• Plant Journal
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• v.14 no.4
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• pp.33-38
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• 2018

In this study, it was confirmed whether the cooling water bypass ratio of packing for plume abatement matched designed value during winter operation of combined cycle power plant. Designed operating wet bulb temperature of the plume abatement cooling tower with 29 Gcal/h capacity had a range from $13^{\circ}C$ to $-20^{\circ}C$, while its designed bypass ratio was from 0 % to 78%, so that increasing rate of the designed bypass ratio was $2.36%/^{\circ}C$ when the external temperature decreased. When the wet bulb temperature at cooling tower inlet had a range from $7.8^{\circ}C$ to $-11.8^{\circ}C$ in a normal operation, it was measured that actual bypass ratio of packing for plume abatement had a range from 23.8 % to 74.3%. While increasing rate of the actual bypass ratio was $2.71%/^{\circ}C$ in a range from $7.8^{\circ}C$ to $-9.55^{\circ}C$, it was $1.61%/^{\circ}C$ under $-10^{\circ}C$ in cold weather condition according to atmospheric temperature drop, therefore it was confirmed that the increasing rate of the bypass ratio for packing was lowered than its design.

• Journal of the Korean Wood Science and Technology
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• v.33 no.6 s.134
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• pp.25-30
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• 2005

This experiment was carried out for the improvement of drying schedules for 50 mm-thick Japanese red pine (Pinus densiflora Sieb. et Zucc.) lumber. Drying rates were analyzed comparatively after drying to 15% of final moisture content through the applications of conventional kiln drying schedule, time schedule, continuously rising temperature schedule, and drying rate schedule. As results drying rate of 50 mm-thick red pine lumber was 0.53%/hr with conventional kiln drying schedule, 0.9%/hr with time schedule, 2.29%/hr with continuously rising temperature schedule, and 1.52%/hr with drying rate schedule, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.80-92
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• 1977

This experiment investigated the effect of various moisture levels on the top and root growth of barley and its yield. Resistant varieties to excess moisture injury shortened plant height, but tillered more, having creeping plant type compared with ordinary one, and greater portion of root of this varieties occured at the deeper soil depths with longer root length. However, susceptible one to excess moisture injury showed an inversed trend when compared with the untreated one. Oversaturated treatment compared with the untreated increased a little bit soil temperature and Eh of soil. Increased root activity and increased yield were obtained with resistant varieties compared with the untreated. Lower root activity and less yield than those of the untreated were observed in both extreme treatments. Yield reduction in both the extreme treatments was mainly due to reduction of tiller number, grain number and 1, 000-grain weight. Highest yield reduction was marked at the stage of internode elongation in the oversaturated and at the booting stage in the overdried treatment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.9
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• pp.779-785
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• 2003

The present work proposed a newly developed fluidized bed-type psychrometer that could be applicable to the high temperature and contaminant gases. The psychrometer is a device that test gas passes through the water in a glass bottle as a bubbly flow to obtain the adiabatic saturation temperature. A fluidized bed-type psychrometer was made and its characteristics were compared with the Assmann Psychrometer. The characteristic time was in the order of a hundred seconds, and decreased for the decrease of the mass of water and the increase of the air flow rate. The air flow rate and the insulation of the glass bottle were definitely important in the accurate measurement of the wet bulb temperature. The error in wet bulb temperature became less than 5 percent of the difference of dry and wet bulb temperatures if the air velocity in the glass bottle was greater than 1.5m/s.

• Proceedings of the KAIS Fall Conference
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• 2010.05b
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• pp.1123-1126
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• 2010

본 연구에서는 외기온습도에 따른 히트펌프 칠러의 난방성능을 조사하고자 하였다. 난방표준 온도조건에서 건구온도 및 습구온도 변화에 따른 히트펌프 칠러의 난방능력과 COP를 획득하기 위하여 항온항습 챔버와 항온수조를 사용하였다. 실험은 건구온도 $7^{\circ}C{\sim}17^{\circ}C$, 상대습도 67%~87%에서 수행하였다. 외기온도가 증가함에 따라 난방능력은 약 27%, COP는 약 28% 증가하였지만, 상대습도 증가에 따른 난방능력과 COP의 변화는 거의 없었다. 따라서 난방운전 시 건구온도의 영향은 크고, 상대습도의 영향은 미미함을 알 수 있었다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.439-444
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• 1983

