JP7113775B2 - Antifungal method for air conditioner and air conditioner using the same - Google Patents

Description

The present invention relates to a mold prevention method for an air conditioner.

Patent Documents 1 and 2 disclose air conditioners. For example, in Japan, condensed water is generated on the surface of the indoor heat exchanger during cooling operation in summer. Condensed water is a factor in breeding mold. Mold causes unpleasant odors. Indoor units of air conditioners are required to suppress mold.

JP-A-10-62000 JP 2016-65687 A

The air conditioners described in Patent Documents 1 and 2 heat the heat exchanger to dry the inside of the main body of the indoor unit after cooling operation in order to suppress the growth of bacteria and fungi. However, although such heating for drying can suppress the growth of bacteria and fungi, it does not lead to so-called sterilization, which kills the bacteria and fungi to reduce their numbers. If the heat exchanger is dry, the temperature must be above 150 degrees Celsius to kill and reduce the number of bacteria and fungi. Generally, the temperature of the heat exchanger during the heating operation for drying the heat exchanger of the air conditioner is set to about 40 degrees Celsius. When the cooling operation is resumed, there is a latent possibility that the bacteria and fungi whose growth has been suppressed will grow again.

SUMMARY OF THE INVENTION An object of the present invention is to provide a mold prevention method for an air conditioner that realizes so-called sterilization, in which bacteria and fungi are killed by heating a heat exchanger to reduce their numbers.

One aspect of the present invention is an air purifier comprising the steps of wetting a surface of a heat exchanger with condensed water, heating the heat exchanger based on condensation of a refrigerant, and heating the heat exchanger without evaporating the condensed water. The present invention relates to a mold prevention method (mold control method) for a harmony machine.

Bacteria and mold are heated together with the condensed water. By applying heat to bacteria and fungi in a high-humidity state, it is possible to kill the bacteria and reduce their numbers at a temperature lower than that in a dry state (hereinafter referred to as "moist heat sterilization"). Since the number of bacteria and fungi can be reduced more than when the growth is simply suppressed, generation of unpleasant odors is prevented.

The temperature of the heat exchanger during heating may be set to 45 degrees Celsius or higher. When the temperature is set to 45 degrees Celsius or higher, the condensed water is heated to 45 degrees Celsius or higher to kill bacteria and mold.

A mold prevention method for an air conditioner may be achieved by evaporating the refrigerant in the heat exchanger when wetting the surface of the heat exchanger. The temperature of the heat exchanger is lowered, and condensed water is efficiently generated on the surface of the heat exchanger. Sufficient wetting can be ensured on the surfaces of the heat exchanger.

A mold prevention method for an air conditioner includes providing a connecting body for connecting a front side body and a rear side body of the heat exchanger to each other when heating the heat exchanger, transferring heat from the heat exchanger, and providing the connecting body. Condensation of the refrigerant may be carried out until reaches a set temperature. In this way, in the heat exchanger, the connecting body that interconnects the front side body and the rear side body is heated to a sufficient set temperature, so that the condensed water generated on the surface of the connecting body and the bacteria and mold are sufficiently heated, resulting in a moist heat. Sterilization is performed.

The connecting body that connects the heat exchangers blocks the air gap between the front side body and the rear side body of the heat exchanger. The connecting body receives heat transferred from the heat exchanger whose temperature has decreased due to the evaporation of the refrigerant, and condensed water is generated on the surface of the connecting body. Since the connecting body blocks the wind, it is difficult for the condensed water to evaporate in the vicinity of the connecting body. It was difficult to dry the vicinity of the connecting body. By performing moist heat sterilization, it is possible to kill and reduce the number of bacteria and fungi in the vicinity of the connecting body where air is difficult to circulate.

A mold prevention method for an air conditioner includes a drain pan connected to the heat exchanger to receive condensed water falling from the heat exchanger when heating the heat exchanger, and Heat may be transferred from an exchanger and the condensation may be performed until the condensed water accumulated in the drain pan reaches a set temperature. Since the condensed water accumulated in the drain pan is sufficiently heated to the set temperature in this way, bacteria and fungi are sufficiently heated together with the condensed water accumulated in the drain pan, and wet heat sterilization is performed.

The overload condition of the compressor set during the condensation may be relaxed compared to the overload condition of the compressor set during the heating operation. During condensing, the compressor overload condition is relaxed, so the heat exchanger can be heated to a higher temperature than during heating operation. Moist heat sterilization of bacteria and fungi is realized.

In the air conditioner mold prevention method, rotation of the blower fan may be stopped during heating of the heat exchanger. Evaporation of condensed water can be reliably suppressed.

Another aspect of the present invention is a heat exchanger, a drain pan molded from a heat conductive material and disposed below the heat exchanger, and a and heat transfer members connected to condensed water.

