• Title/Summary/Keyword: WHIP

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A Study of Bearing Oil Whip Treatment in 300MW Steam Turbine with Oil Temperature Change (300MW급 증기터빈의 베어링 윤활유 온도조정에 의한 오일휩 제거방법에 관한 연구)

  • Hwang, Dal-Y.;Kim, Hwa-Y.;Moon, Seung-J.;Lee, Jae-H.
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.244-247
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    • 2008
  • The phenomena of oil whip in steam turbine takes place for the un-balancing force between rotor shaft and bearing oil film. The several parameters that affect onset of oil whip have been well known. However, the major parameter of oil whip is shaft mis-alinement. A oil whip causes the high vibration and the shutdown of rotor system. We mostly stop the steam turbine to adjust a shaft re-alinement concerning oil whip. In this case, It needs many costs for maintenance and long shutdown times. In this study, we study and observe the oil whip of the 300MW steam turbine in many years and we conduct the field test for another steam turbine for reducing vibration from oil whip. The results of this study are that a oil whip takes place with a particular rotating speed or a particular turbine output and the oil temperature change is a very effective method for on-line oil whip treatment.

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Size Reduction of HF Whip Antenna for Ship Communication (선박 통신용 HF 휩 안테나의 소형화)

  • Park, Dong-Kook;Yang, Gyu-Sik;Jeong, Gi-Ryong;Kim, Jeong-Chang;Jung, Sung-Hun
    • Journal of Advanced Navigation Technology
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    • v.16 no.1
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    • pp.35-40
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    • 2012
  • In this paper, we present the size reduction method of HF whip antenna for ship communication. To reduce the size of the HF whip, the end part of linear whip is modified to helical type. We designed the whip antenna with 60% size of the commercial whip antenna and carried out communication experiments using the commercial and the designed whip antennas. From the experimental results, we found that the proposed whip antenna can replace the commercial whip antenna for ship communication.

A Case Study on the Reduction of Noise and Vibration at the Backpass Heat Surface in the Power Plant Boiler (300MW급 증기터빈의 베어링 윤활유 온도조정에 의한 오일휩 제거방법에 관한 연구)

  • Hwang, Dal-Yeon;Moon, Seung-Jae;Lee, Jae-Heon
    • Plant Journal
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    • v.4 no.4
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    • pp.56-61
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    • 2008
  • The phenomena of oil whip in steam turbines take place for the unbalance force between a rotor shaft and bearing oil film. The several parameters that affect onset of oil whip have been well known. However, the major parameter of oil whip is shaft mis-alinement. A oil whip causes the high vibration and the shutdown of rotor system. We mostly stop the steam turbine to adjust a shaft re-alinement concerning oil whip. In this case, it needs many costs for maintenance and long shutdown times. In this study, we study and observe the oil whip of the 300MW steam turbine in many years and we conduct the field test for another steam turbine for reducing vibration from oil whip. The results of this study are that a oil whip takes place with a particular rotating speed or a particular turbine output and the oil temperature change is a very effective method for on-line oil whip treatment.

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Risk assessment of vibriosis by Vibrio cholerae and Vibrio vulnificus in whip-arm octopus consumption in South Korea

