Multi-response optimization of ejector for proton exchange membrane fuel cell anode systems by the response surface methodology and desirability function approach

ABSTRACT

In a fuel cell system, the performance of the ejector is limited when it operates under off-design conditions. To improve the performance of the ejector under all operating conditions in the fuel cell system, this study employs a multi-response optimization approach to optimize the structural parameters of the ejector. The optimization objectives are the entrainment ratio under low-power and high-power operating conditions, with the optimization variables including the mixing tube diameter (D_m), primary nozzle exit position (L_nxp), and mixing tube length (L_m). A quadratic polynomial model is proposed to correlate the key structural parameters of the ejector with the entrainment ratio using the response surface methodology based on the Box-Behnken design. The optimal structural parameters of the ejector are obtained using the desirability function approach. The results demonstrate that this optimization approach significantly improves the ejector performance under off-design conditions while the performance remains essentially unchanged under high-power operating conditions.

KEYWORDS:

• Fuel cell system
• ejector
• multi-response optimization
• Box–Behnken design
• response surface methodology
• desirability function approach

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the [National Natural Science Foundation of China] under Grant [Number U21A20166]; [Key Technology R&D Program of Anhui Province] under Grant [Number 2019b05050004].