Outdoor unit of air conditioner

Abstract

To provide an outdoor unit of an air conditioner capable of effectively suppressing stagnation and diffusion of a flammable refrigerant in a machine chamber for a long period of time when the flammable refrigerant leaks.SOLUTION: An outdoor unit 100 of an air conditioner comprises a compressor 2 that compresses a refrigerant, a heat exchanger 4 that exchanges heat between the refrigerant and outside air, and a blower fan 8 that blows outside air to the heat exchanger. The refrigerant is a flammable refrigerant (for example, propane, ethane, isobutane, or the like). A machine chamber 120 in which the compressor 2 is installed, comprises a removable or replenishable adsorbent (for example, activated carbon, zeolite, or the like) that adsorbs the flammable refrigerant. The adsorbent may be integrated with a soundproof material surrounding the compressor 2, housed in a removable container installed in the machine chamber 120, or applied onto an inner surface of the machine chamber 120.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an outdoor unit of an air conditioner that uses a flammable refrigerant. [Background technology]

[0002] In recent years, there has been a demand for further reductions in the global warming potential (GWP) of refrigerants for refrigeration and air conditioning equipment in order to prevent global warming. Refrigerants with low GWP include natural refrigerants such as carbon dioxide, ammonia, and hydrocarbons. Hydrocarbon-based refrigerants such as propane and isobutane can be used in a pressure range similar to that of commonly used refrigerants, so a switch from conventional refrigerants to these refrigerants is being considered.

[0003] While hydrocarbon refrigerants can achieve operating pressures similar to those of conventional refrigerants, they are flammable and pose a risk of ignition if they leak from refrigerant piping, etc. If flammable refrigerant that has leaked from refrigerant piping, etc., accumulates or diffuses inside the outdoor unit, there is a risk of it igniting when electrical components are activated, etc. To mitigate this risk, measures to capture leaked flammable refrigerant are being considered.

[0004] Patent Document 1 describes a refrigeration unit in which a refrigerant adsorption material is disposed on at least a portion of the inner wall surface of the refrigeration unit, which has a refrigeration circuit formed by sequentially connecting a compressor, a condenser, a pressure reducer, and an evaporator with a refrigerant pipe, or on at least a portion of the outer surface of the refrigerant pipe located outside the unit. Patent Document 1 also describes a refrigeration unit in which a refrigerant adsorption material is disposed on the inner wall surface of a machine chamber of an outdoor unit. Examples of the refrigerant adsorption material include powder, granules, fibers, and sheets. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-105003 Summary of the Invention [Problem to be solved by the invention]

[0006] There is a need for long-term measures to reduce the risk of flammable refrigerants leaking from refrigerant pipes in the outdoor units of air conditioners. Outdoor units have many welds connecting refrigerant pipes to compressors, valves, etc., and many joints between dissimilar metals, such as those connecting refrigerant pipes to heat transfer tubes in heat exchangers. These joints are prone to contact with outside air, making them prone to the formation of corrosion holes that penetrate the walls of the refrigerant pipes and the progression of corrosion that can lead to the rupture of the refrigerant pipes.

[0007] In particular, the machine room inside the outdoor unit, where the compressor and other components are installed, is a semi-enclosed space with many welds and joints between dissimilar metals, and is close to the electrical component box and fan motor, making it a place where there is a high risk of leaked flammable refrigerant accumulating and igniting. Therefore, there is a need for technology that can effectively prevent flammable refrigerant from accumulating and spreading in the machine room of the outdoor unit over the long period from the time the air conditioner is installed until it is in use.

[0008] In Patent Document 1, a refrigerant adsorption material molded into a powder, granules, fiber, sheet, or other form is disposed on at least a portion of the inner wall surface of a refrigeration unit, at least a portion of the outer surface of a refrigerant pipe outside the unit, or the inner wall surface of a machine room of an outdoor unit. Patent Document 1 states that it is preferable to provide a film-like, sheet-like, or other layer on the refrigerant adsorption material disposed on the inner surface of the outdoor unit or the outer surface of the refrigerant pipe for purposes such as waterproofing and fixation.

[0009] However, if the refrigerant adsorption material is directly disposed on the inner wall surface, the adsorption capacity of the refrigerant adsorption material may be significantly depleted by the time of a flammable refrigerant leak. Furthermore, condensation and other factors may inhibit refrigerant adsorption onto the refrigerant adsorption material. If a film or sheet-like layer is placed on the refrigerant adsorption material, contact of the refrigerant with the refrigerant adsorption material and replenishment of the refrigerant adsorption material are likely to be hindered. Conventional technologies have problems such as difficulty in replacing or replenishing the refrigerant adsorption material and poor breathability, making it difficult to achieve long-term collection capacity or the high collection speed required in the event of a leak.

[0010] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an outdoor unit for an air conditioner that can effectively prevent stagnation and diffusion of flammable refrigerant in a machine room for a long period of time in the event of a flammable refrigerant leak. [Means for solving the problem]

[0011] In order to solve the above problems, the outdoor unit of an air conditioner according to the present invention is an outdoor unit of an air conditioner that includes a compressor that compresses a refrigerant, a heat exchanger that exchanges heat between the refrigerant and outside air, and a blower fan that blows outside air to the heat exchanger, wherein the refrigerant is a flammable refrigerant, and a removable or replenishable adsorbent that adsorbs the flammable refrigerant is provided in a machine room in which the compressor is installed. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an outdoor unit for an air conditioner that can effectively prevent stagnation and diffusion of flammable refrigerant in a machine room for a long period of time in the event of a flammable refrigerant leak. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram showing the overall configuration of an air conditioner. [Figure 2] FIG. 1 is a diagram illustrating an example of a refrigerant circuit of an air conditioner. [Figure 3] FIG. 2 is a front view of the outdoor unit of the air conditioner, showing the structure of the outdoor unit. [Figure 4] FIG. 2 is an exploded view of the outdoor unit of the air conditioner, showing the structure of the outdoor unit. [Figure 5] FIG. 10 is a diagram showing an example of a configuration in which an adsorbent is installed. [Figure 6] FIG. 10 is a diagram showing an example of a configuration in which an adsorbent is installed. [Figure 7] FIG. 10 is a diagram showing an example of a configuration in which an adsorbent is installed. [Figure 8] FIG. 10 is a diagram showing an example of a configuration in which an adsorbent is installed. [Figure 9] FIG. 2 is a diagram showing the structure of the bottom of the outdoor unit of the air conditioner. [Figure 10] FIG. 10 is a diagram showing an example of a configuration in which an adsorbent is installed. [Figure 11] FIG. 10 is a diagram showing an example of a configuration in which an adsorbent is installed. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an outdoor unit of an air conditioner according to one embodiment of the present invention will be described. Note that common components in the following drawings will be given the same reference numerals, and duplicated explanations will be omitted.

[0015] Fig. 1 is a diagram showing the overall configuration of an air conditioner. As shown in Fig. 1, the air conditioner 1 comprises an outdoor unit 100 that is installed outdoors, and an indoor unit 200 that is installed on a wall or the like inside the room. The outdoor unit 100 and the indoor unit 200 are connected to each other via connection piping 300 through which refrigerant piping and electrical wiring pass. A remote control 400 is also provided as a separate unit. The remote control 400 is operated by a user and sends operation signals to the indoor unit 200 for operation.

[0016] The air conditioner 1 is a device that adjusts the temperature and humidity of a space by blowing out heated air, cooled air, dehumidified air, etc. A refrigerant circulates between the outdoor unit 100 and the indoor unit 200 through refrigerant piping. In the outdoor unit 100, heat exchange occurs between the refrigerant and outside air. In the indoor unit 200, heat exchange occurs between the refrigerant and indoor air. The indoor unit 200 exchanges heat between the air drawn in from inside the room and the refrigerant, and then blows the air out into the room to adjust the temperature and humidity inside the room.

[0017] Fig. 2 is a diagram showing an example of a refrigerant circuit of an air conditioner. As shown in Fig. 2, the air conditioner 1 is equipped with a refrigerant circuit 10 that constitutes a heat pump. The refrigerant circuit 10 executes a cooling cycle and a heating cycle. The refrigerant circuit 10 is made up of devices such as a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an expansion valve 5, an indoor heat exchanger 6, and an accumulator 7, as well as refrigerant piping that circulates the refrigerant.

