Ventilation Device

The present application is a bypass continuation of International Application No. PCT/JP2024/007501, filed Feb. 29, 2024, which claims priority to Japanese Patent Application No. 2023-043493, filed Mar. 17, 2023, the entire contents of each of which is incorporated herein by reference in their entirety.

The present disclosure relates to a ventilation device.

Patent Document 1 discloses an air conditioner including an air intake/exhaust device that discharges indoor air to the outside of a room. That is, the air conditioner forms a ventilation device that ventilates an indoor space, which is a target space.

Patent Document 1: Japanese Patent No. 3992722

A first aspect is directed to a ventilation device including: a ventilation unit configured to ventilate a target space; an irradiation unit configured to sterilize air in the target space with an ultraviolet ray; and a control unit configured to control a ventilation amount of the ventilation unit and an output of the irradiation unit in coordination.

Embodiments of the present disclosure will be described in detail below with reference to the drawings. The present disclosure is not limited to the embodiments shown below, and various changes can be made within the scope without departing from the technical concept of the present disclosure. Since each of the drawings is intended to illustrate the present disclosure conceptually, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for the sake of ease of understanding.

A ventilation device of the present embodiment forms an air conditioner (). The air conditioner () adjusts the temperature of air in an indoor space (I), which is a target space. The air conditioner () includes a ventilation unit () that ventilates the indoor space (I), and an irradiation unit () that sterilizes air in the indoor space (I) with ultraviolet rays. The air conditioner () includes a control unit (C) that controls the ventilation amount of the ventilation unit () and the output of the irradiation unit () in coordination.

As illustrated in, the air conditioner () has an outdoor unit (), an indoor unit (), and two connection pipes (,). The outdoor unit () and the indoor unit () are connected to each other via the two connection pipes (,) to form a refrigerant circuit (). The refrigerant circuit () circulates refrigerant therethrough to perform a refrigeration cycle.

The outdoor unit () is installed outdoors. The outdoor unit () has an outdoor casing (), a compressor (), an outdoor heat exchanger (), an expansion valve (), a four-way switching valve (), and an outdoor fan ().

The four-way switching valve () switches between a first state (state indicated by a solid line in) and a second state (state indicated by a broken line in).

As illustrated in, the indoor unit () is installed in the indoor space (I). The indoor unit () has an indoor casing () which is a first casing, an indoor heat exchanger () which is a first heat exchanger, an indoor fan (), and a flap (). The indoor unit () has the irradiation unit () that emits ultraviolet rays.

The indoor casing () houses the indoor heat exchanger () and the indoor fan (). The indoor casing () has an inlet () and an outlet (). The inlet () is formed in an upper portion of the indoor casing (). The outlet () is formed near the front side in a lower portion of the indoor casing (). An air passage () is formed between the inlet () and the outlet ().

The indoor heat exchanger () is disposed upstream of the indoor fan () in the air passage (). The indoor heat exchanger () allows heat exchange between the refrigerant flowing through the indoor heat exchanger () and air transferred by the indoor fan ().

The indoor fan () is rotationally driven by a fan motor (). The indoor fan () transfers the air in the air passage (). The indoor fan () is configured to be capable of adjusting the volume of blown air to be supplied to the indoor space (I) through the outlet (). The number of rotations of the fan motor () is adjusted to adjust the volume of blown air.

As illustrated in, the ventilation unit () has a duct (), a ventilation casing () connected to the duct (), and a ventilation fan () housed in the ventilation casing ().

The duct () forms a communication passage that allows communication between the indoor space (I) and an outdoor space (O). The duct () is a member forming a flow path through which air flows, and includes a flexible hose and tube. A through-hole () is formed in a wall (W) partitioning the indoor space (I) and the outdoor space (O). The duct () passes through the through-hole () together with the connection pipes (,). One end of the duct () is connected to the air passage () in the indoor casing (). As illustrated in, the air passage () is provided with a connection port () to which one end of the duct () is connected. The connection port () is formed in the indoor casing (). The other end of the duct () communicates with the outdoor space (O).

The ventilation casing () is installed outdoors. The ventilation casing () has a first opening () and a second opening (). The other end of the duct () is connected to the first opening (). The second opening () opens toward the outdoor space (O). A flow path through which air flows is formed inside the ventilation casing ().

The ventilation fan () is disposed inside the ventilation casing (). The ventilation fan () transfers air in the duct (). The ventilation fan () of the present embodiment is an exhaust fan that transfers air in the duct () toward the outdoor space (O). The ventilation fan () is configured such that an air volume is variable. Specifically, a first motor () of the ventilation fan () is configured such that the number of rotations is variable.

As schematically illustrated in, the ventilation unit () has an opening/closing mechanism (). The opening/closing mechanism () opens and closes the flow path in the duct (). The opening/closing mechanism () comprises a damper, a shutter, an on-off valve, etc. The opening/closing mechanism () opens and closes the connection port () of the duct ().

