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

[Technical Field]

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

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

[0003] [Patent Document 1] International Publication No. 2021 / 166028 Summary of the Invention [Problem to be solved by the invention]

[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. [Means for solving the problem]

[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. [Effects of the Invention]

[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. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing an example of a refrigeration cycle device (closed refrigerant circuit) according to a first embodiment. [Figure 2] 1 is a schematic cross-sectional view of a filter according to a first embodiment. [Figure 3] 3 is a flowchart of an odorant removal method in the refrigerant cycle apparatus according to the first embodiment. [Figure 4] FIG. 10 is a schematic diagram showing an example of a refrigeration cycle device (closed refrigerant circuit) according to a second embodiment. [Figure 5] 1 is a graph showing saturated vapor diagrams of a refrigerant and an odorant. [Figure 6] 1 is a graph showing saturated vapor diagrams of propane and tetrahydrothiophene. [Figure 7] FIG. 10 is a schematic diagram showing an example of an odorant removal method according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[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] Embodiment 1 <Configuration of refrigeration cycle device (refrigerant circuit)> FIG. 1 is a schematic diagram showing an example of a refrigeration cycle device (closed refrigerant circuit 100) according to the first embodiment.

[0014] The refrigeration cycle device is, for example, a refrigeration cycle device for air conditioning, and as shown in Fig. 1, mainly comprises 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 fan 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 fan 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 the 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] Refrigeration oil is disposed inside the compressor 3. The refrigeration oil maintains the lubrication of the sliding parts of the compressor 3. The refrigeration 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 refrigeration oil circulates within the closed refrigerant circuit 100 together with the refrigerant. Note that a mixture of the refrigerant containing the odorant and the refrigeration oil is used as the 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 the absorption or release of heat. 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 the absorption or release of heat.

[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, for example.

[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 to either 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 either 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 to either 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 includes 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 a molecular sieve. 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] Each of the switching mechanisms 12 and 13 may be provided with a flow rate adjusting mechanism inside or before or after 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 components of the refrigerant excluding the odorant and impurities (air, moisture, by-products that may be mixed in during the synthesis and refinement of the refrigerant compound, etc.). 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 constituent materials of the refrigerant.

[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 them (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 an extremely 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, a refrigerant in a mixture of hydrocarbons having 1 to 4 carbon atoms and halogenated hydrocarbons may be filled into the closed refrigerant circuit 100. 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] Halogenated hydrocarbons include, for example, 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 1 to 4 carbon atoms, the flammability of the refrigerant can be reduced.

[0044] The odorant may have a unique odor. Because the odorant has a unique 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 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 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. If the odorant is contained in the refrigerant, the cooling performance of the refrigerant's main components will decrease. 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 decreasing 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 oxygenated oil and a hydrocarbon oil. Examples of the oxygenated oil include polyalkylene 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 refrigeration 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 5mm 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] That is, 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 refinement 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 refrigeration oil may contain, as 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 additives in the oil, the additives in the oil may be prevented from precipitating when the temperature of the working fluid in the expansion valve 6 drops.

[0054] The adsorbent 11a filled in the filter 11 is a substance capable of adsorbing odorants due to the porous structure and metal cations on its surface. The pore size 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 size of the adsorbent 11a is 5.0 × 10 -10 m, and may be less than 4.0 x 10 -10 It may be less than m.

[0055] As described above, odorants are compounds with polarity. Therefore, by using the adsorbent 11a that can preferentially adsorb polar compounds, the influence of hydrocarbons in the mixture of hydrocarbons, refrigeration 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, but 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] <How to remove odorant> 3 is a flowchart of an odorant removal method in a refrigeration cycle apparatus according to Embodiment 1. In the odorant removal method in a refrigeration cycle apparatus according to Embodiment 1, first, a step (S1) is performed in which a refrigerant containing an odorant is caused to flow together with refrigeration oil. In this step (S1), the refrigerant containing an odorant is caused to flow from the evaporator 7 into a bypass circuit 9 having a filter 11, together with refrigeration oil.