[0018] These devices are connected to each other via refrigerant piping. The devices and refrigerant piping form a refrigerant circuit 10, which is a closed circuit through which refrigerant circulates, between the outdoor unit 100 and the indoor unit 200. Refrigerant is sealed in the refrigerant circuit 10 when the air conditioner 1 is installed or during maintenance. The refrigerant circulates through the refrigerant circuit 10 and mediates heat exchange to implement the cooling cycle and the heating cycle.

[0019] An outdoor blower fan 8 is installed near the outdoor heat exchanger 4. An indoor blower fan 9 is installed near the indoor heat exchanger 6. The compressor 2, four-way valve 3, outdoor heat exchanger 4, expansion valve 5, accumulator 7, and outdoor blower fan 8 are housed in an outdoor unit 100. The indoor heat exchanger 6 and indoor blower fan 9 are housed in an indoor unit 200.

[0020] The compressor 2 is a device that compresses a refrigerant, sucking in a low-pressure gas refrigerant, compressing it adiabatically, and discharging it as a high-pressure gas refrigerant. The compressor 2 variably controls the amount of refrigerant circulated by inverter control. The compressor 2 can be of any suitable type, such as a scroll type, piston type, rotary type, screw type, or centrifugal type.

[0021] The four-way valve 3 has four ports and changes the flow path between the ports depending on the operating mode, such as cooling operation or heating operation, of the air conditioner 1. The four-way valve 3 switches the circulation direction in the refrigerant circuit 10 of the refrigerant discharged from the compressor 2.

[0022] The outdoor heat exchanger 4 is a heat exchanger that exchanges heat between the refrigerant and outside air, and functions as a condenser during cooling operation and as an evaporator during heating operation. The outdoor blower fan 8 blows outside air to the outdoor heat exchanger 4 to promote heat exchange. The outdoor blower fan 8 is composed of a propeller fan. The expansion valve 5 is a valve with an adjustable opening, and functions as a pressure reducer during heating operation.

[0023] The indoor heat exchanger 6 is a heat exchanger that exchanges heat between the refrigerant and the indoor air, and functions as an evaporator during cooling operation and as a condenser during heating operation. The indoor blower fan 9 blows air into the indoor heat exchanger 6 to promote heat exchange, and also blows the air that has exchanged heat with the refrigerant into the room. The indoor blower fan 9 is composed of a cylindrical cross-flow fan.

[0024] The accumulator 7 is a tank-shaped device that separates the refrigerant gas from the liquid refrigerant, and stores the liquid refrigerant contained in the refrigerant gas. By removing the liquid refrigerant that has not yet evaporated from the refrigerant gas on the suction side of the compressor 2, liquid compression by the compressor 2, which can lead to abnormal noise and breakdowns, is prevented.

[0025] Cooling operation of the air conditioner 1 is performed as follows. High-temperature, high-pressure refrigerant gas is adiabatically compressed in the compressor 2 and sent to the outdoor heat exchanger 4 through the four-way valve 3. The high-temperature, high-pressure refrigerant gas is condensed into liquid refrigerant through heat exchange with outside air in the outdoor heat exchanger 4, which functions as a condenser. The liquid refrigerant is decompressed and expanded in the expansion valve 5, becoming a low-temperature, low-pressure, two-phase gas-liquid refrigerant containing a small amount of refrigerant gas.

[0026] The low-temperature, low-pressure, two-phase gas-liquid refrigerant is sent to the indoor heat exchanger 6. The two-phase gas-liquid refrigerant evaporates through heat exchange with the indoor air in the indoor heat exchanger 6, which functions as an evaporator, and becomes a low-temperature, low-pressure gas refrigerant. The low-temperature, low-pressure gas refrigerant passes through the four-way valve 3, and after the liquid refrigerant is separated in the accumulator 7, it returns to the compressor 2. The indoor air loses heat through heat exchange with the refrigerant in the indoor heat exchanger 6, which also functions as an evaporator. This cycle is repeated to cool the room.

[0027] Heating operation of the air conditioner 1 is performed in a cycle reverse to that of cooling operation. The high-temperature, high-pressure refrigerant gas discharged after adiabatic compression by the compressor 2 is sent to the indoor heat exchanger 6 by switching the four-way valve 3. The high-temperature, high-pressure refrigerant gas is cooled by heat exchange with the indoor air in the indoor heat exchanger 6, which functions as a condenser, and becomes liquid refrigerant. The liquid refrigerant is decompressed by the expansion valve 5 to become low-temperature, low-pressure liquid refrigerant.

[0028] The low-temperature, low-pressure liquid refrigerant is sent to the outdoor heat exchanger 4. The low-temperature, low-pressure liquid refrigerant evaporates through heat exchange with the outside air in the outdoor heat exchanger 4, which functions as an evaporator, and becomes a low-temperature, low-pressure gas refrigerant. The low-temperature, low-pressure gas refrigerant passes through the four-way valve 3, and after the liquid refrigerant is separated in the accumulator 7, it returns to the compressor 2. Indoor air is given heat through heat exchange with the refrigerant in the indoor heat exchanger 6, which functions as a condenser. This cycle is repeated to heat the room.

[0029] In the air conditioner 1 according to this embodiment, a flammable refrigerant is used as the refrigerant circulating through the refrigerant circuit 10. Flammable refrigerants generally have a low GWP but are flammable. By using a flammable refrigerant with a low GWP, the weighted average GWP of the refrigerant used can be improved to 450 or less. In the air conditioner 1, as the flammable refrigerant, a highly flammable single refrigerant classified as Class A3 or B3 in the ASHRAE standard, a flammable single refrigerant classified as Class A2 or B2, or a mixed refrigerant containing these refrigerants is used.

[0030] The refrigerant circulating through the refrigerant circuit 10 is not particularly limited as long as it is flammable. For example, hydrocarbon refrigerants, HFCs (hydrofluorocarbons), HFOs (hydrofluoroolefins), highly flammable refrigerants among HFCs (hydrofluorocarbons), and mixed refrigerants containing these refrigerants can be used. The hydrocarbon refrigerant can include one or more of propane (R290), ethane (R170), isobutane (R600a), normal butane (R600), and propylene (R1270). An example of an HFO is HFO-1234yf. An example of an HFC is R32. Furthermore, in some embodiments of the present invention, a refrigerant with a specific gravity greater than that of air may be suitable.

[0031] Fig. 3 is a front view of the outdoor unit showing the structure of the outdoor unit of the air conditioner. Fig. 4 is an exploded view of the outdoor unit showing the structure of the outdoor unit of the air conditioner. In Fig. 3, a part of the housing of the outdoor unit 100 of the air conditioner 1 is cut away to show the internal structure of the housing as seen from the front of the outdoor unit 100. In Fig. 4, a part of the outdoor unit 100 of the air conditioner 1 is exploded to show the main internal structure of the housing. As shown in Figs. 3 and 4, the outdoor unit 100 has a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an expansion valve 5, an accumulator 7, an outdoor blower fan 8, etc. built in.

[0032] The outdoor unit 100 has a housing with a hollow structure that is roughly shaped like a rectangular parallelepiped. The lower surface of the housing is formed by a bottom base 101 that is roughly rectangular in plan view. The upper surface of the housing is formed by a top plate 102. The front surface of the housing is formed by a front plate 103. The side and rear surfaces of the housing are formed by left and right side plates 104 that are L-shaped in plan view. The housing is formed from a steel plate or the like that is painted to prevent corrosion.

[0033] The interior of the housing of the outdoor unit 100 is divided by a partition plate 105 into a heat exchanger chamber 110 on one side and a machine chamber 120 on the other side. An electric equipment box 130 is provided at the top of the interior of the housing, above the partition plate 105. An outdoor heat exchanger 4 and an outdoor blower fan 8 are installed in the heat exchanger chamber 110. A compressor 2, a four-way valve 3, an expansion valve 5, an accumulator 7, etc. are installed in the machine chamber 120. A control board and electrical components are housed in the electric equipment box 130.

[0034] The heat exchanger chamber 110 is a section where heat exchange is performed by the outdoor heat exchanger 4. An air outlet 111 covered with a lattice is provided on the front side of the heat exchanger chamber 110. Inlets are provided on the side and back sides of the heat exchanger chamber 110. The outdoor blower fan 8 is disposed near the center of the heat exchanger chamber 110, in a position concentric with the air outlet 111. The outdoor heat exchanger 4 is disposed along the back and side sides of the outdoor blower fan 8.

