Odorant removal method, filter, deodorization device, and refrigeration cycle device

Abstract

This odorant removal method comprises: a step (S1) for introducing an odorant-containing refrigerant, together with a refrigerator oil, from an evaporator (7) to a bypass circuit (9) having a filter (11); and a step (S2) for removing the odorant using the filter (11) after the introduction step (S1). In the removal step (S2), the odorant is introduced to the filter (11) together with the refrigerator oil.

Description

Odorant removal method, filter, deodorizing device, and refrigeration cycle device

[0001] The present disclosure relates to an odorant removal method, a filter, a deodorizing device, and a refrigeration cycle device.

[0002] International Publication No. 2021 / 166028 (Patent Document 1) discloses a refrigeration cycle device in which a refrigerant contains an odorant so that the refrigerant can be recognized by the sense of smell.

[0003] International Publication No. 2021 / 166028

[0004] However, when the refrigerant is discharged from the refrigeration cycle device, the odorant must be removed from the refrigerant.

[0005] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide an odorant removal method, a filter, a deodorizing device, and a refrigeration cycle device that can efficiently remove odorants.

[0006] An odorant removal method according to the present disclosure includes a step of flowing an odorant-containing refrigerant together with refrigeration oil from an evaporator into a bypass circuit having a filter, and a step of removing the odorant using the filter after the flowing step. In the removing step, the odorant flows into the filter together with the refrigeration oil.

[0007] A filter according to the present disclosure is attached to a refrigeration cycle device, and includes an adsorbent that adsorbs an odorant.

[0008] A deodorizing device according to the present disclosure includes a pipe and a filter, through which a refrigerant containing an odorant passes, and the filter is disposed in the pipe.

[0009] A refrigeration cycle device according to the present disclosure includes a filter.

[0010] According to the above, it is possible to obtain an odorant removal method, a filter, a deodorizing device, and a refrigeration cycle device that can efficiently remove odorants.

[0011] FIG. 1 is a schematic diagram showing an example of a refrigeration cycle apparatus (closed refrigerant circuit) according to embodiment 1. FIG. 2 is a schematic cross-sectional view of a filter according to embodiment 1. FIG. 3 is a flowchart of an odorant removal method in a refrigerant cycle apparatus according to embodiment 1. FIG. 4 is a schematic diagram showing an example of a refrigeration cycle apparatus (closed refrigerant circuit) according to embodiment 2. FIG. 5 is a graph showing saturated vapor diagrams of a refrigerant and an odorant. FIG. 6 is a graph showing saturated vapor diagrams of propane and tetrahydrothiophene. FIG. 7 is a schematic diagram showing an example of an odorant removal method according to embodiment 3.

[0012] Hereinafter, embodiments of the present disclosure will be described. Unless otherwise specified, the same or corresponding parts in the following drawings will be denoted by the same reference numerals, and the description thereof will not be repeated.

[0013] First Embodiment <Configuration of Refrigeration Cycle Apparatus (Refrigerant Circuit)> Fig. 1 is a schematic diagram showing an example of a refrigeration cycle apparatus (closed refrigerant circuit 100) according to a first embodiment.

[0014] The refrigeration cycle device is, for example, a refrigeration cycle device for air conditioning, and as shown in Fig. 1, mainly includes an outdoor unit 1 and an indoor unit 2. The outdoor unit 1 and the indoor unit 2 are connected by a gas pipe 10.

[0015] The outdoor unit 1 has a compressor 3, a condenser 4 which is a first heat exchanger, an outdoor blower 5, and an expansion valve 6. The compressor 3 is connected to the condenser 4 by piping. The condenser 4 is connected to the expansion valve 6 by piping. The indoor unit 2 has an evaporator 7 which is a second heat exchanger, and an indoor blower 8.

[0016] The compressor 3 of the outdoor unit 1 and the evaporator 7 of the indoor unit 2 are connected by a gas pipe 10. The condenser 4 of the outdoor unit 1 and the evaporator 7 of the indoor unit 2 are connected by a liquid pipe. This configuration of the refrigeration cycle device forms a closed refrigerant circuit 100. Refrigerant and odorant circulate within the closed refrigerant circuit 100 via the gas pipe 10.

[0017] The compressor 3 compresses the refrigerant that has become gaseous in the gas pipe 10. The condenser 4 cools the gaseous refrigerant compressed by the compressor 3, changing the refrigerant from gaseous to high-pressure liquid or two-phase gas-liquid. The expansion valve 6 reduces the pressure of the high-pressure liquid or two-phase gas-liquid refrigerant. The evaporator 7 heats the reduced pressure refrigerant to change it to low-pressure gaseous refrigerant. The compressor 3 draws in the refrigerant that has become low-pressure gaseous by the evaporator 7 and compresses it again.

[0018] The closed refrigerant circuit 100 may be provided with any one of an accumulator, a suction muffler, and a receiver between the compressor 3 and the evaporator 7. The accumulator and the suction muffler are devices that separate liquid and gas and supply the gas to the compressor. The receiver is a device that stores the liquid refrigerant liquefied in the condenser 4. The provision of the accumulator, the suction muffler, and the receiver prevents a large amount of liquid refrigerant from flowing into the compressor 3. As a result, it is possible to prevent the refrigeration oil from being excessively diluted and the lubrication of the sliding parts of the compressor 3 from being deteriorated.

[0019] Refrigerating machine oil is disposed inside the compressor 3. The refrigerating machine oil maintains the lubrication of the sliding parts of the compressor 3. The refrigerating machine oil is discharged into the gas pipe 10 together with the refrigerant compressed by the sliding parts of the compressor 3 and the odorant. Therefore, the refrigerating machine oil circulates within the closed refrigerant circuit 100 together with the refrigerant. Note that a mixture of the refrigerant containing the odorant and the refrigerating machine oil is used as a working fluid.

[0020] The outdoor fan 5 sends air to the condenser 4. The outdoor fan 5 is provided to facilitate heat exchange between the refrigerant flowing through the condenser 4 and the air, thereby facilitating heat absorption or release. The indoor fan 8 sends air to the evaporator 7. The indoor fan 8 is provided to facilitate heat exchange between the refrigerant flowing through the evaporator 7 and the air, thereby facilitating heat absorption or release.

[0021] In the refrigeration cycle apparatus according to the first embodiment, the condenser 4 and the evaporator 7 are heat exchangers that exchange heat with air. In the refrigeration cycle apparatus according to the first embodiment, the condenser 4 and the evaporator 7 may exchange heat with a liquid such as water instead of air.

[0022] In the refrigeration cycle device of this embodiment 1, the evaporator 7 is provided in the indoor unit 2 and the condenser 4 is provided in the outdoor unit 1, but for example, the evaporator 7 may be provided in the outdoor unit 1 and the condenser 4 may be provided in the indoor unit 2.

[0023] The expansion valve 6 may be provided in the indoor unit 2 instead of in the outdoor unit 1. The expansion valve 6 may be provided in both the outdoor unit 1 and the indoor unit 2. A plurality of indoor units 2 may be provided in the closed refrigerant circuit 100. A plurality of outdoor units 1 may be provided in the closed refrigerant circuit 100.

