Introduction of Using Simulink to examine the factors that affect the performance of a heat exchanger

        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.