Abstract: In a heat exchanger, each of a plurality of heat exchange members includes: a flat pipe; and a heat transfer plate integrated with the flat pipe along a longitudinal direction of the flat pipe. A width direction of each of the flat pipes intersects with a direction in which the plurality of heat exchange members are arranged side by side. Each of the heat transfer plates includes an extending portion extending outward in the width direction of each of the flat pipes from at least one of one end of a corresponding one of the flat pipes in the width direction and another end of the corresponding one of the flat pipes in the width direction. Each of the flat pipes has one or more flat pipe bent portions, each forming a groove extending along the longitudinal direction of the flat pipes.

Abstract: Device for heat transfer between a first fluid and one second fluid includes a housing with first housing element, second housing element and heat transfer element. Housing is developed with a first connecting fitting and a second connecting fitting for each fluid. Heat transfer element is disposed in a volume completely enclosed in a housing and is developed for through-conduction of the first fluid. Housing is developed for conduction of the second fluid about the heat transfer element. Connecting fittings for second fluid are either disposed on the first housing element and the connecting fittings for the first fluid are disposed on the second housing element, wherein within the second housing at least one flow path for conducting the first fluid is implemented which extends between a connecting fitting and a collector region or the connecting fittings for the fluids are disposed on the first housing element.

Abstract: There is provided a helmet engageable with a human head portion. The helmet includes an inner shell, an outer shell and a shock absorbing layer. The shock absorbing layer is located between the inner shell and the outer shell, include at least one 3D structure and is defined by a plurality of interconnected 5 surfaces with a plurality of openings defined inbetween. A designing process is provided, including steps of providing a virtual inner shell model and outer shell model of the virtual helmet model, positioning virtual curves on the virtual inner shell/outer shell model, and generating virtual minimal surfaces. A manufacturing process is 10 further provided, including steps of conceiving the virtual helmet model using at least some steps of the designing process and additive manufacturing at least a portion of the helmet.

Abstract: A method for manufacturing an annular heat exchanger intended to be mounted on the radially inner or outer face of an annular shell of a casing of a double-flow turbomachine, the method including: obtaining by extrusion a heat exchanger preform by a die shaped so that the preform includes: first pipes for the circulation of a fluid to be cooled, second pipes arranged on either side of the first pipes in a direction perpendicular to the direction of extrusion; making a hole from the outside in the preform, the hole leading into one of the second pipes of the preform; and introducing into the hole of the second given pipe a member for partially closing off its passage cross-section.

Abstract: Aspects of the disclosure are directed to methods and/or apparatuses involving one or more of a conductive polymer, deposition of a conductive polymer and 3D (three-dimensional) printing of a continuous bead of material. As may be implemented in accordance with one or more embodiments characterized herein, a 3D structure is formed as follows. A stacked layer is formed by depositing a continuous bead of material along an uninterrupted path that defines a first layer of the 3D structure. A sidewall of the 3D structure is formed with opposing surfaces respectively defined by successive stacked layers of the 3D structure by, for each stacked layer (including the first layer), depositing the continuous bead of material along the path and with a surface thereof in contact with a surface of the continuous bead of material of an adjacent one of the stacked layers.

Abstract: In a refrigeration cycle apparatus, each set of air heat exchangers among plural sets of air heat exchangers is one set of one or more of single heat exchangers, and the single heat exchangers each have an upper header pipe, a lower header pipe, a heat transfer tube, and a fin. During a cooling operation, a series refrigerant flow path is formed in which refrigerant flows in series through each set of the air heat exchangers; in the series refrigerant flow path, the refrigerant flows downward from above through the heat transfer tubes that all single heat exchangers have. During a heating operation, a parallel refrigerant flow path is formed in which the refrigerant flows in parallel through each set of the air heat exchangers; in the parallel refrigerant flow path, the refrigerant flows upward from below through the heat transfer tubes that all single heat exchangers have.

Abstract: A modular heat exchanger for battery thermal management having a plurality of similarly constructed heat exchange elements affixed to a cover plate and fluidly coupled with one another via a single external manifold structure that functions as both an inlet manifold and an outlet manifold for each of the heat exchange elements. Rigidity is improved with alternating tabs or overlapping tabs between adjacent elements, and/or side edges between adjacent elements having cutouts for receiving stiffening ribs formed in the cover plate. The external manifold structure provides additional stiffening for the interconnected heat exchange elements.

