Air conditioner

Abstract

To provide an air conditioner that can suppress progression of corrosion of an indoor heat exchanger due to a corrosive gas more than before.SOLUTION: An air conditioner is configured to blow air from outside the room into a space between a suction port of an indoor unit and an indoor heat exchanger when the concentration of a corrosive gas in the room where the indoor unit is installed becomes higher than the concentration of a corrosive gas of the air outside the room.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an air conditioner that can supply air outside a room in which an indoor unit is installed to the inside of the room. [Background technology]

[0002] An air conditioner performs cooling operation or heating operation. Hereinafter, cooling operation and heating operation will be collectively referred to as air conditioning operation. That is, air conditioning operation is either cooling operation or heating operation. When performing air conditioning operation, an air conditioner takes in air from the room in which the indoor unit is installed into the indoor unit, exchanges heat between the taken-in air and an indoor heat exchanger, and returns the air after heat exchange to the room, thereby cooling or heating the room in which the indoor unit is installed. Some such air conditioners have been proposed that are equipped with a ventilation device that supplies air from outside the room to the room in which the indoor unit is installed and ventilates the room (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7223905 Summary of the Invention [Problem to be solved by the invention]

[0004] If corrosive gases are mixed in the air passing through the indoor heat exchanger, the corrosive gases will come into contact with the indoor heat exchanger, corroding it and shortening the lifespan of the air conditioner.In other words, air conditioners have had the problem of the indoor heat exchanger being corroded by the corrosive gases in the air passing through it.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide an air conditioner that can suppress the progression of corrosion of an indoor heat exchanger due to corrosive gases more than conventional air conditioners. [Means for solving the problem]

[0006] An air conditioner according to the present disclosure comprises an indoor unit and a ventilation device, the indoor unit comprising an indoor heat exchanger, the indoor heat exchanger being provided between an air intake of the indoor unit and an air outlet of the indoor unit, the ventilation device comprising a connecting air duct connecting the inside of a room in which the indoor unit is installed to the outside of the room, a ventilation fan sending air from the outside of the room to the connecting air duct, a first sensor detecting the concentration of a corrosive gas inside the room, and a second sensor detecting the concentration of a corrosive gas in the air outside the room, the connecting air duct having a first opening and a second opening formed therein, the first opening being a front opening. The first opening is an opening that opens between the indoor heat exchanger and the outlet, and the second opening is an opening that opens between the inlet and the indoor heat exchanger. The ventilation device is equipped with a switching mechanism that switches the destination of the air sent from the ventilation fan to the connecting air duct between the first opening and the second opening, and when the concentration of corrosive gas detected by the first sensor becomes higher than the concentration of corrosive gas detected by the second sensor, the switching mechanism switches the destination of the air to the second opening, and the ventilation fan is driven. [Effects of the Invention]

[0007] The air conditioner according to the present disclosure can reduce the amount of corrosive gas that comes into contact with the indoor heat exchanger compared to conventional air conditioners, and therefore can suppress the progression of corrosion of the indoor heat exchanger due to corrosive gas compared to conventional air conditioners. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing an air conditioner according to a first embodiment. [Figure 2] FIG. 4 is a schematic diagram showing another example of the air conditioner according to the first embodiment. [Figure 3] 1 is a block diagram for explaining a control device for an air conditioner according to a first embodiment. [Figure 4]4 is a flowchart for explaining the operation when the air conditioner according to the first embodiment performs a condensation removal operation. [Figure 5] 10 is a flowchart for explaining the operation when the air conditioner according to the second embodiment performs an air conditioning operation. [Figure 6] FIG. 10 is a schematic diagram showing another example of an air conditioner according to the second embodiment. [Figure 7] 7 is a flowchart for explaining the operation of the air conditioner shown in FIG. 6 when it performs air conditioning operation. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiment 1 FIG. 1 is a schematic diagram showing an air conditioner according to the first embodiment. The air conditioner 1 according to the first embodiment includes an indoor unit 10, an outdoor unit 20, and a ventilation device 30.

[0010] The indoor unit 10 includes a housing 11, an indoor heat exchanger 14, and an indoor fan 15. The housing 11 has, for example, a substantially rectangular parallelepiped shape. An air inlet 12 is formed, for example, on the top surface of the housing 11. An air outlet 13 is formed, for example, on one of the side surfaces of the housing 11. The indoor heat exchanger 14 and the indoor fan 15 are housed in the housing 11. Specifically, the indoor heat exchanger 14 is provided between the air inlet 12 and the air outlet 13. The indoor fan 15 is provided between the air inlet 12 and the air outlet 13, and is located downstream of the indoor heat exchanger 14 in the air flow direction inside the housing 11. The indoor unit 10 is provided, for example, on a wall of a room 100. When the indoor fan 15 is driven, air from the room 100 is drawn into the housing 11 through the air inlet 12. The air drawn into the housing 11 then passes through the indoor heat exchanger 14 and is blown out of the housing 11 through the air outlet 13. That is, the air drawn into the housing 11 passes through the indoor heat exchanger 14 and is blown out into the room 100 .

