Heat exchangers | Basics | Interview QnA
Hello Readers
In this blog we will discuss about Heat exchangers Interview questions with answers which has probability of asking in technical
interview.
Define effectiveness of heat exchangers?
What do you mean by heat duty of a heat exchanger?
Which are two parameters which are measured on site for heat exchanger to evaluate the performance?
This is beyond the general
questions so read it carefully.
1. Define effectiveness of heat
exchangers?
Heat exchangers effectiveness can
be found by
Where
to = Cold water outlet temperature
ti = Cold fluid inlet temperature
Ti = Hot water inlet temperature
2. What do you mean by heat duty of
a heat exchanger?
Heat duty of a heat exchanger is
define as the heat that is transferred from hot fluid to cold fluid per unit
time.
3. Which are two parameters which
are measured on site for heat exchanger to evaluate the performance?
1. Hot and cold fluid inlet and
outlet temperatures
2. Mass flowrate of cold and hot
fluids
4. What is meaning by capacity
ratio in heat exchanger?
Capacity ratio is
to = Cold water outlet temperature
ti = Cold fluid inlet temperature
Ti = Hot water inlet temperature
To = Hot fluid outlet temperature
5. find the over all heat transfer
co efficient for a shell and tube counter flow heat exchanger.
Data
Heat exhausted = 11.27 GJ/ hour
Heat transfer area = 96m2
LMTD = 76°C
Heat transfer co efficient can be
calculated by following equation
U = Q / ( A * LMTD )
= 11.27 * 10 ^6
/ ( 3600 * 96 * 76 )
= 0.43 kW / m2 K
6. Give the equation to calculate
overall heat transfer co efficient?