Heat is reliably transferred from the heat exchanger to the condensed water accumulated in the drain pan through the heat transfer member. Therefore, when the heat exchanger is heated by condensation of the refrigerant, the condensed water accumulated in the drain pan is reliably heated to the set temperature. The condensed water stored in the drain pan can be sufficiently heated. Bacteria and fungi are sterilized in the heated condensed water. In this way, bacteria and fungi can be killed and their numbers reduced.

As described above, according to the disclosed method, a mold prevention method for an air conditioner that achieves more effective sterilization than conventional methods is provided.

1 is a conceptual diagram schematically showing the configuration of an air conditioner according to an embodiment of the present invention; FIG. 1 is a perspective view schematically showing the appearance of an indoor unit according to one embodiment; FIG. Fig. 3 is a perspective view schematically showing the configuration of the main body of the indoor unit; Fig. 2 is an exploded perspective view schematically showing the structure of the indoor unit; Fig. 4 is an enlarged vertical sectional view of the main body of the indoor unit; 4 is a block diagram schematically showing the configuration of a control unit; FIG. 4 is a flowchart schematically showing an antifungal treatment operation;

An embodiment of the present invention will be described below with reference to the accompanying drawings.

(1) Configuration of Air Conditioner FIG. 1 schematically shows the configuration of an air conditioner 11 according to one embodiment of the present invention. The air conditioner 11 has an indoor unit 12 and an outdoor unit 13 . The indoor unit 12 is installed, for example, in an indoor space inside a building. In addition, the indoor unit 12 may be installed in a space corresponding to the indoor space. An indoor heat exchanger 14 is incorporated in the indoor unit 12 . The outdoor unit 13 incorporates a compressor 15 , an outdoor heat exchanger 16 , an expansion valve 17 and a four-way valve 18 . Indoor heat exchanger 14 , compressor 15 , outdoor heat exchanger 16 , expansion valve 17 and four-way valve 18 form refrigeration circuit 19 . The outdoor unit 13 may be installed outdoors where heat exchange with outdoor air is possible.

The refrigerating circuit 19 has a first circulation path 21 . The first circulation path 21 connects the first port 18a and the second port 18b of the four-way valve 18 to each other. A compressor 15 is provided in the first circulation path 21 . A suction pipe 15a of the compressor 15 is connected to a first port 18a of a four-way valve 18 via a refrigerant pipe. The gas refrigerant is supplied to the suction pipe 15a of the compressor 15 from the first port 18a. Compressor 15 compresses the low-pressure gas refrigerant to a predetermined pressure. A discharge pipe 15b of the compressor 15 is connected to a second port 18b of the four-way valve 18 via a refrigerant pipe. Gas refrigerant is supplied from the discharge pipe 15 b of the compressor 15 to the second port 18 b of the four-way valve 18 . The refrigerant pipe may be, for example, a copper pipe.

The refrigerating circuit 19 further includes a second circulation path 22 . The second circulation path 22 connects the third port 18c and the fourth port 18d of the four-way valve 18 to each other. The second circulation path 22 incorporates the outdoor heat exchanger 16, the expansion valve 17, and the indoor heat exchanger 14 in order from the third port 18c side. The outdoor heat exchanger 16 exchanges heat energy between the passing refrigerant and the surrounding air. The indoor heat exchanger 14 exchanges thermal energy between the passing refrigerant and the surrounding air.

A blower fan 23 is incorporated in the outdoor unit 13 . The blower fan 23 ventilates the outdoor heat exchanger 16 . The blower fan 23 generates an airflow according to rotation of an impeller, for example. Airflow passes through the outdoor heat exchanger 16 by the action of the blower fan 23 . Outdoor air passes through the outdoor heat exchanger 16 and exchanges heat with the refrigerant. The cold air or warm air that has undergone heat exchange is blown out from the outdoor unit 13 . The flow rate of airflow passing through is adjusted according to the rotation speed of the impeller.

A blower fan 24 is incorporated in the indoor unit 12 . The blower fan 24 ventilates the indoor heat exchanger 14 . The blower fan 24 generates airflow according to the rotation of the impeller. Indoor air is sucked into the indoor unit 12 by the action of the blower fan 24 . Indoor air passes through the indoor heat exchanger 14 and exchanges heat with the refrigerant. The heat-exchanged cool or warm airflow is blown out from the indoor unit 12 . The flow rate of airflow passing through is adjusted according to the rotation speed of the impeller.

The indoor unit 12 is provided with vertical wind direction plates 25a and 25b. The vertical wind direction plates 25 a and 25 b regulate the direction of the airflow blown out from the indoor unit 12 . The details of the structure of the vertical wind direction plates 25a and 25b will be described later.

