• 제목/요약/키워드: mechanical HVAC

검색결과 96건 처리시간 0.031초

교반동력에 의한 기능성 물질 함유 수용액의 빙부착 평가 (Evaluation of Ice Adhesion in an Aqueous Solution with Functional Materials by Stirring Power)

  • 승현;백종현;홍희기;강채동
    • 설비공학논문집
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    • 제16권8호
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    • pp.720-727
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    • 2004
  • In the process of ice-slurry making, the phenomenon of ice adhesion influences extremely to ice making system. In this study, the effect on the ice adhesion by thermal storage material with additives is investigated quantitatively. Various solutions of 300 g in a stainless vessel were frozen under stirring. Through the experiment the ice adhesion between cooling wall and ice-slurry was compared with each other by measuring the stirring power. From the experiment, the stirring power in EG, SCA solution was smaller than those in the solution containing functional materials, such as poly-vinyl-alcohol or kitchen detergent.

지하역사 공기조화기에 적용 가능한 미세먼지 제거용 사이클론의 수치해석적 연구 (CFD Analysis of Axial Flow Cyclone Separator for Subway Station HVAC System)

  • 김진관;김호중;김명준;김태성;권순박
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 동계학술발표대회 논문집
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    • pp.546-550
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    • 2008
  • In this study, 3-dimensional Computational Fluid Dynamics (CFD) analysis was induced to simulate air flow and particle motion in the axial flow cyclone separator. The commercialized CFD code FLUENT was used to visualize pressure drop and particle collection efficiency inside the cyclone. We simulated 4 cyclone models with different shape of vane, such as turning angle or shape of cross section. For the air flow simulation, we calculated the flow field using standard ${\kappa}-{\varepsilon}$ turbulence viscous model. Each model was simulated with different inlet or outlet boundary conditions. Our major concern for the flow filed simulation was pressure drop across the cyclone. For the particle trajectory simulation, we adopted Euler-Lagrangian approach to track particle motion from inlet to outlet of the cyclone. Particle collection efficiencies of various conditions are calculated by number based collection efficiency. The result showed that the rotation angle of the vane plays major roll to the pressure drop. But the smaller rotation angle of vane causes particle collection efficiency difference with different inlet position.

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실공간 사용 공기조화가용 열교환기의 공기측 파울링 특성 예측 (Prediction of the Air-side Particulate Fouling in Finned-Tube Heat Exchangers of Air Conditioners used in the Field)

  • 황유진;김길태;정성일;이재근;안영철
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2005년도 동계학술발표대회 논문집
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    • pp.306-310
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    • 2005
  • The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performance of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. An empirical modeling equation is derived from the experimental results using accelerated tests and it shows good predictions of the fouling characteristics of the slitted finned tube heat exchangers. However the modeling equation predicts only the fouling characteristics of new heat exchangers and it can not predicts fouling characteristics obtained from actual field data. The purpose of this study is to modify the previous modeling equation using the actual field data Therefore an modified modeling equation is proposed and it shows good predictions of the actual fouling characteristics of finned-tube heat exchangers.

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Simulation of the Air Conditioning System Using Fuzzy Logic Control

  • Mongkolwongrojn, M.;Sarawit, W.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.2270-2273
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    • 2003
  • Fuzzy logic control has been widely implemented in air conditioning and ventilation systems which has uncertainty or high robust system. Since the dynamic behaviors of the systems contain complexity and uncertainty in its parameters , several fuzzy logic controllers had been implemented to control room temperature in the field of air conditioning system. In this paper, the fuzzy logic control has been developed to control room temperature and humidity in the precision air conditioning systems. The nonlinear mathematical model was formulated using energy and continuity equations. MATLAB was used to simulate the fuzzy logic control of the multi-variable air conditioning systems. The simulation results show that fuzzy logic controller can reduce the steady-state errors of the room temperature and relative humidity in multivariable air conditioning systems. The offset are less than 0.5 degree Celsius and 3 percent in relative humidity respectively under random step disturbance in heating load and moisture load respectively

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수용액의 교반/냉각을 동반한 슬러리 얼음의 빙부착 (Adhesion of Ice Slurry in an Aqueous Solution Cooling with Stirring)

  • 강채동;손권;백종현;홍희기
    • 설비공학논문집
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    • 제14권12호
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    • pp.1071-1077
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    • 2002
  • Ice adhesion on cooling wall is very important in continuous ice formation. The purpose of the present study is to investigate the possibilities of a three-component aqueous solution as a thermal storage material for the continuous ice formation. By freezing under stirring the solution of 300 mL in a stainless steel vessel which was immersed and cooled in a temperature controlled bath, an ice slurry was formed experimentally with measuring the temperature and stirring load variation. From the experiment, the ice adhesion was suppressed when the supercooling degree decreased and the concentration of aqueous solution increased.

시뮬레이션 모델기반 냉난방 설비 일별 최적 기동/정지 제어기법 개발 (Development of Simulation Model Based Optimal Start and Stop Control Daily Strategy)

  • 이찬우;구준모
    • 한국지열·수열에너지학회논문집
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    • 제14권1호
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    • pp.16-21
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    • 2018
  • This work aims to develop a platform to investigate the effect of operation schedules on the building energy consumption and to derive a simulation model based optimal start and stop daily strategy. An open-source building energy simulation tool DOE2 is used for the engine, and the developed simulation model is validated using ASHRAE guideline 14. The effect of late-start/early-stop operation of HVAC system on the daily building energy consumption was analyzed using the developed simulation model. It was found that about 10% of energy consumption cut was possible using the control strategy for an hour of advance of the stop operation, and about 3% per an hour of delay of the start operation.

차량용 에어컨필터 교환시점 알림 시스템 및 과농도 먼지 차단 시스템 (Auto Alarm System of Replacement Period for Vehicle Cabin Filter & Interception System of High Concentration Dust)

  • 이규세;변성욱;김영민;박성우;염영진
    • 대한기계학회논문집A
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    • 제32권11호
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    • pp.1035-1040
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    • 2008
  • Replacement period for vehicle cabin filter of most automobiles is fixed without consideration of conditions of filter and environment. Auto alarm system of replacement period at vehicle cabin filter and interception system of high concentration dust were developed. Control program which is related with the AQS has been developed based on the circuit drive algorithm. This system is expected to be beneficial to passenger's health and to extend the life of the filter which regulates vehicle HVAC system by ventilation mode change at the time of high concentration dust.

부산시 500m 메시 레벨에서의 건물용도 구성에 따른 유형화 분석 (An Analysis on the 500m - Mesh Classification based on the Combinations of Building Needs in Busan)

  • 황광일;최덕인;김다혜;양잉찬;윤소라
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2010년도 춘계학술대회
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    • pp.191-192
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    • 2010
  • 본 연구는 부산광역시를 대상으로 작성한 500m메시 별 건물용도별 면적 구성에 근거한 유형화에 대한 연구이다. 본 연구에서는 3289개의 유효한 메시를 대상으로 7개 용도군에 대한 데이터 베이스를 구축하였고, 그중 주거용, 상업용, 교육용 공간이 전체 공간의 92.4%를 차지하고 있으며, 용적율 50% 이상인 메시는 325개로 전체의 약 10% 수준이었다. 다양한 변수를 단순화하기 위해 주성분분석을 수행하였고 그 결과를 이용하여 클러스터분석을 수행하여 모든 메시를 5개 유형으로 분류하였다.

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