Heat exchange element

Abstract

Provided is a heat exchange element (100) in which partition films (1) and rib frames (2A, 2B) are layered alternately, wherein: each rib frame (2A, 2B) has a plurality of air passage rib frames (7A, 7B) that are in contact with each of the two partition films (1) that sandwich the rib frame (2A, 2B); air flow openings (6A, 6B) through which processing air passes are formed in at least two non-adjacent side portions of the outer periphery of the rib frame (2A, 2B); the air passage rib frames (7A, 7B) comprise a plurality of airflow distribution ribs each having one end disposed in the airflow opening (6A, 6B), and a plurality of airflow opposing ribs that connect, either directly or through a lateral bridge rib, the other ends of two of the airflow distribution ribs having one end disposed in different airflow openings (6A, 6B); and at least one of the airflow opposing ribs has a length in an airflow direction that is shorter than the length of an outer frame rib installed in parallel, and that is different from the length of another adjacent airflow opposing rib.

Description

Heat Exchange Element

[0001] The present disclosure relates to a heat exchange element for exchanging at least one of sensible heat and latent heat between two air streams.

[0002] In order to reduce the power load of air conditioners and other equipment, ventilation systems are equipped with heat exchange elements that exchange heat between "exhaust air," which is air discharged outdoors, and "supply air," which is air supplied indoors. Heat exchange elements are generally classified into sensible heat exchange elements, which exchange only sensible heat, and total heat exchange elements, which exchange both sensible and latent heat. Total heat exchange elements use a paper or resin partition membrane, which selectively allows only water vapor in the air to pass through, as a member separating the supply air and the exhaust air, and sensible heat and latent heat are exchanged through the partition membrane. Sensible heat exchange elements use a partition membrane, which does not allow water vapor in the air to pass through, as a member separating the supply air and the exhaust air, and sensible heat is exchanged through the partition membrane.

[0003] Heat exchange elements are broadly divided into two types: AC heat exchange elements and counterflow heat exchange elements, depending on the material of the partition membrane and the structure of the components that hold the partition membrane. AC heat exchange elements have an air path structure in which the supply air and the exhaust air flow crosswise across the entire heat exchange element via the partition membrane. Counterflow heat exchange elements have an air path structure in which the supply air and the exhaust air flow opposite each other via the partition membrane at the center of the heat exchange element. In general, the amount of sensible heat and latent heat exchanged per unit area of ​​a heat exchange element is greater in counterflow heat exchange elements than in AC heat exchange elements.

[0004] Counterflow type total heat exchange elements are generally constructed in the shape of a polygonal pillar with an even number of corners (6 or more) by alternately stacking ribbed frames that maintain the airflow paths for the intake and exhaust air and partition membranes. Counterflow type total heat exchange elements consist of two regions: a header section that introduces airflow into the element, and a counterflow section that exchanges sensible and latent heat between the intake air and the exhaust air with high efficiency.

[0005] Counterflow heat exchange elements installed in ventilation systems are required to reduce pressure loss and improve heat exchange efficiency. For example, the total heat exchange element disclosed in Patent Document 1 is constructed by alternately stacking a rib frame including air passage ribs constructed by combining plastic hollow boards of different shapes and partition membranes. In this configuration, pressure loss is reduced by using the hollow portions of the air passage ribs made of the plastic hollow boards as air passages.

[0006] JP 2012-13728 A

[0007] However, at the connection between the header section and the counterflow section, there is a region where the air path shape changes suddenly, such as where the cross-sectional area of ​​the air path changes suddenly or the air path bends. Generally, at locations where the air path shape changes suddenly, separation vortices that become water-stopping areas in the flow are generated. Therefore, in conventional counterflow type total heat exchange elements, if the apex angle of the header section is increased to expand the area of ​​the counterflow section, the separation vortex area at the connection between the header section and the counterflow section increases, resulting in increased static pressure loss. Also, there was a problem that the heat exchange efficiency decreases as the water-stopping area increases due to the generation of separation vortices.

[0008] The present disclosure has been made in consideration of the above, and aims to obtain a heat exchange element that suppresses an increase in static pressure loss at the connection point between the header section and the counterflow section, thereby improving heat exchange efficiency.

[0009] In order to solve the above-mentioned problems and achieve the object, the present disclosure provides a heat exchange element in which thin partition membranes and rib frames that maintain the spacing between the partition membranes are alternately stacked to form an intake air passage through which supply air flows and an exhaust air passage through which exhaust air flows independently between the partition membranes and the rib frames, and heat exchange between the supply air and the exhaust air is performed via the partition membranes, wherein the outer shapes of the partition membranes and the rib frames are each a polygon with at least 6 sides. The rib frame has outer frame ribs that maintain the outer periphery of the partition membranes, a plurality of air passage rib frames that contact each of the two partition membranes that sandwich the rib frame, and a plurality of cross ribs that are not in contact with at least one of the two partition membranes that sandwich the rib frame and connect the plurality of air passage rib frames to the outer frame ribs, and air flow openings through which process air passes are formed on at least two non-adjacent sides of the outer periphery of the rib frame. The air passage rib frame includes a plurality of airflow distribution ribs, one end of which is arranged at the airflow opening, and a plurality of airflow opposing ribs, one end of which is arranged at different airflow openings, and the other end of each of the two airflow distribution ribs is connected directly or via a crossover rib. The airflow opposing ribs are arranged parallel to an outer frame rib that is arranged on the outer periphery of the partition membrane along the side that is not arranged at the airflow opening. At least one of the airflow opposing ribs has a length in the airflow direction that is shorter than that of the outer frame rib that is arranged parallel to it and that is different from that of the other adjacent airflow opposing ribs.

