Air conditioner, control method, program, and storage medium

Abstract

To provide an air conditioner which inhibits a dew condensation phenomenon caused by ventilation operation, and to provide a control method, a program, and a storage medium.SOLUTION: An air conditioner includes a ventilation device and a control unit. The ventilation device is configured so as to supply outdoor air to a control space, which is subject to air conditioning control of the air conditioner. The control unit is configured to acquire a setting temperature regarding cooling control in a cooling ventilation mode and an indoor temperature in the control space in the cooling ventilation mode, in which cooling operation and ventilation operation by the ventilation device may be performed, and perform dehumidification operation, in which an expansion valve of the air conditioner is narrowed, and perform air supply ventilation by the ventilation device when it is determined that a temperature difference obtained by subtracting the setting temperature from the indoor temperature is lower than a first temperature threshold.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to an air conditioner, a control method, a program, and a storage medium.

Background Art

[0002] Conventionally, as described in Patent Document 1, an air conditioner including an indoor unit disposed in a room to be air-conditioned and an outdoor unit disposed outdoors is known. This air conditioner is configured to supply outdoor air from the outdoor unit to the indoor unit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding conventional air conditioners, outdoor air can be supplied to the indoor unit. However, when supplying outdoor air to the indoor unit, there is a problem that dew condensation occurs on the fan in the indoor unit.

[0005] An object of the present disclosure is to provide an air conditioner, a control method, and a program that suppress the dew condensation phenomenon of the fan in the indoor unit caused by the ventilation operation.

Means for Solving the Problems

[0006] In order to solve the above-described problems, the present disclosure provides an air conditioner, a control method, and a program.

[0007] An air conditioner according to one embodiment of the present disclosure includes a ventilation device and a control unit. The ventilation device is configured to supply outdoor air to a control space that is subject to the 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 acquires the set temperature for cooling control in the cooling ventilation mode and the indoor temperature of the control 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, it is configured to perform a dehumidification operation by throttling the expansion valve of the air conditioner and to perform supply air ventilation by the ventilation device.

[0008] One embodiment of the control method relating to this disclosure is a control method for an air conditioner having a ventilation device. The ventilation device is configured to supply air ventilation by supplying outdoor air to a control space that is the target of the air conditioning control of the air conditioner. The control method includes the steps of: obtaining the set temperature for the cooling control of the cooling ventilation mode and the indoor temperature of the control space in a cooling ventilation mode in which both cooling operation and ventilation operation by the ventilation device can be performed; determining whether the 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, executing a dehumidification operation by throttling the expansion valve of the air conditioner and performing supply air ventilation by the ventilation device.

[0009] Other embodiments of the program relating to this disclosure cause the air conditioner to execute a control method.

[0010] Furthermore, other embodiments of the storage medium relating to this disclosure are non-temporary, computer-readable storage media on which a computer program is stored. The control method is realized when the computer program is executed by a processor. [Effects of the Invention]

[0011] In this disclosure, the air conditioner, control method, program, and storage medium can suppress condensation on the fan in the indoor unit. [Brief explanation of the drawing]

[0012] [Figure 1] Block diagram showing an example of the schematic configuration of an air conditioner in Embodiment 1 [Figure 2] Schematic diagram of an air conditioner in Embodiment 1 [Figure 3] Schematic diagram of a ventilation device in Embodiment 1 [Figure 4] Schematic diagram of a ventilation device during ventilation operation in Embodiment 1 [Figure 5] Flowchart of an example of a control method in Embodiment 1 [Figure 6] Schematic diagram of an example of a cooling region during dehumidification operation in Embodiment 1 [Figure 7] Schematic diagram of an example of a cooling region and nozzles in Embodiment 2 [Figure 8] Schematic diagram of an example of a cooling region and nozzles in Embodiment 2 [Figure 9] Schematic diagram of an example of a cooling region and nozzles in Embodiment 2 [Figure 10] Schematic diagram of an example of a cooling region and nozzles in Embodiment 2 [Figure 11] Flowchart of an example of a control method in Embodiment [Figure 12A] Flowchart of an example of a control method in Embodiment 4 [Figure 12B] An example of a timing diagram in Embodiment 4 [Figure 13A] Flowchart of an example of a control method in Embodiment 5 [Figure 13B] An example of a timing diagram in Embodiment 5 [Figure 14] Flowchart of an example of a control method in Embodiment 6

Embodiments for Carrying Out the Invention

[0013] First, various aspects of an air conditioner, a control method, a program, and a storage medium will be described.

[0014] The air conditioner according to 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 control space that is the target of air conditioning control of the air conditioner. In the cooling ventilation mode in which both the cooling operation and the ventilation operation by the ventilation device can be executed, the control unit acquires the set temperature related to the cooling control in the cooling ventilation mode and the indoor temperature of the control space, and when it is determined that the temperature difference obtained by subtracting the set temperature from the indoor temperature is lower than the first temperature threshold, a dehumidification operation of narrowing the expansion valve of the air conditioner is executed, and it is configured to execute supply air ventilation by the ventilation device.

[0015] In the air conditioner according to the second aspect of the present disclosure, in the first aspect, the control unit may be further configured to maintain a predetermined ventilation rate in the ventilation operation.

[0016] The air conditioner according to the third aspect of the present disclosure may further include a heat exchanger located in the control space in the first aspect or the second aspect. The ventilation device may include a nozzle that blows outdoor air to a part of the heat exchanger.

[0017] In the air conditioner according to the fourth aspect of the present disclosure, in the third aspect, the heat exchanger includes a cooling region defined according to the opening degree of the expansion valve, and the cooling region may be at least a part of the heat exchanger. The nozzle may have an opening facing the cooling region. In the dehumidification operation, the opening of the nozzle may blow outdoor air to the cooling region of the heat exchanger.

[0018] In the air conditioner according to the fifth aspect of the present disclosure, in the fourth aspect, in the dehumidification operation, the cooling region is a part of the heat exchanger, and the refrigerant flowing in the cooling region may be in a liquid refrigerant state.

[0019] In the air conditioner according to the sixth aspect of the present disclosure, in the fourth aspect, in the cooling operation, the cooling region may be the entire region of the heat exchanger.

[0020] The seventh embodiment of the present disclosure may further include a compressor in any one of the first to sixth embodiments. The control unit may be further configured to perform a cooling operation in which the rotational speed of the compressor is equal to or greater than a first rotational speed threshold when it determines that the temperature difference is equal to or greater than a second temperature threshold. The second temperature threshold is higher than the first temperature threshold.

[0021] 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 a cooling operation in which the rotational speed of the compressor is lower than the first rotational speed threshold when it determines that the temperature difference is lower than the second temperature threshold and equal to or greater than the first temperature threshold.

[0022] In the ninth embodiment of the present disclosure, in any one of the first to eighth embodiments, the control unit may be further configured to switch from dehumidification to cooling operation if it determines that, after performing dehumidification operation, the temperature difference obtained by subtracting the set temperature from the room temperature after the operation is greater than or equal to a third temperature threshold. The third temperature threshold is higher than the first temperature threshold.

