• Title/Summary/Keyword: Energy saving system

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A Study on the Implementation of BPSK Demodulator with Remodulation Method for Power Line Carrier Communication (전력선 통신용 재변조방식의 BPSK복조기 실현에 관한연구)

  • 오상기;나채동;진달복
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.8 no.4
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    • pp.38-45
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    • 1994
  • It is very imprtant and necessary to predict luminous enviroment in an interior space. This paper has de scribed about energy saving and evaluated interior visual environment in a office building having on/off turning control lighting system utilizing daylight. In order to predict the interior varior illumination distribution, the scale model w a m~a de and examined under various conditions, such ad difference of window glass, and color pattern of wall, floor, and also ceiling lighting system type. Ths paper suggests that basic fundamental data of lighting design ~rformancein the concept and schematic stages of design.

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Restoration of Tactility of Architectural Glass: Perceptual & Sensible Tactility - Focused on the Analysis of Laminata Glass House -

  • Kim, Sung-Wook;Kim, Do-Sik
    • Architectural research
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    • v.12 no.2
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    • pp.23-30
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    • 2010
  • The study of the expression of architectural glass has recently expanded due to various factors such as the development of architectural technology, the reinforcement of environmental standards, an increased interest in energy saving, and the commercialism of the exterior of buildings. The background for restoring the tactile capability of the sense of sight has been prepared by agitating oculocentricism pertaining to the Renaissance era. The restoration of tactility can be considered in two ways. One is the tactility 'perceived' through complex experiences and the other is the tactility 'sensed' from the challenges on the materiality of the glass itself. Perceptual tactility is achieved from compound visual experiences and connecting these complex experiences in the brain. Sensible tactility, in contrast to perceptual tactility, is a more direct tactility which works within the nervous system, bypassing the brain. This is attained by reversion of the materiality, tectonics and connection method of the glass. Among rare examples, Laminata House built in Leerdam, Netherlands is a fine example of direct and sensible tactility. In this paper, the process of restoring tactility in architecture is studied at each stage based on the restoration of tactility in painterly aesthetics.

A Study on the Performance Analysis in the Plate and Shell Heat Exchanger (판각형 열교환기 성능해석에 관한 연구)

  • Seo, M.K.;Park, J.H.;Kim, Y.S.
    • Journal of Power System Engineering
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    • v.5 no.1
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    • pp.35-43
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    • 2001
  • Heat exchangers are called with important devices which have been widely used in industrial fields. Therefore, the design method for a heat exchanger is an important study in the aspect of energy saving. In this study, performance analyses for two types of plate and shell heat exchangers having a corrugated trapezoid shape of a chevron angle with $45^{\circ}$, were executed and compared with experiments. For this study, the operation liquids were adopted with non-phase changing water. In the analysis, ${\epsilon}-NTU$ method was used for a plate and shell heat exchanger and a program was constructed. Independent variables for a plate and shell heat exchanger are flow rate and inlet temperature. Compared with experimental data, the accuracy of the developed are ${\pm}2.5%\;and\;{\pm}5%$ at the type A and type B in the heat transfer rate, respectively. In the pressure drop, the accuracy of the proposed program for a plate and shell heat exchanger is within ${\pm}3%$ and 5% error bounds for the type A and type B, respectively.

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Development of ANN- and ANFIS-based Control Logics for Heating and Cooling Systems in Residential Buildings and Their Performance Tests (인공지능망과 뉴로퍼지 모델을 이용한 주거건물 냉난방 시스템 조절 로직 및 예비 성능 시험)

  • Moon, Jin-Woo
    • Journal of the Korean housing association
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    • v.22 no.3
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    • pp.113-122
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    • 2011
  • This study aimed to develop AI- (Artificial Intelligence) based thermal control logics and test their performance for identifying the optimal thermal control method in buildings. For this objective, a conventional Two-Position On/Off logic and two AI-based variable logics, which applied ANN (Artificial Neural Network) and ANFIS (Adaptive Neuro-Fuzzy Inference System), have developed. Performance of each logic was tested in a typical two-story residential building in U.S.A. using the computer simulation incorporating MATLAB and IBPT (International Building Physics Toolbox). In the analysis of the test results, AI-based control logic presented the advanced thermal comfort with stability compared to the conventional logic while they did not show significant energy saving effects. In conclusion, the predictive and adaptive AI-based control logics have a potential to maintain interior air temperature more comfortably, and the findings in this study could be a solid foundation for identifying the optimal thermal control method in buildings.

