Refrigeration cycle device

Abstract

The total capacity of the compressor can be suppressed compared with a case in which the refrigerant circulation amount is increased to secure the refrigeration capacity. A refrigeration cycle device is provided with: a first compression member that compresses a suctioned refrigerant and discharges the compressed refrigerant to a first flow path; a heat sink which is provided in the first flow path, through which the refrigerant passes, and which dissipates heat taken out from the refrigerant that passes through the heat sink; a branching section that branches the refrigerant, which has passed through the radiator in the first flow path, into a first branch and a second branch; a first pressure reducing member that reduces the pressure of the refrigerant branched to the first branch and flows to the second flow path; a heat exchanger that exchanges heat between the refrigerant flowing through the second flow path and the refrigerant branched to the second branch; a second pressure reducing member that reduces the pressure of the refrigerant heat-exchanged by the heat exchanger in the second branch; a cooler that cools an object by heat exchange between the object and the refrigerant decompressed by the second decompressing member, and that sucks the heat-exchanged refrigerant into the first compression member; a second compression member that sucks in the refrigerant that has been subjected to heat exchange by the heat exchanger in the second flow path, compresses the refrigerant, and discharges the compressed refrigerant to a third flow path; and a merging part that merges the third flow path and the first flow path.

Description

Technical Field

[0001] The present invention relates to a refrigeration cycle device. Background Art

[0002] Patent Document 1 describes a compressor system in which a plurality of compressors are connected in parallel.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 5758818 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] For example, there is a refrigeration cycle device that uses the compressor system described in Patent Document 1 to increase the refrigerant circulation rate, thereby increasing the amount of refrigerant available for cooling the object, thereby ensuring refrigeration capacity. In such a refrigeration cycle device, the greater the refrigeration capacity required to cool the object, the greater the total capacity of the compressors must be. More specifically, this requires increasing the number of compressors or increasing the capacity of each compressor, which results in increased equipment costs and an increase in the overall size of the refrigeration cycle device.

[0008] The present disclosure proposes a refrigeration cycle device that suppresses the total capacity of compressors compared to a case where the refrigerant circulation amount is increased to ensure refrigeration capacity.

[0009] Means for solving problems

[0010] A refrigeration cycle device according to a first aspect includes: a first compression element that compresses sucked refrigerant and discharges it to a first flow path; a radiator that is provided in the first flow path, allows the refrigerant to pass through, and dissipates heat extracted from the passing refrigerant; a branching portion that branches the refrigerant in the first flow path after passing through the radiator into a first branch and a second branch; a first decompressing element that decompresses the refrigerant branched into the first branch and flows it to a second flow path; a heat exchanger that exchanges heat between the refrigerant flowing in the second flow path and the refrigerant branched into the second branch; a second decompressing element that decompresses the refrigerant after heat exchange in the second branch by the heat exchanger; a cooler that cools an object by heat exchange between the refrigerant decompressed by the second decompressing element and the object, and draws the refrigerant after heat exchange into the first compression element; a second compression element that draws the refrigerant in the second flow path after heat exchange in the heat exchanger, compresses it, and discharges it to a third flow path; and a merging portion that merges the third flow path with the first flow path. In this case, the total capacity of the compressors is suppressed compared to the case where the refrigerant circulation amount is increased to ensure the refrigeration capacity.

[0011] In a second aspect, the refrigeration cycle device is configured as the refrigeration cycle device of the first aspect, wherein the merging portion merges the third flow path at a position in the first flow path after the flow path passes through the radiator. The refrigeration cycle device further includes a second radiator disposed in the third flow path for dissipating heat extracted by allowing the refrigerant compressed by the second compression element to pass through the third flow path. In this case, compared to a case where the merging portion merges the third flow path at a position in the first flow path before the flow path passes through the radiator, heat dissipation from the radiator can be increased.

[0012] Regarding the refrigeration cycle device of the third aspect, in addition to the refrigeration cycle device of the second aspect, the capacity of the first compression element is larger than the capacity of the second compression element. In this case, compared with the case where the capacity of the first compression element is smaller than the capacity of the second compression element, heat dissipation from the radiator can be increased.

[0013] A refrigeration cycle device according to a fourth aspect is the refrigeration cycle device according to the third aspect, further comprising a third decompression element disposed in the third flow path for decompressing the refrigerant after passing through the second radiator. In this case, the compression ratio of the second compression element can be set to a higher value.

[0014] A refrigeration cycle device according to a fifth aspect is the refrigeration cycle device according to the second aspect, further comprising a fourth decompression element. The fourth decompression element is disposed in the first flow path after passing through the radiator and before merging with the third flow path at the merging portion, and decompresses the refrigerant after passing through the radiator. In this case, the compression ratio of the first compression element can be set to a higher value.

[0015] A refrigeration cycle device according to a sixth aspect is the refrigeration cycle device according to any one of the first to fifth aspects, wherein at least a portion of the refrigerant composition is carbon dioxide. In this case, heat dissipation in the radiator is greater than when a non-azeotropic refrigerant mixture containing no carbon dioxide is used.

[0016] A refrigeration cycle device according to a seventh aspect is the refrigeration cycle device according to the first aspect, further comprising: a temperature sensor for measuring the temperature of the refrigerant at a position in the first flow path before passing through the radiator and before merging with the third flow path at the merging portion, and at a position in the third flow path before merging with the first flow path at the merging portion; and a control unit for controlling the circulation of the refrigerant based on the refrigerant temperatures measured by the temperature sensors, wherein when the refrigerant temperature measured in the first flow path is higher than the refrigerant temperature measured in the third flow path, the control unit controls the flow resistance of the first decompression element to increase. In this case, the enthalpy difference between the refrigerant compressed by the first compression element and the refrigerant compressed by the second compression element decreases.

[0017] A refrigeration cycle device according to an eighth aspect is the refrigeration cycle device according to the first aspect, further comprising: a temperature sensor for measuring the temperature of the refrigerant at a position in the first flow path before passing through the radiator and before merging with the third flow path at the merging portion, and at a position in the third flow path before merging with the first flow path at the merging portion; and a control unit for controlling the circulation of the refrigerant based on the refrigerant temperatures measured by the temperature sensors, wherein when the refrigerant temperature measured in the first flow path is higher than the refrigerant temperature measured in the third flow path, the control unit controls the flow rate of the second compression element to increase. In this case, the enthalpy difference between the refrigerant compressed by the first compression element and the refrigerant compressed by the second compression element decreases. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram showing a schematic configuration example of an air-conditioning apparatus to which this embodiment is applied.

[0019] Figure 2 This is a schematic diagram of the refrigerant circuit according to the first embodiment.

[0020] Figure 3 This is a pressure-specific enthalpy diagram illustrating the refrigeration cycle of the refrigerant circulating in the refrigerant circuit of the first embodiment.