Abstract: An electric heating device may heat an air flow through a duct of a ventilation, heating and/or air-conditioning installation of an automotive vehicle. The heating device may include at least one heating module that is contained in a heating body. The heating body may include a housing for controlling and supplying electrical power to the at least one heating module. The housing may include, in its interior, a printed circuit board from which a power supply connector and a control connector protrude. The housing may also include a power supply opening such that the power supply connector emerges from the housing and a control opening such that the control connector emerges from the housing. The housing may include a skirt that protrudes in parallel to the control connector on the periphery of the control opening. The skirt may be formed as a single part with the housing.

Abstract: A heat exchanger and methods of manufacturing and assembling a heat exchanger, and more particularly to an air-flow heat exchanger having a mechanically assembled header for use in a motor vehicle. The heat exchanger comprises an all-metal bonded matrix including a plurality of substantially parallel metallic tubes and a plurality of metallic fins. The tubes have a heat transfer portion that is elongate in cross-sectional shape, and which comprises two opposing, longer sides, and two opposing shorter sides. At least one of the tubes is mechanically joined at a first end portion thereof to a first header of the heat exchanger by at least one compliant member. The compliant member extends around the first end portion of the tube to provide a seal and to permit relative movement between the mechanically joined tube and the first header due to thermal expansion and contraction of the matrix.

Abstract: The invention relates to a heat exchanger for motor vehicles, comprising: a core (2) comprising a tube bundle of open ends stacked tubes (3) and comprising a top and a bottom extreme tubes (3a,3b); headers (4,5), each having a shaped flange (4a,5a) with corners (4b,5b) and being connected with open ends of the tubes (3,3a,3b); and side housing parts (6, 7) situated on opposite sides of the core (2) and extending at least partly between the extreme tubes (3a,3b) and between the header (4,5).

Abstract: The heat exchanger (1) has a plurality of heat exchange units (10) stacked in a direction of a gas flow passage of combustion exhaust gas, each of the heat exchange units (10) includes an internal space (14) through which a fluid to be heated flows, a plurality of gas vents (13) penetrating the internal space (14) in a non-communicating state and through which the combustion exhaust gas passes, and an inwardly directed step portion (17) reducing a height of the internal space (14) between adjacent gas vents (13).

Abstract: An apparatus and methods are provided for finless heat exchanger cores. A heat exchanger core includes an inlet header and an outlet header. The heat exchanger core also includes one or more curved channel frames disposed at least partially between the inlet header and the outlet header. The one or more curved channel frames have a first end and a second end, and one or more fluid passageways that direct flow of a first fluid in a first direction therethrough from the first end to the second end. In some embodiments, at least one of the one or more curved channel frames includes a rounded leading edge and a tapered trailing edge.

Abstract: In a featured embodiment, a heat exchanger includes a plate including a plate portion having outer walls. A plurality of internal passages extend between end portions. A ratio between an outer wall cross-sectional thickness at one of the end portions and a cross-sectional wall thickness of the outer wall within the plate portion is greater than 2.5 and no more than 10. An inlet manifold is attached to the inlet end. An outlet manifold is attached to the outlet end.

Abstract: A one-piece heat exchanger manufactured using an additive manufacturing process is described. The heat exchanger includes a plurality of channels formed therein. At least some of the plurality of channels may be configured to provide structural support to the heat exchanger to reduce its weight. Different coolant media may be used in a first set and a second set of the plurality of channels to provide different types of cooling in an integrated one-piece heat exchanger structure.

Abstract: A heat exchanger plate having a planar plate having an inlet and outlet proximate to a first edge of the heat exchanger plate. The planar plate having a plurality of ribs and a plurality of channels, with the plurality of channels being in a plane different from the planar plate. The plurality of channels being in fluid communication from the inlet to the outlet permitting fluid flow from the inlet to the outlet. A protrusion coupled to the planar plate proximate to the first edge of the heat exchanger plate and laterally extending from an axis, with the heat exchanger plate being susceptible to bending about the axis.

Abstract: An automotive heat exchanger (10) has a heat exchanger core (12) including a header part (16) with a plurality of heat transfer tubes (38) and a head tank (20) with an opening receives end portions of the heat transfer tubes (38). A plastic header plate (18) is secured with the header tank (20) and header part (16). The header plate (18) includes a plurality of apertures (24) extending through the plate (18) that enable fluid passage. Each aperture (24) includes a cutout portion (28) that receives an end of a heat transfer tube (38). The cutout portion (28) has a complimentary shape to mate with the end of the heat transfer tube (30). A seal (50), in the cutout portion (28), seals the end of the heat transfer tube (28) with the header plate (18).

