• 융복합기술연구소 논문집
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• 제2권1호
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• pp.1-6
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• 2012

The cold chain system in South-East Asia is requiring to maintain freshness of refrigerated or frozen food. In this study, Thermal storage system using Phase change material (PCM) was developed and evaluated its performance about temperature and cold keeping time. For various application of cold chain system, we developed portable cold box, cold roll container and freezing station. Keeping time on laboratory tests of portable cold box in case of refrigeration and freezing were 6 hours and 4 hours, respectively. Cold container was developed to 2.5 ton scale. Evaluation in Indonesia, it was showed to keep the setting temperature of $-10^{\circ}C$ over 40 hours at $30^{\circ}C$ of ambient air. Freezing station using PCM was kept over 24 hours under $-20^{\circ}C$.

• JSTS:Journal of Semiconductor Technology and Science
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• 제8권1호
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• pp.1-10
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• 2008

The present status of technical development of a highly scalable, high-speed non-volatile PCM is overviewed. Major technical challenges are described along with solutions that are being pursued in terms of innovative device structures and fabrication technologies, new phase change materials, and new memory schemes.

• 한국의류산업학회지
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• 제16권2호
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• pp.326-332
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• 2014

To develop cool touch feeling fabrics for summer clothing material, it was manufactured several compositions of woven fabrics, having rayon multi-filament yarn (non-twisted) as warp and various kinds of yarn, such as viscose rayon multi-filament yarn (twisted), tencel$^{(R)}$ spun yarn, PET high absorbance quick dry filament yarn, and PET based rayon-like yarn, as weft. After preparing the fabrics, basic properties of the fabrics were investigated, such as air-permeability, tensile strength, absorption rate, drying rate, etc. Also, surface warm / cool sensations of the woven fabrics were assessed by Qmax Warm / Cool Touch Tester. It was observed that the fabrics composed of viscose rayon multi-filament yarn (warp) and PET high absorbance quick dry filament yarn (weft) showed excellent surface cool touch sensation-the highest Qmax value. This is because the fabric having flat shaped PET high absorbance quick dry filament shows the largest contact area with Qmax measuring plate. And, the fabric also showed superior high absorbance and quick dry property as expected. In addition, we treated phase change material (PCM) on the surface of the fabric composed of viscose rayon multi-filament yarn (warp) and PET high absorbance quick dry filament yarn(weft) to improve the cool touch feeling. However, the surface cool touch feeling was impaired by resin treated with PCM during the finishing process.

• 융합신호처리학회논문지
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• 제23권4호
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• pp.228-233
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• 2022

본 연구는 수중 무인 이동체의 장기 운용을 위한 전기 에너지의 생성을 위하여 상변화물질(PCM)을 활용하는 방안에 대한 실험적 연구이다. 상변화물질이 온도에 따라 고체와 액체의 상태로 변하면서 발생하는 부피의 변화가 한정된 공간에서 고압으로 변환되어 이를 통해 유체의 흐름을 만들어 발전하는 방식이다. 상변화물질로 해양의 온도를 고려하여 폴리에틸렌글리콜(Polyethylene glycol)을 사용하였으며, 고체상태인 저온(1℃~2℃)과 액체 상태인 고온(21℃~25℃)에서 부피 변화를 압력으로 변환 시켜주는 전기 에너지 생성 장치를 제작하여 전기 에너지 생성 실험을 수행하였다. 실험 결과, 상(Phase)변화에 따른 압력 변화는 1시간에서 2시간 사이에 급격히 발생하였으며, 4시간 이후에는 약 24MPa 정도의 압력을 유지하였다. 이를 통해 상변화물질과 온도 차를 이용하여 수중 무인 이동체의 전원으로 활용할 수 있음을 확인하였고, 이를 적용하기 위해서는 좀 더 개선된 설계가 이루어져야 함을 알 수 있었다.

• 설비공학논문집
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• 제11권4호
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• pp.549-559
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• 1999

An experimental study was peformed to measure the viscosity of microencapsulated PCM slurries as the functions of its concentration and temperature, and also influence to its fluid dynamics. For the viscosity measurement, a rotary type viscometer, which was equipped with temperature control system, was adopted. The slurry was mixed with water and Sodium Lauryl Sulphate as a surfactant by which its suspended particles were dispersed well without the segregation of particles during the experiment. The viscosity was increased as the concentration of MicroPCM particle added. The surfactant increased 5% of the viscosity over the working fluid without particles. Experiments were proceeded by changing parameters such as PCM particles'concentration as well as the temperature of working fluid. As a result, a model to the functions of temperature for the working fluid and its particle concentration is proposed. The proposed model, for which its standard deviation shows 0.8068, is agreed well with the reference's data. The pressure drop was measured by U-tube manometer, and then the friction factor was obtained. It was noted that the pressure drop was not influenced by the state of PCM phase, that is solid or liquid in its core materials at their same concentration. On the other hand, it was described that the pressure drop of the slurry was much increased over the working fluid without particles. A friction factor was placed on a straight line in all working fluids of the laminar flow regardless of existing particles as we expected.

