Engine Tests with Ambixtra Ignition System Comparision of Ambixtra Ignition System with a Coil Ignitions System with Single Spark Dr. Ralf Tröger, Dr.-Ing. Thomas Emmrich, Sascha Nicklitzsch Chemnitz, 26th of June till 1st of July 2011 Excellence in Automotive R&D
Objectives performing of engine tests based on the prior tests on the flow chamber comparison the performance of the Ambixtra ignition system with a coil ignition system (single spark) in different operation conditions further optimisation of the setup of Ambixtra ignition system conditions: EGR variation in low load state variation of A/F-ratio at 2000 rpm/2 bar offset variation between EOI and ignition angle in stratified mode cold start ignition system parameter study (examples) IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 2
Test Engine Technical parameters: 4 Cylinder gasoline DI-inline engine displacement: 1995 cm³ compression ratio: 12 stratified and homogeneous operation cooled high pressure EGR (max EGR) turbocharger with waste gate and intercooler variable camshaft phasing for intake and outlet side IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 3
Test Bench Equipment and Measurements test bench automatisation: AVL PUMA open 1.4 emission analyser: Horiba MEXA 7000 indication system: Knock indication system: ECU access: optical access: AVL indiset 620 (high and low pressure indication) IAV KIS ETAS ES 1000 + INCA AVL VisioScope IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 4
IAV Test Bench configuration intake manifold wire connector air box engine intercooler EGR pipe IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 5
IAV Test Bench configuration fuel meter ETAS ES 1000 light unit optical access pressure signal amplifier Dyno IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 6
Ambixtra Spark Ignition System EGR variation in low load state homogeneous mode, n = 2000 rpm, BMEP = 2 bar coefficient of variation (COV) 0 10 20 30 40 50 60 70 80 % 100 250 275 300 325 350 375 400 425 450 g/kwh 500 COV p mi_ge coil ignition, single spark Ambixtra 0 2 4 6 8 10 12 14 16 % 20 A/F 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0-5.0 A/F-ratio (λ BS ) -1.5-1.3-1.1-0.9-0.7-0.5-0.3-0.1 0.1 bar 0.5 p mi_ge Ambixtra system delivers similar results like the coil ignition system up to 10 % EGR-rate higher EGR-rates higher inertgas-ratio increase of COV (more unstable operation) in case of coil ignition particular cylinders start to deviate with higher EGR with Ambixtra-system more stable operation cycle-tocycle and cylinder-tocylinder at EGR > 10% EGR-rate IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 7
Ambixtra Spark Ignition System Variation of A/F-ratio (2000 rpm/ BMEP = 2 bar) homogeneous mode, n = 2000 rpm, BMEP = 2 bar coefficient of variation (COV) 0 10 20 30 40 50 60 70 80 % 100 BFSC 200 225 250 275 300 325 350 375 400 g/kwh 450 C O V coil ignition, single spark Ambixtra 0.8 0.9 1.0 1.1 1.2 1.3 1.4-1.6 A/F p mi_ge 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0-5.0 A/F-ratio (λ BS ) -1.5-1.3-1.1-0.9-0.7-0.5-0.3-0.1 0.1 bar 0.5 p mi_ge from A/F-ration 0.9 up to 1.3 there are no sifgnificant differences in operation between Ambixtra ignition system and coil ignition system with A/F-ratios higher than 1.3 the increase of engine roughness is less with the Ambixtra system A/F-ratio (λ) IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 8
Ambixtra Spark Ignition System Offset variation between EOI and ignition angle in stratified mode stratified mode, n = 2000 rpm, BMEP = 2 bar, p intake =1000 mbar coefficient of variation (COV) 0 10 20 30 40 50 60 70 80 % 100 250 275 300 325 350 375 400 425 450 g/kwh 500 A/F coil ignition, single spark Ambixtra 180 185 190 195 200 CA 210 EOI2 α Q50 COV 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0-5.0 A/F-ratio (λ BS ) -30-24 -18-12 -6 0 6 12 18 atdc 30 α Q50 the offset between EOI and ignition angle is a very sensitive parameter in stratified mode with the Ambixtra system with the long spark duration, a quiet larger shift to later EOI s is possible combustion system less sensitive to cyclic deviations (put injection on the secure side) potential for stratification using lateral injector IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 9
Ambixtra Spark Ignition System Cold start homogeneous, n = 0 - > 1100 min -1, p me = 0 ->2 bar HC 0 1500 3000 4500 6000 7500 ppm 10500 Ambixtra1 coil ignition, single spark Ambixtra2 0 50 100 150 200 250 C 350 exhaust temperature (T exh_ut ) slightly lower HC-emission better combustion higher exhaust temperature upstream turbo light off temperature of catalyst could be reached earlier higher implemented ignition energy and longer spark duration lead to more stable inflammation for more detailed information, start tests with fast exhaust gas analysis systems (specially HC) are recommended potential for more retarded ignition timing not tested 0 10 20 30 40 50 60 70 80 s 100 Time IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 10
Ambixtra Spark Ignition System Ignition system parameter study (examples) homogeneous mode, n = 2000 rpm, BMEP = 2 bar, A/F-ratio = 1,5 coefficient of variation (COV) 0 10 20 30 40 50 60 70 80 % 100 250 270 290 310 330 350 370 390 410 g/kwh 450 p mi_ge A/F COV DC on, at 8 ms DC off spark amount = 20 0 1 2 3 4 5 6 ms 8 0.0 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2-4.0 A/F-ratio (λ BS ) -1.0-0.9-0.8-0.7-0.6-0.5-0.4-0.3-0.2 bar -0.0 p mi_ge with longer spark duration, engine roughness and decrease longer spark duration is an advantage for lean mixture inflammation on 8 ms the DC is off effect to be shown later spark duration IAV GmbH 07/2011 TE1 MO-A1 Results_engine_Ambixtra.ppt 11
Thank you Dr. Ralf Tröger dr.ralf.troeger@iav.de Dr.-Ing. Thomas Emmrich dr.thomas.emmrich@iav.de Sascha Nicklitzsch sascha.nicklitzsch@iav.de IAV GmbH Ingenieurgesellschaft Auto und Verkehr Excellence in Automotive R&D