[0010] The heat exchange element according to the present disclosure has the advantage of being able to suppress an increase in static pressure loss at the connection point between the header section and the counterflow section, thereby improving heat exchange efficiency.

[0011] FIG. 1 is a diagram showing the installation state of a heat exchange element according to embodiment 1; FIG. 2 is an external view of a heat exchange element according to embodiment 1; FIG. 3 is an exploded perspective view of a heat exchange element according to embodiment 1; FIG. 4 is a diagram showing the configuration of a first partition unit of a heat exchange element according to embodiment 1; FIG. 5 is a diagram showing the configuration of a second partition unit of a heat exchange element according to embodiment 1; FIG. 1 shows the configuration of the partition unit of the heat exchange element according to embodiment 2. FIG. 1 shows the configuration of the second partition unit of the heat exchange element according to embodiment 2. FIG. 2 shows a cross-sectional view along the airflow-facing auxiliary rib of the heat exchange element according to embodiment 2. FIG. 3 shows the flow of intake air and exhaust air currents inside the heat exchange element according to embodiment 2. FIG. 4 shows the installation state of the heat exchange element according to embodiment 3. FIG. 5 shows a side view of the heat exchange element according to embodiment 3, viewed from the stacking direction of the heat exchange element. FIG. 6 shows the configuration of the first partition unit of the heat exchange element according to embodiment 3. FIG. 7 shows the configuration of the second partition unit of the heat exchange element according to embodiment 3. FIG. 8 shows the flow of intake air and exhaust air currents inside the heat exchange element according to embodiment 3.

[0012] Hereinafter, a heat exchange element according to an embodiment will be described in detail with reference to the drawings.

[0013] Embodiment 1. Figure 1 is a diagram showing the installation state of a heat exchange element according to embodiment 1. The heat exchange element 100 according to embodiment 1 is a polygonal prism having an even number of corners (six or more). The heat exchange element 100 is arranged along an air supply / exhaust partition member 102 installed inside an air conditioner housing 101. Here, we will take as an example a heat exchange element 100 that is a counterflow type total heat exchange element in the shape of a hexagonal prism with a typical apex angle 108 of 120 degrees.

[0014] Fig. 2 is an external view of the heat exchange element according to embodiment 1. An airflow of supply air 103 and an airflow of exhaust air 104 pass through heat exchange element 100. The solid arrow in Fig. 2 indicates the flow direction of the airflow of supply air 103, and the dashed arrow in Fig. 2 indicates the flow direction of the airflow of exhaust air 104.

[0015] FIG. 3 is an exploded perspective view of a heat exchange element according to the first embodiment. FIG. 4 is a diagram illustrating the configuration of a first partition unit of the heat exchange element according to the first embodiment. FIG. 5 is a diagram illustrating the configuration of a second partition unit of the heat exchange element according to the first embodiment. The heat exchange element 100 is configured in a columnar shape by alternately stacking partition membranes 1 each having a hexagonal outer shape and rib frames 2 each having a hexagonal outer shape. Cover frames 11 are installed at the upper and lower ends of the stacked partition membranes 1 and rib frames 2. Here, the stacking direction of the partition membranes 1 and rib frames 2 is defined as the Z direction. The direction perpendicular to the Z direction and parallel to one side of the outer shapes of the partition membranes 1 and rib frames 2 is defined as the X direction. The direction perpendicular to both the X direction and the Z direction is defined as the Y direction.

[0016] The partition membrane 1 is a thin plate having a thickness of 0.2 mm or less. The partition membrane 1 has high moisture permeability and low air permeability due to a resin film coating on a substrate such as paper, nonwoven fabric, or porous material.

[0017] The rib frame 2 is made of a plastic resin such as polypropylene, or a light metal such as aluminum. The rib frame 2 has a point-symmetric shape with the center of the outer shape in the XY plane as the center of symmetry. Hereinafter, to distinguish the stacking direction of the rib frame 2, it will be referred to as rib frame 2A and rib frame 2B. Note that when simply referring to the rib frame 2, it will refer to both the rib frame 2A and the rib frame 2B. Furthermore, when describing the components of the rib frame 2, a reference numeral with an "A" suffix indicates the component of the rib frame 2A, and a reference numeral with an "B" suffix indicates the component of the rib frame 2B. The rib frames 2A and 2B have a mirror-symmetric structure with the YZ plane passing through the center of the outer shape in the XY plane as the plane of symmetry.

[0018] At least two sides of the periphery of the rib frames 2A, 2B are provided with air flow openings 6A, 6B, which are openings through which the supply air 103 and the exhaust air 104 pass to the inside and outside of the heat exchange element 100. In this embodiment, the air flow openings 6A, 6B are provided on opposing sides of the rib frames 2A, 2B.

