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히트파이프형 이중진공관 태양열 집열기의 열성능에 관한 연구

A Study on Thermal Performance of the Heat Pipe Type Solar Collector Using a Glass Concentric Evacuated Tube,

강창호 (Kang, Chang-Ho, 경상대학교 대학원)

원문보기

  • 발행기관 경상대학교 대학원
  • 지도교수 서정세
  • 발행년도 2006
  • 학위수여년월 2006. 2
  • 학위명 박사
  • 소속대학원 및 학과 대학원 기계공학과
  • 전공 열및유체공학전공
  • 원문페이지 xx, 149
  • 본문언어 한국어
초록/요약moremore
Solar energy collectors are special kind of heat exchangers that transform solar radiation energy to internal energy of fluid(usually water). The major component of any solar system is the solar collector. This is a device which absorbs the incoming solar radiation, converts it into heat, and transf...
Solar energy collectors are special kind of heat exchangers that transform solar radiation energy to internal energy of fluid(usually water). The major component of any solar system is the solar collector. This is a device which absorbs the incoming solar radiation, converts it into heat, and transfers this heat to a fluid flowing through the collector. The solar energy thus collected is carried from the circulating fluid to a thermal energy storage tank. There are various type of solar collectors. Conventional simple flat-plate solar collectors were developed for use in sunny and warm climates. Their benefits however are greatly reduced when conditions become unfavorable during cold, cloudy and windy days. Furthermore, Weathering influences such as condensation and moisture will cause early deterioration of materials resulting in reduced performance and system failure. CETC(Concentric Evacuated Tube Solar Collector) operate differently than flat-plate collector. CETC have demonstrated the combination of a selective surface and an effective convection suppressor can result in good performance at high temperature. The vacuum envelope reduces convection and conduction losses, so the collector can operate at higher temperature. In this study, the heat pipe or thermosyphon is placed inside a vacuum-sealed tube. The thermal characteristics of grooved heat pipe and thermosyphon for solar collectors was investigated experimentally. For the heat pipe and thermosyphon experiment, The effects of parameters such as heat input, coolant temperature and tilt angle of heat pipe have been investigated. After that, the experiments were also carried out a concentric evacuated tube solar collector with heat pipe or thermosyphon under the field conditions of Jinju, Korea. the collector was designed, constructed and tested at transient conditions to study its performance for different cooling water mass flow rates at different inlet cooling water temperature. Subsequently, long term system performance is estimated by using TRNSYS model run with the weather values for Jinju, Korea. From many of experiments and simulations, the conclusions are as follows. As the heat input increases in the grooved heat pipe, the thermal resistance decreases. It showed similar working characteristics without regard to the inclination angle. the temperature difference between inlet and outlet water in grooved collector is bigger than the thermosyphon collector. The grooved collector has little fluctuation of temperature. It's considerable the grooved collector do not has geyser boiling and has more stable working characteristics. The solar energy collecting efficiency of the grooved heat pipe collector is higher 8-15% than the thermosyphon collector. Especially the grooved collector is higher efficiency in condition of low incident. The result of a simulation, it is predicted that annual solar fraction for domestic hot water system with grooved wick heat pipe and thermosyphon are 73% and 65%, respectively.
목차moremore
제1장 서론 = 1
1.1 연구배경 = 1
1.2 연구동향 = 3
...
제1장 서론 = 1
1.1 연구배경 = 1
1.2 연구동향 = 3
1.3 연구 목적 및 내용 = 7
1.3.1 연구목적 = 7
1.3.2 연구내용 = 7
제2장 관련기초 이론 = 10
2.1 태양복사 = 10
2.2 태양열 집열기 = 14
2.2.1 구조 및 특성 = 14
2.2.2 열회수 방법 = 18
2.3 집열기 이론 = 21
2.3.1 진공이론 = 21
2.3.2 집열량 = 22
2.3.3 집열효율 = 24
2.4 히트파이프 이론 = 28
2.4.1 작동원리 = 28
2.4.2 열수송능력 = 30
2.4.3 작동유체량 계산 = 32
2.5 집열시스템 성능 예측 이론 = 34
2.5.1 해석해 = 34
2.5.2 축열조 에너지 방정식 = 35
2.5.3 수학적 모델링 = 37
제3장 히트파이프 해석 및 실험 = 41
3.1 작동특성 해석 = 42
3.1.1 해석방법 = 42
3.1.2 해석결과 및 고찰 = 44
3.2 실험 장치 및 방법 = 53
3.2.1 실험장치 = 53
3.2.2 실험방법 = 56
3.3 실험 결과 및 고찰 = 57
3.3.1 써모사이폰 = 57
3.3.2 그루브윅 히트파이프 = 76
3.4 맺음말 = 87
제4장 이중진공관 집열기의 열성능 실험 = 88
4.1 시스템 구성 개요 = 88
4.2 실험장치 = 89
4.2.1 집열기 = 91
4.2.2 축열조 = 94
4.2.3 순환장치 = 97
4.2.4 제어장치 = 97
4.3 실험방법 = 99
4.4 실험 결과 및 고찰 = 102
4.4.1 유량에 따른 입 · 출구온도 = 102
4.4.2 집열기 형식에 따른 입 · 출구온도 = 110
4.4.3 유량에 따른 집열량 = 113
4.4.4 일사량에 따른 집열효율 = 117
4.4.5 유량에 따른 집열효율 = 122
4.5 맺음말 = 127
제5장 태양열 집열시스템의 성능평가 해석 = 128
5.1 시스템 구성 = 128
5.2 시뮬레이션 결과 = 133
5.3 맺음말 = 138
제6장 결론 = 139
Reference = 142