• Title/Summary/Keyword: Thermal environment control

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Development of Integrated Control Methods for the Heating Device and Surface Openings based on the Performance Tests of the Rule-Based and Artificial-Neural-Network-Based Control Logics (난방시스템 및 개구부의 통합제어를 위한 규칙기반제어법 및 인공신경망기반제어법의 성능비교)

  • Moon, Jin Woo
    • KIEAE Journal
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    • v.14 no.3
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    • pp.97-103
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    • 2014
  • This study aimed at developing integrated logic for controlling heating device and openings of the double skin facade buildings. Two major logics were developed-rule-based control logic and artificial neural network based control logic. The rule based logic represented the widely applied conventional method while the artificial neural network based logic meant the optimal method. Applying the optimal method, the predictive and adaptive controls were feasible for supplying the advanced thermal indoor environment. Comparative performance tests were conducted using the numerical computer simulation tools such as MATLAB (Matrix Laboratory) and TRNSYS (Transient Systems Simulation). Analysis on the test results in the test module revealed that the artificial neural network-based control logics provided more comfortable and stable temperature conditions based on the optimal control of the heating device and opening conditions of the double skin facades. However, the amount of heat supply to the indoor space by the optimal method was increased for the better thermal conditioning. The number of on/off moments of the heating device, on the other hand, was significantly reduced. Therefore, the optimal logic is expected to beneficial to create more comfortable thermal environment and to potentially prevent system degradation.

An Approach of Indoor thermal Environment Control and Energy Saving Using the PMV Index (PMV지표를 이용한 공동주택의 난방제어에 따른 온열환경 및 에너지소비량 시뮬레이션)

  • Seong, Nam-Chul;Yoon, Dong-Won
    • Land and Housing Review
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    • v.1 no.1
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    • pp.19-25
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    • 2010
  • Thermal comfort provide satisfaction of thermal environment and affects productivity of occupants in residential building. However, temperature control can not provide the thermal comfort at all the time. because thermal comfort is influenced by many environmental variables such as temperature, relative humidity, air velocity, radiation temperature, activity level and clothing insulation. The purpose of this study is that predicted mean vote(PMV) index is used as control. And, Thermal comfort is evaluated both PMV control and temperature control by simulation. Each other cases were compared, in which set-point temperatures of $22^{\circ}C$ and $24^{\circ}C$ and, set-point PMV index through the respective heating season in the simulation. The results show that PMV control is better to maintain comfort state and save energy than temperature control.

Thermal Environment Analysis of a Classroom by CFD Simulation to Determine Optimal Temperature Sensor Position in Ceiling Type Air-Conditioning System (천정형 에어컨 온도센서의 최적 위치 결정을 위한 교실의 CFD 열환경 분석)

  • Li, M.H.;Kim, D.G.;Kum, J.S.;Jeong, S.K.
    • Journal of Power System Engineering
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    • v.10 no.4
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    • pp.43-49
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    • 2006
  • Nowadays, the thermal environments of classrooms are usually adjusted by the ceiling type air-conditioning system with a temperature sensor installed on inlet of an air-conditioner. However, it is not clear that the conventional temperature sensor position is proper to satisfy both thermal comport and energy saving in summer especially. Therefore, this study is aimed at finding out the best position of the temperature sensor on the purpose of the comfort thermal environment and energy saving. The different 5 positions for the temperature sensor are supposed in this paper to analyze thermal environment by CFD. From the analysis through the CFD simulations, the best position of the temperature sensor satisfying for both comfort thermal environment and energy saving is obtained.

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Changes of residents' indoor environment control behavior as a result of provided education and environmental information (거주자의 실내환경 관리행동에 교육 및 정보제공이 미치는 효과)

  • Bae, Nu-Ri;Choi, Yoo-Rim;Chun, Chung-Yoon
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2006.11a
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    • pp.269-274
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    • 2006
  • The purposes of this research are, first, to investigate the present condition of indoor thermal environment in winter. Second, to find out how residents' knowledge, consciousness, and behavior changed after provided with education and information of indoor climate. Finally, to reveal how this changes make alteration to their indoor environment. Thirty apartments were collected, and then divided into three groups as Control Group, Education Group, and Edu-information Group in order to conduct the purposes. Provided education and environmental information turn out to have a positive effect to residents' knowledge, consciousness, and behavior, and consequently, it leads residents to control their indoor environment more actively in some cases. Thus, it is important to provide residents with environmental education and information, and it should be conducted regularly in order to maximize the positive effect of education since it tends to decrease as time goes by.

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An application to HVAC control system based on occupants' thermal response in office buildings (공조제어 적용을 위한 재실자 온열반응 데이터의 유효성 분석에 관한 연구)

  • Han, Hyesim;Kim, Jonghun;Jeong, Hakgeun;Jang, Cheol-Yong
    • KIEAE Journal
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    • v.14 no.4
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    • pp.111-117
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    • 2014
  • In South Korea, the government has recently enforced regulations associated with buildings. Temperature restriction in indoor environment is one of the common ways of energy reduction in order not to dissipate heating and cooling energy; however the people who are in restricted temperature feels uncomfortable. Furthermore, occupants cannot feel the same thermal sensation even they are in the same place. For the reason, occupants should express their thermal sensation and HVAC system should be able to apply their demand. It is proved by an adaptive principle. The adaptive model means that people react in ways which tend to restore their comfort, when change occurs such as to produce discomfort. In order to design HVAC control strategies based on adaptive model, we designated an existing office building as a reference building to gather data from actual field. Furthermore, we gathered occupants' thermal sensation and clothing insulation in real-time. We filtered the data with Kalman's filter method. The data was reasonable when there is an alarm messages for asking questionnaire. The response ratio were different in occupants' thermal condition. In conclusion, the filtered occupants' thermal sensation can be used as a real time HVAC control and input value of HVAC control.

