Evaluation of R-449A as a Replacement for R-22 in Low and Medium Temperature Refrigeration

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1 Evaluation of R-449A as a Replacement for R-22 in Low and Medium Temperature Refrigeration Andrew Pansulla, The Chemours Company Charles Allgood, The Chemours Company July 11-14, 2016

2 Agenda Regulations HFOs/R-449A introduction Thermodynamic modeling Calorimeter testing System testing in an environmental chamber TXV considerations Conclusions July 11-14, 2016 Purdue Conferences 2

3 Environmental Considerations Ozone Depletion Potential (ODP) The potential for a refrigerant to reduce the amount of ozone in the stratosphere. Global Warming Potential (GWP) The potential effect that certain substances have on climate change.

4 The Regulatory Challenge: R-22 is going away The Montreal Protocol is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. The EPA has published a final rule on the amount of virgin R-22 allowed to be consumed until production ceases in 2020.

5 Fluorocarbon Refrigerant History 1930s 1950s 1990s TODAY CFCs (R-12) Chlorine Single Bond HCFCs (R-22) Less Chlorine Single Bond HFCs (R-134a) No Chlorine Single Bond HFOs (R-1234yf) No Chlorine Double Bond High ODP Highest GWP Lower ODP High GWP No ODP High GWP No ODP Very Low GWP

6 What is an HFO HFC Hydro fluorocarbon HFO Hydro fluoro olefin

7 Pressure, MPa R-1234yf Introduction a 1234yf Same operating conditions as 134a (similar P/T curve) Thermally stable under extreme use conditions Capacity and efficiency similar to R- 134a Mildly flammability (A2L) Temperature, o C R-134a HFO-1234yf Formula CH 2 FCF 3 CF 3 CF=CH 2 Molecular Weight ODP 0 0 GWP 100 (AR5) 1300 < 1 T Critical Point 102 ºC 95ºC Boiling Point -26ºC -29ºC

8 R-449A Physical Properties R-449A is an HFO blend originally developed as a low GWP replacement for R-404A (and R-22) Composition (weight percent): R-32 (24.3%)/R-125 (24.7%)/R-1234yf (25.3%)/R-134a (25.7%) 8

9 Thermodynamic Modeling Assumptions R-449A condensing and evaporating pressures calculated to have the same average condensing and evaporating temperatures as R-22 Superheat and sub cooling calculated from average T c and T e of R-449A to give the same return gas and liquid line temperatures for all models Maximum discharge temperature = 135 o C Isentropic efficiency = 0.70 All models had the same theoretical compressor displacement July 11-14, 2016 Purdue Conferences 9

10 R-22 and R-449A Thermodynamic Modeling ASHRAE # Relative Capacity Relative COP Relative Mass Flow Suction Pressure (kpa [abs]) Discharge Pressure (kpa [abs]) Discharge Temp ( C) Low Temperature 1 Medium Temperature 2 R-22 3 R-449A R-22 R-449A R-449A Performance: Equivalent to 3% larger capacity 4-6% lower COP 11-14% larger mass flow 1 LT Conditions: -30 C Evap/40 C Cond/3.89 K Sub Cool/-10 C Return Gas Temperature 2 MT Conditions: -10 C Evap/40 C Cond/3.89 K Sub Cool/10 o C Return Gas Temperature 3 Assumes liquid injection to maintain a maximum discharge temperature of 135 o C

11 Compressor Calorimeter Testing Semi hermetic compressor Compartment temp = 35 o C LT Evaporator condition = o C MT evaporator condition = -6.7 o C Sub Cool Amount = 5.5 K Maximum discharge temp = 135 o C Return gas and condensing temperatures were varied July 11-14, 2016 Purdue Conferences 11

