Hot Gas Stand durability tests for Turbine Housing design validation SyTec M2A 2015 13 th October 2015 A. Loret - Turbo Engineering 2015 MITSUBISHI TURBOCHARGER AND ENGINE EUROPE BV All Rights Reserved.
1. Scope 2. Hot Gas Stand test set-up 3. Endurance test cycles 4. Validation results 5. Summary 1
Scope Context of the study New Turbine Housing concept was implemented on turbocharger prototypes for performance testing on Renault Diesel engine. In partnership with Renault S.A.S, pre-development activities were defined to validate the main risks identified with this new technology. Durability validation activities were performed by MTEE on Hot Gas Stand test benches. Most of these Hot Gas Stand durability tests were conducted using CRITT test facilities and CRITT engineering support. 2
Scope Targets of the Hot Gas Stand durability tests Purpose of the HGS endurance tests is to evaluate the Turbine Housing design durability under thermo-mechanical stress levels representative of actual engine operating conditions. Main objectives are: - Assess the Turbine Housing durability level for implementation on industrial project - Validate the Turbine Housing design to secure performance testing on engine with prototypes parts 3
Hot Gas Stand test set-up Thermal shock endurance test in MHI First evaluation of the Turbine Housing new design is performed on MHI Hot Gas Stand on the turbocharger only. 4
Hot Gas Stand test set-up Thermal shock endurance test in CRITT A durability test on the complete engine exhaust face is performed on CRITT Hot Gas Stand. For this purpose, specific adaptation parts are designed and manufactured by CRITT : - A hot gas distribution unit in austenetic stainless steel, which function is to split the gas flow coming from the burner and divide it in 4 equal gas streams. - An aluminium plate with watercooling connection. It is fixed on distribution unit with a seal to guaranty that no leak occurs. - A mobile support rack which function is to support the distribution unit and provide fixation points for bracketing of the engine exhaust face components. 5
Hot Gas Stand test set-up Burner Distribution unit 3D model of the test installation at CRITT Aluminium plate with watercooling Tested system: engine exhaust face Mobile support racks 6
Hot Gas Stand test set-up 3D model of the test installation at CRITT 7
Hot Gas Stand test set-up Picture of the test installation at CRITT 8
Endurance test cycles Endurance MHI : thermal shock cycle Turbine inlet temperature measurement results in cycle Test conditions Duration time 1 cycle Turbine inlet Temperature 200 hours 550 sec (Hot 160 sec / Cold 390 sec) Hot 850 degc / Cold 100 degc 9
Endurance test cycles 1 st Endurance CRITT : thermal shock cycle Turbine inlet temperature measurement results in cycle Test conditions Duration time 1 cycle Turbine inlet Temperature 200 hours 530 sec (Hot 130 sec / Cold 400 sec) Hot 800 degc / Cold 110 degc 10
Endurance test cycles 2 nd Endurance CRITT : steady state + thermal shock cycle Test conditions (1 st part steady state) Duration time 50 hours 1 cycle 1 hour Time 15 s 15 s 15 s 15 s Turbine inlet temperature 650 degc 770 degc 770 degc 50 degc Gas flow rate 105 kg/h 220 kg/h 470 kg/h 260 kg/h Test conditions (2 nd part heat cycle) Duration time 1 cycle T3 10 hours 530 sec (Hot 130sec / Cold 400 sec) Hot 800 degc / Cold 110 degc 11
Validation test results Endurance MHI : Investigation results after 200hrs of thermal shock cycle cracks cracks 12
Validation test results Design optimization From the thermal shock endurance part investigation results, cracks are observed near inlet flange. The initial crack was detected after 100 hours. MTEE analysis is that it comes from high stress due to heat capacity differences between the inlet flange and the scroll part. This was confirmed by FEM results. As a countermeasure, MTEE implemented thinner inlet flange (hollow shape) for the first sample part tested on CRITT Hot Gas Stand. cracks (a) (b) 13
Validation test results Thermal characterization on CRITT Hot Gas Stand Time Engine reference data CRITT thermal shock cycle data Hot phase (T3=800degC) Skin temperature of monitoring point Test results comparison on exhaust manifold Duration Skin temperature of monitoring point Duration 670 degc 115 sec 668 degc 130 sec Cold phase 100 degc 410 sec 110 degc 400 sec Monitoring point 14
Validation test results Thermal characterization on CRITT Hot Gas Stand Test results comparison on reference Turbocharger 15
Validation test results 1 st Endurance CRITT : Plastic deformation comparison 270 Deformation level between Support plate and Shroud area 0 4.50 4.00 315 3.50 45 3.00 2.50 2.00 1.50 1.00 0.50 0.00 90 Support Plate Shroud area 225 135 200hrs thermal shock CRITT 200hrs thermal shock MHI 180 16
Validation test results Design optimization From the thermal shock endurance part investigation results, severe plastic deformation is observed on Turbine Housing. No cracks were detected at the end of the CRITT endurance test. As a countermeasure, MTEE implemented reinforcements between turbine outlet flange and support plate in order to increase the structural stiffness of the Turbine Housing. This modification was implemented on a second sample part tested on CRITT Hot Gas Stand. 17
Validation test results 2 nd Endurance CRITT : Plastic deformation comparison 270 Deformation level between Support plate and Shroud area 0 0.7 315 0.6 0.5 0.4 0.3 0.2 0.1 0-0.1-0.2-0.3-0.4 45 90 Support Plate Shroud area 225 135 40hrs engine performance test 10hrs engine performance test 50hrs + 10hrs CRITT endurance 180 18
Summary Endurance test campaign performed on Hot Gas Stand benches allowed to achieve below targets: - Assess the Turbine Housing durability level for implementation on industrial project. Further design optimization steps are required to achieve the durability target requirements with a design suitable for mass production. - Validate the Turbine Housing design to secure performance testing on engine with prototypes parts. 2 design optimization loops were implemented based on the thermal shock endurance tests results. The sample with optimized design could meet the durability targets defined for performance testing on engine. All engine performance test have been performed successfully with this optimized Turbine Housing design. 19
2015 MITSUBISHI TURBOCHARGER AND ENGINE EUROPE BV All Rights Reserved. 20