The irradiation unit () inactivates viruses and bacteria in air by irradiating the air with ultraviolet rays. As illustrated in, the irradiation unit () has a light emitting diode (LED) () and a circuit board () that controls the LED ().

The LED () is a light emitting source that emits ultraviolet rays. The peak wavelength of the ultraviolet ray emitted from the LED () is 280 nm or less. Thus, it is possible to enhance the air sterilization effect. The peak wavelength of the ultraviolet ray emitted from the LED () is preferably 255 nm or more and 275 nm or less. Thus, it is possible to enhance the air sterilization effect in particular. The peak wavelength of the ultraviolet ray emitted from the LED () may be 230 nm or less. This can improve safety for the human body in terms of exposure in the event of ultraviolet ray leakage from the indoor casing ().

The circuit board () includes a control board for controlling the LED (). Specifically, the circuit board () includes a control device for switching the LED () ON and OFF and adjusting the output of the LED () (specifically, the illuminance of the LED ()). The control device of the circuit board () may be provided in the control unit (C) for controlling the air conditioner ().

As illustrated in, the irradiation unit () of the present embodiment is disposed, in the air passage (), downstream of the connection port () of the duct () in an air flow. The irradiation unit () is disposed between the indoor heat exchanger () and the indoor fan (). The irradiation unit () may be disposed between the connection port () and the indoor heat exchanger ().

As illustrated in, the air conditioner () includes a remote controller (). The remote controller () has an operation unit () and a display unit (). The operation unit () allows a user to input various instructions to the air conditioner (). The operation unit () comprises a button, a switch, a touch panel, and the like. The instructions described herein include those for switching the air conditioner () ON and OFF, selecting the operating mode of the air conditioner (), and changing the set temperature of the indoor space (I). The display unit () displays information on the state and operation of the air conditioner (). This information includes the operating mode and set temperature of the air conditioner ().

In the present embodiment, the user can set the target ventilation amount of the ventilation unit () and the target output of the irradiation unit () by operating the operation unit (). Here, the output of the irradiation unit () is equivalent to the intensity or illuminance of the LED ().

As illustrated in, the air conditioner () has a plurality of sensors. In the present embodiment, the plurality of sensors includes an indoor temperature sensor (), an infrared sensor (), and an outdoor temperature sensor (). The indoor temperature sensor () detects the temperature of the indoor air in the indoor space (I). The indoor temperature sensor () is disposed, for example, near the inlet (). The infrared sensor () is a human detection unit that detects the number of persons present in the indoor space (I). The infrared sensor () is disposed on the front surface of the indoor casing (). The outdoor temperature sensor () detects the temperature of the outdoor air in the outdoor space (O). The outdoor temperature sensor () is provided in the outdoor unit ().

The control unit (C) controls the air conditioner (), which is the ventilation device. As illustrated in, the control unit (C) has an indoor control unit (IC), an outdoor control unit (OC), and an operation control unit (RC). The indoor control unit (IC), the outdoor control unit (OC), and the operation control unit (RC) are configured to communicate with each other in a wired or wireless manner. Each of the indoor control unit (IC), the outdoor control unit (OC), and the operation control unit (RC) includes a micro control unit (MCU), an electric circuit, and an electronic circuit. The MCU includes a central processing unit (CPU), a memory, and a communication interface. The memory stores various programs to be executed by the CPU.

The outdoor control unit (OC) is provided in the outdoor unit (). The outdoor control unit (OC) is disposed inside the outdoor casing (). The outdoor control unit (OC) controls a mechanical element provided in the outdoor unit (). The outdoor control unit (OC) controls the ventilation amount of the ventilation unit (). Specifically, the outdoor control unit (OC) switches the ventilation fan () ON and OFF and adjusts the air volume of the ventilation fan (). Here, the air volume of the ventilation fan () is equivalent to the ventilation amount of the ventilation unit (). The outdoor control unit (OC) controls the number of rotations of the first motor () to adjust the air volume of the ventilation unit (). The detection signal of the outdoor temperature sensor () is input to the outdoor control unit (OC).

The indoor control unit (IC) is provided in the indoor unit (). The indoor control unit (IC) is disposed inside the indoor casing (). The indoor control unit (IC) controls a mechanical element provided in the indoor unit (). The indoor control unit (IC) controls the output of the irradiation unit (). Here, the output of the irradiation unit () of the present embodiment is the illuminance (ultraviolet intensity) of the LED (). The indoor control unit (IC) switches the LED () of the irradiation unit () ON and OFF and adjusts the output (ultraviolet intensity) of the LED (). The detection signals of the indoor temperature sensor () and the infrared sensor () are input to the indoor control unit (IC).

The operation control unit (RC) transmits, to the indoor control unit (IC), a command related to the operating mode or the set temperature input by a user using the operation unit (). This command is transmitted from the indoor control unit (IC) to the outdoor control unit (OC).

The air conditioner () performs a cooling operation, a heating operation, and a ventilation operation.

