Experimental investigation of performance of plate heat exchanger for water as working fluid

IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
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Volume: 04 Issue: 03 | Mar-2015, Available @ http://www.ijret.org 372
EXPERIMENTAL INVESTIGATION OF PERFORMANCE OF PLATE
HEAT EXCHANGER FOR WATER AS WORKING FLUID
Tambe Shahanwaj K1
, Pandhare Nitin T2
, Bardeskar Santosh J3
, Khandekar S.B4
1
Student of B.E., Mechanical Engineering, Rajendra Mane College of Engineering and Technology, Devrukh,
Maharashtra, India
2
Maharashtra, India
3
Maharashtra, India
4
Assistant professor, Mechanical Engineering, Rajendra Mane College of Engineering and Technology, Devrukh,
Maharashtra, India
Abstract
Compact heat exchangers are most widely used for heat transfer applications in industries. Plate heat exchanger is one such
compact heat exchanger, provides more area for heat transfer between two fluids in comparison with shell and tube heat
exchanger. Plate type heat exchangers are widely used for liquid-to-liquid heat transfer applications with high density working
fluids. This study is focused on use of plate type heat exchanger for water as a working fluid. This research work deals with
experimental investigation of plate type heat exchanger with evaluation of convective heat transfer coefficient, overall heat
transfer coefficient, exchanger effectiveness. The heat exchanger used for carrying out this work consists of thin metal welded
plates of stainless steel with 1mm thickness, rectangular geometry and distance between two plates is 7mm. This test setup
consists of total 16 numbers of plates and it is designed to withstand with 850
C temperature, pressure drop is neglected. Tests are
conducted by varying operating parameters like mass flow rate, inlet temperatures of hot water. The main objective of this work is
to find effects of these parameters on performance of plate heat exchanger with parallel flow arrangement. Results show that,
overall heat transfer coefficient and convective heat transfer coefficient increases with increase in mass flow rate and Reynolds
number. Also the effectiveness varies slightly with heat capacity ratio. In this study, maximum effectiveness achieved for plate heat
exchanger with water as a working fluid is 0.48.Use of plate heat exchanger is more advantageous than the tube type heat
exchanger with same effectiveness, as it occupies less space.
Keywords: Plate heat exchanger, Convective heat transfer coefficient, Effectiveness, Overall heat transfer coefficient,
Reynolds number.
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1. INTRODUCTION
Heat exchanger is a device in which transfer of thermal
energy takes place between two of more fluids across a solid
surface. These exchangers are classified according to
construction, flow arrangement; number of fluids,
compactness, etc. The use of heat exchanger gives higher
thermal efficiency to the system. In many applications like
power plants, petrochemical industries, air conditioning etc.
heat exchangers are used. Plate heat exchanger is generally
used in dairy industry due to its ease of cleaning and thermal
control. The plate heat exchangers are built of thin metal
heat transfer plates and pipe work is used to carry streams of
fluid. Plate heat exchangers are widely used in liquid to
liquid heat transfer and not suitable for gas to gas heat
transfer due to high pressure drop.
R. K. Shah and S. G. Kandilkar, have experimentally
investigated the influence of number of thermal plates on
effectiveness of heat exchanger for 1 pass 1, 2 pass 1, 3 pass
1 flow arrangements and number of plates up to 41. Results
were plotted for number of plates and F, NTU and F, for
different pass arrangements. They concluded, for 1pass1
flow arrangement with an even number of thermal plates,
fluid in the outermost channels is same. The heat transfer
rate of multi pass arrangement may be higher or lower than
that of 1pass1 for same N and R which depends upon heat
transfer characteristics of plate material. For N < 40, end
effect is considerable. When there is significant imbalance
in flow rates, R < 2, 1pass1 arrangement is desirable. For
(R=2, 3) 2pass1 arrangement is desirable and for R > 4, 3
pass 1 arrangement is desirable and for 1 pass 1 exchanger
with an even number of thermal plates the fluid in outermost
channel is same. The exchanger effectiveness is slightly
higher if outer fluid has higher heat capacity as compared to
other fluid having one less flow channel. [1]
H. Dardour, S. Mazouz, and A. Bellagi had done numerical
analysis of the thermal performance of a plate type heat
exchanger with parallel flow configuration. The
computation is based on the effectiveness- NTU model. The
numerical results illustrate the evolution of the most
important parameters of the plate heat exchanger. A