[0021] Figure 4 This is a schematic diagram of a refrigerant circuit according to the second embodiment.

[0022] Figure 5 This is a schematic diagram of a refrigerant circuit according to a third embodiment.

[0023] Figure 6 This is a schematic diagram of a refrigerant circuit according to a fourth embodiment.

[0024] Figure 7 It is a diagram illustrating a refrigerant circuit of an application example.

[0025] Figure 8 These are diagrams for explaining a conventional refrigeration cycle device, wherein (a) is a schematic diagram of a refrigerant circuit in the conventional refrigeration cycle device, and (b) is a pressure-specific enthalpy diagram illustrating a refrigeration cycle of a refrigerant circulating in the refrigerant circuit. DETAILED DESCRIPTION

[0026] First, a description will be given of a conventional technique to which the embodiments of the present invention are not applied.

[0027] Figure 8 The figures are used to explain a conventional refrigeration cycle device, (a) is a schematic diagram of a refrigerant circuit 10' in the conventional refrigeration cycle device, and (b) is a pressure-specific enthalpy diagram illustrating the refrigeration cycle of the refrigerant circulating in the refrigerant circuit 10'. Figure 8 In (b), the horizontal axis is specific enthalpy [kJ / kg], and the vertical axis is absolute pressure [MPa.abs] based on absolute vacuum.

[0028] exist Figure 8 In (a), the lines connecting the various devices are pipes that form the flow path of the refrigerant. Figure 8 In (b), the refrigeration cycle 300' is represented by a bold line, and the points 10a' to 10f' on the refrigeration cycle 300' correspond to the positions 10a' to 10f' of the refrigerant circuit 10', respectively. Therefore, the points 10a' to 10f' in the refrigeration cycle 300' are marked as positions 10a' to 10f'. Figure 8 In (b), in addition to the refrigeration cycle 300 ′, a saturated liquid line 301 , a saturated vapor line 302 , a critical point 303 , and a 45° C. isotherm 304 of the carbon dioxide refrigerant are also shown.

[0029] like Figure 8 As shown in (a), the refrigerant circuit 10' includes two compressors 12' and 13' connected in parallel, a radiator 14', a pressure reducing valve 18', and a cooler 19', and circulates carbon dioxide as an example of a refrigerant. In more detail, the refrigerant that has undergone heat exchange with the object through the cooler 19' branches into two branches at the branch portion 30' (position 10a'). The refrigerant flowing into one branch of the branched refrigerants is compressed by the compressor 12', and the refrigerant flowing into the other branch is compressed by the compressor 13', and then merges at the confluence portion 20' (position 10b'). The merged refrigerant dissipates heat through the radiator 14' (position 10e'). Then, the refrigerant after dissipating heat is reduced in pressure by the pressure reducing valve 18' (position 10f'), and passes through the cooler 19' (position 10a') again.

[0030] At each position of the refrigerant circuit 10', the specific enthalpy and pressure of the refrigerant change according to each device, thereby establishing a refrigeration cycle of the refrigerant. Figure 8 As shown in (b), from position 10a' to position 10b', the refrigerant's pressure and specific enthalpy increase due to compression and heat of compression by compressors 12' and 13'. Furthermore, from position 10b' to position 10e', the refrigerant's specific enthalpy decreases due to heat dissipation in radiator 14'. Furthermore, from position 10e' to position 10f', the refrigerant's pressure decreases due to pressure reduction by pressure reducing valve 18'. Furthermore, from position 10f' to position 10a', the refrigerant's specific enthalpy increases due to heat exchange with the object in cooler 19'.

[0031] In a refrigeration cycle device, the ability of a cooler to cool an object (sometimes referred to as "cooling capacity") is determined by the amount of heat (heat absorption) removed from the object by the refrigerant passing through the cooler. Therefore, in a conventional refrigeration cycle device using refrigerant circuit 10', the cooling capacity of cooler 19' is determined by the product of the change in specific enthalpy when moving from position 10f' to position 10a' and the amount of refrigerant passing through cooler 19'.

[0032] In conventional refrigeration cycle devices using refrigerant circuit 10', in order to increase the refrigeration capacity of cooler 19', the amount of refrigerant circulating within refrigerant circuit 10' is increased, thereby increasing the amount of refrigerant passing through cooler 19'. More specifically, the number of compressors connected in parallel with compressors 12' and 13' is increased, or the capacity of compressors 12' and 13' is increased. Therefore, in conventional refrigeration cycle devices using refrigerant circuit 10', the greater the refrigeration capacity to be ensured, the greater the total capacity of the compressors. Furthermore, "total capacity" refers to the value obtained by summing the capacities of all compressors installed in the refrigerant circuit.

[0033] The refrigeration cycle apparatus according to the embodiment to which the present invention is applied has a configuration capable of suppressing the total capacity of the compressors, compared with a case where the refrigerant circulation amount is increased to ensure refrigeration capacity.

[0034] Hereinafter, embodiments of the present invention will be described in detail.

[0035] <First embodiment>

[0036] (Air conditioning device 1)

[0037] Figure 1 This is a diagram showing a schematic configuration example of an air-conditioning apparatus 1 to which this embodiment is applied.

[0038] As shown in the figure, the air conditioner 1 to which this embodiment is applied comprises a refrigerant circuit 10 for circulating refrigerant, and a control unit 50 for controlling the circulation of the refrigerant in the refrigerant circuit 10. The control unit 50 communicates with each device (using a controller) included in the refrigerant circuit 10 via wired or wireless communication. Figure 2 (described later) connection, capable of sending control signals to each device.

[0039] The air-conditioning apparatus 1 is an example of a refrigeration cycle apparatus in this embodiment.

[0040] The air conditioner 1 cools the air taken in and supplies it to the space as cold air, thereby cooling the space. Figure 2 The refrigerant (described in detail later) exchanges heat with the air as an example of an object, thereby removing heat from the air, thereby cooling the air. The cooled air is then supplied as cold air from the indoor unit's outlet (not shown) to the room, thereby cooling the room.

[0041] (Control Unit 50)

[0042] The control unit 50 controls the circulation of the refrigerant in the refrigerant circuit 10 by sending control signals to each device included in the refrigerant circuit 10. In addition, the air-conditioning device 1 controls the amount of cold air supplied to the space. The control unit 50 of this embodiment has, for example, an operation panel or a controller that accepts operations from the user, and performs control based on operational inputs such as temperature settings or air volume settings from the user. In addition, for example, it has a temperature sensor that measures the temperature of the space, and controls based on the measured value. In addition, for example, it has a temperature sensor that measures the temperature of the refrigerant in the refrigerant circuit 10, and controls based on the measured value.

