The present disclosure relates to a heat-exchange element that performs heat exchange by allowing two fluids to pass through between stacked plates and a heat-exchange ventilation apparatus.
Flow forms of two-fluid heat exchange used in heat-exchange elements of this type include a cross-flow form in which two fluids flow perpendicularly to each other and a counter-flow form in which two fluids flow in opposite directions, facing each other. Under the same conditions of pressure loss, the amount of heat exchange per unit volume is theoretically larger in the counter-flow form.
A counter-flow heat-exchange element typically includes a counter-flow portion that performs heat exchange, and header portions that change the directions of a supply air current and an exhaust air current to opposite directions in the counter-flow portion between inlet and outlet ports and the counter-flow portion. Patent Literature 1 includes a central portion corresponding to the counter-flow portion and end portions corresponding to the header portions. The end portions include a plurality of equidistant parallel flow paths from the inlet and outlet ports toward the central portion.
Patent Literature 1US 2017/0370609 A
In Patent Literature 1, since the end portions have the plurality of equidistant parallel flow paths from the inlet and outlet ports toward the central portion, air currents in the end portions are not uniform flows, resulting in large pressure loss and causing flow stagnation.
The present disclosure has been made in view of the above. It is an object of the present disclosure to provide a heat-exchange element that can reduce pressure loss in header portions and allows air currents to uniformly flow into a counter-flow portion, and a heat-exchange ventilation apparatus.
To solve the above-described problem and achieve the object, a heat-exchange element of the present disclosure includes hexagonal first partition plates and hexagonal second partition plates stacked alternately, a plurality of first flow paths that are each formed between a front surface of one of the first partition plates and a back surface of an adjacent one of the second partition plates and through each of which air flows from a first inlet to a first outlet, and a plurality of second flow paths that are each formed between a back surface of one of the first partition plates and a front surface of an adjacent one of the second partition plates and through each of which air flows from a second inlet to a second outlet Each of the first partition plates includes a first counter-flow portion disposed in a region sandwiched between a first edge and a second edge that are opposite edges of a hexagon, the first counter-flow portion including a plurality of third flow paths extending in parallel to the first edge and the second edge, a first header portion disposed in a region enclosed by a third edge and a fourth edge of the hexagon disposed on one side of the first edge and the second edge and the first counter-flow portion, the first header portion including a plurality of first ribs extending from the third edge that is an edge adjacent to the first edge, of the third edge and the fourth edge, along the fourth edge toward the first counter-flow portion, and a second header portion disposed in a region enclosed by a fifth edge and a sixth edge of the hexagon disposed on the opposite aide of the first edge and the second edge and the first counter-flow portion, the second header portion including a plurality of second ribs extending from the fifth edge that is an edge adjacent to the second edge, of the fifth edge and the sixth edge, along the sixth edge toward the first counter-flow portion. Each of the second partition plates includes a second counter-flow portion disposed in a region sandwiched between a seventh edge and an eighth edge that are opposite edges of a hexagon, the second counter-flow portion including a plurality of fourth flow paths extending in parallel to the seventh edge and the eighth edge, a third header portion disposed in a region enclosed by a ninth edge and a tenth edge of the hexagon disposed on one side of the seventh edge and the eighth edge and the second counter-flow portion, the third header portion including a plurality of third ribs extending frost the tenth edge that is an edge adjacent to the eighth edge, of the ninth edge and the tenth edge, along the ninth edge toward the second counter-flow portion, and a fourth header portion disposed in a region enclosed by an eleventh edge and a twelfth edge of the hexagon disposed on the opposite side of the seventh edge and the eighth edge and the second counter-flow portion, the fourth header portion including a plurality of fourth ribs extending from the twelfth edge that is an edge adjacent to the seventh edge, of the eleventh edge and the twelfth edge, along the eleventh edge toward the second counter-flow portion. The first partition plates and the second partition plates are stacked alternately such that the first edge is placed on the seventh edge, and the third edge is placed on the ninth