• Journal of Advanced Marine Engineering and Technology
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• 제31권8호
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• pp.1035-1041
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• 2007

An improvement of driving motor burning damages on a couplingless type warship fire pump is studied. The pump consists of an induction motor a pump-motor shaft and a volute type impeller. The burning damage had occured by changing the material of the pump-motor shaft from carbon steel(SM 45C) to stainless steel(STS 316) for improving anti-corrision properity in sea water. It is shown that a material change on the pump-motor shaft can reduce the efficiency of driving motor and may cause motor burning in the process of pump development stage. This kind of motor burning problem can be solved by increasing the efficiency of the motor and changing the geometry of the inner parts.

• 한국안전학회지
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• 제37권4호
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• pp.20-27
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• 2022

This article aims to develop an algorithm that detects fire pump defects by analyzing the current signals of an induction motor, which are triggered by changes in the flow rate and pressure of multistage volute pumps that are used for fire services. The operational status of the pumps was categorized into three: first, normal operation; second, a defect that is caused by a change in the current value; and third, a defect occasioned by a change in current, pressure, and flow rate. When a fire pump was in normal operation, the motor's operating current was measured between 5.06 A and 6.9 A, the flow rate was estimated at 0-0.27 m³/min, and the pressure ranged from 0 to 0.47 MPa. In the event that a defect was caused by an abnormal current value in the motor, it was attributed to the pump's adherence. Furthermore, if there was no source of water, the defect was considered to have been induced by phase-loss operation, no-load operation, or run-stop operation, with the current value of each scenario being measured at > 52.8 A, < 4.13 A, > 45.15 A, and < 3.8 A, respectively, placing its overall range between 0 and 50 A. The sources of defects were detected based on an analysis of the flow rate, pressure, and current, which represent the following causes: air inflow into the casing, inadequate suction of water, and reverse-phase operation, respectively. Each cause entailed the following values: when air seeped into the casing, the pressure was measured at 0.24 MPa irrespective of changes in the flow rate; when there was inadequate suction of water, the pressure was recorded between 0 and 0.05 MPa despite changes in the flow rate; and when the power line's reverse-phase loss was the cause of the defect, the pressure was measured at 0.33 MPa for a flow rate of 0 L/min, and a higher flow rate decreased the pressure to nearly 0 MPa. The results of this study will enable engineers to develop a pump defect detection algorithm that is based on an analysis of current, and this algorithm will facilitate the execution of a program that will control a fire pump defect detection system.

• 한국안전학회지
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• 제37권4호
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• pp.28-35
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• 2022

This study is aimed to develop a safety diagnosis system for fire pumps that detects normal and abnormal signals for the stable operation of the system. Hence, the following activities were carried out: first, a threshold value was identified for the normal operation and six abnormal operations (adherence of impeller, absence of water source, separation of pump and motor, run-stop operation, air inflow into the casing, and reverse-phase loss of the power line) reflecting changes in the current, flow and pressure of fire pumps; secondly, based on the identified signals, an algorithm capable of detecting three abnormal signals was developed and in terms of hardware, a current, pressure and flow sensor suitable for the analogue input values of NI-6009 was designed and installed. This combination of the hardware and software is applicable as a diagnosis system to ensure the stable operation of fire pumps.

• 한국화재소방학회논문지
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• 제26권4호
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• pp.10-17
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• 2012

본 연구에서는 목조 사찰 화재시 펌프(물탱크)차의 현장 도착 가능여부에 따라 사찰화재 유형별 진압대책을 4가지 유형으로 분류하고, 각 유형별 화재진압 전술 및 방법을 도출하였다. 연구결과, 펌프(물탱크)차의 접근 및 소방용수 확보가 가능한 사찰은 일반 건축물화재 진압전술을 적용하지만, 그렇지 않은 경우는 헬기, Water Bag, 연계급수 집중 진압전술, 무선통신을 이용한 소방차 수위 자동전송 System 및 급수낭을 활용하고, 사찰 인근 소방서에 화재진압 장비(동력펌프, 호스, 노즐, 급수낭 등)를 적재한 일반 4륜구동 차량 배치와 A자 사다리를 활용한 진압대책 등이 필요한 것으로 나타났다.

