• 한국태양에너지학회 논문집
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• 제30권3호
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• pp.108-115
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• 2010

Global warming and heat island make the outdoor air temperature ascend. Tall office buildings are covered with glass window facades as a design aspect and the portion of window area to facade area is increasing. Hence, cooling load for solar radiation passing through glass window is rising. Cooling air to a certain room is supplied equally despite the face of the room in most office buildings. Especially, the west part of the office cannot maintain the required temperature that occupant needs because of the solar heat coming through windows.?In this study, we projected the water spray system to reduce the solar heat transfer and to reflect the solar ray through windows. We perform the experiments to evaluate the performance of the solar heat protection devices. We measured the room temperature of two separated office rooms for solar heat control devices. The investigation's results show that the water spray system is sufficient to the coated glass and the venetian blinds for the decrease of the solar heat inflow.

• 수산해양교육연구
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• 제22권4호
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• pp.604-610
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• 2010

Busan subway transportation system has been established a key role in the society last 20 years. However many people are suffering from hot and humid environment at subway station and platform due to deteriorated ventilation system as well as insufficient air conditioning system in existing stations and platforms. As a result, these systems require revitalization. There is about 5400tons of low temperature underground water is generated from subway stations every day. By using this method and air washer we are trying to lower the temperature. Air washer is commonly used for removing humidity but in this experiment it will be used as air precooling. This research offers result of experiment using air washer system to lower the temperature in large spaces like subway station. The experiment result has shown when L/G was the same, at condition which water spray temperature at $18^{\circ}C$ resulting inlet and outlet temperature difference larger. Also, in the same water spray temperature conditions, larger L/G condition showed a greater temperature difference. LCC evaluation of both system were shown that air washer system of using underground water will save 53% of the initial cost than refrigeration system, and save 75% of operating cost.

• 펄프종이기술
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• 제37권4호통권112호
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• pp.38-43
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• 2005

Natural Com Starch(NCS) spray system has been widely used In multiply board mill for the better bonding strength between board layers. However the unsuitable NCS spray system could lead to a drop in plybond efficiency of multiply board. It could also result in the accumulation of unretained-starch in the white water system, which could not only rise in BOD and COD level but also reduce the effects of rosin-alum sizing system and other additives. In this study, the simple and rapid method by UV-spectroscopy for measuring the starch contents in the white water was proposed, and the quantitative analysis for dissolved starch content in white water was carried out in two kinds of board production process. It could be confirmed that about 150 ppm of oxidized starch was retained in white water dewatered from undertop ply of multiply board process, and about 470 ppm of natural starch was dissolved in white water originated from unsuitable spraying system in the multiply board production lines for cup base paper.

• 한국분무공학회지
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• 제28권1호
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• pp.43-48
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• 2023

The waste-heat-recovery boiler with water spray (HR-B/WS) applies the heat exchange between the inlet air and exhaust gas with the water spray into the inlet air. The evaporation of water in the inlet air promotes heat recovery from the exhaust gas so that thermal efficiency can be improved by the enhanced condensing effect. The NOx emission can also be reduced by lowering the flame temperature due to the dilution effect of the water. In this study, the validity of this concept is examined by the practical boiler test performed with a 24 kW condensing boiler under the full load condition according to the water injection amount. The theoretical amount of water injection is calculated under the assumption of full evaporation of the sprayed water, which is calculated as 50 g/min. Since the injected water cannot evaporate fully in the actual system, the maximum water spray amount is set as 100 g/min. The results showed that the water injection can increase the thermal efficiency up to 95.59% and reduce NOx and CO emissions simultaneously to 8.9 ppm and 35 ppm at 0% of O₂. Although the heat energy loss increased due to the unevaporated water, the increase in water injection amount caused higher thermal efficiency due to the increased amount of the evaporated water.

• 한국화재소방학회논문지
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• 제22권3호
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• pp.216-220
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• 2008

물분무소화설비는 화원의 냉각, 주변공기의 희석, 미세한 물방울의 증발에 의한 열차단과 같은 소화특성을 이용한다. 미분무수의 운동량은 입자가 큰 물방울에 비해 상대적으로 낮으며 화원의 침투능력도 효과적이지 못하다. 증발된 수증기에 의한 기여는 무게가 가볍고 밀도가 희박하여 화원에 일부분으로 제한되는 경향이 있다. 반면, 사이클식 미분무 패턴은 성층화된 분무 특성에 의해 공기 추출능력과 침투력이 개선될 것으로 예상된다. 이 논문에서는 유체공학적 화재모델인 FDS를 사용하여 교번식 미분무 패턴에 대해 분석된 소화능력을 다룬다. 저자는 이 분석이 미분무 노즐의 표본을 개발하기 위한 기본 개념을 제공할 수 있기를 기대한다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.334-339
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• 2008

An closed cooling tower is a device similar to a general cooling tower, but with cooling tower replaced by a heat exchanger. The purpose of this study is to evaluate thermal performance of heat exchanger at various conditions and to provide design datebase. The experimental study regarding heat exchanger for closed cooling tower was conducted. Experimental apparatus consists of constant temperature bath, water pump, spray nozzle, heat exchanger, fan, and date acquisition system. Heat transfer rates at various air velocitys, water flow rates, two different spray modes were measured and heat transfer coefficient were calculated to compare the thermal performances. This study provides that the heat transfer coefficient increases with increasing spray water flow rate and with increasing air velocity. The wet mode was more effective than dry mode for closed cooling tower to this study.

