Pressurized

MW~muIti MW PRESSURIZED SYSTEM PROPOSED

Fig.l Outline of Development Plan at Mitsubishi Electric Corp.

The main targets of AIR concept are scale-up (lm2 cell, 200kW stack), life elongation up to 40,000hours and high power density (pressurized) operation of IR stacks. Two lOkW AIR stacks of which electrode area is lm 2 have been manufactured and tested, recently. One stack is operated at the atmospheric pressure and another stack is operated at 0.5MPa, which is the first pressurized IR stack in the world. In this paper, the AIR technology for large scale cells is reported laying stress on the performance of these two stacks.

LARGE CELL (lm 2 ) ADVANCED INTERNAL REFORMING (AIR) STACK DESIGN

The AIR configuration consists of plate reformers piled in every 6 cells and catalyst beds also installed in the anode gas channels. The AIR is elegant scheme in order to reduce the stack cooling duty and to get suitable temperature distributions in the stack.

It is the point to optimize the temperature distribution in order to develop large scale and high power density IR stacks. The temperature distribution dominates performance and life characteristics. It is significant to make energy balance between endothermic reforming reaction and exothermic cell reaction, locally as well as totally in the IR stacks. Triple gas flows i.e. fuel gas (LNG+steam), anode gas and cathode gas are arranged in the 1 dimensional configuration, as for the lm 2 cell IR stacks. Fig.2

shows such AIR stack configuration. The bipolar plate configuration used in the lm 2 cell is also shown in Fig. 3. The counter flow scheme is adopted between the anode gas

ANODE CAS OUTLCT-jj-MATRIX ANODE

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