환경적 평가 기준에 따른 태양열 급탕시스템의 설계 최적화

최두성,고명진,박광태 청운대학교 건설환경연구소 2015 청운대학교 건설환경연구소 논문집 Vol.10 No.1

This paper presents an optimization design method to determine the optimal size and configuration for a solar water heating system using genetic algorithm while minimizing greenhouse gas emissions and satisfying the constraints such as energy balance, available space to install collector and the solar fraction. As a case study, we designed a solar water heating system in an office building in Incheon, South Korea. The evolution of possible solutions through generation and the characteristics of optimal solution is discussed. The result shows that greenhouse gas of 6% and 57% can be reduced using the proposed method compared to that for the best and worst solutions in the initial population. 본 연구는 최적해 탐색 알고리즘인 유전 알고리즘을 이용하여 온실가스 배출량 최소화라는 환경적 평가 기준에 따라 태양열 급탕시스템의 최적 용량과 구성을 결정하는 최적화 설계 방법을 나타낸다. 아울러 제안한 설계 방법의 적용 타당성을 확보하기 위해 태양열 급탕시스템의 에너지 균형, 설치가능 면적, 태양열 의존율을 제약조건으로 반영하였다. 사례연구로서 인천지역 사무소 건물의 태양열 급탕시스템에 대한 최적화 설계를 수행하고, 도출된 최적 설계안의 특성에 대한 분석을 실시하였다. 사례연구 분석 결과, 최적 설계안은 초기 군집의 가장 우수하고 열악한 설계안들과 비교하여 각각 약 6%와 57%의 온실가스 배출량을 절감할 수 있는 것으로 나타났다.

상부 코일히터를 갖춘 나선재킷형 태양열 축열조의 성능예측을 위한 CFD 해석모델 개발 및 검증

백승만(Seung Man Baek),종일명(Yiming Zhong),남진현(Jin Hyun Nam),정재동(Jae Dong Chung),홍희기(Hiki Hong) 대한기계학회 2013 大韓機械學會論文集B Vol.37 No.4

태양열 온수급탕 시스템에서는 태양열 에너지가 집열판에서 획득되고 열매체로 전달되어 최종적으로 온수의 형태로 축열조에 저장된다. 본 연구에서는 상부 코일히터를 갖춘 나선재킷형 축열조의 축열성능 특성을 정확하게 해석할 수 있는 전산유체역학 모델을 개발하였다. 본 연구에서 고려한 축열조는 벽면에 열매체의 나선유로가 형성된 맨틀형 축열조의 일종으로 시스템 설계 단순화, 저유량 운전, 성층화 촉진 등의 장점을 지닌다. 또한 축열조 내부에 추가적인 코일히터가 장착되어 축열성능과 성층화의 추가적인 향상을 도모할 수 있다. 본 연구에서 개발된 해석모델의 검증은 실제 태양열 온수급탕 시스템의 실증실험 결과와 비교를 통하여 수행되었으며, 온수의 온도변화, 열매체의 온도변화, 성층화 온도분포의 측면에서 잘 일치하는 결과를 얻었다. In a solar domestic hot water (SDHW) system, solar energy is collected using collector panels, transferred to a circulating heat transfer fluid (brine), and eventually stored in a thermal storage tank (TST) as hot water. In this study, a computational fluid dynamics (CFD) model was developed to predict the solar thermal energy storage in a hybridtype TST equipped with a helical jacket heater (mantle heat exchanger) and an immersed spiral coil heater. The helical jacket heater, which is the brine flow path attached to the side wall of a TST, has advantages including simple system design, low brine flow rate, and enhanced thermal stratification. In addition, the spiral coil heater further enhances the thermal performance and thermal stratification of the TST. The developed model was validated by the good agreement between the CFD results and the experimental results performed with the hybrid-type TST in SDHW settings.

