Patent ID: 7611786
Filing Date: 2009-11-03
Classification: H01M,Y02E

Abstract:
1. A polymer electrolyte fuel cell power generation system comprising: a fuel cell having (I) a cell stack formed by stacking a plurality of cells each having (i) an MBA having a polymer electrolyte membrane, an anode and a cathode, the anode being formed on one face of the polymer electrolyte membrane and the cathode being formed on the other face of the polymer electrolyte membrane, (ii) an electrically-conductive, thermally-conductive plate-like anode-side separator which is disposed on one side of the MEA such that the front face of the anode-side separator is in contact with the anode and which has a groove-like fuel gas passage in a region of the front face, the region being in contact with the anode, and (iii) an electrically-conductive, thermally-conductive plate-like cathode-side separator which is disposed on the other side of the MEA such that the front face is in contact with the cathode and which has a groove-like oxidizing gas passage in a region of the front face, the region being in contact with the cathode, (II) an inlet of fuel gas, (III) an inlet of oxidizing gas, (IV) an inlet of a cooling fluid, (V) an outlet of the cooling fluid, and (VI) a power generation region constituted by the anode and the cathode; a fuel gas supply apparatus for feeding the fuel gas to the inlet of the fuel gas; an oxidizing gas supply apparatus for feeding the oxidizing gas to the inlet of the oxidizing gas; a cooling fluid supply system for causing the cooling fluid to flow through the inlet of the cooling fluid, a cooling fluid path and the outlet of the cooling fluid, thereby cooling the fuel cell; and a control unit, wherein a fuel gas supply manifold, a fuel gas discharge manifold, an oxidizing gas supply manifold, an oxidizing gas discharge manifold, a cooling fluid supply manifold and a cooling fluid discharge manifold are disposed within the cell stack so as to extend in a stacking direction of the cells, wherein the fuel gas passage of each of the anode-side separators is formed so as to connect the fuel gas supply manifold to the fuel gas discharge manifold, wherein the oxidizing gas passage of each of the cathode-side separators is formed so as to connect the oxidizing gas supply manifold to the oxidizing gas discharge manifold, wherein a cooling fluid passage is formed for each cell or every two cells so as to connect the cooling fluid supply manifold to the cooling fluid discharge manifold in a region located on the back face of at least either the anode-side separator or the cathode-side separator, the region overlapping the power generation regions when viewed in the stacking direction of the cells wherein the upstream end of the fuel gas supply manifold is communicated with the inlet of the fuel gas and the downstream end of the fuel gas discharge manifold is communicated with the outside, wherein the upstream end of the oxidizing gas supply manifold is communicated with the inlet of the oxidizing gas and the downstream end of the oxidizing gas discharge manifold is communicated with the outside, wherein the upstream end of the cooling fluid supply manifold is communicated with the inlet of the cooling fluid and the downstream end of the cooling fluid discharge manifold is communicated with the outlet of the cooling fluid, wherein the respective most upstream portions of the fuel gas passage and the oxidizing gas passage and the most upstream portion of the cooling fluid passage are located at approximately the same position when viewed from the stacking direction of the cells, and the respective most downstream portions of the fuel gas passage and the oxidizing gas passage and the most downstream portion of the cooling fluid passage are located at approximately the same position when viewed from the stacking direction of the cells, and wherein when electric power is generated accompanied with heat generation by a reaction between the fuel gas and the oxidizing gas within the power generation regions of the fuel cell, and in a case where the cooling fluid passage is formed for each cell on the back face of at least either the anode-side separator or the cathode-side separator, the control unit controls a temperature (hereinafter referred to as “cooling fluid inlet temperature”) of the cooling fluid at the inlet of the cooling fluid through the cooling fluid supply system so as to simultaneously satisfy a first requirement in which T when electric power is generated accompanied with heat generation by a reaction between the fuel gas and the oxidizing gas within the power generation regions of the fuel cell, and in a case where the cooling fluid passage is formed for every two cells on the back face of at least either the anode-side separator or the cathode-side separator, the control unit controls the cooling fluid inlet temperature through the cooling fluid supply system so as to simultaneously satisfy the first requirement, the second requirement, and a fourth requirement in which T