• 제목/요약/키워드: Water flow rate

검색결과 3,044건 처리시간 0.033초

공기보조식 (air-assisted) 플래쉬 분무의 분무 각 확대 특성 연구 (Analysis of spray cone angle of air assisted flash atomization)

  • 류태우;김세원;방병열
    • 한국분무공학회지
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    • 제10권1호
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    • pp.1-9
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    • 2005
  • When the water jets heated up to the saturation temperature at a high line pressure are sprayed into a reduced (atmospheric) pressure through an air-assisted nozzle, the jets experience sudden exposure into a reduced pressure, get superheated and produce steam bubbles while atomization processes of jets are taking place. This process is called flash atomization. In this study the flash atomization of superheated water jets assisted by air has been studied. Sprays with flash atomization have been photographed at various water and air flow rates and water superheats. It has been found that the spray angle with flash atomization increases with water superheat and water flow rate but decreases with air flow rate. The degree of change of spray angle has been analyzed and correlated as a function of superheat, air and water flow rates.

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냉각수 계통의 운전변수가 중앙냉방시스템의 에너지소비량에 미치는 영향 (The Effects of Operational Conditions of Cooling Water System on Energy Consumption for Central Cooling System)

  • 안병천
    • 한국지열·수열에너지학회논문집
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    • 제13권4호
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    • pp.8-13
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    • 2017
  • The effects of operational conditions of cooling water system on energy consumption for central cooling system are researched by using TRNSYS program. Cooling tower water pump flow rate, cooling tower fan flow rate, and condenser water temperature with various dry-bulb and wet-bulb temperatures are varied and their effects on total and component power consumption are studied. If the fan maximum flow rates of cooling tower is decreased, cooling tower fan and total power consumptions are increased. If the cooling tower water pump maximum flow rates is decreased, chiller and total power consumptions are increased. If condenser water set-point temperature is increased, chiller power consumption is increased and cooling tower fan power consumption is decreased, respectively.

양수장 용수공급 논 지대의 물수지 (Water Balance in a Paddy Field with Pumping Irrigation System)

  • 정운태;이근후;이인영
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 1998년도 학술발표회 발표논문집
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    • pp.1-7
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    • 1998
  • To investigate the water balance in a paddy rice field with the pumping station for irrigation water supply, flow measurements and analysis on various components of water balance were carried out. The investigated area is 103.7 ha, and the irrigation water was supplied for 102 days during the total irrigation period starting from June 1. It was found that the consumption rate was increased as the growing stage was progressed. The variation of evapotranspiration rate was shown same tendency as the consumption rate, while no apparent tendency was found in infiltration rate upon different growing stages. And the ground water input to the area was predominant during the early stage of growing period, while ground water output from the study area was predominant at the end of the growing stage. The range of return flow rate, the ratio of total outflow to total inflow in every decad, was 57.6 to 85.7%. These values are slightly higher than reported values from the other investigation projects.

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합류식 하수관거 월류수 저장 시설에 대한 효과 - 강우시 합류식 하수관거에서의 오염물질 유출특성 분석 (Effect for CSOs Storage Construction - Analysis of Storm Water Run-off Characteristics in combined sewer system)

  • 박진규;이남훈;김해룡;이웅;이채영
    • 상하수도학회지
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    • 제25권6호
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    • pp.949-957
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    • 2011
  • This aim of study was to investigate the characteristics of discharge of pollutants as well as the correlation between flow rate and water quality constituents in a combined sewer system according to the characteristics of rainfall. For the loading rates for each pollutant, the median concentrations of all pollutants except T-N was increased when a CSO took place. The loading rates of BOD, COD, SS, T-N, T-P, Cu and Zn at the CSOs were 328-1255, 25-129, 83-2009, 4-12, 14-51, 5-11 and 5-13 times higher than the DWF (Dry Whether Flow), respectively. Especially, SS loading rate was found to be highest in all pollutants. On the other hand, the range of the first flush coefficient, b for water quality constituents such as BOD, COD, SS, T-N, T-P, Cu and Zn were 0.537-0.878, 0.589-0.888, 0.516-1.062, 0.852-1.031, 0.649-0.954, 0.975-1.015 and 0.900-1.114, respectively. In term of correlation between flow rate and pollutant concentrations, SS concentration was highly correlated to flow rate. However, there was an inverse correlation between EC (Electrical Conductivity) and flow rate because of the high dilution of flow rate. In case of correlation between pollutants, there was a high correlation between SS and T-P.

경험식과 요인분석을 통한 오염물질 유출 특성 연구 - 남한강 상·하류 수계 주요 하천을 중심으로 (A Study on the Discharged Characteristics of the Pollutants using the Empirical Equation and Factor Analysis - Case Study of the Upper and Lower Watershed of South Han River)

  • 박지형;손수민;류덕희
    • 한국물환경학회지
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    • 제27권6호
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    • pp.905-913
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    • 2011
  • This study was conducted to characterize the discharge feature of pollutant load from the upper and lower watershed influencing on the water quality of South Han River using the empirical equation and Factor Analysis. The results of regression analysis between flow rate and pollutant load were as follows. In the streams of the upper watershed of South Han river, $BOD_5$ and $COD_{Mn}$ were increased as the flow rate was increased. Also, steep increases in SS and TP were observed with positive correlation with the flow rate while change in TN was slightly shown. On the other hand, in the streams of the lower watershed of South Han river, $BOD_5$ was negatively correlated with the flow rate, being decreased with the increase in the flow rate. However, changes in $COD_{Mn}$, TN, SS, and TP showed a similar trend with those observed in the upper watershed. With Factor Analysis of the water quality and various components, it was appeared that the flow rate, SS, and TP were significantly correlated each other and they were indicated as the principal component influencing on water quality in the streams of the upper watershed. In contrast, $BOD_5$, $COD_{Mn}$ and TOC were significantly correlated each other and they were included as the principal pollution component of the streams in the lower watershed. From these results, it was conclusive that the upper watershed of South Han River was mainly affected by non point source pollutants while the lower watershed was influenced by point source pollutants from the developed areas.

