Ten years of VTT s bus performance evaluation

Transcription

1 Ten years of VTT s bus performance evaluation Advanced bus technologies and alternative fuels Messukeskus, Helsinki, Kimmo Erkkilä VTT Technical Research Centre of Finland

2 2 Index City bus emissions and energy efficiency - Mission New laboratory 2002 & test methodology City bus emissions and energy efficiency Concurrent projects and spin-offs Summary

3 3 City bus emissions and energy efficiency Mission Original mission for city bus research (Nylund & Mäkinen, 2001) Promote the implementation of new clean and energy efficient technologies Improve competitiveness and attractiveness of public traffic Developement of evaluation methods Comparison of real-life performance of new and used vehicle technologies New knowledge will used as criterias for tendering of bus traffic in fair and economical manner The primary motivation for the work is to promote the implementation of new low-emission and energy efficient bus technologies, thus improving the competitiveness and attractiveness of public bus transport. Methodology to assess the performance (exhaust emissions, energy consumption, possibly noise) of buses will be developed. The methodology will be used to assess the true emission performance of both new vehicles and vehicles already in service. The unbiased information on the performance of various types of vehicles and exhaust gas after-treatment devices will be helpful for the municipalities responsible for the procurement of bus services in defining emission criteria. It is also expected that the data to be generated will have an impact on vehicle procurement by the transport companies.

4 4 New laboratory 2002 VTT commissioned new heavy-duty laboratory in 2002 Testing of complete vehicles on chassis dynamometer Distance based real-life emissions and energy consumption Effect of driving cycle Comparison of technologies Fuels Drivelines Available bus models Calibrations and components

5 5 Chassis dynamometer First tests in May 2002 Today 240 buses and some 120 trucks have been tracked by VTT (inc. follow-ups) Accuracy: Fuel consumption +1 % Emissions +15 %

6 6 Driving cycles Transient type test cycles the most commonly used cycle is the Braunschweig bus cycle 70 Braunschweig Bus Cycle Speed (km/h) Time (s) Creating reference values: in the Braunschweig cycle the engine of a half-laden 2-axle bus delivers some 1.8 kwh of work on the crankshaft per kilometre the Euro III limit value for NOx is 5 g/kwh (engine test) Braunschweig Euro III NOx reference value 1.8 * 5= 9 g/km

7 7 City bus emissions and energy efficiency Establishing the city bus database RakeBus, Bus fleet emission evaluation, Development of methodology Euro I.. EEV (CNG) real-life emissions Diesel & CNG CRT s, Miljö klass 1 fuel Follow-up measurements Participants YTV & HKL (currently HRT Helsiki Region Transport) Ministry of Transport an Communication Gasum Oy (natural gas company) The Swedish Road Administration VTT

8 8 City bus emissions and energy efficiency Extending the city bus database RASTU Heavy-duty vehicles: Safety, environmental impacts and new technology ( ) First Euro IV & EEV Diesel & CNG Follow-up measurements HDEniq Energy efficent and intelligent heavy-duty vehicle ( ) Focus on new EEV buses Diesel & CNG First hybrid vehicles Follow-up measurements

9 9 City bus emissions and energy efficiency Database 2010 Average results of 2-axle citybuses, Braunschweig cycle, half load Updated Braunschweig Number n Mileage Min Mileage Max CO g/km HC g/km CH4* g/km NOx g/km PM g/km CO2 g/km CO2 eqv** g/km FC kg/100k m Diesel Euro Diesel Euro Diesel Euro Diesel Euro Diesel Euro 5*** Diesel EEV CNG Euro CNG Euro CNG EEV *For CNG vehicles CH4 = THC * 0.95, for diesel CH4 = 0 ** CO2 eqv = CO * CH4 *** Euro 5 emission factors are estimated by Euro 4 results FC MJ/km New database will be published in few weeks, including average values of four hybrids

10 10 City bus emissions and energy efficiency

11 11 City bus emissions and energy efficiency Development of fuel consumption and CO2 emissions Fuel Consumption MJ/km FC MJ/km CO2 g/km CO2 emissions g/km 0 Diesel Euro 1 Diesel Euro 2 Diesel Euro 3 Diesel Euro 4 Diesel EEV Diesel Light Weight Diesel Hybrid CNG Euro 2 CNG Euro 3 CNG EEV 0

12 12 Concurrent bus projects and spin-offs EU EU HDVCertif IT Drivers aid New project? Electric Fuels CNG study Hybrid Kabus Hybrid Kabus proto B Optibio IEABUS ebus à HDCycle Baltic biogas bus Basis HDEnergy RakeBus PLL Bus RASTU HDEniq New project à Finnish accreditation Chassis for methods (FINAS) dyno start-up Lab upgrade for electric measurements

13 13 Concurrent bus projects and spin-offs RakeBus Bus fleet emission evaluation ( ) Establishing the database HDEnergy Fuel savings for heavy-duty vehicles ( ) Accurate fuel consumption measurement methods CNG Study Transit bus emission study: Emissions from diesel and natural gas buses ( ) Comparison of newest diesel and CNG buses IANGV collaboration

14 14 HDEnergy For the project, a target of permanent fuel savings of 5 10 % was set. Vehicles & technology Targeted fuel saving 5-10 % System & operations Driver & information Annual budget /a, in total approximately subprojects, 6 research parties, 20 sponsors

15 15 Identification of fuel saving potentials reduced vehicle weight and improved aerodynamics up to 30 % guiding the driver using technical devices 20 % variations from one vehicle brand to another 5 15 % tyres 5 % type of trailer 3 % (fuel consumption of the vehicle combination) lubricants 1 2 % HDEnergy Main achievements