[0023] An air conditioner of the tenth embodiment of the present disclosure may further include a compressor in any one of the first to ninth embodiments. The control unit may be further configured to stop the compressor for a predetermined period of time if, after performing a dehumidification operation, it determines that the temperature difference obtained by subtracting the set temperature from the room temperature after the operation is lower than a fourth temperature threshold.

[0024] The eleventh aspect of the control method relating to this disclosure is a control method for an air conditioner having a ventilation device. The ventilation device is configured to perform supply air ventilation by supplying outdoor air to a control space that is the target of the air conditioning control of the air conditioner. The control method includes the steps of: obtaining the set temperature for cooling control in the cooling ventilation mode and the indoor temperature of the control space in a cooling ventilation mode in which both cooling operation and ventilation operation by the ventilation device can be performed; determining whether the 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 by throttling the expansion valve of the air conditioner and performing supply air ventilation by the ventilation device.

[0025] The control method of the twelfth embodiment of the present disclosure allows a predetermined ventilation rate to be maintained during ventilation operation, in the eleventh embodiment.

[0026] A control method according to the 13th embodiment of the present disclosure may further include, in the 11th embodiment, the steps of determining whether the temperature difference is greater than or equal to a second temperature threshold, and, if it is determined that the temperature difference is greater than or equal to the second temperature threshold, performing a cooling operation in which the rotational speed of the compressor of the air conditioner is greater than or equal to a first rotational speed threshold. The second temperature threshold is higher than the first temperature threshold.

[0027] A control method according to the 14th embodiment of the present disclosure may further include, in the 13th embodiment, the steps of determining whether the temperature difference is lower than a second temperature threshold and greater than or equal to a first temperature threshold, and, if it is determined that the temperature difference is lower than a second temperature threshold and greater than or equal to a first temperature threshold, performing a cooling operation in which the rotational speed of the compressor is lower than a first rotational speed threshold.

[0028] The control method of the 15th aspect of the present disclosure may further include, in any one of the 11th to 14th aspects, the steps of: determining whether the temperature difference obtained by subtracting the set temperature from the room temperature after execution is greater than or equal to a third temperature threshold after performing a dehumidification operation; and, if it is determined that the temperature difference obtained by subtracting the set temperature from the room temperature after execution is greater than or equal to a third temperature threshold, switching from dehumidification operation to cooling operation. The third temperature threshold is higher than the first temperature threshold.

[0029] The control method of the 16th aspect of the present disclosure may further include, in any one of the 11th to 15th aspects, the steps of: determining whether the temperature difference obtained by subtracting the set temperature from the room temperature after execution is lower than a fourth temperature threshold after performing a dehumidification operation; and, if it is determined that the temperature difference obtained by subtracting the set temperature from the room temperature after execution is lower than a fourth temperature threshold, stopping the compressor of the air conditioner for a predetermined period of time.

[0030] The program of the 17th aspect relating to this disclosure causes the air conditioner to execute a control method.

[0031] The storage medium of the 18th aspect of this disclosure is a non-temporary, computer-readable storage medium on which a computer program is stored. The control method is realized when the computer program is executed by a processor.

[0032] 《Technical concept》 Before describing specific embodiments of the air conditioner, control method, program, and storage medium relating to this disclosure, the technical concepts described herein will first be explained using an example. In this example, the air conditioner has a ventilation device, which can supply outdoor air to a control 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 control space by the indoor unit's fan. The air conditioner can perform a cooling-ventilation mode that performs both cooling control and ventilation control according to the user's command.

[0033] Conventionally, air conditioners can supply outdoor air to the controlled space. However, when outdoor air is supplied to the indoor unit, condensation occurs on the fan (cross-flow fan) of the indoor unit if the outdoor air comes into contact with the cold fan. The water droplets from this condensation may leak out of the indoor unit or be blown into the room with the airflow from the fan (water splashing).

[0034] The main concept of the control method disclosed herein is that when the indoor temperature falls below a predetermined level, the air conditioner performs a dehumidification operation by throttling the expansion valve and performs supply air ventilation using a ventilation device. For example, if a heat exchanger located indoors (e.g., a heat exchanger in the indoor unit, hereinafter sometimes abbreviated as "indoor heat exchanger") is cooled by cooling control, the cooling operation is switched to a dehumidification operation before supply air ventilation is performed. The air conditioner suppresses condensation on 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.

[0035] This system suppresses the temperature drop of the indoor heat exchanger during ventilation, thereby reducing condensation on the indoor unit's fan caused by ventilation, and preventing water leakage and splashing due to condensation. Furthermore, by considering the set temperature and indoor temperature related to cooling control to determine whether or not to perform dehumidification, it is possible to prevent condensation while maintaining the indoor temperature near the set temperature.

[0036] Furthermore, the control method disclosed herein can perform supply air ventilation while preventing condensation, even in operating modes where condensation on the fan is possible (cooling ventilation mode). Therefore, a constant number of ventilation cycles can be ensured throughout the operation of this mode, and a sufficient amount of ventilation can be provided to the controlled space.

[0037] 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 illustrative and not limiting to the present disclosure. Among the components in Embodiment 1 below, those components that are not described in the independent claim representing the highest-level concept are described as optional components.

[0038] In each of the embodiments described below, variations may be shown for certain elements, and other elements may be combined with any configuration as appropriate, with each combined configuration producing its respective effect. In each embodiment, the effects of each variation are achieved by combining the configurations of each variation.

[0039] In the following detailed descriptions, terms such as “First,” “Second,” etc., are used for illustrative purposes only and should not be understood as expressing or implying relative importance or ranking of technical features. Features designated as “First” or “Second” express or imply that they include one or more such features.

[0040] Embodiment 1 Hereinafter, Embodiment 1 of the air conditioner, control method, program, and storage medium relating to this disclosure will be described in detail with reference to the drawings as appropriate. The air conditioner controls a specific internal space as the target of air conditioning control (hereinafter referred to as the control space) and harmonizes the air within the control space.

[0041] Figure 1 is a block diagram showing an example of the schematic configuration of the air conditioner 10 in Embodiment 1. Figure 1 is a schematic diagram created from the perspective of causing the air conditioner to execute the control method and its program, and from the perspective of the relationship between the air conditioner and other external devices. The air conditioner 10 can execute the control method and suppress condensation caused by ventilation.

[0042] In the embodiment shown in Figure 1, the air conditioner 10 includes a storage 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 its functions. The air conditioner 10 may also include a display for displaying visual information to the user. In the embodiment shown in Figure 1, the air conditioner 10 includes an indoor unit 20 and an outdoor unit 30. The storage 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 can at least provide supply air ventilation by supplying outdoor air to the room.

[0043] In this disclosure, "ventilation" refers to mechanical ventilation, and more specifically, to the exchange of indoor air with outside air by supplying outdoor air to the indoor space (i.e., the controlled space). The air conditioner 10 in this disclosure may perform supply air ventilation using the ventilation device 50 on its own, or it may perform both supply air ventilation and exhaust ventilation in cooperation with another ventilation device that can exhaust indoor air to the outside. Furthermore, if the ventilation device 50 has an exhaust fan that discharges indoor air to the outside, the air conditioner 10 may perform exhaust ventilation, or it may perform both supply air ventilation and exhaust ventilation together on its own. However, the main objective of this disclosure is to suppress the condensation phenomenon that may occur on the fan 24 of the indoor unit 20 when the ventilation device 50 performs supply air ventilation.

