Refrigerating device

Abstract

To provide a refrigerating device that comprises air heat exchangers arranged side by side on a windward side and a leeward side of a flow of air, and restrains a decrease in heat exchange efficiency of the air heat exchanger on the leeward side.SOLUTION: A refrigerating device 10 comprises: a first refrigerant circuit RC1 including a first compressor 21, a first heat exchanger 31, a first expansion valve 41, and a utilization side heat exchanger 34, and using a first refrigerant R1; a second refrigerant circuit RC2 including a second compressor 22, a second heat exchanger 32, and a second expansion valve 42, and using a second refrigerant R2; a third heat exchanger 33 for exchanging heat between the first refrigerant R1 and the second refrigerant R2; and a fan 15. A heat transfer pipe constituting the second heat exchanger 32 is a flat perforated pipe 32a. The second heat exchanger 32 is arranged on a windward side of the first heat exchanger 31 in a direction F of a flow of air generated by the fan 15.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to refrigeration devices. [Background technology]

[0002] A refrigeration system is disclosed that includes a unit including a first refrigerant circuit that is responsible for the main cooling capacity, a second refrigerant circuit that supplements the cooling capacity of the first refrigerant circuit, and a heat exchanger that exchanges heat between the first refrigerant in the first refrigerant circuit and the second refrigerant in the second refrigerant circuit (see Patent Document 1). In the refrigeration system, the first refrigerant and the second refrigerant are different types of refrigerant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2014 / 181399 Summary of the Invention [Problem to be solved by the invention]

[0004] In the refrigeration device, the first air heat exchanger of the first refrigerant circuit and the second air heat exchanger of the second refrigerant circuit may be arranged side by side on the upwind side and downwind side in the flow direction of the air to be heat exchanged. The air heat exchanger generates an area where the air flow is stagnant on the downwind side of the heat transfer tube. Hereinafter, this area is referred to as a "dead water area." Therefore, when the first and second air heat exchangers are arranged side by side on the upwind side and downwind side, the heat exchange efficiency of the air heat exchanger on the downwind side may decrease due to the influence of the dead water area.

[0005] The present disclosure aims to suppress a decrease in heat exchange efficiency of the air heat exchanger on the downwind side in a refrigeration device having air heat exchangers arranged side by side on the upwind and downwind sides of the air flow. [Means for solving the problem]

[0006] (1) The refrigeration device of the present disclosure includes a first refrigerant circuit including a first compressor, a first heat exchanger, a first expansion valve, and a user side heat exchanger, and using a first refrigerant, a second refrigerant circuit including a second compressor, a second heat exchanger, and a second expansion valve, and using a second refrigerant, a third heat exchanger that exchanges heat between the first refrigerant and the second refrigerant, and a fan, wherein a heat transfer tube that constitutes the second heat exchanger is a flat multi-hole tube, and the second heat exchanger is positioned upwind of the first heat exchanger in the flow direction of air generated by the fan.

[0007] The refrigeration device of the present disclosure includes a second heat exchanger using flat multi-hole tubes as heat transfer tubes. A heat exchanger using flat multi-hole tubes as heat transfer tubes can reduce the dead water area formed on the leeward side compared to a heat exchanger using circular tubes as heat transfer tubes. The refrigeration device of the present disclosure can suppress interference between the heat transfer tubes and the dead water area in the first heat exchanger on the leeward side by arranging the second heat exchanger using flat multi-hole tubes on the windward side of the first heat exchanger. This can suppress a decrease in heat exchange efficiency for the first heat exchanger located on the leeward side in the air flow direction.

[0008] (2) The refrigeration device of (1) of the present disclosure preferably includes a plurality of the flat multi-hole tubes and a plurality of heat transfer tubes constituting the first heat exchanger, and a central position of the flat multi-hole tube in the arrangement direction of the plurality of flat multi-hole tubes and a central position of the heat transfer tube in the arrangement direction of the plurality of heat transfer tubes constituting the first heat exchanger preferably have a portion that is offset when viewed from the air flow direction.

[0009] In the refrigeration device of the present disclosure, in the portion where the center position of the flat multi-hole tube and the center position of the heat transfer tube are misaligned, the dead water area formed on the leeward side of the second heat exchanger is formed at a position misaligned from the heat transfer tube of the first heat exchanger. Therefore, in the refrigeration device of the present disclosure, in the first heat exchanger on the leeward side, interference between the dead water area formed on the leeward side of the second heat exchanger and the heat transfer tube can be suppressed. This makes it possible to suppress a decrease in heat exchange efficiency for the first heat exchanger located on the leeward side in the air flow direction.

[0010] (3) In the refrigeration device of (2) of the present disclosure, it is preferable that the heat transfer tubes constituting the first heat exchanger are circular tubes, and a first pitch of the circular tubes in the arrangement direction of the plurality of circular tubes is different from a second pitch of the flat multi-hole tubes in the arrangement direction of the plurality of flat multi-hole tubes.

[0011] In the refrigeration device configured as above, by making the first pitch of the multiple circular tubes located on the leeward side different from the second pitch of the multiple flat multi-hole tubes located on the windward side, it is possible to provide a portion where the center position of the flat multi-hole tube is offset from the center position of the heat transfer tube, thereby suppressing interference between the dead water area formed on the leeward side of the second heat exchanger and the circular tubes constituting the leeward first heat exchanger. This makes it possible to suppress a decrease in heat exchange efficiency for the first heat exchanger located on the leeward side in the air flow direction.

[0012] (4) In the refrigeration device according to any one of aspects (1) to (3) of the present disclosure, it is preferable that the second heat exchanger is configured with a heat exchanger including a plurality of the flat multi-hole tubes and serpentine fins arranged between adjacent flat multi-hole tubes.

[0013] The refrigeration device of the present disclosure can efficiently exchange heat by the second heat exchanger, and can reduce the amount of the second refrigerant used.

[0014] (5) The refrigeration device according to the aspect (1) of the present disclosure preferably includes a plurality of the flat multi-hole tubes and a plurality of heat transfer tubes constituting the first heat exchanger, the heat transfer tubes constituting the first heat exchanger being circular tubes, the first heat exchanger preferably including a first heat transfer tube group in which the plurality of circular tubes are arranged in a first arrangement direction, and a second heat transfer tube group adjacent to the downwind side of the first heat transfer tube group in the air flow direction and in which the plurality of circular tubes are arranged in a second arrangement direction parallel to the first arrangement direction, wherein a central position of the circular tube included in the first heat transfer tube group in the first arrangement direction and a central position of the circular tube included in the second heat transfer tube group in the second arrangement direction are offset from each other as viewed in the air flow direction, and the central position of the flat multi-hole tube in the arrangement direction of the plurality of flat multi-hole tubes and a central position of the circular tube included in the first heat transfer tube group in the first arrangement direction are preferably offset from each other as viewed in the air flow direction.