[0011] The outdoor unit 20 includes a housing 21, an outdoor heat exchanger 24, and an outdoor fan 25. The housing 21 has, for example, a substantially rectangular parallelepiped shape. An air inlet 22 is formed, for example, on one of the side surfaces of the housing 21. Furthermore, an air outlet 23 is formed, for example, on one of the side surfaces of the housing 21. The outdoor heat exchanger 24 and the outdoor fan 25 are housed in the housing 21. Specifically, the outdoor heat exchanger 24 is provided in a position facing the air inlet 22. Furthermore, the outdoor fan 25 is provided in a position between the outdoor heat exchanger 24 and the air outlet 23. The outdoor unit 20 is provided outside the room 100. Hereinafter, the outside of the room 100 may also be referred to as the outdoors. When the outdoor fan 25 is driven, outdoor air is drawn into the housing 21 through the air inlet 22. The air drawn into the housing 21 passes through the outdoor heat exchanger 24 and is blown out of the housing 21 from the air outlet 23 .

[0012] The ventilation device 30 includes a housing 31, a connecting air passage 33, a ventilation fan 34, a first sensor 35, a second sensor 36, and a switching mechanism 40. The housing 31 has, for example, a substantially rectangular parallelepiped shape. An air vent 32 is formed in, for example, one of the side surfaces of the housing 31. Outdoor air passes through the air vent 32 to move between the outside of the housing 31 and the inside of the housing 31. The connecting air passage 33 is an air passage that connects the inside of the room 100 with the outside of the room 100. The connecting air passage 33 is formed with a first opening 33a and a second opening 33b as openings that open to the inside of the indoor unit 10. The first opening 33a is an opening that opens between the indoor heat exchanger 14 and the air outlet 13. The second opening 33b is an opening that opens between the air inlet 12 and the indoor heat exchanger 14. The connecting air passage 33 also has an outdoor opening 33c that opens to the outdoors. In the first embodiment, outdoor opening 33c is disposed inside housing 31. Ventilation fan 34 sends outdoor air to connecting air passage 33. Specifically, when ventilation fan 34 is driven, outdoor air is taken into housing 31, and the taken outdoor air is sent to connecting air passage 33.

[0013] The first sensor 35 detects the concentration of a corrosive gas inside the room 100. In other words, the first sensor 35 detects the proportion of the corrosive gas contained in the air inside the room 100. The second sensor 36 detects the concentration of a corrosive gas outdoors. In other words, the second sensor 36 detects the proportion of the corrosive gas contained in the air outdoors. Here, corrosive gases include hydrogen sulfide, chlorine, and ammonia. In chemical formulas, hydrogen sulfide is H2S, chlorine is Cl2, and ammonia is NH3. Hydrogen sulfide is generated, for example, during the processing of petroleum and natural gas. Hydrogen sulfide is also generated, for example, during the production process of petroleum and natural gas. Chlorine is generated, for example, in industrial processes using chlorine bleach and chlorine gas. Ammonia is contained in animal urine. It has been reported that ammonia contained in pet urine, in particular, can cause corrosion of the indoor heat exchanger 14.

[0014] In the first embodiment, the first sensor 35 is disposed inside the indoor unit 10. Specifically, the first sensor 35 is disposed at a position between the air inlet 12 and the indoor heat exchanger 14. However, the position of the first sensor 35 is not limited to this position. For example, the first sensor 35 may be disposed at a position between the indoor heat exchanger 14 and the air outlet 13. Furthermore, for example, the first sensor 35 may be disposed at a position outside the indoor unit 10 inside the room 100. However, the first sensor 35 is preferably disposed at a position between the air inlet 12 and the indoor heat exchanger 14. As will be described later, the air conditioner 1 according to the first embodiment reduces the amount of corrosive gas that comes into contact with the indoor heat exchanger 14 and suppresses corrosion of the indoor heat exchanger 14 due to the corrosive gas. When the first sensor 35 is disposed at a position between the air inlet 12 and the indoor heat exchanger 14, the concentration of the corrosive gas in the air flowing into the indoor heat exchanger 14 through the air inlet 12 can be detected more accurately. For this reason, the first sensor 35 is preferably disposed at a position between the air inlet 12 and the indoor heat exchanger 14.

[0015] Furthermore, in the first embodiment, the second sensor 36 is disposed inside the outdoor unit 20. Specifically, the second sensor 36 is disposed at a position between the air inlet 22 and the outdoor heat exchanger 24. However, the position of the second sensor 36 is not limited to this position. For example, the second sensor 36 may be disposed at a position between the outdoor heat exchanger 24 and the air outlet 23. Furthermore, for example, the second sensor 36 may be disposed at a position outside the outdoor unit 20, such as inside the housing 31 of the ventilation device 30.

[0016] The switching mechanism 40 switches the destination of the air sent from the ventilation fan 34 to the connecting air passage 33, between the first opening 33a and the second opening 33b. The switching mechanism 40 according to the first embodiment includes a first damper 41 that opens and closes the first opening 33a, and a second damper 42 that opens and closes the second opening 33b. The switching mechanism 40 shown in FIG. 1 is merely an example. For example, the switching mechanism 40 may be configured as follows.

