Abstract: A measurement method for a steam valve according to at least one embodiment of the present disclosure, includes: a step of measuring acceleration of a valve stem when a slave valve is opened by driving the valve stem with an actuator from a fully closed state of a master valve and the slave valve; a step of detecting a timing at which the slave valve is fully opened, based on the measured acceleration of the valve stem; and a step of calculating an amount of movement of the valve stem from a reference position to a position where the slave valve is fully opened.

Abstract: The support structure of the present disclosure is a piping support structure that supports piping comprising: a header pipe extending in a first direction within a cross section of a duct and having an inlet formed therein through which a high-temperature fluid flows; and a plurality of nozzle pipes integrally provided with the header pipe, extending in a second direction orthogonal to the first direction, and arranged in the first direction. The support structure comprises: ridges protruding from surfaces on at least one side of the outer peripheral surfaces of the nozzle pipes in a third direction orthogonal to the first direction and the second direction; and a support member fixed to the duct and having formed therein a guide groove to which the ridge is fitted and which guides the ridge in the direction of heat extension of the header pipe and the nozzle pipes.

Abstract: The support structure of the present disclosure is a piping support structure that supports piping comprising: a header pipe extending in a first direction within a cross section of a duct and having an inlet formed therein through which a high-temperature fluid flows; and a plurality of nozzle pipes integrally provided with the header pipe, extending in a second direction orthogonal to the first direction, and arranged in the first direction. The support structure comprises: ridges protruding from surfaces on at least one side of the outer peripheral surfaces of the nozzle pipes in a third direction orthogonal to the first direction and the second direction; and a support member fixed to the duct and having formed therein a guide groove to which the ridge is fitted and which guides the ridge in the direction of heat extension of the header pipe and the nozzle pipes.

Abstract: A measurement method for a steam valve according to at least one embodiment of the present disclosure, includes: a step of measuring acceleration of a valve stem when a slave valve is opened by driving the valve stem with an actuator from a fully closed state of a master valve and the slave valve; a step of detecting a timing at which the slave valve is fully opened, based on the measured acceleration of the valve stem; and a step of calculating an amount of movement of the valve stem from a reference position to a position where the slave valve is fully opened.

Abstract: A steam valve according to at least one embodiment of the present disclosure, includes: a valve body that includes a steam flow path through which steam flows, and a valve seat disposed in the middle of the steam flow path and having an opening portion; and a stop valve that includes a valve stem which extends in an axial direction, where an axis extends, and is movable back and forth in the axial direction, and a first valve disc which is fixed to a distal end part of the valve stem and is abutted against the valve seat to close the steam flow path. The valve stem is partitioned into a first valve stem to which the first valve disc is fixed and a second valve stem different from the first valve stem.

Abstract: A supporting force inspection device for inspecting a supporting force of a vibration suppression member interposed between bend portions of a plurality of heat transfer tubes of a steam generator includes: an acceleration sensor for detecting a vibration state of the bend portion; a sensor holding part disposed inside the heat transfer tube and configured to hold the acceleration sensor; and a vibration force generation part configured to generate a vibration force for vibrating the heat transfer tube along a plane in which a curvature circle of the bend portion exists. The vibration force generation part is configured to cooperate with the sensor holding part and vibrate the heat transfer tube along the plane in which the curvature circle exists.

Abstract: A supporting force inspection device for inspecting a supporting force of a vibration suppression member interposed between bend portions of a plurality of heat transfer tubes of a steam generator includes: an acceleration sensor for detecting a vibration state of the bend portion; a sensor holding part disposed inside the heat transfer tube and configured to hold the acceleration sensor; and a vibration force generation part configured to generate a vibration force for vibrating the heat transfer tube along a plane in which a curvature circle of the bend portion exists. The vibration force generation part is configured to cooperate with the sensor holding part and vibrate the heat transfer tube along the plane in which the curvature circle exists.

Abstract: There is provided a contact force evaluation method for evaluating a contact force against a supporting member of a tube bundle positioned in a fluid and supported by the supporting member, including a contact force setting step of setting a contact force of the tube bundle, a probability density function calculation step of calculating a probability density function of a reaction force received by the supporting member from the tube bundle in response to a predetermined input, using a vibration analysis model of the tube bundle and the supporting member, a probability calculation step of calculating a probability that a reaction force equal to or higher than the set contact force occurs, based on the calculated probability density function, and an evaluation step of evaluating the set contact force, based on the calculated probability.

Abstract: A vibration damping structure for a heat-transfer tube bundle including columns arranged at an interval and each composed of a plurality of heat-transfer tubes curved in a common plane and arranged in parallel to each other. The vibration damping structure includes a first vibration damping member and a second vibration damping member disposed between the columns so as to intersect the array direction of the columns. The first vibration damping member and the second vibration damping member are disposed at different positions in an axial direction of each heat-transfer tube, and thicknesses of the first vibration damping member and the second vibration damping member in the array direction are larger than an average value of a clearance between the columns under operation.

Abstract: An amphibious vehicle includes a vehicle body; a flap supported at a lower portion in a traveling direction of the vehicle body to be able to swing in a direction in which an upper edge portion approaches and separates from the vehicle body; a support column which has a fluid actuator capable of expanding and contracting in accordance with a pressure of a working fluid to a cylinder chamber, is connected to the flap in at least a first end portion in a longitudinal direction, and performs adjustment of a swinging angle of the flap by expansion and contraction of the fluid actuator; a power source which supplies the working fluid to the cylinder chamber; and a safety valve which communicates with the cylinder chamber, and opens when an internal pressure of the cylinder chamber becomes greater than a predetermined pressure to discharge the working fluid in the cylinder chamber.

