• 청정기술
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• 제19권2호
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• pp.105-112
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• 2013

폴리아닐린 기반 이산화티타늄 복합체(폴리아닐린-이산화티타늄 복합체)를 다른 소성온도 조건에서 제조하여 일반 공기질 수준의 트리클로로에틸렌과 테트라클로로에틸렌에 대한 제어 적용성 연구를 수행하였다. 모든 조사대상 오염물질에 대하여 폴리아닐린-이산화티타늄 복합체의 제어효율은 제조 시 적용된 소성온도 변화에도 아무런 경향을 나타내지 않았다. 대신에, 소성온도를 $350^{\circ}C$에서 $450^{\circ}C$로 증가시켰을 때 3시간의 광촉매 공정 동안에 폴리아닐린-이산화티타늄 복합체의 제어효율은 트리클로로에틸렌과 테트라클로로에틸렌에 대하여 61%에서 72%로, 21%에서 39%로 각각 증가하였다. 그러나, 소성온도를 $450^{\circ}C$에서 $550^{\circ}C$와 $650^{\circ}C$로 더 증가시켰을 경우에는 폴리아닐린-이산화티타늄 복합체에 의한 트리클로로에틸렌과 테트라클로로에틸렌의 제어효율이 점진적으로 감소하였다. 이러한 결과는 폴리아닐린-이산화티타늄 복합체 내 아나타제 결정상의 생성량과 입자의 비표면적 변화 때문으로 판단되었고, 이러한 특성 변화는 X-선 회절과 주사전자현미경 분석결과를 통하여 확인하였다. 가장 낮은 주입농도(0.1 ppm) 조건에서 트리클로로에틸렌과 테트라클로로에틸렌의 평균 제어효율은 각각 72%와 39%이었고, 반면에 가장 높은 주입농도(1.0 ppm) 조건에서는 트리클로로에틸렌과 테트라클로로에틸렌의 평균 제어효율은 각각 52%와 18%로 나타났다. 공급 유량을 0.1 L $min^{-1}$에서 1.0 L $min^{-1}$로 증가시켰을 때 트리클로로에틸렌과 테트라클로로에틸렌의 평균 제어효율이 각각 약 100%에서 47% 그리고 약 100%에서 18%로 감소하였다. 또한, 상대 습도를 20%에서 95%로 증가시켰을 때 트리클로로에틸렌과 테트라클로로에틸렌의 평균 제어효율이 각각 약 100%에서 23% 그리고 약 100%에서 8%로 대폭 감소하였다. 본 연구결과를 종합해볼 때, 작동조건을 최적화할 경우 폴리아닐린-이산화티타늄 복합체가 일반 공기질 농도 수준의 염소계 화합물질 제어를 위해서 효율적으로 이용될 수 있는 것으로 나타났다.

• 한국산업보건학회지
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• 제16권4호
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• pp.364-374
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• 2006

Natural ventilation technique could be the substitute for or the complement to the local exhaust ventilation system in the sense of protecting work environment. Moreover, it has many strong points ; almost no mechanical parts, no energy use and no noise. If applied appropriately, it could have the very high ventilation rate and save a lot of energy expense. But, it depends on the outdoor environment, especially temperature and wind speed/direction. Predicting the capacity of natural ventilation is not an easy job because it comes from both buoyancy and wind effect. Another problem is too much flow through the ventilator especially in winter time due to too much difference between indoor and outdoor temperature. Thus some ventilators in industries are sealed by door or plastic sheet, resulting in bad work environment. Various types of dampers are used to control the flow rate through ventilators. The capabilities of flow control by damper has not been estimated. In addition, it was not tested whether the damper could obstruct the flow through ventilator when fully opened. To answer these questions, 4 types of dampers were tested by using computational fluid dynamics. 10 different configurations includes no damper, full open and half open. Flow rates were estimated and airflow fields were analysed to clarify the before-mentioned questions. The dual type damper was the best choice for controling the capability of ventilator. In addition, the upward grill type damper was the best for not obstructing the air flow when fully opened.

