Examination of Diesel Aftertreatment Systems at NIOSH Lake Lynn Laboratory. Specific Aims of the Study

Transcription

1 Examination of Diesel Aftertreatment Systems at NIOSH Lake Lynn Laboratory Aleksandar D. Bugarski, George H. Schnakenberg, Jr., Jon A. Hummer, Emanuele Cauda, Samuel J. Janisko, and Larry D. Patts NIOSH Pittsburgh Research Laboratory 13th Annual Mining Diesel Emissions Conference, Toronto, October 1-5, 2007 Specific Aims of the Study To assess the effects of three types of uncatalyzed diesel particulate filters (DPFs), a diesel oxidation catalytic converter () and three types of high temperature disposable filter elements (HT DFEs) on the concentrations and size distribution of diesel aerosols and concentration of nitric oxides in underground mine air. Characterize nano and ultrafine aerosols. 2 S3P1-1

2 Methodology Testing performed in occupational setting: NIOSH Mobile Engine Emissions Laboratory (MEEL) at Lake Lynn Laboratory (LLL) Avoid laboratory uncertainties introduced with various simulations of processes Bridge gap between inherently inaccurate field and unrealistic laboratory experiments This facility offers unique environment for field testing with laboratory accuracy. 3 NIOSH Lake Lynn Laboratory (LLL) Portal D Drift E Drift Ventilation Shaft 4 S3P1-2

3 NIOSH Diesel Laboratory at LLL 5 Engine/Dynamometer Systems 150 kw eddy current dynamometer coupled to Isuzu C240 Engine Dynamometer and engine controls on board of the system remotely operated from downstream station Air intake, fuel and other engine and dynamometer operating parameters acquired by 32-channel data acquisition system onboard of the system 6 S3P1-3

4 Measurement and Sampling Stations Downstream station Upstream station Tailpipe station Ventilation control and measurement system 7 Downstream Station Real-time concentrations of aerosols and selected gases: SMPS; ELPI; TEOM; NDIR; CLD Ambient parameters 8 S3P1-4

5 Instrumentation at Downstream Station 9 Upstream Station Real-time concentrations of aerosols: SMPS TEOM 10 S3P1-5

6 Tailpipe Station Concentrations of CO 2,CO, and HC Relevant engine, dynamometer, and ambient parameters 11 Ventilation Control and Measurement System 25,000 ft 3 /min Venturi meter Auxiliary fan Ventilation stopping Real-time flow-rate measurements Ambient parameters 12 S3P1-6

7 Ventilation Parameters Total air flow rate through D-drift was maintained constant: 5.69 ± 0.06 m 3 /s ( ± ft 3 /min) This resulted in the following dilution ratios and ambient conditions: Mode Dilution Ratio R R I I Mode Air LFE Air Downstream Station Relative LFE Relative Downstream Station º C º C % % Minimum Maximum Plume Propagation, Thermal Stratification and Forced Mixing 1.40E E+06 I100 z=61 m, x=58 cm, y=168 cm W/O deflector z=61 m, x=58 cm, y=140 cm W/O deflector z=61 m, x=58 cm, y=112 cm W/O deflector 1.00E+06 z=61 m, x=58 cm, y=84 cm W/O deflector dn/dlog(d_p) [#/cm^3] 8.00E E E+05 z=61 m, x=58 cm, y=168 cm with deflector z=61 m, x=58 cm, y=140 cm with deflector z=61 m, x=58 cm, y=112 cm with deflector z=61 m, x=58 cm, y=84 cm with deflector 2.00E E D_p [nm] 14 S3P1-7

8 Repeatability 1.00E E+06 Muffler R100 (4/26/07) R100 (6/12/07) R100 (8/8/2007) dn/dlog(d_p) [#/cm^3] 1.00E E E E D_p [nm] 15 Control Technologies Diesel particulate filter (DPF) systems Cordierite element SiC element Sintered metal element Filtration systems with air-to-air heat exchanger and high-temperature disposable filter elements (DFE) New and laundered DFE from supplier #1 New DFE from supplier #2 Diesel oxidation catalytic converter The baseline was established using standard muffler 16 S3P1-8

