The overall efficiency of a concentrating solar power (CSP) plant depends on the effectiveness of thermal energy storage (TES) system (Kearney and Herrmann, 2002, “Assessment of a Molten Salt Heat Transfer Fluid,” ASME). A single tank TES system consists of a thermocline region which produces the temperature gradient between hot and cold storage fluid by density difference (Energy Efficiency and Renewable Energy, http://www.eere.energy.gov/basics/renewable_energy/thermal_storage.html). Preservation of this thermocline region in the tank during charging and discharging cycles depends on the uniformity of the velocity profile at any horizontal plane. Our objective is to maximize the uniformity of the velocity distribution using a pipe-network distributor by varying the number of holes, distance between the holes, position of the holes and number of distributor pipes. For simplicity, we consider that the diameter of the inlet, main pipe, the distributor pipes and the height and the width of the tank are constant. We use Hitec® molten salt as the storage medium and the commercial software Gambit 2.4.6 and Fluent 6.3 for the computational analysis. We analyze the standard deviation in the velocity field and compare the deviations at different positions of the tank height for different configurations. Since the distance of the holes from the inlet and their respective arrangements affects the flow distribution throughout the tank; we investigate the impacts of rearranging the holes position on flow distribution. Impact of the number of holes and distributor pipes are also analyzed. We analyze our findings to determine a configuration for the best case scenario.

References

References
1.
Kearney
,
D.
,
Herrmann
,
U.
,
Kelly, B.
,
Mahoney
,
R.
,
Cable
,
R.
,
Blake
,
D.
,
Price
,
H.
,
Potrovitza
,
N.
,
Pacheco
,
J.
,
2003
, “
Assessment of a Molten Salt Heat Transfer Fluid in a Parabolic Trough Solar Field
,”
ASME J. Sol. Energy Eng.
,
125
, pp.
170
176
.10.1115/1.1565087
2.
Energy Efficiency and Renewable Energy
,
2013
, “
Thermal Storage Systems for Concentrating Solar Power
,” U.S. Dept. of Energy, Washington, DC, http://www.eere.energy.gov/basics/renewable_energy/thermal_storage.html
3.
Pilkington Solar International
,
2000
, “
Survey of Thermal Storage for Parabolic Trough Power Plants
,” Pilkington Solar International GmbH, Cologne, Germany, Report No. NREL/SR-550-27925.
4.
Chao
,
X.
,
Zhifeng
,
W.
,
Yaling
,
H.
,
Xin
,
L.
, and
Fengwu
,
B.
,
2011
, “
Sensitivity Analysis of the Numerical Study on the Thermal Performance of a Packed-Bed Molten Salt Thermocline Thermal Storage System
,”
Appl. Energy
,
92
, pp.
65
75
.10.1016/j.apenergy.2011.11.002
5.
Luptowski
,
B.
,
2010
, “
Reducing the Cost of Thermal Energy Storage (TES) for Parabolic Trough Solar Power Plants
,” U.S. Dept. of Energy, Energy Efficiency and Renewable Energy, Washington, DC, May 25. Available at: http://www1.eere.energy.gov/solar/review_meeting/pdfs/prm2010_cspposter_abengoa_thermalstorage_luptowski.pdf
6.
NREL, 2010, “Parabolic Trough Thermal Energy Storage Technology,” National Renewable Energy Laboratory, Golden, CO,
www.nrel.gov/csp/troughnet/thermal_energy_storage.html
7.
Yang
,
Z.
, and
Garimella
,
S. V.
,
2010
, “
Molten-Salt Thermal Energy Storage in Thermoclines Under Different Environmental Boundary Conditions
,
Appl. Energy
,
87
, pp.
3322
3329
.10.1016/j.apenergy.2010.04.024
8.
Mawire
,
A.
, and
McPherson
,
M.
,
2009
, “
Experimental and Simulated Temperature Distribution of an Oil-Pebble Bed Thermal Energy Storage System With a Variable Heat Source
,”
Appl. Therm. Eng.
,
29
(
5–6
), pp.
4766
4778
.10.1016/j.applthermaleng.200
9.
Van Lew
,
J. T.
,
Piewen
,
L.
,
Choe
,
L. C.
, and
Wafaa
,
K.
,
2011
, “
Analysis of Heat Storage and Deliver of a Thermocline Tank Having Solid Filler Material
,”
ASME J. Sol. Energy Eng.
,
133
(
2
), p.
021003
.10.1115/1.4003685
10.
Donghyun
,
S.
, and
Debjyoti
,
B.
,
2011
, “
Enhancement of Specific Heat Capacity of High-Temperature Silica-Nanofluids Synthesized in Alkali Chloride Salt Eutectics for Solar Thermal-Energy Storage Applications
,”
Int. J. Heat Mass Transfer
,
54
, pp.
1064
1070
.10.1016/j.ijheatmasstransfer.2010.11.017
11.
Jones
,
B. G.
,
Roy
,
R. P.
, and
Bohl
,
R. W.
,
1977
, “
Molten Salt Energy Storage System—A Feasibility Study
,”
Heat Transfer in Energy Conservation, Proceedings of the Winter Annual Meeting, American Society of Mechanical Engineers
,
Atlanta, GA
, November 27–December 2, pp.
39
45
.
12.
Pacheco
,
J. E.
,
Showalter
,
S. K.
, and
Kolb
,
W. J.
,
2001
, “
Department, Development of a Molten-Salt Thermocline Thermal Storage System for Parabolic Trough Plants
,” Proceedings of ASME Forum 2001—Solar Energy: The Power to Choose, Washington, DC, April 21–25.
13.
Kleinbach
,
E. M.
,
Beckman
,
W. A.
, and
Klein
,
S. A.
,
1993
, “
Performance Study of One-Dimensional Models for Stratified Thermal Storage Tanks
,”
Sol. Energy
,
50
, pp.
155
166
.10.1016/0038-092X(93)90087-5
14.
Wafaa
,
K.
,
Jon
,
T. V. L.
,
Peiwen
,
L.
,
Cho
,
L. C.
, and
Jake
,
S.
,
2010
, “
Heat Transfer in Thermocline Storage System With Filler Materials: Analytical Model
,”
ASME 4th International Conference on Energy
Sustainability (
ES2010
),
Phoenix, AZ
, May 17–22, ASME Paper No. ES2010-90209.10.1115/ES2010-90209
15.
HITEC Heat Transfer Salt
, Coastal Chemical Co., L.L.C. Brenntag Company, http://coastalchem.com
16.
CFD Online, 2013, “Incompressible Flow,”
http://www.cfd-online.com/Wiki/Incompressible_flow
17.
Pacheco
,
J. E.
,
Showalter
,
S. K.
, and
Kolb
,
W. J.
,
2002
, “
Development of a Molten-Salt Thermocline Thermal Storage System for Parabolic Trough Plants
,”
ASME J. Sol. Energy Eng.
,
124
, pp.
153
159
.10.1115/1.1464123
You do not currently have access to this content.