[0044] The air conditioner 10 can connect to a terminal device 70 and / or a server 80 via a communication unit 13. For example, the air conditioner 10 may connect to a terminal device 70, which is the remote controller of the air conditioner 10, via infrared. The air conditioner 10 may also connect to a terminal device 70, which is the user's smartphone, via the Internet. Furthermore, the air conditioner 10 may connect 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.

[0045] The following is an overview of each component.

[0046] <Air conditioner 10> The air conditioner 10 is designed to control an interior space of a room in a home or office, for example, as the control space subject to air conditioning control. It has an indoor unit 20 installed on the wall or ceiling of the control space and an outdoor unit 30 installed outdoors, in a central air conditioning room or other location outside the control space. The air conditioner 10 has, for example, a cooling function, a heating function, a dehumidifying function, and / or an air purifying function. The air conditioner 10 includes a ventilation device 50 capable of supplying outdoor air to the control space. In addition to the ventilation function, the ventilation device 50 may also have a dehumidifying function and / or a humidifying function. These functions and operating modes can be freely combined (for example, a cooling dehumidifying function, a heating humidifying function, a cooling ventilation mode, etc.).

[0047] In cooling mode, the air conditioner 10 can perform cooling operation, weak cooling operation (also known as compressor-type dehumidification or refrigeration cycle dehumidification), and dehumidification operation by throttling the expansion valve. The control method disclosed herein mainly utilizes dehumidification operation by throttling the expansion valve, but it is also possible to use compressor-type dehumidification.

[0048] <Storage section 11> The storage unit 11 is a recording medium for recording various information and control programs, and may also be a memory that functions as a work area for the control unit 12. The storage unit 11 can be implemented as, for example, flash memory, RAM (Random Access Memory), ROM (Read Only Memory), other storage devices, or a combination thereof as appropriate.

[0049] The storage unit 11 may store criteria, thresholds, and upper limits for ventilation control, and may store various thresholds, such as a threshold for determining whether or not to perform dehumidification operation. The storage unit 11 may also store information obtained from various sensors, such as the indoor temperature sensor 14. Information obtained from the terminal device 70, server 80, or external information source 90 may also be stored in the storage unit 11. This information can be read out by the control unit 12 when the control method is performed.

[0050] The storage unit 11 may store a computer program (sometimes abbreviated as "program" in this disclosure) that causes the air conditioner 10 to execute a control method. The storage unit 11 may also include a non-temporary computer-readable storage medium on which the computer program is stored.

[0051] <Control Unit 12> The control unit 12 is a controller that is responsible for controlling 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 realizes predetermined functions by executing a program. The control unit 12 can realize various controls in the air conditioner 10 by calling and executing a control program stored in the memory unit 11. The control unit 12 can also work with the memory unit 11 to read and write data stored in the memory unit 11. The control unit 12 is not limited to realizing predetermined functions through the cooperation of hardware and software, but may also be a hardware circuit specifically designed to realize predetermined functions.

[0052] The control unit 12 can receive various commands and setting values ​​from the user via the communication unit 13 from the terminal device 70 (for example, a command to activate the cooling ventilation mode of the air conditioner 10, and a temperature setting command related to cooling control). Based on these setting values ​​and detection values ​​received from various sensors (for example, indoor humidity, outdoor humidity), the control unit 12 controls each component of the air conditioner 10 so that it performs its cooling, heating, and ventilation functions. The control unit 12 also performs ventilation control of the air conditioner 10 based on a control method described later.

[0053] <Communications Department 13> The communication unit 13 can also communicate with the server 80, the user's terminal device 70, etc., and can, for example, send and receive Internet packets. As described above, the control unit 12 may cooperate with the server 80 and / or 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®, IEEE802.2, IEEE802.3, 3G, LTE, intranet, extranet, LAN, ISDN, VAN, CATV communication network, virtual private network, telephone line network, mobile communication network, satellite communication network, infrared, Bluetooth®, etc., and send and receive data.

[0054] <Sensors such as indoor temperature sensor 14> The indoor temperature sensor 14 detects the temperature of the indoor air drawn into the indoor unit 20 from the control space. In one embodiment, the indoor temperature sensor 14 is provided at the air intake port of the indoor unit 20 where indoor air is drawn in.

[0055] In addition to the indoor temperature sensor 14, the air conditioner 10 may also be equipped with sensors to acquire various information from outside the air conditioner 10 in order to perform its function. For example, the air conditioner 10 may include an outside air temperature sensor that detects the outside air temperature of the controlled space.

[0056] These sensors, including the indoor temperature sensor 14, can acquire information necessary for performing ventilation operations. The information detected by the sensor 14 is input to and stored in the storage unit 11, and later used by the control unit 12 or transmitted to the terminal device 70 or server 80.

[0057] 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 on other home appliances, or at any location inside or outside the smart home, or it may be an independent sensor device. When the air conditioner 10 executes the control method, it can obtain the indoor temperature from the indoor temperature sensor 14 regardless of where the indoor temperature sensor 14 is mounted.

[0058] <Ventilation device 50> The ventilation device 50 is configured to supply outdoor air to the indoor space, and in this embodiment, it is installed outdoors together with the outdoor unit 30. The ventilation device 50 can dehumidify or humidify the indoor air in the control space by supplying dehumidified outdoor air or outdoor air containing moisture to the control space. The specific structure and operation of the ventilation device 50 will be described later with reference to Figure 2.

[0059] <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 multiple types of home appliances. Alternatively, the terminal device 70 may be an information terminal capable of data communication with the air conditioner 10, such as a smartphone, mobile phone, tablet, wearable device, or computer with a dedicated related application 72 installed.

[0060] The control unit 12 or server 80 of the air conditioner 10 can obtain settings or commands entered by the user via the terminal device 70. Generally, the terminal device 70 includes a display for displaying a graphical 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, the display.

[0061] <Server 80> The server 80 may be, for example, a management server of the 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 performed by the control unit 12 of the air conditioner 10, but the control method can also be performed by the server 80.

[0062] <External information source 90> The external information source 90 is a source that provides information about services not directly related to the air conditioner 10, such as weather information or information about outside air temperature in a specific area. For example, the external information source 90 may be the Japan Meteorological Agency's website. The server 80 may transfer the information obtained from the external information source 90 to the air conditioner 10 or the terminal device 70. The air conditioner 10 may connect directly to the external information source 90 to obtain some of the information necessary for ventilation control from the external information source 90, or it may connect indirectly to the external information source 90 via the server 80 or the terminal device 70 to obtain the necessary information.

[0063] The following describes the mechanical configuration of the air conditioner 10, and in particular the ventilation function of the ventilation device 50, with reference to the drawings.

[0064] <Ventilation function by ventilation device 50> Figure 2 is a schematic diagram of an air conditioner 10 according to one embodiment of the present disclosure. Figure 2 is a schematic diagram of an air conditioner 10 prepared from the viewpoint of showing the mechanical configuration that performs the ventilation function.

[0065] As shown in Figure 2, the air conditioner 10 according to this embodiment has an indoor unit 20 located in the indoor area Rin to be air-conditioned, and an outdoor unit 30 located in the outdoor area Rout.

