• Title/Summary/Keyword: river water

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LCC Analysis of a Heat Pump System Using River Water (하천수 열원 이용 열펌프 시스템의 LCC 분석)

  • Han, Sang-Soo;Park, Cha-Sik;Kim, Yong-Chan
    • Proceedings of the SAREK Conference
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    • pp.1424-1428
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    • 2009
  • The performance of a heat pump using river water as a heat source was compared with that of a conventional air-conditioner for cooling and a boiler system for heating. The heat pump system using river water considered the 1-stage cycle for cooling and the 2-stage cycle for heating. The COPs of the river water source heat pump were $0.5{\sim}1.1$ higher than those of the conventional system in the cooling season. The LCC of the river water source heat pump system was lower 13.5% and 32.4% than that of the conventional system I and II. In addition, when the initial cost ratios of the river water source heat pump system to the conventional system I and II were less than 1.2 and 1.4, respectively, an acceptable payback was found to be less than 5 years.

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Assessment of Trophic State for Daecheong reservoir Using Landsat TM Imagery Data (Landsat TM 영상자료를 이용한 대청호의 영양상태 평가)

  • Han, E.J.;Kim, K.T.;Jeong, D.H.;Cheon, S.Y.;Kim, S.J.;Yu, S.J.;Hwang, J.Y.;Kim, T.S.;Kim, M.H.
    • Journal of Environmental Impact Assessment
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    • v.7 no.1
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    • pp.81-91
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    • 1998
  • The objective of this study was to use remotely sensed data, combined with in situ data, for the assessment of trophic state for Daecheong reservoir. Three Landsat TM(Thematic Mapper) imagery data were processed to portray trophic state conditions. The remotely sensed data and the measured data were obtained on 20 June 1995. Regression models have been developed between the chlorophyll-a concentration and reflectance which was converted to Landsat TM digital data. The regression model was determined based on the correlation coefficient which was higher than 0.7 and was applied to the entire study area to generate a distribution map of chlorophyll-a and trophic state. The equation, providing estimates of chlorophyll-a concentration, represented the year-to-year spatial variation of trophic zones in the reservoir. Satellite remote sensing data derived from Landsat TM had been successfully used for trophic slate mapping in Daecheong reservoir.

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Evaluation of Bank Filtrate Water Quality in Galjon, the Downstream of the Nakdong River (낙동강 하류 갈전지역에서의 강변여과수 수질평가)

  • Lee, Sooyoung;Chung, Taihak
    • Journal of Korean Society of Water and Wastewater
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    • v.17 no.4
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    • pp.487-494
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    • 2003
  • In this research, water qualities of river water and bank-filtrate were compared for six months including winter season. The location studied was Galjon area, the downstream of the Nakdong river. The well for bank-filtrate was installed 40 m apart from riverside. Main analytic results of bank-filtrate and river water were summarized as followings; the average concentrations in bank-filtrate were turbidity 0.8NTU, TN 0.4mg/l, $BOD_5$, 0.1mg/l, $KMnO_4$ consumption 1.6mg/l, heterotrophic bacteria 350cfu/ml, Fe 0.5mg/l, Mn 0.99mg/l while the average concentrations in river water were turbidity 6.1NTU, TN 3.9mg/l, $BOD_5$, 3.6mg/l, $KMnO_4$ consumption 11mg/l, heterotrophic bacteria 1,640cfu/ml, Fe 0.28mg/l, Mn 0.04mg/l. Water quality of bank-filtrate was mostly shown a good results than it of river water excepting Fe and Mn. In even basic constituents such as water temperature and pH, bank-filtrate was very settled while river water was extraordinary changable and high. In case of nitrogen, especially, total nitrogen of river water was 3.9mg/l while it of bank-filtrate was 0.4mg/l and its reduction was very high. The reason is that $NH^+_4-N$ among total nitrogen in the river water is nitrified and then denitrified in soil layer when it is pumped up as bank-filtrate. But Fe and Mn caused by the characteristics of soil was very high in bank-filtrate while Mn in river water was particularly very low and settled. As the distance between riverside and well was longer, concentration of Fe and Mn may be went up while its bacteria may be reduced.