  • Oh, Hyemin;Yoon, Yohan;Ha, Jimyeong;Lee, Jeeyeon;Shin, Il-Shik;Kim, Young-Mog;Park, Kwon-Sam;Kim, Sejeong
    • Fisheries and Aquatic Sciences
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    • v.24 no.6
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    • pp.207-218
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    • 2021
  • This study evaluated the risk of foodborne illness from highly pathogenic Vibrio spp. (Vibrio vulnificus and V. cholerae) by raw whip-arm octopus (Octopus minor) consumption. In total 180 samples of raw whip-arm octopus were collected from markets and examined for the prevalence of V. vulnificus and V. cholerae. Predictive models describing the kinetic behavior of Vibrio spp. in raw whip-arm octopus were developed, and the data on amounts and frequency of raw whip-arm octopus consumption were collected. Using the collected data, a risk assessment simulation was conducted to estimate the probability of foodborne illness raw whip-arm octopus consumption using @RISK. Initial contamination levels of Vibrio spp. in raw whip-arm octopus were -3.9 Log colony-forming unit/g, as estimated by beta distribution fitting. The developed predictive models were appropriate to describe Vibrio spp. in raw whip-arm octopus during distribution and storage with R2 values of 0.946-0.964. The consumption frequency and daily consumption amounts of raw whip-arm octopus per person were 0.47% and 57.65 g, respectively. The probability of foodborne illness from raw whip-arm octopus consumption was estimated to be 8.71 × 10-15 for V. vulnificus and 7.08 × 10-13 for V. cholerae. These results suggest that the risk of Vibrio spp. infection from raw whip-arm octopus consumption is low in South Korea.

Finite Element Analysis of Pipe Whip Restraint Behavior Under Jet Thrust Forces (유체 분사 추진력을 받는 배관 휩 구속장치 거동에 관한 유한요소해석)

  • Sugoong Koh;Lee, Young-Shin
    • Nuclear Engineering and Technology
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    • v.25 no.3
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    • pp.353-360
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    • 1993
  • Many types of pipe whip restraints are installed to protect the structural components from the anticipated pipe whip phenomena of high energy lines in nuclear power plants. It is necessary to investigate these phenomena accurately in order to design the pipe whip restraints properly and/or to evaluate the acceptability of the pipe whip restraint design. Various research programs have been conducted in many countries to develop analytical methods and to verify the validity of the methods. In this study, various types of finite elements in ANSYS[1], the general purpose finite element computer program, was used to simulate the postulated pipe whips to obtain impact loads and the calculated results were compared with the specific experimental results from the sample pipe whip test for the U-shaped pipe whip restraints. Some calculational models, having the gap element or the spring element between the pipe whip restraint and the pipe line, give reasonably good transient responses of the restraint forces compared with the experimental results, and could be useful in evaluating the acceptability of the pipe whip restraint design.

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The Standardized Recipe and Nutrient Analysis of Stir-fried Whip-arm Octopus in Busan (부산지역 낙지볶음의 표준조리법 개발 및 영양소 분석)

  • Lyu, Eun-Soon
    • Journal of the Korean Society of Food Culture
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    • v.18 no.1
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    • pp.9-16
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    • 2003
  • The purpose of this study was to develop the standardized recipe and to analyze the nutrients of stir-fried whip-arm octopus as one of the kind of traditional local foods in Busan. The standardized recipe was developed by using cookbooks, home recipes, and the recipes by commercial food restaurants. The nutrient was analyzed by using an AOAC method. Sensory evaluations were made on nine sensory attributes by a 12-member panel. As the results, the whip-arm octopus was recorded as a food source for health, rejuvenation in Jasanobo. Since early 1900, the stir-fried method has been used for cooking with the ship-arm octopus. The main ingredients were whip-arm octopus, onion, large green onion as the local stir-fried whip-arm octopus in Busan. The ingredients of soup were shrimp, little neck clam, and water. Seasoning sauce was mixed with red pepper powder, soy sauce, sesame oil, chopped garlic, chopped onion, and sugar. The seasoning sauce was fermented for three days. The results of sensory scores were salty seasoning 3.66/5.00, taste 3.75/5.00, thickness 3.84/5.00, and smell 4.09. Nutrient retention per 100g of the stir-fried whip-arm octopus was 67.54kcal, protein 6.43g, fat 1.66g, Ca 28.06mg, Fe 2.56mg, cholesterol 68mg, and taurin 51mg. Fatty acid consists of various unsaturated fatty acids such as linoleic acid(46.24%) and oleic acid(33.67%).

