Filling method

Abstract

With a charging method, a refrigeration apparatus 1 is filled with a refrigerant and an odor component. The charging method includes a first step of providing a cylinder 51 containing a mixed liquid in which the odor component is dissolved, a second step of connecting the cylinder 51 to a refrigerant circuit 10 of the refrigeration apparatus 1, and a third step of filling the refrigerant circuit 10 with the mixed liquid supplied from the cylinder 51. Since the refrigerant and the odor component are mixed in a liquid phase, the odor component can be stably supplied and charged into the refrigerant circuit 10 at an appropriate concentration.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a charging method.BACKGROUND ART

[0002] Conventionally, there has been known a refrigeration apparatus in which a strongly combustible refrigerant is sealed in a refrigerant circuit as a refrigerant having a low GWP (global warming potential) value. In this type of refrigeration apparatus, it is important to recognize leakage of the refrigerant from the refrigerant circuit at an early stage to avoid combustion of the refrigerant.

[0003] Patent Document 1 discloses a refrigeration cycle device in which an odor component, which is a sulfur-based odorant, is sealed in a refrigerant circuit in addition to a refrigerant. When the odor component leaks together with the leakage of the refrigerant from the refrigerant circuit, it becomes possible for people around to recognize the abnormality and take necessary measures.RELATED ART DOCUMENTSPATENT DOCUMENT

[0004] Patent Document: Japanese Patent No. 7162786SUMMARY OF THE INVENTIONPROBLEMS TO BE SOLVED BY THE INVENTION

[0005] Conventionally, to fill a refrigerant circuit with a refrigerant when a device is installed, the refrigerant circuit may be filled with a gaseous refrigerant. To fill a refrigerant circuit with a refrigerant, for example, a technician connects a refrigerant cylinder to a shutoff valve of the refrigerant circuit which has been evacuated in advance via a hose. Then, when the technician opens the shutoff valve, the pressure difference between the refrigerant cylinder and the refrigerant circuit causes the refrigerant in the cylinder to flow into the refrigerant circuit. As the refrigerant is charged into the refrigerant circuit, the pressure of the refrigerant in the refrigerant circuit increases, thereby gradually reducing the pressure difference and decreasing the charging rate of the refrigerant. In the charging process, the refrigerant may be supplied while the compressor is in operation. This causes the pressure difference with respect to the inside of the refrigerant cylinder to be increased, and thus the charging rate of the refrigerant can be increased.

[0006] However, charging a gaseous refrigerant and a gaseous odor component into the refrigerant circuit may cause problems. For example, during a course of charging, while the refrigerant in the cylinder successively evaporates from a liquid phase to a gas phase, the concentration of the odor component that has evaporated into the gaseous refrigerant is significantly lower than that concentration that has dissolved into the liquid refrigerant, and the dissolved odor component does not necessarily evaporate in synchronization with the refrigerant. For this reason, when the refrigerant and the odor component are charged into the refrigerant circuit, there is a possibility that the supply of the odor component to the refrigerant circuit is insufficient. As a result, even if the odor component of the refrigerant circuit leaks together with the refrigerant, there is a risk that the intended performance of inducting evacuation behavior in nearby persons is not achieved.

[0007] The present disclosure provides a technology that enables a refrigerant circuit to be filled with an odor component at an appropriate concentration.MEANS FOR SOLVING THE PROBLEMS

[0008] According to one aspect of the present disclosure, a method of charging a refrigerant and an odor component into a refrigeration apparatus includes: a first step of providing a cylinder containing a mixed liquid in which the odor component is dissolved; a second step of connecting the cylinder to a refrigerant circuit of the refrigeration apparatus; and a third step of filling the refrigerant circuit with the mixed liquid supplied from the cylinder.

[0009] According to the above, with the charging method, the refrigerant circuit can be filled with an odor component at an appropriate concentration by charging a mixed liquid in which the odor component is mixed into the refrigerant circuit. Since the refrigerant circuit is filled with the odor component at an intended concentration, the performance of the odor component can be stably exhibited. The mixed liquid charged in the refrigerant circuit turns into a gas phase in the refrigerant circuit, and the volume of the mixed liquid expands accordingly. For this reason, compared to filling with a gaseous refrigerant or the like, filling with a mixed liquid enables an appropriate amount of an odor component to be charged in a shorter time, making it possible to improve work efficiency.

[0010] The cylinder includes a supply opening through which the mixed liquid is supplied, and a cylindrical body connected to the supply opening and in which mainly the refrigerant is sealed. In the third step, the supply opening is positioned below a bottom of the cylindrical body in a vertical direction so as to fill the refrigerant circuit with the mixed liquid from the cylinder.

[0011] Thus, with the charging method, the mixed liquid can be smoothly circulated from the cylinder to the refrigerant circuit, allowing the mixed liquid to be charged into the refrigerant circuit.

[0012] The cylinder includes a siphon tube in which the mixed liquid and the refrigerant in a gas phase are sealed at a high pressure and configured to supply the mixed liquid by a pressure of the refrigerant in the gas phase. In the third step, the refrigerant circuit is filled with the mixed liquid through the siphon tube.

[0013] Even in this case, with the charging method, the mixed liquid can be easily supplied from the cylinder, allowing the mixed liquid to be charged into the refrigerant circuit.

[0014] The refrigeration apparatus includes the refrigerant circuit in which a compressor, a heat source-side heat exchanger, a pressure reducing device, and a use-side heat exchanger are connected in this order. A refrigerant charging part through which the refrigerant is charged into the refrigerant circuit is provided between the pressure reducing device and the use-side heat exchanger. In the second step, the cylinder is connected to the refrigerant charging part. In the third step, the refrigerant charging part is filled with the mixed liquid supplied from the cylinder.

[0015] Thus, with the charging method, the liquid line of the refrigerant circuit can be easily filled with the mixed liquid through the refrigerant charging part provided between the pressure reducing device and the use-side heat exchanger.

[0016] Alternatively, the refrigeration apparatus includes the refrigerant circuit in which a compressor, a heat source-side heat exchanger, a pressure reducing device, and a use-side heat exchanger are connected in this order. A refrigerant charging part through which the refrigerant is charged into the refrigerant circuit is provided between the compressor and the use-side heat exchanger. A gas-liquid separator is provided between the compressor and the refrigerant charging part. In the second step, the cylinder is connected to the refrigerant charging part. In the third step, the refrigerant charging part is filled with the mixed liquid supplied from the cylinder.

[0017] Even in this case, with the charging method, the gas line of the refrigerant circuit can be filled with the mixed liquid through the refrigerant charging part provided between the compressor and the use-side heat exchanger.

[0018] In the third step, the compressor is driven to move the mixed liquid charged into the refrigerant charging part to the gas-liquid separator and cause a gas separated by the gas-liquid separator to be suctioned into the compressor.

[0019] Thus, the mixed liquid supplied to the gas line of the refrigerant circuit can be smoothly separated into gas and liquid in the gas-liquid separator, the gas can be transferred to the compressor, and the efficiency of charging the mixed liquid into the refrigerant circuit even from the gas line can be improved.

[0020] The refrigerant is a strongly combustible refrigerant.

[0021] Thus, the refrigeration apparatus can fill the refrigerant circuit with a refrigerant having a low GWP value, thereby performing heat exchange through the refrigerant in the condenser and evaporator efficiently. Moreover, at the time of charging, the refrigerant can be charged with the refrigerant in a mixed liquid state in which an odor component is dissolved, thereby avoiding insufficient charging of an odor component and providing an appropriate amount of odor when the refrigerant leaks from the refrigeration apparatus.

[0022] The refrigerant is propane.

[0023] The propane can be easily stored in the cylinder in a liquid phase, and a mixed liquid state can be well maintained in the cylinder.

[0024] The refrigerant contains mercury at an amount equal to or less than 0.1 mg / L.

[0025] Thus, with the refrigerant circuit being filled with the refrigerant, it is possible to prevent the formation of leakage points caused by a significant loss of material strength due to alloying (amalgamation) reactions between the metals in the refrigerant circuit, particularly the amalgamation of aluminum with mercury. Specifically, by adopting this charging method and controlling the mercury content to 0.1 mg / L or less, the strength of the metal material in the refrigerant circuit can be stably maintained. As a result, refrigerant leakage can be effectively suppressed, and an effect of prompting an evacuation action induced by the odor component can be obtained, thereby achieving a dual safety measure.

[0026] The odor component is a substance having a boiling point higher than that of the refrigerant.

[0027] It is thus possible to maintain the refrigerant in a liquid phase and the odor component in a liquid phase, with the cylinder filled with the refrigerant and the odor component as a mixed liquid.

[0028] The odor component is a sulfur-based odorant.

[0029] Thus, the odor component filled in the refrigerant circuit can stably prompt an evacuation action when the refrigerant circuit leaks.