Abstract: A heat transfer device includes a base and a heat sink coupled to the base. The heat sink includes a fin with a surface for receiving a cooling medium to travel across, thereby defining an upstream end and a downstream end for the fin. An airflow projection is coupled to the surface of the fin, in which the airflow projection includes an upstream end and a downstream end with the downstream end of the airflow projection cantilevered above the surface of the fin.

Abstract: A stacking-type header according to the present invention includes: a first plate-shaped unit; and a second plate-shaped unit stacked on the first plate-shaped unit, and having a distribution flow passage, in which the distribution flow passage includes a branching flow passage including: a first flow passage; and a second flow passage, and in which the branching flow passage is smaller in difference in flow resistance between the first flow passage and the second flow passage than a branching flow passage in a state in which a flow-passage resistance in the first flow passage and a flow-passage resistance in the second flow passage are equal to each other, and in a state in which the first flow passage and the second flow passage are point symmetric with each other about the opening port.

Abstract: A plate-type heat exchanger may include a housing. The housing may include a plurality of rectangular plate-like components that are box-like components each having the same shape and having a standing wall section along a peripheral edge. One of the box-like components may be layered on another components reversed in the horizontal direction to form a layered structure having an upper layer component and a lower layer component such that an upper portion of a standing wall section of the lower layer component of the layered structure is fit into a lower portion of a standing wall section of the upper layer component of the layered structure. The angle (?) of the standing wall sections may be ??30°, and at least a portion of a contact region between the upper portion and the lower portion may be joined by solid phase diffusion bonding.

Abstract: The invention relates to a plate heat exchanger (9) with a plurality of heat exchanger plates (1, 13), each comprising at least one section showing indentations (2, 3, 14, 15), intended to be placed against corresponding indentations (2, 3, 14, 15) of a heat exchanger plate (1, 13) of a corresponding design. The heat exchanger (9) has a first type of indentations (2, 14) and a second type of indentations (3, 15), wherein the number of said first type of indentations (2, 14) and said second type of indentations (3, 15) are differing.

Abstract: A heat exchanger assembly has a front portion, a middle portion rearward of the front portion, a rear portion rearward of the middle portion, a top part and a bottom part disposed below the top part. At least one of the front and rear portions is curved from the middle portion. The at least one of the front and rear portions extends below the middle portion. The bottom part is joined to the top part. At least one of the top and bottom parts defines a recess. The top and bottom parts define therebetween a passage formed in part by the recess. A width of the passage varies along a length of the heat exchanger assembly. The passage has an inlet and an outlet. A snowmobile with a heat exchanger assembly and a method of manufacturing a heat exchanger assembly are also disclosed.

Abstract: A heat exchanger having at least one collecting tank with a plurality of tube openings and with a tube bundle of tubes, whereby the ends of the tubes engage in openings of the collecting tank, whereby the tubes have a broad side with the length L with opposite tube side walls and two narrow sides at the ends with the width B each with a tube wall arc, whereby the tube wall arc has a diameter that is greater than the distance of the opposite tube side walls.

Abstract: A heat exchanger (1) for tempering of an object (7), in particular of an electric energy reservoir (8), has two components (2, 3), which are interconnected and delimit at least in part a flow compartment (17) for the flow of a tempering fluid. Furthermore, at least one of the components (2, 3) is produced from a composite fiber plastic. Improved handling and/or a more compact design is obtained in that at least one of the components (2, 3) has a depression (9) in which a functional element can be at least partially accommodated.

Abstract: Methods, apparatus, and systems for improving and/or simplifying one or more seals in a fuel cell stack, such as a vehicle fuel cell stack. In some implementations, a plate or assembly for the stack may be extruded through an extrusion die so as to create a plate comprising a top surface, a bottom surface, and a plurality of cavities disposed between the top and bottom surfaces. At least a subset of the cavities may be filled with a cavity-filler material distinct from a material used to form the plate, such as a foam material. One or more headers, such as grommet seals, may then be overmolded into the plate to form corresponding conduits between the top surface and the bottom surface of the plate/assembly.

Abstract: A bracket for mounting a heat exchanger to a mounting structure. The bracket includes a heat exchanger engagement portion having a heat-shrink material configured to contract and shrink onto a portion of the heat exchanger when heated to secure the heat exchanger engagement portion to the heat exchanger. A mounting portion extends from the heat exchanger engagement portion and is configured to be affixed to the mounting structure to rigidly mount the heat exchanger.

