Air conditioning device

Abstract

To provide a technique for improving the efficiency of an air conditioning device.SOLUTION: In an air conditioning device 1, a voltage conversion unit 12 converts an inputted AC voltage to a first DC voltage V1. A boosting unit 14 boosts the first DC voltage V1 converted by the voltage conversion unit 12 to a second DC voltage V2. An air blower unit 30 has a motor 32 for blowing air. A drive unit 16 drives the air blower unit 30 on the basis of the second DC voltage V2 boosted by the boosting unit 14. A voltage detection unit 18 detects a voltage corresponding to the AC voltage. A control unit 20 determines a target value of the second DC voltage V2 at the boosting unit 14 on the basis of the voltage detected by the voltage detection unit 18.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an air conditioning apparatus. [Background technology]

[0002] The air conditioner includes, for example, a rectifier circuit connected to an AC power supply, a boost chopper circuit, an inverter, and a motor for a blower fan (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-175882 Summary of the Invention [Problem to be solved by the invention]

[0004] Air conditioners are known that can operate when connected to any of multiple types of AC power supplies with different AC voltages. The present inventors recognized that there is room for improvement in the efficiency of such air conditioners when connected to an AC power supply with a relatively low AC voltage.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a technique that can improve the efficiency of air conditioners. [Means for solving the problem]

[0006] In order to solve the above problems, an air conditioning apparatus according to one aspect of the present disclosure includes a voltage conversion unit that converts an input AC voltage into a first DC voltage, a boost unit that boosts the first DC voltage converted by the voltage conversion unit to a second DC voltage, a blower unit having a motor for blowing air, a drive unit that drives the blower unit based on the second DC voltage boosted by the boost unit, a voltage detection unit that detects a voltage corresponding to the AC voltage, and a control unit that determines a target value for the second DC voltage of the booster unit based on the voltage detected by the voltage detection unit.

[0007] Any combination of the above components and conversion of the expressions of the present disclosure into methods, devices, systems, etc. are also valid aspects of the present disclosure. [Effects of the Invention]

[0008] According to the present disclosure, it is possible to provide a technique that can improve the efficiency of an air conditioner. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a block diagram showing a schematic configuration of an air conditioning apparatus according to an embodiment. [Figure 2] 2 is a flowchart showing a process of determining a target value of the second DC voltage in FIG. 1; DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments for carrying out the present disclosure will be described with reference to the accompanying drawings. In the embodiments and modified examples, identical or equivalent components and members are designated by the same reference numerals, and redundant explanations will be omitted where appropriate. Furthermore, the dimensions of the members in each drawing are enlarged or reduced as appropriate for ease of understanding. Furthermore, some members that are not important for explaining the embodiments will be omitted from the drawings.

[0011] FIG. 1 is a block diagram showing a schematic configuration of an air conditioning apparatus 1 according to an embodiment. The air conditioning apparatus 1 is an air conditioning device capable of blowing air, such as an air conditioner, a heat exchange type ventilation apparatus, a ventilation apparatus that ventilates without heat exchange, or an air purifier. Below, an example in which the air conditioning apparatus 1 is an air conditioner will be described. The air conditioning apparatus 1 can be installed, for example, on the ceiling or side wall of a building, and performs air conditioning control on air drawn in from an indoor space and sends the temperature-adjusted air out into the indoor space. The air conditioning apparatus 1 includes, for example, an indoor unit and an outdoor unit, not shown.

[0012] The air conditioner 1 includes a drive unit 10 and a blower unit 30. The drive unit 10 is connected to an AC power supply 50 and drives the blower unit 30 based on AC power supplied from the AC power supply 50. When the air conditioner 1 is used in Japan, the AC power supply 50 is, for example, a 100V AC or 200V AC commercial AC power supply. The air conditioner 1 can operate whether the AC power supply 50 is a 100V AC or 200V AC power supply. The two types of voltages of the AC power supply 50 may differ depending on the country in which the air conditioner 1 is used. The air conditioner 1 may also be operable whether the AC power supply 50 is of any of three or more types of AC voltages.