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parametric analysis is presented which brings out the effect
of NTU and the R parameter, the heat capacity rate ratio, on
the performance of the plate heat exchanger (PHE). To
check the validity of the presented simplified model
established to describe the energy balances in the PHE and
the numerical scheme adopted, simulated performance has
been compared to the performance evaluated by theoretical
relations. Comparison shows an excellent agreement
between them. The temperature gradients through each
channel and heat fluxes through each active plate are also
evaluated. [2]
Murugesan M.P. and Balasubramani R. had done the test for
the investigation of milk adhesion and the stability of the
coatings on corrugated plates. A number of coatings and
surface treatments were tested. Heat exchanger plates coated
with different nano-composites as well as electro polished
plates installed in the heating section of the pasteurizer were
tested. Significant differences were observed between
coated and uncoated plates. The coated plates showed that
reduced deposit buildup in comparison with the uncoated
stainless steel plates. The time required for cleaning place
with the coated plates was reduced by 75% compared to
standard stainless steel plates. [3]
Murugesan M.P. and Balasubramani R. had experimentally
investigated heat transfer performance of plate type heat
exchanger by varying operating parameters and design
parameters. Heat transfer coefficient was studied for various
fluids like water and ethylene glycol. The increase mass
flow rate with subsequently increase in the flow velocity has
led to an increased overall heat transfer coefficient as well
as individual heat transfer coefficient. [4]
T K S Sai Krishna, S G Rajasekhar, C Pravarakhya modeled
the plate type heat exchanger in solid works and the fluid
flow analysis is done on the modeled fluid part. The analysis
stated that when the thickness of the plates decreases then
the heat flow is higher and if the number of plates increases
then the outlet temperature difference of the fluids increased
and the pressure contour stated that, there is little pressure
drop in the entry and outlet of the fluid, From the turbulent
contour it is interfered that there is very high turbulence in
the entry and outlets due to sudden change in cross section
along the plates. [5]
This paper focuses on thermal design of plate heat
exchanger for one pass one arrangement and water-water
heat transfer. The main objective of this paper is
performance analysis of plate heat exchanger with regard to
overall heat transfer coefficient, effectiveness.
2. METHODOLOGY
2.1 Thermal Design
Design procedure of heat exchange involves rating and
sizing of heat exchanger. Rating problem deals with
determination of rate of heat transfer, heat transfer
coefficient, outlet temperature. Sizing problem involves
selection of plate material, flow arrangement, determining
physical size of heat exchanger to meet specified heat
transfer. Plate heat exchanger used for carrying out this
research work comprises plane steel plates with material as
XYZ. This heat exchanger design involves calculation of
heat transfer coefficient and physical size in terms of plate
dimensions and number of plates with following
information:
Hot water inlet temp=85ºC,
Hot water outlet temp=65ºC, Cold water inlet temp=30ºC
Mass flow rate of hot water mh= 0.3 kg/sec, and mass flow
rate of cold water mc= 0.3 kg/sec
2.1.1 Heat Duty (Q)
Heat duty is defined as the product of mass flow rate
specific heat capacity and the temperature difference
between inlet and outlet fluid temperatures.
……………. (1)
Heat rejected by hot water
Where, mh =mass flow rate of hot water in Kg/s,
Cph= specific heat capacity of hot water J/Kg K,
∆Th= temperature difference between inlet and outlet of hot
water in K
Heat absorbed by cold water
Where, mc =mass flow rate of cold water in Kg/s,
Cpc= specific heat capacity of hot water in J/Kg K,
∆Tc=Temperature difference between inlet and outlet of
cold water in K
Hot water mean temp = = 75ºC
Cold water mean temp = = 40ºC

