Heat exchange unit and air handling unit

Abstract

A heat exchange unit includes a plurality of flat tubes, a first header, a second header, and a drain pan. The first header and the second header are connected to both ends of the plurality of flat tubes and are arranged to extend in a first direction in which the plurality of flat tubes is arranged. Each of the plurality of flat tubes includes a first portion, a second portion, and a connecting portion. The drain pan includes a first wall, a second wall, and a receiving portion. The first wall surrounds an opening. The second wall is located outside the first wall. The receiving portion connects the first wall and the second wall below the first header and below the second header. The receiving portion has a first surface that is an upper surface inclined to have a downward gradient from the first wall toward the second wall.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a Continuation of PCT International Application No. PCT / JP2024 / 034641, filed on September 27, 2024, which claims priority under 35 U.S.C. § 119(a) to Patent Application No. JP 2023-170906, filed in Japan on September 29, 2023, and Patent Application No. JP 2023-170908, filed in Japan on September 29, 2023, all of which are hereby expressly incorporated by reference into the present application.TECHNICAL FIELD

[0002] The present disclosure relates to a heat exchange unit and an air handling unit.BACKGROUND ART

[0003] Conventionally, as disclosed in PTL 1 (U.S. Patent No. 5,284,027), there is a known air handling unit including a heat exchange unit that exchanges heat between a refrigerant and air. The heat exchange unit includes a drain pan that temporarily stores and discharges drainage water.SUMMARY

[0004] A heat exchange unit according to a first aspect includes a plurality of flat tubes, a first header, a second header, and a drain pan. The plurality of flat tubes is arranged along a first direction and allows a refrigerant to flow therein. The first header and the second header are connected to both ends of the plurality of flat tubes and arranged to extend in the first direction. The drain pan receives condensation water from the plurality of flat tubes, the first header, and the second header. The plurality of flat tubes each includes a first portion, a second portion, and a connecting portion. The first portion is connected to the first header and extends in a predetermined direction when viewed from the first direction. The second portion is connected to the second header and extends in a predetermined direction when viewed from the first direction. The connecting portion connects the first portion and the second portion such that an angle between a direction in which the first portion extends and a direction in which the second portion extends when viewed from the first direction is less than 180°. The plurality of flat tubes is arranged such that the connecting portion is located above the first header and the second header. The drain pan includes a first wall, a second wall, and a receiving portion. The first wall surrounds an opening through which air passes, which flows in a second direction orthogonal to a direction in which the drain pan extends when viewed from the first direction. The second wall is located outside the first wall when viewed from the second direction. The receiving portion connects the first wall and the second wall below the first header and below the second header. The first wall includes a third wall extending in the first direction when viewed from the second direction. The receiving portion has a first surface that is an upper surface inclined to have a downward gradient from the third wall toward the second wall.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] FIG. 1 is a side view illustrating the inside of an air handling unit 10 according to a first embodiment when viewed from a first direction D1.

[0006] FIG. 2 is a side view illustrating the inside of the air handling unit 10 according to the first embodiment when viewed from a third direction D3.

[0007] FIG. 3 is a perspective view of a heat exchange unit 20 according to the first embodiment.

[0008] FIG. 4 is a side view of the heat exchange unit 20 according to the first embodiment when viewed from the first direction D1. FIG. 4 is a cross-sectional view of a drain pan 24.

[0009] FIG. 5 is a top view of the heat exchange unit 20 according to the first embodiment when viewed from a second direction D2.

[0010] FIG. 6 is a side view of the heat exchange unit 20 according to the first embodiment when viewed from the third direction D3.

[0011] FIG. 7 is a perspective view of the drain pan 24 according to the first embodiment.

[0012] FIG. 8 is a top view of the drain pan 24 according to the first embodiment.

[0013] FIG. 9 is a cross-sectional view of the drain pan 24 according to the first embodiment when viewed from the first direction D1.

[0014] FIG. 10 is a cross-sectional view of the drain pan 24 according to a second embodiment when viewed from the first direction D1.

[0015] FIG. 11 is a cross-sectional view of the drain pan 24 according to a third embodiment when viewed from the first direction D1.

[0016] FIG. 12 is a cross-sectional view of the drain pan 24 according to a fourth embodiment when viewed from the first direction D1.

[0017] FIG. 13 is a side view of the heat exchange unit 20 according to a seventh embodiment when viewed from the first direction D1. FIG. 13 is a cross-sectional view of the drain pan 24.

[0018] FIG. 14 is a perspective view of the drain pan 24 according to the seventh embodiment.

[0019] FIG. 15 is a top view of the drain pan 24 according to the seventh embodiment.

[0020] FIG. 16 is a cross-sectional view of the drain pan 24 according to the seventh embodiment when viewed from the first direction D1.

[0021] FIG. 17 is a cross-sectional view of the drain pan 24 according to an eighth embodiment when viewed from the first direction D1.

[0022] FIG. 18 is a cross-sectional view of the drain pan 24 according to a ninth embodiment when viewed from the first direction D1.

[0023] FIG. 19 is a cross-sectional view of the drain pan 24 according to a tenth embodiment when viewed from the first direction D1.

[0024] FIG. 20 is a cross-sectional view of the drain pan 24 according to a twelfth embodiment when viewed from the first direction D1.

[0025] FIG. 21 is a side view illustrating the inside of the air handling unit 10 according to a fourteenth embodiment when viewed from the first direction D1.

[0026] FIG. 22 is a side view illustrating the inside of the air handling unit 10 according to the fourteenth embodiment when viewed from the third direction D3.

[0027] FIG. 23 is a perspective view of the heat exchange unit 20 according to the fourteenth embodiment.

[0028] FIG. 24 is a side view of the heat exchange unit 20 according to the fourteenth embodiment when viewed from the first direction D1. FIG. 24 is a cross-sectional view of the drain pan 24.

[0029] FIG. 25 is a top view of the heat exchange unit 20 according to the fourteenth embodiment when viewed from the second direction D2.

[0030] FIG. 26 is a side view of the heat exchange unit 20 according to the fourteenth embodiment when viewed from the third direction D3.

[0031] FIG. 27 is a perspective view of the drain pan 24 according to the fourteenth embodiment.

[0032] FIG. 28 is a top view of the drain pan 24 according to the fourteenth embodiment.

[0033] FIG. 29 is a cross-sectional view of the drain pan 24 according to the fourteenth embodiment when viewed from the first direction D1.

[0034] FIG. 30 is a cross-sectional view of the drain pan 24 according to the fifteenth embodiment when viewed from the first direction D1.

[0035] FIG. 31 is a cross-sectional view of the drain pan 24 according to a sixteenth embodiment when viewed from the first direction D1.

[0036] FIG. 32 is a cross-sectional view of the drain pan 24 according to a seventeenth embodiment when viewed from the first direction D1.

[0037] FIG. 33 is a cross-sectional view of the drain pan 24 according to Modification I when viewed from the first direction D1.

[0038] FIG. 34 is a cross-sectional view of the drain pan 24 according to Modification J when viewed from the first direction D1.DESCRIPTION OF EMBODIMENTS-FIRST EMBODIMENT-(1) Overall Configuration of Air Handling Unit 10

[0039] An air handling unit 10 includes a casing 11, a support 12, a heat exchange unit 20, and a blower unit 30. As illustrated in FIGS. 1 and 2, the air handling unit 10 is installed vertically such that the longitudinal direction of the casing 11 extends along the vertical direction. The internal space of the casing 11 is partitioned by the support 12 into a heat exchange chamber 17 and a blower chamber 18. The heat exchange chamber 17 is located above the blower chamber 18. A heat exchange unit 20 is installed in the heat exchange chamber 17. A blower unit 30 is installed in the blower chamber 18.

[0040] A suction port 13 is formed in an upper surface 11a of the casing 11. A blow-out port 14 is formed in a lower surface 11b of the casing 11. A suction duct 15 is connected to the top of the suction port 13. A blow-out duct 16 is connected to the bottom of the blow-out port 14. The suction port 13 is connected to the suction duct 15 and the heat exchange chamber 17. The blow-out port 14 is connected to the blow-out duct 16 and the blower chamber 18. The heat exchange chamber 17 communicates with the blower chamber 18.

