Heat exchange unit and air handling unit

Abstract

With respect to heat exchange units, drain water in a drain pan may be scattered by a flow of air to be heat-exchanged. Provided is a heat exchange unit (20) comprising: a plurality of flat tubes (23); a first header (21); a second header (22); and a drain pan (24). The first header (21) and the second header (22) are connected to both ends of the plurality of flat tubes (23), and are disposed so as to extend in a first direction (D1) in which the plurality of flat tubes (23) are aligned. Each of the plurality of flat tubes (23) has a first part (23a), a second part (23b), and a connection part (23c). The drain pan (24) has a first wall (24a), a second wall (24b), and a receiving part (24c). The first wall (24a) surrounds an opening (24f). The second wall (24b) is positioned outside the first wall (24a). The receiving part (24c) connects the first wall (24a) and the second wall (24b) below the first header (21) and below the second header (22). The receiving part (24c) has a first surface (24e) which is an upper surface that is inclined so as to have a downward gradient from the first wall (24a) toward the second wall (24b).

Description

Heat exchange unit and air handling unit

[0001] The present invention relates to a heat exchange unit and an air handling unit.

[0002] As disclosed in Patent Document 1 (U.S. Pat. No. 5,284,027), an air handling unit including a heat exchange unit that exchanges heat between a refrigerant and air has been known. The heat exchange unit has a drain pan for temporarily storing and discharging drain water.

[0003] When the header of the heat exchange unit is placed inside the drain pan so that its longitudinal direction is aligned with the bottom surface of the drain pan, the volume of the drain pan is reduced by the header, making it difficult for the drain water in the drain pan to be discharged.

[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 are aligned along a first direction, and a refrigerant flows through the flat tubes. The first and second headers are connected to both ends of the plurality of flat tubes and are 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. Each of the plurality of flat tubes has 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 the predetermined direction when viewed from the first direction. The connecting portion connects the first portion and the second portion such that an angle between the direction in which the first portion extends and the direction in which the second portion extends is less than 180 degrees when viewed from the first direction. The plurality of flat tubes are arranged such that the connecting portion is located above the first and second headers. The drain pan has a first wall, a second wall, and a receiving portion. The first wall surrounds an opening through which air flows in a second direction perpendicular to the extension direction of the drain pan when viewed from a 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. When viewed from the second direction, the first wall includes a third wall extending in the first direction. The receiving portion has a first surface that is an upper surface that slopes downward from the third wall toward the second wall.

[0005] In the heat exchange unit of the first aspect, the bottom surface of the drain pan is inclined downward from the side (center) of the opening through which the air to be heat exchanged passes to the outside, thereby improving the drainage of drain water in the drain pan.

[0006] A heat exchange unit according to a second aspect is the heat exchange unit according to the first aspect, wherein the height position of the upper end of the third wall is the same as or higher than the height positions of the upper ends of the first header and the second header.

[0007] In the heat exchange unit according to the second aspect, the upper end of the side wall of the drain pan on the central side is at a height equal to or higher than the upper end of the header, thereby preventing the drain water from splashing and flowing into the opening.

[0008] A heat exchange unit according to a third aspect is the heat exchange unit according to the first or second aspect, wherein the third wall includes a fourth wall that is a part of the third wall and includes an upper end of the third wall, and the fourth wall extends toward a side of the second wall that is on the opposite side of the opening from the fourth wall when viewed from the first direction.

[0009] In the heat exchange unit according to the third aspect, the upper part of the side wall of the drain pan on the central side (third wall) faces the flat tube side, thereby preventing the drain water from splashing and flowing into the opening.

[0010] A heat exchange unit according to a fourth aspect is the heat exchange unit according to any one of the first to third aspects, wherein the distance between the third wall and the first header when viewed from the first direction is 50% or more of the width of the first header, and the distance between the third wall and the second header when viewed from the first direction is 50% or more of the width of the second header.

[0011] The heat exchange unit according to the fourth aspect has a configuration in which a sufficient distance can be secured between the side wall of the central portion of the drain pan and the header, thereby preventing the drain water from splashing and flowing into the opening.

[0012] A fifth aspect of the present invention is a heat exchange unit according to any one of the first to fourth aspects, wherein the drain pan has a drain outlet for discharging condensation water, and the first surface is further inclined downwardly toward the drain outlet.

[0013] In a heat exchange unit according to a fifth aspect, the bottom surface of the drain pan is configured to slope downwardly toward the drain outlet in the longitudinal direction (first direction) of the header, thereby improving the drainage performance of the drain pan.

[0014] A heat exchange unit according to a sixth aspect is the heat exchange unit according to any one of the first to fifth aspects, wherein a plurality of heat exchange sections, each having a plurality of flat tubes, a first header, and a second header, are arranged along the second direction. When viewed from the first direction, the lower end of the first header of the heat exchange section is positioned lower than the lower end of the first header of the heat exchange section located more inward. When viewed from the first direction, the lower end of the second header of the heat exchange section is positioned lower than the lower end of the second header of the heat exchange section located more inward.

[0015] A heat exchange unit according to a sixth aspect of the present invention includes a plurality of heat exchange sections each having a plurality of flat tubes, and the lower header of the outer heat exchange section is positioned lower than the lower header of the inner heat exchange section, thereby increasing the effective length of the heat exchanger and improving the heat exchange efficiency.

[0016] A heat exchange unit according to a seventh aspect is the heat exchange unit according to the first or second aspect, wherein the third wall, when viewed from the first direction, overlaps with the area occupied by the first header and the second header in the second direction.

[0017] In a seventh aspect of the present invention, a wall (first wall) on the side of the opening (center side) of the drain pan (first wall) has a dimension that overlaps with a part of the header in the air flow direction (second direction), thereby preventing drain water in the drain pan from splashing and flowing into the opening due to the flow of air undergoing heat exchange.

[0018] The heat exchange unit of the eighth aspect is the heat exchange unit of the seventh aspect, wherein the third wall, when viewed from the first direction, extends in the second direction to a position where the first header and the first part are connected and to a position where the second header and the second part are connected.

[0019] In the heat exchange unit of an eighth aspect, an end of a wall of the drain pan on the central side extends to a connection between the header and the flat tubes, thereby preventing the drain water from splashing and flowing into the opening.

[0020] A heat exchange unit according to a ninth aspect is the heat exchange unit according to the seventh or eighth aspect, wherein the third wall includes a fourth wall that is a part of the third wall and includes a first end of the third wall. When viewed from the first direction, the fourth wall extends toward the second wall on the opposite side of the opening from the third wall. The first end is the end closer to the connection portion in the second direction.

[0021] In a heat exchange unit according to a ninth aspect, an upstream end (fourth wall) of a central wall of the drain pan in the second direction is bent toward the flat tube, thereby preventing the drain water from splashing and flowing into the opening.

[0022] A heat exchange unit according to a tenth aspect is the heat exchange unit according to any one of the seventh to ninth aspects, wherein the drain pan has a drain outlet for draining condensation water, and the receiving portion has an upper surface that slopes downwardly toward the drain outlet.

[0023] In a heat exchange unit according to a tenth aspect, the bottom surface of the drain pan is configured to slope downwardly toward the drain outlet in the longitudinal direction (first direction) of the header, thereby improving the drainage performance of the drain pan.

[0024] A heat exchange unit of an eleventh aspect is a heat exchange unit of any one of the seventh to tenth aspects, in which, when viewed from a first direction, the distance between the first wall and the first header is 50% or more of the width of the first header, and the distance between the first wall and the second header is 50% or more of the width of the second header.

[0025] The heat exchange unit according to the eleventh aspect has a configuration in which a sufficient distance can be secured between the side wall of the central portion of the drain pan and the header, thereby preventing the drain water from splashing and flowing into the opening.

