• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2641-2646
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• 2009

The more growing on home automation system at automatic control, the more efficiency required for energy consumption and for recycling energy in near future. Heating is essential in general apartment. Heating method is two types in apartment. One uses electricity, and other one uses warm water. If use electricity, is not efficient by rise of electric charges. But, It can reduce much in expense aspect, if use warm water. When use warm water, temperature of warm water is not equal from all pipe parts. Therefore, indoor tempera can be unequal with set point. Solution of these problems is as following. Temperature sensor in warm water attach pipe. The measured temperature transmits by real time. Temperature of warm water controls in receiver side. In this paper, we propose an automatic temperature transmission system for the heating pipe at home, that is a low-power based, and supply the energy source from a small AC motor resided in bottom cement mortal. The proposed system is used in power mechanism from a collision process of water-jet using propeller water-difference and also designed a CPU module by Atmega8 at ATMEL co., Inc. and a communication module by CC1020 at Chipcon co., Inc.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.56-61
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• 2009

Paradigm depending only on fossil fuel for building heat source is rapidly changing. Accelerating the change, as it has been known, is obligation for reducing green house gas coming from use of fossil fuel, i.e. reaction to United Nations Framework Convention on Climate Change. In addition, factors such as high oil price, unstable supply, weapon of petroleum and oil peak, by replacing fossil fuel, contributes to advance of environmental friendly renewable energy which can be continuously reusable. Therefore, current new energy policies, beyond enhancing effectiveness of heat using equipments, are to make best efforts for national competitiveness. Our country supports 11 areas for new renewable energy including sun light, solar heat and wind power. Among those areas, ocean thermal energy specifies tidal power generation using tide of sea, wave and temperature differences, wave power generation and thermal power generation. But heat use of heat source from sea water itself has been excluded as non-utilized energy. In the future, sea water heat source which has not been used so far will be required to be specified as new renewable energy. This research is to survey local heating system in Europe using sea water, central solar heating plants, seasonal thermal energy store and to analyze large scale central solar heating plants in German. Seasonal thermal energy store necessarily need to be equipped with large scale thermal energy store. Currently operating central solar heating system is a effective method which significantly enhances sharing rate of solar heat in a way that stores excessive heat generating in summer and then replenish insufficient heat for winter. Construction cost for this system is primarily dependent on large scale seasonal heat store and this high priced heat store merely plays its role once per year. Since our country is faced with 3 directional sea, active research and development for using sea water heat as cooling and heating heat source is required for seashore villages and building units. This research suggests how to utilize new energy in a way that stores cooling heat of sea water into seasonal thermal energy store when temperature of sea water is its lowest temperature in February based on West Sea and then uses it as cooling heat source when cooling is necessary. Since this method utilizes seasonal thermal energy store from existing central solar heating plant for heating and cooling purpose respectively twice per year maximizing energy efficiency by achieving 2 seasonal thermal energy store, active research and development is necessarily required for the future.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.67-76
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• 2018

This study reviews three eco-friendly energy towns with hybrid thermal energy supply systems and borehole thermal energy storage (BTES) in Canada and Denmark. The district heating and cooling systems were designed by using multi-source energy for the higher efficiency and reliability as well as environment. ADEU (Alexandra District Energy Utility) located at the developing area in the city of Richmond, Canada was designed to supply district energy with the installation of 726 borehole heat exchangers (BHEs) and a backup boiler using natural gas. DLSC (Drake Landing Solar Community) located in the town of Okotoks, Canada is a district system to store solar thermal energy underground during the summer season by seasonal BTES with 144 BHEs. Brædstrup Solpark district heating system located in Denmark has been conducted energy supply from multiple energy sources of solar thermal, heat pump, boiler plants and seasonal BTES with 48 BHEs. These systems are designed based on social and economic benefits as well as nature-friendly living space according to the city based energy perspective. Each system has the energy center which distribute the stored thermal energy to each house for heating during the winter season. The BHE depth and ground thermal storage volume are designed by the heating and cooling load as well as the condition of ground water flow and thermophysical properties of the ground. These systems have been proved the reliance and economic benefits by providing consistent energy supply with competitive energy price for many years. In addition, the several expansions of the service area in ADEU and Brædstrup Solpark have been processed based on energy supply master plan. In order to implement this kind of project in our country, the regulation and policy support of government or related federal organization are required. As well as the government have to make a energy management agency associated with long-term supply energy plan.

