Refrigeration Cycle Equipment

Abstract

In a refrigeration cycle device having a plurality of refrigerant circuits filled with different types of refrigerant, the occurrence of erroneous filling of refrigerant is suppressed. [Solution] A refrigeration cycle device (100) includes a first refrigerant circuit (10) filled with a first refrigerant and a second refrigerant circuit (50) filled with a second refrigerant. The second refrigerant circuit is pre-filled with the second refrigerant. The refrigeration cycle device includes a first path (70) and a second path (80) connected to the second refrigerant circuit. When charging the second refrigerant circuit with the second refrigerant, the second refrigerant is charged into the second refrigerant circuit from a charge port of the first path. When discharging the second refrigerant from the second refrigerant circuit, the second refrigerant is discharged to the outside of the second refrigerant circuit from a discharge port of the second path. The first path is provided with a blocking portion that prevents the second refrigerant from being recharged. The second path is provided with a check valve that prevents the second refrigerant from flowing from the discharge port into the second refrigerant circuit.

Description

[Technical Field]

[0001] The present invention relates to a refrigeration cycle device, and more particularly to a refrigeration cycle device including a plurality of refrigerant circuits filled with different types of refrigerants. [Background technology]

[0002] BACKGROUND ART Conventionally, as disclosed in Patent Document 1 (WO 2014 / 181399), a refrigeration cycle apparatus is known that includes a plurality of refrigerant circuits filled with different types of refrigerant.

[0003] In such a refrigeration cycle device, each refrigerant circuit is provided with an opening for filling with refrigerant, and when filling with refrigerant, a piping for filling with refrigerant is connected to this opening, and the refrigerant is filled into the refrigerant circuit through this opening.

[0004] Conventionally, such a refrigeration cycle device is configured so that it is possible to fill each of the plurality of refrigerant circuits with refrigerant at the installation site. Summary of the Invention [Problem to be solved by the invention]

[0005] In this way, if it is possible to fill multiple refrigerant circuits of the refrigeration cycle device with refrigerant at the installation location of the refrigeration cycle device, there is a possibility that an operator may inadvertently make the mistake of filling refrigerant that should be filled into one refrigerant circuit into another refrigerant circuit. [Means for solving the problem]

[0006] A refrigeration cycle apparatus according to a first aspect includes a first refrigerant circuit filled with a first refrigerant and a second refrigerant circuit filled with a second refrigerant. In the refrigeration cycle apparatus, the second refrigerant circuit is previously filled with the second refrigerant. The refrigeration cycle apparatus includes a first path connected to the second refrigerant circuit and a second path connected to the second refrigerant circuit. The first path has a first opening. When the second refrigerant is being filled into the second refrigerant circuit, the second refrigerant is filled from the first opening into the second refrigerant circuit. The second path has a second opening. When the second refrigerant is being discharged from the second refrigerant circuit, the second refrigerant is discharged from the second opening to the outside of the second refrigerant circuit. The first path is provided with a first structure that prevents the second refrigerant from being recharged at the installation location of the refrigeration cycle apparatus. The second path is provided with a second structure. The second structure allows the second refrigerant to flow from the second refrigerant circuit to the second opening and prevents the second refrigerant from flowing from the second opening into the second refrigerant circuit.

[0007] In the refrigeration cycle apparatus of the first aspect, the second refrigerant cannot be recharged at the installation location of the refrigeration cycle apparatus, which prevents an operator from bringing a refrigerant container filled with the second refrigerant to the installation location of the refrigeration cycle apparatus, thereby reducing the risk of an operator carelessly charging the first refrigerant circuit with the second refrigerant or the risk of an operator carelessly charging the second refrigerant circuit with the first refrigerant.

[0008] A refrigeration cycle apparatus according to a second aspect is the refrigeration cycle apparatus according to the first aspect, further comprising a casing that houses the entire second refrigerant circuit.

[0009] In the refrigeration cycle apparatus of the second aspect, since the second refrigerant circuit is entirely housed in the casing, the amount of the second refrigerant charged is relatively small to begin with, and therefore, even if the second refrigerant cannot be charged on site, the operation of the refrigeration cycle apparatus is unlikely to be affected.

[0010] A refrigeration cycle apparatus according to a third aspect is the refrigeration cycle apparatus according to the second aspect, further comprising a first heat exchanger disposed in the casing and performing heat exchange between the first refrigerant and the second refrigerant. The first refrigerant circuit includes a second heat exchanger and a third heat exchanger. The second heat exchanger is housed in the casing. In the second heat exchanger, the first refrigerant exchanges heat with the first heat source medium. The third heat exchanger is disposed outside the casing. In the third heat exchanger, the first refrigerant exchanges heat with a medium whose temperature is to be adjusted. The second refrigerant circuit includes a fourth heat exchanger housed in the casing. In the fourth heat exchanger, the second refrigerant exchanges heat with the second heat source medium.

[0011] In the refrigeration cycle device of the third aspect, the first refrigerant circuit is a main refrigerant circuit that adjusts the temperature of a medium to be temperature-adjusted, and the second refrigerant circuit is a sub-refrigerant circuit that assists the main refrigerant circuit. Therefore, the amount of the second refrigerant charged into the second refrigerant circuit is originally relatively small. Therefore, even if the second refrigerant cannot be charged on-site, the operation of the refrigeration cycle device is unlikely to be affected.

[0012] Furthermore, in the refrigeration cycle device, the risk of the second refrigerant being mistakenly filled into the first refrigerant circuit due to carelessness on the part of an operator and being transported to the vicinity of the temperature adjustment target (to the third heat exchanger) can be reduced.

[0013] A refrigeration cycle apparatus according to a fourth aspect is the refrigeration cycle apparatus according to the second or third aspect, wherein the first passage and the second passage are disposed inside the casing, and the first opening and the second opening are disposed below the center of the casing in the vertical direction.

[0014] In the refrigeration cycle apparatus of the fourth aspect, the first opening and the second opening are disposed in the lower part of the casing, and therefore the workability of filling the second refrigerant circuit with the second refrigerant is high.

[0015] A refrigeration cycle apparatus according to a fifth aspect is the refrigeration cycle apparatus according to any one of the second aspect to the fourth aspect, wherein the second refrigerant circuit includes a compressor disposed inside the casing, and the first opening and the second opening are disposed below a terminal of the compressor.

[0016] In the refrigeration cycle device of the fifth aspect, the second refrigerant is a flammable refrigerant, and even if the refrigerant leaks from the first opening or the second opening, the occurrence of a fire accident caused by the terminal as an ignition source can be suppressed.

[0017] A refrigeration cycle device according to a sixth aspect is the refrigeration cycle device according to any one of the first aspect to the fifth aspect, wherein the first structure irreversibly obstructs the flow of the second refrigerant in the first path.

[0018] In the refrigeration cycle device of the sixth aspect, the first structure irreversibly obstructs the flow of the second refrigerant in the first path, and therefore physically prevents the second refrigerant from refilling from the first path into the second refrigerant circuit.

[0019] A refrigeration cycle device of a seventh aspect is a refrigeration cycle device of any one of the first aspect to the sixth aspect, wherein the first structure includes a pinch portion in which the piping connecting the first opening and the second refrigerant circuit is narrowed, and the gap between the inner walls of the pinch portion is sealed with a sealing material.