Conceptual Directions of Village Community Center into a Rural Elderly's Welfare Service Space in Chonbuk Province (농촌 마을회관의 노인 복지서비스 공간으로의 활용 방안 - 평면과 이용행태 분석을 중심으로 -)

  • Choi, Byungsook;Park, Sunhee;Oh, Chanok;Hong, Chansun;Im, Sangbong
    • Journal of the Korean Institute of Rural Architecture
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    • v.8 no.2
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    • pp.80-93
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    • 2006
  • This purpose was to explore various directions of elderly service welfare space in village community center. Data were collected 3 types that floor plans of village community centers from 24 villages, interview data of these centers use and needs from 24 aged leaders or 96 elderly. The results were as followed: 1) The floor plans of more than 50% was type IV that was composed a basic spaces(entrance, living room, two rooms, kitchen), a toilet space, a heating system space and a storage space. This type was a current basis of the rural village community centers for elderlies. 2) Elderlies used the centers at winter or out of agricultural season, and visited these to pass the time and to promote friendship among them. 3) Also they went these to take a meal together and to save down personal heating expenses. Their needs for centers were a temporary share dwelling space at winter, a maintain social relationship throughout a health, a education and a side work activity, supplying health or sports facilities, and setting up toilet space. Therefore the current centers were needed to add functions of a temporary share dwelling, a energy saving heat system and a social promoting relationship, and so these could be represented to a elderly welfare service center in rural villages.

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Development of automatic illumination controller for energy saving (에너지 절약형 자동조명 장치 개발)

  • 최명호;강형곤;김민기;한병성
    • Electrical & Electronic Materials
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    • v.9 no.10
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    • pp.1027-1032
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    • 1996
  • The auto-illumination controller for office, residence, and so on was studied. The system consists of parts of a power supply, a signal oscillator, a lamp controller and two kinds of sensor. The lamp controller has two thyristors triggered by the IR sensor(SCRI) and CdS sensor(SCR2) respectively, When the illuminance around this system is higher than operating value of its sensor, lamp is turned off automatically. Otherwise, the light of lamp gets dim by CdS sensor. In case IR sensor senses the body heat of people around itself, the illuminance of the lamp gets maximum. The illuminance of the lamp can be changed dimmly by control of the variable resistor (RV) connected with SCR2 in series. The turning - on time of the lamp can be also controlled using a variable resistor(Rt) connected with a signal oscillator in parallel. Changing resistance Rt changes the time constant(.tau.), which triggers the gate of SCR2. Though people left the surrounding of lamp, the lamp keeps light for a while.

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A Research on the $CO_2$ Peak Point Control According to Ventilation Rate During Sleeping (취침 시 환기횟수에 따른 $CO_2$ 피크치 제어에 관한 연구)

  • Kim, Se-Hwan;Kim, Dong-Gyu;Park, Jong-Il
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.1
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    • pp.49-54
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    • 2009
  • Ventilation requirement of apartment was mandated according to building equipment standards in 2006. When ventilation unit was considering for indoor air quality maintenance, we needed energy saving and efficiency ventilation control methods. This study carried out experiment of ventilation rate 0.7 adequacy. When we lived in apartment, we assumed that sleeping time was long stayed time in unconsciousness. Experiments carried out ventilation rate 0, 0.1, 0.4 and 0.7 in environment chamber from 22 o'clock to 06 o'clock, the concentration of $CO_2$, temperature and humidity rate measured. Analyzing the results, conclusions are as follows. 1) When we sleep in bedroom, ventilation rate 0.4 meet the requirements of domestic legal standards. Conform fan of similarity law, ventilation rate 0.4 reduced power cost about 80% than 0.7. 2) In generally sleeping time 8 hours, peak point control reduced running time of ventilation unit about 43% than normal control.