[0026] A heat exchange unit according to a twelfth aspect is the heat exchange unit according to any one of the seventh to eleventh aspects, wherein a plurality of heat exchange sections, each having a plurality of flat tubes, a first header, and a second header, are arranged along a second direction. When viewed from the first direction, a lower end of the first header of a heat exchange section is positioned lower than a lower end of a first header of a heat exchange section located more inward, and a lower end of the second header of a heat exchange section is positioned lower than a lower end of a second header of a heat exchange section located more inward.

[0027] A heat exchange unit according to a twelfth aspect of the present invention includes a plurality of heat exchange sections each having a plurality of flat tubes, and the lower header of the outer heat exchange section is positioned lower than the lower header of the inner heat exchange section, thereby increasing the effective length of the heat exchanger and improving the heat exchange efficiency.

[0028] An air handling unit according to a thirteenth aspect includes the heat exchange unit according to any one of the first to twelfth aspects and a blower unit. The blower unit generates a flow of air that flows in a second direction and exchanges heat with a refrigerant in the heat exchange unit.

[0029] The air handling unit of the thirteenth aspect prevents drain water from being discharged together with the air that has undergone heat exchange.

[0030] FIG. 1 is a side view of the interior of the air handling unit 10 of the first embodiment, as viewed from a first direction D1. FIG. 2 is a side view of the interior of the air handling unit 10 of the first embodiment, as viewed from a third direction D3. FIG. 3 is a perspective view of the heat exchange unit 20 of the first embodiment. FIG. 4 is a side view of the heat exchange unit 20 of the first embodiment, as viewed from the first direction D1. FIG. 5 is a cross-sectional view of the drain pan 24. FIG. 6 is a top view of the heat exchange unit 20 of the first embodiment, as viewed from a second direction D2. FIG. 7 is a side view of the heat exchange unit 20 of the first embodiment, as viewed from a third direction D3. FIG. 8 is a perspective view of the drain pan 24 of the first embodiment. FIG. 9 is a top view of the drain pan 24 of the first embodiment. FIG. 10 is a cross-sectional view of the drain pan 24 of the first embodiment, as viewed from the first direction D1. FIG. 11 is a cross-sectional view of the drain pan 24 of the second embodiment, as viewed from the first direction D1. FIG. 12 is a cross-sectional view of the drain pan 24 of the third embodiment, as viewed from the first direction D1. FIG. 13 is a cross-sectional view of the drain pan 24 of the fourth embodiment, as viewed from the first direction D1. 13 is a side view of the heat exchange unit 20 of the seventh embodiment as viewed from the first direction D1. FIG. 13 shows a cross-sectional view of the drain pan 24. FIG. 14 is a perspective view of the drain pan 24 of the seventh embodiment. FIG. 15 is a top view of the drain pan 24 of the seventh embodiment. FIG. 16 is a cross-sectional view of the drain pan 24 of the seventh embodiment as viewed from the first direction D1. FIG. 17 is a cross-sectional view of the drain pan 24 of the eighth embodiment as viewed from the first direction D1. FIG. 18 is a cross-sectional view of the drain pan 24 of the ninth embodiment as viewed from the first direction D1. FIG. 19 is a cross-sectional view of the drain pan 24 of the tenth embodiment as viewed from the first direction D1. FIG. 20 is a cross-sectional view of the drain pan 24 of the twelfth embodiment as viewed from the first direction D1. FIG. 21 is a side view of the interior of the air handling unit 10 of the fourteenth embodiment as viewed from the first direction D1. FIG. 22 is a side view of the interior of the air handling unit 10 of the fourteenth embodiment as viewed from the third direction D3. FIG. 23 is a perspective view of the heat exchange unit 20 of the fourteenth embodiment. FIG. 24 is a side view of the heat exchange unit 20 of the fourteenth embodiment as viewed from the first direction D1. 24 shows a cross-sectional view of the drain pan 24. FIG. 24 is a top view of the heat exchange unit 20 of the fourteenth embodiment as seen from the second direction D2. FIG. 24 is a side view of the heat exchange unit 20 of the fourteenth embodiment as seen from the third direction D3. FIG. 24 is a perspective view of the drain pan 24 of the fourteenth embodiment. FIG. 24 is a top view of the drain pan 24 of the fourteenth embodiment.14 is a cross-sectional view of the drain pan 24 of the fourteenth embodiment when viewed from the first direction D1. FIG. 15 is a cross-sectional view of the drain pan 24 of the fifteenth embodiment when viewed from the first direction D1. FIG. 16 is a cross-sectional view of the drain pan 24 of the sixteenth embodiment when viewed from the first direction D1. FIG. 17 is a cross-sectional view of the drain pan 24 of the seventeenth embodiment when viewed from the first direction D1. FIG. 18 is a cross-sectional view of the drain pan 24 of modified example I when viewed from the first direction D1. FIG. 19 is a cross-sectional view of the drain pan 24 of modified example J when viewed from the first direction D1.

[0031] - First embodiment - (1) Overall configuration of air handling unit 10 Air handling unit 10 includes a casing 11, a support member 12, a heat exchange unit 20, and a blower unit 30. As shown in Figures 1 and 2, air handling unit 10 is installed upright with the longitudinal direction of casing 11 aligned vertically. The internal space of casing 11 is divided by support member 12 into a heat exchange chamber 17 and a blower chamber 18. Heat exchange chamber 17 is located above blower chamber 18. Heat exchange unit 20 is installed in heat exchange chamber 17. Blower unit 30 is installed in blower chamber 18.

[0032] An intake port 13 is formed on the upper surface 11a of the casing 11. An exhaust port 14 is formed on the lower surface 11b of the casing 11. An intake duct 15 is connected above the intake port 13. An exhaust duct 16 is connected below the exhaust port 14. The intake port 13 is connected to the intake duct 15 and a heat exchange chamber 17. The exhaust port 14 is connected to the exhaust duct 16 and an air blowing chamber 18. The heat exchange chamber 17 communicates with the air blowing chamber 18.

[0033] The blower unit 30 has 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 flows from the suction port 13 through the heat exchange chamber 17 and the blower chamber 18 toward the outlet 14. The airflow flows vertically downward through the internal space of the casing 11 from the suction port 13 toward the outlet 14. The air carried by the airflow is heat exchanged by the heat exchange unit 20 as it passes through the heat exchange chamber 17. The air handling unit 10 draws air through the suction port 13 and blows out the air from the outlet 14 after having its temperature adjusted by heat exchange in the heat exchange unit 20.

[0034] (2) Detailed Configuration of Heat Exchanger Unit 20 The heat exchanger unit 20 includes a plurality of flat tubes 23, a first header 21, a second header 22, and a drain pan 24. The heat exchanger unit 20 constitutes a part of a refrigerant circuit that performs a vapor compression refrigeration cycle.

[0035] (2-1) Multiple Flat Tubes 23 As shown in FIGS. 1 to 6 , the multiple flat tubes 23 are arranged side by side in a predetermined direction. Hereinafter, the direction in which the multiple flat tubes 23 are arranged is referred to as the first direction D1. The first direction D1 is parallel to the horizontal direction. In FIGS. 3 , 5 , and 6 , the flat tubes 23 located in the center of the first direction D1 are omitted. The vertically downward direction is referred to as the second direction D2. The second direction D2 is the direction in which air flows through the internal space of the casing 11. The direction perpendicular 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 horizontal direction. The third direction D3 is the direction in which the drain pan 24 extends when viewed from the first direction D1. Refrigerant that exchanges heat with air passing through the heat exchange chamber 17 flows inside each of the multiple flat tubes 23. A first header 21 and a second header 22 are connected to both ends of the plurality of flat tubes 23 .

