Refrigeration device

Abstract

A refrigeration device 10 of the present disclosure is provided with: a first refrigerant circuit RC1 including a first compressor 21, a first heat exchanger 31, a first expansion valve 41, and a use-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. The heat transfer pipe constituting the first heat exchanger 31 is a circular pipe 31a, the heat transfer pipe constituting the second heat exchanger 32 is a flat multi-hole pipe 32a, and the second heat exchanger 32 is disposed on the leeward side of the first heat exchanger 31 in a flow direction F of air generated by the fan 15.

Description

Refrigeration equipment

[0001] The present disclosure relates to refrigeration devices.

[0002] Patent Document 1 discloses a refrigeration system including a unit including a first refrigerant circuit that provides a primary 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. In the refrigeration system, the first refrigerant and the second refrigerant are different types of refrigerant.

[0003] International Publication No. 2014 / 181399

[0004] In the refrigeration apparatus, 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 and downwind sides of the flow direction of the air to be heat exchanged. When the second air heat exchanger is arranged on the upwind side of the first air heat exchanger, the second air heat exchanger is arranged on the outermost side of the unit. In a unit with such a configuration, the second air heat exchanger is susceptible to damage during transportation because external forces are likely to act on it.

[0005] The present disclosure aims to reduce the risk of damage to the second air heat exchanger in a refrigeration device having a unit including first and second air heat exchangers.

[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 the heat transfer tubes that make up the first heat exchanger are circular tubes, and the heat transfer tubes that make up the second heat exchanger are flat multi-hole tubes, and the second heat exchanger is positioned on the downwind side of the first heat exchanger in the flow direction of air generated by the fan.

[0007] The refrigeration apparatus of the present disclosure includes a first heat exchanger using circular tubes as heat transfer tubes and a second heat exchanger using flat multi-hole tubes as heat transfer tubes. Flat multi-hole tubes are more susceptible to external forces than circular tubes. In the refrigeration apparatus of the present disclosure, the first heat exchanger is disposed on the windward side of the second heat exchanger in the air flow direction, so that the first heat exchanger is disposed outside the second heat exchanger. In the refrigeration apparatus of the present disclosure, the first heat exchanger using circular tubes as heat transfer tubes is disposed on the windward side of the second heat exchanger using flat multi-hole tubes as heat transfer tubes in the air flow direction, so that the risk of damage to the second heat exchanger when an external force acts on a unit including the first heat exchanger and the second heat exchanger can be reduced.

[0008] (2) In the refrigeration device of (1) of the present disclosure, it is preferable that the second heat exchanger is configured by a heat exchanger including a plurality of the flat multi-hole tubes and serpentine fins arranged between adjacent flat multi-hole tubes.

[0009] In the heat exchanger of the above configuration, the flat multi-hole tubes and the fins are flush with each other, so the flat multi-hole tubes are not protected by the fins. Therefore, in the heat exchanger of the above configuration, the flat multi-hole tubes are easily subjected to direct external forces and are easily damaged. When the refrigeration device of the present disclosure employs the heat exchanger of the above configuration as the second heat exchanger, the risk of damage to the flat multi-hole tubes can be reduced. By employing the heat exchanger of the above configuration, the refrigeration device of the present disclosure can reduce the amount of second refrigerant used.

[0010] (3) In the refrigeration device of (1) or (2) of the present disclosure, it is preferable that the fan is arranged on the downwind side of the second heat exchanger in the air flow direction, and the second heat exchanger is fixed to a support member that supports the fan.

[0011] In the refrigeration system having the above configuration, the fan is disposed on the downwind side of the second heat exchanger in the air flow direction, and therefore, the refrigeration system of the present disclosure can fix the second heat exchanger using the support member for fixing the fan.

[0012] (4) In a refrigeration device according to any one of aspects (1) to (3) of the present disclosure, it is preferable that the first heat exchanger has a first region that overlaps with the second heat exchanger when viewed from the air flow direction, and a second region that does not overlap with the second heat exchanger when viewed from the air flow direction.