[0020] In the refrigeration cycle device of the seventh aspect, a pinch section where the piping is narrowed is provided in the first path, and the gap between the inner walls of the piping at the pinch section is sealed with a sealing material, so that refilling of the first refrigerant from the first path to the second refrigerant circuit is likely to be reliably hindered.

[0021] The refrigeration cycle device of an eighth aspect is a refrigeration cycle device of any one of the first aspect to the sixth aspect, wherein the first structure includes a cover brazed to a port to which a pipe for filling with refrigerant is connected as a first opening of the first path.

[0022] In the refrigeration cycle apparatus of the eighth aspect, the cover is fixed to the first path by brazing, so that refilling of the first refrigerant from the first path into the second refrigerant circuit is likely to be reliably hindered.

[0023] A ninth aspect of the refrigeration cycle device is a refrigeration cycle device according to any one of the first to fifth aspects, wherein the first structure includes a mechanical coupling attached to a port to which a pipe for filling the refrigerant is connected as a first opening of the first path.

[0024] In the refrigeration cycle device of the ninth aspect, by using a mechanical joint that cannot be removed without a special tool or a mechanical joint that can be tightened with a specified torque, it is possible to prevent the first refrigerant from being refilled from the first path into the second refrigerant circuit.

[0025] A refrigeration cycle device according to a tenth aspect is the refrigeration cycle device according to any one of the first aspect to the ninth aspect, wherein the second opening is a port to which a pipe for discharging a refrigerant is connected.

[0026] A refrigeration cycle apparatus according to an eleventh aspect is the refrigeration cycle apparatus according to any one of the first to tenth aspects, wherein the first refrigerant is a flammable refrigerant.

[0027] In the refrigeration cycle apparatus of the eleventh aspect, it is possible to reduce the risk of an operator carelessly filling the first refrigerant circuit with the flammable second refrigerant. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a schematic configuration diagram of a refrigeration cycle device according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a schematic perspective view of a heat source unit of the refrigeration cycle device of FIG. [Figure 3A] 2 is an enlarged view of a first path and a second path in the schematic configuration diagram of the refrigeration cycle device of FIG. 1. FIG. [Figure 3B] FIG. 3B is a diagram for explaining an obstructed portion (narrowed pinched portion) of the first path in FIG. 3A. [Figure 4] 1. FIG. 4 is a diagram for explaining the height positions of a first opening and a second opening in a casing of a heat source unit of the refrigeration cycle apparatus of FIG. [Figure 5] FIG. 2 is a control block diagram of the refrigeration cycle device of FIG. [Figure 6]2 is a diagram showing the flow of refrigerant during heating operation of the refrigeration cycle device of FIG. 1. FIG. [Figure 7] 2 is a diagram showing the flow of refrigerant during cooling operation of the refrigeration cycle device of FIG. 1. FIG. [Figure 8] 10 is an enlarged view of a first path portion in a schematic configuration diagram of a refrigeration cycle device of Modification A. FIG. [Figure 9] 10 is an enlarged view of a first path portion in a schematic configuration diagram of a refrigeration cycle device of a modified example B. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0029] The refrigeration cycle device of the present disclosure will be described with reference to the drawings.

[0030] (1) Overall structure 1 is a schematic diagram of a refrigeration cycle apparatus 100 according to an embodiment of the present disclosure. The refrigeration cycle apparatus 100 includes a first refrigerant circuit 10 filled with a first refrigerant and a second refrigerant circuit 50 filled with a second refrigerant that is different from the first refrigerant.

[0031] The refrigeration cycle apparatus 100 of this embodiment performs a vapor compression refrigeration cycle operation to cool and heat the interior of a building or the like. However, the refrigeration cycle apparatus 100 may also be an apparatus dedicated to cooling. Furthermore, the use of the refrigeration cycle apparatus 100 is not limited to an air conditioning apparatus, and it may be an apparatus that cools / heats a medium whose temperature is to be adjusted.

[0032] The refrigeration cycle device 100 here has a binary circuit made up of a vapor compression type first refrigerant circuit 10 and a vapor compression type second refrigerant circuit 50, and is a device that performs a binary refrigeration cycle.

[0033] The refrigeration cycle apparatus 100 includes a heat source unit 2, a utilization unit 3, communication pipes 4 and 5, and a control unit 6. The heat source unit 2 includes a first refrigerant circuit 10. The heat source unit 2 includes a part of a second refrigerant circuit 50. The heat source unit 2 and the utilization unit 3 are connected to each other via the communication pipes 4 and 5, thereby forming the second refrigerant circuit 50.

[0034] (2) Detailed configuration The first refrigerant circuit 10, the second refrigerant circuit 50, the heat source unit 2, the utilization unit 3, the connection pipes 4 and 5, the first path 70, the second path 80, and the control unit 6 will be described in detail.

[0035] (2-1) 1st refrigerant circuit The first refrigerant circuit 10 is filled with a first refrigerant, and the first refrigerant flows through the inside of the first refrigerant circuit 10. The first refrigerant circuit 10 cools / heats the air in the space to be air-conditioned (the medium to be temperature-adjusted).

[0036] The first refrigerant filled into the first refrigerant circuit 10 is, for example, a non-flammable, non-toxic, and highly safe refrigerant. The first refrigerant is, for example, a refrigerant with a low global warming potential, such as a GWP of 500 or less. The first refrigerant is, for example, a refrigerant with a critical temperature of less than 45°C. The first refrigerant may be a single refrigerant or a mixed refrigerant. For example, the first refrigerant is a natural refrigerant that contains carbon dioxide. In this embodiment, the first refrigerant is a single refrigerant of carbon dioxide. However, the type of the first refrigerant is not limited to refrigerants having the above-mentioned properties or the exemplified types of refrigerants.

[0037] The first refrigerant circuit 10 is a main circuit, and is configured to use a first refrigerant to cool or heat the air in the space to be air-conditioned, which is a medium to be temperature-adjusted.

[0038] As shown in FIG. 1, the first refrigerant circuit 10 mainly includes a first compressor 12, a switching mechanism 14, a second heat exchanger 16, a first heat exchanger 30, a first expansion mechanism 18, a third heat exchanger 20, a first accumulator 22, a first shut-off valve 24, and a second shut-off valve 26.

[0039] The first compressor 12, the switching mechanism 14, the second heat exchanger 16, the first heat exchanger 30, the first expansion mechanism 18, the first accumulator 22, the first shut-off valve 24, and the second shut-off valve 26 are housed within a casing 2a of the heat source unit 2 described later.

[0040] The first compressor 12 is a device that compresses the first refrigerant. The first compressor 12 is, for example, a positive displacement compressor such as a scroll type, whose operating capacity can be changed by inverter control of the motor. In this embodiment, the first compressor 12 discharges the first refrigerant in a supercritical state.

