• Title/Summary/Keyword: Combined Load

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The Development of Methodology in order to consider Combined Heat and Power in the Basic Plan of Long Term Electricity Supply & Demand (전력수급기본계획에 열병합발전 설비 반영 방법론의 개발)

  • Kim, Yong-Ha;Kim, Mi-Ye;Woo, Sung-Min;Cho, Sung-Rin;Lim, Hyun-Sung
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.12
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    • pp.570-575
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    • 2006
  • This paper develops methodology in order to consider CHP(Combined Heat and Power) capacity in the Basic Plan of Long Term Electricity Supply & Demand. We develop generating cost of CHP considering electric and heat. Also we develop mixed load duration curve which includes the electric load and heat load and then apply CHP capacity to SCM(Screening Curve Method) considering CHP feature. Accordingly, it decide the optimal CHP capacity in the Basic Plan of Long Term Electricity Supply & Demand. Also, We perform the sensitivity analysis according to cost variation.

The Effect of Initial Combined Load on the Lateral Free Vibration on the Arch and P-M Interactive Curve (아치의 곡률면외 자유진동 해석과 P-M 상관도 작성)

  • 전교영;한금호;한상윤;강영종
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.10a
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    • pp.452-461
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    • 2003
  • The effect of initial combined load on the lateral free vibration of arches is investigated. For the analysis, P-M interaction own for the arches are obtained. The arches are circular arches which have constant cross-section and simply supported. Also, the arches are subjected both radial uniform distributed load which results in an axial compression on the cross-section and end moments that cause uniform bending action at the same time. All analysis are performed by finite element method based on Kang and Yoo's curved beam theory.

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Analysis of Storm Water Run-off Characteristics during Wet Weather (강우시 합류식 하수관거의 유출특성 분석)

  • Choi, Sung-Hyun;Choi, Seung-Chol;Park, Eun-Young;Rim, Jay-Myoung
    • Journal of Industrial Technology
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    • v.22 no.B
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    • pp.95-101
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    • 2002
  • Much of domestic city is served by combined sewer system rather than separate sanitary or storm sewers. During wet weather, when the volume of sanitary sewage and storm water entering the combined sewers exceeds the system capacity, the system is designed to overflow at several designated CSOs. The objective of this research is to have grasp of characteristics of combined sewer runoff and to evaluate efficiently the intercepted volume of CSOs. During the wet weather in first rainfall, SS load at each site H-1, H-2, and H-3 were 600kg/event, 370kg/event, and 289kg/event, SS load at each site in second rainfall were 216kg/event, 113kg/event, and 37.2kg/event. EMCs at each site were 702mg/L, 816mg/L, 861mg/L in first rainfall and 99.9mg/L, 161.9mg/L, 103.6mg/L in second rainfall, respectively. First flush coefficients b at each site were 0.237, 0.166, and 0.151.

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Unified equivalent frame method for flat plate slab structures under combined gravity and lateral loads - Part 2: verification

  • Choi, Seung-Ho;Lee, Deuck Hang;Oh, Jae-Yuel;Kim, Kang Su;Lee, Jae-Yeon;Shin, Myoungsu
    • Earthquakes and Structures
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    • v.7 no.5
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    • pp.735-751
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    • 2014
  • In the previous paper, authors proposed the unified equivalent frame method (UEFM) for the lateral behavior analysis of the flat plate structure subjected to the combined gravity and lateral loads, in which the rotations of torsional members were distributed to the equivalent column and the equivalent slab according to the relative ratio of gravity and lateral loads. In this paper, the lateral behavior of the multi-span flat plate structures under various levels of combined gravity and lateral loads were analyzed by the proposed UEFM, which were compared with test results as well as those estimated by existing models. In addition, to consider the stiffness degradation of the flat plate system after cracking, the stiffness reduction factors for torsional members were derived from the test results of the interior and exterior slab-column connection specimens, based on which the simplified nonlinear push-over analysis method for flat plate structures was proposed. The simplified nonlinear analysis method provided good agreements with test results and is considered to be very useful for the practical design of the flat plate structures under the combined gravity and lateral loads.

Experimental study on seismic performance of concrete filled tubular square column-to-beam connections with combined cross diaphragm

  • Choi, Sung-Mo;Yun, Yeo-Sang;Kim, Jin-Ho
    • Steel and Composite Structures
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    • v.6 no.4
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    • pp.303-317
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    • 2006
  • The connection with combined cross diaphragm is developed for the connection of square CFT column and steel beam and proposed to be used for the frame with asymmetric span length. The structural characteristics of this connection lie in the penetration of the beam flange in the direction of major axis through the column for the smooth flow of stress. The purpose of this study is to analyze the dynamic behavior and stress flow of suggested connection and to evaluate the resistance to shock of connection. Four T-type CFT column-to-beam specimens; two with combined cross diaphragm and the others with interior and through diaphragms, the existing connection types, were made for cyclic load test guided by the load program of ANSI/AISC SSPEC 2002. The results show that the proposed connection is more efficient than existing ones in terms of strength, stress flow and energy absorption and satisfies the seismic performance required in the region of weak/moderate earthquakes.