[0019] Fig. 4 is a diagram showing the configuration of a first partition unit of a heat exchange element according to embodiment 1. Fig. 5 is a diagram showing the configuration of a second partition unit of a heat exchange element according to embodiment 1. The heat exchange element 100 has a structure in which first partition units each consisting of a partition membrane 1 and a rib frame 2A and second partition units each consisting of a partition membrane 1 and a rib frame 2B are alternately stacked. Note that the illustrated rib frame 2 shows an example of a point-symmetric shape with the center of the outer shape in the XY plane as the center of symmetry, and the rib frame 2 may have a shape different from the illustrated shape.

[0020] 4, the rib frame 2A is composed of an outer frame rib 5A for maintaining the structure and strength of the heat exchange element 100, at least one air passage rib frame 7A that forms an airflow passage inside the heat exchange element 100, and at least one horizontal rib 8A for supporting the air passage rib frame 7A. The air passage rib frame 7A contacts each of the two partition membranes 1 that sandwich the rib frame 2A. Air flow openings 6A are formed on two non-adjacent sides of the outer periphery of the rib frame 2A, through which supply air 103, which is the process air, passes.

[0021] 5, the rib frame 2B is composed of an outer frame rib 5B for maintaining the structure and strength of the heat exchange element 100, at least one air passage rib frame 7B that forms an airflow passage inside the heat exchange element 100, and at least one cross rib 8B for supporting the air passage rib frame 7B. The air passage rib frame 7B contacts each of the two partition membranes 1 that sandwich the rib frame 2B. Air flow openings 6B are formed on two non-adjacent sides of the outer periphery of the rib frame 2B, through which exhaust air 104, which is the process air, passes.

[0022] A plurality of through holes 106 for determining the stacking position are provided on the outer periphery of the rib frame 2A, the rib frame 2B, and the partition membrane 1. Note that, although the rib frames 2A and 2B having a structure with through holes 106 are given here as an example, as long as the stacking position can be determined, the structure is not limited to holes and may have positioning notches. As shown in Figure 3, the partition membrane 1 is installed sandwiched between the rib frame 2A and the rib frame 2B.

[0023] As shown in Figure 3, supply air 103 flows through supply air duct 3, which is a space formed by two partition membranes 1 sandwiching rib frame 2A, and exhaust air 104 flows through exhaust air duct 4, which is a space formed by two partition membranes 1 sandwiching rib frame 2B, and they pass through the heat exchange element 100 without mixing with each other. For example, in a residential air treatment device, supply air 103 is an air flow supplied from the outside to the inside of the room, and exhaust air 104 is an air flow exhausted from the inside to the outside of the room. As shown in Figure 2, the air flow of supply air 103 and the air flow of exhaust air 104 flow in opposite directions at the center of heat exchange element 100 via partition membrane 1.

[0024] The Z-direction surfaces of the outer frame ribs 5A, 5B are formed with a plurality of uneven portions 105 for positioning the alternately stacked rib frames 2A and 2B, and for holding the partition membrane 1 and preventing slippage. Furthermore, the Z-direction surfaces, which are the stacking direction of the outer frame ribs 5A, 5B, are formed with a plurality of through holes 106 for passing members for fixing the rib frame 2. Note that the shapes of the uneven portions 105 and through holes 106 shown in this embodiment are merely examples, and the number and shape are not limited as long as the positioning of the rib frame 2 and the holding and prevention of slippage of the partition membrane 1 are possible.

[0025] As shown in Fig. 3, the rib frame 2A and air-passage rib frame 7A are connected by at least two air-passage rib frame fixing members 107A. The rib frame 2B and air-passage rib frame 7B are connected by at least two air-passage rib frame fixing members 107B. The air-passage rib frame fixing members 107A, 107B are convex-shaped members, and when the rib frames 2 are stacked, for example, as shown in Fig. 3, the air-passage rib frame fixing member 107A of the rib frame 2A is fitted together by wrapping the partition membrane 1 into the concave portion of the concave-convex portion 105 of the adjacent rib frame 2B due to the stacking.

[0026] 4 and 5, the air passage rib frames 7A, 7B are composed of air flow distribution ribs 9A, 9B and air flow opposing ribs 10A, 10B. The air passage rib frames 7A, 7B are members that form the supply air passage 3 and the exhaust air passage 4 inside the heat exchange element 100. The thickness of the air passage rib frames 7A, 7B in the Z direction is equal to the thickness of the outer frame ribs 5A, 5B in the Z direction or slightly thinner than the thickness of the outer frame ribs 5A, 5B in the Y direction. Both ends of the air passage rib frames 7A, 7B are fixed to multiple air passage rib frame fixing members 107A, 107B and are positioned in the air flow openings 6A, 6B.

