• 한국수자원학회논문집
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• 제49권5호
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• pp.399-410
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• 2016

유속계수는 상수도 설계, 운영, 유지관리 등의 과정에서 항상 현장 실정이 고려된 값이 사용되어야 한다. 본 연구는 광역상수도 정밀안전진단 과정에서의 174개 실측자료를 바탕으로 유속계수와 주요 인자 간의 관계를 통계적 기법을 활용하여 분석하였다. 이들 관계를 분석하기 위해서 교차분석, 일원배치 분산분석, 상관분석 등을 수행하였으며, 그 결과 유속계수와 사용년수 및 관경이 높은 상관관계를 나타내고 여러 범주형 자료 형태 영향인자 중에 내부도장재가 상대적으로 유속계수에 많은 영향을 주는 것으로 검토되었다. 반면 다중회귀분석의 결과에서는 사용년수, 관경 및 수종이 중요한 영향인자인 것으로 검토되었다. 군집분석 결과, 유속계수는 기본적으로 사용년수 약 20년, 관경 1500mm를 기준으로 분류되는 경향이 있었으며, 유속계수는 전반적으로 사용년수에 많은 영향은 받으나 대구경 관에서는 상대적으로 사용년수보다 관경에 많은 영향을 받는 것으로 검토되었다. 마지막으로 본 연구에서는 회귀분석과 군집분석을 사용하여 유속계수 산정식들을 제안하였으며, 이러한 추정식들은 추후 광역상수도의 유속계수 결정 및 사용 시에 판단기준이 될 수 있을 것으로 판단된다.

• 한국산학기술학회논문지
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• 제15권2호
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• pp.1096-1101
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• 2014

본 연구(II)는 연구(I)에서 제안한 대구경 관로의 노후도 평가 모형을 수도권 광역상수도 1단계를 대상으로 이를 적용하였다. 노후도 평가 방법별 적용 결과에서, 총 30개 관로 중에서 1995년 평가방법은 24개, 2002년 평가방법은 27개 관로가 개량이 필요한 것으로 나타났다. 또한 개발된 모형과 기존의 2개 평가방법의 결과는 거의 일치하는 것으로 산정되었다. 즉, 본 연구에서 개발한 간편모형은 기존의 많은 인자를 이용하여 노후도를 평가하는 방법과 비교에서 신뢰할 수 있는 부합되는 결과를 보여 주었다. 따라서, 본 연구에서 개발한 모형은 기존의 노후관 평가방법과 비교시 실험 및 분석 등에 필요한 시간적 경제적 비용을 절약할 수 있어 실무적 적용에 많은 도움을 줄 수 있으리라 기대된다.

• 한국유체기계학회 논문집
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• 제8권5호
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• pp.22-28
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• 2005

As the water supply facilities are recently getting larger, the domestic waterworks become multi-regional water supply system. Large water supply facilities generally consist of the intake pumping station, water treatment plant and water supply/distribution facilities. Although the pumping stations and the pipeline systems are used to pump up water, it often happens pipeline damage and flooding accident by the water hammer. In this paper, the intake pumping station is guaranteed by both the computer simulation and the field test analysis. This study is contributed to the safe operation program for the pumping station in which results of the adjustment on the safety plan of the pumping station, the air valve and the valve closing time.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.199-207
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• 2004

Water supply facilities are recently getting larger according as domestic waterworks become multi regional water supply system. Large water supply facilities generally consist of the intake pumping station, water treatment station and water supply & distribution facilities. Although pumping stations and pipeline systems are used to pump up water, it often happens pipeline damage and flooding accident by the water hammer. As a result of this study, a pumping station is guaranteed by the computer simulation and field test analysis. Therefore these are contributed safety operation in pumping station through adjustment of the pumping station safety plan, air valve and valve closing time.

• 상하수도학회지
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• 제25권4호
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• pp.511-517
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• 2011

To evaluate carbon emission in water treatment processes, LCA (life cycle assessment) was applied to 8 multi-regional water treatment plants (WTPs) from intake to supply of tap water. Investigation of 8 WTPs revealed that average carbon emission for 1 $m^3$ of tap water was 221 g. Major carbon emission sources in water supply system were intake and supply processes. Meanwhile, mixing process was the main carbon emission source in unit water treatment processes. Carbon emission was proportional to the turbidity and COD of raw water. Intake of better raw water and minimization of energy consumption in unit processes are needed to reduce carbon emission in the WTPs. In addition, comparison of carbon emission among WTPs can be used as a parameter for optimization of operation and maintenance of water treatment processes.