• KIEAE Journal
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• 제14권4호
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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.

• 생물환경조절학회지
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• 제26권3호
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• pp.181-187
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• 2017

간척지 온실의 환경설계 기술 개발을 위한 기초자료 제공을 목적으로, 첨단 시설원예단지 설치 계획이 있는 국내 7개 대규모 간척지 주변의 기후조건을 분석하였으며, 새만금 간척지 내에 설치된 3연동 플라스틱 온실을 대상으로 하절기에 시설 내외의 열적 환경계측 실험을 통하여 자연환기 및 온도 상승 특성을 분석하고, 간척지 온실의 환경 설계에 적용해야 할 부분을 검토하였다. 작물의 유무에 따른 온실의 환기율을 비교한 결과, 작물이 있으면 온실의 환기율은 낮아지지만 작물의 증발산에 의해 실내기온 상승은 감소하는 것으로 나타났다. 작물이 있는 경우 온실의 환기회수는 대체로 0.3~0.9회/min의 범위에 있었고, 평균 0.7 회/min으로 나타났다. 실외기온 대비 실내기온 상승은 $1{\sim}5^{\circ}C$정도의 범위에 있었고, 평균 $2.5^{\circ}C$로 나타났다. 간척지에 설치된 실험온실의 자연환기 성능은 여름철 권장 환기율을 거의 만족시키고, 실외기온 대비 실내기온 상승도 작물재배 환경을 크게 벗어나지 않으므로 새만금 간척지에서는 냉방설비 없이 자연환기 만으로 온실의 작물 재배가 가능할 것으로 판단된다. 간척지는 해안에 위치하고 있어 내륙지역에 비하여 바람이 강하고, 안개가 자주 끼는 특성을 보이는 것으로 나타났다. 이와 같이 강한 풍속은 온실의 환기율을 증가시키므로 냉방부하의 감소요인으로 작용하게 될 것으로 판단된다. 또한 안개지속시간이 내륙지역에 비하여 현저하게 길기 때문에 기간냉방부하는 감소할 것으로 예상되며 이는 냉방설비의 운전경비 측면에서 유리할 것으로 판단된다. 또한 간척지 온실의 환기 및 냉방시스템 설계 시에는 주변의 기상관측소 자료를 그대로 이용하지 말고, 온실 설치 지역에서 실측한 기상자료 또는 현장 여건을 반영하여 보정된 기상자료를 사용하여 설계하도록 할 필요가 있다.

• KIEAE Journal
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• 제16권3호
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• pp.89-94
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• 2016

Purpose: This study aimed at developing an artificial neural network (ANN) model to predict the optimal start moment of the setback temperature during the normal occupied period of a building. Method: For achieving this objective, three major steps were conducted: the development of an initial ANN model, optimization of the initial model, and performance tests of the optimized model. The development and performance testing of the ANN model were conducted through numerical simulation methods using transient systems simulation (TRNSYS) and matrix laboratory (MATLAB) software. Result: The results analysis in the development and test processes revealed that the indoor temperature, outdoor temperature, and temperature difference from the setback temperature presented strong relationship with the optimal start moment of the setback temperature; thus, these variables were used as input neurons in the ANN model. The optimal values for the number of hidden layers, number of hidden neurons, learning rate, and moment were found to be 4, 9, 0.6, and 0.9, respectively, and these values were applied to the optimized ANN model. The optimized model proved its prediction accuracy with the very storing statistical correlation between the predicted values from the ANN model and the simulated values in the TRNSYS model. Thus, the optimized model showed its potential to be applied in the control algorithm.

