Since the small screen must be watched at the production and manufacturing site, when using the monitor without a separate paper for work and production instructions, it is necessary to look at the work instruction screen installed in a separate space to prevent work efficiency from deteriorating. It plays a role through a monitoring system using DPS or Barcode and RF-ID recognition as a safety device for installing heterogeneous parts in manufacturing and missing parts, but due to the high cost of introducing the system and difficulty in maintaining management, Visual POP is put into the production line. This study was produced by paying attention to the following five points in order to reduce the weight of these industrial Visual POPs and have global specifications and uses. These include instrument design and design, processing production, UI and control, application, thermal stress analysis and thermal analysis. In this study, it is considered to thermal stress analysis and thermal analysis of Visual POP for Models 1 and 2.

This study numerically investigated thermal-structural characteristics of a liquefied hydrogen (LH) storage cylinder with varying inner pressures and surrounding temperatures. A thermal-structure coupled analysis approach was used to predict the thermal-structural characteristics of the LH storage cylinder. For the simulation, the shape of the LH storage cylinder was simplified using SUS 316L and Carbon Fiber Reinforced Plastic (CFRP) materials. As a result, the inner pressure was a crucial factor determining the structural property (i.e., stress and deformation) of the LH storage cylinder. The high pressure led to increased stress and deformation. Additionally, the surrounding temperature affected the stress and deformation of the LH storage cylinder. For example, at a high surrounding temperature, the temperature gradient along the cylinder increased, thereby causing the occurrence of thermal stress. However, this temperature effect on the stress was negligible compared to the effect of inner pressure. The findings of this study will provide meaningful data for improving the structural safety of LH storage systems.

본 연구는 서울시를 대상으로 여름철 지표온도(LST)에 영향을 미치는 공간적 요인을 분석하고, 지역별 영향력의 이질성을 파악하고자 하였다. 이를 위해 Landsat 8 위성영상을 활용하여 2024년 여름철 평균 지표온도를 산출하고, 자연환경, 도시구조, 인구활동, 토지이용 변수들을 250m 격자 단위로 구축하였다. 전역적 회귀분석(OLS)과 지리가중회귀분석(GWR)을 수행한 결과, GWR 모형이 더 높은 설명력(R2 = 0.878)과 낮은 AIC 값을 보여 공간적 적합도가 우수함을 확인하였다. 또한 Local R2 분포를 통해 모형의 설명력이 지역별로 상이함을 확인하였고, 변수별 회귀계수의 공간 분포를 통해 열환경 형성 요인의 비선형성과 공간 비정상성을 실증적으로 확인하였다. 본 연구는 서울시의 열환경 대응을 위한 지역 맞춤형 공간정책 수립에 기초자료를 제공하며, 도시열섬의 불균형 해소 및 열취약지역 관리 전략의 수립에 기여하고자 하였다.

In the development of a digital multi-process welding machine, we aimed to analyze the heat dissipation effects resulting from changes in the transformer's shape. Two installation configurations for the transformer, vertical and horizontal, were proposed. Thermal-flow analysis was conducted for the welding machine, taking into account variations in spacing between each proposed configuration. The results indicated that the shape and spacing of the components did not significantly alter the airflow around the reactor coil, which is the main heat-generating component of the machine. When comparing the heat dissipation effects across models with different transformer spacings, it was observed that models with narrower spacing exhibited improved heat dissipation, while the vertical configuration demonstrated a slightly higher heat dissipation effect overall. Transient analysis revealed the irregularities in internal flow and the resulting scattered temperature distribution over time within the welding machine.

The recent surge in energy consumption has sharply increased the use of fossil fuels, leading to a steep rise in the concentration of greenhouse gases in the atmosphere. Interest in hydrogen is growing to mitigate the issue of global warming. Currently, hydrogen energy is transported in the form of high-pressure gaseous hydrogen, which has the disadvantages of low safety and energy efficiency. To develop commercial hydrogen vehicles, liquid hydrogen should be utilized. Liquid hydrogen storage tanks have supports between the inner and outer cylinders to bear the weight of the cylinders and the liquid hydrogen. However, research on the design to improve the structural safety of these supports is still insufficient. In this study, through a thermal-structural coupled analysis of liquid hydrogen storage tanks, the model with three supports, which had the lowest maximum effective stress in the outer tank, inner tank, and supports as proposed in the author's previous research, was used to create analysis models based on the diameter of the supports. A structurally safe design for the supports was proposed.