• Ocean and Polar Research
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• v.45 no.3
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• pp.141-153
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• 2023

Biological pump processes generated by diatom production in the surface water of the Southern Ocean play an important role in exchanging CO₂ gas between the atmosphere and ocean. In this study, the biogenic opal content of the sediments was measured to elucidate the variation in the primary production of diatoms in the surface water of the Southern Ocean since the last glacial period. A piston core (COR-1bPC) was collected from the Conrad Rise, which is located in the Indian sector of the Southern Ocean. The sediments were mainly composed of siliceous ooze, and sediment lightness increased and magnetic susceptibility decreased in an upward direction. The biogenic opal content was low (38.9%) during the last glacial period and high (73.4%) during the Holocene, showing a similar variation to that of Antarctic ice core ΔT and CO₂ concentration. In addition, the variation of biogenic opal content in core COR-1bPC is consistent with previous results reported in the Antarctic Zone, south of the Antarctic Polar Front, in the Southern Ocean. The glacial-interglacial biogenic opal production was influenced by the extent of sea ice coverage and degree of water column stability. During the last glacial period, the diatom production was reduced due to the penetration of light being limited in the euphotic zone by the extended sea ice coverage caused by the lowered seawater temperature. In addition, the formation of a strong thermocline in more extensive areas of sea ice coverage led to stronger water column stability, resulting in reduced diatom production due to the reduction in the supply of nutrient-rich subsurface water caused by a decrease in upwelling intensity. Under such environmental circumstances, diatom productivity decreased in the Antarctic Zone during the last glacial period, but the biogenic opal content increased rapidly under warming conditions with the onset of deglaciation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.56-66
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• 2021

In this study, a waste heat recovery system was devised and the performances of components incorporated to recover the heat generated during the processing of aerobic liquid-composting in a livestock manure treatment facility were analyzed. In addition, the availability of recovered heat was confirmed. The heat generated by liquid fermentation in the livestock manure treatment facility was also checked. Experimental temperatures were set at 35, 40, and 45 ℃ based on considerations of the uniformity of aerobic liquid-composting fermentation tank temperature and its operating range (34.5 ~ 43.9 ℃). Recovered heat energies from the combined heat exchanger, which consisted of PE and STS pipes, were 53.5, 65.6, 74.4 MJ/h, The heat pump of capacity 5 RT was heated at 95.6, 96.1, 98.9 MJ/h and the heating COPs of the pump were 4.53, 4.62, and 4.65, respectively. The maximum hot water production capacity of the heat exchanger assuming a fermentation tank temperature of 45 ℃ confirmed an energy supply of 56 360 kcal/day. The heating capacity of the FCU linked to the heat storage tank was 20.8 MJ/h, and the energy utilization efficiency was 96.1%. When livestock manure was dried using the FCU, it was confirmed that the initial function rate was reduced by 50.5 to 45.8 % after drying.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.3
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• pp.43-48
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• 2019

Since the revision of the Rationalization of Energy Use Law, the spread of new and renewable energy in buildings has been promoted. In addition, the production of electric power and thermal energy is an important issue in the change of energy paradigm centered on the use of distributed energy. Among them, geothermal energy is attracting attention as a high-performance energy-saving technology capable of coping with heating / cooling and hot water load by utilizing the constant temperature zone of the earth. However, there is a disadvantage that the initial investment cost is high as a method of calculating the capacity of a geothermal facility by calculating the maximum load. The disadvantages of these disadvantages are that the geothermal energy supply is getting stagnant and the design of the geothermal system needs to be supplemented. In this study, optimization design of geothermal system was carried out using optimization tool. As a result of the optimization, the ground heat exchanger decreased by 30.8%, the capacity of the heat pump decreased by 7.7%, and the capacity of the heat storage tank decreased by about 40%. The simulation was performed by applying the optimized value to the program and confirmed that it corresponds to the load of the building. We also confirmed that all of the constraints used in the optimization design were satisfied. The initial investment cost of the optimized geothermal system is about 18.6% lower than the initial investment cost.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.607-613
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• 2006

For the reasonable use of low grade-shallow geothermal energy by Standing Column Well(SCW) system, the basic requirements are depth-wise increase of earth temperature like $2^{\circ}C$ per every 100m depth, sufficient amount of groundwater production being about 10 to 30% of the design flow rate of GSHP with good water quality and moderate temperature, and non-collapsing of borehole wall during reinjection of circulating water into the SCW. A closed loop type-vertical ground heat exchanger(GHEX) with $100{\sim}150m$ deep can supply geothermal energy of 2 to 3 RT but a SCW with $400{\sim}500m$ deep can provide $30{\sim}40RT$ being equivalent to 10 to 15 numbers of GHEX as well requires smaller space. Being considered as an alternative of vertical GHEX, many numbers of SCW have been widely constructed in whole country without any account for site specific hydrogeologic and geothermal characteristics. When those are designed and constructed under the base of insufficient knowledges of hydrgeothermal properties of the relevant specific site as our current situations, a bad reputation will be created and it will hamper a rational utilization of geothermal energy using SCW in the near future. This paper is prepared for providing a guideline of SCW design comportable to our hydrogeothermal system.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.369-374
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• 2015