When cooling operation is carried out in the refrigerating circuit 19, the four-way valve 18 connects the second port 18b and the third port 18c to each other, and connects the first port 18a and the fourth port 18d to each other. Therefore, the high-temperature and high-pressure refrigerant is supplied to the outdoor heat exchanger 16 from the discharge pipe 15 b of the compressor 15 . The refrigerant flows through the outdoor heat exchanger 16, the expansion valve 17 and the indoor heat exchanger 14 in order. The outdoor heat exchanger 16 radiates heat from the refrigerant to the outside air. The expansion valve 17 reduces the pressure of the refrigerant to a low pressure. The decompressed refrigerant absorbs heat from the surrounding air in the indoor heat exchanger 14 . Cold air is generated. Cool air is blown into the indoor space by the operation of the blower fan 24 .

When the refrigeration circuit 19 performs heating operation, the four-way valve 18 connects the second port 18b and the fourth port 18d to each other, and connects the first port 18a and the third port 18c to each other. A high-temperature, high-pressure refrigerant is supplied from the compressor 15 to the indoor heat exchanger 14 . The refrigerant flows through the indoor heat exchanger 14, the expansion valve 17 and the outdoor heat exchanger 16 in order. In the indoor heat exchanger 14, heat is radiated from the refrigerant to the ambient air. Warm air is generated. The warm air is blown into the indoor space by the operation of the blower fan 24. - 特許庁The expansion valve 17 reduces the pressure of the refrigerant to a low pressure. The depressurized refrigerant absorbs heat from the surrounding air in the outdoor heat exchanger 16 . The refrigerant then returns to the compressor 15 .

The air conditioner 11 has a temperature sensor 26a and a humidity sensor 26b. A temperature sensor 26 a is connected to the indoor heat exchanger 14 . A temperature sensor 26 a measures the temperature of the indoor heat exchanger 14 . The temperature sensor 26a outputs a temperature signal containing temperature information of the measured temperature. The humidity sensor 26b is installed inside the indoor unit 12 . The humidity sensor 26b measures the relative humidity inside the indoor unit 12 . The humidity sensor 26b outputs a humidity signal including humidity information of the measured humidity.

The air conditioner 11 has a control section 27 . The control unit 27 is formed on a control board (not shown) incorporated in the outdoor unit 13, for example. The four-way valve 18, the expansion valve 17, and the compressor 15 in the outdoor unit 13 are electrically connected to the controller 27 by separate signal lines. Similarly, the drive motor for the blower fan 24 in the indoor unit 12, the drive source for the vertical wind direction plates 25a and 25b, the temperature sensor 26a, and the humidity sensor 26b are electrically connected to the control unit 27 via individual signal lines. . Based on the temperature signal from the temperature sensor 26a and the humidity signal from the humidity sensor 26b, the control unit 27 controls the four-way valve 18, the expansion valve 17 and the compressor 15 in the outdoor unit 13, and the blower fan 24 in the indoor unit 12. controls the behavior of As a result of such control, as will be described later, the cooling operation, the heating operation, and the antifungal treatment operation of the air conditioner 11 are realized. The control unit 27 controls the operation of the blower fan 24 and the vertical wind direction plates 25a and 25b during the cooling operation and the heating operation based on the operation signal input to the indoor unit 12 from the remote control, thereby adjusting the air volume of cool air and warm air. or change the direction of the wind.

(2) Configuration of Indoor Unit FIG. 2 schematically shows the appearance of the indoor unit 12 according to one embodiment. A main body (housing) 28a of the indoor unit 12 is covered with an outer panel 28b. A blowout port 29 is formed in the lower surface of the main body 28a. The air outlet 29 opens toward the interior of the room. The main body 28a can be fixed, for example, to an indoor wall surface. Cold air or warm air is generated in the indoor heat exchanger 14 , and the airflow of cold air or warm air is blown out from the outlet 29 .

A pair of front and rear wind direction plates 25 a and 25 b are arranged at the outlet 29 . The vertical wind direction plates 25a, 25b can rotate around horizontal axes 32a, 32b parallel to the longitudinal direction of the main body, respectively. The vertical wind direction plates 25a and 25b open and close the outlet 29 according to the rotation. The direction of the blown airflow can be changed according to the angles of the vertical wind direction plates 25a and 25b.

As shown in FIG. 3, a suction port 33 is formed in the main body 28a. The suction port 33 opens at the front and top surfaces of the main body 28a. Indoor air is taken into the main body 28 a through the suction port 33 and supplied toward the indoor heat exchanger 14 .

An air filter assembly 34 is arranged in the suction port 33 in a direction parallel to the horizontal axes 32a, 32b. Air filter assembly 34 includes air filter 35 and dust box 36 . Air filter 35 is held in dust box 36 . The dust box 36 is detachably attached to the main body 28a. When the dust box 36 is set on the main body 28 a, the air filter 35 is arranged over the entire surface of the suction port 33 .

