事務所建物 空調設備의 豫防保全 最適點檢周期가 信賴性向上 및 期待利益에 미치는 영향

곽노열,박병윤,손장열 대한건축학회 2003 대한건축학회논문집 Vol.19 No.5

In this study, using Monte Carlo simulation about inspection model applied practically in air-conditioning facilities of office building, the optimal preventive maintenance inspection period is suggested to improve the reliability of the units, and effect on expected profit of optimal preventive maintenance inspection period is computed. The main results of this study are summarized as follows: 1) Simulation program for sensitivity analysis and optimal preventive maintenance inspection period is made, in order to execute precisely sensitivity analysis of maintenance factors, by using Monte Carlo simulation's flow chart and compute optimal preventive maintenance inspection period. 2) Using models for the relationship between reliability and inspection frequency per unit time and model between inspection and expected profit of preventive maintenance by CBM, the optimal preventive maintenance inspection period of air-conditioning facilities is computed, and it is revealed that the range of that is 90∼175 hr and, correlation curve of the original MTBF and optimal preventive maintenance inspection period by CBM is derived. 3) And effect on expected profit of preventive maintenance's activity by optimal preventive maintenance inspection period is computed. It is found that the larger the original MTBF, like MTBF of centrifugal compression chiller and AHU is, and the smaller the expected profit increased, and the smaller the original MTBF, like MTBF of boiler, absorption chiller and turbo case cooling tower is, and larger the expected profit increased.

u-City 시설물의 예방적 유지관리를 위한 연구

조유정(Jo, Yoo-Jung),박찬현(Park, Chan-Hyun),김도년(Kim, Do-Nyun) 한국도시설계학회 2014 도시설계 : 한국도시설계학회지 Vol.15 No.4

지금까지 건설된 국내 u-City는 u-Service의 이름으로 다양한 도시기반시설물을 구축 · 운영하고 있으나, 기존 도시와 u-City의 가장 큰 차이라고 할 수 있는 시설물의 통합운영관리 활용을 최대화하지 못하고 있는 실정이다. 또한, 적극적인 유지관리로서 예방적 유지관리의 필요성이 대두되고 있는 현 시점에서, 시설물의 단순한 이력관리 및 수동적인 사후관리가 이루어지고 있어 이에 대한 개선이 필요하다. 따라서 본 연구의 목적은 u-City 도시기반시설물의 예방적 유지관리를 위한 기반을 마련하는 데 있다. 연구의 방법은 선행조사와 본조사로 구분된다. 선행조사에서는 첫째, 문헌을 통하여 예방적 유지관리에 관한 이론적 근거를 확보하였다. 둘째, 유지관리에 고려해야 하는 사회적 요소에 관하여 고찰하였다. 셋째, 예방적 유지관리를 적용한 사례를 통해 시사점을 도출하였다. 본조사에서는 첫째, 선행조사의 결과를 기반으로 하여 화성 동탄 u-City에 기 구축된 유지관리 DB를 분석하였다. 이로써 동탄의 시설물 유지관리 현황분석을 통해 예방적 유지관리를 위한 개선방법을 도출하였다. 둘째, DB의 통합구축을 위한 방안을 제시하였다. 셋째, 공익과 설문조사 결과에 기초한 시설물의 중요도를 도출하였다. 시설물의 중요도는 사회적 요인에 의한 유지관리 의사결정에 객관적 자료로 활용하며, 시설물의 수명주기를 적용하여 구축한 통합관리 DB는 예방적 유지관리의 기반이 된다. Though Korea has established and operates a variety of urban infrastructure under the name of u-City, it has failed to unify infrastructure operations, which can be considered the biggest difference between existing city and u-Cities. In light of the growing need for active maintenance, there is a need to improve both the simple historical management and passive post-management. The aim of the study is to establish preventive maintenance for u-City infrastructure. Thus, the theoretical basis for preventive maintenance was established through documents and suggestions were offered by examples of preventive maintenance. Based on this, the study analysis a maintenance database established in Dongtan u-City. Analysing maintenance in Dongtan helped deduce how to improve the preventive maintenance. Not only was a method for integrated database construction suggested but also the importance of infrastructure was deduced from both public interest and a survey of residents. Infrastructure’s importance can be applied to decision making on public maintenance as objective data. Applying understanding of the life cycle of infrastructure to the integrated management database helps establish a foundation preventive maintenance.