Abstract: The preset application relates to a vibration damping structure for a heat-transfer tube bundle including columns arranged at an interval and each composed of a plurality of heat-transfer tubes curved in a common plane and arranged in parallel to each other. The vibration damping structure includes a first vibration damping member and a second vibration damping member disposed between the columns so as to intersect the array direction of the columns. The first vibration damping member and the second vibration damping member are disposed at different positions in an axial direction of each heat-transfer tube, and thicknesses of the first vibration damping member and the second vibration damping member in the array direction are larger than an average value of a clearance between the columns under operation.

Abstract: A self-excited vibration evaluation method for evaluating self-excited vibration of a tube bundle arranged in a fluid so as to be supported by a support member includes: for each of at least one eigenmode of the tube bundle, a time history response analysis step of performing time history response analysis of simulating a change in vibration amplitude of the tube bundle, while changing a negative damping ratio corresponding to an excitation force of the fluid; calculating a critical flow velocity of the fluid on the basis of a minimum negative damping ratio at which the change of the vibration amplitude of the tube bundle diverges in the time history response analysis; inputting an expected flow velocity of the fluid; and evaluating the self-excited vibration of the tube bundle for each eigenmode by comparing the expected flow velocity of the fluid with the critical flow velocity.

Abstract: An amphibious vehicle includes a vehicle body; a flap supported at a lower portion in a traveling direction of the vehicle body to be able to swing in a direction in which an upper edge portion approaches and separates from the vehicle body; a support column which has a fluid actuator capable of expanding and contracting in accordance with a pressure of a working fluid to a cylinder chamber, is connected to the flap in at least a first end portion in a longitudinal direction, and performs adjustment of a swinging angle of the flap by expansion and contraction of the fluid actuator; a power source which supplies the working fluid to the cylinder chamber; and a safety valve which communicates with the cylinder chamber, and opens when an internal pressure of the cylinder chamber becomes greater than a predetermined pressure to be able to discharge the working fluid in the cylinder chamber.

Abstract: There is provided a contact force evaluation method for evaluating a contact force against a supporting member of a tube bundle positioned in a fluid and supported by the supporting member, including a contact force setting step of setting a contact force of the tube bundle, a probability density function calculation step of calculating a probability density function of a reaction force received by the supporting member from the tube bundle in response to a predetermined input, using a vibration analysis model of the tube bundle and the supporting member, a probability calculation step of calculating a probability that a reaction force equal to or higher than the set contact force occurs, based on the calculated probability density function, and an evaluation step of evaluating the set contact force, based on the calculated probability.

Abstract: There is provided a method for manufacturing a one-piece dental implant having a ceramic abutment and a titanium or titanium alloy implant fixture firmly adhesively fixed to each other. A one-piece dental implant having an abutment 2 and an implant fixture 1 integrated to each other is manufactured by cooling the implant fixture 1 to room temperature after a projecting part 2a of the abutment 2 at room temperature is press-fitted into a recess part 1a of the implant fixture 1 being in a state where the implant fixture 1 is heated to 100-300° C. The implant fixture 1 formed of titanium or a titanium alloy is perforated to have a truncated circular cone-shaped recess part 1a. The recess part 1a has a taper that is tapered from an intraoral side to a jawbone side. The abutment 2 formed of ceramic has a prosthetic fixing part 2b provided on an opposite side of the jawbone side and a truncated circular cone-shaped projecting part 2a provided on the jawbone side.

Abstract: A heat exchanger tube vibration suppression device and a steam generator are provided. The heat exchanger tube vibration suppression device includes: a plurality of sleeves disposed in a heat exchanger tube with a predetermined gap in relation to an inner surface of the heat exchanger tube so as to extend in a longitudinal direction of the heat exchanger tube; and a connecting member that connects the plurality of sleeves so as to be movable between a contracted position at which adjacent sleeves overlap at least partially and an extended position at which the amount of overlap of the adjacent sleeves is minimized. In this way, it is possible to suppress the vibration of the heat exchanger tube appropriately.

Abstract: An upper hole 37A and a lower hole 37B are provided at two positions, namely, upper and lower portions, of a side surface of a guide tube 27, and a thimble tube 22 is pressed against an inner circumferential surface of the guide tube 27, by a differential pressure between coolant inside and outside the upper hole 37A and the lower hole 37B.

Abstract: A hollow fiber membrane is produced through a thermally induced phase separation process by dissolving a highly hydrophilic polyamide resin in a high-boiling-point solvent such as an aprotic polar solvent at a temperature of not lower than 100° C. The hollow fiber membrane has a membrane surface having a water contact angle of not greater than 80 degrees, and has a water permeability of not less than 100 L/m2·atm·h and a 0.1-?m particle rejection percentage of not less than 90%.

Abstract: A heat transfer tube repairing apparatus including a wire that is flexible and is insertable into a heat transfer tube, a sleeve that is fixed to a predetermined position in the longitudinal direction of the wire, a pair of pressing members that is provided at the front and rear sides of the sleeve in the longitudinal direction of the wire and is able to press the inner surface of the heat transfer tube, and operation members that are able to move the pressing members between a pressing position where the pressing members press the inner surface of the heat transfer tube and a separating position where the pressing members are separated from the inner surface of the heat transfer tube.

Abstract: A steam generator includes: an annular member (21) that surrounds a U-bent portion (18) obtained by collectively disposing bent portions of a plurality of heat transfer tubes and is provided between an outer peripheral portion of the U-bent portion (18) and a tube bundle shroud (3) surrounding the outer peripheral portion so as to have a predetermined gap with respect to the U-bent portion (18); a second support member (22) that is provided between the annular member (21) and the tube bundle shroud (3); and a third support member (23) that is attached to a cylinder portion (2) accommodating a plurality of heat transfer tubes and supports the second support member (22).