[0027] The horizontal ribs 8A, 8B are components that connect adjacent air passage rib frames 7A, 7B, or adjacent rib frames 2A, 2B and air passage rib frames 7A, 7B. The Z-direction thickness of the horizontal ribs 8A, 8B is smaller than the Z-direction thickness of the rib frames 2A, 2B. The cross-sectional shape of the horizontal ribs 8A, 8B in the X-direction, which is the longitudinal direction of the air passage rib frames 7A, 7B, is a rounded shape such as an ellipse or aerofoil shape. In this embodiment, as shown in FIG. 8 , the cross-sectional shape of the horizontal ribs 8A, 8B in the X-direction of the air passage rib frames 7A, 7B is an ellipse. An intake air passage 3 or an exhaust air passage 4 is formed between the partition membrane 1 and the horizontal ribs 8A, 8B. It is preferable that the horizontal ribs 8A, 8B be positioned so as not to contact the partition membrane 1, but they may be positioned so as to contact either of the adjacent partition membranes 1.

[0028] As shown in FIGS. 4 and 5, the airflow distribution ribs 9A, 9B and the airflow opposing ribs 10A, 10B are connected at bent portions 12. As shown in FIG.

[0029] 4 and 5 , one end 91A, 91B of each of the airflow distribution ribs 9A, 9B is disposed in the airflow openings 6A, 6B, and the other end 92A, 92B is fixed to the airflow-opposing rib 10A, 10B. Here, a configuration in which the other end 92A of each of the airflow distribution ribs 9A is directly connected to the airflow-opposing rib 10A is illustrated as an example. However, the other end 92A of each of the airflow distribution ribs 9A may be connected to the airflow-opposing rib 10A via a crossover rib 8A, so that the airflow distribution rib 9A, the crossover rib 8A, and the airflow-opposing rib 10A are connected in a crank shape. Similarly, the other end 92B of each of the airflow distribution ribs 9B may be connected to the airflow-opposing rib 10B via a crossover rib 8B, so that the airflow distribution rib 9B, the crossover rib 8B, and the airflow-opposing rib 10B are connected in a crank shape. That is, the airflow-facing ribs 10A, 10B connect the other ends 92A, 92B of the airflow distribution ribs 9A, 9B directly or via the crossover ribs 8A, 8B. The airflow distribution ribs 9A, 9B are installed non-parallel to the adjacent airflow distribution ribs 9A, 9B. That is, the airflow distribution ribs 9A, 9B are installed so that the airflow distribution air-passage width 13 becomes wider toward the inside of the heat exchange element 100. That is, the distance between the first ends 91A of the airflow distribution ribs 9A is narrower than the distance between the other ends 92A of the airflow distribution ribs 9A, and the distance between the first ends 91B of the airflow distribution ribs 9B is narrower than the distance between the other ends 92B of the airflow distribution ribs 9B.

[0030] As shown in Figures 4 and 5, the airflow-opposing ribs 10A, 10B connect at least two airflow distribution ribs 9A, 9B, one end 91A, 91B of which is located at at least two different airflow openings 6A, 6B. The airflow-opposing ribs 10A, 10B are arranged so as to be parallel to the adjacent airflow distribution ribs 9A, 9B or outer frame ribs 5A, 5B. Although Figures 4 and 5 show a configuration in which the airflow-opposing ribs 10A, 10B are parallel to the adjacent outer frame ribs 5A, 5B, the airflow-opposing ribs 10A, 10B may also be non-parallel to the adjacent airflow distribution ribs 9A, 9B or outer frame ribs 5A, 5B. Furthermore, the X-direction length of each air flow-opposing rib 10A, 10B, i.e., the length in the air flow direction parallel to the flow of the supply air 103 or the exhaust air 104 flowing between the air flow-opposing ribs 10A, 10B, is different from the length of at least one adjacent air flow-opposing rib 10A, 10B, and the X-direction length of at least one of each air flow-opposing rib 10A, 10B is equal to or less than the X-direction length of the outer frame rib 5A, 5B arranged parallel to the air flow-opposing rib 10A, 10B. As shown in Figures 4 and 5, in this embodiment, the X-direction length of each air flow-opposing rib 10A, 10B decreases and increases stepwise from the air flow-opposing rib 10A, 10B adjacent to the outer frame rib 5A, 5B at one end in the Y direction to the air flow-opposing rib 10A, 10B adjacent to the outer frame rib 5A, 5B at the other end in the Y direction. For this reason, in this embodiment, the X-direction lengths of the installed air flow-opposing ribs 10A, 10B decrease along the Y direction toward the center of the outer shape in the XY plane. That is, the X-direction lengths of the air flow-opposing ribs 10A, 10B increase as they are disposed closer to the outer frame ribs 5A, 5B. The air flow-opposing ribs 10A, 10B are installed so as to be mirror-symmetrical with respect to the XZ plane that passes through the center of the outer shape in the XY plane.

[0031] FIG. 6 is a cross-sectional view perpendicular to the airflow-opposing rib of the heat exchanger element according to the first embodiment. FIG. 6 shows a cross-section taken along line VI-VI in FIG. 4. FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 4. FIG. 8 is a cross-sectional view parallel to the airflow-opposing rib of the heat exchanger element according to the first embodiment. FIG. 8 shows a cross-sectional view taken along line VIII-VIII in FIG. 4. As shown in FIGS. 4, 5, and 6, in this embodiment, the spacing between the airflow-opposing ribs 10A, 10B, i.e., the airflow-opposing air passage width 14, is uniform. However, the width is not limited as long as the ribs are arranged in mirror symmetry with respect to the XZ plane passing through the center of the outer shape in the XY plane.