• Journal of Biosystems Engineering
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• 제29권3호
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• pp.217-224
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• 2004

This research was conducted to test the feasibility of utilizing high-pressure water jets of over 1.0㎫ as a means of breaking and peeling garlic bulbs. High-pressure plunger pumps and flat-spray nozzles of varying orifice diameters and spray angles were utilized to supply water jets into a prototype peeling chamber made of transparent acrylic plates. Water jets were discharged from a total of six nozzles installed in such a way that three parallel nozzles face the other three. The cross-sectional area of the peeling chamber and the installation angle of the nozzles had critical effects on peeling performance. Small cross-sectional area was required so that total impact force of water jets on garlic could be increased. The optimum installation angles were around 4, 8, and 16$^{\circ}$ for the nozzles having 15, 40, and 65$^{\circ}$ spray angles, respectively. Best performance with 61.4% of completely-peeled garlics was obtained at a pressure of 1.94㎫ and a flow rate of 9.07 $\ell$/min for each nozzle. The peeling efficiency of the system was generally unsatisfactory due to the limited flow rate of the plunger pumps utilized. For better performance, it is recommended to increase flow rate while reducing operating pressure by utilizing other type of pumps.

• 마이크로전자및패키징학회지
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• 제10권4호
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• pp.65-71
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• 2003

압전 세라믹스를 이용하여 약품 분사용 초음파분사 노즐을 제작하였다. 정수장의 혼화 공정에 사용되는 약품(응집제)의 고효율 분산을 위해 분사 노즐을 설계하였으며 압전세라믹을 최적화하였다. 제작된 초음파 약품 분사 노즐을 패키징하여 정수장의 약품 혼화 과정에 적용하여 약품사용의 고 효율화와 사용량 저감을 위한 연구를 진행하였다. 압전체는 실리콘으로 마감처리를 하였으며 Al으로 패키징하였다. 본 초음파 분사 노즐 시스템을 적용하여 혼화지에 실험한 결과 약품의 순간 혼화를 촉진시키는 기술로 투입 약품량을 저감시킬 수 있을 것으로 판단된다. 초음파 발진 약품 분사시, 무발진과 비교하여 대장균 제거 효율에서 현저하게 높아졌다.

• 한국재난정보학회 논문집
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• 제17권1호
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• pp.120-127
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• 2021

연구목적: 본 연구는 미분무 소화설비의 FDS모델링 수행에 있어 액적과 관련된 변수의 설정 변화가 살수밀도에 미치는 영향을 알아보았다. 연구방법: 미분무 노즐의 살수 현상을 FDS에서 해석할 경우 액적과 관련하여 설정할 수 있는 항목 중 초당액적수, 액적속도, 입경분포함수, 분사패턴형태의 값을 입력하여 분석된 결과를 검토하였다 연구결과: 분석결과에서, 초당미립자 수 설정은 일정 값 이상이 되면 유사한 바닥면의 살수밀도를 보여주었다. 액적속도는 낮아짐에 따라 중심부분의 살수밀도를 높이지만 0.15m 이상 떨어진 거리에서는 낮아짐을 알 수 있었다. 입경분포함수의 변화에 대한 분석에서, 𝛾값의 증가는 중심부분의 살수밀도의 증가를 가져오지만, 떨어진 위치에서의 값은 감소를 가져온다는 점을 알 수 있었다. 가우시안 분포를 적용한 결과에 비하여 균등분포를 적용하는 경우 중앙값은 극적으로 낮아지지만 인접위치에서의 값은 증가함을 보여준다. 결론: FDS의 액적특성에 관련된 변수들은 각각 바닥면의 살수밀도에 영향을 준다. 그러므로 화재 진압이나 냉각 등의 해석에 들어가기 전 신뢰성을 확보하기 위하여 입력변수에 대한 면밀한 검토가 필요하다.

• 한국입자에어로졸학회지
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• 제13권2호
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• pp.65-77
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• 2017

In recent large-scale semiconductor manufacturing cleanrooms, the energy consumption in outdoor air conditioning (OAC) systems to heat, humidify, cool and dehumidify outdoor air(OA) represents about 40~50 % of the total cleanroom power consumption required to maintain cleanroom environment. Therefore, the assessment of energy consumption in outdoor air conditioning systems is essential for reducing the outdoor air conditioning load for a cleanroom. In the present study, an experiment with an outdoor air flow rate of $1,000m^3/h$ was conducted to compare the energy consumption in steam humidification, simple air washer, exhaust air heat recovery type air washer and dry cooling coil(DCC) return water heat recovery type air washer OAC systems. Besides, a numerical analysis was carried out to evaluate the annual energy consumption of the aforementioned four OAC systems. It was shown that the simple air washer, exhaust air heat recovery type air washer and DCC return water heat recovery type air washer OAC systems using water spray humidification were more energy-efficient than the steam humidification OAC system. Furthermore the DCC return water heat recovery type air washer OAC system was the most energy-efficient.