[0043] Furthermore, the control unit 50 may acquire information related to the operation, such as the effective value of the operation relative to the control value, for each device included in the refrigerant circuit 10 and perform control based on the acquired information.

[0044] (Refrigeration Circuit 10)

[0045] The refrigerant circuit 10 is a circuit that establishes a refrigeration cycle as the refrigerant circulates, and cools an object through heat exchange with the refrigerant. More specifically, the refrigerant circuit 10 of this embodiment establishes a refrigeration cycle for the carbon dioxide refrigerant, an example of which is a refrigerant, by regulating its specific enthalpy and pressure. This allows the refrigerant to circulate while removing heat from the air through heat exchange on the low-pressure side, thereby cooling the air. In the following description, the carbon dioxide refrigerant circulating in the refrigerant circuit 10 may be simply referred to as "refrigerant."

[0046] In the refrigerant circuit 10 , not only the refrigerant circulates, but also a fluid different from the refrigerant, such as lubricating oil for ensuring lubrication in a compressor described later, may circulate.

[0047] Figure 2 It is a schematic diagram of the refrigerant circuit 10 according to the first embodiment.

[0048] As shown in the figure, the refrigerant circuit 10 of the first embodiment includes: compressors 12 and 13 for compressing the refrigerant; a radiator 14 for extracting heat from the refrigerant and dissipating the heat; a refrigerant-refrigerant heat exchanger 17 for performing heat exchange between refrigerants; electric valves 16 and 18 capable of adjusting the opening; and a cooler 19 for cooling the air by utilizing heat exchange with the refrigerant passing through.

[0049] The refrigerant circuit 10 also includes a temperature sensor 501 for measuring the temperature of the refrigerant compressed and discharged by the compressor 12, and a temperature sensor 502 for measuring the temperature of the refrigerant compressed and discharged by the compressor 13. In addition to the aforementioned components, the refrigerant circuit 10 may also include a pressure sensor or temperature sensor for measuring the pressure or temperature of the refrigerant at various locations, a receiver tank capable of storing the refrigerant, a pressure switch as a protective mechanism, a filter or radiator, an oil separator, and the like.

[0050] exist Figure 2 In the embodiment, the lines connecting the devices are flow paths through which the refrigerant flows, and are, for example, metal pipes.

[0051] As shown in the figure, a branch portion 15 for branching the flow path and a confluence portion 20 for merging the flow paths are provided on the flow path of the refrigerant circuit 10. Here, the section from the compressor 12 to the branch portion 15 is marked as the first flow path 101, the section from the electric valve 16 to the compressor 13 is marked as the second flow path 102, the section from the compressor 13 to the confluence portion 20 is marked as the third flow path 103, and the section from the electric valve 18 to the compressor 12 is marked as the fourth flow path 104. In addition, the side of the flow path branched out through the branch portion 15 that is connected to the electric valve 16 is marked as the first branch 151, and the other side that is connected to the cooler 19 via the electric valve 18 is marked as the second branch 152. Each flow path can be composed of a seamless pipe, or it can be composed of two or more pipes connected by a flange structure or the like (not shown). In addition, various devices can also be included in the middle of the flow path.

[0052] Compressor 12 compresses refrigerant drawn in from fourth flow path 104 and discharges it to first flow path 101. Compressor 13 compresses refrigerant drawn in from second flow path 102 and discharges it to third flow path 103. The mechanisms of compressors 12 and 13 are not limited; for example, various mechanisms such as an oscillating type, a scroll type, and a rotary type may be employed.

[0053] The compressors 12 and 13 suck in the refrigerant in accordance with the refrigerant supplied by the control unit 50 (see Figure 1 ) is controlled by the control unit 50 to compress and discharge the refrigerant at a compression ratio (= pressure of discharged refrigerant / pressure of inhaled refrigerant). In the compressors 12 and 13 of the present embodiment, the operating frequency, the amount of inhaled / discharged refrigerant, etc. are controlled based on the control signal from the control unit 50. In addition, the "operating frequency" refers to the operating frequency of the components for compressing the refrigerant in the compressor. Specifically, for example, it is the swing frequency of the swing body in the swing compressor, and the rotation frequency of the rotating body in the scroll compressor or the rotary compressor.

[0054] The compressor 12 is an example of a first compression element, and the compressor 13 is an example of a second compression element.

[0055] Radiator 14 is provided in first flow path 101. It extracts heat from the refrigerant and dissipates it through heat exchange between the refrigerant passing through it and a fluid such as air or water. As shown in the figure, in the refrigerant circuit 10 of the first embodiment, radiator 14 is provided between the confluence 20 and the branch 15 in first flow path 101. Various heat exchangers, such as a tubular heat exchanger or a plate heat exchanger, can be used as radiator 14.

[0056] In radiator 14, the fluid that exchanges heat with the refrigerant is heated by the heat extracted from the refrigerant. Therefore, for example, air can be used as the fluid, and the heated air can be supplied to a space as warm air, thereby heating the space. Alternatively, for example, water can be used as the fluid, and the heated water can be supplied to users, thereby providing hot water. In this way, radiator 14 can also function as a heater that heats the fluid.

[0057] Electric valves 16 and 18 are constructed by including valves such as ball valves and motors that drive the valves. The motors regulate the valve openings to adjust the pressure of the refrigerant flowing through them. More specifically, electric valve 16 is located between first branch 151 and second flow path 102. It applies throttling expansion corresponding to the valve opening to the refrigerant flowing in from first branch 151, thereby reducing its pressure and directing the refrigerant toward second flow path 102. Furthermore, electric valve 18 is located between refrigerant-refrigerant heat exchanger 17 and cooler 19 in second branch 152. It applies throttling expansion corresponding to the valve opening to the refrigerant flowing in from the refrigerant-refrigerant heat exchanger 17, thereby reducing its pressure and directing the refrigerant toward cooler 19. The openings of electric valves 16 and 18 are regulated by driving and controlling their respective motors based on control signals from control unit 50.

[0058] Furthermore, the electric valves 16 and 18 have flow resistances corresponding to their respective openings. Flow resistance is an indicator of how difficult it is for the refrigerant to flow through the electric valves 16 and 18. A higher opening makes it harder for the refrigerant to flow, resulting in a higher flow resistance. A lower opening makes it easier for the refrigerant to flow, resulting in a lower flow resistance.

[0059] Here, the electric valve 16 is an example of a first pressure reducing member, and the electric valve 18 is an example of a second pressure reducing member. Figure 1 ) In addition to electric valves, solenoid valves driven by solenoids can also be used as pressure reducing components controlled by the valve.

