The aim of this assignment is to use
Simulink to develop models for parallel flow and counter flow heat exchangers.
The models will be validated against experimental readings from a heat
exchanger. Following this, the Simulink models will be used to examine the
factors that affect the performance of a heat exchanger.
Using Simulink software of a heat
exchanger
The First Table for Parallel Flow and a
graph showing temperature profile as you see in figure 1.
The third table show the relation between Effectiveness
counter flow Effectiveness parallel when we change the length and a graph showing
the change as you see in figure 3.
Figure 3
Using Experiment Calculation:
Effectiveness for Parallel flow = (1321.098
W /3191.848 W) = 0.414
Effectiveness for counter flow = (1354.259
W/3191.845 W) = 0.423
Using Simulink software:
Effectiveness for Parallel flow = 0.3968
Effectiveness for counter flow = 0.4119
The table show the relation between Effectiveness and Mass flowrate (kg/s) and a graph showing the change of the flow
ratio when we change the Effectiveness as you see in figure 4.
Discussion of Results of a heat
exchanger
The
common characteristics of parallel along with counter flow heat exchanger could
be observed from the table. The exit pressure of the hot fluid would be higher
than the exit pressure of clod fluid, in the parallel flow configuration. By
the data taken this is supported. On the other hand we observed that the exit
temperature is higher than the entrance chapter of the cold fluid on the
counter flow configuration. Even though in this case this is also supported by
the data and the exits temperature is still hotter than the temperature of cold
fluid. In overall effectiveness from the calculations resulting, as we observed
that the parallel flow is less effective than the counter flow heat exchanger.
In table 3 and table 4 the data is shown, the
difference of temperature is shown. Under the condition of the constant flow
rate, as well as the ratio among the temperature difference also constant. If
in the hot fluid the temperature is high so as a result there is also a rise in
temperature in cold fluid. First law of thermodynamics is governed by this
case. According to the first law of thermodynamics energy is transferred from
the hot to cold fluid with mass flow rate constant. Even though the numerical
values the ratio among the temperature difference doesn’t change.
Conclusion of a heat
exchanger
It is concluded that the lab is follow the basic law
of thermodynamics as well as this could be shown in the experiment. For the
configuration of parallel flow the exits temperature of the hot fluid is hotter
than the cold fluid. And that thing is support the clausius statement that heat
might be not transferred from cold to o hotter body or framework. It is also
concluded that we achieve the aim of our lab report by drawing the circuit on
the Matlab Simulink and run the program without any error. It is concluded that
for high effectiveness the counter flow configuration is preferred in practical
application. We clearly observe in this lab report that counter is better than
parallel flow configuration.