Abstract: Provided is a heat exchanger, which includes a plurality of flat tubes in which refrigerant flows, a fin including tube couplers in which the flat tubes are inserted, wherein the refrigerant exchanges heat with a fluid through the fin, and a header coupled to at least one side portion of the flat tubes and distributing the refrigerant to the flat tubes. The fin includes a first fin coupled to a part of the flat tubes, the part of the flat tubes constituting a first row, and a second fin provided on a side portion of the first fin and coupled to another part of the flat tubes, the another part of the flat tubes constituting a second row.

Abstract: A heat exchanger (such as a radiator) that provides for a consistent tank-to-header joint location. The header generally includes a drafted wall that is movable adjacent to or within a tank and may include a curved fillet to maintain header alignment.

Abstract: A heat exchanger (such as a radiator) that provides for a consistent tank-to-header joint location. The tank generally includes at least two indentations and at least one isolator having a base at least partially disposed in one of the indentations and a coupler extending from the base for coupling the tank to at least one other component of the heat exchanger.

Abstract: According to an embodiment, a heat exchanger is provided with a manifold, a heat exchange unit and a first porous body. The manifold has an inlet for a medium and an outlet for the medium. The heat exchange unit has a channel which communicates with the outlet. The first channel has a cross section of a typical length which is not more than a predetermined constant. The porous body is provided between the inlet and the outlet, and contains a plurality of pores with a mean diameter which is not more than the typical length.

Abstract: A heat exchanger assembly and method of servicing is described and illustrated, and in some embodiments includes a pair of core units in an end-to-end arrangement, and a fluid tank arranged between the core units. Each core unit includes air fins arranged in parallel with one another and spaced apart in a core stacking direction, and parallel arranged fluid conveying tubes located between and bonded to adjacent air fins. The fluid tank includes a first end sealingly attached to a header plate of one core unit and a second end sealingly attached to a header plate of the other core unit. The fluid tank can be crimped to adjacent core units, and can be located entirely within the core stacking direction outermost boundaries of at least one of the core units.

Abstract: A heat exchanger with headering system is provided. The heat exchanger includes a body that extends between first and second headers. The central span of the body includes two sets of channels arranged in a checkerboard pattern to provide efficient heat transfer between heat transfer fluids in each set. End portions of the body, within the headers, include offsets that transition the sets of channels from a linear alignment to the checkerboard pattern. This configuration allows heat exchange fluids to be introduced into the appropriate sets of channels through the headers with less complexity. A method of manufacturing the heat exchanger is also provided.

Abstract: A heat exchanger includes a pair of header tanks and a plurality of heat exchange tubes. The header tank includes the three tank constituting members having laminated portions. Each of the laminated portions is composed of an outer vertical wall portion, an inner vertical wall portion, and an intermediate vertical wall portion. A fillet is formed between an outer surface of the intermediate vertical wall portion with respect to an air-passing direction and an inner surface of the outer vertical wall portion with respect to the air-passing direction. Another fillet is formed between an inner surface of the intermediate vertical wall portion with respect to the air-passing direction and an outer surface of the inner vertical wall portion with respect to the air-passing direction.

Abstract: The invention relates to a heat exchanger (e.g., a charge air cooler) having a cooling body composed of flat tubes arranged at intervals and having corrugated fins positioned in the intervals. The charge air in the flat tubes can be cooled by cooling air flowing through the corrugated fins. The heat exchanger can include a flow connector and an integrated pre-cooler in which a medium, for example charge air, is cooled by means of a coolant. The pre-cooler/post cooler can be integrated into a section of the cooling body. A flow connector composed of at least two tubular parts which can be plugged one into the other, locked and sealed, can include a partitioning wall extending in one of the parts. At least one inlet connection and/or at least one outlet connection can be arranged on one or the other of the parts.

Abstract: A modular panel for a solar boiler includes an inlet header, an outlet header, and a plurality of tubes fluidly connecting the inlet header to the outlet header. The tubes are substantially coplanar with one another forming a solar receiver surface and an opposed internal surface. The panel is modular in terms of height, width, number of tubes, and size of tubes, for improved handling of high heat flux and resultant thermally induced stresses.

