World Pumps ◽  
2021 ◽  
Vol 2021 (6) ◽  
pp. 18-20
Keyword(s):  

Author(s):  
Jan W. Gooch
Keyword(s):  

2011 ◽  
Vol 33 (2) ◽  
pp. 2351-2358 ◽  
Author(s):  
Hyoung Jin Lee ◽  
Yeong Ryeon Kim ◽  
Sei-Hwan Kim ◽  
In-Secuk Jeung

Author(s):  
Ashwin Padmanaban Iyer ◽  
Anne Goj ◽  
Omar K. Ahmed

This study provides a methodology that can be used to evaluate the dynamic performance of fast depressurization devices used in liquid-filled oil transformers. Liquid-filled transformers are susceptible to explosions due to internal arcing if the dielectric insulation fails. The internal arc vaporizes a portion of the liquid and generates a sudden pressure wave. The first peak of the pressure wave has been measured to be as high as 13 bars, with time durations on the order of milliseconds [1]. Transformer tanks have a typical static withstand limit of approximately 1 bar gauge [2]. It is thus imperative that the tank be depressurized before the static pressure reaches such a threshold. One industry-accepted Fast Depressurization System [3] used to depressurize transformers after an internal arc is based on a patented rupture disk design [4]. This study compares the dynamic performance of this disk to results from a successful test campaign using a rupture disk as the depressurization device. Limiting loading rate values from the test campaign are then used to comment on the effectiveness of the design. The evaluation methodology is based on Pressure-Impulse (P-I) curves. The P-I curve was generated by running a series of Implicit Dynamic analysis using Code_Aster [5]. This iterative process first required establishing a failure mode that is consistent with actual observed failure in the field and observable in the Finite Element Analysis (FEA) model. The criteria were then used in interpreting the response of the Rupture Disk to a series of different half-sine wave pulse loading of varying amplitudes and time-periods. The generated P-I curve was then compared to loading rates observed in the test campaign [1] as well as three other higher loading rates (1.28 times, 2 times, 3.8 times, and 10.25 times the reported experimental rate) to qualitatively assess the effectiveness of the design. Results indicated that disk functions extremely effectively as a Fast Depressurization System as also corroborated by the test campaign. Although this methodology is used for the rupture disk, it is expected that this methodology can be extended to compare the dynamic performance of other depressurization devices.


2020 ◽  
Vol 153 ◽  
pp. 111485
Author(s):  
Keelan Keogh ◽  
Chang-Hwan Choi ◽  
David Cooper ◽  
Steven Craig ◽  
David Hamilton ◽  
...  

2012 ◽  
Vol 16 (3) ◽  
pp. 49-56
Author(s):  
Houk-Seop Han ◽  
Won-Bok Lee ◽  
Song-Hoe Koo ◽  
Bang-Eop Lee

1999 ◽  
Author(s):  
Kevin B. Ramsden ◽  
Raubin Randels

Abstract The RELAP5 Mod 3.1 computer code has been utilized to study the causes of exhaust line rupture disk actuation that occurred without indication of overpressure conditions. A series of cases have been investigated to determine the conditions in the RCIC upstream steam supply as well as the exhaust piping that would lead to dynamic behavior capable of causing exhaust system rupture disk failure. It has been demonstrated that the presence of moisture in the turbine and/or its immediate exhaust piping, are necessary to achieve the pressures necessary to fail the rupture disk. The upstream steam supply conditions can significantly influence the transient, particularly if saturated water is able to enter the turbine. Saturated water ingestion to the turbine can lead to significantly higher exhaust pressure behavior. The upstream supply conditions cannot, however, result in rupture disk failure if there is not water present in the turbine/exhaust line at startup. This paper discusses the modeling methods, as well as the results obtained from the computer simulation.


2016 ◽  
Author(s):  
Zhengchun Liu ◽  
Robello Samuel ◽  
Adolfo Gonzales ◽  
Yongfeng Kang

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