• 한국염색가공학회:학술대회논문집
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• 한국염색가공학회 2010년도 제3회 국제학회
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• pp.80-81
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• 2010

We prepared polymer-PCM gels such as prepared frozen gel from polypropylene and n-Paraffin for thermal storage and release materials, their basic properties and possible applications especially in latent heat storage. The preparation methods are used to melting method and absorption method respectively. The composition and properties of prepared frozen gels from polypropylene and n-Paraffin were observed by DSC, FT-IR spectra, ARES and Elemental analysis. We can prepare frozen gels in different temperature for latent heat storage materials as controlling composition of phase change material as well as using different incorporating phase change materials. These frozen gels can be used to latent heat storage materials for several applications.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.66-67
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• 2020

The synthesis of stearic acid composite phase change material (PCM) was investigated and the samples produced were characterized for use in latent heat storage, using a simple chemical sol-gel process. The PCM was encapsulated to tetraethyl orthosilicate by various preparation ratios of stearic acid (5, 10, 15, 20, 30 and 50%). Fourier transformation infrared spectroscope (FT-IR) and X-Ray diffraction (XRD) were performed to determine the chemical structure and crystalloid phase of the microencapsulated PCM. SATEOS1 (5%) shows the best proportion for the PCM. With the presence of stearic acid as core materials and SiO2 as the supporting materials, it does not show any chemical reaction between both of them. SATEOS1 shows promising potential for thermal energy storage as it shows a better encapsulation efficiency and good thermal stability.

• 한국산업융합학회 논문집
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• 제12권3호
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• pp.163-169
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• 2009

A preheating module for domestic heating facility will increase a energy efficiency. That collects the wasted heat of exhaust gas and saves the energy. So a heating load is decreased because of a preheating that has a heating energy. Using of a preheating module, a boiler can reduce frequent operation of a burner. So it is increased persistence, decreased discharging noxious gases. Therefore we will intend to develop a heating facility that is a convenient system for the saving energy.

• 한국태양에너지학회 논문집
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• 제33권1호
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• pp.73-78
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• 2013

Hexadecane and exfoliated graphite nanoplate (xGnP)composite was prepared as a shape-stabilized phase change material (SSPCM) in a vacuum to develope thermal energy storage. The Hexadecane as an organic phase change material (PCM) is very stable against phase separation of PCM and has a melting point at $18^{\circ}C$ that is under the thermally comfortable temperature range in buildings. The xGnP is a porous carbon nanotube material with high thermal conductivity. Scanning electron microscope (SEM) and Fourier transformation infrared spectrophotometer (FT-IR)were used to confirm the chemical and physical stability of Hexadecane/xGnP SSPCM. In addition, thermal properties were determined by Deferential scanning calorimeter(DSC) and Thermogravimetric analysis (TGA). The specific heat of Hexadecane/xGnPSSPCM was $10.0J/g{\cdot}K$ at $21.8^{\circ}C$. The melting temperature range of melting and freezing were found to be $16-25^{\circ}C$ and $17-12^{\circ}C$. At this time, the laten heats of melting and freezing were 96.4J/g and 94.8J/g. The Hexadecane was impregnated into xGnP as much about 48.8% of Hexadecane/xGnP SSPCM's mass fraction.

• 에너지공학
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• 제2권3호
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• pp.258-267
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• 1993

본 연구에서는 초고온 잠열 축열재를 이용한 에너지 저장 시스템을 개발하기 위한 첫 단계로 에너지 저장 시스템 내부를 구성하는 단일 축열재 모듈에 대한 축방열 특성에 관한 수치모델을 개발하였다. 잠열축열재는 Si와 Al이 각각 96.8%와 2.7%인 합금으로 Ca, Fe 및 Ti 등의 불순물을 함유하고 있으며, 그것을 둘러 싼 캡슬은 SiC와 흑연이 각각 58%와 42%인 합금으로 융점은 약 1673 K다. 재료분석 결과에 준하여 수치모델 개발에 필요한 물리·화학적 데이타를 참고문헌으로부터 인용하였으며 유체의 온도와 속도를 축열재의 축방열 특성에 관한 변수로 사용하였다. 상전이에 관한 해석은 겉보기 열용량 법(apparent capacity method)과 postiterative 법의 장점들을 이용하여 해석하였다. 수치해석 결과 가스의 온도가 실제 조업에 가까운 1773 K의 경우 잠열재가 축방향으로 빨리 용융되고 상대적으로 가스의 온도가 높아 온도 차이가 큰 3000 K의 경우 잠열재가 반경방향으로 빨리 용융되는 현상이 일어났다. 가스의 유속은 온도에 관계없이 느린 경우에만 용융시간에 영향을 주고 빠른 경우에는 융용시간이나 용융형태에 거의 영향을 주지 못하며, 유속이 느릴수록 축열재 내부 온도구배의 앞·뒤 비대칭성이 심해지는 것이 예측되었다.