[0024] The outdoor unit 1 as described above may be provided with, for example, a switching mechanism (not shown). The switching mechanism switches between the suction pipe and the discharge pipe of the compressor 3 by arranging a four-way valve or a combination of multiple valves. By providing the switching mechanism, the heat exchanger in the outdoor unit 1 can function as an evaporator, and the heat exchanger in the indoor unit 2 can function as a condenser. In this way, the refrigeration cycle device can be used as a heater that uses outdoor heat to heat the room.

[0025] The refrigeration cycle device may be, for example, a device capable of both cooling and heating, a device capable of only cooling, or a device capable of only heating.

[0026] The use of the refrigeration cycle apparatus according to the first embodiment is not limited to air conditioning, but may also be used for freezing, refrigeration, or hot water supply.

[0027] As shown in Fig. 1, the closed refrigerant circuit 100 includes a bypass circuit 9. The bypass circuit 9 is used to remove odorants contained in the refrigerant. The bypass circuit 9 is provided in parallel with a gas pipe 10 that connects the evaporator 7 and the compressor 3. Specifically, the bypass circuit 9 is connected to the gas pipe 10 via a switching mechanism 12 and a switching mechanism 13. The bypass circuit 9 may be provided inside the outdoor unit 1, inside the indoor unit 2, or in extension piping outside the outdoor unit 1 and the indoor unit 2.

[0028] In the odorant removal operation, the switching mechanism 12 and the switching mechanism 13 are operated to cause the working fluid to flow through the bypass circuit 9. Note that in the odorant removal operation, the gas pipe 10 between the switching mechanism 12 and the switching mechanism 13 may be in a closed state or an open state.

[0029] The switching mechanism 12 switches the flow path for the working fluid between the gas pipe 10 connected to the compressor 3 or the bypass circuit 9. In this way, the working fluid flowing from the evaporator 7 flows into the gas pipe 10 connected to the compressor 3 or the bypass circuit 9. The switching mechanism 13 switches the flow path for the working fluid between the gas pipe 10 connected to the evaporator 7 or the bypass circuit 9. In this way, the working fluid flowing from either the evaporator 7 or the bypass circuit 9 flows to the compressor 3.

[0030] The bypass circuit 9 has a filter 11. Next, the filter 11 will be described. FIG. 2 is a schematic cross-sectional view of the filter 11 according to the first embodiment. As shown in FIG. 2, the filter 11 has an adsorbent 11a. The adsorbent 11a is at least one of silica gel, activated carbon, and synthetic zeolite. The synthetic zeolite may be molecular sieves. The adsorbent 11a adsorbs odorants. The adsorbent 11a is filled in a portion of the pipe 11c between the switching mechanism 12 and the switching mechanism 13.

[0031] 2, the filter 11 may have a pair of filtration filters 11b. The adsorbent 11a may be disposed so as to be sandwiched between the pair of filtration filters 11b. The working fluid flowing through the switching mechanism 12 flows into the filtration filters 11b and the adsorbent 11a. The adsorbent 11a adsorbs the odorant from the working fluid that has flowed into the adsorbent 11a.

[0032] The lower the temperature on the surface of the adsorbent 11a, the higher the adsorption amount at adsorption equilibrium. As a result, the saturated adsorption amount increases. Therefore, in order to increase the odorant adsorption efficiency of the adsorbent 11a, the filter 11 provided in the bypass circuit 9 may be cooled from the outside. The filter 11 may be cooled by blowing air cooled by the evaporator 7 onto the filter 11, or the filter 11 may be cooled using an external cooling source.

[0033] A flow rate adjusting mechanism may be provided inside or before or after each of the switching mechanisms 12 and 13. This makes it possible to control the flow rate of the working fluid flowing into the bypass circuit 9 or the filter 11.

[0034] In an operation in which the odorant is not removed, the switching mechanisms 12 and 13 may be controlled so that the working fluid does not flow into the bypass circuit 9. This prevents the odorant from being unintentionally removed by the filter 11, thereby preventing the odor of the refrigerant from being unintentionally reduced.

[0035] The refrigerant used in the refrigeration cycle device contains a main component including hydrocarbons with one to four carbon atoms and an odorant for detecting refrigerant leaks. Here, the "main component" refers to the refrigerant components excluding the odorant and impurities (such as air, moisture, and by-products that may be mixed in during the synthesis and refinement of the refrigerant compound). The main component of the refrigerant may be either a single compound or a mixture of multiple compounds. The main component in the refrigerant may account for 90 mass percent or more, or 95 mass percent or more, of the refrigerant's constituent materials.

[0036] The boiling point of the odorant is higher than that of the main component of the refrigerant. As a result, when the temperature of the refrigerant at the outlet of the evaporator 7 reaches a temperature between the boiling points of the odorant and the refrigerant, a two-phase gas-liquid state is formed in which the main component of the refrigerant is concentrated in the gas phase and the odorant is concentrated in the liquid phase. In this way, the odorant can be selectively liquefied.

[0037] Examples of hydrocarbons having 1 to 4 carbon atoms include R-50 (methane), R-170 (ethane), R-1150 (ethylene), R-290 (propane), R-1270 (propylene), R-600 (butane), and R-600a (isobutane).

[0038] The hydrocarbon having 1 to 4 carbon atoms may be, for example, methane, ethane, ethylene, propane, propylene, butane, isobutane, or a mixture containing any of these (R-433A, R-433B, R-433C, R-436A, R-436B, R-436C, R-487A, R-487B, R-489A, R-490A, R-493A, R-493B, R-493C, etc.), which have an operating pressure suitable for use in a refrigeration cycle device.

[0039] From the viewpoint of oxidation stability, the hydrocarbon having 1 to 4 carbon atoms may be, for example, either propane or isobutane. According to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), the global warming potential (GWP) of propane is 0.02. As such, propane as a refrigerant has a very low GWP value and high cooling performance. Therefore, it can contribute to reducing the environmental impact during the manufacture and operation of refrigeration cycle devices.

[0040] The main component of the refrigerant may be a mixture of hydrocarbons having 1 to 4 carbon atoms and halogenated hydrocarbons. Halogenated hydrocarbons are compounds in which the hydrogen atoms of hydrocarbons are replaced with halogen atoms, and have lower flammability than hydrocarbons. As a result, mixing halogenated hydrocarbons with hydrocarbons having 1 to 4 carbon atoms can reduce the flammability of the refrigerant. For example, the closed refrigerant circuit 100 may be filled with a refrigerant in a mixture of hydrocarbons having 1 to 4 carbon atoms and halogenated hydrocarbons. Additional hydrocarbons having 1 to 4 carbon atoms may be filled into the closed refrigerant circuit 100 already filled with halogenated hydrocarbons, or into the closed refrigerant circuit 100 with a small amount of residual halogenated hydrocarbons.

[0041] Examples of halogenated hydrocarbons include chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluoroolefins, and fluoroiodocarbons.

[0042] Examples of halogenated hydrocarbons include HFC-23, HFC-32, HFC-41, HFC-125, HFC-134, HFC-134a, HFC-143, HFC-143a, HFC-152, HFC-152a, HFC-161, HFO-1141, HFO-1132a, HFO-1132(E), HFO-1132(Z), HFO-1123, and HFO-1225ye. (Z), HFO-1225ye(E), HFO-1225zc, HFO-1234yf, HFO-1234ze(E), HFO-1234ze(Z), HFO-1234ye(Z), HFO-1234ye(E), HFO-1243zf, HFO-1252zf, HFO-1261yf, FIC-13I1 (CF3I), HCFC-22, CFC-12, and the like.

