Test procedure development

1. Mobile Air Conditioning (MAC) Test procedure development Stakeholder meeting, Brussels, 07-10-2010

2. Contents • Project overview • Draft of the test procedure • Chassis dynamometer tests • Influence of glazing quality • Test Evaluation • Preliminary results • Next steps Fonts: blue = Optiongreen = suggestet

3. Project overview Goal: To develop test conditions and procedures for MAC • Main evaluation parameter: impact on fuel consumption • Procedure should be clearly discriminative of different systems • Target accuracy and repeatability need to be clearly established

4. Project overview • Test conditions based on typical European: • Climatic conditions (temperature, humidity) • Operational conditions • Consumer habits • Three basic operational modes: • Cool down • To simulate vehicle interior cool-down after heat soak • Constant temperature • To simulate operation with a constant temperature interior • Simulation based or HIL (Hardware in the Loop) • E.g. COP map with duty cycle

5. Project overview • Definition of a test procedure(s) for MAC performance at type approval • Focus on physical testing: • Cost efficiency • Realistic representation of MAC efficiency • Use previous experience (ADAC 2007)

6. MAC test conditions • Simulation of “Seasonal Performance” of MAC system to determine most important ambient conditions • Analysis of Weather Data • Simulations by means of “Seasonal Performance” (LCCP) • Results presented in last meetings for Athens, Frankfurt, HelsinkiSummary: • main share in additional fuel consumption between 20°C and 30°C ambient temperature  25°C at 50% RH defined. • 21°C interior temperature defined as representative. • 700 W/m² suggested as solar radiation (higher than EU average to consider heat up during parking, which is not part of the test procedure).

7. Factors to be considered in test procedure Option for test procedure: Test vehicle on the chassis dynamometer with and without MAC.Difference is the additional fuel consumption from the MAC system. Define following settings: • Test cycle („easy to drive” for repeatable results at small fuel consumption effects) • Ambient temperature and humidity • Interior temperature to be reached with MAC • Mass flow of the MAC system • Simulation of heat from sun radiation • Evaluation method for test results

8. MAC test cycle Chasis dyno tests Test cycle: Options tested = 2-step, 3-step, NEDC Selected: 3-Step cycle(developed by ACEA) Advantages:Covers 3 speed ranges (different rpm for compressor)Tests MAC-on and MAC-off within same analysers calibration  less uncertainty

9. MAC on, m >230 kg/hPre conditioning (ti = 21°C) MAC test cycle Chassis dyno test 1) Preconditioning as defined in EC 692/2008for emission tests2) Soak >8h at 25°C (+/-2°C) at 50% RH (+/-5%RH)3) start MAC test, until second 1400 the MAC setting shall be found for 21°C cabin temperature (alternative 15°C vent outlet) MAC onmeasurement MAC offmeasurement Evaluation periods suggested: MAC on MAC off Additional MAC FC = Weighted average [kg/h] MAC on- Weighted average [kg/h] MAC off

10. Chassis dyno tests Positions of sensors “ambient temperature” 25°C and 50% RH measured at testbed-blower inlet Vehicle temperature measured in the cabin (details see next slide) 30 mm Ta, ja 330 mm to roof TC3 blower ml To CVS, exhaust gas analyser g CO2/km airstream ma Chassis dynamometer

11. 30 mm 330 mm to roof Chassis dyno tests Positions of sensors for cabin temperature Option a): weighted average of 3 positions for cabin temperature This avoids special optimisation of vent(s) for one temperature sensor position.Sensors position in the vehicle as shown in the picture: Option b): highest vent outlet temperature shall be <15°C. Effect of option b): vehicle size has nearly no influence on test results.No effort necessary to optimise flow in vehicle for the sensors positions.Not guaranteed that this setting would reach 21°C in the cabin. What we suggest: option c = a+bgain experience in pilot phase where temperatures are recorded for both options

12. Chassis dyno tests Set up of option „vent outlet“ 4 x „vent outlet temperature

13. Chassis dyno tests Other options to be discussed: Conditioning of the state of charge (SOC) of the batteryBackground: basically air conditioning could be driven electrically only from battery  no additional fuel consumption if battery not charged during test. Option a): measure energy flow and correct for difference kWh in/out with constant efficiency (e.g. 50% hel at 230 g/kWh). Option b): as a) but with measured efficiency. Option c): start one test with minimum SOC and a second test with maximum SOC. In actual tests SOC differences were small, future technologies may behave different. Suggestion:default = Option a), alternative = Option b) on OEM demand

14. Chassis dyno tests Other options to be discussed: Test of low ambient temperature behaviour Background: According to (Weilenmann et.al., 2010) “two-thirds of CO2 and fuel consumption from MAC activity could be saved without discomfort by switching off the MAC below 18 °C. Option:First preconditioning before soaking at <18°C with MAC in automatic position. If MAC is not activated with engine start a “bonus” for the MAC fuel consumption could be granted (20% to 50% of the MAC fuel consumption measured later?) Question: any important disadvantages) MAC activation for de-fogging, defrosting etc. shall not be prohibited. Ambient conditions need to be specified to avoid condensation issues

15. Glazing Good glazing quality can save MAC energy demand  Incentive for good quality shall be given in test procedure Tests with solar lamps are expensive In-Use tests are not repeatable  laboratory tests of glazing quality according to ISO 13837 & Simulation • Simulation of heat entrance into the vehicle cabin • Consider this heat entrance by • Option a) with a correction value in the evaluation • Option b) during tests by adapting the MAC mass flow or • Option c) during tests by adapting the test cell temperature

