• 수산해양기술연구
• /
• 제60권2호
• /
• pp.194-206
• /
• 2024

This study focuses on analyzing the energy-saving effects of the recirculation aquaculture system using seawater source heat pumps and solar power generation. Based on the thermal load analysis conducted using the transient system simulation tool, the annual energy consumption of the recirculation aquaculture system was analyzed and the energy-saving effects of utilizing the photovoltaic system was evaluated. When analyzing the heat load, the sea areas where the fish farms are located, the type of breeding tank, and the circulation rate of breeding water were taken into consideration. In addition, a method for determining the appropriate capacity for each operation time was examined when applying the energy storage system instead of the existing diesel generator as an emergency power, which is required to maintain the water temperature of breeding water during power outage. The results suggest that, among the four seas considered, Jeju should be estimated to achieve the highest energy-saving performance using the solar power generation, with approximately 45% energy savings.

• 상하수도학회지
• /
• 제27권6호
• /
• pp.771-778
• /
• 2013

Gas hydrate (GH) process is a new desalination technology, where GH is a non- stoichiometric crystalline inclusion compounds formed by water and a number of gas molecules. Seawater GH is produced in a low temperature and a high pressure condition and they are separated from the concentrated seawater. The drawback of the GH process so far is that salt contents contained in its product does not meet the fresh water quality standard. This means that the GH process is not a standalone process for seawater desalination and it needs the help of other desalting process like reverse osmosis (RO). The objective of this study is to investigate the effect of GH process on energy saving for RO process in seawater desalination. The GH product water quality data, which were obtained from a literature, were used as input data for RO process simulation. The simulation results show that the energy saving effect by the GH process is in a range of 68 % to 81 %, which increases as the salt removal efficiency of the GH process increases. Boron (B) and total dissolved solids (TDS) concentrations of the final product of the hybrid process of GH and RO were also investigated through the RO process simulation to find relavant salt rejection efficiency of the GH process. In conclusion, the salt rejection efficiency of the GH process should exceed at least 78% in order to meet the product water quality standards and to increase the energy saving effect.

• 수산해양기술연구
• /
• 제49권1호
• /
• pp.58-66
• /
• 2013

Most of steam power plant in Korea are heating the feed water system to prevent freezing water flowing in the pipe in winter time. The heating system is operated whenever the ambient temperature around the power plant area below 5 degree Centigrade. But this kind of heat supplying system cause a lot of energy consuming. If we think about the method that the temperature of the each pipe is controled by attaching the temperature measuring sensor like RTD sensor and heat is supplied only when the outer surface temperature of the pipe is under 5 degree Centigrade, then we can save a plenty of energy. In this study, the computer program package for simulation is used to compare the energy consumption load of both systems. Energy saving rate is calculated for the location of Youngweol area using the data of weather station in winter season, especially the January' severe weather data is analyzed for comparison. Various convection heat transfer coefficients for the ambient air and the flowing water inside the pipe was used for the accurate calculation. And also the various initial flowing water temperature was used for the system. Steady state analysis is done previously to approximate the result before the simulation. The result shows that the temperature control system using RTD sensor represents the high energy saving effect which is more than 90% of energy saving rate. Even in the severe January weather condition, the energy saving rate is almost 60%.

• 유공압시스템학회논문집
• /
• 제4권3호
• /
• pp.7-12
• /
• 2007

This paper presents an energy saving hydrostatic pressure exchanger for sea water desalination equipment. In a reverse osmosis(RO) system for desalinating sea water, more than 70 percent of the supplied sea water, brines which were impassable through RO membrane are bypassed, resulting in high energy losses. In this paper, a hydrostatic pressure exchanger consisting of an embedded water hydraulic piston motor and a water hydraulic piston pump was proposed and investigated in order to recover the energy of the bypassed brines. The pressurized brines are supplied to the embedded water hydraulic piston motor as power sources and the water hydraulic piston pump is driven by the output torque of the embedded water hydraulic piston motor as well as electric motor. Consequently, the energy of the bypassed brines can be recovered. To examine the electric energy saving characteristics of the hydrostatic pressure exchanger, a simulation model was constructed using commercial software and experiments were conducted. Through the results of simulation and experiment, the feasibility of the electric energy saving effect of the proposed hydrostatic pressure exchanger was investigated.