[0036] As shown in Fig. 4, the heat exchange unit 20 has a configuration in which a first heat exchange section 40a and a second heat exchange section 40b are arranged along the second direction D2. The first heat exchange section 40a and the second heat exchange section 40b are each a unit including a plurality of flat tubes 23, one first header 21, and one second header 22. When viewed from the first direction D1, the first heat exchange section 40a is located outside the second heat exchange section 40b. In other words, the upper end of the first heat exchange section 40a is located higher than the upper end of the second heat exchange section 40b. The first heat exchange section 40a is connected to the second heat exchange section 40b via a refrigerant pipe 25.

[0037] Each flat tube 23 has one first portion 23a, one second portion 23b, and one connecting portion 23c. As shown 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 shown in FIG. 4 , the connecting portion 23c connects the first portion 23a and the second portion 23b so 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 degrees. The connecting portion 23c may also connect the first portion 23a and the second portion 23b so that the angles α and β are 90 degrees or less.

[0038] One end of the first portion 23a is connected to the first header 21. The other end of the first portion 23a is connected to the connection portion 23c. One end of the second portion 23b is connected to the second header 22. The other end of the second portion 23b is connected to the connection portion 23c. The multiple flat tubes 23 are arranged such that the connection portion 23c is located above the first header 21 and the second header 22. Therefore, as shown in FIG. 4 , the multiple flat tubes 23 have a V-shape rotated 180 degrees when viewed from the first direction D1.

[0039] The first portion 23a and the second portion 23b are flat multi-hole pipes having a plurality of passages through which the refrigerant passes. When viewed from the first direction D1, the plurality of passages in the first portion 23a are aligned along a direction perpendicular to the extension direction of the first portion 23a. When viewed from the first direction D1, the plurality of passages in the second portion 23b are aligned along a direction perpendicular to the extension direction of the second portion 23b. As shown in Figures 5 and 6, the connection portion 23c is a flat multi-hole pipe that is partially curved to connect the plurality of passages in the first portion 23a with the plurality of passages in the second portion 23b.

[0040] As shown in Figures 4 to 6, the first portions 23a and the second portions 23b are arranged such that their main surfaces extend along the second direction D2 and the third direction D3. The first portions 23a and the second portions 23b are arranged at a predetermined interval along the first direction D1, which is perpendicular to the main surfaces. Fins are arranged in the gaps between the multiple first portions 23a arranged along the first direction D1. The first portions 23a and the fins are joined by brazing. Fins are arranged in the gaps between the multiple second portions 23b arranged along the first direction D1. The second portions 23b and the fins are joined by brazing. The fins are, for example, corrugated fins formed by plastically deforming a flat metal plate into a corrugated shape.

[0041] (2-2) First Header 21 and Second Header 22 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 above the drain pan 24. The first header 21 and the second header 22 are connected to an external refrigerant circuit via refrigerant piping 25.

[0042] (2-3) Drain Pan 24 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 that is 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 due to its own weight along the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22, and is received in the drain pan 24. The drain pan 24 is fixed to the support member 12.

[0043] 7 to 9, the drain pan 24 has a first wall 24a, a second wall 24b, a receiving portion 24c, and a drain port 24d. When viewed from the second direction D2, the drain pan 24 has a substantially rectangular shape.

[0044] The first wall 24a surrounds an opening 24f through which air flowing through the heat exchange chamber 17 in the second direction D2 passes. The opening 24f is located in the center of the drain pan 24 when 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 air blower chamber 18. The second wall 24b is located outside the first wall 24a when viewed from the second direction D2.

[0045] The receiving portion 24c connects the lower end of the first wall 24a and the lower end of the second wall 24b. The receiving portion 24c corresponds to the bottom of the drain pan. The receiving portion 24c is located below the first header 21 and below the second header 22. The space surrounded by the first wall 24a, the second wall 24b, and the receiving portion 24c is a space for receiving condensed water and temporarily storing it as drain water. The drain outlet 24d is formed in the second wall 24b. The drain outlet 24d is formed in a corner of the rectangular shape of the drain pan 24 when viewed from the second direction D2. The drain outlet 24d is a hole for discharging drain water to the outside of the drain pan 24. As shown 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 wall 24k is two of the four first walls 24a that surround the substantially rectangular opening 24f and that are aligned in the direction in which the first header 21 and the second header 22 extend.

[0046] 9, the receiving portion 24c has a first surface 24e, which is an upper surface that slopes downward from the third wall 24k to 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 located, to the outside, where the second wall 24b is located. The first surface 24e corresponds to the bottom surface of the drain pan 24. The first surface 24e is the surface that comes into contact with the drain water.

[0047] It is sufficient that the first surface 24e is 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, it is sufficient that at least the first surface 24e located below the first header 21 and the second header 22 is inclined downward in the third direction D3 from the third wall 24k toward the second wall 24b.

[0048] 7 and 8, the receiving portion 24c has a protrusion 24j protruding from the first surface 24e. The protrusion 24j supports the first header 21 and the second header 22, as shown in FIG.

[0049] (3) Features The heat exchange unit 20 includes a first header 21 and a second header 22 that are disposed along the bottom surface of the drain pan 24. In the heat exchange chamber 17 in which the heat exchange unit 20 is disposed, air that exchanges heat with the refrigerant flowing inside the flat tubes 23 flows from above downward.

[0050] In a heat exchange unit having the above configuration, the volume of the drain pan is reduced by the header, which may cause a problem that the drain water in the drain pan becomes difficult to discharge.

[0051] To solve this problem, the heat exchange unit 20 of this embodiment has a configuration in which the first surface 24e, which is the bottom surface of the drain pan 24, is inclined downward from the side (center) of the opening 24f through which the air undergoing heat exchange passes toward the outside. As a result, when the drain pan 24 is viewed from the second direction D2, drain water on the first surface 24e is likely to flow from the center where the third wall 24k is located toward the outside where the second wall 24b is located. In FIG. 9 , the direction of drain water flow on the first surface 24e is indicated by arrow P1. This flow of drain water on the first surface 24e facilitates the drain water reaching the drain outlet 24d. As a result, drain water in the drain pan 24 is more efficiently drained. Furthermore, the vertically downward airflow (the flow of air undergoing heat exchange) prevents drain water in the drain pan 24 from scattering and flowing into the opening 24f. Therefore, air handling unit 10 including heat exchange unit 20 has the effect of suppressing drain water from being discharged together with the heat-exchanged air.

[0052] Second Embodiment The heat exchange unit 20 of this embodiment has all the components of the heat exchange unit 20 of the first embodiment. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the first embodiment.

[0053] In this embodiment, as shown in FIG. 10 , when the drain pan 24 is viewed from the first direction D1, the height position of the upper end 24l of the third wall 24k is the same as or higher than the first height position. The first height position refers to the height position of the upper end 21a of the first header 21 that is closest to the third wall 24k in the third direction D3 and the height position of the upper end 22a of the second header 22 that is closest to the third wall 24k in the third direction D3. If 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 the higher height position. The third wall 24k extends upward to the same height position as the first height position or to a height position higher than the first height position.

[0054] In the heat exchange unit 20, the first header 21 and the second header 22 are arranged along the bottom surface of the drain pan 24, so there is a risk that condensation water will remain on the upper surfaces of the first header 21 and the second header 22 and not fall into the drain pan 24. Therefore, there is a risk that the condensation water on the upper surfaces of the first header 21 and the second header 22 will be blown up and scattered by the air flowing from above to below in the heat exchange chamber 17, and will flow into the opening 24f.

[0055] The heat exchange unit 20 of this embodiment has a configuration in which the upper end 24l of the third wall 24k is 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 if condensation water adhering to the upper surfaces of the first header 21 and the second header 22 is blown up, the third wall 24k prevents the condensation water from scattering and flowing into the opening 24f. Furthermore, the blown up condensation water adheres to the third wall 24k and falls onto the first surface 24e of the drain pan 24, making it easier for drain water to accumulate in the drain pan 24. Therefore, by ensuring a sufficient vertical height dimension of the third wall 24k, drain water can be easily discharged from the drain pan 24.