edge. The first inlet is a space between the third edge and the ninth edge. The first outlet is a space between the fifth edge and the eleventh edge. The second inlet is a space between the twelfth edge and the sixth edge, the second outlet is a space between the tenth edge and the fourth edge, and the first flow paths are formed by the first ribs, the third flow paths, and the second ribs. The second flow paths are formed by the fourth ribs, the fourth flow paths, and the third ribs. The extending direction of a fifth rib that is one of the plurality of first ribs of the first header portion is closer to the extending direction of the third flow paths than the extending direction of a sixth rib that is a rib of the plurality of first ribs closer to the fourth edge than the fifth rib. The extending direction of a seventh rib that is one of the plurality of second ribs of the second header portion is closer to the extending direction of the third flow paths than the extending direction of an eighth rib that is a rib of the plurality of second ribs closer to the sixth edge than the seventh rib. The extending direction of a ninth rib that is one of the plurality of third ribs of the third header portion is closer to the extending direction of the fourth flow paths than the extending direction of a tenth rib that is a rib of the plurality of third ribs closer to the ninth edge than the ninth rib. The extending direction of an eleventh rib that is one of the plurality of fourth ribs of the fourth header portion is closer to the extending direction of the fourth flow paths than the extending direction of a twelfth rib that is a rib of the plurality of fourth ribs closer to the eleventh edge than the eleventh rib.
The present disclosure can reduce pressure loss in the header portions and allows air currents to uniformly flow into the counter-flow portion.
Hereinafter, a heat-exchange element and a heat-exchange ventilation apparatus according to an embodiment will be described in detail with reference to the drawings.
Six edge portions of the first partition plate 1 are formed such that openings are formed only at the portion of the third edge 1c corresponding to the first inlet 11 and the portion of the fifth edge 1e corresponding to the first outlet 13, and the portions of the first edge 1a, the second edge 1b, the fourth edge 1d, and the sixth edge 1f are closed when the second partition plate 2 is placed thereon. That is, the portions of the first edge 1a, the second edge 1b, the fourth edge 1d, and the sixth edge 1f are formed, for example, in a rising shape to be closed. In the first partition plate 1 illustrated in
The first counter-flow portion 10 includes a plurality of flow paths extending in parallel to the first edge 1a and the second edge 1b. The plurality of flow paths formed in the first counter-flow portion 10 correspond to third flow paths in the claims.
As illustrated in
The plurality of first ribs 12a extend from the third edge 1c along the fourth edge 1d toward the first counter-flow portion 10. Each of the plurality of first ribs 12a has an S shape. The closer to the fourth edge 1d the first ribs 12a are, the longer their lengths are. The plurality of second ribs 14a extend from the fifth edge 1e along the sixth edge 1f toward the first counter-flow portion 10. Each of the plurality of second ribs 14a has an S shape. The closer to the sixth edge 1f the second ribs 14a are, the longer their lengths are. Details of the first ribs 12a and the second ribs 14a will be described later.
Six edge portions of the second partition plate 2 are formed such that openings are formed only at the portion of the twelfth edge 2f corresponding to the second inlet 21 and the portion of the tenth edge 2d corresponding to the second outlet 23, and the portions of the seventh edge 2a, the eighth edge 2b, the ninth edge 2c, and the eleventh edge 2e are closed when the first partition plate 1 is placed thereon. That is, the portions of the seventh edge 2a, the eighth edge 2b, the ninth edge 2c, and the eleventh edge 2e are formed, for example, in a rising shape to be closed. In the second partition plate 2 illustrated in
The second counter-flow portion 20 includes a plurality of flow paths extending in parallel to the seventh edge 2a and the eighth edge 2b. The plurality of flow paths formed in the second counter-flow portion 20 correspond to fourth flow paths in the claims. As illustrated in
As illustrated in
The plurality of third ribs 24a extend from the tenth edge 2d along the ninth edge 2c toward the second counter-flow portion 20. Each of the plurality of third ribs 24a has an inverted S shape. The closer to the ninth edge 2c the third ribs 24a are, the longer their lengths are. The plurality of fourth ribs 22a extend from the twelfth edge 2f along the eleventh edge 2e toward the second counter-flow portion 20. Each of the plurality of fourth ribs 22a has an inverted S shape. The closer to the eleventh edge 2e the fourth ribs 22a are, the longer their lengths are. Details of the third ribs 24a and the fourth ribs 22a will be described later.