• 한국화재소방학회논문지
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• 제30권2호
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• pp.106-113
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• 2016

초고압 용적형 펌프는 로터의 회전에 의한 주기적인 용적의 변화를 이용하는 펌프로 고압, 고유량을 동시에 만족하며 로터의 저속 및 고속 회전에 따라 변화 없이 일정하게 상대적으로 높은 펌프 효율을 유지할 수 있는 장점을 가진다. 많이 사용되고 있는 원심펌프와는 달리 별도의 진공펌프가 없이도 자흡 성능을 가지고 있으며, 비교적 단순한 구조로 인하여 경량화, 소형화가 가능한 특성을 자기고 있다. 유체를 높은 압력으로 이송할 수 있으며, 압력의 변동에 따라 유량의 변동이 적은 정량 토출이 가능하다. 이러한 용적형 펌프를 사용하는 이유는 흡입된 유체가 유량의 변화 없이 토출되는 장점이 있기 때문이다. 본 연구에서는 유량의 변화가 없다는 장점이 있는 용적형 펌프의 체절시스템을 개발하여 펌프의 고압 운전시의 안전성을 확보하고자 하였다. 체절시스템은 컨트롤러 프로그램, 전자클러치, 릴리프밸브의 3가지로 이루어져, 한 가지 시스템이 작동하지 않아도 다른 시스템이 작동하는 시스템으로 이루어져 있다. 컨트롤러 프로그램과 전자 클러치의 작동을 확인하기 위한 과속도 시험과 릴리프 밸브의 유체유동해석, venting 실험을 통해 현재 개발한 초고압 용적형 펌프의 체절시스템이 작동됨을 확인하였다.

• 한국화재소방학회논문지
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• 제19권3호
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• pp.20-27
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• 2005

본 논문에서는 화재 모델 CFAST를 사용하여 원자력발전소에 있는 8개 펌프실의 화재 안전 수준을 평가해 보고, 그 결과를 조건부 노심손상확률에 반영하여 분석해 보았다. 분석 대상 구역은 원자력발전소 일차보조건물에 위치한 고압안전주입 펌프실 A/B,저압안전주입 펌프실 A/B, 격납건물 살수 펌프실 A/B 및 모터구동 보조급수 펌프실 A/B 총 8곳이었다. 각 화재구역의 상부층 가스 온도를 분석하였으며, 분석 결과를 바탕으로 상부층에 위치한 케이블의 손상 유무를 파악하였다. 분석 결과에 의하면 총 8개 화재구역의 상부층 케이블은 건전성을 유지하는 것으로 확인되었다. 케이블의 건전성 평가 결과를 바탕으로 각 화재구역의 조건부 노심손상확률을 평가한 결과, 기존의 보수적인 가정 하에 수행된 화재위험도분석 결과보다 약 2배정도 감소하는 보다 현실적이고 불확실성이 감소한 결과를 도출할 수 있었다.

• 한국안전학회지
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• 제33권6호
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• pp.136-143
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• 2018

In this study, we conducted a pilot study on the multiple spurious operations (MSO) analysis in the fire probabilistic safety assessment (PSA) of domestic nuclear power plant (NPP) to identify the degree of influence of the operator actions used in the MSO mitigation strategies. The MSO scenario of the domestic reference NPP selected for this study is refueling water tank (RWT) drain down event. It could be caused by spurious operations of the containment spray system (CSS) of the reference NPP. The RWT drain down event can be stopped by the main control room (MCR) operator actions for stopping the operation of CSS pump or closing the CSS motor operated valve if the containment spray actuation signal (CSAS) is spuriously actuated. Outside the MCR, it can be stopped by operator actions for closing the CSS manual valves or motor operated valve or stopping the operation of CSS pump. The quantification result of a fire PSA model that takes into account all recovery actions for the RWT drain down event lead to risk reduction by about 95%, compared with quantification result of fire PSA model without considering them. Among the various operator actions, the recovery action for the spurious CSAS operations and the operator action for the manual valve are identified as the most important operator actions. This study quantitatively showed the extent to which the operator actions used as MSO countermeasures have affected the fire PSA quantification results. In addition, we can see the rank of importance among the operator recovery actions in quantitative terms.