The cooling operation is an operation for cooling air in the indoor space (I) so that the air in the indoor space (I) approaches a set temperature (target temperature). In the cooling operation, the control unit (C) operates the compressor (), the outdoor fan (), and the indoor fan (), brings the four-way switching valve () into the first state, and adjusts the opening degree of the expansion valve (). The control unit (C) brings the opening/closing mechanism () into a closed state and stops the ventilation fan () and the irradiation unit ().

In the cooling operation, the refrigerant compressed in the compressor () dissipates heat in the outdoor heat exchanger () and is then decompressed by the expansion valve (). The decompressed refrigerant evaporates in the indoor heat exchanger (). The air cooled in the indoor heat exchanger () is supplied to the indoor space (I). The refrigerant evaporated in the indoor heat exchanger () is sucked into the compressor ().

The heating operation is an operation for heating air in the indoor space (I) so that the air in the indoor space (I) approaches the set temperature (target temperature). In the heating operation, the control unit (C) operates the compressor (), the outdoor fan (), and the indoor fan (), brings the four-way switching valve () into the second state, and adjusts the opening degree of the expansion valve (). The control unit (C) brings the opening/closing mechanism () into the closed state, and stops the ventilation fan (). The control unit (C) brings the opening/closing mechanism () into the closed state and stops the ventilation fan () and the irradiation unit ().

In the heating operation, the refrigerant compressed in the compressor () dissipates heat in the indoor heat exchanger () and is then decompressed by the expansion valve (). The air heated in the indoor heat exchanger () is supplied to the indoor space (I). The decompressed refrigerant evaporates in the outdoor heat exchanger (), and is then sucked into the compressor ().

The ventilation operation is an operation for ventilating the indoor space (I). In the ventilation operation of the present embodiment, the indoor air in the indoor space (I) is discharged to the outdoor space (O). In the ventilation operation, the ventilation unit () and the irradiation unit () are operated to reduce viruses and bacteria in the indoor space (I). The ventilation operation includes a ventilation-only operation, a cooling ventilation operation, and a heating ventilation operation.

In the ventilation-only operation, the control unit (C) stops the compressor () and the outdoor fan () and operates the indoor fan (). The control unit (C) brings the opening/closing mechanism () into an open state and operates the ventilation fan (). The control unit (C) turns on the irradiation unit () as appropriate according to an operation condition.

In the ventilation-only operation, the indoor air in the indoor space (I) flows into the air passage () through the inlet (). Part of the air in the air passage () flows into the duct () through the connection port () (see a solid arrow in). The air that has flowed into the duct () is discharged to the outdoor space (O). The remaining air in the air passage () passes through the irradiation unit () in the ON state.

The LED () of the irradiation unit () irradiates the air with ultraviolet rays. This inactivates viruses and bacteria in the air. The air that has passed through the irradiation unit () is supplied to the indoor space (I) through the outlet ().

In the cooling ventilation operation, the control unit (C) operates the compressor (), the outdoor fan (), and the indoor fan (), brings the four-way switching valve () into the first state, and adjusts the opening degree of the expansion valve (). At the same time, the control unit (C) opens the opening/closing mechanism () and operates the irradiation unit () and the ventilation unit (). Thus, the indoor space (I) is cooled and ventilated at the same time.

In the heating ventilation operation, the control unit (C) operates the compressor (), the outdoor fan (), and the indoor fan (), brings the four-way switching valve () into the second state, and adjusts the opening degree of the expansion valve (). At the same time, the control unit (C) opens the opening/closing mechanism () and operates the irradiation unit () and the ventilation unit (). Thus, the indoor space (I) is heated and ventilated at the same time.

In the ventilation operation described above, the control unit (C) controls the irradiation unit () and the ventilation unit () in coordination. Details of the coordinated control will be described with reference to. In the air conditioner () of the present embodiment, the ventilation amount of the ventilation unit () is determined in preference to the output of the irradiation unit ().

When a ventilation operation start command is input to the control unit (C), the control unit (C) specifies the number of persons present in the indoor space (I), which is the target space, in Step ST. Specifically, the control unit (C) specifies the number of persons in the indoor space (I) based on the signal detected by the infrared sensor ().

In Step ST, the control unit (C) calculates a required ventilation amount Vn for the indoor space (I). The required ventilation amount Vn means a ventilation amount required for measures against viral infection. The required ventilation amount Vn is expressed by, for example, Expression (1) below.

Vn=α×n . . .   (1)

Here, α is a required ventilation amount per person in the indoor space (I), and is, for example, 30 [m/h/person]; and n is the number of persons present in the indoor space (I).

In Step ST, the control unit (C) determines the target ventilation amount of the ventilation unit (). The target ventilation amount is equivalent, for example, to a set ventilation amount set in advance by the user.

In Step ST, the control unit (C) determines an equivalent ventilation amount of the irradiation unit () at which the total ventilation amount Vt of the air conditioner () is the required ventilation amount Vn or more.

Here, the total ventilation amount Vt is expressed by Expression (2) below.

Total Ventilation Amount Vt=Ventilation Amount V1 of Ventilation Unit+Forced Ventilation Amount V2+Equivalent Ventilation Amount Ve . . .   (2)