Heat Exchanger and Types of Heat Exchanger HMT Tutorial- 19, Heat and Mass Transfer, Mechanical Engineering, GATE Video Lecture | Study Topper Handwritten Notes & Videos for GATE ME - Mechanical Engineering | Best Video for Mechanical Engineering

all right my dear so this is a very
close well total if you wanted to learn
about heat exchanger I'm sure it is
known as as II hate exchanger so I was
thinking why not to provide you some
basic information about fixed heat
exchanger well I have already said we do
couple of videos related to heat and
mass transfer so one of my student
already asked me sir provide some basic
approach to topic so I have a started
providing basic approach that's why this
video is for you okay so as you know
what is basically heat exchanger so if
you will say technically then it is a
steady flow open system device you can
say write steady flow open system yeah I
need to share with you because based on
this concept we have a very good
numerical approach steady flow open
system so basically what is the main
purpose or objective of redux led to
transfer heat from one body or one place
to another place that is the main
purpose purpose and we utilize heat in
that way
suppose that we use heat exchanger in
water cooler air created super heater
and even economizer
and we use economizer too - too hot or
must say - in case a temp out - you must
say tempest the word is the temperature
of water that's why it would have to use
a flue gases for increase the
temperature of water it would increase
the efficiency of the power plant even
okay so this is all about heat heat
exchanger okay now most important if
I'll talk about classification then
there are many ways to classify heat
exchanger many ways just like direct
contact with Accenture target contact
heat Accenture and it will ask example
of direct contact with exchanger then I
must say cooling tower so basically what
happens in case of direct contact with
Accenture we we allow hot fluid hot
fluid and cold fluid both mix of we
allow it that hot food and cold fluid
can be mix and then and then exchange
heat because of temperature difference
because heat exchange only can take
place if there is temperature difference
between two bodies or two places
all right now next one is direct contact
with extension is direct contact with
exchanger so what is it in direct
contact with exchanger that means it
will not allow to contact hot fluid and
core fluid the way till then we mix up
their easy care
suppose that hot fluid is flowing to it
and must be cold fever and there would
be a separating wall that's why both the
fluid will not mix up this is known as
indirect contact heat exchanger now
another example which is most important
as well as crucible that is the
regenerative type or maybe storage type
somebody said storage type storage type
or three generative
heat exchanger let me share with you a
diagram that's why you can understand
about it proper properly for health
codes suppose that hot fluid entering
here and cold fluid is entering here and
cold flavors is cold fluid is out in
here and our fluid is out of here
what happened in this type of heat
exchanger we xnz it first we have flowed
one of the one of the few at a time and
then we we float them the field that is
why what will happen this in this way is
way we exchange heat from hot for you
too cold field and you know what
happened here this this is the all these
and matrixes and this matrix is our of
salaries cellulose cellulose matrix this
is salvos matrix and this is how it
exchange it other than this we have also
rotating matrix type of regenerative
heat exchanger but I am NOT going to
share with that because I have few more
types of heat exchanger those are most
important for competitive examination
that's why I will share with you all
those types according to flow according
to flow there are three types of heat
exchanger a one is first one is parallel
flow second is counter flow and third
one is parallel flow counter flow and
third one is you know that cross flow
and let me share with you my dear if
you'll be paying for complete
examination it will ask question from
here they will ask all the application
pushed over time we have seen this but
if they will ask numerical then they
will ask from these two on this parallel
flow and counter flow
and most of our time they asked question
lmpd you need to find out LM telling you
once you will come to know all these
things you can do much better in the
complete examination well one of the
most one of the most basic quotient is
quotient they asked this which right now
I am going to share hope you will
understand and not hope you will
definitely understand I will share with
you in that way that's why you can
understand about the question right now
let's go for that
have you ever think what will happen if
first law of thermodynamics applied to
heat exchanger because as I have already
shared with you this the steady flow
open system then what will happen you
will apply first law of thermodynamics
to two heat exchanger them changing
enthalpy is equal to zero and because
net change in enthalpy of headaches and
regio then we can say enthalpy change of
hot fluid or fluid plus enthalpy change
of cold fluid cold fluid is equal to you
simple and as we can also say these
Delta hot fluid is equal to cold fluid
we can also write this right now rate of
enthalpy decrees of hot fluid and rate
of enthalpy increase of cold fluid based
on these we use Vedic eight a question
in the complete domination I hope you
wanted to know that right so basically
what happens what happened suppose that
we have even a question okay we have
space here I can share with you some
interesting fact suppose that we have
given a question that there is a part
and this four temperature water is 20
degrees in
it okay and here we have a rod this is a
steel rod and this temperature is 120
degree centigrade okay if we will put
this rod into this water then what will
happen what will happen I mean what
would be temperature temperature of
water after after sometime two minutes
three minutes five minutes that would be
depend on the quotient so if you will
see this type of question then remember
this is just a gift for you because I am
going to share with you a that's why you
can solve this type of question quite
easy suppose that if they will change
they will sell with you rate of heat
transfer is two Joule per seconds okay Q
Joule per second that means in what and
they ask you what will happen after two
minutes then you must multiple this Q
into two minutes to find out to find out
into June Joule per second okay you have
to convert into per second first second
second second thing which from blah you
need to use the simple formula Q is
equal to MC delta T from here
MC already is equal to MC delta T this
is for a steel and this is for water use
both the formula they will definitely
give you mass mass specificity
specificity change in temperature change
in
so you need to find out you need to find
out its changing temperature okay you
change in temperature and definitely you
can find out it okay so this is how we
can find out and one more thing I have
an already share with you this minus
sign will work here will work here this
minus sign will work here for a steal we
have to multiple the minus sign then
what will happen T 1 minus T 2 1 here T
2 minus T 1 this is how we can find out
temperature the I mean what will be the
temperature of this water after 2
minutes or 5 minutes that would be
different question I hope you understand
the most basic concept of heat exchanger
and some numerical approach I mean
numerical approach to solve numerical
problems practical approach I must say
that ok thanks for watching see you soon
in my next video bye bye