Thermal Analysis of High-Pressure Metal Hydride Tank for Automotive Application
- PDF / 282,617 Bytes
- 8 Pages / 595 x 842 pts (A4) Page_size
- 109 Downloads / 144 Views
0927-EE01-07
Thermal Analysis of High-Pressure Metal Hydride Tank for Automotive Application Keiji Toh1, Hidehito Kubo1, Yoshihiro Isogai1, Daigoro Mori2, Katsuhiko Hirose2, and Nobuo Kobayashi3 1
Research & Development Dept., TOYOTA INDUSTRIES CORPORATION, 8, Chaya, Kyowa-cho, Obu-shi, 474-8601, Japan 2
Fuel Cell System Development Div., TOYOTA MOTOR CORPORATION, 1200, Mishuku, Susono-shi, 410-1193, Japan 3
Fuel Cell System Engeering Div., TOYOTA MOTOR CORPORATION, 1, Toyota-cho, Toyota-shi, 471-8572, Japan ABSTRACT A new type of hydrogen storage tank has been developed for fuel cell vehicles FCHV.
The
tank design is based on the 35MPa high-pressure cylinder vessel and the heat exchanger module including hydrogen absorbing alloy with high dissociation pressure is integrated in it. To hydrogen absorbing alloy, for example, Ti-Cr-Mn alloy with AB2 laves phase is applied. Its effective hydrogen weight capacity is 1.9 wt% and reaction enthalpy is -22 kJ/molH2. To optimize the heat exchanger, thermal analyzing method was developed to predict the amount of hydrogen absorption or desorption. The simulation consists of heat and mass balance. Heat balance is made by the hydrogen absorbing alloy, heat exchanger and coolant.
Also reaction
heat of the hydrogen absorbing alloy and compressed heat are considered. The reaction heat is calculated from the equation of reaction rate that is derived experimentally. Furthermore, an additional simulation to predict the charging performance of on-board high-pressure MH tank system by the radiator cooling will be reported.
With this simulation, it
will become possible to make parameter studies to investigate how the operating conditions influence the performance of tank system. INTRODUCTION Various hydrogen storage materials, such as the metal hydrides (ionic, covalent, metallic), complex chemical hydrides, carbonaceous materials (carbon, hydrocarbon, graphite, nano-tubes, etc.), inorganic and organic-inorganic hybrid materials, have been developed for automotive applications [1,2]. Recently the hydrogen storage systems by means of complex chemical hydrides were reported. Na alanate, that is one of the chemical hydrides, has high capacity of hydrogen 5.6wt%.
But it can serve as reversible hydrogen storage media only when it is
catalyzed by transition metal [3].
Because it dissociates the hydrogen at high temperature over
150 degree C, it requires an external heating equipment. In expectation of high volumetric density of hydrogen, fast kinetics and operation at room temperature, we have developed the hydrogen storage tank with the metal hydride for the fuel cell vehicles for ten years.
Once we developed low-pressure metal-hydride tank system
operated under 1MPa with Ti-Mn-V alloy [4,5], but some technical issues still remain unsolved such as the system weight, hydrogen charging time, bad low temperature characteristics and difficulties in control.
For on board hydrogen storage system, charging time is the one of the
most serious problems. On the other hand, the high-pr
Data Loading...