[0056] Third Embodiment The heat exchange unit 20 of this embodiment has all of the configurations of the heat exchange unit 20 of any one of the first and second embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the first embodiment.

[0057] In this embodiment, as shown in FIG. 11 , the third wall 24k includes a fourth wall 24m that is part of the third wall 24k and includes an upper end 24l of the third wall 24k. In other words, the fourth wall 24m is the upper end of the third wall 24k. When viewed from the first direction D1, the fourth wall 24m extends toward the second wall 24b, which is on the opposite side of the opening 24f from the fourth wall 24m. In other words, the fourth wall 24m extends upward from the center, where the third wall 24k is located, toward the outside, where the second wall 24b is located. It is preferable that the height position of the upper end of the fourth wall 24m be the same as or higher than the first height position.

[0058] In this embodiment, for the same reasons as in the second embodiment, even if condensed water adhering to the upper surfaces of the first header 21 and the second header 22 is blown up, the third wall 24k prevents the condensed water from scattering and flowing into the opening 24f. Furthermore, the blown up condensed water adheres to the third wall 24k and falls onto the first surface 24e of the drain pan 24, making it easier for drain water to accumulate in the drain pan 24. Therefore, by ensuring a sufficient vertical dimension of the third wall 24k, drain water can be easily discharged from the drain pan 24.

[0059] Fourth Embodiment The heat exchange unit 20 of this embodiment has all of the configurations of the heat exchange unit 20 of any one of the first to third embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the first embodiment.

[0060] 12 , when viewed from the first direction D1, the 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 the width T1 of the first header 21. Also, when viewed from the first direction D1, the 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 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 dimensions in the third direction D3.

[0061] In the present embodiment, a sufficient distance is ensured between the third wall 24k on the central side of the drain pan 24 and the first header 21 and the second header 22. Therefore, even if condensed water adhering to the upper surfaces of the first header 21 and the second header 22 is blown up, the condensed water is prevented from scattering and flowing into the opening 24f.

[0062] Fifth Embodiment The heat exchange unit 20 of this embodiment has all the configurations of the heat exchange unit 20 of any one of the first to fourth embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the first embodiment.

[0063] In this embodiment, the first surface 24e of the drain pan 24 is further inclined downward toward the drain outlet 24d. In Figure 8, a dotted arrow P2 is shown pointing in the first direction D1 from the side opposite the drain outlet 24d toward the drain outlet 24d. In the first direction D1, the height position of the first surface 24e decreases along the direction of the arrow P2.

[0064] In this embodiment, the first surface 24e, which is the bottom surface of the drain pan 24, has a downward slope toward the drain outlet 24d in the first direction D1. This allows the drain water on the first surface 24e to more easily flow toward the drain outlet 24d, thereby improving the drainage of the drain water in the drain pan 24.

[0065] Sixth Embodiment The heat exchange unit 20 of this embodiment has all of the configurations of the heat exchange unit 20 of any one of the first to fifth embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the first embodiment.

[0066] 4, when viewed from the first direction D1, the lower end of the first header 21 of the first heat exchanger 40a is located lower than the lower end of the first header 21 of the second heat exchanger 40b. Also, when viewed from the first direction D1, the lower end of the second header 22 of the first heat exchanger 40a is located lower than the lower end of the second header 22 of the second heat exchanger 40b.

[0067] In this embodiment, the heat exchange unit 20 has a configuration in which the lower end of the first heat exchange section 40a is located lower than the lower end of the second heat exchange section 40b, which is located further inward. This increases the effective length of the flat tubes 23 of the first heat exchange section 40a, thereby improving the heat exchange efficiency of the heat exchange unit 20.

[0068] Seventh Embodiment The heat exchange unit 20 of this embodiment has all the configurations of the heat exchange unit 20 of the first and second embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the first embodiment.

[0069] (1) Detailed Configuration of Heat Exchange Unit 20 Hereinafter, the terms “upstream side” and “downstream side” are used based on the direction of airflow from the air inlet 13 toward the air outlet 14. The heat exchange chamber 17 is located upstream of the air blower chamber 18.

[0070] 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.

[0071] 14 and 15 , 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 wall 24k is a part of the first wall 24a. Of the four first walls 24a surrounding the substantially rectangular opening 24f, the third wall 24k is two of the first walls 24a that extend along the first header 21 and the second header 22. 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.

[0072] 16 , when viewed from the first direction D1, the third wall 24k overlaps with the areas occupied by the first header 21 and the second header 22 in the second direction D2. In other words, when viewed from the first direction D1, the first header 21 is disposed such that at least a portion of the first header 21 is located below an upper end 24k1 of the third wall 24k that is closest to the first header 21 in the third direction D3. Similarly, when viewed from the first direction D1, the second header 22 is disposed such that at least a portion of the second header 22 is located below an upper end 24k2 of the third wall 24k that is closest to the second header 22 in the third direction D3.

[0073] 14 and 15, the receiving portion 24c has a protrusion 24j protruding from the upper surface thereof. The protrusion 24j supports the first header 21 and the second header 22 as shown in FIG.

[0074] (2) Features The heat exchange unit 20 includes a first header 21 and a second header 22 that are disposed along the bottom surface of the drain pan 24. In the heat exchange chamber 17 in which the heat exchange unit 20 is disposed, air that exchanges heat with the refrigerant flowing inside the flat tubes 23 flows from above downward.

[0075] In a heat exchange unit having the above configuration, the volume of the drain pan is reduced by the header, which may cause a problem that the drain water in the drain pan becomes difficult to discharge.

[0076] To solve this problem, in the heat exchange unit 20 of the present embodiment, the third wall 24k surrounding the opening 24f of the drain pan 24 overlaps with the area 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, 24k2 of the third wall 24k extend in the second direction D2 to the positions of the lower ends of the first header 21 and the second header 22. The upper ends 24k1, 24k2 of the third wall 24k may extend in the second direction D2 to a position even higher than the lower ends of the first header 21 and the second header 22.

[0077] Furthermore, in the heat exchange unit 20, the first header 21 and the second header 22 are arranged so as to be aligned with the bottom surface of the drain pan 24, so there is a risk that condensed water will remain attached to the upper surfaces of the first header 21 and the second header 22 and not fall into the drain pan 24.

[0078] In the heat exchange unit 20 of this embodiment, the third wall 24k, which is a portion of the first wall 24a on the side (center) of the opening 24f of the drain pan 24, is configured to overlap portions 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. This prevents condensation water adhering to the first header 21 and the second header 22 from being blown up and scattered by air flowing from above to below the heat exchange chamber 17 and flowing into the opening 24f. Furthermore, the blown-up condensation water adheres to the third wall 24k and falls to the bottom surface of the drain pan 24, making it easier for drain water to accumulate in the drain pan 24. This facilitates drain water discharge from the drain pan 24. Therefore, the air handling unit 10 including the heat exchange unit 20 effectively prevents drain water from being discharged along with the heat-exchanged air.

[0079] Eighth Embodiment The heat exchange unit 20 of this embodiment has all the components of the heat exchange unit 20 of the seventh embodiment. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the seventh embodiment.

[0080] In this embodiment, as shown 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 the first position 21b where the first header 21 and the first portion 23a are connected 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 than the first position 21b in the second direction D2. As shown in FIG. 17 , the first position 21b is the most upstream position of the points where the first portions 23a of the flat tubes 23 are connected to the first header 21 in the second direction D2.

[0081] Similarly, as shown 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 the second position 22b where the second header 22 and the second portion 23b are connected 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 than the second position 22b in the second direction D2. As shown in FIG. 17 , the second position 22b is the most upstream position of the points where the second portions 23b of the flat tubes 23 are connected to the second header 22 in the second direction D2.

