• Proceedings of the SAREK Conference
• /
• 2006.06a
• /
• pp.215-220
• /
• 2006

Along with socioeconomic development and improving standard of living, the heat demand for heating and cooling in residential and commercial sectors is expected to expand rapidly, reaching over 43 million TOE by 2010 in Korea(about 80% increase compared with that in 1995). Since most of this heat demand is loop temperature below $60^{\circ}C$, the utilization of 'unused energy' is surely one of very effective measures to both environmental preservation and energy conservation. 'Unused energy' in this paper is implicated as 'temperature differential energy' available from treated sewage water, useful and abundant heat source for heat pump(cooler in summer and warmer in winter than outside air). An analysis was carried out to estimate the energy potential of treated sewage water for heat pump heat source. Some analysis were taken to study the characteristics of a heat pump system using the treated sewage water as heat source.

• Journal of the Korean Solar Energy Society
• /
• v.31 no.5
• /
• pp.126-133
• /
• 2011

The current world wide interest in environmental issues has moved from energy conservation to $CO_2$emission reduction. Recently, according to the increase in demand for water resources, insufficient potable water circumstance is supposed, unless there are corresponding in crease in water conservation and water recycling. This study has attempted to analyze $CO_2$emission reduction by water saving strategies like installation water saving devices, rain water harvesting and grey water system. To do this, this research investigates applicable water conservative strategies by literature review and calculated total water saving. The results show that (1) firstly, the water usage and $CO_2$ emission could be reduced up to 44%, (2) $CO_2$ emission reduction by water saving devices and rainwater harvesting system is about 47.7%, and (3) water usage and $CO_2$ emission reduction by grey water system is about 66%. In the future, this paper will be utilized for water management from the early design stage to maintenance stage of water glutton building.

• Journal of Korea Water Resources Association
• /
• v.55 no.1
• /
• pp.11-21
• /
• 2022

The COVID-19 started to spread at early 2020 in South Korea and has been threatening our life in many aspects. Countermeasures such as social distancing to prevent COVID-19 spread have brought many changes in our society an human life. In this study, as a part of the COVID-19 pandemic management, drinking water usage change is analyzed to evaluate potential risks on water supply service. We collected hourly water use data of residential area in S city, which is a mid-size city in South Korea, before and after the COVID-19 pandemic. The collected data were analyzed to reveal the changes in total water consumption, water usage weight, and hourly water-demand pattern caused by the COVID-19 pandemic. The case study revealed the noticeable changes in water consumption caused by the COVID-19 pandemic and required more secured and adaptive operation of drinking water system under the pandemic situation caused by infectious disease.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2002.05a
• /
• pp.267-272
• /
• 2002

The electric heat pump requiring HCFCs as a refrigerant has been for most residential air-conditioners in Korea. They cause a surge up electric power demand during summer. Moreover, the use of HCFCs and HFCs causes a serious problem to the global environment such as global warming and ozone layer destruction. An absorption chiller and heater could solve such problems. It was built and tested for analyzing the performance of the absorption chiller/heater. Experiment was done with a 1.5RT household absorption chiller and heater. It was experimented that the cooling capacity, gas capacity, COP were researched by the temperature of cooling water. The change of the cooling water temperature have effect the temperature(or pressure) of the parts on absorption chiller The result of the change of the cooling water temperature have the effects of the absorption chillers. This data will help to operate the household absorption chiller and heater.

• Korean Journal of Ecology and Environment
• /
• v.40 no.1
• /
• pp.31-39
• /
• 2007

Monitoring data of 48 agricultural irrigation reservoirs from 1999 to 2004 was analyzed for water quality characteristics including biochemical oxygen demand $(BOD_5)$, chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and chl-${\alpha}$. Land uses of the watersheds associated with these reservoirs were determined for residential, forest, upland, paddy and miscellaneous, and regressed against water quality characteristics. Correlation analysis showed that forest land use was negatively correlated with all the water quality characteristics implying it's beneficial effects in water quality perspectives. Other land uses including residential, upland, and paddy generally illustrated positive correlation with water quality characteristics, which indicates most human activities of the watershed could degrade water quality of the receiving water bodies. Paddy land use partially contributed to the water quality degradation in contrast to the previous studies. It might be attributed to the relatively clean water quality of the study area, where even slight pollutant loading could degrade sensitively water quality. Further investigation is recommended for the effect of proximity as well as land use portions on the water quality of receiving water body.

• Journal of the Korean Chemical Society
• /
• v.14 no.3
• /
• pp.243-256
• /
• 1970

Halogen contents of the river water of Seoul city and of municipal reservoirs were investigated from June in 1969 to February in 1970. Bromine contents were ranging from 0.006 to 0.048 mg/1 of the reservoirs, 0.021 to 0.048 mg/1 of Han River, 0.051 to 0.540 mg/1 of rivers running through residential areas and 0.083 to 0.920 mg/1 of rivers running through industrial areas. Bromine contents increased as the river water became contaminated. Most of Br/Cl of Han River and the reservoirs were higher than $3.4{\times}10^{-3}$ of sea water. Bromine contents at 17 different places were the largest in November. The contents of chlorine, iodine and COD (chemical oxygen demand) were nearly correlated with that of bromine. Bromine contents of the river waters in Seoul chiefly originated from consumption of domestic and industrial salt.

