• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.82-84
• /
• 2008

This paper presents the modeling and power quality analysis of Jeju island power system connected with wind farm, and thermal power plant. It is for indicating the influence of wind farm operation in steady and transient state in Jeju island power system during the HVDC system overhaul period. For the computer simulation, three kinds of main item are modeled, which are 67[MW] wind farm, thermal power plant and Jeju power load. To analyze the influence of the wind power generation to the Jeju power system, two kinds of simulations are carried out by using the PSCAD/EMTDC program. One is the steady state operation under the variable speed wind, and the other is the transient state operation when all of wind farms in Jeju island are disconnected from the Jeju power grid instantaneously on the rated power output. With the comparison of these results, it is useful for analyzing the power quality of Jeju power system versus wind power generation.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05a
• /
• pp.571-576
• /
• 1996

Currently most nuclear power plants(NPPs) are adopted the mid-loop operation to minimize the overhaul period and save the operating cost. For mid-loop operation it is essential to install nozzle dam between RCS pipe and steam generator(SG). Because SG remains more highly contaminated with radioactive material than any other parts of the NPPs, the repairmen are very reluctant to carry out installing nozzle dam inside the SG. Until now, unfortunately, it appears that no practically applicable device was developed to provide the longstanding demand. Also the accidents have been reported by licenser event report during this operation mode due to loss of residual heat removal(RHR). The purpose of this paper is to conduct remotely blocking and disintegration of nozzle of a SG which has the highest radiation exposure during the maintenance in NPPs. The remote nozzle blocking device of a SG includes three bladders, hubs, air controller provisions to supply and contact air pressure into the bladders. This remote nozzle block device will give the larger operation margin to prevent the loss of RHR and minimize the radiation exposure dose to the repairman and shorten the overhaul periods.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
• /
• 2002.05a
• /
• pp.403-412
• /
• 2002

Machine condition diagnosis is the technique to perceive the machine errors and the abrasion online without overhaul. We need the steps to predict the life span and reliability of a machine for the abrasion as with perceiving the degree of the abrasion of certain machine parts to make errors. In this study we deals with the methods to check and manage periodically and to configure the judgement criteria for the state of a machine. For the applications of CDT(Condition Diagnosis Technique) we also suggest the methods to check comparing the measured vibration values with the absolute criteria and to check the abnormality by vibration level.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2007.11a
• /
• pp.1090-1094
• /
• 2007

The aim of this study is to estimate the cause of Cooling Tower vibration and eliminate the faults of fan with high vibration in spite of overhaul. The cause of high vibration was that the natural frequency of fan blade coincide with second blade pass frequency. To achieve reduction of Cooling Tower vibration, change motor speed from 1784rpm to 1714rpm, and then the vibration has reduced conspicuously.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.799-802
• /
• 1995

Whale helical gears is used to transmit motion between parallel shafts, the shaft bearings are subjected to both radial and thrust loads. The reliability and life analysis are based on the two-parameter Weibull disribution lives of the component gears and bearings. Two methods of estimating the time between gear system overhauls and the number of replacement components needed were presented. The first method assumes replacement of all components during an overhaul of a failed gear system. the second method assumes replacement of failed comonents only. Renewal theory was presented to estimate the number of comonent replacements in a gear system for both methods.

• 한국연소학회:학술대회논문집
• /
• 2012.11a
• /
• pp.163-165
• /
• 2012

Korea is now the country with shortage of electric power because of limits on power usage of businesses to prevent a possible blackout during the summer and winter. This is due to the failure to predict the total power usage. And the futhermore several accidents in the power plant during the overhaul maintenance threaten the stable power supply. Accidents were due to the combustion of low calorific coal and the shortage of the maintenance time. We should not incur a future great loss by pursuing a present small profit.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.15 no.26
• /
• pp.173-179
• /
• 1992

This paper is concerned with preventive maintenance model for the items whose failures are dependent on their wear level. The previous maintenance models have used time as their decision variable, but it is not appropriate for the case which have wear dependent processes for their failures. In this paper, we consider an operating item which is under periodic review and which is subject to degradation. The scheduled maintenance (overhaul ) is based on the level of item degradation rather time. A functional equation for the total expected cost over an infinite horizon period is formulated and solved.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2006.06a
• /
• pp.130-131
• /
• 2006

하나로에서의 방사성폐기물은 작업공정 특성상 원자로 정기점검(overhaul)시 주로 발생된다. 이에 방사성 폐기물의 발생을 최소화 하고, 규제해제대상 폐기물의 지정 및 분류를 해야 한다. 본 논문에서는 방사성 폐기물의 종류 및 특성을 고려하여 작업절차의 개선, 저감화 대책 및 이를 적용한 실적을 소개하고자 한다.

• Proceedings of the CALSEC Conference
• /
• 2001.02a
• /
• pp.499-520
• /
• 2001

◈ B2B e-commerce is set to grow significantly in the next 5 years ◈ There is a growing trend towards leveraging the information asset to win new business in the Maintenance, Repair and Overhaul (MRO) market ◈ After-market service is forecast to be a significant element of the B2B market ◈ Existing standards do not fully address the product support requirement ◈ PLCS standards will allow support information to be aligned with the changing product over its entire life cycle ◈ Adoption of PLCS standard will lead to reduced operating costs and increased product availability.(omitted)

• Plant Journal
• /
• v.11 no.2
• /
• pp.45-51
• /
• 2015

In this paper, studied condenser operating management which is affecting power plants efficiency considering the cost of poor quality. Sea water temperature and condenser pressure have clear correlation in S power plants. As the sea water temperature changes, condenser pressure changed -1.7~+20 mmHg from design condenser pressure(38.1 mmHg). Use the heat rate correction curve from manufactory company, realized that efficiency and cost of poor quality changed 0.0201%, 12,830 won/h at Unit #1,2 but 0.0155%, 9,832 won/h when condenser pressure 1 mmHg rise. Also, checked that it is changed depend on seasonal corresponding operation, plant ageing and the point of preventive maintenance like overhaul maintenance. This study said if we considered complying with management range and planning overhaul maintenance, then it could help reducing operating maintenance losses minimum 2.5 billion won per 1 year (case : Unit #1, forty days maintenance).