[0035] The outdoor heat exchanger 4 is supported on the bottom base 101. The outdoor heat exchanger 4 is formed by heat transfer tubes through which the refrigerant flows and a plurality of fins joined to the heat transfer tubes. The heat transfer tubes are made of a copper alloy, an aluminum alloy, stainless steel, or the like. The fins are made of an aluminum alloy, a copper alloy, stainless steel, or the like. The heat transfer tubes of the outdoor heat exchanger 4 are connected to refrigerant piping made of a copper pipe or the like.

[0036] The outdoor blower fan 8 is rotatably supported by a fan support 114 installed on the rear side of the heat exchanger chamber 110. A fan motor 115 that drives the rotational motion of the outdoor blower fan 8 is installed on the rear side of the heat exchanger chamber 110. Outside air is drawn into the heat exchanger chamber 110 by the outdoor blower fan 8 through intake ports on the side and rear sides of the heat exchanger chamber 110, and is heat exchanged with the refrigerant by the outdoor heat exchanger 4. The heat-exchanged air is blown out of the housing from an outlet 111 by the outdoor blower fan 8.

[0037] 3 and 4, the outdoor heat exchanger 4 is provided in an L-shape in a plan view, surrounding the back side and one side side of the heat exchanger chamber 110. However, the outdoor heat exchanger 4 may be provided in a U-shape in a plan view, surrounding the back side and both side sides of the heat exchanger chamber 110. Alternatively, the outdoor heat exchanger 4 may be provided in an I-shape in a plan view, surrounding only the back side of the heat exchanger chamber 110.

[0038] The machine room 120 is a compartment that houses devices related to the operation of the outdoor unit 100. The machine room 120 is provided as a semi-sealed space that is separated from the outside of the housing, the heat exchanger room 110, and the electrical equipment box 130. The machine room 120 is equipped with devices such as the compressor 2, the four-way valve 3, the expansion valve 5, and the accumulator 7, as well as refrigerant piping made of copper pipes or the like that is connected to these devices, an inverter unit that controls the compressor 2, and the like.

[0039] As shown in FIG. 3 , a gas-side service valve 121 to which a gas pipe is connected and a liquid-side service valve 122 to which a liquid pipe is connected are attached to the side of the housing facing the machine room 120. The gas pipe connected to the indoor heat exchanger 6 is connected to one port of the four-way valve 3 via the gas-side service valve 121. The other port of the four-way valve 3 is connected to the inlet side of the accumulator 7 via a refrigerant pipe. The outlet side of the accumulator 7 is connected to the suction pipe of the compressor 2 via a refrigerant pipe. The discharge pipe of the compressor 2 is connected to one port of the four-way valve 3 via a refrigerant pipe. The other port of the four-way valve 3 is connected to the heat transfer pipe of the outdoor heat exchanger 4 via a refrigerant pipe. The other end of the heat transfer pipe of the outdoor heat exchanger 4 is connected to the expansion valve 5 via a refrigerant pipe. The liquid pipe connected to the expansion valve 5 is connected to the indoor heat exchanger 6 via the liquid-side service valve 122.

[0040] A refrigerant sensor 12 that detects refrigerant present in the space can be installed in the machine room 120. The refrigerant sensor 12 constitutes a leak detection means that detects leakage of flammable refrigerant into the machine room 120. Various types of sensors can be used as the refrigerant sensor 12, such as a semiconductor sensor, an infrared sensor, a combustion sensor, or a catalytic sensor. When the refrigerant sensor 12 detects a leak of flammable refrigerant, an alarm can be issued or a notification can be sent to a terminal or the like to notify the user of the leak.

[0041] The electrical component box 130 is a box that houses electrical components. The electrical component box 130 houses a control board, electrical components that drive the fan motor 115, and the like. The electrical component box 130 is formed from a steel plate or the like and is closed from above by a cover. The electrical component box 130 is disposed above the machine chamber 120 and the partition plate 105 so that a portion of the electrical component box 130 protrudes into the heat exchanger chamber 110. A heat dissipation fin is provided on the side of the electrical component box 130 that protrudes into the heat exchanger chamber 110. This structure allows the heated electrical components to be efficiently cooled.

[0042] If the flammable refrigerant circulating through the refrigerant circuit 10 leaks from the refrigerant piping that constitutes the refrigerant circuit 10 or from equipment such as the compressor 2 or the four-way valve 3, it may ignite in an unexpected event, resulting in a risk of combustion, fire, explosion, etc. In particular, the machine room 120 of the outdoor unit 100 is a semi-sealed space where refrigerant leakage is likely to occur and where leaked refrigerant is likely to accumulate, and is close to the electrical equipment box 130, fan motor 115, etc., which may be ignition sources, making it a place with a high risk of ignition, fire, etc.

[0043] The machine room 120 of the outdoor unit 100 has many welds where the refrigerant pipes are welded to devices such as the compressor 2 and the four-way valve 3, and many joints between dissimilar metals where the refrigerant pipes are joined to the heat transfer tubes of the outdoor heat exchanger 4. For this reason, corrosion of the refrigerant pipes and electrolytic corrosion caused by contact between dissimilar metals tend to easily form corrosion holes that penetrate the pipe walls of the refrigerant pipes, or progress of corrosion that leads to fracture of the welds and joints.

[0044] Furthermore, the machine room 120 is prone to contact with outside air and organic matter, creating a corrosive environment that accelerates corrosion of the refrigerant piping and the like. Corrosion accelerates in the presence of moisture and oxygen from the outside air. In particular, the presence of moisture from the outside air and organic matter such as oil is known to cause ant nest corrosion in copper pipes used as refrigerant piping. As ant nest corrosion progresses, tiny corrosion holes are formed through the pipe walls, which may result in the leakage of flammable refrigerant from the refrigerant piping.

[0045] In the air conditioner 1 according to this embodiment, to reduce the risks associated with the use of such a flammable refrigerant, an adsorbent that adsorbs flammable refrigerant is installed in the machine room 120 of the outdoor unit 100. By installing an adsorbent in the machine room 120, flammable refrigerant that leaks from devices such as the refrigerant pipes and the compressor 2 can be captured by adsorption onto the adsorbent. This prevents the accumulation and diffusion of flammable refrigerant in the machine room 120, making it possible to prevent combustion, fire, etc. in the outdoor unit 100, and leakage to the outside of the outdoor unit 100.

[0046] The adsorbent that adsorbs the flammable refrigerant is removable or replenishable. This is because, generally, the adsorbent may consume its adsorption capacity by adsorbing components present in the machine room 120 before a flammable refrigerant leak occurs. Also, this is because the adsorption capacity is consumed when the leaked flammable refrigerant is adsorbed. When the adsorbent's adsorption capacity is consumed by adsorbing substances, its adsorption performance decreases and the amount of substances that can be adsorbed reaches a plateau.

[0047] Because the machine room 120 houses equipment such as refrigerant piping and the compressor 2, it is difficult to install an adsorbent that adsorbs all of the flammable refrigerant that leaks from the refrigerant piping, etc. In contrast, if a removable or replenishable adsorbent is used, the risk of flammable refrigerant leakage can be reduced over a long period of time, from the time the outdoor unit 100 is installed until the air conditioner 1 is in use.

[0048] Examples of adsorbents that adsorb flammable refrigerants include activated carbon obtained by activating charcoal, coconut shell charcoal, coke, etc., activated carbon fiber, which is fibrous activated carbon, impregnated activated carbon obtained by impregnating a chemical adsorption component, a chemical, a catalyst component, etc., with activated carbon, synthetic zeolite such as molecular sieve, natural zeolite, MOF (Metal-Organic Framework) membrane, silica gel, activated alumina, silica alumina, activated clay, etc.

[0049] The adsorbent for adsorbing a flammable refrigerant may be in the form of powder, particles, fibers, plates, scales, chunks, or crushed pieces, or may be formed into a spherical, cylindrical, pellet, block, honeycomb, sheet, or film shape. For example, when using fine particles, an adsorbent having a mesh size of about 1 to 100 can be used. The adsorbent may be compounded with a carrier such as alumina or silica, or a resin binder, an inorganic binder, or the like.