국내 출력운전 중 리스크를 고려한 예방정비 수행방법 고찰

김정운,이상대,신원규 대한기계학회 2024 大韓機械學會論文集B Vol.48 No.4

본 논문은 국내원전의 출력운전 중 리스크를 고려한 예방정비 수행방법 개선을 위해 안전설비를 대상으로 비상대응설비 이용 가능 여부에 따른 비상디젤발전기 및 필수냉각해수펌프의 리스크 변화를 분석하였다. 또한 출력운전중 안전설비의 정비가 수행되는 여건을 고려하여 정비중인 안전설비의 비상조치 및 기능 회복계획 수립 등 예방정비 수행방법 개선 항목을 제시하고자 한다. 이를 통해 원전 출력운전중 원전 설비의 예방정비를 최적화하여 설비 신뢰도를 지속적으로 향상하고 선제적 안전성 확보에 기여할 것이다. In this study, we analyzed the changes in the risk of EDG (Emergency Diesel Generator) and ESW (Essential cooling Sea Water) pumps to improve preventive maintenance (PM) method during operation according to the availability of emergency response components. Furthermore, considering the conditions under which safety component maintenance is performed during operation, we present some considerations when performing preventive maintenance, such as contingency and functional recovery plans for safety equipment under maintenance. Through these steps, preventive maintenance of safety facilities can be optimized during nuclear power plant operation, leading to continuous improvement in component reliability and aiding preemptive failure prevention.

잔여 유효 수명 예측 모형과 최소 수리 블록 교체 모형에 기반한 비용 최적 예방 정비 방법

주영석,신승준,Choo, Young-Suk,Shin, Seung-Jun 한국산업경영시스템학회 2022 한국산업경영시스템학회지 Vol.45 No.3

Predicting remaining useful life (RUL) becomes significant to implement prognostics and health management of industrial systems. The relevant studies have contributed to creating RUL prediction models and validating their acceptable performance; however, they are confined to drive reasonable preventive maintenance strategies derived from and connected with such predictive models. This paper proposes a data-driven preventive maintenance method that predicts RUL of industrial systems and determines the optimal replacement time intervals to lead to cost minimization in preventive maintenance. The proposed method comprises: (1) generating RUL prediction models through learning historical process data by using machine learning techniques including random forest and extreme gradient boosting, and (2) applying the system failure time derived from the RUL prediction models to the Weibull distribution-based minimum-repair block replacement model for finding the cost-optimal block replacement time. The paper includes a case study to demonstrate the feasibility of the proposed method using an open dataset, wherein sensor data are generated and recorded from turbofan engine systems.

베이지안 알고리즘을 활용한 열차의 고장 예측 및 FRACAS 연동을 통한 예방 정비 방법

임종국(J. K. Lim),강명구(M. K. Kang),장건(G. Jang) 한국도시철도학회 2015 한국도시철도학회논문집 Vol.3 No.2

In order that complex system, such as train, is important to secure availability on service, reliability and maintainability on cost and safety, the efficient management method on those measures is necessary. According to the necessity, maintenance system which anticipate life-time of a train from failure data has been developed domestically. However, the method has limitation on aspect of preventive maintenance. For preventive maintenance, real-time analysis and prediction of train data are required, but train data is too much to handle in real time due to complexity of modern train system, so large amount of resources and considerable efforts are required to analyze. In order to overcome such difficulties, efficient method on handling the real time data is required. In this paper, Bayesian statistics is introduced to handle the huge amount of real time data efficiently. Bayesian statistics is utilized to generate a pattern of status information of a train. The pattern, then, is used to find out anomalous cases as failure symptom. In addition, the anomalous cases are transferred to FRACAS, FRACAS is possible to make maintenance instruction for those cases as means of effective preventive maintenance.

