• Title/Summary/Keyword: Heating and Cooling System

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Counting People Walking Through Doorway using Easy-to-Install IR Infrared Sensors (설치가 간편한 IR 적외선 센서를 활용한 출입문 유동인구 계측 방법)

  • Oppokhonov, Shokirkhon;Lee, Jae-Hyun;Jung, Jae-Won
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.35-40
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    • 2021
  • People counting data is crucial for most business owners, since they can derive meaningful information about customers movement within their businesses. For example, owners of the supermarkets can increase or decrease the number of checkouts counters depending on number of occupants. Also, it has many applications in smart buildings, too. Where it can be used as a smart controller to control heating and cooling systems depending on a number of occupants in each room. There are advanced technologies like camera-based people counting system, which can give more accurate counting result. But they are expensive, hard to deploy and privacy invasive. In this paper, we propose a method and a hardware sensor for counting people passing through a passage or an entrance using IR Infrared sensors. Proposed sensor operates at low voltage, so low power consumption ensure long duration on batteries. Moreover, we propose a new method that distinguishes human body and other objects. Proposed method is inexpensive, easy to install and most importantly, it is real-time. The evaluation of our proposed method showed that when counting people passing one by one without overlapping, recall was 96% and when people carrying handbag like objects, the precision was 88%. Our proposed method outperforms IR Infrared based people counting systems in term of counting accuracy.

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Research on Heat and Mass Transfer Coefficient in the Packing Layer With a Solar Desiccant Heating/Cooling System (태양열 데시컨트 냉난방시스템 중 충진층에 있어서의 열 물질전달에 관한 연구)

  • Yohana, Eflita;Choi, Kwang-Hwan;Kim, Bu-Ahn;Kim, Dong-Gyu;Paek, Ki-Dong;Kim, Ji-Won
    • Journal of the Korean Solar Energy Society
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    • v.26 no.3
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    • pp.17-24
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    • 2006
  • 최근에 에너지절약 차원에서 종래의 공조방식을 대신할 새로운 냉난방시스템 개발이 요구되고 있는데, 본 논문에서는 태양열 집열기를 이용하는 데시컨트 시스템 중 제습역할을 실질적으로 담당하는 제습기의 충진층 부분에서의 열 및 물질전달에 관한 일련의 해석 결과를 발표하고 있다. 제습과정에서 액체흡수제는 충진층에서 열 뿐만 아니라 물질전달을 수반하게 되는데, 이 결과 건물에 냉방 및 난방효과를 가져다 준다. 따라서 이 충진층의 최적 설계가시스템의 효율을 극대화하기 위해서는 무엇보다도 중요한데, 이를 위해서는 충진층에서의 열 및 물질전달 양상을 규명하여야 한다. 따라서 금번 실험에서는 공기와 액체흡수제와의 접촉면적을 넓히기 위해서 충진재로써 3cm(직경) ${\times}$ 3cm(높이)인 시판중인 플라스틱 재질을 사용하고, 실질적으로 40cm(너비)${\sim}$40cm(깊이)${\times}$40cm(높이)의 충진층을 직접 제작하여 실험을 행하였다. 그 결과, 공기측 열 및 물질전달 계수는 공기 온도와 밀접한 관계를 갖고 있으며, 또한 물질전달계수는 열전달계수와 같은 경향을 보이고 있음을 알 수 있었다.

A Study on Optimization of Vacuum Glazing Encapsulating Process using Frit inside a Vacuum Chamber (진공챔버 내 프리트 이용 진공유리 봉지공정 최적화에 관한 연구)

  • Park, Sang Jun;Lee, Young Lim
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.2
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    • pp.567-572
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    • 2013
  • In houses that use heating and cooling system, most of heat loss occurs through the windows, so that low-E glass, double-layered glass, and vacuum glazing are used to minimize the heat loss. In this paper, an encapsulating process that is a final process in manufacturing the vacuum glazing has been studied, and bonding in a vacuum chamber rather than atmospheric bonding was considered. For the efficiency of the encapsulating process, frit-melting temperature and bonding time were optimized with heater temperature, and the glass preheating temperature was optimized to prevent glass breakage due to thermal stress. Thus the vacuum glass was successfully manufactured based on these results and heat transmission coefficient measured was about $5.7W/m^2K$ which indicates that the internal pressure of the vacuum glazing is $10^{-2}$ torr.