• 한국산학기술학회논문지
• /
• 제16권1호
• /
• pp.860-867
• /
• 2015

본 논문은 PSO 알고리즘을 이용하여 물 재이용 펌프 시스템의 에너지비용을 최소화 할 수 있는 방법을 제안한다. 1시간 단위의 시간대에서 펌프제어를 위해 계시별 요금제를 기반으로 하여 최적화 구간을 설정하고 PSO알고리즘을 이용하여 에너지 비용을 절감할 수 있도록 펌프동작을 제어한다. 물 재이용 펌프시스템에서 고정된 유량을 출력하는 펌프와 입력전력을 가변할 수 있는 펌프에 대해 TOU 기반에서 에너지 비용을 최대로 줄일 수 있도록 시스템을 동작시킨다. 시뮬레이션을 통해 제안한 에너지 비용 절감 방법이 기존 수위기반의 제어방법보다 비용을 절감할 수 있음을 확인할 수 있다.

• 수산해양기술연구
• /
• 제50권1호
• /
• pp.67-74
• /
• 2014

Most of steam power plants in Korea are using the method of heating the feed water whenever the ambient temperature around the power plant area below $5^{\circ}C$ to prevent freezing water flowing in the pipe in winter time. But this kind of heat supplying system is not useful to save energy. If we take the method that the temperature of the each pipe is controled by direct measure of temperature by attaching sensor on the outside surface of the feed water tubes, then we can expect that a plenty of energy can be saved. In this study, the computer simulation is used to compare the energy consumption loads of both systems. Energy saving rate is calculated for the location of Incheon area in winter season. Four convection heat transfer coefficients for the ambient air and three initial flowing water temperature inside the tube were used. The result shows that the temperature control system using sensor represents more than 95% of energy saving rate in Incheon area. Even in the severe January weather condition, the energy saving rate is almost 75% in two days basis and even 83% in one day basis.

• 한국산학기술학회논문지
• /
• 제13권5호
• /
• pp.2414-2419
• /
• 2012

본 논문에서는 물 재이용 펌프 시스템의 에너지 효율적 운전 방법을 제안한다. 1시간 단위의 시간대에서 최적운전제어를 위해 예측구간 스위칭방법과 선형계획법을 적용하고 에너지 비용은 경부하, 중부하, 그리고 최대부하를 포함한 TOU 요금과 피크요금을 통해 산정하도록 한다. 물 재이용 펌프시스템에서의 최적운전은 TOU 요금과 피크요금을 포함한 에너지 비용을 최대로 줄일 수 있도록 수행한다. 시뮬레이션을 통해 제안한 최적운전방법을 적용하면 많은 전력 에너지 비용의 절감과 전력계통의 안정성 향상을 확인할 수 있다.