[0030] The odor component is selected from the group consisting of sulfides and thiophenes.

[0031] Thus, an odor component having a boiling point higher than that of a refrigerant can be adopted, and a mixed liquid state can be well maintained by the refrigerant in the liquid phase and the odor component in the liquid phase in the cylinder.

[0032] The odor component is tetrahydrothiophene.

[0033] Thus, an odor component having a boiling point higher than the ambient temperature outside the cylinder can be adopted, and such odor component at an appropriate concentration can be easily charged into the refrigerant circuit together with the refrigerant, so that refrigerant leakage from the refrigerant circuit can be recognized by people in the vicinity.

[0034] The odor component is dimethyl sulfide.

[0035] Even in this case, an odor component having a boiling point higher than the ambient temperature outside the cylinder can be adopted, and the odor component at an appropriate concentration can be easily charged into the refrigerant circuit together with the refrigerant, so that refrigerant leakage from the refrigerant circuit can be recognized by people in the vicinity.

[0036] The odor component is ethyl methyl sulfide.

[0037] Even in this case, an odor component having a boiling point higher than the ambient temperature outside the cylinder can be adopted, and the odor component at an appropriate concentration can be easily charged into the refrigerant circuit together with the refrigerant, so that refrigerant leakage from the refrigerant circuit can be recognized by people in the vicinity.BRIEF DESCRIPTION OF THE DRAWINGS

[0038] [FIG. 1] FIG. 1 is a diagram schematically illustrating a configuration of an air conditioner according to an embodiment. [FIG. 2] FIG. 2 is a diagram illustrating an installation state of a service port of an outdoor unit. [FIG. 3] FIG. 3 is a diagram illustrating a charging system for charging a refrigerant and an odor component into a refrigerant circuit. [FIG. 4] FIG. 4 is a diagram illustrating a pre-charging configuration of the charging system. [FIG. 5] FIG. 5 is a flowchart illustrating a charging method according to a first embodiment. [FIG. 6] FIG. 6 is a diagram illustrating a charging system according to a modified example. [FIG. 7] FIG. 7 is a flowchart illustrating a charging method according to a second embodiment. DESCRIPTION OF EMBODIMENTS

[0039] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In each of the drawings, the same components are denoted by the same reference numerals, and redundant descriptions may be omitted. In addition, in each of the drawings, dimensions, ratios or numbers may be exaggerated or simplified as necessary for easy understanding of the invention.<Configuration of Refrigeration Apparatus>

[0040] As illustrated in FIG. 1, a refrigeration apparatus 1 according to an embodiment of the present disclosure is an air conditioner for adjusting the temperature of air in a living space. Hereinafter, the refrigeration apparatus 1 is also referred to as an "air conditioner 1". The air conditioner 1 is used for an operation of cooling and heating a living space by performing a vapor compression refrigeration cycle operation. In the cooling operation, the air conditioner 1 adjusts the temperature by cooling the air in the living space. In the heating operation, the air conditioner 1 adjusts the temperature by heating the air in the living space.

[0041] The air conditioner 1 includes a refrigerant circuit 10 in which a refrigerant is sealed, an outdoor unit 20 as a heat source unit installed in the outdoor space, and an indoor unit 30 as a utilization unit installed in the living space. The refrigerant circuit 10 performs the cooling operation and the heating operation by circulating a refrigerant between the outdoor unit 20 and the indoor unit 30. The air conditioner 1 according to the embodiment is a pair type in which one outdoor unit 20 and one indoor unit 30 are connected to each other. The air conditioner 1 may have a configuration in which one outdoor unit 20 and a plurality of indoor units 30 are connected, or a configuration in which a plurality of outdoor units 20 and one indoor unit 30 are connected. During refrigerant charging, the air conditioner 1 may be in a state in which the refrigeration cycle between the outdoor unit 20 and the indoor unit 30 is separated. In this case, after the refrigerant charging, the outdoor unit 20 and the indoor unit 30 are connected to enable the refrigeration cycle.

[0042] The refrigerant circuit 10 includes a first communication pipe 11 and a second communication pipe 12 for connecting the outdoor unit 20 and the indoor unit 30. The first communication pipe 11 and the second communication pipe 12 connect the living space and the outdoor space to circulate a refrigerant between them. The first communication pipe 11 is one or more gas pipes for circulating a gasified refrigerant. The second communication pipe 12 is one or more liquid pipes for circulating a liquid refrigerant.

[0043] Inside the outdoor unit 20 the refrigerant circuit 10 has an outdoor path 13 connected to one end of the first communication pipe 11 and one end of the second communication pipe 12. Inside the indoor unit 30 the refrigerant circuit 10 further has an indoor path 14 connected to the other end of the first communication pipe 11 and the other end of the second communication pipe 12. The refrigerant circuit 10 is an endless circulation circuit formed by the first communication pipe 11, the second communication pipe 12, the outdoor path 13, and the indoor path 14.<Outdoor Unit>

[0044] The outdoor unit 20 constitutes a part of the refrigerant circuit 10 by providing the outdoor path 13 inside a housing 20a. The outdoor unit 20 includes a compressor 21, an outdoor heat exchanger 22, an expansion mechanism 23, a four-way switching valve 24, an outdoor fan 25, and a gas-liquid separator 26. The compressor 21, the outdoor heat exchanger 22, the expansion mechanism 23, and the four-way switching valve 24 are connected to the outdoor path 13 of the outdoor unit 20.

[0045] In a refrigeration cycle operation, the compressor 21 compresses a low-pressure refrigerant suctioned from a suction connection end 21i to increase the pressure, and discharges a high-pressure refrigerant from a discharge connection end 21o. As the compressor 21, a rotary device adopted, for example, in which a sealed compression element is driven in rotation by a compressor motor 21m to increase the pressure of the refrigerant. The suction connection end 21i and the discharge connection end 21o of the compressor 21 are connected to the four-way switching valve 24 via the outdoor path 13.

[0046] The outdoor heat exchanger 22 is a heat source-side heat exchanger (condenser) which radiates heat of a refrigerant by performing heat exchange between the refrigerant flowing inside and outdoor air in a refrigeration cycle operation during a cooling operation. As the outdoor heat exchanger 22, a fin-and-tube type mechanism can be adopted, for example. A gas connection end 22G of the outdoor heat exchanger 22 is connected to the four-way switching valve 24 via the outdoor path 13. A liquid connection end 22L of the outdoor heat exchanger 22 is connected to the expansion mechanism 23 via the outdoor path 13.

[0047] The outdoor fan 25 blows outdoor air to the outdoor heat exchanger 22. For example, a propeller fan having a motor and a propeller (not illustrated) can be used as the outdoor fan 25.

[0048] The expansion mechanism 23 is a pressure reducing device for decompressing a refrigerant flowing in through the outdoor path 13, thereby lowering the temperature of the refrigerant. The expansion mechanism 23 includes an electronic expansion valve or a temperature-sensitive expansion valve for adjusting the opening of an internal flow path. The expansion mechanism 23 may be provided in the indoor unit 30.

[0049] The four-way switching valve 24 reverses the flow of a refrigerant in the refrigerant circuit 10 in order to selectively perform the cooling operation and the heating operation. The four-way switching valve 24 can be switched between a first state illustrated by a solid line in FIG. 1 and a second state illustrated by a broken line in FIG. 1.

[0050] The four-way switching valve 24 is provided with a first port 241, a second port 242, a third port 243, and a fourth port 244 to which a plurality of pipes included in the refrigerant circuit 10 can be connected. The discharge connection end 21o of the compressor 21 is connected to the first port 241 of the four-way switching valve 24 via a pipe of the outdoor path 13. The gas connection end 22G of the outdoor heat exchanger 22 is connected to the second port 242 of the four-way switching valve 24 via a pipe of the outdoor path 13. A pipe of the outdoor path 13 connected to the first communication pipe 11 is connected to the third port 243 of the four-way switching valve 24. The third port 243 is connected to a gas connection end 31G of an indoor heat exchanger 31 via the first communication pipe 11. The suction connection end 21i of the compressor 21 is connected to the fourth port 244 of the four-way switching valve 24 via the piping of the outdoor path 13.

[0051] The four-way switching valve 24 can form a first state in which the first port 241 and the second port 242 are connected to each other and the third port 243 and the fourth port 244 are connected to each other, as illustrated by the solid line in FIG. 1. With the first state, the four-way switching valve 24 connects the discharge connection end 21o of the compressor 21 to the gas connection end 22G of the outdoor heat exchanger 22, and connects, at the same time, the suction connection end 21i of the compressor 21 to the first communication pipe 11 outside the outdoor unit 20. In this first state, a refrigerant flows from the first communication pipe 11 into the outdoor path 13 of the outdoor unit 20 based on the drive of the compressor 21. The refrigerant is compressed by the compressor 21 to become a high pressure and moves to the outdoor heat exchanger 22 through the four-way switching valve 24. The refrigerant dissipates heat in the outdoor heat exchanger 22 and is further decompressed by the expansion mechanism 23 to become a low-pressure, low-temperature liquid and moves to the second communication pipe 12. In other words, the air conditioner 1 can perform a cooling operation by drawing a high-temperature refrigerant through the first communication pipe 11 and sending a low-temperature refrigerant to the indoor unit 30 through the second communication pipe 12.

