Enhancing Worker Digital Experience: A Hands-on Workshop for Partners
Vehicle Manufacturer’s Perspective on Alternative Refrigerant Development
1. A Vehicle Manufacturer’s Perspective on
Alternative Refrigerant Development
Presented By:
June , 2010
Harry Eustice
General Motors Company
Engineering Group Manager 1
3. Perspective Outline
• Status of Near Term New Low Global Warming
Potential Mobile A/C Refrigerants
• Review of Vehicle Manufacturer’s Refrigerant
Strategies and Goals
• Recommended Next Generation Alternative
Refrigerant Development & Study Process
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5. Alternative Refrigerants Evaluated
• New Refrigerant Technologies Recently
Evaluated by the MAC Industry
– Multiple New Candidates Proposed by the Fluoride Chemical
Industry (e.g., DP-1, AC-1,Fluid H etc.)
– Several Flammable Refrigerant s via a Secondary Loop
– R744 (CO2)
– R1234yf
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7. R744 & HFO1234yf System Development
• 2 New Low GWP Refrigerant Candidates were
Initially Identified that Might be Used without a
Secondary Loop
– Under Development for EU 2011 Regulations
and US EPA Fuel Economy Credits
• R744 (CO2)
– All New MAC Technology
• R1234yf
– Modified existing R134a Technology
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9. High Level R744 System Challenges
• All New MAC Technology
– Higher Pressures & Temperatures than R134a Drive All New System Designs
• Reliability Issues
– Sealing - Robust Joint Connections & Hose Couplings Not Available
– Compressor - Maximum Temperature & RPM limitations, Poor Noise & Vibration
• Fuel Economy Impact
– Negative Impact in Hot Ambients
• Cost
– All New MAC Design System on-costs ~$400 USD per Vehicle
• Supplier Readiness
– Extremely Limited Qualified Supplier Base
• Service Impact
– Pressure Guidelines Limit the Reserve Charge Quantities (Limited Field Life)
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11. R1234yf System Challenges
• Material Compatibility
– New PAG Oil Formulations are Required
– New Oil Formulas Drive Considerable Compressor Validation
• A/C Performance
– 10-15% Less Thermodynamic Efficient as Compared to R134a
– Almost “Drop-in” Vehicle Designs but Must be Optimized for Acceptable Comfort
Performance Levels
• Flammability
– SAE Collaborative Risk Assessment Indicated Risks Comparable to R134a
– Managed by DFMEA Practices and New SAE Standards
• Commercialization and Patent Rights
– Global Production Quantities are Hampered by Multiple Patent Claims Control
– Global Supply Shortfall Caused by Patent Controls
• Excessive Unit Cost
– Estimated Refrigerant Cost is $80 to $100 USD per Kilogram
– Current R134a Cost is $4 USD (average) 11
13. Near Term MAC Alternative Refrigerant Status
• R744 Systems have Numerous Technical Challenges
– All New MAC System Designs
─ Very High Total MAC System On-Cost
─ Questionable Reliability
─ After Several Years of Very Active Development Work, Most Work to
Implement R744 in MACs has Stopped
• Global Vehicle Manufacturer’s have Selected R1234yf as the Refrigerant
to Meet the 2011 EU 2011 MAC Regulations
─ Only Low GWP Refrigerant & Technology Available to Meet Deadline
─ Validated by Intensive SAE Collaborative Evaluations
• Challenges that May Prevent R1234yf from Becoming a Global Solution
– High Refrigerant Cost
– Global Production Controlled by Patent Claims
– Anticipated Global Supply Shortages
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15. Reassessment of MAC Refrigerant Goals
• One MAC Refrigerant Globally
• Compliant to EU/US EPA and Other Future Global Initiatives
– Global Warming Potential Less than 150
• Low toxicity
– Comparable to R134a or R1234yf
• Low Cost
– Similar to R134a
• Flammability
– Non-flammable (preferable)
– Comparable to R1234yf
• Single compound, single molecule
– Not a Multiple Compound Blend (preferable)
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17. Reassessment of MAC Refrigerant Goals
• Azeotropic Behavior Like a Single Compound
– Minimal Temperature Glide and Fractionalization
• Similar to R134a or Improved Thermodynamic Properties
– Promotes a Known, Drop-in Technology
– Faster Global Conversion, Lower Design & Retooling Costs
• Chemical stability
– No Sufficient Refrigerant or Oil Breakdown During Extended Usage
• Acceptable Miscibility and Solubility with Current Refrigerant Oils
• Compatibility with Today’s Refrigerant Materials and Elastomers
• Acceptable Dielectric Properties (for Electric Compressors)
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19. Next Generation MAC Alternative Refrigerant
Development Recommendations
• First Establish a Collaborative MAC Industry Effort
– Do Not Wait for a Refrigerant Manufacturer Proposed Solution and Then
React Thru Evaluations with Un-optimized Technology or Hardware.