유전알고리즘 이용 경제적 평가기준에 따른 태양열급탕시스템 최적화 설계에 관한 연구

최두성(Choi Doosung),고명진(Ko Myeongjin),박광태(Park Kwang-Tae) 한국태양에너지학회 2016 한국태양에너지학회 논문집 Vol.36 No.5

To assure maximum economic benefits and the energy performance of solar water heating systems, the proper sizing of components and operating conditions need to be optimized. In recent years, a number of studies to design optimally solar water heating systems have been tried. This paper presents a design method for optimizing the various capacity-related and installation-related design variables based on life cycle cost using a genetic algorithm. The design variables considered in this study included the types and numbers of solar collector and auxiliary heaters; the types of storage tanks and heat exchangers; the solar collector slope; mass flow rates of the fluid on the hot and cold sides. The suggested method was applied for optimizing a solar water heating system for an elementary school in Seoul, South Korea. In addition, the effectiveness of the proposed optimization method was assessed by analyzing the obtained optimal solutions of six case studies, each of which was simulated with different solar fractions. It is observed that a trade-off between the equipment cost and the energy cost results in an optimal design that yields the lowest life cycle cost. Therefore, it could be helpful to apply the optimal solar water heating system by comparing the various design solutions obtained by using the optimization method instead of the engineer"s experience and intuition.

공동주택에 적용된 PV/T 태양열 급탕시스템 연간 열 및 발전성능 분석

임희원(Lim Hee-Won),이왕제(Lee Wang-Je),윤종호(Yoon Jong-Ho),조성구(Cho Sung-Goo),백남춘(Baek Nam-Choon),신우철(Shin U-Cheul) 한국태양에너지학회 2021 한국태양에너지학회 논문집 Vol.41 No.1

A PV/T solar collector, wherein a photovoltaic module and a solar collector are combined into a single component, is considered to be highly reliable, durable, and economically feasible. Additionally, zero-energy buildings have recently drawn significant attention. In this study, the dynamic behavior and energy performance of a PV/T solar hot water system employed in a twenty-storey apartment were analyzed. The said system comprises three 25 EA (a total of 75 EA) PV/T solar collectors and a 15.6 ton storage tank. The TRNSYS 17 software was employed as a simulation tool for conducting the analysis, and the national reference standard weather data (TMY3) of Daejeon, South Korea was incorporated as meteorological data. The obtained results indicate that if the available space is limited and if the aspect of energy efficiency is considered, the usage of PV/T solar hot water systems that simultaneously produce thermal energy and electrical energy can be more advantageous than the usage of standard photovoltaic or solar hot water systems.

단독주택용 태양열/지열 융복합시스템의 태양열 급탕성능 평가

백남춘(Namchoon Baek),한승현(Seunghyun Han),이왕제(Wang Je Lee),신우철(Ucheul Shin) 대한설비공학회 2015 설비공학 논문집 Vol.27 No.11

In this study, an analysis was performed on the performance of the solar water heating system with geo-thermal heat pump for a detached house. This system has a flat plate solar collector (8 ㎡) and a 3 RT heat pump. The heat pump acts as an auxiliary heater of the solar water heating system. These systems were installed at four individual houses with the same area of 100 ㎡. The monitoring results for one year are as follows. (1) The average daily operating time of the solar system appeared to be 313 minutes in spring (intermediate season), and 135 minutes and 76 minutes in winter and summer respectively. The reason for the short operating time in summer is the high storage temperature due to low water heating load. The high storage temperature is caused by a decrease in collecting efficiency as well as by overheating. (2) The geothermal heat pump as an auxiliary heater mainly operates on days of poor insolation during the winter season. (3) Despite controlling for total house area, hot water consumption varies greatly according to the number of people in the family, hot water usage habits, etc. (4) The yearly solar fraction was 69.8 to 91.5 percent, which exceeds the maximum value of 80% as recommended by ASHRAE. So the solar collector area of 8 ㎡ appeared to be somewhat greater for the house with an area of 100 ㎡. (5) The observed annual efficiency of solar systems was relatively low at 13.5 to 23.6%, which was analyzed to be due to the decrease in thermal efficiency and the overheating caused by a high solar fraction.