This study investigates the thermal expansion characteristics of hydroxyl-terminated polybutadiene(HTPB) based solid propellants, focusing on batch-to-batch variability and accelerated aging effects. Coefficient of thermal expansion(CTE) measurements were conducted using thermomechanical analyzer(TMA) on samples from different manufacturing batches and specimens aged at various temperatures for different durations. Results indicate variations in CTE values between batches, highlighting the significance of manufacturing process control. Accelerated aging experiments reveal minimal systematic changes in CTE, suggesting stability of thermal expansion properties under short-term thermal stress. The overall distribution of CTE values shows concentration within a specific range, indicating consistency in thermal expansion characteristics. These findings provide insights into the thermal behavior of HTPB-based solid propellants, contributing to improved missile design and lifecycle prediction models.

The government declared ‘2050 carbon neutrality’ as a national vision in October 2020 and subsequently pursued the establishment of a ‘2050 carbon neutrality scenario’ as a follow-up response. Hydrogen is considered as one of the most promising future energy carriers due to its noteworthy advantages of renewable, environmentally friendly and high calorific value. Liquid hydrogen is thus more advantageous for large-scale storage and transportation. However, due to the large difference between the liquid hydrogen temperature and the environment temperature, an inevitable heat leak into the storage tanks of liquid hydrogen occurs, causing boil-off losses and vent of hydrogen gas. Researches on insulation materials for liquid hydrogen are actively being conducted, but research on support design for minimal heat transfer and enhanced rigidity remains insufficient. In this study, to design support structures for liquid hydrogen storage tanks, a thermal-structural coupled analysis technique was developed using Ansys Workbench. Analytical models were created based on the number and arrangement of supports to propose structurally safe support designs.

Hydrogen is considered as one of the most promising future energy carriers due to its noteworthy advantages of renewable, environmentally friendly and high calorific value. However, the low density of hydrogen makes its storage an urgent technical problem for hydrogen energy development. Compared with the density of gas hydrogen, the density of liquid hydrogen is more than 1.5 times higher. Liquid hydrogen is thus more advantageous for large-scale storage and transportation. However, due to the large difference between the liquid hydrogen temperature and the environment temperature, an inevitable heat leak into the storage tanks of liquid hydrogen occurs, causing boil-off losses and vent of hydrogen gas. Researches on insulation materials for liquid hydrogen are actively being conducted, but research on support design for minimal heat transfer and enhanced rigidity remains insufficient. In this study, to design support for liquid hydrogen storage tank, technique of thermal-structural coupled analysis including geometry, mesh, and boundary condition were developed using Ansys workbench, and equivalent stress and deformation distributions were analyzed.

Recently injection mold processing is necessary for the development of efficient solar concentrator system with a Fresnel lenses. Heat transfer mechanism in the Fresnel lens manufacturing process have a significant influence on precision machining and optical performance of solar power generation. In this study, we analyzed the thermal characteristics of temperature and heat flux distributions near the lens for transient molding process using CFD method. Initially for one second fast temperature variation on the upper surface of the lens leads to high heat flux distribution. It is gradually cooled to around 128℃ over a period of 60 seconds which is largely affected by the mold structure and the characteristics of the cooling lines. There is also high heat flux occurred on the lens upper side and lower surfaces with rapid temperature change. These results can be applied as fundamental design data for the manufacturing process in the development of Fresnel lenses.

The PCHE(Printed Circuit Heat Exchanger)-type heat exchanger, which was fabricated by etching and diffusion bonding, was used to hydrogen station, VHTR(Very High Temperature Reactor), SMR and so on. The hydrogen station equipped with PCHE-type heat exchanger is necessary to inject the hydrogen gas into facilities, for instance, such as HFCV(Hydrogen Fuel Cell Vehicle) and power systems. The purpose of this study is to investigate the thermal characteristics of thin plate of PCHE depending on constraint conditions through numerical analysis. As the results, it showed that thermal stress of thin plate, which was not performed diffusion bonding at all, was larger than that, which was performed perfect diffusion bonding, and its maximum difference was about 3 times. Further it was confirmed that the thermal characteristics of thin plate could be obtained by investigating the heat flux.

Decarbonization plays an important role in future energy systems for establishing a zero-carbon society. Hydrogen is believed to be a promising energy source that can be converted, stored, and utilized efficiently, leading to a broad range of possibilities for future applications. Hydrogen can be stored in various forms, including compressed gas, liquid hydrogen, hydrides, adsorbed hydrogen. Among these, liquid hydrogen has high gravimetric and volumetric hydrogen densities. There are a lot of previous studies on thermal behavior of MLI and VCS and optimization insulation system, but research on the insulation performance by varying the head shape of the tank has not been conducted. In this study, thermal-structural coupled analysis was conducted on the insulation system with VCS positioned between two layers of MLI for a liquid hydrogen storage tank. The analysis considered dome shapes (torispherical, circle, ellipses), and heat flux and temperature were derived from thermal analysis to predict insulation performance. Maximum equivalent stress and deformation were calculated from the structural analysis, and the optimal dome shape was proposed.