[0082] In the heat exchange unit 20 of this embodiment, the end of the third wall 24k on the central side of the drain pan 24 extends to the connection between the first header 21 and the second header 22 and the flat tubes 23. Therefore, the dimension of the third wall 24k in the second direction D2 (vertical direction) is sufficiently ensured. This prevents condensation water adhering to the first header 21 and the second header 22 from being blown up and splashing and flowing into the opening 24f. Furthermore, the blown up condensation water adheres to the third wall 24k and falls to the bottom surface of the drain pan 24, making it easier for drain water to accumulate in the drain pan 24. This makes it easier for drain water to be discharged from the drain pan 24.

[0083] Ninth Embodiment The heat exchange unit 20 of this embodiment has all the configurations of the heat exchange unit 20 of any one of the seventh to eighth embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the seventh embodiment.

[0084] In this embodiment, as shown in FIG. 18 , the third wall 24k includes a fourth wall 24m that is a part of the third wall 24k. The fourth wall 24m includes a first end 24l that is the upper end of the third wall 24k. The first end 24l is the end closer to the connecting portion 23c in the second direction D2. In other words, the fourth wall 24m is the upper end of the third wall 24k. When viewed from the first direction D1, the fourth wall 24m extends toward the second wall 24b that is on the opposite side of the opening 24f from the fourth wall 24m. In other words, the fourth wall 24m extends upward from the center where the third wall 24k is located toward the outer side where the second wall 24b is located. It is preferable that the height position of the first end 24l be the same as or higher than the first position 21b and the second position 22b.

[0085] In the heat exchange unit 20 of this embodiment, the fourth wall 24m, which is the upstream end of the third wall 24k on the central side of the drain pan 24, is bent toward the flat tubes 23. Therefore, the third wall 24k prevents condensation water blown off the surfaces of the first header 21 and the second header 22 by the airflow from scattering and flowing into the opening 24f. Furthermore, the blown-up condensation water adheres to the third wall 24k and falls to the bottom surface of the drain pan 24, making it easier for drain water to accumulate in the drain pan 24. This makes it easier for drain water to be discharged from the drain pan 24.

[0086] Tenth Embodiment The heat exchange unit 20 of this embodiment has all the configurations of the heat exchange unit 20 of any one of the seventh to ninth embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the seventh embodiment.

[0087] In this embodiment, as shown in Fig. 19, the receiving portion 24c has a first surface 24e, which is an upper surface that slopes downward from the first wall 24a to 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 located, to the outside, where the second wall 24b is located. The first surface 24e corresponds to the bottom surface of the drain pan 24. The first surface 24e is the surface that comes into contact with the drain water.

[0088] It is sufficient that the first surface 24e is inclined at least between the third wall 24k, which 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, it is sufficient that at least the first surface 24e located below the first header 21 and the second header 22 is inclined downward in the third direction D3 from the first wall 24a toward the second wall 24b.

[0089] In the heat exchange unit 20 of this embodiment, the first surface 24e, which is the bottom surface of the drain pan 24, is inclined downward from the side (center) of the opening 24f through which the air undergoing heat exchange passes toward the outside. As a result, when the drain pan 24 is viewed from the second direction D2, drain water on the first surface 24e tends to flow from the center, where the first wall 24a is located, toward the outside, where the second wall 24b is located. In FIG. 19 , the direction of drain water flow on the first surface 24e is indicated by arrow P1. This flow of drain water on the first surface 24e facilitates the drain water reaching the drain outlet 24d. As a result, drain water in the drain pan 24 is more efficiently drained. Furthermore, the vertically downward airflow (the flow of air undergoing heat exchange) prevents drain water in the drain pan 24 from scattering and flowing into the opening 24f.

[0090] Eleventh Embodiment The heat exchange unit 20 of this embodiment has all the configurations of the heat exchange unit 20 of any one of the seventh to tenth embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the tenth embodiment.

[0091] In this embodiment, the receiving portion 24c has a first surface 24e, which is an upper surface that slopes downward toward the drain outlet 24d. In Figure 15, a dotted arrow P2 is shown pointing from the side opposite the drain outlet 24d toward the drain outlet 24d in the first direction D1. In the first direction D1, the height position of the first surface 24e decreases along the direction of the arrow P2.

[0092] In the heat exchange unit 20 of this embodiment, the first surface 24e, which is the bottom surface of the drain pan 24, has a downward slope toward the drain outlet 24d in the first direction D1. This allows the drain water on the first surface 24e to more easily flow toward the drain outlet 24d, thereby improving the drainage of the drain water in the drain pan 24.

[0093] - Twelfth embodiment - The heat exchange unit 20 of this embodiment has all of the configurations of the heat exchange unit 20 of any one of the seventh to eleventh embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the seventh embodiment.

[0094] In this embodiment, as shown 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. Also, 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 dimensions in the third direction D3. Here, the first wall 24a refers to the third wall 24k, of the four first walls 24a surrounding the substantially rectangular opening 24f, that is aligned with the direction in which the first header 21 and the second header 22 extend.

[0095] The heat exchange unit 20 of this embodiment has a configuration in which a sufficient distance is secured between the first wall 24a on the central side of the drain pan 24 and the first header 21 and the second header 22. Therefore, even if condensed water adhering to the upper surfaces of the first header 21 and the second header 22 is blown up, the condensed water is prevented from scattering and flowing into the opening 24f.

[0096] - Thirteenth embodiment - The heat exchange unit 20 of this embodiment has all of the configurations of the heat exchange unit 20 of any one of the seventh to twelfth embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the seventh embodiment.

[0097] 13, when viewed from the first direction D1, the lower end of the first header 21 of the first heat exchanger 40a is located lower than the lower end of the first header 21 of the second heat exchanger 40b. Also, when viewed from the first direction D1, the lower end of the second header 22 of the first heat exchanger 40a is located lower than the lower end of the second header 22 of the second heat exchanger 40b.

[0098] In the heat exchange unit 20 of this embodiment, the lower end of the first heat exchange section 40a is located lower than the lower end of the second heat exchange section 40b, which is located further inward. This increases the effective length of the flat tubes 23 of the first heat exchange section 40a, thereby improving the heat exchange efficiency of the heat exchange unit 20.

[0099] - Fourteenth embodiment - (1) Overall configuration of air handling unit 10 Air handling unit 10 includes a casing 11, a support member 12, a heat exchange unit 20, and a blower unit 30. As shown in Figures 21 and 22, air handling unit 10 is installed horizontally with the longitudinal direction of casing 11 aligned horizontally. The internal space of casing 11 is divided by support member 12 into a heat exchange chamber 17 and a blower chamber 18. A water receiving container 19 and a heat exchange unit 20 are installed in heat exchange chamber 17. A blower unit 30 is installed in blower chamber 18. The water receiving container 19 is installed below heat exchange unit 20 and at the bottom of heat exchange chamber 17. The water receiving container 19 is connected to support member 12.

[0100] An intake port 13 is formed on one longitudinal surface 11a of the casing 11. An exhaust port 14 is formed on the other longitudinal surface 11b of the casing 11. An intake duct 15 is connected to the intake port 13. An exhaust duct 16 is connected to the exhaust port 14. The intake port 13 is connected to the intake duct 15 and a heat exchange chamber 17. The exhaust port 14 is connected to the exhaust duct 16 and an air blowing chamber 18. The heat exchange chamber 17 communicates with the air blowing chamber 18.