[0041] The switching mechanism 14 is a mechanism for switching the flow path of the refrigerant. The switching mechanism 14 is a device that switches between a first state (see the solid line drawn in the portion of the switching mechanism 14 in FIG. 1 ) in which the second heat exchanger 16 functions as a radiator of the first refrigerant and the third heat exchanger 20 functions as an evaporator of the first refrigerant, and a second state (see the dashed line drawn in the portion of the switching mechanism 14 in FIG. 1 ) in which the second heat exchanger 16 functions as an evaporator of the first refrigerant and the third heat exchanger 20 functions as a radiator of the first refrigerant. Specifically, in the first state, the switching mechanism 14 connects the discharge side of the first compressor 12 to the gas side of the second heat exchanger 16 and connects the suction side of the first compressor 12 to the gas side of the third heat exchanger 20. In addition, in the second state, the switching mechanism 14 connects the discharge side of the first compressor 12 to the gas side of the third heat exchanger 20, and also connects the suction side of the first compressor 12 to the gas side of the second heat exchanger 16.

[0042] The switching mechanism 14 is, for example, a four-way switching valve, but is not limited to this, and may be configured by piping and multiple valves as long as it is capable of switching between the first state and the second state.

[0043] The second heat exchanger 16 is a device that exchanges heat between the first refrigerant and outdoor air, which is an example of a first heat source medium. When the second heat exchanger 16 functions as a radiator, the first refrigerant radiates heat to the outdoor air. When the second heat exchanger 16 functions as an evaporator, the first refrigerant absorbs heat from the outdoor air. The second heat exchanger 16 is, for example, a fin-and-tube heat exchanger.

[0044] The first expansion mechanism 18 is a device that decompresses the first refrigerant and is, for example, an electrically operated expansion valve with a variable opening. The first expansion mechanism 18 is disposed in the first refrigerant circuit 10 between the second heat exchanger 16 and the third heat exchanger 20. More specifically, the first expansion mechanism 18 is disposed between the first heat exchanger 30 and the first shut-off valve 24.

[0045] The third heat exchanger 20 is a device that exchanges heat between the first refrigerant and the air in the space to be air-conditioned, which is a medium to be temperature-adjusted. The third heat exchanger 20 is, for example, a fin-and-tube heat exchanger. The third heat exchanger 20 is disposed outside the casing 2a of the heat source unit 2. Specifically, the third heat exchanger 20 is disposed inside the casing 3a of the utilization unit 3, which is installed in the space to be air-conditioned or above the ceiling of the space to be air-conditioned, as described below.

[0046] The first accumulator 22 is provided in a suction flow path that connects the switching mechanism 14 and the suction side of the first compressor 12. The first accumulator 22 separates the refrigerant that has flowed in into a liquid refrigerant and a gas refrigerant, and allows the gas refrigerant to flow to the suction side of the first compressor 12.

[0047] The first heat exchanger 30 is a cascade heat exchanger. The first heat exchanger 30 exchanges heat between the first refrigerant and the second refrigerant without mixing them. The first heat exchanger 30 is, for example, a plate-type heat exchanger, but is not limited thereto. The first heat exchanger 30 has a first refrigerant flow path 32 belonging to the first refrigerant circuit 10 and a second refrigerant flow path 34 belonging to the second refrigerant circuit 50. One end of the first refrigerant flow path 32 is connected to the liquid side of the second heat exchanger 16 via a pipe, and the other end is connected to the third heat exchanger 20 via a pipe.

[0048] The first heat exchanger 30 supercools the first refrigerant cooled by the second heat exchanger 16 using the second refrigerant when the second heat exchanger 16 of the first refrigerant circuit 10 functions as a radiator and the fourth heat exchanger 54 described later of the second refrigerant circuit 50 functions as a radiator.

[0049] The first shut-off valve 24 is a valve provided at the connection between the heat source unit 2 and the connecting pipe 4, and in this embodiment, a manual valve with a service port 24a used for refrigerant charging, etc. is used. One end of the first shut-off valve 24 is connected to the first expansion mechanism 18 via a pipe, and the other end of the first shut-off valve 24 is connected to the connecting pipe 4.

[0050] The second shut-off valve 26 is a valve provided at the connection between the heat source unit 2 and the connecting pipe 5, and in this embodiment, a manual valve with a service port 26a used for refrigerant charging, etc. is used. One end of the second shut-off valve 26 is connected to the switching mechanism 14, and the other end of the second shut-off valve 26 is connected to the connecting pipe 5.

[0051] The service ports 24a, 26a may be provided in a portion of the first refrigerant circuit 10 that is included in the heat source unit 2, and are not limited to being provided in the shut-off valves 24, 26.

[0052] As will be described later, the second refrigerant circuit 50 is provided with a first structure (the meaning of "hindering" will be described later) that hinders refilling of the second refrigerant in the first path 70 for charging the second refrigerant and the second path 80 for discharging the second refrigerant, so as to hinder refilling of the second refrigerant at the installation location of the refrigeration cycle device 100.

[0053] In contrast, the first refrigerant circuit 10 does not have any structure in the service ports 24a, 26a or the shut-off valves 24, 26 that would prevent the first refrigerant from being refilled, so that the first refrigerant can be filled even at the installation location of the refrigeration cycle apparatus 100.

[0054] (2-2)Second refrigerant circuit The second refrigerant circuit 50 is filled with the second refrigerant. The second refrigerant circuit 50 is pre-filled with the second refrigerant. The expression "pre-filled with the second refrigerant" includes a case where the second refrigerant is filled at the installation site of the refrigeration cycle apparatus 100 before the refrigeration cycle is started, and a case where the filling with the second refrigerant is completed before the refrigeration cycle apparatus 100 is installed at the installation site (for example, before the refrigeration cycle apparatus 100 is shipped from a manufacturing factory).

[0055] The second refrigerant has a higher critical temperature than the first refrigerant. When the first refrigerant has a critical temperature of less than 45°C, the second refrigerant has a critical temperature of 45°C or higher. In this embodiment, the second refrigerant is a flammable refrigerant (including refrigerants that are slightly flammable according to ISO 817). The second refrigerant is not limited to, but may be, for example, a hydrocarbon refrigerant such as R1234yf, R1234ze, or R32. The second refrigerant may be a single refrigerant or a mixed refrigerant. In this embodiment, the second refrigerant is a single refrigerant, R290 (propane).

[0056] The second refrigerant circuit 50 functions as a subcooling circuit during cooling operation. In other words, the second refrigerant circuit 50 is an assist circuit that assists the capacity of the first refrigerant circuit 10 during cooling operation.

[0057] The second refrigerant circuit 50 mainly includes a second compressor 52, a fourth heat exchanger 54, a second expansion mechanism 56, the first heat exchanger 30, and a second accumulator 58, and these devices are connected by, for example, copper piping. The second refrigerant circuit 50 is preferably housed entirely within the casing 2a of the heat source unit 2. Note that the description that the second refrigerant circuit 50 is housed entirely within the casing 2a of the heat source unit 2 includes not only an embodiment in which all of the devices and piping that make up the second refrigerant circuit 50 are covered by the plate-like members that make up the casing 2a, but also an embodiment in which some of the devices and piping that make up the second refrigerant circuit 50 are attached to the outside of the plate-like members that make up the casing 2a.

[0058] The second compressor 52 is a device for compressing the second refrigerant. The type of the second compressor 52 is not limited, but it may be, for example, a positive displacement compressor such as a scroll type whose operating capacity can be changed by inverter controlling the motor.

