1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2009 SAE International All rights reserved. No part of this publication ma
3、y be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA)
4、Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSURFACEVEHICLESTANDARDJ2766 FEB2009 Issued 2009-02Life Cycle Analysis to Estimate the CO2-Equivalent Emissions from MAC Operation RATIONALEThis standard can be used to compare different refrigerant systems. 1. SCOPE Th
5、is recommended best practice outlines a method for estimating CO2-Equivalent emissions using the GREEN-MAC-LCCP(Global Refrigerants Energy and ENvironmental Mobile Air Conditioning Life Cycle ClimatePerformance) model (also referred to as “the model” in this standard).1.1 History Many companies and
6、other organizations including: Daimler, Fiat, GM, JAMA, NREL (USA), Sintef (Norway), and TNO (The Netherlands), have conducted partial or complete life cycle analysis in the recent past to evaluate the environmental impact of alternative refrigerants. Studies conducted by JAMA, performed partial lif
7、e cycle analyses which assess the Total Equivalent Warming Impact (TEWI) of alternative refrigerants. TEWI consists of two terms: (a) the Direct component which is associated with the direct release of the chemical into the atmosphere, and (b) the Indirect component which is associated with the carb
8、on dioxide (CO2) emissions emitted during the use phase of the MAC (Mobile Air Conditioning) system. The TEWI is expressed by Equation 1. TEWI = GWP (Direct) + GWP (Indirect) (Eq. 1) Direct emissions result from the direct leaks of the refrigerant into the atmosphere and are an aggregate of the foll
9、owing emissions:Regular emissions, which refer to the refrigerant leaks from the A/C system during operation, Irregular emissions, due to accidents, stone hits, product defects etc,Service emissions, from garages during maintenance and repairEnd-of-Life emissions, from the recovery or complete relea
10、se of refrigerant at the end-of-life of the vehicle, Leakage during refrigerant production and transportation.Thus, the direct CO2emissions are evaluated based on the GWP of each chemical and the amount of refrigerant mass emitted into the atmosphere. The direct emissions are expressed in terms of C
11、O2-equivalent (CO2-Eq.) emissionsSAE J2766 Issued FEB2009 Page 2 of 17Indirect Emissions result from the energy consumption associated with manufacturing, use and disposal of the MAC system, and is an aggregate of the following CO2emissions that result from: Manufacturing and end-of-life recycling p
12、rocesses, of various alternative refrigerants,Manufacturing and end-of-life recycling processes, of each component of the MAC system,MAC operation, such as those associated with the operation of the compressor, and engine cooling fan during the lifetime of the vehicle,Fuel consumption due to MACs ma
13、ss transportation onboard the vehicle throughout the lifetime of the vehicle, Thus, the Indirect component is reported in terms of CO2emissions, considering the carbon content of the fuel utilized in each process or during vehicle operation. The JAMA and NREL studies do not include the CO2emissions
14、associated with the end-of-life recycling processes. Furthermore the NREL study considers only the indirect component of the TEWI. Studies conducted by GM assess the LCCP of alternative refrigerants. Such complete LCCP studies include more CO2contributions as compared to TEWI. The complete set of Di
15、rect and Indirect components calculated during an LCCP analysis is expressed in Equation 2: LCCP = GWP Direct from leaks + GWP Direct from additional sources: (atmospheric reaction products of refrigerant) + (manufacturing leakage) + (end-of-life refrigerant emissions) + (Eq. 2) GWP Indirect from MA
16、C operation + GWP Direct from additional sources: (chemical production of refrigerant and transport) + (manufacturing MAC and vehicle assembly) + (end-of-life recycling processes) Assumptions and methodology for either TEWI-based or LCCP-based analyses can have a large impact on the conclusions, as
17、it was indicated in the results presented by such studies. As a result, the JAMA members Denso, Honda, Nissan, and Toyota and several other OEMs including: Daimler, Fiat, Ford Motor Company, VW and Audi, have agreed to work together with GM to develop a common approach to conduct LCCP assessments fo
18、r alternative refrigerants. This new SAE J-standard is the result of the harmonization effort suggested by the US EPA and conducted by the Mobile Air Conditioning Industry. The goal of this standard is to address the LCCP global warming impact of alternative refrigerants, considering various climati