Abstract: A flat tube for a header-plateless heat exchanger has an inner plate and an outer plate that are each press-molded from a metal plate and are curved/folded into a groove shape comprising a groove bottom section and two side wall sections. Both plates are such that the outer plate is fitted to the outside of the inner plate in a manner such that the groove bottom sections oppose each other, and an expanded opening in the thickness direction is formed at both ends of the plates.

Abstract: A heat exchanger can include a core, a first tank, and a set of guide members. The core can include a first end member, a second end member, and a plurality of tubes that can extend longitudinally between the first and second end members. The first tank can be fixedly coupled to the first end member. The first tank and first end member can define a first chamber that can be in fluid communication with a first port of the first tank and a first end of the tubes. The set of guide members can be coupled to the first end member. The set of guide members can cooperate to define a plurality of first funnels. A narrow end of each first funnel can be open to an individual one of the tubes. A wide end of each first funnel can be open to the first chamber.

Abstract: A gearbox and a method for additively manufacturing the gearbox are provided. The gearbox includes a housing having an integral heat exchanger additively manufactured within the housing. The heat exchanger includes a plurality of heat exchange passageways for transferring heat between two or more fluids. The heat exchanger is defined at any suitable location or locations within the housing, for example, within voids defined between the walls of the housing and components housed within housing, such as driveshafts, gears, bearings, etc.

Abstract: A heat exchanger including a stacking block, including: a first plate surface; a second plate surface opposite to the first plate surface; and first and second flow path plates including respective plural first and second through holes that have a standard shape. The first through holes are arranged to line up in a standard array pattern in a first direction in which a first flow path causes a first fluid to flow. The second through holes are arranged in the first direction in the same standard array pattern as the first through holes. Each of the first through holes have an area with a same overlap with the second through holes positioned on both sides of the first through holes, in the first direction. The first flow path is formed by the first and second through holes being mutually joined in the first direction, in the areas of overlap.

Abstract: The invention concerns a header (10) for a heat exchanger of a motor vehicle, configured to receive heat exchange tubes (12). The header comprises: a metal plate (18) through which the tubes (12) pass and which has two longitudinal edges (26) for crimping of the header (10) to a header box (16), and a plate (22) comprising a polymer material placed above the metal plate (18) and provided with openings (42) for receiving the tubes (12).

Abstract: A heat exchanger and a method for additively manufacturing the heat exchanger are provided. The heat exchanger includes a plurality of fluid passageways that are formed by additive manufacturing methods which enable the formation of fluid passageways that are smaller in size, that have thinner walls, and that have complex and intricate heat exchanger features that were not possible using prior manufacturing methods. For example, the fluid passageways may be curvilinear and may include heat exchanging fins that are less than 0.01 inches thick and formed at a fin density of more than four heat exchanging fins per centimeter. In addition, the heat exchanging fins may be angled with respect to the walls of the fluid passageways and adjacent fins may be offset relative to each other.

Abstract: A method is provided to vaporize a working fluid using a heat sourcing fluid. A first portion of the heat sourcing fluid passes through the first section, in counter-flow with the working fluid. A second portion of the heat sourcing fluid passes through the second section, in co-flow with the working fluid. Both the first and second portions pass through the third section, in overall counter-flow with the working fluid. The working fluid passes sequentially through the third section, the first section, and the second section. The method may be used in a Rankine cycle for waste heat recovery or in a refrigerant cycle.

Abstract: A tube (13) has a container of phase change material M for a heat exchange bundle (3) of a heat exchanger (1) of an air conditioning system of a passenger compartment of a vehicle. The tube (13) includes a first plate (15) configured to form a first outer surface (17) of the tube (13), a second plate (19) configured to be sealingly assembled with the first plate (15) and to form a second outer surface (21) opposite the first outer surface (17), and an intermediate plate (23) configured to be sealingly assembled with the first and second plates (15, 19), between the latter, and to define on either sides thereof at least one channel (9) for the flow of a coolant F into the bundle (3) and at least one recess (25) for the phase change material M. The invention also relates to a heat exchange bundle and to a method for assembling a heat exchanger including the tube (13).

Abstract: A heat exchanger according to the present invention includes a heat exchanging unit, and a distributing and joining unit connected to the heat exchanging unit and including a distributing flow passage and a joining flow passage. The distributing and joining unit separately includes a first header including the distributing flow passage formed therein and excluding the joining flow passage, and a second header juxtaposed to the first header and including the joining flow passage formed therein and excluding the distributing flow passage. At least one of the first header and the second header is a stacking type header including a plurality of plate-like members including partial flow passages formed therein and stacked so that the partial flow passages are communicated with each other to form the distributing flow passage or the joining flow passage.