[0050] The adsorbent that adsorbs the flammable refrigerant is preferably a type that selectively adsorbs the flammable refrigerant among the flammable refrigerant that constitutes the refrigerant, refrigerant components other than the flammable refrigerant that constitutes the refrigerant, moisture in the air, nitrogen, oxygen, carbon dioxide, etc. When collecting low-polarity unsaturated hydrocarbons, the adsorbent is preferably a molecular sieve with an effective pore size that can adsorb the molecules of the flammable refrigerant.

[0051] For example, when selectively adsorbing propane or normal butane, it is preferable to use sodium-type molecular sieve 4A or activated carbon with an effective pore size of 4 Å or less. When selectively adsorbing isobutane, it is preferable to use calcium-type molecular sieve 5A or activated carbon with an effective pore size of 5 Å or less. Using an adsorbent that selectively adsorbs flammable refrigerants can ensure the ability to capture leaked flammable refrigerants for a longer period of time.

[0052] The usage status of the adsorbent installed in machine room 120 and the status of flammable refrigerant leakage in machine room 120 can be confirmed by refrigerant sensor 12. In Fig. 3, refrigerant sensor 12 is installed inside the side surface of the housing on the machine room 120 side, near the mid-height in the vertical direction of machine room 120. This arrangement is close to a location where flammable refrigerant leakage is likely to occur, and therefore flammable refrigerant leakage can be detected quickly and stably.

[0053] However, refrigerant sensor 12 can be installed at any position in machine room 120. Refrigerant sensor 12 is preferably placed inside machine room 120, below the midpoint in the vertical direction. This is because many flammable refrigerants have a higher specific gravity than air. Refrigerant sensor 12 is also preferably placed inside machine room 120, behind the rear ends of compressor 2 and accumulator 7, which are at the back of machine room 120. This is because the rear side of machine room 120 has a high density of refrigerant piping and many welds and other joints that are likely to leak flammable refrigerant.

[0054] Next, a specific installation location in the machine room 120 of the adsorbent that adsorbs the flammable refrigerant will be described with reference to the drawings.

[0055] In the air conditioner 1 according to this embodiment, in order to facilitate replacement or replenishment of the adsorbent that adsorbs flammable refrigerants, the adsorbent can be installed in the machine room 120 in a manner that allows it to be attached / detached or replenished freely, by using one or more of the following forms: integrating it into the soundproofing material that surrounds equipment such as the compressor 2 and accumulator 7; storing it in a removable container installed in the machine room 120; or painting it on the inner surface of the machine room 120.

[0056] 5 and 6 are diagrams showing an example of how an adsorbent is installed. FIGS. 5 and 6 show an example in which an adsorbent that adsorbs a flammable refrigerant is integrated into soundproofing material that surrounds equipment such as the compressor 2 and accumulator 7. The openings in the figures are enlarged schematic partial views of an example of the adsorbent. As shown in FIGS. 5 and 6, the compressor 2 and accumulator 7 installed inside the machine room 120 can be surrounded by soundproofing material 150 to suppress operating noise and vibration noise. An adsorbent 160 that adsorbs a flammable refrigerant can be integrated into the soundproofing material 150.

[0057] The compressor 2 includes a cylindrical sealed container 21 that houses a compression mechanism that compresses the refrigerant and an electric motor. In Fig. 4, fixing bolts 124 that fix the compressor 2 are attached at three points on the top surface of the bottom base 101. The compressor 2 is fixed to the fixing bolts 124 via legs 24 shown in Figs. 5 and 6 that have vibration-isolating rubber therebetween. In Figs. 5 and 6, a discharge pipe 22 that discharges compressed refrigerant to the refrigerant circuit 10 is connected to the top of the sealed container 21 of the compressor 2. An accumulator 7 is supported at a predetermined height on the side of the sealed container 21.

[0058] The accumulator 7 includes a cylindrical sealed container 71 that separates liquid refrigerant from gas refrigerant and stores the liquid refrigerant. In Figures 5 and 6, a suction pipe 72 that draws refrigerant from the refrigerant circuit 10 is connected to the upper part of the sealed container 71 of the accumulator 7. One end of a discharge pipe 73 that discharges the gas refrigerant from which the liquid refrigerant has been separated is connected to the lower part of the sealed container 71 of the accumulator 7. The other end of the discharge pipe 73 is connected to a side part of the sealed container 21 of the compressor 2, and communicates with a compression chamber formed inside the sealed container 21.

[0059] Soundproofing material 150 is a member for preventing noise, and is installed to suppress the operating noise and vibration noise of equipment such as compressor 2. In Figures 5 and 6, soundproofing material 150 is made of a flexible sound-absorbing material provided in a sheet shape. As shown in the blow-out portions of Figures 5 and 6, soundproofing material 150 is provided as a molded body obtained by molding fibers formed from adsorbent 160 that adsorbs flammable refrigerant into a sheet shape.

[0060] Such a molded soundproofing material 150 can be formed, for example, by molding activated carbon fibers, which function as an adsorbent, into a sheet. Such soundproofing material 150 can easily ensure that the gas present in the machine room 120 can pass through the adsorbent 160. In addition, because the specific surface area is large, pores that adsorb the flammable refrigerant can be widely distributed, thereby obtaining a large adsorption area.

[0061] However, as long as the soundproofing material 150 is integrated with an adsorbent that adsorbs flammable refrigerants, it may be composed solely of a sound-absorbing material that absorbs sound waves and attenuates sound energy, or of a sound-insulating material that reflects sound waves and blocks sound, or may be composed of a combination of a sound-absorbing material and a sound-insulating material. For example, a laminate of the soundproofing material 150 can be formed by laminating a sound-absorbing material to one or both sides of a sound-insulating material. Of the sound-absorbing and sound-insulating materials that make up the soundproofing material 150, it is preferable that the adsorbent be integrated with a breathable sound-absorbing material.

[0062] Examples of sound-absorbing materials that can be used include nonwoven fabrics such as felt made from animal or synthetic fibers, flexible molded bodies made from fibers shaped like sheets or cushions, flexible foamed bodies made from resins foamed like sponges, and flexible molded bodies made from resins shaped like porous materials. Examples of fibers include activated carbon fiber, glass wool, rock wool, cellulose, and keratin. Examples of resins include urethane resin, melamine resin, acrylic resin, polyester, polystyrene, and phenolic resin. The sound-absorbing material may have irregularities, such as square pyramid shapes, on its surface to suppress sound wave reflection.

[0063] The sound-insulating material may be a resin sheet, a rubber sheet, or the like, which has a high surface density and is flexible. Materials for the resin sheet include polyvinyl chloride, polyvinylidene chloride, polyethylene, polystyrene, polyurethane, polyester, polyamide, polycarbonate, polyether, polyvinyl acetal, polyvinyl alcohol, and acrylic resin. Materials for the rubber sheet include butyl rubber, butadiene rubber, isoprene rubber, chloroprene rubber, and ethylene propylene diene rubber.

[0064] As a method for integrating an adsorbent into soundproofing material 150, instead of using an adsorbent as a material for soundproofing material 150, such as activated carbon fiber, it is also possible to use a method in which an adsorbent is blended into soundproofing material 150 when it is molded, a method in which an adsorbent is blended into the material for soundproofing material 150, or a method in which an adsorbent is supported on the surface of soundproofing material 150. An adhesive or binder may be used to integrate the adsorbent, or a mechanical fixing method such as clamping and pressing the adsorbent may be used without using an adhesive or binder.

[0065] For example, a method in which a coating material in which an adsorbent is mixed with an adhesive or binder is applied to a substrate and then dried or heat-treated, a method in which a coating material in which an adsorbent is mixed with an adhesive or binder is impregnated into fibers or a molded body and then dried or heat-treated, or a method in which zeolite seed crystals are precipitated on a heat-resistant substrate and then a zeolite membrane is formed by hydrothermal synthesis can be used.

[0066] Methods for forming activated carbon fibers include treating spun acrylic resin fibers, cellulose fibers, phenol resin fibers, etc. with flame retardant treatment, carbonization treatment, activation treatment, etc., and treating spun pitch fibers with infusible treatment, activation treatment, etc. As the resin fibers, crystalline fibers with a high degree of crystallinity or amorphous fibers may be treated.

[0067] In addition to the purpose and function of preventing noise, the soundproofing material 150 may also have the purpose and function of acting as a heat insulating material for insulatingly holding the machine room 120 and the equipment. The soundproofing material 150 that also has the purpose and function of acting as a heat insulating material may have a layered air layer or a closed air chamber formed inside, or may be blended with a heat insulating filler such as a hollow structure or an additive such as a flame retardant, as long as the breathability of the gas present in the machine room 120 to the adsorbent is ensured.

