Effects of tank heating on hydrogen release from metal hydride system in VoltaFCEV Fuel Cell Electric Vehicle

• Published in: International journal of hydrogen energy 2023-02, Vol.48 (18), p.6811-6823
• Main Authors: Özdoğan, Emre, Hüner, Bulut, Süzen, Yakup Ogün, Eşiyok, Tayyar, Uzgören, İlayda Nur, Kıstı, Murat, Uysal, Süleyman, Selçuklu, Saltuk Buğra, Demir, Nesrin, Kaya, Mehmet Fatih
• Format: Article
• Language: English
• Subjects: Fuel cell systems; Heat exchanger; Hydrogen electric vehicles; Hydrogen storage; Metal hydride
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2022.07.080

Metal hydride (MH) storage is known as a safe storage method because it does not require complex processes like high pressure or very low temperature. However, it is necessary to use a heat exchanger due to the endothermic and exothermic reactions occurring during the charging and discharging processes of the MH tanks. The performance of the MH is adversely affected by the lack of a heat exchanger or a suitable temperature range and it causes non-stable hydrogen supply to the fuel cell systems. In this study, effect of the tank surface temperature on hydrogen flow and hydrogen consumption performance were investigated for the MH hydrogen storage system of a hydrogen Fuel Cell Electric Vehicle (FCEV). Different temperature values were arranged using an external heat circulator device and a heat exchanger inside the MH tank. The fuel cell (FC) was operated at three different power levels (200 W, 400 W, and 600 W) and its performance was determined depending on the temperature and discharge flow rate of the MH tank. When the heat exchanger temperature (HET) was set to 40 °C, the discharge performance of the MH tank increased compared to lower temperatures. For example, when the FC power was set to 200 W and the HET of the system was at 40 °C, 1600 L hydrogen was supplied to the FC and 2000 Wh electrical energy was obtained. The results show that the amount of hydrogen supplied from the MH tank decreases significantly by increasing the flow rate in the system and rapid temperature changes occur in the MH tank. [Display omitted] •Waste heat of the DC motors to heat the MH tank is simulated for FCEVs.•Desorption performance of the MH tank is investigated in different HET and FC power.•The best performance in the MH tank is achieved in 200 W FC power at 40 °C.•Maximum 1635 L hydrogen is supplied and 2073 Wh electrical energy is obtained in FC.