[0041] The blower unit 30 includes a centrifugal fan such as a sirocco fan and a motor that drives the centrifugal fan. By driving the centrifugal fan, the blower unit 30 generates an airflow that is a flow of air from the suction port 13 toward the blow-out port 14 via the heat exchange chamber 17 and the blower chamber 18. The air flows downward in the vertical direction in the internal space of the casing 11 from the suction port 13 toward the blow-out port 14. The air carried by the airflow is heat-exchanged by the heat exchange unit 20 when passing through the heat exchange chamber 17. The air handling unit 10 suctions the air from the suction port 13 and blows out the air from the blow-out port 14 after the temperature has been adjusted by heat exchange by the heat exchange unit 20.(2) Detailed Configuration of Heat Exchange Unit 20

[0042] The heat exchange unit 20 includes a plurality of flat tubes 23, a first header 21, a second header 22, and a drain pan 24. The heat exchange unit 20 forms a part of a refrigerant circuit that performs a vapor compression refrigeration cycle.(2-1) Plurality of Flat Tubes 23

[0043] As illustrated in FIGS. 1 to 6, the plurality of flat tubes 23 is arranged side by side along a predetermined direction. Hereinafter, the direction in which the plurality of flat tubes 23 is arranged is referred to as a first direction D1. The first direction D1 is parallel to the horizontal direction. In FIGS. 3, 5, and FIG. 6, the flat tubes 23 located at the central portion in the first direction D1 are omitted. A downward direction in the vertical direction is referred to as a second direction D2. The second direction D2 is a direction in which the air flows in the internal space of the casing 11. A direction orthogonal to the first direction D1 and the second direction D2 is referred to as a third direction D3. The third direction D3 is parallel to the horizontal direction. The third direction D3 is a direction in which the drain pan 24 extends when viewed from the first direction D1. The refrigerant that exchanges heat with the air passing through the heat exchange chamber 17 flows inside each of the plurality of flat tubes 23. The first header 21 and the second header 22 are connected to both ends of the plurality of flat tubes 23.

[0044] As illustrated in FIG. 4, the heat exchange unit 20 has a configuration in which a first heat exchange portion 40a and a second heat exchange portion 40b are arranged along the second direction D2. Each of the first heat exchange portion 40a and the second heat exchange portion 40b is a unit including the plurality of flat tubes 23, the one first header 21, and the one second header 22. When viewed from the first direction D1, the first heat exchange portion 40a is located outside the second heat exchange portion 40b. In other words, an upper end of the first heat exchange portion 40a is located at a higher position than an upper end of the second heat exchange portion 40b. The first heat exchange portion 40a is connected to the second heat exchange portion 40b via a refrigerant pipe 25.

[0045] Each of the flat tubes 23 includes one first portion 23a, one second portion 23b, and one connecting portion 23c. As illustrated in FIGS. 4 to 6, the first portion 23a extends in a predetermined direction when viewed from the first direction D1. The second portion 23b extends in a predetermined direction different from the direction in which the first portion 23a extends when viewed from the first direction D1. As illustrated in FIG. 4, the connecting portion 23c connects the first portion 23a and the second portion 23b such that angles α and β between the direction in which the first portion 23a extends and the direction in which the second portion 23b extends when viewed from the first direction D1 are less than 180°. The connecting portion 23c may connect the first portion 23a and the second portion 23b such that the angles α and β are 90° or less.

[0046] One end portion of the first portion 23a is connected to the first header 21. The other end portion of the first portion 23a is connected to the connecting portion 23c. One end portion of the second portion 23b is connected to the second header 22. The other end portion of the second portion 23b is connected to the connecting portion 23c. The plurality of flat tubes 23 is arranged such that the connecting portion 23c is located above the first header 21 and the second header 22. Therefore, as illustrated in FIG. 4, the plurality of flat tubes 23 has a V-shape rotated by 180° when viewed from the first direction D1.

[0047] The first portion 23a and the second portion 23b are flat multi-hole tubes having a plurality of passages through which the refrigerant passes. The plurality of passages of the first portion 23a is arranged side by side along a direction orthogonal to the direction in which the first portion 23a extends when viewed from the first direction D1. The plurality of passages of the second portion 23b is arranged side by side along a direction orthogonal to the direction in which the second portion 23b extends when viewed from the first direction D1. As illustrated in FIGS. 5 and 6, the connecting portion 23c is a flat multi-hole tube that is partially curved to allow the plurality of passages of the first portion 23a and the plurality of passages of the second portion 23b to communicate with each other.

[0048] As illustrated in FIGS. 4 to 6, the first portion 23a and the second portion 23b are arranged such that the main surfaces thereof extend along the second direction D2 and the third direction D3. The first portion 23a and the second portion 23b are arranged at a predetermined interval along the first direction D1 orthogonal to the main surfaces. Fins are provided in the gaps between the plurality of first portions 23a arranged along the first direction D1. The first portion 23a and the fin are joined by brazing. Fins are provided in the gaps between the plurality of second portions 23b arranged along the first direction D1. The second portion 23b and the fin are joined by brazing. The fin is, for example, a corrugated fin formed by plastically deforming a flat plate-shaped metal into a corrugated shape.(2-2) First Header 21 and Second Header 22

[0049] The first header 21 and the second header 22 are connected to both ends of the plurality of flat tubes 23. The first header 21 and the second header 22 are arranged to extend in the first direction D1. The first header 21 and the second header 22 are located in an upper portion of the drain pan 24. The first header 21 and the second header 22 are connected to an external refrigerant circuit via the refrigerant pipe 25.(2-3) Drain Pan 24

[0050] The drain pan 24 receives condensation water from the plurality of flat tubes 23, the first header 21, and the second header 22. The condensation water is water generated on the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22 due to heat exchange between the refrigerant flowing inside the plurality of flat tubes 23 and the air passing through the heat exchange chamber 17. The generated condensation water flows down along the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22 due to its own weight and is received by the drain pan 24. The drain pan 24 is fixed to the support 12.

[0051] As illustrated in FIGS. 7 to 9, the drain pan 24 includes a first wall 24a, a second wall 24b, a receiving portion 24c, and a drain outlet 24d. When viewed from the second direction D2, the drain pan 24 has a substantially rectangular shape.

[0052] The first wall 24a surrounds an opening 24f through which the air flowing through the heat exchange chamber 17 in the second direction D2 passes. The opening 24f is located at a central portion of the drain pan 24 when the drain pans 24 is viewed from the second direction D2. The opening 24f has a substantially rectangular shape when viewed from the second direction D2. The air flowing through the heat exchange chamber 17 in the second direction D2 passes through the opening 24f and flows into the blower chamber 18. The second wall 24b is located outside the first wall 24a when the drain pan 24 is viewed from the second direction D2.

[0053] The receiving portion 24c connects a lower end portion of the first wall 24a and a lower end portion of the second wall 24b. The receiving portion 24c corresponds to a bottom portion of the drain pan. The receiving portion 24c is located below the first header 21 and below the second header 22. A space surrounded by the first wall 24a, the second wall 24b, and the receiving portion 24c is a space for receiving the condensation water and temporarily storing the condensation water as drainage water. The drain outlet 24d is formed in the second wall 24b. When the drain pan 24 is viewed from the second direction D2, the drain outlet 24d is formed at a rectangular corner portion of the drain pan 24. The drain outlet 24d is a hole for discharging the drainage water to the outside of the drain pan 24. As illustrated in FIGS. 7 and 8, the first wall 24a includes a third wall 24k extending in the first direction D1 when viewed from the second direction D2. In other words, the third walls 24k are the two first walls 24a extending along the direction in which the first header 21 and the second header 22 extend among the four first walls 24a surrounding the substantially rectangular opening 24f.

[0054] As illustrated in FIG. 9, the receiving portion 24c has a first surface 24e that is an upper surface inclined to have a downward gradient from the third wall 24k toward the second wall 24b. In other words, when the drain pan 24 is viewed from the second direction D2, the receiving portion 24c has a portion where the height position of the first surface 24e decreases from the center side where the third wall 24k is present toward the outer side where the second wall 24b is present. The first surface 24e corresponds to the bottom surface of the drain pan 24. The first surface 24e is a surface with which the drainage water comes into contact.

[0055] The first surface 24e may be inclined at least between the third wall 24k extending along the first direction D1 and the second wall 24b extending along the first direction D1. In other words, at least the first surface 24e located below the first header 21 and the second header 22 may be inclined to have a downward gradient from the third wall 24k toward the second wall 24b in the third direction D3.