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

[0060] <Action and effect> 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 a bypass circuit 9 having a 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. In this way, 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] [Table 1]

[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.) (product number: 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.) (product number: 137-06085). The adsorbent 11a according to Example 4 is Molecular Sieves 13X 1 / 16 (sold by FUJIFILM Wako Pure Chemical Industries, Ltd.) (product number: 131-07085). The adsorbent 11a according to Example 5 is Molecular Sieves 3A 1 / 16 (sold by 134-06095) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. The adsorbent 11a according to Example 6 is Molecular Sieves 5A 1 / 16 (sold by 130-06075) manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.

[0074] The pore size of activated carbon and silica gel is generally 10.0 × 10 -10 In 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] [Table 2]

[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 cm3 The refrigerant containing the odorant shown in Table 1 was poured into a Tedlar bag in which each of the adsorbents 11a according to Examples 1 to 6 was sealed, at a rate of 2000 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.

[0077] <Test result 1>

[0078] [Table 3]

[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 according to Examples 1 to 6, the odorant concentration was reduced to 1 / 12 or less when one minute had elapsed. In other words, in the operation for removing the odorant, it can be expected that the effect of removing THT can be obtained within one minute after the working fluid is introduced into the filter 11 disposed 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 the extent that the odor of the refrigerant is undetectable 720 minutes after the working fluid is introduced into the filter 11 located in the bypass circuit 9 during 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 believed 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, in the adsorbent 11a according to Examples 1, 2, 4, and 6, contraction of the Tedlar bag and heat generation in the adsorbent 11a were confirmed. This means that the refrigerant propane was adsorbed by the adsorbent 11a. The THT concentration decreased in all 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 thought that if the pore diameter of the adsorbent 11a is small, THT is selectively adsorbed. In addition, the molecular weight of propane is smaller than that of THT. Therefore, in the combination of THT and propane, the molecular size of THT is smaller than that of propane. bigAlthough this is a combination that is considered unlikely, THT was selectively adsorbed onto the adsorbent 11a, which suggests 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 odorants can be efficiently removed. -10 It was found that if the adsorption density is less than m, THT is selectively adsorbed, and odorants 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 equal to or less than 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] [Table 4]

[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] [Table 5]

[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. 4800 cm of refrigerant containing the odorant shown in Table 4 was poured into the Tedlar bags containing each of the adsorbents 11a according to Examples 7 to 11. 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] [Table 6]

[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 increased relative to the mass of THT. 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. 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. 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. In the adsorbents 11a according to Examples 7 to 11, contraction of the Tedlar bag and heat generation in 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]

number

[0097] Here, "odor concentration" refers to the dilution ratio at which the odorant's odor can no longer be detected. 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 the 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, the odor index will decrease by 10. Furthermore, if the concentration of an odorant is reduced to 1 / 100, the odor index will decrease by 20.

[0098] [Table 7]

[0099] [Table 8]

[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 perceived by humans.

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

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

[0104] <Action 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] According to the filter 11, the synthetic zeolite is a molecular sieve. In this way, 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 odorant concentration 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 odorant concentration 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 above-mentioned filter 11. A refrigerant containing an odorant passes through the pipe 11c. The above-mentioned 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 described above. In this way, the filter 11 can be used to efficiently remove the odorant contained in the refrigerant.

[0120] Embodiment 2 <Configuration of refrigeration cycle device (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 to either 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 either 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 to either 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 in which the filter 11 is not 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 that is 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 arranged 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 arranged 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 way, 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 tends to flow into the filter 11. 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 odorant is compatible with refrigeration oil. Refrigeration oil containing the odorant flows into the bypass circuit 9. As a result, the difference in density between the gas and the liquid causes the liquid odorant and refrigeration 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 pressure of the main component of the refrigerant and the odorant can be measured directly.

[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 Figs. 5 and 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 Figure 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, and 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 hydrocarbons was calculated using REFPROP version 10.0, a refrigerant thermophysical property database software, and the saturated vapor pressure of odorants was calculated by interpolation and extrapolation from values ​​listed 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 becomes 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] In Fig. 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] <How to remove odorant> 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, 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. In other words, 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, a step (S2) of removing the odorant is performed. In this step (S2), the odorant is removed from the refrigerant using filter 11. Specifically, the liquid odorant flows into filter 11 together with refrigeration oil. Filter 11 contains adsorbent 11a. Therefore, the liquid odorant is adsorbed by adsorbent 11a. In this way, the odorant can be efficiently removed.