19、c conditions, driving habits in different parts of the world, different vehicle platforms and different fuels. This standard provides the assumptions and methodology of the publically available GREEN-MAC-LCCPmodel (ref.(1). 2. REFERENCES 1. U.S. Environmental Protection Agency, Climate Protection Pa
20、rtnerships; www.epa.gov/cppd/mac2. SAE J2765 Procedure for Measuring System COP Coefficient of Performance of a Mobile Air Conditioning System on a Test Bench; www.sae.org3. U.S Department of Energy, Buildings Technologies Program, found on the DOE internet site under: http:/www.eere.energy.gov/buil
21、dings/energyplus/weatherdata_sources.html4. Reference for the TMY2 is: National Renewable Energy Laboratory (NREL). 1995. Users Manual for TMY2s (Typical Meteorological Years), NREL/SP-463-7668, and TMY2s, Typical Meteorological Years Derived from the 1961-1990 National Solar Radiation Data Base, Ju
22、ne 1995, CD-ROM. Golden, Colorado: National Renewable Energy Laboratory; http:/rredc.nrel.gov/solar/pubs/tmy2/tmy2_index.html5. Wards Automotive Data; http:/ Global Insight Data; http:/ J2766 Issued FEB2009 Page 3 of 177. “Average Age of cars and trucks in USE 1970_2004”, found on the Oak Ridge Nati
23、onal Lab (ORNL) Internet site under: http:/cta.ornl.gov/data/chapter3.shtml; click at Table 3.7 8. European Motor Vehicle Parc 2005, obtained by ACEA; published in January 2007 9. Trend of vehicle possessions in Japan (AIRA); http:/www.aira.or.jp10. Chaney L., Thundiyil K., Chidambaram S., Abbi Y. P
24、., Andersen S., “Fuel Savings and Emission Reductions from Next-Generation Mobile Air Conditioning Technology in India” paper to be presented at Vehicle Thermal Management Systems (VTMS) organized by SAE and IMechE, May, 2007 11. Johnson V. H., “Fuel Used for Vehicle Air Conditioning: A State-by-Sta
25、te Thermal Comfort-Based Approach”, SAE paper 2002-01-1957, SAE Technical Series Paper, 2002 12. Clodic D., Yu Y., “Research study on the definition of the implementation of a method of measurement of annual leak flow rates (LFRs) of MAC systems, ACEA/ARMINES Contract, January 2006 13. Fanger, P. O.
26、 Thermal Comfort, Copenhagen: Danish Technical Press, 1970 14. Parsons, K. Human Thermal Environments, 2ndedition, London pp. 221-226 15. Atkinson W., Hoffpauir E. MACS 2005 Survey 16. Industrial Marketing Research Auto Maintenance Survey data, shared by ARPI (Automotive Refrigeration Product Instit
27、ute)17. Schwarz W., Emission of Refrigerant R-134a from Mobile Air-Conditioning Systems Annual Rate of Emission from Passenger-Car Air-Conditioning Systems up to Seven Years Old, ko-Recherche Bro fr Umweltforschung und -beratung GmbH, September 2001 18. Palandre L., Riachi Y., Tremoulet A., Clodic D
28、., Intermediate report on practice evaluations of small can users,December 2007 3. GREEN-MAC-LCCPINPUT DATA The Direct and Indirect CO2-equivalent emissions of each LCCP term found in Equation 2 are estimated using input data entered in the spreadsheets of the GREEN-MAC-LCCPmodel. The GREEN-MAC-LCCP
29、tool is an excel-based multilayered-spreadsheets model consisting of several input and output spreadsheets. The input spreadsheets require input data entered by the user for each run. Some of the input data are variable and subject to specific engineering properties of each refrigerant, and its inte
30、raction with the MAC System/Components, such as COP Coefficient of Performance, Capacity, etc. These variable input data are entered in purple-colored cells of each input sheet. Other input data have been fixed into the model because they are not subject to change for each alternative refrigerant ev
31、aluated and they have been agreed by the industry during harmonization. The fixed input data include vehicle lifetime, climatic conditions in each city etc. The fixed data are highlighted in the spreadsheets of the model by light yellow color. Table 1 shows the Input Data required to be entered by t
32、he user in the model.The following sections provide in a greater detail the variable and fixed data of the model that result in the complete LCCP model for assessing the CO2-equivalent emissions of each alternative refrigerant. SAE J2766 Issued FEB2009 Page 4 of 17TABLE 1 - INPUT DATA REQUIRED TO BE
33、 INTRODUCED BY THE USER INTO THE MODEL Input Worksheet Name in GREEN-MAC-LCCPModel Variable data Fixed Data Manufacturing Input Sheet 1. Energy and CO2-equivalentemissions to manufacture, recycle and transport the refrigerant 2. Mass of refrigerant leakage during transportation3. Material compositio
34、n of each MAC component (% rate of total mass) 4. Global Warming Potential (GWP)of atmospheric reaction products 5. Global Warming Potential (GWP) for refrigerant 6. Average Leakage Ratio to HFC-134a7. Refrigerant recycling during service 8. Mass for each MAC component, refrigerant charge mass and l