[0056] As illustrated in FIGS. 7 and 8, the receiving portion 24c includes a protruding portion 24j protruding from the first surface 24e. As illustrated in FIG. 4, the protruding portion 24j supports the first header 21 and the second header 22.(3) Feature

[0057] The heat exchange unit 20 includes the first header 21 and the second header 22 provided along the bottom surface of the drain pan 24. In the heat exchange chamber 17 in which the heat exchange unit 20 is provided, the air that exchanges heat with the refrigerant flowing inside the plurality of flat tubes 23 flows downward from above.

[0058] In the heat exchange unit having the above-described configuration, since the volume of the drain pan is reduced due to the header, there may be a problem that the drainage water in the drain pan is unlikely to be discharged.

[0059] In order to solve this problem, the heat exchange unit 20 according to the present embodiment has a configuration in which the first surface 24e, which is the bottom surface of the drain pan 24, is inclined to have a downward gradient from the opening 24f side (center side), through which the heat-exchanged air passes, toward the outer side. Thus, when the drain pan 24 is viewed from the second direction D2, the drainage water on the first surface 24e easily flows from the center side where the third wall 24k is present toward the outer side where the second wall 24b is present. In FIG. 9, the direction in which the drainage water flows on the first surface 24e is indicated by an arrow P1. Since the drainage water flows on the first surface 24e in this manner, the drainage water easily reaches the drain outlet 24d. As a result, the drainage performance of the drainage water in the drain pan 24 is improved. In addition, the drainage water in the drain pan 24 is prevented from scattering due to the airflow (the flow of heat-exchanged air) flowing downward in the vertical direction and from flowing into the opening 24f. Thus, the air handling unit 10 including the heat exchange unit 20 has an effect of suppressing the discharge of the drainage water together with the heat-exchanged air.-Second Embodiment-

[0060] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to the first embodiment. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the first embodiment will be mainly described.

[0061] According to the present embodiment, as illustrated in FIG. 10, when the drain pan 24 is viewed from the first direction D1, the height position of an upper end 24l of the third wall 24k is the same as a first height position or higher than the first height position. The first height position is the height position of an upper end 21a of the first header 21 closest to the third wall 24k in the third direction D3 and the height position of an upper end 22a of the second header 22 closest to the third wall 24k in the third direction D3. In a case where the height position of the upper end 21a of the first header 21 is different from the height position of the upper end 22a of the second header 22, the first height position is a higher height position. The third wall 24k extends upward to the same height position as the first height position or a height position higher than the first height position.

[0062] In the heat exchange unit 20, since the first header 21 and the second header 22 are provided along the bottom surface of the drain pan 24, there is a possibility that the condensation water does not fall into the drain pan 24 while adhering to the upper surfaces of the first header 21 and the second header 22. Therefore, there is a possibility that the condensation water adhering to the upper surfaces of the first header 21 and the second header 22 is blown up and scattered by the air flowing from the upper side to the lower side in the heat exchange chamber 17 and flows into the opening 24f.

[0063] The heat exchange unit 20 according to the present embodiment has a configuration in which the upper end 24l of the third wall 24k is located at a height position equal to or higher than the upper end 21a of the first header 21 and the upper end 22a of the second header 22. Therefore, even when the condensation water adhering to the upper surfaces of the first header 21 and the second header 22 is blown up, the third wall 24k suppresses the condensation water from scattering and flowing into the opening 24f. Further, the blown-up condensation water adheres to the third wall 24k and falls onto the first surface 24e of the drain pan 24 so that the drainage water is likely to accumulate in the drain pan 24. Therefore, by sufficiently securing the height dimension of the third wall 24k in the vertical direction, the drainage water is easily discharged from the drain pan 24.-Third Embodiment-

[0064] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the first and second embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the first embodiment will be mainly described.

[0065] According to the present embodiment, as illustrated in FIG. 11, the third wall 24k includes a fourth wall 24m that is a part of the third wall 24k and includes the upper end 24l of the third wall 24k. In other words, the fourth wall 24m is an upper end portion of the third wall 24k. The fourth wall 24m extends toward the second wall 24b on the opposite side of the opening 24f with respect to the fourth wall 24m when viewed from the first direction D1. In other words, as the fourth wall 24m goes upward, the fourth wall 24m goes from the center side where the third wall 24k is present toward the outer side where the second wall 24b is present. The height position of the upper end of the fourth wall 24m is preferably the same as the first height position or higher than the first height position.

[0066] According to the present embodiment, for the same reason as in the second embodiment, even when the condensation water adhering to the upper surfaces of the first header 21 and the second header 22 is blown up, the third wall 24k suppresses the condensation water from scattering and flowing into the opening 24f. Further, the blown-up condensation water adheres to the third wall 24k and falls onto the first surface 24e of the drain pan 24 so that the drainage water is likely to accumulate in the drain pan 24. Thus, by sufficiently securing the dimension of the third wall 24k in the vertical direction, the drainage water is easily discharged from the drain pan 24.-Fourth Embodiment-

[0067] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the first to third embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the first embodiment will be mainly described.

[0068] According to the present embodiment, as illustrated in FIG. 12, when viewed from the first direction D1, a distance S1 between the third wall 24k and the first header 21 closest to the third wall 24k in the third direction D3 is 50% or more of a width T1 of the first header 21. Further, when viewed from the first direction D1, a distance S2 between the third wall 24k and the second header 22 closest to the third wall 24k in the third direction D3 is 50% or more of a width T2 of the second header 22. The distances S1 and S2 correspond to a distance in the third direction D3. The widths T1 and T2 correspond to a dimension in the third direction D3.

[0069] According to the present embodiment, the distance between the third wall 24k on the center side of the drain pan 24 and the first header 21 or the second header 22 is sufficiently secured. Thus, even when the condensation water adhering to the upper surfaces of the first header 21 and the second header 22 is blown up, the condensation water is prevented from scattering and flowing into the opening 24f.-Fifth Embodiment-

[0070] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the first to fourth embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the first embodiment will be mainly described.

[0071] According to the present embodiment, the first surface 24e of the drain pan 24 is further inclined to have a downward gradient toward the drain outlet 24d. FIG. 8 illustrates, in the first direction D1, a dotted arrow P2 directed from the side opposite to the side where the drain outlet 24d is present toward the side where the drain outlet 24d is present. In the first direction D1, the height position of the first surface 24e decreases along the direction of the arrow P2.

[0072] According to the present embodiment, in the first direction D1, the first surface 24e, which is the bottom surface of the drain pan 24, has a configuration of a downward gradient toward the drain outlet 24d. Thus, since the drainage water on the first surface 24e easily flows toward the drain outlet 24d, the drainage performance of the drainage water in the drain pan 24 is improved.-Sixth Embodiment-

[0073] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the first to fifth embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the first embodiment will be mainly described.

[0074] According to the present embodiment, as illustrated in FIG. 4, when viewed from the first direction D1, a lower end of the first header 21 of the first heat exchange portion 40a is located at a position lower than a lower end of the first header 21 of the second heat exchange portion 40b. Further, when viewed from the first direction D1, the lower end of the second header 22 of the first heat exchange portion 40a is located at a position lower than the lower end of the second header 22 of the second heat exchange portion 40b.

[0075] According to the present embodiment, the heat exchange unit 20 has a configuration in which the lower end of the first heat exchange portion 40a is located at a position lower than the lower end of the second heat exchange portion 40b located further inward. As a result, the effective length of the flat tubes 23 of the first heat exchange portion 40a can be increased, and thus the heat exchange efficiency of the heat exchange unit 20 is improved.-Seventh Embodiment-

[0076] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to the first and second embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the first embodiment will be mainly described.(1) Detailed Configuration of Heat Exchange Unit 20

[0077] Hereinafter, the terms "upstream" and "downstream" are used with reference to the direction of the airflow from the suction port 13 toward the blow-out port 14. The heat exchange chamber 17 is located upstream of the blower chamber 18.

[0078] As illustrated in FIG. 13, the receiving portion 24c is located downstream of the first header 21 and downstream of the second header 22 in the second direction D2. In other words, the receiving portion 24c is located below the first header 21 and below the second header 22.

[0079] As illustrated in FIGS. 14 and 15, the first wall 24a includes the third wall 24k extending in the first direction D1 when viewed from the second direction D2. In other words, the third wall 24k is a part of the first wall 24a. The third walls 24k are the two first walls 24a extending along the first header 21 and the second header 22 among the four first walls 24a surrounding the substantially rectangular opening 24f. When viewed from the first direction D1, the first header 21 or the second header 22 is located between the second wall 24b and the third wall 24k.