[0043] The main component of the refrigerant may include, for example, carbon dioxide (R-744), which has a GWP value of 1. As carbon dioxide has a low GWP value of 1, it can contribute to reducing the environmental impact during the manufacture of refrigeration cycle devices. Carbon dioxide is also non-flammable. Therefore, by mixing carbon dioxide with hydrocarbons having a carbon number of 1 to 4, the flammability of the refrigerant can be reduced.

[0044] The odorant may have a distinctive odor. Because the odorant has a distinctive odor, the refrigerant mixed with the odorant can be detected by olfaction. Materials constituting the odorant include, for example, mercaptans, sulfides, thiophenes, cyclohexene, acrylic acid esters, ammonia, amines, pyrazines, and norbornenes. Examples of mercaptans include methyl mercaptan, ethyl mercaptan, n-propyl mercaptan, isopropyl mercaptan, and tertiary butyl mercaptan. Examples of sulfides include dimethyl sulfide, diethyl sulfide, and methyl ethyl sulfide. Examples of acrylic acid esters include methyl acrylate and ethyl acrylate. Examples of amines include methylamine, dimethylamine, and trimethylamine. Examples of pyrazines include methylethylpyrazine. Examples of norbornenes include 5-ethylidene-2-norbornene. Examples of thiophenes include tetrahydrothiophene. These odorants may be used alone or in combination of two or more. Furthermore, the materials constituting the odorant may contain compounds having a unique odor other than the above-mentioned materials.

[0045] The concentration of the odorant contained in the refrigerant may be equal to or greater than the concentration (olfactory threshold) required for olfactory recognition of the odorant's odor. This allows the refrigerant to be recognized by olfactory recognition. When an odorant is contained in the refrigerant, the cooling performance of the refrigerant's main components is reduced. Therefore, the odorant concentration may be 1 mass percent or less relative to the refrigerant. This allows the refrigerant to be recognized by olfactory recognition, and prevents the cooling performance of the refrigerant from being reduced due to mixing of the refrigerant and the odorant. Odorants are compounds with a lower vapor pressure than the main components of the refrigerant. Therefore, if the odorant concentration exceeds 1 mass percent relative to the refrigerant, temperature glide may affect the performance of the refrigeration cycle device.

[0046] The refrigeration oil includes a base oil. The base oil includes at least one of an oxygen-containing oil and a hydrocarbon oil. Examples of the oxygen-containing oil include polyethylene glycol, polyol ester, and polyvinyl ether. Examples of the hydrocarbon oil include polyalphaolefin, alkylbenzene, alkylnaphthalene, and mineral oil.

[0047] The lubrication of the sliding parts of the compressor 3 depends greatly on the kinematic viscosity of the base oil contained in the refrigerating machine oil. The material constituting the base oil may have a kinematic viscosity higher than that of the refrigerant. The kinematic viscosity of the base oil at 40°C is 5 mm ２ / second or more 250mm ２ / sec or less. By adjusting the molecular structure and degree of polymerization of the materials constituting the base oil, the kinematic viscosity of the base oil can be made to fall within the above range. When the base oil has a kinematic viscosity higher than that of the refrigerant, the cooling efficiency of the refrigeration cycle device is not significantly reduced, and the lubrication of the sliding parts in the compressor 3 is maintained.

[0048] The base oil is partially or completely compatible with the odorant. In this way, the refrigerating machine oil dissolves the odorant. If the base oil is a compound that dissolves the odorant, at least a portion of the odorant filled in the closed refrigerant circuit 100 dissolves in the refrigerating machine oil. Therefore, the refrigerating machine oil in the oil sump of the compressor 3 contains the odorant.

[0049] In other words, the working fluid discharged from the compressor 3 flows into the condenser 4 in a two-phase state consisting of a gaseous odorant contained in the refrigerant and a liquid odorant contained in the refrigerating machine oil. The working fluid condensed in the condenser 4 flows into the expansion valve 6 as a high-pressure mixture of hydrocarbons, which are the main components of the refrigerant, the odorant, and the refrigerating machine oil. The pressure of the high-pressure working fluid is reduced in the expansion valve 6, and the working fluid flows into the evaporator 7 as a low-pressure mixture of hydrocarbons, the odorant, and the refrigerating machine oil. The refrigerant evaporates in the evaporator 7, and the working fluid flows into the bypass circuit 9 in a gas-liquid two-phase state consisting of a gaseous refrigerant and a liquid refrigerating machine oil containing the odorant. Therefore, the refrigerating machine oil flowing into the filter 11 contains a higher concentration of odorant than the refrigerating machine oil discharged from the compressor 3. Therefore, the odorant can be efficiently removed in the filter 11.

[0050] The base oil may be oxygenated oil. Oxygenated oil has high polarity. Therefore, oxygenated oil can dissolve polar compounds. Here, the odorants exemplified as materials constituting the odorant have a nitrogen atom, an oxygen atom, a sulfur atom, or a carbon-carbon double bond in their chemical structure. In other words, the odorants described above are compounds with polarity due to an imbalance in charge. Therefore, refrigeration oil containing oxygenated oil can dissolve the odorant. By dissolving the odorant in refrigeration oil, the liquid odorant flows into the bypass circuit 9 as a mixture with the refrigeration oil. Furthermore, oxygenated oil has polarity, while hydrocarbons with 1 to 4 carbon atoms are nonpolar. Therefore, oxygenated oil has low compatibility with hydrocarbons with 1 to 4 carbon atoms. Therefore, oxygenated oil does not easily dissolve refrigerants that are hydrocarbons with 1 to 4 carbon atoms. Therefore, the amount of hydrocarbons contained in refrigeration oil flowing into the filter 11 can be reduced.

[0051] The base oil is composed of compounds with molecular weights larger than that of the odorant, excluding substances mixed in as impurities. As mentioned above, impurities include moisture, dissolved air, unreacted base oil raw materials, and by-products that may be mixed in during the synthesis and refining of the base oil. If the molecular weight of the base oil is larger than that of the odorant, this means that the molecular size of the base oil is larger than that of the odorant. This reduces the amount of base oil adsorbed into the pore structure of the adsorbent 11a filled in the filter 11. As a result, saturation of the adsorbent 11a and generation of adsorption heat are suppressed, allowing the odorant to be efficiently adsorbed.

[0052] The pour point of the refrigerating machine oil may be lower than the lowest possible temperature of the working fluid (refrigerant, odorant, and refrigerating machine oil) in the evaporator 7. By having the pour point of the refrigerating machine oil lower than the lowest possible temperature of the working fluid (refrigerant, odorant, and refrigerating machine oil), it is possible to suppress a decrease in the flow rate in the bypass circuit 9 due to a decrease in the fluidity of the refrigerating machine oil.

[0053] The refrigerating machine oil may contain, as in-oil additives, antioxidants, acid scavengers, extreme pressure agents (anti-wear agents), oxygen scavengers, fluorescent agents, colorants, etc. However, in order to prevent a decrease in the flow rate of the bypass circuit 9 due to precipitated in-oil additives, the in-oil additives may be prevented from precipitating when the temperature of the working fluid in the expansion valve 6 decreases.