[0060] Refrigerant-to-refrigerant heat exchanger 17 is a device that exchanges heat between the refrigerant flowing in second flow path 102 and the refrigerant flowing in second branch 152. More specifically, refrigerant-to-refrigerant heat exchanger 17 exchanges heat between the refrigerant that branches into first branch 151 at branching portion 15 and flows in second flow path 102 with its pressure reduced by electric valve 16, and the refrigerant that branches into second branch 152 at branching portion 15. During the heat exchange in refrigerant-to-refrigerant heat exchanger 17, the refrigerant flowing in second flow path 102 removes heat from the refrigerant flowing in second branch 152, resulting in the refrigerant flowing in second branch 152 being cooled.

[0061] The cooler 19 is provided in the fourth flow path 104 and is a device that extracts heat from the air and cools the air by heat exchange between the refrigerant passing therethrough and the air. A heat exchanger such as a tube heat exchanger can be used as the cooler 19 .

[0062] The air exchanges heat with the refrigerant in the cooler 19, and the cooled air is supplied to the space through a ventilation path (not shown), thereby cooling the space. Figure 1 ) cooling function.

[0063] The refrigerant circulation in the refrigerant circuit 10 will be described. In the refrigerant circuit 10 of the first embodiment, the refrigerant, after cooling the air in the cooler 19 (position 10a), is compressed by the compressor 12 and discharged into the first flow path 101 (position 10b). The refrigerant discharged into the first flow path 101 merges with the third flow path 103 at the confluence 20 (position 10c). After dissipating heat through the radiator 14, it branches into a first branch 151 and a second branch 152 at the branching portion 15 (position 10d). The refrigerant branching into the first branch 151 is decompressed by the electric valve 16 and flows into the second flow path 102 (position 10g). In the refrigerant-refrigerant heat exchanger 17, it exchanges heat with the refrigerant branching into the second branch 152 (position 10h). It is then compressed by the compressor 13 and discharged into the third flow path 103 (position 10i), where it merges with the first flow path 101 at the confluence 20 (position 10c). On the other hand, the refrigerant branched to the second branch 152 and heat-exchanged in the refrigerant-refrigerant heat exchanger 17 (position 10e) is decompressed by the electric valve 18 (position 10f) and passes through the cooler 19 to cool the air (position 10a).

[0064] By circulating the refrigerant in this manner, the refrigerant circuit 10 establishes a refrigeration cycle of the refrigerant.

[0065] (Refrigeration cycle)

[0066] use Figure 2 、 Figure 3 The refrigeration cycle in the refrigerant circuit (10) will be described in detail.

[0067] Figure 3 This is a pressure-specific enthalpy diagram illustrating the refrigeration cycle 300 of the refrigerant circulating in the refrigerant circuit 10 of the first embodiment. Figure 3 In the figure, the horizontal axis is specific enthalpy [kJ / kg], and the vertical axis is absolute pressure [MPa.abs] based on absolute vacuum.

[0068] exist Figure 3 In FIG. 3 , the refrigeration cycle 300 is represented by a thick line. Points 10a to 10i on the refrigeration cycle 300 are Figure 2The positions 10a to 10i of the refrigerant circuit 10 shown correspond to each other. Therefore, the points 10a to 10i in the refrigeration cycle 300 are marked as positions 10a to 10i. Figure 3 In addition to the refrigeration cycle 300 , a saturated liquid line 301 , a saturated vapor line 302 , a critical point 303 , and a 45° C. isotherm 304 of the carbon dioxide refrigerant are also shown.

[0069] In the refrigerant circuit 10 of the first embodiment, the refrigerant, compressed by the compressor 12 and having gained heat of compression, is discharged into the first flow path 101. Consequently, the refrigerant's pressure and specific enthalpy increase from position 10a to position 10b in the refrigeration cycle 300. Furthermore, because the third flow path 103 merges at the junction 20, the refrigerant's specific enthalpy changes from position 10b to position 10c. Furthermore, the merged refrigerant dissipates heat through heat exchange with the fluid in the radiator 14, resulting in a decrease in the refrigerant's specific enthalpy from position 10c to position 10d. Furthermore, the refrigerant at position 10c is pressurized and heated by the compressors 12 and 13, reaching a temperature exceeding 45°C, for example. Therefore, even if the fluid subject to heat exchange in the radiator 14 is at room temperature (15°C to 25°C), heat can be removed from the refrigerant.

[0070] At position 10d, the first branch 151 branching off from the branching portion 15 flows into the second flow path 102 after being decompressed by the electric valve 16. Consequently, the refrigerant pressure decreases from position 10d to position 10g. Furthermore, as the pressure decreases, the temperature of the refrigerant flowing in the second flow path 102 decreases, becoming lower than the temperature of the refrigerant flowing in the second branch 152. Consequently, the refrigerant flowing in the second flow path 102 removes heat from the refrigerant in the first branch 151 through heat exchange with the refrigerant-refrigerant heat exchanger 17, causing the specific enthalpy to increase from position 10g to position 10h. Conversely, the refrigerant in the second branch 152 removes heat through heat exchange, causing the specific enthalpy to decrease from position 10d to position 10e.

[0071] After passing through the refrigerant-refrigerant heat exchanger 17, the refrigerant in the second branch 152 is decompressed by the electric valve 18. Consequently, the refrigerant pressure decreases from position 10e to position 10f. Furthermore, the decompressed refrigerant exchanges heat with the air in the cooler 19, extracting heat. Consequently, the refrigerant's specific enthalpy increases from position 10f to position 10a. Furthermore, the refrigerant at position 10f, having been decompressed and cooled by the electric valve 18, is sufficiently cool relative to the air being cooled. Therefore, the cooler 19 is able to extract heat from the air being heat exchanged.

[0072] Furthermore, after passing through the refrigerant-refrigerant heat exchanger 17 , the refrigerant in the second flow path 102 is compressed by the compressor 13 and obtains compression heat. Therefore, the pressure and specific enthalpy of the refrigerant increase from the position 10 h to the position 10 i .

[0073] As described above, the refrigeration cycle 300 of the refrigerant circuit 10 is established.

[0074] Here, the refrigerant cooling the air in the cooler 19 loses heat through heat exchange between the refrigerants in the refrigerant-refrigerant heat exchanger 17 before being decompressed by the electric valve 18. Therefore, the refrigerant cooling the air in the cooler 19 of the refrigerant circuit 10 ( Figure 2 、 Figure 3 The position 10f in the conventional refrigerant circuit 10' is the same as the refrigerant ( Figure 8 As a result, in the refrigerant circuit 10, the amount of heat removed per unit amount of refrigerant in the cooler 19 increases compared to a conventional refrigerant circuit 10′ where no heat exchange between refrigerants occurs, thereby ensuring cooling capacity without increasing the amount of refrigerant circulating.