[0017] FIG. 2 is a schematic diagram showing another example of the air conditioner according to the first embodiment. The switching mechanism 40 may be a damper 43 that switches the communication destination of the outdoor opening 33c between the first opening 33a and the second opening 33b.

[0018] The switching mechanism 40 is controlled by the control device 2 based on the detected values ​​of the first sensor 35 and the second sensor 36, etc. In the first embodiment, the control device 2 is housed in the outdoor unit 20, but the location where the control device 2 is housed is not limited to the outdoor unit 20. The control device 2 may be housed in the indoor unit 10, or may be housed separately in the indoor unit 10 and the outdoor unit 20. The control device 2 is configured, for example, as follows.

[0019] FIG. 3 is a block diagram for explaining the control device for the air conditioner according to the first embodiment. The control device 2 is configured with dedicated hardware or a CPU (Central Processing Unit) that executes programs stored in memory. The CPU is also called a central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or processor.

[0020] When the control device 2 is dedicated hardware, the control device 2 may be, for example, a single circuit, a composite circuit, an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a combination thereof. Each functional unit realized by the control device 2 may be realized by a separate piece of hardware, or each functional unit may be realized by a single piece of hardware.

[0021] When the control device 2 is a CPU, each function executed by the control device 2 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in memory. The CPU realizes each function of the control device 2 by reading and executing the programs stored in memory. Here, the memory is, for example, a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM.

[0022] It should be noted that some of the functions of the control device 2 may be realized by dedicated hardware, and other functions may be realized by software or firmware.

[0023] As shown in FIG. 3, the control device 2 includes, as functional units, for example, an acquisition unit 3, a determination unit 4, and an operation unit 5. The acquisition unit 3 is a functional unit that acquires information used in the operation of the air conditioner 1. For example, the acquisition unit 3 acquires detection values ​​of a first sensor 35 and a second sensor 36. In the first embodiment, the acquisition unit 3 is configured to also receive commands from a remote controller (not shown). Commands from the remote controller (not shown) include, for example, commands for an operation mode, a command to start operation, and a command to end operation.

[0024] The determination unit 4 is a functional unit that determines the configuration state of the air conditioner 1 based on the information acquired by the acquisition unit 3. For example, the determination unit 4 determines the state of the switching mechanism 40. Specifically, the determination unit 4 determines that the air sent from the ventilation fan 34 to the connecting air duct 33 should flow out of the connecting air duct 33 through the first opening 33a. The determination unit 4 also determines that the air sent from the ventilation fan 34 to the connecting air duct 33 should flow out of the connecting air duct 33 through the second opening 33b. The determination unit 4 also determines the operation of the ventilation fan 34. Specifically, the determination unit 4 determines whether or not the ventilation fan 34 should be driven. In the first embodiment, the determination unit 4 also determines the operation of the indoor fan 15, the outdoor fan 25, a compressor (not shown), and the like. The operation unit 5 is a functional unit that operates the configuration of the air conditioner 1 so that the configuration of the air conditioner 1 is in the state determined by the determination unit 4.

[0025] The air conditioner 1 configured in this manner is capable of performing at least one of cooling operation and heating operation. Hereinafter, cooling operation and heating operation will be collectively referred to as air conditioning operation. In other words, air conditioning operation is either cooling operation or heating operation.

[0026] When the air conditioner 1 performs air conditioning operation, a compressor (not shown) is driven. As a result, in cooling operation, the indoor heat exchanger 14 functions as an evaporator, and the outdoor heat exchanger 24 functions as a condenser. In heating operation, the indoor heat exchanger 14 functions as a condenser, and the outdoor heat exchanger 24 functions as an evaporator. Furthermore, when the air conditioner 1 performs air conditioning operation, the indoor fan 15 and the outdoor fan 25 are driven, and the ventilation fan 34 is stopped. When the indoor fan 15 is driven, air from the room 100 is drawn into the indoor unit 10. Specifically, the air from the room 100 is drawn into the housing 11 through the air inlet 12. The air from the room 100 drawn into the housing 11 exchanges heat with the indoor heat exchanger 14 as it passes through the indoor heat exchanger 14. Then, the air in room 100 that has exchanged heat with indoor heat exchanger 14 is blown out from air outlet 13 into room 100 and returns to room 100. Specifically, in cooling operation, the air in room 100 that has been taken into housing 11 is cooled by indoor heat exchanger 14 that functions as an evaporator and returns to room 100. In this way, cooling of room 100 is performed. In addition, in heating operation, the air in room 100 that has been taken into housing 11 is heated by indoor heat exchanger 14 that functions as a condenser and returns to room 100. In this way, heating of room 100 is performed.