Abstract: A heat exchanger having a tube bundle disposed within a housing with a resilient end structure disposed in compressed, plug-forming relation at least partially across the heat exchanging cavity. The resilient end structure includes one or more boundary segments extending between an internal wall of the housing and the perimeter of the tube bundle. The boundary segment includes a combination of materials having differing compression characteristics providing enhanced support to the boundary segments.

Abstract: A refrigeration system including a refrigeration circuit that has an evaporator, a compressor, a condenser, and a heat exchanger. The evaporator, compressor, and condenser are fluidly connected and arranged in series with each other. A liquid line fluidly connects the evaporator to the condenser and a suction line fluidly connects the compressor to the evaporator. The heat exchanger includes a plurality of first refrigerant flow tubes that is in fluid communication with one of the suction line and the liquid line, and a second refrigerant flow tube that is in fluid communication with the other of the suction line and the liquid line. Each of the first refrigerant flow tubes and the second refrigerant flow tube have microchannels, and the second refrigerant flow tube positioned between and cooperates with the first refrigerant flow tubes to heat vapor refrigerant flowing in the suction line.

Abstract: A heat exchanger includes an inlet header configured to receive a cooling fluid and an outlet header configured to discharge the cooling fluid. A plurality of microchannel tubes are in fluid communication with and extend between the inlet header and the outlet header. The microchannel tubes define a first heat exchanger region and a second heat exchanger region between the inlet header and the outlet header. The first heat exchanger region has a plurality of fins defining a first fin density that is greater than a second fin density of the second heat exchanger region.

Abstract: A system having a pre-mix burner manifold in a housing that may permit air to be drawn through slots in the housing to flow over an external surface of the manifold. The flow of air may maintain a temperature of the manifold lower than a temperature that the manifold might have without the flow. The manifold may be attached to a burner and heat exchanger.

Abstract: A heat exchanger includes a plurality of heat exchange tubes and corrugated fins. The heat exchange tubes are spaced apart from one another in a vertical direction of the heat exchanger. The corrugated fins are each disposed between adjacent heat exchange tubes. Each of the corrugated fins includes crest portions, trough portions, and connection portions. The crest portions extend in an air passage direction of the heat exchanger. The trough portions extend in the air passage direction. The connection portions connect the crest portions and the trough portions. The number of the crest portions of each of the corrugated fins disposed between adjacent heat exchange tubes falls within a range of a designed number ±2. The designed number is a standard number.

Abstract: A burner system for a furnace. The system may have a wedged or other shaped burner box. An air-fuel mixer may be attached to a smaller end of the burner box at about a right angle relative to a direction of a gas and air mixture leaving the larger box end. A burner head may be attached to the larger end of the box. The burner head may be sufficient for numerous heater sections of a heat exchanger. A spacer and an orifice shield may be situated between the burner head and heat exchanger. A fan may pull in the gas and air mixture from the mixer, through the box and the burner head. The mixture may be ignited into a flame which is pulled into the heat exchanger. Some of the flue gas from the exchanger exhaust may be recirculated by being added with air to the mixer.

Abstract: A sub-cooled condenser for an air conditioning system includes a condenser portion, a sub-cooler portion located below that of the condenser portion, an integral receiver tank having an upper receiver first chamber with a first fluid port in hydraulic connection with the condenser portion and a lower receiver second chamber having a second fluid port in hydraulic connection with the sub-cooler portion, and a refrigerant conduit disposed in the receiver tank. The refrigerant conduit may include a top entry end extending into the upper receiver first chamber and a bottom discharge end extending in the lower receiver second chamber, wherein the bottom discharge end may extend below the second fluid port. The condenser portion may include multiple passes in which the refrigerant flows in an upward direction from the inlet of the condenser portion to the first fluid port that is in hydraulic connection to the upper receiver first chamber.

Abstract: A heat transfer system includes a steam chamber that communicates in an open-loop arrangement with a first steam source for supplying steam to the steam chamber, the steam chamber including a steam exit for supplying steam to air at atmospheric pressure. A heat transfer tube communicates in a closed-loop arrangement with a second steam source for supplying steam to an interior surface of the heat transfer tube, the heat transfer tube vaporizing condensate forming within the heat transfer system back to steam that is supplied to the air via the steam exit. The outer surface of the heat transfer tube is configured to contact the condensate and vaporize the condensate back into steam, wherein the heat transfer tube includes a plurality of pockets formed on the outer surface of the tube, each pocket including a pocket exit/entry portion having a smaller cross-sectional area than the cross-sectional area of the pocket at a root portion thereof adjacent the outer surface of the tube.

