This chart shows the “global” picture – both from a geography and application point of view. We have products for many markets, and all refrigerants. Hence our interest in Energy, Efficiency, Refrigerants, GWP, LCCP and Regulations.
Since the announcement of the Kyoto Conference in 1997 and the Europe F-Gas regulation, further regulations have been proposed globally to amend the Montreal Protocol to gradually phase-down the production of HFCs in the next 20 years due to their high global warming potential (GWP).This chart shows the North American Proposal for both Developed and Developing countries and the last EU Proposal. Due to this, institutes and manufacturers are proposing new refrigerants to substitute HFCs having a high GWP
This chart classifies the fluids based on their GWP and their relative cooling capacity to R22.The conventional refrigerants with high GWP like R-404A, R-407C, R-407A and R-410A are surrounded by a dotted blue line and classified A1 (non flammable, non toxic).These fluids are obtained as a combination of R-32, R-125, R134a and R-143a
The group surrounded by the orange dotted circle represents the HFC refrigerants with GWP below 1500.The base of these refrigerants is mainly R32, R1234yf, R1234ze, R152a and R134a.The dotted black line separate the fluids (excluding the CO2) in 2 groups based on their flammability.In the next charts I am going to talk about the synthetic potential candidates to replace R410A and R404A like R32, L41b, DR5, L40 and DR7
A commercial scroll designed for R410A having a displacement of 25m3/h has been tested with R410A and R32.The table shows the performance of R32 compared to R410A. R32 gives more cooling capacity (at average +7%) and higher COP (average +3%). This performance increase with R32 is lower at low condensing temperatures
These charts show the discharge temperature and the operating envelops of a commercial scroll compressor working with R410A and R32.R32 Discharge temp. goes up to 35 K limiting heavily the operating envelopeIn spite of the high discharge temperatures R32 can be used in A/C with medium ambient temperature, but it shows a serious concern if no additional cooling is added for A/C hot climate and heat pump application.
Discharge Temperature decreases in the range 11 to 16 KCondensing limit at fixed evaporating temp. rises 5 to 8KCooling Capacity increases up to 26%COP Improves up to 14%Reversible Chiller and HP needs VI or Liquid injection to widen the envelopeLI enlarges the application envelope with negative impact on the COP
A residential scroll compressor with a displacement of 5m3/h was tested with R32, L41 and DR5 refrigerants.R32 shows less capacity increase compared to the commercial scroll, meanwhile R32 COP is lower compared to R410. This could be explained by the compression heat rejection which is more sensitive on a small compressor size compared to the large one.DR5 shows similar cooling capacity to R410A and a COP in the range of 95% to 100% vs. R410A. L41 gives 20% less capacity and a COP slightly below R410A. The reference for the performances calculation is based on the dew point temperature for the blends. The performance gap will be reduced in case mid point is used as reference.
A drop-in experiment has been carried out on a R404A compressor having a displacement of 17m3/h.The Figures show DR7 cooling capacity which is very close to R404A, meanwhile L40 has lower cooling capacity in the range of 79 to 95%.L40 and DR7 present higher COP at high condensing temperature and similar at low condensing temperature.
A drop-in system test has been carried on a walk-in system with L40 and DR7 refrigerants.The system charge and the superheat setting have been adjusted for each. DR5 gives more cooling capacity and a COP from 2 to 6% higher vs. R404A. L40 has only 3% less cooling capacity and its COP is 3 to 4% higher compared to R404A.
In commercial candidates, R32 shows good performance, while for residential application an efficiency drop has been observed. The higher discharge temperature with R32 limits the operating application if no additional cooling is added. This added feature will impact the system cost and/or the efficiency depending on the cooling mode adopted. The capacity and efficiency with L41 drop down respectively to 20% This drop should be smaller in case midpoint temperature is used for reference.DR5 performances are closer to R410A performance.
DLT for HFOs blends is manageable more than for R32.