점검-정비 모형에서 열화부품의 발견확률을 고려한 시스템의 최적 점검주기

김대경,박병노,송미옥,임재학 한국신뢰성학회 2022 신뢰성응용연구 Vol.22 No.4

Purpose: The determination of the optimal inspection interval of a system is a critical factor that can influence its maintenance. Frequent inspections yield shorter inspection intervals and higher inspection costs compared with infrequent inspections, which lead to an increase in the total maintenance cost due to the frequent occurrence of failures. The objective of this study is to determine the optimal inspection interval, which minimizes the total expected cost until the system is overhauled. Methods: We developed an inspection - maintenance cost model by considering the unit inspection cost, the cost for preventive maintenance, and the cost for corrective maintenance as well as the cost and quantity of a component, the distribution of the lifetime of components, and the probability of finding fault or failure during inspections. Results: We propose a novel method for determining the optimal inspection interval, which minimizes the total expected cost. The proposed method can be applied to systems consisting of one or more types of components. The data, which is derived from the case study that is documented in the previous research [13], are utilized to illustrate that the proposed method is effective for determining the optimal inspection interval and for conducting sensitivity analysis. Finally, we apply the proposed method to determine the optimal inspection interval pertaining to a component of auxiliary power that is built into railway trains. Consequently, we observed that a relationship exists between the reduction in the cost of operating the system and the current inspection interval. Conclusions: The proposed method can be effective for other repairable systems, which undergo inspection, preventive maintenance, and corrective maintenance.

Estimation problems for failure processes in repairable systems with preventive maintenance

정일한 ( Il Han Chung ) 한국경영공학회 2014 한국경영공학회지 Vol.19 No.2

Estimation problems of failure parameters and maintenance effects in repairable systems are considered. A proportional age reduction model for corrective and preventive maintenances under which the system ages are reduced after maintenances is assumed. The failure data(the points of corrective maintenance) and the points of preventive maintenance are given for analysis, and the maximum likelihood method is used to estimate the parameters of failure distribution and age reduction factors for corrective and preventive maintenances. Four kinds (two kinds of encoding and selection methods) of genetic algorithm is proposed to maximize likelihood function. In numerical examples, We employ simulation to generate failure times and GA is used to estimate parameters of Weibull distribution and improvement factor of PM and CM. In addition, there is comparison of performance of genetic algorithms.

재해 노후화를 위한 공공건축물 방재관리시스템 개발

박태근(Park, Tae-Keun) 대한건축학회 2011 大韓建築學會論文集 : 構造系 Vol.27 No.12

Recently, the incidence of disaster in buildings is increasing due to insufficient crime and fire prevention and carelessness buildings maintenance. That is why establishment of preventive disaster system against a disaster on buildings is more critical. This study aims for the development of preventive disaster management system for public facilities utilizing thermal imaging camera in order to preventively provide against disasters including building collapse, fire, and facility deterioration. The preventive disaster management system is composed of inspection request, inspection management, and inspection history module for preventive disaster, which is developed in Web-base system considering the usability of users, database compatibility, and real-time information exchange. Based on the inspection history information of preventive disaster that can be obtained by utilizing the preventive disaster management system, the result of this study, preventive disaster in terms of deterioration of natural disaster, and an effect minimizing damages through quick action would be expected.

교면포장의 예방적 유지관리를 위한 에폭시 박층포장 공법

조동민,최재순,신현국,고경일 한국아스팔트학회 2023 한국아스팔트학회지 Vol.13 No.2

For bridges with pavements or exposed concrete, maintenance repair is required 10 to 15 years after construction. Therefore, preventive maintenance is required to prevent premature deterioration and further damage to the pavement. The objective of this study is to measure the performance of epoxy thin layer pavement as a method of bridge surface maintenance. By applying 3-6 mm of epoxy over the existing pavement without removing the existing concrete pavement, the deterioration of the concrete pavement can be prevented and the durability of the bridge deck and bridge can be improved. The use of epoxy thin layer pavement is an economical and affordable way to maintain concrete bridges.

예방적 유지보수를 위한 소수성 저점도 AP 표면처리재 개발

최준성,김조순 한국도로학회 2014 한국도로학회논문집 Vol.16 No.2

PURPOSES: Surface treatment is a favorable method in the pavement preventive maintenance. This study (Part Ⅰ) aimed to develop the lowviscosity filling material for waterproof characteristics and high penetrable and weather resistance, and a series of companion study (Part Ⅱ)presents the coating characteristics and performance analysis using field and lab tests. METHODS : Hydrophobic characteristics of the advanced surface treatment material are observed and measured the filling depth and thepermeability for sand and asphalt pavement specimen using the water absorption test and permeability test, X-RAY CT test. Color differencefor the weather resistance using ultraviolet ray accelerated weathering test is compared with asphalt pavement specimens. RESULTS : The developed material shows the decreased water absorption and increased impermeable effect because of the hydrophobiccharacteristics. It is found that the filling depth is about 6mm and weather resistance is better than asphalt pavement specimen. CONCLUSIONS: The advanced hydrophobic - low viscosity filling treatment material is developed in this study (Part Ⅰ) to improve thewaterproof characteristics and high filling capacity and weather resistance for the pavement preventive maintenance.