Experiment on measures of heat collection for passive solar water wall systems that provide heat storage and natural lighting control (축열과 채광조절을 겸한 자연형 태양열 수벽시스템의 집열방식별 성능실험)

  • Oh, Young-hoon;Choi, Ji-eun;Lee, Chul-sung;Yoon, Jong-ho
    • KIEAE Journal
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    • v.16 no.4
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    • pp.63-69
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    • 2016
  • Purpose: This preliminary study investigated a potential of the water wall systems that provide heat storage and natural lighting control simultaneously. Method: In order for transparency of the water wall to be controlled, the study first proposed two measures: to adjust transparency of the water wall; to control transparency of water wall surface. The performance of two measures then was verified and compared by experiments. In addition, a trade-off between heat collect and heat storage resulting from using additive for adjusting transparency was investigated. Result: The experiment showed that the two measures are similar in performance. The investigation of trade-off relation showed the additive should have the same heat storage as the water to prevent decrease in thermal performance of the water wall. As an economical measure to control transparency of the water wall, this study suggested a measure of secondary heat transfer systems using shading device that first absorbs solar radiation and then transfers heat to the water wall. The experiment show that performance of the proposed measure is similar to controlling transparency of water wall surface. In conclusion, it is expected that the performance of the water wall can be economically maximized by using the proposed mean in terms of heating, cooling and lighting energy saving.

Salt Distiller With Mesh-covered Crucible for Electrorefiner Uranium Deposits

  • Kwon, S.W.;Lee, Y.S.;Kang, H.B.;Jung, J.H.;Chang, J.H.;Kim, S.H.;Lee, S.J.
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2017.05a
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    • pp.83-83
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    • 2017
  • Electrorefining is a key step in pyroprocessing. The electrorefining process is generally composed of two recovery steps - the deposit of uranium onto a solid cathode and the recovery of the remaining uranium and TRU elements simultaneously by a liquid cadmium cathode. The solid cathode processing is necessary to separate the salt from the cathode since the uranium deposit in a solid cathode contains electrolyte salt. Distillation process was employed for the cathode processing. It is very important to increase the throughput of the salt separation system due to the high uranium content of spent nuclear fuel and high salt fraction of uranium dendrites. In this study, a mesh-covered crucible was investigated for the sat distillation of electrorefiner uranium deposits. A liquid salt separation step and a vacuum distillation step were combined for salt separation. The adhered salt in uranium deposits was efficiently removed in the mesh-covered crucible. The salt distiller was operated simply since repeated cooling - heating step was not necessary for the change of the crucible. The operation time could be reduced by the use of the mesh-covered crucible and the combined operation of the two steps. A method to preserve a vacuum level was proposed by double O-rings during the operation of the distiller with the mesh-covered crucible. After the salt distillation, the salt content was measured and was below 0.1wt% after the salt distillation. The residual salt after the salt distillation can be removed further during melting of uranium metal.

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A Study on High Efficiency Geothermal Heat Pump System by Improving Flow of Heat Exchanger (열교환기의 흐름개선을 통한 고효율 지열 히트펌프 시스템에 관한 연구)

  • Ahn, Sung-Hwan;Choi, Jae-Sang;Kim, Sang-Bum;Ahn, Hyung-Hwan
    • Journal of the Korean Institute of Gas
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    • v.21 no.4
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    • pp.42-46
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    • 2017
  • As $CO_2$ emission with imprudent using fossil fuel, annual mean temperature of earth is increased in every year. Geothermal energy is inexhaustible energy resource to solve this problem. Heat pump performance and heat exchange efficiency of ground loop are important to distribute widely. Thus, this study are performed to increase heat pump performance and heat exchange efficiency of ground loop with dual expansion valves and spacer. As a results, COP of cooling & heating is obtained improvement up to 11.4% using dual expansion valves, and heat exchange efficiency is increased up to 17.5% using spacer. It will be reduced initial installation cost due to increasing heat pump performance and heat exchange efficiency of ground loop.

A Study on Absorber in Absorption Heat Pump with Methanol-Glycerine System as a Working Fluid (메탄올-글리세린계를 작동유체로 하는 흡수열펌프에서 흡수기 연구)

  • Min, Byong-Hun
    • Applied Chemistry for Engineering
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    • v.17 no.1
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    • pp.111-117
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    • 2006
  • The improvement of energy conservation mandates decrease consumption of fossil fuels and minimize negative impacts on the environment, which originates from large cooling and heating demand. The absorption heat pump technology has a large potential for energy saving in this respect. Adsorption heat pump is a means to upgrade waste heat without addition of extra thermal energy. The increase of absorbed amount is of great importance for absorption heat pump cycle. In this study, in order to improve the performance of absorber, the absorbers of two different types have been investigated using methanol-glycerine as a working fluid. The former was tangential feed of liquid phase without spiral tube in the absorber and the latter was with spiral tube in the absorber. The latter was found to be more effective in enhancing the mass and heat transfer to increase the absorption performance.