• Journal of Korean Society of Water and Wastewater
• /
• v.35 no.6
• /
• pp.497-505
• /
• 2021

This paper investigates the current status of Jeju special self-governing province (JSSGP)'s water infrastructure and recommends directions for improvement. JSSGP relies on groundwater for most of its water resources. Recently, water usage has been steadily increasing due to the increase of residents and tourists while the quality of groundwater has been steadily worsening. Deterioration in water quality of groundwater can be seen through the increase in concentration of nitrate nitrogen and microorganisms. To overcome such problems, water consumption must be reduced by water demand management in all fields including residential and agricultural water use. The quality of water resources should be preserved through the management of pollutants. For efficient management of water resources, great efforts should be made to reduce the leakage rates in household and agricultural water, which is currently at the highest level in the country. Furthermore, diversification of water intake sources other than groundwater is needed, especially for agricultural water supply. For water and sewerage facilities, compliance with drinking water quality standards and discharge water quality standards must be achieved through the optimization of operation management. This process requires recruiting professionals, improving existing workers' expertise, and improving facilities.

• Journal of Electrical Engineering and Technology
• /
• v.13 no.1
• /
• pp.513-520
• /
• 2018

Since Paris Climate Change Conference in 2015, many policies to reduce the emission of greenhouse gas have been accelerating, which are mainly related to renewable energy resources and micro-grid. Presently, the technology development and demonstration projects are mostly focused on diversifying the power resources by adding wind turbine, photo-voltaic and battery storage system in the island-type small micro-grid. It is expected that the large-scaled micro-grid projects based on the regional district and town/complex city, e.g. the block type micro-grid project in Daegu national industrial complex will proceed in the near future. In this case, the economic cost or the carbon emission can be optimized by the efficient operation of energy mix and the appropriate construction of electric and heat supplying facilities such as cogeneration, renewable energy resources, BESS, thermal storage and the existing heat and electricity supplying networks. However, when planning a large residential town or city, the concrete plan of the energy infrastructure has not been established until the construction plan stage and provided by the individual energy suppliers of water, heat, electricity and gas. So, it is difficult to build the efficient energy portfolio considering the characteristics of town or city. This paper introduces an energy mix optimization(EMO) method to determine the optimal capacity of thermal and electric resources which can be applied in the design stage of the real large-scaled residential town or city, and examines the feasibility of the proposed method by applying the real heat and electricity demand data of large-scale residential towns with thousands of households and by comparing the result of HOMER simulation developed by National Renewable Energy Laboratory(NREL).

• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.269-274
• /
• 2006

전국 176개 지자체의 5개년 자료를 이용하여 생활용수의 가격탄력성을 분석 하였다. 기존의 연구에 비해 상대적으로 낮은 결과가 도출되었다. 수도요금 10% 인상에 수요량은 0.5% 감소하는 것으로 나타났다. 따라서 수도요금 인상을 통해 수요량 절감을 달성할 수 있을지 여부는 불투명해 보인다. 따라서 탄력성이 있다는 결론이 자칫 수돗물 값을 몇 % 인상시키면 댐 몇 개가 필요 없다는 식의 논리는 위험한 생각이다. 물 값의 역할은 물수요 절감뿐 아니라 향후 공급에 요구되는 비용의 회복과 시설의 효과적인 유지 및 관리비용임을 명심해야 한다. 국가 정책의 수립을 위해서는 정상적인 가격체계의 도입과 함께 보다 객관적인 연구가 요구된다.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2006.05a
• /
• pp.275-280
• /
• 2006

7대 특.광역시의 시민 1,000명을 대상으로 생활용수의 수요패턴과 서비스 개선에 대한 지불의사를 추정하였다. 생활수준의 향상으로 정수기나 먹는 샘물을 이용하는 가구가 증가하고 있다. 수도요금에 대해서는 일반적으로 큰 부담을 갖고 있지 않으며 요금 상승시 강한 절수 의지를 보였다. 수돗물이 정수기나 먹는 샘물처럼 안전하다면 소비자는 현재보다 약 16%$(153/m^3)$의 수도요금을 추가적으로 지불할 의사가 있는 것으로 추정되었다. 최근 상수도 수요패턴의 변화는 정부가 더 이상 일방적으로 정책을 수립하는 것이 아니라 수요자의 소비 행태 등의 철저한 분석결과를 정책에 반영함으로써 보다 효율적인 상수도 정책이 수립될 수 있을 것이다.