• Environmental Engineering Research
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• 제24권1호
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• pp.63-73
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• 2019

This study suggests a method for calculating the benefits of water pipe renewal based on an estimate of the water supply suspension risk. The proposed method based on five benefit items is more direct and specific than other benefit estimation methods. In addition, a methodology evaluating the economics of pipe renewal based on pipe failure rate is proposed for estimating the optimal renewal point from an economic perspective. By estimating the optimal renewal period based on a yearly benefit cost ratio per pipe in a case study area, it was possible to draft an optimal renewal plan for the subject region from an economic perspective. Compared with other methodologies, a reasonable optimal renewal period was derived from an economic point of view. The result of this study may be used to develop future water pipe renewal plans. Moreover, the proposed methodologies and results derived from this study can be applied to asset management plans.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.453-458
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• 2008

Pump of high lift use to development of a technological level according as a building grow big. Water-Hammer to increase by valve of fast to closing agreeably to pipe laying to accept electronic valve, because by a damage of piping-system and the devil knows injury of vibration. Water-Hammer take a low effect to various method for solve. A New type manufacture develop and testing of pipe line to same to axis use to accumulator for water-Hammer to low effect and liner control of pressure. Impact-pressure of absorption ability and confirmation to decrease of vibration level through to preexistence manufactures and comparative test. Water-hammer and pipe vibration make low of piping system.

• 한국전자통신학회논문지
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• 제6권5호
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• pp.717-722
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• 2011

본 논문은 원통형 세라믹관에서 온수를 순간적으로 가열하여 설정된 온도 및 수량으로 제어하고자 전자 제어기를 개발하였다. 순간온수기의 구조는 유입되는 온수가 원통형 세라믹 히터를 통하여 열량을 공급하여 온도를 제어하고자 설계하였고, 또한 수량센서와 임펠러를 이용한 수량을 제어하는 전자 제어기를 설계하였다. 순간온수의 제어방법은 유입되는 유량에 열량을 공급하는 원통형 세라믹 히터의 수학적인 모델링을 수립하여 제어기 적용하였고, 이에 대한 실험결과는 설정온도에 따라 제어가 잘 적용되어, 효율적이고 실용성 결과를 보였다. 따라서 원통형 세라믹 순간온수기는 향후 실용제품에 적용할 수 있는 제품구조와 제어 방법을 제시하였다.

• 한국지열·수열에너지학회논문집
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• 제13권1호
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• pp.1-6
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• 2017

In this paper, the flow characteristics of water in the water supply pipes of a WBC array were evaluated. We simulated the flow velocities and pressures for a standard pipe, an expansion pipe with a concentric reducer, and an expansion pipe with an eccentric reducer using computational fluid dynamics. In the case of the standard pipe, when the inlet flow velocities were 0.5 m/s and 2.0 m/s, the maximum flow velocities at the center of the WBC array were 0.54 m/s and 2.74 m/s, respectively, which were the greatest values among those of all the pipe models considered. In the case of the expansion pipe, the maximum flow velocities at the center of the WBC array were almost the same under the same conditions regardless of the type of reducer. The pressure losses in the pipe due to the concentric and eccentric reducers were found to be (165.09 ${\times}$ inlet $velocity^{1.6677}$) and (210.98 ${\times}$ inlet $velocity^{1.6478}$), respectively. The coefficient of determination at this time was greater than 0.99 and was the same for both the models. As a simulation result, it was found that in order to reduce the pressure loss when pipe with WBC array is connected with a conventional pipe, diameter of the pipe with WBC array at that section should be enlarged by one step, and then connected to the conventional pipe with a concentric reducer.

• 대한환경공학회지
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• 제39권12호
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• pp.733-740
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• 2017

환경부에서 수립한 "상수도 시설기준(2004)"은 관로 신축이음관 설치기준에 있어서는 용접이음 강관에는 설치하지 않는 것으로 규정하고 있으며, 이에 대한 근거가 명확하지 않고 관로 안정성이 충분히 확보되었는지 확인하기가 어렵다. 금번 연구에서는 강관의 거동 분석을 통한 관로 안정성을 연구하여 신축이음관의 필요여부를 검증하는 것을 목적으로 하였다. 검토결과는 아래와 같다. 첫째, 아스팔트 도복장강관(D2,400 mm)은 온도변화에 따라 4-cycle로 관로 신 수축이 반복되며, 연장 1.24 km에 있어 최대 13.03 mm의 변위를 나타내었다. 둘째, 수도용 강관의 신 수축으로 발생되는 온도응력은 매설깊이(최대 4 m)에 따라 $13.7{\sim}36.1kgf/cm^2$로 발생되며, 강관(STWW 400)의 안정성에 큰 영향을 키치는 주요 비교인자인 허용 인장강도와 피로한도는 $4,100kgf/cm^2$와 $1,840kgf/cm^2$로 산출되었다. 마지막으로, 수도용 강관의 온도응력은 허용 인장강도와 피로한도와 비교시 매우 작음에 따라, 온도변화에 의한 관로의 신 수축이 발생하여도 관로 안정성에는 영향을 끼치지 못함을 알 수 있었다. 결론적으로 금번 연구를 통하여 수도용 강관의 관로부에는 신축이음관을 설치할 필요가 없는 것으로 증명되었다.