[0013] In a refrigeration apparatus including a first heat exchanger and a second heat exchanger, if the two heat exchangers have the same outer dimensions and are located in the same outer positions when viewed from the air flow direction, the two heat exchangers can be easily supported by using a common support member. On the other hand, if the heat exchangers have different outer dimensions and are located in different outer positions when viewed from the air flow direction, it is difficult to support the two heat exchangers using a common support member. In the refrigeration apparatus disclosed herein, even if the first heat exchanger has a first region that overlaps with the second heat exchanger and a second region that does not overlap with the second heat exchanger when viewed from the air flow direction, the second heat exchanger can be fixed using the support member for fixing the fan.

[0014] (5) In a refrigeration device according to any one of aspects (1) to (3) of the present disclosure, when viewed from the air flow direction, the first heat exchanger and the second heat exchanger are preferably configured such that the area of ​​a fourth region defined by the outer shape of the second heat exchanger is smaller than the area of ​​a third region defined by the outer shape of the first heat exchanger, and the fourth region is included in the third region.

[0015] In a refrigeration apparatus including a first heat exchanger and a second heat exchanger, if the two heat exchangers have the same external dimensions, the two heat exchangers can be easily supported by using a common support member. On the other hand, if the two heat exchangers have different external dimensions, the larger heat exchanger can be easily supported by using the frame of the housing that houses the heat exchanger, but it is difficult to support the smaller heat exchanger by using the frame of the housing. In the refrigeration apparatus disclosed herein, even if the external dimensions of the second heat exchanger are smaller than the external dimensions of the first heat exchanger when viewed from the air flow direction and the second heat exchanger fits inside the external dimensions of the first heat exchanger, the second heat exchanger can be fixed using the support member for fixing the fan.

[0016] FIG. 1 is an explanatory diagram of a refrigerant circuit of a refrigeration device according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional explanatory diagram of a plan view of a heat source side unit in a refrigeration device. FIG. 3 is a cross-sectional explanatory diagram of a side view of a heat source side unit in a refrigeration device. FIG. 4 is a cross-sectional explanatory diagram of a side view showing another embodiment of a supporting state of a second heat exchanger. FIG. 5 is a schematic diagram showing a first heat exchanger in a refrigeration device. FIG. 6 is a schematic diagram showing a second heat exchanger in a refrigeration device. FIG. 7 is a partial cross-sectional schematic diagram showing heat transfer tubes and fins that constitute the second heat exchanger. FIG. 8 is an explanatory diagram of the positional relationship when the first heat exchanger and the second heat exchanger according to the first embodiment are viewed from the air flow direction. FIG. 9 is an explanatory diagram of the positional relationship when the first heat exchanger and the second heat exchanger according to the second embodiment are viewed from the air flow direction.

[0017] (Overall Configuration of the Refrigeration Device) An embodiment of the refrigeration device of the present disclosure will be described in detail below 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 , the refrigeration device 10 of the present disclosure includes a heat source unit 11, a user unit 12, refrigerant piping 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 while the refrigeration device 10 illustrated in this embodiment is an air conditioner, the refrigeration device of the present disclosure may be, for example, a refrigerator case, and is not limited to an air conditioner. The refrigerant piping 13 includes a gate valve 18 at the portion where the refrigerant enters and exits the housing of the heat source unit 11.

[0018] 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 user side unit 12 includes a user side heat exchanger 34.

[0019] The refrigeration system 10 includes a first refrigerant circuit RC1 including a first compressor 21, a first heat exchanger 31, a first expansion valve 41, a user-side heat exchanger 34, and refrigerant piping 13 connecting these components, and a second refrigerant circuit RC2 including a second compressor 22, a second heat exchanger 32, a second expansion valve 42, and refrigerant piping 14 connecting these components. 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, which is different from the first refrigerant R1, as a refrigerant and performs a refrigeration cycle operation.

[0020] 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 motors (not shown) whose operating rotation speeds can be adjusted by inverter control. The first compressor 21 and the second compressor 22 are variable-capacity (variable-capacity) compressors whose capacities (capacities) can be changed by inverter control of the motors. However, the first compressor 21 and the second compressor 22 may also be fixed-capacity compressors.

[0021] The four-way selector valve 50 reverses the flow of the first refrigerant R1 in the refrigerant pipe 13 of the first refrigerant circuit RC1, and switches whether the first refrigerant R1 discharged from the first compressor 21 is supplied to the first heat exchanger 31 or the user-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 selector valve 50. Note that the refrigeration system 10 of this embodiment may be used exclusively for cooling, omitting the four-way selector valve.

