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        검색결과 5

        1.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Water supply/intake pumps operation use 70~80% of power costs in water treatment plants. In the water treatment plant, seasonal and hourly differential electricity rates are applied, so proper pump scheduling can yield power cost savings. Accordingly, the purpose of this study was to develop an optimal water supply pump scheduling scheme. An optimal operation method of water supply pumps by using genetic algorithm was developed. Also, a method to minimize power cost for water supply pump operation based on pump performance derived from the thermodynamic pump efficiency measurement method was proposed. Water level constraints to provide sufficient disinfection performance in a clearwell and reservoirs were calibrated. In addition, continuous operation time constraints were calibrated to prevent frequent pump switching. As a result of optimization, savings ratios during 7 days in winter and summer were 4.5% and 5.1%, respectively. In this study, the method for optimal water pump operation was developed to secure disinfection performance in the clearwell and to save power cost. It is expected that it will be used as a more advanced optimal water pump operation method through further studies such as water demand forecasting and efficiency according to pump combination.
        4,600원
        3.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims at providing a basic data for the development of high energy efficient environment system in the cage (poultry buildings) and cold potable water supply to reduce the summer heat stress. For this study, the cage area size was 273m 2 and the air-to-water heat pump capacity was 20RT for heating and cooling. As the result of this study, the temperature of the drinking water supplied by heat pump was maintained at the set temperature of 15℃. However, the water temperature of control was 23~28 ℃ due to the effect of outside temperature. The average internal cage temperature was 25.3 ℃ in the test group and 28.1 ℃ in the control group, which was 2.8 ℃ higher than that of the control group. The relative humidity was 76.2% in the test group and 75.0% in the control group. The broiler drank 23.2 L / day in the test group and 21.5 L / day in the control group. Daily feed intake was 937 g and and 725 g in the cold water and control water respectively. The feed intake of 212 g was higher than that of cold water. The feeding rates were 1.8 and 1.9. Body weights were 1,523 g and 1,164 g in the cold water and control water respectively. The weight gain was 359 g in the test group fed with cold water and 392 g in the control group. When compared with the control group, the mortality rate was reduced by 84% in the cold water feeding test. It is necessary that future research will continue to reduce the incidence of such livestock accidents.’.
        4,000원
        4.
        2014.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fuel pump of a vehicle is a device to supply the fuel from fuel tank to engine. This study analyzed the pulsatility on the shape of fuel supply pipe using a CFD(Computational Fluid Dynamics). Numerical analysis was performed to use 3-dimensional incompressible k-ε turbulent model with measured pressure values at an exit by an experiment. Simulation models used commercial and improved model. In this study, the characteristics of the pulsatility reduced in improved model compared to those in commercial model. The pressure loss, which occurs at the flexure, was effective to pulsatile reduction. Commercial and improved model differed by numbers of flexure. The number of flexure between inlet and outlet decreased the difference of velocity and pressure. Therefore, the design of fuel supply pipe should be considered numbers and shape of flexure.
        4,000원
        5.
        2009.09 KCI 등재 서비스 종료(열람 제한)
        장거리 용수공급 시스템에서 전력비용은 전체 운영비용의 큰 부분을 차지한다. 본 연구는 시간단위의 펌프와 배수지 시스템의 최적 운영계획을 평가하기 위해 동적계획기법에 기초한 방법론을 제시하고 있다. 해석방법은 운영비용 최소화 관점에서 펌프용량 확대를 전제로 현재 가용 펌프의 효율적 운전과 전력요금체계, 시간별 용수수요 추이 그리고 배수지 특성과 송수관로의 제약조건 등을 고려하였다. 이를 위해 적용 가능한 시스템 운영목적과 제약조건이 제시되었고 개발된 방법