9 Diesel Particulate Filter (DPF) Systems 17 High-Temperature Disposable Filter Elements (DFE) Integrated in the Filtration System with Dry Heat Exchanger 18 S3P1-9

10 Diesel Oxidation Catalytic Converter and Muffler 19 Test Modes Mode Description Engine Speed Torque Power R50 R100 I50 I100 Rated speed 50% load Rated speed 100% load Intermediate speed 50% load Intermediate speed 100% load rpm Nm kw S3P1-10

11 Fuel Test Method Result Units BTU, Net ASTM D kj/kg Cetane Number ASTM D Density ASTM D gm/ml Flash Point, PMCC ASTM D-93A 62.2 C Hydrocarbon Type Aromatics ASTM D LV% Olefins ASTM D LV% Saturates ASTM D LV% Oxygen Content 3.45 Wt. % Sulfur Content ASTM D mg/kg 21 Test Strategy Typical test takes approximately 3 hours The test starts after selected steady-state engine operating conditions are achieved The first hour of the test is used to achieve steady-state conditions in complete system The measurements start at the beginning of the second hour. The results obtained by averaging data from the last hour of the test are reported. Selected tests involving DFEs were extended to 5 or 12 hours. The aforementioned approach is also used for measurement and data processing for these tests. 22 S3P1-11

12 Results Effects of Control Technologies on Size Distribution of Aerosols in Mine Air 23 Size Distribution of Aerosols Measured at Downstream Station: R E+07 R E+06 dn/dlog(d_p) [#/cm^3] 1.00E+05 Muffler 1.00E+04 Cordierite DPF Sintered Metal DPF 1.00E+03 DFE #1 LDFE #1 DFE #2 1.00E D_p [nm] 24 S3P1-12

13 Size Distribution of Aerosols Measured at Downstream Station: I E+07 I E+06 dn/dlog(d_p) [#/cm^3] 1.00E+05 Muffler 1.00E+04 Cordierite DPF Sintered Metal DPF 1.00E+03 DFE #1 LDFE #1 DFE #2 1.00E D_p [nm] 25 Size Distribution of Aerosols Measured at Downstream Station: R E+07 R E+06 dn/dlog(d_p) [#/cm^3] 1.00E+05 Muffler 1.00E+04 Cordierite DPF Sintered Metal DPF 1.00E+03 DFE #1 LDFE #1 DFE #2 1.00E D_p [nm] 26 S3P1-13

14 Size Distribution of Aerosols at Downstream Station: I E+07 I E+06 dn/dlog(d_p) [#/cm^3] 1.00E+05 Muffler 1.00E+04 Cordierite DPF Sintered Metal DPF 1.00E+03 DFE #1 LDFE #1 DFE #2 1.00E D_p [nm] 27 Results Indicate Strong Relationship between Size Distributions and Exhaust Temperatures DPFs,, Muffler DFEs Mode Exhaust Temperature at Inlet of Device Temperature at Outlet from Device Exhaust Temperature at Inlet of Device Temperature at Outlet from Device ºC ºC ºC ºC R R I I S3P1-14

15 Size Distribution of Aerosols at Downstream Station: R E+07 R E+06 dn/dlog(d_p) [#/cm^3] 1.00E+05 Muffler 1.00E+04 Cordierite DPF Sintered Metal DPF 1.00E+03 DFE #1 LDFE #1 DFE #2 1.00E D_p [nm] 29 Size Distribution of Aerosols at Downstream Station: I E+07 I E+06 dn/dlog(d_p) [#/cm^3] 1.00E+05 Muffler 1.00E+04 Cordierite DPF Sintered Metal DPF 1.00E+03 DFE #1 LDFE #1 DFE #2 1.00E D_p [nm] 30 S3P1-15

16 Size Distribution of Aerosols at Downstream Station: R E+07 R E+06 dn/dlog(d_p) [#/cm^3] 1.00E+05 Muffler 1.00E+04 Cordierite DPF Sintered Metal DPF 1.00E+03 DFE #1 LDFE #1 DFE #2 1.00E D_p [nm] 31 Size Distribution of Aerosols at Downstream Station: I E+07 I E+06 dn/dlog(d_p) [#/cm^3] 1.00E+05 Muffler 1.00E+04 Cordierite DPF Sintered Metal DPF 1.00E+03 DFE #1 LDFE #1 DFE #2 1.00E D_p [nm] 32 S3P1-16

