JP2024057843A - Air conditioner, control method, program, and storage medium - Google Patents

Abstract

[Problem] To provide an air conditioner, a control method, a program, and a storage medium that suppress condensation caused by ventilation operation. [Solution] The air conditioner includes a ventilation device and a control unit. The ventilation device is configured to supply outdoor air to a controlled space that is the target of air conditioning control of the air conditioner. In a cooling ventilation mode in which both cooling operation and ventilation operation by the ventilation device can be performed, the control unit is configured to acquire a set temperature related to cooling control in the cooling ventilation mode and an indoor temperature of the controlled space, and if it is determined that the temperature difference obtained by subtracting the set temperature from the indoor temperature is lower than a first temperature threshold, to perform a dehumidification operation that throttles the expansion valve of the air conditioner, and to perform supply air ventilation by the ventilation device. [Selected Figure] Figure 5

Description

This disclosure relates to an air conditioner, a control method, a program, and a storage medium.

As described in Patent Document 1, there is a conventional air conditioner that is composed of an indoor unit that is placed in the room to be air-conditioned and an outdoor unit that is placed outside the room. This air conditioner is configured so that outdoor air can be supplied from the outdoor unit to the indoor unit.

JP 2001-91000 A

Conventional air conditioners are capable of supplying outdoor air to the indoor unit. However, when outdoor air is supplied to the indoor unit, there is an issue that condensation occurs on the fan in the indoor unit.

The objective of this disclosure is to provide an air conditioner, a control method, and a program that suppresses the phenomenon of condensation on the fan in the indoor unit caused by ventilation operation.

To solve the above-mentioned problems, the present disclosure provides an air conditioner, a control method, and a program.

An air conditioner according to one aspect of the present disclosure includes a ventilation device and a control unit. The ventilation device is configured to supply outdoor air to a controlled space that is the target of air conditioning control of the air conditioner. In a cooling ventilation mode in which both cooling operation and ventilation operation by the ventilation device can be performed, the control unit is configured to acquire a set temperature related to cooling control in the cooling ventilation mode and an indoor temperature of the controlled space, and to perform a dehumidification operation that throttles the expansion valve of the air conditioner and perform supply ventilation by the ventilation device when it is determined that the temperature difference obtained by subtracting the set temperature from the indoor temperature is lower than a first temperature threshold.

A control method according to one aspect of the present disclosure is a control method for an air conditioner having a ventilation device. The ventilation device is configured to perform supply ventilation to supply outdoor air to a controlled space that is the target of air conditioning control of the air conditioner. The control method includes the steps of, in a cooling ventilation mode in which both cooling operation and ventilation operation by the ventilation device can be performed, acquiring a set temperature related to cooling control in the cooling ventilation mode and an indoor temperature of the controlled space, determining whether a temperature difference obtained by subtracting the set temperature from the indoor temperature is lower than a first temperature threshold, and, if it is determined that the temperature difference is lower than the first temperature threshold, performing a dehumidification operation to throttle the expansion valve of the air conditioner and performing supply ventilation by the ventilation device.

A program according to another aspect of the present disclosure causes an air conditioner to execute a control method.

In another aspect of the storage medium according to the present disclosure, a non-transitory computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the control method is realized.

In this disclosure, the air conditioner, control method, program, and storage medium can suppress condensation on the fan in the indoor unit.

FIG. 1 is a block diagram showing an example of a schematic configuration of an air conditioner according to a first embodiment. Schematic diagram of an air conditioner according to a first embodiment. Schematic diagram of a ventilation device according to a first embodiment. Schematic diagram of a ventilation device during ventilation operation in embodiment 1. 1 is a flowchart illustrating an example of a control method according to the first embodiment. FIG. 1 is a schematic diagram of an example of a cooling region during a dehumidification operation in the first embodiment; FIG. 13 is a schematic diagram of an example of a cooling region and a nozzle according to the second embodiment; FIG. 13 is a schematic diagram of an example of a cooling region and a nozzle according to the second embodiment; FIG. 13 is a schematic diagram of an example of a cooling region and a nozzle according to the second embodiment; FIG. 13 is a schematic diagram of an example of a cooling region and a nozzle according to the second embodiment; 11 is a flowchart showing an example of a control method according to the third embodiment. 13 is a flowchart of an example of a control method according to the fourth embodiment. An example of a timing diagram according to the fourth embodiment 13 is a flowchart showing an example of a control method according to the fifth embodiment. An example of a timing diagram according to the fifth embodiment 13 is a flowchart showing an example of a control method according to the sixth embodiment.

First, various aspects of the air conditioner, control method, program, and storage medium will be explained.

The air conditioner of the first aspect of the present disclosure includes a ventilation device and a control unit. The ventilation device is configured to supply outdoor air to a controlled space that is the target of air conditioning control of the air conditioner. The control unit is configured to, in a cooling ventilation mode in which both cooling operation and ventilation operation by the ventilation device can be performed, acquire a set temperature related to cooling control in the cooling ventilation mode and an indoor temperature of the controlled space, and, if it determines that the temperature difference obtained by subtracting the set temperature from the indoor temperature is lower than a first temperature threshold, perform a dehumidification operation that throttles the expansion valve of the air conditioner and perform supply ventilation by the ventilation device.

In the air conditioner of the second aspect of the present disclosure, in the first aspect, the control unit may be further configured to maintain a predetermined ventilation rate during ventilation operation.

The air conditioner of the third aspect of the present disclosure may further include a heat exchanger located within the control space in the first or second aspect. The ventilation device may include a nozzle that blows outdoor air onto a portion of the heat exchanger.

In the air conditioner of the fourth aspect of the present disclosure, in the third aspect, the heat exchanger includes a cooling area defined according to the opening degree of the expansion valve, and the cooling area may be at least a part of the area of the heat exchanger. The nozzle may have an opening facing the cooling area. In dehumidification operation, the nozzle opening may blow outdoor air into the cooling area of the heat exchanger.

In the fifth aspect of the air conditioner according to the present disclosure, in the fourth aspect, during dehumidification operation, the cooling area may be a partial area of the heat exchanger, and the refrigerant flowing in the cooling area may be in a liquid refrigerant state.

In the sixth aspect of the air conditioner of the present disclosure, in the fourth aspect, the cooling area during cooling operation may be the entire area of the heat exchanger.

The air conditioner of the seventh aspect of the present disclosure may further include a compressor in any one of the first to sixth aspects. When the control unit determines that the temperature difference is equal to or greater than the second temperature threshold, the control unit may be further configured to perform a cooling operation in which the rotation speed of the compressor is equal to or greater than the first rotation speed threshold. The second temperature threshold is higher than the first temperature threshold.

In the air conditioner of the eighth aspect of the present disclosure, in the seventh aspect, the control unit may be further configured to perform cooling operation with the compressor rotation speed lower than the first rotation speed threshold when it is determined that the temperature difference is lower than the second temperature threshold and equal to or higher than the first temperature threshold.

In the air conditioner of the ninth aspect of the present disclosure, in any one of the first to eighth aspects, the control unit may be further configured to switch from the dehumidification operation to the cooling operation when it is determined that the temperature difference obtained by subtracting the set temperature from the indoor temperature after the dehumidification operation is equal to or greater than a third temperature threshold. The third temperature threshold is higher than the first temperature threshold.

The air conditioner of a tenth aspect of the present disclosure may further include a compressor in any one of the first to ninth aspects. The control unit may be further configured to stop the compressor for a predetermined time when it is determined that the temperature difference obtained by subtracting the set temperature from the indoor temperature after performing the dehumidification operation is lower than a fourth temperature threshold value after the dehumidification operation is performed.

The control method of an eleventh aspect according to the present disclosure is a control method for an air conditioner having a ventilation device. The ventilation device is configured to perform supply ventilation to supply outdoor air to a controlled space that is the target of air conditioning control of the air conditioner. The control method includes the steps of acquiring a set temperature for cooling control in the cooling ventilation mode and an indoor temperature of the controlled space in a cooling ventilation mode in which both cooling operation and ventilation operation by the ventilation device can be performed, determining whether a temperature difference obtained by subtracting the set temperature from the indoor temperature is lower than a first temperature threshold, and, if it is determined that the temperature difference is lower than the first temperature threshold, performing a dehumidification operation to throttle the expansion valve of the air conditioner and performing supply ventilation by the ventilation device.