Bachir Bella - Emerson Climate Technologies - REFRIGERANTI A BASSO GWP IN APPLICAZIONI DI CONDIZIONAMENTO E REFRIGERAZIONE
XV EUROPEAN CONFERENCE MILANO 7th-8th JUNE 2013 CSGLatest Technology in Refrigeration and Air ConditioningUnder the Auspices of the PRESIDENCY OF THE COUNCIL OF MINISTERSAn evaluation of low GWP refrigerants inA/C and in Refrigeration15th EUROPEAN CONFERENCETECHNOLOGICAL INNOVATIONSIN REFRIGERATION AND IN AIR CONDITIONINGMilano June 7th 2013Bachir Bella
MarketsRefrigerantsNH3R134aR404A/507R290R134aR404AR404A/507R407AR134aCO2R404A/507R407A/FR134aR290R410AR407CR410AR407CComfortResidentialComfortComm.Emerson – Global Player OfferingProducts Across Entire Landscape
0%20%40%60%80%100%120%2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 2055NAPDeveld CountriesF-Gas Review (Draft)NAPA5 CountriesHFC Phase-Down Proposals Also OnTable: North American Proposal (NAP) And F-Gas ProposalF-Gas ProposalReserved Right ToAmend Based On AnyInternationalAgreement – AllowanceFor NAP Adoption• Baseline Updated2008-2010• Excluded HFOs FromBasket For Phase-down• Fewer Steps In Phase-Down, But End YearAnd Target Held SameNAP Update 4/2013NA ProposalNon A5 CountriesF-Gas ProposalNA ProposalA5 Countries
Refrigerants Choice was a Trade offsbetween Capacity, WP & Performance0.000.501.001.502.002.503.003.504.000 500 1000 1500 2000 2500 3000 3500 4000 4500Capacity Vs. R22GWPR143aR125R134aR32R152aR290R600aR407CR410AR404AR407AR407F1400 < GWP < 4000TodayHFCsR32 R134a R125 R143aR410A 50 0 50 0R407A 20 40 40 0R407C 23 52 25 0R407F 30 40 30 0R404A 0 4 44 52Base for HFCs BlendsODP = 0Class A1 ( Non toxic, Non flammable)
Next Refrigerants will be a Trade offsbetween Performance, GWP and Safety0.000.501.001.502.002.503.003.504.000 500 1000 1500 2000 2500 3000 3500 4000 4500Capacity Vs. R22GWPR143aR125R134aR744R32R152aR290R600aR1234..R407CR410AR404AR407AR407FR404A LikeR410A likeR404A likeR134a LikeBase for HFOsR1234ze R1234yf R152a R32L41a 12 15 0 73L41b 27 0 0 73DR5 0 27.5 0 72.5L40 30 20 10 40DR7 0 64 0 36L20 35 0 20 45Source : Thomas E. Watson “AHRI low-GWP alternative refrigerant Evaluation program” Convegno Aicarr Vicenza, Nov. 2012FlammableNon Flammable
Flammability is evaluated by ‘Chance of Flame occurring’ and ‘Effect of Flame occurring’•Effect of Flame occurring -> Burning Velocity, Heat of CombustionBurning Velocity – Basis For 2 & 2LClassificationReference: Low GWP Refrigerant Options For Unitary AC & Heat Pumps – Mark Spatz, ASHRAE Jan 2011LowEnergyReleaseHighEnergyReleaseUnstable Flame,Low PressureRiseStable Flame,High PressureRise01020304050600 5 10 15 20 25 30 35 40 45 50Burning Velocity, cm/sHeatofCombustion,MJ/kgR152aAmmoniaR32HFO-1234yfR134amethanepropanebutaneASHRAE Class 3ASHRAE Class 2Class 2LgasolineNew A2L Class –R32, R1234yf, R1234ze- IEC 60335-40 and ISO 5149 Are KeyStandards Related To Flammability- Modifications Required For Both Ductedand Non Ducted Applications- Equations For Maximum Charge BeingDeveloped Relating To Room Size, UnitLocation & Height, Ventilation, andRefrigerant LFLTimely A2L Standards Crucial For Commercialization / Meet Phase DownA3A2A2LA1R152aASHRAE 34 Class A (Non-Toxic)Propane R290Isobutane R600aR410A, R134a, R407CHighlyFlammableFlammableMildlyFlammableNon-FlammableNeed To Accelerate A2L StandardsDevelopment Globally
7,620,65010203040506070-40 -30 -20 -10 0 10 20 30ESEERHP MTwarmerHP MTaverageHP MTcolderDefrostDHWR410AR32warmclimatesDischarge temperature and the operatingenvelops with R32 and R410A204060801001201405/50 C -5/50 C -10/45 CDischargetemperature(C)R32R410AR32 Map limited for HP, reversible systems andChillers in warm climatesR32 Discharge temp. rises up to 35 Klimiting heavily the operating envelope