[0054] The adsorbent 11a filled in the filter 11 is a substance capable of adsorbing odorants by the porous structure and metal cations on its surface. The pore diameter of the porous structure may be selected so that the odorants are adsorbed and hydrocarbons and the base oil of the refrigerating machine oil are not easily adsorbed. The adsorbent 11a may also be an adsorbent 11a that is capable of preferentially adsorbing polar substances. The pore diameter of the adsorbent 11a is 5.0 × 10 －１０ m, and may be less than 4.0 × 10 －１０ It may be less than m.

[0055] As described above, odorants are compounds having polarity. Therefore, by using the adsorbent 11a that can preferentially adsorb polar compounds, the influence of hydrocarbons in the mixture of hydrocarbons, refrigerating machine oil, and odorant that flows into the filter 11 can be suppressed, and the odorant can be efficiently adsorbed.

[0056] The adsorbent 11a used in the filter 11 is not limited to use in the refrigeration cycle apparatus as shown in this embodiment, and can also remove odorants by simply contacting the refrigerant containing the odorant. Therefore, the filter 11 may also be used for applications such as contacting the refrigerant containing the odorant with the adsorbent 11a when disposing of the refrigerant to reduce the odor of the refrigerant. After removing the odorant contained in the refrigerant as shown in this embodiment, the refrigerant may be further contacted with the adsorbent 11a when discharging or recovering the refrigerant outside the closed refrigerant circuit 100. In this way, the odor of the refrigerant can be further suppressed.

[0057] 1, the bypass circuit 9 is included in the closed refrigerant circuit 100 of the refrigeration cycle device, but the bypass circuit 9 may be a deodorizing device that can be attached to the refrigeration cycle device. In this way, by attaching the deodorizing device to the refrigeration cycle device, odorants contained in the refrigerant can be efficiently removed.

[0058] <Odorant Removal Method> Fig. 3 is a flowchart of an odorant removal method in the refrigeration cycle apparatus according to Embodiment 1. In the odorant removal method in the refrigeration cycle apparatus according to Embodiment 1, first, a step (S1) is carried out in which a refrigerant containing an odorant is introduced together with refrigeration oil. In this step (S1), the refrigerant containing an odorant is introduced together with refrigeration oil from the evaporator 7 into the bypass circuit 9 having the filter 11.

[0059] Next, an odorant removal step (S2) is performed. In this step (S2), the odorant is removed from the refrigerant using the filter 11. Specifically, the odorant flows into the filter 11 together with the refrigerant and the refrigeration oil. The filter 11 includes an adsorbent 11a. Therefore, the odorant is adsorbed by the adsorbent 11a. In this manner, the odorant can be efficiently removed.

[0060] <Effects> The odorant removal method according to the present disclosure includes a step (S1) of flowing the refrigerant containing the odorant together with refrigerating machine oil from the evaporator 7 into the bypass circuit 9 having the filter 11, and a step (S2) of removing the odorant using the filter 11 after the flowing step (S1). In the removing step (S2), the odorant flows into the filter 11 together with the refrigerating machine oil.

[0061] According to the odorant removal method, the filter 11 includes the adsorbent 11a containing at least one of silica gel, activated carbon, and synthetic zeolite.

[0062] In this way, the adsorbent 11a can adsorb the odorant contained in the refrigerant and efficiently remove the odorant.

[0063] According to the odorant removal method, the synthetic zeolite is a molecular sieve, and the adsorbent 11a can adsorb the odorant contained in the refrigerant and efficiently remove the odorant.

[0064] According to the odorant removal method, the pore diameter of the adsorbent 11a is 5.0 × 10 －１０ It is less than m.

[0065] In this way, the adsorbent 11a can adsorb the odorant contained in the refrigerant and efficiently remove the odorant.

[0066] According to the odorant removal method, the pore diameter of the adsorbent 11a is 4.0 × 10 －１０ m or less.

[0067] In this way, the adsorbent 11a can selectively adsorb the odorant contained in the refrigerant and efficiently remove the odorant.

[0068] According to the odorant removal method, the refrigerant is propane, and the odorant is tetrahydrothiophene (THT).

[0069] In this way, since tetrahydrothiophene is chemically stable as an odorant, decomposition reactions or corrosion reactions are unlikely to occur within the closed refrigerant circuit 100. Furthermore, since the melting point of tetrahydrothiophene is relatively low at −96° C., solidification is unlikely to occur within the closed refrigerant circuit 100.

[0070] In order to verify the effect of the adsorbent 11a according to the first embodiment as described above, the following test was carried out.

[0071] <Test Subject 1> Table 1 shows the refrigerant and odorant used in this test, as well as the concentration of the odorant relative to the refrigerant. The main component of the refrigerant was a hydrocarbon with 1 to 4 carbon atoms, R-290 (product name: Ecofreeze 290) manufactured by Iwatani Industrial Gases Corporation. The odorant used was tetrahydrothiophene (model number: T0114) manufactured by Tokyo Chemical Industry Co., Ltd. The concentration of the odorant contained in the gaseous refrigerant was 60 ppm by volume.

[0072]

[0073] Table 2 shows the substance names of the adsorbents 11a according to Examples 1 to 6. The adsorbent 11a according to Example 1 is medium-sized granular (blue) silica gel (sold by FUJIFILM Wako Pure Chemical Industries, Ltd.) (salesperson: 192-18305). The adsorbent 11a according to Example 2 is granular activated carbon (brand: Granular Shirasagi) manufactured by Osaka Gas Chemicals Co., Ltd. The adsorbent 11a according to Example 3 is Molecular Sieves 4A 1 / 16 (sold by FUJIFILM Wako Pure Chemical Industries, Ltd.) (salesperson: 137-06085). The adsorbent 11a according to Example 4 is Molecular Sieves 13X 1 / 16 (sold by FUJIFILM Wako Pure Chemical Industries, Ltd.) (salesperson: 131-07085). The adsorbent 11a according to Example 5 is Molecular Sieves 3A 1 / 16 (sold by FUJIFILM Wako Pure Chemical Industries, Ltd.) (salesperson: 134-06095). The adsorbent 11a according to Example 6 is Molecular Sieves 5A 1 / 16 (sold by FUJIFILM Wako Pure Chemical Industries, Ltd.) (salesperson: 130-06075).

[0074] The pore size of activated carbon and silica gel is generally 10.0 × 10 －１０In other words, the pore diameter of each of the adsorbents 11a according to Example 1 and Example 2 is 10.0 × 10 －１０ The pore diameter of the adsorbent 11a according to Example 3 is 4.0 × 10 －１０ The pore diameter of the adsorbent 11a according to Example 4 is 10.0 × 10 －１０ The pore diameter of the adsorbent 11a according to Example 5 is 3.0 × 10 －１０ The pore diameter of the adsorbent 11a according to Example 6 is 5.0 × 10 －１０ m.