[0101] The blower unit 30 has 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 flows from the suction port 13 through the heat exchange chamber 17 and the blower chamber 18 toward the outlet 14. The airflow flows horizontally through the internal space of the casing 11 from the suction port 13 toward the outlet 14. The air carried by the airflow is heat exchanged by the heat exchange unit 20 as it passes through the heat exchange chamber 17. The air handling unit 10 draws air through the suction port 13 and blows out the air from the outlet 14 after having its temperature adjusted by heat exchange in the heat exchange unit 20.

[0102] Hereinafter, the terms “upstream side” and “downstream side” are used based on the direction of airflow from the air inlet 13 toward the air outlet 14. The heat exchange chamber 17 is located upstream of the air blower chamber 18.

[0103] (2) Detailed Configuration of Heat Exchanger Unit 20 The heat exchanger unit 20 includes a plurality of flat tubes 23, a first header 21, a second header 22, and a drain pan 24. The heat exchanger unit 20 constitutes a part of a refrigerant circuit that performs a vapor compression refrigeration cycle.

[0104] (2-1) Multiple Flat Tubes 23 As shown in FIGS. 21 to 26 , the multiple flat tubes 23 are arranged side by side in a predetermined direction. Hereinafter, the direction in which the multiple flat tubes 23 are 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 in the center of the first direction D1 are omitted. Furthermore, the direction parallel to the horizontal direction and perpendicular to the first direction D1 is referred to as the second direction D2. The second direction D2 is the direction from the upstream side to the downstream side. Furthermore, the direction perpendicular 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 the direction in which the drain pan 24 extends when viewed from the first direction D1. Refrigerant that exchanges heat with air passing through the heat exchange chamber 17 flows inside each of the multiple flat tubes 23. A first header 21 and a second header 22 are connected to both ends of the plurality of flat tubes 23 .

[0105] 24 , the heat exchange unit 20 has a configuration in which a first heat exchange section 40a and a second heat exchange section 40b are arranged along the second direction D2. The first heat exchange section 40a and the second heat exchange section 40b are units each including a plurality of flat tubes 23, a first header 21, and a second header 22. When viewed from the first direction D1, the first heat exchange section 40a is located outside the second heat exchange section 40b. In other words, the connection section 23c of the first heat exchange section 40a is located upstream of the connection section 23c of the second heat exchange section 40b. The first heat exchange section 40a is connected to the second heat exchange section 40b via a refrigerant pipe 25.

[0106] Each flat tube 23 has one first portion 23a, one second portion 23b, and one connecting portion 23c. As shown 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 shown in FIG. 24 , the connecting portion 23c connects the first portion 23a and the second portion 23b so 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 degrees. The connecting portion 23c may also connect the first portion 23a and the second portion 23b so that the angles α and β are 90 degrees or less.

[0107] One end of the first portion 23a is connected to the first header 21. The other end of the first portion 23a is connected to the connection portion 23c. One end of the second portion 23b is connected to the second header 22. The other end of the second portion 23b is connected to the connection portion 23c. The multiple flat tubes 23 are arranged such that the first header 21 is located above the connection portion 23c, and the connection portion 23c is located above the second header 22. Therefore, as shown in FIG. 24 , the multiple flat tubes 23 have a V-shape rotated 90 degrees clockwise when viewed from the first direction D1.

[0108] The first portion 23a and the second portion 23b are flat multi-hole pipes having a plurality of passages through which the refrigerant passes. When viewed from the first direction D1, the plurality of passages in the first portion 23a are arranged side by side in a direction perpendicular to the extension direction of the first portion 23a. When viewed from the first direction D1, the plurality of passages in the second portion 23b are arranged side by side in a direction perpendicular to the extension direction of the second portion 23b. As shown in Figures 25 and 26 , the connection portion 23c is a flat multi-hole pipe that is partially curved so as to connect the plurality of passages in the first portion 23a with the plurality of passages in the second portion 23b.

[0109] As shown in Figures 24 to 26, the first portions 23a and the second portions 23b are arranged such that their main surfaces extend along the second direction D2 and the third direction D3. The first portions 23a and the second portions 23b are arranged at a predetermined interval along the first direction D1, which is perpendicular to the main surfaces. Fins are arranged in the gaps between the multiple first portions 23a arranged along the first direction D1. The first portions 23a and the fins are joined by brazing. Fins are arranged in the gaps between the multiple second portions 23b arranged along the first direction D1. The second portions 23b and the fins are joined by brazing. The fins are, for example, corrugated fins formed by plastically deforming a flat metal plate into a corrugated shape.

[0110] (2-2) First Header 21 and Second Header 22 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 refrigerant piping 25.

[0111] (2-3) Drain Pan 24 The drain pan 24 receives condensation water from the flat tubes 23, the first header 21, and the second header 22. The condensation water is water that forms on the surfaces of the flat tubes 23, the first header 21, and the second header 22 due to heat exchange between the refrigerant flowing inside the flat tubes 23 and the air passing through the heat exchange chamber 17. Some of the generated condensation water is blown off the surfaces of the flat tubes 23, the first header 21, and the second header 22 by the airflow and is received in the drain pan 24. The drain pan 24 is fixed to the support member 12. The receiving container 19 receives condensation water that falls due to its own weight from the surfaces of the flat tubes 23, the first header 21, and the second header 22. As shown in FIGS. 21 and 22 , the receiving container 19 has one drain outlet 19d.

[0112] 27 to 29, the drain pan 24 has a first wall 24a, a second wall 24b, and a receiving portion 24c. When viewed from the second direction D2, the drain pan 24 has a substantially rectangular shape.

[0113] The first wall 24a surrounds an opening 24f through which air flowing through the heat exchange chamber 17 in the second direction D2 passes. The opening 24f is located in the center of the drain pan 24 when 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 air blower chamber 18. The second wall 24b is located outside the first wall 24a when viewed from the second direction D2.

[0114] The receiving portion 24c connects the downstream end of the first wall 24a and the downstream end of the second wall 24b. The receiving portion 24c corresponds to the bottom 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 condensation water blown 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 in the receiving portion 24c falls and is received in the receiving container 19, where it is temporarily stored as drain water. The drain water is discharged from the drain outlet 19d of the receiving container 19.

[0115] 27 and 28 , 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 wall 24k is a part of the first wall 24a. Of the four first walls 24a surrounding the substantially rectangular opening 24f, the third wall 24k is two of the first walls 24a that extend along the first header 21 and the second header 22. 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.

[0116] 29 , when viewed from the first direction D1, the third wall 24k overlaps with the areas occupied by the first header 21 and the second header 22 in the second direction D2. In other words, when viewed from the first direction D1, the first header 21 is disposed such that at least a portion of the first header 21 is located downstream of an upstream end 24k3 of the third wall 24k that is closest to the first header 21 in the third direction D3. Similarly, when viewed from the first direction D1, the second header 22 is disposed such that at least a portion of the second header 22 is located downstream of an upstream end 24k4 of the third wall 24k that is closest to the second header 22 in the third direction D3.

[0117] (3) Features The heat exchange unit 20 includes a first header 21 and a second header 22 that are 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, air that exchanges heat with the refrigerant flowing inside the plurality of flat tubes 23 flows from the upstream side to the downstream side along the second direction D2. The drain pan 24 is installed downstream of the heat exchange unit 20. The drain pan 24 is installed near the first header 21 and the second header 22 in the second direction D2. Condensed water received in the drain pan 24 and condensed water that falls from the heat exchange unit 20 due to its own weight are received in a water receiving container 19 below the heat exchange unit 20.

[0118] In a heat exchange unit that does not have a drain pan 24, there is a risk that condensation water blown off the surfaces of the multiple flat tubes 23, the first header 21, and the second header 22 by the air flow will flow into the air blower chamber 18 downstream of the heat exchange chamber 17.

[0119] To solve this problem, the heat exchange unit 20 of this embodiment includes a drain pan 24 disposed downstream of the first header 21 and the second header 22. Therefore, condensation water blown off the surfaces of the plurality of flat tubes 23, the first header 21, and the second header 22 by the airflow is received in the drain pan 24.

