Component supplier Delphi Automotive has outlined possible solutions to the emissions challenges facing both petrol and diesel vehicles in technical papers presented at the 21st Aachen Colloquium.
Delphi’s papers describe a near production-ready Selective Catalytic Reduction (SCR) dosing system which, the Company says, provides a very cost-effective approach to urea injection; and a Gasoline Direct Injection Compression Ignition (GDCI) engine that is currently in advanced development.
SCR dosing system
Delphi’s SCR dosing system will provide a cost-effective approach to urea injection. The first paper is entitled Delphi SCR Dosing System: An alternative approach for close-coupled SCR catalyst systems. It explains how a new high pressure water cooled urea doser simplifies the dosing system architecture compared to conventional approaches and how it is suitable for use on close-coupled SCR exhaust systems — where the SCR catalyst is placed closer to the engine for faster light-off. ‘The doser generates an outstanding spray quality enabling high levels of NOx conversion, even at low exhaust temperatures,’ explains David Needham, Delphi’s chief engineer on the SCR system. ‘The innovative arrangement provides a simple and robust solution for NOx reduction to meet Euro 6 Step 2 emissions regulations, and to minimise CO2 emissions without the cost and package increases normally associated with additional aftertreatment.’
The Delphi SCR system, which is suitable for passenger cars and light commercial vehicle applications, is complemented by a new, state-of-the-art ammonia sensor. SCR catalyst systems produce ammonia in order to reduce NOx emissions. Measuring ammonia with this sensor provides excellent feedback for precise urea dosing control, and offers a signal for on-board diagnostics (OBD) and monitoring of the SCR system.
The first production application of Delphi’s SCR dosing system is scheduled for 2015.
Gasoline direct injection compression ignition (GDCI)
Delphi’s second paper, entitled Combustion System for Gasoline Direct Injection Compression Ignition (GDCI), describes Delphi’s pioneering work on a completely new approach to combustion that delivers a combination of breakthrough fuel consumption and low exhaust emissions.
‘GDCI uses precise gasoline injection to enable well-timed and controlled compression ignition for high efficiency with low combustion noise,’ said Harry Husted, chief engineer, Advanced Powertrain.
New two-stage diesel injector
A third paper, presented by Daimler AG, details the joint Daimler-Delphi development of a combustion system using a new prototype two-stage diesel injector from Delphi. The injector uses a new variable orifice nozzle (VON) concept to minimise the conflict between reduced emissions, increased power output and lower combustion noise. The additional control of fuel flow, made possible by the VON, permits greater optimisation of diesel combustion and has already shown improved part-load fuel economy with lower noise and smoke levels.
A range of innovative power electronics products were shown at Aachen, including Delphi’s high-performance inverter, DC/DC converter, on-board battery charger, battery management system and hybrid vehicle control unit.
Delphi’s high-performance inverter uses patented power silicon packaging to reduce cost, size and weight while increasing overall reliability. The packaging eliminates wire bonds, enables higher current and power density, and when combined with dual-side cooling, reduces power semiconductor area. The inverter is expected to start production in 2013.
Delphi’s battery-pack controller calculates state-of-charge, evaluates battery health and determines power available for the vehicle. Using these calculations, it performs cell balancing to maintain cell safety and increase battery life. Delphi’s battery pack controller is scalable, AUTOSAR capable, low cost, compatible with multiple cell chemistries and is currently in production.
Inverters, battery packs and other HEV/EV components create a high-voltage environment that can be dangerous to drivers and service technicians. Delphi’s electrical and electronic architecture systems help keep both safe with physical harness protection systems, battery monitoring devices, plug-in charging systems and a series of connection systems that incorporate the shielding, sealing and high-voltage safety interconnects required for high-voltage/high-power applications.