[0022] The first expansion valve 41 is configured as an electric valve capable of adjusting the flow rate of the first refrigerant R1. During cooling operation, the refrigeration system 10 adjusts the cooling capacity exerted by the first refrigerant circuit RC1 by adjusting the aperture of the first expansion valve 41 with a control device (not shown). During heating operation, the refrigeration system 10 fully opens the first expansion valve 41 with a control device (not shown).

[0023] The second expansion valve 42 is configured as an electric valve capable of adjusting the flow rate of the second refrigerant R2. During cooling operation, the refrigeration system 10 adjusts the cooling capacity exerted by the second refrigerant circuit RC2 by a control device (not shown) adjusting the opening degree of the second expansion valve 42.

[0024] 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 exchanged 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.

[0025] [Heat Source Side Unit] FIG. 2 is a cross-sectional explanatory diagram of a heat source side unit in a refrigeration apparatus, as viewed from above. FIG. 3 is a cross-sectional explanatory diagram of a heat source side unit in a refrigeration apparatus, as viewed from the side. In the following description, the terms "up," "down," "front," "rear," "left," and "right" refer to the arrows shown in FIGS. 2 and 3 . Specifically, for example, in FIGS. 2 and 3 , of the mutually orthogonal arrows X, Y, and Z, the direction indicated by arrow X (first direction) is the left-right direction, the direction indicated by arrow Y (second direction) is the front-rear direction, and the direction indicated by 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, direction X may be interpreted as the front-rear direction and direction Y as the left-right direction.

[0026] As shown in Figures 1 to 3, the heat source unit 11 includes a housing 60. As shown in Figures 2 and 3, the housing 60 is formed in a rectangular parallelepiped shape and is rectangular in plan view. The interior 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 and 65 are formed in two adjacent side walls 62 and 63 of the housing 60 located 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.

[0027] The machine room S1 houses 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 houses 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 the devices constituting the refrigeration device 10 are controlled by this control board.

[0028] 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 rotary shaft of the fan motor 16 and is driven to rotate by the fan motor 16.

[0029] The first refrigerant R1 circulating in the first refrigerant circuit RC1 flows through a heat transfer tube (heat transfer tube 31a described later) of the first heat exchanger 31. 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 is connected to the second compressor 22 in the machine room S1 via a heat transfer tube (heat transfer tube 32a described later).

[0030] The fan 15 is positioned such that its positive pressure side faces the side wall 66 on which the air outlet 67 is formed, and its negative pressure side faces the side wall 62 on which the air intake 64 is formed. When the fan motor 16 is activated, the fan 15 rotates, and air is drawn into the heat exchange chamber S2 through the air intakes 64 and 65. The air drawn into the heat exchange chamber S2 passes through the first heat exchanger 31 to exchange heat with the first refrigerant R1, then passes through the second heat exchanger 32 to exchange heat with the second refrigerant R2, and is then exhausted through the air outlet 67. The fan 15 generates an air flow that passes through the first heat exchanger 31 and the second heat exchanger 32. The refrigerant passing through 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 FIGS. 1 to 3 , the direction of the air flow generated by the fan 15 is indicated by arrow F. In the following description, the air flow direction will be referred to as air flow direction F.

[0031] The first heat exchanger 31 shown in this embodiment is formed in an L-shape in a plan view. The first heat exchanger 31 is bent near a corner 68 between two side walls 62, 63 in which air intakes 64, 65 are formed, and is disposed along the two side walls 62, 63. Note that the shape of the first heat exchanger 31 provided in the refrigeration device 10 of the present disclosure is not limited to this, and may be, for example, rectangular in a plan view.

[0032] 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 along a portion that follows the side wall 62 of the first heat exchanger 31, on the downwind side of the first heat exchanger 31 in the air flow direction F. Note that the shape of the second heat exchanger 32 provided in the refrigeration device 10 of the present disclosure is not limited to this.

[0033] [First Heat Exchanger] Figure 5 is a schematic diagram showing a first heat exchanger in the refrigeration system. As shown in Figure 5, the first heat exchanger 31 constituting the refrigeration system 10 of the present disclosure is a so-called cross-fin type fin-and-tube heat exchanger. The first heat exchanger 31 has a heat transfer tube 31a, multiple fins 31b, and a pair of tube plates 31c, 31d. The first heat exchanger 31 exchanges heat between the first refrigerant R1 in the first refrigerant circuit RC1 and air passing through the first heat exchanger 31.