[0075] Furthermore, in refrigerant circuit 10, the carbon dioxide refrigerant reaches a supercritical state in a portion of refrigeration cycle 300. This causes a greater change in refrigerant density associated with changes in refrigerant pressure than in a non-supercritical state. Consequently, the refrigeration capacity of compressors 12 and 13, which ensures compression work, is greater than when the refrigerant does not pass through a supercritical state. This also applies to the refrigerant circuits of the second to fourth embodiments described below.

[0076] Here, use Figure 2 、 Figure 8 1 and Table 1, the performance of the refrigerant circuit 10 of the first embodiment is compared with the performance of the conventional refrigerant circuit 10'.

[0077] Table 1 shows the capacities and coefficients of performance (COP) of compressors 12, 13 / 12', and 13' in an air conditioner 1 using the refrigerant circuit 10 of the first embodiment and an air conditioner using a conventional refrigerant circuit 10'. The COP is the value obtained by dividing the cooling effect of the coolers 17 / 17' of the refrigerant circuits 10 / 10' by the power consumed by the operation of the refrigerant circuits 10 / 10', and corresponds to the efficiency of the cooling effect relative to the power consumed.

[0078] [Table 1]

[0079] Refrigerant circuit 10 Refrigerant circuit 10 Compressor 12 / 12 capacity cc l 06 81.5 Compressor 13 / 13' capacity cc 33 81.5 Total capacity cc l 39 l 63 COP l.990 l.60 Total capacity comparison % 85 l00 (benchmark) COP Comparison % l 19 l00 (benchmark)

[0080] As shown in Table 1, the COP of air conditioner 1, when the capacity of compressor 12 in refrigerant circuit 10 is set to 106cc and the capacity of compressor 13 is set to 33cc, for a total capacity of 139cc, is 1.90. On the other hand, the COP of air conditioner 1, when the capacity of compressors 12' and 13' in conventional refrigerant circuit 10' is set to 81.5cc, for a total capacity of 163cc, is 1.60. In other words, assuming the total capacity and COP of the air conditioner using conventional refrigerant circuit 10' are 100% (baseline), the COP of air conditioner 1 using refrigerant circuit 10 can be reduced to 85% while improving to 119%.

[0081] As described above, in the air-conditioning device 1 using the refrigerant circuit 10, the refrigeration capacity is ensured by the heat exchange between the refrigerants in the refrigerant-refrigerant heat exchanger 17. Therefore, compared with the case of using the previous refrigerant circuit 10 in which the refrigeration capacity is ensured by increasing the refrigerant circulation amount, the refrigeration effect of the air-conditioning device 1 can be improved even when the total capacity of the compressor is suppressed.

[0082] (Control by the Control Unit 50)

[0083] In addition, the control unit 50 of the air-conditioning device 1 (see Figure 1 ) can also be based on the temperature sensors 501, 502 (refer to Figure 2 ) to control the refrigerant circulation by measuring the refrigerant temperature.

[0084] For example, the control unit 50 may also control the flow resistance by reducing the opening of the electric valve 16 when the temperature of the refrigerant measured by the temperature sensor 501 is higher than the temperature of the refrigerant measured by the temperature sensor 502. In addition, for example, when the temperature of the refrigerant measured by the temperature sensor 501 is higher than the temperature of the refrigerant measured by the temperature sensor 502, the control unit 50 may control the flow resistance by increasing the amount of refrigerant sucked into the compressor 13 and increasing the flow rate of the refrigerant in the compressor 13. By performing these controls, the refrigerant compressed by the compressor 12 ( Figure 2 Position 10b) and the refrigerant compressed by the compressor 13 ( Figure 2 As a result, the compression ratio of the compressor 13 can be set to be larger.

[0085] In addition, the positions of the temperature sensors 501 and 502 used for control are not limited to Figure 2The positions illustrated can be such that the temperature sensor 501 is located before the first flow path 101 passes through the radiator 14 and before it merges with the third flow path 103 via the confluence portion 20, and the temperature sensor 502 is located before it merges with the first flow path 101 via the confluence portion 20.

[0086] <Second embodiment>

[0087] (Refrigeration circuit 10-2)

[0088] The air conditioner 1 according to the second embodiment is different from the first embodiment in that the refrigerant circuit 10 (see Figure 2 ) and has a refrigerant circuit 10-2.

[0089] Figure 4 It is a schematic diagram of a refrigerant circuit 10 - 2 according to the second embodiment.

[0090] As shown in the figure, the refrigerant circuit 10 of the second embodiment differs from the refrigerant circuit 10 of the first embodiment only in that the radiator 21 is provided in the third flow path 103 and that the merging portion 20 merges the third flow path 103 at a position in the first flow path 101 after passing through the radiator 14. Therefore, the same names and reference numerals are used for the common structures between the refrigerant circuit 10 and the refrigerant circuit 10, and detailed descriptions are omitted.

[0091] Radiator 21 is provided in third flow path 103 and is a device that extracts heat from the refrigerant and dissipates it through heat exchange between the refrigerant passing through it and a fluid such as air or water. In other words, radiator 21 extracts heat from the refrigerant compressed by compressor 13 by exchanging heat between the refrigerant and the fluid.

[0092] As the radiator 21, a heat exchanger similar to the radiator 14 can be used. Moreover, similar to the radiator 14, the radiator 21 can also be used as a heater for heating a fluid.

[0093] The radiator 21 is an example of a second radiator.

[0094] In refrigerant circuit 10-2, the refrigerant, having cooled the air in cooler 19, is compressed by compressor 12 and discharged into first flow path 101. The refrigerant discharged into first flow path 101 dissipates heat through radiator 14, merges with third flow path 103 at junction 20, and then branches into first branch 151 and second branch 152 at branching portion 15. The refrigerant branching into first branch 151 is decompressed by motorized valve 16 and flows into second flow path 102. In refrigerant-to-refrigerant heat exchanger 17, it exchanges heat with the refrigerant branching into first branch 151. It is then compressed by compressor 13 and discharged into third flow path 103, dissipating heat through radiator 21 before merging with first flow path 101 at junction 20. Meanwhile, the refrigerant branching into second branch 152, after undergoing heat exchange in refrigerant-to-refrigerant heat exchanger 17, is decompressed by motorized valve 18 and then passes through cooler 19 to cool the air.

[0095] By such refrigerant circulation, the refrigerant circuit 10 - 2 establishes a refrigeration cycle of the refrigerant.

[0096] In the second embodiment using the refrigerant circuit 10 - 2 described above, similarly to the first embodiment, the total capacity of the compressors is suppressed compared to the case of using the conventional refrigerant circuit 10 that ensures refrigeration capacity by increasing the refrigerant circulation amount.

[0097] In addition, in the refrigerant circuit 10-2, the merging portion 20 merges the third flow path 103 at a position after passing through the radiator 14 in the first flow path 101, so that the heat dissipation from the radiator 14 can be increased compared to the case where the third flow path 103 merges at a position before passing through the radiator 14.

