[en] Many commodities such as food, medicines & vaccines are required to be kept in commercial cold storages within a specified temperature range. problems arise in these systems within times of failure, power cuts, or transportation. The absence of refrigeration leads to an increase in temperature within the system which may lead to spoilage of products stored inside. Phase change materials may pose as a promising solution as they absorb the latent heat of the system at the expense of the phase change absorbing, latent heat. Ethylene glycol is selected as the phase change material due to its high latent heat content and negligible hazards. The system incorporated with phase change material was found to retain the cooling effect after cut off. In this paper, for investigation we conducted four experiments namely 0/0%, 75/25%, 50/50%, 100/0% Ethylene glycol and water respectively as phase change material for studying the retention of cooling within the system during power failures. The result shows that the retention of cooling in cold storage unit with 100% Ethylene glycol phase change material is very low 50% Ethylene glycol and 50% water has more retention of cooling. This indicates that addition of water in the phase change material increases the retention of cooling in cold storage unit. (paper)

[en] The thermal protective performance of the fire fighter protective clothing is of vital importance for fire fighters. In the study fabrics treated by phase change materials (PCMs) were applied in the multi-layered fabrics of the fire fighter protective clothing ensemble. The PCM fabrics were placed at the different layers of the clothing and their thermal protective performance were measured by a TPP tester. Results show that with the application of the PCM fabrics the thermal protection of the multi-layered fabrics was greatly increased. The time to reach a second degree burn was largely reduced. The location of the PCM fabrics at the different layers did not affect much on the thermal protective performance. The higher amount of the PCM adds on, the higher thermal protection was brought. The fabrics with PCMs of a higher melting temperature could contribute to higher thermal protection. (paper)

[en] We demonstrate an energy-efficient programmable via concept using indirectly heated phase-change material. This via structure has maximum phase-change volume to achieve a minimum on resistance for high performance logic applications. Process development and material investigations for this device structure are reported. The device concept is successfully demonstrated in a standard CMOS-compatible technology capable of multiple cycles between on/off states for reconfigurable applications.

[en] Improvements are proposed to the well-known T-history method, which is widely used for thermal properties measurement of phase change materials (PCM). Our improvements refer to the experimental arrangement, to the way of measurement processing, as well as to the kind and presentation format of the final results. The proposed arrangement has a controlled indoor environment and is fully automatic, without need for staff attendance, even for repeated sets of measurements of the same or different PCM simultaneously. The proposed way of measurement processing is based on the use of thermal delay (i.e. temperature difference) between PCM and a reference fluid at any specified time and not in the use of their time delay at any specified temperature. This fundamental change leads to increased accuracy and considerable reduction of duration and labour of the measurement processing, as proved by the performed measurements of various PCM. The effective thermal capacity function as a final result is proved to be more useful than the results of the original method. The new procedure is a first step towards defining specifications for the measurement of PCM thermal properties

[en] Building sectors are large consumers of energy worldwide, responsible for approximately 40% of the world’s primary energy consumption. This paper analyzes the thermal performance of two passive roof construction technologies as a means of improving the indoor thermal conditions under summer conditions. Three identical Test Cell Structures (TCS) were constructed. All the TCSs were calibrated and two types of roofing technologies, Radiant Barrier (RB) and Phase Change Material (PCM) were individually applied to a TCS and their performance in terms of indoor air temperature reduction was compared. A one-way analysis of variance (ANOVA) was calculated for the study. The experimental results show that the thermal performance of RB obtained the best thermal improvement. TCS equipped with RB registered indoor air temperature 1.6 °C (2.9 °F) lower than the control test structure. (paper)

[en] In this paper, the thermal characterization of the chosen phase change materials (PCMs) was done using a conventional DSC analysis initially. However, the thermophysical properties of a very small amount of measured samples differ from those of the bulk measurements, including heterogeneous additives. Inconsistent results were observed in the DSC analysis, particularly for the inorganic PCM samples. Hence, a T-History experimental characterization for PCM investigation was carried out. The results obtained using DSC and fabricated T-History evaluation were compared and discussed in detail. The validated results showed that the T-History method of characterization is better compared to DSC analysis, especially, in the case of inorganic salt-hydrated PCMs due to its consistent and reasonable accuracy in measurements. The validated results also suggest that the RT28 and HS29 PCMs could be employed either as building integrated components or in separate energy storage modules in order to enhance passive cooling in future building construction. (paper)

[en] The endurance characteristics of phase change memory are studied. With operational cycles, the resistances of reset and set states gradually change to the opposite direction. What is more, the operational conditions that are needed are also discussed. The failure and the changes are concerned with the compositional change of the phase change material. An abnormal phenomenon that the threshold voltage decreases slightly at first and then increases is observed, which is due to the coaction of interface contact and growing active volume size changing. (paper)

[en] In an attempt to increase the heat transfer rate and reduce the convective currents during the freezing of phase change materials (PCM) in storage tanks, externally finned circular tubes are studied experimentally. The parameters analysed in this work include number of fins, fin length, initial degree of superheat and freezing time

[en] Highlights: • Five PCM are characterized using tow techniques for PV temperature regulation. • Thermophysical properties of interest are determined and compared with literature. • Determined PCM properties are discussed as criteria for PV temperature regulation. • One PCM identified as potential candidate for PV temperature regulation. - Abstract: Five solid–liquid phase change materials comprising three basic classes, paraffin waxes, salt hydrates and mixtures of fatty acids were thermophysically characterized for thermal regulation applications in photovoltaics. The PCM were investigated using Differential Scanning Calorimetry and Temperature History Method to find their thermophysical properties of interest. The relationship between thermophysical properties of the PCM and their choice as temperature regulators in photovoltaics is discussed in relation to the ambient conditions under which PV systems operate

[en] This study evaluates the energy and thermal performance of a radiant cooling panel system with integrated phase change materials (PCMs) for application in building retrofit projects. The focus is on the energy saving potential of using two different strategies to avoid condensation in very hot and humid climate conditions. The cooling energy consumption of a DOE medium office prototype building model with a conventional all-air system is used as a baseline for comparing the proposed configurations. The results show that the radiant system yielded energy savings of around 48% compared to the all-air system for existing office buildings. Results also show that the proposed system is able to operate only during the night-time, which improves the plant efficiency. Thus, the energy savings are mainly due to a reduction in the energy consumption of the cold generation system and lower energy use for ventilation compared with conventional air systems. (paper)