• 제목/요약/키워드: Optimum heating environment

검색결과 61건 처리시간 0.027초

양방향수전해 기반 수소제조용 초고온스팀 생산시스템의 엑서지 분석 (Exergy Analysis on the System of Superheated Steam (700℃, 3 atm) Production for the Reversible Electrolysis: Based Hydrogen Production)

  • 한단비;박성룡;조종표;백영순
    • 한국수소및신에너지학회논문집
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    • 제29권3호
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    • pp.235-242
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    • 2018
  • Hydrogen can be produced by reforming reaction of natural gas (NG) and biogas, or by water electrolysis. In this study, hydrogen production through water-electrolysis needs superheated steam above $700^{\circ}C$ for high efficiency. The production method of hydrogen like this was recommended for the 4-type processes for superheated steam ($700^{\circ}C$, 3 atm) by Bio-SRF combustion furnace. The 4-type processes to produce superheated steam at $700^{\circ}C$ from the heat source of SRF combustion furnace was simulated using PRO II. The optimum process was selected through exergy analysis. The difference of process 1 and 2 is to the order of depressure and heating process to change $180^{\circ}C$ and 7 atm to $700^{\circ}C$ and 3 atm. Process 3 and 4 is to utilize 25% of steam to generate superheated steam and remaining to use for the power generation by steam generator.

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
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    • 제27권7호
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    • pp.380-394
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    • 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.

건축물 열환경 특성제어를 위한 상변화 축열재 (Heat Storage Material by Using Phase Change Materials to Control Buildings Thermal Environment Characteristics)

  • 윤희관;한성국;심명진;안대현;이웅목;박종순;김재용
    • 공업화학
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    • 제21권5호
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    • pp.522-526
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    • 2010
  • 축열이용기술은 열저장효과를 이용하여 냉난방 부하가 적을 때 남는 열을 저장하였다가 부하가 증가할 때 이용하는 방법으로써, 열저장 물질의 온도이용 특성에 따라 현열축열과 잠열축열로 구분한다. 잠열축열은 특정 온도 범위에서 상변화 할 때 높은 잠열을 갖는 물질을 이용하여 열을 저장하는 방법으로 동일한 열저장을 위해 소요되는 공간 크기가 현열 축열에 비하여 작아지게 되고 일정한 온도범위에서 열의 흡수 및 방출이 가능한 특성이 있다. 본 연구는 건축물의 냉난방시 소요되는 에너지를 절약하기 위하여 상온 상변화물질을 축열재로 사용하여, 건축자재로 범용적으로 사용되고 있는 시멘트, 석고 등에 적용하고자 하였다. 제조된 물질이 에너지절약성능은 물론 건축자재로서 필요한 물성을 갖추기 위하여 최적배합 방법 및 비율을 도출하고자 하였다. 그에 따라 중량비로 3% 들어간 축열모르타르의 냉각지연효과는 약 19%로 나타났다.

연료전지 자동차용 이산화탄소 열펌프 시스템에서의 냉방 성능에 관한 실험적 연구 (An experimental study on the cooling performance of carbon dioxide heat pump system for fuel cell vehicles)

  • 김성철;박민수;김민수;황인철;노영우;박문수
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.378-383
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    • 2005
  • This experimental study presents the results of the cooling performance test of a $CO_2$ heat pump system for fuel cell vehicles. The experimental facility provides the cool ing and heating environment for cabin and heat releasing component. The test loop is designed to target the cooling capacity of 5kW and its coefficient of performance (COP) of 2.2. The cooling performance of the heat pump system is strongly dependent on the refrigerant charge and the degree of superheat. We carried out basic experiments to obtain optimum refrigerant charge and the degree of superheat level at the internal heat exchanger outlet. The heat pump system for fuel cell vehicles is different from that of engine-driven vehicles, where the former has an electricity-driven compressor and the latter has the belt-driven (engine-driven) compressor. In the fuel cell vehicle, the compressor speed is an independent operating parameter and it is controlled to meet the cooling/heating loads. Experiments were carried out at cooling mode with respect to the compressor speed and the incoming outdoor air speed. The results obtained in this study can provide the fundamental cool ing performance data using the $CO_2$ heat pump system for fuel cell vehicles.