[0015] The refrigeration device of the present disclosure can suppress interference between the dead water area formed on the leeward side of the second heat exchanger and the circular tubes included in the first heat transfer tube group, thereby suppressing a decrease in heat exchange efficiency for the first heat exchanger located on the leeward side in the air flow direction.

[0016] (6) The refrigeration device of the aspect (1) of the present disclosure preferably includes a plurality of the flat multi-hole tubes and a plurality of heat transfer tubes constituting the first heat exchanger, the heat transfer tubes constituting the first heat exchanger being flat multi-hole tubes, and a central position of the flat multi-hole tube in the arrangement direction of the plurality of flat multi-hole tubes in the second heat exchanger and a central position of the flat multi-hole tube in the arrangement direction of the plurality of flat multi-hole tubes in the first heat exchanger preferably have a portion that coincides when viewed from the air flow direction.

[0017] In the refrigeration device of the above configuration, when both the heat transfer tubes of the first heat exchanger and the heat transfer tubes of the second heat exchanger are flat multi-hole tubes, the refrigeration device can suppress a decrease in heat exchange efficiency for the first heat exchanger located on the downwind side in the air flow direction.

[0018] (7) In the refrigeration device according to any one of the aspects (1) to (6) of the present disclosure, it is preferable that the second refrigerant is a refrigerant that is flammable, toxic, or has a global warming potential of 4 or more.

[0019] The refrigeration device having the above configuration can reduce the amount of the second refrigerant used when a refrigerant that is flammable, toxic, or has a global warming potential of 4 or more is used as the second refrigerant. [Brief description of the drawings]

[0020] [Figure 1] 1 is an explanatory diagram of a refrigerant circuit of a refrigeration device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional explanatory plan view of a heat source side unit in the refrigeration device. [Diagram 3] FIG. 2 is a cross-sectional explanatory side view of a heat source unit in the refrigeration apparatus. [Figure 4] FIG. 2 is a schematic diagram of a first heat exchanger according to the first and second embodiments. [Figure 5A] FIG. 2 is a partial cross-sectional schematic view showing a heat transfer tube and fins that configure a first heat exchanger according to the first embodiment. [Figure 5B] FIG. 11 is a partial cross-sectional schematic view showing a heat transfer tube and fins that configure a first heat exchanger according to a second embodiment. [Figure 6] FIG. 11 is a schematic diagram of a first heat exchanger according to a third embodiment. [Figure 7] FIG. 11 is a partial cross-sectional schematic view showing a heat transfer tube and fins that configure a first heat exchanger according to a third embodiment. [Figure 8] FIG. 4 is a schematic diagram showing a second heat exchanger. [Figure 9] 4 is a partial cross-sectional schematic view showing a heat transfer tube and fins that configure a second heat exchanger. FIG. [Figure 10A] FIG. 11 is an explanatory diagram of the formation of a dead water area when the heat transfer tube is a circular tube. [Figure 10B] FIG. 11 is an explanatory diagram of the formation of dead water areas when the heat transfer tube is a flat multi-hole tube. [Figure 11]FIG. 4 is an explanatory diagram of a case where the first heat exchanger according to the first embodiment is disposed on the downwind side of the second heat exchanger. [Figure 12] FIG. 11 is an explanatory diagram of a case in which a first heat exchanger according to a second embodiment is disposed on the downwind side of a second heat exchanger. [Figure 13] FIG. 11 is an explanatory diagram of a case in which a first heat exchanger according to a third embodiment is disposed on the downwind side of a second heat exchanger. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] (Overall configuration of the refrigeration system) Hereinafter, an embodiment of the refrigeration device of the present disclosure will be described in detail with reference to the accompanying drawings. FIG. 1 is an explanatory diagram of a refrigerant circuit of a refrigeration device according to an embodiment of the present disclosure. As shown in FIG. 1, a refrigeration device 10 of the present disclosure includes a heat source unit 11, a user unit 12, a refrigerant pipe 13 connecting the heat source unit 11 and the user unit 12, and a fan 15. The refrigeration device 10 illustrated in this embodiment is an air conditioner that conditions a target space using the user unit 12. The refrigeration device 10 is a separate type air conditioner separated into a heat source unit (outdoor unit) 11 and a user unit (indoor unit) 12. Note that, although the refrigeration device 10 illustrated in this embodiment is an air conditioner, the refrigeration device of the present disclosure may be, for example, a refrigeration case, and is not limited to an air conditioner. The refrigerant pipe 13 includes a gate valve 18 at a portion where the refrigerant enters and leaves the housing of the heat source unit 11.

[0022] The heat source side unit 11 includes a first compressor 21, a second compressor 22, a first heat exchanger 31, a second heat exchanger 32, a third heat exchanger 33, a first expansion valve 41, a second expansion valve 42, a four-way switching valve 50, a first accumulator 51, and a second accumulator 52. The utilization side unit 12 includes a utilization side heat exchanger 34.

[0023] The refrigeration device 10 includes a first refrigerant circuit RC1 including a first compressor 21, a first heat exchanger 31, a first expansion valve 41, a utilization side heat exchanger 34, and a refrigerant pipe 13 connecting these, and a second refrigerant circuit RC2 including a second compressor 22, a second heat exchanger 32, a second expansion valve 42, and a refrigerant pipe 14 connecting these. The first refrigerant circuit RC1 uses a first refrigerant R1 as a refrigerant and performs a refrigeration cycle operation. The second refrigerant circuit RC2 uses a second refrigerant R2 different from the first refrigerant R1 as a refrigerant and performs a refrigeration cycle operation.

[0024] The first compressor 21 and the second compressor 22 suck in low-pressure gas refrigerant and discharge high-pressure gas refrigerant. The first compressor 21 and the second compressor 22 are equipped with a motor (not shown) capable of adjusting the operating rotation speed by inverter control. The first compressor 21 and the second compressor 22 are variable capacity type (variable capacity type) in which the capacity (capacity) can be changed by inverter control of the motor. However, the first compressor 21 and the second compressor 22 may be a fixed capacity type.

[0025] The four-way switching valve 50 reverses the flow of the first refrigerant R1 in the refrigerant pipe 13 of the first refrigerant circuit RC1, and can switch whether the first refrigerant R1 discharged from the first compressor 21 is supplied to the first heat exchanger 31 or the utilization side heat exchanger 34. The refrigeration system 10 can switch between cooling operation and heating operation by switching the flow direction of the first refrigerant R1 with the four-way switching valve 50. Note that the refrigeration system 10 of this embodiment may be used exclusively for cooling by omitting the four-way switching valve.