[0052] The four-way switching valve 24 can form a second state in which the first port 241 and the third port 243 are connected to each other and the second port 242 and the fourth port 244 are connected to each other, as illustrated by the dotted line in FIG. 1. With the second state, the four-way switching valve 24 connects the discharge connection end 21o of the compressor 21 to the external first communication pipe 11 of the outdoor unit 20, and connects the suction connection end 21i of the compressor 21 to the gas connection end 22G of the outdoor heat exchanger 22. In the second state, a refrigerant flows from the second communication pipe 12 to the outdoor path 13 of the outdoor unit 20 based on the drive of the compressor 21. The refrigerant moves to the outdoor heat exchanger 22 via the expansion mechanism 23, and further moves from the outdoor heat exchanger 22 to the compressor 21. The refrigerant is compressed in the compressor 21 to become a high-pressure, high-temperature gas, and moves to the first communication pipe 11 via the four-way switching valve 24. In other words, the air conditioner 1 can perform a heating operation by drawing a low-temperature refrigerant via the second communication pipe 12 and sending a high-temperature refrigerant to the indoor unit 30 via the first communication pipe 11.

[0053] The outdoor path 13 of the outdoor unit 20 can be divided into a gas line 13G for circulating mainly a gasified refrigerant, and a liquid line 13L for circulating mainly a liquid refrigerant. The gas line 13G is a path for connecting a connection point between the gas line 13G and the first communication pipe 11 to the gas connection end 22G of the compressor 21 and the outdoor heat exchanger 22. The liquid line 13L is a path for connecting the connection point between the liquid line 13L and the second communication pipe 12 to the liquid connection end 22L of the expansion mechanism 23 and the outdoor heat exchanger 22.

[0054] A first shutoff valve 41 is provided at the connection point between the gas line 13G and the first communication pipe 11. The first shutoff valve 41 opens and closes the flow path of the gas line 13G based on a technician's operation. A second shutoff valve 42 is provided at the connection point between the liquid line 13L and the second communication pipe 12. The second shutoff valve 42 opens and closes the flow path of the liquid line 13L based on a technician's operation.

[0055] The first shutoff valve 41 has a gas service port 44. The second shutoff valve 42 has a liquid service port 45. The first shutoff valve 41 is larger than the second shutoff valve 42. The gas service port 44 and the liquid service port 45 are used as a refrigerant charging part configured to charge the refrigerant circuit 10 of the air conditioner 1 with a refrigerant. Furthermore, the gas service port 44 and the liquid service port 45 are also used when a refrigerant is discharged from the outdoor unit 20, when the refrigerant circuit 10 is evacuated, when the pressure of a refrigerant is measured, and so on.

[0056] As illustrated in FIG. 2, the housing 20a of the outdoor unit 20 has a shutoff valve arrangement space therein. The first shutoff valve 41 and the second shutoff valve 42 are provided in the shutoff valve arrangement space of the housing 20a. The first shutoff valve 41 exposed from the housing 20a is connected to the first communication pipe 11. The second shutoff valve 42 exposed from the housing 20a is connected to the second communication pipe 12.

[0057] The first shutoff valve 41 has a base portion 411 at its center and has an outdoor connector 412, a communication pipe connector 413, a valve operating portion 414, and a gas service port 44, which protrude from the base portion 411 in mutually different directions.

[0058] The outdoor connector 412 is connected to a pipe of the gas line 13G of the outdoor path 13 arranged in the housing 20a. A fixing mechanism 412a for fixing the first shutoff valve 41 to the housing 20a of the outdoor unit 20 is provided on the outer peripheral surface of the outdoor connector 412.

[0059] Like the first shutoff valve 41, the second shutoff valve 42 has a base portion 421 at its center, and has an outdoor connector 422, a communication pipe connector 423, a valve operating portion 424, and a liquid service port 45 (refrigerant charging part), which protrude from the base portion 421 in mutually different directions.

[0060] The outdoor connector 422 is connected to a pipe of the liquid line 13L of the outdoor path 13 arranged in the housing 20a. A fixing mechanism 422a for fixing the second shutoff valve 42 to the housing 20a of the outdoor unit 20 is provided on the outer peripheral surface of the outdoor connector 422.

[0061] Returning to FIG. 1, the gas-liquid separator 26 is an accumulator provided between the compressor 21 and the first shutoff valve 41 (gas service port 44) for separating gas and liquid. The gas-liquid separator 26 separates liquid from gas in the gas line 13G, thereby suppressing inflow of liquid into the compressor 21. The installation position of the gas-liquid separator 26 is not particularly limited as long as the gas-liquid separator 26 is positioned between the compressor 21 and the gas service port 44. For example, the gas-liquid separator 26 may be attached to the compressor 21. A plurality of gas-liquid separators 26 may be provided in such a manner that they are provided together with the compressor 21 and at other locations of the gas line 13G.<Indoor Unit>

[0062] The indoor unit 30 is installed in a living space. The indoor unit 30 is provided with the indoor path 14 inside the housing 30a, thereby constituting a part of the refrigerant circuit 10. The indoor unit 30 is provided with an indoor heat exchanger 31 and an indoor fan 32. The indoor heat exchanger 31 is connected to the indoor path 14 of the indoor unit 30.

[0063] The indoor heat exchanger 31 is a use-side heat exchanger that exchanges heat between indoor air and a refrigerant circulating inside the air conditioner 1 during operation of the air conditioner 1. The indoor heat exchanger 31 can thereby cool the indoor air by taking heat from the indoor air when the temperature of the refrigerant is lower than that of the indoor air and can warm the indoor air by releasing heat to the indoor air when the temperature of the refrigerant is higher than that of the indoor air. As the indoor heat exchanger 31, a fin-and-tube mechanism can be adopted, for example. The gas connection end 31G of the indoor heat exchanger 31 is connected to the first communication pipe 11 through the indoor path 14. A liquid connection end 31L of the indoor heat exchanger 31 is connected to the second communication pipe 12 via the indoor path 14.

[0064] The indoor fan 32 blows indoor air to the indoor heat exchanger 31. The indoor fan 32 is, for example, a crossflow fan having a motor and a cylindrical impeller (not illustrated). The indoor air conveyed by the indoor fan 32 passes through the indoor heat exchanger 31 and is blown from the indoor heat exchanger 31 to the living space.

[0065] The indoor unit 30 has a power circuit connected to a commercial power source. The air conditioner 1 operates the indoor unit 30 based on the supply of power from the commercial power source and operates the outdoor unit 20 via a power line (not illustrated).<Controller of Air Conditioner>

[0066] The air conditioner 1 includes a controller 90 configured to control the operation of each component. The controller 90 includes a first controller 91, a second controller 92, and a remote controller 93. The remote controller 93 is a device with which a user inputs various instructions to the air conditioner 1, and may be a dedicated controller or a portable terminal, such as a smartphone or a tablet.

[0067] Each of the first controller 91, the second controller 92, and the remote controller 93 is a computer (specifically, a micro control unit (MCU)) having a processor, a memory, an input / output interface, and a communication interface. The processor is a combination of one or more of a CPU (central processing unit), a GPU (graphics processing unit), an ASIC (application specific integrated circuit), an FPGA (field-programmable gate array), a circuit consisting of a plurality of discrete semiconductors, and the like. The memory includes a nonvolatile memory and a volatile memory. A program for controlling various processing is stored in the memory, and the processor controls various operations by reading and executing the program stored in the memory.

[0068] The first controller 91 is provided in the outdoor unit 20 and controls each component of the outdoor unit 20. The second controller 92 is provided in the indoor unit 30 and controls each component of the indoor unit 30. The first controller 91 and the second controller 92 can transmit and receive information between each other through wired communication or wireless communication. The second controller 92 and the remote controller 93 can transmit and receive information between each other by wired communication or wireless communication. The controller 90 selectively performs the cooling operation and the heating operation in response to an operation instruction that is input by a user through the remote controller 93.<Refrigerant>

[0069] It is preferable that a refrigerant sealed in the refrigerant circuit 10 have a GWP value as low as possible and impose a minimal load on the environment. Examples of the material of such a preferable refrigerant include refrigerants mainly composed of one to four carbon hydrocarbons, such as R290 (propane), R1270 (propylene), and R600a (isobutane). These refrigerants are strongly combustible refrigerants having higher combustibility than hydrofluorocarbons. In the present embodiment, a case where propane is used as a refrigerant will be described. A refrigerant may be methane (R50), ethane (R170), butane (R600), ammonia (R717) or the like.

