• Culinary science and hospitality research
• /
• v.19 no.5
• /
• pp.196-205
• /
• 2013

This study showed the chemico-physical characteristics and sensory evaluation of beef loin and ribs with various kinds of cooking apparatus and methods like pan heating, boiling, grilling, steaming, cooking heating, charcoal heating and double layer pan heating. Double layer pan filled with Phase Change Materials(PCM) heating was also tested. Heating time of beef loin and ribs by oven heating was the longest as 55.5 and 25.7 min. Cooking loss of beef loin and ribs were 40.49%, 27.98% each and showed biggest in charcoal heating(p<0.05). In the chemical analysis, grilling resulted in the highest protein contents of 29.3% in the loin and double layer pan heating had 28.6% in the ribs. In the loin, 20.3% of crude fat was the highest in the double layer pan heating, and 21.9% of crude fat of ribs in the PCM heating(p<0.05). In the test of shearing forces, double layer pan heating had the lowest result of $9.14kg/cm^2$ in the loin and $7.03kg/cm^2$ in the ribs. In the 9 point-scale sensory evaluation, PCM treatment showed the best result of 7.67 in the juiciness of loin and single layer pan heating and grilling treatment had the highest score of 7.00 in the ribs. Loin in the PCM heating had 7.11 and ribs in the grilling had 7.13, showing the best in overall acceptability. With this experiments, we could find the chemico-physical and sensory characteristics of beef loin and ribs were affected by various cooking methods.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 2001.04b
• /
• pp.31-33
• /
• 2001

잠열축열 그린하우스 난방 시스템의 난방특성을 분석하기 위하여 이에 대한 열평형 이론을 정립하고 수치해석에 의하여 컴퓨터 시뮬레이션 모델을 개발하고자 잠열축열 그린하우스 난방 시스템의 열저항 회로망을 구성하였다. 그리고 그린하우스의 피복재, 내부 공기, 토양표면, 잠열 축열재와의 열평형 방정식을 구성하였으며, Newton-Raphson반복법을 이용하여 수치해석을 하였고, 실험 분석을 통하여 수치해의 타당성을 검증하였다. 시뮬레이션 모델을 위하여 C언어를 사용하였으며, 겨울철 (11월-2월)의 기후 조건이 유사한 여러 날을 선정하여 온도, 태양강도, 상대습도, 토양 수분함량 등을 자료로 하여 모델링을 하였다. 여기에 사용된 토양 조건은 사양토로 건조한 상태를 유지하였다. 이상과 같은 분석에 의하여 그린하우스내 경시적 공기온도 변화와 열전달 현상의 실험치와 이론분석 결과가 잘 일치하고 있음을 알 수 있었다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.13 no.2
• /
• pp.80-87
• /
• 2001

Microencapsulated PCM particles are mixed with distilled water and utilized to evaluate its characteristics and performance as a thermal storage medium transporting heat. For the present study, tetradecane(C$_14H_30, T_m=5.5^{\circ}C$) is capsulated in the core with the melamine of its surface. The size of particles is well-controlled under 10${\mu}{\textrm}{m}$ in the way of in-situ polymerization with melamine-formaldehyde resin. For the experiment, the concentrations of slurries are prepared for 20wt%, 30wt%, and 40wt%. The results are compared with those of water and 100% tetradecane oil. The pure water and tetradecane start solidifying within 20 minutes after introducing cooling water into the thermal storage tank whose tank whose flow rates are varied by 125cc/min, 250cc/min, and 500cc/min. However, MicroPCM slurries are required relatively longer period of time for their phase change than pure phase change materials. That is, the entrained MicroPCM particles control its heat transfer in terms of natural convection and conducting to them.

• Journal of Bio-Environment Control
• /
• v.6 no.3
• /
• pp.216-224
• /
• 1997

In the recent 10 years the protected cultivation area in Korea has been increased rapidly, and now it is very important issue to develop the heating and cooling system using the renewable energy, because the greenhouse heating and cooling cost is increased with the fossil fuel price rises. Actually the development of the cooling system is more difficult than that of the heating system, since the cooling load of greenhouse in the summer season is 2―3 times larger than the heating load in the winter season. In this study low temperature phase change materials (LTPCM) for the cold storage system were selected and developed. The theoretical and experimental analysis of thermal characteristics of LTPCM makes it possible to control the phase change temperature and stabilize the thermo-physical properties. LTPCM developed in this study has good advantages to be used as the cold storage not only for the house and working space in factory but also for the cold storage of agricultural and live-stock products.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.8 no.4
• /
• pp.576-582
• /
• 1996

