태양열 시스템의 제어조건에 따른 난방 및 급탕 실증연구

곽희열(Kwak Hee-Youl),김정배(Kim Jeong-Bae),주홍진(Joo Hong-Jin),김종보(Kim Jong-Bo) 한국태양에너지학회 2006 한국태양에너지학회 논문집 Vol.26 No.4

This study describes thermal performance of heating and cooling demonstration system using ETSC(Evacuated tubular solar collector) installed at Seo-gu art center of Kwangju. For demonstration study, a reading room with about 350㎡ was heated and cooled using that system. The demonstration system was consisted of ETSCs, storage tank, hot water supply tank, subsidiary boiler, and subsidiary tank. From January to March in 2006, demonstration test were performed with 4 control mode to find the optimum control condition for solar thermal system. After experiments and analysis, this study found that solar thermal system of control mode IV was corresponded to 78% for the hot water supply and 49% for space heating.

1단 증발식 해수담수화 시스템의 계절별 성능 평가

곽희열(Kwak Hee-Youl),주홍진(Joo Hong-Jin),주문창(Joo Moon-Chang),김정배(Kim Jung Bae) 한국태양에너지학회 2008 한국태양에너지학회 학술대회논문집 Vol.- No.-

This study was carry out evaluation of seasonal performance for the decentralized desalination system with the solar thermal system and tile photo voltaic power system. First operating demonstration system was set up in Cheju in 2006. These system comprises the desalination unit with designed daily fresh water capacity of 2 ㎡ and is supplied by a 120 ㎡ evacuated tubular solar collector, a 6㎡ heat storage tank, and a 5㎾ photovoltaic power generation supply the electricity for hydraulic pumps to move the working fluids. In a spring season day average 392W/ ㎡ the daily fresh water showed to produce about 340liter. In a summer season day average 296W /㎡, the daily fresh water showed to produce about 328liter. In a autumn season day average 349W/㎡, the daily fresh water showed to produce about 277liter. In a winter season day average 342W/㎡, the daily fresh water showed to produce about 271liter.

태양에너지 해수담수화 시스템 운전 성능

곽희열(Kwak Hee-Youl),윤응상(Yoon Eung-Sang),주문창(Joo Moon-Chan),주홍진(Joo Hong-Jin) 한국태양에너지학회 2009 한국태양에너지학회 학술대회논문집 Vol.- No.-

This study was analyzed the long term performance of the demonstration system for solar energy desalination in Jeju. we used a solar thermal system as heat source of the single-stage fresh water generator with plate-type heat exchangers and a photovoltaic power system as electric source for hydraulic pumps. The demonstration system was designed and installed at Jeju-island in 2006. The system was comprised of the desalination unit with daily fresh water capacity designed as 2㎥, a 120㎡ evacuated tubular solar collector to supply the heat, a 6㎥ heat storage tank, and a 5kW photovoltaic power generation to supply the electricity of hydraulic pumps for the heat medium fluids. Through the operation during about 3 years, In a clear day more than 400W/㎡, the daily fresh water showed to produce more than about 500liter, and from January, 2007 to March, 2009 for 3 years, solar irradiance daily averaged was measured 370W/㎡, the daily fresh water yield showed that can be produced about 330liter.

태양열 구동 흡수식 냉방 시스템 실증연구

곽희열(Kwak Hee-Youl),주홍진(Joo Hong-Jin) 한국태양에너지학회 2006 한국태양에너지학회 학술대회논문집 Vol.- No.-

This paper presents demonstration study results derived through field testing of a part load solar energized cooling system for the library of a cultural center building located in Gwangju, Korea. The area of demanded cooling for building was about 350㎡. Solar hot water was delivered by means of a 200㎡ array of evacuated tubular solar collector (ETSC) to drive a single-effect (LiBr/H2O) absorption chiller of 35㎾ nominal cooling capacity. During the demonstration tests, operating conditions of the solar cooling system are established through modifications of the various control parameters. Operation data for 10 stable hours at a clear sky day during the summer season are achieved and analyzed for the verification of the availability, stability, and reliability of the present system.

