Abstract: Ultrasonic flaw detection uses a phased-array ultrasonic-flaw-detection probe. The flaw detection probe is placed such that the center of curvature of the flaw detection probe coincides with a reference center of curvature of a subject. The flaw detection probe is translated along a scan direction. The flaw detection probe emits an ultrasonic beam such that the position upon which the ultrasonic beam converges coincides with the center of curvature of the curve of the outline of the cross section of the subject at the scan position, receives the resulting reflected beam, and estimates the length of a flaw in the circumferential direction of the subject. In addition, the estimated length of the flaw is corrected using a correction coefficient corresponding to the distance between the center of curvature of the reference scan position and the center of curvature of the scan position in the thickness direction of the subject.

Abstract: A fuel cell power generation module includes a first fuel cell module, and a second fuel cell module capable of generating power with a first exhaust fuel gas exhausted from the first fuel cell module. It is configured such that a first recirculation line recirculates from a second exhaust fuel gas line through which a second exhaust fuel gas exhausted from the second fuel cell module flows, and the second exhaust fuel gas is supplied to a fuel-side electrode of the second fuel cell module.

Abstract: A fuel cell power generation system includes: a fuel cell; a peripheral device used to operate the fuel cell; a resource storage part; and a resource supply part. The resource storage part is capable of storing a resource generated in the fuel cell in an operation/stop process of the fuel cell. The resource supply part is capable of supplying the resource stored in the resource storage part to at least either of the fuel cell or the peripheral device.

Abstract: A fuel cell power generation system includes: a first fuel cell; and a second fuel cell connected to a downstream side of the first fuel cell via an exhaust fuel gas line, the second fuel cell being capable of generating electric power using an exhaust fuel gas from the first fuel cell. A water recovery unit is disposed on the exhaust fuel gas line, the water recovery unit being capable of recovering water contained in the exhaust fuel gas. A bypass line brings an upstream side and a downstream side of the exhaust fuel gas line with respect to the water recovery unit into communication. At least one flow control valve is disposed on at least one of the exhaust fuel gas line or the bypass line. A control unit controls an opening degree of the at least one flow control valve.

Abstract: A biogas-utilizing methanation system includes: a solid oxide fuel cell using a to-be-treated gas as a fuel gas; a hydrogen production device capable of producing hydrogen by using power of a renewable energy power generation device; and a methanation device capable of methanating carbon dioxide in the system with the hydrogen produced by the hydrogen production device. The carbon dioxide in the system can be stored in a storage device on the basis of the supply amount of the to-be-treated gas or the power of the renewable energy power generation device.