دانلود رایگان مقاله تحلیل اکسرژی و بهینه سازی سلول سوخت تبادل پروتون با ستفاده از الگوریتم ژنتیک

abstract

The exergy of a high temperature proton exchange membrane fuel cell has been studied and analyzed in this research. In the present work a genetic algorithm code was developed using MATLAB software to calculate and optimize work, exergy, exergy efficiency and thermodynamic irreversibility. Also, a membrane fuel cell was modeled and simulated. The polarization curve is in good agreement with experimental data. The results were studied for current density range¼0.05 A/cm2 to 1 A/cm2 , temperature range¼393 K to 453 K, pressure range¼1 atm to 3 atm and membrane thickness¼0.016–0.02 cm. The optimum value of work was calculated 0.496 W/cm2 that was obtained at current density of 1 A/cm2 , temperature¼453 K, pressure¼2.6 atm and membrane thickness¼0.016 cm. The optimum value for irreversibility and exergy efficiency are0.007 W/cm2 and 0.46 at the same point. The optimum point of multi-objective function was obtained at current density 0.49363 A/cm2 , temperature 451.231 K, pressure 2.5 atm and membrane thickness 0.016 cm. At this optimum point work, irreversibility and exergy efficiency were calculated as 0.2767 W/cm2 , 0.1542 W/cm2 and 0.3545 simultaneously.

4. Conclusion

In this research exergy analysis of a HT-PEMFC was considered and carried out under steady state condition. The cost optimization of the produced electrical power is dependent to energy waste. The exergy of a fuel cell is wasted by heat, work and output mass. The exergy balance of the fuel cell was modeled and simulated using Ansys Fluent V.15.0 software. Also, genetic algorithm was proposed for exergy analysis of a defined fuel cell by MATLAB software. The results were compared and validated by experimental data. The polarization curve was depicted at T¼453 K and P¼1 atm. The results show that there is good agreement between theoretical and experimental data. The exergy efficiency was plotted against the current density at different temperature and pressure (current density¼0.05–1 A/cm2 and temperatures ¼393–453 K). The exergy efficiency increases with temperature rising due to the increasing W Ex ̇ ̇ / FC mass in, function. Also, exergy efficiency is a function of membrane thickness but pressure has no important effect. The results show the thermodynamic irreversibility decreased with increasing temperature and pressure. The main objective of this work is optimization of fuel cell performance. Therefore, the exergy efficiency and work was described as single-objective functions and maximized. Also, thermodynamic irreversibility of the system should be minimized in order to optimization the system. The optimization code was developed using MATLAB software. Decision variables of these single-objective functions were selected as current density, temperature, pressure and membrane thickness. The best fitness for these single-objective functions were carried out at different generation number. Also, a multi-objective function was carried out and optimized by genetic algorithm method. The dimensionless functions were obtained by LINMAP method. The pareto front graph was plotted. The optimum point of multi objective functions was reported in Table 6. This point was obtained at Work¼0.276733 W/cm2 , Irreversibility¼0.154178 W/cm2 and Exergy efficiency¼0.354485.