터빈 유량계를 사용한 이상유동의 측정

  • 심재우
    • 한국해양공학회지
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    • 제12권2호통권28호
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    • pp.147-152
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    • 1998
  • In this study turbine flowmeters were used to predict volumetric flow rate of each phase in two-phase, gas-liquid, flowing in a vertical tube. To determine volumetric flow rates of two-phase, air-water, flowing vertically upward through the polycarbonate tube(57mm ID-inside diameter), two turbine flow meters were used. For void fraction measurements, two gamma densitometers were used at each location of the turbine flow meter, one at the upstream and the other at the downstream. It was determined that the turbine flowmeter's outputs were a function of actual volumetric flow rate of each of the two phases. A two-phase flow model was developed.

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정유량 밸브의 카트리지의 오리피스 구멍의 유출계수 (Discharge Coefficients of Orifice Hole in the Cartridge of Constant Flow Control Valve)

  • 유선학;강승덕;양의석;박경암
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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    • pp.305-308
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    • 2004
  • The constant flow control valve is used to control the flow rate of heating water in the large apartment complex and buildings. It is important to have similar heating flow rate in the apartments, even though the apartment is top or bottom floors. To achieve those purposes, the constant flow control valve was developed. The performance of this control valve is effected by hole area and discharge coefficients of the cartridge holes. The discharge coefficients of orifice hole in the cartridge were testes with various sizes of holes and various flow direction in the holes. The discharge coefficients decreased as the hole size increased due to the collision at the cartridge wall of water jet. The effects of the flow direction at the hole were not significant on the discharge coefficients.

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수직관내 고-액 슬러리 유동 계측 실험연구 (Experimental Study of Solid-water Slurry Flow in Vertical Pipe)

  • 최종수;홍섭;양찬규
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 추계학술대회 논문집
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    • pp.160-163
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    • 2001
  • In order to develop a nodule conveying system through a flexible pipe out of the deep-seabed manganese nodule miner, an experimental study of the solid-water slurry flow in vertical pipe is performed as the first stage of total experiments. Hydraulic characteristics of the pipe slurry flow such as slip velocity, transport concentration and pressure gradient are investigated for the size of particle, load ratio, and flow rate of water. The higher the load ratio is, the larger the transport concentration and pressure gradient become. The bigger the size of particles is, the larger the pressure gradient becomes. The effectiveness of the flow rate to hydraulic performance is also investigated. This results are to be used for designing crusher and pump, and operating the conveying device.

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지류하천의 유황분석을 통한 BOD5 농도변화 유형 분석 (Study of BOD5 Variation Patterns with Flow Regime Alteration in the Tributaries)

  • 정우혁;김영일;김홍수;문은호;박상현;이상진;정상만;조병욱;최정호
    • 한국물환경학회지
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    • 제27권4호
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    • pp.499-508
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    • 2011
  • We analyzed the variations of water quality with flow regime alterations to determine the characteristics of the stream where the stream management is considerably difficult due to the high variability of the flow rates. In this study, both flow rates and water qualities were monitored at the tributaries, 34 in count, of both Geum River and Sabgyo Lake Basins. The variation of water qualities were divided into 2 types, based on their stream flow rates, known as Type I and Type II. If the water quality of a stream increases during low flow rate periods compared with high flow rate periods, it is classified as Type I; if the water quality of the stream increases during high flow rate periods compared with low flow rate periods, it falls under Type II. The analysis for the variations of water qualities, of all 43 basins, resulted to 24 basins under Type I and Nineteen 19 basins under Type II. The variations of water qualities were analyzed first by using Regression Analysis followed by Statistical Analysis. The average slope of the variations of water qualities and the slope of the standard deviations were 0.00135 and 0.00477, respectively. The Probability Distributions of both Type I and Type II basins were 61.1% and 38.9%, respectively. The basin having a probability distribution of 61.1% and is also known as Type I, increases during periods of low flow rates, due to the presence of point sources. Therefore, the basin should be enforced with stream management. Before the stream management can be implemented in all streams falling under Type II, the sources of contaminants should first be estimated. These contaminants can be classified into two parts, the first is Point source pollution and the second is Non-point source pollution, where the Non-Point source pollution can be sub-divided into two types, with storm runoff and without storm runoff.

A PROPOSED CORRELATION FOR CRITICAL FLOW RATE OF WATER FLOW

  • KIM, YEON-SIK
    • Nuclear Engineering and Technology
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    • 제47권1호
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    • pp.135-138
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    • 2015
  • A new correlation predicting the idealized critical mass-flow rates of water for subcooled and saturated liquid water including two-phase water flow was developed for a wide range of upstream stagnation pressures (e.g., 0.5-20.0 MPa). A choking correction factor dependent on the upstream stagnation pressure and subcooled temperature was introduced into a new correlation, and its values were suggested to satisfy the idealized nozzle data within 10% error ranges. The suggested correlation will be instructive and helpful for related studies and/or engineering works.