DIMEG - University of L Aquila ITALY EXPERIMENTAL ACTIVITY ENGINE LABORATORY

Transcription

1 DIMEG - University of L Aquila ITALY EXPERIMENTAL ACTIVITY ENGINE LABORATORY

2 Torre di Raffreddamento Bilan cia Combustibile DIMEG:ENGINE LABORATORY PLANTS Torre di Raffreddamento P C o o z l z d o P C o o z l z d o P H o o z t z o Serbatoi per uso giornaliero Container stoccaggio combustibili Bilan cia Combustibile Elettroaspiratore Bilancia Combustibile

3 EXPERIMENTAL ACTIVITIES HC HC non non stationary measurement (FFID (FFID CAMBUSTION) NOx NOxnon stationary measurement A/F A/F electronic control in in spark spark ignited ICE ICE (engine AVL AVL 5401) 5401) Stationary AVL AVL test test bench bench (diesel (diesel turbocharged engine Alfa Alfa Romeo cm cm 3 3 )) Non Non stationary (dynamic) AVL AVL test test bench bench (spark (sparkignited engine Lancia Lancia cm cm 3 3 )) Diesel and and biodiesel spray spray optical (Laser) (Laser) analysis Combustion optical camera analysis in in combustion chamber (AVL (AVL module) LPG LPG(GPL) supply supplysystem control and and air-spray interaction analysis Engine unsteady gasdynamic reserarch Thermal transient analysis in in ICE ICE (engine AVL AVL 540) 540)

4 FFID: FAST RESPONSE FLAME IONIZATION DETECTOR HFR400 CAMBUSTION MCU (MAIN CONTROL UNIT) Measure head DCS (DYNAMIC CALIBRATION SYSTEM) LHC (LINE HEATER CONTROLLER) P=400mmHg Ion Collector P=300mmHg Sampling point

5 FAST RESPONSE FLAME IONIZATION DETECTOR HFR400 CAMBUSTION: Stationary measurement

6 FAST RESPONSE FLAME IONIZATION DETECTOR HFR400 CAMBUSTION: Transient measurement: acceleration-deceleration

7 AVL 5401: 1 cylinder, 4 stroke, 2 valves Swept volume: dm 3 ; Max power: 25 kw; Compression ratio 10.5 AVL 5401 research engine :: A/F A/F control experimental activity model model based based air air (MOIC-QPM-MTF )) estimator & fuel fuel dynamic compensator Throttle ( ) Lambda Speed (rpm) Time (s) Throttle ( ) Lambda Speed (rpm) Time (s)

8 AVL 5401: test test bench layout

9 AVL stationary test bench: engine Alfa Alfa Romeo diesel turbocharged swept volume 2480 cm cm valves Max power kw kw AVL non-stationary (dynamic) test bench: engine Lancia spark ignition swept volume1600 cm cm valves Max power kw kw

10 AVL stationary test benches: functional diagrams ARIA IN INGRESSO SC. Acqua/Acqua FILTRO MOTORE DINAMOMETRO V a s o d i r a c o l t a T2 T1 MOTORE Intercooler Acqua dal circuito interno SC. Acqua/Olio T4 T3 DINAMOMETRO T5 ACQUA AL POZZO CALDO Intercooler T7 T8 T6 C T TURBOCOMPRESSORE T9 SCARICO ACQUA DALLA RETE

11 AVL test bench PUMA :: control unit unit diagram (torque-speed) AVL test bench PUMA: control unit unit diagram (alpha-speed) Ramp generator Demand Engine (coppia) Controller Actual (coppia) Set (alpha) Demand Engine ( % alpha) Ramp generator Set (alpha) Demand Dyno (rpm) Cotroll er - Controller Set (coppia) Demand Dyno (rpm) - Controller Set (coppia) Actual (giri) Dyno Engine Actual (giri) Dyno Engine

12 AVL test bench PUMA :: USER CONSOLE

13 GDI (gasoline direct injection) diesel Common Rail sprays experimental and numerical analysis In recent years both Direct-Injection (DI) diesel engines, equipped with high-pressure electronically controlled Common Rail (CR) injection systems, and Gasoline Direct Injection (GDI) Spark-Ignition engines, essentially wall-guided type, have been widely introduced in global markets. They are environmentally friendly and offer attractive improvements in fuel efficiency and power output. CR injection systems allow to shape the injection curve with high flexible engine management, reduction in noise, fuel consumption and emissions. The electronic control of the injector enables to manage the injection strategy in terms of timing, pressure, numbers of injection per cycle and, above all, a de-coupling with the engine. The multiple injection, available with an electronically controlled CR apparatus, has shown to be effective in reducing the peak of heat release and the NOx and smoke exhaust emissions.

14 Diesel engine fueled with diesel fuel - biodiesel blends: spray analysis An experimental study on spray evolution and characteristics has been conducted using pure diesel fuel and pure biodiesel and the results obtained have been compared with the numerical ones, obtained using a new breakup model. Experimental apparatus The structure and the spatial and temporal evolutions of the throttling pintle type injector spray were obtained using a system, able to gather and process spray images, including a CCD camera, a frame grabber and a stroboflash.

15 The comparison between experimental and numerical spray characteristics points out the following results: The shape of the spray is asymmetric, due to the pintle injector geometry. biodiesel spray is characterized by an earlier injection, a higher penetration velocity and higher values of injection mass and injection duration. The breakup process is evident. There is a first linear dependence of spray penetration on time and, after a short transition, a quadratic dependence can be observed. The numerical code gives good spray penetration and profile predictions, showing the usefulness of a numerical simulation tool in order to clear up, to analyze and to deeper understand the main phenomena of injection process Spray penetration [mm] Diesel engine fueled with diesel fuel - biodiesel blends: spray analysis: results 0 Diesel experimental Biodiesel experimental Diesel numerical Biodiesel numerical Time from trigger signal [ms] Experimental and numerical spray penetrations

16 AVL 513 VIDEO SYSTEM (Camera combustion display) CCD AVL 513 ENGINE VIDEO SYSTEM Video camera CCD Immagine di una fase della combustione Endoscopio Encoders Direct/undirect Injection sparay analysis Camera view of the flame front propagation inside the combustion chamber Camera view of the spark ignition (SI ICE) Camera view of the spontaneous ignition Camera view of phenomena dealing with some mechanical components (valve, gears).

17 LPG liquid-phase injection: experimental setup

18 LPG liquid-phase injection: devices of of injection system regulation Injector model Pressure regulator model

19 Air-Dynamics: theoretical and and experimental validation of of models representing unsteady gasdynamic phenomena in in engines

20 Air-Dynamics: theoretical and and experimental analysis Validation of mathematical models: MOC, QPM, MOIC, MTF Valve tension [V] Some results P [kpa] Tank exit Measurements MOC Valve needle lift [mm] Time after valve opening start [ms] P [kpa] Mid-duct Measurements MOC 0 a a Tank a Ext φ Possible valve boundary conditions (for various φ) Possible stationary flow conditions (for various φ and a Tank ) φ=1 Possible tank boundary condition (for various a Tank ) u Optimal R L Optimal R φ σ MOC [kpa] P [kpa] P [kpa] Valve seat Measurements MOC Time after valve opening start [ms]