[0032] As shown in Figures 4 and 5, the crossover ribs 8A, 8B have a bent portion that curves convexly toward the center of the rib frames 2A, 2B in the X direction between the outer frame ribs 5A, 5B at one end in the Y direction (perpendicular to the X direction) and the outer frame ribs 5A, 5B at the other end in the Y direction. The crossover ribs 8A, 8B are arranged to pass through a curved portion 12 at which the airflow distribution ribs 9A, 9B and the airflow-opposing ribs 10A, 10B connect. The crossover ribs 8A, 8B are connected to the curved portion 12 at which the airflow distribution ribs 9A, 9B and the airflow-opposing ribs 10A, 10B connect, without being perpendicular to the airflow-opposing ribs 10A, 10B. As shown in Figure 7, an intake air passage 3 or an exhaust air passage 4 is formed in the gap between the partition membrane 1 and the crossover ribs 8A, 8B. As shown in FIG. 8, in this embodiment, the supply air 103 and the exhaust air 104 are divided into two flows above and below the crossover ribs 8A, 8B at the locations where the crossover ribs 8A, 8B are arranged.

[0033] Fig. 9 is a diagram showing the flow of intake and exhaust airflows within the heat exchange element according to embodiment 1. As shown in Figs. 4 and 5, the crossover ribs 8A, 8B have a portion that bends convexly toward the center of the rib frames 2A, 2B in the X direction between the outer frame ribs 5A, 5B at one end in the Y direction, which is perpendicular to the X direction, and the outer frame ribs 5A, 5B at the other end in the Y direction. As a result, as shown in Fig. 9, the heat exchange element 100 has an airflow header region 15 that is rectangular in the XY plane view and an airflow opposing region 16 that is concavely hexagonal in the XY plane view. In the airflow header region 15, airflow distribution ribs 9A and 9B are stacked. In the airflow opposing region 16, airflow opposing ribs 10A and 10B are stacked. The airflow header region 15 forms the intake airflow passage 3 and the exhaust airflow passage 4, through which the intake air 103 and the exhaust airflow 104 communicate via the partition membrane 1. On the other hand, the airflow facing region 16 becomes the supply air duct 3 and the exhaust air duct 4, where the supply air 103 and the exhaust air 104 face each other across the partition membrane 1. The X direction, which is the airflow direction, is the same direction as the extension of an imaginary line K connecting the center of the inlet side and the center of the outlet side of the airflow facing region 16.

[0034] In the heat exchange element 100 of this embodiment, the flow of the supply air 103 and the flow of the exhaust air 104 are symmetrical, so the explanation will be given taking the supply air 103 as an example. The supply air 103 flows making an obtuse-angle bend when it flows from the airflow header region 15 to the airflow opposing region 16 and when it flows from the airflow opposing region 16 to the airflow header region 15, and as shown in Figure 9, a separation vortex region 17 is formed in the wake of this obtuse-angle bend, which reduces pressure loss and decreases sensible heat and latent heat exchange efficiency.

[0035] Generally, the separation vortex region 17 increases as the airflow velocity at the bending portion 12 increases and as the airflow bends more sharply. In the heat exchange element 100 of the present embodiment, the distance between the airflow distribution ribs 9A and 9B, i.e., the airflow distribution air passage width 13, is arranged so that it is at its widest at the connection point between the airflow header region 15 and the airflow opposing region 16, thereby reducing the airflow velocity at the bending portion 12. Furthermore, in the heat exchange element 100 of the present embodiment, the airflow opposing region 16 is formed as a concave polygon with at least one concave corner and a square or more sides in the XY plane view, thereby increasing the bending angle of the airflow compared to the heat exchange element disclosed in Patent Document 1. These features make it possible to reduce the separation vortex region 17 generated at the bending portion 12 of the intake air 103 and the exhaust air 104, thereby reducing the pressure loss of the heat exchange element 100 and improving the sensible heat and latent heat exchange efficiency.

[0036] Embodiment 2. Fig. 10 is a diagram showing the configuration of a first partition unit of a heat exchange element according to embodiment 2. Fig. 11 is a diagram showing the configuration of a second partition unit of a heat exchange element according to embodiment 2. Fig. 12 is a cross-sectional view along an airflow-facing auxiliary rib of a heat exchange element according to embodiment 2. Fig. 12 shows a cross-section along line XII-XII in Figs. 10 and 11. The heat exchange element 100 according to embodiment 2 differs from the heat exchange element 100 according to embodiment 1 in that the apex angle 108 is a shape exceeding 120 degrees. Descriptions of parts similar to those of the heat exchange element 100 according to embodiment 1 will be omitted, and only differences will be described.

[0037] 10, in the heat exchange element 100 according to the second embodiment, the rib frame 2A has an airflow-facing auxiliary rib 21A. Also, at least one of the airflow distribution ribs 9A has an airflow distribution rib bend 18A.