[0013] The blower 30 is a blower for transporting air from an indoor space through an air inlet (not shown) into the indoor unit of the air conditioner 1. The blower 30 has a fan (not shown) and a motor 32 for rotating the fan to blow air.

[0014] When the blower unit 30 operates, air from the indoor space is taken into the indoor unit of the air conditioner 1 and directed toward an indoor heat exchanger (not shown) inside the indoor unit. The indoor heat exchanger is located downstream of the blower unit 30 and cools or heats the introduced air. The indoor heat exchanger is connected to the outdoor unit. The outdoor unit is an outdoor unit installed in an outdoor space. Various known configurations can be used for the blower unit 30, indoor unit, indoor heat exchanger, and outdoor unit, so further detailed explanation is omitted. The blower unit 30 may be located inside the outdoor unit, or may send air to the outdoor heat exchanger.

[0015] The driving device 10 includes a voltage conversion unit 12 , a voltage boosting unit 14 , a driving unit 16 , a voltage detection unit 18 , and a control unit 20 .

[0016] Voltage conversion unit 12 converts AC voltage input from AC power supply 50 via a power plug (not shown) into first DC voltage V1. Voltage conversion unit 12 is a rectifying and smoothing circuit that rectifies the input AC voltage, smoothes the rectified voltage, and outputs first DC voltage V1. Voltage conversion unit 12 has, for example, a full-wave rectifying circuit formed by a diode bridge and a smoothing circuit formed by a capacitor.

[0017] The boost unit 14 boosts the first DC voltage V1 converted by the voltage conversion unit 12 to a second DC voltage V2 and outputs the boosted second DC voltage V2. The boost unit 14 boosts the first DC voltage V1 so that the second DC voltage V2 approaches a target value. The target value is determined based on the input AC voltage and is instructed by the control unit 20, as described below. The boost unit 14 can be called, for example, a boost converter or a boost chopper. Although not shown, the boost unit 14 has, for example, an inductor and a diode connected in series between the input terminal and the output terminal, and a switching element connected between the connection node of the inductor and the diode and ground, and boosts the voltage by the switching operation of the switching element.

[0018] The drive unit 16 drives the blower unit 30 based on the second DC voltage V2 boosted by the booster unit 14. The drive unit 16 has, for example, a three-phase inverter that converts the second DC voltage V2 into a three-phase AC voltage and supplies the converted three-phase AC voltage to the motor 32 of the blower unit 30. In other words, the drive unit 16 converts the output power of the booster unit 14 into three-phase AC power and drives the motor 32 with the three-phase AC power. The drive unit 16 has a plurality of switching elements (not shown) and drives the motor 32 by the switching operation of the plurality of switching elements. The drive unit 16 and the motor 32 can also be collectively referred to as a DC motor.

[0019] Since known configurations can be used for the voltage conversion unit 12, the voltage step-up unit 14, the drive unit 16, and the motor 32, further detailed explanations will be omitted.

[0020] The voltage detection unit 18 detects a voltage corresponding to the AC voltage input from the AC power supply 50 and supplies information about the detected voltage to the control unit 20. The voltage detection unit 18 detects a first DC voltage V1 as a voltage corresponding to the input AC voltage. For example, the voltage detection unit 18 includes a voltage dividing resistor and an A / D converter (not shown). The voltage detection unit 18 detects the first DC voltage V1 using the A / D converter based on a voltage obtained by resistively dividing the first DC voltage V1 using the voltage dividing resistor. The voltage detection unit 18 may be connected to an input terminal of the voltage conversion unit 12 and may detect the AC voltage input to the input terminal from the AC power supply 50 as a voltage corresponding to the AC voltage.

[0021] The control unit 20 determines a target value of the second DC voltage V2 of the boost unit 14 based on the voltage detected by the voltage detection unit 18. The control unit 20 determines the target value, for example, when the power plug of the air conditioning apparatus 1 is connected to the AC power supply 50 and power supply from the AC power supply 50 to the voltage conversion unit 12 begins. The control unit 20 outputs the determined target value to the boost unit 14 as a voltage command value.