[0068] 5 and 6, the soundproofing material 150 includes a first side soundproofing material 151 that covers the entire side surface of the sealed container 21 of the compressor 2, a second side soundproofing material 152 that covers the entire side surface of the sealed container 71 of the accumulator 7, a third side soundproofing material 153 that covers the entire side surface of the sealed container 21 of the compressor 2 and the sealed container 71 of the accumulator 7 together, and a top soundproofing material 154 that covers the top surface of the sealed container 21 of the compressor 2 and the top surface of the sealed container 71 of the accumulator 7.

[0069] The first side surface soundproofing material 151, the second side surface soundproofing material 152, and the third side surface soundproofing material 153 are each provided in the form of a long flexible sheet, and are wound around the sealed container 21 of the compressor 2 and the sealed container 71 of the accumulator 7 so that their ends partially overlap. The top surface soundproofing material 154 is provided in the form of a sheet, and is installed so as to close the upper opening surrounded by the third side surface soundproofing material 153. The top surface soundproofing material 154 is formed with a through hole 156 through which the discharge pipe 22 is inserted, and a through hole 157 through which the suction pipe 72 is inserted.

[0070] Such a structure in which the side and top sides are surrounded by soundproofing material 150 or a structure in which multiple soundproofing materials 150 surround the compressor 2 and accumulator 7 provides high soundproofing against the operation and vibration of compressor 2 and accumulator 7. Furthermore, since adsorbent 160 integrated into soundproofing material 150 is disposed so as to surround compressor 2 and accumulator 7, flammable refrigerant leaking from compressor 2 and accumulator 7 or flammable refrigerant remaining in gaps around compressor 2 and accumulator 7 can be quickly collected.

[0071] However, the soundproofing material 150 may be installed only to surround the compressor 2, or only to surround the compressor 2 and the accumulator 7 individually, or only to surround the compressor 2 and the accumulator 7 collectively. Any number of soundproofing materials 150 can be installed in the machine room 120, with any number of layers. The soundproofing material 150 may be provided in a divided structure made up of multiple members, from the viewpoint of facilitating attachment and detachment to the compressor 2 and the accumulator 7. The adsorbent that adsorbs the flammable refrigerant may be integrated into all of the soundproofing materials 150 surrounding the compressor 2 and the accumulator 7, or may be integrated into some of the soundproofing materials 150.

[0072] Furthermore, the soundproofing material 150 may be installed to cover the entire sealed container 21 of the compressor 2 or the sealed container 71 of the accumulator 7, or a combination of a material that covers the side surface of the sealed container 21 of the compressor 2 or the side surface of the sealed container 71 of the accumulator 7 and a material that covers the top surface of the sealed container 21 of the compressor 2 or the top surface of the sealed container 71 of the accumulator 7 may be installed.

[0073] The soundproofing material 150 covering the upper surface of the sealed container 21 of the compressor 2 and the upper surface of the sealed container 71 of the accumulator 7 can be disposed above the sealed container 21 of the compressor 2 and the upper surface of the sealed container 71 of the accumulator 7. Alternatively, a sheet extending from the side surface can be drawn around the discharge pipe 22 and the suction pipe 72 to form a drawn shape that covers the side surface and the upper surface. When the soundproofing material is formed in a drawn shape, there is no need to form the through holes 156, 157. The adsorbent that adsorbs the flammable refrigerant may be integrated into all of the soundproofing material 150 that covers the side surface and the upper surface of the compressor 2 and the accumulator 7, or may be integrated into only a part of the soundproofing material 150.

[0074] The soundproofing material 150 is detachably disposed around the compressor 2 and the accumulator 7. For example, the soundproofing material 150 can be fixed by binding the overlapping ends of the sheet-like soundproofing material 150 that has been rolled up, or the tightly contacted sides or faces of the sheet. The soundproofing material 150 can be bound using strings, bands, staples, pins, clips, rivets, tacks, adhesives, or the like. The soundproofing material 150 may be provided with binding holes for inserting binding strings or bands, grommets for reinforcing the binding holes, hook-and-loop fasteners for binding the faces of the sheet.

[0075] The soundproofing material 150 surrounding the compressor 2 is preferably provided with a width greater than the length from the bottom to the top of the sealed container 21 of the compressor 2. The soundproofing material 150 surrounding the accumulator 7 is preferably provided with a width greater than the length from the bottom to the top of the sealed container 71 of the accumulator 7. With such a width, the entire structure can be enclosed to improve soundproofing, and the adsorbent 160 integrated into the soundproofing material 150 can be distributed over a wide area. Furthermore, a throttle shape that closes the top of the compressor 2 and the accumulator 7 can be easily formed.

[0076] 5 and 6, the soundproofing material 150 may be provided in the form of a cushion, a block, a cover, or a bag containing an adsorbent, which are flexible and breathable. A gap may be formed between the soundproofing material 150 and the sealed container 21 of the compressor 2, or between the soundproofing material 150 and the sealed container 71 of the accumulator 7 for soundproofing or heat insulation, or no gap may be formed. Forming a gap makes it easier for the gas present in the machine room 120 to breathe through to the adsorbent.

[0077] The soundproofing material 150 can also be placed between the compressor 2 or accumulator 7 and the inner wall surface of the machine room 120. For example, the soundproofing material 150 in a sheet or board shape can be placed between the compressor 2 or accumulator 7 and the front panel 103, between the compressor 2 or accumulator 7 and the side panel 104, between the compressor 2 or accumulator 7 and the partition panel 105, above the compressor 2 or accumulator 7, etc.

[0078] In a configuration in which the adsorbent is integrated into the soundproofing material 150, when the usage time of the adsorbent reaches a predetermined time after installation of the outdoor unit 100, or when the adsorption capacity of the adsorbent is consumed and its adsorption performance for flammable refrigerant decreases, the machine room 120 can be opened and the soundproofing material 150 to which the adsorbent is fixed can be replaced or replenished.

[0079] By integrating the adsorbent into the soundproofing material 150, the adsorbent that adsorbs flammable refrigerant can be dispersed over a wide area around the compressor 2. The soundproofing material 150 can be easily disposed in gaps around the compressor 2 and the accumulator 7, where leaked flammable refrigerant tends to accumulate, and can efficiently capture flammable refrigerant that has diffused into the gaps, reducing the risk of flammable refrigerant leaking from refrigerant piping, etc. Furthermore, because the soundproofing material 150 can be attached and detached by opening the machine room 120, the adsorbent can be easily replaced or replenished. By appropriately replacing or replenishing the adsorbent, the risk of flammable refrigerant leaking from refrigerant piping, etc. can be reduced over the long term.

[0080] Fig. 7 is a diagram showing an example of an adsorbent installation form. Fig. 7 shows an example in which an adsorbent that adsorbs a flammable refrigerant is housed in a removable container installed in the machine room 120 of the outdoor unit 100. In Fig. 7, the main components of the outdoor unit 100 are omitted, and only the outdoor heat exchanger 4, bottom base 101, etc. are shown. As shown in Fig. 7, a removable adsorbent container 170 that houses an adsorbent that adsorbs a flammable refrigerant can be installed in the machine room 120.

[0081] The adsorbent container 170 has an air-permeable structure that allows gas to flow between the inside and outside of the container. The adsorbent container 170 can be formed, for example, by a hollow container body 171 that can accommodate an adsorbent, and a container lid 172 that closes the container body 171. The container lid 172 or the like has a vent hole that communicates between the inside and outside of the container. The adsorbent that adsorbs the flammable refrigerant can be accommodated in the adsorbent container 170 in an air-permeable bag, an air-permeable cartridge, or alone.

[0082] The adsorbent container 170 is detachably installed in the machine room 120. Methods for installing the adsorbent container 170 include placing it on the bottom of the machine room 120, placing it on or fixing it to equipment installed in the machine room 120, or fixing it to the inner wall surface of the machine room 120. Methods for detachably fixing the adsorbent container 170 include adhering it using a pressure sensitive adhesive, adhesive, or the like, fixing it using a magnet, using a hanging device such as a hook or screw, or hanging it from a fixed location using a string, band, wire, or the like.