The control method of the twelfth aspect of the present disclosure is capable of maintaining a predetermined ventilation rate during ventilation operation in the eleventh aspect.

The control method of the thirteenth aspect of the present disclosure may further include, in the eleventh aspect, a step of determining whether the temperature difference is equal to or greater than a second temperature threshold, and, if it is determined that the temperature difference is equal to or greater than the second temperature threshold, a step of performing a cooling operation in which the rotation speed of the compressor of the air conditioner is equal to or greater than a first rotation speed threshold. The second temperature threshold is higher than the first temperature threshold.

The control method of the 14th aspect of the present disclosure may further include, in the 13th aspect, a step of determining whether the temperature difference is lower than the second temperature threshold and equal to or higher than the first temperature threshold, and a step of performing cooling operation with the compressor rotation speed lower than the first rotation speed threshold when it is determined that the temperature difference is lower than the second temperature threshold and equal to or higher than the first temperature threshold.

The control method of the 15th aspect of the present disclosure may further include, in any one of the 11th to 14th aspects, a step of determining whether or not a temperature difference obtained by subtracting a set temperature from an indoor temperature after the dehumidification operation is equal to or greater than a third temperature threshold, and a step of switching from the dehumidification operation to the cooling operation when it is determined that the temperature difference obtained by subtracting the set temperature from an indoor temperature after the dehumidification operation is equal to or greater than the third temperature threshold. The third temperature threshold is higher than the first temperature threshold.

The control method of the 16th aspect of the present disclosure may further include, in any one of the 11th to 15th aspects, a step of determining whether or not a temperature difference obtained by subtracting a set temperature from an indoor temperature after performing a dehumidification operation is lower than a fourth temperature threshold, and a step of stopping the compressor of the air conditioner for a predetermined time if it is determined that the temperature difference obtained by subtracting a set temperature from an indoor temperature after performing the dehumidification operation is lower than the fourth temperature threshold.

The program of the seventeenth aspect of the present disclosure causes an air conditioner to execute a control method.

The storage medium of the eighteenth aspect of the present disclosure is a non-transitory computer-readable storage medium in which a computer program is stored. When the computer program is executed by a processor, the control method is realized.

Technical Concepts
Before describing specific embodiments of the air conditioner, control method, program, and storage medium according to the present disclosure, the technical concept described in the present disclosure will be described using an example. In this example, the air conditioner has a ventilation device, and the ventilation device is capable of supplying outdoor air to a controlled space that is the target of the air conditioning control of the air conditioner. The outdoor air supplied to the indoor unit by the ventilation device is blown into the controlled space by a fan of the indoor unit. The air conditioner can execute a cooling ventilation mode in which both cooling control and ventilation control are performed according to a user's command.

Conventionally, air conditioners are capable of supplying outdoor air to a controlled space. However, when outdoor air is supplied to an indoor unit, if the outdoor air hits a cold fan (crossflow fan) in the indoor unit, condensation occurs on the fan. Water droplets caused by condensation can leak out of the indoor unit or fly into the room together with the air blown by the fan (water splashes).

The main concept of the control method disclosed herein is that when the indoor temperature falls below a predetermined level, a dehumidification operation is performed by throttling the expansion valve of the air conditioner, and supply ventilation is performed by the ventilation device. For example, when a heat exchanger located indoors (e.g., a heat exchanger in an indoor unit, hereinafter sometimes abbreviated as "indoor heat exchanger") is cooled by cooling control, the cooling operation is switched to dehumidification operation and then supply ventilation is performed. The air conditioner suppresses condensation at the fan by limiting its ability to cool the outdoor air supplied to the controlled space. The control unit of the air conditioner can switch between dehumidification operation and cooling operation based on the temperature difference between the indoor temperature and the set temperature for cooling control.

Because it is possible to suppress the drop in temperature of the indoor heat exchanger when ventilating, it is possible to suppress condensation on the indoor unit fan caused by ventilation operation, and also to suppress the leakage of water droplets and splashes caused by condensation. In addition, because the setting temperature related to cooling control and the indoor temperature are taken into consideration to determine whether or not to perform dehumidification operation, it is possible to prevent condensation while maintaining the indoor temperature close to the set temperature.

The control method disclosed herein can also perform supply ventilation while preventing condensation even in an operating mode in which condensation on the fan is possible (cooling ventilation mode). This makes it possible to ensure a constant ventilation rate throughout the operation of that mode, and provide a sufficient amount of ventilation to the controlled space.

Each of the embodiments described below is an example of the present disclosure. The numerical values, shapes, configurations, steps, and order of steps shown in each of the following embodiments are examples and do not limit the present disclosure. Among the components in the following embodiment 1, those components that are not described in an independent claim showing the highest concept are described as optional components.

In each of the embodiments described below, certain elements may be modified, and other elements may include any appropriate combination of configurations, with each combination providing its own effect. In the embodiments, the configurations of each modification may be combined to provide the effect of each modification.

In the following detailed description, the terms "first," "second," etc. are used for descriptive purposes only and should not be understood as expressing or implying the relative importance or ranking of technical features. Features qualified as "first" and "second" expressly or imply the inclusion of one or more of that feature.

First Embodiment
Hereinafter, a first embodiment of an air conditioner, a control method, a program, and a storage medium according to the present disclosure will be described in detail with reference to the drawings as appropriate. The air conditioner targets a specific internal space as a target for air conditioning control (hereinafter, referred to as a controlled space) and conditions the air within the controlled space.

Figure 1 is a block diagram showing an example of the schematic configuration of an air conditioner 10 in embodiment 1. Figure 1 is a schematic diagram created from the perspective of causing the air conditioner to execute a control method and its program, and from the perspective of the relationship between the air conditioner and other external devices. The air conditioner 10 executes the control method and is able to suppress condensation caused by ventilation.

In the embodiment of FIG. 1, the air conditioner 10 includes a memory unit 11, a control unit 12, a communication unit 13, and an indoor temperature sensor 14. The air conditioner 10 may further include various sensors, such as an outdoor temperature sensor, to perform functions. The air conditioner 10 may include a display for displaying visual information to a user. Also, in the embodiment of FIG. 1, the air conditioner 10 includes an indoor unit 20 and an outdoor unit 30. The memory unit 11, the control unit 12, the communication unit 13, and the indoor temperature sensor 14 may be provided in the indoor unit 20. The air conditioner 10 further includes a ventilation device 50, which is capable of at least supply ventilation to supply outdoor air to the room.

In this disclosure, "ventilation" refers to mechanical ventilation, and in particular refers to exchanging indoor air with outside air by supplying outdoor air to the room (i.e., the controlled space). The air conditioner 10 of the present disclosure may perform supply ventilation using the ventilation device 50 alone, or may perform both supply ventilation and exhaust ventilation in cooperation with another ventilation device that can exhaust indoor air to the outside. In addition, if the ventilation device 50 has an exhaust fan that exhausts indoor air to the outside, the air conditioner 10 may perform exhaust ventilation, or may perform both supply ventilation and exhaust ventilation alone. However, in this disclosure, the main objective is to suppress condensation that may occur on the fan 24 of the indoor unit 20 when the ventilation device 50 performs supply ventilation.

The air conditioner 10 can be connected to a terminal device 70 and/or a server 80 via the communication unit 13. For example, the air conditioner 10 may be connected to a terminal device 70, which is a remote controller for the air conditioner 10, via infrared rays. The air conditioner 10 may be connected to a terminal device 70, which is a smartphone of a user of the air conditioner 10, via the Internet. The air conditioner 10 may also be connected to a server 80 related to the air conditioner 10 and an external information source 90 from which some of the information necessary for ventilation control can be obtained via the Internet.

The following provides an overview of each component.