[0026] The first expansion valve 41 is configured with an electric valve capable of adjusting the flow rate of the first refrigerant R1. During cooling operation, the refrigeration device 10 adjusts the cooling capacity exerted by the first refrigerant circuit RC1 by adjusting the opening of the first expansion valve 41 with a control device (not shown). During heating operation, the refrigeration device 10 fully opens the first expansion valve 41 with a control device (not shown).

[0027] The second expansion valve 42 is configured by an electric valve capable of adjusting the flow rate of the second refrigerant R2. During cooling operation, the refrigeration device 10 adjusts the cooling capacity exerted by the second refrigerant circuit RC2 by adjusting the opening degree of the second expansion valve 42 using a control device (not shown).

[0028] The refrigeration system 10 supplements the cooling capacity of the first refrigerant circuit RC1 with the cooling capacity of the second refrigerant circuit RC2 by exchanging heat between the first refrigerant R1 and the second refrigerant R2 in the third heat exchanger 33. During cooling operation, the refrigeration system 10 adjusts the amount of heat exchange between the first refrigerant R1 and the second refrigerant R2 by a control device (not shown) adjusting the opening degree of the second expansion valve 42.

[0029] [Heat source unit] FIG. 2 is a cross-sectional explanatory diagram of a heat source unit in a refrigeration device in a plan view. FIG. 3 is a cross-sectional explanatory diagram of a heat source unit in a refrigeration device in a side view. FIG. 3 shows a cross section taken along line AA in FIG. 2. In the following description, the descriptions of up, down, front, rear, left, and right follow the arrows shown in FIG. 2 and FIG. 3. Specifically, for example, in FIG. 2 and FIG. 3, among the mutually orthogonal arrows X, Y, and Z, the direction indicated by the arrow X (first direction) is the left-right direction, the direction indicated by the arrow Y (second direction) is the front-rear direction, and the direction indicated by the arrow Z (third direction) is the up-down direction. In the following description, the left-right direction is also referred to as the first direction X, the front-rear direction is also referred to as the second direction Y, and the up-down direction is also referred to as the third direction Z. However, these descriptions are merely examples, and for example, the direction X may be read as the front-rear direction, and the direction Y may be read as the left-right direction.

[0030] As shown in Figs. 1 to 3, the heat source side unit 11 includes a housing 60. As shown in Figs. 2 and 3, the housing 60 is formed in a rectangular parallelepiped shape, and is formed in a rectangular shape in a plan view. The inside of the housing 60 is divided into a machine chamber S1 and a heat exchange chamber S2 by a partition wall 61. Air intakes 64, 65 are formed in two adjacent side walls 62, 63 of the housing 60 arranged on the heat exchange chamber S2 side. An air outlet 67 is formed in the other side wall 66 adjacent to the one side wall 63 in which the air intake 65 is formed.

[0031] The machine room S1 accommodates the first compressor 21, the second compressor 22, the third heat exchanger 33, the first accumulator 51, and the second accumulator 52. In addition to these, the machine room S1 also accommodates a four-way switching valve 50 (not shown), a first expansion valve 41 (not shown), a second expansion valve 42 (not shown), an oil separator, etc. A control board (not shown) is disposed in the machine room S1, and each device constituting the refrigeration device 10 is controlled by this control board.

[0032] The heat exchange chamber S2 accommodates a first heat exchanger 31, a second heat exchanger 32, a fan 15, and a fan motor 16. The fan 15 is connected to a rotating shaft of the fan motor 16, and is driven to rotate by the fan motor 16.

[0033] The first heat exchanger 31 has a heat transfer tube (heat transfer tube 31a described later) through which the first refrigerant R1 circulating in the first refrigerant circuit RC1 flows. The first heat exchanger 31 is connected to the first compressor 21 in the machine room S1 via a refrigerant pipe 13 (see FIG. 1). The second heat exchanger 32 has a heat transfer tube (heat transfer tube 32a described later) through which the second refrigerant R2 circulating in the second refrigerant circuit RC2 flows. The second heat exchanger 32 is connected to the second compressor 22 in the machine room S1 via a refrigerant pipe 14 (see FIG. 1).

[0034] The fan 15 is disposed in such a position that the positive pressure side faces the side wall 66 on which the air outlet 67 is formed, and the negative pressure side faces the side wall 62 on which the air inlet 64 is formed. When the fan motor 16 is operated, the fan 15 rotates, and air is taken into the heat exchange chamber S2 through the air inlets 64 and 65. The air taken into the heat exchange chamber S2 passes through the first heat exchanger 31 and is heat exchanged with the first refrigerant R1, and then passes through the second heat exchanger 32 and is heat exchanged with the second refrigerant R2, and is then exhausted from the air outlet 67. The fan 15 generates an air flow passing through the first heat exchanger 31 and the second heat exchanger 32. The refrigerant passing through the insides of the first heat exchanger 31 and the second heat exchanger 32 exchanges heat with the air passing through the first heat exchanger 31 and the second heat exchanger 32. As shown in FIG. 1 to FIG. 3, the direction of the air flow generated by the fan 15 is indicated by an arrow F. In the following description, the air flow direction will be referred to as air flow direction F.

[0035] The first heat exchanger 31 shown in this embodiment has a portion extending in the left-right direction and a portion extending in the front-rear direction, and is bent near a corner 68 to form an L-shape in a plan view. Note that the shape of the first heat exchanger 31 provided in the refrigeration device 10 of the present disclosure is not limited thereto, and may be, for example, rectangular in a plan view.

[0036] The second heat exchanger 32 shown in this embodiment is formed in a rectangular shape in a plan view. The second heat exchanger 32 is disposed on the windward side of the first heat exchanger 31 in the air flow direction F along a side wall 62 in which an air intake 64 is formed.

[0037] [First heat exchanger (first embodiment)] FIG. 4 is a schematic diagram of the first heat exchanger according to the first and second embodiments. FIG. 5A is a partial cross-sectional schematic diagram showing a heat transfer tube and a fin constituting the first heat exchanger according to the first embodiment. In FIG. 4 and FIG. 5A, a first embodiment of the first heat exchanger 31 constituting the refrigeration device 10 of the present disclosure is shown. In the following description, the first heat exchanger 31 according to the first embodiment is also referred to as the first heat exchanger 31A. The first heat exchanger 31A according to the first embodiment is a so-called cross-fin type fin-and-tube heat exchanger. The first heat exchanger 31A has a heat transfer tube 31a, a plurality of fins 31b, and a pair of tube plates 31c, 31d. The first heat exchanger 31A exchanges heat between the first refrigerant R1 in the first refrigerant circuit RC1 and the air passing through the first heat exchanger 31.