Abnormal Vibration of Turbine due to Oil Whip (Oil Whip에 의한 터빈의 이상진동)

  • Koo, Jae-Raeyang;Hwang, Jae-Hyeon
    • Proceedings of the KSME Conference
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    • 2001.11a
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    • pp.539-543
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    • 2001
  • Almost all rotating machinery has bearings. Bearing is one of the most important part of rotating machinery. Vibration of rotating machinery depend on its bearing conditions. Bearing conditions are followings ; oil gap, bearing type, bearing temperature, bearing oil condition. Especially, bearing oil condition influences on rotating machinery vibration directly. In this paper we have discussed the abnormal vibration of turbine due to oil condition. oil whip problem was occured in the certain power plant. and we had sloved this problem through the control of operating values and alignment.

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Fielding indices for explaining runs lost combining adjusted WHIP and the number of home runs allowed in Korean professional baseball (한국 프로야구에서 수정된 WHIP와 피홈런 수를 결합한 실점 설명 수비지표들)

  • Kim, Hyuk Joo
    • The Korean Journal of Applied Statistics
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    • v.29 no.7
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    • pp.1283-1294
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    • 2016
  • We studied fielding indices to explain runs lost for Korean professional baseball teams, successively motivated by OPS and weighted OPS obtained by combining on-base percentage and slugging average that can adequately explain the run productivity of teams. We considered several combined indices made by combining fielding indices highly correlated with the runs lost of teams. Data analysis from all games in the regular seasons of 1982-2015 shows that weighted adjusted WPH 2 (defined as weighted average of adjusted WHIP and number of home runs allowed per inning) best explains runs lost. Weighted adjusted WPH 2 consisting of adjusted WHIP (with weight 34%) and number of home runs allowed per inning (with weight 66%) was found to be optimal weighted adjusted WPH 2 having correlation coefficient 0.95362 with average runs lost per game. This result is an improvement of the result of the index obtained in Kim and Kim (2015a). Analysis by chronological periods provides results that are not much different. Also we made a list of top 10 pitchers for each of the recent three years, based on the obtained index.

MF/HF Marine Whip Antenna with Side Whips (보조 휩을 갖는 중 ${\cdot}$ 단파대 선박용 휩 안테나)

  • Park, Dong-Kook;Ahn, Dong-Hun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.1A
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    • pp.41-46
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    • 2003
  • A MF/HF marine whip antenna with side whips, which are connected at an angle with the straight main whip, has reported In this paper, the effects of side whips on the antenna are simulated by using NEC-WIN and a novel MF/HF ship antenna with side whips is designed First of all, the gain, return loss, and radiation pattern of the antenna on infinite perfect conductor plane are simulated as function of the parameters of the side whip, such as the number, the location, the length of the side whip and the angle with the main whip. After that, the size of the antenna is decided and set up on an experimental ship in Korea Maritime University. The antenna on the ship are simulated and the simulated input impedances are good agreement with the measured results.

Evaluation of Blast Wave and Pipe Whip Effects According to High Energy Line Break Locations (고에너지배관 파단위치에 따른 배관휩과 충격파의 영향 평가)

  • Kim, Seung Hyun;Chang, Yoon-Suk;Choi, Choengryul;Kim, Won Tae
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.13 no.1
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    • pp.54-60
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    • 2017
  • When a sudden rupture occurs in high energy lines, ejection of inner fluid with high temperature and pressure causes blast wave as well as thrust forces on the ruptured pipe itself. The present study is to examine pipe whip behaviors and blast wave phenomena under postulated pipe break conditions. In this context, typical numerical models were generated by taking a MSL (Main Steam Line) piping, a steam generator and containment building. Subsequently, numerical analyses were carried out by changing break locations; one is pipe whip analyses to assess displacements and stresses of the broken pipe due to the thrust force. The other is blast wave analyses to evaluate the broken pipe due to the blast wave by considering the pipe whip. As a result, the stress value of the steam generator increased by about 7~21% and von Mises stress of steam generator outlet nozzle exceeded the yield strength of the material. In the displacement results, rapid movement of pipe occurred at 0.1 sec due to the blast wave, and the maximum displacement increased by about 2~9%.