• 제목/요약/키워드: thermal control

검색결과 3,098건 처리시간 0.037초

A Review of EOS Thermal Control Logic for MSC on KOMPSAT-2

  • Heo H.P.;Kong J.P.;Kim Y.S.;Park J.E.;Youn H.S.;Paik H.Y.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.452-455
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    • 2004
  • MSC (Multi-Spectral Camera) system is a remote sensing instrument to obtain high resolution ground image. EOS (Electro-Optic System) for MSC mainly consists of PMA (Primary Mirror Assembly), SMA (Secondary Mirror Assembly), HSTS (High Stability Telescope Structure) and DFPA (Detector Focal Plane Assembly). High performance of EOS makes it possible for MSC system to provide high resolution and high quality ground images. Temperature of the EOS needs to be controlled to be in a specific range in order not to have any thermal distortion which can cause performance degradation. It is controlled by full redundant CPU based electronics. The validity of thermistor readings can be checked because a few thermistors are installed on each control point on EOS. Various kinds of thermal control logics are used to prevent 'Single Point Failure'. Control logic has a few set of database in order not to be corrupted by SEU (Single Event Upset). Even though the thermal control logic is working automatically, it can also be monitored and controlled by ground-station operator. In this paper, various ways of thermal control logic for EOS in MSC will be presented, which include thermal control mode and logic, redundancy design and status monitoring and reporting scheme.

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태양광 발전의 성능향상을 위한 PV/T 시스템 개발 (Development of PV/T for Performance Improvement of Photovoltaic System)

  • 최정식;고재섭;강성준;백정우;장미금;문주희;정동화
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2010년도 하계학술대회 논문집
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    • pp.95-96
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    • 2010
  • This paper proposes photovoltaic thermal hybrid module to get the electrical and Thermal performance of building integrated photovoltaic(BIPV) system. BIPV system is decreased the system efficiency because output of PV is decreased by the thermal rising on generating. In order to improve the efficiency of BIPV module, water cooling system is applied and generated thermal is used the warm water system. Water cooling system uses the flux control algorithm considering water temperature and power loss. Electrical and thermal performance of proposed photovoltaic thermal hybrid module is confirmed through the actual experiment and herby proved the valid of this paper.

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실시간 제어를 위한 고속 열처리 공정에서 웨어퍼 온도 분포 추정 기법 (A Prediction Method of Temperature Distribution on the Wafer for Real-Time Control in a Rapid Thermal Process System)

  • 심영태;이석주;김학배
    • 제어로봇시스템학회논문지
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    • 제6권9호
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    • pp.831-835
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    • 2000
  • The uniformity of themperature on a wafer is a wafer is one the most important parameters to conterol the RTF(Rapid Thermal Process) with proper input signals. It is impossible to achieve the uniformity of temperature without the exact estimation of temperature ar all points on the wafer. There fore, it is difficult to understand the internal dynamics as well as the structural complexities of the RTP, which is aprimary obstacle to measure the distributed temperatures on the wafer accurately. Furthermore, it is also hard to accomplish desirable estimation because only a few pyrometers are available in the general equipments. In the paper, a thermal model based on the chamber grometry of the AST SHS200 RTP system is developed to effectively control the thermal uniformity on the wafer. First of all, the estimation method of one-point measurement is developed, which is properly extended to the case of multi-point measurements. This thermal model is validated through simulation and experiments. The proposed work can be utilized to building a run-by -run or a real-time control of the RTP.

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바닥난방 시스템의 열환경 개선을 위한 제어방안 연구 (A Study on Thermal Heating Control Performance of Automatic Thermostatic Valves in Floor Radiant Heating System)

  • 송재엽;안병천;김경철;장사윤
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.973-978
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    • 2009
  • In this study, the thermal environment characteristics of On-Off control and thermal difference proportional control method in floor radiant heating system were researched by computer simulation. For the analysis of unsteady heat transfer phenomena in household, the method of using electrical equivalent R-C circuit is applied, and radiation heat transfer between panel, ceiling and walls in household is calculated by enclosure analysis method. The parametric study on two control methods, conventional on-off control and temperature error based time control(T.E.B.T.C.) method, are performed to compare thermal heating control performances, respectively.

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Nonlinear Optimal Control of an Input-Constrained and Enclosed Thermal Processing System

  • Gwak, Kwan-Woong;Masada, Glenn Y.
    • International Journal of Control, Automation, and Systems
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    • 제6권2호
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    • pp.160-170
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    • 2008
  • Temperature control of an enclosed thermal system which has many applications including Rapid Thermal Processing (RTP) of semiconductor wafers showed an input-constraint violation for nonlinear controllers due to inherent strong coupling between the elements [1]. In this paper, a constrained nonlinear optimal control design is developed, which accommodates input constraints using the linear algebraic equivalence of the nonlinear controllers, for the temperature control of an enclosed thermal process. First, it will be shown that design of nonlinear controllers is equivalent to solving a set of linear algebraic equations-the linear algebraic equivalence of nonlinear controllers (LAENC). Then an input-constrained nonlinear optimal controller is designed based on that LAENC using the constrained linear least squares method. Through numerical simulations, it is demonstrated that the proposed controller achieves the equivalent performances to the classical nonlinear controllers with less total energy consumption. Moreover, it generates the practical control solution, in other words, control solutions do not violate the input-constraints.

