Refrigerant Selection HVAC & R Applications Refrigerant Properties & Refrigeration Technology Physical Properties Performance Thermodynamics HFO-based blends allow for the development of reduced GWP solutions for various market segments of HVAC & Refrigeration Blend compositions are adapted for applications & systems architectures New technical challenges are ahead in the coming decades
Thank you!