This study analyzed analyzes the energy performance of six houses in Daejeon completed which were built in 2011. Observed The observed houses, which were all designed and constructed inof the same size and structure, are were highly insulated with triple Low-E coating windows; the insulation level of the walls is was $0.13W/m^2K$ and that of the roof is was $0.10W/m^2K$. As electric houses, all of the energy supplied to the houses, including for cooking, is was supplied by electricity. A and 3~4 kWp of photovoltaic system and a 3~5 kW of ground source heat pump (GSHP) were installed in each house tofor providing provide space heating/and cooling and hot water are installed. We constructed a Web-based remote monitoring system in order to understand energy consumption and the dynamic behavior of the energy system. T, and the results of our metering data analysis of 2013 are as follows. First, the annual residential energy consumption is was 4,400 kWh (${\sigma}=1,209$) and GSHP energy consumption is was 5,182 kWh (${\sigma}=1,164$). Second, residential energy consumption ranked highest in average energy usage, with at 45% of the total, followed by heating with at 30%, hot water supply with at 17% and cooling with at 6%. Third, the average energy independence rate is was 51.8%, the GFA (Gross gross floor area) criteria average energy consumption unit is was $48.7kWh/m^2yr$ (${\sigma}=10.1$), and the net energy consumption unit (except the energy yield of the PV systems) is was $24.7kWh/m^2yr$ (${\sigma}=8.8$).

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.118-118
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• 2017

지구 온난화에 따른 환경변화로 인하여 최근 10년('02~'11)간 여름의 일수는 4일, 겨울 일수는 16일 각각 증가하였다. 현재 육계사 내의 고밀도 밀집사육으로 인하여 고온스트레스로 하절기 육계의 폐사율이 증가하고 있는 실정이다. 2016년 폭염으로 닭 406.1천수, 오리 15.7천수, 메추리 70천수, 돼지 8천수가 폐사하였다. 이에 혹서기 가축이 약430만수가 폐사하였으며 피해 보상금액 128억원 소요되었다. 본 연구에서는 하절기 고온스트레스 경감과 폐사율 저감을 위해 계사 냉난방 공조와 냉온 음용수 급수를 병행할 수 있는 고효율 환경 개선 시스템을 개발하여 고온스트레스 저감 및 생산성 향상에 목적이 있다. 계사 냉난방 공조 및 냉온음용수 급수 병행 시스템 설계요인을 분석하고 냉난방 공조부하, 냉온수 생산 부하를 고려한 시스템 용량 산정하고 히트펌프, 축열조, 냉난방 및 냉온수 분배장치 등 구성요소로서 공조 및 냉온음용수 급수시스템을 설치하였다. 시스템 용량은 공기-물 히트펌프(10kW,1대), 축열조(10톤), 음용수조(2톤), 열교환기(열교환량,5만kcal/h), 물순환펌프(250W,2대) 및 팬코일유닛(1만kcal/h,4대)으로 시스템 모니터링 및 제어 시스템 개발하여 계사 내 환경, 시스템 성능에 대한 실시간 모니터링을 통하여 저장하였다. 조사항목으로 위치별 온습도, 체중, 사료섭취량, 페사율 등을 조사 분석하였다. 연구결과 계사의 내부온도는 시험구에서는 평균 $25.3^{\circ}C$를 나타내었고 대조구에서는 평균 $28.1^{\circ}C$로서 $2.8^{\circ}C$ 높게 나타났으나 상대습도는 시험구 76.2%, 대조구 75.0%로 큰 차이가 없었다. 냉수급여에 따른 계사 높이별 내부온도는 상하의 온도차가 $4.5^{\circ}C$로 크게 차이가 났다. 육계의 음수량은 혹서기 냉수를 급여한 시험구에서 일일 23.2L, 대조구에서는 21.5L를 섭취하였다. 일일 사료섭취량은 냉수를 급여한 시험구에서 937g, 대조구에서는 725g을 섭취하였다. 사료섭취량은 냉수를 급여한 시험구가 212g 많이 섭취하였으며 사료요구율은 시험구는 1.86, 대조구는 1.91로서 시험구가 낮게 나타났다. 체중은 냉수를 급여한 시험구가 359g 많았으며 증체량은 냉수를 급여한 시험구에서 495g, 대조구에서는 392g으로 나타났다. 폐사율은 냉수를 급여한 시험구에서 84%가 폐사율을 줄일 수 있었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.453-458
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• 2016

While the design of weirs requires a scour-considered strategy, research on the analysis of the effectiveness of hydraulic energy dissipaters and design criteria are scarce due to the limited experimental facilities and restraint in the experiment conduction period. The study analyzed the scour dissipation effect of multidirectional dissipaters to improve the scour problems of a weir downstream and suggests design criteria to minimize scour. A hydraulic model experiment was conducted for Nakdong River Hapcheon-Changnyeong Weir and a model in 1/25 of horizontal accumulation and 1/25 of vertical accumulation was produced. The experimental equipment was classified into channels and a flow rate supply and an underwater pump were installed to enable flow at a maximum of 2.0 m3/s. The experimental inflow was 1.3 m3/s, the upstream water level was 0.36 m, downstream water level was 0.24 m, and a cylinder wooden baffle, a dissipater, with a diameter of 0.05 m was made. A 3D scanner was also used for an accurate scour depth comparison for a length change of the baffle before and after installing the baffle. When the baffle was arranged in the shape of a V, the depth of scour decreased by 36% while the scour length decreased by 49% due to flow reduction compared to that before installing the baffle.