enhancing process efficiency through improved temperature ......mar 22, 2017 · wp1, overview....
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EMPRESS Workshop
Advanced Forming Research Centre, March 22, 2017
Enhancing process efficiency through improved temperature
measurement
“Low-drift contact temperature sensors to above 2000 °C”
PTB, WG: “Thermoelectrics”
WP1, Overview
Seite 2EMPIR 2014
WP 1: Low-drift contact temperature sensors to above 2000 °C
Partners: PTB1, JV1, NPL1, Elkem2, MUT2, STRATH2, CCPI3
1 Internal funded partner (National Metrology Institutes (NMI))2 External funded partner (Industry, University)3 Unfunded partner
PTB Physikalisch-Technische Bundesanstalt, Germany
JV Justervesenet, Norway
NPL National Physical Laboratory, United Kingdom
Elkem Elkem AS Technology, Norway
MUT MUT Advanced Heating GmbH, Germany
STRATH University of Strathclyde, United Kingdom
CCPI CCPI Europe, United Kingdom
WP 1
Seite 3EMPIR 2014
Objective: Development and characterisation of three novel sensors that have in-process traceableuncertainty of better than 3 °C at 1450 C and better than 5 °C at T > 2000 °C.
• Conventional Pt/Rh thermocouples types S, R, B → thermoelectric instability (vapour pressure of Pt- andRh-oxides) → historical „accidents“ rather than established on basis of optimisation → modelling Pt-/Rhoxide transport + experimental determination of optimum compositions
• Above 1800 °C refractory thermocouples (W/Re) → drifts of ten of degrees → two approaches
WP 1
3 new or optimized sensors
Optical contact thermometer:Sapphire tube with dedicated optical readout components (1900 °C)
Carbon-based thermocouplesup to 2000°C
Seite 4
-1.0
-0.5
0.0
0.5
1.0
Drift r
ate
mK
/h
0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4
Calculated dS/dc µV/K%
1315 °C
1350 °C
1400 °C
40/20
40/17
30/17
25/17
40/1330/13
25/13
17/10
20/1025/10
20/13
30/10
40/10
EMPIR 2014
Task 1.1
Development of new and optimised Pt-Rh thermocouples (1450 °C)
• Developing of a model to characterise the influence of vapour transport of Pt and Rh oxides on the composition of the wires
• Annealing of multi-wire thermocouples with different Ptx%Rh-alloys: x = 5, 8, 10, 13, 17, 20, 25, 30, 40 at different temperature
between about 1315 °C and 1480 °C (6000 hours)
• Determination of a draft reference function of Pt40Rh/Pt6%Rh
13
1017
2025
30
40
-1000
0
1000
2000
3000
4000
5000
T
0 1000 2000 3000 4000 5000 6000
Annealing time / h
40/10
30/10
25/10
20/10
17/10
30/17
40/13
30/13
25/13
20/13
40/20
40/17
25/17
/ m
K
Annealing: 1315 °C 1350 °C 1400 °C 1450 °C
Drift rates
at Co-C
(1324 °C)
Seite 5EMPIR 2014
Task 1.1
Development of new and optimised Pt-Rh thermocouples (1450 °C)
Seite 6EMPIR 2014
Task 1.2
Development of a sapphire tube thermometer (<1900 °C)
• A prototype thermometer was developed based on thermal radiation.
• It consists of a sensing element (blackbody), which is placed inside a sapphire tube with suitable optics
channeling the thermal radiation on to a light detector (electronics)
• Based on the Planck radiation law, a model for the signal as a function of temperature was developed.
Tungsten filament
Seite 7EMPIR 2014
Task 1.2
Development of a sapphire tube thermometer (<1900 °C)
Sodium heatpipe
more modelling work to compensatethe influence of the immersion profile
Main problem:the temperatureprofile along thetube disturbsthe signal
Seite 8EMPIR 2014
Task 1.3
Development of carbon thermocouples
• Selection of suitable carbon thermocouple materials (3 graphite materials + glassy carbon)
• Solving constructional problems due to the use of non-metal thermoelements
• Metrological characterization to about 2000 °C
Absolute Seebeck coefficients
Head design MUT
Pt 100
Rod
Tube
Seite 9EMPIR 2014
Task 1.3
7500
7520
7540
7560
7580
7600
7620
7640
em
f /
µV
0 120 240 360 480 600 720 840 960time / min
15.08.2016
16.08.2016
17.08.2016
75/76-N01
1500 °C
10 K
S~~ 4 µV/K
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
em
f /
µV
8100
8200
8300
8400
em
f /
µV
0 30 60 90time / min
70 80 90 100 110
time / min
75/76-N01
ca. 1750 °C ca. 1950 °C
Thermocouple: C/C 76/75-N01 (after annealing)
1500 °C 1950 °C
R7660/R7510 not suitable
above 1700 °C
Seite 10EMPIR 2014
Task 1.4
Testing of the three new temperature sensors under industrial conditions
Nov 17 – Apr 18
Physikalisch-Technische Bundesanstalt
Braunschweig and Berlin
Abbestraße 2-12
10587 Berlin
Frank Edler
E-Mail: [email protected]
Stand:04/17