Abstract: Systems are disclosed for battery modules with cooling systems. In accordance with disclosed embodiments, the cooling system may be disposed against an external surface of a housing of the battery module. The cooling system may utilize a coolant to remove heat generated by cells within the battery module, to prevent the cells from aging prematurely. Embodiments of the cooling system may include cold plates, tubes, fins, and plates, or a combination thereof, which may route the coolant along the surface of the battery module housing. Such features may create a large effective cooling surface against the battery module housing to promote a high heat transfer rate from the cells to the coolant.

Abstract: A header unit having an improved assembly method of a body and a header and a heat exchanger having the same, capable of preventing a body from being incompletely bonded to a cover at an inner side of the header as a result of the instability of a manufacturing process, and thus capable of preventing the leaking of the refrigerant in between two tanks at an inside of the header. The heat exchanger includes a body, and a cover coupled to the body, wherein the body includes a base part forming a bottom surface of the body, and a middle partition protrudedly formed from the base part, and the cover includes a coupling groove to which the middle partition of the body is coupled while passing through the coupling groove.

Abstract: Disclosed herein is a once-through evaporator comprising an inlet manifold; one or more inlet headers in fluid communication with the inlet manifold; one or more tube stacks, where each tube stack comprises one or more substantially horizontal evaporator tubes; the one or more tube stacks being in fluid communication with the one or more inlet headers; where one or more tube stacks are used for a start-up of the once-through evaporator; one or more outlet headers in fluid communication with one or more tube stacks; a separator in fluid communication with the one or more outlet headers; a first flow control device in fluid communication with the separator and at least one of the tube stacks used for startup; a second flow control device in fluid communication with a superheater to bypass the separator and at least one of the tube stacks used for startup; and a controller for controlling the actuation of the first and second flow control devices in response to a parameter of the evaporator.

Abstract: A heat exchanger includes a plurality of tubes extending between two tank bodies. At least one tank body includes a crown portion. At least one groove is formed in the crown portion. In order to avoid the creation of a thinner wall section in the crown portion, the inner and outer surfaces that form the groove are offset from each other.

Abstract: A tank body 125 comprising header tanks 120 of a radiator is composed with a polyamide composition containing polyamide 6,10, glass fiber, copper and nucleating agent. At this time, the polyamide composition contains, based on the total weight of the polyamide 6,10, the glass fiber, the copper and the nucleating agent, (a) 48.9 to 79.988 percent by weight of the polyamide 6,10, (b) 20 to 50 percent by weight of the glass fiber, (c) 0.002 to 0.1 percent by weight of the copper, and (d) 0.01 to 1.5 percent by weight of the nucleating agent, and the result of measuring half-crystallization time of the polyamide composition is 5 minutes or less. In addition, the polyamide 6,10 used has a relative viscosity, as measured in 98 percent sulfuric acid, of 2.3 to 2.9.

Abstract: A heat exchanger, such as a condenser or gas cooler, having a collecting tube which has a wall and which can be produced by deformation of a single metal strip, which collecting tube has, in its base, at least one row of openings in which heat exchanger tubes, each of which has two narrow and two wide sides, are fastened at their ends. The collecting tube can have at least two chambers, which adjoin one another approximately at a central longitudinal axis, and also a reinforcement, which is formed by the longitudinal edge strips of the metal strip.

Abstract: Thermal expansion of U-shaped tubes is permitted to prevent damage to it. A heat exchanger includes a casing having a first fluid inlet provided at one end thereof and a first fluid outlet provided at the other end thereof, the first fluid inlet and the first fluid outlet being connected to each other via a first flow path extending in a straight line from the first fluid inlet to the first fluid outlet; and multiple tube sets accommodated inside the casing so that a fluid that flows through the interiors thereof undergoes heat exchange with a fluid that flows via the first flow path. The multiple tube sets are arrayed along the first flow path, and multiple U-shaped tubes constituting the tube sets are fixed only to a tube plate disposed parallel to the first flow path and located at both ends of the U-shaped tubes.