[0059] The fourth heat exchanger 54 is a device that exchanges heat between the second refrigerant and outdoor air, which is an example of a second heat source medium. The fourth heat exchanger 54 functions as a radiator, and the second refrigerant radiates heat to the outdoor air. The fourth heat exchanger 54 is, for example, a fin-and-tube heat exchanger or a microchannel heat exchanger. One end of the fourth heat exchanger 54 is connected to the discharge side of the second compressor 52 via a pipe, and the other end is connected to the gas side of the first heat exchanger 30 via a pipe.

[0060] The second expansion mechanism 56 is a device that decompresses the second refrigerant, and is, for example, an electrically operated expansion valve with a variable opening. The second expansion mechanism 56 is disposed in the second refrigerant circuit 50 between the fourth heat exchanger 54 and the first heat exchanger 30.

[0061] As described above, the first heat exchanger 30 has the second refrigerant flow path 34 belonging to the second refrigerant circuit 50. The first heat exchanger 30 functions as an evaporator of the second refrigerant that absorbs heat from the first refrigerant (cools the first refrigerant). One end of the second refrigerant flow path 34 is connected to the liquid side of the fourth heat exchanger 54 via a pipe, and the other end is connected to the suction side of the fourth heat exchanger 54 via a pipe.

[0062] The second accumulator 58 is provided in a suction flow path that connects the first heat exchanger 30 and the suction side of the second compressor 52. The second accumulator 58 separates the refrigerant that has flowed in into a liquid refrigerant and a gas refrigerant, and allows the gas refrigerant to flow to the suction side of the second compressor 52.

[0063] (2-3) Heat source unit The heat source unit 2 will be described with reference to Fig. 2. In describing the heat source unit 2, expressions indicating directions such as "up," "down," "front (front)," "rear (back)," "left," and "right" will be used for convenience, but these expressions do not limit the contents of this disclosure unless otherwise specified.

[0064] 2 is a schematic perspective view illustrating a state in which members covering the front right and right sides of the casing 2a of the heat source unit 2 have been removed. Furthermore, in FIG. 2, of the components arranged in the space (second chamber A) in which the compressors 12, 52, etc. are installed, components other than the first compressor 12 and the second compressor 52, the first shut-off valve 24 and the second shut-off valve 26, and the first path 70 and the second path 80 are not illustrated.

[0065] The heat source unit 2 is placed in a location different from the utilization unit 3. For example, the heat source unit 2 is installed on the roof of a building, near the exterior wall of a building, in a machine room, or the like.

[0066] The heat source unit 2 here is a side-blowing type unit that takes in outdoor air through an opening (not shown) on the back of the casing 2a and an opening (not shown) on the left side, and blows out the outdoor air that has been heat exchanged in the second heat exchanger 16 and the outdoor air that has been heat exchanged in the fourth heat exchanger 54 from an opening (air outlet OP) on the front of the casing 2a (see Figure 2).

[0067] The interior of the casing 2a of the heat source unit 2 is divided into a first chamber (not shown) in which the second heat exchanger 16, the fourth heat exchanger 54, and the first fan 60 are mainly arranged, and a second chamber A in which the first compressor 12, the switching mechanism 14, the first expansion mechanism 18, the first accumulator 22, the first shut-off valve 24, the second shut-off valve 26, the second compressor 52, the second expansion mechanism 56, the second accumulator 58, the first heat exchanger 30, the first path 70, and the second path 80 are mainly arranged, and the first chamber and the second chamber are separated by a partition plate (not shown).

[0068] The first fan 60 supplies outdoor air to the second heat exchanger 16 and the fourth heat exchanger 54, and promotes heat exchange between the outdoor air and the first refrigerant flowing through the second heat exchanger 16 and the second refrigerant flowing through the fourth heat exchanger 54. In this embodiment, one first fan 60 supplies outdoor air to the second heat exchanger 16 and the fourth heat exchanger 54, but the heat source unit 2 may be provided with multiple fans, and different fans may supply outdoor air to the second heat exchanger 16 and the fourth heat exchanger 54, respectively.

[0069] (2-4) Usage unit The utilization unit 3 is installed in the space to be air-conditioned or above the ceiling of the space to be air-conditioned, etc. The utilization unit 3 is connected to the heat source unit 2 via connecting pipes 4 and 5.

[0070] The utilization unit 3 mainly includes a third heat exchanger 20, a second fan 28, and a casing 3a. The third heat exchanger 20 and the second fan 28 are housed in the casing 3a.

[0071] The second fan 28 supplies air from the space to be air-conditioned to the third heat exchanger 20 in order to promote heat exchange between the first refrigerant flowing through the third heat exchanger 20 and the air from the space to be air-conditioned.

[0072] (2-5) Connecting piping The connecting pipes 4, 5 are refrigerant pipes that are installed on-site when the refrigeration cycle apparatus 100 is installed in an installation location such as a building. One end of the connecting pipe 4 is connected to a shutoff valve 24 arranged at the liquid side end of the heat source unit 2, and the other end of the connecting pipe 4 is connected to a liquid side end of the third heat exchanger 20 of the utilization unit 3. One end of the connecting pipe 5 is connected to a shutoff valve 26 arranged at the gas side end of the heat source unit 2, and the other end of the connecting pipe 5 is connected to a gas side end of the third heat exchanger 20 of the utilization unit 3.

[0073] (2-6) Pathway 1 and Pathway 2 The first path 70 and the second path 80 will be described with reference to FIG. 3, which is an enlarged view of the first path 70 and the second path 80 in the schematic configuration diagram of FIG.

[0074] The first path 70 is connected to the second refrigerant circuit 50 and is a refrigerant flow path used when charging the second refrigerant circuit 50 with the second refrigerant. The second path 80 is connected to the second refrigerant circuit 50 and is a refrigerant flow path used when discharging the second refrigerant from the second refrigerant circuit 50. The second path 80 is used, for example, to discharge the second refrigerant from the second refrigerant circuit 50 when the refrigeration cycle apparatus 100 is removed and discarded.

[0075] 3A , the first path 70 has a fill port 72 of the first path 70 which is an example of a first opening, a first valve 74, and a closing portion 76 which is an example of a first structure. The closing portion 76 is a structure that prevents the second refrigerant circuit 50 from being recharged with the second refrigerant at the installation location of the refrigeration cycle apparatus 100. Note that the structure that prevents the second refrigerant circuit 50 from being recharged with the second refrigerant refers to a structure that prevents the second refrigerant circuit 50 from being charged with the second refrigerant via the first path 70 in a method of charging a refrigerant circuit with a normal refrigerant. The closing portion 76 is not provided until charging of the second refrigerant circuit 50 with the second refrigerant is complete, but is provided after charging of the second refrigerant circuit 50 with the second refrigerant is complete.

[0076] The charging of the second refrigerant circuit 50 with refrigerant and the formation of the blocked portion 76 will now be described.

[0077] When the second refrigerant circuit 50 is charged with the second refrigerant in advance, air is removed from the inside of the second refrigerant circuit 50, and one end of a pipe (such as a hose) connected (directly or indirectly) to a container containing the second refrigerant is connected to the fill port 72, and the other end of the pipe (such as a hose) is opened. A first valve 74 is placed between the fill port 72 and the second refrigerant circuit 50, to which the first path 70 is connected. At this time, a second valve 84 of the second path 80, which will be described later, is also closed. In this state, the second refrigerant in the refrigerant container flows from the fill port 72 through the first path 70 into the second refrigerant circuit 50. In other words, when charging the second refrigerant circuit 50 with the second refrigerant, the second refrigerant is charged into the second refrigerant circuit 50 from the fill port 72. When a predetermined amount of the second refrigerant has been charged into the second refrigerant circuit 50, the first valve 74 is closed.