[0080] As illustrated in FIG. 16, when viewed from the first direction D1, the third wall 24k overlaps with the range occupied by the first header 21 and the second header 22 in the second direction D2. In other words, the first header 21 is arranged such that, when viewed from the first direction D1, at least a part of the first header 21 is located below an upper end 24k1 of the third wall 24k closest to the first header 21 in the third direction D3. Similarly, the second header 22 is arranged such that, when viewed from the first direction D1, at least a part of the second header 22 is located below an upper end 24k2 of the third wall 24k closest to the second header 22 in the third direction D3.

[0081] As illustrated in FIGS. 14 and 15, the receiving portion 24c includes a protruding portion 24j protruding from the upper surface. As illustrated in FIG. 13, the protruding portion 24j supports the first header 21 and the second header 22.(2) Feature

[0082] The heat exchange unit 20 includes the first header 21 and the second header 22 arranged along the bottom surface of the drain pan 24. In the heat exchange chamber 17 in which the heat exchange unit 20 is arranged, the air that exchanges heat with the refrigerant flowing inside the plurality of flat tubes 23 flows downward from above.

[0083] In the heat exchange unit having the above-described configuration, since the volume of the drain pan is reduced due to the header, there may be a problem that the drainage water in the drain pan is unlikely to be discharged.

[0084] In order to solve this problem, in the heat exchange unit 20 according to the present embodiment, the third wall 24k surrounding the opening 24f of the drain pan 24 overlaps with the range occupied by the first header 21 and the second header 22 in the second direction D2 when viewed from the first direction D1. In other words, the upper ends 24k1 and 24k2 of the third wall 24k extend to the positions of the lower ends of the first header 21 and the second header 22 in the second direction D2. The upper ends 24k1 and 24k2 of the third wall 24k may extend to a position further above the lower ends of the first header 21 and the second header 22 in the second direction D2.

[0085] In addition, in the heat exchange unit 20, since the first header 21 and the second header 22 are arranged along the bottom surface of the drain pan 24, there is a concern that the condensation water does not fall into the drain pan 24 while adhering to the upper surfaces of the first header 21 and the second header 22.

[0086] The heat exchange unit 20 according to the present embodiment has a configuration in which the third wall 24k, which is a part of the first wall 24a on the opening 24f side (center side) of the drain pan 24, has a dimension that overlaps with a part of the first header 21 and the second header 22 in the second direction D2. Therefore, the dimension of the third wall 24k in the second direction D2 (vertical direction) is sufficiently secured. Thus, the third wall 24k suppresses the condensation water adhering to the first header 21 and the second header 22 from being blown up, scattering, and flowing into the opening 24f due to the air flowing downward from above in the heat exchange chamber 17. Further, the blown-up condensation water adheres to the third wall 24k and falls on the bottom surface of the drain pan 24 so that the drainage water is likely to be accumulated in the drain pan 24. Therefore, the drainage water is easily discharged from the drain pan 24. Therefore, the air handling unit 10 including the heat exchange unit 20 has an effect of suppressing the discharge of the drainage water together with the heat-exchanged air.-Eighth Embodiment-

[0087] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to the seventh embodiment. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the seventh embodiment will be mainly described.

[0088] According to the present embodiment, as illustrated in FIG. 17, when the drain pan 24 is viewed from the first direction D1, the third wall 24k closest to the first header 21 in the third direction D3 extends to a first position 21b at which the first header 21 and the first portion 23a are connected to each other in the second direction D2. In other words, the upper end 24k1 of the third wall 24k extends to the first position 21b in the second direction D2. The upper end 24k1 of the third wall 24k may extend to a position further upstream of the first position 21b in the second direction D2. As illustrated in FIG. 17, the first position 21b is the most upstream position among the places where the first portions 23a of the flat tubes 23 are connected to the first header 21 in the second direction D2.

[0089] Similarly, as illustrated in FIG. 17, when the drain pan 24 is viewed from the first direction D1, the third wall 24k closest to the second header 22 in the third direction D3 extends to a second position 22b at which the second header 22 and the second portion 23b are connected to each other in the second direction D2. In other words, the upper end 24k2 of the third wall 24k extends to the second position 22b in the second direction D2. The upper end 24k2 of the third wall 24k may extend to a position further upstream of the second position 22b in the second direction D2. As illustrated in FIG. 17, the second position 22b is the most upstream position among the places where the second portions 23b of the flat tubes 23 are connected to the second header 22 in the second direction D2.

[0090] The heat exchange unit 20 according to the present embodiment has a configuration in which the end portion of the third wall 24k on the center side of the drain pan 24 extends to the connecting portion between the first header 21 or the second header 22 and the flat tube 23. Therefore, the dimension of the third wall 24k in the second direction D2 (vertical direction) is sufficiently secured. Thus, the third wall 24k suppresses the condensation water adhering to the first header 21 and the second header 22 from being blown up, scattering, and flowing into the opening 24f. Further, the blown-up condensation water adheres to the third wall 24k and falls onto the bottom surface of the drain pan 24 so that the drainage water is likely to be accumulated in the drain pan 24. Thus, the drainage water is easily discharged from the drain pan 24.-Ninth Embodiment-

[0091] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the seventh and eighth embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the seventh embodiment will be mainly described.

[0092] According to the present embodiment, as illustrated in FIG. 18, the third wall 24k includes the fourth wall 24m that is a part of the third wall 24k. The fourth wall 24m includes the first end 24l that is an upper end of the third wall 24k. The first end 24l is an end closer to the connecting portion 23c in the second direction D2. In other words, the fourth wall 24m is an upper end portion of the third wall 24k. The fourth wall 24m extends toward the second wall 24b on the opposite side of the opening 24f with respect to the fourth wall 24m when viewed from the first direction D1. In other words, as the fourth wall 24m goes upward, the fourth wall 24m goes from the center side where the third wall 24k is present toward the outer side where the second wall 24b is present. The height position of the first end 24l is preferably the same as the first position 21b and the second position 22b or is preferably higher than the first position 21b and the second position 22b.

[0093] The heat exchange unit 20 according to the present embodiment has a configuration in which the fourth wall 24m, which is the upstream end portion of the third wall 24k on the center side of the drain pan 24, is bent toward the flat tubes 23. Therefore, the third wall 24k prevents the condensation water blown off by the airflow from the surfaces of the first header 21 and the second header 22 from scattering and flowing into the opening 24f. Further, the blown-up condensation water adheres to the third wall 24k and falls on the bottom surface of the drain pan 24 so that the drainage water is likely to be accumulated in the drain pan 24. Therefore, the drainage water is easily discharged from the drain pan 24.-Tenth Embodiment-

[0094] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the seventh to ninth embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the seventh embodiment will be mainly described.

[0095] According to the present embodiment, as illustrated in FIG. 19, the receiving portion 24c has the first surface 24e that is an upper surface inclined to have a downward gradient from the first wall 24a toward the second wall 24b. In other words, when the drain pan 24 is viewed from the second direction D2, the receiving portion 24c has a portion where the height position of the first surface 24e decreases from the center side where the first wall 24a is present toward the outer side where the second wall 24b is present. The first surface 24e corresponds to the bottom surface of the drain pan 24. The first surface 24e is a surface with which the drainage water comes into contact.

[0096] The first surface 24e may be inclined at least between the third wall 24k that is the first wall 24a extending along the first direction D1 and the second wall 24b extending along the first direction D1. In other words, at least the first surface 24e located below the first header 21 and the second header 22 may be inclined to have a downward gradient from the first wall 24a toward the second wall 24b in the third direction D3.

[0097] The heat exchange unit 20 according to the present embodiment has a configuration in which the first surface 24e, which is the bottom surface of the drain pan 24, is inclined to have a downward gradient from the opening 24f side (center side), through which the heat-exchanged air passes, toward the outer side. Accordingly, when the drain pan 24 is viewed from the second direction D2, the drainage water on the first surface 24e easily flows from the center side where the first wall 24a is present toward the outer side where the second wall 24b is present. In FIG. 19, the direction in which the drainage water flows on the first surface 24e is indicated by an arrow P1. Since the drainage water flows on the first surface 24e in this manner, the drainage water easily reaches the drain outlet 24d. As a result, the drainage performance of the drainage water in the drain pan 24 is improved. In addition, the downward airflow (the flow of the heat-exchanged air) in the vertical direction suppresses the drainage water in the drain pan 24 from scattering and flowing into the opening 24f.-Eleventh Embodiment-

[0098] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the seventh to tenth embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the tenth embodiment will be mainly described.