<Air conditioner 10>
The air conditioner 10 treats, for example, the internal space of a room in a home or office as a controlled space that is the target of air conditioning control. It has an indoor unit 20 installed on a wall or ceiling of the controlled space, and an outdoor unit 30 installed outdoors, in a central air-conditioned room other than the controlled space, etc. The air conditioner 10 has, for example, a cooling function, a heating function, a dehumidification function, and/or an air cleaning function. The air conditioner 10 includes a ventilation device 50 capable of supplying outdoor air to the controlled space. The ventilation device 50 may have a dehumidification function and/or a humidification function in addition to the ventilation function. These functions and operation modes can be freely combined (for example, a cooling and dehumidification function, a heating and humidification function, a cooling and ventilation mode, etc.).

In cooling mode, the air conditioner 10 can perform cooling operation, weak cooling operation (also called compressor-type dehumidification or refrigeration cycle dehumidification), and dehumidification operation that throttles the expansion valve. The control method disclosed herein mainly uses dehumidification operation that throttles the expansion valve, but it is also possible to use compressor-type dehumidification.

<Storage unit 11>
The storage unit 11 is a recording medium for recording various information and control programs, and may be a memory that functions as a work area for the control unit 12. The storage unit 11 is realized, for example, by a flash memory, a RAM (Random Access Memory), a ROM (Read Only Memory), other storage devices, or an appropriate combination of these.

The memory unit 11 may store standards, thresholds, and upper limits for ventilation control, and may store various thresholds, such as a threshold for determining whether or not to perform a dehumidification operation. The memory unit 11 may store information acquired from various sensors, such as the indoor temperature sensor 14. Information acquired from the terminal device 70, the server 80, or the external information source 90 may also be stored in the memory unit 11. This information may be read out by the control unit 12 when the control method is performed.

The storage unit 11 may store a computer program (sometimes abbreviated as a program in this disclosure) for causing the air conditioner 10 to execute the control method. The storage unit 11 may also include a non-transitory computer-readable storage medium in which the computer program is stored.

<Control Unit 12>
The control unit 12 is a controller that controls at least some of the functions of the air conditioner 10. The control unit 12 includes a general-purpose processor such as a CPU, MPU, MCU, FPGA, DSP, or ASIC that executes a program to realize a predetermined function. The control unit 12 can realize various controls in the air conditioner 10 by calling and executing a control program stored in the storage unit 11. The control unit 12 can also work with the storage unit 11 to read and write data stored in the storage unit 11. The control unit 12 is not limited to a unit that realizes a predetermined function through the cooperation of hardware and software, and may be a hardware circuit designed specifically to realize a predetermined function.

The control unit 12 can receive various commands and setting values from the user (e.g., a command to start the cooling ventilation mode of the air conditioner 10, a temperature setting command related to cooling control) from the terminal device 70 via the communication unit 13. The control unit 12 controls each component of the air conditioner 10 so that the air conditioner 10 performs its cooling function, heating function, ventilation function, etc. based on these setting values and detection values received from various sensors (e.g., indoor humidity, outdoor humidity). The control unit 12 also performs ventilation control of the air conditioner 10 based on a control method described below.

<Communication unit 13>
The communication unit 13 can also communicate with the server 80, the user's terminal device 70, etc., and can also transmit and receive Internet packets, for example. As described above, the control unit 12 may cooperate with the server 80 and/or the terminal device 70 via the communication unit 13. The communication unit 13 may communicate between the air conditioner 10 and the terminal device 70, the server 80, or the external information source 90 in accordance with standards such as Wi-Fi (registered trademark), IEEE 802.2, IEEE 802.3, 3G, LTE, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication network, etc., infrared, Bluetooth (registered trademark), etc., and may transmit and receive data.

<Sensors such as indoor temperature sensor 14>
The indoor temperature sensor 14 detects the temperature of the indoor air drawn from the control space into the indoor unit 20. In one embodiment, the indoor temperature sensor 14 is provided at an intake port of the indoor unit 20 through which the indoor air is drawn.

In addition to the indoor temperature sensor 14, the air conditioner 10 may be equipped with sensors for acquiring various information from outside the air conditioner 10 in order to perform its functions. For example, the air conditioner 10 may include an outdoor air temperature sensor that detects the outdoor air temperature of the controlled space.

These sensors, including the indoor temperature sensor 14, can obtain information for performing ventilation operation. Information detected by the sensor 14 is input and stored in the memory unit 11, and is later used by the control unit 12 or transmitted to the terminal device 70 or server 80.

In the examples described below, the indoor temperature sensor 14 is mounted on the indoor unit 20, but the indoor temperature sensor 14 may be mounted, for example, on another home appliance or at any location inside or outside the smart home, or may be an independent sensor device. When executing the control method, the air conditioner 10 can obtain the indoor temperature from the indoor temperature sensor 14 regardless of where the indoor temperature sensor 14 is mounted.

<Ventilation device 50>
The ventilation device 50 is a device configured to supply outdoor air to the room, and in this embodiment is installed outdoors together with the outdoor unit 30. The ventilation device 50 can dehumidify or humidify the indoor air in the controlled space by supplying dehumidified outdoor air or outdoor air containing moisture to the controlled space. The specific structure and operation of the ventilation device 50 will be described later with reference to FIG. 2.

<Terminal Device 70>
The terminal device 70 is a device related to the air conditioner 10. The terminal device 70 may be, for example, a controller for the air conditioner 10, or a controller capable of managing and controlling a plurality of types of home appliances. The terminal device 70 may also be an information terminal capable of performing data communication with the air conditioner 10, such as a smartphone, a mobile phone, a tablet, a wearable device, or a computer incorporating a dedicated related application 72.

The control unit 12 or the server 80 of the air conditioner 10 can obtain settings or commands input by the user via the terminal device 70. Typically, the terminal device 70 includes a display for displaying a graphic user interface (GUI). However, when interacting with the user via a voice user interface (VUI), the terminal device 70 may include a speaker and a microphone instead of or in addition to a display.

<Server 80>
The server 80 may be, for example, a management server of a manufacturer of the air conditioner 10 for managing at least one air conditioner 10 or for collecting data. Alternatively, the server 80 may be an application server. In this embodiment, the control method is executed by the control unit 12 of the air conditioner 10, but the control method can also be executed by the server 80.

<External Information Source 90>
The external information source 90 is an information source that provides information about services that are not directly related to the air conditioner 10, such as weather information or information about the outside air temperature in a specific area. For example, the external information source 90 may be a website of the Japan Meteorological Agency. The server 80 may transfer information acquired from the external information source 90 to the air conditioner 10 or the terminal device 70. The air conditioner 10 may directly connect to the external information source 90 and acquire part of the information required for ventilation control from the external information source 90, or may indirectly connect to the external information source 90 via the server 80 or the terminal device 70 to acquire the required information.

The mechanical configuration of the air conditioner 10, particularly the ventilation function of the ventilation device 50, will be explained below with reference to the drawings.

<Ventilation function by ventilation device 50>
Fig. 2 is a schematic diagram of the air conditioner 10 according to one embodiment of the present disclosure. Fig. 2 is a schematic diagram of the air conditioner 10 created from the perspective of showing the mechanical configuration that performs the ventilation function in particular.

As shown in FIG. 2, the air conditioner 10 according to this embodiment has an indoor unit 20 arranged in the room Rin to be air-conditioned, and an outdoor unit 30 arranged in the outdoor Rout.

The indoor unit 20 is provided with an indoor heat exchanger 22 that exchanges heat with the indoor air A1, and a fan 24 that draws the indoor air A1 into the indoor unit 20 and blows the indoor air A1 after heat exchange with the indoor heat exchanger 22 into the room Rin.

The outdoor unit 30 is provided with an outdoor heat exchanger 32 that exchanges heat with the outdoor air A2, and a fan 34 that draws the outdoor air A2 into the outdoor unit 30 and blows the outdoor air A2 after heat exchange with the outdoor heat exchanger 32 out to the outdoor Rout. The outdoor unit 30 is also provided with a compressor 36, an expansion valve 38, and a four-way valve 40 that execute a refrigeration cycle with the indoor heat exchanger 22 and the outdoor heat exchanger 32.