17 Results Effects of Control Technologies on Total Aerosol Number and Mass Concentrations 33 Effects of Control Technologies on Total Aerosol Number and Mass Concentrations: R50 Total Concentration Change [%] R50-20 Cordierite Cordierite DPF Sintered Metal DPF SMPS ELPI TEOM Engine Operating Mode DFE #1 LDFE DFE #2 34 S3P1-17

18 Effects of Control Technologies on Total Aerosol Number and Mass Concentrations: I50 Total Concentration Change [%] I50-40 Cordierite Cordierite DPF Sintered Metal DPF SMPS ELPI TEOM Engine Operating Mode DFE #1 LDFE DFE #2 35 Effects of Control Technologies on Total Aerosol Number and Mass Concentrations: R100 Total Concentration Change [%] R Cordierite Cordierite DPF Sintered Metal DPF SMPS ELPI TEOM Engine Operating Mode DFE #1 LDFE DFE #2 36 S3P1-18

19 Effects of Control Technologies on Total Aerosol Number and Mass Concentrations: I I100 Total Concentration Change [%] Cordierite Cordierite DPF Sintered Metal DPF SMPS ELPI TEOM Engine Operating Mode DFE #1 LDFE DFE #2 37 Effects of Control Technologies on NO x concentrations 4 NOx Concentrations [ppm] Muffler Cordierite Cordierite DPF Sintered Metal DPF DFE I LDFE I DFE II Technology 38 S3P1-19

20 Effects of Control Technologies on Percentage of NO 2 and NO X concentrations NO2 / NOx Concentrations [%] R50 R100 I50 I100 Muffler Cordierite Cordierite DPF Sintered Metal DPF DFE # LDFE DFE # Technology 39 Conclusion The effects of the on number and mass concentrations were found to be engine operating mode dependent. The results indicate that the effects of on number and mass concentrations were the most pronounced for high-load and high-temperature I100 engine operating modes. The tested DPF and DFE systems in the majority of test cases caused a 10-fold reduction of the total mass concentrations measured by TEOM. In the majority of the cases total mass reductions were accompanied with comparable reductions in total number concentrations. The exceptions were the cases R50, SM R100) when high concentrations of nucleation particles resulted in significantly lower reductions or even an increase in total particle number. 40 S3P1-20

21 Conclusion The percentages of NO 2 in total NO X are found to be strongly dependent on engine operation mode / exhaust temperature. The four fold increase in percentages of NO 2 in total NO X over baseline case was observed for the when the engine was operated at R100 and I100 (high exhaust temperature) modes. The same did not promote oxidation of NO to NO 2 in the cases when engine was operated at the lower temperature R50 and I50 modes. The substantial increase in NO 2 fraction in total NO X was observed for DFE#1 and DFE#2 when the engine was operated at the I50 mode. 41 Thank you for your attention! The findings and conclusion of this publication have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be constituted to represent any agency determination or policy. Mention of any company or product does not constitute endorsement by NIOSH. Aleksandar Bugarski NIOSH PRL, phone: abugarski@cdc.gov 42 S3P1-21

22 Total Aerosol Concentrations by Number During Long Tests of Fresh DFEs, R Total Concentrations [#/cm^3] DFE #1 Laundered DFE #1 DFE # Time [min] 43 Effectiveness of DFEs in Reducing Total Number of Particles Calculated Using SMPS Data, R50: Number vs. Range Reduction Effectiveness [%] DFE #1 Laundered DFE #1 DFE #2 Lowest 20-Minute Average Minute Average Highest 20-Minute Average Mode 44 S3P1-22

23 Size Distribution of Aerosols Measured at Downstream Station in the first minutes from the start of operating Fresh DFE at I100 Conditions 1.00E+07 I E+06 dn/dlog(d_p) [#/cm^3] 1.00E E+04 DFE #1 / 6 min after the start DFE #1 / 12 min after the start 1.00E+03 DFE #1 / 18 min after the start DFE #1 / 18 hours after the start Muffler 1.00E D_p [nm] 45 S3P1-23