WO2024105856A1

WO2024105856A1 - Air conditioner

Info

Publication number: WO2024105856A1
Application number: PCT/JP2022/042733
Authority: WO
Inventors: 俊光鎌田; 尚平石村
Original assignee: 三菱電機株式会社
Priority date: 2022-11-17
Filing date: 2022-11-17
Publication date: 2024-05-23
Also published as: JP7490143B1; JPWO2024105856A1

Abstract

An air conditioner according to the present disclosure comprises: a refrigerant circuit including a compressor, a flow path switch, an indoor heat exchanger, a pressure reducer, and an outdoor heat exchanger, the compressor and the flow path switch being provided midway along one refrigerant pipe connecting the indoor heat exchanger and the outdoor heat exchanger, and the pressure reducer being provided midway along another refrigerant pipe connecting the indoor heat exchanger and the outdoor heat exchanger; a water collecting tank for collecting water generated by cooling outside air by means of the outdoor heat exchanger; a bypass pipe which branches from a branch portion provided in the refrigerant pipe between the compressor and the indoor heat exchanger, and which is connected to a merging portion provided in the refrigerant pipe between the branch portion and the pressure reducer; a bypass valve which is provided midway along the bypass pipe and which changes a flow rate of a refrigerant flowing through the bypass pipe; an auxiliary heat exchanger which is provided midway along the bypass pipe and which heats the water collected in the water collecting tank to 55°C or higher; a humidification element which is supplied with water from the water collecting tank; and a humidification duct which sends air that has been humidified by passing through the humidification element into a room.

Description

Air conditioners

This disclosure relates to an air conditioner with a humidification function.

An air conditioner with a humidification function can prevent the air in the room from drying out by operating the humidification function during air conditioning operation. In addition, as shown in Patent Document 1, for example, an air conditioner with a humidification function that uses water generated by condensing water vapor contained in the outside air for humidification, and does not require the supply of moisture from outside, is disclosed.

Patent No. 6987320 Public Relations

However, in such air conditioners, in order to maintain the quality of the humidified air, it is necessary to prevent the growth of bacteria in the humidifying water. One effective method for preventing the growth of bacteria in the humidifying water is sterilization by heating, but the heating process increases power consumption. For this reason, there is an issue that preventing the growth of bacteria in the humidifying water increases the power consumption of the air conditioner.

An air conditioner having a compressor, a flow path switching device, an indoor heat exchanger, a pressure reducer, and an outdoor heat exchanger, the compressor and the flow path switching device being provided in one of the refrigerant pipings connecting the indoor heat exchanger and the outdoor heat exchanger, the pressure reducer being provided in the other of the refrigerant pipings connecting the indoor heat exchanger and the outdoor heat exchanger, a refrigerant circuit, a water tank for storing water generated by cooling outdoor air by the outdoor heat exchanger, a bypass piping that branches off from a branching part provided in the refrigerant piping between the compressor and the indoor heat exchanger and is connected to a junction part provided in the refrigerant piping between the branching part and the pressure reducer, a bypass valve provided in the bypass piping and changing the flow rate of refrigerant flowing through the bypass piping, an accessory heat exchanger provided in the bypass piping and heating the water stored in the water tank to 55°C or higher, a humidification element installed at a position where water is supplied from the water tank, and a humidification duct for sending air humidified by passing through the humidification element into the room.

According to the present disclosure, it is possible to provide an air conditioner that prevents the growth of bacteria in the humidification water while suppressing increases in power consumption.

Schematic diagram of a refrigerant circuit of an air conditioner 1 according to embodiment 1. FIG. 1 is a schematic diagram showing an internal structure of an outdoor unit 110 according to a first embodiment. Schematic diagram of a refrigerant circuit of an air conditioner 1 according to embodiment 2. Schematic cross-sectional view of an outdoor unit 110 according to a third embodiment. 13 is a schematic cross-sectional view of an auxiliary heat exchanger 26 according to a fourth embodiment of the present invention; FIG. 13 is a schematic cross-sectional view of an auxiliary heat exchanger 26 according to a modification of the fourth embodiment. 13 is a schematic cross-sectional view of an outdoor unit 110 according to a fifth embodiment of the present invention; 13 is a schematic cross-sectional view of an outdoor unit 110 according to a sixth embodiment of the present invention; A flow diagram showing an example of control of the air conditioner 1 according to the sixth embodiment.