고정식과 방위추적식 태양열 급탕시스템의 집열성능 비교

이종석(Jong Suk Lee) 대한기계학회 2014 大韓機械學會論文集B Vol.38 No.2

강릉원주대학교는 캠퍼스 내에 저탄소 녹색기술 아이템들을 설치하였다. 그 중에 태양열 급탕시스템은 태양열 집열판을 고정식과 방위추적식의 두 가지 방식으로 설치하였으며, 기존의 고정식 집열판과 새로운 방위추적식 집열판을 사용하는 급탕시스템의 집열량을 비교하기 위해 모니터링을 실시하였다. 본 논문에서는 태양열 급탕시스템의 구성 및 모니터링 시스템을 소개하고 모니터링 결과를 통해 고 정식과 방위추적식 태양열 집열판을 사용한 두 가지 급탕시스템의 집열성능을 비교하였다. 방위추적식의 집열량이 고정식보다 맑은 날에는 19%, 비온 날에는 23%, 평균 21% 만큼 더 크다는 것을 보여준다. The solar water heating system is one of the seven green campus items installed at the Gangneung campus of Gangneung-Wonju National University. The solar water heating system has two types of solar collectors, four storage tanks and monitoring equipment. Fixed and azimuth-tracking solar collectors were installed to collect heat from the sun. The amount of heat collected by the two different types of solar collectors was calculated from the temperature of the monitored storage tanks. Our results showed that the amount of solar heat collected by the azimuth-tracking solar collector was 19% greater on a sunny day and 23% greater on a rainy day than that collected by the fixed solar collector; therefore, the azimuth-tracking solar collectors are, on an average, 21% more efficient than the fixed solar collectors.

ASPEN PLUS<SUP>®</SUP>를 이용한 태양열 유기랭킨사이클 열병합 발전시스템의 공동주택 적합도 분석

임석연(Seokyeon Im),김형근(Hyung-Geun Kim),유상석(Sangseok Yu) 대한기계학회 2015 大韓機械學會論文集B Vol.39 No.4

본 연구에서는 아파트단지에 적용되는 태양열 급탕 시스템의 에너지 활용도를 높이기 위해 유기랭킨사이클을 적용하여 해석적 연구를 수행하였다. 시스템 해석은 Aspen Plus<SUP>®</SUP> 을 활용하였으며 태양열 집열기는 급탕 온도와 유기랭킨 사이클의 운전 조건을 고려하여 진공관형 집열기를 적용하였다. R134a, R141a, R245fa 등의 냉매를 작동유체로 선정하였으며, 시스템 성능해석을 통하여 R245fa 냉매가 적용가능성이 가장 높게 나타났다. 비가역성 해석과 민감도 해석을 통해 유기랭킨 사이클 시스템의 효율 및 성능 확보를 위해서는 증발기와 터빈에 대한 기술 개발이 매우 중요하다는 것을 밝혀냈으며, 순수 급탕으로만 활용하는 시스템에 전기 생산 설비를 추가하게 되면 약 50%의 추가적인 경제성이 확보됨을 확인하였다. In this study, a solar thermal system is designed to provide hot water and electricity for improvement of solar thermal energy availability in an apartment complex. The electricity is generated with Organic Rankine Cycle (ORC) by the solar thermal energy. R134a, R141b and R245fa are selected for operating fluid of the solar thermal ORC system. ORC with R245fa shows the best performance based on the variation of pressure. The irreversibility of component showed that the technology advance of the evaporator ensures a performance improvement. The sensitivity study results indicate that the turbine performance is most effective way to improve the performance of ORC system. An economic analysis showed that approximately 50% more income could be achieved by a solar thermal ORC system with a hot water supply.