응고/융해 잠열을 이용한 위성용 열제어장치의 실험적 연구 (Satellite Thermal Control Device Enhanced by Latent Heat of the Phase Change Material)

  • 김태수;신윤섭;김택영;서정기;현범석;전형열
    • 한국항공우주학회지
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    • 제44권10호
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    • pp.887-894
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    • 2016
  • 고상-액상 상변화물질(PCM, Phase Change Material)을 이용한 위성부품 열제어장치를 설계 및 제작하였으며 열환경시험을 수행함으로써 온도제어 성능을 분석하였다. 설계온도에 부합하는 n-Hexadecane을 PCM으로 채용하였고, 낮은 열전도도를 보완하기 위하여 내부에 전열휜이 장착된 용기를 Al6061로 제작하였다. 위성에 장착하였을 때와 동일한 작동조건을 확보하기 위하여, 부품과 방열판 사이를 열관으로 연결하였으며 열관의 단열부가 관통하도록 PCM 열제어장치를 설치하였다. 동일한 모양과 부피의 열적완충질량(TBM, Thermal Buffer Mass)도 제작하여, 주기적인 가열-냉각 실험을 수행하였다. 실험결과 상변화 잠열에 의한 PCM의 열제어 성능을 확인할 수 있었으며, TBM에 비하여 질량과 보온히터의 소모전력을 절감할 수 있음을 확인하였다.

공동주택의 냉방시 실내온열환경 평가 연구 (Evaluation of Indoor Thermal Environment for Cooling in Apartment House)

  • 김난행;안병욱
    • 한국주거학회논문집
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    • 제14권3호
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    • pp.1-8
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    • 2003
  • It is not sufficient to control the indoor thermal environment using only one or two parameters by itself as human response for the control of indoor thermal environment. So a proper environmental thermal index is required for the control of indoor thermal environment effectively. In this study, the physical environment was measured and analysed and the skin temperature of the subjects and their response were investigated to evaluate the optimum thermal comfort range for cooling season in an apartment house. As a result, the optimal temperature was 26.1$^{\circ}C$ and the temperature ranges which more than 80% responded as satisfactory were 24.1~28.$0^{\circ}C$, respectively. As the OT had most significant interrelation with the PMV, it is desirable to use the OT in evaluating the thermal environment during cooling. Also, the comfort range was concluded between OT 25.5~27.3$^{\circ}C$ by appointing the PMV of -0.5~0.5 as the optimum comfort condition. In addition, the Human responses were compared with calculated PMV, OT and MRT and the relationships are suggested in order to utilize to control indoor thermal environment.

인공위성 추진제 탱크의 열적 반응 및 민감도 해석 (Thermal Response and Sensitivity Analysis of Satellite Propulsion Tank)

  • 한조영;이균호;유명종
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2004년도 추계 학술대회논문집
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    • pp.131-136
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    • 2004
  • Thermal control of satellite propellant tank is achieved by patch heaters enabled by thermostat's behavior. It is important to attach the thermostat on the appropriate position of the propellant tank. However its position cannot be given with exact numerics because tank is spherical. Actually the position for thermostat is designated in relevant drawing approximately, therby, the engineer practices depending on his own experience and intuition. The sensitivity analysis for the position of thermostat is performed such that the influence on the thermal behavior and control of tank is examined quantatively. When assembling tank module, the reasonable performance on the thermal control is believed with possible human errors if the uncertainty in the position of thermostat is not quite large.

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게인 스케쥴링과 캐스케이드 제어에 의한 가상현실용 열환경의 실시간 구현 (Implementation of Real-Time Thermal Environment for Virtual Reality Using Gain Scheduling and Cascade Control)

  • 신영기;장영수;김영일
    • 제어로봇시스템학회논문지
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    • 제7권7호
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    • pp.567-573
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    • 2001
  • A real-time HVAC system is proposed which implements real-time control of thermal environment for virtual reality. It consists of a pair of hot and cold loops that serve as thermal reservoirs, and a mixing box to mix hot and cold air streams flowing if from loops. Their flow rates are controlled in real-time to meet a set temperature and flow rate. A cascade control algorithm along with gain scheduling is applied to the system and test results shows that the closed-loop response approached set values within 3 to 4 seconds.

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Automatic adjustment of feedforward signal in boiler controllers of thermal power plants

  • Egashira, Katsuya;Nakamura, Masatoshi;Eki, Yurio;Nomura, Masahide
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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    • pp.83-86
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    • 1995
  • This paper proposes an auto-tuning method of feedforward signal in boiler control of thermal power plants by using the neural network. The neural network produces an optimal feedforward signal by tuning the weights of the network. The weights are adapted effectively by using the teaching signal of PI control output. The proposed method was evaluated based on a detailed simulator which expressed non-linear characteristics of the 600 MW actual thermal power plant at load chaning operations, showed effectiveness in the learning of the weights of the neural network, and gave an accurate control performance in the temperature control of the system. Through the evaluation, the proposed method was proved to be effectively applicable to the actual thermal plants as the automatic adjustment tool.

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