Jun 20, 2022 10:34
1 yr ago
28 viewers *
French term
sur vireur
French to English
Tech/Engineering
Engineering: Industrial
Incidents in a turbine which are being analysed and counter-analysed by the respective parties' experts.
[expert AAA:]
"Comme il est supposé que le déséquilibre thermique est causé sur le piston d'équilibrage et qu'il n'y a qu'un contact avéré entre les balais oxydés et raidis pendant le fonctionnement de l'engrenage de rotation, l'influence principale sera vue sur les capteurs qui ont physiquement une distance plus élevée - aux roulements arrière.
Après la montée en régime de l'arbre, le rotor est soulevé et, par conséquent, ses vibrations changent.
L'amplitude et la phase changent en conséquence.
Par conséquent, les signaux des capteurs observés ne sont pas surprenants.
Pour autant, il est clair qu’à partir du mois de juin 2018, le comportement vibratoire s’est détérioré de façon croissante.
1/2 - [expert] BBB écrit aussi que « le plus aberrant est le fait d’évoquer un balourd thermique pour justifier la dérive des vibrations alors que la turbine est sur vireur à une vitesse de rotation de 150 tr/mn, et la valeur énorme du balourd nécessaire pour accroitre les vibrations de 10 μm.
Un décalage de plusieurs dixièmes de millimètres voire millimètres de l’ensemble du rotor par rapport à son axe de rotation serait nécessaire, ce qui physiquement n’a aucun sens »."
This could be a spelling mistake of course. Survireur means "oversteer" in a vehicle context, which this ain't obviously.
[expert AAA:]
"Comme il est supposé que le déséquilibre thermique est causé sur le piston d'équilibrage et qu'il n'y a qu'un contact avéré entre les balais oxydés et raidis pendant le fonctionnement de l'engrenage de rotation, l'influence principale sera vue sur les capteurs qui ont physiquement une distance plus élevée - aux roulements arrière.
Après la montée en régime de l'arbre, le rotor est soulevé et, par conséquent, ses vibrations changent.
L'amplitude et la phase changent en conséquence.
Par conséquent, les signaux des capteurs observés ne sont pas surprenants.
Pour autant, il est clair qu’à partir du mois de juin 2018, le comportement vibratoire s’est détérioré de façon croissante.
1/2 - [expert] BBB écrit aussi que « le plus aberrant est le fait d’évoquer un balourd thermique pour justifier la dérive des vibrations alors que la turbine est sur vireur à une vitesse de rotation de 150 tr/mn, et la valeur énorme du balourd nécessaire pour accroitre les vibrations de 10 μm.
Un décalage de plusieurs dixièmes de millimètres voire millimètres de l’ensemble du rotor par rapport à son axe de rotation serait nécessaire, ce qui physiquement n’a aucun sens »."
This could be a spelling mistake of course. Survireur means "oversteer" in a vehicle context, which this ain't obviously.
Proposed translations
(English)
| 4 +2 | jacking / turning gear |
Bourth
|
| 3 | gear |
Conor McAuley
|
| 3 -2 | over-revving |
Jennifer Levey
|
Proposed translations
+2
1 hr
Selected
jacking / turning gear
Personally I'm familiar with 'turning gear' from my nuclear and aero-engine days, but it seems 'jacking gear' is also said.
"A jacking gear (also known as a turning gear) is a device placed on the main shaft of an engine or the rotor of a turbine. The jacking gear rotates the shaft or rotor and associated machinery (such as reduction gears and main steam or gas turbines), to ensure uniform cool-down."
[Wikipedia]
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Note added at 3 hrs (2022-06-20 13:39:31 GMT)
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Re. your question below, 'on jacking gear' should be sufficient for anyone who knows the field, e.g. "The bearings are required to operate at speeds ranging from 0.1 rpm*, WHEN ON JACKING GEAR, to 100 or more rpm in either direction of rotation", i.e. they won't think the turbine is physically place on/above some sort of lifting jack. Another expression I've found is "on its jacking gear MOTOR", i.e. being rotated by that motor (not by steam).
* I've seen several sites discussing jacking gear for marine engines; the jacking rotation speeds are incredibly slow; one mentioned a full turn in 10 minutes!
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Note added at 3 hrs (2022-06-20 13:44:27 GMT)
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For examples of the formulation with "on", you'll find considerably more relevant instances of (turbine + "on turning gear") than of (turbine + "on jacking gear").
"A jacking gear (also known as a turning gear) is a device placed on the main shaft of an engine or the rotor of a turbine. The jacking gear rotates the shaft or rotor and associated machinery (such as reduction gears and main steam or gas turbines), to ensure uniform cool-down."
