Evaluation Result of HFO-1234yf as an Alternative Refrigerant for Automotive Air Conditioning

Transcription

1 Evaluation Result of HFO-1234yf as an Alternative Refrigerant for Automotive Air Conditioning VDA Alternative Refrigerant Winter Meeting /13/08

2 Contents 1 I. Development Background II. Development History at Hyundai/Kia III. What is HFO-1234yf IV. Performance Test System Bench V. Flammability Test Ignition Test per various concentration Ignition Test for various discharge condition VI. Future Activity

3 I. Development Background 2 Kyoto Protocol in 1997 under United Nations Framework Convention on Climate Change (UNFCCC) to reduce greenhouse gas emissions by 8% from 1990 level by 2008~2012. USA MAC Directive 2006/40/EC: GWP>150 Refrigerant leak rate < 40g/yr for single evaporator system < 60g/yr for dual evaporator system 08, June 28: New type of vehicles 09, June 28: All new vehicles GWP>150 Refrigerant phase-out 11, Jan 1: New type of vehicles 17, Jan 1: All new vehicles CARB s AB1493(Pavley) & AB32: Early Action Measures Restrict sales & use of DIY refrigerant cans Low GWP Refrigerant implementation Strengthening test and repair requirements. EPA denied California s Greenhouse Gas Waiver proposal and 16 states, including California, have sued the federal agency.

4 II. Development History 3 What has Hyundai/Kia completed in the past: 2004 ~ 05 Hyundai Santa Fe has been retrofitted with R744 A/C system: Performance verification purpose 2006 Hyundai Tucson has been retrofitted with R744 A/C system: Performance & Durability verification purpose Hyundai Accent has been retrofitted with Fluid H A/C system: Performance & Durability verification purpose Presented at 06 SAE Alternative Refrigerant Symposium for Ride & Drive Along with Visteon CO2 system and Honeywell Fluid H system CO2 H Tucson FCEV have been built with R744 A/C system: Fleet monitoring purpose 2. Participated in EU A/C workshop 3. Joined CRP1234yf

5 II. Development History 4 What is Hyundai/Kia doing currently? In 2007, Hyundai/Kia has established a TFT to develop an engineering strategy to satisfy every changing refrigerant regulation requirements. Purse both R744 and alternative refrigerant until one becomes more obvious choice for engineering reasons and/or economical issues. ~ 2007 R&D Division forum. Why did alternative refrigerant development all of sudden? In 2006/2007, Hyundai had conducted an extensive study of R744 A/C system implementation feasibility for plants in Korea. Result Two different refrigerant systems must be built at the plant (R744 for EU / R134a for other regions) Minimum 20 months of preparation time required Plant floor needs to be redesigned and rearranged (additional charging equipment, storage tank for R744 system) Recommendation Develop a single refrigerant solution to satisfy global needs because R744 A/C system is concluded that it is not economically feasible if two refrigerant systems are in production.

6 II. Development History 5 Alternative Refrigerant Choice? Honeywell/DuPont HFO-1234yf. Why? 1. ODP = 0 / GWP = 4 (R134a = 1300) 2. Good toxicity characteristics 3. Good LCCP Any other concerns? 1. Flammability, significantly less than other proposed alternative refrigerants Ultimate question is is it acceptable for direct expansion system in the cabin? How to overcome? 1. Series of performance testing in process 2. Series of flammability testing in process 3. Industry joint effort for the risk assessment in process, such as CRP1234yf

7 III. What is HFO-1234yf 6 HFO-Hydro-Fluoro-Olefin 2,2,2,3 Tetrafluoropropene Major component of Fluid H Refrigerant Very similar refrigerant properties Lower LCCP Lower than R134a and R744, JAMA, EU A/C workshop, Nov Average 15% lower than R134a, Honeywell, EU A/C workshop, Nov. 2007

8 IV. Performance Evaluation 7 Purpose : to evaluate A/C cooling performance of HFO-1234yf in R134a A/C system without any modification. Test conditions Compressor: HS 18, Fixed Swash Plate Evaporator: 275*215*60 Condenser: 677*426*16 Sub-Cool TXV: L-Type 1.5RT Plumbing: Suction = 16mm Discharge =12mm Liquid = 8mm Driving Pattern

9 IV. Performance Evaluation 8 Result : Without any modification to the current R134a A/C system, HFO-1234yf produces less cooling capacity, 3 ~ 7%, and less COP, 1 ~ 3%. Conclusion : Cooling capacity and COP of HFO-1234yf can match the one of current R134a system with minimum modification.

10 V. Flammability Test 9 Purpose : to evaluate ignition possibility at various concentration Test set up and condition 1.0 m Camera 1.0 m Transparent Acryl Temperature = 18 o C ~ 23 o C Humidity = <50% 1.0 m Blower Butane lighter Hose Battery short CHARGE CYLINDER General Materials in Vehicles (PP,MICA,ACETAL,RUBBER, FOAM & etc)

11 V. Flammability Test 10 Result: NO IGNITION!!!! Mixing blower fan CAM, HVAC DOORS, FOAM, RUBBER

12 V. Flammability Test 11 Purpose : to evaluate ignition status in vehicle set up, simulating 3 different leak conditions Butane lighter Acryl Window HVAC Battery short Ref. Amount 650 g Discharge time 60 sec 360 sec 600 sec

13 V. Flammability Test 12 Result: NO IGNITION!!!! Summary : 1. All Tests conducted in mild temperature, 10 o C ~25 o C 2. Concentration of refrigerant was not measured 3. Ignition sources and location may not be adequate. Too far / Too weak

14 VI. Future Activity 13 System Bench Testing: GOAL = optimize heat exchanger and other components to match performance against R134a without adding additional component. Flammability Testing: GOAL = conduct flammability in various conditions to evaluate the risk of having direct expansion HFO-1234yf system in the cabin. Vehicle Testing Performance / Durability GOAL = Evaluate performance of HFO-1234yf A/C against the one of R134a at the vehicle level in wind tunnel and on the field during summer of vehicles (same color, same trim level): - equipped with both R134a A/C and HFO-1234yf - Wind tunnel test for A/C, Trailer Towing - Field test in Death Valley and Galveston, TX for high temp & high humidity - 70K durability in California high desert and Death Valley

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