Project Report: Study of Heat Exchangers at Institution of Engineers

This project report details a study of heat exchangers conducted at The Institution of Engineers, Kolkata. The project explores the characteristics, objectives, and classifications of heat exchangers, with a focus on shell and tube types. The author's responsibilities included research, documentation, and ...Read More

CE 1.1 Project Information
Name of the project: Study of Heat Exchangers
Location of the project: The Institution of Engineers, Kolkata, India
Project Duration: April 2011 to July 2011
Organization: The Institution of Engineers, Kolkata, India
Role and Designation during the time: Project Developer
CE 1.2 Project Background
CE 1.2.1 Characteristics of the project
The project of Study of Heat Exchangers was eventually developed to provide various
important and significant benefits to the society. Heat exchangers within any process system
subsequently allow transfer of heat from any one source to the other. All of these heat
exchangers remain in single line equipments and in case of any type of failure would be
requiring the ceasing of the unit operation. The main guidelines of metallurgy, inspection,
testing and construction were properly checked as well as studied within this project. Since,
this was my first major project in engineering career; I made sure that the project was well
executed. This project comprised of the detailed research of heat exchangers.
CE 1.2.2 Objectives developed for the project
This particular project of Study of Heat Exchangers has various significant objectives.
They are as follows:
 To study and research heat exchangers with details.
 To learn about heat exchangers and the various classifications.

Head of the Department
Project Supervisor
Me (Mechanical Engineering)
CE 1.2.3 My area of work
The project of Study of Heat Exchangers was first major project in mechanical
engineering career. My major area of work was to research as well as document the entire
project with details and with utmost sincerity. During this tenure of research and
documentation, I acquired immense and important knowledge regarding heat exchangers.
Moreover, I even assisted my project supervisor in this project and took proper follow ups for
identifying the flaws.
CE 1.2.4 Project Group
Figure 1: People involved in the project
CE 1.2.5 My responsibilities throughout the project
I was an important part of the project. I had various and several roles and
responsibilities throughout this project and I was successful in executing all of them. My first
responsibility was to evaluate the mechanical as well as electromechanical systems or
products by the help of designing and conducting the research programs. I even applied

principles of heat transfer and developed manufacturing processes. The testing methods were
also tested properly in this case. Proper coordination of maintenance and repairing of services
were my other important responsibilities throughout the project.
CE 1.3 Distinctive Activity
CE 1.3.1 Engineering knowledge and skills applied in the project
I have successfully utilized my mechanical engineering knowledge and skills for the
major success of this project. I knew that if I will apply my skills and knowledge in the
project properly, it is evident that the project will be a huge success. I am a hardworking
person and have excellent problem solving skills. Since I was a quick learner, I utilized my
experience in this particular project. My power of critical thinking was also applied here.
CE 1.3.3 Comprehending the Theory of Project
The heat exchanger is considered for the sole purpose of types of shell as well as tube
type comprise of the tube bundles that is enclosed within a shell for transferring heat. There
are four classifications of heat exchangers. They are as follows:
i) TEMA style shell and tube heat exchanger
ii) Double Pipe or Hairpin Exchangers
iii) Air Cooled Heat Exchanger
iv) Compact and non tubular heat exchanger
The shell and the tube heat exchanger were my major research subject within this
particular project. This heat exchanger comprises of the tube bundles that are encased within
a shell. The transfer of heat occurs between flowing liquids in tubes. The principal types of
construction in this heat exchanger are as follows:

