• 한국수자원학회논문집
• /
• 제57권8호
• /
• pp.561-569
• /
• 2024

본 연구에서는 상수도관망의 시간에 따른 누적피해도를 정량적으로 산정하기 위해 추계학적 방법으로 상수도관망의 누적피해도 산정모형을 개발하였으며 이를 실제 도시에 적용하여 사용연수 증가에 따른 상수도관망의 누적피해도 변화를 분석하였다. 상수도관망 전체 피해율을 분석하기 위해 개별 관로의 누적피해도 평가모형을 수립하였고 누적피해도에 직접적인 영향을 미치는 노후지수는 MCS (Monte Carlo Simulation)을 사용하여 분석하였으며 부식으로 인한 두께변화 예측을 위해 Romanoff의 실측데이터를 사용하였다. 또한 단위관망(중블럭, 소블럭)별 상수도관망의 피해도를 분석하기 위한 누적피해도 모형을 수립하고 이를 통해 최대 50년 동안의 단위관망의 누적피해도를 예측할 수 있었다. 분석결과, 대상 지역인 청주시 내덕 1동 상수도관망의 경우 사용연수가 20년, 30년, 50년으로 증가함에 따라 누적피해도가 7%, 43%, 79%로 증가하는 것을 확인할 수 있었다.

• 상하수도학회지
• /
• 제20권1호
• /
• pp.35-43
• /
• 2006

Concerns related to protecting, identifying, and isolating of subsystems of a water distribution network have led to the realization of the increased importance of valves in the system. The most important purpose of valves in water distribution systems is to isolate a subsystem due to breakage, maintenance activities, or contamination. A subsystem called segment is isolated by the closure of adjacent valves. Minimizing the pipe failure impact, an efficient algorithm is required to identify adjacent valves quickly. In this paper, an algorithm to identify adjacent valves to be closed to isolate a subsystem from the remainder of a network when a pipe failure is presented. The algorithm is operated on a matrix called the valve location matrix containing the information of valve locations. An application to an existing water distribution system demonstrates the developed algorithm efficiently locates the adjacent valves for the isolation of a broken pipe.

• Korean Journal of Hydrosciences
• /
• 제6권
• /
• pp.107-118
• /
• 1995

The water distribution system problem consists of finding a minimum cost system design subject to hydraulic and operation constraints. The design of new branchin network in a paddy irrigation system is presented here. The program based on the linear programming formulation is aimed at finding the optimal economical combination of two main factors : the capital cost of pipe network and the energy cost. Two loading conditions and booster pumps for design of pipe network are considered to obtain the least cost design.

• 한국수자원학회논문집
• /
• 제36권1호
• /
• pp.105-115
• /
• 2003

본 연구에서는 상수관망의 신뢰도해석을 위해 수리적 신뢰도와 기계적 신뢰도를 통합적으로 해석할 수 있는 통합신뢰도 해석모형을 개발하였다. 수리적 신뢰도는 불화실성을 가진 변수들에 대하여 적절한 변동계수를 가진 확률 분포형을 적용시켜 임의변수로 고려하였고 기계적 신뢰도는 관망의 각 구성물에 대해 순차적 고장을 발생시켜 각 고장에 대한 영항을 해석하여 신뢰도를 산정하였다. 덕 연구모형을 실제관망에 대한 적용결과 본 모형은 실제관망에 대한 불확실한 요소를 고려한 신뢰도를 잘 모의하고 있었다. 앞으로 신뢰성있는 상수관망 설계 및 기존 관망의 신뢰도 판정에 본 모형이 적용된다면 기계적 및 수리적으로 객관성이 있는 신뢰도를 가진 상수관망의 건설 및 유지관리가 될 수 있다고 판단된다.

• 상하수도학회지
• /
• 제27권4호
• /
• pp.413-428
• /
• 2013

In this study, Ant Colony Algorithm(ACO) was used for optimal model. ACO which are metaheuristic algorithm for combinatorial optimization problem are inspired by the fact that ants are able to find the shortest route between their nest and food source. For applying the model to water distribution systems, pipes, tanks(reservoirs), pump construction and pump operation cost were considered as object function and pressure at each node and reservoir level were considered as constraints. Modified model from Ostfeld and Tubaltzev(2008) was verified by applying 2-Looped, Hanoi and Ostfeld's networks. And sensitivity analysis about ant number, number of ants in a best group and pheromone decrease rate was accomplished. After the verification, it was applied to real water network from S water treatment plant. As a result of the analysis, in the Two-looped network, the best design cost was found to $419,000 and in the Hanoi network, the best design cost was calculated to $6,164,384, and in the Ostfeld's network, the best design cost was found to $3,525,096. These are almost equal or better result compared with previous researches. Last, the cost of optimal design for real network, was found for 66 billion dollar that is 8.8 % lower than before. In addition, optimal diameter for aged pipes was found in this study and the 5 of 8 aged pipes were changed the diameter. Through this result, pipe construction cost reduction was found to 11 percent lower than before. And to conclusion, The least cost design model on water distribution system was developed and verified successfully in this study and it will be very useful not only optimal pipe change plan but optimization plan for whole water distribution system.