• 상하수도학회지
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• 제37권6호
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• pp.347-361
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• 2023

Water utilities are making various efforts to reduce water losses from water networks, and an essential part of them is to recognize the moment when a pipe burst occurs during operation quickly. Several physics-based methods and data-driven analysis are applied using real-time flow and pressure data measured through a SCADA system or smart meters, and methodologies based on machining learning are currently widely studied. Water utilities should apply various approaches together to increase pipe burst detection. The most intuitive and explainable water balance method and its procedure were presented in this study, and the applicability and detection performance were evaluated by applying this approach to water supply pipelines. Based on these results, water utilities can establish a mass balance-based pipe burst detection system, give a guideline for installing new flow meters, and set the detection parameters with expected performance. The performance of the water balance analysis method is affected by the water network operation conditions, the characteristics of the installed flow meter, and event data, so there is a limit to the general use of the results in all sites. Therefore, water utilities should accumulate experience by applying the water balance method in more fields.

• International Journal of Air-Conditioning and Refrigeration
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• 제11권1호
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• pp.40-49
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• 2003

Dynamic characteristics of water hammer arresters installed in a building water supply system have been investigated numerically by utilizing a commercial code that employs the method of characteristics. Some preliminary results with those arrester models produced in this study agree well with the previously reported. Then, the arrester models have been incorporated into a water supply pipe system of a 59 $m^2$apartment unit constructed by a leading construction company, and their dynamic characteristics have been investigated, especially on the reduction in the water hammer pressure. It is found that the setting of the arresters in the pipe system, which is recommended by the company, may not be proper for reducing the pressure down below 1,082.0 kPa (10.0 kg$g_f$/$cm^2$) when quick-closure valves in the pipe system are closed within 30 ms at the static pressure of 542.6 kPa (4.5 kg$g_f$/$cm^2$). More arresters in the system may be required to meet pressure criteria stated on the related standards and codes.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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• pp.403-408
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• 2001

In order to control hydration heat in mass concrete, pipe cooling method has been widely used. However, open pipe cooling system cannot be applied to the mass concrete structures when cooling water supply is difficult. To control hydration heat of high strength mass foundation, closed loop pipe cooling system was developed to solve the cooling water supply. This paper reports the performance result of hydration heat control with closed loop pipe cooling system.

• 상하수도학회지
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• 제13권3호
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• pp.73-82
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• 1999

In this study, the optimal analysis for pipe network is performed for the combined ideal pipe network system(CASE 1, CASE 2 and CASE 3) which is composed of 25 nodes, 41 elements, and 1 fixed nodal head with evaluating pressure variation distribution of main and branch in grid composed drainage pipe network. The linear analysis technique used as the analysis method in this study, the KYPIPE being used extensively as the linear technique to design and analysis of pipe network is applied. Firstly, in the analysis of pipe network, the CASE 2 and CASE 3 supply same thing(value) in the result of considering the total flow provided each pipeline, but in the general intension in the case of CASE 2, relative width of supply is more large than CASE 1 and CASE 3. Secondly, in the analysis technique of pipe network, CASE 3 is analysed largest as a result of comparing with same heads, and in the order of their size CASE 2 and CASE 1 were determined but the difference doesn't appear to be obvious. Thirdly, as the result of determining main factor, pressure in the design and analysis of net work. CASE 3 is from Node 3 to 25 than CASE 1 and CASE 2 and it is determined in the order of their size, CASE 2 and CASE 1. Finally, in this study, discharge flow distribution is evaluated in the same condition with 3-type CASE in the case of branch position for designing optimal composed drainage pipe network. As the result of that, branch pipe perform. Therefore, it is thought that the efficient and reasonable management of water supply and sewerage design will be possible if it give all our energies to study at the pipe system design in and out of country in the future.

• 한국수자원학회논문집
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• 제55권spc1호
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• pp.1187-1195
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• 2022

관망의 세그먼트를 파악하기 위한 알고리즘을 구동시키기 위해서는 관망의 주요 구성요소들인 절점, 파이프, 및 밸브 간의 상대적인 위치 관계를 세그먼트 탐색 알고리즘의 입력정보로 준비해야 한다. 실제 지자체 관망에 존재하는 세그먼트를 보다 정확하게 파악하기 위해서는 관망 수리해석 프로그램 구동을 위해 모델링된 관망 정보를 이용하기 보다는, 모든 제수밸브가 포함된 지자체 상수도 관망 GIS/CAD 데이터베이스를 이용하여 세그먼트 탐색에 적합하게 재구성된 관망 정보를 이용할 필요가 있다. 본 연구에서는 지자체 상수도 관망 GIS/CAD 데이터를 이용하여 관망 세그먼트 탐색에 적합한 노드-파이프-밸브 간의 상대적 위치관계를 수립할 수 있는 컴퓨터 계산 알고리즘을 개발하였으며, 이를 구현할 수 있는 MATLAB 프로그램을 개발하였다. 개발된 MATLAB 프로그램을 국내 지자체 상수도 관망에 적용하여 그 실효성을 확인하였다.