i) Fixed Tube sheet heat exchanger: The tube sheet is welded within the shell. Thus
the tube sheet and shell materials are welded with one another. The cost of this heat
exchanger is lower and no shell side gasket is present.
ii) Floating heat exchanger: The one tube sheet is subsequently fixed to the shell and
any other tube sheet for packing rings that are compressed in the stuffing box by the packing
follower rings. The floating heat exchanger utilized for the shell side services up to the 4137
kPa gauge pressure at temperature 31 degree C.
iii) U Tube heat Exchanger: The third type is the u tube heat exchanger. The tube
bundles comprise of stationary tube sheet, support plates or baffles and hairpin tubes or
spacers. This bundle could be removed from shell of heat exchanger. The main advantages of
U tube heat exchanger mainly include providing minimum clearance within outer tube limit
or other tubes. The utilization of the u tube construction has eventually increased properly
with the major development of various hydraulic tube cleaners that could remove fouling
residues.
Baffles are utilized for supporting tubes and also for enabling the most desirable
velocity that is to be perfectly maintained as well as prevented from the vibration of
induced flow. All of these baffles are responsible for incrementing the overall heat transfer
for producing cross flow and turbulence. The highest baffle spacing could be restricted by
the need for providing sufficient support for these tubes. The spacing of closer baffle
would eventually result in the penetration of poor bundle by fluid of shell side and thus
comprise of difficulties in mechanical cleaning of the outside parts of tubes. Since the
baffle spacing is reduced the drop of pressure increments to much faster rates than it does
the coefficient of heat transfer. Hence, there is a spacing of optimum baffle, which would
be resulting in higher efficiency and effectiveness.

There are some of the basic selection criteria of the heat exchangers. The
maintenance aspects of shell and tube heat exchangers are given for determining when heat
exchanger should be located within vertical or horizontal position for requirements of
inspection and maintenance. The fluid allocation of shell side and tube side comprises of
various criteria like most corrosive, high pressure, severe fouling, pressure drop and many
more.
The fixed tube sheet heat exchanger comprise of straight tubes, which are
absolutely secured in every end to the tube sheets welded to shell. This construction might
have the removable covers of channel, integral tube sheets and bonnet type covers of
channel. The major benefit of fixed tube sheet construction is for the lower cost and
simpler construction. The u tube heat exchanger is bent as the U shape. The advantage of a
U-tube heat exchanger is that because one end is free, the bundle can expand or contract in
response to stress differentials.
CE 1.3.4 Identified issues and their solutions
1.3.4.1 Issues
There were some of the major issues that I faced during this particular project. These
problems were extremely vital and were required to be removed on an urgent basis. The first
and the foremost problem that I came across in the project of heat exchanger was that my
project was facing vibration issues. Due to the presence of vibration issues, the non stationary
fluid dynamic processes are often ceased and the heat exchanger tube bundles up to fail due
to the excess vibration. The second issue or challenge that I faced in this project was the
increment in exchanger energy consumption. When the energy consumption is higher, the
heat exchanger does not work efficiently and effectively. Leakage was the third important
problem in this project. Both exchanger and thermal leakage occurred in this particular

project. The pass partition bypassing was the type of thermal leakage that was experienced by
me. The final issue that I came across in this particular project of heat exchangers was
fouling. The deposition of the undesired material over the transfer of heat surfaces is known
as fouling. It undoubtedly created an impact on the thermal or mechanical performance of the
heat exchangers. This specific phenomenon alters as per time and cost. Due to these issues or
challenges, my project was delayed.
1.3.4.2 Solutions
I was able to solve all the above mentioned issues within this project of study of heat
exchangers. I knew that these problems could result in an underperforming exchanger. The
most important issue was to determine the specific problem, which requires to be solved for
improving the overall performances. For the problem of leakage in the heat exchanger, this
could be found for coming from the issues of flowing distribution. When the flow within the
exchanger is not at all uniform, the higher flow of velocities could eventually cause an extra
problem, which is vibration. I suggested utilizing CFD services, such as CALGAVIN for
addressing the issues in flow distribution and hence the flow could be manipulated. For the
second issue, there are tubes and areas over the shell side where poor transfer of heat took
place as compared to all other areas within the heat exchanger. For the issue of pass partition,
I suggested to have onsite audits for determining the problems of air recirculation. I used
filtration for removing fouling issue from heat exchanger in my project.