[0078] If the condition remains as it is (if the blocked portion 76 does not exist), the second refrigerant can be filled into the second refrigerant circuit 50 even at the installation location of the refrigeration cycle device 100 by connecting one end of a pipe connected to a container containing the second refrigerant to the filling port 72 and opening the first valve 74.

[0079] However, in the refrigeration cycle apparatus 100 of this embodiment, the first structure (blocked portion 76) is formed after the second refrigerant circuit 50 has been completely filled with the second refrigerant. The blocked portion 76 is a structure that irreversibly obstructs the flow of the second refrigerant in the first path 70. A structure that irreversibly obstructs the flow of the second refrigerant in the first path 70 (referred to as an obstructing structure) means a structure that prevents the second refrigerant from flowing from the filling port 72 to the second refrigerant circuit 50 without removing an obstructing structure that is permanently provided in the first path 70 or deforming an obstructing structure of the first path 70 that is not configured to be deformable (not intended to be deformed).

[0080] The blocking portion 76 is formed by squeezing the piping connecting the fill port 72 and the second refrigerant circuit 50, more specifically, the piping connecting the fill port 72 and the first valve 74, to form a pinched portion 76a in the piping (explained using FIG. 3B, this is achieved by deforming a piping having an inner wall shaped as shown by the dashed line into a shape as shown by the solid line), and then sealing the gap between the inner walls of the pinched portion 76a with a sealing material 76b (shown by hatching in FIG. 3B). The sealing material 76b is, for example, a brazing material, but is not limited to this and may be a resin or the like.

[0081] By providing such a blocking portion 76, even if one end of a tube connected to a container containing the second refrigerant is connected to the filling port 72 and the other end of the tube is opened, the second refrigerant cannot be filled into the second refrigerant circuit 50 (unless the blocking portion 76 is removed, etc.).

[0082] Therefore, normally, an operator would not bring a refrigerant container filled with the second refrigerant to the installation location of the refrigeration cycle apparatus 100. This reduces the risk of an operator carelessly filling the first refrigerant circuit 10 with the second refrigerant. In particular, in this embodiment, the second refrigerant is the flammable R290. Therefore, if the first refrigerant circuit 10 is accidentally filled with the second refrigerant, the flammable second refrigerant will be carried all the way to the utilization unit 3 (in this embodiment, all the way to the space to be air-conditioned or its vicinity). However, in the refrigeration cycle apparatus 100 of this embodiment, a refrigerant container filled with the second refrigerant is basically not brought to the installation location of the refrigeration cycle apparatus 100, thereby reducing the occurrence of such an incident.

[0083] Furthermore, if the second refrigerant were to be available for on-site charging, depending on the type of second refrigerant (for example, if the second refrigerant is a substance with a variety of uses that does not require a high level of purity for some uses), there is a risk that contaminated and insufficiently controlled second refrigerant may be brought in. R290 is one example of such a refrigerant. However, by prohibiting on-site charging of the second refrigerant, damage (such as corrosion) to the piping and components of the second refrigerant circuit due to contamination can be reduced.

[0084] 3 , the second path 80 has a discharge port 82 of the second path 80 as an example of a second opening, a second valve 84, and a check valve 86 as an example of a second structure. When the second refrigerant is discharged from the second refrigerant circuit 50 through the second path 80, the second refrigerant is discharged from the discharge port 82 to the outside of the second refrigerant circuit 50. The check valve 86 allows the second refrigerant to flow from the second refrigerant circuit 50 to the discharge port 82, but prevents the second refrigerant from flowing from the discharge port 82 to the second refrigerant circuit 50.

[0085] When the second refrigerant is discharged from the second refrigerant circuit 50, one end of a pipe (such as a hose) is connected (directly or indirectly) to a container (referred to as a refrigerant recovery container) that recovers the second refrigerant. The other end of the pipe (such as a hose) is connected to the discharge port 82, and a second valve 84 is opened, the second valve 84 being arranged between the discharge port 82 and the second refrigerant circuit 50 to which the second path 80 is connected. A check valve 86 is arranged between the discharge port 82 of the second path 80 and the second valve 84, or between the second valve 84 of the second path 80 and the second refrigerant circuit 50. As described above, the check valve 86 allows the second refrigerant to flow from the second refrigerant circuit 50 to the discharge port 82. Therefore, when the second valve 84 is opened, the second refrigerant in the second refrigerant circuit 50 can be recovered in the refrigerant recovery container.

[0086] On the other hand, even if an operator mistakenly connects one end of a hose, the other end of which is connected to a refrigerant container containing the second refrigerant, to the discharge port 82 and opens the second valve 84, the presence of the check valve 86 prevents the second refrigerant from being filled into the second refrigerant circuit 50.

[0087] (2-7) Arrangement of the intake port of the first path and the exhaust port of the second path The arrangement of the fill port 72 of the first passage 70 and the discharge port 82 of the second passage 80 will be described with reference to FIGS.

[0088] The filling port 72 of the first passage 70 and the discharge port 82 of the second passage 80 are preferably disposed inside the casing 2 a of the heat source unit 2 .

[0089] Although the second refrigerant circuit 50 cannot be refilled, it is initially filled with the second refrigerant through a fill port 72 of the first path 70. Furthermore, the second refrigerant in the second refrigerant circuit 50 is discharged from a discharge port 82 of the second path 80 as needed. Therefore, the fill port 72 of the first path 70 and the discharge port 82 of the second path 80 are located in positions accessible from the front side of the heat source unit 2 when the members located on the front right side of the casing 2a are removed (see FIG. 2).

[0090] As described above, the first refrigerant circuit 10 is configured to be rechargeable with refrigerant through the service ports 24a, 26a. In other words, the first refrigerant circuit 10 may be charged with the first refrigerant through the service ports 24a, 26a even at the installation site of the refrigeration cycle apparatus 100. For this reason, the service ports 24a, 26a for the first refrigerant are preferably located before (at a more accessible position than) the fill port 72 of the first path 70 and the discharge port 82 of the second path 80, as shown in FIG. 2 . This allows an operator to recharge the first refrigerant circuit 10 with the first refrigerant as needed, and also prevents an operator from mistakenly connecting a hose for charging the first refrigerant to the fill port 72 or the discharge port 82.

[0091] In the refrigeration cycle apparatus 100 of this embodiment, it is assumed that an operator will access the fill port 72 of the first path 70, the discharge port 82 of the second path 80, and the service ports 24a, 26a from the front of the heat source unit 2, but this is not limited to this. For example, the refrigeration cycle apparatus may be configured so that an operator can access the fill port 72 of the first path 70, the discharge port 82 of the second path 80, and the service ports 24a, 26a from the right side of the heat source unit 2.