[Wikipedia]
--------------------------------------------------
Note added at 3 hrs (2022-06-20 13:39:31 GMT)
--------------------------------------------------
Re. your question below, 'on jacking gear' should be sufficient for anyone who knows the field, e.g. "The bearings are required to operate at speeds ranging from 0.1 rpm*, WHEN ON JACKING GEAR, to 100 or more rpm in either direction of rotation", i.e. they won't think the turbine is physically place on/above some sort of lifting jack. Another expression I've found is "on its jacking gear MOTOR", i.e. being rotated by that motor (not by steam).
* I've seen several sites discussing jacking gear for marine engines; the jacking rotation speeds are incredibly slow; one mentioned a full turn in 10 minutes!
--------------------------------------------------
Note added at 3 hrs (2022-06-20 13:44:27 GMT)
--------------------------------------------------
For examples of the formulation with "on", you'll find considerably more relevant instances of (turbine + "on turning gear") than of (turbine + "on jacking gear").
Note from asker:
| Thanks. Good to have someone with relevant experience and for whom this makes sense. I'm not quite sure how you mean to translate the whole expression: "... when the turbine is **on** its jacking gear..."? Or maybe "**using** its jacking gear..."? Something like that maybe? |
Peer comment(s):
| neutral |
philgoddard
: The turbine is jacking gear?
16 mins
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I'm not sure I know how I'm supposed to react to that, but maybe only because I have a dirty mind.
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| agree |
Tony M
: Yes, that's right! They're saying that because it is being externally turned very slowly (compared to its nominal operating speed), the vibration cannot be accounted for. The 'jacking' is the 'soulevé' mentioned by AAA.
1 hr
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I don't know where the term 'jacking' comes from, here. With 'jacking oil', the pressure does indeed lift the rotor off its bearings.
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| agree |
Daryo
: that corresponds perfectly to the description of "un vireur" given in the ref found by Emmanuella
3 hrs
|
4 KudoZ points awarded for this answer.
Comment: "Thanks very much."
-2
56 mins
Jennifer Levey
Chile
Chile
Native in English
Chile
Human-scale Globalization
Native in: English (Variant: British) 
Works in: Spanish to English, French to English, English to Spanish, and 2 more.
Related KudoZ points
:
45
over-revving
I suspect the author is using 'sur vireur' to mean 'sur-régime' - i.e. the turbine is designed to run at speeds up to 150 rpm without causing vibration problems such as those observed by AAA.
Peer comment(s):
| disagree |
Tony M
: 150 rpm is a very low speed; normal running speed will be e.g. 1500 rpm.
1 hr
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Asker hasn't told us what kind of turbine this is. What are you assuming in that regard? (Hint: there's mention of l'engrenage de rotation)
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| disagree |
Daryo
: over-revving at 150 rpm? exactly the opposite! // "vireur" is some kind of device used to move this steam turbine much more slowly than in normal use, when there is no supply of steam.
4 hrs
|
2 hrs
Conor McAuley
France
France
Native in English
France
Excellence, Expertise & Experience
Native in: English (Variants: Wales / Welsh, UK, Scottish, Irish, British)
Works in: French to English, English
Related KudoZ points
:
11
gear
See diagrams 6 and 7 in this patent (item marked 24 in both diagrams):
https://patents.google.com/patent/EP1659286B1/fr
As previously mentioned here, the gear is part of a wind turbine, and I would interpret as a mechanical gear that adjusts the power of the turning rotors so that the "power" transmitted is suitable for mechanical power to electrical power conversion.
The diagrams should be a great help.
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Note added at 2 hrs (2022-06-20 13:25:02 GMT)
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Substitute energy for power above.
https://patents.google.com/patent/EP1659286B1/fr
As previously mentioned here, the gear is part of a wind turbine, and I would interpret as a mechanical gear that adjusts the power of the turning rotors so that the "power" transmitted is suitable for mechanical power to electrical power conversion.
The diagrams should be a great help.
--------------------------------------------------
Note added at 2 hrs (2022-06-20 13:25:02 GMT)
--------------------------------------------------
Substitute energy for power above.
Discussion
=
the biggest nonsense is to resort to claiming that a thermal imbalance (eccentricity of the centre of mass due to uneven thermal dilation) would be the cause for the runaway vibrations, while the turbine is coupled to / moved by / driven by this "vireur" device at a rotational speed of 150 rotations per minutes (very slow for a turbine) given the huge value for this (thermal) imbalance that would be required to increase (the amplitude of the) vibrations by 10 μm (one hundredth of a millimetre).
Operation and Maintenance of Large Turbo-Generators
John Wiley & Sons, 11 août 2004 - 560 pages