• 제목/요약/키워드: Air Heater

검색결과 485건 처리시간 0.028초

램제트 엔진의 지상시험용 Vitiated Air Heater의 특성에 관한 실험적 연구 (An Experimental Study on the Characteristics of the Vitiated Air Heater in the Ramjet Engine Ground-Testing)

  • 윤현진;손창현;이충원
    • 한국추진공학회지
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    • 제3권4호
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    • pp.51-57
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    • 1999
  • Ramjet 엔진에서 Ramjet 입구의 초음속 유동에 의한 압축과정은 연소기내로 유입되는 공기의 온도를 상승시킨다. 따라서 고도와 비행조건에 따라 변하는 실제비행조건을 모사하기 위해서는 공기의 온도와 속도를 정확하게 제어할 필요가 있다. 본 연구에서는 Vitiated Air Heater를 제작하여 공기, 수소, 산소의 안을 변화시키면서 Vitiated Air Heater 연소가스(Vitiated Air)의 온도분포와 속도분포, 그리고 연소가스 성분을 측정함으로써 Vitiated Air Heater의 성능을 평가하였다. 그 결과 Ramjet 엔진의 지상실험범위에 요구되는 Ramjet 연소기 입구의 유입 속도범위(80~120 ㎧)와 온도범위(400~800 K)를 만족하였으며, 균일한 속도 및 온도분포로 대기공기와 같은 산소성분비를 가지는 Vitiated hir를 얻을 수 있었다.

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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.

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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태양열 이용 난방용 공기가열기 개발을 위한 기초 운전 특성 (Basic Operational Characteristics for Developments of Solar Air Heater for Air Heating in Winter)

  • 김종열;홍부표;우종수;최광환
    • 한국태양에너지학회 논문집
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    • 제31권4호
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    • pp.87-94
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    • 2011
  • To develop the solar air heater, prototype of solar heater with test room set up on the roof of test chamber and operation characteristics were examined with solar radiation. Air induced from outside was supplied by a blower and also heated air was supplied to the test chamber(size of 1,000mm(inwidth)*2,000mm(in length)*2,000mm(in depth)) established already for performance. It was clear that almost 30% of solar radiation was converted into effective heating energy at maximum and the highest air temperature was $46^{\circ}C$, and thus solar air heater in winter could be used as an possible alternative heating system in building. Furthermore, heat energy obtained from solar air heater can be applied to regenerate absorber in the solar desiccant cooling system.

대용량 청정 공기 가열 장치 설계 (Design of Large Capacity Clean Air Heater)

  • 김정우;정광수;전민준;이규준
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2010년도 제35회 추계학술대회논문집
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    • pp.115-118
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    • 2010
  • 공기 가열 장치는 크게 연소식과 열교환식 2가지가 있으며, 본 논문은 공기를 오염시키지 않은 열교환 방식인 청정 공기 가열 장치의 설계 방법을 기술하였다. 가열 장치는 크게 연소기 (Burner), 가열로 (Furnace), 열교환기 (Heat Exchanger), 배기구로 구성되어 되며, 가열되는 공기 유량과 입/출구 온도값으로부터 가열원인 연소기의 열용량과 연소기 연료인 LNG의 소요량을 구한다. 열교환기 내부에서 연소기의 뜨거운 연소가스와 가열되는 차가운 공기간의 열매체를 통한 간접 열교환이 이루어지므로, 가열되는 공기의 입/출구 온도에서 열교환기의 용량, 크기, 작동 최대 온도를 얻을 수 있게 된다.

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시설원예용 온풍난방기내의 온도분포에 관한 연구 (I) - 난방유 사용시 온도특성 - (Temperature Distributions inside a Space Heater for Greenhouse (I) - Temperature Characteristics with Heating Oil -)

  • 서정덕;김종진;최규성;신창식;노수영
    • Journal of Biosystems Engineering
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    • 제24권4호
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    • pp.335-342
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    • 1999
  • Air and flue gas temperature distributions in the space heater for greenhouse were measured to develop a thermal design technology for the space heater. Also, the characteristics of the fan supplying air to the space heater were investigated. The temperature of the flue gas inside the flue gas tube was linearly decreased as the lenght of than those of the flue gas with the oxygen concentration of 8.25% at the last exit of the second flue gas tube. Thus, the operating efficiency of the space heater could be increased with low air ratio decreased exhausting gas temperature and saved the energy consumption with decreased excess air flow. The temperature of the air supplied by fan was increased slowly around the first flue gas tube, meanwhile, increased sharply around the second flue gas tube due to large LMTD (Logarithmic Mean Temperature Difference) at the first flue gas tube than which of the second flue gas tube.

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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.

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.

Gas air heater 시스템 소개 (Introduction of Gas Air Heater)

  • 한승철;김종규;사공운곤
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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    • pp.15-16
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    • 2006
  • LNGC 에 Gas Air Heater를 적용함에 따라 Market 경쟁력 확보 및 System의 효율 개선을 통한 DSME 만의 독창력 확보.

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계획예방정비가 발전소 공기예열기의 성능에 미치는 영향 (Effect of Preventive Maintenance on Performance of Air Heater in a Power Plant)

  • 장진형;홍은기;황광원;윤린
    • 대한기계학회논문집B
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    • 제34권5호
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    • pp.465-469
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    • 2010
  • 발전설비 내 공기예열기는 보일러 연소가스로부터 열을 회수하여 유효열의 손실을 감소시킴으로서 보일러의 열효율을 높이기 위해 설치된다. 본 연구에서는 계획예방정비가 공기예열기의 성능에 미치는 영향을 고찰하였다. 공기예열기의 성능지표들은 공기예열기의 계획예방정비 전후의 운전 상태와 성능변화 모두를 고려하여 계산되었고, 공기예열기의 중요한 성능지표로는 가스 측 온도효율, 공기누설률, 열회수율, 열관류율과 열용량비들이다. 계획예방정비 전후의 공기예열기 성능평가로부터 공기예열기의 모든 성능 지표가 계획예방정비 후 향상되었다.