A new mathematical model of single-blow transient testing technique is proposed for the determination of heat transfer and dispersion coefficients in plate heat exchangers (PHEs) in which the flow maldisrtibution effects are separated from the fluid back-mixing. The fluid axial dispersion is used to characterize the back-mixing and other deviations from plug flow. Single-blow experiments are carried out with different number of plates for various flow rates with three different plate geometries of 30 deg, 60 deg, and mixed (30 deg/60 deg) chevron angles. The outlet temperature response to an exponential inlet temperature variation is solved numerically using finite difference method. In the present work, the whole curve matching technique is used to determine the values of Nusselt number and dispersive Peclet number. Since the maldistribution effects are separated, these data are independent of test conditions and hence using a regression analysis, general correlations are developed for Nusselt number and Peclet number of the present plate heat exchangers. The applicability of the single-blow test data is validated using a two-fluid experiment. Two-fluid experiments are conducted on the same plate heat exchanger with smaller and larger number of plates and the results have been compared with its simulation which used the Nusselt number and Peclet number correlations developed by the new model of single-blow test as the inputs.

References

References
1.
Heggs
,
P. J.
, and
Burns
,
D.
,
1988
, “
Single-Blow Experimental Prediction of Heat Transfer Coefficients—A Comparison of Four Commonly Used Techniques
,”
Exp. Therm. Fluid Sci.
,
1
, pp.
243
251
.10.1016/0894-1777(88)90003-9
2.
Wolf
,
J.
,
1964
, “
General Solutions of the Equations of the Parallel Flow Multi-Channel Heat Exchangers
,”
Int. J. Heat Mass Transfer
,
7
, pp.
901
919
.10.1016/0017-9310(64)90146-2
3.
Jackson
,
B. W.
, and
Troupe
,
R. A.
,
1966
, “
Plate Heat Exchanger Design by
ɛ-NTU
Method
,”
Chem. Eng. Prog., Symp. Ser.
,
62
(
64
), pp.
185
190
.
4.
Das
,
S. K.
,
Spang
,
B.
, and
Roetzel
,
W.
,
1995
, “
Dynamic Behaviour of Plate Heat Exchangers—Experiments and Modeling
,”
ASME J. Heat Transfer
,
117
(4)
, pp.
859
864
.10.1115/1.2836302
5.
Roetzel
,
W.
, and
Luo
,
X.
,
1997
, “
Extended Temperature Oscillation Measurement Technique for Heat Transfer and Axial Dispersion Coefficients
,”
Proceedings of the International Conference on Compact Heat Exchangers for the Process Industries
, pp. 381–388.
6.
Balzereit
,
F.
, and
Roetzel
,
W.
,
1997
, “
Determination of Axial dispersion Coefficients in Plate Heat Exchangers Using Residence Time Measurements
,”
Proceedings of the International Conference on Compact Heat Exchangers for the Process Industries
, pp. 389–400.
7.
Roetzel
,
W.
, and
Na Ranong
,
C.
,
1999
, “
Consideration of Maldistribution in Heat Exchangers Using the Hyperbolic Dispersion Model
,”
Chem. Eng. Process
,
38
, pp.
675
681
.10.1016/S0255-2701(99)00067-7
8.
Bassiouny
,
M. K.
, and
Martin
,
H.
,
1984
, “
Flow Distribution and Pressure Drop in Plate Heat Exchangers-I, U-Type Arrangement
,”
Chem. Eng. Sci.
,
39
, pp.
693
700
.10.1016/0009-2509(84)80176-1
9.
Tereda
,
F. A.
,
Srihari
,
N.
,
Sunden
,
B.
, and
Das
,
S. K.
,
2007
, “
Experimental Investigation on Port to Channel Flow Maldistribution in Plate Heat Exchangers
,”
Heat Transfer Eng.
,
28
(
5
), pp.
435
442
.10.1080/01457630601163769
10.
Muley
,
A.
, and
Manglik
,
R. M.
,
1999
, “
Experimental Study of Turbulent Flow Heat Transfer and Pressure Drop in a Plate Heat Exchanger With Chevron Plates
,”
ASME J. Heat Transfer
,
121
(1)
, pp.
110
117
.10.1115/1.2825923
11.
Srihari
,
N.
, and
Das
,
S. K.
,
2008
, “
Experimental and Theoretical Analysis of Transient Response of Plate Heat Exchanger in Presence of Nonuniform Flow Distribution
,”
ASME J. Heat Transfer
,
130
(5)
, p.
051801
.10.1115/1.2885153
12.
Kakac
,
S.
, and
Liu
,
H.
,
2002
,
Heat Exchangers—Selection, Rating, and Thermal Design
,
2nd
ed.,
CRC Press
,
New York
.
13.
Moffat
,
R. J.
,
1988
, “
Describing the Uncertainties in Experimental Results
,”
Exp. Therm. Fluid Sci.
,
1
, pp.
3
17
.10.1016/0894-1777(88)90043-X
14.
Danckwerts
,
P. V.
,
1953
, “
Continuous Flow Systems: Distribution of Residence Times
,”
Chem. Eng. Sci.
,
2
, pp.
1
13
.10.1016/0009-2509(53)80001-1
You do not currently have access to this content.