• 설비공학논문집
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• 제16권2호
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• pp.175-183
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• 2004

Performance of the water/air direct contact air conditioning system, in which heat and mass are directly transferred between air and water droplet, is simulated using semi-empirical method. Direct contact system improves transport efficiency compared to conventional indirect contact system. In this study, correlations for h$_{c}$A / c$_{pm}$ which represent the capacity of direct contact system are derived as a function of air and water flowrate from the experimental data. Cooling and heating performance of the water/air direct contact air conditioning system are evaluated using these correlations.ons.

• Journal of Mechanical Science and Technology
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• 제18권6호
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• pp.1002-1009
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• 2004

Direct contact air conditioning systems, in which heat and mass are transferred directly between air and water droplets, have many advantages over conventional indirect contact systems. The purpose of this research is to investigate the cooling and heating performances of direct contact air conditioning system for various inlet parameters such as air velocity, air temperature, water flow rate and water temperature. The experimental apparatus comprises a wind tunnel, water spray system, scrubber, demister, heater, refrigerator, flow and temperature controller, and data acquisition system. The inlet and outlet conditions of air and water are measured when the air contacts directly with water droplets as a counter flow in the spray section of the wind tunnel, and the heat and mass transfer rates between air and water are calculated. The droplet size of the water sprays is also measured using a Malvern Particle Analyzer. In the cooling conditions, the outlet air temperature and humidity ratio decrease as the water flow rate increases and as the water temperature, air velocity and temperature decrease. On the contrary, the outlet air temperature and humidity ratio increase in the heating conditions as the water flow rate and temperature increase and as the air velocity decreases.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집D
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• pp.158-163
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• 2001

Performance of the water direct contact air conditioning system, in which heat and mass are transferred directly between air and water droplet, is simulated by semi-empirical method. This system improves transport efficiency compared to conventional indirect contact system and cooling, heating, dehumidification and humidification are attained with one unit. In this study, temperature and flowrate for air and water are measured in the various cooling and heating conditions, and correlations for $h_{c}A/c_{pm}$ are derived from these data. Cooling and heating characteristics of the water direct contact air conditioning system are investigated using correlations.

• 설비공학논문집
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• 제20권1호
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• pp.75-80
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• 2008

The objective of this research was to investigate the enhancement of heat transfer by mesh in water/air direct contact air conditioning system. Mesh is inserted as a turbulent promoter in front of the water injection nozzle. The heat transfer characteristics with and without mesh and the effect of the number of inserted mesh and mesh porosity size have been studied experimentally. Inserted mesh improves heat transfer efficiency compared to non~inserted mesh system and heat transfer efficiency increased as the number of mesh is increased. Meanwhile, heat transfer efficiency decreased as the porosity of the mesh is increased. With inserted mesh, inlet and outlet temperature difference of air increased more than 50%. Heat exchange time of water/air to reach the 100% humidity decreased less than 30%. This result shows inserted mesh can enhance the performance of the water/air direct contact air conditioning system.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1161-1166
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• 2008

The objective of this research was to investigate the enhancement of heat transfer by mesh in water/air direct contact air conditioning system. Mesh is inserted as a turbulent promoter in front of the water injection nozzle. The heat transfer characteristics with and without mesh and the effect of the number of inserted mesh and mesh porosity size have been studied experimentally. Inserted mesh improves heat transfer efficiency compared to non-inserted mesh system and heat transfer efficiency increased as the number of mesh is increased. Meanwhile, heat transfer efficiency decreased as the porosity of the mesh is increased. With inserted mesh, inlet and outlet temperature difference of air increased more than 50%. Heat exchange time of water/air to reach the 100% humidity decreased less than 30%. This result shows inserted mesh can enhance the performance of the water/air direct contact air conditioning system.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.442-447
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• 2006

In semiconductor manufacturing clean rooms, it becomes important to remove airborne molecular contaminants as well as particulate contaminant in outdoor air introduced into clean rooms. One suitable control technique for these chemical contaminants is air washing by water in an outdoor air handling unit. In order to enhance the removal efficiency of chemical contaminants the effect of adding a heating and humidifying process before an air washer was examined.