[0098] In the refrigerant circuit 10-2 of the second embodiment, the capacity of the compressor 12 may be larger than that of the compressor 13. This configuration increases heat dissipation from the radiator 14 compared to a case where the capacity of the compressor 12 is smaller than that of the compressor 13.

[0099] <Third embodiment>

[0100] (Refrigeration circuit 10-3)

[0101] The air conditioning apparatus 1 according to the third embodiment is different from the first embodiment in that the refrigerant circuit 10 (see Figure 2 ) and has a refrigerant circuit 10-3.

[0102] Figure 5 This is a schematic diagram of a refrigerant circuit 10 - 3 according to the third embodiment.

[0103] As shown in the figure, the refrigerant circuit 10-3 of the third embodiment differs from the refrigerant circuit 10-2 of the second embodiment only in that it includes a motor-operated valve 22 for decompressing the refrigerant after passing through the radiator 21. Therefore, common structures between the refrigerant circuits 10-2 and 10-3 are designated using the same names and reference numerals, and detailed descriptions are omitted.

[0104] The electric valve 22 is provided in the third flow path 103 at a position after the refrigerant passes through the radiator 21 , and decompresses the refrigerant passing through the third flow path 103 .

[0105] The electric valve 22 may have the same structure as the electric valve 16 or the electric valve 18 , and its opening degree may be adjusted by the control unit 50 .

[0106] The electric valve 22 is an example of a third pressure reducing member.

[0107] In refrigerant circuit 10-3, the refrigerant, after cooling the air in cooler 19, is compressed by compressor 12 and discharged into first flow path 101. The refrigerant discharged into first flow path 101 dissipates heat through radiator 14, merges with third flow path 103 at junction 20, and then branches into first branch 151 and second branch 152 at branching portion 15. The refrigerant branching into first branch 151 is decompressed by electric valve 16 and flows into second flow path 102. In refrigerant-refrigerant heat exchanger 17, it exchanges heat with the refrigerant branching into first branch 151. Then, after being compressed by compressor 13 and discharged into third flow path 103, it dissipates heat through radiator 21 and merges with first flow path 101 at junction 20, having further reduced its pressure by electric valve 22. On the other hand, the refrigerant that has branched into the second branch 152 and undergone heat exchange in the refrigerant-refrigerant heat exchanger 17 is decompressed by the electric valve 18 and then passes through the cooler 19 to cool the air.

[0108] By such refrigerant circulation, the refrigerant circuit 10 - 3 establishes a refrigeration cycle of the refrigerant.

[0109] In the third embodiment using the refrigerant circuit 10 - 3 , similarly to the first and second embodiments, the total capacity of the compressors is suppressed compared to the case of using the conventional refrigerant circuit 10 that ensures refrigeration capacity by increasing the refrigerant circulation amount.

[0110] Furthermore, in the refrigerant circuit 10 - 3 , the refrigerant compressed by the compressor 13 is decompressed by the electric valve 22 , so that the compression ratio in the compressor 13 can be increased compared to a case where the electric valve 22 is not provided.

[0111] <Fourth embodiment>

[0112] (Refrigeration circuit 10-4)

[0113] The air conditioner 1 according to the fourth embodiment is different from the first embodiment in that the refrigerant circuit 10 (see Figure 2 ) and has a refrigerant circuit 10-4.

[0114] Figure 6 This is a schematic diagram of a refrigerant circuit 10 - 4 according to the fourth embodiment.

[0115] As shown in the figure, the refrigerant circuit 10 of the fourth embodiment differs from the refrigerant circuit 10-2 of the second embodiment only in that it includes a motor-operated valve 23 for decompressing the refrigerant after passing through the radiator 14. Therefore, the common structures between the refrigerant circuit 10-2 and the refrigerant circuit 10-4 are designated by the same names and reference numerals, and detailed descriptions are omitted.

[0116] The electric valve 23 is provided in the first flow path 101 at a position after the refrigerant passes through the radiator 14 and before the refrigerant merges with the third flow path 103 at the merging portion 20 , and decompresses the refrigerant passing therethrough.

[0117] As the electric valve 23 , the same structure as the electric valves 16 , 18 , and 22 can be used, and the opening degree can be adjusted by the control unit 50 .

[0118] The electric valve 23 is an example of a fourth pressure reducing member.

[0119] In the refrigerant circuit 10-4, the refrigerant, after cooling the air in the cooler 19, is compressed by the compressor 12 and discharged into the first flow path 101. The refrigerant discharged into the first flow path 101 dissipates heat through the radiator 14 and is decompressed by the electric valve 23. It then merges with the third flow path 103 at the confluence 20 and branches into the first branch 151 and the second branch 152 at the branch 15. The refrigerant branching into the first branch 151 is decompressed by the electric valve 16 and flows into the second flow path 102. In the refrigerant-refrigerant heat exchanger 17, it exchanges heat with the refrigerant branching into the second branch 152. It is then compressed by the compressor 13 and discharged into the third flow path 103, dissipating heat through the radiator 21, and then merges with the first flow path 101 at the confluence 20. On the other hand, the refrigerant that has branched into the second branch 152 and undergone heat exchange in the refrigerant-refrigerant heat exchanger 17 is decompressed by the electric valve 18 and then passes through the cooler 19 to cool the air.

[0120] By such refrigerant circulation, the refrigerant circuit 10 - 4 establishes a refrigeration cycle of the refrigerant.

[0121] In the fourth embodiment using the refrigerant circuit 10 - 4 described above, similarly to the first to third embodiments, the total capacity of the compressors is suppressed compared to the case of using the conventional refrigerant circuit 10 that ensures refrigeration capacity by increasing the refrigerant circulation amount.

[0122] Furthermore, in the refrigerant circuit 10 - 4 , the refrigerant compressed by the compressor 12 is decompressed by the electric valve 23 , so that the compression ratio in the compressor 12 can be increased compared to a case where the electric valve 23 is not provided.

[0123] <Application Examples>

[0124] (Cooling / heating switching)

[0125] However, in air conditioning device 1, there are cases where a cooling function is switched between supplying cool air to a space to cool it, and a heating function is switched between supplying warm air to heat it. In this case, if the heat exchanger that cools the air in the cooling function and the heat exchanger that heats the air in the heating function are shared, the air supply path used in the heat exchanger or the ventilation path that supplies the cool / warm air after heat exchange to the space can be shared.

[0126] The refrigerant circuit of the application example includes a switching unit that switches the cooler 19 (see Figure 2 、 Figures 4 to 6 ) switches to a state where the heat exchanger cools the air in the cooling function and to a state where the heat exchanger heats the air in the heating function.