[0027] The air conditioner 1 according to the first embodiment is also capable of performing a ventilation operation to ventilate the room 100. When the air conditioner 1 performs a ventilation operation, the compressor (not shown), the indoor fan 15, and the outdoor fan 25 are stopped. The ventilation fan 34 is driven. The switching mechanism 40 is configured to direct the air sent from the ventilation fan 34 to the connecting air duct 33 through the first opening 33a. Specifically, when the switching mechanism 40 is configured as shown in FIG. 1, the first damper 41 opens the first opening 33a, and the second damper 42 closes the second opening 33b. When the ventilation fan 34 is driven, outdoor air is drawn into the housing 31 of the ventilation device 30 through the air vent 32. The air drawn into the housing 31 is sent by the ventilation fan 34 to the connecting air duct 33 and blown out through the second opening 33b into the indoor unit 10. The outdoor air blown into the indoor unit 10 flows to the air outlet 13 of the indoor unit 10 without passing through the indoor heat exchanger 14, and is supplied from the air outlet 13 into the room 100. This allows the room 100 to be ventilated.

[0028] In the above description, the air conditioner 1 performs ventilation operation by supplying air to the room 100. However, this is not limiting. The air conditioner 1 may also perform ventilation operation by exhausting air from the room 100 to the outside. When the air conditioner 1 performs ventilation operation by exhausting air, the ventilation fan 34 operates to rotate in the opposite direction to that of the supplying air operation. By driving the ventilation fan 34 in this manner, air from the room 100 is drawn into the indoor unit 10 through the air outlet 13 of the indoor unit 10 and drawn into the connecting air duct 33. The air from the room 100 drawn into the connecting air duct 33 flows into the housing 31 of the ventilation device 30 and is then blown out of the housing 31 through the air vent 32. This method also allows ventilation of the room 100.

[0029] Furthermore, the air conditioner 1 according to the first embodiment performs a condensation removal operation to remove water droplets adhering to the indoor heat exchanger 14. Condensation may occur on the indoor heat exchanger 14 while the air conditioner 1 is performing an air conditioning operation. That is, water droplets may adhere to the indoor heat exchanger 14 while the air conditioner 1 is performing an air conditioning operation. In such a case, the air conditioner 1 performs a condensation removal operation to remove water droplets adhering to the indoor heat exchanger 14 by air passing through the indoor heat exchanger 14. The condensation removal operation will be described in detail later.

[0030] If a corrosive gas is mixed in the air passing through the indoor heat exchanger 14, the corrosive gas will come into contact with the indoor heat exchanger 14, corroding the indoor heat exchanger 14 and shortening the lifespan of the air conditioner 1. Therefore, when the concentration of the corrosive gas detected by the first sensor 35 becomes higher than the concentration of the corrosive gas detected by the second sensor 36, the air conditioner 1 according to the first embodiment enters a corrosion-suppression state in which the progression of corrosion of the indoor heat exchanger 14 is suppressed. In the corrosion-suppression state, the switching mechanism 40 directs the air sent from the ventilation fan 34 to the connecting air duct 33 to flow out of the connecting air duct 33 through the second opening 33b. In addition, in the corrosion-suppression state, the ventilation fan 34 is driven. Below, an example in which the air conditioner 1 enters the corrosion-suppression state during condensation removal operation will be described.

[0031] FIG. 4 is a flowchart for explaining the operation when the air conditioner according to the first embodiment performs the condensation removal operation. When the acquisition unit 3 of the control device 2 acquires an air conditioning operation start command sent from a remote controller (not shown) or the like, the control device 2 starts the control shown in FIG. 4 in step S1. Then, in step S2 after step S1, the control device 2 executes the air conditioning operation. Specifically, the operation unit 5 of the control device 2 drives the compressor, indoor fan 15, and outdoor fan 25 (not shown). Note that the ventilation fan 34 is stopped. At this time, the state of the switching mechanism 40 is arbitrary. Specifically, the destination of the air sent from the ventilation fan 34 to the connection air duct 33 may be either the first opening 33a or the second opening 33b.

[0032] During air conditioning operation, when the conditions for starting the condensation removal operation in step S3 are met, the control device 2 starts the condensation removal operation. In the first embodiment, the condition for starting the condensation removal operation is that a specified time has elapsed since the start of the air conditioning operation. This specified time may be a fixed time, or may be a time that changes depending on the temperature of the indoor heat exchanger 14, etc.

[0033] When performing the condensation removal operation, the control device 2 compares the concentration of the corrosive gas detected by the first sensor 35 with the concentration of the corrosive gas detected by the second sensor 36 in step S4. That is, the control device 2 compares the concentration of the corrosive gas inside the room 100 with the concentration of the corrosive gas outdoors. If the concentration of the corrosive gas detected by the second sensor 36 is higher than the concentration of the corrosive gas detected by the first sensor 35, the control device 2 proceeds to step S5 and performs the first condensation removal operation. In other words, if the concentration of the corrosive gas outdoors is higher than the concentration of the corrosive gas inside the room 100, the control device 2 proceeds to step S5 and performs the first condensation removal operation. If the concentration of the corrosive gas detected by the first sensor 35 is higher than the concentration of the corrosive gas detected by the second sensor 36, the control device 2 proceeds to step S10 and performs the second condensation removal operation. In other words, when the concentration of the corrosive gas inside the room 100 is higher than the concentration of the corrosive gas outdoors, the control device 2 proceeds to step S10 and executes the second condensation removal operation.