A front filter rail 38 is formed in the dust box 36 . A rear filter rail 39 is formed on the main body 28a so as to correspond to an extension line of the front filter rail 38. As shown in FIG. Filter rails 38, 39 extend along vertical planes perpendicular to horizontal axes 32a, 32b. Left and right ends of the air filter 35 are slidably held by filter rails 38 and 39 . The air filter 35 is driven by a second driven gear 52 to be described later and moves along filter rails 38 and 39 .

As shown in FIG. 4, the blower fan 24 is rotatably supported by the main body 28a. A cross-flow fan, for example, is used as the blower fan 24 . The blower fan 24 rotates around a rotating shaft 41 parallel to the horizontal axes 32a, 32b. The rotating shaft 41 of the blower fan 24 extends horizontally when the main body 28a is installed. The blower fan 24 is arranged parallel to the outlet 29 . A driving force around the rotating shaft 41 is transmitted to the blower fan 24 from a driving source (not shown). The driving source is supported by the main body 28a. The airflow passes through the indoor heat exchanger 14 according to the rotation of the blower fan 24 . As a result, a cool or warm airflow is generated. Cool or warm airflow is blown out from the outlet 29 .

The indoor heat exchanger 14 has a front body 14a and a rear body 14b. The front body 14a faces the blower fan 24 from the front side of the blower fan 24. - 特許庁The rear body 14b faces the blower fan 24 from the rear side of the blower fan 24. - 特許庁The front body 14a and the rear body 14b are interconnected at their upper ends as will be described later. The front body 14a and the rear body 14b have refrigerant pipes 42a. That is, the refrigerant pipe 42a extends parallel to the horizontal axes 32a and 32b, is folded back at the left and right ends of the main body 28a when viewed from the front, extends again parallel to the horizontal axes 32a and 32b, and is folded again at the left and right ends of the main body 28a when viewed from the front. , which are repeated. The refrigerant pipe 42 a forms part of the second circulation path 22 . A plurality of radiating fins 42b are coupled to the refrigerant pipe 42a. The radiation fins 42b extend parallel to each other while being perpendicular to the horizontal axes 32a and 32b. The refrigerant pipe 42a and the heat radiating fins 42b can be made of a metallic material such as copper or aluminum. Heat exchange is realized between the refrigerant and the air through the refrigerant pipes 42a and the radiation fins 42b.

As shown in FIG. 4, air filter assembly 34 includes filter cleaning unit 43 . Dust box 36 serves as one component of filter cleaning unit 43 . The dust box 36 has an upper dust box 45 and a lower dust box 46 . The upper dust box 45 is arranged on the front side of the air filter 35 . The upper dust box 45 has a cover 47 . The cover 47 opens and closes the storage space 49 of the box body 48 . The lower dust box 46 is arranged on the rear side of the air filter 35 . The upper dust box 45 and the lower dust box 46 sandwich the air filter 35 . When cleaning the air filter 35 , dust on the front surface of the air filter 35 is generally collected in the box body 48 of the upper dust box 45 , and dust on the rear surface of the air filter 35 is collected in the lower dust box 46 .

The filter cleaning unit 43 has a first driven gear 51 and a second driven gear 52 . The first driven gear 51 is supported by the upper dust box 45 . The first driven gear 51 rotates around a horizontal shaft 53 . The teeth of the first driven gear 51 are partially exposed from the outer surface of the upper dust box 45 . Similarly, the second driven gear 52 is supported by the lower dust box 46 . A second driven gear 52 rotates about a horizontal axis 54 . The second driven gear 52 drives the air filters 35 at both ends of the lower dust box 46 . The teeth of the second driven gear 52 are partially exposed from the outer surface of the lower dust box 46 . When the air filter assembly 34 is set on the main body 28a, the first driven gear 51 meshes with the first driving gear (not shown) mounted on the main body 28a, and similarly the second driven gear 52 engages the first driving gear (not shown) mounted on the main body 28a. 2 drive gear (not shown). A drive source (not shown) such as an electric motor is individually connected to each drive gear. The first driven gear 51 and the second driven gear 52 rotate individually according to the driving force supplied from each driving source.

As shown in FIG. 5, the filter cleaning unit 43 comprises cleaning brushes 66 . The cleaning brush 66 is housed inside the upper dust box 45 . The cleaning brush 66 has a brush base 67 . The brush base 67 can be rotated around the horizontal shaft 68 by the driving force from the first driven gear 51 . The brush bristles 69 are arranged over a predetermined center angle range on the cylindrical surface of the brush base 67 . The brush bristles 69 have a spread across the air filter 35 in the axial direction of the brush pedestal 67 . The cleaning brush 66 brings the bristles 69 into contact with the air filter 35 at a predetermined rotational position, and separates the bristles 69 from the air filter 35 at other rotational positions. When the air filter 35 moves in a direction perpendicular to the horizontal axes 32 a and 32 b while the bristles 69 are in contact with the air filter 35 , the dust adhering to the front surface of the air filter 35 is caught by the bristles 69 . can be

The filter cleaning unit 43 has a brush receiver 71 . The brush receiver 71 is housed inside the lower dust box 46 . The brush receiver 71 has a receiving surface 72 . The receiving surface 72 faces the cleaning brush 66 . When the brush bristles 69 contact the air filter 35 , the receiving surface 72 sandwiches the air filter 35 with the brush bristles 69 . In addition, brush bristles may be planted on the receiving surface 72 .

