According to one embodiment, a heat transport apparatus includes an evaporator, a cooling unit, a channel structure, and a heating mechanism. The evaporator vaporizes a refrigerant by heat generated by a heat-generating element. The cooling unit is provided above the evaporator and cools and condenses the refrigerant vaporized in the evaporator. The channel structure constitutes a channel through which the refrigerant circulates between the evaporator and the cooling unit. The heating mechanism heats the cooling unit and suppresses solidification of the refrigerant at the cooling unit.

A modular plate and shell heat exchanger in which welded pairs of heat transfer plates are placed in the shell in order to transfer heat from a secondary fluid to a primary fluid. The heat transfer plates are removably connected using gaskets to header pipes which are connected to a primary fluid inlet and a primary fluid outlet nozzle. The header pipes are 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 plates for inspection and replacement.

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.

A transition piece for joining heat pipe segments in a joining process is provided. The transition piece comprises a head section, a body section, a tail section and alignment tabs configured to facilitate a rotational alignment of an end of the body section and an end of a heat pipe segment during the joining process. The body section comprises a wick and an outer wall. Each of the alignment tabs comprises an end portion axially extending away from the body section. The body section and the alignment tabs are configured as an integral structure. A method for producing a transition piece of a heat pipe and a method for joining segments of a heat pipe are also provided.

A depressurization and cooling system for steam and/or condensable gases located in a containment. The system contains a steam condenser having an upstream port connected to the containment through an exhaust line and a downstream port connected to the containment through a backfeed line. The backfeed line contains a backfeed compressor. A re-cooling system for re-cooling the steam condenser is provided. The depressurization and cooling system is effective for re-cooling of the steam condenser. Accordingly, this is achieved as the re-cooling system is self-sustainable.

The invention relates to the nuclear energy field, including systems for passive heat removal from the pressurized water reactor through the steam generator. The invention increases heat removal efficiency, coolant flow stability and system reliability. The system includes at least one coolant circulation circuit comprising a steam generator and a section heat exchanger above the steam generator in the cooling water supply tank and connected to the steam generator through the inlet and outlet pipelines. The heat exchanger is divided into parallel sections wherein L/D20, L being the half-section length, D being the header bore, and includes an upper and lower header interconnected by heat-exchange tubes, startup valves with different nominal bores are installed on the outlet pipeline. The inlet and outlet pipeline sections of the circulation circuit comprise a set of branched parallel pipelines individually connected to each of the above heat exchanger sections.

A heat exchanger module having at least two fluid circuits, of longitudinal axis including a stack of plates, defining at least two fluid circuits, at least a part of the plates each including fluid circulation channels, the channels of at least one of the two circuits, referred to as first circuit, having at least one fluid supply and distribution zone for supplying and distributing fluid from outside the stack, forming a fluid pre-header, in which zone the channels are delimited by studs distributed over the surface of the plate; an exchange zone continuous with the pre-header and wherein the channels are each delimited by a groove separated from one another by a rib and extending along the longitudinal axis.

A plate heat exchanger for homogenous fluid flows between ducts includes primary passages and secondary passages. The secondary passages include a first group fluidly connecting a first secondary supply collector to a secondary discharge collector. The first group of secondary passages have a first total passage section at half-length between the first secondary supply collector and the secondary discharge collector. The first group of secondary passages have a second total passage section at the output of the first secondary supply collector of less than 10% of the first total passage section of the first group of secondary passages.

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 is configured to allow for relative translation between the first end tank and the third end tank in the first direction.

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.