Optimizing Design and Controls for Thermal Energy Storage
Thermal Ragone Framework
Fluid outlet temperature (°C)
++
16
1Wm¹K¹
14
Cutoff temperature
12
10
00
09
40 W m¹ K¹
1C
200
160
Specific power (W kg)
120
80
40
1WmK¹
20
40 W m¹K¹
1Wm1K1
10 W m¹ K-1
1 W m¹K¹
10 W m¹ K¹
2
2.5 W m¹ K¹
5Wm1K1
20 W m¹ K¹
-1
10
2.5 W m¹ K-1
20 W m¹ K-1
40 W m¹ K-1
5W m¹K¹
40 W m¹ K¹
0
I
100
80
60
40
20
20
6
0
10
20
30
40
50
State of charge (%)
Specific energy (W h kg¯¹)
Woods et al. 2021
1 C
0
60
60
•
Ragone plots have been recently applied to PCM thermal energy storage devices to illustrate the tradeoffs
between power requirements and energy storage capacity
• A cutoff temperature can be defined to determine when the useful storage capacity has been depleted
• Material and geometric properties like the PCM thermal conductivity and spacing of the heat transfer fluid
channels can have significant impacts on the shape of the Ragone plot for a particular storage deviceView entire presentation