[0038] The heat transfer tube 31a is a circular tube made of metal. The metal constituting the heat transfer tube 31a may be copper, copper alloy, stainless steel, aluminum, aluminum alloy, or the like. Hereinafter, the heat transfer tube 31a is also referred to as the circular tube 31a. The multiple fins 31b are thin metal plates, formed into a rectangular shape in a side view, and arranged parallel to each other at a predetermined interval in the width direction. The metal constituting the fins 31b may be aluminum, aluminum alloy, or the like.

[0039] The circular tube (heat transfer tube) 31a includes a plurality of straight tube sections 31x formed in a linear shape and a plurality of curved tube sections 31y formed in a U-shape. The straight tube sections 31x penetrate the fins 31b in the direction in which the fins 31b are arranged. The curved tube sections 31y are disposed at the width direction end of the first heat exchanger 31 and connect two adjacent straight tube sections 31x to each other.

[0040] The tube sheets 31c, 31d are metal plates formed into a rectangular shape in a side view, and are arranged in pairs on both sides in the width direction of the first heat exchanger 31. The tube sheets 31c, 31d are connected to both ends of each straight tube portion 31x of the circular tube 31a, and support the circular tube 31a. The tube sheets 31c, 31d are arranged parallel to the fins 31b, as shown in FIG.

[0041] [First heat exchanger (second embodiment)] FIG. 5B is a partial cross-sectional schematic diagram showing a heat transfer tube and a fin constituting the first heat exchanger according to the second embodiment. In FIG. 4 and FIG. 5B, a second embodiment of the first heat exchanger 31 constituting the refrigeration device 10 of the present disclosure is shown. In the following description, the first heat exchanger 31 according to the second embodiment is also referred to as the first heat exchanger 31B. The first heat exchanger 31B according to the second embodiment is a so-called cross-fin type fin-and-tube heat exchanger. The first heat exchanger 31B has a heat transfer tube 31a, a plurality of fins 31b, and a pair of tube plates 31c, 31d. The first heat exchanger 31B exchanges heat between the first refrigerant R1 in the first refrigerant circuit RC1 and the air passing through the first heat exchanger 31. The first heat exchanger 31B shown in this embodiment has the heat transfer tube 31a, the fins 31b, and the tube plates 31c, 31d in common with the first heat exchanger 31A according to the first embodiment.

[0042] [First heat exchanger (third embodiment)] FIG. 6 is a schematic diagram of a first heat exchanger according to a third embodiment. FIG. 7 is a partial cross-sectional schematic diagram showing a heat transfer tube and a fin constituting the first heat exchanger according to the third embodiment. In FIGS. 6 and 7, a third embodiment of the first heat exchanger 31 constituting the refrigeration device 10 of the present disclosure is shown. In the following description, the first heat exchanger 31 according to the third embodiment is also referred to as a first heat exchanger 31C. The refrigeration device 10 of this embodiment may employ a microchannel type heat exchanger as the first heat exchanger 31, instead of a cross-fin type fin-and-tube heat exchanger (see FIGS. 4, 5A, and 5B).

[0043] As shown in Figures 6 and 7, the first heat exchanger 31C according to the third embodiment is a microchannel type heat exchanger. The first heat exchanger 31C has a plurality of heat transfer tubes 31e, fins 31f, and a pair of headers 31g, 31h. The heat transfer tubes 31e, the fins 31f, and the headers 31g, 31h are made of aluminum or an aluminum alloy. The first heat exchanger 31C exchanges heat between the first refrigerant R1 in the first refrigerant circuit RC1 and the air passing through the first heat exchanger 31C.

[0044] As shown in FIG. 7, the heat transfer tube 31e in the first heat exchanger 31C according to the third embodiment is configured as a multi-hole tube having a plurality of refrigerant flow paths 35 therein. The cross section of the heat transfer tube 31e has a flat shape having a short side direction and a long side direction. The long side direction of the heat transfer tube 31e is the direction in which the plurality of refrigerant flow paths 35 are arranged. The plurality of refrigerant flow paths 35 are arranged along the air flow direction F. Hereinafter, the heat transfer tube 31e in the first heat exchanger 31 according to the third embodiment is also referred to as a flat multi-hole tube 31e.

[0045] 6 and 7, in the first heat exchanger 31C, a plurality of heat transfer tubes 31e are arranged in the longitudinal direction. The headers 31g and 31h are arranged with their longitudinal directions facing the short side direction of the heat transfer tube 31e. One end of the heat transfer tube 31e is connected to the header 31g, and the other end of the heat transfer tube 31e is connected to the header 31h. The fins 31f are arranged in a serpentine manner between the adjacent heat transfer tubes 31e.

[0046] The first heat exchanger 31C of this embodiment is a so-called parallel flow type heat exchanger among microchannel type heat exchangers. The heat transfer tubes 31e constituting the first heat exchanger 31C are flat multi-hole tubes, and the fins 31f are serpentine fins arranged between adjacent flat multi-hole tubes. The fins 31f constituting the first heat exchanger 31C are so-called corrugated fins. In general, when a cross-fin type heat exchanger and a parallel flow type heat exchanger having the same heat exchange amount are compared, the parallel flow type heat exchanger has a smaller internal volume (internal liquid amount) than the cross-fin type heat exchanger. Therefore, by adopting the parallel flow type first heat exchanger 31C, the refrigeration device 10 can suppress the usage amount of the first refrigerant R1 compared to the case of adopting the cross-fin type heat exchanger.

[0047] [Second heat exchanger] FIG. 8 is a schematic diagram showing the second heat exchanger. FIG. 9 is a partial cross-sectional schematic diagram showing the heat transfer tubes and fins constituting the second heat exchanger. The second heat exchanger 32 constituting the refrigeration device 10 of the present disclosure is a microchannel type heat exchanger. As shown in FIGS. 8 and 9, the second heat exchanger 32 has a plurality of heat transfer tubes 32a, fins 32b, and a pair of headers 32c, 32d. The heat transfer tubes 32a, the fins 32b, and the headers 32c, 32d are formed of aluminum or an aluminum alloy. The second heat exchanger 32 exchanges heat between the second refrigerant R2 in the second refrigerant circuit RC2 and the air passing through the second heat exchanger 32. In the refrigeration device 10 of this embodiment, the second heat exchanger 32 is supported by using a support member 70 (see FIGS. 2 and 3) for supporting the fan 15.

[0048] As shown in FIG. 9, the heat transfer tube 32a is configured as a multi-hole tube having a plurality of refrigerant flow paths 36 therein. The cross section of the heat transfer tube 32a has a flat shape having a short side direction and a long side direction. The heat transfer tube 32a has a longitudinal direction in which the plurality of refrigerant flow paths 36 are arranged. The plurality of refrigerant flow paths 36 are arranged along the air flow direction F. As shown in FIG. 8 and FIG. 9, the plurality of refrigerant flow paths 36 are arranged in the second direction Y and extend in the first direction X. Hereinafter, the heat transfer tube 32a is also referred to as a flat multi-hole tube 32a.