[0075]

[0076] <Test Method 1> A Tedlar bag (product number: 1-2711-02) manufactured by AS ONE Corporation was prepared, in which each of the adsorbents 11a according to Examples 1 to 6 was enclosed. The volume of the Tedlar bag was 50 cm ３ Into the Tedlar bag in which each of the adsorbents 11a according to Examples 1 to 6 was sealed, 2000 cm of refrigerant containing an odorant shown in Table 1 was poured. ３ The change in the concentration of the odorant (THT) contained in the refrigerant over time after the odorant-containing refrigerant was filled into the Tedlar bag was evaluated. The concentration of the odorant contained in the gaseous refrigerant was analyzed using a gas chromatograph mass spectrometer (model number: JMS-K9) manufactured by JEOL Ltd.

[0077] <Test result 1>

[0078]

[0079] Table 3 shows the odorant concentration versus elapsed time, whether or not the Tedlar bag contracted, and whether or not the adsorbent 11a generated heat. As shown in Table 3, the effectiveness of removing THT from the odorant was confirmed for all of silica gel, granular activated carbon, and molecular sieves. In the adsorbents 11a of Examples 1 to 6, the odorant concentration was reduced to 1 / 12 or less when the elapsed time was 1 minute. In other words, in the operation to remove the odorant, it can be expected that the effect of removing THT can be obtained within 1 minute after the working fluid is introduced into the filter 11 located in the bypass circuit 9.

[0080] Furthermore, the concentration of the odorant contained in the refrigerant could not be detected at 720 minutes after the elapsed time. In other words, it is expected that the odorant can be removed to an extent that the odor of the refrigerant is undetectable 720 minutes after the working fluid is introduced into the filter 11 disposed in the bypass circuit 9 during the odorant removal operation. In Table 3, "Not Detected" means that the odorant concentration could not be detected using the gas chromatograph mass spectrometer, and also that the odor of THT could not be detected even when the experimenter performed a sensory evaluation of the odor. In other words, the olfactory threshold of THT is 0.6 ppb by volume. Therefore, it is considered that the concentration of the odorant contained in the refrigerant had decreased to approximately 0.6 ppb by volume or below 0.6 ppb by 720 minutes after the elapsed time.

[0081] As shown in Table 3, contraction of the Tedlar bag and heat generation by the adsorbent 11a were confirmed for the adsorbent 11a according to Examples 1, 2, 4, and 6. This means that the refrigerant propane was adsorbed by the adsorbent 11a. The THT concentration decreased in each of the adsorbents 11a according to Examples 1 to 6, indicating that THT was preferentially adsorbed over propane.

[0082] On the other hand, neither contraction of the Tedlar bag nor heat generation of the adsorbent 11a was observed in the adsorbent 11a according to Examples 3 and 5. In other words, propane was not adsorbed by the adsorbent 11a according to Examples 3 and 5. This is thought to be due to the fact that propane is a substance with low polarity, unlike THT, and the pore diameter of the adsorbent 11a is small.

[0083] As described above, the pore diameter of the adsorbent 11a according to Example 3 is 4.0 × 10 －１０ The pore diameter of the adsorbent 11a according to Example 6 is 5.0 × 10 －１０ m. It is believed that THT is selectively adsorbed when the pore diameter of the adsorbent 11a is small. Furthermore, the molecular weight of propane is smaller than that of THT. Therefore, even though the combination of THT and propane is a combination in which THT is thought to have a smaller molecular size, THT was selectively adsorbed by the adsorbent 11a, and it is believed that molecular sieves have the effect of preferentially adsorbing polar substances.

[0084] From the above results, it can be seen that the adsorbents 11a according to Examples 1 to 6 all have the effect of efficiently removing odorants. That is, the adsorbent 11a may contain any of silica gel, activated carbon, and synthetic zeolite. Furthermore, if the synthetic zeolite used as the adsorbent 11a is a molecular sieve, the adsorbent 11a can preferentially adsorb polar substances. Furthermore, if the pore diameter of the adsorbent 11a is 5.0 × 10 －１０ It was found that if the pore diameter of the adsorbent 11a is less than 4.0 × 10 m, THT is selectively adsorbed and the odorant can be efficiently removed. －１０ It was found that if the thickness is 100 μm or less, THT is selectively adsorbed, and the odorant can be removed more efficiently.

[0085] The pore diameter of the adsorbent 11a is 4.0 × 10 －１０ The following test was carried out to examine the mass of the adsorbent 11a and the rate of decrease in odorant concentration when the adsorbent 11a is less than 1 / 2 m.

[0086] <Test Subject 2> Table 4 shows the refrigerant and odorant used in this test, as well as the concentration of the odorant relative to the refrigerant. The main component of the refrigerant was a hydrocarbon with 1 to 4 carbon atoms, R-290 (product name: Ecofreeze 290) manufactured by Iwatani Industrial Gases Corporation. The odorant used was tetrahydrothiophene (model number: T0114) manufactured by Tokyo Chemical Industry Co., Ltd. The concentration of the odorant contained in the gaseous refrigerant was 800 ppm by volume.

[0087]

[0088] The adsorbent 11a used in this test was Molecular Sieves 3A 1 / 16 (sold by FUJIFILM Wako Pure Chemical Industries, Ltd.) (sales source: 134-06095).

[0089] <Test Method 2>

[0090]

[0091] Table 5 shows the amount of adsorbent 11a used and the mass ratio of adsorbent 11a to odorant according to Examples 7 to 11. The mass ratio of adsorbent 11a to odorant is the value obtained by dividing the mass of adsorbent 11a by the mass of odorant contained in the gaseous refrigerant. In other words, in Test Method 2, the mass ratio of adsorbent 11a to odorant is the ratio of the mass of adsorbent 11a to the mass (0.014 g) of odorant (THT). Tedlar bags (product number: 1-2711-04) manufactured by AS ONE Corporation containing each of the adsorbents 11a according to Examples 7 to 11 were prepared. Refrigerants containing the odorants shown in Table 4 were poured into the Tedlar bags containing each of the adsorbents 11a according to Examples 7 to 11 at a flow rate of 4800 cm. ３ The change in the concentration of the odorant (THT) contained in the refrigerant over time after the odorant-containing refrigerant was filled into the Tedlar bag was evaluated. The concentration of the odorant contained in the gaseous refrigerant was analyzed using a gas chromatograph mass spectrometer (model number: JMS-K9) manufactured by JEOL Ltd.

[0092] <Test result 2>

[0093]

[0094] Table 6 shows the rate of decrease in odorant concentration over time, whether or not the Tedlar bag contracted, and whether or not the adsorbent 11a generated heat. As shown in Table 6, it was confirmed that the rate of decrease in THT concentration over the same elapsed time increased as the mass of the adsorbent 11a relative to the mass of THT increased. For the adsorbents 11a according to Examples 8 to 11, when the mass of the adsorbent 11a was 279 times or more relative to the mass of THT, the concentration of the odorant (THT) decreased to 1 / 10 or less at 720 minutes after the elapsed time. Furthermore, for the adsorbents 11a according to Examples 10 and 11, the concentration of the odorant (THT) decreased to 1 / 100 or less at 720 minutes after the elapsed time. On the other hand, for the adsorbent 11a according to Example 7, when the mass of the adsorbent 11a was 140 times the mass of THT, the concentration of the odorant (THT) did not decrease to 1 / 10 or less at 720 minutes after the elapsed time. In the adsorbents 11a according to Examples 7 to 11, contraction of the Tedlar bag and heat generation by the adsorbents 11a were not observed.