[0034] Specifically, the acquisition unit 3 of the control device 2 acquires the concentration of the corrosive gas detected by the first sensor 35 and the concentration of the corrosive gas detected by the second sensor 36. Then, the decision unit 4 of the control device 2 decides whether to perform the first condensation removal operation or the second condensation removal operation, depending on the concentration of the corrosive gas detected by the first sensor 35 and the concentration of the corrosive gas detected by the second sensor 36. Note that if the concentration of the corrosive gas detected by the first sensor 35 and the concentration of the corrosive gas detected by the second sensor 36 are the same, either the first condensation removal operation or the second condensation removal operation may be performed.

[0035] The first condensation removal operation in step S5 is a normal condensation removal operation. In the first condensation removal operation in step S5, the operation unit 5 of the control device 2 stops the compressor (not shown) to prevent refrigerant from flowing through the indoor heat exchanger 14. This makes the indoor heat exchanger 14 less susceptible to condensation. When the indoor fan 15 supplies air from the room 100 to the indoor heat exchanger 14 in this state, the air from the room 100 passes through the indoor heat exchanger 14, blowing off water droplets adhering to the indoor heat exchanger 14 and removing the water droplets. Note that in the first condensation removal operation, the ventilation fan 34 is stopped. At this time, the state of the switching mechanism 40 is arbitrary. Specifically, the air sent from the ventilation fan 34 to the connecting air duct 33 may flow out of the connecting air duct 33 through either the first opening 33a or the second opening 33b.

[0036] In the second condensation removal operation in step S10, the operation unit 5 of the control device 2 stops the compressor (not shown) and prevents refrigerant from flowing through the indoor heat exchanger 14, as in the first condensation removal operation in step S5. This makes the indoor heat exchanger 14 less susceptible to condensation. Furthermore, in the second condensation removal operation in step S10, the operation unit 5 places the air conditioner 1 in a corrosion-suppressing state in steps S11 and S12. Specifically, in step S11, the operation unit 5 places the switching mechanism 40 in a state where the air sent from the ventilation fan 34 to the connecting air duct 33 flows out of the connecting air duct 33 through the second opening 33b. When the switching mechanism 40 has the configuration shown in FIG. 1, the first damper 41 closes the first opening 33a, and the second damper 42 opens the second opening 33b. Furthermore, the operation unit 5 drives the ventilation fan 34 in step S12. In the second condensation removal operation, the outdoor air blown out from the second opening 33b of the connecting air passage 33 mixes with the air from the room 100 supplied by the indoor fan 15, and the air passes through the indoor heat exchanger 14. The air then blows off water droplets adhering to the indoor heat exchanger 14, removing the water droplets adhering to the indoor heat exchanger 14. Note that steps S11 and S12 may be performed in the reverse order or simultaneously.

[0037] The second condensation removal operation is performed when the concentration of corrosive gas inside the room 100 is higher than the concentration of corrosive gas outdoors. Therefore, the mixed air of the outdoor air blown out from the second opening 33b of the connecting air duct 33 and the room 100 air supplied by the indoor fan 15 contains a smaller proportion of corrosive gas than the room 100 air alone. Therefore, when the concentration of corrosive gas inside the room 100 is higher than the concentration of corrosive gas outdoors, performing the second condensation removal operation can reduce the amount of corrosive gas that comes into contact with the indoor heat exchanger 14 compared to performing the first condensation removal operation. In other words, when the concentration of corrosive gas inside the room 100 is higher than the concentration of corrosive gas outdoors, performing the second condensation removal operation can suppress the progression of corrosion of the indoor heat exchanger 14 due to corrosive gas compared to performing the first condensation removal operation. This means that the life of the air conditioner 1 can be extended.

[0038] Here, if water droplets are attached to the indoor heat exchanger 14, the water droplets will take in corrosive gas. Therefore, when water droplets are attached to the indoor heat exchanger 14, the indoor heat exchanger 14 is in contact with the corrosive gas for a longer period of time than when no water droplets are attached to the indoor heat exchanger 14, and corrosion of the indoor heat exchanger 14 is more likely to progress. For this reason, the air conditioner 1 entering a corrosion-suppressing state during condensation removal operation is particularly effective in suppressing the progression of corrosion of the indoor heat exchanger 14.

[0039] If the termination condition for the condensation removal operation in step S6 is met while the first or second condensation removal operation is being performed, the control device 2 returns to step S2 and resumes air conditioning operation. In the first embodiment, the termination condition for the condensation removal operation is that a specified time has elapsed since the start of the condensation removal operation. The control device 2 continues the control shown in Fig. 4 until the acquisition unit 3 acquires a command to stop the air conditioning operation sent from a remote controller (not shown) or the like.

[0040] In the first embodiment, the air conditioner 1 performs the condensation removal operation during the air conditioning operation. However, the present invention is not limited to this, and the air conditioner 1 may perform the condensation removal operation after the air conditioning operation has finished. In this case, by performing the first condensation removal operation or the second condensation removal operation described above depending on the concentration of the corrosive gas detected by the first sensor 35 and the concentration of the corrosive gas detected by the second sensor 36, the progression of corrosion of the indoor heat exchanger 14 can be suppressed.