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Table -1: Properties of water at mean temperature [10]
Property Unit
(metric)
Hot water
(mean
temp)
Cold water
(mean
temp)
Heat capacity
(Cp)
J/kgK 4193 4179
Thermal
conductivity (k)
W/mK 0. 668 0. 6316
Dynamic
viscosity (µ)
Ns/m2
0. 0003746 0. 0006566
Density (ρ) Kg/m3
1000 1000
2.1.2 Hydraulic Diameter
The hydraulic diameter is defined as the ratio of the cross
sectional area of the channel to the wetted perimeter of the
channel.
……………. (2) [9]
2.1.3 Flow Area for Water:
It is given by,
…………… (3)
Where,
A= flow area for water in m2
, N=number of water chambers,
W =width of plate in m,
b =distance between two plates in m
The flow area for hot water
Here, Nh= 7, W=0.25 m, b =0.007 m
The flow area for hot water
Here, Nh= 8, W=0.25 m, b =0.007 m
2.1.4 Velocity of Water
………………… (4)
Where, V= velocity of hot water in m/s,
m =mass flow rate in Kg/s, A = flow area for water in m2
,
ρ = density of water in Kg/ m3
For hot water,
Here, mh =0.3 Kg/s, Ah =0.01225 m2
, ρh = 1000 Kg/ m3
For cold water
Here, mc=0.3 Kg/s, Ac =0.014 m2
, ρc = 1000 Kg/ m3
2.1.5 Reynolds Number
Reynolds number is defined as,
……………. (5)
Where, Re= Reynolds number,
De = hydraulic diameter in m, V= velocity of water in m/s,
ρ = density of water in Kg/ m3
µ= Dynamic viscosity in Ns/m2
For hot water:
Here, ρh = 1000 Kg/ m3
, Vh = 0.02448 m/s, De = 0.014 m,
µh = 0.0003746 Ns/m2

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For cold water:
Here, ρc = 1000 Kg/ m3
, Vc = 0.02142 m/s, De = 0.014 m
µh = 0.0003746 Ns/m2
2.1.6 Prandlt Number
Prandlt number is defined as,
……………. (6)
µ= Dynamic viscosity in Ns/m2
,
Cp= specific heat capacity of water J/Kg K
k = thermal conductivity of water in W/mK
For hot water,
Here, µh= 0.0003746 Ns/m2
, Cph= 4193 J/Kg K,
kh =0.668 W/mK
For cold water,
Here, µc= 0.0006566 Ns/m2
, Cpc= 4179 J/Kg K,
kc =0.6316 W/mK
2.1.7 Nusselt Number:
It is defined as,
………… (7)
Where, h= heat transfer coefficient in W/m2
K,
De = diameter in m. k= thermal conductivity in W/mK,
Here Re < 2000 so taking relation for laminar flow,
…………. (8)
For hot water
Here, kh =0.668 W/mK, Reh=914.89, Prh=2.35
Where, hh is the hot fluid heat transfer coefficient
For cold water
Here, kc =0.6316 W/mK, Rec=456.71, Prc=4.35
Where hc is the cold fluid heat transfer coefficient
2.1.8 Overall Heat Transfer Coefficient
The overall heat transfer coefficient for a clean surface is
given by,
………….. (9)
Where, Kp is the thermal conductivity of the metal plate and
t is its thickness.
Here, hh =1270.17 W/m2
.K, hc =1041.41 W/m2
.K,
Kp = 14 W/m2
K

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2.1.9 LMTD
The logarithmic mean temperature difference is preferably
used when the temperature difference varies within the
exchanger. It provides an average temperature difference
that reflects the difference more accurate compared to what
a regular mean temperature difference does. To determine
the logarithmic mean temperature difference, inlet and outlet
temperatures of the fluid have to be known for both sides of
the heat exchanger. It is defined as,
………. (10)
Where, Th1= hot water inlet temperature
Th2= hot water inlet temperature
Tc1= cold water inlet temperature
Tc2= cold water inlet temperature
For parallel flow
2.1.10 Area Required
…………. (11)
Assume additional for pipe work and side plates
So, total area required, A=1.6 m2
Total no of plates =16
Actual heat transfer plates = 14×
Plate dimension = 400mm × 250mm
Assume length: plate ratio as 1.8:1
2.2 Experimental Setup
2.2.1 Test Setup
The experimental setup consists of plate heat exchanger,
thermometer, reservoirs, stop watch, flow rate measuring
flask. The heat exchanger has total 16 plates and it is
constructed using stainless steel 304. Each plate is flat and
has thickness of 1 mm. The total heat transfer area is 1.4 m2
.
The heat exchanger is designed for 850
C temperature and
120 mm pack length. It has height of 400 mm, width of 200
mm and gap between two plates is 7 mm. External pipes are
used to carry hot and cold water streams. Inlet pipes are
connected to bottom side while outlet pipes are connected to
top side of exchanger. Cold fluid is supplied at room
temperature. Fluid flow varied by ball valves and measured
between 0.1 to 1 Kg/sec. Thermometers are placed to
measure inlet and outlet temperatures of hot and cold water.
2.2.2 Test Procedure
The plate heat exchanger with flat plates is used for trials.
The fluids used are hot and cold water. Two flow
arrangements implemented which are parallel flow and
counter flow. Trials conducted with different mass flow rate
of hot and cold water and also hot water inlet flow rate was
kept constant while cold water inlet flow rate varied.
Procedure repeated for getting more accurate results and
results plotted.
Assumptions:
 The plate heat exchanger operates under steady state
conditions,
 No phase change occurs; both fluids are single phase
and are unmixed,
 Heat losses to surrounding are negligible,
 The temperature in the fluid streams is uniform,
 The fluids have constant specific heats,