In the heat-exchange element 100 according to the embodiment, the first partition plates 1 and the second partition plates 2 are stacked alternately such that the first edge 1a is placed on the seventh edge 2a, and the third edge 1c is placed on the ninth edge 2c. More specifically, furthermore, the second edge 1b is placed on the eighth edge 2b, the fourth edge 1d is placed on the tenth edge 2d, the fifth edge 1e is placed on the eleventh edge 2e, and the sixth edge 1f is placed on the twelfth edge 2f.
By placing the first partition plates 1 and the second partition plates 2 on top of each other, the first inlet 11 is formed between the third edge 1c of the first partition plate 1 and the ninth edge 2c of the second partition plate 2. The first outlet 13 is formed between the fifth edge 1e of the first partition plate 1 and the eleventh edge 2e of the second partition plate 2. The second inlet 21 is formed between the twelfth edge 2f of the second partition plate 2 and the sixth edge 1f of the first partition plate 1. The second outlet 23 is formed between the tenth edge 2d of the second partition plate 2 and the fourth edge 1d of the first partition plate 1.
Further, by placing the first partition plates 1 and the second partition plates 2 on top of each other, the first flow paths indicated by the arrows F1, F2, F3, F4, and F5 illustrated in
As indicated by the arrows F1, F2, F3, F4, and F5 illustrated in
The first inlet 11, the plurality of first ribs 12a, the plurality of flow paths in the first counter-flow portion 10, the plurality of second ribs 14a, and the first outlet 13, and the second outlet 23, the plurality of third ribs 24a, the plurality of flow paths in the second counter-flow portion 20, the plurality of fourth ribs 22a, and the second inlet 21 are arranged such that the first flow paths indicated by the arrows F1, F2, F3, F4, and F5 and the second flow paths indicated by the arrows G1, G2, G3, G4, and G5 illustrated in
The extending directions of the four first ribs 12a illustrated in
Each downstream rib 122 has a curved shape that is a single-R shape formed by one arc. The single-R shapes of the downstream ribs 122 of the plurality of first ribs 12a individually have different radii. The radii of the downstream ribs 122 of the plurality of first ribs 12a increase in curvature with increasing distance from the fourth edge 1d.
When attention is paid to the upstream rib 120 and the downstream rib 122 of one of the first ribs 12a, the curvature of the upstream rib 120 is set to be larger than the curvature of the downstream rib 122.
As described above, the overall shape of the first ribs 12a is almost an S shape including a straight line, in other words, the shape of a letter S elongated lengthwise. The extending directions of the first ribs 12a described above are represented by the extending directions of the middle ribs 121.
The angular differences between the direction of the upstream ends of the upstream ribs 120 and the direction of the downstream ends of the downstream ribs 122 and the extending direction F3 of the flow paths in the first counter-flow portion 10 are smaller than the angular differences between the directions of the middle ribs 121 and the extending direction F3. Specifically, the upstream ends of the upstream ribs 120 are almost perpendicular to the third edge 1c constituting the first inlet 11.
The direction of the downstream end of each downstream rib 122 is at an angle nearly parallel to the extending direction F3 of the flow paths in the first counter-flow portion 10. The relationship between each downstream rib 122 and the flow paths in the first counter-flow portion 10 will be described in more detail with reference to
The upstream ribs 120 and the downstream ribs 122, which have been illustrated with the examples of the single-R arc shapes, may each have a curved shape that combines arcs having different radii R. The middle ribs 121, which have been illustrated with the example of the linear shape, may each have a slight curve as long as they are almost linear as a whole.
Next, the plurality of second ribs 14a of the second header portion 14 that is an outlet-side header will be described with reference to
The extending directions of the four second ribs 14a illustrated in FIG, 8 are represented by angles φ1 to φ4 with respect to the sixth edge 1f. φ1 is the angle of the second rib 14a closest to the sixth edge 1f, φ2 is the angle of the second rib 14a second closest to the sixth edge 1f, φ3 is the angle of the second rib 14a third closest to the sixth edge 1f, and φ4 is the angle of the second rib 14a farthest from the sixth edge 1f. The relationship φ1<φ2<φ3<φ4 is established among the plurality of second ribs 14a.
