Manipal University
Department of Chemical Engineering
CE 2230- TRANSPORT PHENOMENA LABORATORY-2
II YEAR, 4th SEMESTER, 2022
EXPERIMENT #3
SHELL AND TUBE HEAT TRANSFER
INSTRUCTOR:
Dr.Harsh Pandey
Yogesh Malani
Experiment carried on:
Report submitted on :
February 21 , 2022
March 2 , 2022
PRELAB
EXECUTIVE SUMMARY
INTRODUCTION/OBJECTIVES/SCOPE/PROCEDURE
RESULTS & DISCUSSION
CONCLUSIONS
REFERENCES
APPENDIX
a) Original data, sample calculations, other information
GENERAL COMPLETENESS
a) Conciseness and neatness
(10)
(10)
(30)
(30)
(5)
(5)
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______
______
______
______
______
(5)
______
(5)
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TOTAL
(100)
TABLE OF CONTENTS
1.AIM
2.INTRODUCTION/THEORY
3.EXPERIMENT
(a) Schematic Diagram with Working Principle
(b) Procedure
4.RESULTS and DISCUSSION
5.CONCLUSION
6.REFRENCES
7.APPENDIX
(a) Observation Table
(b) Sample Calculations
______
AIM : To Calculate LMTD, Heat Transfer Rate and Overall Heat
Transfer Coefficient.
INTRODUCTION : A heat exchanger is a device that facilitates the transfer of
thermal energy between two or more fluids. For majority of heat exchangers,
heat transfer occurs indirectly, this is done via a heat transfer surface that
separates the fluids ensuring they do not come into direct contact with each
other or leak. However, there are a few heat exchangers where direct contact
occurs between the two fluids to exchange heat. The transfer of heat happens
by three principle means: conduction, convection and radiation. Heat is
transferred from the fluid to the solid wall of the pipe/plate by conduction and
heat is transferred from one fluid to another by convection; radiation is not a
factor within heat exchangers.
Shell-and-tube heat exchangers are the most common heat exchanger found in
the process industry. This heat exchanger consists of bundles of tubes that are
mounted within a cylindrical shell, flow distribution here permits the flow of
fluid within the bundles of tubes while the others flow across them. Shell-andtube heat exchangers are primarily used for liquid-to-liquid, gas-to-liquid, and
gas to- gas heat transfer applications
EXPERIMENT :
PROCEDURE :
a) Allow water to circulate in the inner copper tube by opening flow controller
valve, monitor the flow rate.
b) Operate the valve system to make water flow either in parallel or counter
flow direction.
c)Use drain valve to remove water, if any condensed in outer shell.
d) Switch ON the temperature indicator and allow for the temperature
becomes Steady. Switch ON the channel selector to the required thermocouple
and observe Temperature variations with time.
e) After steady state is reached, note the temperatures T1 – cold water inlet,
T2 – cold water outlet, T3 – hot water inlet, T4 - hot water outlet.
f) After the experiments is completed, switch OFF the heater, stop water
circulation and drain the water collected in the pipe.
Heat exchanger calculations
Heat transfer occurs by convection in fluids and by conduction from the fluid to the wall of
the pipe. This heat transfer is down to the difference in temperature between the hot fluid
and the cold fluid. This process can be defined using the overall heat transfer coefficient ‘U’
where:
𝑄 = 𝑈𝐴𝑠Δ𝑇𝑙𝑚
𝐴𝑠 is the available surface area of the heat exchanger, the surface area for all three heat
exchangers investigated are given as: double pipe heat exchanger 𝐴𝑠=0.025m2 , shell-andtube heat exchanger 𝐴𝑠=0.02m2 and the plate heat exchanger 𝐴𝑠=0.048m2 .
The overall driving temperature difference in equation 1 is known as the logarithmic mean
temperature difference, this depicts the exponential decay of the local temperature
difference, which is defined as:
Δ𝑇𝑙𝑚 =
Δ𝑇1 − Δ𝑇2
ln(Δ𝑇1 /Δ𝑇2)
where for a parallel flow heat exchanger:
Δ𝑇1 = 𝑇ℎ𝑜𝑡 𝑖𝑛 − 𝑇𝑐𝑜𝑙𝑑 𝑖𝑛 , Δ𝑇2 = 𝑇ℎ𝑜𝑡 𝑜𝑢𝑡 − 𝑇𝑐𝑜𝑙𝑑 𝑜𝑢𝑡
and for counter flow heat exchanger:
Δ𝑇1 = 𝑇ℎ𝑜𝑡 𝑖𝑛 − 𝑇𝑐𝑜𝑙𝑑 𝑜𝑢𝑡 , Δ𝑇2 = 𝑇ℎ𝑜𝑡 𝑜𝑢𝑡 − 𝑇𝑐𝑜𝑙𝑑 𝑖𝑛
The heat transfer rate is dependent on the mass flow rate 𝑚̇, the specific heat Cp and the
absolute temperature, T.