[0066] The indoor unit 20 is equipped with an indoor heat exchanger 22 that exchanges heat with indoor air A1, and a fan 24 that draws indoor air A1 into the indoor unit 20 and blows the indoor air A1, which has exchanged heat with the indoor heat exchanger 22, out into the indoor Rin.

[0067] The outdoor unit 30 is equipped 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, which has exchanged heat with the outdoor heat exchanger 32, out to the outdoor Rout. The outdoor unit 30 is also equipped with an indoor heat exchanger 22 and an outdoor heat exchanger 32, a compressor 36, an expansion valve 38, and a four-way valve 40 that execute the refrigeration cycle.

[0068] The indoor heat exchanger 22, outdoor heat exchanger 32, compressor 36, expansion valve 38, and four-way valve 40 are each connected by refrigerant piping through which the refrigerant flows. In cooling and low-cooling operation, the air conditioner 10 performs a refrigeration cycle in which the refrigerant flows sequentially from the compressor 36 through the four-way valve 40, outdoor heat exchanger 32, expansion valve 38, indoor heat exchanger 22, and back to the compressor 36. In heating operation, the air conditioner 10 performs a refrigeration cycle in which the refrigerant flows sequentially from the compressor 36 through the four-way valve 40, indoor heat exchanger 22, expansion valve 38, outdoor heat exchanger 32, and back to the compressor 36.

[0069] In addition to air conditioning operation using a refrigeration cycle, the air conditioner 10 also performs air conditioning operation by introducing outdoor air A3 into indoor Rin. For this purpose, the air conditioner 10 has a ventilation device 50. The ventilation device 50 is installed on the outdoor unit 30.

[0070] Figure 3 is a schematic diagram of the ventilation device 50.

[0071] As shown in Figure 3, the ventilation device 50 is equipped with an absorbent material 52 through which the outdoor air A3 and A4 pass.

[0072] The absorbent material 52 is a member through which air can pass and which collects moisture from the passing air or adds moisture to the passing air. In this embodiment, the absorbent material 52 is disc-shaped and rotates around a rotation centerline C1 that passes through its center. The absorbent material 52 is rotationally driven by a motor 54.

[0073] The absorbent material 52 is preferably a polymer adsorbent that adsorbs moisture from the air. The polymer adsorbent is, for example, composed of a crosslinked sodium polyacrylate. Compared to adsorbents such as silica gel and zeolite, the polymer adsorbent absorbs a larger amount of moisture per unit volume, can desorb the supported moisture at a low heating temperature, and can support moisture for a long period of time.

[0074] Inside the ventilation device 50, there are a first flow path P1 and a second flow path P2 through which 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.

[0075] 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 conduit 56.

[0076] In this embodiment, the first flow path P1 includes a plurality of branch flow paths P1a and P1b upstream of the absorbent material 52. In this specification, "upstream" and "downstream" are used in relation to airflow.

[0077] Multiple branch channels P1a and P2a merge upstream of the absorbent material 52. Each of the branch channels P1a and P1b is equipped with first and second heaters 58 and 60 for heating the outdoor air A3.

[0078] The first and second heaters 58 and 60 may have the same heating capacity or they may have different heating capacities. Furthermore, it is preferable that the first and second heating heaters 58 and 60 be PTC (Positive Temperature Coefficient) heaters, which increase electrical resistance as current flows and the temperature rises, that is, which can suppress an excessive rise in heating temperature. In the case of heaters using nichrome wire or carbon fiber, the heating temperature (surface temperature) continues to rise as current flows, so it is necessary to monitor the temperature. In the case of PTC heaters, the heater itself adjusts the heating temperature within a certain temperature range, so it is not necessary to monitor the heating temperature.

[0079] The first flow path P1 is provided with a first fan (hereinafter also called the "supply fan") 62 that generates a flow of outdoor air A3 toward the indoor unit 20. In this embodiment, the first fan 62 is positioned downstream of the absorbent material 52. When the first fan 62 operates, the outdoor air A3 flows from the outdoor Rout into the first flow path P1 and passes through the absorbent material 52.

[0080] Furthermore, 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 either the indoor Rin (i.e., the indoor unit 20) or the outdoor Rout. In this embodiment, the damper device 64 is located 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 conduit 56 and is blown out to the indoor Rin by the fan 24.

[0081] The second flow path P2 is the flow path for outdoor air A4. Unlike the outdoor air A3 that flows through the first flow path P1, the outdoor air A4 that flows through the second flow path P2 does not go towards the indoor unit 20. After passing through the absorbent material 52, the outdoor air A4 that flows through the second flow path P2 flows out to the outdoor Rout.

[0082] The first flow path P1 is provided with a second fan 66 that generates a flow of outdoor air A4. In this embodiment, the second fan 66 is positioned downstream of the absorbent material 52. When the second fan 66 operates, the outdoor air A4 flows from the outdoor Rout into the second flow path P2, passes through the absorbent material 52, and then flows out to the outdoor Rout.

[0083] The ventilation device 50 selectively uses the absorbent material 52, motor 54, first heater 58, second heater 60, first fan 62, damper device 64, and second fan 66 to selectively perform ventilation operation or other operations.

[0084] Figure 4 is a schematic diagram of the ventilation system during ventilation operation.

[0085] Ventilation operation is an air conditioning operation in which outdoor air A3 is supplied directly to indoor Rin (i.e., indoor unit 20) via the ventilation conduit 56. As shown in Figure 4, during 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 are not heating the outdoor air A3. The first fan 62 is in the ON state, causing outdoor air A3 to flow 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 no flow of outdoor air A4 is generated in the second flow path P2.

[0086] In this type of ventilation operation, the outdoor air A3 flows into the first flow path P1 and passes through the absorbent material 52 without being heated by the first and second heaters 58 and 60. The outdoor air A3 that has passed through the absorbent material 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 conduit 56 is blown out into the indoor Rin by the fan 24. In this type of ventilation operation, the outdoor air A3 is supplied directly to the indoor Rin, and the indoor Rin is ventilated.

[0087] Up to this point, we have provided a general overview of the configuration and operation of the air conditioner 10 according to this embodiment. From here on, we will describe the features of the air conditioner, control method, program, and storage medium using the air conditioner 10 according to this embodiment.

[0088] <Control method for air conditioner 10> The air conditioner 10 executes the control method. More specifically, the control unit 12 of the air conditioner 10 works in cooperation with the memory unit 11 and the indoor temperature sensor 14 to execute the control method. According to this control method, condensation on the fan 24 in the indoor unit 20 caused by ventilation operation can be suppressed.

[0089] Figure 5 is a flowchart of the control method in Embodiment 1, and the control method includes steps S100 to S400.

[0090] In one embodiment, the control unit 12 may perform the cooling and ventilation functions by executing steps S100 to S400 after the air conditioner 10 enters the cooling and ventilation mode based on a user command. In another embodiment, for example, in automatic operation mode, the control unit 12 may automatically enter the cooling and ventilation mode and execute steps S100 to S400 when it determines, based on information, that there is a need for room temperature adjustment and a need for ventilation. In the cooling and ventilation mode, both cooling operation and ventilation operation by the ventilation device 50 can be performed.

