상변화물질과 열전소자를 사용한 건물외피 폐열회수 패시브 발전장치 성능 평가

변유석(Yoo-Suk Byon),동혜원(Hye-won Dong),유소(Liu Su),정재원(Jae-Weon Jeong) 대한설비공학회 2018 대한설비공학회 학술발표대회논문집 Vol.2018 No.11

The purpose of this research is to design a block that harvests solar energy accumulated on outer building walls. A thermoelectric module and a phase-change material (PCM) were integrated in a concrete block. The thermoelectric module can generate electricity from the temperature difference between two sides of the module through Seebeck effect. Although the energy conversion rate is significantly small, the thermoelectric generator (TEG) is beneficial in the sense that it can harvest energy from heat otherwise wasted. To improve energy conversion, cooling of the cold side of the TEG is necessary. In this research, a PCM was employed as a cooling component. By using a paraffin-based n-Heptadecane material, the cold side of the TEG can be controlled to stay at the temperature of melting point of the PCM. The PCM requires no energy to perform as a cooling component, and when the sun sets, the PCM solidifies again because the ambient temperature drops at night. When this happens, the hot side, which acts as a heat-absorbing panel with daylight, acts as a heat dissipating panel. Both TEG and PCM are integrated and designed to be in a building block. Typical dimensions of 190×90×75 ㎣ were applied. Simulations were performed with an engineering equation solver. Component models of the TEG and PCM were designed. The results showed 1 V and 0.2 W of energy harvested from a single block per day. This TEG-PCM block can be stacked to become a wall forming a series in order to generate more energy.

열전소자 기반 에너지 하베스팅 블럭의 건물외피 적용시 발전량 예측

변유석(Yoo-Suk Byon),천성용(Seong-Yong Cheon),황유진(Yujin Hwang),정재원(Jae-Weon Jeong) 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.-

The purpose of this research is to predict annual electricity generation from the energy harvesting block when it is installed on exterior wall of a building. By incorporating thermoelectric generator and phase change material, the energy harvesting block can passively generate electricity from waste heat. Since exterior walls of buildings has waste heat that is accumulated in daytime and dissipated during night, which makes the waste heat on walls be unused, the energy harvesting block is installed on building walls to collect the unused heat. The experiment to evaluate the electricity generation was done according to the representative wall temperature ranges of summer, winter and of a day that has the biggest range. Experimental results showed that the electricity generation depended on the magnitude of the range and both summer and winter condition results showed 0.090 Wh of electricity generated for a day. Because a single energy harvesting block can generate 0.090 Wh of electricity, when the energy harvesting block is installed in a scale of 1 m2, total 5,810 Wh can be generated for a year.

열전소자 기반 에너지 하베스팅 블럭의 계절별 에너지 회수량 분석

변유석(Yoo-Suk Byon),임한솔(Hansol Lim),강용권(Yong-Kwon Kang),윤수열(Soo-Yeol Yoon),정재원(Jae-Weon Jeong) 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.11

The purpose of this research is to predict annual electricity generation from the energy harvesting block from thermoelectric energy conversion from waste heat recovery. The energy harvesting block consists of thermoelectric generator and phase-change material. The waste heat on building exterior causes temperature difference between the exterior wall and the interior of the building. By implementing the energy harvesting block, the waste heat can be converted into electricity. To predict the amount of annual generation, representative monthly wall temperature profiles of April, July, October, and January (Spring, Summer, Autumn, and winter respectively) were calculated through TRNSYS 19. Peltier plate was used to mimic wall temperature by controlling plate temperature that is attached to the energy harvesting block. The result showed 205 Wh/㎡, 30 Wh/㎡, 223 Wh/㎡, 281 Wh/㎡ of electricity generation respectively for 4 seasons. The experiment showed feasibility of the energy harvesting block of generating electricity at night or day and regardless of the seasons. Total predicted annual electricity generation was 2217 Wh/㎡.