• Environmental Engineering Research
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• 제20권3호
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• pp.230-236
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• 2015

26 multi-regional water treatment plants (WTPs) were investigated, to determine the characteristics of manganese (Mn) concentration and removal in Korea. Mn concentrations of raw water in most WTPs were higher than the drinking water standard (i.e., 0.05 mg/L); thus, proper removal of Mn at the WTPs is needed. Mn concentration was generally higher in lakes than rivers due to seasonal lake turnovers. The Mn concentrations of treated water at 26 WTPs in 2012 were less than 0.05 mg/L, due to strict law enforcement and water treatment processes optimization. However, before 2010, those concentrations were more than 0.05 mg/L, which could have led to an accumulation of Mn oxides in the distribution system. This could be one of the main reasons for black water occurrence. Therefore, regular monitoring of Mn concentration in the distribution system, flushing, and proper Mn removal at WTPs are needed, to supply clean and palatable tap water.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.171.2-171.2
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• 2010

Geothermal effects on the underground water conveyance pipe system have been investigated through the multiregional water supply system from Paldang water intake station. To make an investigation of raw water thermal energy, temperature sensors are installed the surface of the pipes of metropolitan area water supply system. In 2009 winter and early spring seasons, the monthly averaged temperatures at Paldang 2 intake stations are $1.94^{\circ}C$ in February, $4.96^{\circ}C$ in March, and $10.56^{\circ}C$ in April. After the transfer in 26.0 km distance of tunnel and buried pipe, the raw water temperatures are raised to $3.13^{\circ}C$, $6.04^{\circ}C$, and $11.39^{\circ}C$ respectively. As the temperature difference between the raw water and the air reduces, the temperature increasement is reduced by $1.19^{\circ}C$ in Feb., $1.08^{\circ}C$ in Mar., and $0.83^{\circ}C$ in Apr. Since the flowrate is over 1,150,000 $m^3$/day, it is estimated that the water exchanges a huge amount of heat over 1.0 Tcal a day with the ground.

• 기술사
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• 제42권3호
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• pp.22-26
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• 2009

As Korea's water resources are dominated by intense summer rainfall and steep mountainous territory, it is inevitable for most of the rainfall in Korea to flow into sea immediately and directly. It cannot help having severe conditions which droughts and floods occur repeatedly due to the seasonal and geological conditions in Korea. Those kinds of disasters will be expected more frequently and seriously in the future because of the unexpected climate changes in the world. Therefore, Korean government will plan to develop small and medium-size dams environmentally friendly, multi-regional water supply system continuously and alternative water resources such as river bank filtrations, rainwater storages and underground dams, in order to prevent floods as well as to secure stable water supply.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2008년도 학술발표회 논문집
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• pp.500-504
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• 2008

The objective of this paper is to evaluate the feasibility of using an optimization model as a effective way to search conjunctive operation scheme to meet two conditions; one is to minimize the electric cost for pumping and another is to meet the water demand for satisfying customers. The feasibility is confirmed as comparing the best combinations of pumps between multi-regional water supply networks from multiple sources which are obtained through an optimization modeling and EPAnet modeling. KModsim model, a network optimization model, was used to determine conjunctive operation scheme in the pipe system. KModsim, based on Lagrangian Relaxation algorithm, is useful for modeling network system and obtaining simultaneously pump combination and water allocation with given input option such as energy unit cost supplying from a source into a consumer, operating pumping combination. This study develops the procedure of determining optimal conjunctive operation scheme with using KModsim model. As a study region, the water supplying systems of the Geojae-city in the Geongsang Namdo Province was selected and investigated. The EPAnet hydraulic simulation result(Ryu et al, 2007, KSWW) gave input data for optimization model; energy unit price(won/$m^3$), water service available area etc.. It was assured that the combination of pump operation through optimum conjunctive operation is to be optimum scheme to obtain the best economic water allocation with comparison to the hydraulic simulation result such as electric cost and pump combination cases. The results obtained through the study are as follows. First, It was found that a well-allocated water supply scheme, the best combination of pump operation through optimum joint operation, promises to save the electric cost and satisfy all operational goals such as stability and revenues during the period. Second, an application of KModSim, a network model, gave the amount of water allocation from each source to a consumer with consideration of economic supply. Finally, in a service area available to supply through conjunctive operation of existing inter-regional water supply networks within short distance, a conjunctive operation is useful for determining each transmission pipeline's service area and maximizing the effectiveness of optimizations in pumping operation time.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.202-202
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• 2011

Performance of the raw water-source heat pump system with a thermal storage tank has been analyzed in winter season. The raw water is transferred through the multi-regional water supply system from Han river. Raw water is large temperature difference resource compared with groundwater. Although the raw water temperature drops to $0.6^{\circ}C$ due to the heavy snowfall and the severe cold in late January and early February, 2010, the system has been normally operated without any trouble this winter. The unit COP and system COP considered all pump power consumption were estimated based on the second-by-second data of the all sensors. The monthly averaged unit COP and system COP are 3.37 and 2.76 respectively with $1.4^{\circ}C$ of raw water in January, 3.55 and 2.89 with $1.6^{\circ}C$ raw water in February, 3.82 and 3.15 with $5.4^{\circ}C$ raw water in March. The performance of the system are increased with raw water temperature, and the COPs are higher than the water-to-air heat pump system using relatively high temperature raw water from Daecheong reservoir because the water-to-water system was operated on the full load condition and was stopped when the thermal storage tank was full of the high temperature water.