• A New Alternative can be Developed Faster by Several Key MAC
Sectors Collaborating together Simultaneously.
– For Example: A Lower Cost MAC Refrigerant may Need to Operate at
Slightly Different Pressure Regimes. The Required Heat Exchangers &/or
Compressors Revisions could be Developed in Parallel during any Long
Lead Toxicity Testing Period (if needed).
• Consider a Public Effort
– Use Universities & Industry to Propose Refrigerant Candidates,
– Form a Global Evaluation Team of Key Vehicle Manufacturers,
HVAC Suppliers and Refrigerant Producers.
– Utilize Global Engineering Societies, such as, CRAA, SAE & JAMA for
Sanction and Guidance
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21. Follow the Latest SAE Process to Evaluate
Alternative Refrigerants
Major SAE Refrigerant Successes
─ The MAC Industry Worked Together for the Conversion from R-12 to R-134a
─ R-134a Successfully Used Over the Past 19 years
─ Formed Lasting Global Committee of SAE Engineers Dedicated
to Improving MAC Systems
─ Developed standards Covering all Aspects of R134a & R1234yf Usage
including: Emissions, System Design, Safety, Best Practices,
Service Equipment and Recovery
─ Developed good working relationship with EU & US EPA
• Over the Past 3 years, SAE has Organized Cooperative Research Programs (CRP)
• The Cooperative Research Programs Focused the MAC Industry to Successfully
Address the Final Technical Hurdles of R1234yf Implementation
23. Follow the Latest SAE Process to Evaluate
Alternative Refrigerants
Establish Cooperative Research Teams
• Follow the SAE Cooperative Research Program Process
• Sponsored by Vehicle Manufacturers and HVAC & Refrigerant Suppliers
• Utilize Universities to Help Define Possible Refrigerant Candidates
• Utilize International Laboratories to Access the Best Available Expertise
and to Guarantee Acceptance
• Focused Investigations should Include:
– Safety and risk assessment
• Toxicity
• Flammability
– Air-conditioning system efficiency and performance
– Material compatibility
25. New SAE Alternative Refrigerant Standards
Incorporate New SAE Standards
Five Sub-Committees
Industry Experts
Develop Documents
Interior Climate Control
Standards Committee Members
• Vehicle OEMs
• A/C System Suppliers
• Chemical Industry
27. New SAE Alternative Refrigerant Standards
An Excellent Example: New R1234yf SAE Standards
(Under development or revision to be published in 2010)
Refrigerant Standard
• J2844 Refrigerant Purity and Container Requirements for New HFO-1234yf
Refrigerant Used in Mobile Air-Conditioning Systems
System Design Standards
• J2772 Measurement of Passenger Compartment Refrigerant Concentrations
under system refrigerant leakage conditions
• J2773 R-744 and HFO-1234yf Refrigerant Standard for Safety and Risk Analysis
for use in Mobile Air Conditioning Systems
• J2842 HFO-1234yf and R-744 Design Criteria and Certification for OEM Mobile
Air Conditioning Evaporator and Service Replacements
• J2064 R-134a and HFO-1234yf Refrigerant Automotive Air-Conditioning Hose
and Assemblies
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29. New SAE Alternative Refrigerant Standards
Service Equipment Standards
• J2843 HFO-1234yf Recovery/Recycling/Recharging Equipment for Flammable
Refrigerants for Mobile Air-Conditioning Systems
• J2851 HFO-1234yf Refrigerant Recovery Equipment for Mobile Automotive
Air-Conditioning Systems
• J2888 HFO-1234yf Service Hose, Fittings and Couplers for Mobile Refrigerant
Systems Service Equipment
• J2912 HFO-1234yf Refrigerant Identification Equipment for Use with Mobile
Air Conditioning Systems
• J2913 HFO-1234yf Refrigerant Electronic Leak Detectors, Minimum
Performance Criteria
Technician Requirement Standards
• J2845 Technician Training for Safe Service and Containment of Refrigerants
Used in Mobile A/C Systems (R-744 and HFO-1234yf)
• J2911 Procedure For Certification That Requirements For Mobile Air
Conditioning System Components, Service Equipment and Service Technicians
Meet SAE J Standards
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31. New SAE Alternative Refrigerant Standards
Incorporate SAE System Design Standards
• J639 Safety Standards for Motor
Vehicle Refrigerant Vapor