[0041] As described above, the air conditioner 1 according to the first embodiment includes an indoor unit 10 and a ventilation device 30. The indoor unit 10 includes an indoor heat exchanger 14. The indoor heat exchanger 14 is provided between the air inlet 12 of the indoor unit 10 and the air outlet 13 of the indoor unit 10. The ventilation device 30 includes a connecting air duct 33, a ventilation fan 34, a first sensor 35, and a second sensor 36. The connecting air duct 33 is an air duct that connects the inside of the room 100 in which the indoor unit 10 is installed with the outside of the room 100. The ventilation fan 34 sends air from outside the room 100 to the connecting air duct 33. The first sensor 35 is a sensor that detects the concentration of corrosive gas inside the room 100. The second sensor 36 is a sensor that detects the concentration of corrosive gas in the air outside the room 100. The connecting air duct 33 is formed with a first opening 33a and a second opening 33b. The first opening 33a is an opening that opens between the indoor heat exchanger 14 and the air outlet 13. The second opening 33b is an opening that opens between the air inlet 12 and the indoor heat exchanger 14. The ventilation device 30 is equipped with a switching mechanism 40 that switches the destination of the air sent from the ventilation fan 34 to the connecting air duct 33, from the connecting air duct 33, between the first opening 33a and the second opening 33b. In the air conditioner 1 according to the first embodiment, when the concentration of the corrosive gas detected by the first sensor 35 becomes higher than the concentration of the corrosive gas detected by the second sensor 36, the switching mechanism 40 switches the destination of the air sent from the connecting air duct 33 to the second opening 33b, and the ventilation fan 34 is driven.

[0042] As described above, compared to conventional air conditioners, the air conditioner 1 configured in this manner can reduce the amount of corrosive gas that comes into contact with the indoor heat exchanger 14. Therefore, compared to conventional air conditioners, the air conditioner 1 configured in this manner can suppress the progression of corrosion of the indoor heat exchanger 14 due to corrosive gas.

[0043] Embodiment 2 In the first embodiment, the air conditioner 1 entered the corrosion suppression state during condensation removal operation. However, the operating mode in which the air conditioner 1 enters the corrosion suppression state is not limited to condensation removal operation. In the second embodiment, an example in which the air conditioner 1 enters the corrosion suppression state during air conditioning operation will be described. Note that matters not specifically mentioned in the second embodiment are the same as those in the first embodiment. Furthermore, in the second embodiment, components that perform the same functions as the components shown in the first embodiment will be given the same symbols as those in the first embodiment.

[0044] 5 is a flowchart for explaining the operation when the air conditioner according to Embodiment 2 performs air conditioning operation. The structure of the air conditioner 1 according to Embodiment 2 is the same as that of Embodiment 1. When the acquisition unit 3 of the control device 2 acquires an air conditioning operation start command transmitted from a remote controller (not shown) or the like, the control device 2 starts the control shown in FIG. 5 in step S21. Then, in step S22 following step S21, the control device 2 executes the air conditioning operation. Specifically, the operation unit 5 of the control device 2 drives the compressor, indoor fan 15, and outdoor fan 25 (not shown). Note that the ventilation fan 34 is stopped. At this time, the state of the switching mechanism 40 is arbitrary. Specifically, the destination of the air sent from the ventilation fan 34 to the connection air duct 33 may be either the first opening 33a or the second opening 33b.

[0045] In step S23 after step S22, the control device 2 compares the concentration of the corrosive gas detected by the first sensor 35 with the concentration of the corrosive gas detected by the second sensor 36. Specifically, the acquisition unit 3 of the control device 2 acquires the concentration of the corrosive gas detected by the first sensor 35 and the concentration of the corrosive gas detected by the second sensor 36. Then, the determination unit 4 of the control device 2 compares the concentration of the corrosive gas detected by the first sensor 35 with the concentration of the corrosive gas detected by the second sensor 36.

[0046] If the concentration of corrosive gas detected by the first sensor 35 is higher than the concentration of corrosive gas detected by the second sensor 36, the control device 2 places the air conditioner 1 in a corrosion-suppression state in steps S24 and S25. In other words, if the concentration of corrosive gas inside the room 100 is higher than the concentration of corrosive gas outdoors, the control device 2 places the air conditioner 1 in a corrosion-suppression state in steps S24 and S25. Specifically, if the concentration of corrosive gas detected by the first sensor 35 is higher than the concentration of corrosive gas detected by the second sensor 36, the decision unit 4 decides to place the air conditioner 1 in a corrosion-suppression state in step S23. Then, in step S24, the operation unit 5 sets the switching mechanism 40 to a state where the air sent from the ventilation fan 34 to the connecting air duct 33 flows out of the connecting air duct 33 through the second opening 33b. Furthermore, in step S25, the operation unit 5 drives the ventilation fan 34. That is, in the air conditioner 1 according to the second embodiment, when the concentration of the corrosive gas detected by the first sensor 35 becomes higher than the concentration of the corrosive gas detected by the second sensor 36, during air conditioning operation, the switching mechanism 40 causes the air sent from the ventilation fan 34 to the connecting air duct 33 to flow out of the connecting air duct 33 to the second opening 33b, and the ventilation fan 34 is driven. Note that steps S24 and S25 may be executed in the reverse order or simultaneously.

