WLTP-06-14e Ambient Temperature Correction Test for WLTP WLTP IG Meeting, Vienna, 26-28.3.2014 Contact: Andreas.EA.Eder@bmw.de
Page 2 Motivation: In order to reflect the CO 2 values obtained under real life temperature conditions, an additional test is proposed to be conducted on a regional base. For this test, the vehicle shall be soaked at a defined regional temperature T reg over a defined soak/park time (t soak ). No restrictions for oil and water temperature. Approach for Europe: Typical use cases for soak time are overnight parking ~10-12h and daytime parking at work ~8h. This leads to t soak = 9h. Climate data derived from FAT Study (Prof. Köhler, Technical University Braunschweig, Germany) The ATCT (measurement) shall be performed only once for a temperature correction vehicle family.
Vehicle Family for ATCT Type I Test Test cell, soak: 23 C Soak time: 6 36 h Engine oil, water: 23 C CO2_3 CO2_1 CO2_2 Ambient Temperature Correction Test FCF Test cell, soak: Treg, e.g. [14] C for EU Soak time: tsoak, eg. [9 + 2] h for EU Engine oil, water: no restrictions CO2@Creg CO2 @ Creg CO2 _ Type I For one vehicle out of a family (measurement) CO2 _ ATCT CO2 _ Type I FCF For all vehicles in one family (calculated value) FCF = Family Correction Factor CO2_Type-I = TA CO2 value for Type-I test (23 C) CO2_ATCT = corrected CO2 value Creg = regional conditions Page 3
Family criteria check and ATCT (example for 14 C and 9h) 23 C Test a. Correction of F0,F1,F2 to 20 C => GTR Annex 4 4.5 b. Adjust dyno settings @ 14 C c. Pre Con WLTC for warm up @23 C For each CO2 family b. Adjust dyno settings @ 23 C c. Pre Con WLTC for warm up @23 C d. Soak @23 C for 6-36h (forced cool down) until engine oil & water = 23 C e. WLTC with emissions measurement f. Soak @23 C for at least 9 h with natural cool down. Tolerance between test end and start cool down 10 min. Logged temperatures: engine oil & water, soak area temperature. - CO2 @ 23 C - Cool down curves @23 C for Temperature Criteria check Selection of ATCT family representative vehicle. Criteria: Temperature and vehicle requirements. d. Soak @14 C for 9h and natural cool down with no restrictions. Tolerance between test end and start cool down 10 min. Logged temperatures: engine oil & water, soak area temperature. e. WLTC with emissions measurement CO2 @ 14 C FCF CO2 @ 14 C CO2 @ 23 C Page 4 For each ATCT family 14 C Test a. Correction of F0,F1,F2 to 14 C => GTR Annex 4 4.5 Road load determination
Page 5 Requirements for family criteria check: The following characteristics should be equal within the family: - temperature at the end of soak time within a tolerance of [5/10] K - combustion process (two stroke, four stroke, rotary) - number of cylinders - configuration of the cylinder block (in-line, V, radial, horizontally opposed, ) The inclination or orientation of the cylinders is not a criteria - method of engine fuelling (e.g. indirect or direct injection) - type of cooling system (air, water, oil) - method of aspiration (naturally aspirated, pressure charged) - fuel for which the engine is designed (petrol, diesel, NG, LPG, etc.) - engine cylinder capacity of the largest engine within the family minus [20] % Additional provisions for emissions control and heat storage systems available
Vehicle 328xi Limo (MT) 320iA GT (AT) Engine coolant temperature @23 C, 9h Test1 Test2 T_amb+8.8 T_amb+6.4 T_amb+7.3 T_amb+5.7 Check, if ATCT family temperature criteria is met. ΔT=3.1K ATCT at Treg=14 C and tsoak=9h Vehicle 328xi Limo (MT) 320iA GT (AT) FCF Test1 +1,8% +2,0% FCF Test2 +1,5% +1,4% FCF ATCT (CO2 @14 C ) Type1(CO2 @ 23 C ) PSA results show similar behavior. ACEA proposal [5]K absolute temperature tolerance Page 6
Page 7 ATCT FOR PHEVS? The correction is complex and requires significant lab ressources: Correction of Charge Sustaining CO 2 value: possible (like ICE) Correction of electric range for Utility Factor and CO 2 :?
UF [%] ATCT FOR PHEVS IN WLTP. ATCT IMPACT ON THE ELECTRIC RANGE OF CD TEST. Type I @ 23 C charging @ 14 C / 9h ATCT @ 14 C -3% erange BMW i3 Range Extender Page 8 100 90 80 70 60 50 40 30 20 10 10 20 30 40 50 60 70 Electric Range [km] Example PHEV (40km erange, 100g CO 2 /km) -3% @ 40 km electric range + Shift in UF curve ΔCO 2 1 g/km For i3 Range Extender, the influence would be <<1g/km CO 2
Page 9 ATCT FOR PHEVS IN WLTP. ACEA proposal for ATCT and PHEVs : Correction of Charge Sustaining according to ICE procedure No correction of e-range and UF.
Page 10 Status and Summary: Detailed proposal for ATCT Procedure drafted by Audi/BMW. Validation tests successfully conducted at BMW and PSA. For PHEV, only Charge Sustaining CO 2 shall be temperature corrected.