[0038] The airflow distribution ribs 9A having the airflow distribution rib bends 18A are classified into airflow introduction parallel ribs 19A whose ends are arranged at the airflow openings 6A, and airflow introduction ribs 20A connected to the airflow opposing ribs 10A.

[0039] The airflow introduction parallel ribs 19A are arranged so as to be parallel to the portions of the outer frame ribs 5A that are installed on the sides of the partition membrane 1 that are not parallel to the airflow distribution ribs 9A.

[0040] As shown in Figures 10 and 12, the airflow-opposing auxiliary rib 21A is connected to a part of the crossover rib 8A. The airflow-opposing auxiliary rib 21A is installed parallel to the airflow-opposing rib 10A. The thickness of the airflow-opposing auxiliary rib 21A in the Z direction is the same as that of the airflow-opposing rib 10A, and it has the function of assisting in holding the partition membrane 1.

[0041] 10 , in this embodiment, the length of each air flow-facing rib 10A in the X direction decreases and increases in two steps from the air flow-facing rib 10A adjacent to the outer frame rib 5A at one end in the Y direction to the air flow-facing rib 10A adjacent to the outer frame rib 5A at the other end in the Y direction. The air flow-facing ribs 10A are arranged in mirror symmetry with respect to the XZ plane that passes through the center of the outer shape in the XY plane.

[0042] As in the first embodiment, the rib frame 2B has a mirror image of the rib frame 2A. Specifically, the rib frame 2B has an airflow-opposing auxiliary rib 21B. At least one of the airflow distribution ribs 9B has an airflow distribution rib bend 18B. The airflow distribution ribs 9B having the airflow distribution rib bend 18B are classified into airflow introduction parallel ribs 19B, the ends of which are located at the airflow openings 6B, and airflow introduction ribs 20B, which are connected to the airflow-opposing ribs 10B. The airflow introduction parallel ribs 19B are arranged parallel to the sides of the outer frame ribs 5B that are not parallel to the airflow distribution rib 9B. The airflow-opposing auxiliary rib 21B is connected to a portion of the crossover rib 8B, as shown in FIGS. 11 and 12 . The airflow-opposing auxiliary rib 21B is arranged parallel to the airflow-opposing rib 10B. The thickness of the airflow-opposing auxiliary rib 21B in the Z direction is the same as that of the airflow-opposing rib 10B, and it functions to assist in holding the partition membrane 1. As shown in Figure 11, in this embodiment, the length of each airflow-opposing rib 10B in the X direction decreases and increases in two steps from the airflow-opposing rib 10B adjacent to the outer frame rib 5B at one end in the Y direction to the airflow-opposing rib 10B adjacent to the outer frame rib 5B at the other end in the Y direction. In addition, the airflow-opposing ribs 10B are arranged so as to be mirror-symmetrical with respect to the XZ plane that passes through the center of the outer shape in the XY plane.

[0043] The cross ribs 8A, 8B have two bent portions that are convex toward the center of the rib frames 2A, 2B in the X direction, between the outer frame ribs 5A, 5B at one end in the Y direction, which is perpendicular to the X direction, and the outer frame ribs 5A, 5B at the other end in the Y direction.

[0044] 13 is a diagram showing the flow of intake air and exhaust air within the heat exchange element according to embodiment 2. In the heat exchange element 100 according to embodiment 2, as shown in FIGS. 10 and 11, the crossover ribs 8A, 8B have two bent portions that are convex toward the center of the rib frames 2A, 2B in the X direction between the outer frame ribs 5A, 5B at one end in the Y direction, which is perpendicular to the X direction, and the outer frame ribs 5A, 5B at the other end in the Y direction. As shown in FIG. 13, the stacked airflow distribution ribs 9A and 9B form an airflow header region 15 having a concave hexagonal shape with angle brackets, and the stacked airflow opposing ribs 10A and 10B form an airflow opposing region 16 having a concave decagonal shape with two constrictions. In the airflow header region 15, the intake air duct 3 and the exhaust air duct 4 are formed, through which the intake air 103 and the exhaust air 104 communicate via the partition membrane 1. In the airflow opposing region 16, the supply air 103 and the exhaust air 104 form an intake air duct 3 and an exhaust air duct 4 that face each other across the partition membrane 1. The X direction, which is the airflow direction, is the same direction as the extension of an imaginary line K that connects the center of the inlet side and the center of the outlet side of the airflow opposing region 16.

[0045] As in the first embodiment, the distance between the airflow introduction ribs 20A, 20B, i.e., the airflow distribution airflow path width 13, is arranged to be maximum at the connection point between the airflow header region 15 and the airflow opposing region 16, thereby reducing the airflow velocity at the bending portion at the boundary between the airflow header region 15 and the airflow opposing region 16. These functions make it possible to reduce the separation vortex region 17 generated at the bending portion 12 of the supply air 103 and the exhaust air 104, and even in a heat exchange element 100 having an apex angle 108 exceeding 120 degrees as described in this embodiment, it is possible to reduce pressure loss and improve sensible heat and latent heat exchange efficiency.

