Emitec System introduction 21/5/2013 Magic yang Content System layout and components Control----Working flow 2 1/13/2014 System Layout 3 1/13/2014 Components Dosing Pump Unit ECM Urea tank (level and temp sensor) Air tank Pipeline (suction line, backflow line, mixture line, air flow line) Urea injector nozzle EGP (Temp sensor, Nox sensor) 4 1/13/2014 Dosing Unit 1. Urea in from tank 2. Air supply in (vehicle air tank/compressor) 3. Urea out to Injector nozzle (Urea & Air mix) 4. Urea return to tank (only used during prime) 5. 37 PIN ITT Can connector broadcasting on the J1939 6. Power supply to Solenoid 2 pin connector 5 1/13/2014 Dosing Unit Specifications Function : deliver urea according to the message sent by engine ECM. Built-in heating device : allows the doser to operate with outside temperatures < –11C, if the vehicle also has heated Urea lines and tank. It will also function in a working temp > 80C, but Urea > 50degC for extended periods will damage the doser Unit. Integrated self-diagnostic procedure, informing the Engine ECM about its status by sending messages via the J1939 CAN link. Accommodate both 12 VDC & 24 VDC supply voltages. The desired flow rate repeatability :1% 6 1/13/2014 Cummins Confidential Dosing Unit Components A: Air Tank B: Air filter C: Doser unit D: Engine ECM E: Wema Sensor F: Urea Tank G: Nozzle H: EGP Inlet Temp I:EGP Outlet Temp J: EGP Dosing Unit Components Valves & lines Motor PCB Dosing Pump controller Pump heater Temperature sensor Temp sensor on the PCB Connector 8 1/13/2014 Valves & lines 1 B 2 3 6 4 5 UDS limits A 1. Air valve (controlled by solenoid) 2. Air pressure regulator @ 4 bar 11 P 10 7 AIR UNIT 8 3. Orifice 4. Air Check Valve (ACV) 5. Back Pressure Valve (BPV) OBD MIXING VALVE 9 6. Mixing chamber 7. Outlet check valve (spring loaded) 8. Actuated membrane MEMBRANE PUMP D C 9. Inlet check valve (spring loaded) 10. Pressure switch 11. Air Actuated Valve (AAV) 9 1/13/2014 UREA TANK Dosing Unit 10 1/13/2014 Dosing Unit 11 1/13/2014 Dosing Unit 12 1/13/2014 Dosing Unit 13 1/13/2014 Pump motor Stepper Motor Stroke One piston movement (back and force) Origo System which gives the membrane origin (Hall effect sensor) Parking Position Best position for parking: In this position, the membrane can move easily during urea expansion (freezing); After the thawing of the pump head, the pump cycle will start with the suction phase. So, this avoids increasing of pressure in the pump head if the return line is frozen. 14 1/13/2014 Pump motor : Parking 15 1/13/2014 Connector 16 1/13/2014 Urea injector nozzle 17 1/13/2014 Urea injector nozzle location 18 1/13/2014 Urea injector nozzle location 19 1/13/2014 SCR SCR Urea Injector catalyst Gas Flow Urea Decomposition and Hydrolysis in Exhaust: (NH2)2CO (s) NH3 (g) + HNCO (g) HNCO (g) + H2O (g) NH3 (g) + CO2 (g) NOx Reduction in SCR Catalyst: NO + NO2 + 2NH3 → 2N2 + 3H2O Fast Reaction 4NO + 4NH3 + O2 → 4N2 + 6H2O Dominant Reaction 2NO2 + 4NH3 + O2 → 3N2 + 6H2O Slow 6NO2 + 8NH3 → 7N2 + 12H2O 6NO + 4NH3 → 5N2 + 6H2O 20 1/13/2014 Slow Slow Content System layout and components Control----Working flow 21 1/13/2014 Priming phase (1) 1 B 2 3 6 4 5 A 11 P 10 7 8 Air valve closed (air solenoid valve off) Pump motor working at max capacity (7.5l/h) 9 Urea back to tank, not build pressure Pressure switch not activated D C UREA TANK 22 1/13/2014 Prime phase (2) (continued) After 30s the air solenoid valve open – air pressure closes the air activated valve (AAV), the solenoid can be heard “clicking” on Doser continues to pump urea for 10 strokes, building pressure in the urea path During the 10 strokes monitor pressure switch If urea is present, and air bubbles have been purged out, then the pressure switch will activate, indicating the presence of urea and a successful prime, transition to dosing state 23 1/13/2014 Prime phase (3) (continued) If no urea is present, the doser will be unable to build pressure; priming will be unsuccessful The air solenoid valve will be deactivated, to allow urea to circulate back to the tank and the prime sequence will be repeated After retrying 20 times, the doser will report UREA_DOSER_LOW_AIR_UREA_ERR 24 1/13/2014 Prime phase (4) (continued) At the end of the Priming phase Air solenoid valve open Pump motor stop Pressure switch activated When priming is complete, the doser automatically enter the “Dosing” state, but with a urea dosing rate of 0 ml/h. Urea dosing phase B 2 3 6 4 5 1 A P 10 7 11 Air valve open (air solenoid on) 8 OBD Pump working at required capacity Urea injected in nozzle line 9 Pressure switch activated D C UREA TANK 26 1/13/2014 Purging phase B 2 3 6 4 5 1 A P Clear nozzle line 10 7 11 8 Air valve open (air solenoid on) OBD Pump motor stopped (0l/h) 9 Only air injected in nozzle line Pressure switch activated D C UREA TANK 27 1/13/2014 Purging phase Air solenoid valve opens Pump motor stop Pressure switch activated Air removes urea droplets that could crystallise and block the pump valves, urea lines or the injection nozzle. Lasts for 30 seconds then the system switches off, the solenoid can be heard “clicking” off. Stop phase 1 B 2 3 6 4 5 A 11 P 10 7 Air closed (air solenoid off) 8 Pump stopped to parking position No urea neither air flow Pressure switch not activated 9 D C UREA TANK 29 1/13/2014 THANKS! 30 1/13/2014