Performance Characteristics and Economic Assessment of a River Water: Source Heat Pump System (하천수 열원 열펌프 시스템의 성능 특성 및 경제성 평가)

  • Park, Cha-Sik;Jung, Tae-Hun;Park, Hong-Hee;Kim, Yong-Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.11
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    • pp.621-628
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    • 2009
  • The objectives of this study are to analyze the performance of a river water-source heat pump and to carry out economic assessment for the heat pump. The COP of the river water-source heat pump was 3-21% higher than that of the air-source heat pump because river water provides stable operating temperature compared with air temperature throughout the year. The economic analysis was carried out by comparing the initial and operating cost of the river water-source heat pump with those of the conventional air-source heat pump. The ratio of the life cycle operating cost to the life cycle cost increased with the increase of building capacity. The payback period was found to be less than 3.5 years when the capacity of the river water-source heat pump was larger than 10 RT.

An Experimental Study on the Part-Load Performance of a River Water Source 2-Stage Heat Pump (하천수 열원 2단 압축 열펌프시스템의 부분부하 운전특성에 관한 실험적 연구)

  • Kim, Ji-Young;Baik, Young-Jin;Lee, Young-Soo;Ra, Ho-Sang
    • Proceedings of the KSME Conference
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    • pp.1964-1968
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    • 2007
  • The river water heat source heat pump has the advantage in the performance compared to air source heat pump. Although its better performance, the large temperature difference between load and source makes system performance worse by nature. In this study, 2-stage compression is considered as the solution of this problem. Generally, heat pump is designed for maximum capacity rate, but it actually operates at part load condition in many cases. Therefore, an information on the part-load character is very important in view of the system overall performance. In this study, part-load performance tests of a R134a 2-stage compression heat pump were carried out over the river water and supply heating water temperature changes. The experimental results show that the system performance is influenced by the part load rates, river water temperature, load temperature, etc.

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Simulation on the Heating Performance of a 2-Stage Compression Heat Pump System Using River Water (하천수열원을 이용한 2단압축 열펌프의 난방성능 시뮬레이션)

  • Park Chasik;Kim Bohyun;Kim Yongchan;Lee Young Soo;Bang Ki-young
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.11
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    • pp.1005-1013
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    • 2005
  • The use of river water as a heat source of a heat pump has the advantage in the performance compared to the use of atmospheric air because the temperature variation of river water over the year is relatively small. In this study, the performance of the heat pump system using river water as a heat source was numerically investigated. A simulation model for the 2-stage compression heat pump system was developed with each component model composed of compressors, heat exchangers, a flash tank and electronic expansion devices. The peformance of the heat pump system using river water was improved by $50\%$ compared to that using atmospheric air in winter conditions.

Distribution of the Organic Contents in Reservoir Sediment (호소 퇴적물의 유기물 분포)

  • Hwang, Jong Yeon;Han, Eui Jung;Yu, Soon Ju;Yoon, Young Sam;Cheon, Se Eug;Kim, Tae Keun
    • Journal of Environmental Impact Assessment
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    • v.8 no.2
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    • pp.95-107
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    • 1999
  • The organic contents of reservoir sediment can offer a good indicator to events in history of lake life. Reservoir sediment have many information of the past and future fingerprint about development direction of life cycle in biological animals. So, in this study we made an effort to know the distribution of organic contents in Daecheong reservoir sediment. Items for this investigations are such as follows: Loss on ignition, COD, Organic carbon, TN, TP, heavy metal contents, Loss on ignitions were determined in 6.44~15.91% and COD were determined in 1.606~6.859%, organic carbon in 1,077~3.743%. Contents of TP and TN were in the range of 0.083~0.757%, and 0.645~0.926%, respectively.

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A Study on the Potential Energy Reserve Amount of Domestic River Water as Unutilized Energy Resource (국내 하천수 미활용에너지 부존량에 관한 조사연구)

  • Park Il-Hwan;Yoon Hyung-Kee;Park Jun-Taek;Chang Ki-Chang;Lee Young-Soo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.6
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    • pp.521-528
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    • 2005
  • This study has been conducted to investigate the potential energy reserve amount of river water as energy resource with useful temperature difference. Since the river water temperature is one of the primary parameters deciding the potential amount of river water energy reserve amount, the climate change effects on it are critically important. In this study, the heat exchange processes and the inter-relationship between the air temperature and river water temperature have been theoretically analyzed. Based on the present study, the potential energy reserve of river water is calculated to amount to 192,000 Tcal/year. Among this, it is estimated that approximately 2,000 Tcal/year can be directly utilized for heat pump energy sources.