The indoor heat exchanger 22, the outdoor heat exchanger 32, the compressor 36, the expansion valve 38, and the four-way valve 40 are each connected by a refrigerant pipe through which the refrigerant flows. In cooling and weak cooling operations, the air conditioner 10 executes a refrigeration cycle in which the refrigerant flows from the compressor 36 through the four-way valve 40, the outdoor heat exchanger 32, the expansion valve 38, and the indoor heat exchanger 22 in that order, and then returns to the compressor 36. In heating operation, the air conditioner 10 executes a refrigeration cycle in which the refrigerant flows from the compressor 36 through the four-way valve 40, the indoor heat exchanger 22, the expansion valve 38, and the outdoor heat exchanger 32 in that order, and then returns to the compressor 36.

In addition to air conditioning operation using the refrigeration cycle, the air conditioner 10 also performs air conditioning operation that introduces outdoor air A3 into the room Rin. To achieve this, the air conditioner 10 has a ventilation device 50. The ventilation device 50 is provided in the outdoor unit 30.

Figure 3 is a schematic diagram of the ventilation device 50.

As shown in FIG. 3, the ventilation device 50 has an absorbent material 52 inside through which the outdoor air A3 and A4 pass.

The absorbent material 52 is a member through which air can pass and which collects moisture from the air passing through it or which gives moisture to the air passing through it. In this embodiment, the absorbent material 52 is disk-shaped and rotates around a rotation center line C1 that passes through its center. The absorbent material 52 is rotationally driven by a motor 54.

The absorbent 52 is preferably a polymeric adsorbent that adsorbs moisture in the air. The polymeric adsorbent is, for example, composed of a cross-linked sodium polyacrylate. Compared to adsorbents such as silica gel and zeolite, the polymeric adsorbent absorbs a greater amount of moisture per volume, can desorb the moisture it holds at a low heating temperature, and can hold the moisture for a long period of time.

Inside the ventilation device 50, a first flow path P1 and a second flow path P2 are provided through which the outdoor air A3 and A4 flow, respectively, passing through the absorbent material 52. The first flow path P1 and the second flow path P2 pass through the absorbent material 52 at different positions.

The first flow path P1 is a flow path through which outdoor air A3 flows toward the indoor unit 20. The outdoor air A3 flowing through the first flow path P1 is supplied to the indoor unit 20 via the ventilation duct 56.

In this embodiment, the first flow path P1 includes multiple tributary paths P1a and P1b upstream of the absorbent material 52. In this specification, the terms "upstream" and "downstream" are used with respect to the air flow.

The multiple tributary channels P1a, P2a join upstream of the absorbent material 52. The multiple tributary channels P1a, P1b are each provided with a first and second heater 58, 60 that heats the outdoor air A3.

The first and second heaters 58, 60 may be heaters with the same heating capacity or heaters with different heating capacities. In addition, the first and second heaters 58, 60 are preferably PTC (Positive Temperature Coefficient) heaters, which increase electrical resistance when current flows and the temperature rises, i.e., can suppress excessive increases in heating temperature. In the case of heaters using nichrome wire or carbon fiber, the heating temperature (surface temperature) continues to rise when current continues to flow, so the temperature needs to be monitored. In the case of a PTC heater, the heater itself adjusts the heating temperature within a certain temperature range, so there is no need to monitor the heating temperature.

A first fan (hereinafter also referred to as the "air supply fan") 62 is provided in the first flow path P1 to generate a flow of outdoor air A3 toward the indoor unit 20. In this embodiment, the first fan 62 is disposed downstream of the absorbent material 52. When the first fan 62 is operated, the outdoor air A3 flows from the outdoor Rout into the first flow path P1 and passes through the absorbent material 52.

The first flow path P1 is provided with a damper device 64 that distributes the outdoor air A3 flowing through the first flow path P1 to the room Rin (i.e., the indoor unit 20) or the outdoor Rout. In this embodiment, the damper device 64 is disposed downstream of the first fan 62. The outdoor air A3 distributed to the indoor unit 20 by the damper device 64 enters the indoor unit 20 via the ventilation duct 56 and is blown out to the room Rin by the fan 24.

The second flow path P2 is a flow path through which the outdoor air A4 flows. Unlike the outdoor air A3 flowing through the first flow path P1, the outdoor air A4 flowing through the second flow path P2 does not flow toward the indoor unit 20. The outdoor air A4 flowing through the second flow path P2 passes through the absorbent material 52 and then flows out to the outdoor Rout.

A second fan 66 that generates a flow of outdoor air A4 is provided in the first flow path P1. In this embodiment, the second fan 66 is disposed downstream of the absorbent material 52. When the second fan 66 is operated, the outdoor air A4 flows from the outdoor Rout into the second flow path P2, passes through the absorbent material 52, and flows out to the outdoor Rout.

The ventilation device 50 selectively performs ventilation operation or other operation by selectively using the absorbent material 52, the motor 54, the first heater 58, the second heater 60, the first fan 62, the damper device 64, and the second fan 66.

Figure 4 is a schematic diagram of the ventilation device during ventilation operation.

The ventilation operation is an air conditioning operation in which the outdoor air A3 is supplied directly to the room Rin (i.e., the indoor unit 20) through the ventilation duct 56. As shown in FIG. 4, during the ventilation operation, the motor 54 continues to rotate the absorbent material 52. The first heater 58 and the second heater 60 are in the OFF state and do not heat the outdoor air A3. The first fan 62 is in the ON state, so that the outdoor air A3 flows through the first flow path P1. The damper device 64 distributes the outdoor air A3 in the first flow path P1 to the indoor unit 20. The second fan 66 is in the OFF state, so that no flow of the outdoor air A4 is generated in the second flow path P2.

According to this type of ventilation operation, the outdoor air A3 flows into the first flow path P1 and passes through the absorbent 52 without being heated by the first and second heaters 58, 60. The outdoor air A3 that has passed through the absorbent 52 is distributed to the indoor unit 20 by the damper device 64. The outdoor air A3 that has passed through the damper device 64 and reached the indoor unit 20 via the ventilation duct 56 is blown out into the room Rin by the fan 24. According to this type of ventilation operation, the outdoor air A3 is supplied as is to the room Rin, and the room Rin is ventilated.

So far, we have provided an overview of the configuration and operation of the air conditioner 10 according to this embodiment. From here on, we will explain the features of the air conditioner, control method, program, and storage medium that use the air conditioner 10 according to this embodiment.

<Control method of air conditioner 10>
The air conditioner 10 executes the control method. More specifically, the control unit 12 of the air conditioner 10 executes the control method in cooperation with the memory unit 11 and the indoor temperature sensor 14. According to this control method, it is possible to suppress condensation on the fan 24 in the indoor unit 20 caused by ventilation operation.

Figure 5 is a flowchart of the control method in embodiment 1, which includes steps S100 to S400.

In one embodiment, the control unit 12 may perform the cooling function and the ventilation function by executing steps S100 to S400 after the air conditioner 10 enters the cooling ventilation mode at the command of the user. In another embodiment, the control unit 12 may automatically enter the cooling ventilation mode and execute steps S100 to S400 when, for example, in the automatic operation mode, it determines based on information that there is a need for room temperature adjustment and a need for ventilation. In the cooling ventilation mode, both cooling operation and ventilation operation by the ventilation device 50 can be performed.

In the cooling ventilation mode, the control unit 12 acquires the set temperature for cooling control in the cooling ventilation mode and the indoor temperature of the controlled space (step S100). The set temperature in this disclosure may be a user set temperature input by the user via the controller of the air conditioner 10 or a smartphone associated with the air conditioner 10, or may be an internal set temperature at which the air conditioner 10 actually operates. The control unit 12 may acquire the set temperature by reading the set temperature from the memory unit 11. The control unit 12 may then acquire the indoor temperature by querying the indoor temperature sensor 14 or by reading the most recently written indoor temperature from the memory unit 11.

Next, the control unit 12 determines whether the temperature difference obtained by subtracting the set temperature from the acquired indoor temperature is lower than the first temperature threshold (step S200). The first temperature threshold is a negative number. That is, in step S200, the control unit 12 determines whether the indoor temperature is lower than the set temperature by a predetermined amount. The first temperature threshold may be, for example, -0.1°C, -0.5°C, -1°C, or -1.5°C.