to extend the EnvelopeVapor or Liquid Injection could be used Cooling Capacity increases up to 26% COP Improves up to 14% Discharge Temperature drops in the range 11 to 16 K This temperature drop will extend the envelope by 5 / 8 K Reversible Chiller and HP needs VI or Liquid injection to widen the envelope LI enlarges the application envelope with negative impact on the COP20 m3/h Scroll compressor w/ vapor injectionEvap.Temp.Cond.Temp.Cooling Cap. COPDischargeTemp.(°C) (°C) (%) (%) (K)-20 25 17% 10% -16-15 35 20% 12% -11-10 45 26% 14% -12-5 50 24% 13% -11Variation with Vapor Injection10011012013014015040 45 50 55DischargeTemperature(C)Condensing Temperature ( C)R32 Discharge temperature w/ Vapor Injection+ 5K CondensingReliabilit LimitTevap= -10°CNO VIwith VI
Drop in Tests w/ LGWP Refrigerantson Residential Comfort Scroll70%80%90%100%110%Variationvs.R410AR32 DR5 L41bCoolingCapacity COPcSH = 11K, SC 8K5°C / 50°C70%80%90%100%110%-6.7/35 °C -6.7/50 °C -6.7/35 -6.7/50Variationvs.R410AR32 DR5 L41bHeating Capacity COPh• R32 capacity increases less towards commercial scroll, and COP is lower vs. R410A• DR5 performances are close to R410A• L41b is 20% less capacity(*) Blends Performance are referred to the Dew Point at standard conditionsHFOs should better perform when referred to the mid-point instead of dew point5 m3/h Scroll compressor
A drop-in experiment has been carried outon a R404A compressor with DR7 and L4012• DR7 Capacity close to R404A• L40 Lower capacity in the range 79% to 95%.• Either L40 or DR7 offer better efficiency at high condensingtemperatureMed. Temp.Low Temp. Med. Temp.Low Temp.0.9210.940.9750.951.040.790.850.820.860.830.950.70.750.80.850.90.9511.051.1-31.7/21.1 °C -31.7/40.6 °C -17.8/21.1 °C -17.8/37.8 °C -6.7/21.1 °C -6.7/48.9 °CDR7, L40 Relative Capacity vs. R404A (Dew Point Based)Actual compressor Tests - 6HpScroll11 K Superheat, 0 k SubcoolDR-7 L-401.041.111.011.071.001.11.031.11.021.071.001.130.70.750.80.850.90.9511.051.11.151.2-31.7/21.1 °C -31.7/40.6 °C -17.8/21.1 °C -17.8/37.8 °C -6.7/21.1 °C -6.7/48.9 °CDR7, L40 Relative COP vs. R404A (Dew Point Based)Actual compressor Tests - 6HpScroll11 K Superheat, 0 k SubcoolDR-7 L-4017 m3/h Scroll compressor
Drop-in System tests Carried out on walk-insystem with DR7 and L4013• Walk-In System• Box Temperature -23°C– Standard AHRI 1250DR7 and L40 Exhibit Relatively Better Performancevs. theoretical due to Mid-Point vs. Dew-Point96%98%100%102%104%106%108%110%112%85% 90% 95% 100% 105% 110%%R404COP% R404 CapacityL-40DR-7• DR5 gives more cooling capacity and a COP from 2 to 6% higher vs. R404A.• L40 has only 3% less capacity and its COP is 3 to 4% higher compared to R404A.
Performance Summary• Potential w/ these candidates with optimized scroll compressor• The blends should perform better in a real system as the referenceis the mid point temperatureApplication Reference AlternativeCoolingCapacityCOPDischargeTemp.R32 +4 / 13 % -2 / +6% Up to +40 KL41DR5R32 +2 / +6 % -7 / 0% Up to +40 KL41 -20 / -18% -8 / -2%DR5 -5 / -2% -5 / 0%L40 -21 / -5% 0 / +13% HigherDR7 -8 / +4% 0 /+11% HigherR410AResidential A/C & HPRefrigeration R404ACommercial A/C & HP
Conclusions Important To Reduce GWP Without Sacrificing EfficiencyDue To Increasing Efficiency Standards R32 Shows Limitation due to Higher DischargeTemperature While R32 based Blends have LessLimitation HFO Blends Overall Performance Potentially ComparableTo today HFCs But Cost And Availability Still Unknown Both Compressors and Systems Can Be furtherOptimized For R32 and HFO Blends Acceleration Of A2L Standards Development For NewEquipment Is Critical to Reach Phase Down Targets