[0120] Furthermore, in the heat exchange unit 20 of this embodiment, the third wall 24k, which is a portion of the first wall 24a on the side (center) of the opening 24f of the drain pan 24, is configured to overlap with portions 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. This prevents condensation water adhering to the first header 21 and the second header 22 from being blown up and scattered by air flowing from the heat exchange chamber 17 toward the blower chamber 18 and flowing into the opening 24f. Therefore, the air handling unit 10 including the heat exchange unit 20 effectively prevents drain water from being discharged along with the heat-exchanged air.

[0121] Fifteenth Embodiment The heat exchange unit 20 of this embodiment has all the configurations of the heat exchange unit 20 of the fourteenth embodiment. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the fourteenth embodiment.

[0122] In the present embodiment, as shown 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 where the first header 21 and the first portion 23a are connected in the second direction D2. In other words, the upstream end 24k3 of the third wall 24k extends to the first position 21b in the second direction D2. The upstream end 24k3 of the third wall 24k may extend to a position further upstream than the first position 21b in the second direction D2. As shown in FIG. 30 , the first position 21b is the most upstream position of the points where the first portions 23a of the flat tubes 23 are connected to the first header 21 in the second direction D2.

[0123] Similarly, as shown 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 in the second direction D2. In other words, the upstream end 24k4 of the third wall 24k extends to the second position 22b in the second direction D2. The upstream end 24k4 of the third wall 24k may extend to a position further upstream than the second position 22b in the second direction D2. As shown in FIG. 30 , the second position 22b is the most upstream position in the second direction D2 where the second portion 23b of the flat tube 23 is connected to the second header 22.

[0124] In the heat exchange unit 20 of this embodiment, the end of the third wall 24k on the central side of the drain pan 24 extends to the connection between the first header 21 and 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 ensured. As a result, the third wall 24k prevents condensation water adhering to the first header 21 and the second header 22 from being blown up, scattered, and flowing into the opening 24f.

[0125] Sixteenth Embodiment The heat exchange unit 20 of this embodiment has all of the configurations of the heat exchange unit 20 of any one of the fourteenth to fifteenth embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the fourteenth embodiment.

[0126] In this embodiment, as shown in FIG. 31 , the third wall 24k includes a fourth wall 24m that is a part of the third wall 24k. The fourth wall 24m includes a first end 24l that is the upstream end of the third wall 24k. The first end 24l is the end closer to the connecting portion 23c in the second direction D2. When viewed from the first direction D1, the fourth wall 24m extends toward the second wall 24b that is on the opposite side of the opening 24f from the fourth wall 24m. In other words, the fourth wall 24m extends from the center, where the third wall 24k is located, toward the outside, where the second wall 24b is located, as it moves upstream. It is preferable that the position of the first end 24l in the second direction D2 be the same as the first position 21b and the second position 22b, or be upstream of the first position 21b and the second position 22b.

[0127] In the heat exchange unit 20 of this embodiment, the fourth wall 24m, which is the upstream end of the third wall 24k on the central side of the drain pan 24, is bent toward the flat tubes 23. Therefore, the third wall 24k prevents condensation water blown off the surfaces of the first header 21 and the second header 22 by the airflow from scattering and flowing into the opening 24f.

[0128] - Seventeenth embodiment - The heat exchange unit 20 of this embodiment has all of the configurations of the heat exchange unit 20 of any one of the fourteenth to sixteenth embodiments. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the fourteenth embodiment.

[0129] As shown 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 vertically above the two third walls 24k.

[0130] The first header 21 is disposed such that at least a portion of the first header 21 is located above the fifth wall 24 n when viewed from the first direction D1. In other words, the first header 21 is disposed in a position overlapping with the fifth wall 24 n in the second direction D2.

[0131] The fifth wall 24n has a second surface 24o, which is an upper surface that slopes downward in 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 to the downstream side. The second surface 24o is the surface that comes into contact with the drain water.

[0132] In the heat exchange unit 20 of this embodiment, the second surface 24o of the fifth wall 24n, located above the opening 24f and below the first header 21, is inclined downward toward the second direction D2, which is the direction of the airflow. Therefore, for example, condensation water that falls from the first header 21 onto the second surface 24o flows toward the downstream receiver 24c. In FIG. 32 , the direction of drain water flow on the second surface 24o is indicated by arrow P3. The drain water flowing downstream on the second surface 24o prevents the drain water from flowing upstream on the second surface 24o and flowing into the opening 24f. Furthermore, condensation water blown off the surface of the first header 21 by the airflow is prevented from flowing into the opening 24f.

[0133] - Eighteenth embodiment - The heat exchange unit 20 of this embodiment has all the configurations of the heat exchange unit 20 of the seventeenth embodiment. The following description will focus on the differences between the heat exchange unit 20 of this embodiment and the heat exchange unit 20 of the seventeenth embodiment.

[0134] In this 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 downward in the first direction D1. In Figure 28, a dotted arrow P4 is shown pointing from one side of the drain pan 24 to the other in the first direction D1. In the first direction D1, the height position of the second surface 24o decreases in the direction of the arrow P4.

[0135] In this embodiment, in the first direction D1, the second surface 24o, which is the upper surface of the fifth wall 24n, has a configuration including a portion that is inclined in the longitudinal direction of the first header 21. This makes it easier for the drain water on the second surface 24o to fall from the second surface 24o and be received in the water receiving container 19, thereby improving the drainage of the drain water in the drain pan 24.

[0136] -Modifications- (1) Modification A In the first to eighteenth embodiments, the heat exchange unit 20 has a first heat exchange section 40a and a second heat exchange section 40b. However, the heat exchange unit 20 may have only one of the first heat exchange section 40a and the second heat exchange section 40b. Furthermore, the heat exchange unit 20 may have three or more heat exchange sections similar to the first heat exchange section 40a and the second heat exchange section 40b. When the heat exchange unit 20 has multiple heat exchange sections, it is preferable that the downstream end of an outer heat exchange section be located downstream of the downstream end of an inner heat exchange section.

[0137] (2) Modification B In the first to sixth and tenth embodiments, the first surface 24e of the receiving portion 24c is inclined downward from the third wall 24k toward the second wall 24b. The inclination angle of the first surface 24e may vary along the third direction D3. For example, 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.

[0138] (3) Modification C In the first to sixth and tenth embodiments, the first surface 24e of the receiving portion 24c is inclined downward from the third wall 24k toward the second wall 24b. However, a portion of the first surface 24e does not have to be inclined in the third direction D3.

[0139] (4) Modification D In the first to thirteenth embodiments, the drain pan 24 has one drain outlet 24d, but may have multiple drain outlets 24d. For example, if the drain pan 24 has two drain outlets 24d, 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 that the first surface 24e has a configuration that slopes downward in the first direction D1 from the center toward both sides of the two second walls 24b where the drain outlets 24d are formed.

[0140] (5) Modification E In the seventeenth embodiment, the second surface 24o of the fifth wall 24n is inclined downward from the upstream side to the downstream side. The inclination angle of the second surface 24o may change from the upstream side to the downstream side. For example, in order to prevent condensation water from flowing into the opening 24f, the inclination angle of the second surface 24o may gradually increase from the upstream side to the downstream side.

[0141] (6) Modification F In the fourteenth to eighteenth embodiments, the receiving container 19 has one drain outlet 19 d, but may have multiple drain outlets 19 d. In this case, it is preferable that the receiving container 19 has a sloped bottom surface in order to improve the drainage performance of the receiving container 19.