태양열 집열기용 히트파이프 응축부 형상 변화에 따른 열성능 연구

곽희열(Kwak Hee-Youl),주홍진(Joo Hong-Jin) 한국태양에너지학회 2008 한국태양에너지학회 논문집 Vol.28 No.2

The purpose of this study was experimentally to investigate thermal performance of heat pipe for evacuated tubular solar collector. Two sets of evacuated tubular solar collector with different condenser shape of heat pipe were prepared. The experiments were performed under the same operating condition with an indoor testing apparatus. Also, the experiments were carried out various testing conditions including inclination, flow rate, and incident heat flux. The results of thermal performance of collector with enlarged condenser showed that FR(τα) was 0.6572 and FR UL was -2.0086 at 40°. And the results of thermal performance of collector with straight condenser showed that FR(τα) was 0.6233 and FRUL was -1.4996 at the same inclined angle.

태양열 냉ㆍ난방 및 급탕 시스템 열성능

곽희열(Kwak Hee-Youl),주홍진(Joo Hong-Jin),이호(Lee Ho) 한국태양에너지학회 2009 한국태양에너지학회 학술대회논문집 Vol.- No.-

This paper presents demonstration study results derived through field testing of a solar assisted cooling and heating system for the library of a cultural center building located in Gwangju, Korea. The area of demanded cooling and heating for building was about 350㎡. Solar hot water was delivered by means of a 200㎡ array of evacuated tubular solar collector (ETSC) to drive a single-effect (LiBr/H2O) absorption chiller of 10RT nominal cooling capacity. From March in 2008 to February in 2009, demonstration test were performed for solar cooling and heating system. After experiments and analysis, this study found that solar thermal system was 84% for the solar hot water supply and 12% for space heating and 4% for space cooling.

태양열 냉방 실증시스템의 난방 및 급탕 열성능

곽희열(Kwak Hee-Youl),주홍진(Joo Hong-Jin) 한국태양에너지학회 2007 한국태양에너지학회 학술대회논문집 Vol.- No.-

This study describes thermal performance of heating and cooling demonstration system using ETSC(Evacuated tubular solar collector) installed at Seo-gu art center of Kwangju. For demonstration study, a reading room with about 350㎡ was heated and cooled using that system. The demonstration system was consisted of ETSCs, storage tank, hot water supply tank, subsidiary boiler, and subsidiary tank. The results of the experimental study From January to February in 2007, The solar fraction were 58% for solar heating, 30% for solar hot water in January and 79% for solar heating, 33% for solar hot water in February.

산업용 고효율 태양열집열기 개발 필요성

곽희열(Hee Youl Kwak) 한국태양에너지학회 1998 한국태양에너지학회 논문집 Vol.18 No.2

국내 소비 에너지 사용량의 97%를 수입에 의존하고 있고, 지구온난화와 관련된 환경문제가 심각하게 대두되고 있는 실정이다. 또한 우리나라 에너지 부문별 소비형태에서 47%를 차지하는 산업용의 에너지 소비는 대부분 유류에 의존하고 있고, 그 중에서도 제조부분의 소비가 91.5%로 나타나고 있어, 이 부분에 대체에너지원의 개발, 대체 시스템의 적용이 절실히 요구되고 있다.<br/> 우리나라에서도 국가적 에너지 절약과 쾌적한 주거환경 및 생활의 편리함을 위해 기존 화석에너지로부터 무공해 청정에너지(Clean Energy)로 그 사용형태가 바뀌어 가는 지금 그 양과 질적인 면에서 무한정이고 무공해인 대체 에너지원으로서의 태양에너지는 다양한 이용분야가 개발되어 실용화되고 있다. 국내의 경우 대표적으로 평판형 태양열집열기를 이용한 온수급탕 시스템을 들 수 있고, 냉난방, 산업공정열 및 태양열 발전 분야에 대한 실용화 및 타당성 연구가 활발히 진행되고 있다.<br/> 따라서 본 고에서는 태양열 시스템의 중요한 구성요소인 고효율 집열기술에서 산업용 응용(70~150℃)에 적합한 것으로 기대되는 진공유리관형 태양열집열기, 국내·외 기술개발 동향과 산업공정열의 대체 가능성에 대하여 기술하였다. Solar energy is a quantitatively unlimited, clean and non-pollutant source. It has a great potential for industrial commercial usages. For example, solar hot water system for domestic usage has been very popular in many counties.<br/> In Korea, the industries consume 47.7% of the total national energy, and the manufacturing sector uses 91.5% out of it. The main energy resoures available in Korea are oils, coals, and gases. There have been continuous efforts among the industries to reduce such energy consumptions by using alternative energy resources, such as solar energy, yet the technology has limited its proper applications to a level of satisfaction. In some advanced countries, research and development programs in solar energy applicable to the industrial usages are very active, and some systems are in the commercial market.<br/> Therefore, this paper describes the status and the feasibility for high-efficiency evacuated solar collector which was anticipated to applied for industrial process heat as an alternative of fossil energy.