This study aims to evaluate the structural safety of a structural thermal barrier, installed inside the structure of a building and performed the role of a load-bearing element and an insulation simultaneously, contributing to the realization of net-zero buildings. To ensure the reliability of the analysis model, the analysis results derived from LS-DYNA were compared with the experimental results. Based on the results shown through the flexural experiment, the reliability of the thermal cross-section insulation structure model for slabs was validated. In addition, the effect of the UHPC block on the load support performance and its contribution to vertical deflection was verified.

본 연구에서는 육계사에 차열 페인트와 히트펌프의 적용에 따른 내부 온도 변화를 분석 하였다. 이를 위하여 환기율, 환기 방법, 시간별 환기 변화에 따른 실험 조건을 설정하였으며 육 계사 외부 및 내부 기온을 측정하였다. 그 결과, 차열 페인트를 도포한 육계사에서는 최대 1－2°C 실내 기온 상승을 억제하 는 효과가 나타났으며 히트펌프를 가동한 육계사에서는 외기 온도의 영향을 제일 적게 받는 환기율 0%일 때 내부 기온 감소 가 제일 크게 나타났다. 계사 내부의 온도가 외기 온도보다 높 을 경우에는 환기율을 높게 설정하여 환기팬을 이용한 냉방이 더욱 효과적이나 계사 내부 온도가 외기 온도와 유사하거나 낮을 경우에는 히트펌프를 이용하는 것이 가장 효과적일 것으 로 판단된다. 히트펌프 가동 시 외기 온도의 영향이 적은 환기 율을 0%로 설정하였을 때 내부 기온이 가장 큰 폭으로 감소하 였으나 실제 육계사에서는 분진, 이물질, 암모니아 등을 고려 하여 최소환기율 정도로 환기율을 설정한 후 히트펌프를 가동 하는 것이 가장 효율적일 것으로 판단된다. 본 연구는 실험 기 간이 짧아 데이터가 많지 않으며 실제 육계가 사육되고 있는 환경에서 실험을 진행한 것이 아니라는 한계가 있다. 향후 후 속 연구로 실제 닭이 사육되고 있는 환경에서의 히트펌프 효 과 분석과 히트펌프의 전력사용량, 냉방부하, 환기팬 가동시 간 등 다양한 환경인자를 포함한 연구가 진행되어야 할 것으 로 판단된다.

In this study, the thermal equilibrium of a motor operated in the sea and the temperature in the equilibrium were studied. To predict the equilibrium temperature in the sea, the cooling performance of the motor was studied by comparing results of analysis and experimental results in the air condition. By this study, the method of prediction of the cooling performance of a motor in various environments could be useful.

This study deals with the maximum thermal load analysis and optimal capacity determination method of tank culture system for applying seawater source heat pump to save energy and realize zero energy. The location of the fish farm was divided into four sea areas, and the heat load in summer and winter was analyzed, respectively. In addition, two representative methods, the flow-through aquaculture system and the recirculation aquaculture system were reviewed as water treatment methods for fish farms. In addition, the concept of the exchange rate was introduced to obtain the maximum heat load of the fish farms. Finally, power consumption for heat pumps was analyzed in the view point of sea areas, tank capacity, and exchange rate based on the calculated maximum thermal load.

In this study, we performed thermal safety design of the electric module of a heat-loaded equipment with consideration of its heat dissipation performance. Initially, we calculated the heat dissipation of natural convection to choose a cooling method. Based on this, we found that some modules required forced convection and selected an air-cooling method with an outdoor temperature of 43 degrees Celsius, which is the maximum temperature in Korea. Prior to module production, we performed thermal analysis of each module and proceeded with a design to increase the thermal conductivity of the module as a primary step, and subsequently proceeded with Heat Sink design to maximize the heat dissipation performance. After considering various constraints according to the system requirements and designing the cooling path, we experimentally and analytically secured thermal safety at the operating temperature of the equipment.

The shell & tube-type heat exchanger has been frequently used because it shows simple structure, easy manufacturing and wide operation conditions among many heat exchangers. This study aims to investigate the characteristics for thermal flow of coolant and the possibility of damage for tube equipped with shell due to thermal stress. For these purposes, The thermal flow of coolant in tube was simulated using ANSYS-CFX program and thus the behaviors of coolant were evaluated with standard k-ε turbulence model. As the results, as the flow rate of coolant in tube was increased, the mean relative pressure was also increased with quadratic curve, however, as the surface temperature of tube was increased, mean temperature difference was linearly increased. Finally it showed that the damage of tube could be predicted, that is, which tube was the most weak due to thermal stress.