[0142] (7) Modification G In the seventh to thirteenth embodiments, air handling unit 10 is installed vertically so that the longitudinal direction of casing 11 is aligned vertically. However, air handling unit 10 of the seventh to thirteenth embodiments may also be installed horizontally so that the longitudinal direction of casing 11 is aligned horizontally. In this case, air handling unit 10 further includes a member for receiving condensation water that falls from the flat tubes 23, first header 21, and second header 22 due to their own weight, such as water receiving container 19 of the fourteenth to eighteenth embodiments.

[0143] (8) Modification H In the fourteenth to eighteenth embodiments, the air handling unit 10 is installed horizontally so that the longitudinal direction of the casing 11 is horizontal. However, the air handling unit 10 of the fourteenth to eighteenth embodiments may also be installed vertically so that the longitudinal direction of the casing 11 is vertical. In this case, condensation water that falls from the flat tubes 23, the first header 21, and the second header 22 due to their own weight is received in the drain pan 24 and temporarily stored as drain water. The drain pan 24 preferably has a hole for discharging the drain water stored in the drain pan 24, like the drain outlet 24d in the seventh to thirteenth embodiments.

[0144] (9) Modification I In the first to thirteenth embodiments, the heat exchange unit 20 has a first heat exchange section 40a and a second heat exchange section 40b. The height positions of the first header 21 and the second header 22 differ between the first heat exchange section 40a and the second heat exchange section 40b. For example, in the second embodiment, as shown in FIG. 10 , the height position of the upper end 21a of the first header 21 of the first heat exchange section 40a differs from the height position of the upper end 21a of the first header 21 of the second heat exchange section 40b. Furthermore, the height position of the upper end 22a of the second header 22 of the first heat exchange section 40a differs from the height position of the upper end 22a of the second header 22 of the second heat exchange section 40b.

[0145] This modification can be applied to the first to thirteenth embodiments and their modifications. In this modification, the height positions of the first header 21 and the second header 22 are the same between the first heat exchange section 40a and the second heat exchange section 40b. Specifically, as shown in FIG. 33 , the height position of the upper end 21a of the first header 21 of the first heat exchange section 40a is the same as the height position of the upper end 21a of the first header 21 of the second heat exchange section 40b. Furthermore, the height position of the upper end 22a of the second header 22 of the first heat exchange section 40a is the same as the height position of the upper end 22a of the second header 22 of the second heat exchange section 40b.

[0146] (10) Modification J In the first to thirteenth embodiments, the drain pan 24 has a receiving portion 24c. In the first embodiment, as shown in Fig. 9, the first surface 24e, which is the upper surface of the receiving portion 24c, is inclined downward from the third wall 24k toward the second wall 24b.

[0147] This modification can be applied to the first to thirteenth embodiments and their modifications. In this modification, the first surface 24e has a stepped shape. Specifically, the first surface 24e is composed of multiple surfaces at different height positions. The height positions of the multiple surfaces constituting the first surface 24e decrease from the third wall 24k to the second wall 24b. The multiple surfaces constituting the first surface 24e may be inclined downward from the third wall 24k to the second wall 24b.

[0148] In this modification, when the drain pan 24 is viewed from the second direction D2, the drain water on the first surface 24e tends to flow from the center where the third wall 24k is located toward the outside where the second wall 24b is located. In Figure 34, the direction in which the drain water flows on the first surface 24e is indicated by an arrow P1.

[0149] - Conclusion - Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims.

[0150] DESCRIPTION OF SYMBOLS 10: Air handling unit 20: Heat exchange unit 21: First header 22: Second header 23: Flat tube 23a: First section 23b: Second section 23c: Connection section 24: Drain pan 24a: First wall 24b: Second wall 24c: Receiving section 24d: Drain outlet 24e: First surface 24f: Opening 24k: Third wall 24l: First end 24m: Fourth wall 30: Blower unit 40a: First heat exchange section (heat exchange section) 40b: Second heat exchange section (heat exchange section) D1: First direction D2: Second direction

[0151] U.S. Patent No. 5,284,027

Claims

1. A cooling system comprising: a plurality of flat tubes (23) arranged along a first direction (D1) and through which a refrigerant flows; a first header (21) and a second header (22) connected to both ends of the plurality of flat tubes and arranged to extend in the first direction; and a drain pan (24) for receiving condensation water from the plurality of flat tubes, the first header, and the second header, wherein each of the plurality of flat tubes has: a first portion (23a) connected to the first header and extending in a predetermined direction when viewed from the first direction; a second portion (23b) connected to the second header and extending in a predetermined direction when viewed from the first direction; and a connection portion (23c) connecting 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 is less than 180 degrees when viewed from the first direction; and the plurality of flat tubes are arranged such that the connection portion is located above the first header and the second header, the drain pan has a first wall (24a) surrounding an opening (24f) through which air flowing in a second direction (D2) perpendicular to a direction in which the drain pan extends when viewed from the first direction, a second wall (24b) located outside the first wall when viewed from the second direction, and a receiving portion (24c) connecting the first wall and the second wall below the first header and below the second header, wherein the first wall includes a third wall (24k) extending in the first direction when viewed from the second direction, and the receiving portion has a first surface (24e) that is an upper surface that slopes downwardly from the third wall toward the second wall.

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

3. A heat exchange unit as described in claim 1 or 2, wherein the third wall includes a fourth wall (24m) that is part of the third wall and includes an upper end of the third wall, and the fourth wall extends toward a side of the second wall that is opposite the opening relative to the fourth wall when viewed from the first direction.

4. A heat exchange unit as described in any one of claims 1 to 3, wherein when viewed from the first direction, the distance between the third wall and the first header is 50% or more of the width of the first header, and the distance between the third wall and the second header is 50% or more of the width of the second header.

5. A heat exchange unit as described in any one of claims 1 to 4, wherein the drain pan has a drain outlet (24d) for discharging condensed water, and the first surface is further inclined downwardly toward the drain outlet side.

6. A heat exchange unit as described in any one of claims 1 to 5, wherein a plurality of heat exchange sections (40a, 40b) having the plurality of flat tubes, the first header and the second header are arranged along the second direction, and when viewed from the first direction, a lower end of the first header of the heat exchange section is positioned lower than a lower end of the first header of the heat exchange section located more inward, and a lower end of the second header of the heat exchange section is positioned lower than a lower end of the second header of the heat exchange section located more inward.

7. A heat exchange unit as described in claim 1 or 2, wherein the third wall, when viewed from the first direction, overlaps with an area occupied by the first header and the second header in the second direction.

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

9. A heat exchange unit as described in claim 7 or 8, wherein the third wall includes a fourth wall (24m) that is part of the third wall and includes a first end (24l) of the third wall, the fourth wall extending toward the second wall on the opposite side of the opening relative to the third wall when viewed from the first direction, and the first end being the end closer to the connection portion in the second direction.

10. A heat exchange unit as described in any one of claims 7 to 9, wherein the drain pan has a drain outlet (24d) for draining condensation water, and the receiving portion has an upper surface that slopes downwardly toward the drain outlet.

11. A heat exchange unit as described in any one of claims 7 to 10, wherein when viewed from the first direction, the distance between the first wall and the first header is 50% or more of the width of the first header, and the distance between the first wall and the second header is 50% or more of the width of the second header.

12. A heat exchange unit as described in any one of claims 7 to 11, wherein a plurality of heat exchange sections (40a, 40b) having the plurality of flat tubes, the first header and the second header are arranged along the second direction, and when viewed from the first direction, a lower end of the first header of the heat exchange section is positioned lower than a lower end of the first header of the heat exchange section located more inward, and a lower end of the second header of the heat exchange section is positioned lower than a lower end of the second header of the heat exchange section located more inward.

13. An air handling unit (10), comprising: a heat exchange unit (20) according to any one of claims 1 to 12; and a blower unit (30) for generating a flow of air flowing in the second direction and exchanging heat with a refrigerant in the heat exchange unit.

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