[0095] The odor concentration in gas and the odor intensity perceived by humans are explained by the Weber-Fechner law. Therefore, the relationship between the odor index and odor concentration satisfies the following formula (1). In Japan, odor regulations are discussed using the logarithmic function expressed in formula (1).

[0096]

[0097] Here, "odor concentration" refers to the dilution ratio at which the odor of an odorant can no longer be perceived. The odor concentration can be said to be the value obtained by dividing the concentration of an odorant by the olfactory threshold of that odorant (the lowest concentration at which a human can detect the presence of an odorant through olfaction). The odor index is a value obtained by multiplying the common logarithm of the odor concentration by 10. From equation (1), if the concentration of an odorant is reduced to 1 / 10 times, the odor index will decrease by 10. Furthermore, if the concentration of an odorant is reduced to 1 / 100 times, the odor index will decrease by 20.

[0098]

[0099]

[0100] Table 7 shows the six-level odor intensity indication method taken from the "Odor Index Regulation Guidelines" issued by the Ministry of the Environment in March 2001. Table 8 shows the relationship between the odor index and odor intensity taken from the above-mentioned "Odor Index Regulation Guidelines."

[0101] According to Table 8, from the difference between the odor index when the odor intensity is 2.5 and the odor index when the odor intensity is 3.5, it can be seen that a decrease in the odor index of 10 reduces the odor intensity by 1.0 or more. In other words, a decrease in the concentration of odorous substances by 1 / 10 reduces the odor intensity by 1.0 or more. In other words, it can be said that a decrease in the concentration of odorous substances by 1 / 10 results in a clear change in the odor intensity sensed by humans.

[0102] A 1 / 100 reduction in the concentration of odorous substances reduces the odor intensity by 2.0 or more. In other words, a 1 / 100 reduction in the concentration of odorous substances is thought to result in a more pronounced change in the odor intensity sensed by humans.

[0103] From the above, in order to reduce the concentration of odorous substances by 1 / 10, it is possible to make the mass of the adsorbent 11a 279 times or more the mass of the odorant, as shown in Table 6. In this way, the odor intensity is reduced by 1.0 or more. Furthermore, in order to reduce the concentration of odorous substances by 1 / 100, it is possible to make the mass of the adsorbent 11a 1215 times or more the mass of the odorant, as shown in Table 6. In this way, the odor intensity is reduced by 2.0 or more.

[0104] <Operation and Effect> The filter 11 according to the present disclosure is a filter 11 that is attached to a refrigeration cycle device. The filter 11 includes an adsorbent 11a that adsorbs an odorant.

[0105] In this way, by using a deodorizing device and a refrigeration cycle device containing the adsorbent 11a, the odorant contained in the refrigerant can be adsorbed and efficiently removed.

[0106] According to the filter 11, the filter 11 includes the adsorbent 11a containing at least one of silica gel, activated carbon, and synthetic zeolite.

[0107] In this way, the adsorbent 11a can adsorb the odorant contained in the refrigerant and efficiently remove the odorant.

[0108] In the filter 11, the synthetic zeolite is a molecular sieve, and the adsorbent 11a can adsorb the odorant contained in the refrigerant and efficiently remove the odorant.

[0109] According to the filter 11, the pore diameter of the adsorbent 11a is 5.0 × 10 －１０ It is less than m.

[0110] In this way, the adsorbent 11a can adsorb the odorant contained in the refrigerant and efficiently remove the odorant.

[0111] According to the filter 11, the pore diameter of the adsorbent 11a is 4.0 × 10 －１０ m or less.

[0112] In this way, the adsorbent 11a can selectively adsorb the odorant contained in the refrigerant and efficiently remove the odorant.

[0113] According to the odorant removal method, the mass of the adsorbent 11a is 279 times or more the mass of the odorant.

[0114] In this way, the concentration of the odorant can be reduced to 1 / 10 or less, which means that the odor intensity of the refrigerant, which is one of six levels, can be reduced by 1.0 or more.

[0115] According to the odorant removal method, the mass of the adsorbent 11a is 1215 times or more the mass of the odorant.

[0116] In this way, the concentration of the odorant can be reduced to 1 / 100 or less, which means that the odor intensity of the refrigerant, which is one of six levels, can be reduced by 2.0 or more.

[0117] The deodorizing device according to the present disclosure includes a pipe 11c and the filter 11. A refrigerant containing an odorant passes through the pipe 11c. The filter 11 is disposed in the pipe 11c.

[0118] In this way, by attaching a deodorizing device to the refrigeration cycle device, the odorant contained in the refrigerant can be efficiently removed.

[0119] The refrigeration cycle device according to the present disclosure includes the filter 11. In this way, the filter 11 can be used to efficiently remove odorant contained in the refrigerant.

[0120] Embodiment 2. <Configuration of Refrigeration Cycle Apparatus (Refrigerant Circuit)> Fig. 4 is a schematic diagram showing an example of a refrigeration cycle apparatus (closed refrigerant circuit 100) according to embodiment 2. Fig. 4 corresponds to Fig. 1. The refrigeration cycle apparatus shown in Fig. 4 basically has the same configuration as the refrigeration cycle apparatuses shown in Figs. 1 and 2 and can obtain the same effects, but differs in that the odorant in the working fluid is removed by utilizing the difference in boiling point between the odorant and the refrigerant.

[0121] As shown in Fig. 4, the closed refrigerant circuit 100 includes a bypass circuit 9. The bypass circuit 9 is used to remove odorants contained in the refrigerant. The bypass circuit 9 is provided in parallel with a gas pipe 10 that connects the evaporator 7 and the compressor 3. Specifically, the bypass circuit 9 is connected to the gas pipe 10 via a switching mechanism 12 and a switching mechanism 13. The bypass circuit 9 may be provided inside the outdoor unit 1, inside the indoor unit 2, or in extension piping outside the outdoor unit 1 and the indoor unit 2.

[0122] In the odorant removal operation, the switching mechanism 12 and the switching mechanism 13 are operated to cause the working fluid to flow through the bypass circuit 9. Note that in the odorant removal operation, the gas pipe 10 between the switching mechanism 12 and the switching mechanism 13 may be in a closed state or an open state.

[0123] The switching mechanism 12 switches the flow path for the working fluid between the gas pipe 10 connected to the compressor 3 or the bypass circuit 9. In this way, the working fluid flowing from the evaporator 7 flows into the gas pipe 10 connected to the compressor 3 or the bypass circuit 9. The switching mechanism 13 switches the flow path for the working fluid between the gas pipe 10 connected to the evaporator 7 or the bypass circuit 9. In this way, the working fluid flowing from either the evaporator 7 or the bypass circuit 9 flows to the compressor 3.

[0124] The bypass circuit 9 has a switching mechanism 14, a switching mechanism 15, and a filter 11. The switching mechanism 14 and the switching mechanism 15 switch the flow path of the working fluid that has flowed into the bypass circuit 9. During operation to remove odorant, the working fluid that has flowed into the bypass circuit 9 passes through the switching mechanism 14 and the switching mechanism 15.