[0144] <Action and effect> According to the odorant removal method, the boiling point of the odorant is higher than that 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 increases. As a result, the amount of odorant that can be removed increases compared to when refrigerating machine oil does not flow into the bypass circuit 9.

[0146] Embodiment 3 <How to remove odorant> FIG. 7 is a schematic diagram showing an example of an odorant removal method according to the third embodiment. First, a step of preparing a refrigeration cycle device is carried out. The odorant removal method according to the third embodiment 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 with respect 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 and the inlet of the oil separator 16 were connected by a hose. The oil separator 16 and the hose may be commercially available. Next, the outlet of the oil separator 16 and the inlet of the switching mechanism 17 were connected by 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 odor of the refrigerant collected in collection container 19 and collection container 20 was checked. The odor of the refrigerant was checked by five testers using their sense of smell. As a result, the refrigerant collected in collection container 20 had a distinct THT odor. On the other hand, the refrigerant that passed through filter 11 and was collected in collection container 19 was odorless. This was because the THT was removed by 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. In addition, 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] (Appendix 1) a step of flowing the odorant-containing refrigerant together with refrigerating machine oil from the evaporator into a bypass circuit having a filter; and removing the odorant using the filter after the inflow step, In the removing step, The odorant removal method, wherein the odorant flows into the filter together with the refrigeration oil. (Appendix 2) 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. (Appendix 3) 3. The odorant removal method according to claim 2, wherein the synthetic zeolite is a molecular sieve. (Appendix 4) The pore size of the adsorbent is 5.0 × 10 -10 The odorant removal method according to claim 2 or 3, wherein the odorant removal rate is less than m. (Appendix 5) The pore size of the adsorbent is 4.0 × 10 -10 5. The odorant removal method according to any one of claims 2 to 4, wherein the odorant removal rate is 100 m or less. (Appendix 6) 6. The 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. (Appendix 7) 7. The odorant removal method according to any one of claims 2 to 6, wherein the mass of the adsorbent is 1215 times or more the mass of the odorant. (Appendix 8) the refrigerant is propane; 8. The odorant removal method according to any one of claims 1 to 7, wherein the odorant is tetrahydrothiophene. (Appendix 9) the boiling point of the odorant is higher than the boiling point of the refrigerant, In the step of infusing, An odorant removal method according to any one of claims 1 to 8, wherein the temperature of the refrigerant containing the odorant at the outlet of the evaporator is between the boiling point of the odorant and the boiling point of the refrigerant. (Appendix 10) A filter to be attached to a refrigeration cycle device, The filter includes an adsorbent that adsorbs an odorant. (Appendix 11) 11. The filter of claim 10, wherein the adsorbent comprises at least one of silica gel, activated carbon, and synthetic zeolite. (Appendix 12) 12. The filter of claim 11, wherein the synthetic zeolite is a molecular sieve. (Appendix 13) The pore size of the adsorbent is 5.0 × 10 -10 13. The filter of any one of claims 10 to 12, wherein the filter length is less than m. (Appendix 14) The pore size of the adsorbent is 4.0 × 10 -10 10. The filter of claim 3, wherein the filter width is less than or equal to m. (Appendix 15) The refrigerant used in the refrigeration cycle device is propane, 15. The odorant removal method according to any one of claims 10 to 14, wherein the odorant is tetrahydrothiophene. (Appendix 16) a pipe through which a refrigerant containing the odorant passes; A deodorizing device comprising: a filter according to any one of Supplementary Note 10 to Supplementary Note 15, arranged in the pipeline. (Appendix 17) A refrigeration cycle device comprising the filter according to any one of Supplementary Note 10 to Supplementary Note 15. [Explanation of symbols]

[0155] 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 piping, 12, 13, 14, 15, 17 switching mechanism, 16 oil separator, 19, 20 recovery container, 100 closed system refrigerant circuit, V region.