Abstract: An isothermal chemical reactor (1) comprising an array of radially arranged plate-like heat exchange elements (11) inside a reaction space, each element comprising feeding and collecting ducts and a bundle of parallel tubes (15) defining channels (12) for a heat exchange medium, the tubes (15) having an elongated cross section and being disposed with a variable orientation relative to the radial direction of the reactor, so that inner tubes near the axis of the reactor have the cross-section major axis aligned with said radial direction, and outer tubes have the same axis perpendicular to the radial direction. The preferred structure of a plate-like heat exchange element is also disclosed.

Abstract: A liquid-cooled computer memory system includes first and second blocks in fluid communication with a chilled liquid source. A plurality of spaced-apart heat transfer pipes extend along a system board between memory module sockets from the first manifold block to the second manifold block. The heat transfer pipes may be liquid flow pipes circulating the chilled liquid between the memory module sockets. Alternatively, the heat transfer pipes may be closed heat pipes that conduct heat from the memory modules to the liquid-cooled blocks. A separate heat spreader is provided to thermally bridge each memory module to the adjacent heat transfer pipes.

Abstract: A heat exchanger having a plurality of spaced-apart plate pairs, where each plate pair defines a flow passage for the flow of a first fluid. One or more fins are thermally coupled and sandwiched by the spaced-apart plate pairs for flow of a second fluid. A fluid manifold being fluidly coupled to the flow passages of the spaced-apart plate pairs is also provided. The heat exchanger has a front face and side faces defined by at least the plurality of spaced-apart plate pairs and the one or more fins. And, a bypass seal complementary to the front face or one of the side faces and engagingly coupled to the front face or one of the side faces for blocking a gap between the heat exchanger and a housing for receiving the heat exchanger. Also disclosed is a heat exchanger assembly having the heat exchanger disclosed.

Abstract: A heat exchanger 302 comprising: an inlet manifold 304; an outlet manifold 306; and a tube matrix 310 comprising a plurality of tubes 308, each tube 308 being connected at one end to the inlet manifold 304 and at the other end to the outlet manifold 306; wherein each tube extends generally along a longitudinal axis defined between the connection of the tube 308 with the inlet manifold 304 and the connection of the tube 308 with the outlet manifold 306; and wherein a single portion 314 of each tube 308 is offset to one side of the longitudinal axis.

Abstract: A heat exchanger is provided. The heat exchanger may include a plurality of refrigerant tubes extending in a horizontal direction, at least one fin coupled to the plurality of refrigerant tubes, a vertically oriented header coupled to corresponding ends of the plurality of refrigerant tubes, the header distributing refrigerant into the plurality of refrigerant tubes, and a partition device that partitions an inner space of the header, the partition device including at least two through holes that guide refrigerant into the plurality of refrigerant tubes.

Abstract: An installation tool for installation of earth loops includes a cylindrical body with slots in its outer surface, for receiving of tubes of the earth loops, and a central passage extending therethrough from a grout fitting to a central opening at a leading end face of the cylindrical body. An anchor fits over the end face and includes a face plate with tube apertures extending therethrough, a retainer ring which serves to hold the earth loops in place within the slots during insertion of the tool into the borehole, and a pair of flexible plates extending from opposing positions on the retainer ring, approximately in parallel with the longitudinal axis of the cylindrical body.

Abstract: A system capable of providing a liquid purification process using heat regenerating or recovering via heat exchangers (“HEs”). The system, in one embodiment, includes a first set of thermal conductive channels (“TCC”), a second set of TCC, and a third set of TCC. The first set of TCC configured in a first HE is arranged in cylindrical shape which is able to surround or enclose a boiler. A function of TCC is to guide a liquid flow traveling through an HE. The second set of TCC configured in a second HE guides a second liquid flow traveling through the second HE. The third liquid flow such as a cold water stream, for example, flows through the third set of TCC adjacent to the first set of TCC and extracts heat from the first liquid flow such as hot purified water via TCC.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided that include multichannel tube configurations designed to reduce refrigerant pressure drop through a heat exchanger manifold. In certain embodiments, tubes inserted within the manifold adjacent to a refrigerant inlet have non-rectangular or recessed end profiles configured to increase flow area near the inlet, thereby reducing a pressure drop through the manifold. In further embodiments, insertion depths of the tubes within the manifold vary based on distance from the inlet. This configuration may establish a larger flow area adjacent to the inlet, thus reducing the pressure drop and increasing heat exchanger efficiency.

