Air conditioning device

Abstract

In the air conditioning device (1), a voltage conversion section (12) converts an input alternating voltage into a first direct current voltage (V1). A step-up section (14) steps up the first direct current voltage (V1) converted by the voltage conversion section (12) into a second direct current voltage (V2). A blowing section (30) has a motor (32) for blowing. A driving section (16) drives the blowing section (30) based on the second direct current voltage (V2) stepped up by the step-up section (14). A voltage detection section (18) detects a voltage corresponding to the alternating voltage. A control section (20) determines a target value of the second direct current voltage (V2) of the step-up section (14) based on the voltage detected by the voltage detection section (18).

Description

Technical Field

[0001] This invention relates to air conditioning devices. Background Technology

[0002] Air conditioning devices may include, for example, a rectifier circuit connected to an AC power source, a boost chopper circuit, an inverter, and an electric motor for a blower fan (see, for example, Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-175882 Summary of the Invention

[0006] An air conditioning device is known that can operate regardless of which of a variety of AC power sources with different AC voltages it is connected to. The inventors of the present invention recognize that there is room for improvement in the efficiency of such an air conditioning device when connected to an AC power source with a relatively low AC voltage.

[0007] This invention provides a technique that can improve the efficiency of air conditioning devices.

[0008] An air conditioning device according to one aspect of the present invention 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 into a second DC voltage; an air supply unit having a motor for supplying air; a drive unit that drives the air supply 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 of the second DC voltage of the boost unit based on the voltage detected by the voltage detection unit.

[0009] Furthermore, any combination of the above-mentioned constituent elements, as well as solutions obtained by converting the description of the present invention among methods, apparatuses, systems, etc., are also valid as embodiments of the present invention.

[0010] Invention Effects

[0011] According to the present invention, a technique is provided that can improve the efficiency of an air conditioning device. Attached Figure Description

[0012] Figure 1 This is a block diagram that roughly represents the structure of an air conditioning device according to an embodiment.

[0013] Figure 2 It means Figure 1 The flowchart shows the process for determining the target value of the second DC voltage. Detailed Implementation

[0014] Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. In the embodiments and variations, the same or equivalent constituent elements and components are labeled with the same reference numerals, and repeated descriptions are omitted where appropriate. Furthermore, the dimensions of the components in each drawing are appropriately enlarged or reduced for ease of understanding. In addition, in each drawing, parts of components that are not important for illustrating the embodiments are omitted.

[0015] Figure 1 This is a block diagram that schematically illustrates the structure of an air conditioning device 1 according to an embodiment. The air conditioning device 1 is, for example, an air conditioner, a heat exchange type ventilation device, a ventilation device that performs ventilation without heat exchange, an air purifier, or other air conditioning equipment capable of delivering air. Hereinafter, an example of an air conditioning device 1 being an air conditioner will be described. The air conditioning device 1 can be installed, for example, in the ceiling or side wall of a building, to perform air conditioning control on air drawn in from an indoor space and to deliver temperature-conditioned air to the indoor space. The air conditioning device 1 includes, for example, an indoor unit and an outdoor unit (not shown).

[0016] The air conditioning unit 1 includes a drive unit 10 and an air supply unit 30. The drive unit 10 is connected to an AC power supply 50 and drives the air supply unit 30 based on the AC power supplied from the AC power supply 50. When the air conditioning unit 1 is used in Japan, the AC power supply 50 is, for example, a commercial AC power supply of AC 100V or AC 200V. The air conditioning unit 1 can operate regardless of whether the AC power supply 50 is AC 100V or AC 200V. The two voltages of the AC power supply 50 may vary depending on the country where the air conditioning unit 1 is used. The air conditioning unit 1 may also be configured to operate regardless of whether the AC power supply 50 is any of three or more AC voltages.

[0017] The air supply unit 30 is a fan used to deliver air from the indoor space through an intake port (not shown) to the indoor unit of the air conditioning unit 1. The air supply unit 30 has a fan (not shown) and an electric motor 32 for rotating the fan to deliver air.

