Heat-exchanger module with improved heat exchange and compactness, use with liquid metal and gas

Abstract

The invention relates to a heat-exchanger module with a longitudinal axis (X) comprising at least two fluid circuits, the first of which comprises at least one pair of channels ( 1, 2 ) for fluid circulation, each extending parallel to the longitudinal axis (X), wherein the two channels of a single pair are stacked on top of one another and are in communication with one another in a plurality of crossing areas ( 3 ) each defining an area for mixing the fluid with itself inside the first circuit.

1 . A heat-exchanger module with a longitudinal axis comprising at least two fluid circuits, the first fluid circuit comprising, at least one pair of channels for fluid circulation, each extending parallel to the longitudinal axis, wherein the two channels of the same pair are stacked on top of one another and are in communication with one another in a plurality of crossing areas, each defining an area for mixing the fluid with itself in the first circuit. 
     
     
         2 . The heat-exchanger module as claimed in  claim 1 , wherein each channel has at least in part a curved zigzag profile. 
     
     
         3 . The heat-exchanger module as claimed in  claim 2 , wherein the curved zigzag profile is regular along its length. 
     
     
         4 . The heat-exchanger module as claimed in  claim 3 , wherein the regular curved zigzag profile includes bends and straight segments, a straight segment connecting two consecutive bends. 
     
     
         5 . The heat-exchanger module as claimed in  claim 4 , wherein the radius of curvature of the bends being is between 0.5 and 3 Dh inclusive, Dh being the hydraulic diameter of the channel. 
     
     
         6 . The heat-exchanger module as claimed in  claim 4 , wherein the length of the straight segment is between 4 and 8 Dh inclusive, Dh being the hydraulic diameter of the channel. 
     
     
         7 . The heat-exchanger module as claimed in  claim 4 , wherein the angle between the straight segment and the longitudinal axis is between 10 and 45° inclusive. 
     
     
         8 . The heat-exchanger module as claimed in of  claim 2 , wherein the curved zigzag profiles is identical for the two channels and symmetrical to one another with respect to the longitudinal axis or a parallel axis. 
     
     
         9 . The heat-exchanger module as claimed in  claim 1 , wherein the channels have an oval, circular, rectangular or square section. 
     
     
         10 . The heat-exchanger module as claimed in  claim 1 , wherein the two channels of the same pair join at their longitudinal ends in the same rectilinear channel portion substantially parallel to the longitudinal axis. 
     
     
         11 . The heat-exchanger module as claimed in  claim 1  for two fluids, wherein each of the two fluid circuits includes at least one pair of fluid circulation channels each extending parallel to the longitudinal axis, the two channels of the same pair being stacked on one another and in communication with one another in a plurality of crossing areas each defining an area for mixing the fluid with itself in the first or second circuit. 
     
     
         12 . The heat-exchanger module as claimed in  claim 1  for two fluids, such as a liquid metal (Na) and an inert gas (N2), wherein the first fluid circuit includes at least one pair of fluid circulation channels each extending parallel to the longitudinal axis, the two channels of the same pair being stacked on one another and in communication with one another in a plurality of crossing areas each defining an area for mixing the fluid with itself in the first circuit, the second fluid circuit including at least one pair of channels of straight shape. 
     
     
         13 . A method of producing the heat exchange module as claimed in  claim 1 , comprising the following steps: 
       machining at least one first groove in a first metal plate; 
       machining at least one second groove in a second metal plate; 
       positioning the machined second plate against the machined first plate so that the first and second grooves each delimit a fluid circulation channel each extending parallel to a longitudinal axis, the two channels being stacked on one another and in communication with one another in a plurality of crossing areas each defining an area for mixing the fluid with itself;
 assembling the first and second metal plates with one another, either by hot isostatic pressing (HIP) or by a process commonly called hot uniaxial diffusion welding, so as to produce diffusion welding between them, or by brazing. 
 
     
     
         14 . A heat exchanger comprising a plurality of heat-exchanger modules as claimed in  claim 1  each extending parallel to the central axis of the enclosure and each arranged inside the enclosure. 
     
     
         15 . The use of the heat exchanger as claimed in  claim 14 , the first fluid, as the secondary fluid, being a gas or a mixture of gases and the second fluid, by way of primary fluid, being a liquid metal. 
     
     
         16 . The use of the heat exchanger as claimed in  claim 15 , the first fluid primarily comprising nitrogen and the second fluid being liquid sodium. 
     
     
         17 . The use as claimed in  claim 15 , the first or second fluid coming from a nuclear reactor. 
     
     
         18 . A nuclear installation comprising a fast neutron reactor cooled with liquid metal, notably liquid sodium (FNR-Na or SFR), and a heat exchanger comprising a plurality of heat-exchanger modules as claimed in  claim 1 .