scholarly journals Thermal Performance Test of a Phase-Change-Material Cool Roof System by a Scaled Model

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Suk Goo Yoon ◽  
Young Kwon Yang ◽  
Tae Won Kim ◽  
Min Hee Chung ◽  
Jin Chul Park
Keyword(s):  
Temperature Distribution ◽  
Low Temperature ◽  
Surface Temperature ◽  
Phase Change ◽  
Phase Change Material ◽  
Thermal Performance ◽  
Room Temperature ◽  
Roof System ◽  
Cool Roof ◽  
Change Material

General cool roof is effective for reduction of cooling load, but it has a problem of increasing heating load. Therefore, the purpose of this study is to complement the disadvantages of the cool roof system by utilizing phase change characteristics of phase change material (PCM). The study was carried out to verify the thermal performance of the PCM cool roof system by measuring the temperature on the top and bottom of the PCM cool roof system by making a miniature model (600 × 600 × 600 mm). PCM was inserted and not inserted, and the temperature difference according to the finish color (brown and white) was compared. As a result, the plate surface temperature using PCM was lower than that without PCM, and time-lag of temperature increase occurred. As a result of the comparison of temperature according to the finish color (brown and white), white showed a low temperature distribution up to 16.35°C. Even at room temperature, white maintained a low temperature distribution of 5.40°C than brown. The use of PCM cool roof system in roof finishes could lower the surface temperature and keep the room temperature low.

Temperature-induced reversible structural phase transition of 1,4-dimethyl-1,4-diazabicyclo[2.2.2]octane bis(perchlorate)

RSC Advances ◽  
2015 ◽  
Vol 5 (69) ◽  
pp. 55914-55919 ◽  
Author(s):  
Li-Zhuang Chen ◽  
Xing-Xing Cao ◽  
Deng-Deng Huang ◽  
Qi-Jian Pan
Keyword(s):  
Phase Transition ◽  
Low Temperature ◽  
Phase Change ◽  
Phase Change Material ◽  
Structural Phase Transition ◽  
Room Temperature ◽  
Paraelectric Phase ◽  
Structural Phase ◽  
Disorder Transition ◽  
Change Material

A novel molecular-based phase change material was synthesized. The phase transition from a room temperature to a low temperature paraelectric phase might be driven by the order–disorder transition of ClO4− anions and the ordering of twisting motions of the dabco ring.

scholarly journals A numerical model and validation of phase change material integrated thermoelectric radiant cooling panel

2019 ◽  
Vol 111 ◽  
pp. 01001
Author(s):  
Hansol Lim ◽  
Hye-Jin Cho ◽  
Seong-Yong Cheon ◽  
Soo-Jin Lee ◽  
Jae-Weon Jeong
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Numerical Model ◽  
Surface Temperature ◽  
Phase Change ◽  
Transfer Coefficient ◽  
Phase Change Material ◽  
Overall Heat Transfer Coefficient ◽  
Radiant Cooling ◽  
Change Material

A phase change material based radiant cooling panel with thermoelectric module (PCM-TERCP) is proposed in this study. It consists of two aluminium panels, and phase change materials (PCMs) sandwiched between the two panels. Thermoelectric modules (TEMs) are attached to one of the aluminium panels, and heat sinks are attached to the top side of TEMs. PCM-TERCP is a thermal energy storage concept equipment, in which TEMs freeze the PCM during the night whose melting temperature is 16○C. Therefore, the radiant cooling panel can maintain a surface temperature of 16◦C without the operation of TEM during the day. Furthermore, it is necessary to design the PCM-TERCP in a way that it can maintain the panel surface temperature during the targeted operating time. Therefore, the numerical model was developed using finite difference method to evaluate the thermal behaviour of PCM-TERCP. Experiments were also conducted to validate the performance of the developed model. Using the developed model, the possible operation time was investigated to determine the overall heat transfer coefficient required between radiant cooling panel and TEM. Consequently, the results showed that a overall heat transfer coefficient of 394 W/m2K is required to maintain the surface temperature between 16○C to 18○C for a 3 hours operation.

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