• 제목/요약/키워드: Purge efficiency

검색결과 32건 처리시간 0.019초

설비공학 분야의 최근 연구 동향 : 2016년 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 2016)

  • 이대영;김사량;김현정;김동선;박준석;임병찬
    • 설비공학논문집
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    • 제29권6호
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    • pp.327-340
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    • 2017
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2016. 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 flow, heat and mass transfer, the reduction of pollutant exhaust gas, cooling and heating, the renewable energy system and the flow around buildings. CFD schemes were used more for all research areas. (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 of the long-term performance variation of the plate-type enthalpy exchange element made of paper, design optimization of an extruded-type cooling structure for reducing the weight of LED street lights, and hot plate welding of thermoplastic elastomer packing. In the area of pool boiling and condensing, the heat transfer characteristics of a finned-tube heat exchanger in a PCM (phase change material) thermal energy storage system, influence of flow boiling heat transfer on fouling phenomenon in nanofluids, and PCM at the simultaneous charging and discharging condition were studied. In the area of industrial heat exchangers, one-dimensional flow network model and porous-media model, and R245fa in a plate-shell heat exchanger were studied. (3) Various studies were published in the categories of refrigeration cycle, alternative refrigeration/energy system, system control. In the refrigeration cycle category, subjects include mobile cold storage heat exchanger, compressor reliability, indirect refrigeration system with $CO_2$ as secondary fluid, heat pump for fuel-cell vehicle, heat recovery from hybrid drier and heat exchangers with two-port and flat tubes. In the alternative refrigeration/energy system category, subjects include membrane module for dehumidification refrigeration, desiccant-assisted low-temperature drying, regenerative evaporative cooler and ejector-assisted multi-stage evaporation. In the system control category, subjects include multi-refrigeration system control, emergency cooling of data center and variable-speed compressor control. (4) In building mechanical system research fields, fifteenth 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, renewable energies, etc. Proposed designs, performance tests using numerical methods and experiments provide useful information and key data which could be help for improving 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 analyses of indoor thermal environments controlled by portable cooler, the effects of outdoor wind pressure in airflow at high-rise buildings, window air tightness related to the filling piece shapes, stack effect in core type's office building and the development of a movable drawer-type light shelf with adjustable depth of the reflector. The subjects of building energy were worked on the energy consumption analysis in office building, the prediction of exit air temperature of horizontal geothermal heat exchanger, LS-SVM based modeling of hot water supply load for district heating system, the energy saving effect of ERV system using night purge control method and the effect of strengthened insulation level to the building heating and cooling load.

효모배양물의 수준별 급여가 육성·비육돈의 생산성, 영양소 소화율, 돈육의 이화학적 특성 및 지방산 조성에 미치는 영향 (Effect of Dietary Supplementation of Yeast Culture on the Performance, Nutrient Digestibility and Physico-Chemical characteristics of the Pork in Growing-Finishing Pigs)

  • 박재홍;임오채;나종삼;류경선
    • Journal of Animal Science and Technology
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    • 제45권2호
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    • pp.219-228
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    • 2003
  • 본 연구는 양돈 사료에 효모배양물을 수준별로 급여(0, 0.1, 0.2, 0.4%)하여 총 2회 시행하였다. 실험 1에서는 처리구당 3반복으로 반복당 10두씩 총 120두를 공시하여 이유시부터 출하시까지 112일 동안 사양실험을 통하여 생산성을 조사하였고, 실험 2에서는 실험 종료후 도축된 돈육 등심의 품질을 고찰하였다. 효모배양물을 급여하여 112일 동안 성장 단계별로 조사한 증체량과 사료요구율은 효모배양물 급여구와 대조구간에서 차이를 보이지 않았다. 영양소 소화율은 조단백질과 조섬유 소화율에서 효모배양물 0.1과 0.2% 급여구가 대조구에 비하여 증가하였다. 효모배양물을 급여하여 생산된 돈육 등심의 일반성분 중 조단백질의 함량은 효모배양물 0.1%를 급여한 처리구가 대조구에 비하여 증가하였다. 돈육의 pH, 포장 감량 및 조리 감량은 처리구간에 차이가 없었고, 육색도 대조구와 비교해서 차이가 없는 것으로 나타났다. 돈육의 shearing force는 효모배양물 0.1% 급여구에서 대조구에 비하여 현저하게 낮았으나 cohesiveness, springiness, gumminess 및 brittleness에 있어서는 차이가 없었다. 돈육의 지방산 조성에서 포화지방산, 단가불포화지방산 및 다가불포화지방산은 효모배양물 급여구와 대조구간에 아무런 차이도 없었으며, 콜레스테롤 함량에서도 차이가 없었다.