A combination heat exchanger comprises a first heat exchanger assembly and a second heat exchanger assembly. The first heat exchanger assembly includes a first end tank, a second end tank, and a first heat exchanger core including a plurality of first heat exchanger tubes extending longitudinally in a first direction. The second heat exchanger assembly includes a third end tank, a fourth end tank, and a second heat exchanger core including a plurality of second heat exchanger tubes extending longitudinally in the first direction. A first coupling includes a first attachment portion rigidly coupled to the first end tank, a second attachment portion rigidly coupled to the third end tank, and a thermal expansion portion extending between the first attachment portion and the second attachment portion. The first coupling allows for relative translation between the first end tank and the third end tank in the first direction.

A heat exchanger for exchanging heat between two fluids, use of the exchanger with liquid metal and gas, and application to a fast neutron nuclear reactor cooled with liquid metal. The present invention concerns a heat exchanger (1) for exchanging heat between a first fluid (N.sub.2) and a second fluid (Na). According to the invention, the structure of the heat exchanger makes it possible to supply and recover the primary fluid, such as sodium (Na), to and from a given longitudinal end (2a) opposite the longitudinal end (2b) by which the secondary fluid, such as nitrogen (N.sub.2), is supplied and recovered. This allows a physical separation between the paths of the two fluids in the exchanger, with the possibility, in particular, of having restricted access for one of the fluids, such as sodium (Na) and non-restricted access for the other of the fluids, such as nitrogen (N.sub.2).

A method for producing heat exchangers having at least two fluid circuits each having channels, including the following steps: producing one or a plurality of elements of a first fluid circuit, each element having at least two metal plates, at least one of which has first grooves; stacking the at least two metal plates of each element in such a way that the first grooves form the channels of the first circuit; assembling each element of the first circuit by diffusion welding between the two stacked metal plates; producing one or a plurality of elements of at least one second fluid circuit, each element of the second circuit having at least a portion of the channels of the second circuit; assembling, either by diffusion welding, or by brazing, or by diffusion brazing between the element or elements of the first circuit and the element or elements of the second circuit.

Devices and methods for fabrication of a multiscale porous high-temperature heat exchanger for high-temperature and high-pressure applications are disclosed. The heat exchanger can include a core with macrochannels formed in a checkerboard pattern to facilitate alternative flow of working fluid having hot and cold temperatures between adjacent macrochannels. Each macrochannel can include a two-dimensional microchannel array that further distributes flow throughout the heat exchanger to enhance heat transfer and mechanical strength without significant pressure drop penalty. The heat exchanger can further include a header integrated therewith to distribute working fluid flowing through the heat exchanger through the outlets such that it flows evenly therethrough. Methods of fabricating heat exchangers of this nature are also disclosed.

Shell-and-tube devices typically require regular maintenance. Described herein is an automated method for tracking the status of individual tubes during maintenance activities and recording status data for review and analysis. Status data may optionally be reported in real-time summary format and/or used to predict time-to-completion. The method minimizes omission errors and helps to reduce the expense of performing maintenance activities in shell-and-tube devices, including shell-and-tube reactors and heat exchangers.

A modular plate and shell heat exchanger in which welded pairs of heat transfer plates are tandemly spaced and coupled in parallel between an inlet and outlet conduit to form a heat transfer assembly. The heat transfer assembly is placed in the shell in order to transfer heat from a secondary to a primary fluid. Modules of one or more of the heat transfer plates are removably connected using gaskets at the inlet and outlet conduits which are connected to a primary fluid inlet and a primary fluid outlet nozzle. The heat transfer assembly is supported by a structure which rests on an internal track which is attached to the shell and facilitates removal of the heat transfer plates. The modular plate and shell heat exchanger has a removable head integral to the shell for removal of the heat transfer assembly for inspection, maintenance and replacement.

A plurality of heat transfer pipes; a first header and a second header to which both ends of each of the heat transfer pipes that are disposed in parallel are fixed, respectively; a plurality of plate-shaped fins through which each of the heat transfer pipes is penetrated and that are provided at intervals in a direction in which the heat transfer pipes extend between the first header and the second header; and a fan that circulates an airflow between the plate-shaped fins are included. The first header and the second header are formed to be sectioned into multiple rows, the heat transfer pipes are disposed densely in an sectioned area of the first header and the second header, and the heat transfer pipes are disposed sparsely in an area between the sectioned areas of the first header and the second header.

A printed circuit heat exchanger for use in a reactor includes a core formed from a stack of plates diffusion bonded together. The core has: a top face, a bottom face disposed opposite the top face, a first side face extending between the top face and the bottom face, and a second side face disposed opposite the first side face. The printed circuit heat exchanger includes: a plurality of primary channels defined in the core, each of the primary channels extending from a primary inlet defined in the first side face to a primary outlet defined in the second side face; and a plurality of secondary channels defined in the core, each of the secondary channels extending among at least some of the primary channels from a secondary inlet defined in the top face to a secondary outlet defined in the top face.

This invention provides a nuclear reactor design that can enable automated or semi-automated manufacturing of a small reactor in a mechanized factory. This is possible by following a layered approach to combine simple plate geometries with the use of diffusion bonding and computer aided manufacturing techniques that integrate all the fuel, axial reflectors, axial gamma and neutron shields, fuel gas plenum, heat removal mechanism, primary heat exchangers and moderator all in one block or component. The final assembled block has no welds and limits or eliminates manual operations. This design has the potential to reduce the fabrication time of an entire nuclear reactor to just a few days.

Heat exchanger assemblies are provided that can include: a heat exchanger housing; at least one primary conduit operably coupled to the heat exchanger housing and configured to convey a primary heat exchange fluid; at least one secondary conduit operably coupled to the heat exchanger housing and configured to convey a secondary heat exchange fluid; at least one thermal interface between the primary and secondary fluids; and at least one sensor operably engaged with the thermal interface. Heat exchanger assemblies including molten salt, liquid metal, or water/steam as part of the heat exchange fluids of the heat exchanger assembly are provided. The heat exchanger assemblies can include: at least one thermal interface between primary and secondary heat exchange fluids of the heat exchanger assembly; and a sensor operably engaged with the at least one interface.