Below is an example of an air conditioner according to the present disclosure, but it is not limited to the embodiment shown below, and can be modified as desired without departing from the gist of the present disclosure. Also, for convenience, repeated explanations may be omitted.

Embodiment 1.
(overall structure)
Fig. 1 is a schematic diagram of a refrigerant circuit of an air conditioner 1 according to embodiment 1. Fig. 2 is a schematic diagram showing the internal structure of an outdoor unit 110 according to embodiment 1.
As shown in FIG. 1, the air conditioner 1 according to the first embodiment includes a refrigerant circuit passing through an outdoor unit 110 and an indoor unit 120. The refrigerant circuit includes a compressor 11, a flow path switching device 12 that switches the inlet and outlet flow paths of the compressor 11, an indoor heat exchanger 14, a pressure reducing device 15, and an outdoor heat exchanger 17. The compressor 11 and the flow path switching device 12 are provided in one refrigerant pipe that connects the indoor heat exchanger 14 and the outdoor heat exchanger 17, and the pressure reducing device 15 is provided in the other refrigerant pipe that connects the indoor heat exchanger 14 and the outdoor heat exchanger 17. In addition, the refrigerant circuit shown in the first embodiment includes a bypass pipe 24 that connects a branching portion 22 provided in the refrigerant pipe between the compressor 11 and the indoor heat exchanger 14 and a junction portion 23 provided in the refrigerant pipe between the branching portion 22 and the pressure reducing device 15. A bypass valve 25 that changes the flow rate of the refrigerant flowing through the bypass pipe 24 and an auxiliary heat exchanger 26 are provided in the middle of the bypass pipe 24. Furthermore, the air conditioner shown in the first embodiment has a water tank 21 that stores water generated by cooling outdoor air with the outdoor heat exchanger 17 and condensing water vapor. The auxiliary heat exchanger 26 functions as a heating unit that heats the water stored in the water tank 21. The air conditioner is provided with a humidifier 130 that humidifies the room using the water in the water tank 21 that has been heated by the auxiliary heat exchanger 26, which is a heating unit. Furthermore, the outdoor unit 110 is provided with an outdoor fan 16 for supplying airflow to the outdoor heat exchanger 17, and the indoor unit 120 is provided with an indoor fan 13 for supplying airflow to the indoor heat exchanger 14. The controller 18 controls the devices that constitute the air conditioner 1, including the compressor 11, and controls the operation of each necessary device so that the air conditioner 1 operates toward the set indoor target temperature and target humidity. 1, the controller 18 is shown in the outdoor unit 110, but the location of the controller 18 is not limited to the outdoor unit 110 as long as it can appropriately control the operation of each device, and a plurality of controllers may be installed. The humidifier 130 includes an air preheater 31, a humidifier element 32, an air heater 33, a humidifier fan 34, and a water supply regulator 37, and the humidifier 130 and the indoor unit 120 are connected by a humidifier duct 36. Although the drawings in this disclosure do not include a mechanism for supplying water to the water collection tank 21 from the outside, the water collection tank 21 may include a mechanism for supplying water from the outside.

(Heating operation)
First, the operation of the heating operation will be described. In the case of the heating operation, the bypass valve 25 in Fig. 1 is closed, the flow path switching device 12 is in the state shown by the solid line in Fig. 1, the pressure reducing device 15 is set to a predetermined opening degree, and the compressor 11 is started. The high-temperature, high-pressure refrigerant discharged from the compressor 11 is condensed in the indoor heat exchanger 14 and then reduced in pressure by the pressure reducing device 15. The reduced-pressure, low-temperature, low-pressure refrigerant evaporates in the outdoor heat exchanger 17, passes through the flow path switching device 12, and is sucked into the compressor 11. When the refrigerant condenses in the indoor heat exchanger 14, the heat of the refrigerant is released through the indoor heat exchanger 14, so that the air that has received the heat is blown into the room as warm air by the indoor fan 13. The operation of the devices constituting the air conditioner 1, including the compressor 11, is controlled by the controller 18, for example, so that the indoor temperature becomes a set target indoor temperature.

