158
The main advantage of molten salts is their relatively high and wide range of
melting and working temperatures for TES applications. However, in terms of
specific heat capacity, molten salts show much smaller differences, not far away
from 1.5 J/g °C. Table 1 gives the specific heat capacity of a series of molten salt
mixtures. Therefore, any approach, such as addition of nanoparticulates, that can
increase the specific heat capacity of molten salts is worthy of research and
commercial efforts as discussed in the following sections.
Table 1 Specific heat capacity of some typical inorganic molten salt eutectics
Molten salt
Composition ratio
Specific heat capacity
(J/g °C)
Reference
Solid phase
Liquid
phase
NaNO 3 –KNO 3
60–40 wt.%
1.604
1.648
Chieruzzi et al. [10]
1.21
1.47
Dudda and Shin
[11]
1.48
Andreu-Cabedo
et al. [9]
1.54
Wang et al. [16]
NaNO 3 –NaNO 2 –KNO 3 7–40–53 wt.%
1.37–1.48 Ho and Pan [13]
1.42
Wang et al. [16]
LiNO 3 –NaNO 3 –KNO 3 –
NaNO 2
17.5–14.2–50.5–
17.8 wt.%
1.66
Li 2 CO 3 –K 2 CO 3
62–38 mol.%
1.25
1.59
Tiznobaik and Shin
[22]
1.62
Tiznobaik et al.
[29]
0.987–1.244
Shin and Banerjee
[20]
1.21
1.61
Tao et al. [21]
1.61
Jo and Banerjee
[18]
45–55 mol.%
1.44
50–50 mol.%
1.54
Li 2 CO 3 –K 2 CO 3 –
Na 2 CO 3
32.1–34.5–33.4 wt.%
1.61
An et al. [25]
1.230
1.414
Zhang et al. [30]
32–35–33 wt.%
1.42
1.68
Liu et al. [19]
22–62–16 wt.%
1.25
1.56
MgCl 2 –NaCl
52–48 wt.%
1.07
MgCl 2 –KCl
64–36 wt.%
0.73
NaCl–KCl–ZnCl 2
8.1–3.3–60.6 wt.%
0.919
Xu et al. [28]
10.0–15.1–74.9 wt.%
0.913
7.5–23.9–68.6 wt.%
0.900
NaCl–KCl–MgCl 2
20.5–30.9–48.6 wt.%
1.115
21.9–18.6–59.5 wt.%
1.182
LiF–NaF–KF
46.5–11.5–42 wt.%
1.75–2.05 Khokhlov et al. [31]
LiF–NaF–ZrF
42–29–29 wt.%
1.25–1.42
X. Guo et al.