• 한국대기환경학회지
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• 제11권2호
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• pp.185-190
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• 1995

Recently, because of the worse of the air pollution, the excessive airtught of building and the inferiority of air conditioning system, the development of high efficiency air purification technology was enlarged to the environmental improvement of an indoor or a harmful working condition. The air purification technology has used chemical filters or charcoal filters or charcoal to remove hazardouse gaseous pollutants (SO$_{x}$, NO$_{x}$, NH$_{3}$, etc.) by air pollutant control technology, but they have many problems of high pressure loss, short life, wide space possession, and treatment of secondary wastes. For these reason, the object of reasearch shall be hazardous gaseous pollutants removal by the surface discharge induced plasma chemical process that is A.C. discharge of multistreams applied A.C. voltage and frequency between plane induced eletrode and line discharge eletrode of tungsten, platinum or titanium with a high purified alumina sheet having a film-like plane. As a result, the control performance for hazardous gaseous pollutants showed very high efficiency in the normal temperature and pressure. Also, after comtact oxidation decomposition of harmful gaseous pollutants, the remainded ozone concentration was found much lower than that of ACGIH or air pollution criteria in Korea.rea.

• 설비공학논문집
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• 제19권2호
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• pp.183-190
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• 2007

Controlling superheat of indoor units associated with a multi-type heat pump is one of difficult tasks to be addressed. This study suggests a dynamic model of an evaporator based on heat and mass balance. Thermodynamic properties are calculated by a commercial software, Refprop. The model is programmed in MFC Visual C++ for controller interface in real-time mode. The simulation results shows that PI control works for a narrow range of superheat. Beyond the range, the temperature behavior of the refrigerant is quite nonlinear mainly due to phase change. Thus, it is concluded that PI control of superheat has to be supplemented by nonlinear control ideas to avoid saturation and excessive superheat.

• 한국수산과학회지
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• 제46권5호
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• pp.565-570
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• 2013

Physiological studies on the salinity tolerance with respect to survival rate and body composition changes of the abalone Haliotis discus hannai were conducted by rapidly changing the salinity in an indoor rearing system. The survival rate of the control (35 psu), 30 and 25 psu groups at $15^{\circ}C$ was 100%. The survival rate of the 20 psu group was $35{\pm}5.0%$. Survival rate of the 15 psu group was 0%. At $15^{\circ}C$ and 35, 30, 25, 20, 15 psu, the moisture contents of abalone muscle were $82.1{\pm}0.7$, $82.5{\pm}0.7$, $84.9{\pm}0.5$, $86.9{\pm}0.3$ and $86.6{\pm}0.4%$, respectively. Crude lipid contents were $0.47{\pm}0.03$, $0.47{\pm}0.03$, $0.47{\pm}0.09$, $0.77{\pm}0.09$ and $0.63{\pm}0.03%$, respectively and crude ash contents were $1.30{\pm}0.12$, $1.33{\pm}0.15$, $1.13{\pm}0.23$, $1.87{\pm}0.15$ and $1.40{\pm}0.31%$, respectively. At salinity below 20 psu, these values increased compared with the control. The general components of abalone muscles significantly increased below 20 psu, while amino acid composition showed no significant difference with salinity and water temperature.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1727-1731
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• 2004

We propose an ART2 neural network-based fault diagnosis method to diagnose of sensor in the gas monitoring system. In the proposed method, using thermal modulation of operating temperature of sensor, the signal patterns are extracted from the voltage of load resistance. Also, fault classifier by ART2 NN (adaptive resonance theory 2 neural network) with uneven vigilance parameters is used for fault isolation. The performances of the proposed fault diagnosis method are shown by simulation results using real data obtained from the gas monitoring system.

• 설비공학논문집
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• 제18권9호
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• pp.707-713
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• 2006

To improve heating performance of the heat pump in winter season, refrigerant heating device was applied to conventional heat pump. The refrigerant heating device operates at the heating capacity does not enough to the heating load requirement of the conditioning space. When the discharge air temperature of the indoor heat exchanger goes down to below $40^{\circ}C$ which is criterion for comfort of the occupants in the conditioning space, the system also starts. The refrigerant heating system has new concept of auxiliary heating device for heat pump in winter. In this study, the system performance was analyzed through experiments and parametric study was conducted to improve the COP and control strategies.