[0034] The heat transfer tube 31a is a circular tube made of metal. Metals that can be used to form the heat transfer tube 31a include copper, copper alloy, stainless steel, aluminum, and aluminum alloy. Hereinafter, the heat transfer tube 31a will also be referred to as the circular tube 31a. The multiple fins 31b are thin metal plates that are rectangular in side view and are arranged parallel to one another at predetermined intervals in the width direction (first direction X). Metals that can be used to form the fins 31b include aluminum and aluminum alloy.

[0035] 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 (first direction X). The curved tube sections 31y are arranged at the end of the first heat exchanger 31 in the width direction (first direction X) and connect two adjacent straight tube sections 31x to each other.

[0036] The tube sheets 31c, 31d are metal plates formed into a rectangular shape in a side view and arranged in pairs on both sides in the width direction (first direction X) of the first heat exchanger 31. The tube sheets 31c, 31d are connected to both ends of each straight pipe portion 31x of the circular pipes 31a and support the circular pipes 31a. As shown in FIG. 5, the tube sheets 31c, 31d are arranged parallel to the fins 31b.

[0037] [Second Heat Exchanger] Figure 6 is a schematic diagram showing a second heat exchanger in the refrigeration system. Figure 7 is a partial cross-sectional schematic diagram showing heat transfer tubes and fins that constitute the second heat exchanger. The second heat exchanger 32 constituting the refrigeration system 10 of the present disclosure is a microchannel heat exchanger. As shown in Figures 6 and 7, 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, fins 32b, and headers 32c, 32d are made 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 air passing through the second heat exchanger 32.

[0038] As shown in Fig. 7 , the heat transfer tube 32a is configured as a multi-hole tube having a plurality of refrigerant flow paths 35 therein. The cross section of the heat transfer tube 32a has a flattened shape having a short side direction and a long side direction. The long side direction of the heat transfer tube 32a is the direction in which the plurality of refrigerant flow paths 35 are aligned. The plurality of refrigerant flow paths 35 are aligned along the air flow direction F. As shown in Figs. 6 and 7 , the plurality of refrigerant flow paths 35 are aligned in the second direction Y and extend in the first direction X. Hereinafter, the heat transfer tube 32a will also be referred to as a flat multi-hole tube 32a.

[0039] 6 and 7 , in the second heat exchanger 32, a plurality of heat transfer tubes 32a are arranged side by side 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 pattern 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 system 10 of this embodiment is not limited thereto; for example, the second heat exchanger 32 may be used in an orientation in which the third direction Z faces the left-right direction.

[0040] 7, the end surfaces of the flat multi-hole pipe 32a in the third direction Z, in other words, the upper and lower surfaces of the flat multi-hole pipe 32a, are flat surfaces along the first direction X and the second direction Y. Both end surfaces of the flat multi-hole pipe 32a in the first direction X are curved surfaces whose cross sections are curved in a semicircular shape.

[0041] The fins 32b have approximately the same length as the flat multi-hole tubes 32a in the second direction Y. Therefore, the flat multi-hole tubes 32a and the fins 32b are flush with each other on both end faces of the second heat exchanger 32 in the second direction Y.

[0042] In general, heat transfer tubes made of flat multi-hole tubes (flat multi-hole tubes 32a) are more susceptible to damage when subjected to external forces than heat transfer tubes made of circular tubes (circular tubes 31a). Therefore, when an external force acts on the flat multi-hole tubes 32a, there is a higher risk of serious damage compared to when an external force acts on the circular tubes 31a. Therefore, the second heat exchanger 32, which includes the flat multi-hole tubes 32a, has a higher protection priority than the first heat exchanger 31, which includes the circular tubes 31a, and is preferably located in a location less susceptible to external forces.

[0043] The second heat exchanger 32 in this embodiment is a so-called parallel-flow heat exchanger, a type of microchannel heat exchanger. 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. Generally, when comparing a cross-fin heat exchanger and a parallel-flow heat exchanger with equivalent heat exchange capacities, the parallel-flow heat exchanger has a smaller internal volume (amount of liquid held within) than the cross-fin heat exchanger. Therefore, by employing a parallel-flow heat exchanger as the second heat exchanger 32, the refrigeration system 10 can reduce the amount of second refrigerant R2 used compared to when using a cross-fin heat exchanger.