[0022] If the voltage detected by voltage detection unit 18 is lower than a predetermined threshold, control unit 20 determines that the voltage corresponds to an AC 100V system. If the voltage detected by voltage detection unit 18 is equal to or higher than the threshold, control unit 20 determines that the voltage corresponds to an AC 200V system. The threshold can be determined appropriately through experiments or simulations so that the AC 100V system and the AC 200V system can be distinguished from each other.

[0023] When the voltage detected by the voltage detection unit 18 corresponds to the AC 100V system, the control unit 20 determines the target value of the second DC voltage V2 to be a predetermined first voltage. When the voltage detected by the voltage detection unit 18 corresponds to the AC 200V system, the control unit 20 determines the target value of the second DC voltage V2 to be a predetermined second voltage. The first voltage is lower than the second voltage.

[0024] The overall efficiency of the drive unit 16 and the motor 32 falls within a predetermined range when the second DC voltage V2 is the first voltage and when the second DC voltage V2 is the second voltage. The predetermined range can be determined as appropriate through experiments or simulations. For example, the overall efficiency of the drive unit 16 and the motor 32 may be equivalent when the second DC voltage V2 is the first voltage and when the second DC voltage V2 is the second voltage.

[0025] The range of the second DC voltage V2 within which the overall efficiency of the drive unit 16 and the motor 32 falls within a predetermined range is determined in advance through experiments or simulations, and is, for example, a range of 300 V to 400 V. This numerical range of the second DC voltage V2 may vary depending on the respective performance of the drive unit 16 and the motor 32. In this numerical example, the first voltage is, for example, 300 V, and the second voltage is, for example, 400 V.

[0026] The above processing by the control unit 20 corresponds to the control unit 20 determining the target value of the second DC voltage V2 so that the lower the voltage detected by the voltage detection unit 18, the lower the target value, and so that the target value falls within a range of the second DC voltage V2 in which the overall efficiency of the drive unit 16 and the motor 32 falls within a predetermined range. If the air conditioning apparatus 1 is configured to be able to operate with AC power supplies 50 of three or more types of AC voltages, the control unit 20 may set different target values ​​for each of the three or more types of AC voltages.

[0027] The drive unit 16 may be controlled so that the workload of the motor 32 is equal when the target value of the second DC voltage V2 is the first voltage and when the target value of the second DC voltage V2 is the second voltage.

[0028] The configuration of the voltage detection unit 18 and the control unit 20 can be realized by a combination of hardware and software resources, or by hardware resources alone. Hardware resources include analog elements, microcomputers, DSPs, ROMs, RAMs, ASICs, FPGAs, and other LSIs. Software resources include programs such as firmware.

[0029] Fig. 2 is a flowchart showing the process of determining the target value of the second DC voltage V2 in Fig. 1. The process in Fig. 2 is started, for example, when the power plug of the air conditioning apparatus 1 is connected to the AC power supply 50 and power supply from the AC power supply 50 to the voltage conversion unit 12 is started. This process may be executed periodically.

[0030] The voltage detection unit 18 detects the first DC voltage V1 (S10). If the detected voltage is lower than the threshold value (Y in S12), the control unit 20 determines the target value of the second DC voltage V2 to be the first voltage (S14), and the process ends. If the detected voltage is equal to or higher than the threshold value (N in S12), the control unit 20 determines the target value of the second DC voltage V2 to be the second voltage (S16), and the process ends.

[0031] Here, a comparative example of a drive device will be considered. In the comparative example, the configurations of the voltage conversion unit 12, the boost unit 14, the drive unit 16, and the blower unit 30 are the same as those in the embodiment, but the target value of the second DC voltage V2 of the boost unit 14 is different from those in the embodiment. In the comparative example, the target value is a constant value, for example, 400 V, regardless of whether the AC power supply 50 is a 100 V AC system or a 200 V AC system. In other words, the second DC voltage V2 is a constant 400 V regardless of the AC voltage of the AC power supply 50. Therefore, in the case of a 100 V AC system, the boost ratio of the boost unit 14 is larger than in the case of a 200 V AC system, and the peak current of the output current of the boost unit 14 is larger. As a result, in the case of a 100 V AC system, the efficiency of the boost unit 14 is worse than in the case of a 200 V AC system, and the overall efficiency of the drive device is also worse.