태양열 온수급탕 및 난방 실증시스템 열성능

곽희열(Kwak Hee-Youl),김정배(Kim Jeongbae),신우철(Shin U-Cheul),김진희(Kim Jin-Hee),주홍진(Joo Hong-Jin) 한국태양에너지학회 2006 한국태양에너지학회 학술대회논문집 Vol.- No.-

This study describes heating thermal performance of heating and cooling demonstration system using ETSC(Evacuated tubular solar collector) installed at Seo-gu art center of Kwangju. For demonstration study, a reading room with about 331㎡ was heated and cooled using that system. The demonstration system was consisted of ETSC, storage tank, hot water supply tank, subsidiary boiler, and subsidiary tank.<br/> When evaluated the results obtained at January of winter season, 40% of required total energy used as hot water supply and 26% for space heating was supplied from the ETSC system and the rest, 34 %, was fulfilled by the subsidiary boiler. Here, the solar energy was mainly used for space heating, then if the surplus energy was being, the rest of solar energy was used as the hot water supply. 20% of hot water supply energy used in that building was supplied by the solar system.

SUS - 물을 사용한 2상 밀폐 열싸이폰의 작동특성에 관한 연구

곽희열(Kwak Hee-Youl),김종보(Kim Chong-Bo) 한국태양에너지학회 1994 한국태양에너지학회 논문집 Vol.14 No.3

2상 밀폐 열싸이폰은 용기 내에서 증발과 응축을 반복하면서 많은 양의 열을 수송하는 매우 효과적인 열전달 장치이다. 증발부에서의 증발 현상은 자연대류, 핵비등, 급속한 기포의 주기적인 폭발(Geyser boiling)과 또한 정상상태에서의 국부적인 열전달한계(Dry-out)로 인한 시동 및 작동특성이 매우 복잡하므로, 본 논문에서는 SUS-물을 사용한 열싸이폰의 시동성과 작동 특성을 증발부와 응축부의 열 환경에 따른 액체 풀(Pool)의 높이, 즉 증발부 체적에 대한 작동유체의 충전량과 경사각에 따른 특성을 고찰하였다. The two-phase closed thermosyphon is a heat transfer device capable of transferring large quantities of heat from a source to a sink by taking advantage of the high heat transfer rate associated with the evaporation and condensation of a working fluid within the device. The boiling patterns in the evaporator of thermosyphons are very complicated, considering natural convection in pool, surface evaporation on film, intermittent periodical geyser boiling, and semi-stable froth boiling. Also, heat transfer limit was found in dry-out where some portion of the evaporator ceases to be cooled effectively by the falling film and rivulets, resulting in a wall temperature excursion. In the present investigation, ex periments with a SUS-Water thermosyphon with 1m in length and 19㎜ in outer diameter have been carried out. The unsteady and steady state operations have been investigated for the influence of liquid filling charges and inclination angles of the device.