If it is determined that the temperature difference is lower than the first temperature threshold, the control unit 12 executes a dehumidification operation by throttling the expansion valve 38 of the air conditioner 10, and executes supply ventilation by the ventilation device 50 (step S300). In one embodiment, the control unit 12 executes the dehumidification operation for a predetermined time and then executes supply ventilation. In one embodiment, the control unit 12 executes supply ventilation when it starts executing the dehumidification operation. In one embodiment, the control unit 12 starts supply ventilation before executing the dehumidification operation.

On the other hand, if it is determined that the temperature difference between the indoor temperature and the set temperature is equal to or greater than the first temperature threshold, i.e., if the indoor temperature is not lower than the set temperature by a predetermined amount, the control unit 12 performs cooling operation to lower the indoor temperature (step S400). In this case, since the fan 24 of the indoor unit 20 is not at a low enough temperature to easily cause condensation, the control unit 12 may perform supply ventilation while performing cooling operation, or may perform supply ventilation after performing cooling operation for a predetermined period of time.

In the ventilation operation, the control unit 12 may maintain a predetermined ventilation rate. The ventilation rate is a value indicating how many times the air in the controlled space is replaced per hour. For example, for supply ventilation, the ventilation rate may be the value obtained by dividing the amount of air (ventilation rate) flowing into the controlled space per hour by the indoor volume of the controlled space (e.g., floor area x ceiling height). The predetermined ventilation rate in step S300 may be, for example, 0.2 times, 0.5 times, 0.8 times, or 1 time. The predetermined ventilation rate may be set by user input, or may be automatically set by the control unit 12 based on the indoor and outdoor environment and the needs of ventilation control. The control unit 12 may calculate the ventilation rate (supply air volume) based on the indoor volume of the controlled space and the ventilation rate, and control the first fan 62 of the ventilation device 50.

By maintaining the ventilation rate in this way, it is possible to provide a sufficient amount of ventilation to the controlled space, even if the air conditioner 10 continues to operate for a long period of time, or even if it is hot and cooling operation is the norm.

In one embodiment, when the cooling ventilation mode is entered, the control unit 12 may first perform cooling operation. That is, cooling operation may be performed before step S100. In this case, the control unit 12 switches from cooling operation to dehumidification operation in step S300. The control unit 12 may perform supply ventilation after a predetermined time has elapsed since switching from cooling operation to dehumidification operation and the surface temperatures of the indoor heat exchanger 22 and the fan 24 of the indoor unit 20 have increased. In this way, condensation and water splashing due to ventilation can be more reliably prevented.

Below, we will explain in more detail the difference between dehumidification operation, which throttles the expansion valve 38, and cooling operation, from the perspective of controlling the opening degree of the expansion valve 38.

The indoor heat exchanger 22 includes a cooling area defined according to the opening degree of the expansion valve 38, and the cooling area is at least a part of the area of the indoor heat exchanger 22. The cooling area is an area in which the refrigerant flowing therethrough is in a liquid refrigerant state. In cooling operation, the cooling area is the entire area of the indoor heat exchanger 22. That is, in cooling operation, liquid refrigerant flows throughout the entire area of the indoor heat exchanger 22, and the indoor heat exchanger 22, entirely cooled by the liquid refrigerant, cools the air in the control space.

On the other hand, in dehumidification operation, the cooling area is a part of the indoor heat exchanger 22. FIG. 6 is a schematic diagram of an example of the cooling area during dehumidification operation in embodiment 1. As shown in FIG. 6, the indoor heat exchanger 22 has a cooling area CA (also called the wet path or wet area) and other areas (also called the dry path or dry area). In the example shown in FIG. 6, the area surrounded by a dotted line including the refrigerant inlet in the upper left direction of FIG. 6 indicates the cooling area CA, and the hatched circle indicates the wet path.

The "wet path" and "dry path" are wet and dry regions that are generated in the indoor heat exchanger 22 by controlling the frequency of the compressor 36 and the opening of the expansion valve 38 during dehumidification operation. Specifically, the wet path is a wet region that is formed upstream in the refrigerant flow direction in the indoor heat exchanger 22 by reducing the frequency of the compressor 36 and the opening of the expansion valve 38 during dehumidification operation. The dry path is a dry region that is formed downstream of the wet path in the indoor heat exchanger 22 by reducing the frequency of the compressor 36 and the opening of the expansion valve 38 during dehumidification operation.

The cooling area CA (wet path, wet area) is an area in the indoor heat exchanger 22 that is wetter than other areas. On the other hand, an area other than the cooling area CA in the indoor heat exchanger 22 (dry path, dry area) is an area in the indoor heat exchanger 22 that is dryer than other areas. Such a cooling area CA can be determined experimentally or by simulation.

In the indoor heat exchanger 22, the temperature of the refrigerant flowing in from the refrigerant inlet is lower than in other parts. Therefore, the upstream side of the refrigerant flow path of the indoor heat exchanger 22 functions as a cooling area CA and is in a wet state. The cooling area CA is the part where the refrigerant flowing in the indoor heat exchanger 22 becomes a low-pressure liquid refrigerant by narrowing the opening of the expansion valve 38.

In dehumidification operation, some areas of the indoor heat exchanger 22 are cooled by the liquid refrigerant, but the overall temperature drop is relatively small. Therefore, the fan 24 and the air in the controlled space are cooled less than in cooling operation. The control unit 12 of the air conditioner 10 automatically switches to dehumidification operation and can suppress the drop in temperature of the indoor heat exchanger 22 during ventilation. This can suppress the phenomenon of outdoor air condensing on the surface of the fan 24 of the indoor unit 20, and can also suppress the leakage and splashing of water droplets due to condensation. In addition, the control unit 12 determines whether or not to perform dehumidification operation based on the indoor temperature and the set temperature related to cooling control, so condensation can be prevented while maintaining the indoor temperature near the set temperature.

According to the above-mentioned control method, even if the cooling mode, which may cause condensation on the fan, is combined with ventilation operation to set up the cooling ventilation mode, it is possible to perform supply ventilation while preventing condensation. Therefore, a certain number of ventilations can be secured in the cooling ventilation mode, and a sufficient amount of ventilation can be provided to the controlled space.

As a result, the control unit 12 of the air conditioner 10 completes the ventilation control process using the ventilation device 50. During the cooling ventilation mode, the control unit 12 may periodically repeat steps S100 to S400.

In one embodiment, the air conditioner 10 has a program that is used to execute the control method as described above. The program causes the air conditioner 10 to execute the control method.

In one embodiment, the air conditioner 10 has a non-transitory computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the control method of the present disclosure is realized. The storage medium may be the same as the storage unit 11 of the air conditioner 10, may be included in the storage unit 11, or may be a component separate from the storage unit 11.

Second Embodiment
<Arrangement of Air Supply Nozzles of Ventilation Device 50>
In the second embodiment, the ventilation device 50 includes a nozzle that blows the outdoor air onto a part of the indoor heat exchanger 22. By using a nozzle that blows the outdoor air onto a part of the indoor heat exchanger 22 instead of the whole, it is possible to further suppress condensation on the fan 24 inside the indoor unit 20.

Figure 7 is a schematic diagram of an example of the cooling area CA and nozzle 51 in embodiment 2. As can be seen from Figure 4, the ventilation device 50 includes a ventilation duct 56 that supplies the outdoor air A3 flowing through the first flow path P1 into the indoor unit 20. The nozzle 51 of the ventilation device 50 is attached to the outlet of the ventilation duct 56 on the indoor unit 20 side, and has an opening 51a. In the example of Figure 7, the opening 51a faces the cooling area CA of the indoor heat exchanger 22. More specifically, the opening 51a faces the cooling area CA in dehumidification operation in which the expansion valve 38 is throttled.

According to this structure, in dehumidification operation, the opening 51a of the nozzle 51 blows outdoor air into the cooling area CA. In dehumidification operation, the outdoor air blown out from the opening 51a passes through the cooling area CA, is cooled by the cooling area CA, and is then blown out into the control space by the fan 24. With this structure, for example, high-temperature and high-humidity outdoor air in the summer can be quickly cooled and dehumidified.

