• 제목/요약/키워드: Hot air heater

검색결과 105건 처리시간 0.032초

온풍난방기의 열효율 증대를 위한 열교환기 구조개선 (Mechanism Improvement of the Heat Exchanger for the Thermal Efficiency Increase of Hot Air Heater)

  • 강금춘;강연구;유영선;김영중;이시영;백이
    • Journal of Biosystems Engineering
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    • 제34권5호
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    • pp.363-370
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    • 2009
  • Hot air heater with light oil combustion is used as the most common heater for greenhouse heating in the winter season. Hot air heaters of 256,246 units have been supplied as main greenhouse heating equipment until 2008 and greenhouse heating cost has reached to 620 billions won in Korea. In order to improve the thermal efficiency of the hot air heater and to reduce the expenses for greenhouse heating, prototype hot air heater was manufactured and tested in this experiment. The heat exchanger of tested prototype hot air heater was circular and hexagonal pipe type and inline and stagger arrangement type. Capacity of the heating was 43,062 kJ/h and total heat transfer area of the heat exchanger was $10.728\;m^2$. According to the performance test, it could supply heat of 38,240 to 35,100 kJ/h depending on the fan motor speed of 1,740~1,220 rpm, respectively. Thermal efficiency of hot air heater was 87.0% to 80.8% in the same conditions. As a result, thermal efficiency of hot air heater with hexagonal pipe-stagger arrangement heat exchanger developed in this study was higher 10.2% than that of conventional hot air heater and heating energy saving rate of 14.3% increased.

열펌프 열풍건조기를 이용한 표고버섯의 건조 품질특성 (Drying Quality Characteristics of Shiitake Mushroom by Heat Pump Hot-air Dryer)

  • 신은정;이호준
    • 한국지열·수열에너지학회논문집
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    • 제11권4호
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    • pp.22-27
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    • 2015
  • Quality characteristics of Shiitake mushroom using two types of dryers, energy-efficient heat pump hot-air dryer and electric heater hot-air dryer were compared. Energy consumed during drying by heat pump hot-air dryer and electric heater hot-air dryer were 22.8 kWh and 28.9 kWh, respectively. Total polyphenol content of heat pump hot-air dryer and electric heater hot-air dryer after drying were $290.55{\pm}10.56ppm$ and $192.99{\pm}6.53ppm$, respectively. No differences were observed between dryers in reconstitution rate and browning ratio after drying. Also, there were no differences between dryers in color value and ${\Delta}E$ value after drying. Shiitake mushroom drying at $45^{\circ}C$ by heat pump hot-air dryer was proved to be more efficient in energy consumption than by electric heater hot-air dryer.

복합형 태양열 가열기에서 열매체 단일운전에 따른 기기성능 평가 (Performance Estimation of Hybrid Solar Air-Water Heater on Single Working of Heating Medium)

  • 최휘웅;윤정인;손창효;최광환
    • 한국태양에너지학회 논문집
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    • 제34권6호
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    • pp.49-56
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    • 2014
  • Research about hybrid solar air-water heater that can make heated air and hot water was conducted as a part of improving efficiency of solar thermal energy. At this experiment, ability of making heating air and hot water was investigated and compared with traditional solar air heater and flat plate solar collector for hot water when air or liquid was heated respectively. Comparing hybrid solar air-water heater that used in this experiment to other solar air heater studied already, it has a lower efficiency at same mass flow rate. Air channel structure, fin's shape and arrangement in the air channel result in these difference then the ability of air heating need to be improved with changing these thing. In case of making hot water, performance was shown as similar with traditional system although the air channels were established beneath absorbing plate. But the heat loss coefficient was shown higher value by installing of air channel. Also the performance of hot water making was shown lower value at same liquid mass flow rate with traditional flat plate solar collector for hot water. So the necessity of performance improvement at lower mass flow rate of each heating medium can be confirmed.