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무창분만돈사의 온.습도 환경 분석 (Environmental Analysis of a Windowless Delivery Swine Building : Temperature and Relative Humidity)

  • 이성현;조한근;장유섭
    • 한국축산시설환경학회지
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    • 제3권2호
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    • pp.77-85
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    • 1997
  • Recently, local swine producers are rapidly adopting the indoor production system which developed in foreign countries. However, this imported system is reported as not functioning properly because of different climate conditions. The objective of this project was to investigate the environment characteristics of a windowless delivery swine building. The parameters studied were the heating and cooling loads, the daily changes of indoor temperature and relative humidity, the horizontal and the vertical distributions of indoor temperature, and the effect of mist cooling on indoor temperature. From this study, the following are founded : 1. The maximum cooling and heating loads were - 317.0kcal/㎡$.$h and 336.5kal/㎡$.$h in summer and in winter. The large loads seems to be on account of inappropriate operations of ventilating fans. 2. The daily variations of relative humidity in indoor were smaller than those in outside. Those values both in summer and in winter as relative humidities in door was lower than optimum for growing pigs, the additional humidifier might be helpful to increase the relative humidity in indoor. 3. The horizontal distribution of the indoor temperature was found to be uniform in the variation range of 1$^{\circ}C$. 4. The vertical distribution of the indoor temperature was not found to be uniform; the temperature of upper part was higher than that of slot part. 5. Average values of indoor temperature became lower by 3$^{\circ}C$ by mist cooling. But the variation of temperature was found to be larger; The middle part of the room was cooled down, but the corner part of the room was not affected by misting due to uneven nozzle configuration.

가온 재배 시 '피오네' 포도(Vitis vinifera × V. labrusca)의 엽과비에 따른 과실 특성 (Fruit Characteristics Based on Leaf to Fruit Ratio in 'Pione' Grapevine (Vitis vinifera × V. labrusca) during Cultivation with Heating)

  • 윤석규;박서준;정성민;김정배;윤익구;남은영;유덕준;이희재
    • 한국환경농학회지
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    • 제33권1호
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    • pp.57-62
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    • 2014
  • BACKGROUND: Defoliation in grapevine cultivation is practically used to improve light environment within the canopy and thereby fruit quality. Effects of defoliation in five-year-old 'Pione' grapevine during cultivation with heating were investigated to find out optimum ratio of leaf area to fruit cluster weight (L/F). METHODS AND RESULTS: The grapevines were defoliated with berry-thinning 20 days after full bloom to provide various levels of L/F. At harvest, total leaf area values of fruit bearing branches were between 0.23 and $0.60m^2$. With increasing L/F, soluble solids and anthocyanin contents curvilinearly increased ($R^2=0.76^{**}$). At L/F over $0.6m^2/kg$, soluble solids content (SSC) leveled off. With increasing L/F, titratable acidity (TA) linearly decreased ($R^2=0.87^{**}$), but the ratio of SSC to TA linearly increased ($R^2=0.86^{**}$). Anthocyanin content was significantly correlated with SSC and the ratio of SSC to TA ($R^2=0.80^{**}$ and $0.82^{**}$, respectively). When total leaf area per fruit bearing branch was maintained $0.40m^2$, soluble solids and anthocyanin contents linearly decreased ($R^2=0.79^{**}$ and $0.85^{**}$, respectively), but TA linearly increased with increasing fruit cluster weight ($R^2=0.70^{**}$). Fruit was low in quality when the L/F was below $0.6m^2/kg$. CONCLUSION: L/F is recommended to be maintained at least $0.6m^2/kg$ in 'Pione' grapevine during cultivation with heating to produce higher-quality fruits.