[0125] The switching mechanism 14 switches the flow path for the working fluid to the pipe 11c in which the filter 11 is disposed, or to a pipe not in which the filter 11 is disposed and which is directly connected to the switching mechanism 15. In this way, the working fluid that has flowed into the bypass circuit 9 flows to the pipe 11c in which the filter 11 is disposed, or to a pipe directly connected to the switching mechanism 15.

[0126] The switching mechanism 15 switches the flow path through which the working fluid flows to the pipe 11c in which the filter 11 is disposed or to a pipe directly connected to the switching mechanism 15. In this way, the working fluid flowing from either the pipe 11c in which the filter 11 is disposed or the pipe directly connected to the switching mechanism 15 flows into the gas pipe 10 via the switching mechanism 15.

[0127] The switching mechanism 14 is disposed at a higher position than the filter 11. On the other hand, the switching mechanism 15 is disposed at a lower position than the filter 11. In this manner, there is a difference in elevation between the switching mechanism 14 and the filter 11 and between the filter 11 and the switching mechanism 15. Therefore, when the working fluid is a gas-liquid two-phase flow, the liquid flows preferentially into the filter 11 due to the difference in density between the gas and the liquid. The liquid refrigerating machine oil circulates within the closed refrigerant circuit 100. Therefore, the refrigerating machine oil is likely to flow into the filter 11. In order to improve the efficiency of gas-liquid separation between the gaseous refrigerant and the liquid refrigerating machine oil containing the odorant, the switching mechanism 14 may be a gas-liquid separator having an opening and closing function.

[0128] At the outlet of the evaporator 7, the refrigerant containing the odorant flows into the bypass circuit 9 in a two-phase gas-liquid state together with the refrigerating machine oil. The boiling point of the odorant is higher than that of the refrigerant. The temperature of the refrigerant at the outlet of the evaporator 7 is between the boiling points of the odorant and the refrigerant. In this way, when the filter 11 is used to remove the odorant from the working fluid, the main component of the refrigerant is concentrated in the gas phase at the outlet of the evaporator 7, and the odorant is concentrated in the liquid phase.

[0129] Liquid odorants are compatible with refrigerating machine oil. The refrigerating machine oil containing the odorants flows into the bypass circuit 9. As a result, the difference in density between the gas and the liquid causes the liquid odorant and refrigerating machine oil to flow into the filter 11. In this way, the odorant can be efficiently removed.

[0130] The state of the main component of the refrigerant and the odorant may be determined by using the saturated vapor pressure of each of the main component of the refrigerant and the odorant.

[0131] The respective states of the main component of the refrigerant and the odorant may be determined from information obtained from measuring instruments provided at the inlet and outlet of the evaporator 7. Specifically, the measuring instruments may measure at least the temperature of the working fluid. By measuring the temperature of the working fluid at the inlet and outlet of the evaporator 7, the vapor pressures of the main component of the refrigerant and the odorant can be calculated from the temperature at the inlet of the evaporator 7. As a result, the degree of superheat of the main component of the refrigerant can be determined from the temperatures at the inlet and outlet of the evaporator 7.

[0132] The measuring instrument may measure the temperature and pressure of the working fluid. By measuring the pressure at the inlet and outlet of the evaporator 7, the vapor pressures of the main component of the refrigerant and the odorant can be directly measured.

[0133] Fig. 5 is a graph showing saturated vapor diagrams of a refrigerant and an odorant. Fig. 6 is a graph showing saturated vapor diagrams of propane and tetrahydrothiophene. In Fig. 5 and Fig. 6, the horizontal axis indicates the temperature (unit: °C) of the refrigerant and the odorant, and the vertical axis indicates the saturated vapor pressure (unit: MPa) of the refrigerant and the odorant. The vertical axis is a common logarithmic scale axis. The horizontal axis is a linear scale axis.

[0134] In Fig. 5, the saturated vapor pressures of the main refrigerant components R-290 (propane), R-1270 (propylene), and R-600a (isobutane) are shown by solid lines, while the saturated vapor pressures of the odorants ethyl mercaptan (EM), tertiary butyl mercaptan (TBM), dimethyl sulfide (DMS), tetrahydrothiophene (THT), and cyclohexene are shown by dotted lines.

[0135] The saturated vapor pressure of the hydrocarbon was calculated using REFPROP version 10.0, which is a refrigerant thermophysical property database software. The saturated vapor pressure of the odorant was calculated by interpolation and extrapolation from values ​​published in the NIST Chemistry WebBook, a database of the National Institute of Standards and Technology (NIST).

[0136] An odorant is used that has a vapor pressure lower than that of the main component of the refrigerant within the temperature range of the refrigerant that can be achieved in the closed refrigerant circuit 100. In this way, when the refrigerant evaporates in the evaporator 7, the odorant is concentrated in a liquid phase, and at least a portion of the odorant is liquefied and separated from the main component of the gaseous refrigerant. The main component of the refrigerant and the odorant used in the refrigeration cycle device may be appropriately selected from Figure 5.

[0137] 6, the saturated vapor pressure of R-290 (propane) as the main component of the refrigerant is shown by a solid line, and the saturated vapor pressure of tetrahydrothiophene (THT) as the odorant is shown by a dotted line.

[0138] As shown in Fig. 6, the saturated vapor pressures of propane and THT are different. Specifically, the saturated vapor pressure of propane is higher than the saturated vapor pressure of THT. Therefore, when the refrigerant used in the refrigeration cycle device is propane and the odorant is THT, if the temperature and pressure of the refrigerant and odorant at the outlet of the evaporator 7 are within region V shown in Fig. 6, THT can be concentrated into a liquid phase. Note that, as shown in Fig. 6, region V is a region sandwiched between the saturated vapor pressure of propane and the saturated vapor pressure of THT.

[0139] For example, if the vapor pressure of the refrigerant at the outlet of the evaporator 7 is 0.1 MPa and the temperature of the refrigerant is between −42° C. and 120° C., the propane will be concentrated in the gas phase and the THT will be concentrated in the liquid phase. Therefore, the liquid odorant will be separated from the gaseous hydrocarbons.

[0140] <Odorant Removal Method> The odorant removal method in the refrigeration cycle apparatus according to the second embodiment basically includes the same steps as the odorant removal method according to the first embodiment shown in FIG.

[0141] First, a step (S1) is performed in which the refrigerant containing odorant is introduced together with the refrigerating machine oil. In this step (S1), the refrigerant containing odorant is introduced together with the refrigerating machine oil from the evaporator 7 into the bypass circuit 9 having the filter 11. In the refrigerant and odorant used in the refrigeration cycle device, the boiling point of the odorant is higher than the boiling point of the refrigerant. Therefore, the temperature of the refrigerant containing odorant at the outlet of the evaporator 7 is controlled to a temperature between the boiling point of the odorant and the boiling point of the refrigerant.

[0142] By doing this, at the outlet of the evaporator 7, the main components of the refrigerant are concentrated in the gas phase, and the odorant is concentrated in the liquid phase. The liquid odorant is compatible with the refrigerating machine oil. That is, a portion of the odorant is liquefied and included in the refrigerating machine oil. The refrigerating machine oil containing the odorant flows into the bypass circuit 9.