(Humidifying and heating operation)
Next, the operation of the heating operation with humidification, that is, the humidification heating operation will be described. In the heating operation, as in the heating operation, the high-temperature, high-pressure refrigerant discharged from the compressor 11 releases heat when condensing in the indoor heat exchanger 14, and the air that has received the heat is blown into the room, thereby warming the room. The condensed refrigerant is then decompressed in the pressure reducer 15, and becomes a low-temperature, low-pressure refrigerant, which flows through the outdoor heat exchanger 17. In the outdoor heat exchanger 17, the low-temperature, low-pressure refrigerant absorbs heat from the outdoor air and evaporates, and the water vapor in the outdoor air that has lost heat becomes below the dew point temperature and condenses into water, which is then used as water for humidification. The operation of the outdoor unit 110 will be described more specifically with reference to FIG. 2. The outdoor air passes through the outdoor heat exchanger 17 in the direction indicated by the arrow A1, and heat exchange takes place between the outdoor air and the refrigerant. As a result of the heat exchange, the water vapor in the outdoor air condenses into water, which adheres to the surface of the outdoor heat exchanger 17. Water adhering to the surface of the outdoor heat exchanger 17 flows down in the direction of the arrow W1 by gravity and accumulates in the water collection tank 21 through the water supply port 35. The water accumulated in the water collection tank 21 is supplied to the humidification element 32 after the water supply amount adjustment unit 37 adjusts the water amount. As shown in FIG. 1 and FIG. 2, the humidification element 32 is located below the water supply amount adjustment unit 37, and by opening the water supply amount adjustment unit 37, the water in the water collection tank 21 flows down to the humidification element 32. Furthermore, by driving the humidification fan 34, the outside air is taken into the humidification device 130 as shown by the arrow A2, passes through the air preheater 31, the humidification element 32, and the air heater 33 in this order, and flows toward the room through the humidification duct 36. As described above, water is supplied to the humidification element 32, so that the air passing through the humidification element 32 is humidified, and the humidified air is supplied to the room through the humidification duct 36. By controlling the heating by the air preheater 31, the temperature of the air supplied to the humidification element 32 is changed, and the amount of saturated water vapor is adjusted. As a result, the amount of water vapor contained in the air humidified by passing through the humidification element 32 can be controlled. In addition, by heating the humidified air sent to the humidification duct 36 by the air heater 33, the humidity can be kept relatively low compared to unheated air. Furthermore, since the humidification duct 36 is heated, condensation is prevented from occurring on the inner surface of the humidification duct 36. Note that, for example, an electric heater can be applied as the air preheater 31 and the air heater 33 to enable heating with good controllability, but this is not limited to an electric heater and other heating means may be used.

(Heat sterilization of water for humidification)
As described above, in an air conditioner having a humidifying function, it is required to prevent the growth of bacteria in the humidifying water so as not to pollute the air quality in the room. One of the methods for preventing the growth of bacteria in the humidifying water is sterilization by heating. For example, if Legionella bacteria, which are widely distributed in nature and require caution because they can cause pneumonia and the like when infected by humans, are used as an indicator, according to Non-Patent Documents 1, 2, and 3, it is said that the bacteria can be killed by setting the temperature of the water at 55°C or higher, and that it can be sterilized at a temperature of 60°C in 5 minutes. In addition, according to Non-Patent Document 4, the heating time required for sterilization can be further shortened by increasing the heating temperature, and for example, at a temperature of 80°C, the effect can be obtained by heating for a few seconds. Therefore, it is effective to apply a heating treatment at 55°C or higher as a method for preventing the growth of bacteria in the humidifying water. However, if the humidifying water is heated only by an electric heater, for example, electricity for the heating treatment is required in addition to the heating operation. Therefore, if the growth of bacteria in the humidifying water is prevented, the power consumption of the air conditioner as a whole increases.