𝑄 = 𝑚̇𝐶𝑝Δ𝑇
Heat transfer for a hot fluid:
𝑄ℎ𝑜𝑡 = 𝑚̇ℎ𝑜𝑡𝐶𝑝ℎ𝑜𝑡 (𝑇ℎ𝑜𝑡𝑜𝑢𝑡 − 𝑇ℎ𝑜𝑡𝑖𝑛)
Heat transfer for a cold fluid:
𝑄𝑐𝑜𝑙𝑑 = 𝑚̇𝑐𝑜𝑙𝑑𝐶𝑝𝑐𝑜𝑙𝑑 (𝑇𝐶𝑜𝑙𝑑𝑜𝑢𝑡 − 𝑇𝐶𝑜𝑙𝑑𝑖𝑛 )
Qm is the mean value for Qhot and Qcold. This value is used to calculate the overall heat
transfer coefficient when Qhot and Qcold values differ.
𝑄𝑚 = (−𝑄ℎ𝑜𝑡) + (𝑄𝑐𝑜𝑙𝑑)2=(𝑄𝑐𝑜𝑙𝑑 − 𝑄ℎ𝑜𝑡) 2
The overall heat transfer coefficient ‘U’ is used to compare the performance of different
types of heat exchanger. The higher overall heat transfer coefficient the better the
performance.
𝑈 =𝑄𝑚 𝐴𝑠Δ𝑇𝑙𝑚
RESULTS AND DISCUSSION
FIG. 1
FIG.2
When cold mass flow rates were increased, for both hot and cold fluids, the
rate of heat transfer, Q, increased as well. The rate of heat transfer is
dependent on the mass flow rate, the relationship can be described as directly
proportional. when cold mass flow rates increased as did both parallel and
counter flow Qm values. Figures show the temperature curve for parallel flow
and counter flow respectively. Figure clearly displays the expected outcome for
a parallel flow arrangement, a with both hot and cold fluids converging
towards one another at the outlet point. Counter flow temperature curves
should show both hot and cold fluids parallel to each other, there should be no
visible converging at one end. Figure seemingly portraits more characteristics
of a parallel flow arrangement, with the outlet points again converging as seen
in figure 9, this may have resulted from an error concerning the hot inlet
temperature
CONCLUSION
So overall, in conclusion, shell and tube heat exchanger follows the basic law of
Thermodynamics and fulfilled the study of Heat Transfer. In parallel (co
current) flow configuration, the exit temperature of the hot fluid is always
higher than the exit temperature of the cold fluid. In counter current flow
configuration, the exit temperature of the hot fluid is also higher than the exit
temperature of the cold fluid. But then, in the configuration of counter
current flow, the exit temperature of the cold fluid is higher than the exit
temperature of the cold fluid in co-current configuration. So, this stands the
statement that counter current flow heat exchanger has a higher effectiveness
than the parallel flow configuration. Besides, the experiment shows that the
flow rate of one of the streams is directly proportional to the rate of heat
transfer since the rate of heat transfer is increases as the flow rate of fluid
increases.
Furthermore, the amount of heat loss forms the hot water is not equal to the
heat gain by the cold
water due to the heat loss to the surrounding. From the calculations done, the
LMTD (log mean temperature difference) for co-current flow is higher than the
counter-current flow. In a nut shell, counter current flow configuration of heat
exchanger is more preferred for practical application.
One of the application of heat exchanger is oil cooler
REFERENCES:
1. Holman, J.P., “Heat Transfer”,8th ed., McGraw Hill, NY, 1976.
2. Kern, D.Q., “Process Heat Transfer”, 1st ed., McGraw Hill, NY, 1965.
3. Perry, R.H., Green, D.(editors), “Perry’s Chemical Engineers’
Handbook”, 6th ed., McGraw Hill, NY, 1985.
4. McCabe, W.L., Smith, J.C., Harriott, P., “Unit Operations of Chemical
Engineering”, 4th ed. McGraw Hill, NY, 1985.
OBSERVATION TABLE :
SAMPLE CALCULATIONS