Abstract: There are disclosed a tank having a structure which achieves both a burst strength and a fatigue strength, and a manufacturing method of the tank. In order to realize this, in a tank comprising a liner, and an FRP layer including a hoop layer and a helical layer formed by winding fibers around the outer periphery of the liner, at least an innermost helical layer is formed as a smooth helical layer. When the smooth helical layer, i.e., a helical layer which does not have any unevenness or which has only little unevenness is formed, the unevenness can be prevented from being transferred to the hoop layer adjacent to the helical layer. When structural bends (undulations) of the fibers of the hoop layer are suppressed, a fatigue strength of the fibers themselves can be enhanced.

Abstract: A tank that includes layers of fiber reinforced plastics (FRP) formed by alternately winding hoop and helical bundles of fiber over its outer surface. The winding produces stepped portions, i.e. unevenness, in a helical layer positioned as the innermost layer. Such unevenness affects an outer layer (especially a hoop layer) directly adjacent to the innermost helical layer and lowers fatigue strength of the adjacent outer layer. In order to prevent this fatigue strength decrease, the bundle of fiber used for the innermost helical layer has a smaller sectional area than the bundles used for the outer layers. Consequently, decreasing the sectional area of the innermost helical bundle decreases the stepped portions, which, in turn, decreases the transfer of unevenness to the outer layer (especially a hoop layer) directly adjacent to the helical layer. As a result, fatigue strength of the adjacent outer layer (especially a hoop layer) increases.

Abstract: There is avoided a phenomenon where owing to an influence of a stepped portion of the surface of a helical layer positioned in an inner layer of an FRP layer, a fatigue strength of a layer (especially, a hoop layer) adjacent to the outside of the helical layer lowers. To realize this, there is disclosed a tank comprising a liner, and an FRP layer constituted of hoop layers and helical layers alternately formed by winding fiber bundles around the outer periphery of the liner, and in at least one of a plurality of helical layers positioned in an inner layer of the FRP layer, a sectional area of the fiber bundle constituting the helical layer is set to be smaller than that of the fiber bundle constituting another layer formed outside the helical layer. When the helical layer is formed by using this fiber bundle having the small sectional area, unevenness in the helical layer becomes small, and the unevenness can be prevented from being transferred to the other layer (e.g.

Abstract: There are disclosed a tank having a structure which achieves both a burst strength and a fatigue strength, and a manufacturing method of the tank. In order to realize this, in a tank comprising a liner, and an FRP layer including a hoop layer and a helical layer formed by winding fibers around the outer periphery of the liner, at least an innermost helical layer is formed as a smooth helical layer. When the smooth helical layer, i.e., a helical layer which does not have any unevenness or which has only little unevenness is formed, the unevenness can be prevented from being transferred to the hoop layer adjacent to the helical layer. When structural bends (undulations) of the fibers of the hoop layer are suppressed, a fatigue strength of the fibers themselves can be enhanced.

Abstract: A fuel cell system includes a fuel cell (10), a supply passage (11) through which fuel gas and oxidizing gas are supplied to the fuel cell, an exhaust passage (12) through which the fuel gas and the oxidizing gas are discharged from the fuel cell, and a reactor (13) provided in the exhaust passage (12) such that a fuel off-gas from the fuel cell is oxidized. The fuel cell system further includes a bypass passage (14) that extends from the supply passage (11) to reach the reactor (13) and returns to the supply passage (11) such that at least a portion of the fuel gas and the oxidizing gas supplied to the fuel cell upon activation thereof is supplied to the bypass passage 14 and heated in the reactor (13). The bypass passage (14) is communicated with an inside of the reactor (13) such that the gas is heated and humidified under a reaction in the reactor (13) upon activation of the fuel cell.