[0046] Embodiment 3. Fig. 14 is a diagram showing the installation state of a heat exchange element according to embodiment 3. Fig. 15 is a side view of the heat exchange element according to embodiment 3 as seen from the stacking direction. The heat exchange element 100 according to embodiment 3 differs from the heat exchange element 100 according to embodiment 1 in that it has a concave decagonal prism shape with two constrictions.

[0047] As shown in Fig. 14, the outer shape of heat exchange element 100 in the XY plane is a concave decagon, and the cross-sectional shape of heat exchange element 100 in the XY plane is a shape of two hexagons lined up with one side in common. As shown in Fig. 14, heat exchange element 100 is placed inside air conditioner housing 101 partitioned by supply / exhaust partition member 102 so that supply air 103 and exhaust air 104 flow in opposite directions inside.

[0048] Fig. 16 is a diagram showing the configuration of a first partition unit of a heat exchange element according to embodiment 3. As shown in Fig. 16, in the heat exchange element 100, at least two air flow openings 6A are provided on adjacent sides of the polygonal outer shape of the rib frame 2. As shown in Fig. 16, the rib frame 2A has four air flow openings 6A, and of these, the air flow openings 6A that introduce the supply air 103 into the heat exchange element 100 are provided on two adjacent sides of the decagonal outer shape of the rib frame 2A. The crossover rib 8A has two bent portions that are convex toward the center of the rib frame 2A in the X direction, between the outer frame rib 5A at one end in the Y direction, which is a direction perpendicular to the X direction, and the outer frame rib 5A at the other end in the Y direction. The length of the airflow-facing rib 10A in the X direction decreases and increases stepwise twice from the airflow-facing rib 10A adjacent to the outer frame rib 5A at one end in the Y direction, which is a direction perpendicular to the X direction, to the airflow-facing rib 10A adjacent to the outer frame rib 5A at the other end in the Y direction.

[0049] FIG. 17 is a diagram showing the configuration of the second partition unit of the heat exchange element according to the third embodiment. As in the first embodiment, the rib frame 2B has a mirror-symmetrical shape relative to the rib frame 2A. That is, the rib frame 2B has at least two airflow openings 6B located on adjacent sides of the polygonal outer shape of the rib frame 2B. As shown in FIG. 17, the rib frame 2B has four airflow openings 6B, and the airflow openings 6B that introduce the exhaust gas 104 into the heat exchange element 100 are located on two adjacent sides of the decagonal outer shape of the rib frame 2B. The crossover rib 8B has two bent portions that are convex toward the center of the rib frame 2B in the X direction, between the outer frame rib 5B at one end in the Y direction, which is perpendicular to the X direction, and the outer frame rib 5B at the other end in the Y direction. The length of the air flow-facing rib 10B in the X direction decreases and increases stepwise twice from the air flow-facing rib 10B adjacent to the outer frame rib 5B at one end in the Y direction, which is a direction perpendicular to the X direction, to the air flow-facing rib 10B adjacent to the outer frame rib 5B at the other end in the Y direction.

[0050] As shown in FIGS. 16 and 17, the rib frames 2A and 2B of the heat exchange element 100 have at least three airflow openings 6A and 6B on the sides of a polygon that forms the outer shape in the XY plane.

[0051] Figure 18 is a diagram showing the flow of intake and exhaust airflow within a heat exchange element according to embodiment 3. As shown in Figures 16 and 17, the crossover ribs 8A, 8B have two bent portions that are convex toward the center of the rib frames 2A, 2B in the X direction between the outer frame ribs 5A, 5B at one end in the Y direction, which is perpendicular to the X direction, and the outer frame ribs 5A, 5B at the other end in the Y direction. As shown in Figure 18, the heat exchange element 100 has an airflow header region 15 having a concave octagonal region formed by stacking the airflow distribution ribs 9A and 9B. The heat exchange element 100 also has an airflow facing region 16 having a concave decagonal region with two constricted portions formed by stacking the airflow facing ribs 10A and 10B. In the airflow header region 15, the intake airflow duct 3 and the exhaust airflow duct 4 are formed, through which the intake airflow 103 and the exhaust airflow 104 communicate via the partition membrane 1. In the opposing airflow region 16, the supply air 103 and the exhaust air 104 form an intake air passage 3 and an exhaust air passage 4 that face each other with the partition film 1 interposed therebetween.

[0052] As in the first embodiment, the airflow-opposing ribs 10A, 10B and the airflow-opposing auxiliary ribs 21A, 21B are arranged so that the distance between the airflow distribution ribs 9A, 9B, i.e., the airflow distribution airflow path width 13, is greatest at the connection point between the airflow header region 15 and the airflow-opposing region 16, thereby reducing the airflow velocity at the bending portion 12 at the boundary between the airflow header region 15 and the airflow-opposing region 16. These functions make it possible to reduce the separation vortex region 17 that occurs at the bending portion of the intake air 103 and the exhaust air 104, and even in a heat exchange element 100 in which the outer shape of the rib frame 2 is a polygon such as a decagon, as described in this embodiment, it is possible to reduce pressure loss and improve sensible heat and latent heat exchange efficiency.