탄소나노히팅파이프를 이용한 온실 난방에너지 절감효과 (Energy Saving Effects of Carbon Nano Heating Pipe for Heating of Greenhouse)

  • 백이;전종길;윤남규
    • 한국기계기술학회지
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    • 제13권3호
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    • pp.107-111
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    • 2011
  • This carbon nano heating system was consisted of power supply equipment, a carbon fiber and a stainless flexible hose. carbon nano heating system was manufactured by carbon fiber of a power capacity 30kw/h and light-oil hot air heater in control plot was the heating capacity 30,000kcal/h, As the result, Temperature difference due to carbon nano heating system and hot air heater in greenhouse showed that air temperature at experimental greenhouse, comparison greenhouse were $14.8^{\circ}C$, $13.4^{\circ}C$ respectively. It was found that carbon nano heating system and light-oil hot air heater heating cost were 1,095,740won, 2,683,628won. therefore as heating cost saving 60%. Yield of tomatoes cultured in greenhouse using carbon nano heating pipe was 4% inclease. Economic analysis comparison between the carbon nano heating pipe and the hot air heater in greenhouse were 41% respectively.

전기히터식 및 지열원 히트펌프식 농산물 열풍건조기의 에너지 성능 비교 (Energy Performance Comparison of Electric Heater and Geothermal Source Heat Pump type Agricultural Hot Air Dryers)

  • 양원석;김영일;박승태
    • 한국지열·수열에너지학회논문집
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    • 제14권4호
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    • pp.7-12
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    • 2018
  • Energy performance of electric heater and geothermal source heat pump type hot air dryers are compared in this study. For set temperatures of $30^{\circ}C$, $35^{\circ}C$ and $40^{\circ}C$, radish is dried from initial mass 60 kg until it gets 5 kg, where the difference equals the amount of water removed. As set temperature is increased, drying time is shortened for both electric heater and heat pump types, however energy efficiency is decreased due to increasing electricity consumption. Moisture extraction rate(MER) of electric heater is 2.58~2.84 kg/h, and for heat pump type 2.56~2.71 kg/h, showing little difference between the two types. Specific moisture extraction rate (SMER) of electric heater is 0.94~0.96 kg/kWh, and for heat pump type 1.72~2.21 kg/kWh. SMER of heat pump type is greater by 0.78~1.25 kg/kWh than the electric heater hot air dryer, which is 1.8~2.3 times better in terms of energy efficiency.

농업용 온풍난방기에서 동물성바이오디젤의 연소특성 (Characterizing Animal-fats Biodiesel as Heating Fuel for Agricultural Hot Air Heater)

  • 김영중;박석호;김충길;김영진
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 추계학술대회 초록집
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    • pp.115-115
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    • 2011
  • Biodiesel (BD) was made from animal-fats reacting with methanol and potassium hydroxide in the laboratory. The biodiesel made in the laboratory was sent to K-petro, the government agency, to inspect the quality of animal-fats biodiesel, of which generally the quality was acceptable for heating oil for agricultural hot air heater. Kinematic viscosity and calorific values of the biodiesels were measured. BD20(K), kerosene based biodiesel, showed 18cSt at $-20^{\circ}C$. It seems that BD100 can not be suitable for heating fuel under some temperature. As BD content increased calorific value decreased, up to 40,000J/g for 100% BD, while light oil calorific value was 45,567J/g, showing difference of 5,567J/g, about 12% difference. Several different fuels, BD20, BD50, BD100 and light oil, were prepared and tested for fuel combustion qualities for agricultural hot air heater and their combustion performances were compared and analyzed. Flame dimensions of biodiesels and light oil were almost same shape at the same combustion condition in the burner of the hot air heater. Generally $CO_2$ amounts of BDs are greater than light oil. But,the differences are so small that it is hard to tell there was significant difference existed between the BDs combustion and light oil.

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태양열 온수기를 이용한 다목적 공조시스템의 재생효율에 관한 연구(제1보 액체흡수제 온도가 재생량에 미치는 영향) (Research on the Performance of Regenerator using Hot Water from Solar Water Heater(1st paper : On the Effect of Solution Temperature to Regeneration Rate))