[0099] According to the present embodiment, the receiving portion 24c has the first surface 24e that is the upper surface inclined to have a downward gradient toward the drain outlet 24d. FIG. 15 illustrates, in the first direction D1, a dotted arrow P2 directed from the side opposite to the side where the drain outlet 24d is present toward the side where the drain outlet 24d is present. In the first direction D1, the height position of the first surface 24e decreases along the direction of the arrow P2.

[0100] The heat exchange unit 20 according to the present embodiment has a configuration in which, in the first direction D1, the first surface 24e, which is the bottom surface of the drain pan 24, has a downward gradient toward the drain outlet 24d. Accordingly, since the drainage water on the first surface 24e easily flows toward the drain outlet 24d, the drainage performance of the drainage water in the drain pan 24 is improved.-Twelfth Embodiment-

[0101] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the seventh to eleventh embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the seventh embodiment will be mainly described.

[0102] According to the present embodiment, as illustrated in FIG. 20, when viewed from the first direction D1, the distance S1 between the first wall 24a and the first header 21 closest to the first wall 24a in the third direction D3 is 50% or more of the width T1 of the first header 21. Further, when viewed from the first direction D1, the distance S2 between the first wall 24a and the second header 22 closest to the first wall 24a in the third direction D3 is 50% or more of the width T2 of the second header 22. The distances S1 and S2 correspond to the distance in the third direction D3. The widths T1 and T2 correspond to the dimension in the third direction D3. Here, the first wall 24a refers to the third wall 24k extending along the direction in which the first header 21 and the second header 22 extend among the four first walls 24a surrounding the substantially rectangular opening 24f.

[0103] The heat exchange unit 20 according to the present embodiment has a configuration in which the distance between the first wall 24a on the center side of the drain pan 24 and the first header 21 or the second header 22 is sufficiently secured. Therefore, even when the condensation water adhering to the upper surfaces of the first header 21 and the second header 22 is blown up, the condensation water is prevented from scattering and flowing into the opening 24f.-Thirteenth Embodiment-

[0104] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the seventh to twelfth embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the seventh embodiment will be mainly described.

[0105] According to the present embodiment, as illustrated in FIG. 13, when viewed from the first direction D1, the lower end of the first header 21 of the first heat exchange portion 40a is located at a position lower than the lower end of the first header 21 of the second heat exchange portion 40b. Further, when viewed from the first direction D1, the lower end of the second header 22 of the first heat exchange portion 40a is located at a position lower than the lower end of the second header 22 of the second heat exchange portion 40b.

[0106] The heat exchange unit 20 according to the present embodiment has a configuration in which the lower end of the first heat exchange portion 40a is located at a position lower than the lower end of the second heat exchange portion 40b located further inward. As a result, the effective length of the flat tubes 23 of the first heat exchange portion 40a can be increased, and thus the heat exchange efficiency of the heat exchange unit 20 is improved.-Fourteenth Embodiment-(1) Overall Configuration of Air Handling Unit 10

[0107] The air handling unit 10 includes the casing 11, the support 12, the heat exchange unit 20, and the blower unit 30. As illustrated in FIGS. 21 and 22, the air handling unit 10 is installed horizontally such that the longitudinal direction of the casing 11 extends along the horizontal direction. The internal space of the casing 11 is partitioned into the heat exchange chamber 17 and the blower chamber 18 by the support 12. A water receiving container 19 and the heat exchange unit 20 are installed in the heat exchange chamber 17. The blower unit 30 is installed in the blower chamber 18. The water receiving container 19 is installed below the heat exchange unit 20 and at the bottom of the heat exchange chamber 17. The water receiving container 19 is connected to the support 12.

[0108] The suction port 13 is formed on one surface 11a in the longitudinal direction of the casing 11. The blow-out port 14 is formed on the other surface 11b in the longitudinal direction of the casing 11. The suction duct 15 is connected to the suction port 13. The blow-out duct 16 is connected to the blow-out port 14. The suction port 13 is connected to the suction duct 15 and the heat exchange chamber 17. The blow-out port 14 is connected to the blow-out duct 16 and the blower chamber 18. The heat exchange chamber 17 communicates with the blower chamber 18.

[0109] The blower unit 30 includes a centrifugal fan such as a sirocco fan and a motor that drives the centrifugal fan. By driving the centrifugal fan, the blower unit 30 generates an airflow that is a flow of air from the suction port 13 toward the blow-out port 14 via the heat exchange chamber 17 and the blower chamber 18. The air flows in the horizontal direction in the internal space of the casing 11 from the suction port 13 toward the blow-out port 14. The air carried by the airflow is heat-exchanged by the heat exchange unit 20 when passing through the heat exchange chamber 17. The air handling unit 10 suctions the air from the suction port 13 and blows out the air from the blow-out port 14 after the temperature has been adjusted by heat exchange by the heat exchange unit 20.

[0110] Hereinafter, the terms "upstream" and "downstream" are used with reference to the direction of the airflow from the suction port 13 toward the blow-out port 14. The heat exchange chamber 17 is located upstream of the blower chamber 18.(2) Detailed Configuration of Heat Exchange Unit 20

[0111] The heat exchange unit 20 includes the plurality of flat tubes 23, the first header 21, the second header 22, and the drain pan 24. The heat exchange unit 20 forms a part of a refrigerant circuit that performs a vapor compression refrigeration cycle.(2-1) Plurality of Flat Tubes 23

[0112] As illustrated in FIGS. 21 to 26, the plurality of flat tubes 23 is arranged side by side along a predetermined direction. Hereinafter, the direction in which the plurality of flat tubes 23 is arranged is referred to as the first direction D1. The first direction D1 is parallel to the horizontal direction. In FIGS. 23, 25, and 26, the flat tubes 23 located at the central portion in the first direction D1 are omitted. Further, the direction parallel to the horizontal direction and orthogonal to the first direction D1 is defined as the second direction D2. The second direction D2 is a direction from the upstream side toward the downstream side. Further, the direction orthogonal to the first direction D1 and the second direction D2 is referred to as the third direction D3. The third direction D3 is parallel to the vertical direction. The third direction D3 is a direction in which the drain pan 24 extends when viewed from the first direction D1. The refrigerant that exchanges heat with the air passing through the heat exchange chamber 17 flows inside each of the plurality of flat tubes 23. The first header 21 and the second header 22 are connected to both ends of the plurality of flat tubes 23.

[0113] As illustrated in FIG. 24, the heat exchange unit 20 has a configuration in which the first heat exchange portion 40a and the second heat exchange portion 40b are arranged along the second direction D2. Each of the first heat exchange portion 40a and the second heat exchange portion 40b is a unit including the plurality of flat tubes 23, the first header 21, and the second header 22. When viewed from the first direction D1, the first heat exchange portion 40a is located outside the second heat exchange portion 40b. In other words, the connecting portion 23c of the first heat exchange portion 40a is located upstream of the connecting portion 23c of the second heat exchange portion 40b. The first heat exchange portion 40a is connected to the second heat exchange portion 40b via the refrigerant pipe 25.

[0114] Each of the flat tubes 23 includes the one first portion 23a, the one second portion 23b, and the one connecting portion 23c. As illustrated in FIGS. 24 to 26, the first portion 23a extends in a predetermined direction when viewed from the first direction D1. The second portion 23b extends in a predetermined direction different from the direction in which the first portion 23a extends when viewed from the first direction D1. As illustrated in FIG. 24, the connecting portion 23c connects the first portion 23a and the second portion 23b such that the angles α and β between the direction in which the first portion 23a extends and the direction in which the second portion 23b extends when viewed from the first direction D1 are less than 180°. The connecting portion 23c may connect the first portion 23a and the second portion 23b such that the angles α and β are 90° or less.

[0115] One end portion of the first portion 23a is connected to the first header 21. The other end portion of the first portion 23a is connected to the connecting portion 23c. One end portion of the second portion 23b is connected to the second header 22. The other end portion of the second portion 23b is connected to the connecting portion 23c. The plurality of flat tubes 23 is arranged such that the first header 21 is located above the connecting portion 23c and the connecting portion 23c is located above the second header 22. Therefore, as illustrated in FIG. 24, when viewed from the first direction D1, the plurality of flat tubes 23 has a V-shape rotated 90° clockwise.