[0018] Air from the indoor space is drawn into the indoor unit of the air conditioning unit 1 via the air supply section 30 and flows to the indoor heat exchanger (not shown) within the indoor unit. The indoor heat exchanger is located downstream of the air supply section 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 located in the outdoor space. Since various known structures can be used for the air supply section 30, indoor unit, indoor heat exchanger, and outdoor unit, more detailed descriptions are omitted. Alternatively, the air supply section 30 can also be located within the outdoor unit or supply air to the outdoor heat exchanger.

[0019] The drive unit 10 includes a voltage conversion unit 12, a boost unit 14, a drive unit 16, a voltage detection unit 18, and a control unit 20.

[0020] The voltage conversion unit 12 converts the AC voltage input from the AC power supply 50 via a power plug (not shown) into a first DC voltage V1. The voltage conversion unit 12 is a rectification and smoothing circuit that rectifies the input AC voltage and smooths the rectified voltage to output the first DC voltage V1. The voltage conversion unit 12 may include, for example, a full-wave rectifier circuit composed of a diode bridge and a smoothing circuit composed of capacitors.

[0021] 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. Here, the target value is determined based on the input AC voltage, as indicated by the control unit 20, as described later. The boost unit 14 can be referred to, for example, as a boost converter or boost chopper. Although not shown in the figure, the boost unit 14, for example, has an inductor and a diode connected in series between the input and output terminals, and a switching element connected between the connection node of the inductor and diode and ground, and boosts the voltage through the switching operation of this switching element.

[0022] The drive unit 16 drives the air supply unit 30 based on the second DC voltage V2 boosted by the boost unit 14. The drive unit 16, for example, includes 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 air supply unit 30. In other words, the drive unit 16 converts the output power of the boost unit 14 into three-phase AC power and drives the motor 32 using this three-phase AC power. The drive unit 16 has multiple switching elements (not shown), and the motor 32 is driven by the switching operation of these multiple switching elements. The drive unit 16 and the motor 32 can also be collectively referred to as a DC motor.

[0023] Since known structures can be used for the voltage conversion unit 12, the boost unit 14, the drive unit 16, and the motor 32, more detailed descriptions are omitted.

[0024] The voltage detection unit 18 detects the voltage corresponding to the AC voltage input from the AC power supply 50 and sends the detected voltage information to the control unit 20. The voltage detection unit 18 detects a first DC voltage V1 as the voltage corresponding to the input AC voltage. For example, the voltage detection unit 18 has a voltage divider resistor (not shown) and an A / D converter. The voltage detection unit 18 detects the first DC voltage V1 based on the voltage after resistive voltage division of the first DC voltage V1 by the voltage divider resistor, using the A / D converter. Alternatively, the voltage detection unit 18 can also be connected to the input terminal of the voltage conversion unit 12, and can also detect the AC voltage input from the AC power supply 50 to that input terminal as the voltage corresponding to the AC voltage.

[0025] Based on the voltage information detected by the voltage detection unit 18, the control unit 20 determines the target value of the second DC voltage V2 of the boost unit 14. For example, when the power plug of the air conditioning unit 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 determines the target value. The control unit 20 outputs the determined target value as a voltage command value to the boost unit 14.

[0026] If the voltage detected by the voltage detection unit 18 is lower than a threshold, the control unit 20 determines that the voltage corresponds to an AC 100V specification. If the voltage detected by the voltage detection unit 18 is higher than the threshold, the control unit 20 determines that the voltage corresponds to an AC 200V specification. The threshold can be appropriately set through experimentation or simulation, enabling the control unit 20 to distinguish between AC 100V and AC 200V specifications.

[0027] When the voltage detected by the voltage detection unit 18 corresponds to an AC 100V specification, the control unit 20 determines the target value of the second DC voltage V2 as a predetermined first voltage. When the voltage detected by the voltage detection unit 18 corresponds to an AC 200V specification, the control unit 20 determines the target value of the second DC voltage V2 as a predetermined second voltage. The first voltage is lower than the second voltage.