• 대한토목학회논문집
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• 제4권4호
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• pp.113-125
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• 1984

우리 나라는 수공급(水供給)을 주로 댐개발(開發)에 의존(依存)하여 왔으나 이와 같은 방식(方式)은 앞으로 댐적지(適地)의 감소(減少), 건설비(建設費)의 앙등(昻騰), 수몰지역주민(水沒地域住民)의 생활재건대책(生活再建對策), 환경영향(環境影響) 등의 제요인(諸要因)으로 인하여 계속하여 개발(開發)하기 어려운 상황(狀況)에 있다. 한편 수수요(水需要)는 도시(都市)로의 인구집중(人口集中), 생활수준(生活水準)의 향상(向上), 산업발전(産業發展) 등으로 인하여 계속 증가(增加)되고 있으며 앞으로도 인구(人口)의 증가(增加)와 경제활동(經濟活動)의 고도화(高度化)에 따른 도시기능(都市機能)의 향상(向上)에 의해 증가(增加)될 것으로 예상(豫想)된다. 따라서, 앞으로 늘어날 수수요(水需要)에 대처(對處)하기 위해서는 지하수(地下水)의 개발(開發), 해수(海水)의 담수화(淡水化), 그리고 물을 순환재이용(循環再利用)하는 중수도(中水道)의 도입(導入)이 절실(切實)하며 그 연구(硏究) 또한 시급하다. 중수도(中水道)란 종래(從來) 수도(水道)에 의해서 급수(給水)되고 있던 용도(用途)가운데 반드시 음용수(飮用水)와 같은 정도(程度)의 청정(淸淨)을 요(要)하지 않는 용도(用途)에 대(對)하여 각(各) 용도(用途)에 적합(適合)한 수질(水質)의 중수(中水)를 공급(供給)하는 것으로써 사람이 마시기에 적합(適合)하지 않은 물을 공급(供給)하는 시설(施設)의 총체(總體)라고 정의(定義)한다. 이와 같은 중수도(中水道)의 용도(用途)로는 수세식(水洗式) 변소용수(便所用水), 에어컨냉각용보급수(冷却用補給水), 세차용수(洗車用水), 살수용수(撒水用水), 가로청소용수(街路淸掃用水), 조경용보급수(造景用補給水), 소화용수(消火用水) 등을 들 수 있으며, 원수(原水)로는 건물내(建物內)에서 발생(發生)하는 잡배수(雜排水), 수세식(水洗式) 변소용수(便所用水), 냉동냉각배수(冷凍冷却排水), 하수처리수(下水處理水), 오탁하천수(汚濁河川水), 그리고 우수(雨水), 지하수(地下水) 등을 생각할 수 있다. 그러나, 원수(原水)를 선정(選定)할 때는 수질(水質)과 함께 수량(水量)이 풍부(豊富)한가에 대해서도 고려(考慮)하여야 한다. 중수도(中水道)의 형태(形態) 및 분류(分類)는 개방계(開放系) 순환방식(循環方式)과 폐쇄계(閉鎖系) 순환방식(循環方式)으로 대별(大別)되며, 이를 규모(規模)에 따라 개별순환방식(個別循環方式), 지구순환방식(地區循環方式), 광역순환방식(廣域循環方式)의 3 가지로 나눈다. 중수도처리방식(中水道處理方式)은 활성오니법(活性汚泥法), 회전원판법(回轉圓板法), 접촉폭기법(接觸曝氣法)을 포함(包含)한 생물화학적(生物化學的) 처리법(處理法)과 의집심의법(擬集沈擬法), 사려과법(砂濾慮過法), 활성탄처리법(活性炭處理法), ozone 처리법(處理法), 염소처리법(鹽素處理法), 막처리(膜處理) 등을 포함(包含)한 물리화학적(物理化學的) 처리법(處理法)으로 대별(大別)된다. 또한 현재(現在) 외국(外國)에서 실시(實施)하고 있는 중수도(中水道)의 예(例) 조사(調査)하였으며, 중수도이용(中水道利用)의 효과(效果)를 직접적(直接的) 효과(效果)와 부수적(附隨的) 효과(效果)로 나누어 기술(記述)하였다. 또한 중수도(中水道) 개발시(開發時)의 문제점(問題點)을 순환방식별(循環方式別)로 조사(調査)하였으며, 기술(技術), 위생(衛生), 관리상(管理上)의 문제(問題)와 비용문제(費用問題), 법령상(法令上)의 문제(問題)를 다루었다. 중수도(中水道)를 개발(開發)하기 위해 사업자(事業者)(설치자(設置者))와 행정기관(行政機關)의 역할(役割) 중수도(中水道)를 위한 시설(施設)의 구조기준(構造基準) 및 유지관리기준(維持管理基準), 재정적(財政的) 조치(措置) 등에 대해서 연구(硏究)하였다.