[0116] The first portion 23a and the second portion 23b are flat multi-hole tubes having a plurality of passages through which the refrigerant passes. The plurality of passages of the first portion 23a is arranged side by side along a direction orthogonal to the direction in which the first portion 23a extends when viewed from the first direction D1. The plurality of passages of the second portion 23b is arranged side by side along a direction orthogonal to the direction in which the second portion23b extends when viewed from the first direction D1. As illustrated in FIGS. 25 and 26, the connecting portion 23c is a flat multi-hole tube that is partially curved to allow the plurality of passages of the first portion 23a and the plurality of passages of the second portion 23b to communicate with each other.

[0117] As illustrated in FIGS. 24 to 26, the first portion 23a and the second portion 23b are arranged such that the main surfaces thereof extend along the second direction D2 and the third direction D3. The first portion 23a and the second portion 23b are arranged at a predetermined interval along the first direction D1 orthogonal to the main surfaces. Fins are arranged in the gaps between the plurality of first portions 23a arranged along the first direction D1. The first portion 23a and the fin are joined by brazing. Fins are arranged in the gaps between the plurality of second portions 23b arranged along the first direction D1. The second portion 23b and the fin are joined by brazing. The fin is, for example, a corrugated fin formed by plastically deforming a flat plate-shaped metal into a corrugated shape.(2-2) First Header 21 and Second Header 22

[0118] The first header 21 and the second header 22 are connected to both ends of the plurality of flat tubes 23. The first header 21 and the second header 22 are arranged to extend in the first direction D1. The first header 21 and the second header 22 are located upstream of the drain pan 24. The first header 21 and the second header 22 are connected to an external refrigerant circuit via the refrigerant pipe 25.(2-3) Drain Pan 24

[0119] The drain pan 24 receives condensation water from the plurality of flat tubes 23, the first header 21, and the second header 22. The condensation water is water generated on the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22 due to heat exchange between the refrigerant flowing inside the plurality of flat tubes 23 and the air passing through the heat exchange chamber 17. A part of the generated condensation water is blown off by the airflow from the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22, and is received by the drain pan 24. The drain pan 24 is fixed to the support 12. The water receiving container 19 receives the condensation water that has fallen due to its own weight from the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22. As illustrated in FIGS. 21 and 22, the water receiving container 19 has one drain outlet 19d.

[0120] As illustrated in FIGS. 27 to 29, the drain pan 24 includes the first wall 24a, the second wall 24b, and the receiving portion 24c. When viewed from the second direction D2, the drain pan 24 has a substantially rectangular shape.

[0121] The first wall 24a surrounds the opening 24f through which the air flowing through the heat exchange chamber 17 in the second direction D2 passes. The opening 24f is located at a central portion of the drain pan 24 when the drain pan 24 is viewed from the second direction D2. The opening 24f has a substantially rectangular shape when viewed from the second direction D2. The air flowing through the heat exchange chamber 17 in the second direction D2 passes through the opening 24f and flows into the blower chamber 18. The second wall 24b is located outside the first wall 24a when the drain pan 24 is viewed from the second direction D2.

[0122] The receiving portion 24c connects a downstream end portion of the first wall 24a and a downstream end portion of the second wall 24b. The receiving portion 24c corresponds to a bottom portion of the drain pan. The receiving portion 24c is located downstream of the first header 21 and downstream of the second header 22 in the second direction D2. The receiving portion 24c receives the condensation water blown off by the airflow from the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22. The condensation water received by the receiving portion 24c falls and is received by the water receiving container 19, and is temporarily stored as drainage water in the water receiving container 19. The drainage water is discharged from the drain outlet 19d of the water receiving container 19.

[0123] As illustrated in FIGS. 27 and 28, the first wall 24a includes the third wall 24k extending in the first direction D1 when viewed from the second direction D2. In other words, the third wall 24k is a part of the first wall 24a. The third walls 24k are the two first walls 24a extending along the first header 21 and the second header 22 among the four first walls 24a surrounding the substantially rectangular opening 24f. When viewed from the first direction D1, the first header 21 or the second header 22 is located between the second wall 24b and the third wall 24k.

[0124] As illustrated in FIG. 29, the third wall 24k overlaps with the range occupied by the first header 21 and the second header 22 in the second direction D2 when viewed from the first direction D1. In other words, when viewed from the first direction D1, the first header 21 is arranged such that at least a part of the first header 21 is located downstream of an upstream end portion 24k3 of the third wall 24k closest to the first header 21 in the third direction D3. Similarly, when viewed from the first direction D1, the second header 22 is arranged such that at least a part of the second header 22 is located downstream of an upstream end portion 24k4 of the third wall 24k closest to the second header 22 in the third direction D3.(3) Feature

[0125] The heat exchange unit 20 includes the first header 21 and the second header 22 arranged along the receiving portion 24c of the drain pan 24. In the heat exchange chamber 17 in which the heat exchange unit 20 is arranged, the air that exchanges heat with the refrigerant flowing inside the plurality of flat tubes 23 flows from the upstream side toward the downstream side along the second direction D2. The drain pan 24 is installed on the downstream side of the heat exchange unit 20. The drain pan 24 is arranged near the first header 21 and the second header 22 in the second direction D2. The condensation water received by the drain pan 24 and the condensation water that has fallen from the heat exchange unit 20 by its own weight are received by the water receiving container 19 below the heat exchange unit 20.

[0126] In the heat exchange unit that does not include the drain pan 24, there is a concern that the condensation water that has been blown off by the airflow from the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22 will flow into the blower chamber 18 on the downstream side of the heat exchange chamber 17.

[0127] In order to solve this problem, the heat exchange unit 20 according to the present embodiment includes the drain pan 24 located downstream of the first header 21 and the second header 22. Therefore, the condensation water blown off by the airflow from the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22 is received by the drain pan 24.

[0128] In addition, the heat exchange unit 20 according to the present embodiment has a configuration in which the third wall 24k, which is a part of the first wall 24a on the opening 24f side (center side) of the drain pan 24, has a dimension that overlaps with a part of the first header 21 and the second header 22 in the second direction D2. Therefore, the dimension of the third wall 24k in the second direction D2 (horizontal direction) is sufficiently secured. Thus, the third wall 24k suppresses the condensation water adhering to the first header 21 and the second header 22 from being blown up, scattering, and flowing into the opening 24f by the air flowing from the heat exchange chamber 17 toward the blower chamber 18. Therefore, the air handling unit 10 including the heat exchange unit 20 has an effect of suppressing the discharge of the drainage water together with the heat-exchanged air.-Fifteenth Embodiment-

[0129] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to the fourteenth embodiment. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the fourteenth embodiment will be mainly described.

[0130] According to the present embodiment, as illustrated in FIG. 30, when the drain pan 24 is viewed from the first direction D1, the third wall 24k closest to the first header 21 in the third direction D3 extends to the first position 21b at which the first header 21 and the first portion 23a are connected to each other in the second direction D2. In other words, the upstream end portion 24k3 of the third wall 24k extends to the first position 21b in the second direction D2. The upstream end portion 24k3 of the third wall 24k may extend to a position further upstream of the first position 21b in the second direction D2. As illustrated in FIG. 30, the first position 21b is the most upstream position among the places where the first portions 23a of the flat tubes 23 are connected to the first header 21 in the second direction D2.

[0131] Similarly, as illustrated in FIG. 30, when the drain pan 24 is viewed from the first direction D1, the third wall 24k closest to the second header 22 in the third direction D3 extends to the second position 22b where the second header 22 and the second portion 23b are connected to each other in the second direction D2. In other words, the upstream end portion 24k4 of the third wall 24k extends to the second position 22b in the second direction D2. The upstream end portion 24k4 of the third wall 24k may extend to a position further upstream of the second position 22b in the second direction D2. As illustrated in FIG. 30, the second position 22b is the most upstream position among the places where the second portions 23b of the flat tubes 23 are connected to the second header 22 in the second direction D2.

[0132] The heat exchange unit 20 according to the present embodiment has a configuration in which the end portion of the third wall 24k on the center side of the drain pan 24 extends to the connecting portion between the first header 21 or the second header 22 and the flat tubes 23. Therefore, the dimension of the third wall 24k in the second direction D2 (horizontal direction) is sufficiently secured. Thus, the third wall 24k suppresses the condensation water adhering to the first header 21 and the second header 22 from being blown up, scattering, and flowing into the opening 24f.-Sixteenth Embodiment-

[0133] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the fourteenth and fifteenth embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the fourteenth embodiment will be mainly described.