[0032] In contrast to this, according to the embodiment, the target value of the second DC voltage V2 of the booster 14 is determined based on the voltage detected by the voltage detector 18, so that the boost ratio of the booster 14 can be set to a value according to the AC voltage of the AC power supply 50. Therefore, in the case of an AC power supply 50 with a relatively low AC voltage, the efficiency of the booster 14 can be improved by setting the boost ratio smaller than in the comparative example.

[0033] When the voltage detected by the voltage detection unit 18 corresponds to the AC 100V system, the target value is determined to be the first voltage lower than the second voltage, so the peak current of the output current of the boost unit 14 can be made smaller than in the comparative example. Therefore, in the case of an AC power supply 50 of the AC 100V system, the efficiency of the boost unit 14 can be improved.

[0034] Furthermore, when the second DC voltage V2 is the first voltage and when the second DC voltage V2 is the second voltage, the overall efficiency of the drive unit 16 and the motor 32 is within a predetermined range, so when the AC power supply 50 is of the AC 100V system, the overall efficiency of the drive device 10 can also be improved compared to the comparative example. Therefore, the efficiency of the air conditioner 1 can be improved.

[0035] The present disclosure has been described above based on the embodiments. These embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component or each treatment process, and that such modifications are also within the scope of the present disclosure.

[0036] For example, the air conditioning device may be a heat exchanger type ventilation device as mentioned above, but an example of a heat exchanger type ventilation device will also be described. A heat exchanger type ventilation device can be installed in the ceiling, in the side wall, or under the floor of a building, and is a ventilation device that supplies and exhausts air to and from indoor spaces. A heat exchanger type ventilation device is a ventilation device that has the function of exchanging heat when supplying and exhausting air.

[0037] A heat exchange ventilation system ventilates by exchanging heat between air exhausted from a designated indoor space to the outdoors (exhaust air flow) and air supplied from the outdoors to a designated indoor space (supply air flow). For example, in the summer in Japan, a heat exchange ventilation system not only performs ventilation but also transfers heat from the supply air flow to the exhaust air flow during ventilation, thereby suppressing unnecessary inflow of heat. In addition, in the winter in Japan, a heat exchange ventilation system not only performs ventilation but also transfers heat from the exhaust air flow to the supply air flow during ventilation, thereby suppressing unnecessary outflow of heat.

[0038] A heat exchange element is used for heat exchange between the exhaust air flow and the intake air flow. The heat exchange element is a component for exchanging heat between the exhaust air flow and the intake air flow. The heat exchange can be sensible heat exchange, which exchanges temperature between the exhaust air flow and the intake air flow, or total heat exchange, which exchanges both sensible heat and latent heat, which exchanges humidity between the exhaust air flow and the intake air flow.

[0039] The heat exchange element is a total heat exchange element formed from heat transfer paper (heat transfer plate) based on cellulose fiber. However, the material is not limited to this. For example, a moisture-permeable resin film based on polyurethane or polyethylene terephthalate, or a paper material based on cellulose fiber, ceramic fiber, or glass fiber can be used as the heat transfer plate constituting the heat exchange element. Furthermore, the heat transfer plate constituting the heat exchange element can be a thin sheet with heat conductivity that is impermeable to gases. In this case, the heat exchange element becomes a sensible heat exchange element.

[0040] The heat exchange ventilation device includes an exhaust fan for generating an exhaust airflow and an intake fan for generating an intake airflow. When performing heat exchange ventilation, the heat exchange ventilation device operates the exhaust fan and the intake fan, and heat exchange occurs between the exhaust airflow and the intake airflow in the heat exchange element. As a result, when performing ventilation, the heat exchange ventilation device transfers heat from the intake airflow taken into a designated indoor space to the exhaust airflow discharged outdoors, thereby suppressing the inflow of unnecessary heat. As a result, during Japan's summer, when performing ventilation, it is possible to suppress an increase in indoor temperature due to air with a high outdoor temperature. Furthermore, during ventilation, the heat exchange ventilation device transfers heat from the exhaust airflow discharged outdoors to the intake airflow taken into a designated indoor space, suppressing the release of unnecessary heat and recovering heat indoors. As a result, during Japan's winter, when performing ventilation, it is possible to suppress a decrease in indoor temperature due to air with a low outdoor temperature.