[0049] As shown in Figs. 8 and 9, in the second heat exchanger 32, a plurality of heat transfer tubes 32a are arranged in the third direction Z. The headers 32c and 32d are arranged with their longitudinal directions facing the third direction Z. One end of the heat transfer tube 32a is connected to the header 32c, and the other end of the heat transfer tube 32a is connected to the header 32d. The fins 32b are arranged in a serpentine manner between the heat transfer tubes 32a adjacent to each other above and below. Note that the orientation of the second heat exchanger 32 in the refrigeration device 10 of this embodiment is not limited thereto, and may be used in an orientation in which the third direction Z faces the left-right direction, for example.

[0050] 9, the end faces of the flat multi-hole tube 32a in the third direction Z, in other words, the upper and lower faces of the flat multi-hole tube 32a, are flat surfaces along the first direction X and the second direction Y. Both end faces of the flat multi-hole tube 32a in the first direction X are curved surfaces whose cross sections are curved in a semicircular shape.

[0051] The fins 32b have approximately the same length as the flat multi-hole tubes 32a in the second direction Y. Therefore, in the second heat exchanger 32, the flat multi-hole tubes 32a and the fins 32b are flush with each other at both end faces in the second direction Y.

[0052] The second heat exchanger 32 of this embodiment is a so-called parallel flow type heat exchanger among microchannel type heat exchangers. The heat transfer tubes constituting the second heat exchanger 32 are flat multi-hole tubes 32a, and the fins 32b are serpentine fins arranged between adjacent flat multi-hole tubes. The fins 32b are so-called corrugated fins. In general, when a cross-fin type heat exchanger and a parallel flow type heat exchanger having the same heat exchange amount are compared, the parallel flow type heat exchanger has a smaller internal volume (internal liquid amount) than the cross-fin type heat exchanger. Therefore, by adopting a parallel flow type heat exchanger as the second heat exchanger 32, the refrigeration device 10 can reduce the usage amount of the second refrigerant R2 compared to the case where a cross-fin type heat exchanger is adopted.

[0053] [Third heat exchanger] The third heat exchanger 33 constituting the refrigeration device 10 of the present disclosure is a plate-type heat exchanger. As shown in FIG. 1, the third heat exchanger 33 has a first flow path 33a and a second flow path 33b formed between stacked plates. In the third heat exchanger 33, the first flow path 33a is connected to the first refrigerant circuit RC1, and the first refrigerant R1 flows through the first flow path 33a. In the third heat exchanger 33, the second flow path 33b is connected to the second refrigerant circuit RC2, and the second refrigerant R2 flows through the second flow path 33b. The third heat exchanger 33 exchanges heat between the first refrigerant R1 flowing through the first flow path 33a and the second refrigerant R2 flowing through the second flow path 33b. The refrigeration device 10 exchanges heat between the first refrigerant R1 and the second refrigerant R2 by the third heat exchanger 33, and supplements the cooling capacity of the first refrigerant circuit RC1 with the cooling capacity of the second refrigerant circuit RC2.

[0054] (First and second refrigerants) The refrigeration device 10 of the present disclosure preferably uses natural refrigerants as the first refrigerant R1 and the second refrigerant R2. Natural refrigerants are refrigerants that use substances that originally exist in nature, and include, for example, ammonia (NH3), carbon dioxide (CO2), water (H2O), and hydrocarbons (HC). The refrigeration device 10 of this embodiment uses carbon dioxide (CO2: R744) as the first refrigerant R1 and propane (C3H8: R290) as the second refrigerant R2. The global warming potential (GWP) of carbon dioxide (CO2) is "1", and the global warming potential (GWP) of propane (C3H8) is "3". Note that the first refrigerant R1 used in the refrigeration device of the present disclosure is not limited to carbon dioxide (CO2), and the second refrigerant R2 used in the refrigeration device of the present disclosure is not limited to propane (C3H8). The second refrigerant R2 used in the refrigeration apparatus of the present disclosure may be R32, R1234yf, R474a, R600a (isobutane), R454B, R454C, or the like.

[0055] The refrigeration system 10 of the present disclosure has a configuration suitable for employing a harmful natural refrigerant as the second refrigerant R2. Here, "harmful" means flammability (including mild flammability), toxicity, and a global warming potential of 4 or more. The refrigeration system 10 of the present disclosure is configured to use the second heat exchanger 32, which is a "parallel flow type heat exchanger," and therefore can reduce the amount of use of such a "harmful" second refrigerant R2.

[0056] (About dead water areas) FIG. 10A is an explanatory diagram of the formation of a dead water area when the heat transfer tube is a circular tube. FIG. 10B is an explanatory diagram of the formation of a dead water area when the heat transfer tube is a flat multi-hole tube. When air passes through the first heat exchanger 31, as shown in FIG. 10A and FIG. 10B, a "dead water area" is formed on the leeward side of the heat transfer tube (heat transfer tubes 31a, 31e). The "dead water area" is an area formed on the downstream side of an object placed in the flow, where large and small eddies exist and the fluid is in a stationary state. Since the "dead water area" is a part that is not related to the flow of fluid, when the heat transfer tube interferes with the dead water area, the greater the degree of interference, the lower the heat exchange efficiency between the heat transfer tube and the air in the area where the interference occurs.

[0057] In the following description, as shown in FIG. 10A, the "dead water area" formed on the leeward side of the heat transfer tube (circular tube) 31a constituting the first heat exchanger 31 is referred to as the first dead water area D1, and the formation length of the first dead water area D1 in the air flow direction F is referred to as the first formation length L1. In the following description, as shown in FIG. 10B, the "dead water area" formed on the leeward side of the heat transfer tube 31e constituting the first heat exchanger 31 is referred to as the second dead water area D2, and the formation length of the second dead water area D2 in the air flow direction F is referred to as the second formation length L2. The heat transfer tube 31e is a flat multi-hole tube. In the following description, the heat transfer tube 31e that is a flat multi-hole tube is also referred to as the flat multi-hole tube 31e.

[0058] When comparing a heat exchanger having a heat transfer tube 31a as the heat transfer tube and a heat exchanger having a flat multi-hole tube 31e as the heat transfer tube, which have the same heat exchange capacity, the first formation length L1 of the first dead water area D1 in the heat transfer tube 31a is generally larger than the second formation length L2 of the second dead water area D2 in the heat transfer tube 31e.