[0070] A refrigerant sealed in the refrigerant circuit 10 is adjusted to have a mercury content of 0.1 mg / L or less. Mercury is included in the refrigerant of the cylinder 51 as a remnant derived from a raw material in the process of manufacturing a refrigerant (propane). This remnant mercury is charged into the refrigerant circuit 10 together with the refrigerant from the cylinder 51 filled with the liquid-phase refrigerant, for example. When the refrigerant contaminated with the remnant mercury is charged into the refrigerant circuit 10, the metal material in the refrigerant circuit, particularly aluminum and the mercury, undergo alloying (i.e., amalgamation), resulting in a significantly reduction in strength of the metal material, which causes a leakage point. Therefore, in the present embodiment, the influence of mercury is suppressed by setting the content of mercury to 0.1 mg / L or less. The strength of a metal material in the refrigerant circuit 10 can be thereby stably maintained, and the leakage of a refrigerant can be suppressed. Mercury mixed in a refrigerant can be removed by, for example, charging an adsorbent into the cylinder 51 or using an adsorbent before the refrigerant is charged into the cylinder 51.<Odor component>

[0071] As described above, in order to make a person recognize the leakage of a strongly combustible refrigerant from the refrigerant circuit 10, an odor component is sealed in the air conditioner 1 together with a refrigerant. An odor component may be, for example, a sulfur-based odorant, which is a sulfur-based compound. A sulfur-based odorant is more preferably selected from the sulfide-based group or the thiophene-based group. For example, an odor component may be a thiophene-based odor component, such as tetrahydrothiophene (THT), a sulfide-based odor component, such as dimethyl sulfide (DMS), ethyl methyl sulfide, or the like, or a mixture of thiol, thioether, or the like with a sulfide-based odor component.

[0072] The charged amount of a sulfur-based odorant to be charged into the refrigerant circuit 10 is preferably designed to be, for example, 50 ppm to 2,000 ppm by weight with respect to the charged amount of a refrigerant. Thus, when the refrigerant and the odor component leak from the refrigerant circuit 10, abnormality can be recognized by people in the vicinity through the odor of the odor component. If the charged amount of an odor component is up to 2,000 ppm by weight, the decrease in viscosity of refrigerating machine oil and the decrease in the cooling and heating performance can be maintained within an acceptable range.

[0073] Furthermore, as an odor component, it is preferable to use a substance having a boiling point higher than that of a refrigerant. Thus, the state of a refrigerant in a liquid phase and the state of an odor component in a liquid phase can be maintained favorably, while the refrigerant and the odor component are contained in the cylinder 51 (which is described later) as a mixed liquid.<Refrigerating Machine Oil>

[0074] In the air conditioner 1, refrigerating machine oil is sealed in the refrigerant circuit 10 together with a refrigerant and an odor component. The refrigerating machine oil is stored in the refrigerant circuit 10 mainly at the bottom of the compressor 21 and circulated to the compression element in the compressor 21 to maintain the lubricity of the sliding part. A part of the refrigerating machine oil circulates in the refrigerant circuit 10 together with the refrigerant and the odor component. In other words, the refrigerating machine oil is mixed with the refrigerant and the odor component to use as a working fluid for the refrigeration apparatus. The filling ratio of the refrigerating machine oil to the total amount of the working fluid for the refrigeration apparatus is preferably equal to or greater than 10 wt% and equal to or less than70 wt% , and more preferably equal to or greater than 20 wt% and equal to or less than 60 wt%.

[0075] Examples of the refrigerating machine oil include oxygen-containing synthetic oils (ester refrigerating machine oil, ether refrigerating machine oil, polyalkylene glycol oil, etc.) and hydrocarbon-based refrigerating machine oils. Among them, polyalkylene glycol oil (PAG oil) is preferable as a hydrocarbon-based (hydrocarbon) refrigerant from the viewpoint of compatibility. A refrigeration oil may be used individually as a single type, or a combination of two or more types may be employed.<Charging Odor Component>

[0076] The air conditioner 1 configured as described above performs a cooling or heating operation by circulating a refrigerant and an odor component within the refrigerant circuit 10. The amount of the refrigerant charged into the refrigerant circuit 10 affects the cooling and heating performance of the air conditioner 1. Therefore, when the air conditioner 1 is installed after shipment from the manufacturing factory, it is required to charge the refrigerant circuit 10 formed in the installed air conditioner 1 with a refrigerant at an appropriate amount according to the design (length, volume, etc.) of the refrigerant circuit 10.

[0077] At this time, an odor component can also be charged into the refrigerant circuit 10 together with the refrigerant. However, as described above, when a refrigerant and an odor component in a gas phase are charged into the refrigerant circuit 10, there is a possibility that the refrigerant circuit 10 may be charged with the refrigerant and the odor component having a composition ratio deviating from an intended ratio of an original design due to the difference in vapor pressure characteristics between the refrigerant and the odor component. The concentration of the odor component remaining in the cylinder gradually increases as the refrigerant circuit is repeatedly charged, and when the cylinder becomes nearly empty, a large portion of the odor component remains inside the cylinder. Moreover, because a part of the odor component is dissolved in the refrigerating machine oil in the refrigerant circuit 10, the concentration of the odor component circulating in the refrigerant circuit 10 tends to be low. In other words, the concentration of the odor component becomes lower than that of the intended concentration, and there is a possibility that the performance of the odor component cannot be fully exhibited. In view of this, in the air conditioner 1 according to the embodiment, the refrigerant circuit 10 is to be filled with a refrigerant and an odor component in a liquid phase. The reason why the refrigerant circuit 10 is to be filled with a refrigerant and an odor component in a liquid phase is explained hereinafter. An odor component charged into a cylinder together with a refrigerant is distributed to the refrigerant in a liquid phase and the refrigerant in a gas phase. If the boiling point of the odor substance is lower than the ambient temperature (room temperature or outside air temperature) outside the cylinder due to high pressure, the mixing concentration of the odor component mixed in the refrigerant a gas phase by evaporation is one order of magnitude smaller than the dissolution concentration of the odor component mixed in the refrigerant in a liquid phase by condensation. In other words, the odor component in the cylinder is present primarily in a liquid phase. Accordingly, it can be said that an odor component should be in a liquid phase in order to achieve filling the refrigerant circuit 10 with the odor component at an appropriate concentration.

[0078] Specifically, when the air conditioner is installed, the technician forms a charging system 50 as illustrated in FIGS. 3 and 4. The charging system 50 is formed as a system configured to fill the refrigerant circuit 10 with a mixed liquid L, in which a refrigerant of a liquid phase and an odor component of a liquid phase are mixed, through the liquid service port 45 of the outdoor unit 20. In FIGS. 3 and 4, for ease of understanding, the second shutoff valve 42 having the liquid service port 45 is illustrated in an exaggerated form protruding from the housing 20a of the outdoor unit 20.

[0079] Piping of the liquid line 13L (see FIG. 2) of the outdoor path 13 is connected in advance to the outdoor connector 422 of the second shutoff valve 42. The second communication pipe 12 is connected to the communication pipe connector 423 of the second shutoff valve 42 by an operation performed by a technician during installation of the apparatus. Although not illustrated, piping of the gas line 13G of the outdoor path 13 is connected in advance to the outdoor connector 412 of the first shutoff valve 41. The first communication pipe 11 is connected to the communication pipe connector 413 of the second shutoff valve 42 by an operation performed by a technician during installation of the apparatus. The refrigerant circuit 10 is thereby formed in the air conditioner 1. At the time of charging the refrigerant, the outdoor unit 20 and the indoor unit 30 need not to be connected by the first communication pipe 11 and the second communication pipe 12. The outdoor unit 20 and the indoor unit 30 may be connected after charging the refrigerant, and the refrigeration cycle is enabled thereafter.

[0080] The charging system 50 has a cylinder 51 containing a mixed liquid L, a platform truck 52, and one or more hoses 53 (see FIG. 3). The charging system 50 forms a pre-charging configuration before charging the mixed liquid L (see FIG. 4). The charging system 50 of the pre-charging configuration has a vacuum pump 58 for making the refrigerant circuit 10 in a vacuum state, and one or more hoses 59. After making the refrigerant circuit 10 in a vacuum state by the pre-charging configuration, the technician arranges the cylinder 51 and the platform truck 52 at positions near the outdoor unit 20, and connects the service port 45 for liquid of the second shutoff valve 42 and the cylinder 51 by the hose 53. The charging system 50 is thereby enabled to fill the refrigerant circuit 10 with the mixed liquid L.