[0134] According to the present embodiment, as illustrated in FIG. 31, the third wall 24k includes the fourth wall 24m that is a part of the third wall 24k. The fourth wall 24m includes the first end 24l that is an upstream end portion of the third wall 24k. The first end 24l is an end closer to the connecting portion 23c in the second direction D2. The fourth wall 24m extends toward the second wall 24b on the opposite side of the opening 24f with respect to the fourth wall 24m when viewed from the first direction D1. In other words, as the fourth wall 24m goes to the upstream side, the fourth wall 24m goes from the center side where the third wall 24k is present toward the outer side where the second wall 24b is present. The position of the first end 24l in the second direction D2 is preferably the same as the first position 21b and the second position 22b or is preferably upstream of the first position 21b and the second position 22b.

[0135] The heat exchange unit 20 according to the present embodiment has a configuration in which the fourth wall 24m, which is the upstream end portion of the third wall 24k on the center side of the drain pan 24, is bent toward the flat tubes 23. Therefore, the third wall 24k prevents the condensation water blown off by the airflow from the surfaces of the first header 21 and the second header 22 from scattering and flowing into the opening 24f.-Seventeenth Embodiment-

[0136] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to any one of the fourteenth to sixteenth embodiments. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the fourteenth embodiment will be mainly described.

[0137] As illustrated in FIG. 32, the first wall 24a includes a fifth wall 24n extending in the first direction D1 above the opening 24f when viewed from the second direction D2. In other words, the fifth wall 24n is a part of the first wall 24a. The fifth wall 24n is one of the four first walls 24a surrounding the substantially rectangular opening 24f. The fifth wall 24n is the third wall 24k located on the upper side in the vertical direction among the two third walls 24k.

[0138] The first header 21 is arranged such that at least a part of the first header 21 is located above the fifth wall 24n when viewed from the first direction D1. In other words, in the second direction D2, the first header 21 is arranged at a position overlapping with the fifth wall 24n.

[0139] The fifth wall 24n has a second surface 24o that is an upper surface inclined to have a downward gradient toward the second direction D2. In other words, the fifth wall 24n has a portion where the height position of the second surface 24o decreases from the upstream side toward the downstream side. The second surface 24o is a surface with which the drainage water comes into contact.

[0140] The heat exchange unit 20 according to the present embodiment has a configuration in which the second surface 24o of the fifth wall 24n located above the opening 24f and below the first header 21 is inclined to have a downward gradient toward the second direction D2, which is the direction of the airflow. Therefore, for example, the condensation water that has fallen from the first header 21 to the second surface 24o flows toward the receiving portion 24c on the downstream side. In FIG. 32, the direction in which the drainage water flows on the second surface 24o is indicated by an arrow P3. Since the drainage water flows on the second surface 24o toward the downstream side, the drainage water is prevented from flowing on the second surface 24o toward the upstream side and flowing into the opening 24f. Further, the condensation water blown off from the surface of the first header 21 by the airflow is prevented from flowing into the opening 24f.-Eighteenth Embodiment-

[0141] The heat exchange unit 20 according to the present embodiment has all the configurations included in the heat exchange unit 20 according to the seventeenth embodiment. Hereinafter, differences between the heat exchange unit 20 according to the present embodiment and the heat exchange unit 20 according to the seventeenth embodiment will be mainly described.

[0142] According to the present embodiment, the second surface 24o of the drain pan 24 is further inclined in the first direction D1. For example, the second surface 24o is further inclined to have a downward gradient in the first direction D1. FIG. 28 illustrates a dotted arrow P4 directed from one side to the other side of the drain pan 24 in the first direction D1. In the first direction D1, the height position of the second surface 24o is lowered along the direction of the arrow P4.

[0143] According to the present embodiment, there is a configuration in which, in the first direction D1, the second surface 24o, which is the upper surface of the fifth wall 24n, includes a portion inclined in the longitudinal direction of the first header 21. Thus, the drainage water on the second surface 24o falls from the second surface 24o and is easily received by the water receiving container 19 so that the drainage performance of the drainage water in the drain pan 24 is improved.-Modification-(1) Modification A

[0144] According to the first to eighteenth embodiments, the heat exchange unit 20 includes the first heat exchange portion 40a and the second heat exchange portion 40b. However, the heat exchange unit 20 may include only one of the first heat exchange portion 40a and the second heat exchange portion 40b. Further, the heat exchange unit 20 may include three or more heat exchange portions similar to the first heat exchange portion 40a and the second heat exchange portion 40b. When the heat exchange unit 20 includes a plurality of heat exchange portions, the heat exchange unit 20 preferably has a configuration in which the downstream end portion of the outer heat exchange portion is located downstream of the downstream end portion of the inner heat exchange portion.(2) Modification B

[0145] According to the first to sixth and tenth embodiments, the first surface 24e of the receiving portion 24c is inclined to have a downward gradient from the third wall 24k toward the second wall 24b. The inclination angle of the first surface 24e may change along the third direction D3. For example, in order to improve the drainage performance of the drain pan 24, the inclination angle of the first surface 24e may gradually increase from the third wall 24k toward the second wall 24b.(3) Modification C

[0146] According to the first to sixth and tenth embodiments, the first surface 24e of the receiving portion 24c is inclined to have a downward gradient from the third wall 24k toward the second wall 24b. However, a part of the first surface 24e does not need to be inclined in the third direction D3.(4) Modification D

[0147] According to the first to thirteenth embodiments, the drain pan 24 includes the one drain outlet 24d, but may include a plurality of drain outlets 24d. For example, when the drain pan 24 includes the two drain outlets 24d, the one drain outlet 24d may be formed in each of the two second walls 24b located at both ends of the drain pan 24 in the first direction D1. In this case, in order to improve the drainage performance of the drain pan 24, it is preferable to have a configuration in which the first surface 24e has a downward gradient from the central portion toward both sides where the two second walls 24b are present, in which the drain outlets 24d are formed, in the first direction D1.(5) Modification E

[0148] According to the seventeenth embodiment, the second surface 24o of the fifth wall 24n is inclined to have a downward gradient from the upstream side toward the downstream side. The inclination angle of the second surface 24o may change from the upstream side toward the downstream side. For example, the inclination angle of the second surface 24o may gradually increase from the upstream side toward the downstream side in order to suppress the inflow of the condensation water into the opening 24f.(6) Modification F

[0149] According to the fourteenth to eighteenth embodiments, the water receiving container 19 includes the one drain outlet 19d, but may include the plurality of drain outlets 19d. In this case, in order to improve the drainage performance of the water receiving container 19, the water receiving container 19 preferably has a configuration in which the bottom surface of the water receiving container 19 is inclined.(7) Modification G

[0150] According to the seventh to thirteenth embodiments, the air handling unit 10 is installed vertically with the longitudinal direction of the casing 11 extending along the vertical direction. However, the air handling unit 10 according to each of the seventh to thirteenth embodiments may be installed horizontally with the longitudinal direction of the casing 11 extending along the horizontal direction. In this case, the air handling unit 10 further includes a member that receives the condensation water that has fallen from the plurality of flat tubes 23, the first header 21, and the second header 22 due to its own weight, like the water receiving container 19 according to the fourteenth to eighteenth embodiments.(8) Modification H

[0151] According to the fourteenth to eighteenth embodiments, the air handling unit 10 is installed horizontally with the longitudinal direction of the casing 11 extending along the horizontal direction. However, the air handling unit 10 according to each of the fourteenth to eighteenth embodiments may be installed vertically with the longitudinal direction of the casing 11 extending along the vertical direction. In this case, the condensation water that has fallen due to its own weight from the plurality of flat tubes 23, the first header 21, and the second header 22 is received by the drain pan 24 and is temporarily stored as drainage water. The drain pan 24 preferably has a hole for discharging the drainage water stored in the drain pan 24 like the drain outlet 24d according to the seventh to thirteenth embodiments.(9) Modification I

[0152] According to the first to thirteenth embodiments, the heat exchange unit 20 includes the first heat exchange portion 40a and the second heat exchange portion 40b. The height position of the first header 21 and the height position of the second header 22 are different between the first heat exchange portion 40a and the second heat exchange portion 40b. For example, according to the second embodiment, as illustrated in FIG. 10, the height position of the upper end 21a of the first header 21 of the first heat exchange portion 40a is different from the height position of the upper end 21a of the first header 21 of the second heat exchange portion 40b. Further, the height position of the upper end 22a of the second header 22 of the first heat exchange portion 40a is different from the height position of the upper end 22a of the second header 22 of the second heat exchange portion 40b.