12 Low Temperature Capacity and COP Purdue Conferences July 11-14,

13 Medium Temperature Capacity and COP 13

14 Environmental Chamber System Testing Experimental set up was run in accordance with ASHRAE standard 72 All tests were run with POE lubricant EEV was used to regulate evaporator superheat Defrost every 12 hours Charge was optimized based on the equivalent liquid volume ratio for the recommended charge Performance measurements were taken every six seconds for over a 24 hour period Indoor temperature/humidity = 23.9 ± 0.27 o C dry bulb and 14.4 ± 0.27 o C wet bulb Outdoor temperature/humidity = 27.8 ± 0.27 o C dry bulb and 13.3 ± 0.27 o C wet bulb July 11-14, 2016 Purdue Conferences 14

15 System Testing Semi-Hermetic Compressor with a single condensing unit Med/Low Temp Open Display Case 15

16 Display Case Performance Data Condition Refrigerant Discharge Pressure (kpa) Discharge Temperature ( o C) Evap Superheat (K) Evaporator Discharge Air Temp ( o C) LT R LT R-449A MT R MT R-449A July 11-14, 2016 Purdue Conferences 16

17 Temperature [ C] Product temperatures Low Temp Medium Temp AT CTSA WTSA CTS WTS AT CTSA WTSA CTS WTS AT = Average temperature of all test simulators CTSA = Coldest test simulator average temperature R-22 R-449A WTSA = Warmest test simulator average temperature CTS = Minimum temperature recorded of the coldest simulator average WTS = Maximum simulator temperature recorded July 11-14, 2016 Purdue Conferences 17

18 Energy Consumption [kwh/24h] Energy comparison Med/Low Temp Open Display Case with EEV in Environmental Chamber Energy Consumption R-22 R-449A Low Temp Medium Temp July 11-14, 2016 Purdue Conferences 18

19 Background on adjustments During refrigeration operation, a TXV balances three pressure forces P1 Opening force of the powerhead P2 Closing force of the suction pressure P3 Closing force of the spring pressure

20 Pressure (kpa) Adjustable R-22 TXVs Suction pressure differences for the same average evaporator temp» LT: 10.5 kpa higher» MT: 37.9 kpa higher Set point pressure to reach the same average evaporator temperature for R-22 and R-449A TXVs may need to be opened to reach target superheats Mass flow of R-449A is roughly 11-14% higher than R R-22 R-449A Temperature ( o C)

21 Energy (Kwh) Field Trial MT R-22 retrofit to R-449A Rack Energy vs Ambient Temperature R-22 R-449A Hourly Average Temperature ( o C) July 11-14, 2016 Purdue Conferences 21

22 Conclusions R-22 is being phased out HFOs were developed as low GWP and zero ODP alternatives to current HFCs R-449A is a HFO containing blend that has exhibited similar or better performance relative to R-22 in: - Cycle Modeling - Calorimeter Testing - System Testing During retrofits, minor adjustments to valves might be needed to reach target superheats July 11-14, 2016 Purdue Conferences 22

23 References AHRI, Standard 210/ , Unitary A/C and Air Source Heat Pump Standard, Arlington, VA, ASHRAE, Standard 23.1 Methods of Testing for Performance Rating Positive Displacement Refrigerant Compressors and Condensing Units That Operate at Subcritical Temperatures of the Refrigerant, American Society of Heating, Refrigerating and Air-Conditioning Engineers, ASHRAE, Standard 72 Method of Testing Open and Closed Commercial Refrigerators and Freezers, American Society of Heating, Refrigerating and Air-Conditioning Engineers, IPCC Climate Change 2013: The physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. J. Steven Brown, Piotr A. Domanski, Eric W. Lemmon. (2015). Cycle D Version 5.0. National Institute of Standards and Technology. Powell, P. (2014). EPA Finalizes R-22 Phaseout Plan. ACHR News. UNEP The Montreal Protocol on Substances that Deplete the Ozone Layer. The Vienna Convention for the Protection of the Ozone Layer & The Montreal Protocol on Substances that Deplete the Ozone Layer. UNON, Nariobi, Kenya. July 11-14, 2016 Purdue Conferences 23

24 QUESTIONS July 11-14, 2016 Purdue Conferences 24