• 제목/요약/키워드: energy based design

검색결과 3,513건 처리시간 0.036초

Conceptual Design of Sandglass-like Separator for Immobilized Anionic Radionuclides Using Particle Tracking Based on Computational Fluid Dynamics

  • Park, Tae-Jin;Choi, Young-Chul;Ham, Jiwoong
    • 방사성폐기물학회지
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    • 제18권3호
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    • pp.363-372
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    • 2020
  • Anionic radionuclides pose one of the highest risks to the long-term safety assessments of disposal repositories. Therefore, techniques to immobilize and separate such anionic radionuclides are of crucial importance from the viewpoints of safety and waste volume reduction. The main objective of this study is to design a separator with minimum pressure disturbance, based on the concept of a conventional cyclone separator. We hypothesize that the anionic radionuclides can be immobilized onto a nanomaterial-based substrate and that the particles generated in the process can flow via water. These particles are denser than water; hence, they can be trapped within the cyclone-type separator because of its design. We conducted particle tracking analysis using computational fluid dynamics (CFD) for the conventional cyclone separator and studied the effects due to the morphology of the separator. The proposed sandglass-like design of the separator shows promising results (i.e., only one out of 10,000 particles escaped to the outlet from the separation zone). To validate the design, we manufactured a laboratory-scale prototype separator and tested it for iron particles; the efficiency was ca. 99%. Furthermore, using an additional magnetic effect with the separator, we could effectively separate particles with ~100% efficiency. The proposed sandglass-like separator can thus be used for effective separation and recovery of immobilized anionic radionuclides.

A lateral load pattern based on energy evaluation for eccentrically braced frames

  • Fakhraddini, Ali;Fadaee, Mohammad Javad;Saffari, Hamed
    • Steel and Composite Structures
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    • 제27권5호
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    • pp.623-632
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    • 2018
  • Performance-Based Plastic Design (PBPD) method has been recently developed to evaluate the behavior of structures in different performance levels. The PBPD method utilizes a base shear force and a lateral load pattern that are estimated based on energy and yielding mechanism concepts. Using of current lateral force pattern results in weak structural members in upper stories of a structure so that the values of the story drift in these stories are larger than the target drift, particularly in high-rise buildings. Therefore, such distribution requires modifications to overcome this drawback. This paper proposes a modified lateral load pattern for steel Eccentrically Braced Frames (EBFs) based on parametric study. In order to achieve the modified load pattern, a group of 26 EBFs has been analyzed under a set of 20 earthquake ground motions. Additionally, results of nonlinear dynamic analyses of EBFs have been post-processed by nonlinear regression analysis in order to derive the new load pattern. To prove the efficiency of present study, three EBFs as examples were designed by modified pattern and current PBPD distribution. Inelastic dynamic analyses results showed that the story drifts using modified lateral load pattern were well within the target values in comparison with current pattern in PBPD, particularly where the effect of the height is significant. The modified load pattern reduces the possibility of underdesigning in upper levels and overdesigning in lower levels of the frames.

비휘발성 메모리 기반 캐시의 쓰기 작업 최적화를 위한 캐시 시뮬레이터 설계 (Cache Simulator Design for Optimizing Write Operations of Nonvolatile Memory Based Caches)

  • 주용수;김명회;한인규;임성수
    • 대한임베디드공학회논문지
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    • 제11권2호
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    • pp.87-95
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    • 2016
  • Nonvolatile memory (NVM) is being considered as an alternative of traditional memory devices such as SRAM and DRAM, which suffer from various limitations due to the technology scaling of modern integrated circuits. Although NVMs have advantages including nonvolatility, low leakage current, and high density, their inferior write performance in terms of energy and endurance becomes a major challenge to the successful design of NVM-based memory systems. In order to overcome the aforementioned drawback of the NVM, extensive research is required to develop energy- and endurance-aware optimization techniques for NVM-based memory systems. However, researchers have experienced difficulty in finding a suitable simulation tool to prototype and evaluate new NVM optimization schemes because existing simulation tools do not consider the feature of NVM devices. In this article, we introduce a NVM-based cache simulator to support rapid prototyping and evaluation of NVM-based caches, as well as energy- and endurance-aware NVM cache optimization schemes. We demonstrate that the proposed NVM cache simulator can easily prototype PRAM cache and PRAM+STT-RAM hybrid cache as well as evaluate various write traffic reduction schemes and wear leveling schemes.

