A method for analyzing a heat exchanger includes a structural model creation step (S1) of creating a structural model of a heat exchanger; a iron-linear model creation step (S4) of creating a iron-linear model in which a non-linear spring element in an out-of-plane direction, in which a load is generated only at me time of contact between a heat transfer tube and an anti-vibration member, is applied to an opposing portion between the heat transfer tube and the anti-vibration member in a structural model, and a load distribution acquisition step (S5) of performing analysis in which a load in the out-of-plane direction is applied to the non-linear model to acquire load distribution of the heat exchanger from a value of the load in each opposing portion.

Apparatus for a steam generator that employs tube support plates within a shroud that is in turn disposed within a shell. The tube support plates are made of a material having a coefficient of thermal expansion lower than that of the shroud. The tube support plates are aligned during fabrication, with minimal clearances between components. Using a tube support displacement system, a controlled misalignment is then imposed on one or more tube support plates, as the steam generator heats up. The tube support plate displacement system has only one part, a push rod, which is internal to the steam generator shroud, thereby minimizing the potential of loose parts. The tube support plate displacement system can be used to provide controlled misalignments on one or more tube support plates, in the same or varying amounts and directions, and with one or more apparatus for each individual tube support plate.

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.

A vibration-inhibiting bar is provided that is interposed between bends of the tubes of two adjacent banks of tubes of a U tube bundle of a steam generator and includes at least one internal element, referred to as a damping element, designed to mechanically damp the vibrations of the tubes; and at least one external element, referred to as percussion element, in contact with the damping element, the percussion element being designed to be in contact with the bends of the tubes of the bundle.

A method for analyzing a heat exchanger includes a structural model creation step (S1) of creating a structural model of a heat exchanger; a iron-linear model creation step (S4) of creating a iron-linear model in which a non-linear spring element in an out-of-plane direction, in which a load is generated only at me time of contact between a heat transfer tube and an anti-vibration member, is applied to an opposing portion between the heat transfer tube and the anti-vibration member in a structural model, and a load distribution acquisition step (S5) of performing analysis in which a load in the out-of-plane direction is applied to the non-linear model to acquire load distribution of the heat exchanger from a value of the load in each opposing portion.

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.

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.

A means of offsetting semi-circular tube support plates typically present in heat exchangers with cross flow baffles, such as axial flow economizers, utilizing the motive force of steam generator pressurization. The offset slightly flexes the tubes, thereby providing a preload which minimizes the potential for tube vibration and wear.

Apparatus for a steam generator that employs tube support plates within a shroud that is in turn disposed within a shell. The tube support plates are made of a material having a coefficient of thermal expansion lower than that of the shroud. The tube support plates are aligned during fabrication, with minimal clearances between components. Using a tube support displacement system, a controlled misalignment is then imposed on one or more tube support plates, as the steam generator heats up. The tube support plate displacement system has only one part, a push rod, which is internal to the steam generator shroud, thereby minimizing the potential of loose parts. The tube support plate displacement system can be used to provide controlled misalignments on one or more tube support plates, in the same or varying amounts and directions, and with one or more apparatus for each individual tube support plate.