An evaluation equation of load capacities for CFT square column-to-beam connections with combined diaphragm

  • Choi, Sung-Mo;Jung, Do-Sub;Kim, Dae-Joong;Kim, Jin-Ho
    • Steel and Composite Structures
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    • v.7 no.4
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    • pp.303-320
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    • 2007
  • The objective of this study is to clarify the structural features of members consisting of connection, as a series of the previous study on the CFT column-to-beam tensile connection with combined cross diaphragm. This connection has the merits that the stress is distributed evenly on the beam flange and the diaphragm and the stress concentration is reduced, by improving the stress transfer route and restraining abrupt deformation of diaphragm. The finite element analysis was performed to find out the stress transfer through sleeve which is an important member of the connection with combined cross diaphragm. The length and thickness of sleeve were used as variables for the analysis. As the analysis results, the length and thickness of sleeve didn't influence on the capacity of the connection and played a role of a medium to transfer the stress from the diaphragm to the filled concrete. It is proposed that the appropriate length of sleeve be the same value as the diameter of sleeve and the appropriate ratio of sleeve diameter to sleeve thickness be 20. Two equations for evaluation of the load-carrying capacity of the connection were also proposed through the modification of the evaluation equation suggested in the previous study.

Design and ultimate behavior of RC plates and shells: two case studies

  • Min, Chang-Shik
    • Structural Engineering and Mechanics
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    • v.14 no.2
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    • pp.171-190
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    • 2002
  • Two cases of design are performed for the hyperbolic paraboloid saddle shell (Lin-Scordelis saddle shell) and the hyperbolic cooling tower (Grand Gulf cooling tower) to check the design strength against a consistent design load, therefore to verify the adequacy of the design algorithm. An iterative numerical computational algorithm is developed for combined membrane and flexural forces, which is based on equilibrium consideration for the limit state of reinforcement and cracked concrete. The design algorithm is implemented in a finite element analysis computer program developed by Mahmoud and Gupta. The amount of reinforcement is then determined at the center of each element by an elastic finite element analysis with the design ultimate load. Based on ultimate nonlinear analyses performed with designed saddle shell, the analytically calculated ultimate load exceeded the design ultimate load from 7% to 34% for analyses with various magnitude of tension stiffening. For the cooling tower problem the calculated ultimate load exceeded the design ultimate load from 26% to 63% with similar types of analyses. Since the effective tension stiffening would vary over the life of the shells due to environmental factors, a degree of uncertainty seems inevitable in calculating the actual failure load by means of numerical analysis. Even though the ultimate loads are strongly dependent on the tensile properties of concrete, the calculated ultimate loads are higher than the design ultimate loads for both design cases. For the cases designed, the design algorithm gives a lower bound on the design ultimate load with respect to the lower bound theorem. This shows the adequacy of the design algorithm developed, at least for the shells studied. The presented design algorithm for the combined membrane and flexural forces can be evolved as a general design method for reinforced concrete plates and shells through further studies involving the performance of multiple designs and the analyses of differing shell configurations.

A Study on the Improvement of Optimal Load Range for Sliding Pressure Operation of coal-fired Power Plant (석탄화력 발전소 최적 변압운전 부하 범위 개선에 대한 연구)

  • Lee, Sang-Hun;Wang, Min-Seok;Wee, Sang-Bong;Son, Yung-Deug
    • Journal of IKEEE
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    • v.23 no.2
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    • pp.675-680
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    • 2019
  • The coal-fired power plant is operated by a combined operation method, which is operated by sliding pressure operation under low load and by fixed pressure operation under high load for improved efficiency. The combined operation is divided into two and three valve open modes. Each plant is operated by selecting the turbine control valve mode in accordance with the manufacturer's recommendation, but is not really operating at the optimal sliding pressure operation according to load range, also Load range of each plant is configured differently. The internal efficiency of the high-pressure turbines is reduced due to loss of the turbine valves and the plant efficiency is reduced. To solve these problems, In this paper, the optimum load range is selected through the analysis method of thermal performance by each load in order to improve the optimum variable pressure operation load range by turbine control valve mode.

Load Modeling of KTX Using Parameter Identification (파라미터 식별법에 의한 KTX의 부하모델링)

  • Kim, Joo-Rak;Shim, Keon-Bo;Kim, Jung-Hoon
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1634-1636
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    • 2005
  • The electric load components have different characteristics against variation of voltage and frequency. This paper presents the load modeling of electric locomotive by the parameter identification method. Proposed method for load modeling is very simple and easy for application. Proposed load model of the electric locomotive is the combined load of the static and dynamic characteristic load. This load modeling is applied to the KTX to verify the effectiveness of the proposed method. The results of the proposed load modeling by parameter identification follow the field measurements very exactly.

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