(Heated by attached heat exchanger)
One method for preventing the growth of bacteria in the humidification water while suppressing the increase in the power consumption of the air conditioner is to heat the water by using the heat of the refrigerant. In the case of the configuration shown in FIG. 1, the humidification water stored in the water collection tank 21 can be heated by flowing a part of the high-temperature, high-pressure refrigerant flowing from the compressor 11 to the indoor heat exchanger 14 to the auxiliary heat exchanger 26 during heating operation. More specifically, first, the bypass valve 25 is opened, and a part of the high-temperature, high-pressure refrigerant discharged from the compressor 11 flows into the bypass piping 24. The high-temperature, high-pressure refrigerant that has flowed into the bypass piping 24 flows through the auxiliary heat exchanger 26 provided in the water collection tank 21, and heats the humidification water stored in the water collection tank 21. Therefore, by adjusting the opening degree of the bypass valve 25, the refrigerant required for the heating operation can be flowed to the indoor heat exchanger 14, while the refrigerant required for the heating process of the humidification water can be flowed to the auxiliary heat exchanger 26. The refrigerant that has passed through the auxiliary heat exchanger 26 joins with the refrigerant that has passed through the indoor heat exchanger 14 at the joining section 23 and flows to the pressure reducer 15. The flow of the refrigerant after the pressure reducer 15 is omitted because it is the same as that in the heating operation. The amount of water heated by the auxiliary heat exchanger 26 can be controlled by the controller 18 to control the opening degree of the bypass valve 25 and the amount of refrigerant discharged by the compressor 11 based on one or a combination of parameters related to the air conditioner 1, such as the amount of water stored in the water collection tank 21, the water temperature, the refrigerant temperature, and the flow rate of refrigerant required for the heating operation. This makes it possible to adjust the flow rate of refrigerant required for the heating operation and the flow rate of refrigerant required for the heating treatment of the water for humidification, so that the heat of the refrigerant can be used to heat the water for humidification while performing the heating operation. In other words, by using the heat of the refrigerant also for the heating treatment of the water for humidification, the power consumption required for the heating treatment can be suppressed, and the increase in power consumption of the air conditioner as a whole can be suppressed.

As described above, the air conditioner 1 of embodiment 1 is capable of heating the water for humidification stored in the water collection tank 21 by flowing a portion of the high-temperature, high-pressure refrigerant flowing from the compressor 11 to the indoor heat exchanger 14 through the auxiliary heat exchanger 26 during heating operation, and is therefore an air conditioner that can use the heat of the refrigerant to heat the water for humidification while performing heating operation.
An air conditioner configured in this manner can also use the heat of the refrigerant to heat the water for humidification, thereby suppressing the increase in power consumption associated with preventing the growth of bacteria in the water for humidification.

Therefore, by applying the air conditioner shown in embodiment 1, it is possible to provide an air conditioner that prevents the growth of bacteria in the humidification water while suppressing increases in power consumption.

Embodiment 2.
(Modification of refrigerant circuit)
FIG. 3 is a schematic diagram of a refrigerant circuit of the air conditioner 1 according to the second embodiment.
The air conditioner 1 of the second embodiment differs from the first embodiment in that the junction 23 is provided between the branch 22 and the indoor heat exchanger 14. When the junction 23 is provided between the branch 22 and the indoor heat exchanger 14, unlike the first embodiment, even if a part of the refrigerant flows to the auxiliary heat exchanger 26, the refrigerant that has passed through the auxiliary heat exchanger 26 can be merged with the refrigerant that has not passed through the auxiliary heat exchanger 26 at the junction 23 and flow to the indoor heat exchanger 14. By configuring the refrigerant circuit in this way, the heat of the refrigerant after heating the humidification water can be used for heating the room without being wasted.

As described above, the air conditioner 1 of embodiment 2 is capable of heating the water for humidification stored in the water collection tank 21 by flowing a portion of the high-temperature, high-pressure refrigerant flowing from the compressor 11 to the indoor heat exchanger 14 through the auxiliary heat exchanger 26 during heating operation, and is therefore an air conditioner that can use the heat of the refrigerant to heat the water for humidification while performing heating operation.
An air conditioner configured in this manner can also use the heat of the refrigerant to heat the humidification water, thereby suppressing the increase in power consumption that would be associated with preventing the growth of bacteria in the humidification water, and furthermore, the heat of the refrigerant after heating the humidification water can be used for heating operation.

Therefore, by applying the air conditioner shown in embodiment 2, it is possible to provide an air conditioner that prevents the growth of bacteria in the humidification water while suppressing an increase in power consumption, and further allows the heat of the refrigerant after heating the humidification water to be used for heating operation.