[0044] [Third Heat Exchanger] The third heat exchanger 33 constituting the refrigeration system 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. The first flow path 33a of the third heat exchanger 33 is connected to the first refrigerant circuit RC1, and the first refrigerant R1 flows through the first flow path 33a. The second flow path 33b of the third heat exchanger 33 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 using the third heat exchanger 33, and the cooling capacity of the first refrigerant circuit RC1 is supplemented by the cooling capacity of the second refrigerant circuit RC2.

[0045] (Regarding the First Refrigerant and the Second Refrigerant) The refrigeration system 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 naturally occur in nature, such as ammonia (NH3), carbon dioxide (CO2), water (H2O), and hydrocarbons (HC). The refrigeration system 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 system of the present disclosure is not limited to carbon dioxide (CO2), and the second refrigerant R2 used in the refrigeration system of the present disclosure is not limited to propane (C3H8). The first refrigerant R1 and the second refrigerant R2 used in the refrigeration device of the present disclosure may be R32, R1234yf, R474a, R600a (isobutane), R454B, R454C, or the like.

[0046] (Regarding the arrangement of the first heat exchanger and the second heat exchanger) As shown in Figures 1 to 3, in the refrigeration device 10, the second heat exchanger 32 is arranged on the downwind side of the first heat exchanger 31 in the flow direction F of the air generated by the fan 15.

[0047] In the heat source side unit 11, when the second heat exchanger 32 is disposed downwind of the first heat exchanger 31 in the air flow direction F, the first heat exchanger 31 is disposed outside the second heat exchanger 32. When an external force acts on the heat source side unit 11 configured in this manner, such as during transportation, the external force acts primarily on the first heat exchanger 31, which is located further outward, rather than on the second heat exchanger 32. Therefore, in the refrigeration apparatus 10, when an external force acts on the heat source side unit 11 including the first heat exchanger 31 and the second heat exchanger 32, the external force is less likely to act directly on the second heat exchanger 32, thereby reducing the risk of damage to the second heat exchanger 32.

[0048] 8A is an explanatory diagram of the arrangement of the first heat exchanger and the second heat exchanger according to the first embodiment when viewed from the air flow direction. In the refrigeration device 10 according to the first embodiment, the first heat exchanger 31 may have a first region A1 that overlaps with the second heat exchanger 32 when viewed from the air flow direction F, and a second region A2 that does not overlap with the second heat exchanger 32 when viewed from the air flow direction F. In this description, the region representing the first heat exchanger 31 is the region between the pair of tube sheets 31c, 31d (see FIG. 5), and the region representing the second heat exchanger 32 is the region between the pair of headers 32c, 32d (see FIG. 6).

[0049] As shown in Figure 8A, when the two heat exchangers 31 and 32 have different external dimensions and are misaligned when viewed from the air flow direction F, it is difficult to support the two heat exchangers 31 and 32 using a common support member, and it becomes necessary to provide a support member for supporting the second heat exchanger 32 separately from the support member for the first heat exchanger 31.

[0050] In the refrigeration apparatus 10 of this embodiment, by disposing the second heat exchanger 32 on the downwind side of the first heat exchanger 31 in the air flow direction F, the second heat exchanger 32 can be supported using the support member 70 (see FIGS. 2 and 3 ) that supports the fan 15. Specifically, as shown in FIG. 3 , the second heat exchanger 32 is supported at its lower part by a first stay 71 provided at the lower part of the support member 70. Note that, as shown in FIG. 4 , the second heat exchanger 32 may be further supported at its upper part by a second stay 72 provided midway in the vertical direction of the support member 70. Therefore, in the refrigeration apparatus 10 of this embodiment, even if the first heat exchanger 31 is configured to have a first region A1 that overlaps with the second heat exchanger 32 and a second region A2 that does not overlap with the second heat exchanger 32 when viewed from the air flow direction F, the second heat exchanger 32 can be supported by the support member 70 without a separate support member for supporting the second heat exchanger 32.