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 The fouling resistance is negligible,
 Pressure drop across heat exchanger is negligible.
3. RESULTS AND DISCUSSION
For water to water heat transfer different results are plotted
based on different parameters such as overall heat transfer
coefficient, exchanger effectiveness, NTU, heat capacity
ratio, Reynolds number.
537.3
615.9
942.03
883.17
1129.89
500
600
700
800
900
1000
1100
1200
100 200 300 400 500
HeattransfercoefficientW/m2K
Reynolds number
mass flow rate
in Kg/s
Chart -1: Heat transfer coefficient Vs Reynolds number
Chart-1 shows the variation of convective heat transfer
coefficient with Reynolds number. From chart-1 it observed
that, heat transfer coefficient increases with Reynolds
number. Increase in Reynolds number is an indication that
flow is becoming more turbulent and results into higher heat
transfer rates.
537.3
615.9
759.85 883.17
942.03
1129.89
500
600
700
800
900
1000
1100
1200
0.04 0.09 0.14 0.19 0.24 0.29 0.34
HeattransfercoefficientW/m2K
Mass flow rate Kg/sec
mass flow rate
in Kg/s
Chart -2: Mass flow rate Vs Heat transfer coefficient
Chart-2 shows variation of convective heat transfer
coefficient with respect to mass flow rate. Increase in mass
flow rate results into increase in flow velocity of fluid, so
Reynolds number increases which ultimately increases heat
transfer rate.

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118.65
183.57
409.96
312.28
467.37
100
150
200
250
300
350
400
450
500
10 110 210 310 410 510 610 710
OverallheattransfercoefficientW/m2K
Rynolds number
mass flow
rate in Kg/s
Chart -3: Reynolds number Vs Overall heat transfer coefficient
Chart-3 shows the variation of overall heat transfer
coefficient with Reynolds number. From chart-3, it is seen
that, overall heat transfer coefficient increases with
Reynolds number. Overall heat transfer coefficient is also
dependant on convective heat transfer coefficient so increase
in Reynolds number results into higher heat transfer rates.
118.65
183.57
312.28
467.37
100
150
200
250
300
350
400
450
500
8 10 12 14 16 18 20 22 24
OverallheattransfercoefficientW/m2K
Nusselt number
mass flow rate in
Kg/s
Chart -4: Over all heat transfer coefficient Vs Nusselt number
This chart shows the effect of Nusselt number on overall
heat transfer coefficient. Nusselt number is function of
Reynolds number so, as Nusselt number increases overall
heat transfer coefficient increases.