열교환기 형식에 따른 열교환기의 에너지 및 엔트랜시 성능 특성 해석 (Energy and Entransy Characteristic Analysis of Heat Exchangers Depending on Heat Exchanger Type)

  • 김경훈;정영관;한철호
    • 한국수소및신에너지학회논문집
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    • 제31권1호
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    • pp.112-121
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    • 2020
  • In this work energy and entransy characteristics of heat exchangers are analyzed for 12 different flow arrangements of heat exchangers. The dimensionless parameters are number of entransy dissipation (Ng), number of entransy dissipation-based thermal resistance (Nr), and entransy dissipation-based effectiveness of heat-exchanger (εg). The dimensionless parameters are expressed analytically in terms of the effectiveness of heat exchanger (ε), heat capacity ratio (c), and number of transfer unit (N) for optimal performance of heat exchangers. Results showed that the dimensionless parameters based on the entransy dissipation can be useful concepts for optimal design of heat exchangers.

A Novel Double-Loop Vector Control Strategy for PMSMs Based on Kinetic Energy Feedback

  • Wang, Anbang;Wang, Qunjing;Jiang, Weidong
    • Journal of Power Electronics
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    • 제15권5호
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    • pp.1256-1263
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    • 2015
  • A novel vector control strategy for a permanent magnet synchronous motor (PMSM) based on the kinetic energy stored in the rotor is proposed in this paper. The novel strategy is composed of two closed loops, in which the current loop is the inner loop, and the kinetic energy serves as the outer loop. The theoretical basis and the design procedure of the two loops are given. The feasibility of the proposed control strategy is verified by experimental results. When compared with traditional vector control strategies, the proposed vector control strategy based on energy feedback has better dynamic performance. In addition, an effective estimation solution for the load variation is put forward.

Expected damage for SDOF systems in soft soil sites: an energy-based approach

  • Quinde, Pablo;Reinoso, Eduardo;Teran-Gilmore, Amador;Ramos, Salvador
    • Earthquakes and Structures
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    • 제17권6호
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    • pp.577-590
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    • 2019
  • The seismic response of structures to strong ground motions is a complex problem that has been studied for decades. However, most of current seismic regulations do not assess the potential level of damage that a structure may undergo during a strong earthquake. This will happen in spite that the design objectives for any structural system are formulated in terms of acceptable levels of damage. In this article, we analyze the expected damage in single-degree-of-freedom systems subjected to long-duration ground motions generated in soft soil sites, such as those located in the lakebed of Mexico City. An energy-based methodology is formulated, under the consideration of input energy as the basis for the evaluation process, to estimate expected damage. The results of the proposed methodology are validated with damage curves established directly with nonlinear dynamic analyses.

강체모델 기반 시스템 안정성을 고려한 자기부상 플라이휠 에너지 저장장치의 최적 설계 (Optimal Design of Magnetically Levitated Flywheel Energy Storage System Based on System Stability Using Rigid-Body Model)