  • 우종수;최광환
    • 한국태양에너지학회 논문집
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    • 제24권1호
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    • pp.53-61
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    • 2004
  • Absorption potential of desiccant solution significantly decreases after absorbing moisture from humid air, and a regeneration process requires a great amount of energy to recover absorption potential of desiccant solution. In an effort to develop an efficient solar water heater, this study examines a regeneration process using hot water obtained from solar water heater to recover absorption potential by evaporating moisture in the liquid desiccant. In this paper, a solar absorption dehumidifying system with solar water heater is suggested to save the electricity for operating an air conditioner. LiGl(lithium chloride) solution was adopted as a liquid desiccant in the proposed system, and hot water obtained from the solar water heater was used for regenerating the liquid desiccant. As a result, it was clear that the dilute LiCl solution could be regenerated by hot water, and the regeneration rate depends mostly on temperature level of liquid desiccant. The regeneration rates were about 2.4kg/h with $40^{\circ}C$, 4.0kg/h with $50^{\circ}C$, and 6.2kg/h with $60^{\circ}C$ of hot water respectively.

고온 고압 공기가열기 성능시험 I (Performance test of Vitiated Air Heater with High Temperature and High Pressure I)

  • 이정민;나재정;홍윤기;강경택
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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    • pp.301-303
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    • 2017
  • 본 연구는 고온 고압의 연소식 공기가열기의 성능시험에 대한 것이다. 약 2000K의 고온 공기를 공급 할 수 있는 연소식 공기가열기를 설계하여 성능시험을 진행 중이다. 설계된 공기가열기는 메탄, 산소, 공기를 사용하며, 믹싱헤드면의 냉각을 혼합되는 공기를 이용한다. 따라서 고온의 화염에 안정적인 내열특성을 갖도록 설계되어야 하며, 시험을 통해 이를 확인하여야 한다. 본 논문에서는 시험 결과의 일부를 통해 연소식 공기가열기의 성능시험을 고찰하였다.

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복합형 태양열 가열기의 일일 운전 특성 및 축열 성능에 관한 연구 (A Study on Thermal Storage Performance and Characteristics of Daily Operation of a Hybrid Solar Air-Water Heater)

  • 최휘웅;파쿠르 로커만;윤정인;손창효;최광환
    • 한국태양에너지학회 논문집
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    • 제35권3호
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    • pp.73-79
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    • 2015
  • In this study, a thermal storage performance and characteristics of daily operation were investigated when the air and the liquid were heated simultaneously by a hybrid solar air-water heater that can make hot water as well as heated air. The hybrid solar air-water heater is kind of a flat plate solar collector that can make hot water and heated air by installing air channel beneath absorber plate of traditional flat plate solar collector for hot water. As a result of daily operation, maximum water temperature reached in a thermal storage was shown $44^{\circ}C$ on 73kg/h of air mass flow rate and about $40^{\circ}C$ on 176kg/h of air mass flow rate. Thus, the necessity of heating water in thermal storage by operating only liquid side was confirmed when the temperature of liquid in thermal storage is lower than we need. In case of efficiency investigated on daily operation, the thermal efficiency of the liquid side was decreased with increment of the inlet liquid temperature and decrement of the solar radiation, but efficiency of the air side was increased with increment of inlet liquid temperature difference as the traditional solar air heater. Total thermal efficiency of the collector was shown from 65.85% to 78.23% and it was decreased with increment of the inlet liquid temperature and decrement of solar radiation same as the traditional system.

원적외선 면상발열체에 의한 온실 난방시스템의 열특성 분석 (Thermal Energy Characteristics for Greenhouse Heating System with Far-Infrared Heater)

  • 노정근;김희준;리혁;한충수;조성찬
    • Journal of Biosystems Engineering
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    • 제31권6호
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    • pp.529-534
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    • 2006
  • The greenhouse heating system with far-infrared heater was built to analyze various thermal characteristics, such as greenhouse air temperature, soil temperature, energy flow, energy consumption in far-infrared heater, and other factors, which could be used in comparison with other greenhouse heating system in this study. The results showed that the inside air temperature of the far-infrared greenhouse heating system was $5^{\circ}C$ higher than that of hot air heating system. Heat loss of daytime was found to be larger than that of night time as much as 44.8% for the heating system with far-infrared heater. In the heating system with far-Infrared heater, when the lowest ambient temperature was -8 $\sim$ -7$^{\circ}C$, the air temperature of greenhouse was 12 $\sim$ 15$^{\circ}C$, thus the far-infrared heating system was shown to be feasible for heating system. Energy consumption of far-infrared heating system was shown to be less than that of hot air heating system.