[0053] The configurations shown in the above embodiments are merely examples of the content, and may be combined with other known technologies, or parts of the configurations may be omitted or modified without departing from the spirit of the invention.

[0054] 1 Partition membrane, 2, 2A, 2B Rib frame, 3 Air intake duct, 4 Exhaust duct, 5A, 5B Outer frame rib, 6A, 6B Air flow opening, 7A, 7B Air duct rib frame, 8A, 8B Horizontal rib, 9A, 9B Air flow distribution rib, 10A, 10B Air flow opposing rib, 11 Cover frame, 12 Bending portion, 13 Air flow distribution duct width, 14 Air flow opposing duct width, 15 Air flow header region, 16 Air flow opposing region, 17 Separation vortex region, 18A, 18B Air flow distribution rib bending portion, 19A, 19B Air flow introduction parallel rib, 20A, 20B Air flow introduction rib, 21A, 21B Air flow opposing auxiliary rib, 91A, 91B One end, 92A, 92B Other end, 100 Heat exchange element, 101 Air conditioner housing, 102 supply / exhaust partition member, 103 intake air, 104 exhaust air, 105 uneven portion, 106 through hole, 107A, 107B air passage rib frame fixing member, 108 apex angle.

Claims

1. A heat exchange element in which a thin plate-like partition film and a rib frame that holds the interval of the partition film are alternately laminated, so that an air supply passage through which supply air flows and an exhaust passage through which exhaust air flows are independently formed between the partition film and the rib frame, and heat exchange is performed between the supply air and the exhaust air through the partition film, wherein each of the outer shapes of the partition film and the rib frame is a polygon with six or more sides, the rib frame includes an outer frame rib that holds the outer periphery of the partition film, a plurality of air passage rib frames that are in contact with each of the two partition films sandwiching the rib frame, and a plurality of transverse ribs that are not in contact with at least one of the two partition films sandwiching the rib frame and connect the plurality of air passage rib frames and the outer frame rib, at least two non-adjacent side portions of the outer periphery of the rib frame are formed with air flow openings through which processing air passes, the air passage rib frame includes a plurality of air flow distribution ribs having one end portion disposed at the air flow openings, and a plurality of air flow opposing ribs that directly connect or connect through the transverse ribs the other end portions of the two air flow distribution ribs having one end portion disposed at different air flow openings, the air flow opposing ribs are installed in parallel with the outer frame rib installed on a side of the outer periphery of the partition film where the air flow openings are not disposed, and at least one of the air flow opposing ribs is characterized in that the length in the air flow direction is shorter than the outer frame rib installed in parallel and is different from other adjacent air flow opposing ribs.

2. The heat exchange element according to claim 1, wherein the transverse rib is connected to a connection portion between the air flow distribution rib and the air flow opposing rib without being orthogonal to the air flow opposing rib.

3. The heat exchange element according to claim 1 or 2, wherein the transverse rib has at least one portion that bends so as to protrude toward the center of the rib frame in the air flow direction between the outer frame rib at one end portion in the direction perpendicular to the air flow direction and the outer frame rib at the other end portion in the direction perpendicular to the air flow direction.

4. The heat exchange element according to claim 3, wherein the transverse rib has one portion that bends so as to protrude toward the center of the rib frame in the air flow direction between the outer frame rib at one end portion in the direction perpendicular to the air flow direction and the outer frame rib at the other end portion in the direction perpendicular to the air flow direction.

5. The heat exchange element according to claim 3, wherein a plurality of the transverse ribs are bent so as to protrude toward the center of the rib frame in the air flow direction between the outer frame rib at one end in the direction perpendicular to the air flow direction and the outer frame rib at the other end in the direction perpendicular to the air flow direction.

6. The heat exchange element according to claim 1 or 2, wherein the length of each of the air flow opposing ribs in the air flow direction decreases and increases stepwise at least once from the air flow opposing rib adjacent to the outer frame rib at one end in the direction perpendicular to the air flow direction to the air flow opposing rib adjacent to the outer frame rib at the other end in the direction perpendicular to the air flow direction.

7. The heat exchange element according to any one of claims 1 to 6, further comprising air flow opposing auxiliary ribs installed in parallel with the air flow opposing ribs and connecting the transverse ribs to each other.

8. The heat exchange element according to claim 1 or 2, further comprising air flow opposing auxiliary ribs installed in parallel with the air flow opposing ribs and connecting the transverse ribs to each other, wherein the length of each of the air flow opposing ribs and the air flow opposing auxiliary ribs in the air flow direction decreases and increases stepwise at least once from the air flow opposing rib adjacent to the outer frame rib at one end in the direction perpendicular to the air flow direction to the air flow opposing rib adjacent to the outer frame rib at the other end in the direction perpendicular to the air flow direction.

9. The heat exchange element according to any one of claims 1 to 8, wherein at least one of the air flow distribution ribs has a bent portion, and a portion between the bent portion and the one end of the air flow distribution rib having the bent portion is parallel to a portion of the outer frame rib where the air flow distribution rib of the partition film is not parallel.

10. The heat exchange element according to any one of claims 1 to 9, wherein the transverse rib has an elliptical or wing-shaped cross-sectional shape.

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