  • 김정완;유승열;배용채;노명규
    • 대한기계학회논문집A
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    • 제34권3호
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    • pp.283-289
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    • 2010
  • 친환경기술과 신재생 에너지 자원에 대한 세계적인 관심이 증가하면서, 플라이휠 에너지 저장 장치는 화학전지나 연료전지와 같은 기존의 에너지 저장 시스템의 대안 중 하나로 부상하고 있다. 플라이휠 에너지 저장장치의 에너지 저장 용량은 극질량 관성모멘트와 회전속도의 제곱에 비례하기 때문에, 가능한 높은 회전속도와 높은 극질량 관성모멘트를 갖도록 설계하는 것이 중요하다. 하지만, 시스템의 운전안정성 확보가 최적설계의 구속조건으로 작용할 수 있다. 본 논문에서는 에너지 저장 용량을 최대화하고 운전안정성 및 외란에 대한 강인성을 확보하는 플라이휠 시스템의 최적설계를 제안한다. 그리고, 기존의 PD 제어에 비교하여 교차궤환제어법이 자이로스코프효과를 줄이고, 에너지 저장밀도를 높이는데 필수적임을 확인하였다.

기존 학교 건물의 외피 성능 개선 방안에 관한 연구 (The Improvement of Building Envelope Performance in Existing School Building)

  • 방아영;박세현;김진희;김용재;김준태
    • KIEAE Journal
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    • 제15권4호
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    • pp.69-76
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    • 2015
  • Purpose: This study is to investigate the effects of facade insulation and window remodeling of an existing old middle school building on the reduction of energy consumption. Method: To analyze energy performance of building, using DesignBuilder v3.4, building energy simulation tool based EnergyPlus engine. Energy consumption and problem of target building was analyzed based on data and survey. Based on building energy simulations it analyzed the variation of energy demand for the building according to U-value of wall, glazing properties and external shading devices. Result: When insulation of building was reinforced, cooling and heating load was decreased. Glazing properties that minimize cooling and heating energy consumption were analyzed. In conclusion, it is important to choose SHGC and U-value of window fit in characteristic of target building. Setting external blind for cooling load decreases 5%.

공동주택에서 외피단열성능기준 강화에 따른 건축물에너지 효율등급 변화에 관한 연구 (A Study on the Building Energy Efficiency Rating Changes by Enhanced Thermal Insulation Performance of Building Envelope Standards in Apartment Houses)

  • 조영욱;박선효;정광섭
    • 설비공학논문집
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    • 제29권2호
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    • pp.89-95
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    • 2017
  • This study aimed to compare the primary heating energy consumption of regional apartment houses based on the enhanced thermal insulation performance of building envelope standards. The difference of the heating energy consumption based on the enhanced thermal insulation performance of building envelope standards in the southern region, the largest regional difference in primary heating energy consumption, is $10.3kWh/(m^2{\cdot}year)$. The difference of the heating energy consumption based on the enhanced thermal insulation performance of building envelope standards in the central region is $8.0{\sim}8.5kWh/(m^2{\cdot}year)$ and that of the Jeju region is $0.5kWh/(m^2{\cdot}year)$. These energy consumption differences do not result in building energy efficiency ratings changing. The building energy efficiency ratings have the possibility to be changed.

Analysis, Design and Implementation of Flexible Interlaced Converter for Lithium Battery Active Balancing in Electric Vehicles

  • Dai, Shuailong;Wang, Jiayu;Li, Teng;Shan, Zhifei;Wei, Yewen
    • Journal of Power Electronics
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    • 제19권4호
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    • pp.858-868
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    • 2019
  • With the widespread use of modern clean energy, lithium-ion batteries have become essential as a more reliable energy storage component in the energy Internet. However, due to the difference in monomers, some of the battery over-charge or over-discharge in battery packs restrict their use. Therefore, a novel multiphase interleaved converter for reducing the inconsistencies of the individual cells in a battery pack is proposed in this paper. Based on the multiphase converter branches connected to each lithium battery, this circuit realizes energy transferred from any cell(s) to any other cell(s) complementarily. This flexible interlaced converter is composed of an improved bi-directional Buck-Boost circuit that is presented with its own available control method. A simulation model based on the PNGV model of fundamental equalization is built with four cells in PSIM. Simulation and experimental results demonstrate that converter and its control achieve simple and fast equalization. Furthermore, a comparison of traditional methods and the HNFABC equalization is provided to show the performance of the converter and the control of lithium-based battery stacks.