Abstract: Corrugated fins that have high heat transfer performance and do not cause clogging even in a gaseous environment in which particulate matter such as dust is present have wall surfaces on which are formed alternating parallel ridges and furrows with an angle of inclination of 10-60°. Defining Wh as the height of the ridges and furrows, Wp as the period of the ridges and furrows, Pf as the period of the corrugated fins, and Tf as the thickness of the plate forming the fins, the following conditions hold. Wh?0.3674·Wp+1.893·Tf?0.1584, 0.088<(Wh?Tf)/Pf<0.342, and a·Wp2+b·Wp+c<Wh, where a=0.004·Pf2?0.0696·Pf+0.3642 b=?0.0036·Pf2+0.0625·Pf?0.5752, and c=0.0007·Pf2+0.1041·Pf+0.2333.

Abstract: The invention relates to a plate-type heat exchanger, in particular for motor vehicles, having a plurality of plate pairs for forming first, second and third flow paths, a spatial region for fourth flow paths being formed between adjacent plate pairs, the plate pairs being formed from at least one first plate and a second plate in order to form the first flow paths and the second flow paths between the first and second plates, the third flow paths also being formed between the first plate and the second plate or an attachment plate being placed upon the first and/or the second plate in order to form the third flow path between the first plate and the attachment plate and/or between the second plate and the attachment plate.

Abstract: A gasket comprises an annular gasket portion arranged to enclose a port hole of a heat exchanger plate. An inner edge of the gasket portion defines an area including a reference point coinciding with a center point of a biggest imaginary circle fittable within the area. The area has a form defined by a number of corner points of an imaginary plane geometric figure of which at least one is displaced from an arc of the circle, and the same number of thoroughly curved lines connecting the corner points, wherein a first corner point is a first distance from the reference point, a second one is closest to the first corner point in a clockwise direction and on a second distance from the reference point, and a third one is closest to the first corner point in a counter clockwise direction and on a third distance from the reference point.

Abstract: A plate-type heat exchanger, in particular for motor vehicles, is described which includes plate pairs. In one example, a plate pair includes a first plate and a second plate that form a first flow path and a second flow path between the plates. In this configuration, the first and the second plate are associated with a first attachment plate and a second attachment plate, respectively. A third flow path is formed between the first plate and the second attachment plate and the first flow path is formed between the second plate and the first attachment plate. Alternatively, the third flow path is formed between the first plate and the first attachment plate and the first flow path is formed between the second plate and the second attachment plate. A spatial region for a fourth flow path may also be formed between adjacent plate pairs.

Abstract: An arrangement for storing thermal energy has at least two tunnels (1a, 1b) for holding a fluid. The tunnels (1a, 1b) are connected to each other by at least one channel (2), such that fluid communication is allowed between the tunnels (1a, 1b). Each of the inner tunnel (1a) and the outer tunnel (1b) is configured as a helix, the inner tunnel (1a) forming an inner helix and the outer tunnel (1b) forming an outer helix.

Abstract: The present invention relates to a method and equipment for recovering heat from exhaust gas removed from an industrial process, such as an electrolysis process for the production of aluminum. Heat is recovered by means of an extraction/suction system, where the exhaust gas contains dust and/or particles. The heat is recovered as the exhaust gas being brought into contact with heat-recovery elements. Flow conditions and the design of the heat recovery elements are such that the deposits of the dust and/or particles on the surfaces stated are kept at a stable, limited level. In preferred embodiments, the heat-recovery elements have a circular or an extended, elliptical cross-section and may be equipped with fins or ribs.

Abstract: The invention relates to a flux shield to prevent flux introduction into the tubes of a heat exchanger core while a flux application process, with the flux shield comprising a first part and a second part, with the flux shield being placeable on a heat exchanger core, where the second part is insertable into the first part along an insertion-direction, with the first part forming a guidance element for the second part and with the two parts being translational movable relative to each other along the insertion-direction. The invention relates furthermore to a method for the production of a heat exchanger.

Abstract: In a catalytic reactor including catalyst carriers inserted into a plurality of channels defined by corrugated fins, the corrugated fins include a first corrugated fin, and a second corrugated fin arranged to adjoin the first corrugated fin. When viewed from the first corrugated fin toward the second corrugated fin along the channels, at least a portion of side walls of the second corrugated fin is located between two adjacent ones of side walls of the first corrugated fin at adjoining end faces of the first and second corrugated fins.