[0092] Furthermore, since the second refrigerant circuit 50 is filled with the second refrigerant through the fill port 72 of the first path 70 and the second refrigerant is discharged from the second refrigerant circuit 50 through the discharge port 82 of the second path 80, it is preferable that the fill port 72 and the discharge port 82 are arranged vertically below the center of the casing 2a (the height position indicated by the symbol H / 2) as shown in Fig. 4. This configuration improves the workability when filling the second refrigerant circuit 50 with the second refrigerant and when discharging the second refrigerant from the second refrigerant circuit 50. It is preferable that the service ports 24a, 26a be configured in a similar manner.

[0093] Furthermore, as shown in Fig. 4, the fill port 72 and the discharge port 82 are preferably arranged below the terminal 52a of the second compressor 52 to which a power line supplying power to the motor of the second compressor 52 is connected. Furthermore, as shown in Fig. 4, the fill port 72 and the discharge port 82 are preferably arranged below the terminal 12a of the first compressor 12 to which a power line supplying power to the motor of the first compressor 12 is connected. Since refrigerants generally have a higher specific gravity than air, this configuration makes it less likely that a fire will occur even if the second refrigerant is flammable and leaks from the fill port 72 or the discharge port 82. If the first refrigerant is a flammable refrigerant, the service ports 24a, 26a are preferably configured similarly.

[0094] (2-8) Control unit The control unit 6 is a device that controls the components of the refrigeration cycle apparatus 100. The control unit 6 is configured by being communicatively connected to an electrical component unit, etc., provided in the heat source unit 2, and a control board, etc., provided in the utilization unit 3. Note that in FIG. 1, the electrical component unit, etc., provided in the heat source unit 2 and the control board, etc., provided in the utilization unit 3 are not shown, and for convenience, the control unit 6 is drawn at a position separated from the heat source unit 2 and the utilization unit 3.

[0095] As shown in Figures 1 and 5, the control unit 6 is electrically connected to the first compressor 12, the switching mechanism 14, the first expansion mechanism 18, the first fan 60, the second compressor 52, the second expansion mechanism 56, the second fan 28, etc., and controls the operation of these devices.

[0096] The control unit 6 is a computer, and mainly includes a control and arithmetic device and a storage device. The control and arithmetic device can be a processor such as a CPU or GPU of an electrical equipment unit provided in the heat source unit 2 or a control board provided in the utilization unit 3. The control and arithmetic device reads a program stored in the storage device and performs predetermined image processing and arithmetic processing in accordance with the program. Furthermore, the control and arithmetic device can write the results of calculations to the storage device and read information stored in the storage device in accordance with the program.

[0097] (3) Operation The operation of the refrigeration cycle apparatus 100 will be described with reference to Fig. 6 showing the flow of refrigerant during heating operation and Fig. 7 showing the flow of refrigerant during cooling operation. The refrigeration cycle apparatus 100 performs cooling operation to cool the air in the air-conditioned space and heating operation to heat the air in the air-conditioned space in order to air-condition the space. In cooling operation and heating operation, the operation of the refrigeration cycle apparatus 100 is controlled by a control unit 6.

[0098] (3-1) Heating operation The operation of the refrigeration cycle apparatus 100 during heating operation will be described with reference to FIG.

[0099] During heating operation, the switching mechanism 14 is switched to the second state (the connection state shown by the dashed line in the switching mechanism 14) so ​​that the second heat exchanger 16 functions as an evaporator of the first refrigerant and the third heat exchanger 20 functions as a radiator of the first refrigerant. During heating operation, the second compressor 52 is not operated, and the second refrigerant does not circulate through the second refrigerant circuit 50.

[0100] In the first refrigerant circuit 10, the first refrigerant in a supercritical state discharged from the first compressor 12 flows out of the heat source unit 2 through the switching mechanism .

[0101] The refrigerant that flows out of the heat source unit 2 flows into the utilization unit 3 via the gas-side connection pipe 5. In the utilization unit 3, the first refrigerant is sent to the third heat exchanger 20. The first refrigerant sent to the third heat exchanger 20 exchanges heat with the air in the space to be air-conditioned, which is supplied by the second fan 28, thereby releasing heat and being cooled. The air that has been heated through heat exchange with the first refrigerant is blown into the space to be air-conditioned by the airflow generated by the second fan 28. The first refrigerant that has released heat in the third heat exchanger 20 flows out of the utilization unit 3.

[0102] The first refrigerant that flows out of the utilization units 3 flows into the heat source unit 2 via the liquid-side connection pipe 4. In the heat source unit 2, the first refrigerant is sent to the second heat exchanger 16 via the first expansion mechanism 18 and the first refrigerant flow path 32 of the first heat exchanger 30 (during heating operation, the second refrigerant does not circulate in the second refrigerant circuit 50, so the first refrigerant does not undergo any particular heat exchange in the first heat exchanger 30). The first refrigerant sent to the second heat exchanger 16 is heated and evaporated through heat exchange with outdoor air supplied by the first fan 60. The first refrigerant that has evaporated in the second heat exchanger 16 is sucked back into the first compressor 12 via the switching mechanism 14 and the first accumulator 22.

[0103] (3-2) Cooling operation The operation of the refrigeration cycle apparatus 100 during cooling operation will be described with reference to FIG.

[0104] During cooling operation, the switching mechanism 14 is switched to the first state (the connection state shown by the solid line in the switching mechanism 14) so ​​that the second heat exchanger 16 functions as a radiator of the first refrigerant and the third heat exchanger 20 functions as an evaporator of the first refrigerant. Furthermore, during cooling operation, the second compressor 52 is operated and the second refrigerant circulates through the second refrigerant circuit 50.

[0105] In the first refrigerant circuit 10, the first refrigerant in a supercritical state discharged from the first compressor 12 is sent to the second heat exchanger 16 via the switching mechanism 14. The first refrigerant sent to the second heat exchanger 16 is cooled by exchanging heat with outdoor air supplied by the first fan 60, thereby dissipating heat. The first refrigerant that has dissipated heat in the second heat exchanger 16 is sent to the first refrigerant flow path 32 of the first heat exchanger 30. The first refrigerant sent to the first refrigerant flow path 32 is further cooled in the first heat exchanger 30 by exchanging heat with the second refrigerant flowing through the second refrigerant flow path 34. The first refrigerant that has been further cooled in the first heat exchanger 30 is decompressed by the first expansion mechanism 18 and then flows out of the heat source unit 2.

[0106] The first refrigerant that flows out of the heat source unit 2 flows into the utilization unit 3 via the liquid side connection pipe 4. In the utilization unit 3, the first refrigerant is sent to the third heat exchanger 20. The first refrigerant sent to the third heat exchanger 20 exchanges heat with the air in the space to be air-conditioned that is supplied by the second fan 28, where it is heated and evaporates. The air that has been cooled through heat exchange with the first refrigerant is blown into the space to be air-conditioned by the airflow generated by the second fan 28. The first refrigerant that has evaporated in the third heat exchanger 20 flows out of the utilization unit 3.

[0107] The first refrigerant that flows out of the utilization units 3 passes through the gas-side connection pipe 5 and flows into the heat source unit 2. In the heat source unit 2, the first refrigerant passes through the switching mechanism 14 and the first accumulator 22 and is sucked into the first compressor 12 again.