The indoor heat exchanger 14 includes a connector 73 that interconnects the front body 14a and the rear body 14b. The connector 73 is coupled to the upper end of the front body 14a and the upper end of the rear body 14b. The connecting body 73 is made of a metal material with good thermal conductivity such as copper or aluminum. A first heat transfer member 74a that transfers heat from the front body 14a to the connection body 73 is sandwiched between the front body 14a and the connection body 73. As shown in FIG. The front body 14a and the connecting body 73 are in close contact with each other, and a high heat transfer coefficient is established between the front body 14a and the connecting body 73. As shown in FIG. For the first heat transfer member 74a, a heat transfer adhesive containing a large number of copper particles or silver particles as a resin filler, a heat transfer solder material, or a heat transfer welding material may be used. Thus, heat is efficiently transferred from the indoor heat exchanger 14 to the connecting body 73 from the front side body 14a. Similarly, a second heat transfer member 74b that transfers heat from the rear body 14b to the connection body 73 is sandwiched between the rear body 14b and the connection body 73. As shown in FIG. The rear body 14b and the connecting body 73 are in close contact with each other, and a high heat transfer coefficient is established between the rear body 14b and the connecting body 73. As shown in FIG. The second heat transfer member 74b is made of the same material as the first heat transfer member 74a. Thus, heat is efficiently transferred from the indoor heat exchanger 14 to the connecting body 73 from the rear body 14b .

The indoor heat exchanger 14 has a lower body 14a1 below the front body 14a. A windshield 88 is provided to shield the gap between the front body 14a and the lower body 14a1. The wind shield 88 is coupled to the lower end of the front body 14a and the upper end of the lower body 14a1. The wind shield 88 is made of a metal material with good thermal conductivity, such as copper or aluminum. The front body 14a and the wind shield 88, and the lower body 14a1 and the wind shield 88 are in contact with each other. Heat is transferred to the wind shield 88 from the front body 14a and the lower body 14a1. Thus, heat is transferred from the indoor heat exchanger 14 to the wind shield 88 . In this way, heat is transferred to the condensed water that has collected on the lee side of the wind shield 88 .

The indoor unit 12 of the air conditioner 11 includes a drain pan arranged below the indoor heat exchanger 14 . The drain pans include a first drain pan 75a arranged below the front body 14a and a second drain pan 75b arranged below the rear body 14b. The first drain pan 75a is supported in front of the blower fan 24 by the main body 28a. The second drain pan 75b is supported behind the blower fan 24 by the main body 28a. The heat of the heat exchanger may be transferred to a part of the first drain pan 75a and the second drain pan 75b by a heat conducting material. Condensed water generated on the surface of the front body 14a flows down to the first drain pan 75a due to the action of weight. Condensed water generated on the surface of the rear body 14b similarly flows down to the second drain pan 75b due to gravity. The first drain pan 75a and the second drain pan 75b each gently incline toward the lowermost discharge port (not shown). A pipe leading to the outdoor unit 13 is connected to each outlet.

A third heat transfer member 76 is sandwiched between the front body 14a and the first drain pan 75a to transfer heat from the front body 14a to the condensed water accumulated in the first drain pan 75a. A heat conductive material may be used for the third heat transfer member 76 . Thus, heat is transferred from the indoor heat exchanger 14 to the condensed water accumulated in the first drain pan 75a.

A fourth heat transfer member 77 is sandwiched between the front body 14a and the second drain pan 75b to transfer heat from the rear body 14b to the condensed water accumulated in the second drain pan 75b. A material similar to that of the third heat transfer member 76 is used for the fourth heat transfer member 77 . Thus, heat is transferred from the indoor heat exchanger 14 to the condensed water accumulated in the second drain pan 75b.

(3) Configuration of Control System As shown in FIG. 6, the control unit 27 includes a cooling operation unit 78 that manages the cooling operation, a heating operation unit 79 that manages the heating operation, and an antifungal treatment. An antifungal processing unit 81 that manages the operation is provided. A valve switching control unit 82, an opening degree control unit 83, a compressor control unit 84, a blower fan control unit 85, and a wind direction control unit 86 are connected to the cooling operation unit 78, the heating operation unit 79, and the antifungal processing unit 81. . The valve switching control section 82 is connected to the four-way valve 18 . The valve switching controller 82 outputs a control signal to the four-way valve 18 . The four-way valve 18 is switched between first and second positions in response to received control signals. In the first position, the four-way valve 18 interconnects the second port 18b and the third port 18c and interconnects the first port 18a and the fourth port 18d. In the second position, the four-way valve 18 interconnects the second port 18b and the fourth port 18d and interconnects the first port 18a and the third port 18c. Valve switching control section 82 generates a control signal specifying the first position or the second position in accordance with an instruction from cooling operation section 78 , heating operation section 79 or antifungal processing section 81 .