However, the arrangement of the nozzle 51, the opening 51a of the nozzle 51, or the cooling area CA is not limited to the embodiment shown in FIG. 7. As described below, the opening 51a of the nozzle 51 does not have to face the cooling area CA, and the cooling area CA can be provided in a different part of the indoor heat exchanger 22.

Figures 8 and 9 are schematic diagrams of modified cooling area CA and nozzle 51 in embodiment 2. In dehumidification operation, the cooling area CA is a partial area of the indoor heat exchanger 22, but the opening 51a of the nozzle 51 does not have to blow outdoor air into the cooling area CA. As shown in Figures 8 and 9, the opening 51a of the nozzle 51 faces a dry area other than the cooling area CA (wet area) in the indoor heat exchanger 22, and blows outdoor air into the dry area. When the surface temperature of the dry area is lower than the outdoor temperature, the outdoor air can be cooled and dehumidified.

The cooling area CA, where the refrigerant flowing in the dehumidifying operation is in a liquid refrigerant state, is a part of the indoor heat exchanger 22, but the part is not limited to this. As shown in Figs. 6 to 9, the cooling area CA may occupy a part of the outside of the indoor heat exchanger 22 (the side opposite the fan 24), including the refrigerant inlet, for example, half or one third of the outside area. Also, as shown in Fig. 10, the cooling area CA may occupy the entire outside area of the indoor heat exchanger 22. The indoor heat exchanger 22 in Fig. 10 has higher cooling and dehumidifying capacity than the indoor heat exchanger 22 in Figs. 6 to 9. Also, when the cooling area CA is arranged as in Fig. 10, the nozzle 51 can blow outdoor air into the cooling area CA through its opening 51a, regardless of how it is arranged.

In this way, the nozzle 51, the opening 51a of the nozzle 51, and the cooling area CA can be positioned freely. Also, if it is desired to cool and dehumidify the outdoor air relatively efficiently, it is conceivable to position the opening 51a of the nozzle 51 so that it faces the cooling area CA, or to position the cooling area CA relatively widely.

Third Embodiment
<Cooling control based on the temperature difference between the room temperature and the set temperature>
In the third embodiment, the control unit 12 can control the cooling operation in the cooling ventilation mode based on the temperature difference between the room temperature and the set temperature.

Figure 11 is a flowchart of an example of a control method in embodiment 3. Embodiment 3 is the same as embodiment 1 in that dehumidification operation and supply air ventilation are performed when it is determined that the temperature difference is lower than the first temperature threshold.

In the third embodiment, the control unit 12 of the air conditioner 10 calculates a temperature difference by subtracting the set temperature for cooling control from the acquired indoor temperature. The control unit 12 determines whether the temperature difference is lower than a first temperature threshold (step S200), and further determines whether the temperature difference is lower than a second temperature threshold (step S500). Here, the second temperature threshold is higher than the first temperature threshold. The second temperature threshold may be a positive number, for example, 0.2°C, 0.5°C, 0.8°C, or 1.0°C. Note that step S500 can be performed before or after step S200.

If the temperature difference obtained by subtracting the set temperature from the indoor temperature is lower than the first temperature threshold and the second temperature threshold ("YES" in step S500 and "YES" in step S200), the control unit 12 performs dehumidification operation by throttling the expansion valve 38 and supply air ventilation. If the temperature difference is equal to or greater than the second temperature threshold ("NO" in step S500), it means that the indoor temperature is not sufficiently close to the set temperature. Therefore, the control unit 12 performs cooling operation in which the rotation speed of the compressor 36 is equal to or greater than the first rotation speed threshold to lower the indoor temperature (step S410).

The temperature difference is equal to or greater than the second temperature threshold, i.e., the temperature difference is relatively large. Therefore, in step S410, the control unit 12 rotates the compressor 36 at or greater than the first rotation speed threshold so as to reduce the indoor temperature relatively quickly. In another embodiment, in step S410, the control unit 12 rotates the compressor 36 at the maximum rotation speed at which the compressor 36 can rotate so as to reduce the indoor temperature as quickly as possible. The first rotation speed threshold may be, for example, 95%, 90%, 80%, or 75% of the maximum rotation speed.

On the other hand, if the temperature difference is lower than the second temperature threshold and equal to or greater than the first temperature threshold ("YES" in step S500 and "NO" in step S200), it means that the indoor temperature is approaching the set temperature to some extent. In this case, the indoor temperature should be lowered, but may be lowered relatively slowly. Therefore, the control unit 12 may perform cooling operation with the rotation speed of the compressor 36 lower than the first rotation speed threshold (step S420).

The control unit 12 may perform cooling operation for a certain period of time in step S410 or step S420, and may then perform dehumidification operation for a certain period of time before performing supply ventilation. In another embodiment, the control unit 12 may perform supply ventilation while performing cooling operation in step S410 or step S420. The control unit 12 may also perform supply ventilation after step S410 or step S420, i.e., after performing cooling operation for a certain period of time.

This completes the cooling control process based on the temperature difference between the indoor temperature and the set temperature. After step S300, step S410, or step S420, the control method may be repeated by returning to step S100. In the cooling ventilation mode, the control unit 12 executes the cooling operation when the indoor temperature is not yet sufficiently close to the set temperature. Also, the rotation speed of the compressor 36 is controlled based on the comparison result between the temperature difference and the second temperature threshold value. In this way, in the cooling ventilation mode, the indoor temperature can be appropriately controlled while maintaining ventilation performance.

Fourth Embodiment
<Control for switching from dehumidification operation to cooling operation>
Since the cooling power of the dehumidification operation is relatively weaker than that of the cooling operation, the indoor temperature may gradually rise after the dehumidification operation is performed. In the fourth embodiment, the control unit 12 can switch from the dehumidification operation to the cooling operation based on the indoor temperature after the dehumidification operation is performed so as to maintain the indoor temperature close to the set temperature.

The control unit 12 may periodically acquire the indoor temperature to control the temperature, humidity, and/or ventilation in the controlled space. For example, the control unit 12 can monitor the indoor temperature of the controlled space by acquiring the indoor temperature by the indoor temperature sensor 14 every 3 minutes, every 5 minutes, or every 10 minutes. The control unit 12 can continue to monitor the indoor temperature even after performing the dehumidification operation in step S300.

Figure 12A is a flowchart of an example of a control method in embodiment 4. Steps S100 to S400 in Figure 12A are similar to steps S100 to S400 in Figure 5 of embodiment 1, and therefore a duplicated description will be omitted here.

After performing the dehumidification operation in step S300, the control unit 12 obtains the indoor temperature after the operation. Then, the control unit 12 calculates the temperature difference obtained by subtracting the set temperature from the indoor temperature after the dehumidification operation (hereinafter, sometimes abbreviated as "temperature difference after dehumidification"). Next, the control unit 12 determines whether the temperature difference after dehumidification is equal to or greater than the third temperature threshold (step S600). Here, the third temperature threshold is higher than the first temperature threshold. The third temperature threshold may be a positive number, and may be, for example, 0.5°C, 0.8°C, 1.0°C, or 1.5°C.

The temperature difference after dehumidification being equal to or greater than the third temperature threshold means that the indoor temperature has risen and is moving away from the set temperature. If the temperature difference after dehumidification is equal to or greater than the third temperature threshold, the control unit 12 executes cooling operation to lower the indoor temperature and maintain it close to the set temperature (step S400). That is, the control unit 12 stops the dehumidification operation being executed and switches to cooling operation. Even after switching to cooling operation, the control unit 12 can execute supply ventilation. For example, the control unit 12 may execute supply ventilation within a certain time after switching to cooling operation, that is, when the surface temperature of the fan 24 is still in a state where condensation is unlikely to occur.

On the other hand, if the temperature difference after dehumidification is lower than the third temperature threshold ("NO" in step S600), it can be said that the indoor temperature is still close to the set temperature and the controlled space is still cool. Therefore, the control unit 12 may continue to perform the dehumidification operation and perform supply ventilation to maintain the ventilation frequency.

In this disclosure, the control method is described using an example in which the set temperature in cooling operation and the set temperature in dehumidification operation are the same, but these two set temperatures may be different. When the set temperatures differ for each operation, the control unit 12 may calculate the temperature difference after dehumidification using the set temperature in cooling operation, or may calculate the temperature difference after dehumidification using the set temperature in dehumidification operation.

