• 제목/요약/키워드: Evaporative condenser

검색결과 7건 처리시간 0.021초

증발냉각에 의한 공랭 응축기의 성능향상 가능성에 관한 연구 (Cooling Enhancement Potential of an Air-Cooled Condenser by Evaporative Cooling)

  • 이대영;백영진;김영일
    • 설비공학논문집
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    • 제16권3호
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    • pp.203-210
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    • 2004
  • This paper describes the potential advantages in applying evaporative cooling to air-cooled condensers. The cooling characteristics of an air-cooled condenser with its surface fully covered with thin water film are investigated and compared with that of an air-cooled condenser with usual dry surface. By applying the evaporative cooling, the cooling performance of the condenser is shown to improve enormously. When the outdoor air is 35$^{\circ}C$ and 40% in relative humidity, the condensing temperature of the refrigerant is decreased by 2$0^{\circ}C$. Even when the incoming air is fully saturated with water vapor, the evaporation from the wet surface occurs to cause a decrease in the condensing temperature by 1$0^{\circ}C$. The main reason for this improvement is assessed as the addition of an efficient cooling mechanism which is the water evaporation resulting in latent heat absorption.

다중 영역법을 이용한 증발식 응축관 주위의 열 및 물질전달 해석 (Numerical study of heat and mass transfer around an evaporative condenser tube by multi-zone method)

  • 윤일철;이재헌
    • 대한기계학회논문집
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    • 제19권12호
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    • pp.3317-3328
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    • 1995
  • The objective of the present study is to predict the characteristics of heat and mass transfer around an evaporative condenser. Numerical calculations have been performed using multi-zone method to investigate heat transfer rate and evaporation rate with the variation of inlet condition(velocity, relative humidity and temperature) of the moist air, the flow rate of the cooling water and the shape of the condenser tube. From the results it is found that the profile of heat flux is the same as that of evaporation rate since heat transfer along the gas-liquid interface is dominated by the transport of latent heat in association with the vaporization(evaporation) of the liquid film. The evaporation rate and heat transfer rate is increased as mass flow rate increases or relative humidity and temperature decrease respectively. But the flow rate of the cooling water hardly affect the evaporation rate and heat flux along the gas-liquid interface. The elliptic tube which the ratio of semi-minor axis to semi-major axis is 0.8 is more effective than the circular tube because the pressure drop is decreased. But the evaporation rate and heat flux shown independency on the tube shape.

온실 내 수분제어를 위한 제습장치 개발 (Development of Dehumidifier to Control Moisture in Greenhouse)

  • 김문기;권혁진
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2001년도 학술발표회 발표논문집
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    • pp.286-290
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    • 2001
  • This study was carried out to develope dehumidifier using underground water for controling moisture in greenhouse. The dehumidifier was designed as horizontal shell type condenser, and experiment was carried out with evaporative cooling system. In shading condition, evaporative cooling with the dehumidifier makes decrease of relative humidity and temperature in the down place of greenhouse than without dehumidifier, so it is expect that the dehumidifier is useful for effective evaporative cooling.

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A Study on Autocascade Refrigeration System Using Carbon Dioxide and R134a Mixture

  • Park, Soo-Nam;Kim, Min-Soo
    • International Journal of Air-Conditioning and Refrigeration
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    • 제9권1호
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    • pp.39-49
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    • 2001
  • Investigation of the performance of an autocascade refrigeration system using the refrigerant mixtures of R744 (carbon dioxide) and R134a (1,1,1,2-tetrafluoroethane) has been carried out by simulation and experiment. Cycle simulation using a constant UA model in heat exchangers has been performed for R744/134a mixtures of the compositions ranging from 10/90 to 30/70 by weight. Variations of mass flow rate of refrigerant, compressor work, refrigeration capacity and COP with respect to mass fraction of R744/134a mixture were presented. Performance test has been executed in the autocascade refrigeration system by varying secondary fluid temperatures at evaporator and condenser inlets. Experimental results match quite well with those obtained from the simulation.

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이산화탄소와 R134a의 혼합냉매를 이용한 오토캐스케이드 냉동시스템의 성능 (Performance of autocascade refrigeration system using carbon dioxide and R134a)

  • 박수남;김민수
    • 설비공학논문집
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    • 제11권6호
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    • pp.880-890
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    • 1999
  • The purpose of this study is to investigate the performance of an autocascade refrigeration system using the refrigerant miktures of R744 (carbon dioxide) and R134a (1,1,1,2-tetrafluoroethane) as working fluids by simulation and experiment. Cycle simulation using a constant UA model in heat exchangers has been performed for R744/134a mixtures of the compositions in the range of from 10/90 to 30/70 by weight percentage. Variations of mass flow rate of refrigerant, compressor work, refrigeration capacity and COP with respect to mass fraction of R744/134a mixture were presented. Performance test has been executed in an autocascade refrigeration system by varying secondary fluid temperatures at evaporator and condenser inlets. Experimental results show similar trend with those from the simulation.

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태양에너지 해수담수화를 위한 3중 효용 증발식 담수기 개발 (Development of 3th Effects Evaporative desalination system for Solar Desalination System)

  • 황인선;주홍진;윤응상;곽희열
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.201-201
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    • 2010
  • The evaporative desalination system with solar energy would be the efficient and attractive method to get fresh water. This study was described the development of Multi Effect Distillation(MED) with solar energy desalination system. The system was designed and manufactured Multi effect distillation on the capacity of $3m^3$/day. The experimental apparatus consists mainly of ejector pump, Hot water pump, flow meter, demister, cooler, evaporator and condenser. Evaporator and condenser were made Shell&Tube Heat Exchanger type with corrugated tube. The experimental variables were chosen $75^{\circ}C$ for hot water inlet temperature, 40, 60 and $80{\ell}$/min for hot water inlet volume flow rate, 6.0 and $8.0{\ell}$/min for evaporator feed seawater flow rate, $18^{\circ}C$ for sea water inlet temperature to cover the average sea water temperature and the salinity of sea water is measured about 33,000 PPM (parts per million). for a year in Korea. This study was analyzed the results of thermal performance of Multi Effect Distillation. The results are as follows, The experimental Multi effect distillation is required about 40 kW heat source for production of $3m^3$/day fresh water. Various operating flow rate was confirm in the experiments to get the optimum design data and the results showed that the optimum total flow was $8.0{\ell}$/min. Comparison of Single Effect Distillation with Multi Effect Distillation showed MED is at least more than double of SED.

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