The opening controller 83 is connected to the expansion valve 17 . The opening controller 83 outputs a control signal to the expansion valve 17 . The degree of opening of the expansion valve 17 is adjusted according to the received control signal. The control signal specifies the degree of opening of the expansion valve 17 . In setting the temperature of the indoor heat exchanger 14, the adjustment of the opening degree of the expansion valve 17 is used together with the control of the compressor 15, which will be described later. The opening controller 83 generates a control signal specifying the opening of the expansion valve 17 according to an instruction from the cooling operation unit 78 , the heating operation unit 79 or the antifungal processing unit 81 .

Compressor control unit 84 is connected to compressor 15 . Compressor control unit 84 outputs a control signal to compressor 15 . The operation of compressor 15 is controlled in response to received control signals. The control signal specifies, for example, the rotation speed of the compressor 15 . When setting the temperature of the indoor heat exchanger 14, the opening of the expansion valve 17 and the operation of the compressor 15 are adjusted. Compressor control unit 84 generates a control signal specifying the number of revolutions of compressor 15 in accordance with an instruction from cooling operation unit 78 , heating operation unit 79 , or antifungal processing unit 81 .

The blower fan controller 85 is connected to the blower fans 23 and 24 . The blower fan controller 85 outputs control signals to the blower fans 23 and 24 . The rotation of the blower fans 23, 24 is controlled according to the received control signal. The control signal switches, for example, the blower fans 23, 24 between rotating and stationary. When the blower fans 23 and 24 are rotating, the control signal specifies the number of rotations of the blower fans 23 and 24 . The amount of heat energy exchanged in the indoor heat exchanger 14 or the outdoor heat exchanger 16 is adjusted according to the air volume based on the rotation of the blower fans 23 and 24 . The blower fan controller 85 generates a control signal for stopping the operation or specifying the number of rotations of the blower fans 23 and 24 in response to an instruction from the cooling operation unit 78, the heating operation unit 79, or the antifungal processing unit 81. FIG.

The wind direction control unit 86 is connected to the vertical wind direction plates 25a and 25b. The wind direction control unit 86 outputs control signals to the vertical wind direction plates 25a and 25b. The attitude of the vertical wind vanes 25a, 25b about the horizontal axis 32a, 32b is controlled according to the received control signals. The control signals specify, for example, the angle of the vertical deflectors 25a, 25b about the horizontal axis 32a, 32b. The vertical wind direction plates 25a and 25b close the outlet 33 at the minimum angle. At the maximum angle, the vertical wind direction plates 25a and 25b open the outlet 33 to the maximum. The wind direction control unit 86 generates a control signal specifying the angles of the vertical wind direction plates 25a and 25b in accordance with instructions from the cooling operation unit 78, the heating operation unit 79, or the antifungal processing unit 81. FIG.

The cooling operation unit 78 instructs the valve switching control unit 82 to establish the cooling operation. The cooling operation unit 78 controls the opening of the expansion valve 17 and the rotation speed of the compressor 15 by instructing the opening degree control unit 83 and the compressor control unit 84 according to the set temperature and the air volume during the cooling operation. The heating operation unit 79 instructs the valve switching control unit 82 to establish the heating operation. The heating operation unit 79 controls the opening degree of the expansion valve 17 and the rotation speed of the compressor 15 by instructing the opening control unit 83 and the compressor control unit 84 according to the set temperature and the air volume during the heating operation.

A temperature sensor 26 a and a humidity sensor 26 b are connected to the antifungal processing unit 81 . The temperature sensor 26a and the humidity sensor 26b may also be used as sensors used for cooling operation or heating operation of the air conditioner. The antifungal processing unit 81 estimates the amount of condensed water generated on the surface of the indoor heat exchanger 14 based on the temperature of the indoor heat exchanger 14 and the humidity inside the main body 28a. Here, the antifungal processing unit 81 may estimate the amount of condensed water based on the amount of saturated water vapor for each temperature detected by the temperature sensor 26a and the elapsed time of the cooling operation.

A timer 87 is connected to the antifungal processing unit 81 . A timer 87 keeps time according to an instruction from the antifungal processing unit 81 . The duration of operation of the air conditioner and the elapsed time from the end of operation are measured. The timer 87 outputs a timing signal to the antifungal processing section 81 . The clock signal identifies the value of time clocked. The antifungal processing unit 81 controls the operation of the valve switching control unit 82, the operation of the opening degree control unit 83, and the operation of the compressor control unit 84 in accordance with the measured time value.