Embodiment 3.
(Configuration of water collection tank and attached heat exchanger)
4 is a schematic cross-sectional view of the outdoor unit 110 according to embodiment 3. The cross-sectional position corresponds to the X-X cross section shown in FIG.
The third embodiment is different from the first embodiment in that the auxiliary heat exchanger 26 constitutes the bottom of the water collection tank 21 as shown in Fig. 4. According to this configuration, the water stored in the water collection tank 21 is heated at the bottom, so that the water with a higher temperature rises toward the water surface and the water with a relatively lower temperature falls, which is called convection heat transfer, and therefore there is no need to stir the water in the water collection tank 21. As a result, the water for humidification can be efficiently heated without adding a mechanism and power for stirring the water. In the third embodiment, an example in which the bottom is constituted by the auxiliary heat exchanger 26 is shown, but since it is sufficient that convection heat transfer occurs in the water for humidification, it is not necessarily required that the bottom is constituted by the auxiliary heat exchanger 26. It is sufficient that the auxiliary heat exchanger 26 is provided near the bottom of the water collection tank 21 and that the water at the bottom of the water collection tank 21 can be heated.

As described above, the air conditioner 1 of embodiment 3 is an air conditioner that can generate convective heat transfer in the humidification water stored in the water collection tank 21 and heat it by configuring the bottom portion of the water collection tank 21 with an attached heat exchanger 26.
An air conditioner configured in this manner can heat the water to be humidified by generating convective heat transfer without adding a mechanism or power for stirring the water in the water collection tank, thereby efficiently heating the water to be humidified.

Therefore, by applying the air conditioner shown in embodiment 3, in addition to the effect of embodiment 1, it is possible to provide an air conditioner that can efficiently heat water for humidification without adding a mechanism or power for stirring the water.

Embodiment 4.
(Structure of accessory heat exchanger 1)
FIG. 5 is a schematic cross-sectional view of an auxiliary heat exchanger 26 according to the fourth embodiment.
In the fourth embodiment, as shown in Figs. 4 and 5, the auxiliary heat exchanger 26 is different from the first embodiment in that it is a flat multi-hole tube having a plate-like external shape. According to this configuration, the flat multi-hole tube has a pressure resistance as a flow path through which the refrigerant flows, and has a heat transfer performance superior to that of a tube-type heat exchanger, so that the water for humidification can be heated more efficiently. Furthermore, since the external shape is plate-like, it is easy to install it at the bottom of the water collection tank 21, so that the water for humidification can be heated efficiently as described above. In addition, a specific example of the material of the auxiliary heat exchanger 26 shown in the fourth embodiment is 1000-series aluminum, which has good thermal conductivity, and is also preferable as a material because it can be extruded and is easy to manufacture. However, the material of the auxiliary heat exchanger 26 is not limited to 1000-series aluminum, and other alloys of different specifications can be applied according to the pressure resistance of the refrigerant flow path required for the air conditioner to be applied.

As described above, the air conditioner 1 of the fourth embodiment is an air conditioner to which the auxiliary heat exchanger 26 constituted by a flat multi-hole tube is applied.
An air conditioner configured in this manner can obtain better heat transfer performance than a tubular heat exchanger, and can therefore perform heating treatment of water for humidification more efficiently.

Therefore, by applying the air conditioner shown in embodiment 4, in addition to the effects of embodiment 1, it is possible to configure an auxiliary heat exchanger with superior thermal conductivity, and therefore it is possible to provide an air conditioner that can more efficiently heat the water for humidification.

A modified example of embodiment 4.
(Structure of accessory heat exchanger 2)
FIG. 6 is a schematic cross-sectional view of an auxiliary heat exchanger 26 according to a modified example of the fourth embodiment.
In the modified example of the fourth embodiment, as shown in Fig. 4 and Fig. 6, the auxiliary heat exchanger 26 is different from the first embodiment in that, instead of the flat multi-hole tube having a plate-like external shape shown in the fourth embodiment, the auxiliary heat exchanger 26 is a member in which an inner fin made by pressing a plate material into a corrugated shape is surrounded by a roll-formed plate material and the ends are joined. With this configuration, as in the fourth embodiment, a heat transfer performance superior to that of a tube-type heat exchanger can be obtained, and the water for humidification can be heated more efficiently. Furthermore, since the external shape is plate-like, it is easy to install it at the bottom of the water collection tank 21, and the water for humidification can be heated efficiently as described above.

As described above, the air conditioner according to the modified example of the fourth embodiment is an air conditioner to which the auxiliary heat exchanger 26 is applied, which is configured from a member formed by roll-forming the periphery of a corrugated inner fin.
As in the fourth embodiment, the air conditioner configured in this manner can obtain better heat transfer performance than a tubular heat exchanger, and can therefore perform heating of water for humidification more efficiently.