[0083] The adsorbent container 170 is preferably disposed inside the machine room 120, below the midpoint in the vertical direction of the machine room 120. It is also preferably disposed below the upper ends of the compressor 2 and the accumulator 7, and more preferably disposed on the bottom base 101, which is the bottom of the machine room 120. With such an arrangement, flammable refrigerant that has a higher specific gravity than air and flammable refrigerant that accumulates in gaps around the compressor 2 and the accumulator 7 can be efficiently captured while limiting the amount of adsorbent disposed.

[0084] The adsorbent container 170 is preferably disposed inside the machine room 120, rearward of the rear ends of the compressor 2 and the accumulator 7 at the rear side of the machine room 120, or forward of the front ends of the compressor 2 and the accumulator 7 at the front side of the machine room 120. This is because the rear side of the machine room 120 is densely populated with refrigerant piping and has many welds and other joints at which flammable refrigerant is likely to leak. By disposing the adsorbent container 170 at the rear, flammable refrigerant leaking from such locations can be quickly collected and its diffusion to the surrounding area suppressed. On the other hand, by disposing the adsorbent container 170 at the front, the adsorbent container 170 can be easily replaced or refilled from the front side of the machine room 120.

[0085] The adsorbent container 170 is preferably disposed closer to the refrigerant sensor 12 constituting the leak detection means than to the refrigerant piping through which the flammable refrigerant flows, which is installed inside the machine room 120. With this arrangement, even when the leaked flammable refrigerant is collected by the adsorbent, the refrigerant sensor 12 can detect with high sensitivity leakage from refrigerant piping that is likely to leak flammable refrigerant. Therefore, the status of adsorbent use and the status of flammable refrigerant leakage can be reliably confirmed by the refrigerant sensor 12.

[0086] The adsorbent container 170 may be disposed around the refrigerant sensor 12 that constitutes the leak detection means. For example, the adsorbent container 170 may be disposed closer to the refrigerant sensor 12 than the compressor 2 or the accumulator 7. With this arrangement, even if the location of the flammable refrigerant leakage is far from the refrigerant sensor 12 or even if the amount of flammable refrigerant leakage is small, the leaked flammable refrigerant can be collected by the adsorbent.

[0087] The adsorbent container 170 can be provided in an appropriate shape, such as a hollow rectangular parallelepiped, cubic, or cylindrical shape. A porous material may be provided inside the container lid 172 as a filter. The adsorbent container 170 may be provided as a breathable box-shaped container made of resin, metal, or the like, or as a breathable bag-shaped container made of resin, laminate film, cloth, paper, or the like. One or more adsorbent containers 170 may be placed inside the machine room 120.

[0088] In a configuration in which the adsorbent is stored in the adsorbent container 170, when the usage time of the adsorbent reaches a predetermined time after the installation of the adsorbent container 170, or when the adsorption capacity of the adsorbent is exhausted and its adsorption performance for flammable refrigerant decreases, the machine room 120 can be opened to replace or replenish the adsorbent container 170 containing the adsorbent, or to replace or replenish the adsorbent stored in the adsorbent container 170.

[0089] By storing the adsorbent in the adsorbent container 170, the adsorbent can be easily replaced or replenished, thereby easily reducing the risk of flammable refrigerant leaking from refrigerant piping, etc., over the long term. Furthermore, the adsorbent can be arranged at low cost, and the degree of freedom in arranging the adsorbent in the machine room 120 can be improved. By arranging the adsorbent container 170 in a location where flammable refrigerant is likely to leak can be reduced, allowing for efficient collection while limiting the amount of adsorbent arranged, and rapid collection that minimizes diffusion in the event of a leak.

[0090] Fig. 8 is a diagram showing one example of how an adsorbent is installed. Fig. 8 shows an example in which an adsorbent that adsorbs a flammable refrigerant is painted on the inner surface of the machine chamber 120 of the outdoor unit 100. In Fig. 8, the main components of the outdoor unit 100 are omitted, and only the outdoor heat exchanger 4, bottom base 101, etc. are shown. As shown in Fig. 8, the adsorbent that adsorbs a flammable refrigerant can be installed as a coating material 180 by painting it on the inner surface of the machine chamber 120.

[0091] Coating material 180 is provided so as to cover a part or all of the inner surface of machine room 120 by applying an adsorbent that adsorbs flammable refrigerant to the inner surface of machine room 120. The adsorbent that adsorbs flammable refrigerant is fixed on the surface or inside of coating material 180 so as to be able to come into contact with gas present in machine room 120. Coating material 180 may be provided in the form of a film, a foam, or a mortar using aggregate.

[0092] The coating material 180 may be formed by directly applying paint containing an adsorbent that adsorbs flammable refrigerant to the inner surface of the machine room 120, or by applying the paint to a base material that is installed like wallpaper along the inner surface of the machine room 120. The base material may be a resin sheet, a resin film, a rubber sheet, or waterproof paper. The base material can be detachably attached to the inner wall surface or bottom surface of the machine room 120. For example, a method of attaching the base material using a water-resistant adhesive tape or double-sided tape, a method of attaching the base material using a water-resistant adhesive, or a method of fastening the base material with magnets or rivets can be used.

[0093] Coating material 180 can be formed by applying paint containing an adsorbent that adsorbs flammable refrigerant and drying it, or by spraying paint by spraying or the like and drying it. Examples of paint that can be used include those in which a binder such as urethane resin, acrylic resin, silicone resin, polyester, polystyrene, fluororesin, or epoxy resin is dissolved in an adsorbent in inactive water, a strong solvent, or a weak solvent, or those in which a cement material such as gypsum or lime is mixed with water together with aggregate, a water-reducing agent, a thickener, or the like.

[0094] The paint containing an adsorbent that adsorbs a flammable refrigerant may be blended with a foaming agent, a foam stabilizer, aggregates such as sand, and fillers. Examples of fillers include hollow fillers such as shirasu balloons, fly ash balloons, glass balloons, and resin balloons, inorganic fillers such as alumina, silica, calcium carbonate, magnesium carbonate, diatomaceous earth, talc, and clay, organic fillers such as polyethylene, polypropylene, and polystyrene, foam fillers such as foamed polyethylene, foamed polypropylene, and foamed polystyrene, fibrous fillers such as glass wool, rock wool, and resin fibers, wood flour, and coconut shell powder.

[0095] 8, coating material 180 is provided in the form of a thin film, but it may be provided in the form of a thick board or cushion as long as it can hold an adsorbent that adsorbs a flammable refrigerant. The adsorbent that adsorbs a flammable refrigerant may be held on the surface of coating material 180 with low breathability, or may be held on the surface or inside of coating material 180 with high breathability. It is preferable that coating material 180 is not covered with a sheet, film, layer, or the like, except for fire-resistant material 190, which will be described later.

[0096] In Figure 8, the coating material 180 is formed on the inner wall surfaces on the left and right sides of the machine chamber 120. However, the coating material 180 can also be formed on one or more of the front inner wall surface of the machine chamber 120, the side inner wall surface of the machine chamber 120, the rear inner wall surface of the machine chamber 120, the upper inner wall surface of the machine chamber 120, and the bottom surface of the machine chamber 120. For example, the coating material 180 can be formed on the inner surface of the top plate 102, the inner surface of the front plate 103, the inner surface of the side plate 104, the surface of the partition plate 105 facing the machine chamber 120, the upper surface of the bottom base 101, etc. The coating material 180 may be formed on the entire area of ​​each surface, or on a portion of each surface.

[0097] Coating material 180 is preferably formed at least on the inner wall surfaces of the sides of machine room 120, and is preferably formed on the inner surfaces of side panels 104 and the surface of partition panel 105 facing the machine room 120. This is because the rear side of machine room 120 is densely populated with refrigerant piping and has many welds and other joints at which flammable refrigerant is likely to leak. By forming coating material 180 on the inner wall surfaces of the sides of machine room 120, flammable refrigerant leaking from such locations can be quickly captured and prevented from diffusing to the surrounding area. Furthermore, coating material 180 can be easily replenished from the front side of machine room 120.

[0098] In a configuration in which the adsorbent is painted on the inner surface of the machine room 120, when the usage time of the adsorbent reaches a predetermined time after installation of the outdoor unit 100, or when the adsorbent's adsorption capacity is consumed and its adsorption performance for flammable refrigerant decreases, the machine room 120 can be opened and the adsorbent can be replenished by painting a paint containing the adsorbent. Also, the adsorbent can be replaced by peeling off the base material and repainting.