[0091] 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 entered by the user via the controller of the air conditioner 10 or a smartphone associated with the air conditioner 10, or it may be the internal set temperature in which the air conditioner 10 actually operates. The control unit 12 may acquire the set temperature by reading the set temperature from the storage unit 11. The control unit 12 may also acquire the indoor temperature by querying the indoor temperature sensor 14 or by reading the most recently written indoor temperature from the storage unit 11.

[0092] Next, the control unit 12 determines whether the temperature difference obtained by subtracting the set temperature from the acquired room 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 room temperature is lower than the set temperature by a predetermined amount. The first temperature threshold may be, for example, -0.1℃, -0.5℃, -1℃, or -1.5℃.

[0093] If the control unit 12 determines that the temperature difference is lower than the first temperature threshold, it performs a dehumidification operation by throttling the expansion valve 38 of the air conditioner 10 and performs supply air ventilation using the ventilation device 50 (step S300). In one embodiment, the control unit 12 performs supply air ventilation after performing the dehumidification operation for a predetermined time. In one embodiment, the control unit 12 performs supply air ventilation when it starts performing the dehumidification operation. In one embodiment, the control unit 12 starts supply air ventilation before performing the dehumidification operation.

[0094] On the other hand, if the control unit 12 determines that the temperature difference between the indoor temperature and the set temperature is equal to or greater than the first temperature threshold, that is, 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 cold enough to cause condensation, the control unit 12 may perform supply air ventilation while performing cooling operation, or it may perform supply air ventilation after performing cooling operation for a predetermined time.

[0095] During ventilation operation, the control unit 12 may maintain a predetermined ventilation rate. The ventilation rate is a numerical value that indicates how many times the air in the controlled space is replaced per hour. For example, for supply air ventilation, the ventilation rate may be calculated by dividing the amount of air flowing into the controlled space per hour (ventilation rate) by the indoor volume of the controlled space (e.g., floor area × 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 can be set by user input, or it can be set automatically by the control unit 12 based on the indoor and outdoor environment and the ventilation control needs. The control unit 12 may calculate the ventilation rate (supply airflow rate) based on the indoor volume of the controlled space and the ventilation rate, and control the first fan 62 of the ventilation device 50.

[0096] By maintaining the ventilation rate in this way, for example, 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 maintained in principle, a sufficient amount of ventilation can be provided to the controlled space.

[0097] In one embodiment, when the control unit 12 enters the cooling ventilation mode, it may first perform cooling operation. That is, it may perform cooling operation 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 also perform supply air ventilation after a predetermined time has elapsed since switching from cooling operation to dehumidification operation, and the surface temperature of the indoor heat exchanger 22 and fan 24 of the indoor unit 20 has risen. In this way, condensation and water splashing due to ventilation can be prevented more reliably.

[0098] Below, we will explain in more detail the differences between dehumidification operation and cooling operation, from the perspective of controlling the opening degree of the expansion valve 38.

[0099] The indoor heat exchanger 22 includes a cooling region defined according to the opening degree of the expansion valve 38, and this cooling region is at least a part of the indoor heat exchanger 22. The cooling region is the region in which the refrigerant flowing is in a liquid state. In cooling operation, the cooling region is the entire region of the indoor heat exchanger 22. That is, in cooling operation, liquid refrigerant flows throughout the entire region of the indoor heat exchanger 22, and the indoor heat exchanger 22, which is cooled entirely by liquid refrigerant, cools the air in the controlled space.

[0100] On the other hand, in dehumidification operation, the cooling region is a part of the indoor heat exchanger 22. Figure 6 is a schematic diagram of an example of the cooling region during dehumidification operation in Embodiment 1. As shown in Figure 6, the indoor heat exchanger 22 has a cooling region CA (also called the wet path or wet region) and other regions (also called the dry path or dry region). In the embodiment shown in Figure 6, the area enclosed by the dotted line, including the refrigerant inlet in the upper left direction of Figure 6, represents the cooling region CA, and the hatched circle represents the wet path.

[0101] The "wet path" and "dry path" are wet and dry regions in the indoor heat exchanger 22, which are created by controlling the frequency of the compressor 36 and the opening degree of the expansion valve 38 during dehumidification operation. Specifically, the wet path is a wet region formed upstream of the refrigerant flow direction in the indoor heat exchanger 22 by reducing the frequency of the compressor 36 and the opening degree of the expansion valve 38 during dehumidification operation. The dry path is a dry region formed downstream of the wet path in the indoor heat exchanger 22 by reducing the frequency of the compressor 36 and the opening degree of the expansion valve 38 during dehumidification operation.

[0102] The cooling region CA (wet path, wet region) is a region in the indoor heat exchanger 22 that is wetter than other regions. On the other hand, regions in the indoor heat exchanger 22 other than the cooling region CA (dry path, dry region) are regions in the indoor heat exchanger 22 that are drier than other regions. Such cooling regions CA can be identified experimentally or by simulation.

[0103] 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 in the indoor heat exchanger 22 functions as a cooling region CA and becomes humid. The cooling region CA is the part in which the refrigerant flowing through the indoor heat exchanger 22 becomes a low-pressure liquid refrigerant state by narrowing the opening of the expansion valve 38.

[0104] In dehumidification operation, the indoor heat exchanger 22 is cooled in some areas by liquid refrigerant, but the overall temperature drop is relatively small. Therefore, the fan 24 and the air in the control space are not cooled as much as during cooling operation. The control unit 12 of the air conditioner 10 can automatically switch to dehumidification operation to suppress the temperature drop of the indoor heat exchanger 22 during ventilation. As a result, the phenomenon of condensation of outside air on the surface of the fan 24 of the indoor unit 20 can be suppressed, and leakage of water droplets and splashing due to condensation can also be suppressed. Furthermore, since 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, condensation can be prevented while maintaining the indoor temperature near the set temperature.

[0105] According to the control method described above, even when the cooling mode, which may cause condensation on the fan, is combined with ventilation operation to create a cooling-ventilation mode, it is possible to perform supply air ventilation while preventing condensation. Therefore, a certain number of ventilation cycles can be ensured in cooling-ventilation mode, and a sufficient amount of ventilation can be provided to the controlled space.

[0106] 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.

[0107] In one embodiment, the air conditioner 10 has a program used to perform the control method described above. The program causes the air conditioner 10 to perform the control method.

[0108] In one embodiment, the air conditioner 10 has a non-temporary, computer-readable storage medium in which a computer program is stored. The control method of the present disclosure is realized when the computer program is executed by a processor. 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 different component from the storage unit 11.

[0109] Embodiment 2 <Arrangement of air supply nozzles for ventilation device 50> In Embodiment 2, the ventilation device 50 includes a nozzle that blows outdoor air onto a portion of the indoor heat exchanger 22. By blowing outdoor air onto a portion of the indoor heat exchanger 22 rather than the entire unit, condensation on the fan 24 inside the indoor unit 20 can be further suppressed.

[0110] Figure 7 is a schematic diagram of an example of the cooling region CA and nozzle 51 in Embodiment 2. As can be seen from Figure 4, the ventilation device 50 includes a ventilation conduit 56 that supplies 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 conduit 56 on the indoor unit 20 side and has an opening 51a. In the embodiment of Figure 7, the opening 51a faces the cooling region CA of the indoor heat exchanger 22. More specifically, the opening 51a faces the cooling region CA during dehumidification operation when the expansion valve 38 is throttled.