[0081] The cylinder 51 of the charging system 50 is a high-pressure vessel for storing a refrigerant in a liquid phase and an odor component in a liquid phase by cooling and applying a pressure to the refrigerant and the odor component. For example, when propane (R290) is used as the refrigerant, propane is sealed in the cylinder 51 at a saturation pressure of about 0.8 MPa at normal temperature. Thus, propane is maintained primarily in a liquid phase in the cylinder 51. However, a part of propane is also sealed in a gas phase. For example, when tetrahydrothiophene (THT) is used as the odor component, its boiling point (121 °C) is sufficiently higher than that of propane (-42 °C). The boiling points of dimethyl sulfide (DMS) and ethyl methyl sulfide are also 37 °C and 66 °C, respectively, which are sufficiently higher than those of propane. These temperatures of the boiling point are at atmospheric pressure; when under higher pressure, such as inside a cylinder, the boiling point increases. Generally, a high-pressure gas container must be kept at 40 °C or lower by law, and even dimethyl sulfide, which has the lowest boiling point among the odor components described above, is 40 °C or higher. Therefore, the odor component tends to dissolve in the refrigerant in the liquid phase in the cylinder 51.

[0082] The cylinder 51 stores the mixed liquid L in which the odor component in a liquid phase dissolved in the refrigerant, which is primarily in a liquid phase. By filling the refrigerant circuit 10 with the mixed liquid L, the charging system 50 can fill the refrigerant circuit 10 with the refrigerant and the odor component without reducing the intended concentration of the odor component with respect to the refrigerant. The concentration of the odor component to be charged into the refrigerant circuit 10 can be designed based on the ratio of the refrigerant and the odor component in the mixed liquid L in the cylinder 51. For example, the concentration of the odor component in a gas phase with respect to the charged amount of the refrigerant in a gas phase is determined in advance, and the concentration is converted into the storage amount of the refrigerant in a liquid phase when stored in the cylinder 51 and the storage amount of the odor component in a liquid phase, so that the refrigerant and the odor component can be stored at the intended mixing ratio.

[0083] The cylinder 51 includes a cylindrical body 511 capable of storing the mixed liquid L, and a supply port 512 provided at one end of the cylindrical body 511 and configured to supply the mixed liquid L. The cylindrical body 511 and the supply port 512 are integrally connected, and the cylinder 51 has an appropriate pressure resistance that allows it to seal the liquid. The cylindrical body 511 is provided with a cylindrical side portion and a bottom portion provided at the other end of the side portion and these portions form an internal space 51s capable of storing the mixed liquid L. The size, volume, and the like of the cylinder 51 are appropriately determined in accordance with the amount of refrigerant to be charged into the refrigerant circuit 10. The cylinder 51 is not particularly limited in size and may be called a tank.

[0084] The supply port 512 is formed as a connector to which the hose 53 can be connected. The supply port 512 has a passage (not illustrated) connected to the internal space 51s of the cylindrical body 511, and a supply opening 512o provided at a projecting end and connected to the passage. The supply port 512 supplies the mixed liquid L through the supply opening 512o connected to the internal space 51s.

[0085] The supply port 512 is provided with an opening / closing valve 55 for opening and closing the passage of the supply port 512. The opening / closing valve 55 is operated by a technician to open the passage so that the mixed liquid L can be supplied through the supply opening 512o. The opening / closing valve 55 is operated by a technician to open the passage so that the supply of the mixed liquid L through the supply opening 512o can be stopped.

[0086] The platform truck 52 has a platform 521 on which a support body 56 for supporting the cylinder 51 and an electronic scale 54 are mounted, a push handle 522 standing from one side of the platform 521, and a plurality of casters 523 rotatably provided at a lower part of the platform 521. The support body 56 is fixed on the upper surface of the platform 521. The technician can check whether or not the refrigerant is supplied at a predetermined amount based on a detection result by the electronic scale 54.

[0087] The cylinder 51 is mounted on the support body 56 in such a manner that the supply port 512 of the cylinder 51 is oriented vertically downward. In other words, the supply opening 512o of the cylinder 51 is arranged below the bottom of the cylindrical body 511 in the vertical direction. An electronic scale 54 for measuring the weight of the mounted cylinder 51 is installed below the support body 56. The charging system 50 is not limited to a form in which the cylinder 51 is supported and fixed on the platform truck 52 and the support body 56 in advance of the refrigerant charging, but the cylinder 51 may be mounted on the support body 56 by a technician at an installation site where the apparatus is installed. The platform truck 52 may be omitted.

[0088] The hose 53 of the charging system 50 has flexibility and is provided at each end with a connector compatible with the supply port 512 of the cylinder 51 and a connector compatible with the control valve 57 connected to the liquid service port 45 of the outdoor unit 20. The connectors at the respective ends of the hose 53 may be of a common standard or may be formed in an exclusive shape so as to be connected to individual connection objects. The hose 53 is an example of the present embodiment and may not be flexible.

[0089] The control valve 57 is a component which is connected to the liquid service port 45 and enables the hose 53 to be attached and detached while maintaining the airtightness of the refrigerant circuit 10. For example, the control valve 57 is formed in a T-shape, and a screw rotating shaft (not illustrated), which is integrally provided inside a valve operating portion which is rotated by a technician moves forward and backward relative to the liquid service port 45, thereby pushing in or separating a valve core (not illustrated) of the liquid service port 45. In other words, the technician can open and close the flow path in the second shutoff valve 42 having the liquid service port 45 by moving the valve core in accordance with the operation of the valve operating portion.

[0090] The charging system 50 may be provided with a valve for opening and closing the flow path in the hose 53 at an intermediate position or the like of the hose 53. The charging system 50 may be provided with a flow regulator for adjusting a flow rate of the mixed liquid L flowing through the flow path in the hose 53 (in other words, the amount of the mixed liquid L charged into the refrigerant circuit 10). The charging system 50 may be provided with a flow integrator for detecting a cumulative charged amount of the mixed liquid L flowing through the flow path at an intermediate position or the like of the hose 53.

[0091] As illustrated in FIG. 4, the pre-charging configuration of the charging system 50 is formed by connecting the vacuum pump 58 to the liquid service port 45 via the hose 59. The vacuum pump 58 generates suction pressure in the connected hose 59 to suction air and water present in the refrigerant circuit 10, thereby suppressing air and water from mixing with a refrigerant and an odor component to be charged. The type of the vacuum pump 58 is not particularly limited, and an electric type or a manual type can be adopted. For example, when the electric vacuum pump 58 is adopted, a target suction pressure is applied to the flow path of the charging system 50 by rotation of a drive motor (not illustrated).<Charging method according to First Embodiment>

[0092] The charging system 50 according to the embodiment is basically configured as described above, and its operation (the charging method according to the first embodiment) will be described below with reference to the flowchart of FIG. 5. In the charging method, a technician fills the refrigerant circuit 10 with a refrigerant and an odor component together as one by sequentially performing steps S101 through S109 illustrated in FIG. 5, for example.

[0093] Specifically, the technician first installs the outdoor unit 20 and the indoor unit 30 of the air conditioner 1 at the installation site, and connects the first communication pipe 11 and the second communication pipe 12 to the outdoor unit 20 and the indoor unit 30 to form the refrigerant circuit 10 (step S101). In step S101, the outdoor unit 20 and the indoor unit 30 may be maintained in a separate state without being connected to each other. In this case, the outdoor unit 20 and the indoor unit 30 may be connected after the refrigerant is charged to enable the refrigeration cycle.

[0094] Next, in the charging method, equipment such as the cylinder 51, the platform truck 52, the hoses 53 and 59, and the vacuum pump 58 of the charging system 50 are provided at the site of the air conditioner 1 (step S102, corresponding to "first step"). For example, various equipment of the charging system 50 are prepared by the technician bringing them to the site. The site where the charging method is performed may include the manufacturing factory. In other words, the charging method according to the embodiment may be performed at the manufacturing factory.

[0095] Furthermore, the technician connects the control valve 57 to the liquid service port 45 of the outdoor unit 20 (step S103). The mixed liquid L can be thereby charged into the refrigerant circuit 10 via the control valve 57. However, at the time of connection, the control valve 57 closes the valve core in the liquid service port 45 and blocks outflow of gas from the liquid service port 45.

[0096] Subsequently, in the charging method, the vacuum pump 58 is connected to the refrigerant circuit 10 before being filled with the refrigerant and the odor component to form a pre-charging configuration for performing an evacuation on the refrigerant circuit 10 illustrated in FIG. 4 (step S104). Specifically, the hose 59 to which the vacuum pump 58 is connected is connected to the control valve 57 to form a pre-charging configuration in which the liquid service port 45, the control valve 57, the hose 59, and the vacuum pump 58 are sequentially formed.