Each upstream rib 142 has a curved shape that is a single-R shape formed by one arc. The single-R shapes of the upstream ribs 142 of the plurality of second ribs 14a individually have different radii. The radii of the upstream ribs 142 of the plurality of second ribs 14a increase in curvature with increasing distance from the sixth edge 1f.
When attention is paid to the downstream rib 140 and the upstream rib 142 of one second rib 14a, the curvature of the downstream rib 140 is set to be larger than the curvature of the upstream rib 142.
Thus, the overall shape of the second ribs 14a is almost an S shape including a straight line, in other words, the shape of a letter S elongated lengthwise. The extending directions of the second ribs 14a described above are represented by the extending directions of the middle ribs 141.
The angular differences between the direction of the downstream ends of the downstream ribs 140 and the direction of the upstream ends of the upstream ribs 142 and the extending direction F3 of the flow paths in the first counter-flow portion 10 are smaller than the angular differences between the directions of the middle ribs 141 and the extending direction F3. Specifically, the downstream ends of the downstream ribs 140 are almost perpendicular to the fifth edge 1e constituting the first outlet 13.
The direction of the upstream end of each upstream rib 142 is at an angle nearly parallel to the extending direction F3 of the flow paths in the first counter-flow portion 10. Like the downstream rib 122 of the first rib 12a illustrated in
The downstream ribs 140 and the upstream ribs 142, which have been illustrated with the examples of the single-R arc shapes, may each have a curved shape that combines arcs having different radii R. The middle ribs 141, which have been illustrated with the example of the linear shape, may each have a slight curve as long as they are almost linear as a whole.
Thus, according to the embodiment, the plurality of ribs on each header portion are formed to establish the relationship θ1<θ2<θ3<θ4 or the relationship φ1<φ2<φ3<φ4. Consequently, in the header portion, the flow path widths of the plurality of flow paths formed by the plurality of ribs are larger near the counter-flow portion than near the inlet. This can reduce pressure loss in the header portion and allows air currents to uniformly flow into the counter-flow portion.
In this embodiment, the upstream ribs of the inlet-side header are formed in an arc shape so that the upstream ends of the upstream ribs are perpendicular to the edge constituting the inlet. Consequently, the inflow direction of an air current at the inlet agrees with the direction of the upstream ribs of the inlet-side header, reducing pressure loss at the inlet. The downstream ribs of the outlet-side header are formed in an arc shape so that the downstream ends of the downstream ribs are perpendicular to the edge constituting the outlet.
Consequently, the outflow direction of an air current at the outlet agrees with the direction of the downstream ribs of the outlet-side header, reducing pressure loss at the outlet.
In this embodiment, the extending directions of the upstream ribs are made closer to the extending direction of the flow paths in the counter-flow portion than the extending directions of the middle ribs, and the extending directions of the downstream ribs are made closer to the extending direction of the flow paths in the counter-flow portion than the extending directions of the middle ribs. This can reduce pressure loss in the header portions.
In this embodiment, the downstream end of the downstream rib 122 of each first rib 12a faces the upstream edge of the first counter-flow portion 10 across the gap Δt, the downstream rib 122 of each first rib 12a has an arc shape, the virtual extension line 125 of the downstream rib 122 of each first rib 12a touches the extending direction F3 of the flow paths in the first counter-flow portion 10, the upstream end of the upstream rib 142 of each second rib 14a faces the downstream edge of the first counter-flow portion 10 across the gap, the upstream rib 142 of each second rib 14a has an arc shape, and the virtual extension line of the upstream rib 142 of each second rib 14a touches the extending direction F3 of the flow paths in the first counter-flow portion 10. This can reduce pressure loss in flows from the first ribs 12a to the first counter-flow portion 10 and flows from the first counter-flow portion 10 to the second ribs 14a.