• 한국작물학회지
• /
• 제49권6호
• /
• pp.441-446
• /
• 2004

효율적인 물 관리방식 개발의 기초 자료를 얻고자 논의 물 관리 차이가 벼의 생육과 수확량에 미치는 영향을 2002년부터 2003년까지 조사한 결과는 다음과 같다. 1. 물 관리 방법별 벼 생육 및 수량은 DWI는 VSII에 비해 출수기의 초장이 길었고, 경수가 적었으나 유효경 비율은 약간 높았고, VSII의 등숙비율은 다른 물 관리에 비해 $1\%$ 낮아 쌀 수량은 $2.1\%$ 적었으나 통계적 유의성은 없었다. 2. 관개량과 유효강우량 등 총 물 공급량은 DWI에서 777.2mm로 가장 많았고, VS팀에서 527mm로 가장 적어, SII에서는 DWI에 비해 약 $15.9\%$, VSII에서는 $32.2\%$정도의 물 절약효과가 있었다. 3. 절간장은 N3, N4절은 관수심이 깊을수록 길었으며, 간벽두께, 간기중, 줄기직경은 DWI에서 감소하였으나, 좌절중, Pushing resistance는 VSII가 DWI에 비해 매우 높고 도복지수가 낮았다. 4. VSII의 성숙기 근장은 27cm로 DWI보다 깊게 내려갔으며, 토양 표면으로부터 10cm이상 깊이에서는 VSII의 뿌리 발생량이 많았으나, 토양 표면으로부터 10cm까지는 DWI의 뿌리분포가 많았다. 5. 물 관리 차이에 따른 잡초 발생양상은 최고 분얼기에는 VSII가 DWI에 비해 일년생 잡초와 다년생 잡초 모두 본수가 2배 이상 많았으며, 출수기에는 일년생 잡초 본수는 물 관리 차이에 관계없이 비슷하였으나, 다년생 잡초 본수는 VSII에서 DWI에 비해 3배 이상 많았다. 이상의 결과에서 담수심을 얕게 하여 용수를 절약하여도 관행 심수 관개 방식에 비해 벼 생육 및 수량에는 차이가 없었고, 오히려 내도복성을 향상시킬 수 있었으므로 최적 용수 공급량 산출의 기초 자료로 활용할 수 있었다.

• 한국태양에너지학회 논문집
• /
• 제34권2호
• /
• pp.53-59
• /
• 2014

Ice Rink is energy intensive building type. Concern of energy saving from buildings is one of very important issues nowadays. New and renewable energy sources for buildings are especially important when we concern about energy supply for buildings. Among new and renewable energy sources, use of seawater for heating and cooling is an emerging issue for energy conscious building design. The options of energy use from sea water heat sources are using deep sea water for direct cooling with heat exchange facilities, and using surface layer water with heat pump systems. In this study, energy consumptions for an Ice Rink building are analyzed according to the heat sources of air-conditioning systems; existing system and sea water heat source system, in a coastal city, Kangnung. The location of the city Kangnung is good for using both deep sea water which is constant temperature throughout the year less than $2^{\circ}C$, and surface layer water which should be accompanied with heat pump systems. The result shows that using sea water from 200m and 30m under sea lever can save annual energy consumption about 33% of original system and about 10% of that using seawater from 0m depth. Annual energy consumption is similar between the systems with seawater from 200m and 30m. Although the amount of energy saving in summer of the system with 200m depth is higher than that with 30m depth, the requirement of energy in winter of the system with 200m depth is bigger than that with 30m depth.

• 환경영향평가
• /
• 제22권6호
• /
• pp.581-589
• /
• 2013

Generally, Sewage Treatment Plants(STPs) are complexes systems in which a range of physical, chemical and biological processes occur. However, their performance strongly depends on the know-how acquired by the field-engineer. Recently, in order to solve this situations, various operation and management technologies based on the Instrumentation, Control and Automation(ICA) have been developed. As a economies-environmental affect point of view, this study was for the performance evaluation and assessment of results from the Smart Operation System(SOS) in full-scale STP. The SOS in STP consisted of the process monitoring module, including real-time influent prediction and effluent simulation, and the Smart Air Control(SAC) module. According to the results from field test for 2 years, the results of economical evaluation, amount of benefits and cost saving by the SOS have shown to be much higher than that of traditional operation. Nevertheless, the removal load(kg/yr) of BOD 13.3 %, COD 28.2 %, TN 44.4 % and TP 20.8 % were increased, respectively. Remarkable improvement of removal load could be achieved after the SOS was adapted. It was concerned that the SOS offer a user friendly functionalities and cost saving needed by the field-engineers. In addition, it was expected that the results of this study would supply helpful information for design and cost saving for the SOS in full-scale STP.