• 제목/요약/키워드: Thermal controls

검색결과 118건 처리시간 0.02초

열원 및 공조설비 통합 최적제어기법 구현에 관한 연구 (Real Time Near Optimal Control Application Strategy for Heat Source and HVAC System)

  • 송재엽;안병천;주영덕;김진
    • 대한설비공학회:학술대회논문집
    • /
    • 대한설비공학회 2008년도 하계학술발표대회 논문집
    • /
    • pp.60-65
    • /
    • 2008
  • The near-optimal control algorithm for central cooling and heating system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air and chilled or hot water temperatures. The near optimal control algorithm has been implemented by using LabVIEW program in order to analyze energy performance for central cooling and heating control system.

  • PDF

중앙냉방시스템의 실시간 준최적제어 적용에 따른 실험적 연구 (Real Time Near Optimal Control Application Strategy of Central Cooling System)

  • 안병천;송재엽;주영덕;김진
    • 설비공학논문집
    • /
    • 제20권7호
    • /
    • pp.470-477
    • /
    • 2008
  • The near-optimal control algorithm for central cooling system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor cooling load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air and chilled water temperatures. The near optimal control algorithm has been implemented by using LabVIEW program in order to analyze energy performance for central cooling control system.

근통증이 유발된 흰쥐에 있어 TENS와 냉적용이 이차성 열 통각과민에 미치는 영향 (The Effects of TENS and cold application on secondary thermal hyperalgesia in rats induced by muscle pain)

  • 채윤원;김상엽;김진상;박래준;구현모;임창훈
    • The Journal of Korean Physical Therapy
    • /
    • 제16권2호
    • /
    • pp.181-194
    • /
    • 2004
  • The aim of this study was to investigate the effects of TENS and cold application on secondary thermal hyperalgesia in rats induced by muscle pain. Muscle pain was induced in male Sprague-Dowley rats by intra-muscular injection of gastrocnemius with $3\%$ carrageenan. The paw withdrawal latency(PWL) and tail flick test(TFT) to heat were used to detect secodary thermal hyperalgesia induced by the muscle pain. PWL and TFT were quantified before and 4, 10, and 24 h after induction of muscle pain and after application of TENS(100Hz, $100{\mu}s$, sensory intensity) and cold($4^{\circ}C$). TENS and cold significantly reduced the PWL and TFT to heat stimuli when compared with controls receiving no TENS and cold(p<.05). These results suggested that application of TENS and cold attributed to decrease secodary thermal hyperalgesia in rat induced by muscle pain.

  • PDF

전극 구조가 간편한 삼상 교류 플라즈마 토치 (Three-Phase AC Plasma Torch with Simple Electrode System)

  • 김광수;박점문;김영배;이홍식;임근희
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2000년도 하계학술대회 논문집 C
    • /
    • pp.1859-1861
    • /
    • 2000
  • The high temperature thermal plasma technology applied to waste treatment has undoubtedly gained high importance owing to its outstanding properties such as flexibility, compact reactor. and clean treatment as the environmental problem goes to a main issue in public talks, because the thermal plasma with temperature of around 10,000K or little less is particularly suitable for waste treatment. Since the thermal plasma is, in general, governed by a number of parameters, some complicated and elaborate controls might be mandatory. The high maintenance cost caused by big input power has been a main obstacle to the growth of the waste treatment plant based on thermal plasma technology, but the recent R&D on the waste-to-energy shows that the problem could be solved soon. In this paper, the authors introduce the current R&D activity related to three-phase ac plasma torch in KERI.

  • PDF

주거용 건물의 유형에 따른 환경조절요구에 대한 분석 (An Analysis of Demand for Environmental Controls on Different Residential Building Types)

  • 이승복;원종서
    • 설비공학논문집
    • /
    • 제16권10호
    • /
    • pp.960-968
    • /
    • 2004
  • One of the most important functions of a building is to provide thermally comfortable indoor environmental conditions for the occupants. Therefore, a great deal of energy is consumed for heating and cooling to satisfy those thermal requirements. In order to provide thermal comfort with minimum heating and cooling energy consumption, optimal design of building affecting indoor climate is required. This study used the TRNSYS for modeling and simulation of the energy flows of residential building types, and examined the energy efficient measures to reduce the thermal loads. The residential building types are classified into the detached house, apartment house and high-rise residential complex. The results of the simulation show that the heating energy consumption in the detached house is especially high, whereas the cooling load is an important determinant in the apartment house and high-rise residential complex. The measures examined are the insulation thickness, various types of glazing, infiltration, natural and controlled ventilation, solar shading, orientation and etc. Comparative evaluations and sensitivity analyses revealed the effects of these variables and identified their energy efficient building design strategies.