Compression Systems
– This document provides design
standards and safety requirements
– Also included are cautionary
statements for the mobile air
conditioning service industry
– J639 Provides requirements and
identifies SAE J Standard
requirements for MAC systems
including: J2842 Certification for OEM
• System Design Requirements
• Service Equipment
Mobile Air Conditioning
• Technician Certification Evaporator and Service
Replacements
J2845 Technician Training for
Safe Service and Containment
of Refrigerants 31
33. Follow the Latest SAE Process to Evaluate
Risk of Alternative Refrigerants
Implement Detailed Risk Assessments
• Establish Fault Tree Analysis Method for Key Exposure Scenarios
– Vehicle exposures
– Repair exposures
– HF Concentrations Produced by Thermal Decomposition
• Incorporate Qualitative Evaluation of other Scenarios
– Assembly plant workers
– Parking garages, tunnels
– Ecological impacts
• Base Fault Tree Inputs on Measured data, Public Databases, and by
Consensus of Vehicle Manufacturers HVAC and Safety engineers
• Compare Results to other Refrigerant Risk Assessments
& non-AC Related Automotive Risks
35. SAE Risk Assessment Process to Evaluate
Alternative Refrigerants
Potential risk of open flame
in Engine Compartment Top Event
AND
Frequency of Probability Probability of
Probability
Initiating Event Refrigerant Sufficient Ignition
attenuating
(e.g. vehicle Concentration Source occurs
factors absent
collision) Exceeds LFL (e.g. hot surface)
Considered •Event causes Considered normal •No other break in
collisions, AC and refrigerant release operation, system fault, system
non-AC failures, •Refrigerant not and extreme operating •Person present
vehicle fires dispersed by air conditions •Person doesn’t leave
•Concentration in •Windows/doors closed
contact with •Blower
ignition source •Vehicle speed
exceeds LFL •OSA/recirc
37. SAE Risk Assessment Process to Evaluate
Alternative Refrigerants
Top Risk Event
AND
Speed Independent
Speed Independent
Events
OR
Speed Dependent
High Medium Low
Events
Speed Speed Speed
OR
Frontal Side Impact Location
Impact Impact
Events
Initiating event AND Other factors required for exposure
(e.g., collision)
AND AND
Pre-Crash Breakage
Breakage Breakage Refrigerant Energy or Volume or
Windows/ Windows/ Type Occupant Occupant Timeline
of concern of other AC Concentration Temperature Size
Doors/ Doors/ Frequency Location Mobility
component component
Blower Blowers
System and Passenger Variables Ignition or HBL Variables
38. SAE 对替代制冷剂的风险评估流程
Top Risk Event
AND
Speed Independent
Speed Independent
Events
OR
Speed Dependent
High Medium Low
Events
Speed Speed Speed
OR
Frontal Side Impact Location
Impact Impact
Events
Initiating event AND Other factors required for exposure
(e.g., collision)
AND AND
Pre-Crash Breakage
Breakage Breakage Refrigerant Energy or Volume or
Windows/ Windows/ Type Occupant Occupant Timeline
of concern of other AC Concentration Temperature Size
Doors/ Doors/ Frequency Location Mobility
component component
Blower Blowers
System and Passenger Variables Ignition or HBL Variables
39. The SAE Process Provides the Basis of
Industrial Confidence
“Voice of the MAC Industry” = Basis of Confidence
• Focused Collaboration
– Multiple & Parallel Resources, Speed, Best Customer Value
• SAE Standards
– Standards and Practices to Assure Proper System Design, Engineering,
Manufacturing and Servicing for MAC Alternative Refrigerants
• Risk Analyses
– Conservative Assumptions
– Scientifically Valid
– Reviewed by Industry Experts
– Ensures that Refrigerant & Vehicle are Acceptable for Market
–
• Addresses Regulatory Concerns
• Ensures that Vehicle Safety Will Not Be Compromised
41. GM Pioneering Refrigerant History
• In the 1930’s GM Frigidaire Led the Refrigerant
Industry to Develop R-12 Technology
• In the 1940’s GM Cadillac Pioneered
Mobile A/C System Design & Development
• In the 1990’s GM Helped the Globe Implement R134a
• Recently GM has Accelerated the Global
Development of Several Low GWP Refrigerants
“Today….GM Continues to Lead and Assist
MAC Alternate Refrigerant Initiatives that
Will Protect the Global Environment”
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