[0028] 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 specified range. Here, the specified range can be appropriately set through experimentation or simulation. For example, 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 can be equal.

[0029] The range of the second DC voltage V2, within which the overall efficiency of the drive unit 16 and the motor 32 is within a specified range, is appropriately set in advance through experimentation or simulation, for example, a range of 300V to 400V. The numerical range of this second DC voltage V2 can vary depending on the individual performance of the drive unit 16 and the motor 32. In this numerical example, the first voltage is, for example, 300V, and the second voltage is, for example, 400V.

[0030] The above processing by the control unit 20 is equivalent to the control unit 20 determining the target value of the second DC voltage V2 in such a way that the lower the voltage detected by the voltage detection unit 18, the lower the target value, and the target value falls within the range of the second DC voltage V2 where the overall efficiency of the drive unit 16 and the motor 32 is within a specified range. When the air conditioning device 1 is configured to operate under AC power supplies 50 with three or more AC voltages, the control unit 20 can set different target values ​​for each of the three or more AC voltages.

[0031] Alternatively, the drive unit 16 can be controlled so that the amount of work done by the motor 32 is the same when the target value of the second DC voltage V2 is the first voltage and the second voltage.

[0032] The structure of the voltage detection unit 18 and the control unit 20 can be implemented through the cooperation of hardware and software resources or solely through hardware resources. As hardware resources, analog components, microcomputers, DSPs, ROMs, RAMs, ASICs, FPGAs, and other LSIs can be utilized. As software resources, firmware and other programs can be used.

[0033] Figure 2 It means Figure 1 The flowchart shows the process for determining the target value of the second DC voltage V2. Figure 2 The process shown begins, for example, when the power plug of the air conditioning unit 1 is connected to the AC power source 50, and power supply from the AC power source 50 to the voltage conversion unit 12 begins. This process can also be performed periodically.

[0034] The voltage detection unit 18 detects the first DC voltage V1 (S10). If the detected voltage is lower than the threshold (Yes (Y) in S12), the control unit 20 determines the target value of the second DC voltage V2 as the first voltage (S14), and the process ends. If the detected voltage is higher than the threshold (No (N) in S12), the control unit 20 determines the target value of the second DC voltage V2 as the second voltage (S16), and the process ends.

[0035] Here, the drive device of the comparative example is discussed. In the comparative example, the structure of the voltage conversion unit 12, the boost unit 14, the drive unit 16, and the air supply unit 30 is the same as in the embodiment, but the target value of the second DC voltage V2 of the boost unit 14 is different from that in the embodiment. In the comparative example, regardless of whether the AC power supply 50 is AC 100V or AC 200V, the target value is a fixed value, for example, 400V. That is, regardless of the AC voltage of the AC power supply 50, the second DC voltage V2 is a fixed 400V. Therefore, in the case of AC 100V, compared with the case of AC 200V, the boost ratio of the boost unit 14 is larger, and the peak current of the output current of the boost unit 14 is larger. As a result, in the case of AC 100V, compared with the case of AC 200V, the efficiency of the boost unit 14 is worse, and the overall efficiency of the drive device is also worse.

[0036] In contrast, according to the embodiment, since the target value of the second DC voltage V2 of the boost unit 14 is determined based on the voltage detected by the voltage detection unit 18, the boost ratio of the boost unit 14 can be set to a value corresponding 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, by setting the boost ratio to be smaller than that in the comparative example, the efficiency of the boost unit 14 can be improved.

[0037] When the voltage detected by the voltage detection unit 18 corresponds to an AC 100V specification, since the target value is determined to be a first voltage lower than the second voltage, the peak current of the output current of the boost unit 14 can be reduced compared to the comparative example. Therefore, in the case of an AC power supply 50 with an AC 100V specification, the efficiency of the boost unit 14 can be improved.