35、ubricant mass 1. Life Cycle Analysis energy and CO2emissions for manufacturing each material found per MAC component2. End-of-Life CO2emissions associated with recycling or disposal of each MAC component Leakage Input Sheet 1. Estimated loss before Service 2. % Do-It-Yourself 1. Regular leak emissio
36、ns 2. Irregular leak emissions 3. Number of Services 4. Refrigerant loss per service for Professional Service 5. Refrigerant loss from can heels for Professional Service 6. Refrigerant loss per service for DIYer Service 7. Refrigerant loss from can heels for DIYer Service 8. End-of-Life refrigerant
37、emissions without refrigerant capture 9. End-of-Life refrigerant emissions with refrigerant capture 10. Refrigerant emissions from vehicle assembly Capacity and COP Input Sheets 1. Capacity and COP data from bench tests at 900, 1500, 2500, 4000 engine RPMs for T=15 C, T=25 C, T=35 C, T=45 C 2. The d
38、ata are obtained according to the Test Matrix included in the model1. Idle conditions weighting factor2. Weighting factors for evaporator conditions at T=3 C and T=10 C, evaporator outlet temperatureDrive-Cycle Input Sheet 1. Engine to Compressor Ratio 2. Engine RPMs from vehicle drive cycle tests 1
39、. Alternator Efficiency 2. Belt Efficiency 3. Alternator/Engine Ratio 4. Incremental Engine EfficiencyFan Power 1. Fan Power at each ambient temperature included in the model at various speedsFuel Data 1. Fuel Consumption per unit mass 2. Fuel Heating Value 3. Fuel CO2emissions per liter fuel consum
40、edSAE J2766 Issued FEB2009 Page 5 of 17TABLE 1 - INPUT DATA REQUIRED TO BE INTRODUCED BY THE USER INTO THE MODEL (CONTINUED) Input Worksheet Name in GREEN-MAC-LCCPModel Variable data Fixed Data Climate Data 1. % Drive time at Ambient during 6AM to 24PM for each city 2. Annual average temperature per
41、 city 3. Driving distance per city 4. Driving time per city 5. Vehicle lifetime per city 6. % time A/C is on per each bin included in the model and per each city Manual A/C system 7. % time A/C is on per each bin included in the model and per each city Automatic A/C system 8. Solar Conditions per ea
42、ch city and per temperature bin included in the model9. Relative Humidity per each city and per temperature bin included in the model10. Relative Humidity correction using Relative humidity data from tests and city conditions Global Vehicle Registrations 1. Vehicle Scrap Rate 2. Vehicle Sales 3. Veh
43、icle Registrations 4. % A/C penetration per city 4. ENGINE AND COMPRESSOR RPM PROFILE Collect engine RPM data second by second from the recommended drive schedule, shown in Table 2, for a representative vehicle that is chosen for analysis. Obtain engine RPMs at different drive cycles as shown in Fig
44、ure 1. Each city is assigned of one of the drive cycles shown in Figure 1. Typical vehicle engine RPM are included into the model but the user has the option to enter his/her own. Engine to compressor RPM ratio is then entered in the purple cells, or the default value of 1.35 can be used. The engine
45、 RPM data is then multiplied by the compressor to engine drive ratio.The model provides fixed values for the Alternator efficiency, 65%, and Belt efficiency, 95%. The Incremental Engine efficiency for a gasoline vehicle and for a diesel vehicle are variable. TABLE 2 - REGIONAL DRIVE CYCLES AND VEHIC
46、LE INPUT PARAMETERSSAE J2766 Issued FEB2009 Page 6 of 17FIGURE 1 - DRIVE CYCLES FOR EACH COUNTRY WITH BOTH CITY AND HIGHWAY PORTIONSThe default incremental engine efficiency values were based on advanced modeling of engines operating at different drive cycles, A/C loads, model vehicles with respect
47、to gasoline and diesel fueled vehicles. The modeling work was performed at GM and NREL. In addition, incremental engine efficiency data were received by JAMA, Daimler and Audi based on vehicle tests.The incremental engine efficiency of any given vehicle is a function of: (a) drive cycle, (b) A/C loa
48、d, (c) vehicle engine and vehicle transmission type, (d) engine fuel type (gasoline vs. diesel, etc.). Due to the specificity of various engines and associated engine maps for the same class vehicles, as well as for different vehicle classes across all OEMs operated at different drive cycles, the in
49、cremental engine efficiency datapoints included into the model were based on the average data presented by Audi, Daimler, GM, JAMA and NREL. There were too many effects to make this variable fixed at this time.5. LEAK RATES Leak rates for each city and each alternative refrigerant considered are included into the model. The