핵 연료 요소내의 접촉 열전도도 측정 (Measurement of The Thermal Contact Conductance in Nuclear Fuel Element)

  • ;윤병조
    • Nuclear Engineering and Technology
    • /
    • 제22권1호
    • /
    • pp.75-81
    • /
    • 1990
  • 핵연료봉내의 온도 분포를 결정하는데 있어서 중요한 핵연료소자와 피복판 사이의 접촉 열전도도를 결정하기 위한 실험을 수행하였다. 이 실험에 사용된 측정장치는 접촉압력을 임의로 변화시켜 줄 수 있는 가압기와 열전대, 진공펌프, 핵연료소자, 봉형태의 피복관, 그리고 두 개의 히터 등으로 구성되어 있다. 접촉 열전도도는 $UO_2$ 소자와 Zircaloy-2 피복관 사이의 접촉 압력과 표면 조도를 변화시키면서 측정하였다. 그 결과 두 물체사이의 접촉압력이 증가함에 따라, 그리고 표면이 매끄러울수록 접촉 열전달계수는 증가하였다. 실험에서 얻은 값을 가지고 상관식을 만들었으며 일반적으로 사용되고 있는 상관식과 비교하였다.

  • PDF

설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰 (Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
    • /
    • 제27권7호
    • /
    • pp.380-394
    • /
    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

흡기관분사식 수소기관의 특성 및 역화한계당량비의 해석 (A Study on Characteristics and the Back Fire Limit Equivalnce Ratio of Hydrogen Fueled Engine with External Mixture)

  • 백성호;이종태
    • 한국수소및신에너지학회논문집
    • /
    • 제7권1호
    • /
    • pp.55-62
    • /
    • 1996
  • As an essential step for development of a duel injection hydrogen fueled engine which can obtain high thermal efficiency and power in overall operating range, performance and BFL(back fire limit) equivalance ratio in hydrogen fueled engine with external mixture are investigated. As the results, BFL equivalence ratio in hydrogen fueled engine with external mixture is approximately 0.7. It is deduced that controls of driving conditions are required in transient stage from external mixture type to inner injection type. And in order to increase thermal efficiency, it is also found that BFL equivalence ratio should be expanded as much as possible.

  • PDF

CNG와 경유의 2원 연료 디젤기관의 성능 및 배출가스 개선을 위한 실험연구 (Improving Performance and Emissions in a Diesel Engine Dual Fueled with Compressed Natural Gas)

  • 김복석;;박찬국
    • 한국자동차공학회논문집
    • /
    • 제8권2호
    • /
    • pp.57-63
    • /
    • 2000
  • This paper deals with a study on combustion and emission characteristics of a direct injection diesel engine dual fueled with natural gas. Dual fuelling systems tend to emit high unburned fuel especially at low load, resulting in a decreased thermal efficiency. This is because natural gas-air mixtures are too lean for flame to propagate under low load conditions. Suction air quantity and injection timing controls are very useful to improve emissions and thermal efficiency at low load.

  • PDF

플라즈마 용사법에 의한 지르코니아 코팅에서의 잔류응력에 대한 연구 (Residual stresses on plasma sprayed zirconia coatings)

  • 류지호;강춘식
    • Journal of Welding and Joining
    • /
    • 제7권4호
    • /
    • pp.46-55
    • /
    • 1989
  • Zirconia coatings are performed by the plasma spraying on the substrate of Al-Si alloy. In case of plasma sprayed ceramic coatings, it is important to control properly residual stress occurred during cooling process. Residual stress in coating layer varies with sprayed conditions and is influenced greatly by the coating layer thickness. Surface residual stress due to coating layer thickness is measured by X-ray diffraction method and the residual stress in coating layer is estimated by the deflection of coating layer when the restraint force in substrate was removed. When zirconia was coated on the substrate, tensile residual stress remains on zirconia coated surface layer. The tensile stress is increased to 0.35mm thickness and after 0.45mm thickness it is decreased abrouptly. A thick bond and composite coating reduce the zirconia surface stress and composite coating controls effectively the thick zirconia surface stress.

  • PDF