Numerical Simulation and Experimental Research on Oil Mist Overflowing for a Giant Hydropower Generator

Deng, Yangbing; Xu, Jin; Ling, Yang; Feng, Guichao

doi:10.1080/15567036.2018.1563243

Cited by 7 publications

(9 citation statements)

References 23 publications

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“…The existence of the oil film (the scale is micron) is ignored in the modeling process, so the flow scale span in the whole oil tank is somewhat important. Despite the standard model is often used for the multi-phase flow in the oil tank [17,22] , the RNG k   model is used here due to the advantages for capturing the fluid rotation [23,24] . Namely, this model adapts to the swirling flow caused by shaft spinning and reflects substantially correct the streamline bending [25] .…”

Section:    mentioning

confidence: 99%

“…Because oil mist accumulation and leakage are or not sequenced, depending on the sealing performance, scholars examine the sealing effectiveness such as the seal teeth and thrust head (static and dynamic parts) through the top tank's pressure distribution [15][16][17]22] . Furthermore, the pressure distribution in the oil tank has a specific influence on the distribution of oil mist.…”

Section: Influence Of Rotating Speed Change On Oil Tank Pressurementioning

confidence: 99%

“…An analysis was made between the lubricating oil viscosity and the generated oil level and pressure distribution. Deng et al [17] dealt with the oil mist leakage of the hydro-generator bearing by optimizing the structure of the oil tank cover, based on flow theory analysis. In this case, the impeller's optimized scheme generated an oil-recovering pressure drop, reducing the oil mist rate from 4.9m 3 /h to 0.36m 3 /h.…”

Section: Introductionmentioning

confidence: 99%

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Study on the Influence of Rotational Speed and Pad Temperature of Pumped-Storage Set on Oil Mist Leakage of Thrust Bearing

Sun

Zhang

Zheng

et al. 2021

Preprint

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The accumulation of oil mist in the thrust bearings compromises the safety of the unit and prompts financial and environmental losses. To discuss the strategies for limiting its impact, the model uses the VOF approach to calculate the air-oil-oil mist three-phase flow, combined with the Lee model, to solve the evaporation and mass transfer process between the oil and oil mist. Our attention is drawn into the influence of unit speed and pad temperature, on the occurrence of external and internal leaks from the oil tank. A comparison of cases is made with five unit speeds (100 to 500 rpm) at constant temperature (60°C), and with one unit speed (500 rpm) at different temperatures (56°C,60°C,62°C). With constant speed, the rise of pad temperature promotes the evaporation of the lubricating oil in an uneven manner, augmenting the occurrence of oil leaks. From findings, the increase of speed reduces the pressure change rate at the wall of the inner tank (external oil leaks) by 5.95 %, and of the oil slinger (internal leaks), by 44.64%. The present results might help to suggest courses of action to reduce the oil mist leakage.

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Section:    mentioning

confidence: 99%

Section: Influence Of Rotating Speed Change On Oil Tank Pressurementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Study on the Influence of Rotational Speed and Pad Temperature of Pumped-Storage Set on Oil Mist Leakage of Thrust Bearing

Sun

Zhang

Zheng

et al. 2021

Preprint

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show abstract

“…An analysis was performed between the lubricating oil viscosity and the generated oil level and pressure distribution. Deng et al [25] dealt with the oil mist leakage of the hydrogenerator bearing by optimizing the structure of the oil tank cover based on flow theory analysis. In this case, the optimized scheme of the impeller generated an oil-recovering pressure drop, reducing the oil mist rate from 4.9 to 0.36 m 3 /h.…”

Section: Introductionmentioning

confidence: 99%

Study on the Influence of Rotational Speed and Pad Temperature of Pumped-Storage Set on Oil Mist Leakage of Thrust Bearing

Sun

Zhang

et al. 2023

Sustainability

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The accumulation of oil mist in the thrust bearings poses a threat to the safety of the unit, leading to financial and environmental losses. To investigate the generation and influencing factors of oil mist in the oil tank of the thrust bearing in a pumped-storage power station, a novel numerical simulation method is proposed for calculating the oil–oil mist–air multi-phase flow based on the VOF model, RNG k−ε turbulence model, and Lee model. The proposed numerical method’s reliability is verified using field operation data. The effects of rotational speed and pad temperature on the formation of oil mist inside the oil tank were examined from two perspectives of internal and external oil leaks. The research revealed two accumulation areas where oil mist is generated and accumulated: between the thrust head and the oil-retaining ring and near the oil slinger. The former causes external oil leaks due to pressure differences, while the latter causes internal oil leaks due to the rotor blast effect. An increase in temperature and rotational speed exacerbates the formation of oil mist. Furthermore, an increase in speed decreases the pressure change rate at the wall of the inner tank (external oil leaks) by 5.95% and at the oil slinger (internal leaks) by 44.64%. Consequently, compared to external oil leaks, internal oil leaks are more likely to occur.

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“…However, a literature review shows that enhancing the oil circulation system can only decrease, but not entirely eradicate, the formation of oil mist. For instance, the research by the authors [8] made modifications to the oil bath cover of the generator thrust bearing, decreasing oil mist leakage from 4.9 m 3 /h to 0.36 m 3 /h. In addition to enhancing seal quality, methods to lower oil vapour concentrations involve fitting oil deflectors to condense and return oil to the oil bath.…”

mentioning

confidence: 99%

Investigation of Oil Vapours in Hydro-Generator

Shubina,

Verkhovtsev,

Gulay

et al. 2024

JPEE

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The article discusses engineering approaches to solving the problem of oil vapours in generators. Due to the design characteristics of each power plant, it is difficult to find a typical solution. Nevertheless, the article suggests ways to reduce the amount of oil mist. For their implementation, a calculation methodology based on the substitution scheme of the hydraulic path of the bearing support unit is created which takes into account the design features of the bearing and the parameters of the environment around the oil bath. The methodology employed is presented. The numerical method of modelling the aerodynamic fields of the entire hydro generator is used to estimate the air flows and pressures in the oil bath zone of the thrust bearing. Additionally, the method made it possible to track suspected oil particles that could get from the thrust-bearing bath into the surrounding area of the generator. Measures are proposed to reduce the level of oil mist through the competent design of the oil vapour removal system from the bearing bath.

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Numerical Simulation and Experimental Research on Oil Mist Overflowing for a Giant Hydropower Generator

Cited by 7 publications

References 23 publications

Study on the Influence of Rotational Speed and Pad Temperature of Pumped-Storage Set on Oil Mist Leakage of Thrust Bearing

Study on the Influence of Rotational Speed and Pad Temperature of Pumped-Storage Set on Oil Mist Leakage of Thrust Bearing

Study on the Influence of Rotational Speed and Pad Temperature of Pumped-Storage Set on Oil Mist Leakage of Thrust Bearing

Investigation of Oil Vapours in Hydro-Generator

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