태양열 계간축열 시스템 적용에 의한 시설원예 난방의 에너지 절감 효과 분석

변유석(Yoo-Suk Byon),동혜원(Hye-Won Dong),강용권(Yong-Kwon Kang),김범준(Beom-Jun Kim),정재원(Jae-Weon Jeong) 대한설비공학회 2018 대한설비공학회 학술발표대회논문집 Vol.2018 No.6

Seasonal thermal energy storage (STES) is widely researched because it utilizes excess energy that would be wasted otherwise. The purpose of this study is to analyze the energy efficiency of seasonal solar thermal energy systems as heating systems for greenhouses and to compare it with conventional variable air volume (VAV) heating systems. A greenhouse was chosen as a simulation model, because it requires constant and stable heating through the winter to extend the growing season and also because greenhouses can provide enough area to install solar collectors and heat storage tanks. When STES is used in greenhouse buildings to control the temperature, it is expected to perform at its full capacity, because greenhouses only need heating, and a large amount of heating is needed. The proposed seasonal solar thermal energy storage system consists of a solar thermal collector, fully mixed heat storage tank, and VAV heating system. Energy simulation was conducted in two steps: heat storing throughout the year and heating in the winter. 125 greenhouses with area of 32 m2 each, 125 solar thermal collectors of 10 m2 each, and heat storage tank of 2000 m3 was designed. TRNSYS 18 and an engineering equation solver were implemented for simulation and calculation of the system’s thermal data. Simulation results showed STES heating contributing to 29% of the total heating load.

기체분리막 제습이 적용된 외기전담시스템의 에너지 성능 분석

천성용(Seong-Yong Cheon),변유석(Yoo-Suk Byon),이수진(Soo-Jin Lee),정재원(Jae-Weon Jeong) 대한설비공학회 2019 대한설비공학회 학술발표대회논문집 Vol.2019 No.-

A vacuum membrane dehumidifier-assisted dedicated outdoor air system (VMD-DOAS) is proposed and its energy performance is investigated by detailed energy simulation. The dehumidification performance and operation energy consumption of the proposed system were compared with two conventional dedicated outdoor air systems; the DOAS assisted by the cooling coil (Reference A) and the DOAS with desiccant wheel (Reference B). The result shows that the average coefficient of performance of studied systems was 1.98 in the VMD-DOAS, 2.70 in Reference A, and 1.73 in Reference B and the average latent cooling ratio of studied systems was 1, 0.43, and 0.25, respectively. Although the coefficient of performance of the VMD is lower (or similar) than Reference cases, the energy consumption of the VMD could be reduced as its latent heat ratio (energy convergence ratio of total to latent energy for dehumidification) is higher than Reference cases. Also, reheating coil energy can be reduced by preventing the overcooling process as the isothermal dehumidification process of the VMD. The dehumidification energy consumption of the VMD was reduced. Consequently, the proposed system reduced the total annual operation energy by 40.5% compared with Reference B and by 21.8% compared with Reference A.

열전소자 기반 복사 냉방 패널의 최적배열 설계

임한솔(Hansol Lim),리쓰잉(Shiying Li),천성용(Seong-Yong Cheon),변유석(Yoo-Suk Byon),정재원(Jae-Weon Jeong) 대한설비공학회 2018 대한설비공학회 학술발표대회논문집 Vol.2018 No.6

This paper proposes a thermoelectric module radiant cooling panel (TEM-RCP) and its desirable arrangement of thermoelectric modules (TEMs) for uniform temperature distribution. The design methods for the TME-RCP was developed based on the semi-black box model of TEM and the two-dimensional finite difference method. A mock-up model of the TEM-RCP was constructed to verify the proposed model and results. The constructed TEM-RCP consists of seven TEMs, an aluminum panel, a heat sink attached to the TEMs, air duct and fan for heat rejection. The TEM is a solid state heat pump operated by direct current based on the Peltier effect. When the panel temperature at the aluminum radiant panel was maintained at 16°C during operation, the heat rejection was occurred at the hot side of TEM and it was removed using forced convection by outside air. The main design factor in this study was the panel temperature distribution. Therefore, the suitable arrangement and interval between TEMs were investigated not to exceed the maximum temperature difference of 3°C across a given grid. As a result, the triangular grid was found as the best grid for an uniform temperature distribution of the TEM-RCP. The optimal interval between the TEMs was 0.2 m to 0.3 m according to the room condition and operation characteristics of the TEM. The optimized results were validated through experiments using the mock-up model of TEM-RCP.