[0047] The mixed air of outdoor air blown out from the second opening 33b of the connecting air duct 33 and room 100 air supplied by the indoor fan 15 contains a smaller proportion of corrosive gases than room 100 air alone. Therefore, by placing the air conditioner 1 in a corrosion-suppressing state during air-conditioning operation, the amount of corrosive gas that comes into contact with the indoor heat exchanger 14 can be reduced compared to when the air conditioner 1 is not placed in the corrosion-suppressing state during air-conditioning operation. In other words, when the concentration of corrosive gas inside the room 100 is higher than the concentration of corrosive gas outdoors, placing the air conditioner 1 in a corrosion-suppressing state during air-conditioning operation can suppress the progression of corrosion of the indoor heat exchanger 14 due to the corrosive gas compared to when the air conditioner 1 is not placed in the corrosion-suppressing state during air-conditioning operation. In other words, the life of the air conditioner 1 can be extended.

[0048] After step S25, when the specified time in step S26 has elapsed, the control device 2 returns to step S23.

[0049] On the other hand, if the concentration of corrosive gas detected by the second sensor 36 is higher than the concentration of corrosive gas detected by the first sensor 35 in step S23, the control device 2 skips steps S24 and S25. In other words, if the concentration of corrosive gas outdoors is higher than the concentration of corrosive gas inside the room 100, the control device 2 does not place the air conditioner 1 in the corrosion-suppressed state. Then, after the specified time in step S26 has elapsed, the control device 2 returns to step S23. In other words, if the concentration of corrosive gas detected by the second sensor 36 is higher than the concentration of corrosive gas detected by the first sensor 35, the ventilation fan 34 of the air conditioner 1 is stopped during air-conditioning operation.

[0050] 5 until the acquisition unit 3 acquires a command to stop air conditioning operation transmitted from a remote controller (not shown) or the like. When the concentration of the corrosive gas detected by the first sensor 35 is the same as the concentration of the corrosive gas detected by the second sensor 36, the control unit 2 may or may not place the air conditioner 1 in a corrosion-suppressing state.

[0051] Here, when the air conditioner 1 is put into a corrosion-suppressing state during air conditioning operation, the indoor unit 10 of the air conditioner 1 preferably includes a flap 16 as follows.

[0052] Fig. 6 is a schematic diagram showing another example of an air conditioner according to Embodiment 2. Fig. 7 is a flowchart for explaining the operation of the air conditioner shown in Fig. 6 when it performs air conditioning operation. The indoor unit 10 of the air conditioner 1 shown in FIG. 6 includes a flap 16 that opens and closes the air inlet 12. In the air conditioner 1 configured in this manner, when the air conditioner 1 is placed in a corrosion-suppressing state during air conditioning operation, the operation unit 5 of the control device 2 causes the flap 16 to close the air inlet 12 in step S31. That is, in the air conditioner 1 configured in this manner, when the concentration of corrosive gas detected by the first sensor 35 becomes higher than the concentration of corrosive gas detected by the second sensor 36, the flap 16 closes the air inlet 12, as indicated by the two-dot chain line in FIG. 6. Note that steps S24 and S31 may be performed in reverse order or simultaneously. Furthermore, steps S25 and S31 may also be performed in reverse order or simultaneously.

[0053] As a result, when the concentration of corrosive gas detected by first sensor 35 becomes higher than the concentration of corrosive gas detected by second sensor 36, only the outdoor air blown out from second opening 33b of connecting air passage 33 passes through indoor heat exchanger 14. Therefore, the air conditioner 1 equipped with flap 16 can further reduce the amount of corrosive gas that comes into contact with indoor heat exchanger 14, and can further suppress the progression of corrosion of indoor heat exchanger 14 due to corrosive gas. In other words, the lifespan of the air conditioner 1 can be further extended.