[0097] After that, the technician opens the valve core in the liquid service port 45 and operates the connected vacuum pump 58 to evacuate the refrigerant circuit 10, thereby adjusting the pressure in the refrigerant circuit 10 to a target pressure (step S105). In this evacuation, the vacuum pump 58 evacuates air and moisture from the refrigerant circuit 10 through the liquid service port 45 and the hose 59 to bring the refrigerant circuit 10 into a vacuum state. After the vacuum state is created, the technician operates the control valve 57 so as to close the valve core in the liquid service port 45 and removes the hose 59 from the control valve 57 to release the pre-charging configuration.

[0098] Next, the technician places the cylinder 51 on the support body 56 in such a manner that the supply port 512 of the cylinder 51 is oriented vertically downward, connects the other end of the hose 53 to the control valve 57, and connects the cylinder 51 to one end of the hose 53, thereby connecting the cylinder 51 to the refrigerant circuit 10 (step S106, corresponding to "second step"; see also FIG. 3). Since the valve core of the control valve 57 is closed, the airtightness of the liquid service port 45 can be maintained even when the hose 53 and the hose 59 are replaced. Before connecting the hose 53, the flow path in the hose 53 is air purged to prevent air from entering the refrigerant circuit 10. Thus, entering of air and water can be suppressed when the mixed liquid L is charged.

[0099] The cylinder 51 connected to the refrigerant circuit 10 is supported by the support body 56, and as described above, the supply opening 512o is positioned below the bottom of the cylindrical body 511 in the vertical direction. Thus, the mixed liquid L is positioned below the cylindrical body 511 in the vertical direction in the cylinder 51, and only the mixed liquid L is present in the vicinity of the supply opening 512o.

[0100] Thereafter, the technician opens the valve core and the opening / closing valve 55 in the liquid service port 45, thereby allowing the mixed liquid L to flow out from the supply opening 512o of the cylinder 51 and to be charged into the refrigerant circuit 10 via the hose 53 (step S107, corresponding to "third step"). At this time, in the cylinder 51, the gaseous refrigerant exerts pressure on the mixed liquid L, thereby enabling the mixed liquid L to be delivered toward the supply opening 512o. The mixed liquid L in the cylinder 51 flows into the refrigerant circuit 10 from the cylinder 51 through the hose 53 according to a pressure difference between the cylinder 51 and the refrigerant circuit 10, which is in a vacuum state. The mixed liquid L charged into the refrigerant circuit 10 is easily vaporized to become a gas-phase state, thereby increasing the pressure of the refrigerant circuit 10. When the mixed liquid L is charged, the technician may drive the compressor 21. Thus, the mixed liquid L flows toward the compressor 21 and is decompressed in the expansion mechanism 23, thereby promoting vaporization.

[0101] The mixed liquid L is charged into the refrigerant circuit 10 by the technician based on the detection result of the electronic scale 54, until the target amount to be charged is reached. When the mixed liquid L is charged into the refrigerant circuit 10 from the cylinder 51, the technician monitors the weight measured by the electronic scale 54 to monitor whether the charging of the mixed liquid L has been finished (step S108). If the charging of the mixed liquid L has not been finished (No in step S108), the charging of the mixed liquid L from the cylinder 51 is continued. On the other hand, if the charging of the mixed liquid L has been finished (Yes in step S108), this means that the refrigerant circuit 10 is filled with the target amount of the refrigerant and the odor component, and the technician proceeds to step S109. The completion of the charging of the mixed liquid L may be determined by, for example, monitoring the cumulative charging amount of the mixed liquid L by a flow integrator.

[0102] In step S109 after the completion of the refrigerant charging, the technician closes the opening / closing valve 55 of the charging system 50 and operates the control valve 57 so as to close the valve core in the liquid service port 45, thereby disconnecting the charging system 50.

[0103] For example, in the disconnecting operation, the technician first disconnects the control valve 57 to which the hose 53 is connected from the liquid service port 45. As a result, since the valve core in the liquid service port 45 is already closed in the second shutoff valve 42, the refrigerant and the odor component vaporized after being charged or the refrigerant and the odor component in the liquid phase are reliably prevented from leaking from the refrigerant circuit 10. The technician then separates the control valve 57, the hose 53, the cylinder 51, and the like. As a result, the air conditioner 1 is satisfactorily formed in a state in which the refrigerant and the odor component are sealed in the refrigerant circuit 10.

[0104] As described above, in the charging method, the refrigerant circuit 10 is filled with the mixed liquid L in which the refrigerant in the liquid phase and the odor component in the liquid phase are mixed. As a result, the concentration of the odor component in the refrigerant circuit 10 sufficiently approximates or matches a predetermined concentration. When the odor component leaks from the refrigerant circuit 10, its performance (evacuation action of people in the vicinity) can be sufficiently exhibited.

[0105] The charging method according to the present disclosure is not limited to the above-described first embodiment, and can be modified in various ways. For example, the charging method has been described in such a manner that the connection between the vacuum pump 58 and the cylinder 51 is switched between the pre-charging configuration and the filling state of the mixed liquid L. However, the charging system 50 may be configured in such a manner that both the vacuum pump 58 and the cylinder 51 are connected through use of a coupling meter or a three-way switching valve (not illustrated). In this case, the vacuum pump 58 is first connected to the coupling meter or the three-way switching valve to perform evacuation, and then the cylinder 51 is connected to the coupling meter or the three-way switching valve to fill the refrigerant circuit 10 with the mixed liquid L from the cylinder 51. The foregoing description has been given of an example in which charging of the mixed liquid L is carried out within a refrigeration cycle in which the outdoor unit 20 and the indoor unit 30 are connected and the shutoff valve (first shutoff valve 41, second shutoff valve 42) is open. However, the charging of the mixed liquid L may be performed, with the outdoor unit 20 and the indoor unit 30 being not connected, or with the refrigeration cycle being shut off by closing the shutoff valve (first shutoff valve 41, second shutoff valve 42). Therefore, the mixed liquid L may be previously charged into the outdoor unit 20 at a factory or the like.<Modified Examples>

[0106] The charging system 50 according to a modified example illustrated in FIG. 6 differs from the cylinder 51 according to the above embodiment in that a cylinder 51A for storing the mixed liquid L includes a siphon tube 513 in the cylindrical body 511. In the following description, components having the same functions as those of the air conditioner 1 and the charging system 50 according to the embodiment are denoted by the same reference numerals and detailed description thereof is omitted.

[0107] The mixed liquid L is stored in an internal space 51s of a cylinder 51A, but as described above, a part of the refrigerant evaporated in the internal space 51s is sealed therein in a gas phase (gaseous). Thus, the internal space 51s is in a state of high pressure. The siphon tube 513 is connected at one end to the supply port 512, and extends linearly from the supply port 512 along the central axis of the cylindrical body 511, while the other end thereof is located near the bottom. The flow path in the siphon tube 513 is connected to the internal space 51s and with the supply opening 512o.

[0108] The cylinder 51A thus constructed presses the mixed liquid L in the internal space 51s by the pressure of the gas-phase refrigerant. Therefore, when the opening / closing valve 55 of the supply opening 512o is opened with the supply opening 512o positioned above the bottom of the cylindrical body 511 in the vertical direction, the mixed liquid L pressed by the gas-phase refrigerant automatically rises in the flow path in the siphon tube 513. As a result, the cylinder 51A can supply the mixed liquid from the supply opening 512o via the siphon tube 513.

[0109] Therefore, in the charging method, the technician can keep the supply opening 512o of the cylinder 51A positioned above the vertical direction without tilting or inverting the cylinder 51. The technician connects one end of the hose 53 to the supply port 512 of the cylinder 51A and connects the other end of the hose 53 to the liquid service port 45 (control valve 57) to form the charging system 50. In the step of filling the refrigerant circuit 10 with the mixed liquid L in the charging method (step S107 in FIG. 5), the technician performs an operation to open the opening / closing valve 55 so that the mixed liquid L automatically flows through the siphon tube 513, the supply port 512, and the hose 53 in this order. The refrigerant circuit 10 is thereby filled with the mixed liquid L supplied from the cylinder 51A.<Charging method according to Second Embodiment>

[0110] Next, a charging method according to the second embodiment will be described with reference to a flowchart in FIG. 7. The charging method according to the second embodiment differs from the charging method according to the first embodiment in that the mixed liquid L is charged into the refrigerant circuit 10 through the gas service port 44 connected to the cylinder 51. In this charging method, the technician integrally fills the refrigerant circuit 10 with the refrigerant and the odor component together as one by sequentially performing steps S201 through S209 illustrated in FIG. 7, for example.

[0111] In the charging method according to the second embodiment, steps S201 and S202 are the same as steps S101 and S102 described above. In step S203, the technician connects the control valve 57 to the gas service port 44 of the outdoor unit 20. This makes it possible to fill the refrigerant circuit 10 with the mixed liquid L via the control valve 57.

