Investigation of the accelerated thermal aging behavior of polyetherimide and lifetime prediction at elevated temperature

2021 ◽  
pp. 51955
Author(s):  
Chungyeon Cho ◽  
Seo Lin Nam ◽  
A. Paulina de la Mata ◽  
James J. Harynuk ◽  
Anastasia L. Elias ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Thermal Aging ◽  
Lifetime Prediction ◽  
Aging Behavior ◽  
Accelerated Thermal Aging

Accelerated thermal aging of grease-based magnetorheological fluids and their lifetime prediction

2018 ◽  
Vol 5 (8) ◽  
pp. 085702 ◽  
Author(s):  
Jiajia Zheng ◽  
Yancheng Li ◽  
Jiong Wang ◽  
E Shiju ◽  
Xiping Li
Keyword(s):  
Thermal Aging ◽  
Magnetorheological Fluids ◽  
Lifetime Prediction ◽  
Accelerated Thermal Aging

scholarly journals Comparative study on the accelerated thermal aging behavior between palm and rapeseed natural ester oils

2019 ◽  
Vol 8 (3) ◽  
pp. 735-743
Author(s):  
N. L. M. Ridzuan ◽  
N. A. Bakar ◽  
S. A. Ghani ◽  
I. S. Chairul ◽  
N. H. A. Aziz
Keyword(s):  
Thermal Aging ◽  
Rapeseed Oil ◽  
Mineral Oil ◽  
Relative Content ◽  
Power Transformers ◽  
Environmental Concerns ◽  
Aging Behavior ◽  
Decay Products ◽  
Natural Ester ◽  
Accelerated Thermal Aging

The suitability of natural ester oils as an insulating medium in power transformers is discussed in this paper. Owing to environmental concerns, natural ester oils have great potential as mineral oil substitutes in power transformers. In this paper, the aging behaviors of palm and rapeseed natural ester oils were compared with that for mineral oil. The performance of these natural ester oils was assessed based on their properties (moisture content, acidity, and relative content of dissolved decay products) after accelerated thermal aging. The results showed that the palm oil has better performance compared to the rapeseed oil after accelerated thermal aging for 1500 h because of its lower acidity. This was further supported by the presence of sludge in the rapeseed oil after 1500 h of aging.

Thermal Aging Behavior of CoSb3 with Protective Mo Coating

2014 ◽  
Vol 787 ◽  
pp. 215-220 ◽  
Author(s):  
De Gang Zhao ◽  
Min Zuo ◽  
Xin Ying Teng ◽  
Hao Ran Geng
Keyword(s):  
Weight Loss ◽  
Magnetron Sputtering ◽  
Thermal Aging ◽  
Body Centered Cubic ◽  
Dc Magnetron Sputtering ◽  
Aging Behavior ◽  
Columnar Crystal ◽  
Aging Test ◽  
Cubic Structure ◽  
Accelerated Thermal Aging

In order to prevent the sublimation of Sb, protective Mo coatings were deposited on the CoSb3 substrate by DC magnetron sputtering. Thermal aging behavior of CoSb3 with Mo coating was investigated by accelerated experiment at 650oC for 24h. The results indicated that Mo coatings exhibit columnar crystal and body-centered cubic structure. It was found that the weight loss decreases with the increasing thickness of Mo coating. In comparison with naked CoSb3 material, the degradation of thermoelectric properties of CoSb3 with Mo coatings decreases under accelerated thermal aging test.

Evaluation of the resource and characteristics of the insulation of traction motors of locomotives by means of accelerated heat aging method

2021 ◽  
Vol 18 (1) ◽  
pp. 80-94
Author(s):  
D. I. Prokhor ◽  
◽  
N. V. Grachev ◽  
Keyword(s):  
Mobile Devices ◽  
Thermal Aging ◽  
Operating Conditions ◽  
Diesel Locomotive ◽  
Insulation System ◽  
Insulating Materials ◽  
Holding Company ◽  
Traction Motors ◽  
Operational Tests ◽  
Accelerated Thermal Aging

Objective: An equivalent mode of accelerated thermal aging of the insulation system of electrical ma- chines is described to confirm the resource corresponding to a given period and operating conditions. Methods: The equivalent mode of accelerated heat aging was determined based on the Montzinger rule and tested in the course of research and development work (R&D) on the development, manufacture and implementation of a set of bench and operational tests of the insulation system of an increased heat resistance class of a diesel locomotive traction motor. Results: The relevance of R&D has been revealed, as a result of which the implementation of the idea was required, based on the statement about the re- duction of the insulation resource of electrical machines when the permissible heating is exceeded by 8–12 °С to various types of insulating materials. The advantages of the method presented in the article in relation to traditional solutions of this problem are demonstrated, and also improved consumer proper- ties of the traction electric motor of a diesel locomotive with a replaced insulation system of an increased class of heat resistance are presented. Generally, experimental tests and preliminary operational data are an acceptable basis for thermal evaluation of electrical insulating materials. However, it is important to remember that the scientific criterion is met and not to use the results of different types of tests in the analysis. Based on the world experience in diagnostics of additional insulation parameters for monitoring the state of insulation parameters, the possibility of using the “Doctor” series insulation monitoring de- vices has been determined and practically confirmed. Together with the results of subsequent operational tests, during which the insulation was also monitored using these mobile devices, it is argued that after carrying out the relevant research work, thanks to the mobile devices of the “Doctor” series, it is pos- sible to carry out predictive analytics of the failure of traction motors (TED) in any operating conditions. The functional value is determined and applied in practice. The “H” class insulation system developed by the specialists of JSC “VNIKTI” is mainly based on insulating materials produced by JSC “Holding Company „Elinar“”; the compound “Elplast 180ID” (JSC “Electroizolit”) or its analogue “Elkom-180” JSC “Holding company „Elinar“”), for anchor coils and equalizers, a wound PPIPK-2 wire in polyimide- fluoroplastic insulation (GC “Moskabelmet”) is used. Practical importance: It is stated that all stages of manufacturing and testing, determined at the initial stage of R&D, confirmed the results of the deve- lopment stages (overhaul (manufacture) of prototypes of TED using a new isolation system according to the design documentation of JSC “VNIKTI”). Bench tests have confirmed typical characteristics, speci- fied resource and insulation characteristics with equivalent accelerated thermal aging corresponding to an electric motor’s service life of 20 years in ordinary operation on a diesel locomotive, residual life of elements of the insulation system of naturally cut armature segments, main and auxiliary poles coils. In the specialized laboratory of JSC “Holding Company „Elinar“”, an experimental TED diesel locomotive set with the investigated insulation system was manufactured and installed on two sections of the main- line diesel locomotive 2TE116. Operational tests of an experimental TED diesel locomotive set under operating conditions were successful.

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