[0038] 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 the specified range. Therefore, when using an AC power supply 50 with an AC 100V specification, the overall efficiency of the drive unit 10 can be improved compared to the comparative example. As a result, the efficiency of the air conditioning device 1 can be improved.

[0039] The present invention has been described above based on embodiments. These embodiments are examples, and those skilled in the art should understand that various modifications can be made to the combination of these constituent elements or processes, and these modifications are also included within the scope of the present invention.

[0040] For example, air conditioning unit 1 can also be a heat exchange type ventilation device as described above. Examples of air conditioning unit 1 being a heat exchange type ventilation device will also be described. A heat exchange type ventilation device (not shown) can be installed above the ceiling (within the ceiling), inside the side wall, or below the floor within a building, and is a ventilation device for supplying and exhausting air into an indoor space. A heat exchange type ventilation device is a ventilation device that has the function of exchanging heat during air supply and exhaust.

[0041] Heat exchange type ventilation devices perform ventilation by simultaneously exchanging heat between the air exhausted from a designated indoor space to the outside (exhaust airflow) and the air supplied from the outside to a designated indoor space (supply airflow). For example, in Japanese summers, during ventilation, the heat exchange type ventilation device transfers heat from the supply airflow to the exhaust airflow, thereby suppressing unnecessary heat inflow. Furthermore, in Japanese winters, during ventilation, the heat exchange type ventilation device transfers heat from the exhaust airflow to the supply airflow, thereby suppressing unnecessary heat outflow.

[0042] Heat exchange between the exhaust gas flow and the supply gas flow is achieved using a heat exchange element (not shown). A heat exchange element is a component used to exchange heat between the exhaust gas flow and the supply gas flow. Furthermore, heat exchange corresponds to sensible heat exchange, which involves the exchange of temperature between the exhaust gas flow and the supply gas flow, or total heat exchange, which involves both sensible heat exchange and latent heat exchange, which involves the exchange of humidity between the exhaust gas flow and the supply gas flow.

[0043] A heat exchange element is a total heat exchange element formed from heat transfer paper (heat transfer plate) with cellulose fiber as the substrate. However, the material is not limited to this. For example, a moisture-permeable resin membrane with polyurethane or polyethylene terephthalate as the substrate, or a paper material with cellulose fiber, ceramic fiber, or glass fiber as the substrate, can be used as the heat transfer plate constituting the heat exchange element. Furthermore, a thin sheet with heat transfer properties and gas impermeability can be used as the heat transfer plate constituting the heat exchange element. In this case, the heat exchange element becomes a sensible heat exchange element.

[0044] The heat exchange type ventilation system includes an exhaust fan for generating exhaust airflow and an air supply fan for generating supply airflow. During heat exchange ventilation, both the exhaust and supply fans operate, and heat exchange occurs between the exhaust and supply airflows in the heat exchange element. Thus, during ventilation, the heat exchange type ventilation system transfers heat from the supply airflow entering a designated space within the room to the exhaust airflow released outdoors, thereby suppressing unnecessary heat inflow. As a result, in Japanese summers, ventilation can prevent indoor temperature rise caused by warmer outdoor air. Furthermore, during ventilation, the heat exchange type ventilation system transfers heat from the exhaust air released outdoors to the supply airflow entering a designated space within the room, thereby suppressing unnecessary heat release and recovering heat into the room. As a result, during Japanese winters, ventilation can prevent indoor temperature drop caused by cooler outdoor air.

[0045] In a heat exchange type ventilation device, the aforementioned exhaust fan and air supply fan are equivalent to Figure 1 The air supply section shown.

[0046] One aspect of the present invention is described below.

[0047] [Project 1]

[0048] An air conditioning device comprising:

[0049] The voltage conversion unit converts the input AC voltage into a first DC voltage;

[0050] The boost unit boosts the first DC voltage converted by the voltage conversion unit into a second DC voltage.