[0143] Next, an odorant removal step (S2) is performed. In this step (S2), the odorant is removed from the refrigerant using the filter 11. Specifically, the liquid odorant flows into the filter 11 together with the refrigerating machine oil. The filter 11 contains an adsorbent 11a. Therefore, the liquid odorant is adsorbed by the adsorbent 11a. In this way, the odorant can be efficiently removed.

[0144] <Effects> According to the odorant removal method, the boiling point of the odorant is higher than the boiling point of the refrigerant. In the inflow step (S1), the temperature of the refrigerant containing the odorant at the outlet of the evaporator 7 is between the boiling points of the odorant and the refrigerant.

[0145] By doing this, the main components of the refrigerant are concentrated in the gas phase at the outlet of the evaporator 7, and the odorant is concentrated in the liquid phase. The liquid odorant is compatible with the refrigerating machine oil. That is, a portion of the odorant is liquefied and included in the refrigerating machine oil. The refrigerating machine oil containing the odorant flows into the bypass circuit 9. As a result, the amount of odorant removed by the refrigeration cycle device is increased. As a result, the amount of odorant that can be removed is increased compared to when refrigerating machine oil does not flow into the bypass circuit 9.

[0146] Embodiment 3. <Odorant Removal Method> Figure 7 is a schematic diagram showing an example of an odorant removal method according to embodiment 3. First, a step of preparing a refrigeration cycle device is carried out. The odorant removal method according to embodiment 3 was carried out using a commercially available home room air conditioner as the refrigeration cycle device. For example, a commercially available home room air conditioner manufactured by Mitsubishi Electric Corporation was used. The model number of the indoor unit 2 included in the refrigeration cycle device is MSZ-RW35VG-E1. The model number of the outdoor unit 1 included in the refrigeration cycle device is MUZ-RW35VGHZ-E1.

[0147] Next, a step of sealing a refrigerant and an odorant into the refrigeration cycle device was carried out. Specifically, 390 g of R-290 was sealed as the main component of the refrigerant into the closed refrigerant circuit 100 of the refrigeration cycle device. 0.625 g of THT (1600 mass ppm relative to the mass of the refrigerant) was sealed as a sulfur-based odorant into the closed refrigerant circuit 100 of the refrigeration cycle device. 300 g of commercially available polyalkylene glycol was sealed into the compressor 3.

[0148] Next, a step of collecting the refrigerant in the outdoor unit 1 was carried out. Specifically, after the refrigeration cycle device (household room air conditioner) was operated, the refrigerant was collected in the outdoor unit 1 by pumping down.

[0149] Next, a process of installing the deodorizing device in the refrigeration cycle device was carried out. Specifically, a service port (not shown) of the outdoor unit 1 was connected to the inlet of the oil separator 16 with a hose. The oil separator 16 and the hose may be commercially available. Next, the outlet of the oil separator 16 was connected to the inlet of the switching mechanism 17 with a hose. The switching mechanism 17 has two outlets. Each of the two outlets was connected to the inlet of the filter 11 and the collection container 20. The outlet of the filter 11 was connected to the collection container 19. 345 g of molecular sieves 3A 1 / 16 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 134-06095) was enclosed in the filter 11 as the adsorbent 11a.

[0150] Next, the odorant removal process was carried out. Specifically, the refrigerant was released together with the refrigerating machine oil from the service port. The oil separator 16 separated the refrigerant from the refrigerating machine oil. The refrigerant separated from the refrigerating machine oil was collected in the recovery container 19 and the recovery container 20 by operating the switching mechanism 17. That is, the refrigerant that passed through the filter 11 was collected in the recovery container 19. On the other hand, the refrigerant that did not pass through the filter 11 was collected in the recovery container 20.

[0151] After the refrigerant was released, the odors of the refrigerant collected in recovery containers 19 and 20 were checked. Five testers checked the odors of the refrigerant using their sense of smell. As a result, the refrigerant collected in recovery container 20 had a distinct THT odor. On the other hand, the refrigerant that passed through filter 11 and was collected in recovery container 19 was odorless. This was because the THT was removed by the adsorbent 11a of filter 11.

[0152] In this way, it was confirmed that the use of the adsorbent 11a effectively removed the odorant from the refrigerant. In the odorant removal method according to the third embodiment, the refrigerant was collected through the service port of the outdoor unit 1, but it may be collected from another location. Furthermore, the oil separator 16 does not need to be provided between the outdoor unit 1 and the switching mechanism 17.

[0153] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The basic scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0154] 1 outdoor unit, 2 indoor unit, 3 compressor, 4 condenser, 5 outdoor blower, 6 expansion valve, 7 evaporator, 8 indoor blower, 9 bypass circuit, 10 gas pipe, 11 filter, 11a adsorbent, 11b filtration filter, 11c pipe, 12, 13, 14, 15, 17 switching mechanism, 16 oil separator, 19, 20 recovery container, 100 closed system refrigerant circuit, V region.

Claims

1. A method for removing an odorant, comprising: a step of flowing a refrigerant containing an odorant together with refrigeration oil from an evaporator into a bypass circuit having a filter; and a step of removing the odorant using the filter after the flowing step, wherein in the removing step, the odorant flows into the filter together with the refrigeration oil.

2. The odorant removal method according to claim 1, wherein the filter includes an adsorbent containing at least one of silica gel, activated carbon, and synthetic zeolite.

3. The odorant removal method according to claim 2, wherein the synthetic zeolite is a molecular sieve.

4. The pore diameter of the adsorbent is 5.0 x 10 －１０ The odorant removal method according to claim 2 or 3, wherein the average particle diameter is less than m.

5. The pore diameter of the adsorbent is 4.0 x 10 －１０ The odorant removal method according to any one of claims 2 to 4, wherein the average molecular weight of the odorant is 1000 or less.

6. An odorant removal method according to any one of claims 2 to 5, wherein the mass of the adsorbent is 279 times or more the mass of the odorant.

7. An odorant removal method according to any one of claims 2 to 6, wherein the mass of the adsorbent is 1,215 times or more the mass of the odorant.

8. An odorant removal method according to any one of claims 1 to 7, wherein the refrigerant is propane and the odorant is tetrahydrothiophene.

9. An odorant removal method described in any one of claims 1 to 8, wherein the boiling point of the odorant is higher than the boiling point of the refrigerant, and in the flowing step, the temperature of the refrigerant containing the odorant at the outlet of the evaporator is a temperature between the boiling point of the odorant and the boiling point of the refrigerant.

10. A filter to be attached to a refrigeration cycle device, the filter including an adsorbent that adsorbs an odorant.

11. The filter of claim 10, wherein the adsorbent comprises at least one of silica gel, activated carbon, and synthetic zeolite.

12. The filter of claim 11, wherein the synthetic zeolite is a molecular sieve.

13. The pore size of the adsorbent is 5.0 x 10 －１０ 13. A filter according to any one of claims 10 to 12, wherein the .lambda.

14. The pore size of the adsorbent is 4.0 x 10 －１０ 14. The filter of claim 10, wherein the .lambda.

15. A deodorizing device comprising: a pipe through which a refrigerant containing the odorant passes; and a filter according to any one of claims 10 to 14, which is disposed in the pipe.

16. A refrigeration cycle device comprising a filter according to any one of claims 10 to 14.

Images