• 상하수도학회지
• /
• 제20권3호
• /
• pp.357-366
• /
• 2006

In order to compute pressure variation for a water distribution system, an expression for the friction factor as a function of Reynolds number and the relative roughness needs to be properly incorporated in computational algorithm. Considering Moody s friction variation, Developed Unsteady Network Analyzer (UNA) has been modified to match computational results with EPANET 2.0. Substantial improvement can be found in the application of Improved UNA to both an hypothetical pipeline network and a real system located in Ulsan City. Random number generator is employed to represent the uncertainty of water use in real pipeline network. Comparisons of application between EPANET 2.0 and improved UNA 2.0 indicate advantages and potentials of this approach.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2004년도 학술발표회
• /
• pp.521-526
• /
• 2004

It is necessary to analyze the unsteady flow in the pipe network for the better operation and controls, but there are some problems in actual pipe network simulation, such as collecting a large amount of information in the field, operating highly upgraded computer system, and keeping a big storage device to run analysis program. The skeletonization method is used to cope with the problems in this paper. It is expected to reduce computation time, researcher's efforts, and costs for the analyzing the pipe network. The impact of individual pipe elements to the behavior of the water distribution system can be accounted in the process of skeletonization. However it is also important to study continuously about how to apply the skeletonization method for each of different cases, because inadequate uses may bring simulation to a false result. This paper introduces basic theories and skeletonizing examples in the actual pipe network in Dae-gu city.

• 상하수도학회지
• /
• 제13권2호
• /
• pp.23-33
• /
• 1999

This study is to investigate the effect of C factor errors on the analysis of water distribution systems. For this purpose, an artificial distribution network and a real distribution network were selected as the study networks. Results are as follows. 1. The C factor of a pipe which has small velocity didn't give significant effect on the analysis of a water distribution system. 2. The effect of decreased value of C factors give more influence on the analysis of water distribution systems than that of the increased values. 3. For the C factor calibration, errors of the residual water heads as well as those of the head losses should be considered together. 4. In the analysis of water distribution systems, changes of C factors can give influences only on the nodes which locate behind the pipe. Therefore, this characteristics should be considered in the selection of nodes for the measurement of water heads.

• 한국지리정보학회지
• /
• 제8권2호
• /
• pp.103-116
• /
• 2005

최근 GIS를 이용한 관망 DB화가 빈번히 이루어지고 있으나 관망해석 모형과의 연계는 미흡한 실정이다. 그 주된 이유는 이들 DB가 관망해석 모형에서 요구하는 전문적인 공간정보의 작성에 어려움이 있기 때문이다. 그로 인해, 배수관망도의 작성과 이의 정확도 향상을 위하여 공간자료를 구축할 수 있는 GIS 기법 적용이 요구되고 있다. 본 연구에서는 배수관망 수리해석 모형구축에 필요한 제반 공간자료를 GIS를 이용하여 손쉽게 작성할 수 있는 방법을 제시하였다. 또한, 관망해석모형의 계산결과를 활용하여 상수관로 위치의 공간적인 적정성(노후도 분석, 표고별 수압분포, 수용가 관리를 위한 유량공급의 분석 등)을 판단할 수 있도록 하였다.

• 한국수자원학회논문집
• /
• 제39권6호
• /
• pp.545-552
• /
• 2006

본 연구에서는 노후관망의 최적개량 계획수립을 위한 의사결정모형을 개발하였다. 각각의 관거에 대한 개량계획을 수립하는 기존에 개발된 다른 모형과 달리 노후화된 상수관망을 소구역으로 구분하여 각 소구역의 개량계획을 수립하였다. 개발된 모형에서는 최적개량 의사결정을 위해 개량비용(교체비용, 갱생비용, 유지보수비용), 개선이익(펌프운영비 감소이익, 누수 감소이익) 및 수리학적 타당성을 고려하였다. 화음탐색법을 최적화기법으로 적용하였으며 수리학적 타당성 검토를 위해 수리해석 모형인 EPANET을 연계하였다. 대구시의 실제 상수도관망에 개발된 모형을 적용하였으며, 매설기간과 관의 종류에 의존하는 기존 방법과 달리 관의 내구성, 통수능, 비용 등을 고려하는 최적개량의사결정 시스템으로 활용될 수 있음을 확인하였다.