[0127] Figure 7 This is a diagram illustrating a refrigerant circuit 10 - 5 according to an application example.

[0128] As shown in the figure, the refrigerant circuit 10-5 of the application example differs from the refrigerant circuit 10 of the first embodiment only in that it includes a four-way switching valve 60 for switching the connection relationship between the four flow paths. Therefore, the common structures between the refrigerant circuit 10 and the refrigerant circuit 10-5 are marked with the same names and reference numerals, and detailed descriptions are omitted.

[0129] The four-way switching valve 60 is provided to connect the flow path from the cooler 19 to the compressor 12 and the flow path from the confluence portion 20 to the radiator 14. Furthermore, under control from the control unit 50, the flow path connection relationship is switched between a first state in which the cooler 19 and the compressor 12 are connected and the confluence portion 20 and the radiator 14 are connected; and a second state in which the cooler 19 and the confluence portion 20 are connected and the compressor 12 and the radiator 14 are connected.

[0130] In addition, the four-way switching valve 60 is an example of a switching unit, and other structures may be used for switching.

[0131] In the first state of the refrigerant circuit 10-5, Figure 2 The refrigerant circuit 10 described above similarly circulates the refrigerant, and the air serving as the heat exchange target in the cooler 19 is cooled. This achieves the cooling function of the air conditioner 1.

[0132] On the other hand, in the refrigerant circuit 10-5 in the second state, the refrigerant circulates in a different manner from that in the first state, and the pressure and specific enthalpy of the refrigerant are different from those in the first state. Figure 3 The path of the previously described refrigeration cycle 300 is reversed. More specifically, the refrigerant compressed by compressors 12 and 13 merges at confluence 20 and then passes through cooler 19. The refrigerant passing through cooler 19 is pressurized and heated by compressors 12 and 13, reaching a sufficiently high temperature relative to the air being heat exchanged. Therefore, the air in cooler 19, which is the object of heat exchange, absorbs heat from the refrigerant and is heated. This achieves the heating function of air conditioner 1.

[0133] exist Figure 7 In the example, the switching unit is applied to the refrigerant circuit 10 of the first embodiment and the refrigerant circuit 10-5 is shown as an application example, but the same switching unit can also be applied to the refrigerant circuit 10-2, refrigerant circuit 10-3, and refrigerant circuit 10-4 of the second, third, and fourth embodiments.

[0134] Furthermore, in the air conditioner 1 of the second, third, and fourth embodiments and the application example using the switching means, the control unit 50 may also be based on the temperature sensors 501 and 502 (see Figure 2 、 Figures 4 to 7 ) to control the refrigerant circulation by measuring the refrigerant temperature.

[0135] <Other>

[0136] In the above embodiment, the refrigeration cycle device is applied to the air conditioning device 1 as an example, but the scope of application is not limited. It can also be applied to various equipment for cooling objects such as refrigerated warehouses, refrigerators, ice makers, etc. Figure 2 As described above, the present invention can also be applied to various devices that heat objects such as heating appliances, boilers, and water heaters by utilizing heat dissipation from the radiator 14 .

[0137] While a carbon dioxide refrigerant is described as an example of a refrigerant circulating in each refrigerant circuit, the type of refrigerant is not limited. A mixed refrigerant made by mixing carbon dioxide with other components may be used, or a single refrigerant or mixed refrigerant that does not contain carbon dioxide may be used. However, by using a refrigerant that contains carbon dioxide in at least part of its composition, as in the carbon dioxide refrigerant of the above-described embodiment, heat dissipation in radiators 14 and 21 is greater than when using a non-azeotropic refrigerant mixture that does not contain carbon dioxide.

[0138] Furthermore, the first compression element and the second compression element can be concentrated in one device, and the compression action in each compression element can be realized by a common motor, etc. However, by setting each compression element as a different device like the compressors 12 and 13 in the above-mentioned embodiment, each compression element can be controlled individually according to the state of the inhaled refrigerant, etc.

[0139] Alternatively, multiple compressors connected in parallel may be used instead of compressor 12, or multiple compressors connected in parallel may be used instead of compressor 13. In this case, the total capacity can be reduced compared to the conventional refrigerant circuit 10' where the refrigerant circulation amount is increased to ensure refrigeration capacity.

[0140] In the above embodiment, an electric valve or a solenoid valve is used as the pressure reducing means so that the opening can be controlled by the control unit 50. When the control is not performed by the control unit 50, a capillary tube or an orifice plate may be used as each pressure reducing means.

[0141] Furthermore, in the above embodiment, the refrigerant is divided into two branches, namely the first branch 151 and the second branch 152. However, the refrigerant may be divided into three or more branches, including the first branch 151 and the second branch 152. Accordingly, multiple flow paths, including the third flow path 103, may be merged with the first flow path 101. Furthermore, when there are three or more branches, the branching may be performed at multiple branching portions, including the branch portion 15, and the merging may be performed at multiple merging portions, including the merging portion 20.

[0142] <Note>

[0143] The above-mentioned embodiment can be understood as follows.

[0144] The air conditioning device 1 of the above embodiment includes a refrigerant circuit 10, 10-2, 10-3, 10-4, and 10-5, wherein the refrigerant circuit 10, 10-2, 10-3, 10-4, and 10-5 include: a compressor 12, which compresses the sucked refrigerant and discharges it to the first flow path 101; a radiator 14, which is provided in the first flow path 101, allows the refrigerant to pass through, and dissipates heat taken out of the refrigerant passing through; a branch portion 15, which branches the refrigerant after passing through the radiator 14 in the first flow path 101 into a first branch 151 and a second branch 152; an electric valve 16, which decompresses the refrigerant branched into the first branch 151 and causes it to flow to the second flow path 102; refrigerant-refrigerant Heat exchanger 17 exchanges heat between the refrigerant flowing in second flow path 102 and the refrigerant branching into second branch 152. Electric valve 18 decompresses the refrigerant after heat exchange in second branch 152 by refrigerant-refrigerant heat exchanger 17. Cooler 19 cools the air by exchanging heat between the refrigerant decompressed by electric valve 18 and the air, and draws the heat-exchanged refrigerant into compressor 12. Compressor 13 draws the refrigerant after heat exchange in second flow path 102 by refrigerant-refrigerant heat exchanger 17, compresses it, and discharges it into third flow path 103. Finally, merging portion 20 merges third flow path 103 with first flow path 101. This configuration allows the combined capacity of compressors 12 and 13 to be reduced compared to an air conditioner having a conventional refrigerant circuit 10', which increases the refrigerant circulation volume to ensure cooling capacity.

