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.

A nuclear reactor includes a heat exchanger that transfers thermal energy from a primary reactor coolant to a secondary coolant. The heat exchanger is formed with a hot flow channel, a cold flow channel, and a porous layer between the hot flow channel and the cold flow channel. The porous layer may be thermally insulative to reduce the efficiency of thermal energy transfer from the hot flow channel to the cold flow channel. The porous layer may have a control gas passed therethrough that can be tailored to control the thermal energy transfer through the porous layer. The control gas can be tested for leakage within the heat exchanger. The control gas may also be used to sequester fission or activation products.

A nuclear reactor includes a vessel incorporating at least one primary power heat exchanger for cooling the primary liquid of the nuclear reactor during the normal operation of the reactor and at least one primary passive safety heat exchanger for cooling the primary liquid of the nuclear reactor in the event of a malfunction in the normal cooling of the primary liquid of the reactor. The vessel includes a compartment arranged in the thickness thereof, wherein the primary passive safety heat exchanger is at least partially contained inside the compartment.

A heat exchanger module with a longitudinal axis including a stack of plates defining at least two fluid circuits, at least a portion of the plates each including fluid circulation channels each delimited, at least in part, by a groove. A communication is produced between the channels within a same plate and between all the plates of a same circuit, in a feed or pre-collector zone, with a succession of channel groupings, two-by-two, in the form of bifurcations.

A pump assisted heat pipe may combine the low mass flow rate required of latent heat pipe transfer loops with a hermetically sealed pump to overcome the typical heat pipe capillary limit. This may result in a device with substantially higher heat transfer capacity over conventional pumped single-phase loops, heat pipes, loop heat pipes, and capillary pumped loops with very modest power requirements to operate. Further, one or more embodiments overcome the gravitation limitations in the conventional heat pipe configuration, e.g., when the heat addition zone is above the heat rejection zone, the capillary forces are required to transfer the liquid from the heat rejection zone to the heat addition zone against gravity.

A heat exchanger may include a main body with an inlet plenum and an outlet plenum at a first end, and a header at a second end. At least one elongated shaft may extend from the outlet plenum to the header. At least one heat pipe may be coupled to the header and a portion of each heat pipe may be positioned within a corresponding elongated shaft defining an annular space between each heat pipe and each corresponding elongated shaft. A flow skirt may include a manifold located between the inlet plenum and the outlet plenum of the main body. At least one elongated tube may extend from the manifold. Each elongated tube may be positioned within a corresponding annular space between each heat pipe and each corresponding elongated shaft, dividing the annular space into two concentric annular channels comprising an inner annular channel and an outer annular channel.

A heat pipe configured to remove heat from a nuclear reactor core is disclosed herein. The heat pipe can include an inner housing defining an inner volume configured to accommodate a heat source and an outer housing configured about the inner housing and the heat source. A wick can be positioned between at least a portion of the inner housing and at least a portion of the outer housing, wherein the wick can include a capillary material, and wherein the wick can define an intermediate volume between the inner housing and the outer housing. A working fluid can be positioned within the intermediate volume, wherein the working fluid can evaporate at a first end of the heat pipe and condense at a second end of the heat pipe adjacent to a heat exchanger, and wherein the wick can return condensed working fluid to the first end of the heat pipe.

Nuclear reactor systems and associated devices and methods are described herein. A representative nuclear reactor system includes a heat pipe network having an evaporator region, an adiabatic region, and a condenser region. The heat pipe network can define a plurality of flow paths having an increasing cross-sectional flow area in a direction from the evaporator region toward the condenser region. The system can further include nuclear fuel thermally coupled to at least a portion of the evaporator region. The heat pipe network is positioned to transfer heat received from the fuel at the evaporator region, to the condenser region. The system can further include one or more heat exchangers thermally coupled to the evaporator region for transporting the heat out of the system for use in one or more processes, such as generating electricity.

A heat exchanger. The heat exchanger comprises a plurality of primary fluid tubes configured to carry a primary fluid, a plurality of secondary fluid tubes configured to carry a secondary fluid, and a plurality of intervening layers, each intervening layer being thermally conductive and impermeable to both the primary and secondary fluids. Each intervening layer has one or more of the primary fluid tubes on a first side, and one or more of the secondary fluid tubes on a second side opposite the first side, such that the region between each pair of neighbouring intervening layers contains either primary fluid tubes or secondary fluid tubes, but not both primary and secondary fluid tubes.

A heat transfer module can include an envelope sealed to define an internal volume that contains a working fluid and a wick disposed on an internal surface of the envelope. The wick and envelope each has a first portion extending through an evaporator region and a second portion extending through adiabatic and condenser regions. The first portion of the wick is a metal hydride. The first portion of the envelope includes a metal liner surrounding the first portion of the wick, a first diffusion barrier layer disposed between the first portion of the wick and the metal liner, and a ceramic matrix composite cladding surrounding the metal liner. The second portions of the wick and envelope each includes a refractory metal and/or stainless steel.