Phase Change Materials: Technology Status and Potential Defence Applications

Abstract

Phase change materials (PCM) are being utilised world over for energy storage and temperature smoothening applications. Defence Laboratory Jodhpur (DLJ) has initiated a R&D programme to apply PCM in solving many heat related problems being faced by Indian forces during desert operations specially failure of mission-critical components. Under the programme, special organic PCM (Patent application no. 2258/DEL/2007 and low melting metal alloys have been developed well tuned to desert diurnal cycle. The PCM panels, when applied as an internal lining in buildings, structures and vehicles can moderate the extreme temperature within human tolerable range (below 40 °C) without the use of any external power for cooling. The panels can also act as power saver in air conditioned buildings. A cool vest has also been developed with chargeable PCM packs to provide comfortable microenvironment to a soldier on field duty (below 30 °C) for 2-3 hrs. To improve reliability of mission critical electronic instruments during desert operation, technology of absorptive PCM heat sinks is under development at DLJ. The special heat sink will absorb heat generated by component for critical mission (up to 1 hr) independent of environment temperature and thus ensure smooth functioning of critical components even in extreme hot conditions. In present paper status of PCM technology world over has been reviewed along with the brief account of research on PCM at DLJ.

Facile functionalized mesoporous silica using biomimetic method as new matrix for preparation of shape‐stabilized phase‐change material with improved enthalpy

“…[2][3][4] Moreover, a growing number of PCMs have been utilized successfully in many fields, such as air conditioning systems, heatremoval systems, solar energy systems, and transportation business. 8 Polyethylene glycol (PEG), as a sort of organic PCMs, has attracted great interests because of its excellent physical and chemical properties, including appropriate phase transition temperature, large phase transition enthalpy, favorable chemical and thermal stability with no super cooling, or volume change in the phase-change process. 8 Polyethylene glycol (PEG), as a sort of organic PCMs, has attracted great interests because of its excellent physical and chemical properties, including appropriate phase transition temperature, large phase transition enthalpy, favorable chemical and thermal stability with no super cooling, or volume change in the phase-change process.…”

“…[5][6][7] PCMs could be classified as organic and inorganic PCMs. 8 Polyethylene glycol (PEG), as a sort of organic PCMs, has attracted great interests because of its excellent physical and chemical properties, including appropriate phase transition temperature, large phase transition enthalpy, favorable chemical and thermal stability with no super cooling, or volume change in the phase-change process. 9 However, the applications of PEG are often restricted due to the leakage that occurs during the process of phase transformation.…”

Micro-Encapsulated Phase Change Materials: A Review of Encapsulation, Safety and Thermal Characteristics

“…Heat storage capacity per volume of these materials is much higher as compared to the heat storage capacity per mass because of their huge density as compared to conventional PCMs [117]. These PCMs are currently studied for the cooling of electronic equipment [118,119], high power LEDs [120], heat exchangers [120] and for exergy from low-grade heat energy to produce electricity [121,122].…”

Led railway signal vs full compliance with colorimetric specifications

“…The use of PCMs has been proposed as a passive cooling technique of electronic systems [17][18][19][20][21]. Every electrical component generates heat during operation; if these components are housed in a confined space, the internal temperature of the housing can rise well above the ambient temperature, resulting degradation of the performance.…”