에너지공유 커뮤니티 구현을 위한 중앙온수급탕 방식의 신재생 열에너지 시스템 적용성 분석

김민휘,이동원,안영섭,주홍진 대한설비공학회 2020 설비공학 논문집 Vol.32 No.11

본 연구에서는 저탄소 에너지공유 커뮤니티 구현을 위한 에너지절감 및 효율개선 방안으로 다양한 신재생열에너지 시스템을 적용한 지열원 급탕 공급시스템을 제안하고, 제안된 시스템에 대한 에너지 절감효과를 분석하였다. 본 시스템을 커뮤니티 시설의 지붕에 설치될 경우 동일 면적에 적용된 경우의 에너지 효율 및 자가소비율에 대해서 분석하였다. 그 결과, ST시스템은 전체 연간 급탕에너지 요구량의 29.6%, PVT 시스템은 10.0%를 담당할 수 있는 것으로 나타났다. PVT 시스템을 적용하는 방식은 PV 시스템 대비 19.1% 낮은 발전량을 나타내었는데, 이는 PVT시스템 발전 모듈의 효율이 낮은 측면과, 비교적 겨울철 높은 온도를 유지하였기 때문으로 나타났다. 하지만, PVT시스템이 적용된 방식에서는 급탕에너지 요구량의 절감으로, PV 시스템과 ST 시스템을 적용하는 방식 대비 각각 22.0%와 37.2%의 운영에너지 절감효과를 가질 수 있는 것으로 나타났다. 반면, 전력의 커뮤니티 단위 자가소비율은 축열조의 사이즈에 따라 사이즈가 작을수록 ST 시스템을 적용하는 방식이 우수하며, 사이즈가 커질수록, PV 시스템을 적용하는 방식이 가장 높은 것을 확인할 수 있었다. 탄소배출저감 효과 또한, 본 제안된 시스템이 기존 시스템 대비 87% 이상의 효과를 얻을 것으로 예측되었다. 본 연구는 태양광 및 태양열 시스템의 성능을 비교적 정확하게 예측하는 TRNSYS 소프트웨어를 사용하여 시뮬레이션을 진행하였으나, 시뮬레이션 연구에 대한 한계가 있으며 결과에 대한 오차가 있다. In this study, a domestic hot water supply system using renewable heat energy systems was proposed for improving energy efficiency and savings to achieve a low-carbon energy sharing community. A smart village in Busan Eco Delta Smart City was selected for this analysis via detailed simulation. This smart village comprises 56 single-family houses and community facilities with a central mechanical center to supply heating, cooling and domestic hot water. In this study, the major thermal energy for domestic hot water is a geothermal heat pump, and applicability of solar energy, such as a photovoltaic (PV) system (Case 1), a solar thermal (ST) system (Case 2), and a photovoltaic and solar thermal (PVT) system (Case 3) was analyzed. As a result of this analysis, it was found that the ST system can account for 30.0% of the annual domestic hot water demand, and the PVT system can account for 10.0%. The PVT system showed 19.1% lower electric generation rates compared with the PV system. However, it was also found that the PVT system can reduce 22.0% and 37.2% of operating energy compared to the PV and ST system, respectively. The PVT can save the thermal demand of domestic hot water even the lower efficiency of PV generation rates. Conversely, it was observed that the PV and ST system showed higher self-sufficiency for the electric energy balance on the community compared to the PVT system depending on the size of the thermal energy storage.

사무소 건물 태양열급탕시스템의 LCC 최적화에 따른 에너지성능 변화 분석

고명진(Ko Myeong-Jin),최두성(Choi Doo-Sung),장재동(Chang Jae-Dong),김용식(Kim Yong-Shik) 한국태양에너지학회 2011 한국태양에너지학회 논문집 Vol.31 No.2

This study examined the energy performance according to the main design parameters of a solar water heating system for an office building using the life cycle cost (LCC) optimization simulations. The LCC optimization simulations of the system were conducted with TRNSYS and GenOpt employing the Hooke-Jeeves algorithm for cases where water temperature was 60℃ and 50℃. The results showed that for water temperature at 60℃ and 50℃ the global radiation incident on the collector could be decreased by 16.98% and 28.52%, collector useful energy gain could be decreased by 15.04% and 22.59%, energy to load from storage tank could be decreased by 10.86% and 18.06% and AH energy to load could be increased by 16.86% and 38.50% respectively compared to a non-optimized system. The annual average collection efficiency of the collector was increased by 0.88% for 60℃ and 2.78% for 50℃ because of increase of collector slope and decrease of the mass flow rate per collector area. The annual average efficiency of the system was increased by 1.74% and 3.47% compared to the basis system. However, the annual solar fraction of the system was decreased by 6.68% for 60℃ and 11.26% for 50℃ due to decrease of collector area and storage tank volume.

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.