This work studies qualitative thermal characteristics of PCM cold storage medium container and its surrounding streams. Experimental parameters are initial PCM temperature and cold water flow rate. A mathematical modeling was establised to estimate temperature distribution and the cooling process. We found that the phase-change temperatures of PCM varies from 6 to $8^{\circ}C$ which is constant for other materials and that the dominant heat transfer resistance is that on the container side taking about 3/4 of the total resistance. The one dimensional mathematical model predicts experimental data quit well.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.18 no.6
• /
• pp.501-508
• /
• 2006

MPCM (Microencapsulated Phase Change Material) slurries show several advantages over the sensible heat transportation system. In this study, a numerical model for a vapor compression refrigeration system using MPCM slurries as a secondary fluid through an evaporator was developed, and the system performance was compared with that using water. Generally, the MPCM system showed higher performance than the water system. The COP of the MPCM system was higher by 16.6 to 18.6% than that of the water system at all conditions. The MPCM slurry yields better performance in the aspect of heat transfer and heat transportation comparing to the sensible heat transfer medium such as water.

• Journal of Advanced Marine Engineering and Technology
• /
• v.28 no.6
• /
• pp.962-971
• /
• 2004

This paper has dealt with thermo-physical properties of microencapsulated phase change material slurry as a latent heat storage material having a low melting point. The measured results of the thermo-physical properties of the test microencapsulated phase change material slurry, those are, density, specific heat, thermal conductivity and viscosity, were discussed for the temperature region of solid and liquid phases of the dispersion material (paraffin). The measurements of these properties of microencapsulated phase change material slurry have been carried out by using a specific-gravity meter, a water calorimeter, a differential scanning calorimeter(DSC), a transient hot wire method and rotating type viscometer, respectively. It was clarified that the additional properties law could be applied to the estimation of the density and specific heat of microencapsulated phase change material slurry and also the Euckens equation could be applied to the estimation of the thermal conductivity of this slurry.

• Food Science and Preservation
• /
• v.23 no.4
• /
• pp.471-478
• /
• 2016

For the distribution of fresh produce, the thermoelectric cooling system combined with thermo electric materials (TEM) and phase change material (PCM) was studied. The PCM used this study was produced by in-situ polymerization technology which referred microencapsulation of hydrocarbon (n-tetradecane and n-hexadecane). In this study, quality characteristics of bell peppers in thermoelectric cooling system combined with TEM and PCM were analyzed and control was placed in an EPS (expanded polystyrene) box. As a result of quality characteristics analysis, weight of bell peppers decreased and moisture content of bell peppers was 90.96~94.43% during storage. Vitamin C content of bell pepper decreased during storage and reduction ratio of control was higher than that of BPT-5 treatment(bell pepper in thermoelectric cooling system with PCM which is kept the temperature at $5^{\circ}C$). The result of color value, on 21 day, ${\Delta}E$ value of BPT-5 treatment was 5.05 while that of control was 41.8. On 21 day, total bacteria count of BPT-5 treated bell pepper shown less than that of control. In conclusion, it suggested that the thermoelectric cooling system combined with PCM improved quality of fresh produce during transportation and storage.

• Proceedings of the KSME Conference
• /
• 2001.06d
• /
• pp.226-231
• /
• 2001

The purpose of this paper is to propose the experimental method of thermal properties of Phase Change Materials (PCMs) by using T-history method. As far, in order to measure the heat of fusion and specific heat of PCMs, conventional thermal analysis methods such as DSC and DTA have been used. Because these methods test very small samples, thermal properties of samples are usually different from those of materials consisting of several components. For these reasons, T-history method, the simple measurement method of the heat of fusion and specific heat of PCMs have been performed. In this paper, we investigated the thermal properties of low temperature PCMs(below $0^{\circ}C$) under the charging process by using T-history method. The results are compared to those of DSC method. The T-history method will be useful for selection of the best PCM from lots of candidates and development of new PCMs.

• Journal of the Korean earth science society
• /
• v.30 no.6
• /
• pp.709-720
• /
• 2009

Field observation and numerical experiments were conducted to understand the impact of water retention pavement on the surface heat budget and on the regional circulation. The numerical model applied in this study is the atmospheric dynamic model Local Circulation Model (LCM) with two dimensional grid system, and a field observation was carried out under the clear sky and calm conditions of the weather on 19 July 2007. In the field observation, the maximum value of surface temperature on pavement covered with water retention material reached the $41.2^{\circ}C$ at 1430 LST and the values was lower for $16.1^{\circ}C$ than that of asphalt without the material. The Case BET03 assumed to be 0.3 for the surface evaporation efficiency was in good agreement with the observation and its sensible and latent heat fluxes were numerically estimated to be 229 and 227 $W/m^2$, respectively. Results of the numerical experiments demonstrated that the water retention pavement tends to induce the increase of latent heat flux associated with the lower surface temperature and mixing height during the daytime. Discontinuity of latent heat caused by the water retention pavement also tends to promote the development of mesoscale circulation called as land-land breeze or country breeze.