[0111] In this structure, during dehumidification operation, the opening 51a of the nozzle 51 blows outdoor air into the cooling area CA. During 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 then blown into the control space by the fan 24. With this structure, for example, high temperature and high humidity outdoor air in summer can be quickly cooled and dehumidified.

[0112] However, the arrangement of the nozzle 51, the opening 51a of the nozzle 51, or the cooling region CA is not limited to the embodiment shown in Figure 7. As described below, the opening 51a of the nozzle 51 does not have to face the cooling region CA, and the cooling region CA can be provided in different parts of the indoor heat exchanger 22.

[0113] Figures 8 and 9 are schematic diagrams of modified examples of the cooling region CA and nozzle 51 in Embodiment 2. In dehumidification operation, the cooling region CA is a part of the indoor heat exchanger 22, but the opening 51a of the nozzle 51 does not have to blow outside air into the cooling region CA. As shown in Figures 8 and 9, the opening 51a of the nozzle 51 faces the dry region other than the cooling region CA (wet region) in the indoor heat exchanger 22, and blows outside air into the dry region. When the surface temperature of the dry region is lower than the outdoor temperature, the outside air can be cooled and dehumidified.

[0114] In dehumidification operation, the cooling region CA, where the flowing refrigerant is in a liquid state, is a portion of the indoor heat exchanger 22, but is not limited to any specific area. As shown in Figures 6 to 9, the cooling region CA may occupy a portion of the outside of the indoor heat exchanger 22 (opposite the fan 24), including the refrigerant inlet, for example, half or one-third of the outer area. Alternatively, as shown in Figure 10, the cooling region CA may occupy the entire outside area of ​​the indoor heat exchanger 22. The indoor heat exchanger 22 in Figure 10 has higher cooling and dehumidification capacity compared to the indoor heat exchanger 22 in Figures 6 to 9. Furthermore, when the cooling region CA is arranged as in Figure 10, the opening 51a of the nozzle 51 can blow outside air into the cooling region CA regardless of how the nozzle 51 is positioned.

[0115] In this way, the nozzle 51, the opening 51a of the nozzle 51, and the cooling area CA can be freely positioned. Furthermore, if it is desired to cool and dehumidify the outdoor air relatively efficiently, the opening 51a of the nozzle 51 can be positioned to face the cooling area CA, or the cooling area CA can be made relatively wide.

[0116] Embodiment 3 <Cooling control based on the temperature difference between the indoor temperature and the set temperature> In Embodiment 3, the control unit 12 can control the cooling operation in the cooling ventilation mode based on the temperature difference between the indoor temperature and the set temperature.

[0117] Figure 11 is a flowchart of an example of the control method in Embodiment 3. Embodiment 3 is the same as Embodiment 1 in that it performs dehumidification and supply air ventilation when it is determined that the temperature difference is lower than the first temperature threshold.

[0118] In Embodiment 3, the control unit 12 of the air conditioner 10 calculates the 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 executed before or after step S200.

[0119] If the temperature difference obtained by subtracting the set temperature from the room temperature is lower than the first and second temperature thresholds (YES in step S500 and YES in step S200), the control unit 12 performs dehumidification operation and supply air ventilation by throttling the expansion valve 38. If the temperature difference is greater than or equal to the second temperature threshold (NO in step S500), it means that the room temperature is not close enough to the set temperature. Therefore, the control unit 12 performs cooling operation in which the rotational speed of the compressor 36 is greater than or equal to the first rotational speed threshold in order to lower the room temperature (step S410).

[0120] The temperature difference is greater than or equal to the second temperature threshold, meaning the temperature difference is relatively large. Therefore, in step S410, the control unit 12 rotates the compressor 36 to a first rotational speed threshold or higher in order to lower the room temperature relatively quickly. In another embodiment, in step S410, the control unit 12 rotates the compressor 36 at the maximum rotational speed at which it can rotate in order to lower the room temperature as quickly as possible. The first rotational speed threshold may be, for example, 95%, 90%, 80%, or 75% of the maximum rotational speed.

[0121] On the other hand, if the temperature difference is lower than the second temperature threshold and greater than or equal to the first temperature threshold (YES in step S500 and NO in step S200), it means that the room temperature is approaching the set temperature to some extent. In this case, the room temperature should be lowered, but it may be lowered relatively gradually. Therefore, the control unit 12 may perform cooling operation with the rotational speed of the compressor 36 lower than the first rotational speed threshold (step S420).

[0122] The control unit 12 may, in step S410 or step S420, perform cooling operation for a certain period of time, then perform dehumidification operation for a certain period of time, and then perform supply air ventilation. In another embodiment, the control unit 12 may perform supply air ventilation while performing cooling operation in step S410 or step S420. Alternatively, the control unit 12 may perform supply air ventilation after step S410 or step S420, that is, after performing cooling operation for a certain period of time.

[0123] 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 performs cooling operation when the indoor temperature is not yet close enough to the set temperature. It also controls the rotation speed of the compressor 36 based on the comparison result between the temperature difference and the second temperature threshold. In this way, the indoor temperature can be appropriately controlled while maintaining ventilation in the cooling ventilation mode.

[0124] Embodiment 4 <Control to switch from dehumidification to cooling operation> Compared to cooling operation, the cooling power of dehumidification operation is relatively weak, so the room temperature may gradually rise after dehumidification operation is performed. In Embodiment 4, the control unit 12 can switch from dehumidification operation to cooling operation based on the room temperature after dehumidification operation is performed, in order to maintain the room temperature near the set temperature.

[0125] The control unit 12 may periodically acquire the indoor temperature in order to control the temperature, humidity, and / or ventilation within the controlled space. For example, the control unit 12 can monitor the indoor temperature of the controlled space by acquiring the indoor temperature using 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.

[0126] Figure 12A is a flowchart of an example of the control method in Embodiment 4. Steps S100 to S400 in Figure 12A are the same as steps S100 to S400 in Figure 5 of Embodiment 1, and therefore, redundant explanations are omitted here.

[0127] After performing the dehumidification operation in step S300, the control unit 12 obtains the room temperature after the operation. The control unit 12 then calculates the temperature difference (hereinafter sometimes abbreviated as "temperature difference after dehumidification") obtained by subtracting the set temperature from the room temperature after the dehumidification operation. Subsequently, the control unit 12 determines whether the temperature difference after dehumidification is greater than or equal to 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, for example, 0.5℃, 0.8℃, 1.0℃, or 1.5℃.

[0128] A temperature difference after dehumidification exceeding 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 exceeds the third temperature threshold, the control unit 12 performs cooling operation to lower the indoor temperature and maintain it near the set temperature (step S400). That is, the control unit 12 stops the ongoing dehumidification operation and switches to cooling operation. Even after switching to cooling operation, the control unit 12 can perform supply air ventilation. For example, the control unit 12 may perform supply air ventilation within a certain period of 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.

[0129] 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 the dehumidification operation and perform supply air ventilation to maintain the ventilation rate.