[0108] In the second refrigerant circuit 50, the second refrigerant discharged from the first compressor 12 is sent to the fourth heat exchanger 54. The second refrigerant sent to the fourth heat exchanger 54 exchanges heat with outdoor air supplied by the first fan 60, dissipating heat and being cooled. The second refrigerant that has dissipated heat in the fourth heat exchanger 54 is decompressed by the second expansion mechanism 56 and then sent to the second refrigerant flow path 34 of the first heat exchanger 30. The second refrigerant sent to the second refrigerant flow path 34 is heated and evaporated in the first heat exchanger 30 through heat exchange with the first refrigerant flowing through the first refrigerant flow path 32. The second refrigerant that has evaporated in the first heat exchanger 30 is sucked back into the second compressor 52 via the second accumulator 58.

[0109] (4) Features (4-1) The refrigeration cycle apparatus 100 includes a first refrigerant circuit 10 filled with a first refrigerant and a second refrigerant circuit 50 filled with a second refrigerant. In the refrigeration cycle apparatus 100, the second refrigerant circuit 50 is previously filled with the second refrigerant. The refrigeration cycle apparatus 100 includes a first path 70 connected to the second refrigerant circuit 50 and a second path 80 connected to the second refrigerant circuit 50. The first path 70 has a fill port 72 as an example of a first opening. When the second refrigerant is being filled into the second refrigerant circuit 50, the second refrigerant is filled into the second refrigerant circuit 50 through the fill port 72. The second path 80 has a discharge port 82 as an example of a second opening. When the second refrigerant is being discharged from the second refrigerant circuit 50, the second refrigerant is discharged from the discharge port 82 to the outside of the second refrigerant circuit 50. The first path 70 is provided with a blocking portion 76 as an example of a first structure that prevents the second refrigerant from being recharged at the installation location of the refrigeration cycle apparatus 100. A check valve 86, as an example of a second structure, is provided in the second path 80. The check valve 86 allows the second refrigerant to flow from the second refrigerant circuit 50 to the discharge port 82, and prohibits the second refrigerant from flowing from the discharge port 82 to the second refrigerant circuit 50.

[0110] The refrigeration cycle apparatus 100 is configured so that recharging with the second refrigerant is not possible at the installation location of the refrigeration cycle apparatus 100, thereby preventing an incident in which an operator brings a refrigerant container filled with the second refrigerant to the installation location of the refrigeration cycle apparatus 100. This reduces the risk of an operator carelessly charging the first refrigerant circuit 10 with the second refrigerant or erroneously charging the second refrigerant circuit 50 with the first refrigerant.

[0111] Furthermore, if the second refrigerant were to be able to be filled on-site, depending on the type of second refrigerant (for example, if the second refrigerant is a substance with a variety of uses that do not require such high purity for some uses), there is a risk that contaminated and insufficiently managed second refrigerant may be brought in. For example, if the second refrigerant is R290 (propane), such a problem could occur. However, by prohibiting on-site filling of the second refrigerant, damage (such as corrosion) to the piping and component equipment of the second refrigerant circuit due to contamination can be suppressed.

[0112] (4-2) The refrigeration cycle apparatus 100 includes a casing 2a (casing 2a of the heat source unit 2) that houses the second refrigerant circuit 50 in its entirety.

[0113] In the refrigeration cycle apparatus 100, the entire second refrigerant circuit 50 (all of the devices constituting the second refrigerant circuit 50) is housed in the casing 2a, and therefore the amount of the second refrigerant charged is relatively small to begin with. Therefore, even if the second refrigerant cannot be charged on site, the operation of the refrigeration cycle apparatus 100 is unlikely to be affected.

[0114] (4-3) The refrigeration cycle apparatus 100 is disposed in the casing 2a and includes a first heat exchanger 30 in which a first refrigerant and a second refrigerant exchange heat. The first refrigerant circuit 10 includes a second heat exchanger 16 and a third heat exchanger 20. The second heat exchanger 16 is housed in the casing 2a. In the second heat exchanger 16, heat exchange occurs between the first refrigerant and outdoor air, which is an example of a first heat source medium. The third heat exchanger 20 is housed in the casing 2a. The third heat exchanger 20 is disposed outside the casing 2a of the heat source unit 2. In the third heat exchanger 20, heat exchange occurs between the first refrigerant and air in a space to be air-conditioned, which is an example of a medium to be temperature-adjusted. The second refrigerant circuit 50 is housed in the casing 2a and includes a fourth heat exchanger 54. In the fourth heat exchanger 54, heat exchange occurs between the second refrigerant and outdoor air, which is an example of a second heat source medium.

[0115] In the refrigeration cycle apparatus 100, the first refrigerant circuit 10 is a main refrigerant circuit that adjusts the temperature of a medium to be temperature-adjusted, and the second refrigerant circuit 50 is a sub-refrigerant circuit that assists the main refrigerant circuit. Therefore, the amount of the second refrigerant charged into the second refrigerant circuit 50 is originally relatively small. Therefore, even if the second refrigerant cannot be charged on-site, the operation of the refrigeration cycle apparatus 100 is unlikely to be affected.

[0116] Furthermore, the refrigeration cycle device 100 reduces the risk that the second refrigerant will be mistakenly filled into the first refrigerant circuit 10 due to carelessness on the part of an operator, and the second refrigerant will be transported to the vicinity of the temperature adjustment target (to the air-conditioned space where the utilization unit 3 is located, or to a space near the air-conditioned space).

[0117] (4-4) In the refrigeration cycle apparatus 100, the first path 70 and the second path 80 are disposed inside the casing 2a. The filling port 72 and the discharge port 82 are disposed below the center of the casing 2a in the vertical direction.

[0118] In the refrigeration cycle apparatus 100, the filling port 72 and the discharge port 82 are disposed in the lower part of the casing 2a, so that the workability of filling the second refrigerant circuit 50 with the second refrigerant is high.

[0119] (4-5) In the refrigeration cycle apparatus 100, the second refrigerant circuit 50 includes a second compressor 52 disposed inside the casing 2a. The charging port 72 and the discharge port 82 are disposed below a terminal 52a of the second compressor 52.

[0120] In this embodiment, the first refrigerant circuit 10 includes a first compressor 12 disposed inside the casing 2a. The charging port 72 and the discharge port 82 are disposed below a terminal 12a of the first compressor 12.

[0121] In this refrigeration cycle device 100, even if the second refrigerant is a flammable refrigerant and leaks from the filling port 72 or the discharge port 82, the occurrence of a fire accident caused by the terminal 12a or the terminal 52a as an ignition source can be suppressed.

[0122] (4-6) In the refrigeration cycle apparatus 100, the blocking portion 76, which is an example of a first structure, irreversibly blocks the flow of the second refrigerant in the first path 70.

[0123] In the refrigeration cycle device 100, the blocking portion 76 irreversibly blocks the flow of the second refrigerant in the first path 70, thereby physically preventing the second refrigerant from being refilled from the first path 70 into the second refrigerant circuit 50.

[0124] (4-7) In the refrigeration cycle device 100, the blocking portion 76 as an example of the first structure includes a pinched portion 76a in which the piping connecting the filling port 72 and the second refrigerant circuit 50 is narrowed, and the gap between the inner walls of the pinched portion 76a is sealed by a sealing material 76b.

[0125] In the refrigeration cycle device 100, a pinched section where the piping is narrowed is provided in the first path 70, and the gap between the inner walls of the piping at the pinched section is sealed with sealing material 76b, so that refilling of the first refrigerant from the first path 70 to the second refrigerant circuit 50 is likely to be reliably hindered.