16 16 CNG Bus study ( ) Relative emissions, worst result = 100% Brauschweig cycle PAH car. CNG EEV LM Euro 3 Diesel +CRT NMHC 100 % Euro 3 Diesel FA 50 % PM# Ames 0 % PM NO2 CO2 NOx muut/2004/transitbusemission.pdf

17 17 Concurrent bus projects and spin-offs HDCycle Evaluation of duty cycles for heavy duty urban vehicles ( ) Effect of driving cycle IEA collaboration Hybrid Kabus Demonstration of hybrid technology ( ) Parallel hybrid with super capasitors development with Kabus Oy Hybrid Kabus proto B ( ) Second development phase, layout consulting and performance measurements

18 18 HDCycle Response to duty cycle 35 Full load ( kg) Euro 3 Diesel EEV CNG Euro 4 SCR NOx g/km Full load ( kg) Euro 3 Diesel EEV CNG Euro 4 SCR NYBUS ADEME ORANGE BR HELS. 1 ECE15 Source: IEA AMF Annex XXIX WTVC PM g/km NYBUS ADEME ORANGE BR HELS. 1 ECE15 WTVC

19 19 Kabus Hybrid project Project group Benchmarking Laboratory tests Simulations Partners Prototype Field & laboratory tests Goal: Simple and cost effective hybrid bus Involved companies: Kabus, VTT, TEC, Tekes, Maxwell, Epec, Vacon Traction, Dynawatt

20 20 Kabus Hybrid project CO2 emission reduction Braunschweig cycle, load 3 000kg % CO2 emission g/km % -50 % m citybus Reference (Euro 3 avg.) Light weight Light weight + Hybrid bus Light weight + Hybrid + NExBTL

21 21 Concurrent bus projects and spin-offs PLL Bus Fuel consumption and exhaust emissions of urban buses ( ) The first direct comparison of bus models and publishing actual names RASTU Heavy-duty vehicles: Safety, environmental impacts and new technology ( ) Bus emission research joins the energy efficiency research Drivers aid ( ) Optimizing the fuel consumption, time and safety with on-line assistance

22 22 Drivers aid ( ) Optimization of city bus driving Reduces fuel consumption Experienced users: Biggest benefits on free flowing traffic. Fuel saving on complete line 1.1 l/100 km and on certain parts of line 4.6 l/100 km New users at rush hours: complete line 2.7 l/100 km and certain parts of line 5.4 l/100 km (over 10%) Keep buses on time, eliminating driving ahead of time Removes overspeeding Overspeeding of 5-10 km/h reduced over 70% and over 10 km/h overspeedings by 85% Tool for creating time tables for bus lines Effect of drivers aid studied on HDEniq and EU TeleFot projects Kuva: Juhani Laurikko

23 23 Concurrent bus projects and spin-offs OPTIBIO Optimized usage of NExBTL renewable diesel fuel ( ) Field trial of 30% and neat HVO fuel on ca. 300 city buses IEABUS Fuel and Technology Alternatives for Buses ( ) WTW analysis for available technology and fuel options HDEniq Energy efficent and intelligent heavy-duty vehicle ( ) Pulishing the city bus database, HSL starts using actual values on tendering

24 24 OPTIBIO ( ) Fleet test of new HVO diesel fuel in ca. 300 city buses in the Helsinki area Long term in-use experience, including cold weather performance Emission and fuel consumption effects for different types of vehicles and engines Chassis dynamometer tests in emission laboratory Long term stability of exhaust emissions HVO in combination with after-treatment devices Engine tests Approval by vehicle manufacturer (Scania) for 100 % HVO (NExBTL)

25 25 OPTIBIO ( ) Average emission reductions with 100% NExBTL diesel (in comparison to 10 ppm S diesel fuel): NOx-emissions approx. -10 % PM-emissions approx. -30 % CO-emissions approx. -35 % THC-emissions approx. -40 % Energy consumption approx. -0,5% Volumetric fuel consumption approx. +4% (as a result of lower density with 100 % NExBTL) Number of buses The effect of 100% NExBTL calculated as reduction of number of buses on Helsinki area -10 % corr. 140 buses -30 % corr. 420 buses The effects of NExBTL fuel on emissions is linear with concentration 0 NOx There are approximately 1400 urban buses in the Helsinki metropolitan area PM

26 26 Concurrent bus projects and spin-offs EU HDVCertif Development and Testing of a certification procedure for CO2 emission and fuel consumption of HDV ( ) EU assignment, VTT, TUG, TÜV, TNO, AVL Baltic biogas bus Increase the use of biogas buses in public transport in urban areas in the Baltic Sea region VTT support the project by determining driving cycles of cities and reallife emissions ( ) ebus Electric bus, research field and facilities ( ) Establishing electric bus research on field and on laboratory

27 27 Summary VTT has established comprehensive city bus emission and energy efficiency database in series of bus fleet emission evaluation projects Effect of driving cycle was studied on HDCycle project Understanding of alternative fuels has been generated for CNG, biogas, ethanol and renewable diesel fuels IT systems have been developed to achieve fuel savings, driving prompt on time and improve safety Steps towards electrification were started with Kabus hybrid projects and a new electric bus project is just started EU is looking for certification procedures for HDV CO2 and fuel consumption. VTT have been a pioner in the topic for years Euro VI is almost here, which will raise the questions on real-life performance and possible fuel penalty à need to continue updating the database

28 28 VTT - 70 years of technology for business and society