[0130] In this disclosure, the control method is described using an example where the set temperature for cooling operation and the set temperature for dehumidification operation are the same, but these two set temperatures may be different. If the set temperature is different for each operation, the control unit 12 may calculate the temperature difference after dehumidification using the set temperature for cooling operation, or it may calculate the temperature difference after dehumidification using the set temperature for dehumidification operation.

[0131] 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 greater than or equal to 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 fall and the temperature difference becomes lower than the first temperature threshold, the control unit 12 switches from cooling operation to dehumidification operation, which restricts the expansion valve 38. In 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. When the indoor temperature rises again and the temperature difference becomes greater than or equal to the first temperature threshold again, the control unit 12 switches from dehumidification operation to cooling operation to lower the indoor temperature. In the example shown in Figure 12B, the temperature of the indoor heat exchanger 22 and fan 24 of the indoor unit 20 does not drop excessively when switching between cooling and dehumidifying operation, so the ventilation device 50 continues to supply outdoor air to the controlled space. In other words, the ventilation device 50 continues to perform supply air ventilation. In another example, supply air ventilation may not be performed during cooling operation, or supply air ventilation may be performed after dehumidifying operation for a certain period of time.

[0132] This completes the process of switching from dehumidification to cooling. 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 dehumidification, the system can switch to cooling and maintain the indoor temperature near the set temperature.

[0133] Embodiment 5 <Thermo-off for dehumidification and cooling operations> Compared to cooling operation, the cooling power of dehumidification operation is relatively weaker, but after dehumidification operation, the room temperature may continue to drop and become too low compared to the set temperature. In Embodiment 5, the control unit 12 can temporarily stop both dehumidification operation and cooling operation based on the room temperature after dehumidification operation to prevent the room temperature from dropping too low.

[0134] Figure 13A is a flowchart of an example of the control method in Embodiment 5. Steps S100 to S400 in Figure 13A are the same as steps S100 to S400 in Figure 5 of Embodiment 1, and therefore, redundant explanations are omitted here.

[0135] As described in Embodiment 4, the control unit 12 can continue to monitor the room temperature even after performing dehumidification in step S300. In Embodiment 5, after performing dehumidification, the control unit 12 calculates the temperature difference (i.e., the temperature difference after dehumidification) by subtracting the set temperature from the room temperature after the operation. The control unit 12 then 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 room temperature has dropped too low, so it may be a negative number. The fourth temperature threshold may be, for example, -1.5°C, -2°C, -2.5°C, or -3°C.

[0136] If the control unit 12 determines that the temperature difference after dehumidification is lower than the fourth temperature threshold, it stops the compressor 36 for a predetermined period of time to suppress the decrease in room temperature (step S800). In other words, in step S800, the control unit 12 temporarily stops the dehumidification and cooling operations and turns off the thermostat of the air conditioner 10.

[0137] In one embodiment, the predetermined time for the thermo-off is a predetermined time, which 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 the thermo-off, and if it determines that the indoor temperature has recovered (risen), it resumes cooling or dehumidifying operation. For example, if the indoor temperature reaches or exceeds a first temperature threshold, the control unit 12 may resume cooling operation.

[0138] The control unit 12 may immediately perform ventilation operation after temporarily stopping the compressor 36 in step S800, or it may perform ventilation operation after a certain period of time has elapsed since the temporary stop. Alternatively, after step S800, the control unit may return to step S100 and repeat the control method.

[0139] On the other hand, if the temperature difference after dehumidification is greater than or equal to the fourth temperature threshold (NO in step S700), the control unit 12 may return to step S700 or step S100 and continue monitoring the room temperature.

[0140] 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 greater than or equal to 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 fall and the temperature difference falls below the first temperature threshold, the control unit 12 switches from cooling operation to dehumidification operation by throttling the expansion valve 38. In dehumidification operation, the cooling capacity of the indoor temperature is maintained at a relatively low level, but the indoor temperature may continue to fall. When the temperature difference falls below the second temperature threshold, the control unit 12 stops the compressor 36 for a predetermined time and performs a thermo-off of the air conditioner 10. During the thermo-off period, the indoor temperature gradually rises. When the indoor temperature rises to a predetermined level, the control unit 12 resumes cooling operation or dehumidification operation. For example, if the control unit 12 determines that the temperature difference is equal to or greater than the second temperature threshold, it may restart the cooling operation.

[0141] In the example shown in Figure 13B, air supply ventilation is performed along with cooling and dehumidifying operations. However, during the thermo-off period, i.e., 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 there is a possibility of condensation occurring on the fan 24, air supply ventilation is not performed. When the thermo-off period ends and cooling operation resumes, the ventilation device 50 also resumes air supply ventilation.

[0142] This completes the thermo-off process based on the indoor temperature. The control unit 12 can control the indoor temperature by performing the thermo-off and provide a comfortable air-conditioned environment. Furthermore, if the indoor temperature is lower than the fourth temperature threshold, performing the thermo-off before starting ventilation operation can suppress condensation on the fan 24, and also suppress leakage and splashing of water droplets due to condensation.

[0143] Embodiment 6 <General examples> The control unit 12 of the air conditioner 10 can comprehensively implement the combinations of embodiments 1 to 5 described above. For example, in embodiment 6, the combination of embodiments 1 to 5 is shown in Figure 14.

[0144] Figure 14 is a flowchart of an example of the control method in Embodiment 6. In Figure 14, the control unit 12 uses the first to fourth temperature thresholds to control the cooling operation, dehumidification operation, and ventilation operation. The control method of the embodiment in Figure 14 includes steps S100 to S300 in Figure 5 of Embodiment 1, steps S410, S420, and S500 in Figure 11 of Embodiment 3, step S600 in Figure 12A of Embodiment 4, and steps S700 and S800 in Figure 13A of Embodiment 5. In Embodiment 6, the cooling region CA of the indoor heat exchanger 22 and the nozzle 51 of the ventilation device 50 during dehumidification operation can be arranged as described in Embodiment 2.

[0145] In Embodiment 6, the relationship between the first to fourth temperature thresholds is "third temperature threshold > second temperature threshold > 0°C > first temperature threshold > fourth temperature threshold". However, the relative relationships of these temperature thresholds are not limited to this. These temperature thresholds can be appropriately set 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.

[0146] 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 obtains 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 performs a cooling operation in which the rotational speed of the compressor 36 is equal to or greater than the first rotational speed threshold in order 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 performs a cooling operation in which the rotational speed of the compressor 36 is lower than the first rotational speed threshold (step S420).

[0147] If the control unit 12 determines that the temperature difference is lower than the second and first temperature thresholds (YES in step S200), it switches from cooling operation to dehumidification operation to prevent condensation, and then performs supply air ventilation (step S300). After that, the control unit 12 continues to monitor the indoor temperature. If the indoor temperature after dehumidification rises and it is determined that the temperature difference from the set temperature is greater than or equal to the third temperature threshold (YES in step S600), the control unit 12 performs cooling operation again (step S410).

[0148] On the other hand, if the room temperature after dehumidification continues to decrease and the temperature difference from the set temperature is determined to be lower than the fourth temperature threshold (YES in step S700), the control unit 12 stops the compressor 36 for a predetermined period of time (step S800).

[0149] The control unit 12 may perform supply air ventilation after step S410, step S420, or step S800, in addition to step S300, in order to maintain a predetermined ventilation rate.