A study on design for free cooling system using dry cooler (드라이쿨러를 적용한 외기냉수냉방 시스템 설계에 관한 연구)

  • Yoon, Jung-In;Baek, Seung-Moon;Heo, Jeong-Ho;Kim, Young-Min;Son, Chang-Hyo
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.9
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    • pp.1027-1031
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    • 2014
  • Free cooling system is used to reduce energy consumption of cooling system. Free cooling system is consisted of cooling group and dry-cooler in which heat exchange of chilled water and out air is conducted. Although this system has an excellent energy saving effect in place having cooling load regularly, data or material of design for free cooling system is lacked. In this study, characteristics analysis of free cooling system is conducted through software HYSYS with changing some facts. The main result is following as : Dry-cooler capacity is influenced by out air temperature, required chilled water temperature and LMTD(Logarithmic Mean Temperature Difference) of heat exchanger. As out air temperature is more low, dry-cooler capacity become increased. in addition, as required chilled water temperature is more high and LMTD is more low, the out air temperature range is widened for using dry-cooler. If out air temperature is below $0^{\circ}C$, antifreeze need to be used because freeze and burst can be occurred. In case of South Korea, antifreeze of 34% of ethylene glycol concentration is proper. When compressor load of R22, R134a and R407C is compared, considering environmental regulation and energy consumption, R134a is best working fluid.

Analysis of the Economic Efficiency of the District Heating and Gas Engine Co-Generation System Compared with the Central Heating System (중앙난방방식을 지역난방과 소형열병합난방 방식으로 전환 시 경제성 비교 분석)

  • Kim, Kyu Saeng
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.10
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    • pp.544-551
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    • 2015
  • This study was conducted to determine the LCC of apartment complexes with district heating and a cogeneration system. For the purpose of analyzing LCC according to the size of the apartment complex, 500, 1,500, and 4,000-unit model apartments were selected. Analysis was performed on the design of the heating system and the life cycle cost including total construction cost, maintenance and operation cost for the duration of the project period (15 years). According to the calculated results, 1) The initial cost of the cogeneration system for 500, 1,500, and 4,000-unit apartments is higher than that of the district heating system by 20%, 13%, and 12%, respectively. 2) In the case of the cogeneration system, the payback period by electric generation was found to be 5.21, 4.92 and 4.47 years, and saving cost was calculated to be 29 billion won, 94 billion won and 262 billion won after the payback period for 500, 1,500, and 4,000-unit apartments, respectively. 3) The LCC values of the cogeneration system were 1.12, 1.07 and 1.06 times larger than those of the district system according to the size of the apartment complex. In this study, the district heating system was found to be more efficient than the cogeneration system in terms of LCC reduction. 4) District heating is affected by fuel bills, so energy efficiency should be improved through recovering waste heat (incineration heat, etc.). Also, district cooling should be provided according to heat use to keep the temperature high in winter and low in summer.

Design of Multivariable 2-DOF PID for Electrical Power of Flow System by Neural Network Tuning Method (신경망 튜우닝에 의한 유량계통 동력 제어용 다변수 2-자유도 PID의 제어기 설계)

  • 김동화
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.12 no.1
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    • pp.78-84
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    • 1998
  • The fluid system such as, the quantity control of raw water, chemicals control in the purification, the waste water system as well as in the feed water or circulation system of the power plant and the ventilation system is controlled with the valve and moter pump. The system's performance and the energy saving of the fluid systems depend on control of method and delicacy. Until, PI controller use in these system but it cannot control delicately because of the coupling in the system loop. In this paper we configure a single flow system to the multi variable system and suggest the application of 2-DOF PID controller and the tuning methods by the neural network to the electrical power of the flow control system. the 2-DOF controller follows to a setpoint has a robustness against the disturbance in the results of simulation. Keywords Title, Intelligent control, Neuro control, Flow control, 2 - DOF control., 2 - DOF control.

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