Therefore, by applying the air conditioner shown in the modified example of embodiment 4, in addition to the effects of embodiment 1, it is possible to configure an auxiliary heat exchanger with superior thermal conductivity, thereby providing an air conditioner that can more efficiently heat water for humidification.

Embodiment 5.
(Use of an auxiliary heating unit independent of the refrigerant circuit)
7 is a schematic cross-sectional view of the outdoor unit 110 according to embodiment 5. The cross-sectional position corresponds to the X-X cross section shown in FIG.
As shown in Fig. 7, the fifth embodiment differs from the first embodiment in that an electric heater 38 is provided in the water collection tank 21 in addition to the auxiliary heat exchanger 26. The electric heater 38 can heat the water for humidification stored in the water collection tank 21. In other words, in the fifth embodiment, the water for humidification stored in the water collection tank 21 can be heated by only the auxiliary heat exchanger 26, by only the electric heater 38, or by both the auxiliary heat exchanger 26 and the electric heater 38. In the heating operation with the configuration shown in the first embodiment, when the difference between the target temperature of the indoor air and the current room temperature is large and the indoor air needs to be heated quickly, it becomes necessary to flow most of the high-temperature, high-pressure refrigerant to the indoor heat exchanger 14, so that the refrigerant supplied to the auxiliary heat exchanger 26 decreases, and the water for humidification cannot be sufficiently heated by only the auxiliary heat exchanger 26. In addition, when there is almost no difference between the target temperature of the indoor air and the current room temperature, and the amount of water in the water collection tank 21 is sufficient and there is no need to generate water for humidification in the outdoor heat exchanger 17, the refrigerant circuit operates only to heat the water for humidification, which results in a loss of power consumption. Furthermore, when there is almost no difference between the target temperature of the indoor air and the current room temperature, and the humidity and dew point temperature of the outdoor air are high, the temperature of the refrigerant discharged from the compressor 11 is not sufficient, and the amount of heat supplied to the auxiliary heat exchanger 26 decreases, which may result in a state in which the water for humidification cannot be sufficiently heated. In this way, when the water for humidification cannot be sufficiently heated by the auxiliary heat exchanger 26 alone, the electric heater 38 is provided as an auxiliary heating section independent of the refrigerant circuit, so that the amount of heat that is insufficient in the auxiliary heat exchanger 26 can be compensated for by the electric heater 38. In addition, in sterilization by heat treatment, the higher the heating temperature, the shorter the treatment time. Therefore, by using the electric heater 38 to increase the heating temperature and shorten the heating treatment time, the start of the humidification operation can be accelerated.
Although the electric heater 38 has been given as an example of an auxiliary heating section independent of the refrigerant circuit, the present invention is not limited to this, and the same effect can be obtained as long as there is an auxiliary heating section independent of the refrigerant circuit.

As described above, the air conditioner of the fifth embodiment is an air conditioner that includes the electric heater 38 in the water collection tank 21 in addition to the auxiliary heat exchanger 26 .
In an air conditioner configured in this manner, even if the heating capacity of the auxiliary heat exchanger alone is insufficient, the electric heater can be used as an auxiliary heating section independent of the refrigerant circuit.

Therefore, by applying the air conditioner shown in embodiment 5, in addition to the effects of embodiment 1, it is possible to provide an air conditioner that is equipped with an auxiliary heating section independent of the refrigerant circuit, and that can more efficiently heat the water for humidification even when the heating capacity of the attached heat exchanger alone is insufficient.