[0150] This completes the control using the first to fourth temperature thresholds. Controlling the system in this way brings about all the effects described above. In particular, it suppresses condensation on the indoor unit's fan caused by ventilation operation, and also reduces leakage and splashing of water droplets due to condensation. Furthermore, with this control, in cooling ventilation mode, it is possible to ensure a certain number of ventilations while appropriately controlling the indoor temperature, providing sufficient ventilation to the controlled space.

[0151] It should be noted that the execution order of each step shown in Figure 14 is merely one example, and other execution orders are possible.

[0152] Furthermore, this disclosure also provides a computer program and storage medium for a control method of the air conditioner 10, corresponding to embodiments 2 to 6.

[0153] The above are merely specific embodiments of the Disclosure, and the scope of protection of the Disclosure is not limited thereto. The Disclosure includes, but is not limited to, the contents described in the drawings and the specific embodiments described above. Various embodiments or examples disclosed can be combined without departing from the scope or spirit of the Disclosure. Any modifications that do not depart from the functional and structural principles of the Disclosure are within the scope of the claims. [Explanation of Symbols]

[0154] 10. Air conditioner 11 Storage section 12 Control Unit 13 Communications Department 14. Indoor temperature sensor 20 Indoor unit 22 Indoor heat exchanger 24 Fans 30 Outdoor unit 32 Outdoor heat exchanger 34 Fans 36 Compressor 38 Expansion valve 40 Square valve 50 Ventilation system 51 nozzles 51a aperture 52 Absorbent material 54 Motor 56 Ventilation conduits 58. First heater 60 Second heater 62 First fan 64 Damper device 66 Second Fan 70 Terminal devices 72 Related Applications 80 servers 90 External information sources A1 Indoor air A2 Outdoor air A3 Outdoor air A4 Outdoor air C1 Rotation centerline P1 First channel P2 Second channel P1a Branch P1b Tributary channel Rin (indoors) Rout outdoor CA cooling area

Claims

1. It is an air conditioner, A ventilation device configured to supply outside air to a control space targeted by the air conditioning control of the aforementioned air conditioner, A control unit, in a cooling-ventilation mode in which both cooling operation and ventilation operation by the ventilation device can be performed, The set temperature for the cooling control of the aforementioned cooling ventilation mode and the indoor temperature of the controlled space are obtained. If it is determined that the temperature difference obtained by subtracting the set temperature from the room temperature is lower than the first temperature threshold, The dehumidification operation is performed by throttling the expansion valve of the aforementioned air conditioner. The aforementioned ventilation device performs supply air ventilation. The control unit is configured as follows: including, Air conditioner.

2. The control unit is further configured to maintain a predetermined number of ventilations during the ventilation operation. The air conditioner according to claim 1.

3. The air conditioner further includes a heat exchanger located within the control space, The ventilation device includes a nozzle that blows outside air into a part of the heat exchanger. The air conditioner according to claim 1.

4. The heat exchanger includes a cooling region defined according to the opening degree of the expansion valve. The cooling region is at least a portion of the heat exchanger, The nozzle has an opening facing the cooling region, In the dehumidification operation described above, the opening of the nozzle blows outside air into the cooling area of ​​the heat exchanger. The air conditioner according to claim 3.

5. In the dehumidification operation described above, the cooling region is a part of the heat exchanger, and the refrigerant flowing within the cooling region is in a liquid refrigerant state. The air conditioner according to claim 4.

6. In the aforementioned cooling operation, the cooling region is the entire region of the heat exchanger. The air conditioner according to claim 4.

7. The aforementioned air conditioner further includes a compressor, The control unit is further configured to perform a cooling operation in which the rotational speed of the compressor is equal to or greater than the first rotational speed threshold when it determines that the temperature difference is equal to or greater than the second temperature threshold. If the second temperature threshold is higher than the first temperature threshold, The air conditioner according to claim 1.

8. The control unit is further configured to perform a cooling operation in which the rotational speed of the compressor is lower than the first rotational speed threshold when it determines that the temperature difference is lower than the second temperature threshold and greater than or equal to the first temperature threshold. The air conditioner according to claim 7.

9. The control unit is further configured to switch from the dehumidification operation to the cooling operation if it determines that the temperature difference obtained by subtracting the set temperature from the room 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 air conditioner according to claim 1.

10. The aforementioned air conditioner further includes a compressor, The control unit is further configured to stop the compressor for a predetermined period of time if it determines that, after performing the dehumidification operation, the temperature difference obtained by subtracting the set temperature from the room temperature after the operation is lower than a fourth temperature threshold. The air conditioner according to claim 1.

11. A control method for an air conditioner having a ventilation device, wherein the ventilation device is configured to supply outdoor air to a control space that is the target of the air conditioning control of the air conditioner, The control method described above is In a cooling-ventilation mode in which both cooling operation and ventilation operation by the ventilation device can be performed, the steps include obtaining the set temperature for the cooling control of the cooling-ventilation mode and the indoor temperature of the controlled space, The steps include determining whether the temperature difference obtained by subtracting the set temperature from the room temperature is lower than a first temperature threshold, If it is determined that the temperature difference is lower than the first temperature threshold, the dehumidification operation is performed by throttling the expansion valve of the air conditioner, and the supply air ventilation is performed by the ventilation device. including, Control method.

12. In the ventilation operation described above, a predetermined number of ventilations is maintained. The control method according to claim 11.

13. The steps include determining whether the temperature difference is greater than or equal to a second temperature threshold, If it is determined that the temperature difference is equal to or greater than the second temperature threshold, the step is to perform a cooling operation in which the rotational speed of the compressor of the air conditioner is equal to or greater than the first rotational speed threshold, It further includes, If the second temperature threshold is higher than the first temperature threshold, The control method according to claim 11.

14. The step of determining whether the temperature difference is lower than the second temperature threshold and greater than or equal to the first temperature threshold, If it is determined that the temperature difference is lower than the second temperature threshold and greater than or equal to the first temperature threshold, the step is to perform a cooling operation in which the rotational speed of the compressor is lower than the first rotational speed threshold. Including, The control method according to claim 13.

15. The steps include: After performing the dehumidification operation, determining whether the temperature difference obtained by subtracting the set temperature from the room temperature after the operation is equal to or greater than the third temperature threshold; If it is determined that the temperature difference obtained by subtracting the set temperature from the room temperature after the above execution is equal to or greater than the third temperature threshold, the step of switching from the dehumidification operation to the cooling operation, It further includes, The third temperature threshold is higher than the first temperature threshold. The control method according to claim 11.

16. The step of determining whether the temperature difference obtained by subtracting the set temperature from the room temperature after the dehumidification operation is lower than the fourth temperature threshold, If it is determined that the temperature difference obtained by subtracting the set temperature from the room temperature after the execution is lower than the fourth temperature threshold, the step of stopping the compressor of the air conditioner for a predetermined time, Including, The control method according to claim 11.

17. A program that causes an air conditioner to execute the control method described in any one of claims 11 to 16.

18. A non-temporary, computer-readable storage medium on which computer programs are stored, When the computer program is executed by the processor, the control method described in any one of claims 11 to 16 is realized. A non-temporary, computer-readable storage medium.

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