Abstract: Provided are a heat exchanger that does not impede downsizing and removes water in the heat absorbing pipe adequately with a simple configuration even when the reduction in diameter of the heat absorbing pipe is made. A heat exchanger 5 in which heat absorbing pipes 51 are disposed in a multi-tier arrangement within a casing 50 which is the passage of combustion exhaust gas, both pipe ends 511,512 of each of the heat absorbing pipes 51 are connected respectively to two headers 54, 55 provided on a side plate 52 of the casing 50, and water introduced from an external pipe 63 to each of the heat absorbing pipes 51 through the header 54 is heat-exchanged and heated by combustion exhaust gas. The pipe ends 511, 512 of the heat absorbing pipes 51 are arranged at a predetermined vertical interval.

Abstract: Each of front and rear side walls of a first member of a tank main body of each header tank of an evaporator has protrusions provided at longitudinal opposite ends thereof and projecting outward in the vertical direction. Front and rear outward projecting walls of a third member are cut away at the longitudinal opposite ends. The third member has protrusions provided at the longitudinal opposite ends of each of the front and rear side walls. Each protrusion is overlappingly located on the inner side of the corresponding protrusion of the first member, and is brazed thereto. Each engagement claw of each end member has a first portion brazed to the outer surface of the corresponding protrusion of the first member, and a second portion bent inward in the front-rear direction such that it engages with the corresponding protrusion, and its distal end is located inward of the outer surface.

Abstract: Systems and methods for improving heat exchangers by implementing self-energizing seals. In one embodiment, a U-tube heat exchanger includes a shell enclosure, a tube sheet, a closure and a set of tubes welded to the tube sheet. The tube sheet separates first and second chambers from a third chamber in the shell enclosure. The closure seals the first and second chambers. Each tube extends from the first chamber, through the third chamber to the second chamber. The improvement comprises a seal between the shell enclosure and either the closure or the tube sheet. The seal includes conically tapered sealing surfaces on the shell enclosure and closure or tube sheet which form a wedge-shaped gap. A seal ring having surfaces complementary to the sealing surfaces of the shell enclosure and closure or tube sheet is positioned between the sealing surfaces to form a self-energized seal.

Abstract: A manifold profile of a heat exchanger. The manifold profile includes two side walls, a top wall connecting the two side walls, a collecting space enclosed on three sides by the two side walls and the top wall, a receiving opening configured to receive a connection piece, the receiving opening being located on one or more of the two side walls and the top wall.

Abstract: A heat transfer apparatus and related methods are provided. The heat transfer apparatus and related methods more evenly distribute fluid flow in two-phase heat exchange systems by restricting fluid flow to one or more tube.

Abstract: A thermal energy exchanger for a heating, ventilating, and air conditioning system of the present invention includes a plurality of first tubes, a plurality of second tubes disposed downstream of the first tubes, and a plurality of third tubes disposed downstream of the second tubes. At least a portion of at least one of the second tubes includes a phase change material disposed therein and at least a portion of at least one of the third tubes includes a phase change material disposed therein.

Abstract: A heat exchanger assembly includes a first tank having a tube side wall and a first reservoir. A first row of apertures extends through the tube side wall of the first tank. A first mounting block is secured to the first tank and has a first aperture. A second tank has a tube side wall and a second reservoir with a second row of apertures extending through its tube side wall. A second mounting block is secured to the second tank with a second aperture extending therethrough. A flow tube with a plurality of fins is received in the first aperture of the first block and the second aperture of the second block.

Abstract: A brazed aluminum microchannel heat exchanger comprising a stack of alternating tubes and serpentine fins includes an expansion relief feature that accommodates uneven thermal expansion in the heat exchanger. The expansion relief feature provides the heat exchanger with sufficient structural support, at least during assembly, so that components of the heat exchanger can be firmly clamped in compression during a controlled-atmosphere brazing process. In some examples, the expansion relief feature is a gap or sliding engagement between adjacent headers of the heat exchanger. In addition or alternatively, the expansion relief feature comprises one or more slits cut into the serpentine fins after the brazing process, wherein each slit extends generally parallel to the tubes.