(4) Antifungal Treatment Operation Next, the antifungal treatment operation performed in the air conditioner 11 will be described. The antifungal processing unit 81 of the control unit 27 operates to perform the antifungal processing operation. The antifungal treatment operation may be performed based on the temperature and humidity of the indoor heat exchanger 14 after cooling operation, for example. Upon execution of such an antifungal processing operation, the antifungal processing unit 81 is supplied with a notification of the end of the cooling operation from the cooling operation unit 78 .

As shown in FIG. 7, upon receiving the notification of the end of the cooling operation, the antifungal processing unit 81 stops the rotation of the blower fan 24 in step S1. The antifungal processing unit 81 supplies a command signal to the blower fan control unit 85 to stop the operation. The command signal specifies that the blower fan 24 should be stopped. Stopping the blower fan 24 suppresses evaporation of condensed water from the surface of the indoor heat exchanger 14 . At this time, the four-way valve 18 is maintained at the position during the cooling operation.

Note that the command signal supplied from the antifungal processing unit 81 in step S1 may be one that reduces the rotation speed of the fan or intermittently rotates the fan. It may be appropriately adjusted according to the amount of condensed water.

In step S<b>2 , the antifungal processing unit 81 identifies the amount of wetting of the indoor heat exchanger 14 from the amount of dew condensation water generated on the surface of the indoor heat exchanger 14 . In specifying the wetting amount, the antifungal processing unit 81 estimates the saturated water vapor amount from the temperature signal and the humidity signal. The antifungal processing unit 81 identifies the amount of condensed water based on the estimated saturated water vapor amount and the duration and elapsed time values measured by the timer 87 . In general, after cooling operation, the temperature of the indoor heat exchanger 14 is low and condensed water is generated on the surface of the indoor heat exchanger 14 .

If the estimated wetting amount falls short of the predetermined amount, the antifungal processing unit 81 cools the indoor heat exchanger 14 in step S3. In cooling the indoor heat exchanger 14 , the antifungal processing unit 81 supplies a command signal to the opening control unit 83 and the compressor control unit 84 . The command signal specifies, for example, the operation of the expansion valve 17 and the compressor 15 to reduce the evaporation temperature of the refrigerant within the indoor heat exchanger 14 . As a result, the temperature of the indoor heat exchanger 14 is lowered, promoting the formation of condensed water. Sufficient wetting can be ensured on the surface of the indoor heat exchanger 14 . The predetermined amount of wetness may be set to a water amount that does not prevent wet heat sterilization due to evaporation during heating of the indoor heat exchanger 14 for wet heat sterilization.

If the estimated wetting amount has reached the predetermined specified amount, the antifungal processing unit 81 heats the indoor heat exchanger 14 in step S4. Condensation of the refrigerant is used to heat the indoor heat exchanger 14 . At this time, the antifungal processing unit 81 supplies a command signal to the valve switching control unit 82 . The command signal specifies switching of the four-way valve 18 . The four-way valve 18 is switched to the position for heating operation. Here, the temperature of the indoor heat exchanger 14 during heating is set to 45 degrees Celsius or higher. Preferably, the temperature of the indoor heat exchanger 14 is set at 60 degrees Celsius or higher. In this way, the indoor heat exchanger 14 is heated without passing through the conventional drying operation and without evaporating the condensed water on the surface of the indoor heat exchanger 14 . The indoor heat exchanger 14 heats the condensed water. Bacteria and fungi are heated in the heated condensed water. Therefore, bacteria and fungi are sterilized by wet heat. It can kill bacteria and mold to reduce their numbers.

In particular, when the temperature of the indoor heat exchanger 14 is set to 45 degrees Celsius or more, the dew condensation water is heated to 45 degrees Celsius or more, and the wet heat sterilization of bacteria and fungi is effectively realized. Furthermore, when the temperature of the indoor heat exchanger 14 is set to 60 degrees Celsius or higher, the moist heat sterilization of bacteria and fungi can be achieved more effectively. The time to sterilization can be shortened. However, since it is desired to suppress evaporation of the condensed water as much as possible, it is desired that the temperature of the indoor heat exchanger 14 is set to the lowest possible temperature of 70 degrees Celsius or less. When the heat exchanger is dry, even if the temperature is set to 45 degrees Celsius or higher, it does not lead to the sterilization of bacteria and fungi.

When heating the indoor heat exchanger 14, the opening of the expansion valve 17 and the rotation of the blower fans 23 and 24 are appropriately adjusted so that the temperature of the indoor heat exchanger 14 does not exceed 60 degrees and become an overload condition. It should be adjusted.