[0112] Step S204 of the charging method is the same as step S104 described above. In step S205, the technician opens the valve core in the gas service port 44 and operates the connected vacuum pump 58 to evacuate the refrigerant circuit 10, thereby adjusting the pressure in the refrigerant circuit 10 to a target pressure. In this evacuation, the vacuum pump 58 evacuates air and moisture from the refrigerant circuit 10 through the gas service port 44 and the hose 59 to bring the refrigerant circuit 10 into a vacuum state. After the vacuum state is created, the technician operates the control valve 57 so as to close the valve core in the liquid service port 45 and removes the hose 59 from the control valve 57 to release the pre-charging configuration.

[0113] Next, the technician connects the other end of the hose 53 to the control valve 57 and connects the cylinder 51 to one end of the hose 53 in such a manner that the supply port 512 of the cylinder 51 is oriented vertically downward, thereby connecting the cylinder 51 to the refrigerant circuit 10 (step 206, corresponding to "second step"; see also FIG. 3). The cylinder 51A having the siphon tube 513 according to the modified example may be used as the cylinder connected to the gas service port 44.

[0114] In the cylinder 51 connected to the refrigerant circuit 10, the supply opening 512o is positioned below the bottom of the cylindrical body 511 in the vertical direction, and only the mixed liquid L is present in the vicinity of the supply opening 512o of the cylinder 51. The technician opens the valve core and the opening / closing valve 55 in the gas service port 44, thereby allowing the mixed liquid L to flow out from the supply opening 512o of the cylinder 51, so that the refrigerant circuit 10 is filled with the mixed liquid L via the gas service port 44 (step 2107, corresponding to "third step"). At this time, the gas-phase refrigerant presses the mixed liquid L in the cylinder 51, so that the mixed liquid L can be pressure-fed toward the supply opening 512o. The mixed liquid L in the cylinder 51 flows into the refrigerant circuit 10 from the cylinder 51 through the hose 53 according to a pressure difference between the cylinder 51 and the refrigerant circuit 10 in a vacuum state.

[0115] The mixed liquid L supplied from the gas service port 44 to the refrigerant circuit 10 flows into the gas-liquid separator 26 through the gas line 13G. The gas-liquid separator 26 separates the mixed liquid into a gas (gas phase) and a liquid (liquid phase), and moves only the gas to the compressor 21. It is preferable that the charging rate at which the mixed liquid is charged from the cylinder 51 through the gas service port 44 be set to be lower than the charging rate at which the mixed liquid is charged through the liquid service port 45. Thus, the mixed liquid can be stably separated into a gas and a liquid in the gas-liquid separator 26. It is preferable that the technician drive the compressor 21 when charging the mixed liquid L. By driving the compressor 21, the mixed liquid L charged through the gas service port 44 smoothly moves to the gas-liquid separator 26, is separated into a gas and a liquid in the gas-liquid separator 26, and the separated gas easily flows into the compressor 21. As a result, a pressure difference between the cylinder 51 and the gas line 13G is increased, and a failure due to liquid compression can be suppressed.

[0116] The mixed liquid L is charged into the refrigerant circuit 10 by the technician based on the detection result of the electronic scale 54, until the target amount to be charged is reached. When the mixed liquid L is charged into the refrigerant circuit 10 from the cylinder 51, the technician monitors the weight measured by the electronic scale 54 to monitor whether the charging of the mixed liquid L has been finished (step S208). If the charging of the mixed liquid L is not finished (No in step S208), the charging of the mixed liquid L from the cylinder 51 is continued. On the other hand, if the charging of the mixed liquid L has been finished (Yes in step S208), this means that the refrigerant circuit 10 is filled with the target amount of the refrigerant and the odor component, and the technician proceeds to step S109. The completion of the charging of the mixed liquid L may be determined by, for example, monitoring the cumulative charging amount of the mixed liquid L by a flow integrator.

[0117] In step S209 after the completion of the refrigerant charging, the technician closes the opening / closing valve 55 of the charging system 50 and operates the control valve 57 so as to close the valve core in the liquid service port 45, thereby disconnecting the charging system 50. For example, in the disconnecting operation, the technician first disconnects the control valve 57 to which the hose 53 is connected from the gas service port 44. Since the valve core in the gas service port 44 is already closed in the first shutoff valve 41, the vaporized (gas-phase) refrigerant and odor component after being charged or the liquid-phase refrigerant and odor component are thereby reliably prevented from leaking from the refrigerant circuit 10. Then, the technician separates the control valve 57, the hose 53, the cylinder 51, and the like. The air conditioner 1 is thus installed, with a state in which the refrigerant and odor component are sealed in the refrigerant circuit 10 being satisfactorily formed.

[0118] As described above, also in the charging method according to the second embodiment, the refrigerant circuit 10 can be filled with the mixed liquid L obtained by mixing the liquid-phase refrigerant and the liquid-phase odor component via the gas service port 44. In the refrigerant circuit 10, the concentration of the odor component sufficiently approximates or becomes equal to the predetermined concentration, and the odor component can sufficiently exhibit its performance when it leaks from the refrigerant circuit 10.<Aspects and Effects of Present Disclosure>

[0119] The embodiments disclosed above have, for example, the following aspects and effects.[Clause 1]

[0120] A method of charging a refrigerant and an odor component into a refrigeration apparatus, the charging method including: a first step of providing a cylinder containing a mixed liquid in which the odor component is dissolved; a second step of connecting the cylinder to a refrigerant circuit of the refrigeration apparatus; a third step of filling the refrigerant circuit with the mixed liquid supplied from the cylinder. [Effect of Clause 1]

[0121] According to the above, with the charging method, the refrigerant circuit can be filled with an odor component at an appropriate concentration by charging a mixed liquid in which the odor component is mixed into the refrigerant circuit. Since the refrigerant circuit is filled with the odor component at an intended concentration, the performance of the odor component can be stably exhibited. The mixed liquid charged in the refrigerant circuit turns into a gas phase in the refrigerant circuit, and the volume of the mixed liquid expands accordingly. For this reason, compared to filling with a gaseous refrigerant or the like, filling with a mixed liquid enables an appropriate amount of an odor component to be charged in a shorter time, making it possible to improve work efficiency.[Clause 2]

[0122] The charging method according to Clause 1, wherein the cylinder includes a supply opening through which the mixed liquid is supplied; and a cylindrical body connected to the supply opening and in which mainly the refrigerant is sealed, and in the third step, the supply opening is positioned below a bottom of the cylindrical body in a vertical direction so as to fill the refrigerant circuit with the mixed liquid from the cylinder. [Effect of Clause 2]

[0123] With the charging method, the mixed liquid can be smoothly circulated from the cylinder to the refrigerant circuit, allowing the mixed liquid to be charged into the refrigerant circuit.[Clause 3]

[0124] The charging method according to Clause 1, wherein the cylinder includes a siphon tube in which the mixed liquid and the refrigerant in a gas phase are sealed at a high pressure and configured to supply the mixed liquid by a pressure of the refrigerant in the gas phase, and in the third step, the refrigerant circuit is filled with the mixed liquid through the siphon tube. [Effect of Clause 3]

[0125] Even in this case, with the charging method, the mixed liquid can be easily supplied from the cylinder, allowing the mixed liquid to be charged into the refrigerant circuit.[Clause 4]

[0126] The charging method according to any one of Clauses 1 to 3, wherein the refrigeration apparatus includes the refrigerant circuit in which a compressor, a heat source-side heat exchanger, a pressure reducing device, and a use-side heat exchanger are connected in this order, a refrigerant charging part through which the refrigerant is charged into the refrigerant circuit is provided between the pressure reducing device and the use-side heat exchanger, in the second step, the cylinder is connected to the refrigerant charging part, and in the third step, the refrigerant charging part is filled with the mixed liquid supplied from the cylinder. [Effect of Clause 4]

[0127] With the charging method, the liquid line of the refrigerant circuit can be easily filled with the mixed liquid through the refrigerant charging part provided between the pressure reducing device and the use-side heat exchanger.[Clause 5]

[0128] The charging method according to any one of Clauses 1 to 4, wherein the refrigeration apparatus includes the refrigerant circuit in which a compressor, a heat source-side heat exchanger, a pressure reducing device, and a use-side heat exchanger are connected in this order, a refrigerant charging part through which the refrigerant is charged into the refrigerant circuit is provided between the compressor and the use-side heat exchanger, a gas-liquid separator is provided between the compressor and the refrigerant charging part, in the second step, the cylinder is connected to the refrigerant charging part, and in the third step, the refrigerant charging part is filled with the mixed liquid supplied from the cylinder. [Effect of Clause 5]

[0129] Even in this case, with the charging method, the gas line of the refrigerant circuit can be filled with the mixed liquid through the refrigerant charging part provided between the compressor and the use-side heat exchanger.[Clause 6]