Embodiment 6.
(Temperature sensor added)
Fig. 8 is a schematic cross-sectional view of the outdoor unit 110 according to embodiment 6. The cross-sectional position corresponds to the X-X cross section shown in Fig. 2. Fig. 9 is a flow diagram showing an example of control of the air conditioner 1 according to embodiment 6.
The sixth embodiment differs from the first embodiment in that a temperature sensor 39 is provided in the water collection tank 21 in addition to the auxiliary heat exchanger 26. By providing the temperature sensor 39, the temperature of the humidification water can be measured, and the amount of heating can be controlled appropriately according to the temperature of the humidification water. As an example, as shown in FIG. 8, an electric heater 38 and a temperature sensor 39 are provided in the water collection tank 21 in addition to the auxiliary heat exchanger 26, and the operation thereof will be described below. In the configuration shown in FIG. 8, a control example is shown in which the amount of humidification water in the water collection tank 21 and the amount of heating by the auxiliary heat exchanger 26 may vary depending on the operating status of the air conditioner and the temperature and humidity of the outside air, and therefore the amount of heating to be performed by the electric heater 38 is not constant. If the amount of heating by the electric heater 38 is too small, the water for humidification cannot be sufficiently heated, and the humidification operation may cause indoor pollution. On the other hand, if the amount of heating by the electric heater 38 is excessive, the amount of water for humidification may be insufficient due to boiling of the water for humidification, or the electric heater 38 may continue heating while exposed from the water surface, resulting in an overheating, which may cause malfunction of the device. Therefore, the controller 18 judges the situation using the temperature measured by the temperature sensor 39, and appropriately controls each device based on the judgment result, thereby enabling more appropriate operation of the air conditioner. As a simple example, it is possible to judge whether the amount of water for humidification has reached the position where the temperature sensor 39 is installed depending on whether the temperature measured by the temperature sensor 39 is within a certain range from the temperature of the refrigerant supplied to the auxiliary heat exchanger 26, and whether heating by the electric heater 38 is necessary depending on whether the temperature measured by the temperature sensor 39 is equal to or higher than the temperature set as the heating process. Furthermore, it is possible to operate more appropriately and efficiently by controlling the operation of each device constituting the air conditioner, including the compressor 11, the outdoor heat exchanger 17, the auxiliary heat exchanger 26, and the electric heater 38, based on each judgment result.
Next, a control example of the air conditioner 1 according to the sixth embodiment will be described with reference to the flow chart of FIG. 9. First, the heating operation is started (STEP 01), and the outdoor heat exchanger 17 is cooled to a temperature equal to or lower than the dew point temperature of the outdoor air (STEP 02). When the outdoor dew point temperature is below freezing, the water vapor contained in the outdoor air forms frost on the surface of the outdoor heat exchanger 17 and adheres thereto. The frost is melted by the defrost operation (STEP 04), and the frost is stored in the water collection tank 21 as water for humidification (STEP 05). Here, as a method of defrost operation, a so-called "reverse cycle defrost" method is generally used in which the refrigerant flows in the opposite direction to that during the heating operation, and the high-temperature, high-pressure refrigerant discharged from the compressor 11 is heated by flowing it through the outdoor heat exchanger 17. However, as long as it is sufficient to melt the frost, a method other than the "reverse cycle defrost" may be used. When the accumulation of water for humidification begins in the water collection tank 21, the supply of high-temperature, high-pressure refrigerant to the auxiliary heat exchanger 26 is started (STEP 06). Next, it is determined whether or not a sufficient amount of water has accumulated for humidification operation, depending on whether or not the difference between the measured value of the temperature sensor 39 and the temperature of the refrigerant supplied to the auxiliary heat exchanger 26 is within a preset range (STEP 07). This is based on the fact that when the water level in the water collection tank 21 rises and reaches the temperature sensor 39, the temperature measured by the temperature sensor 39 approaches the temperature of the refrigerant supplied to the auxiliary heat exchanger 26. When the difference between the measured value of the temperature sensor 39 and the temperature of the refrigerant supplied to the auxiliary heat exchanger 26 falls within a preset range, it is determined that the water accumulated in the water collection tank 21 has reached the position of the temperature sensor 39, and it is determined that there is a sufficient amount of water for humidification operation. Next, it is determined whether or not the temperature of the water in the water collection tank 21 measured by the temperature sensor 39 has reached a preset heating temperature (STEP 08). If it has reached the preset heating temperature, it is determined that the water in the water collection tank 21 has been heated, and the supply of water to the humidification element 32 is started without heating by the electric heater 38 (STEP 12). If the temperature of the water in the water collection tank 21 measured by the temperature sensor 39 does not reach the preset heating temperature, it is determined that the heating by the auxiliary heat exchanger 26 alone is insufficient, and heating by the electric heater 38 is started (STEP 09). After starting heating by the electric heater 38, it is determined whether the temperature of the water in the water collection tank 21 measured by the temperature sensor 39 has reached the preset heating temperature (STEP 10). If the temperature of the water in the water collection tank 21 has reached the preset heating temperature, it is determined that the water in the water collection tank 21 has been heated, heating by the electric heater 38 is stopped (STEP 11), and the supply of water to the humidification element 32 is started (STEP 12). If the temperature of the water in the water collection tank 21 has not reached the preset heating temperature, it is necessary to continue heating by the electric heater 38, so the process returns to STEP 09. In this way, by controlling the air conditioner 1 by the controller 18 based on the temperature measurement value by the temperature sensor 39, the amount of heating by the electric heater 38 can be controlled without excess or deficiency, and the water for humidification can be heated.
Although the electric heater 38 has been described as an auxiliary heating unit independent of the refrigerant circuit, the present invention is not limited to this, and any auxiliary heating unit independent of the refrigerant circuit can provide the same effect. Also, although the method of estimating the water volume in the water collection tank 21 using the temperature sensor 39 has been described, this is not the only method that can be used as long as the water level can be estimated, and for example, a method of measuring the water level using a water immersion sensor may be used.