Abstract: An heat exchanger assembly and a method of use thereof adapted for transferring heat to or from a fluid to a surrounding environment within an apparatus, such as motor vehicle engines, as it enters and leaves a fluid-handling device. The heat exchanger assembly includes first and second manifolds, multiple cooling tubes and a return tube. The first manifold has inlet holes therein and the second manifold has outlet holes therein. The multiple cooling tubes fluidically interconnect the first and second manifolds and the inlet and outlet holes thereof. The return tube passes through the first and second manifolds to fluidically interconnect opposite ends of the heat exchanger assembly. The return tube has a first end adapted to mount the heat exchanger assembly to the apparatus and an oppositely-disposed second end that protrudes from the second manifold and is adapted to secure the fluid-handling device thereto.

Abstract: Provided is a heat exchanger, heat sink or coldwall having a machined manifold for receiving a plurality of individual, modular micro-channel heat exchanger elements. The manifold further includes a parallel flow network or flow distribution network for distributing a cooling fluid uniformly to all micro-channel heat exchanger elements. Each micro-channel heat exchanger element is individually manufactured and tested prior to integration with the manifold. The design of the micro-channel heat exchanger elements may include a straight fin, a high density fin, lanced offset fin, and perforated offset layers fin configurations.

Abstract: A heat exchanger structure includes a monolithic extrusion and a plurality of headers. The extrusion includes a first end; a second end; a first, smooth side; and a second side with a plurality of smooth portions alternating with a plurality of raised portions defining a plurality of parallel flow passages extending from the first end to the second end; and a plurality of headers connecting the plurality of flow passages to form a flow path.

Abstract: The present disclosure relates to automotive heat exchanger assemblies that may withstand high environmental temperature and pressures conditions. By providing a tube strengthener into the tubes at the areas of highest stress, the heat exchanger assembly may be strengthened so that it is substantially more efficient under typical operating conditions.

Abstract: A heat sink assembly includes a base plate coupled to a first side of an electronic device. A plurality of fins extend from the base plate and are positioned within a housing. The housing includes a first manifold defining a plurality of first passages and a second manifold defining a plurality of second passages in fluid communication with the plurality of first passages. At least one of the plurality of first passages extends between an adjacent pair of the plurality of second passages and is oriented to channel fluid toward at least one of the plurality of fins.

Abstract: The thermal efficiency of a heat exchanger which is disposed on a blowing path in a vehicle interior and operates as a condenser is enhanced.

Abstract: A fluid flow diverter is provided in a standard rectangular header of a keel cooler for optimizing the coolant flow towards both the interior tubes and also towards the exterior tubes of the keel cooler. The improvement enhances the internal coolant flow and subsequent heat transfer efficiency similar to what has been realized with a non-rectangular header, for example, a header with a beveled wall.

Abstract: A header tank for a heat exchanger for supplying a heat exchange fluid to a core unit in which a plurality of tubes are provided side by side includes an inlet part for introducing the heat exchange fluid into the header tank, and a plurality of ribs projecting into the header tank, extending in directions intersecting with a central axis direction of the inlet part, arranged side by side in the central axis direction and configured to cause the heat exchange fluid to flow into the tubes. The plurality of ribs project more into the header tank with increasing distance from the inlet part.

Abstract: A heat exchange device includes a heat exchanger having a plurality of heat transfer tubes through which a refrigerant is circulated and functioning as an evaporator, a plurality of communication tubes connected to ends of the heat transfer tubes on the refrigerant discharge side, and a header connected to ends of the plurality of communication tubes on the refrigerant discharge side, the header for joining the refrigerant discharged from the communication tubes. At least a part of the plurality of communication tubes includes a flow passage enlargement communication tube formed in such a manner that a flow passage sectional area on the side of the header is larger than a flow passage sectional area on the side of the heat transfer tubes.

Abstract: The present invention relates to a heat exchanger header, wherein said header includes a lower portion (3) having two longitudinal edges (7), an upper portion (4) forming a cover, and at least one flange (9, 10, 30). According to the invention, said flange (9, 10, 30) has a profile (11, 17, 37) that enables the longitudinal edges (7) of the header, which are provided at least locally folded, to be received at the flanks (12, 19, 38) thereof, so as to simultaneously crimp the flange (9, 10, 30) onto said cover (4) and retain the cover (4) on said lower portion (3).