In this study, to develop and verify the Jeju-type groundwater thermal system design program, the energy consumption and system performance derived by input into the design program based on the load calculated on the demonstration site and the groundwater temperature were compared and analyzed with the actual measured values. The theoretical values ​​of energy consumption and heating and cooling COP ​​obtained through the Jeju-type groundwater thermal system design program were 11.24kW, 5.28 for heating, 13.31kW, 3.94 for cooling respectively. The measured values ​​of energy consumption and COP of the Jeju-type groundwater thermal system were 3967.2kW and 4.5, respectively. The error between the theoretical value and the measured value obtained through the design program is 0% and 2.39%, respectively. The errors that occur in the predicted values ​​and the actual values ​​are due to variables that are ignored in the system assumptions. If users consider errors and use it when designing groundwater thermal systems, they can estimate the cost of required drilling works, heat exchangers, and heat pumps and analyze economic feasibility.

This study presents a numerical modeling and a transient simulation of a desiccant coated heat exchanger (DCHE) that is employed for dehumidification in buildings. DCHE is fabricated by coating type RD silica gel on the fin surfaces of a fin tube heat exchanger. The latent cooling load, which is 25 to 45% of the total cooling load in most weather conditions is removed by adsorption of vapor using DCHE. The saturated adsorbent is then regenerated by using either low-temperature waste heat from industry and/or renewable energy such as solar energy and geothermal energy. A mathematical model is established and a transient simulation has been carried out so as to analyze its performance in terms of average humidity difference (AHD), moisture removal capacity (MRC), latent cooling capacity(QL), and COP. Comparison between the simulation results and the experimental data was carried out and showed good agreement and a similar trend with a maximum discrepancy of 5%. Key results revealed that MRC, AHD, QL, and COP are largely affected by both air dry-bulb temperate and air wet-bulb temperature while they are less affected by the frontal air velocity. Furthermore AHD, MRC and QL are largely improved by hot-water temperature while COP decreases as hot-water temperature increases due to high regeneration energy consumption.

A heat pump system using wasted heat from thermal effluent to supply the heating energy can reduce energy consumption and emissions of greenhouse gases by greenhouse facilities nearby. The Jeju National University consortium constructed a heat pump system using the thermal effluent from the Jeju thermal power plant of KOMIPO to provide with cool or hot water to greenhouse facilities located 2.5km from the power station. In this paper, the system configuration of the heat pump system was summarized, and the results of operations for demonstration of a heating performance carried out during the winter season in 2018 were investigated. Therefore, if the heating control by supplying thermal effluent to the facility greenhouse, it can contribute to reducing the energy cost and improving quality.

We conducted a study on the possibility of using the power plant's thermal effluent system by using a heating system to utilize the thermal effluent from Jeju Power Headquarters of KOMIPO. In this study, growth information such as the size, leaf area, fresh weight and dry weight of subtropical persimmon fruit (A) in the facility cultivation complex were measured. In the comparison group (B), the growth information of the same crop was measured and compared in an unheated greenhouse near Harye-ri, Namwon-eup, Seogwipo. Fruit size was measured at monthly intervals, and leaf area, fresh weight, and dry weight were measured at new shoot season. Measurement results of A and B growth information, 1) Fruit diameter & length, A grew 7.3% and 9.4% than B, 2) Leaf area, A grew 4.7% than B, 3) Fresh weight, the decrease was 8.9%, but the dry weight was 3.6%, indicating that A contains more nutrients than B. Therefore, if the heating control by supplying thermal effluent to the facility greenhouse, it can contribute to reducing the energy cost and improving quality.

In order to enhance the utilization of underground heat including underground water, the comparison between the existing high density polyethylene underground heat exchanger and the newly developed metal heat exchanger was conducted to suggest the potential use of geothermal energy corresponding to the geological characteristics of Jeju Island. When the acquired heat of the underground loop system test condition of the KS B 8292 water-water geothermal heat pump unit was compared by installing heat exchanger of HDPE material and the heat exchanger of STS material under the same bore hole condition, the total heat area of the heat exchanger of STS material was about 15% less than HDPE, but the acquired heat was estimated to be about 4 times or more.

In this study, the yaw misalignment value of wind turbine was measured using Lidar and it was analyzed the effect of vibration reduction and power performance improvement when applied to turbine. It was confirmed that the vibration of the main bearing and the gear box of the wind turbine was partially reduced. Also it was found that the output performance was improved when the wind speed was over 8m/s. As a result, it was also found that the annual energy production(AEP) was improved when the average annual wind speed of the wind farm was over 6m/s. Converted to AEP, the AEP improved about 1% and 4%, when the annual wind speed was 6m/s and 11m/s respectively, which resulted in an improvement of about 1~4% through the yaw misalignment correction of the wind turbine.

In this study, a plate heat exchanger was developed for applying to a heat pump system using the heated effluent from a thermal power plant. Since seawater is used as a heat source and a heat sink in this heat pump system, Titanium was chosen as the heat plate material for its high corrosion resistance. One of the purposes of the study was to get an optimized distribution area in the heat plate in order that better thermal performances could be achieved through equal flow rates along the heat transfer area. It was revealed from the performance tests that the mean heat transfer rate and the overall heat transfer coefficient were enhanced by 2.9% and 7.7%, respectively, compared to those measured before the design optimization.

An icing phenomenon of wind turbine blade are caused by wind speed, air temperature, liquid water content, droplet size, and so on. In this study, the analyses were carried out at a liquid water content of 0.20g/㎥, droplet size of 25 um, wind speed of 11.4m/s and air temperatures of -15, -10, -5℃ using NREL 5MW wind turbine. The software uses FENSAP-ICE's CFD Flow Solver, Drop 3D and ICE 3D. The analysis of icing shape and mass with temperatures according to air foil was derived, and the required heat quantity for de-icing was calculated at NACA 64618 airfoil for air temperature of -15℃. Power curves with wind velocities are suggested for economical analysis.

폴리이미드 고분자막을 사용한 질소부하 장치를 설계하고, 이를 CA 저장에 활용하기 위한 기술적 기본 데이터를 제시하였다. 순수 산소 및 질소의 투과특성은 dual-mode sorption 모델로서 설명될 수 있었으며, 공기 중의 산소의 투과율은 공기 중에 존재하는 질소의 영향으로 순수 산소의 투과율에 비해 크게 감소하나, 공기 중의 질소의 투과율은 산소의 영향으로 순수 질소의 투과율에 비해 증가하였다. 수행한 압력 및 온도 범위 내에서 이상분리인

Temperature, relative humidity and ventilation are closely related one another, and they are the main factors to be controlled for the environmental control system of a storage facility. Conventional environmental control systems do not consider the interrelationship between temperature, relative humidity and ventilation, which results in low performance and high energy consumption. To overcome the inefficiency of the conventional ones, it was developed an on-off control system based on the interrelationship between the factors. The usefulness of the system was illustrated with the results produced by a set of experiments in a real world.

Natural convection in agricultural-products storage system was analysed theoretically, The storage system was modelled by Internally heated fluid saturated porous layer. Darcy's law was used to explain characteristics of fluid motion. Stability equations were obtained under the linear stability theory and transfer characteristics were modelled by the shape assumption. Based on the modelling of transfer characteristics, heat trasnfer correlations were derived theoretically.