[0041] In the heat exchange type ventilation system, the exhaust fan and the intake fan correspond to the blower section shown in FIG.

[0042] One aspect of the present disclosure is as follows.

[0043] [Item 1] a voltage conversion unit that converts an input AC voltage into a first DC voltage; a boosting unit that boosts the first DC voltage converted by the voltage converting unit to a second DC voltage; a blower having a motor for blowing air; a drive unit that drives the blower unit based on the second DC voltage boosted by the boost unit; a voltage detection unit that detects a voltage corresponding to the AC voltage; a control unit that determines a target value of the second DC voltage of the voltage step-up unit based on the voltage detected by the voltage detection unit; An air conditioning device comprising:

[0044] [Item 2] The control unit 2. The air conditioning apparatus according to item 1, wherein the target value is set to a lower value as the voltage detected by the voltage detection unit is lower.

[0045] [Item 3] The control unit The air conditioning apparatus according to item 1, wherein the target value is determined so that the lower the voltage detected by the voltage detection unit, the lower the target value, and the target value falls within a range of the second DC voltage in which the efficiency of the drive unit and the motor falls within a predetermined range.

[0046] [Item 4] The control unit When the voltage detected by the voltage detection unit corresponds to an AC 100V system, the target value is determined to be a first voltage; When the voltage detected by the voltage detection unit corresponds to an AC 200V system, the target value is determined to be a second voltage; the first voltage is lower than the second voltage; 4. The air conditioning apparatus according to any one of items 1 to 3, wherein the efficiency of the drive unit and the motor is within a predetermined range when the second DC voltage is the first voltage and when the second DC voltage is the second voltage.

[0047] [Item 5] The voltage detection unit 5. The air conditioner according to any one of items 1 to 4, wherein the first DC voltage is detected as a voltage corresponding to the AC voltage based on a voltage obtained by resistively dividing the first DC voltage. [Industrial Applicability]

[0048] The present disclosure can be used in air conditioning devices. [Explanation of symbols]

[0049] 1...air conditioner, 10...drive device, 12...voltage conversion section, 14...boosting section, 16...drive section, 18...voltage detection section, 20...control section, 30...blower section, 32...motor

Claims

1. a voltage conversion unit that converts an input AC voltage into a first DC voltage; a boosting unit that boosts the first DC voltage converted by the voltage converting unit to a second DC voltage; a blower having a motor for blowing air; a drive unit that drives the blower unit based on the second DC voltage boosted by the booster unit; a voltage detection unit that detects a voltage corresponding to the AC voltage; a control unit that determines a target value of the second DC voltage of the voltage step-up unit based on the voltage detected by the voltage detection unit; An air conditioning device comprising:

2. The control unit The air conditioner according to claim 1 , wherein the target value is determined to be lower as the voltage detected by the voltage detection unit is lower.

3. The control unit The air conditioning apparatus of claim 1, wherein the target value is determined so that the lower the voltage detected by the voltage detection unit, the lower the target value, and the target value falls within a range of the second DC voltage in which the efficiency of the drive unit and the motor falls within a predetermined range.

4. The control unit When the voltage detected by the voltage detection unit corresponds to an AC 100V system, the target value is determined to be a first voltage; When the voltage detected by the voltage detection unit corresponds to an AC 200V system, the target value is determined to be a second voltage; the first voltage is lower than the second voltage; 4. The air conditioning apparatus according to claim 1, wherein the efficiency of the drive unit and the motor is within a predetermined range when the second DC voltage is the first voltage and when the second DC voltage is the second voltage.

5. The voltage detection unit 4. The air conditioner according to claim 1, wherein the first DC voltage is detected as a voltage corresponding to the AC voltage based on a voltage obtained by resistively dividing the first DC voltage.

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