[0051] 8B is an explanatory diagram of the arrangement of the first heat exchanger and the second heat exchanger according to the second embodiment when viewed from the air flow direction. In the refrigeration device 10 according to the second embodiment, the first heat exchanger 31 and the second heat exchanger 32 may be configured such that, when viewed from the air flow direction F, the area Sa4 of the fourth region A4 defined by the outline of the second heat exchanger 32 is smaller than the area Sa3 of the third region A3 defined by the outline of the first heat exchanger 31 (Sa3 > Sa4), and the fourth region A4 is included in the third region A3.

[0052] 8B , when the two heat exchangers 31 and 32 have different external dimensions, the first heat exchanger 31, which has the larger external dimension, can be easily supported by using the housing 60 that houses the first heat exchanger 31. On the other hand, it is difficult to support the second heat exchanger 32, which has the smaller external dimension, by using the housing 60, and it becomes necessary to provide a support member for the second heat exchanger 32 separately from the support member for the first heat exchanger 31.

[0053] In the refrigeration device 10 of this embodiment, the second heat exchanger 32 is disposed on the downwind side of the first heat exchanger 31 in the air flow direction F, so that the second heat exchanger 32 can be supported using the support member 70 (see FIGS. 2 and 3 ) for supporting the fan 15. Therefore, in the refrigeration device 10 of this embodiment, even if the outer dimensions of the second heat exchanger 32 are smaller than the outer dimensions of the first heat exchanger 31 when viewed from the air flow direction F and the second heat exchanger 32 is configured to fit inside the outer dimensions of the first heat exchanger 31, the second heat exchanger 32 can be supported by the support member 70 without providing a separate support member for supporting the second heat exchanger 32.

[0054] [Operation and Effects of the Embodiment] (1) The refrigeration system 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 user-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 that exchanges heat between the first refrigerant R1 and the second refrigerant R2, and a fan 15. In the refrigeration system 10, the heat transfer tubes constituting the first heat exchanger 31 are circular tubes 31a, and the heat transfer tubes constituting the second heat exchanger 32 are flat multi-hole tubes 32a. In the refrigeration system 10, the second heat exchanger 32 is disposed downwind of the first heat exchanger 31 in the flow direction F of air generated by the fan 15.

[0055] The refrigeration device 10 of the above embodiment includes a first heat exchanger 31 using circular tubes 31a as heat transfer tubes and a second heat exchanger 32 using flat multi-hole tubes 32a as heat transfer tubes. The flat multi-hole tubes 32a are more susceptible to external forces than the circular tubes 31a. In the refrigeration device 10 of the above embodiment, the first heat exchanger 31 is disposed on the windward side of the second heat exchanger 32 in the air flow direction F, so that the first heat exchanger 31 is disposed outside the second heat exchanger 32 in the heat source side unit 11. In the refrigeration device 10 of the above embodiment, the first heat exchanger 31 using circular tubes 31a is disposed on the windward side of the second heat exchanger 32 using flat multi-hole tubes 32a in the air flow direction F. This reduces the risk of damage to the second heat exchanger 32 including the flat multi-hole tubes 32a, which are vulnerable to external forces, when an external force acts on the heat source side unit 11 including the first heat exchanger 31 and the second heat exchanger 32.

[0056] (2) In the refrigeration device 10 of the above embodiment, the second heat exchanger 32 is configured as a heat exchanger (a so-called parallel flow type heat exchanger) including a plurality of flat multi-hole tubes 32a and serpentine fins 32b arranged between adjacent flat multi-hole tubes 32a.

[0057] In the second heat exchanger 32 of the above embodiment, the flat multi-hole tubes 32a and the fins 32b are flush with each other, so the flat multi-hole tubes 32a are not protected by the fins 32b. Therefore, in the second heat exchanger 32 configured as described above, external forces are likely to be applied directly to the flat multi-hole tubes 32a, which may result in damage to the flat multi-hole tubes 32a. In the refrigeration device 10 of the above embodiment, when the second heat exchanger 32 is configured as a parallel-flow heat exchanger, the risk of damage to the flat multi-hole tubes 32a can be reduced. In the refrigeration device 10 of the above embodiment, by configuring the second heat exchanger 32 as a parallel-flow heat exchanger, the amount of second refrigerant R2 used can be reduced.