[0099] By applying the adsorbent to the inner surface of the machine chamber 120, the adsorbent that adsorbs the flammable refrigerant can be dispersed throughout a wide area within the machine chamber 120. This allows for easy ventilation of the gas present in the machine chamber 120 to the adsorbent. Furthermore, the surface area is increased, providing a large adsorption area with widely distributed pores that adsorb the flammable refrigerant. This allows for widespread collection of the flammable refrigerant diffusing within the machine chamber 120, thereby preventing stagnation of the flammable refrigerant within the machine chamber 120. Furthermore, because the coating material 180 is disposed to surround the machine chamber 120, leakage to the outside of the heat exchanger chamber 110 and the outdoor unit 100 can be effectively prevented. Furthermore, because the coating material 180 can be refilled by opening the machine chamber 120, the adsorbent can be easily refilled. Appropriate refilling can reduce the risk of flammable refrigerant leaking from refrigerant piping, etc., over the long term.

[0100] According to the outdoor unit 100 of the air conditioner 1 described above, the adsorbent that adsorbs flammable refrigerant is installed in the machine room 120 in a removable or replenishable form. Therefore, flammable refrigerant leaking from equipment such as the refrigerant pipes or the compressor 2 is captured by adsorption onto the adsorbent, thereby preventing the accumulation or diffusion of flammable refrigerant in the machine room 120. This prevents ignition or fire caused by flammable refrigerant leakage. Furthermore, because the adsorbent can be replaced or replenished and its flammable refrigerant capturing capacity can be maintained at a high level, it is not necessary to excessively install an excessive amount of adsorbent during installation or maintenance of the outdoor unit 100. This effectively prevents the accumulation or diffusion of flammable refrigerant in the machine room over a long period, from the time the outdoor unit is installed until the air conditioner is in use, thereby reducing the risk of flammable refrigerant leakage over the long term.

[0101] Figure 9 is a diagram showing the structure of the bottom of the outdoor unit of an air conditioner. In Figure 9, the main components of the outdoor unit 100 are omitted, and only the outdoor heat exchanger 4, bottom base 101, etc. are shown. As shown in Figure 9, the outdoor unit 100 of the air conditioner 1 can be provided with a refrigerant discharge port 128 at the bottom of the machine chamber 120 for discharging flammable refrigerant.

[0102] The bottom base 101 is formed in a shallow dish shape surrounded by a bank-like wall to receive condensation water and the like. The bottom base 101 is supported at a predetermined height, such as outdoors, by legs 125. A linear protrusion 126 is formed on the top surface of the bottom base 101 to prevent deformation of the bottom base 101 due to the weight and vibration of the compressor 2 and the like. The protrusion 126 is provided from the machine chamber 120 to the heat exchanger chamber 110. The fixing bolt 124 that fixes the compressor 2 is fixed onto the protrusion 126.

[0103] A drain hole 127 is formed on the rear side of the upper surface of bottom base 101 at a height lower than that of protrusion 126. Drain hole 127 is provided as a through-hole that passes vertically through bottom base 101. When condensation or frost occurs on outdoor heat exchanger 4, condensed water formed by condensation and melted water formed by melting frost fall onto bottom base 101. Such condensed water and melted water are discharged to the outside of the housing through drain hole 127.

[0104] In Figure 9, drain holes 127 are formed in three locations on the rear side of bottom base 101: the left and right corners and the center between the left and right corners. Drain holes 127 are formed on the upper surface of bottom base 101 at a height lower than convex portion 126 so that condensed water and melted water can be drained by gravity. Drain holes 127 can be formed in any position on bottom base 101 as long as they can be drained by gravity. Drain holes 127 can be provided in any number and with any appropriate shape and size.

[0105] Refrigerant outlet 128 is used to discharge flammable refrigerant that has leaked into machine chamber 120 to the outside of the housing of outdoor unit 100. In Fig. 9, the inlet side of refrigerant outlet 128 is provided on pedestal 129 that is higher by a predetermined height than the bottom surface of machine chamber 120. Pedestal 129 can be provided, for example, at a height of 3 mm to 20 mm, preferably 5 mm to 10 mm, from the upper surface that is lower than convex portion 126 of bottom base 101. Refrigerant outlets 128 can be provided in any number and with any appropriate shape and size.

[0106] Providing refrigerant discharge port 128 on base 129 prevents condensed water or melted water that has fallen onto bottom base 101 from reaching the height of refrigerant discharge port 128. Therefore, flammable gaseous refrigerant that has a higher specific gravity than air and that has leaked into machine chamber 120 can be preferentially discharged through refrigerant discharge port 128. This prevents refrigerant discharge port 128 from being blocked by a large amount of condensed water or melted water, dust entrained in the water, frosting, freezing, or the like. Therefore, flammable refrigerant that has a higher specific gravity than air can be stably discharged to the outside of the housing.

[0107] Refrigerant discharge port 128 is preferably provided inside machine room 120, rearward of the rear ends of compressor 2 and accumulator 7, which are at the back of machine room 120. This is because refrigerant piping is densely packed at the rear side of the interior of machine room 120, and there are many welds and the like through which flammable refrigerant may leak. By providing refrigerant discharge port 128 at the rear, flammable refrigerant that has leaked into machine room 120 can be quickly discharged, and accumulation of flammable refrigerant in machine room 120 can be suppressed.

[0108] The refrigerant discharge port 128 may be formed inside the machine room 120 at a position other than the bottom of the machine room 120, and below the midpoint in the vertical direction of the inner wall surface of the machine room 120. For example, the refrigerant discharge port 128 may be formed as a louvered or grilled opening on the lower side of the front panel 103 or the lower side of the side panel 104. When the refrigerant discharge port 128 is formed on the inner wall surface of the machine room 120, it is preferable that the refrigerant discharge port 128 be formed in a position close to or adjacent to the bottom of the machine room 120, from the viewpoint of discharging the refrigerant by gravity.

[0109] In the machine room 120 in which the refrigerant discharge port 128 is formed, soundproofing material 150 having an adsorbent fixed thereon that adsorbs flammable refrigerants may be installed, an adsorbent container 170 containing an adsorbent that adsorbs flammable refrigerants may be installed, or a coating material 180 may be formed by painting an adsorbent that adsorbs flammable refrigerants, or two or more of these may be installed in combination.

[0110] Forming a refrigerant discharge port 128 in the machine room 120 and disposing an adsorbent that adsorbs flammable refrigerant therein can more reliably reduce the accumulation and diffusion of flammable refrigerant in the machine room 120. Because flammable refrigerant, which has a higher specific gravity than air, can be efficiently discharged through the refrigerant discharge port 128, the adsorption performance of the adsorbent can be maintained for a longer period of time. Although flammable refrigerant that has locally diffused may be difficult to discharge through the refrigerant discharge port 128, such flammable refrigerant can be continuously captured by an appropriately disposed adsorbent. Furthermore, the frequency of replacing or replenishing the adsorbent can be reduced. Therefore, the accumulation and diffusion of flammable refrigerant in the machine room 120 can be suppressed for a longer period of time.

[0111] 10 and 11 are diagrams showing an example of how an adsorbent is installed. Figs. 10 and 11 show an example in which an adsorbent that adsorbs a flammable refrigerant is fixed to soundproofing material that surrounds equipment such as the compressor 2 and the accumulator 7. The air bubbles in the figures are enlarged partial views that schematically show an example of the adsorbent. As shown in Figs. 10 and 11, a fireproof material 190 can also be installed around the adsorbent 160 that adsorbs a flammable refrigerant.

[0112] The fire-resistant material 190 is a member that provides fire protection and flame retardancy, and is provided to suppress combustion of the flammable refrigerant in the event of a leak of the flammable refrigerant. As the fire-resistant material 190, a member that can ensure permeability to the adsorbent of the gas present in the machine room 120 and has fire resistance and heat resistance is used. As the fire-resistant material 190, for example, a metal mesh, a punched metal, an expanded metal, a ceramic mesh, a fire-resistant resin mesh, etc. can be used.

[0113] 10 and 11, the soundproofing material 150 includes a first side soundproofing material 151 that covers the entire side surface of the sealed container 21 of the compressor 2, a second side soundproofing material 152 that covers the entire side surface of the sealed container 71 of the accumulator 7, a third side soundproofing material 153 that covers the entire circumference of the sealed container 21 of the compressor 2 and the sealed container 71 of the accumulator 7 together, and a top soundproofing material 154 that covers the top surface of the sealed container 21 of the compressor 2 and the top surface of the sealed container 71 of the accumulator 7.