[0059] (Arrangement of the first and second heat exchangers) 1 to 3, in the refrigeration device 10, the second heat exchanger 32 is disposed on the windward side of the first heat exchanger 31 in the flow direction F of the air generated by the fan 15. Below, the relationship between the second dead water area D2 formed downwind of the second heat exchanger 32 and the heat transfer tubes of the first heat exchanger 31 will be described for cases in which three types of first heat exchangers 31 with different configurations are used.

[0060] (When the first heat exchanger according to the first embodiment is disposed) FIG. 11 is an explanatory diagram of a case where the first heat exchanger according to the first embodiment is disposed on the leeward side of the second heat exchanger. FIG. 11 shows the arrangement of the first heat exchanger 31A and the second heat exchanger 32 when the first heat exchanger 31A according to the first embodiment is adopted in the refrigeration device 10. In the following description, the center position of each heat transfer tube 31a in the arrangement direction (third direction Z) of the multiple heat transfer tubes 31a constituting the first heat exchanger 31 is referred to as the center position z1. In the following description, the center position of each heat transfer tube 32a in the arrangement direction (third direction Z) of the multiple heat transfer tubes 32a constituting the second heat exchanger 32 is referred to as the center position z2. The center position z2 is the center in the thickness direction of the flat multi-hole tube 32a. Note that the illustration of the fins 31b and 32b is omitted in FIG. 11.

[0061] When the first heat exchanger 31A is employed in the refrigeration device 10 of the present disclosure, the first heat exchanger 31C and the second heat exchanger 32 are arranged so that there is a portion where the center position z1 of each heat transfer tube 31a and the center position z2 of each heat transfer tube 32a are misaligned. Note that, although the present embodiment illustrates a case where there is no portion where the center position z1 and the center position z2 coincide, the first heat exchanger 31A and the second heat exchanger 32 may be arranged so that there is a portion where the center position z1 and the center position z2 coincide.

[0062] 11, in a portion where the center position z2 of the flat multi-hole tube 32a is offset from the center position z1 of the heat transfer tube 31a, the second dead water area D2 formed on the leeward side of the second heat exchanger 32 is formed at a position offset from the heat transfer tube 31a of the first heat exchanger 31. The refrigeration system 10 configured in this manner can suppress interference between the second dead water area D2 formed on the leeward side of the second heat exchanger 32 and the heat transfer tube 31a. This can suppress a decrease in heat exchange efficiency for the first heat exchanger 31 located on the leeward side of the air flow direction F.

[0063] As shown in FIG. 11, in the refrigeration device 10 of the present disclosure, it is preferable that the first pitch P1 of the heat transfer tube 31a of the first heat exchanger 31 and the second pitch P2 of the heat transfer tube 32a of the second heat exchanger 32 are different. When the first pitch P1 and the second pitch P2 are different, a portion where the center position z2 of the flat multi-hole tube 32a and the center position z1 of the heat transfer tube 31a are misaligned can be inevitably generated. The refrigeration device 10 configured in this manner can suppress interference between the second dead water area D2 formed on the leeward side of the second heat exchanger 32 and the heat transfer tube 31a. This can suppress a decrease in heat exchange efficiency for the first heat exchanger 31 located on the leeward side of the air flow direction F.

[0064] (When the first heat exchanger according to the second embodiment is disposed) 12 is an explanatory diagram of a case where the first heat exchanger according to the second embodiment is arranged on the downwind side of the second heat exchanger. FIG. 12 shows the arrangement of the first heat exchanger 31B and the second heat exchanger 32 when the first heat exchanger 31B according to the second embodiment is adopted in the refrigeration device 10. The first heat exchanger 31B (see FIG. 5B) includes heat transfer tubes 31a in which straight tube portions 31x are arranged in a staggered manner in a side view. As shown in FIG. 12, the heat transfer tubes 31a in the first heat exchanger 31B include a first heat transfer tube group G1 in which a plurality of circular tubes (straight tube portions 31x) are arranged in a first arrangement direction (third direction Z) and a second heat transfer tube group G2 in which a plurality of circular tubes (straight tube portions 31x) are arranged in a second arrangement direction (third direction Z) on the downwind side of the first arrangement direction. In the first heat exchanger 31B, the first arrangement direction and the second arrangement direction are parallel to each other. In the following description, the center position of each heat transfer tube 31a in the first arrangement direction (third direction Z) of the plurality of heat transfer tubes 31a constituting the first heat exchanger 31B is referred to as the center position z1a. In the following description, the center position of each heat transfer tube 31a in the second arrangement direction (third direction Z) of the plurality of heat transfer tubes 31a constituting the first heat exchanger 31B is referred to as the center position z1b. In the first heat exchanger 31B, the center position z1a of each heat transfer tube 31a in the first arrangement direction (third direction Z) of each heat transfer tube 31a included in the first heat transfer tube group G1 is shifted from the center position z1b of each heat transfer tube 31a in the second arrangement direction (third direction Z) of each heat transfer tube 31a included in the second heat transfer tube group G2. In FIG. 12, the fins 31b and the fins 32b are omitted.

[0065] When the first heat exchanger 31B is employed in the refrigeration device 10, the first heat exchanger 31A and the second heat exchanger 32 are arranged such that there is a portion where the center position z1a of each heat transfer tube 31a in the first arrangement direction (third direction Z) and the center position z2 of each heat transfer tube 32a are misaligned. Note that, although the present embodiment illustrates a case where there is no portion where the center position z1a and the center position z2 coincide with each other, the first heat exchanger 31B and the second heat exchanger 32 may be arranged such that there is a portion where the center position z1a and the center position z2 coincide with each other.

[0066] In addition, when the first heat exchanger 31B is adopted in the refrigeration device 10, the first heat exchanger 31A and the second heat exchanger 32 may be configured such that the center position z1b of each heat transfer tube 31a in the arrangement direction of each heat transfer tube 31a included in the second heat transfer tube group G2 among the multiple heat transfer tubes 31a coincides with the center position z2 of each heat transfer tube 32a in the arrangement direction of the multiple heat transfer tubes 32a that constitute the second heat exchanger 32.

[0067] 12, in a portion where the center position z2 of the flat multi-hole tube 32a is offset from the center position z1a of the heat transfer tube 31a included in the first heat transfer tube group G1, the second dead water area D2 formed on the leeward side of the second heat exchanger 32 is formed at a position offset from the heat transfer tube 31a included in the first heat transfer tube group G1. The refrigeration device 10 configured in this manner can suppress interference between the second dead water area D2 formed on the leeward side of the second heat exchanger 32 and the heat transfer tube 31a included in the first heat transfer tube group G1. This can suppress a decrease in heat exchange efficiency for the first heat exchanger 31B located on the leeward side in the air flow direction F.

