1. LAT Durability Task Force
Experimental Activities
Exhaust Line Temperature Measurement
Brussels, 13 September 2017

2. Contents Exhaust temperature measurement
On the vehicle
On the engine test bench
Combined tests
Exhaust aftertreatment ageing testing activities 2

3. Vehicle Exhaust Temperature Measurement: Objectives
Objective: (Surface) Temperature across exhaust line + Emissions (dyno testing)
Cold & hot WLTC
Cold & hot SRC
Open points:
Both gaseous and particulate emissions?
How many repetitions of each test?
Provision of necessary input data for testing (e.g. inertia, road load, data for calculating WLTC gear shifting, dyno mode, test temperature)?
Gear shifting for SRC?
 Run the same protocol with JRC 3

4. Vehicle Exhaust Temperature Measurement: Objectives
(Surface) Temperature across exhaust line (+Emissions, if needed)
Tests with DPF regeneration
RDE test
Notes
For test 1: LAT can run forced and controlled DPF regeneration for some vehicles, on the chassis dyno
For test 2: LAT has run similar tests on the road – Additional safety issues will be considered for the individual vehicles to be tested. 4

5. Vehicle Exhaust Temperature Measurement: Example
Surface temperature measurement across exhaust line
On-road
On the chassis dyno
Random driving & cool down in both cases
Vehicle: Diesel 2lt, MT6, EU6
EAT devices: cDPF, SCR
Temperature measurement:
Engine out (=cDPF in, after turbo)
cDPF out (=SCR in)
SCR out
Additional thermocouples can be installed
engine out
SCR out
cDPF out
SCR
cDPF 5

6. Vehicle On-Road Measurement: Example
Random driving (mainly motorway)
Cool down during soaking 6

7. Vehicle Chassis Dyno Measurement: Example
Random driving (similar to EUDC)
Cool down during soaking 7

8. Exhaust Temperature Measurement: Engine Test Bench
Transient engine dyno at LAT
Euro 6 engine – diesel
Modular exhaust lines (DOC/DPF/SCR/LNT) – capability for close-coupling
Capability to replicate WLTC and SRC for typical vehicles the engine is fitted
Capability to control DPF regeneration
Thermocouples in various position in the exhaust line (before and after EAT devices)
Thermocouples inside the EAT device(s)
Advantage: Very good repeatability (compared to vehicle testing) 8

9. Exhaust Temperature Measurement: Combined Tests
Combined vehicle and engine testing
Vehicle testing: Surface temperature measurement across exhaust line (on exhaust pipe and/or on EAT device surface), during WLTC and SRC (and even on-road testing)
Engine testing: Temperature measurement inside the exhaust line and the EAT devices (+surface measurement)
Use of test data in modeling (AxiHEAT)  correlation between temperature data at various points
Selection of a vehicle fitted with the available engine
The respective EAT devices must be sourced for the engine dyno
LAT has run such an activity in the past, replicating the on-road vehicle behaviour on the engine dyno
Limitations
A rental car will be (probably) used
availability
condition of EAT devices  effect on emissions 9

10. Engine Test Bench Measurements
Usual position of thermocouples
Flow direction
10mm
½ length
5mm
15mm
Plugs 10

11. Active cDPF Regeneration11

12. WLTC Results – cDPF Temperature Distribution12

13. Cold & Hot NEDC – TWC Temperature Distribution13

14. Exhaust Aftertreatment Device Ageing
EAT devices ageing tests
Evaluation of EAT condition: conversion efficiency vs temperature
Engine Test Bench (ETB) (most probably) or Synthetic Gas Bench (SGB)
Vehicle emissions over WLTC with the EAT device at fresh and aged conditions
Surface analysis of the fresh and aged samples
EAT device ageing procedure
engine: thermal + chemical ageing (time consuming, limited availability of equipment)
oven: thermal ageing (possibility also for hydrothermal) 14

15. EAT device surface analysis methods available at LAT/AUTh
Analyzed characteristics
Relevant for
Available at AUTh or accessible If yes: what type, where
TEM1,4 (HAADF-STEM/EDX)
Particle size, dispersion of metals (poisons/Pt migration to SCR)
DOC, SCR,CUC
Yes, Available at AUTh, Physics Department
XRD2,3,4,10
Crystallinity, growth of crystallite size (support sintering), formation of new crystalline size
DOC, SCR, CUC
Yes, Available at AUTh, Department of Chemical Engineering 
TPO/TPR5
Oxidation state of metal
Yes, Available at AUTh, Laboratory of Petrochemical Technology, Chemical Engineering Department
NOx/NH3/S-TPD6,9
Sorption capacity
SCR
Yes, Available at AUTh, Laboratory of Petrochemical Technology, Chemical Engineering Department
CO/H2 Chemisorption8
Dispersion, masking of active sites
DOC
IR (DRIFTS)5
Identify the nature of adsorbed hydrocarbons/coke, sulfur species
DOC, SCR
Yes, Available at AUTh, Laboratory of Petrochemical Technology, Chemical Engineering Department
EPMA7,10
Ash profile
DPF, SCR
XPS1
Depth profiling of elements (detection of surface poisons)
TGA-DTA/ TG-MS3
Amount of deposited carbon (coke)
27Al Solid MAS NMR4
Degree of dealumination
SCR (zeolite catalysts)
Yes, Available at Available at AUTh, Chemical Engineering Department- not clear if the 27Al probe is available
XRF10
Quantitative analysis of distribution of poisons (phosphorus, sulfur)
Yes, Available at AUTh, Department of Chemistry and Geology
BET
Evaluation of surface area
Yes, Available at AUTh, Chemistry Department 
Optical Microscopy11
Visual investigation of ash/fibers/deposits
DPF
Yes, Available at AUTh, Physical Metallurgy Lab, Mechanical Engineering Department
LECO combustion12
Quantitative analysis of carbon and sulfur
Yes
Raman spectroscopy13
Crystal and molecular structure of soot
Yes, Available at AUTh, Chemical Engineering Department
Pulsed and flow measurements for OSC
Oxygen storage capacity and oxygen mobility of CeO2
TWC/LNT/PNA
Yes, Available at AUTh, Petrochemical Technology Lab, Chemical Engineering Department
CT scan
Cracks in ceramic substrate, ash distribution
DPF/SCRF
Yes, Available at AUTh, LAT
SEM/EDS
Particulate Matter (PM) samples and point analysis of areas in order to identify regional variations in Elemental Distribution

16. Surface analysis indicative results
Ash layer inside the channels of a DPF
Pt particles aggregation upon DOC ageing
Fresh DOC
Aged DOC
Pt particles
DPF cracking due to thermal shock after drop-to-idle