[0153] This modification can be applied to the first to thirteenth embodiments and the modifications thereof. According to the present modification, the height position of the first header 21 and the height position of the second header 22 are the same between the first heat exchange portion 40a and the second heat exchange portion 40b. To be specific, as illustrated in FIG. 33, the height position of the upper end 21a of the first header 21 of the first heat exchange portion 40a is the same as the height position of the upper end 21a of the first header 21 of the second heat exchange portion 40b. Further, the height position of the upper end 22a of the second header 22 of the first heat exchange portion 40a is the same as the height position of the upper end 22a of the second header 22 of the second heat exchange portion 40b.(10) Modification J

[0154] According to the first to thirteenth embodiments, the drain pan 24 includes the receiving portion 24c. According to the first embodiment, as illustrated in FIG. 9, the first surface 24e, which is the upper surface of the receiving portion 24c, is inclined to have a downward gradient from the third wall 24k toward the second wall 24b.

[0155] This modification can be applied to the first to thirteenth embodiments and the modifications thereof. According to the present modification, the first surface 24e has a stepped shape. To be specific, the first surface 24e includes a plurality of surfaces having different height positions. The height positions of the plurality of surfaces included in the first surface 24e decrease from the third wall 24k toward the second wall 24b. The plurality of surfaces included in the first surface 24e may be inclined to have a downward gradient from the third wall 24k toward the second wall 24b.

[0156] According to the present modification, too, when the drain pan 24 is viewed from the second direction D2, the drainage water on the first surface 24e easily flows from the center side where the third wall 24k is present toward the outer side where the second wall 24b is present. In FIG. 34, the direction in which the drainage water flows on the first surface 24e is indicated by an arrow P1.-Conclusion-

[0157] Although the embodiments according to the present disclosure are described above, it is understood that various modifications may be made to forms and details without departing from the spirit and scope of the present disclosure described in the scope of claims.REFERENCE SIGNS LIST

[0158] 10 air handling unit

[0159] 20 heat exchange unit

[0160] 21 first header

[0161] 22 second header

[0162] 23 flat tube

[0163] 23a first portion

[0164] 23b second portion

[0165] 23c connecting portion

[0166] 24 drain pan

[0167] 24a first wall

[0168] 24b second wall

[0169] 24c receiving portion

[0170] 24d drain outlet

[0171] 24e first surface

[0172] 24f opening

[0173] 24k third wall

[0174] 24l first end

[0175] 24m fourth wall

[0176] 30 blower unit

[0177] 40a first heat exchange portion (heat exchange portion)

[0178] 40b second heat exchange portion (heat exchange portion)

[0179] D1 first direction

[0180] D2 second directionCITATION LISTPATENT LITERATURE

[0181] PTL 1: U.S. Patent No. 5,284,027

Claims

1. A heat exchange unit comprising:a plurality of flat tubes that is arranged along a first direction and allows a refrigerant to flow therein;a first header and a second header that are connected to both ends of the plurality of flat tubes and arranged to extend in the first direction; anda drain pan that receives condensation water from the plurality of flat tubes, the first header, and the second header, whereinthe plurality of flat tubes each includes:a first portion that is connected to the first header and extends in a predetermined direction when viewed from the first direction;a second portion that is connected to the second header and extends in a predetermined direction when viewed from the first direction; anda connecting portion that connects the first portion and the second portion such that an angle between a direction in which the first portion extends and a direction in which the second portion extends when viewed from the first direction is less than 180°,the plurality of flat tubes is arranged such that the connecting portion is located above the first header and the second header,the drain pan includes:a first wall surrounding an opening through which air passes, which flows in a second direction orthogonal to a direction in which the drain pan extends when viewed from the first direction;a second wall located outside the first wall when viewed from the second direction; anda receiving portion connecting the first wall and the second wall below the first header and below the second header,the first wall includes a third wall extending in the first direction when viewed from the second direction, andthe receiving portion has a first surface that is an upper surface inclined to have a downward gradient from the third wall toward the second wall.

2. The heat exchange unit according to claim 1, wherein a height position of an upper end of the third wall is the same as or higher than a height position of upper ends of the first header and the second header.

3. The heat exchange unit according to claim 1, whereinthe third wall includes a fourth wall that is a part of the third wall and includes an upper end of the third wall, andthe fourth wall extends toward the second wall on the opposite side of the opening with respect to the fourth wall when viewed from the first direction.

4. The heat exchange unit according to claim 1, wherein when viewed from the first direction, a distance between the third wall and the first header is 50% or more of a width of the first header, and a distance between the third wall and the second header is 50% or more of a width of the second header.

5. The heat exchange unit according to claim 1, whereinthe drain pan includes a drain outlet for discharging condensation water, andthe first surface is further inclined to have a downward gradient toward the drain outlet.

6. The heat exchange unit according to claim 1, whereina plurality of heat exchange portions including the plurality of flat tubes, the first header, and the second header is arranged along the second direction, andwhen viewed from the first direction, a lower end of the first header of the heat exchange portion is located at a position lower than a lower end of the first header of the heat exchange portion located further inward, and a lower end of the second header of the heat exchange portion is located at a position lower than a lower end of the second header of the heat exchange portion located further inward.

7. The heat exchange unit according to claim 1, wherein the third wall overlaps with a range occupied by the first header and the second header in the second direction when viewed from the first direction.

8. The heat exchange unit according to claim 7, wherein when viewed from the first direction, the third wall extends to a position where the first header and the first portion are connected to each other and a position where the second header and the second portion are connected to each other in the second direction.

9. The heat exchange unit according to claim 7, whereinthe third wall includes a fourth wall that is a part of the third wall and includes a first end of the third wall,the fourth wall extends toward the second wall on the opposite side of the opening with respect to the third wall when viewed from the first direction, andthe first end is an end closer to the connecting portion in the second direction.

10. The heat exchange unit according to claim 7, whereinthe drain pan includes a drain outlet for discharging condensation water, andthe receiving portion has an upper surface that is inclined to have a downward gradient toward the drain outlet.

11. The heat exchange unit according to claim 7, wherein when viewed from the first direction, a distance between the first wall and the first header is 50% or more of a width of the first header, and a distance between the first wall and the second header is 50% or more of a width of the second header.

12. The heat exchange unit according to claim 7, whereina plurality of heat exchange portions including the plurality of flat tubes, the first header, and the second header is arranged along the second direction, andwhen viewed from the first direction, a lower end of the first header of the heat exchange portion is located at a position lower than a lower end of the first header of the heat exchange portion located further inward, and a lower end of the second header of the heat exchange portion is located at a position lower than a lower end of the second header of the heat exchange portion located further inward.

13. An air handling unit comprising:the heat exchange unit according to claim 1; anda blower unit that generates a flow of air that flows in the second direction and exchanges heat with a refrigerant in the heat exchange unit.

14. The heat exchange unit according to claim 2, whereinthe third wall includes a fourth wall that is a part of the third wall and includes an upper end of the third wall, andthe fourth wall extends toward the second wall on the opposite side of the opening with respect to the fourth wall when viewed from the first direction.

15. The heat exchange unit according to claim 2, wherein when viewed from the first direction, a distance between the third wall and the first header is 50% or more of a width of the first header, and a distance between the third wall and the second header is 50% or more of a width of the second header.

16. The heat exchange unit according to claim 3, wherein when viewed from the first direction, a distance between the third wall and the first header is 50% or more of a width of the first header, and a distance between the third wall and the second header is 50% or more of a width of the second header.

17. The heat exchange unit according to claim 2, whereinthe drain pan includes a drain outlet for discharging condensation water, andthe first surface is further inclined to have a downward gradient toward the drain outlet.

18. The heat exchange unit according to claim 3, whereinthe drain pan includes a drain outlet for discharging condensation water, andthe first surface is further inclined to have a downward gradient toward the drain outlet.

19. The heat exchange unit according to claim 4, whereinthe drain pan includes a drain outlet for discharging condensation water, andthe first surface is further inclined to have a downward gradient toward the drain outlet.

20. The heat exchange unit according to claim 2, whereina plurality of heat exchange portions including the plurality of flat tubes, the first header, and the second header is arranged along the second direction, andwhen viewed from the first direction, a lower end of the first header of the heat exchange portion is located at a position lower than a lower end of the first header of the heat exchange portion located further inward, and a lower end of the second header of the heat exchange portion is located at a position lower than a lower end of the second header of the heat exchange portion located further inward.

Images