[0130] The charging method according to Clause 5, wherein in the third step, the compressor (21) is driven to move the mixed liquid charged into the refrigerant charging part (44) to the gas-liquid separator (26) and cause a gas separated by the gas-liquid separator (26) to be suctioned into the compressor (21).[Effect of Clause 6]

[0131] The mixed liquid supplied to the gas line of the refrigerant circuit can be smoothly separated into gas and liquid in the gas-liquid separator, and the gas can be transferred to the compressor, and the efficiency of filling the mixed liquid even from the gas line can be improved.[Clause 7]

[0132] The charging method according to any one of Clauses 1 to 6, wherein the refrigerant is a strongly combustible refrigerant.[Effect of Clause 7]

[0133] The refrigeration apparatus can fill the refrigerant circuit with a refrigerant having a low GWP value, thereby performing heat exchange through the refrigerant in the condenser and evaporator efficiently. Moreover, at the time of charging, the refrigerant can be charged with the refrigerant in a mixed liquid state in which an odor component is dissolved, thereby avoiding insufficient charging of an odor component and providing an appropriate amount of odor when the refrigerant leaks from the refrigeration apparatus.[Clause 8]

[0134] The charging method according to Clause 7, wherein the refrigerant is propane.[Effect of Clause 8]

[0135] The propane can be easily stored in the cylinder in a liquid phase, and a mixed liquid state can be well maintained in the cylinder.[Clause 9]

[0136] The charging method according to any one of Clauses 1 to 8, wherein the refrigerant contains mercury at an amount equal to or less than 0.1 mg / L.[Effect of Clause 9]

[0137] With the refrigerant circuit being filled with the refrigerant, it is possible to prevent the formation of leakage points caused by a significant loss of material strength due to alloying (amalgamation) reactions between the metals in the refrigerant circuit, particularly the amalgamation of aluminum with mercury. Specifically, by adopting this charging method and controlling the mercury content to 0.1 mg / L or less, the strength of the metal material in the refrigerant circuit can be stably maintained. As a result, refrigerant leakage can be effectively suppressed, and an effect of prompting an evacuation action induced by the odor component can be obtained, thereby achieving a dual safety measure.[Clause 10]

[0138] The charging method according to any one of Clauses 1 to 9, wherein the odor component is a substance having a boiling point higher than that of the refrigerant.[Effect of Clause 10]

[0139] It is thus possible to maintain the refrigerant in a liquid phase and the odor component in a liquid phase, with the cylinder filled with the refrigerant and the odor component as a mixed liquid.[Clause 11]

[0140] The charging method according to any one of Clauses 1 to 10, wherein the odor component is a sulfur-based odorant.[Effect of Clause 11]

[0141] The odor component filled in the refrigerant circuit can stably prompt an evacuation action when the refrigerant circuit leaks.[Clause 12]

[0142] The charging method of Clause 11, wherein the odor component is selected from the group consisting of sulfides and thiophenes.[Effect of Clause 12]

[0143] An odor component having a boiling point higher than that of a refrigerant can be adopted, and a mixed liquid state can be well maintained by the refrigerant in the liquid phase and the odor component in the liquid phase in the cylinder.[Clause 13]

[0144] The charging method of Clause 12, wherein the odor component is tetrahydrothiophene.[Effect of Clause 13]

[0145] An odor component having a boiling point higher than the ambient temperature outside the cylinder can be adopted, and such odor component at an appropriate concentration can be easily charged into the refrigerant circuit together with the refrigerant, so that refrigerant leakage from the refrigerant circuit can be recognized by people in the vicinity.[Clause 14]

[0146] The charging method of Clause 12, wherein the odor component is dimethyl sulfide.[Effect of Clause 14]

[0147] Even in this case, an odor component having a boiling point higher than the ambient temperature outside the cylinder can be adopted, and the odor component at an appropriate concentration can be easily charged into the refrigerant circuit together with the refrigerant, so that refrigerant leakage from the refrigerant circuit can be recognized by people in the vicinity.[Clause 15]

[0148] The charging method according to Clause 12, wherein the odor component is a sulfur-based odorant is ethyl methyl sulfide.[Effect of Clause 15]

[0149] Even in this case, an odor component having a boiling point higher than the ambient temperature outside the cylinder can be adopted, and the odor component at an appropriate concentration can be easily charged into the refrigerant circuit together with the refrigerant, so that refrigerant leakage from the refrigerant circuit can be recognized by people in the vicinity.

[0150] The charging method according to the embodiment disclosed herein is exemplary in all respects and is not restrictive. The embodiments can be modified and improved in various forms without departing from the scope and gist of the appended claims. The matters described in the above embodiments may be constructed in other ways without contradiction, and may be combined without contradiction.

[0151] The present application is based on and claims priority to Japanese patent application No. 2024-171017 filed on September 30, 2024, with the Japan Patent Office, the entire contents of which are hereby incorporated by reference.REFERENCE SIGNS LIST

[0152] 1Air conditioner (refrigeration apparatus) 10Refrigerant circuit 51Cylinder 511Cylindrical body 512oSupply opening 513Siphon tube LMixed liquid

Claims

1. A method of charging a refrigerant and an odor component into a refrigeration apparatus (1), the charging method comprising: a first step of providing a cylinder (51, 51A) containing a mixed liquid (L) in which the odor component is dissolved; a second step of connecting the cylinder (51, 51A) to a refrigerant circuit (10) of the refrigeration apparatus (1); and a third step of filling the refrigerant circuit (10) with the mixed liquid supplied from the cylinder (51, 51A).

2. The charging method according to claim 1, wherein the cylinder (51, 51A) includes a supply opening (512o) through which the mixed liquid is supplied; and a cylindrical body (511) connected to the supply opening (512o) and in which mainly the refrigerant is sealed, and in the third step, the supply opening (512o) is positioned below a bottom of the cylindrical body (511) in a vertical direction so as to fill the refrigerant circuit (10) with the mixed liquid from the cylinder (51).

3. The charging method according to claim 1, wherein the cylinder (51A) includes a siphon tube (513) in which the mixed liquid and the refrigerant in a gas phase are sealed at a high pressure and configured to supply the mixed liquid by a pressure of the refrigerant in the gas phase, and in the third step, the refrigerant circuit (10) is filled with the mixed liquid through the siphon tube (513).

4. The charging method according to any one of claims 1 to 3, wherein the refrigeration apparatus (1) includes the refrigerant circuit (10) in which a compressor (21), a heat source-side heat exchanger (22), a pressure reducing device (23), and a use-side heat exchanger (31) are connected in this order, a refrigerant charging part (45) through which the refrigerant is charged into the refrigerant circuit (10) is provided between the pressure reducing device (23) and the use-side heat exchanger (31), in the second step, the cylinder (51, 51A) is connected to the refrigerant charging part (45), and in the third step, the refrigerant charging part (45) is filled with the mixed liquid supplied from the cylinder (51, 51A).

5. The charging method according to any one of claims 1 to 3, wherein the refrigeration apparatus (1) includes the refrigerant circuit (10) in which a compressor (21) , a heat source-side heat exchanger (22), a pressure reducing device (23), and a use-side heat exchanger (31) are connected in this order, a refrigerant charging part (44) through which the refrigerant is charged into the refrigerant circuit (10) is provided between the compressor (21) and the use-side heat exchanger (31), a gas-liquid separator (26) is provided between the compressor (21) and the refrigerant charging part (44), in the second step, the cylinder (51, 51A) is connected to the refrigerant charging part (44), and in the third step, the refrigerant charging part (44) is filled with the mixed liquid supplied from the cylinder (51, 51A).

6. The charging method according to claim 5, wherein in the third step, the compressor (21) is driven to move the mixed liquid charged into the refrigerant charging part (44) to the gas-liquid separator (26) and cause a gas separated by the gas-liquid separator (26) to be suctioned into the compressor (21).

7. The charging method according to any one of claims 1 to 3, wherein the refrigerant is a strongly combustible refrigerant.

8. The charging method according to claim 4, wherein the refrigerant is propane.

9. The charging method according to any one of claims 1 to 3, wherein the refrigerant contains mercury at an amount equal to or less than 0.1 mg / L.

10. The charging method according to any one of claims 1 to 3, wherein the odor component is a substance having a boiling point higher than that of the refrigerant.

11. The charging method according to any one of claims 1 to 3, wherein the odor component is a sulfur-based odorant.

12. The charging method of claim 11, wherein the odor component is selected from the group consisting of sulfides and thiophenes.

13. The charging method of claim 12, wherein the odor component is tetrahydrothiophene.

14. The charging method of claim 12, wherein the odor component is dimethyl sulfide.

15. The charging method according to claim 12, wherein the odor component is a sulfur-based odorant is ethyl methyl sulfide.

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