[0114] The first side surface soundproofing material 151, the second side surface soundproofing material 152, and the third side surface soundproofing material 153 are each provided in the form of a long flexible sheet, and are wound around the sealed container 21 of the compressor 2 and the sealed container 71 of the accumulator 7 so that their ends partially overlap. The top surface soundproofing material 154 is provided in the form of a sheet, and is installed so as to close the upper opening surrounded by the third side surface soundproofing material 153.

[0115] The fireproof material 190 is provided in a flexible sheet shape and is arranged inside the third side surface soundproofing material 153. The fireproof material 190, together with the third side surface soundproofing material 153, collectively covers the entire periphery of the sealed container 21 of the compressor 2 and the sealed container 71 of the accumulator 7. In FIG. 10 , an end of the third side surface soundproofing material 153 is partially untied to illustrate a portion of the fireproof material 190 arranged inside the third side surface soundproofing material 153.

[0116] By disposing such fire-resistant material 190, even if the flammable refrigerant that has leaked into machine room 120 ignites, the continuation of combustion and the propagation of the flame can be suppressed by the flame-extinguishing effect of fire-resistant material 190. In particular, because fire-resistant material 190 is disposed around the adsorbent, even if the flammable refrigerant adsorbed to the adsorbent ignites, the spread of flame and combustion to the periphery of the adsorbent and surrounding equipment can be effectively suppressed.

[0117] When used together with flexible soundproofing material 150, it is preferable to use a flexible member as fireproofing material 190. For example, flexible fireproofing material 190 can be installed by sandwiching it between soundproofing materials 150, sandwiching it between soundproofing material 150 and equipment, or detachably fixing it to the outside of soundproofing material 150.

[0118] The fire-resistant material 190 may be installed only to surround the compressor 2, or only to surround the compressor 2 and the accumulator 7 individually, or a combination of these and one that collectively surrounds the compressor 2 and the accumulator 7. Any number of fire-resistant materials 190 may be installed inside the machine room 120.

[0119] Furthermore, the fireproof material 190 may be installed to cover the entire sealed container 21 of the compressor 2 or the sealed container 71 of the accumulator 7, or a combination of a material covering the side surface of the sealed container 21 of the compressor 2 or the side surface of the sealed container 71 of the accumulator 7 and a material covering the top surface of the sealed container 21 of the compressor 2 or the top surface of the sealed container 71 of the accumulator 7 may be installed. The fireproof material 190 can be placed above the compressor 2 or the accumulator 7 so as to cover the top surface of the sealed container 21 of the compressor 2 or the top surface of the sealed container 71 of the accumulator 7.

[0120] Fireproof material 190 may be installed around soundproofing material 150 to which an adsorbent that adsorbs a flammable refrigerant is fixed, or may be installed around adsorbent container 170 that contains an adsorbent that adsorbs a flammable refrigerant, or around coating material 180 that is formed by painting an adsorbent that adsorbs a flammable refrigerant. For example, adsorbent container 170 can be covered with a metal mesh or the like, or can be housed in a cage formed with a metal mesh or the like. Furthermore, the surface of coating material 180 can be covered with a metal mesh or the like.

[0121] By installing fire-resistant material 190 around the adsorbent, even if flammable refrigerant leaked into the machine room 120 or flammable refrigerant adsorbed to the adsorbent ignites, the spread of flames and combustion to the surrounding area can be suppressed. This reduces the possibility of flammable refrigerant captured by the adsorbent combusting, and enables quick extinguishing in the event of a combustion, fire, or the like, making it possible to more reliably and long-term suppress damage caused by fire or explosion. Therefore, the risks associated with using a flammable refrigerant can be further reduced compared to when only an adsorbent is used.

[0122] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and includes various modifications without departing from the technical scope. For example, the above-described embodiments are not necessarily limited to those including all of the configurations described above. Furthermore, it is possible to replace part of the configuration of an embodiment with another configuration, or to add another configuration to the configuration of an embodiment. Furthermore, it is also possible to add other configurations to, delete configurations from, or replace part of the configuration of an embodiment.

[0123] For example, the air conditioner 1 may also be equipped with sensors (not shown) and devices that constitute the refrigerant circuit, such as a temperature sensor that measures the outdoor temperature, a temperature sensor that measures the temperature of the refrigerant at the intermediate portion or outlet side of the heat exchanger, a receiver, an oil separator, a dryer, etc. The air conditioner 1 may also be equipped with an injection circuit for injecting refrigerant at an intermediate pressure into the compressor 2. The injection circuit is connected to the compressor 2, bypassing the evaporator from the condenser.

[0124] Furthermore, in the air conditioner 1 described above, the housing of the outdoor unit 100 is formed by a bottom base 101, a top panel 102, a front panel 103, side panels 104, etc., but the specific structure of the outdoor unit 100 is not particularly limited. The arrangement of the electrical equipment box 130, the structure of the bottom, ceiling, and inner wall surfaces of the housing, the structure of the portion to which the compressor 2 is fixed, and the arrangement of the equipment and refrigerant piping in the machine room 120 can be changed as appropriate. Installation of the refrigerant sensor 12 may be omitted in cases where there is no need to continuously detect refrigerant leaks, etc.

[0125] Furthermore, the air conditioner 1 can be a package air conditioner, a home multi-air conditioner, a commercial multi-air conditioner, a building multi-air conditioner, etc. instead of the room air conditioner shown in Fig. 1. In Fig. 2, the outdoor unit 100 and the indoor unit 200 are connected one-to-one, but multiple outdoor units may be connected to one indoor unit, multiple indoor units may be connected to one outdoor unit, or multiple indoor units may be connected to multiple outdoor units. [Explanation of symbols]

[0126] 1. Air conditioner 2 Compressor 3 Four-way valve 4 Outdoor heat exchanger 5 Expansion valve 6 Indoor heat exchanger 7 Accumulator 8 Outdoor ventilation fan 9 Indoor ventilation fan 10 Refrigerant circuit 12 Refrigerant sensor 100 Outdoor unit 101 Bottom base 102 Top plate 103 Front plate 104 Side plate 105 Partition 110 Heat exchanger room 120 Machine room 127 Drain hole 128 Refrigerant outlet 130 Electrical equipment box 150 Soundproofing material 160 Adsorbents 170 Adsorbent container 180 Painting materials 190 Fireproof materials 200 indoor unit 300 Connecting piping 400 Remote Control

Claims

1. An outdoor unit of an air conditioner comprising: a compressor that compresses a refrigerant; a heat exchanger that exchanges heat between the refrigerant and outside air; and a blower fan that blows outside air to the heat exchanger, The refrigerant is a flammable refrigerant, The outdoor unit of the air conditioner is provided with a removable or replenishable adsorbent for adsorbing the flammable refrigerant in a machine room in which the compressor is installed.

2. The outdoor unit of the air conditioner according to claim 1, The outdoor unit of an air conditioner, wherein the adsorbent is integrated into a soundproofing material that surrounds the compressor.

3. The outdoor unit of the air conditioner according to claim 1, The adsorbent is accommodated in a removable container installed in the machine room of the outdoor unit of the air conditioner.

4. The outdoor unit of the air conditioner according to claim 1, a leakage detection means for detecting leakage of the refrigerant in the machine room; The adsorbent is disposed in the outdoor unit of the air conditioner closer to the leak detection means than a refrigerant pipe through which the refrigerant flows that is laid inside the machine room.

5. The outdoor unit of the air conditioner according to claim 1, An outdoor unit of an air conditioner, comprising a fireproof material around the adsorbent that suppresses combustion of the flammable refrigerant.

6. The outdoor unit of the air conditioner according to claim 1, An outdoor unit of an air conditioner, comprising an outlet at the bottom of the machine chamber for discharging refrigerant leaking into the machine chamber to the outside of the machine chamber.

7. The outdoor unit of the air conditioner according to claim 1, The adsorbent is applied to the inner surface of the machine chamber of the outdoor unit of an air conditioner.

8. The outdoor unit of the air conditioner according to claim 1, The outdoor unit of an air conditioner, wherein the flammable refrigerant is a refrigerant containing at least one of propane, ethane, isobutane, normal butane, and propylene.

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