16. Glazing: simulation of heat entrance Energy balance from radiation and convection Heat entrance to cabin = E transmitted +to cabin re-emitted part of E absorbed E total sun radiation= E absorbed + E transmitted + E reflected 100% = ae + TDs + R Ds Measured according to ISO 13837 Share of re-emission into cabin from heat transfer coefficients hi and he in [kW/m²] for defined solar radiation (700W/m²) E interior = TTs x E total sun radiation Details see presentation from Volkmar Offermann (Saint-Gobain Sekurit)

17. Calculation of heat entrance into the cabin due to sun radiation Options for application of the approach discussed with Saint-Gobain Sekurit and NSG, calculation tool provided by Saint-Gobain Sekurit (V. Offermann and F. Manz) Option a): Application of calculation tool. Complex validation of tool necessary before it becomes standard. Option b): Provide look up table for W/m² as function of glazing (TTs value and angle of installation).Interpolation from table and multiplication with pane m². We suggest option b. Draft table could be veryfied by all stakeholders. Eventually diverging results may need further discussion.

18. Summary on suggested procedure for glazing • Heat entrance from solar radiation [kW] from look up table • Additional fuel consumption calculated from other look-up table [kg/h] as function of [kW] 1. k 2.

19. Test evaluation Additional MAC fuel consumption in [kg/h] i….single speed steps (0, 50, 100 km/h) Total result = weighted average according to real world shares: Idling = 15% 50 km/h = 65% 100 km/h = 20% CPei, CCOPi….Correction factors (details next slide) Basic problem of MAC tests: Small value is gained from difference of 6 large values Accurate measurements and affective correction for deviations in settings necessary

20. Test evaluation Suggested correction factors: Correction for variations in vehicle speed during the test (according to ratio of chassis braking power) Correction for variations in test cell temperature, humidity and cabin temperature (according to ratio of variation in cooling capacity) CCOPi-T1 CCOPi-RH CCOPi-TC3 Test bed temperature Test bed RH  Cabin temperature 

21. Test evaluation COP-Correction factorsmultiplication of the single correction factors is simple and no loss in accuracy against detailed simulation  Suggested look-up table for type approval

22. Some test results ACEA (PSA) tested the method on 6 vehicles and found good repeatability: TUG performed 3 repetitions with final test procedure and had one outlier: Option: define maximum standard deviation from >3 tests Test 2 had a DPF regeneration during preconditioning but this hardly explains the difference

23. Utility parameters • Possible need to relate additional fuel consumption to vehicle size • Depending on outcome of a pilot period • Depending on the final goal of the procedure • If needed, a proxy for vehicle size will be required. This proxy should be: • Easy to measure • Unambiguous • If possible already included in the vehicle type approval • Encouraging to fuel efficient MAC technology • Continuous to avoid optimisation at utility steps

24. Utility parameters (2) • Possible utility parameters could be: • Glazing area and inclination • Footprint • Interior volume (possibly based on footprint X height) • Pan area • Etc • Or a combination of the above Pan area

25. Utility parameters (3) Proposed approach: Collect a multitude of vehicle parameters during the pilot phase to enable the calculation of the correlation between these parameters and the additional fuel consumption This would of course need a means of correcting for various MAC technologies in some way MAC and powertrain parameters also needed during pilot phase

26. Utility parameters (4) • Proposed parameters to be collected in the pilot phase: • MAC component data • Compressor swept volume • Compressor type (piston, rotary vane, scroll, swash plate, swivel plate) • Compressor displacement control (fixed or variable displacement) • Compressor control type (internal control, external control) • Clutched compressor (yes / no) • Expansion valve type (fixed expansion valve (FXV), thermostatic expansion valve (TXV)) • Receiver type (integrated / non integrated receiver) • Internal heat exchanger, IHX (yes / no) • Number of evaporators (single / double) • Cabin airflow fan control (PWM / dropping resistor) • Condenser airflow fan control (PWM / dropping resistor) • Refrigerant type • Refrigerant fill quantity • Cabin air recirculation strategy description[1] • MAC control strategy at low ambient temperatures (Auto MAC off at low ambient T/ MAC remains on at low ambient T) • Vehicle data • Vehicle body type (sedan, hatchback, stationwagon, SUV) • Number of seats • Interior volume[2] • Vehicle footprint • Vehicle height • Glazing data; for every pane of glass / transparent plastic • Size • Inclination • Thermal properties (Solar transmittance Tts according to ISO 13837) • Tire size[3] • Powertrain data • Engine fuel type (petrol, diesel, CNG, LPG, etc.) • Engine maximum power • Engine displacement • Engine number of cylinders • Compressor drive method (belt, electric) • Compressor drive ratio if belt driven (crank / compressor pulley ratio)3 • Gearbox type (manual, automatic with torque converter, dual clutch, robotized manual)3 • Base idle speed3 • Gearbox ratios3 • Final drive ratio3 • [1] Possibly, in a follow-up project a control system strategy checklist could be defined which can be used in a “tick-box” manner to describe the control strategy. This would ensure that the control system strategy descriptions would all be in a similar format which should enable easier data handling and analysis. • [2] Possibly calculated from a CAD model, (in or excluding seats and trim?) • [3] This influences the time-speed pattern of the compressor over the test cycle as well as provide an estimate of the difference in CAP at idle and during the other phases of the test. List will be included in the final report

27. Main open options • Best preconditioning before soaking (NEDC?) • Test low temperature behavior? • How to handle battery SOC? • Use cabin temperature or vent outlet temperatures as target? • Which tolerances are reasonable for T’s and RH? • How many test repetitions are necessary for stable result? (>2) • Take glazing quality into consideration by correction factor or by change in MAC air mass flow? • Start a pilot phase?

28. MAC test cycle Thank you for your attention and for the support in this project!