[0058] (3) In the refrigeration device 10 of the above embodiment, the fan 15 is positioned on the downwind side of the second heat exchanger 32 in the air flow direction F, and the second heat exchanger 32 is fixed to a support member 70 that supports the fan 15.

[0059] In this way, the refrigeration device 10 of the above embodiment can fix the second heat exchanger 32 by utilizing the support member 70 for fixing the fan 15 .

[0060] (4) In the refrigeration device 10 of the above embodiment, the first heat exchanger 31 has a first region A1 that overlaps with the second heat exchanger 32 when viewed from the air flow direction F, and a second region A2 that does not overlap with the second heat exchanger 32 (see Figure 8A).

[0061] In a configuration including a first heat exchanger 31 and a second heat exchanger 32, if the heat exchangers 31 and 32 have the same outer dimensions and are positioned in the same outer positions as viewed from the air flow direction F, the two heat exchangers 31 and 32 can be easily supported by using a common support member. On the other hand, if the heat exchangers 31 and 32 have different outer dimensions and are positioned differently as viewed from the air flow direction F, as shown in FIG. 8A , it is difficult to support the two heat exchangers 31 and 32 using a common support member. In the refrigeration device 10 of the above embodiment, even if the first heat exchanger 31 has a first region A1 that overlaps with the second heat exchanger 32 and a second region A2 that does not overlap with the second heat exchanger 32 as viewed from the air flow direction F, the second heat exchanger 32 can be fixed by using the support member 70 for fixing the fan 15.

[0062] (5) In the refrigeration device 10 of the above embodiment, when viewed from the air flow direction F, the area Sa4 of the fourth area A4 defined by the outline of the second heat exchanger 32 is smaller than the area Sa3 of the third area A3 defined by the outline of the first heat exchanger 31, and the fourth area A4 is included in the third area A3 (see Figure 8B).

[0063] In a configuration including a first heat exchanger 31 and a second heat exchanger 32, if the heat exchangers 31 and 32 have the same external dimensions, the two heat exchangers 31 and 32 can be easily supported by using a common support member. On the other hand, if the heat exchangers 31 and 32 have different external dimensions, as shown in FIG. 8B , the larger first heat exchanger 31 can be easily supported by using the housing 60 that houses the first heat exchanger 31, but it is difficult to support the smaller second heat exchanger 32 by using the housing 60. In the refrigeration device 10 of the above embodiment, even if the external dimensions of the second heat exchanger 32 are smaller than the external dimensions of the first heat exchanger 31 when viewed from the air flow direction F and the second heat exchanger 32 fits inside the external dimensions of the first heat exchanger 31, the second heat exchanger 32 can be fixed by using the support member 70 for fixing the fan 15.

[0064] Although the embodiments 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 claims.

[0065] 10: Refrigeration device 15: Fan 21: First compressor 22: Second compressor 31: First heat exchanger 31a: Circular tube 32: Second heat exchanger 32a: Flat multi-hole tube 32b: Fin 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: First refrigerant circuit RC2: Second refrigerant circuit F: Air flow direction

Claims

1. A 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), wherein a heat transfer tube constituting the first heat exchanger (31) is a circular tube (31a), and a 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 downwind side of the first heat exchanger (31) in a flow direction (F) of air generated by the fan (15).

2. The refrigeration device (10) according to claim 1, wherein the second heat exchanger (32) is constituted by 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).

3. A refrigeration system (10) as described in claim 1 or claim 2, wherein the fan (15) is arranged on the downwind side of the second heat exchanger (32) in the air flow direction (F), and the second heat exchanger (32) is fixed to a support member (70) that supports the fan (15).

4. A refrigeration device (10) as described in claim 3, wherein the first heat exchanger (31) has a first region (A1) that overlaps with the second heat exchanger (32) when viewed from the air flow direction (F), and a second region (A2) that does not overlap with the second heat exchanger (32) when viewed from the air flow direction (F).

5. The refrigeration device (10) of claim 3, wherein, when viewed from the air flow direction (F), the first heat exchanger (31) and the second heat exchanger (32) have an area (Sa4) of a fourth region (A4) defined by the contour of the second heat exchanger (32) that is smaller than an area (Sa3) of a third region (A3) defined by the contour of the first heat exchanger (31), and the fourth region (A4) is included in the third region (A3).

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