High-temperature latent heat storage technology to utilize exergy of solar heat and industrial exhaust heat

Abstract

Summary Latent heat storage (LHS) using phase change materials is quite attractive for utilization of the exergy of solar energy and industrial exhaust heat because of its high‐heat storage capacity, heat storage and supply at constant temperature, and repeatable utilization without degradation. In this article, general LHS technology is outlined, and then recent advances in the uses of LHS for high‐temperature applications (over 100 °C) are discussed, with respect to each type of phase change material (e.g., sugar alcohol, molten salt, and alloy). The prospects of future LHS systems are discussed from a principle of exergy recuperation. In addition, the technologies to minimize exergy loss in the future LHS system are discussed on the basis of the thermodynamic analysis by ‘thermodynamic compass’. Copyright © 2016 John Wiley & Sons, Ltd.

Micro- and nano-encapsulated metal and alloy-based phase-change materials for thermal energy storage

“…Inorganic PCMs provide a wide range of operating temperatures in both low-and hightemperature LHS applications (Table 2). The materials most oen studied as PCMs include salt hydrates, [31][32][33][34][35] molten salts (and their eutectics), [36][37][38][39][40] metals, and alloys. [41][42][43][44][45][46][47][48][49][50][51][52][53][54][55] Salt hydrates are inorganic salts containing crystallised water, such as calcium chloride hexahydrate (CaCl 2 $6H 2 O).…”

“…36 They have a high volume expansion ratio during phase transition, and can corrode metallic containers. [38][39][40] Although salt hydrates and molten salts have low thermal conductivity (below $1.0 W m À1 K À1 ), they possess high TES density, acceptable price, and abundant reserve for being applied in TES. [31][32][33][37][38][39][40] Metal and alloy PCMs with high melting temperatures (>300 C) are usually used as PCMs in high-temperature LHS systems.…”

Overview of Compressed Air Energy Storage and Technology Development

“…Compared with the SHS, there are many advantages of LHS, such as high-heat storage capacity, constant heat source at the phase-changing temperature point, and the reversible phase-changing process for repeated uses [76][77][78][79]. Reference [76] concludes that the choice of storage material depends on the desired temperature range, applications of the thermal storage unit and the size of thermal storage system.…”

“…Reference [76] concludes that the choice of storage material depends on the desired temperature range, applications of the thermal storage unit and the size of thermal storage system. As shown in Table 7, there are three kinds of phase change materials that could meet the high-temperature requirements: organic, molten salts, and alloys [77]. PCMs for cold thermal energy storage (less than 20 • C) applications are reviewed in [79] and the results are listed in Table 8.…”

Development of a new methodology for validating thermal storage media: Application to phase change materials

“…[2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] However, it is in the field of latent heat storage materials, which are usually called phase change materials (PCMs), where we can find the majority of these studies. This is due to the large number of PCMs that are suitable for applications in a very wide temperature range [18][19][20][21][22][23] (from 0°C to 800°C). Taking into account that the thermophysical properties that make PCMs suitable as storage media are phase change temperature (T ph-ch ) and enthalpy (ΔH ph-ch ), Figure 1 represents ΔH ph-ch vs T ph-ch for PCMs that undergo solid-liquid transitions together with the temperature ranges of the possible storage applications.…”