Loop-mediated isothermal amplification (LAMP)법을 이용한 Streptococcus parauberis 의 신속 진단 (Loop-mediated Isothermal Amplification (LAMP) for Detection of Streptococcus parauberis)

  • 문경미;김동휘;허문수
    • 생명과학회지
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    • 제24권4호
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    • pp.428-436
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    • 2014
  • Loop-mediated isothermal amplification (LAMP)법은 등온에서 DNA 주형을 변성시키지 않고 실시하기 때문에, autocycling 가닥 변위 DNA 합성에 의존한다. 그래서 고가의 PCR 장비를 필요로 하지 않고 등온 유지가 가능한 저가의 장비인 항온 수조, 오븐, 온장고 등에서 증폭이 가능하다. 본 연구진은 Streptococcus parauberis의 random primer중에서 5개를 선정하여, 신장도가 높은 2개의 primer를 이용하여 최적 반응온도 및 최적 반응시간, 최적 반응 조건들을 확립하였다. 그리고 기존의 PCR과 LAMP의 민감도의 비교 분석을 측정한 결과, LAMP의 높은 검출 한계를 확인할 수 있었다. 본 논문에서는 non-target DNA의 영향을 받지 않고 등온 조건 하에서 DNA를 증폭시킬 수 있는 LAMP법과 SYBR-green I를 이용하여 시각화시켰으며, 기존의 PCR과 비교 분석함으로써, S. parauberis에 대한 신속하고 정확한 진단법을 확립하였다.

동적 시뮬레이션을 이용한 태양광열 시스템의 성능특성 분석 (Study on the Analysis Performance of PVT system using the Dynamic Simulation)

  • 김상열;남유진
    • KIEAE Journal
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    • 제15권2호
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    • pp.95-101
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    • 2015
  • Purpose: A photovoltaic/thermal system is a solar collector combining photovoltaic module with a solar thermal collector, which produces electricity and heat at the same time. PVT system removes heat from PV module through air or liquid that would help to raise the efficiency of the PV systems performance. Many innovative systems and products have been put forward and their quality evaluated by academics and professionals. However, even though various of PVT system were developed and several systems were applied to practical use, there have been few researches for the performance analysis using the dynamic simulation. Method: In this study, the review of recent research and development trend for PVT systems were conducted. Furthermore, in order to develop the optimum design method, the performance analysis for PVT system was conducted by a dynamic simulation. Result: In the results, it was found that the performance of PVT system significantly depends on the ambient temperature and solar radiation. Moreover, in the weather condition of Seoul, average efficiency of electricity and heat in heating season were 13.79 and 41.85%, and they in cooling season were 14.39% and 26.18%, respectively.

원자력시설의 공기조화 시스템 고찰 (Study on HVAC System in Nuclear Facility)

  • 백상열;송웅섭;오연우;주용선;홍권표
    • 한국방사성폐기물학회:학술대회논문집
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    • 한국방사성폐기물학회 2003년도 가을 학술논문집
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    • pp.503-508
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    • 2003
  • 원자력 시설의 공기조화 시스템은 일반시설의 공기조화 시스템에 비하여 더 안정되고 여유있게 설치 및 시공되어야 한다. 그 목적은 최적 작업환경유지, 오염 공기로부터의 작업자 보호, 외부배기로 인한 대기오염 방지 등이다. 낮은 공기오염조차 막는 것이 원자력시설의 안전한 운전을 위해 기본적인 것이다. 설계 시 시스템의 융통성을 갖는 설계가 필요한데 이는 나중에 시스템의 수정보완 등을 고려할 때 중요하다. 본 논문에서는 원자력시설의 공기조화계통 설계에 고려해야 할 내용 및 외국시설에 대하여 검토하였는바, 원자력시설의 공기조화계통 설계에 활용될 수 있겠다.

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원자력 발전소에 대한 밀폐 ${CO}_{2}$ 가스터빈 프로세스의 최적화 연구 I (A Study on the Optimum of Closed ${CO}_{2}$ Gas Turbine Process for Nuclear Energy Power Plant(I))

  • 이찬규;이종원
    • 대한기계학회논문집
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    • 제13권3호
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    • pp.490-499
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    • 1989
  • 본 연구에서의 CO$_{2}$ 프로세스는 1차 루프인 원자로에서 유도되는 나트륨 과 2차 루프인 CO$_{2}$ 가스터빈 사이클로 구성하였고, CO$_{2}$ 임계점 부근에서 압축을 행하였다. 또한 최적의 사이클을 결정하기 위해 h-s 선도와 이에 대한 열역 학적, 칼로리로 유도하였다. 그리고 최적화를 위해 출력을 각각 300,600, 1000MWe로 선택하였고, 터빈 입구압은 150-350bar의 범위로 선택하였으며 이들로부터 열효율에 영향을 주는 각 설계변수의 특성을 연구 분석하였다.