A Field Study on the Mass Concreting in Cold Weather Environment (매스콘크리트의 한중시공에 관한 현장실험연구)

  • 한민철;김현우;김성수;최강순;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.04a
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    • pp.287-292
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    • 1999
  • Mass concreting in cold weather environment should be focused on the control of thermal crack caused by high hydration heat rather than curing method for protecting from frost damage at early age because the thermal stress have much influence on the quality of structure placed in cold weather. Therefore, in this paper, the control of thermal crack of mass concrete in cold weather environment are dealt with preparing the practice plan for mass concrete and placing the concrete according to the plactice plan. According to the results, we can obtain good quality mass concrete without thermal crack caused by the difference of temperature between inner part and outer part.

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An Study on the Evaluation of Thermal Indoor Environment and Thermal Sensations during Winter and Summer in Elderly Welfare Facilities (老人福祉施設의 冬.夏節期 室內 溫熱環境 測定 및 溫熱感 評價)

  • Kwak, Ho;Ryoo, Woo-Dong;Hwang, Kwang-Il;Hong, Won-Hwa
    • Journal of the Korean housing association
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    • v.14 no.1
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    • pp.19-27
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    • 2003
  • This study aims to survey the living spaces of the welfare facilities for the aged to get the objective relationships between the physical thermal environment and the users' subjective responses. The surveys were made twice in winter and once in summer during 2001 and 2002. An ambient temperature, relative humidity, air velocity, globe temperature were measured as physical elements of thermal environment and the ASHRAE Psychophysical Voting Scale were used as an evaluation index for subjective responses. As the results, the aged respond thermally comfortable, in spite of the differences among important factors such as thermal sensations, humidity sensations and air velocity sensations. Also the physical thermal environmental elements and the subjective responses indices exceed thermal comfort range calculated by PMV(Predicted Mean Vote) and PPD(Predicted Percentage Dissatisfied). It shows that the insulation of walls of the facilities is not enough for heating and cooling seasons, and the indoor environmental control is necessary.

Sensing performance evaluation under various environment condition of stroke sensing cylinder using magnetic sensor (자기센서를 이용한 위치검출 실린더의 환경변화에 따른 성능평가)

  • 김성현;이민철;양순용
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.636-639
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    • 1996
  • We have developed a part of hydraulic stroke sensing cylinder using magnetic sensor that can detect each position under severe construction fields. In this paper, for evaluating the developed cylinder under various environment condition, thermal control systems and two hydraulic systems to be coupled consist of. The former is composed of an heater case, temperature sensor, and interface circuits which include SCR(silicon controlled rectifier) for the control of the voltage's phase. The latter is composed of an hydraulic cylinder for position control with solenoid valve (ON/OFF motion) and a load cylinder with proportional reducing valve. To obtain the various performance evaluation, it is carried out under high temperature condition in thermal system controlled by using Ziegler-Nichols PID tuning method and artificial disturbances such as impulse or constant force. The results show that the developed cylinder has good performance under the various environment condition.

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Domestic Construction of a Large Thermal Vacuum Chamber for Space Environment Simulation (우주환경모사를 위한 대형열진공챔버 국산화 구축)

  • Cho, Hyok-Jin;Moon, Guee-Won;Seo, Hee-Jun;Lew, Sang-Hoon;Choi, Seok-Weon
    • Aerospace Engineering and Technology
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    • v.6 no.1
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    • pp.64-73
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    • 2007
  • A Large thermal vacuum chamber (LTVC) for space environment simulation on large satellites was successfully developed and constructed by KARI (Korea Aerospace Research Institute) in Korea with a local company. This chamber has an effective diameter of 8 meters and depth of 10 meters, and is composed of vacuum system, thermal control system, and anti-vibration system. Temperature below $-190^{\circ}C$ is maintained over the thermal shroud wrapping a satellite under $3.7{\times}10^{-5}Pa$ ($5{\times}10^{-7}torr$) vacuum level, and optical test can be done in this chamber by seismic mass with $10^{-5}g_{rms}$ or lower vibration level. In addition, the shroud temperature can be increased up to $123^{\circ}C$ using halogen lamps. Chamber control program based on PLC (Programmable Logic Controller) could control this large thermal vacuum chamber automatically.

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Assessment on Thermal Environment and Human Thermal Comfort in Residential Building Block through Field Measurement (실측을 통한 공동주택 단지 내에서의 온열환경 및 거주자 쾌적감 평가에 관한 연구)

  • Lim, Jong-Yeon;Hwang, Hyo-Keun;Song, Doo-Sam;Kim, Tae-Yeon
    • 한국태양에너지학회:학술대회논문집
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    • 2008.04a
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    • pp.311-317
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    • 2008
  • As outdoor environment become worse due to concentration of population in large cities, the importance of environmental control strategies such as the arrangement of green space or water space and ventilation paths, has been increasingly recognized. However, most of the studies focus on the assessment on outdoor thermal environment, few studies focus on the interrelationship between thermal environment in residential block and human thermal comfort. The aims of this study is to develop the outdoor planning method to reduce the heating/cooling load in an apartment unit or entire block by the sustainable approaches in outdoor environmental design. In this paper, on the basis of the prior studies, the effect of the outdoor thermal environment on human thermal comfort will be analysed.

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