• 제목/요약/키워드: Energy Systems

검색결과 9,199건 처리시간 0.033초

Evaluation Algorithms for Multiple Function of Dispersed Electrical Energy Storage Systems

  • Son, Joon-ho;Choi, Sung-Sik;Rho, Dae-Seok
    • Journal of Electrical Engineering and Technology
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    • 제13권6호
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    • pp.2245-2253
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    • 2018
  • With the increase of electrical consumption and the unbalance of power demand and supply, power reserve rate is getting smaller and also the reliability of the power supply is getting deteriorated. Under this circumstance, the electrical energy storage (EES) System is considered as one of essential countermeasure for demand side management. This paper proposes efficient evaluation algorithms of multiple functions for EES systems, especially the secondary battery energy storage systems, in the case where they are interconnected with the power distribution systems. It is important to perform the economic evaluation for the new energy storage systems in a quantitative manner, because they are very costly right now. In this paper, the multiple functions of EES systems such as load levelling, effective utilization of power distribution systems and uninterruptible power supply are classified, and then the quantitative evaluation methods for their functions are proposed. From the case studies, it is verified that EES systems installed at distribution systems in a dispersed manner have multiple functions involved with direct and indirect benefits and also they can be expected to introduce to distribution systems with respects to economical point of view.

Comparison of theoretical and machine learning models to estimate gamma ray source positions using plastic scintillating optical fiber detector

  • Kim, Jinhong;Kim, Seunghyeon;Song, Siwon;Park, Jae Hyung;Kim, Jin Ho;Lim, Taeseob;Pyeon, Cheol Ho;Lee, Bongsoo
    • Nuclear Engineering and Technology
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    • 제53권10호
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    • pp.3431-3437
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    • 2021
  • In this study, one-dimensional gamma ray source positions are estimated using a plastic scintillating optical fiber, two photon counters and via data processing with a machine learning algorithm. A nonlinear regression algorithm is used to construct a machine learning model for the position estimation of radioactive sources. The position estimation results of radioactive sources using machine learning are compared with the theoretical position estimation results based on the same measured data. Various tests at the source positions are conducted to determine the improvement in the accuracy of source position estimation. In addition, an evaluation is performed to compare the change in accuracy when varying the number of training datasets. The proposed one-dimensional gamma ray source position estimation system with plastic scintillating fiber using machine learning algorithm can be used as radioactive leakage scanners at disposal sites.

기계적 합금화 투입에너지 계산에 의한 이원합금계의 상변태 시간 예측 (Prediction the Phase Transformation Time of Binary Alloy System by calculating the Input Energy of Mechanical Alloying)

  • 박동규;안인섭
    • 한국분말재료학회지
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    • 제26권2호
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    • pp.107-111
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    • 2019
  • The activation energy to create a phase transformation or for the reaction to move to the next stage in the milling process can be calculated from the slop of the DSC plot, obtained at the various heating rates for mechanically activated Al-Ni alloy systems by using Kissinger's equation. The mechanically activated material has been called "the driven material" as it creates new phases or intermetallic compounds of AlNi in Al-Ni alloy systems. The reaction time for phase transformation by milling can be calculated using the activation energy obtained from the above mentioned method and from the real required energy. The real required energy (activation energy) could be calculated by subtracting the loss energy from the total input energy (calculated input energy from electric motor). The loss energy and real required energy divided by the reaction time are considered the "metabolic energy" and "the effective input energy", respectively. The milling time for phase transformation at other Al-Co alloy systems from the calculated data of Al-Ni systems can be predicted accordingly.

Analysis of Induction Motor-pump System Supplied by a Photovoltaic Generator for Agricultural Irrigation in Southeastern Anatolian Region of Turkey

  • Gumus, Bilal;Yakut, Yurdagul Bentesen
    • Journal of Electrical Engineering and Technology
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    • 제10권3호
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    • pp.777-785
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    • 2015
  • In agricultural systems, significant amount of energy is consumed during irrigation periods. Therefore operating irrigation systems with electrical energy produced by solar energy is very important. It is be possible to operate irrigation systems which have small-pump power like drip-irrigation with electrical energy produced by solar energy. Electrical energy produced by photovoltaic panels can vary from the estimated value due to environmental factors. Consequently analysis of a real system's performance is important. Thus, more correct projections can be made for the systems which will be designed. In this study, induction motor-pump mechanism for drip-irrigation system is operated with photovoltaic generator. Solar energy capacity of the established system is evaluated by measurements in irrigation periods. By means of simulations, power values produced by system and gained from the actual system are compared. Additionally the performance of induction motor is analyzed with the help of the driver system that increases the efficiency and controls the motor. As regards of results, design values of the drip-irrigation systems fed with solar energy in Southeastern Anatolian Regions of Turkey are obtained. Performance results of induction motor controlled with driver are also provided.