Formation and evolution of sub-galactic structures around dwarf galaxy-sized halos

  • Chun, Kyungwon;Shin, Jihye;Kim, Sungsoo S.
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.39.4-40
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    • 2016
  • We aim to investigate formation of satellite sub-galactic structures around isolated dwarf galaxies using cosmological hydrodynamic zoom simulations. For this, we modify a cosmological hydrodynamic code, GADGET-3, in a way that includes gas cooling down to T~10K, gas heating by universal reionization when z < 8.9, UV shielding for high density regions of $n_{shield}$ > $0.014cm^{-3}$, star formation in the dense regions ($n_H$ > $100cm^{-3}$), and supernova feedback. To get good statistics, we perform three different simulations for different target galaxies of the same mass of ${\sim}10^{10}M_{sun}$. Each simulation starts in a cubic box of a side length of 1Mpc/h with 17 million particles from z = 49. The mass of dark matter (DM) and gas particle is $M_{DM}=4.1{\times}10^3M_{sun}$ and $M_{gas}=7.9{\times}10^2M_{sun}$, respectively, thus each satellite sub-galactic structure can be resolved with more than hundreds or thousands particles. We analyze total 90 sub-galactic structures that have formed outside of the main halos but infall the main halos. We found that 1) mini halos that interact more with the other mini halos tend to accrete the more mass, 2) mini halos that interact more before the reionization tend to form more stars, 3) mini halos with the more interaction tend to approach closer to the galactic center and have the lower orbital circularity, 4) survivals even in the strong tidal fields evolve baryon dominated system, such as globular clusters.

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A Methodology of Databased Energy Demand Prediction Using Artificial Neural Networks for a Urban Community (인공신경망을 이용한 데이터베이스 기반의 광역단지 에너지 수요예측 기법 개발)

  • Kong, Dong-Seok;Kwak, Young-Hun;Lee, Byung-Jeong;Huh, Jung-Ho
    • 한국태양에너지학회:학술대회논문집
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    • 2009.04a
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    • pp.184-189
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    • 2009
  • In order to improve the operation of energy systems, it is necessary for the urban communities to have reliable optimization routines, both computerized and manual, implemented in their organizations. However, before a production plan for the energy system units can be constructed, a prediction of the energy systems first needs to be determined. So, several methodologies have been proposed for energy demand prediction, but due to uncertainties in urban community, many of them will fail in practice. The main topic of this paper has been the development of a method for energy demand prediction at urban community. Energy demand prediction is important input parameters to plan for the energy planing. This paper presents a energy demand prediction method which estimates heat and electricity for various building categories. The method has been based on artificial neural networks(ANN). The advantage of ANN with respect to the other method is their ability of modeling a multivariable problem given by the complex relationships between the variables. Also, the ANN can extract the relationships among these variables by means of learning with training data. In this paper, the ANN have been applied in oder to correlate weather conditions, calendar data, schedules, etc. Space heating, cooling, hot water and HVAC electricity can be predicted using this method. This method can produce 10% of errors hourly load profile from individual building to urban community.

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Evaluation of thermal stress of poultry according to stocking densities using mumerical BES model (BES 수치모델을 이용한 사육 밀도별 가금류 고온 스트레스 평가)

  • Kwon, Kyeong-seok;Ha, Tahwan;Choi, Hee-chul;Kim, Jong-bok;Lee, Jun-yeob;Jeon, Jung-hwan;Yang, Ka-young;Kim, Rack-woo;Yeo, Uk-hyeon;Lee, Sang-yeon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.456-463
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    • 2019
  • Micro climatic conditions within the livestock facility are affected by various factors such as ventilation, cooling, heating, insulation and latent and sensible heat generation from animals. In this study, numerical BES method was used to simulate energy flow inside the poultry house. Based on the BES method and THI concept, degree of thermal stress of poultry was evaluated according to the locations in South Korea. Comparison of THI values within the poultry house was also carried out according to the stocking densities to reflect recent animal-welfare issue. Significant decrease in thermal stress of poultry was observed when the stocking density of $30kg/m^2$ was applied in the change of the seasons(p<0.05) however, there was no statistically significant difference in summer season(p>0.05). It meant that installation of proper cooling system is urgently needed. For Iksan city of Jeollabuk-do province, total 252 hours of profit for thermal stress was found according to decrease in the stocking density.