Outdoor unit and air conditioner

Abstract

Provided is an outdoor unit (50), wherein: a fan (64) and a cooler (80) are accommodated in a first compartment (71); and electrical components, excluding semiconductor element modules (83a, 83b) and mechanical components, are accommodated in a second compartment (72). The first and second compartments (71, 72) are partitioned by: a power substrate (82); and a partition plate (69) parallel to a right side-surface panel (61). Cooling air for cooling the semiconductor element modules (83a, 83b) flows in from a back panel (57) of a casing (51), and flows out from a blow port (67) formed in the central portion of a front panel (56) via the cooler (80). The semiconductor element modules (83a, 83b) are mounted on a first main surface (82a) positioned on the first compartment (71) side of the power substrate (82), and are disposed in the order of the semiconductor element module (83a) and the semiconductor element module (83b), from the upwind side with respect to the flow direction of the cooling air.

Description

Outdoor units and air conditioners

[0001] The present disclosure relates to an outdoor unit and an air conditioner that include a cooler that cools a semiconductor element module.

[0002] The power supply current, which is the current supplied from an AC power supply to an air conditioner, contains harmonic currents. Harmonic currents are frequency components with frequencies higher than the fundamental frequency. To suppress interference caused by harmonic currents, international regulations have been established for electronic devices that generate harmonic currents. To comply with these regulations, converters take measures to suppress the harmonic currents contained in the power supply current by chopping AC (Alternating Current) or DC (Direct Current).

[0003] Patent Document 1 listed below discloses a power conversion device equipped with a three-phase PWM (Pulse Width Modulation) converter. The three-phase PWM converter is a converter that performs AC chopping. The use of any converter, not limited to a three-phase PWM converter, controls the power supply current to a sinusoidal waveform, thereby reducing the difficulty of suppressing power supply harmonics, which are harmonic currents contained in the power supply current. For this reason, converters are now being installed in the outdoor units of air conditioners.

[0004] Japanese Patent Application Laid-Open No. 2005-151755

[0005] Unlike rectifier circuits, converters are equipped with one or more semiconductor elements. The converter's semiconductor elements, along with the inverter's semiconductor elements, are heat-generating components that generate heat when the compressor is running. Therefore, outdoor units equipped with converters must more efficiently cool the semiconductor element modules housing the semiconductor elements than outdoor units without converters. Furthermore, because outdoor units are installed outdoors, they are prone to internal heat buildup due to direct sunlight and other factors. Furthermore, due to the effects of global warming in recent years, summer days with temperatures exceeding 35°C have become commonplace in Japan, and this climate change is worsening the environmental conditions for outdoor units in the summer. While increasing the size of the outdoor unit is one solution, it is desirable to avoid this approach due to the increased space constraints.

[0006] The present disclosure has been made in consideration of the above, and aims to provide an outdoor unit that can efficiently cool a semiconductor element module while avoiding an increase in size of the outdoor unit.

[0007] To solve the above-mentioned problems and achieve the object, the outdoor unit according to the present disclosure includes mechanical components including a compressor for compressing a refrigerant, a fan that rotates when the compressor is operating, electrical components including a circuit board mounted with a semiconductor device module that houses semiconductor devices that generate heat when the compressor is operating, a cooler that cools the semiconductor device module, and a housing that houses the fan, mechanical components, electrical components, and cooler. The fan and cooler are housed in a first compartment inside the housing, and the mechanical components and electrical components are housed in a second compartment inside the housing. The first and second compartments are separated by the circuit board and a partition plate parallel to the side panels of the housing. An air outlet is formed in the center of a portion of the front panel of the housing that is located in the first compartment. The semiconductor device modules consist of a first semiconductor device module that is a circuit component of a converter that converts AC to DC, and a second semiconductor device module that is a circuit component of an inverter that converts DC to AC. Cooling air that cools the first and second semiconductor device modules flows in from the rear panel of the housing, passes through the cooler, and flows out from the outlet. The first and second semiconductor element modules are mounted on a first main surface of the substrate that is located on the side of the first section, and are arranged in the order of the first and second semiconductor element modules from the upwind side in the direction of the flow of cooling air.

[0008] The outdoor unit according to the present disclosure has the advantage that it is possible to efficiently cool the semiconductor element module while avoiding an increase in size of the outdoor unit.

[0009] 4 is a diagram showing an example of a circuit configuration of a motor drive device mounted in an outdoor unit of an air conditioner according to embodiment 1; FIG. 5 is a diagram showing waveforms of voltages and currents at key points when the power conversion device shown in FIG. 1 is operating; and FIG. 6 is a block diagram showing an example of a hardware configuration for realizing the functions of the control unit shown in FIG. 1.