[0051] The air supply unit has an electric motor for supplying air;

[0052] The drive unit drives the air supply unit based on the second DC voltage boosted by the boost unit.

[0053] The voltage detection unit detects the voltage corresponding to the aforementioned AC voltage; and

[0054] The control unit determines the target value of the second DC voltage of the boost unit based on the voltage detected by the voltage detection unit.

[0055] [Project 2]

[0056] The air conditioning device as described in Project 1, wherein:

[0057] The lower the voltage detected by the voltage detection unit, the lower the target value will be determined by the control unit.

[0058] [Project 3]

[0059] The air conditioning device as described in Project 1, wherein:

[0060] The lower the voltage detected by the voltage detection unit, the lower the target value set by the control unit.

[0061] The aforementioned target value falls within the range of the second DC voltage, where the efficiency of the aforementioned drive unit and the aforementioned motor is within the specified range.

[0062] [Project 4]

[0063] The air conditioning device as described in any one of Items 1 to 3, wherein:

[0064] If the voltage detected by the voltage detection unit corresponds to an AC 100V specification, the control unit determines the target value as the first voltage.

[0065] If the voltage detected by the voltage detection unit corresponds to an AC 200V specification, the control unit determines the target value as the second voltage.

[0066] The first voltage mentioned above is lower than the second voltage mentioned above.

[0067] When the second DC voltage is the same as the first voltage and when the second DC voltage is the same as the second voltage, the efficiency of the drive unit and the motor is within the specified range.

[0068] [Project 5]

[0069] The air conditioning device as described in any one of Items 1 to 3, wherein:

[0070] The voltage detection unit detects the first DC voltage as a voltage corresponding to the AC voltage based on the voltage after the first DC voltage is divided by a resistor.

[0071] Industrial availability

[0072] This invention can be applied to air conditioning devices.

[0073] Explanation of reference numerals in the attached figures

[0074] 1. Air conditioning unit

[0075] 10. Drive unit

[0076] 12 Voltage conversion section

[0077] 14. Boosting Section

[0078] 16 Drive Unit

[0079] 18 Voltage Detection Section

[0080] 20 Control Department

[0081] 30 Air Supply Department

[0082] 32 Electric Motors

[0083] 50 AC power supply

[0084] V1 First DC voltage

[0085] V2 is the second DC voltage.

Claims

1. An air conditioning device, characterized in that, include: The voltage conversion unit converts the input AC voltage into a first DC voltage; The boost unit boosts the first DC voltage, converted by the voltage conversion unit, into a second DC voltage. The air supply unit has an electric motor for supplying air; The drive unit drives the air supply unit based on the second DC voltage boosted by the boost unit; The voltage detection unit detects the voltage corresponding to the AC voltage; and The control unit determines the target value of the second DC voltage of the boost unit based on the voltage detected by the voltage detection unit.

2. The air conditioning device as described in claim 1, characterized in that: The lower the voltage detected by the voltage detection unit, the lower the target value will be determined by the control unit.

3. The air conditioning device as described in claim 1, characterized in that: The lower the voltage detected by the voltage detection unit, the lower the target value will be determined by the control unit. The target value falls within the range of the second DC voltage, where the efficiency of the drive unit and the motor is within a specified range.

4. The air conditioning device according to any one of claims 1 to 3, characterized in that: If the voltage detected by the voltage detection unit corresponds to an AC 100V specification, the control unit determines the target value as the first voltage. If the voltage detected by the voltage detection unit corresponds to an AC 200V specification, the control unit determines the target value as the second voltage. The first voltage is lower than the second voltage. When the second DC voltage is the same as the first voltage and when the second DC voltage is the same as the second voltage, the efficiency of the drive unit and the motor are within the specified range.

5. The air conditioning device according to any one of claims 1 to 3, characterized in that: The voltage detection unit detects the first DC voltage as a voltage corresponding to the AC voltage based on the voltage obtained by voltage division of the first DC voltage by a resistor.

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