[0068] (When the first heat exchanger according to the third embodiment is disposed) Fig. 13 is an explanatory diagram of the positional relationship between the first heat exchanger and the second heat exchanger according to the third embodiment. Fig. 13 shows the arrangement of the first heat exchanger 31C and the second heat exchanger 32 when the first heat exchanger 31C according to the third embodiment is adopted in the refrigeration device 10. In the following description, the center position of each heat transfer tube 31e in the arrangement direction (third direction Z) of the multiple heat transfer tubes 31e constituting the first heat exchanger 31 is referred to as the center position z1. The center position z1 is the center in the thickness direction of the heat transfer tube (flat multi-hole tube) 31e. Note that the fins 31f and fins 32b are omitted from Fig. 13.

[0069] When the first heat exchanger 31C is employed in the refrigeration device 10 of the present disclosure, the first heat exchanger 31C and the second heat exchanger 32 are arranged so that the center position z1 of each heat transfer tube 31a and the center position z2 of each heat transfer tube 32a have a portion where they coincide. Note that, although the present embodiment illustrates a case where the center positions z1 and z2 all coincide, the first heat exchanger 31C and the second heat exchanger 32 may have a portion where the center positions z1 and z2 are misaligned.

[0070] When both the heat transfer tubes 31a of the first heat exchanger 31 and the heat transfer tubes 32a of the second heat exchanger 32 are flat multi-hole tubes, by arranging the first heat exchanger 31 and the second heat exchanger 32 as shown in Figure 13, it is possible to suppress a decrease in heat exchange efficiency for the first heat exchanger 31 located on the downwind side of the air flow direction F.

[0071] [Effects of the embodiment] (1) The refrigeration device 10 of the above embodiment includes a first refrigerant circuit RC1 including a first compressor 21, a first heat exchanger 31, a first expansion valve 41, and a utilization side heat exchanger 34 and using a first refrigerant R1, a second refrigerant circuit RC2 including a second compressor 22, a second heat exchanger 32, and a second expansion valve 42 and using a second refrigerant R2, a third heat exchanger 33 exchanging heat between the first refrigerant R1 and the second refrigerant R2, and a fan 15. In the refrigeration device 10, the heat transfer tube constituting the second heat exchanger 32 is a flat multi-hole tube 32a, and the second heat exchanger 32 is disposed on the windward side of the first heat exchanger 31 in the flow direction F of the air generated by the fan 15.

[0072] The refrigeration device 10 of the above embodiment includes the second heat exchanger 32 using flat multi-hole tubes 32a as heat transfer tubes. A heat exchanger using flat multi-hole tubes as heat transfer tubes can reduce the dead water area formed on the leeward side compared to a heat exchanger using circular tubes as heat transfer tubes. The refrigeration device 10 arranges the second heat exchanger 32 using the flat multi-hole tubes 32a on the upwind side of the first heat exchanger 31, thereby suppressing interference with the dead water area for the heat transfer tubes 31a of the first heat exchanger 31 on the leeward side. This can suppress a decrease in heat exchange efficiency for the first heat exchanger 31 located on the leeward side of the air flow direction F.

[0073] (2) The refrigeration device 10 of the above embodiment includes a plurality of flat multi-hole tubes 32a and a plurality of heat transfer tubes 31a constituting the first heat exchanger 31. The refrigeration device 10 has a portion where a center position z2 of the flat multi-hole tube 32a in the arrangement direction of the plurality of flat multi-hole tubes 32a and a center position z1 of the heat transfer tube 31a in the arrangement direction of the plurality of heat transfer tubes 31a constituting the first heat exchanger 31 are misaligned when viewed from the air flow direction F.

[0074] In the portion where the center position z2 of the flat multi-hole tube 32a is misaligned with the center position z1 of the heat transfer tube 31a, the second dead water area D2 formed on the leeward side of the second heat exchanger 32 is formed at a position misaligned from the heat transfer tube 31a constituting the first heat exchanger 31. Therefore, the refrigeration device 10 of this embodiment can suppress interference between the second dead water area D2 formed on the leeward side of the second heat exchanger 32 and the heat transfer tube 31a of the first heat exchanger 31 on the leeward side. This can suppress a decrease in heat exchange efficiency for the first heat exchanger 31 located on the leeward side in the air flow direction F.

[0075] (3) In the refrigeration device 10 of the above embodiment, the heat transfer tubes constituting the first heat exchanger 31 are circular tubes 31a, and a first pitch P1 of the circular tubes 31a in the arrangement direction of the multiple circular tubes 31a is different from a second pitch P2 of the flat multi-hole tubes 32a in the arrangement direction of the multiple flat multi-hole tubes 32a.

[0076] In the refrigeration device 10 of the above embodiment, the first pitch P1 of the circular tubes 31a located on the leeward side is different from the second pitch P2 of the flat multi-hole tubes 32a located on the windward side, so that a portion where the dead water area formed on the leeward side of the second heat exchanger 32 and the circular tubes 31a of the first heat exchanger 31 are misaligned can be provided. Therefore, the refrigeration device 10 of the present embodiment can suppress interference between the dead water area formed on the leeward side of the second heat exchanger 32 and the circular tubes 31a constituting the leeward side of the first heat exchanger 31. This can suppress a decrease in the heat exchange efficiency of the first heat exchanger 31 located on the leeward side of the air flow direction F.

[0077] (4) In the refrigeration device 10 of the above embodiment, the second heat exchanger 32 is configured by a heat exchanger including a plurality of flat multi-hole tubes 32a and serpentine fins 32b arranged between adjacent flat multi-hole tubes 32a.

[0078] The refrigeration system 10 configured as above can perform efficient heat exchange by the second heat exchanger 32. Furthermore, the refrigeration system 10 configured as above can reduce the amount of the second refrigerant R2 used.

[0079] (5) The refrigeration device 10 of the above embodiment includes a plurality of flat multi-hole tubes 32a and a plurality of heat transfer tubes 31a constituting the first heat exchanger 31. In the refrigeration device 10, the heat transfer tubes constituting the first heat exchanger 31 are circular tubes 31a. The first heat exchanger 31 includes a first heat transfer tube group G1 in which a plurality of circular tubes 31a are arranged in a first arrangement direction, and a second heat transfer tube group G2 adjacent to the downwind side of the first heat transfer tube group G1 in the air flow direction F and in which a plurality of circular tubes 31a are arranged in a second arrangement direction parallel to the first arrangement direction. In the refrigeration device 10, a center position z1a of the circular tube 31a included in the first heat transfer tube group G1 in the first arrangement direction and a center position z1b of the circular tube 31a included in the second heat transfer tube group G2 in the second arrangement direction are shifted from each other as viewed from the air flow direction F. The refrigeration device 10 of this embodiment has a portion where the center position z2 of the flat multi-hole tubes 32a in the arrangement direction of the flat multi-hole tubes 32a and the center position z1a of the circular tube 31a included in the first heat transfer tube group G1 in the first arrangement direction are misaligned when viewed from the air flow direction F.