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0.36
0.4852
0.4036
0.3927
0.3349
0.3334
0
0.1
0.2
0.3
0.4
0.5
0.6
0.9982 0.9984 0.9986 0.9988 0.999 0.9992
Effectiveness
(Cc/Ch)
Heat capacity ratio
(Cc/Ch)
Chart-5: Effectiveness Vs (Cc/Ch)
Chart-5 shows effect of heat capacity ratio on effectiveness
of plate heat exchanger. It is observed that, there is slight
variation in effectiveness with increase in heat capacity
ratio.
4. CONCLUSION
The main focus of this research work is to investigate
experimentally the performance of plate heat exchanger with
parallel flow arrangement with regard to heat exchanger
effectiveness, overall heat transfer coefficient, convective
heat transfer coefficient, mass flow rate, and Reynolds
number. The following are the results of experimental
investigation:
 Convective heat transfer coefficient increases with
increase in mass flow rate, also overall heat transfer
coefficient increases with increase in Reynolds
number. This can be attributed to more turbulent
flow.
 Effectiveness of heat exchanger changes slightly
when there is change in heat capacity ratio.
Maximum effectiveness achieved with parallel flow
arrangement is 0.4852.
This experimental investigation of plate heat exchanger can
be extended with counter flow arrangement and water as
working fluid. This work can also be extended for use of
nano-fluids as working fluid for heat exchanger.
5. REFERENCES
[1]. R.K. Shah and S. G. Kandilkar, “The influence of the
number of thermal plates on plate heat exchanger
performance”, (1989), Journal of Heat Transfer, vol.111,
pp.300-313, ISSN 0167-577
[2]. H. Dardour, S. Mazouz, and A. Bellagi, “Numerical
Analysis of Plate Heat Exchanger Performance in Co-
Current Fluid Flow Configuration”, World Academy of
Science, Engineering and Technology, Vol: 3, 2009-03-29,
ISSN 2278-0181.
[3]. Murugesan M.P. and Balasubramanian R. “To Study the
Fouling of Corrugated Plate Type Heat Exchanger in the
Dairy Industry”, Research Journal of Engineering Sciences,
Vol. 2(1), 5-10, January (2013) ,ISSN 2278 – 9472
[4]. Murugesan M.P. and Balasubramanian R., “The
Experimental Study on Enhanged heat Transfer
Performance in Plate Type Heat Exchanger”, Research
Journal of Engineering Sciences, Vol. 2(2), 16-22,
February (2013), ISSN 2278 – 9472
[5]. T K S Sai Krishna, S. G. Rajasekhar, C. Pravarakhya,
“Design and Analysis of Plate Heat Exchanger with CO2
and R134a as Working Fluids”, International Journal of
Mechanical Engineering And Technology, Volume 4, Issue
4, July - August (2013), pp. 311-318, ISSN 0976 – 6340
(Print) ISSN 0976 – 6359
[6]. R K. Shah and D. P. Sekulic, “Fundamentals of Heat
Exchanger Design” Journal of Heat Exchangers, (2003).
ISBN-0-471—32117
[7]. Kevin M. Lunsford, “Increasing Heat Exchanger
Performance”, Bryan Research and Engineering, Inc. -
Technical Papers (March 1998), Vol 2 ISSN-2278-0181
[8]. Karl Larsson, Fredrik Pihlquist, “Methods of Increasing
Thermal Efficiency Of a Counter Flow Air to Air Heat
Exchanger”, Chalmers University of Technology Goteborg,,
Sweden, Master’s Thesis 2011:08
[9]. R.K. Shah, E.C. Subbarao, R.A.Mashelkar, Heat
transfer equipment design, hemisphere publishing
corporation, USA, 1988 ,pp 231-234, ISBN-0891167293

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[10]. R.C. Sachdeva, Fundamentals of Engineering Heat and
Mass Transfer, New age International Publishers, 2008, pp
.491- 528, ISBN (13) 978-81-224-2138-5, ISBN(10) 81-
224-2138-5
BIOGRAPHIES
Shahanawaj Kasam Tambe, studying final
year mechanical engineering and working
on project “Design and Fabrication of Plate
Heat Exchanger” under the guidance of
Prof. S.B. Khandekar.
Nitin Tukaram Pandhare, studying final
year mechanical engineering and working
on project “Design and Fabrication of Plate
Prof. S.B. Khandekar
Santosh Jeju Bardeskar, studying final year
mechanical engineering and working on
project “Design and Fabrication of Plate
Prof. S.B. Khandekar.
Prof. Khandekar Shailesh B.
M.E.(Mechanical Engg.) working as a
assistant professor in department of
mechanical engineering at Rajendra Mane
College of Engineering and Technology,
Devrukh, (University of Mumbai)
Maharashtra, India.

Experimental investigation of performance of plate heat exchanger for water as working fluid

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Experimental investigation of performance of plate heat exchanger for water as working fluid