[0126] (4-8) In the refrigeration cycle apparatus 100, the second refrigerant is a flammable refrigerant.

[0127] In this refrigeration cycle apparatus 100, the risk of an operator accidentally filling the first refrigerant circuit 10 with the flammable second refrigerant due to carelessness can be reduced.

[0128] (5) Variations (5-1) Variation A In the above embodiment, an example has been described in which the blocking portion 76 is provided in the first path 70 as the first structure in the claims, but the first structure is not limited to the blocking portion 76.

[0129] For example, the first structure may include a cover 176 that is brazed and fixed to a fill port 72 to which a pipe for filling a refrigerant is connected as the first opening of the first path 70. The cover 176 is attached to the fill port 72 and fixed by brazing after the second refrigerant is filled into the second refrigerant circuit 50 through the fill port 72.

[0130] (5-2) Variation B The first structure in the claims is not limited to a structure that irreversibly blocks the flow of the second refrigerant in the first path 70.

[0131] For example, the first structure may be a mechanical joint 276 that is screwed onto the threads of the charging port 72 to which a piping for charging refrigerant, serving as the first opening of the first passage 70, is connected.

[0132] For example, if a cap serving as the mechanical coupling 276 is tightened onto the threads of the filling port 72 with a torque greater than the specified value, the mechanical coupling 276 will spin freely when an attempt is made to remove it, making it impossible to remove the mechanical coupling 276 and preventing the second refrigerant circuit 50 from being refilled with the second refrigerant.

[0133] Furthermore, for example, the mechanical coupling 276 may be a cap that can be attached / detached to / from the fill port 72 only by a special dedicated tool that is not generally available (for example, that is used only in the factory that manufactures the refrigeration cycle apparatus 100). This makes it difficult for an operator to easily remove the mechanical coupling 276, which hinders refilling of the second refrigerant into the second refrigerant circuit 50.

[0134] (5-3) Variation C In the above embodiment, the refrigerant exchanges heat with outdoor air as a heat source in the second heat exchanger 16 and the fourth heat exchanger 54, but the heat source is not limited to outdoor air. In at least one of the second heat exchanger 16 and the fourth heat exchanger 54, the refrigerant may exchange heat with a liquid such as water as a heat source.

[0135] In the above embodiment, the first refrigerant exchanges heat with the air in the space to be air-conditioned in the third heat exchanger 20, but the object of temperature adjustment in the refrigeration cycle apparatus 100 is not limited to the air in the space to be air-conditioned. In the third heat exchanger 20, the first refrigerant may exchange heat with a liquid such as water to be temperature-adjusted.

[0136] (5-4) Variation D In the above embodiment, the first compressor 12, the switching mechanism 14, the second heat exchanger 16, the first heat exchanger 30, the first expansion mechanism 18, the first accumulator 22, the first shut-off valve 24, the second shut-off valve 26, the second compressor 52, the fourth heat exchanger 54, the second expansion mechanism 56, and the second accumulator 58 are housed in one casing 2a, but the present invention is not limited to this. These devices may be housed separately in multiple casings.

[0137] For example, the first compressor 12, the switching mechanism 14, the second heat exchanger 16, the first expansion mechanism 18, the first accumulator 22, the first shut-off valve 24, and the second shut-off valve 26 may be housed in one casing, and the second compressor 52, the fourth heat exchanger 54, the second expansion mechanism 56, the first heat exchanger 30, and the second accumulator 58 may be housed in another casing.

[0138] <Additional Notes> Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims. [Explanation of symbols]

[0139] 2a: Casing 10: 1st refrigerant circuit 16:Second heat exchanger 18: First expansion mechanism 20:Third heat exchanger 30: 1st heat exchanger 50:Second refrigerant circuit 52: Second compressor (compressor) 52a: Terminal 54: 4th heat exchanger 70: Route 1 72: Filling port (first opening) 76:Occluded part (first structure) 76a: Pinch section 76b: Sealing material 80: Second route 82: Exhaust port (second opening) 86: Check valve (second structure) 100: Refrigeration cycle device 176: Cover (first structure) 276: Mechanical joint (first structure) [Prior art documents] [Patent documents]

[0140] [Patent Document 1] International Publication No. 2014 / 181399

Claims

1. A refrigeration cycle device comprising: a first refrigerant circuit (10) filled with a first refrigerant; and a second refrigerant circuit (50) filled with a second refrigerant, wherein the second refrigerant circuit is previously filled with the second refrigerant, a first path (70) having a first opening (72) and connected to the second refrigerant circuit, and during the charging process, the second refrigerant is charged into the second refrigerant circuit through the first opening; a second path (80) having a second opening (82) and connected to the second refrigerant circuit, such that when the second refrigerant is discharged, the second refrigerant is discharged from the second opening to the outside of the second refrigerant circuit; Equipped with a first structure (76, 176, 276) that inhibits recharging of the second refrigerant at an installation location of the refrigeration cycle device is provided in the first path; The second path is provided with a second structure (86) that allows the second refrigerant to flow from the second refrigerant circuit to the second opening and prohibits the second refrigerant from flowing from the second opening to the second refrigerant circuit. A refrigeration cycle device (100).

2. The compressor further includes a casing (2a) that accommodates the entire second refrigerant circuit. The refrigeration cycle device according to claim 1.

3. The system further includes a first heat exchanger (30) disposed in the casing and exchanging heat between the first refrigerant and the second refrigerant, The first refrigerant circuit includes a second heat exchanger (16) housed in the casing and in which the first refrigerant exchanges heat with a first heat source medium, and a third heat exchanger (20) disposed outside the casing and in which the first refrigerant exchanges heat with a medium whose temperature is to be adjusted, the second refrigerant circuit includes a fourth heat exchanger (54) housed in the casing and performing heat exchange between the second refrigerant and a second heat source medium; Including, The refrigeration cycle device according to claim 2.

4. the first path and the second path are disposed inside the casing; The first opening and the second opening are disposed below a center of the casing in the vertical direction. The refrigeration cycle device according to claim 2 or 3.

5. The second refrigerant circuit includes a compressor (52) disposed inside the casing, The first opening and the second opening are disposed below a terminal (52a) of the compressor. The refrigeration cycle device according to claim 2 or 3.

6. the first structure irreversibly inhibits the flow of the second refrigerant through the first path; The refrigeration cycle device according to claim 1 or 2.

7. the first structure (76) includes a pinched portion (76a) in which a pipe connecting the first opening and the second refrigerant circuit is narrowed, and a gap between inner walls of the pinched portion is sealed by a sealing material (76b). The refrigeration cycle device according to claim 6.

8. The first structure (176) includes a cover (176a) brazed to a port to which a tube for charging a refrigerant is connected as the first opening of the first path. The refrigeration cycle device according to claim 6.

9. The first structure (276) includes a mechanical coupling (276a) attached to a port to which a refrigerant-charging tube serving as the first opening of the first path is connected. The refrigeration cycle device according to claim 1 or 2.

10. The second opening is a port to which a pipe for discharging a refrigerant is connected. The refrigeration cycle device according to claim 1 or 2.

11. The second refrigerant is a flammable refrigerant. The refrigeration cycle device according to claim 1 or 2.

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