[0145] In the refrigerant circuit 10 of the second embodiment, the merging portion 15 merges the third flow path 103 at a position within the first flow path 101 after the flow path passes through the radiator 14. Furthermore, the radiator 21 is provided within the third flow path 103 to dissipate heat extracted by the refrigerant compressed by the compressor 13. In this case, compared to a case where the merging portion 15 merges the third flow path 103 at a position within the first flow path 101 before the flow path passes through the radiator 14, the amount of heat dissipated from the radiator 14 can be increased.

[0146] In the refrigerant circuit 10, the capacity of the compressor 12 is larger than that of the compressor 13. In this case, compared with a case where the capacity of the compressor 12 is smaller than that of the compressor 13, heat dissipation from the radiator 14 can be increased.

[0147] In addition to the configuration of the refrigerant circuit 10-2, the refrigerant circuit 10-3 of the third embodiment has a motor-operated valve 22 provided in the third flow path 103 for decompressing the refrigerant after passing through the radiator 21. In this case, the compression ratio of the compressor 13 can be set high.

[0148] In addition to the configuration of refrigerant circuit 10-2, refrigerant circuit 10-4 of the fourth embodiment includes a motor-operated valve 23 for reducing the pressure on the refrigerant after passing through radiator 14, located in first flow path 101 after the refrigerant passes through radiator 14 and before it joins third flow path 103 at junction 20. This allows the compression ratio of compressor 12 to be set higher.

[0149] Here, in the air conditioning apparatus 1 of the above embodiment, carbon dioxide refrigerant is used. In this case, heat dissipation in the radiator 14 is greater than when a non-azeotropic mixed refrigerant containing no carbon dioxide is used.

[0150] Furthermore, in the air conditioning apparatus 1 of the above-described embodiment, temperature sensors 501 and 502 for measuring the refrigerant temperature are provided, respectively, at locations in the first flow path 101 before passing through the radiator 14 and before merging with the third flow path 103 at the merging portion 15, and at locations in the third flow path 103 before merging with the first flow path 101 at the merging portion 15. Furthermore, if the refrigerant temperature measured by the temperature sensor 501 is higher than the refrigerant temperature measured in the third flow path 103, the control unit 50 of the air conditioning apparatus 1 can simply control the electric valve 16 to increase the flow resistance. In this case, the enthalpy difference between the refrigerant compressed by the compressor 12 and the refrigerant compressed by the compressor 13 is reduced.

[0151] Furthermore, in the air conditioning apparatus 1 of the above-described embodiment, the controller 50 may control the compressor 13 so as to increase the flow rate when the temperature of the refrigerant measured in the first flow path 101 is higher than the temperature of the refrigerant measured in the third flow path 103. In this case, the enthalpy difference between the refrigerant compressed by the compressor 12 and the refrigerant compressed by the compressor 13 also decreases.

[0152] Although the embodiments have been described above, it will be understood that various modifications may be made to the form and detailed structure without departing from the spirit and scope of the claims.

[0153] For example, a part of each structure may be omitted, or other functions may be added to each structure. In addition, for example, a structure included in one configuration example may be exchanged with a structure included in another configuration example, or a structure included in one configuration example may be added to another configuration example.

[0154] Description of labels

[0155] 1…air conditioning device; 10, 10-2, 10-3, 10-4, 10-5…refrigerant circuit; 12, 13…compressor; 14, 21…radiator; 15…branch portion; 16, 18, 22, 23…electric valve; 17…refrigerant-refrigerant heat exchanger; 19…cooler; 20…merging portion; 50…control unit; 60…switching circuit; 101…first flow path; 102…second flow path; 103…third flow path; 151…first branch; 152…second branch; 501, 502…temperature sensor.

Claims

1. A refrigeration cycle device, characterized in that: The refrigeration cycle device comprises: a first compression element for compressing the sucked refrigerant and discharging the refrigerant to the first flow path; a radiator disposed in the first flow path, allowing the refrigerant to pass therethrough and dissipating heat extracted from the refrigerant passing therethrough; a branch portion for branching the refrigerant after passing through the radiator in the first flow path into a first branch and a second branch; a first decompression member configured to decompress the refrigerant branched to the first branch and cause the refrigerant to flow toward the second flow path; a heat exchanger configured to perform heat exchange between the refrigerant flowing in the second flow path and the refrigerant branched into the second branch; a second decompression member for decompressing the refrigerant after heat exchange in the second branch through the heat exchanger; a cooler that cools an object by exchanging heat between the refrigerant decompressed by the second decompressing member and the object, and draws the refrigerant after the heat exchange into the first compressing member; a second compression element that draws in the refrigerant that has undergone heat exchange in the heat exchanger in the second flow path, compresses the refrigerant, and discharges the refrigerant to a third flow path; and A merging portion merges the third flow path with the first flow path.

2. The refrigeration cycle device according to claim 1, wherein The merging portion merges the third flow path at a position in the first flow path after the first flow path passes through the radiator. The refrigeration cycle device includes a second radiator provided in the third flow path for radiating heat extracted by passing the refrigerant compressed by the second compression element.

3. The refrigeration cycle device according to claim 2, wherein: The first compression member has a capacity greater than that of the second compression member.

4. The refrigeration cycle device according to claim 3, wherein The refrigeration cycle device includes a third decompressing member provided in the third flow path and configured to decompress the refrigerant after passing through the second radiator.

5. The refrigeration cycle device according to claim 2, wherein: The refrigeration cycle device includes a fourth decompressing member provided in the first flow path after passing through the radiator and before merging with the third flow path at the merging portion, for decompressing the refrigerant after passing through the radiator.

6. The refrigeration cycle device according to any one of claims 1 to 5, characterized in that: At least a part of the refrigerant composition is carbon dioxide.

7. The refrigeration cycle device according to claim 1, wherein The refrigeration cycle device comprises: a temperature sensor for measuring the temperature of the refrigerant at a position in the first flow path before passing through the radiator and before merging with the third flow path at the merging portion, and at a position in the third flow path before merging with the first flow path at the merging portion; as well as a control unit that performs control related to the circulation of the refrigerant based on the temperature of the refrigerant measured by the temperature sensor, The control unit performs control so as to increase the flow resistance of the first decompression member when the temperature of the refrigerant measured in the first flow path is higher than the temperature of the refrigerant measured in the third flow path.

8. The refrigeration cycle device according to claim 1, wherein The refrigeration cycle device comprises: a temperature sensor for measuring the temperature of the refrigerant at a position in the first flow path before passing through the radiator and before merging with the third flow path at the merging portion, and at a position in the third flow path before merging with the first flow path at the merging portion; as well as a control unit that performs control related to the circulation of the refrigerant based on the temperature of the refrigerant measured by the temperature sensor, The control unit performs control to increase the flow rate of the second compression element when the temperature of the refrigerant measured in the first flow path is higher than the temperature of the refrigerant measured in the third flow path.

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