Thermal stratification of solar water storage tanks improves collector efficiency and provides higher quality energy to the user. A crucial aspect of maintaining stratification is preventing mixing in the tank, particularly during solar charging and hot water draws. An effective and simple approach to flow control is an internal stratification manifold. In this paper, the performance of the rigid porous manifold, which consists of a series of vertical hydraulic resistance elements placed within a perforated tube, is considered for charging operation. A 1D model of the governing mass, momentum, and energy conservation equations is used to illustrate the procedure for designing a manifold and to explore its performance over a broad range of operating conditions expected in solar water storage tanks. A manifold performance indicator (MPI) is used to evaluate the effectiveness of the manifold relative to an inlet pipe positioned at the top of the tank. The rigid porous manifold improves the stratification in the tank over a wide range of operating conditions unless the inlet flow rate is significantly reduced from the design point.

References

References
1.
Wuestling
,
M. D.
,
Klein
,
S. A.
, and
Duffie
,
J. A.
,
1985
, “
Promising Control Alternatives for Solar Water Heating Systems
,”
ASME J. Sol. Energy Eng.
,
107
(
3
), pp.
215
221
.10.1115/1.3267681
2.
Andersen
,
E.
, and
Furbo
,
S.
,
2007
, “
Theoretical Comparison of Solar Water/Space-Heating Combi Systems and Stratification Design Options
,”
ASME J. Sol. Energy Eng.
,
129
(
4
), pp.
438
448
.10.1115/1.2770752
3.
Glembin
,
J.
, and
Rockendorf
,
G.
,
2012
, “
Simulation and Evaluation of Stratified Discharging and Charging Devices in Combined Solar Thermal Systems
,”
Sol. Energy
,
86
(
1
), pp.
407
420
.10.1016/j.solener.2011.10.013
4.
Gari
,
H. N.
,
Sharp
,
M. K.
, and
Haberstroh
,
R. D.
,
1978
, “
Passive Technique for Enhancing Thermal Stratification in Liquid Storage Tanks
,” ASME Paper No. 78-HT-50.
5.
Gari
,
H.
,
Loehrke
,
R.
, and
Holzer
,
J.
,
1979
, “
Performance of an Inlet Manifold for a Stratified Storage Tank
,”
ASME/AICHE 18th National Heat Transfer Conference
, San Diego, CA, August 6–8, Paper No. 79-HT-67.
6.
Gari
,
H. N.
, and
Loehrke
,
R. I.
,
1982
, “
Controlled Buoyant Jet for Enhancing Stratification in a Liquid Storage Tank
,”
ASME Trans. J. Fluids Eng.
,
104
(
4
), pp.
475
481
.10.1115/1.3241887
7.
Göppert
,
S.
,
Lohse
,
R.
, and
Urbaneck
,
T.
,
2009
, “
New Computation Method for Stratification Pipes of Solar Storage Tanks
,”
Sol. Energy
,
83
(
9
), pp.
1578
1587
.10.1016/j.solener.2009.05.007
8.
Shah
,
L. J.
,
Andersen
,
E.
, and
Furbo
,
S.
,
2005
, “
Theoretical and Experimental Investigations of Inlet Stratifiers for Solar Storage Tanks
,”
Appl. Therm. Eng.
,
25
(
14–15
), pp.
2086
2099
.10.1016/j.applthermaleng.2005.01.011
9.
Andersen
,
E.
,
Furbo
,
S.
, and
Hampel
,
M.
,
2008
, “
Investigations on Stratification Devices for Hot Water Heat Stores
,”
Int. J. Energy Res.
,
32
(
3
), pp.
255
263
.10.1002/er.1345
10.
Davidson
,
J. H.
, and
Adams
,
D. A.
,
1994
, “
Fabric Stratification Manifolds for Solar Water Heating
,”
ASME J. Sol. Energy Eng.
,
116
(
3
), pp.
130
136
.10.1115/1.2930071
11.
Andersen
,
E.
,
Furbo
,
S.
, and
Fan
,
J.
,
2007
, “
Multilayer Fabric Stratification Pipes for Solar Tanks
,”
Sol. Energy
,
81
(
10
), pp.
1219
1226
.10.1016/j.solener.2007.01.008
12.
Idel'chik
,
I. E.
,
Malyavskaya
,
G. R.
,
Martynenko
,
O. G.
, and
Fried
,
E.
,
1986
,
Handbook of Hydraulic Resistance
,
2nd ed.
,
Hemisphere Publishing Corporation
,
New York
.
13.
Fried
,
E.
, and
Idel'chik
,
I. E.
,
1989
,
Flow Resistance: A Design Guide for Engineers
,
Hemisphere Publishing Company
,
Philadelphia
.
14.
Gari
,
H. N.
,
1983
, “
Stratification Enhancement in Solar Liquid Thermal Storage Tanks: Analysis and Test of Inlet Manifolds
,” Ph.D. thesis, Colorado State University, Fort Collins, CO.
You do not currently have access to this content.