[0054] The above describes preferred embodiments in detail, but the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0055] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) Equipped with an indoor unit and ventilation equipment, The indoor unit includes an indoor heat exchanger, The indoor heat exchanger is provided between an air inlet of the indoor unit and an air outlet of the indoor unit, The ventilation device comprises a connecting air duct that connects the inside of a room in which the indoor unit is installed with the outside of the room, a ventilation fan that sends air from outside the room to the connecting air duct, a first sensor that detects the concentration of a corrosive gas inside the room, and a second sensor that detects the concentration of a corrosive gas in the air outside the room, The connecting air passage has a first opening and a second opening, the first opening is an opening that opens between the indoor heat exchanger and the air outlet, The second opening is an opening that opens between the air inlet and the indoor heat exchanger, the ventilation device includes a switching mechanism for switching a destination of air sent from the ventilation fan to the connection air passage, between the first opening and the second opening; When the concentration of the corrosive gas detected by the first sensor becomes higher than the concentration of the corrosive gas detected by the second sensor, The switching mechanism is configured to set the outlet to the second opening, and the ventilation fan is driven. Air conditioner. (Appendix 2) During the condensation removal operation for removing water droplets adhering to the indoor heat exchanger, when the concentration of the corrosive gas detected by the first sensor becomes higher than the concentration of the corrosive gas detected by the second sensor, The switching mechanism is configured to set the outlet to the second opening, and the ventilation fan is driven. 1. An air conditioner as described in Appendix 1. (Appendix 3) During the dew condensation removal operation, if the concentration of the corrosive gas detected by the second sensor is higher than the concentration of the corrosive gas detected by the first sensor, The ventilation fan is configured to be in a stopped state. Attachment 2: An air conditioner. (Appendix 4) In an air conditioning operation, which is a cooling operation or a heating operation, when the concentration of the corrosive gas detected by the first sensor becomes higher than the concentration of the corrosive gas detected by the second sensor, The switching mechanism is configured to set the outlet to the second opening, and the ventilation fan is driven. An air conditioner according to any one of Supplementary Notes 1 to 3. (Appendix 5) The indoor unit includes a flap that opens and closes the air inlet, During the air conditioning operation, if the concentration of the corrosive gas detected by the first sensor becomes higher than the concentration of the corrosive gas detected by the second sensor, The flap is configured to close the suction port. Attachment 4: An air conditioner according to claim 4. (Appendix 6) During the air conditioning operation, when the concentration of the corrosive gas detected by the second sensor is higher than the concentration of the corrosive gas detected by the first sensor, The ventilation fan is configured to be in a stopped state. 10. The air conditioner according to claim 4 or 5. (Appendix 7) The switching mechanism includes a first damper that opens and closes the first opening, and a second damper that opens and closes the second opening. An air conditioner according to any one of Supplementary Notes 1 to 6. [Explanation of symbols]

[0056] 1 air conditioner, 2 control device, 3 acquisition unit, 4 determination unit, 5 operation unit, 10 indoor unit, 11 housing, 12 intake port, 13 outlet, 14 indoor heat exchanger, 15 indoor fan, 16 flap, 20 outdoor unit, 21 housing, 22 intake port, 23 outlet, 24 outdoor heat exchanger, 25 outdoor fan, 30 ventilation device, 31 housing, 32 vent, 33 connecting air duct, 33a first opening, 33b second opening, 33c outdoor opening, 34 ventilation fan, 35 first sensor, 36 second sensor, 40 switching mechanism, 41 first damper, 42 second damper, 43 damper, 100 room.

Claims

1. Equipped with an indoor unit and ventilation equipment, The indoor unit includes an indoor heat exchanger, The indoor heat exchanger is provided between an air inlet of the indoor unit and an air outlet of the indoor unit, The ventilation device includes a connecting air duct that connects the inside of a room in which the indoor unit is installed with the outside of the room, a ventilation fan that sends air from outside the room to the connecting air duct, a first sensor that detects the concentration of a corrosive gas inside the room, and a second sensor that detects the concentration of a corrosive gas in the air outside the room, The connecting air passage has a first opening and a second opening, the first opening is an opening that opens between the indoor heat exchanger and the air outlet, the second opening is an opening that opens between the air inlet and the indoor heat exchanger, the ventilation device includes a switching mechanism for switching a destination of air sent from the ventilation fan to the connection air passage, between the first opening and the second opening, When the concentration of the corrosive gas detected by the first sensor becomes higher than the concentration of the corrosive gas detected by the second sensor, The switching mechanism is configured to set the outlet to the second opening, and the ventilation fan is driven. Air conditioner.

2. During the condensation removal operation for removing water droplets adhering to the indoor heat exchanger, when the concentration of the corrosive gas detected by the first sensor becomes higher than the concentration of the corrosive gas detected by the second sensor, The switching mechanism is configured to set the outlet to the second opening, and the ventilation fan is driven. The air conditioner according to claim 1.

3. During the dew condensation removal operation, when the concentration of the corrosive gas detected by the second sensor is higher than the concentration of the corrosive gas detected by the first sensor, The ventilation fan is configured to be in a stopped state. The air conditioner according to claim 2.

4. In an air conditioning operation, which is a cooling operation or a heating operation, when the concentration of the corrosive gas detected by the first sensor becomes higher than the concentration of the corrosive gas detected by the second sensor, The switching mechanism is configured to set the outlet to the second opening, and the ventilation fan is driven. The air conditioner according to any one of claims 1 to 3.

5. The indoor unit includes a flap that opens and closes the air inlet, During the air conditioning operation, when the concentration of the corrosive gas detected by the first sensor becomes higher than the concentration of the corrosive gas detected by the second sensor, The flap is configured to close the suction port. The air conditioner according to claim 4.

6. During the air conditioning operation, when the concentration of the corrosive gas detected by the second sensor is higher than the concentration of the corrosive gas detected by the first sensor, The ventilation fan is configured to be in a stopped state. The air conditioner according to claim 4.

7. The switching mechanism includes a first damper that opens and closes the first opening, and a second damper that opens and closes the second opening. The air conditioner according to claim 1.

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