As described above, the air conditioner 1 of the sixth embodiment is an air conditioner that includes the temperature sensor 39 in the water collection tank 21 in addition to the auxiliary heat exchanger 26 .
An air conditioner configured in this manner can control the amount of heating according to the amount and temperature of water for humidification in the water collection tank, and therefore can heat the water for humidification reliably and efficiently.

Therefore, by applying the air conditioner shown in embodiment 6, in addition to the effect of embodiment 1, it is possible to provide an air conditioner that can reliably and more efficiently heat the water for humidification because the amount of heating can be controlled based on information obtained from the temperature sensor.

Reference Signs List 1 Air conditioner 11 Compressor 12 Flow path switch 13 Indoor fan 14 Indoor heat exchanger 15 Pressure reducer 16 Outdoor fan 17 Outdoor heat exchanger 18 Controller 21 Water collection tank 22 Branching section 23 Junction section 24 Bypass piping 25 Bypass valve 26 Auxiliary heat exchanger 31 Air preheater 32 Humidification element 33 Air heater 34 Humidification fan 35 Water supply port 36 Humidification duct 37 Supply water amount adjustment section 38 Electric heater 39 Temperature sensor 110 Outdoor unit 120 Indoor unit 130 Humidification device

Claims

a refrigerant circuit including a compressor, a flow path switching device, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger, the compressor and the flow path switching device being provided in one of the refrigerant pipings connecting the indoor heat exchanger and the outdoor heat exchanger, and the pressure reducing device being provided in the other of the refrigerant pipings connecting the indoor heat exchanger and the outdoor heat exchanger;
a water collection tank for storing water generated by cooling the outdoor air by the outdoor heat exchanger;
a bypass pipe that branches off from a branching portion provided in the refrigerant pipe between the compressor and the indoor heat exchanger and is connected to a junction portion provided in the refrigerant pipe between the branching portion and the pressure reducer;
a bypass valve provided in the bypass pipe to change a flow rate of the refrigerant flowing through the bypass pipe;
an auxiliary heat exchanger provided in the bypass piping and configured to heat the water stored in the water collection tank to 55°C or higher;
a humidification element disposed at a position where water is supplied from the water collecting tank;
a humidification duct for sending air humidified by passing through the humidification element into a room;
An air conditioner equipped with
The junction is provided between the branch and the indoor heat exchanger.
The air conditioner according to claim 1.
The junction is provided between the indoor heat exchanger and the pressure reducer.
The air conditioner according to claim 1.
The auxiliary heat exchanger is provided at the bottom of the water collection tank.
An air conditioner according to any one of claims 1 to 3.
The auxiliary heat exchanger has a flat multi-hole tube structure;
An air conditioner according to any one of claims 1 to 4.
The auxiliary heat exchanger has a structure in which the periphery of a corrugated inner fin is roll-formed.
An air conditioner according to any one of claims 1 to 4.
An auxiliary heating unit that heats the water stored in the water collection tank and is independent of the refrigerant circuit.
An air conditioner according to any one of claims 1 to 6.
The auxiliary heating unit is an electric heater.
8. An air conditioner according to claim 7.
A water supply amount adjusting unit is provided to adjust the amount of water supplied to the humidification element.
An air conditioner according to any one of claims 1 to 8.
A temperature sensor is provided to measure the temperature of the water stored in the water tank;
Based on the water temperature measured by the temperature sensor, the controller controls the amount of heating so that the water temperature becomes a predetermined temperature of 55°C or higher.
An air conditioner according to any one of claims 1 to 9.