Claims

1. Odorants (except ammonia) are fed from the evaporator to a bypass circuit with a filter. a step of introducing a refrigerant containing the refrigerant into the refrigerant tank together with refrigeration oil; and removing the odorant using the filter after the inflow step, In the removing step, The odorant removal method, wherein the odorant flows into the filter together with the refrigeration oil.

2. The odorant is a polar compound, The odorant removal method according to claim 1 , wherein the filter contains a substance that preferentially adsorbs the polar compounds.

3. The material constituting the odorant includes at least one selected from mercaptans, sulfides, thiophenes, acrylic acid esters, amines, pyrazines, and norbornenes; the mercaptans are any of methyl mercaptan, ethyl mercaptan, normal propyl mercaptan, isopropyl mercaptan, and tertiary butyl mercaptan; the sulfides are any of dimethyl sulfide, diethyl sulfide, and methyl ethyl sulfide; The thiophene is tetrahydrothiophene, The acrylic ester is either methyl acrylate or ethyl acrylate, the amines are any of methylamine, dimethylamine, and trimethylamine; The pyrazine is methylethylpyrazine, 3. The odorant removal method according to claim 2, wherein the norbornene is 5-ethylidene-2-norbornene.

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

5. 5. The odorant removal method according to claim 4, wherein the synthetic zeolite is a molecular sieve.

6. The pore size of the adsorbent is 5.0 × 10 －１０ The odorant removal method according to claim 4, wherein the average molecular weight is less than m.

7. The pore size of the adsorbent is 4.0 × 10 －１０ The odorant removal method according to claim 4, wherein the odorant removal rate is 100 m or less.

8. The odorant removal method according to claim 4, wherein the mass of the adsorbent is 279 times or more the mass of the odorant.

9. The odorant removal method according to claim 4, wherein the mass of the adsorbent is 1215 times or more the mass of the odorant.

10. the refrigerant is propane; The odorant removal method according to claim 2, wherein the odorant is tetrahydrothiophene.

11. the boiling point of the odorant is higher than the boiling point of the refrigerant, In the step of infusing, 11. The odorant removal method according to claim 1, wherein the temperature of the refrigerant containing the odorant at the outlet of the evaporator is between the boiling point of the odorant and the boiling point of the refrigerant.

12. The bypass circuit is connected in parallel to the circulation circuit through which the refrigerant circulates, The odorant removal method according to claim 1 , wherein the refrigerant flows from the circulation circuit into the bypass circuit during an operation to remove the odorant.

13. A filter to be attached to a refrigeration cycle device, the filter includes an adsorbent that adsorbs an odorant (excluding ammonia); The odorant is a compound having polarity, The adsorbent preferentially adsorbs the polar compounds.

14. The material constituting the odorant includes at least one selected from mercaptans, sulfides, thiophenes, acrylic acid esters, amines, pyrazines, and norbornenes; the mercaptans are any of methyl mercaptan, ethyl mercaptan, normal propyl mercaptan, isopropyl mercaptan, and tertiary butyl mercaptan; the sulfides are any of dimethyl sulfide, diethyl sulfide, and methyl ethyl sulfide; The thiophene is tetrahydrothiophene, The acrylic ester is either methyl acrylate or ethyl acrylate, the amines are any of methylamine, dimethylamine, and trimethylamine; The pyrazine is methylethylpyrazine, 14. The filter according to claim 13, wherein the norbornene is 5-ethylidene-2-norbornene.

15. 14. The filter of claim 13, wherein the adsorbent comprises at least one of silica gel, activated carbon, and synthetic zeolite.

16. 16. The filter of claim 15, wherein the synthetic zeolite is a molecular sieve.

17. The pore size of the adsorbent is 5.0 × 10 －１０ 14. The filter of claim 13, wherein the .lambda.

18. The pore size of the adsorbent is 4.0 × 10 －１０ 14. The filter of claim 13, wherein the .lambda.

19. The refrigerant used in the refrigeration cycle device is propane, 14. The filter of claim 13, wherein the odorant is tetrahydrothiophene.

20. a pipe through which a refrigerant containing the odorant passes; A deodorizing device comprising: a filter according to any one of claims 13 to 19, which is arranged in the pipe.

21. A refrigeration cycle device comprising the filter according to any one of claims 13 to 19.

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