The downstream ribs 122 of the plurality of first ribs 12a of the first header portion 12 have arc shapes of different radii and increase in curvature with increasing distance from the fourth edge 1d, and the upstream ribs 142 of the plurality of second ribs 14a of the second header portion 14 have arc shapes of different radii and increase in curvature with increasing distance from the sixth edge 1f. This achieves uniform flows from the first ribs 12a to the first counter-flow portion 10 and achieves uniform flows from the first counter-flow portion 10 to the second ribs 14a.
When the heat-exchange element 100 in
Next, a heat-exchange ventilation apparatus 200 including the heat-exchange element 100 will be described.
The heat-exchange ventilation apparatus 200 includes an air supply fan 214, an air exhaust fan 215, the heat-exchange element 100, and a casing 213.
The casing 213 is a box-shaped member that houses the air supply fan 214, the air exhaust fan 215, and the heat-exchange element 100. A supply air passage 216 through which a first air current 207 passes and an exhaust air passage 217 through which a second air current 208 passes are provided in the casing 213. The first air current 207 is a supply air current from the outside to the inside of a room. The second air current 208 is an exhaust air current from the inside to the outside of the room. A supply air outlet 220 and an exhaust air inlet 219 are provided in an interior-side side surface of the casing 213. A supply air inlet 218 and an exhaust air outlet 221 are provided in an exterior-side side surface of the casing 213.
The air supply fan 214 is disposed in the supply air passage 216. The air supply fan 214 takes outside air from the supply air inlet 218 into the supply air passage 216, generating the first air current 207. The first air current 207 flows through the supply air passage 216 and is blown into the room from the supply air outlet 220. The air supply fan 214 generates the first air current 207 from the outside to the inside of the room.
The air exhaust fan 215 is disposed in the exhaust air passage 217. The air exhaust fan 215 takes inside air from the exhaust air inlet 219 into the exhaust air passage 217, generating the second air current 208. The second air current 208 flows through the exhaust air passage 217 and is blown to the outside of the room from the exhaust air outlet 221. The air exhaust fan 215 generates the second air current 208 from the inside to the outside of the room.
The heat-exchange element 100 is provided at the position of the intersection of the supply air passage 216 and the exhaust air passage 217. The heat-exchange element 100 performs total heat exchange between the first air current 207 flowing through the supply air passage 216 and the second air current 208 flowing through the exhaust air passage 217. The heat-exchange ventilation apparatus 200 recovers sensible beat and latent heat of an exhaust air current from inside the room by total heat exchange in the heat-exchange element 100, and transfers the recovered sensible heat and latent heat to a supply air current. Further, the heat-exchange ventilation apparatus 200 recovers sensible heat and latent heat of a supply air current from outside the room by total heat exchange in the heat-exchange element 100, and transfers the recovered sensible heat and latent heat to an exhaust air current. The heat-exchange ventilation apparatus 200 can improve cooling and heating efficiency and dehumidification and humidification efficiency in the room, reducing energy used for air conditioning in the room. The heat-exchange element 100 may be configured to transfer only sensible heat between an exhaust air current and a supply air current.
The configuration described in the above embodiment illustrates an example of the subject natter of the present disclosure, and can be combined with another known art, and can be partly omitted or changed without departing from the scope of the present disclosure.
1 first partition plate; 1a first edge; 1b second edge; 1c third edge; 1d fourth edge; 1e fifth edge; 1f sixth edge; 2 second partition plate; 2a seventh edge; 2b eighth edge; 2c ninth edge; 2d tenth edge; 2e eleventh edge; 2f twelfth edge; 10 first counter-flow portion; 11 first inlet; 12 first header portion; 12a first rib; 13 first outlet; 14 second header portion; 14a second rib; 20 second counter-flow portion; 21 second inlet; 22 fourth header portion; 22a fourth rib; 23 second outlet; 24 third header portion; 24a third rib; 100 heat-exchange element; 120, 142 upstream rib; 121, 141 middle rib; 122, 140 downstream rib; 200 heat-exchange ventilation apparatus.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2020/027272 | 7/13/2020 | WO |