Abstract: A plate heat exchanger includes several heat exchanger plates provided beside each other, which form first and second alternating plate interspaces. Every second heat exchanger plate forms a primary plate and every second secondary plate. Each heat exchanger plate extends in an extension plane and includes a heat transfer area and an edge area around the heat transfer area. The heat transfer area includes a corrugation of longitudinally extending ridges and valleys. The ridges have two edge surfaces and a support surface between the edge surfaces, with a first width transversally to the longitudinal direction. The valleys have two edge surfaces and a support surface between the edge surfaces, with a second width transversally to the longitudinal direction. The support surface of valleys of the primary plates slopes relative to the extension plane and the support surface of ridges of the secondary plates slopes relative to the extension plane.

Abstract: A battery cooler includes at least one support plate and at least one structure plate coupled to the at least one support plate. The at least one structure plate includes a flow channel for receiving a fluid therein. A cross-section of the flow channel has a width greater than a height thereof. The flow channel includes a plurality of webs, wherein one of the webs is disposed adjacent another one of the webs in respect of a direction of flow of the fluid, and the webs decrease the cross-section of the flow channel.

Abstract: A cold chassis and method of making a cold chassis for electronic modules featuring the fabrication of individual brazed cooling ribs each including microchannels along the length thereof and a peripheral flange. A set of adjacent ribs are secured together and assembled onto at least one face of a frame member. The rib flanges are sealed (e.g., friction stir welded) with respect to the frame member.

Abstract: A plate-type heat exchanger comprising a plurality of spaced-apart stacked plate pairs, the plate pairs each comprised of first and second plates. The first and second plates each having an elongated central, planar portion surrounded by peripheral edge portions, the peripheral edge portions of the first and second plates being sealably joined together to form a first set of fluid passages in the heat exchanger. The first and second plates are provided with boss portions at respective ends of the plates, one of the boss portions being an elongated boss portion having a first position and a second position for the location of a fluid opening. The first and second heat exchanger plates are identical in structure and can be used to form various heat exchangers using the single plate design.

Abstract: A heat exchange system is provided that may include a first heat exchanger, a second heat exchanger spaced apart from the first heat exchanger, a connection device provided between the first and second heat exchangers to guide refrigerant into the first and second heat exchangers, and one or more connection pipes that couple the connection device to the first and second heat exchangers, the connection pipes including at least one bent portion.

Abstract: The invention relates to a device (1) for separating droplets, which comprises—an outer casing (2), which has a substantially horizontal cylindrical shell (14) and substantially vertical ends (9);—an inlet connection (7) for a substance to be vaporized for leading a substance to be vaporized into the outer casing;?—a plate pack (3) functioning as an evaporator, which is arranged inside the outer casing, in its lower part (23);—an inlet connection (10) and an outlet connection (11) for a heating substance for leading a heating substance into the plate pack and out of it;—a gravitational droplet separator (4), which is arranged inside the outer casing, above the plate pack;—an outlet connection (8) for vaporized substance for leading the vaporized substance out of the outer casing from its upper part (15);—one or more filler units (12a, 12b) arranged between the outer casing (2) and the plate pack (3) for decreasing the liquid volume of the substance to be vaporized inside the outer casing.

Abstract: The device relates to a heat exchanger in which heat transfer between heating water passing through the inside of heat exchanging pipes and combustion gas is efficiently performed. The heat exchanger includes a plurality of heat exchanging pipes, through the inside of each of which heating water passes. The cross-section of each of the heat exchanging pipes has protrusions and recessions alternately arranged in the width direction of the heat exchanging pipe, so as to extend the flow path for the combustion gas passing between the heat exchanging pipes.

Abstract: A heat exchanger assembled from multiple heat exchanging tubes. Each of the multiple heat exchanging tubes is formed as a flattened tube of 0.5 mm in thickness by press work or bending work of a stainless steel plate member having a thickness of 0.1 mm. Each of the multiple heat exchanging tubes is structured to have multiple lines of sequential wave crests and multiple lines of sequential wave troughs formed on each of flattened faces of the heat exchanging tube. The multiple lines of the sequential wave crests and the multiple lines of the sequential wave troughs are arranged to have a preset angle ? relative to a main stream of an air flow. The lines of the sequential wave crests and the lines of the sequential wave troughs are symmetrically folded back about folding lines arranged at a preset interval W along the main stream of the air flow.