Figure 12B is an example of a timing diagram in embodiment 4. In this example, when the air conditioner 10 is started, the indoor temperature is higher than the set temperature, and the temperature difference obtained by subtracting the set temperature from the indoor temperature is equal to or greater than the first temperature threshold. Therefore, the control unit 12 causes the air conditioner 10 to perform cooling operation to lower the indoor temperature. If the indoor temperature continues to drop and the temperature difference becomes lower than the first temperature threshold, the control unit 12 switches the cooling operation to a dehumidification operation that throttles the expansion valve 38. In the dehumidification operation, the opening of the expansion valve 38 is kept relatively small, and the cooling capacity of the indoor temperature is also kept low. If the indoor temperature rises again and the temperature difference becomes equal to or greater than the first temperature threshold again, the control unit 12 switches the dehumidification operation to a cooling operation to lower the indoor temperature. In the example shown in FIG. 12B, the temperature of the indoor heat exchanger 22 and the fan 24 of the indoor unit 20 does not drop excessively when switching between cooling operation and dehumidification operation, so the ventilation device 50 continues to supply outdoor air to the controlled space. That is, the ventilation device 50 continues to perform supply ventilation. In another example, supply ventilation may not be performed during cooling operation, or supply ventilation may be performed after a certain period of dehumidification operation.

This completes the process of switching from dehumidification operation to cooling operation. After step S400, the control method may be repeated by returning to step S100. In this way, even if the indoor temperature gradually rises due to the execution of the dehumidification operation, the operation can be switched to cooling operation and the indoor temperature can be maintained close to the set temperature.

Fifth Embodiment
<Thermo off for dehumidification and cooling operation>
Although the cooling power of the dehumidification operation is relatively weaker than that of the cooling operation, the indoor temperature may continue to drop after the dehumidification operation is performed and may become too low below the set temperature. In the fifth embodiment, the control unit 12 can temporarily stop the dehumidification operation and the cooling operation based on the indoor temperature after the dehumidification operation is performed so that the indoor temperature does not drop too low.

Figure 13A is a flowchart of an example of a control method in embodiment 5. Steps S100 to S400 in Figure 13A are similar to steps S100 to S400 in Figure 5 of embodiment 1, and therefore redundant explanations will be omitted here.

As described in the fourth embodiment, the control unit 12 can continue to monitor the indoor temperature even after performing the dehumidification operation in step S300. In the fifth embodiment, after performing the dehumidification operation, the control unit 12 calculates the temperature difference obtained by subtracting the set temperature from the indoor temperature after the operation (i.e., the temperature difference after dehumidification). Then, the control unit 12 determines whether the temperature difference after dehumidification is lower than the fourth temperature threshold (step S700). Here, the fourth temperature threshold is a threshold for determining whether the indoor temperature has dropped too much, and therefore may be a negative number. The fourth temperature threshold may be, for example, -1.5°C, -2°C, -2.5°C, or -3°C.

If it is determined that the temperature difference after dehumidification is lower than the fourth temperature threshold, the control unit 12 stops the compressor 36 for a predetermined time to suppress a decrease in the indoor temperature (step S800). That is, in step S800, the control unit 12 temporarily stops the dehumidification operation and the cooling operation, and turns off the thermostat of the air conditioner 10.

In one embodiment, the specified time for thermo-off is a predetermined time, and may be, for example, 5 minutes, 10 minutes, 15 minutes, or 30 minutes. In one embodiment, the control unit 12 continues to monitor the indoor temperature after thermo-off, and resumes cooling or dehumidification operation if it determines that the indoor temperature has recovered (increased). For example, when the indoor temperature becomes equal to or higher than the first temperature threshold, the control unit 12 may resume cooling operation.

After temporarily stopping the compressor 36 in step S800, the control unit 12 may immediately perform ventilation operation, or may perform ventilation operation after a certain period of time has elapsed since the temporary stop. Also, after step S800, the control method may be repeated by returning to step S100.

On the other hand, if the temperature difference after dehumidification is equal to or greater than the fourth temperature threshold ("NO" in step S700), the control unit 12 may return to step S700 or step S100 and continue to monitor the indoor temperature.

Figure 13B is an example of a timing diagram in embodiment 5. In this example, when the air conditioner 10 is started, the indoor temperature is higher than the set temperature, and the temperature difference obtained by subtracting the set temperature from the indoor temperature is equal to or greater than the first temperature threshold. Therefore, the control unit 12 causes the air conditioner 10 to perform cooling operation to lower the indoor temperature. When the indoor temperature continues to drop and the temperature difference becomes lower than the first temperature threshold, the control unit 12 switches the cooling operation to a dehumidification operation that throttles the expansion valve 38. In the dehumidification operation, the cooling capacity of the indoor temperature is maintained relatively low, but the indoor temperature may continue to drop. When the temperature difference becomes lower than the second temperature threshold, the control unit 12 stops the compressor 36 for a predetermined time and turns off the thermostat of the air conditioner 10. During the thermostat-off period, the indoor temperature gradually rises. When the indoor temperature rises to a predetermined level, the control unit 12 resumes the cooling operation or dehumidification operation. For example, if it is determined that the temperature difference is equal to or greater than the second temperature threshold, the control unit 12 may resume cooling operation.

In the example shown in FIG. 13B, supply ventilation is performed along with cooling operation and dehumidification operation. However, supply ventilation is not performed during the thermo-off period, i.e., during the period when the indoor temperature and the temperatures of the indoor heat exchanger 22 and fan 24 of the indoor unit 20 are relatively low and condensation may occur on the fan 24. When thermo-off ends and cooling operation resumes, the ventilation device 50 also resumes supply ventilation.

This completes the thermo-off process based on the indoor temperature. The control unit 12 controls the indoor temperature by turning off the thermo, and can provide a comfortable air-conditioned environment. Furthermore, if the indoor temperature is lower than the fourth temperature threshold, turning off the thermo before running ventilation can suppress condensation on the fan 24, and can also suppress the leakage and splashing of water droplets due to condensation.

Sixth Embodiment
<Comprehensive examples>
The control unit 12 of the air conditioner 10 can comprehensively execute a combination of the above-mentioned embodiments 1 to 5. For example, in embodiment 6, a combination of embodiments 1 to 5 is shown in FIG.

Figure 14 is a flow chart of an example of a control method in the sixth embodiment. In Figure 14, the control unit 12 performs control for cooling operation, dehumidification operation, and ventilation operation using the first to fourth temperature thresholds. The control method of the example in Figure 14 includes steps S100 to S300 in Figure 5 of the first embodiment, steps S410, S420, and S500 in Figure 11 of the third embodiment, step S600 in Figure 12A of the fourth embodiment, and steps S700 and S800 in Figure 13A of the fifth embodiment. In the sixth embodiment, the cooling area CA of the indoor heat exchanger 22 during the dehumidification operation and the nozzle 51 of the ventilation device 50 can be arranged as described in the second embodiment.

In the sixth embodiment, the first to fourth temperature thresholds have the following relationship: "third temperature threshold > second temperature threshold > 0°C > first temperature threshold > fourth temperature threshold." However, the relative relationship between these temperature thresholds is not limited to this. These temperature thresholds can be set appropriately if the first temperature threshold is a negative number, the second temperature threshold is higher than the first temperature threshold, the third temperature threshold is higher than the first temperature threshold, and the fourth temperature threshold is a negative number.

When the cooling ventilation mode is entered and the control method is started, the control unit 12 starts the cooling operation. The control unit 12 then acquires the set temperature and the room temperature (step S100), and calculates the temperature difference by subtracting the set temperature for the cooling operation from the room temperature. The control unit 12 determines whether the temperature difference is lower than the second temperature threshold (step S500). If the temperature difference is equal to or greater than the second temperature threshold, the control unit 12 executes the cooling operation in which the rotation speed of the compressor 36 is equal to or greater than the first rotation speed threshold so as to cool the room temperature relatively quickly (step S410). If the temperature difference is lower than the second temperature threshold but has not decreased to the first temperature threshold, the control unit 12 executes the cooling operation in which the rotation speed of the compressor 36 is lower than the first rotation speed threshold (step S420).