[0080] The refrigeration system 10 having such a configuration can suppress interference between the dead water area formed on the leeward side of the second heat exchanger 32 and the circular tubes 31a included in the first heat transfer tube group G1. This can suppress a decrease in heat exchange efficiency for the first heat exchanger 31 located on the leeward side in the air flow direction F.

[0081] (6) The refrigeration device 10 of the above embodiment includes a plurality of flat multi-hole tubes 32a and a plurality of heat transfer tubes 31e constituting the first heat exchanger 31. In the refrigeration device 10, the heat transfer tubes constituting the first heat exchanger 31 are the flat multi-hole tubes 31e. The refrigeration device 10 has a portion where a center position z2 of the flat multi-hole tube 32a in the arrangement direction of the plurality of flat multi-hole tubes 32a in the second heat exchanger 32 and a center position z1 of the flat multi-hole tube 31e in the arrangement direction of the plurality of flat multi-hole tubes 31e in the first heat exchanger 31 coincide with each other when viewed from the air flow direction F.

[0082] In the refrigeration system 10 having such a configuration, when both the heat transfer tube 31e of the first heat exchanger 31 and the heat transfer tube 32a of the second heat exchanger 32 are flat multi-hole tubes, the decrease in heat exchange efficiency can be suppressed for the first heat exchanger 31 located on the downwind side of the air flow direction F.

[0083] (7) In the refrigeration system 10 of the above embodiment, the second refrigerant R2 is a refrigerant that is flammable, toxic, or has a global warming potential of 4 or greater.

[0084] The refrigeration system 10 having such a configuration can reduce the amount of the second refrigerant R2 used when a "harmful" natural refrigerant that is flammable, toxic, or has a global warming potential of 4 or more is used as the second refrigerant R2.

[0085] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. [Explanation of symbols]

[0086] 10: Refrigeration equipment 15: Fan 21: First compressor 22: Second compressor 31: 1st heat exchanger 31a: Circular tube (heat transfer tube) 31e: Flat multi-hole tube (heat transfer tube) 32:Second heat exchanger 32a: Flat multi-hole tube (heat transfer tube) 32b: Finn 33:Third heat exchanger 34: User side heat exchanger 41: First expansion valve 42: Second expansion valve 70: Support member R1: First refrigerant R2:Second refrigerant RC1: 1st refrigerant circuit RC2: Second refrigerant circuit G1: First heat transfer tube group G2: Second heat transfer tube group F: Air flow direction z1: Center position z1a: center position z1b: Center position z2: Center position P1: First pitch P2: Second pitch

Claims

1. a first refrigerant circuit (RC1) including a first compressor (21), a first heat exchanger (31), a first expansion valve (41), and a utilization side heat exchanger (34) and using a first refrigerant (R1); a second refrigerant circuit (RC2) including a second compressor (22), a second heat exchanger (32), and a second expansion valve (42) and using a second refrigerant (R2); a third heat exchanger (33) for exchanging heat between the first refrigerant (R1) and the second refrigerant (R2); With a fan (15), Equipped with The heat transfer tube constituting the second heat exchanger (32) is a flat multi-hole tube (32a), The refrigeration device (10), wherein the second heat exchanger (32) is disposed on the windward side of the first heat exchanger (31) in a flow direction (F) of air generated by the fan (15).

2. The first heat exchanger (31) includes a plurality of flat multi-hole tubes (32a) and a plurality of heat transfer tubes (31a) constituting the first heat exchanger (31), 2. The refrigeration device (10) according to claim 1, wherein a center position (z2) of the flat multi-hole tube (32a) in an arrangement direction of the flat multi-hole tubes (32a) and a center position (z1) of the heat transfer tube (31a) constituting the first heat exchanger (31) in an arrangement direction of the heat transfer tube (31a) have a portion that is misaligned when viewed from the air flow direction (F).

3. The heat transfer tube constituting the first heat exchanger (31) is a circular tube (31a), 3. The refrigeration system (10) according to claim 2, wherein a first pitch (P1) of the plurality of circular tubes (31 a) in an arrangement direction of the circular tubes (31 a) is different from a second pitch (P2) of the plurality of flat multi-hole tubes (32 a) in an arrangement direction of the flat multi-hole tubes (32 a).

4. The second heat exchanger (32) 3. The refrigeration device (10) according to claim 1 or claim 2, comprising a heat exchanger including a plurality of the flat multi-hole tubes (32a) and serpentine fins (32b) arranged between adjacent flat multi-hole tubes (32a).

5. The first heat exchanger (31) includes a plurality of flat multi-hole tubes (32a) and a plurality of heat transfer tubes (31a) constituting the first heat exchanger (31), The heat transfer tube constituting the first heat exchanger (31) is a circular tube (31a), The first heat exchanger (31) is a first heat transfer tube group (G1) in which a plurality of the circular tubes (31 a) are arranged in a first arrangement direction; a second heat transfer tube group (G2) adjacent to the downwind side of the first heat transfer tube group (G1) in the air flow direction (F), in which a plurality of the circular tubes (31 a) are arranged in a second arrangement direction parallel to the first arrangement direction, a center position (z1a) of the circular tube (31a) included in the first heat transfer tube group (G1) in the first arrangement direction and a center position (z1b) of the circular tube (31a) included in the second heat transfer tube group (G2) in the second arrangement direction are misaligned when viewed from the air flow direction (F); 2. The refrigeration system (10) according to claim 1, wherein a central position (z2) of the flat multi-hole tubes (32a) in an arrangement direction of the plurality of flat multi-hole tubes (32a) and a central position (z1a) of the circular tube included in the first heat transfer tube group (G1) in the first arrangement direction have a portion that is misaligned when viewed from the air flow direction (F).

6. The first heat exchanger (31) includes a plurality of the flat multi-hole tubes (32a) and a plurality of heat transfer tubes (31e) constituting the first heat exchanger (31), The heat transfer tube constituting the first heat exchanger (31) is a flat multi-hole tube (31e), 2. The refrigeration device (10) according to claim 1, wherein a central position (z2) of the flat multi-hole tubes (32a) in the arrangement direction of the plurality of flat multi-hole tubes (32a) in the second heat exchanger (32) and a central position (z1) of the flat multi-hole tubes (31e) in the arrangement direction of the plurality of flat multi-hole tubes (31e) in the first heat exchanger (31) have a portion that coincides when viewed from the air flow direction (F).

7. 3. The refrigeration system (10) of claim 1 or claim 2, wherein the second refrigerant (R2) is a refrigerant that is flammable, toxic, or has a global warming potential of 4 or greater.

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