18 th month Meeting, Paris, 20 th May, 2010

1. 18th month Meeting, Paris, 20th May, 2010 WPB2.3Exhaust Heating/Catalyst concepts Heat exchanger manufacturing Delphi Thermal

2. ECOCAT Catalytic coating application Delphi tasks and interfaces with its partners USTT Heat exchanger concept definition and dimensioning/simulation Laser welding technology DELPHI Heat exchanger concept adaptation and its manufacturability Brazing technology KATCON Caning manufacturing, insulation, sensors

3. 50 300 50 Heat exchanger description Tube forming 0.15 mm Male plate Tube 2.9 mm Female plate 0.15 mm Inflow Fins Outflow

4. Technical challenge • What is the main constraint? • Thermal inertia – Needs to reduce it to improve the efficiency during the cold start • Need to reduce the material thickness of tubes and fins. • High temperature – The heat exchanger has to resist against thermal stress • What is the difficulty? • Need to identify the lowest material thickness for which brazing is still possible in accordance with product requirements • Need to develop the brazing process • Maintain the core straight without gas leak Need for development work

5. Work performed • Development work • Brazing process development • Define quantity and BFM (Braze Filler Metal) type • Braze trials to controlling diffusion of the BFM into the base metal • Define the right braze furnace temperature/time profile • Cross-sectional photo-micrographs: understand the braze joint depth and base metal dissolution • Tooling development • Forming the male and female plates to achieve 2.9 mm of cavity • Build a new stack fixture (device which maintains and compress the stacked core during the brazing in the furnace)

6. Work performed since the 12th Month meeting • Manufacturing work: Main steps of the manufacturing process • Cut the fins and plates by EDM wire cutting • Form the plates • Fit the fins to the plates • Clean the fins and plates • Apply BFM (Braze filler Metal) to the plates • Assemble stack and compress it with the fixture • Braze the stack in the vacuum furnace • Leak check • Machining the headers • Assemble the heat exchanger core with the headers • Apply BFM and maintain the assembly with the fixture • Braze the stack in the vacuum furnace • Leak check Unit for laboratory testing Plates and fins assembly Headers assembly The manufacturing of the heat exchanger core is completed

7. Engine test unit Laboratory unit 50 mm Laboratory unit outflow 50 mm Need for more heat transfer surface inflow 168 mm 50 mm Engine bench unit outflow U turn inflow 84 mm 50 mm 84 mm outflow 50 mm 100 mm Heat exchanger for engine test bench • Build heat exchanger for the engine test bench • Need for more catalytic and heat transfer surface than the laboratory unit • Solution: Build 4 units with 27 channels and assemble them together • Timing: • The work started on week 11 • The work completed on week 19

8. Heat exchanger for engine test bench outflow Fiber Ceramic inflow inflow outflow Fiber Ceramic

9. Heat exchanger for engine test bench Side view Top view

10. Heat exchanger for engine test bench Welding Welding Welding Front view(Inflow) Back view(U turn area) The headers of the 4 units will be welded by Katcon