Environmental Engineering Reference
In-Depth Information
TABLE 7.4 (CONTINUED)
Options for TES in Solar Power Production
Options
Temp.(°C)
StorageMedium
Type
Solid or liquid
decomposition,
evaporation stage
TC
Steam Rankine with molten draw salt
receiver
540
Molten draw salt in
thermocline tank or
two tanks
Sensible
Steam Rankine with liquid metal
receiver
540
Liquid sodium in one
tank, mixed, buffer
only
Sensible
Liquid sodium in two
tanks
Sensible
Air and rocks
Sensible
Brayton with gas-cooled receiver
800
Refractory or cast iron
in pressure vessel
Sensible
Bulk PCM with indirect
HX
Latent
Solid or liquid
decomposition
TC
Brayton with liquid-cooled receiver
800
VHT molten salt in two
tanks
Sensible
VHT molten salt and
refractory (dual
media) in thermocline
tank
Sensible
1100
Bulk glassy slag, liquid
and solid bead storage,
direct HX
Sensible,
latent
Source:
de Winter, F. 1990.
Solar Collectors, Energy Storage, and Materials
, MIT Press, Cambridge
MA. With permission.
PCM = phase change material. HX = heat exchanger. VHT = very high temperature. TC =
thermochemical.
StorageSystems
Two-Tank Direct Storage
In a two-tank direct storage system, the material used to store thermal energy
is the same as the heat transfer fluid used to collect the thermal energy. The
fluid is stored in two tanks: one at a high temperature and the other at a
lower temperature. Fluid from the lower temperature tank flows through a
solar collector or receiver, where solar energy heats it to the high tempera-
ture and it then flows back to the high temperature tank for storage. Fluid