If it is determined that the temperature difference is lower than the second temperature threshold and the first temperature threshold ("YES" in step S200), the control unit 12 switches from cooling operation to dehumidification operation to prevent condensation, and then performs supply air ventilation (step S300). Thereafter, the control unit 12 continues to monitor the indoor temperature. If it is determined that the indoor temperature after dehumidification has risen and the temperature difference with the set temperature is equal to or greater than the third temperature threshold ("YES" in step S600), the control unit 12 performs cooling operation again (step S410).

On the other hand, if it is determined that the indoor temperature after dehumidification continues to decrease and the temperature difference from the set temperature is lower than the fourth temperature threshold ("YES" in step S700), the control unit 12 stops the compressor 36 for a predetermined time (step S800).

The control unit 12 may perform supply ventilation after step S300, step S410, step S420, or step S800 to maintain a predetermined ventilation rate.

This completes the control using the first to fourth temperature thresholds. Controlling in this manner can bring about all of the effects described above. In particular, it is possible to suppress condensation on the indoor unit fan caused by ventilation operation, and also to suppress the leakage and splashing of water droplets caused by condensation. Furthermore, controlling in this manner can ensure a constant number of ventilation cycles while appropriately controlling the indoor temperature in cooling ventilation mode, and provide a sufficient amount of ventilation to the controlled space.

Please note that the execution order of the steps shown in FIG. 14 is merely an example, and other execution orders are possible.

The present disclosure also provides a computer program and a storage medium for a control method for the air conditioner 10 corresponding to embodiments 2 to 6.

The above are merely specific embodiments of the present disclosure, and the scope of protection of the present disclosure is not limited thereto. The present disclosure includes the contents described above in the drawings and the specific embodiments described above, but the present disclosure is not limited thereto. Various disclosed embodiments or examples can be combined without departing from the scope or spirit of the present disclosure. Modifications that do not depart from the functional and structural principles of the present disclosure are within the scope of the claims.

10 Air conditioner 11 Memory unit 12 Control unit 13 Communication unit 14 Indoor temperature sensor 20 Indoor unit 22 Indoor heat exchanger 24 Fan 30 Outdoor unit 32 Outdoor heat exchanger 34 Fan 36 Compressor 38 Expansion valve 40 Four-way valve 50 Ventilator 51 Nozzle 51a Opening 52 Absorbing material 54 Motor 56 Ventilation duct 58 First heater 60 Second heater 62 First fan 64 Damper device 66 Second fan 70 Terminal device 72 Related application 80 Server 90 External information source A1 Indoor air A2 Outdoor air A3 Outdoor air A4 Outdoor air C1 Rotation center line P1 First flow path P2 Second flow path P1a Branch flow path P1b Branch flow path Rin Indoor Rout Outdoor CA Cooling area

Claims (18)

An air conditioner,
A ventilation device configured to perform supply ventilation for supplying outdoor air to a controlled space that is a target of air conditioning control by the air conditioner;
A control unit, in a cooling ventilation mode in which both a cooling operation and a ventilation operation by the ventilation device can be performed,
Acquire a set temperature for cooling control in the cooling ventilation mode and an indoor temperature of the control space;
When it is determined that the temperature difference obtained by subtracting the set temperature from the indoor temperature is lower than a first temperature threshold value,
A dehumidification operation is performed by throttling the expansion valve of the air conditioner,
The control unit is configured to perform supply ventilation by the ventilation device;
including,
Air conditioner. The control unit is further configured to maintain a predetermined ventilation rate in the ventilation operation.
The air conditioner according to claim 1. The air conditioner further includes a heat exchanger located within the control space,
The ventilation device includes a nozzle that blows outdoor air onto a portion of the heat exchanger.
The air conditioner according to claim 1. the heat exchanger includes a cooling area defined according to an opening degree of the expansion valve,
The cooling area is at least a portion of the heat exchanger;
the nozzle has an opening facing the cooling region;
In the dehumidifying operation, the opening of the nozzle blows outdoor air into the cooling area of the heat exchanger.
The air conditioner according to claim 3. In the dehumidification operation, the cooling region is a part of the heat exchanger, and the refrigerant flowing in the cooling region is in a liquid refrigerant state.
The air conditioner according to claim 4. In the cooling operation, the cooling area is the entire area of the heat exchanger.
The air conditioner according to claim 4. The air conditioner further includes a compressor,
The control unit is further configured to, when determining that the temperature difference is equal to or greater than a second temperature threshold, perform a cooling operation in which a rotation speed of the compressor is equal to or greater than a first rotation speed threshold,
the second temperature threshold is higher than the first temperature threshold;
The air conditioner according to claim 1. The control unit is further configured to, when determining that the temperature difference is lower than the second temperature threshold and equal to or higher than the first temperature threshold, perform a cooling operation in which a rotation speed of the compressor is lower than the first rotation speed threshold.
The air conditioner according to claim 7. The control unit is further configured to switch from the dehumidification operation to the cooling operation when it is determined that a temperature difference obtained by subtracting the set temperature from an indoor temperature after the dehumidification operation is equal to or greater than a third temperature threshold value,
the third temperature threshold is higher than the first temperature threshold;
The air conditioner according to claim 1. The air conditioner further includes a compressor,
The control unit is further configured to stop the compressor for a predetermined time when it is determined that a temperature difference obtained by subtracting the set temperature from an indoor temperature after the dehumidification operation is performed is lower than a fourth temperature threshold value after the dehumidification operation is performed.
The air conditioner according to claim 1. A method for controlling an air conditioner having a ventilation device, the ventilation device being configured to perform supply ventilation to supply outdoor air to a controlled space that is a target of air conditioning control of the air conditioner,
The control method includes:
In a cooling ventilation mode in which both a cooling operation and a ventilation operation by the ventilation device can be performed, a setting temperature related to cooling control in the cooling ventilation mode and an indoor temperature of the control space are acquired;
determining whether a temperature difference obtained by subtracting the set temperature from the indoor temperature is lower than a first temperature threshold;
When it is determined that the temperature difference is lower than the first temperature threshold value, a dehumidification operation is performed by throttling an expansion valve of the air conditioner, and supply air ventilation is performed by the ventilation device.
including,
Control methods. In the ventilation operation, a predetermined ventilation rate is maintained.
The control method according to claim 11. determining whether the temperature difference is greater than or equal to a second temperature threshold;
When it is determined that the temperature difference is equal to or greater than the second temperature threshold, performing a cooling operation in which a rotation speed of a compressor of the air conditioner is equal to or greater than a first rotation speed threshold;
Further comprising:
the second temperature threshold is higher than the first temperature threshold;
The control method according to claim 11. determining whether the temperature difference is less than the second temperature threshold and greater than or equal to the first temperature threshold;
When it is determined that the temperature difference is lower than the second temperature threshold and is equal to or higher than the first temperature threshold, performing a cooling operation in which a rotation speed of the compressor is lower than the first rotation speed threshold;
Further comprising:
The control method according to claim 13. a step of determining whether or not a temperature difference obtained by subtracting the set temperature from an indoor temperature after the dehumidification operation is performed is equal to or greater than a third temperature threshold value;
switching from the dehumidification operation to the cooling operation when it is determined that a temperature difference obtained by subtracting the set temperature from the indoor temperature after the execution is equal to or greater than the third temperature threshold;
Further comprising:
the third temperature threshold is higher than the first temperature threshold;
The control method according to claim 11. a step of determining whether or not a temperature difference obtained by subtracting the set temperature from an indoor temperature after the dehumidification operation is performed is lower than a fourth temperature threshold value after the dehumidification operation is performed;
stopping a compressor of the air conditioner for a predetermined time when it is determined that a temperature difference obtained by subtracting the set temperature from the indoor temperature after the execution is lower than the fourth temperature threshold value;
Further comprising:
The control method according to claim 11. A program that causes an air conditioner to execute the control method described in any one of claims 11 to 16. A non-transitory computer-readable storage medium having a computer program stored thereon,
When the computer program is executed by a processor, the control method according to any one of claims 11 to 16 is realized.
A non-transitory computer-readable storage medium.

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