At this time, heat is transmitted from the indoor heat exchanger 14 to the connecting body 73, the first drain pan 75a, and the second drain pan 75b. Condensation of the refrigerant is performed until the coupling body 73 and the first drain pan 75a and the second drain pan 75b reach the set temperature. The temperature of the connecting body 73 and the first drain pan 75a and the second drain pan 75b follow the temperature rise of the indoor heat exchanger 14 with a delay. Based on the temperature detected by the temperature sensor 26a, if the temperature of the indoor heat exchanger 14 exceeds a predetermined temperature for longer than a predetermined time, it may be determined that the set temperature has been reached. In order to directly measure the temperature of the portion to be heated, the connecting body 73 may be provided with a connecting body temperature sensor (not shown) for detecting the temperature of the connecting body. Similarly, a drain pan temperature sensor (not shown) may be provided near the heating of the first drain pan 75a and the second drain pan 75b. In this way, in the indoor heat exchanger 14, the connecting member 73 is sufficiently heated to the set temperature, so that bacteria and fungi are sufficiently heated in the condensed water generated on the surface of the connecting member 73 and are sterilized by wet heat. Similarly, since the first drain pan 75a and the second drain pan 75b are sufficiently heated to the set temperature, bacteria and fungi in the dew condensation water accumulated in the first drain pan 75a and the second drain pan 75b are sufficiently heated and sterilized by wet heat. .

In step S5, the antifungal processing unit 81 determines completion of moist heat sterilization. For example, the anti-mold processing unit 81 uses the timing of the timer 87 for determination. A timer 87 measures the duration of the set temperature. When the duration of the set temperature reaches the specified value, the antifungal processing unit 81 terminates the moist heat sterilization. If the duration of the set temperature is less than the specified value, the antifungal processing unit 81 continues the heating operation. The prescribed value for the duration of the set temperature should be longer than or equal to the time during which the moist heat sterilization effect can be obtained. According to experiments conducted by the applicant, it has been found that the effect of moist heat sterilization can be obtained by sterilizing E. coli for 3 minutes or longer and for black mold for 5 minutes or longer. Moreover, it is known that 10 minutes or longer is desirable for Legionella bacteria. At this time, the antifungal processing unit 81 observes the operation of the compressor 15 in step S6. When an overload of the compressor 15 is detected during heating up to the set temperature, the antifungal processing unit 81 lowers the discharge temperature of the compressor 15 in step S7 and terminates the heating operation. If no overload is detected, the heating operation is continued until the completion of wet heat sterilization is determined in step S5.

Here, the overload condition for the compressor 15 that is set during condensation is relaxed compared to the overload condition for the compressor 15 that is set during the heating operation. In other words, the discharge temperature, which is the threshold for the overload condition, is set high, or the time until the overload protection is activated when the discharge temperature exceeds the threshold for the overload condition for a predetermined time is set long. do. Since the overload condition of the compressor 15 is alleviated during the antifungal treatment operation, the indoor heat exchanger 14 can be heated to a higher temperature than during the heating operation. Moist heat sterilization of bacteria and fungi is realized.

In the antifungal treatment operation of the air conditioner 11, the drying treatment inside the main body 28a may be performed following the moist heat sterilization treatment. In this drying process, the rotation of the blower fan 24 is started while the heating of the indoor heat exchanger 14 is maintained. When the blower fan 24 rotates, the antifungal processing unit 81 supplies a command signal to the blower fan control unit 85 . The command signal specifies the rotation speed of the blower fan 24 . Rotation of the blower fan 24 promotes evaporation of the heated dew condensation water. At this time, the outlet 33 may be closed by the vertical wind direction plates 25a and 25b. The antifungal processing unit 81 supplies a command signal to the wind direction control unit 86 to close the air outlet 33 . The command signal specifies the minimum angle of the vertical wind direction plates 25a, 25b. Blowing out of warm air after the cooling operation is thus avoided. By continuing the dry heating following the wet heat sterilization, the growth of bacteria and fungi remaining after the wet heat sterilization is suppressed.

DESCRIPTION OF SYMBOLS 11... Air conditioner, 14... Heat exchanger (indoor heat exchanger), 14a... Front side body, 14b... Rear side body, 15... Compressor, 24... Blower fan (of indoor unit), 73... Coupled body, 75a Drain pan (first drain pan), 75b Drain pan (second drain pan), 76 Heat transfer member (third heat transfer member), 77 Heat transfer member (fourth heat transfer member).

Claims (1)

a step of wetting the surface of the heat exchanger with condensed water resulting from evaporation of the refrigerant;
While sending airflow to the heat exchanger according to the rotation of the blower fan, the heat exchanger is heated based on the condensation of the refrigerant, the temperature of the heat exchanger is maintained at 45 degrees Celsius or more and 60 degrees Celsius or less, a step of performing sterilization in condensed water ;
A mold prevention method for an air conditioner, comprising:

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