Effects of temperature and soil moisture on the growth and grain-filling of two wheat cultivars were investigated. Two levels of temperature; day 3$0^{\circ}C$/night $25^{\circ}C$ and day 2$0^{\circ}C$/night 15$^{\circ}C$ and two levels of soil moisture; stressed (45-50% of F.C.) and non-5tressed (50-60% of F.C.) were imposed in the green house from heading date to the maturity and grain weight, chlorophyll content of flag leaf and leaf area index(LAI) were observed at weekly interval. Grain maturation was faster in the high temperature than those in the lower temperature. Chlorophyll content of flag leaf and LAI decreased rapidly in the high temperature and chlorophylls disappeared at the 20 days after heading. In lower temperature condition, slower decrements were shown in chlorophyll content and it remained until 45 days after heading. Grain weights in the high and optimum temperature conditions reached to maximum values at 29 days and 45 days after heading, respectively. Differences of grain weight and chlorophyll content of flag leaf were not significant between stressed and non-5tressed soil moisture condition.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2000.10b
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• pp.94-97
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• 2000

온실의 환경설계 중에서 가장 기본이 되는 냉ㆍ난방 설비용량의 결정을 위하여는 설계외기온(냉ㆍ난방설계), 외기의 습구온도 및 수평면 일사량(냉방설계)과 같은 기상자료가 필요하다. 시설재배에 있어서 환경설비의 용량 부족은 혹한기 또는 혹서기에 작물의 생육에 치명적인 영향을 미칠 수 있다. 또한 설비용량의 과대설계는 설치비 면에서 비경제적일 뿐만 아니라 에너지의 효율적 이용 측면에서도 불리하므로 적정 설비용량의 결정은 매우 중요하고, 따라서 설계용 기상자료의 선택은 매우 신중을 기하여야 한다. (중략)

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.07a
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• pp.202-208
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• 2002

진공냉각장치의 효율적인 설계를 위하여 파일럿 규모의 진공냉각장치에서 진공압력에 따른 작물별 냉각특성과 운전조작에 따른 냉각특성을 구명하는 요인실험을 실시한 결과 가. 배추와 같이 조밀하게 결구되어 있는 작물은 프레시 포인트로부터 습구온도와 품온에 따라 진공압을 조절함으로서 표면과 심부의 온도편차를 줄일 수 있고 버섯, 상추와 같이 개체가 작은 작물은 진공압력에 따른 온도편차가 거의 나타나지 않았다. 나. 포장방법에 따른 냉각 특성에서는 무개공 및 개공율 5% 골판지상자, PE 상자, 6mm 통기공이 있는 필름 포장에서의 냉각속도는 유사한 경향을 나타냈으나 0.8mm의 통기공을 가지고있는 필름 포장에서는 냉각속도가 현저히 낮게 나타나 필름 포장을 했을 경우 최소 개공율의 구명이 필요한 것으로 나타났다. 다. 예냉전 농산물 표면에 가수를 했을 경우 배추와 같은 결구성 농산물은 감모율 저하에는 효과적이었으나 무가수에 비해 냉각균일도와 냉각속도가 낮게 나타났으며 버섯에서는 감모율 저하 및 냉각속도 향상에 효과가 있는 것으로 나타났다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.10 no.1
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• pp.88-94
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• 1998

The thermal performance of cooling towers is affected mainly by the velocity, temperature and humidity of the entering air, In this paper, the effects of these variables are experimentally investigated for both counter-flow and cross-flow cooling towers. The cooling performance is reduced by up to 50% as the relative humidity of the entering air is increased from 40% to 80%. The higher air velocity and lower coolant flow show better cooling performance. The coolant loss rates in the present experimental conditions are in the range of 0.4 to 1.7%

• Journal of Advanced Marine Engineering and Technology
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• v.28 no.7
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• pp.1145-1151
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• 2004

The experiment of thermal performance about cross flow type cooling tower was conducted in this study. Generally the ambient air condition can affect the thermal performance of cooling tower to improve or not. However it is hard to control the cooling water temperature that we want under bad air condition or during rainy season. In this paper, the effect of variables, which the ambient air have. especially wet-bulb temperature, are experimentally investigated for controlling the cooling water temperature more successfully. The result is that there is appropriate air flow rate in respective air condition to preserve the cooling performance in the cooling tower and the maximum air flow rate can't overcome the approach under bad air condition.