입구 습도 변화에 따른 관성 충돌 방식의 액적 분리장치의 수분제거효율 변화 (Removal Efficiency of Water Contents using Inertial Impaction Separator with Change in Relative Humidity)

  • 송동근;이신영;홍원석;신완호;김규진;김한석
    • 한국입자에어로졸학회지
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    • 제9권4호
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    • pp.247-252
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    • 2013
  • Removal of water contents in a gas is needed in industrial field of gas processing related on energy production/conversion, and environmental treatment. Inertial separators are economic devices for separating droplets from the gas stream. For design and incorporation of inertial pre-treatment separator, characteristics of removal of water contents with various operation conditions are needed. In this study, removal efficiency of water droplets at various flowrates (5-14 SCMM) and relative humidity (R.H.) conditions (40%, and 90%) has been investigated. At low R.H. condition, the removal characteristic is similar to the removal of solid particles. But, droplet growth resulting from the condensation of water vapor at high R.H. condition, is significant and it made increase in removal efficiency of droplet phase of water contents. For rapid removal of water contents, an effective method to enhancing condensation growth of water droplets is highly needed.

블라인드 도입과 창면적비에 따른 표준건축물의 에너지 수요 저감에 대한 시뮬레이션 연구 (A Study on Simulation for Decreasing Energy Demand According to Window-to-Wall Ratio and Installation Blind System in Building)

  • 강석민;이태규;김정욱
    • 한국건축친환경설비학회 논문집
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    • 제12권6호
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    • pp.531-542
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    • 2018
  • Building energy demands have highly risen in modern society; thus, It is necessary to reduce building energy demands especially commercial buildings adopting a curtain wall architecture. Curtain wall architectures have a high ratio of windows which is a vulnerable in heat insulations as cladding. In order to complement insulation performance of windows in these buildings, there are various methods adopted often such as installing blinds, wing wall and films. There are two suggestions of this paper. 1) WWR (Window-to-Wall Ratio) makes a impaction of energy demands in buildings. 2) Another one is an efficiency of blind systems which are installed in buildings in order to reduce cooling demands. It is also critical to make fundamental model for low-energy building construction by processing a lot of simulation As a result by this study, 1) an external blind system is more useful for reducing cooling energy demands rather than an internal blind system. 2) Buildings which have a large window require more amount of cooling demands. In case of WWR 45%, it needs more cooling energy rather than WWR 15% model's 3) Adopting blind system would reduce energy demands. WWR 45% model with external blind systems reduces about 4% of cooling energy demands compared to same model without any blind systems.4) it is necessary to study an efficiency of blind systems combined with renewable energy and it will be possible to reduce more energy demand in building significantly.

에너지원별 냉방기기 표본설계 (Sample design of cooling systems for each energy source)

  • 강용태;이덕주;김의경;전호철
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.202-208
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    • 2008
  • The objectives of this study are to collect the population of each cooling system for gas and electric driven systems, and propose sample design for five cooling systems; ice storage systems, system air-conditioning system, turbo system as electric driven cooling systems, and absorption system and Gas driven Heat Pump (GHP) system as gas driven cooling systems. The sample design are carried out based on types of business, capacity, installation region and year. This study proposes criterion of the sample design for cooling systems for each energy source.

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병아리 사료에서 일반대사에너지와 순대사에너지의 이론적 정확성 비교를 위한 실험 (Feeding Trials to Compare Theoretical Accuracy between Apparent and True Metabolizable Energy Systems in Chick Diets)

  • 지규만
    • Journal of Nutrition and Health
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    • 제25권7호
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    • pp.543-554
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    • 1992
  • True metabolizable energy(TME) is believed a better indicator for animal performance than apparent metabolizable energy (AME) for excluding the endogenous energy losses from excreta, However few researches have been conducted to compare superiority of any energy systems through practical animal feeding tests. Present study was to compare the energy systems in young chicks in terms of predictability of energy intake for the birds performances including body energy retention and of methodological accuracy by evaluating reproducibility and additi-vity of energy values of feed ingredients and compound diets. Five ingredients such as yellow corn wheat soybean meal fish meal and wheat bran were measured for their various biological energy values. in the first feeding trial chicks were restric-ted-fed the basal diet at 80, 60 and 40% on weight basis of the amount of feed ingested by chicks fed ad libitum the same diet. chicks in the second trial were also restricted-fed diets at levels of 80, 70, 60 and 50% on energy basis of the amount consumed by the basak duet group fed ad libitum The diets in the latter trial were however composed of differeent formulations from the basal diet. One-week-old Single Comb White Leghorn male chicks were individually alloted in a cage on 10 cages/treatment basis and fed the diets for 14 days. Individual carcass energy was measured after the feeding trials. Coefficients of variation of energy measurements were lesser for nitrogen-corrected AME and TME(AMEn & TMEn respectively) than AME and TME values suggesting taht reprodu-cibility of energy determinations by former systems could be better than the latters. The coeffi-cients for AME and TME were almkost of the same values. Additivity obtained by the rations between the calculated values and catual measurements appeared quite satisfactory for all the energy systems. Those of AME and TME however were relatively better than the other systems. Regression coefficient ${r}^2$ between energy intake by various systems and chick performances appeared higher for TME, AMEn and TMEn than AME implying that the former systems could provide better predictability for body weight gain and energy retention than the AME. The ${r}^2$ values for TME and AMEn particularly for body weight gain were on the average 0.967 and 0.960 respectively. In conclusion TME or AMEn can be recommended as choice for dietary energy system in terms of performance predictability of the birds and of procedural convenience for the measurements.

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