[0010] An outdoor unit and an air conditioner according to embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Note that in the accompanying drawings, the scale of each component may differ from the actual scale between components or between drawings to facilitate understanding.

[0011] Embodiment 1. Fig. 1 is a diagram showing an example of the circuit configuration of a motor drive device 100 mounted in an outdoor unit of an air conditioner according to embodiment 1. The motor drive device 100 according to embodiment 1 includes a power conversion device 150. The motor drive device 100 is a drive device that converts DC power output from the power conversion device 150 into AC power and supplies the converted AC power to a motor 120 to drive the motor 120. The power conversion device 150 is also a power conversion device that converts AC voltage output from a three-phase power supply 110, which is a three-phase AC power supply, into DC voltage and applies it to a load 130. As shown in the figure, the phases of the three-phase power supply 110 are represented by R, S, and T, and are referred to as the "R phase," "S phase," and "T phase," respectively.

[0012] As shown in Fig. 1, the power conversion device 150 includes a converter 3, a capacitor 4, a shunt resistor 7 for current detection, a current detection unit 10, a voltage detection unit 11, and a drive circuit 16 which is a first drive circuit. The motor drive device 100 includes the power conversion device 150, and also includes a noise filter 1, a reactor 2, current detectors 5a and 5b, a phase voltage detection unit 6, a control unit 14 which is a first control unit, a control unit 15 which is a second control unit, and a load 130, as shown in Fig. 1.

[0013] The load 130 includes a shunt resistor 8 for current detection, an inverter 9, a current detection unit 12, a drive circuit 17 which is a second drive circuit, current detectors 18a and 18b, and a motor 120. Of the components of the load 130, the shunt resistor 8, the inverter 9, the current detection unit 12, the drive circuit 17, and the current detectors 18a and 18b, excluding the motor 120, are components of the motor drive device 100.

[0014] The converter 3 is electrically connected to the three-phase power supply 110 by electrical wiring 170a, 170b, and 170c, which are first electrical wiring. The noise filter 1 is disposed between the three-phase power supply 110 and the reactor 2. The noise filter 1 operates to reduce noise currents flowing in and out of the power conversion device 150. The reactor 2 is disposed between the noise filter 1 and the converter 3. The reactor 2 is a device including circuit elements that temporarily store electrical energy supplied from the three-phase power supply 110. The reactor 2 also operates to reduce noise currents flowing in and out of the power conversion device 150.

[0015] The current detectors 5a and 5b detect the power supply current, which is an AC current flowing between the three-phase power supply 110 and the power conversion device 150, and output the detected values ​​of the power supply current to the control unit 14. An example of the current detectors 5a and 5b is an ACCT (Alternating Current Transformer). While FIG. 1 illustrates an example in which the current detector 5a detects the R-phase current Ir and the current detector 5b detects the T-phase current It, the present invention is not limited to this example. It is sufficient for the current detectors 5a and 5b to detect the currents of any two of the three phases; the currents of the remaining phases can be calculated by utilizing the fact that the power supply currents are three-phase balanced. The phase voltage detector 6 detects the phase voltages of the three phases output by the three-phase power supply 110, which are the R-phase voltage Vr, the S-phase voltage Vs, and the T-phase voltage Vt, and outputs the detected values ​​to the control unit 14.

[0016] The capacitor 4 is electrically connected to the converter 3 by electrical wiring 172a and 172b, which are second electrical wiring. The converter 3 converts the AC voltage output from the three-phase power supply 110 into a DC voltage and outputs it to the electrical wiring 172a and 172b. The electrical wiring 172a and 172b are called "DC buses," and the voltage between the electrical wiring 172a and the electrical wiring 172b is called "bus voltage."

[0017] The output voltage of converter 3 is applied across capacitor 4. Capacitor 4 smoothes the output voltage of converter 3. Capacitor 4 is electrically connected to electrical wiring 172a and 172b by electrical wiring 174a and 174b, which are third electrical wirings, respectively. Therefore, in the configuration of FIG. 1 , the capacitor voltage, which is the voltage across capacitor 4, is equal to the bus voltage. The connection point between electrical wiring 174a and electrical wiring 172a forms terminal P, and the connection point between electrical wiring 174b and electrical wiring 172b forms terminal N. Terminal P is the high-potential side terminal of capacitor 4, and terminal N is the low-potential side terminal of capacitor 4. The voltage smoothed by capacitor 4 is applied to inverter 9.

[0018] The voltage detection unit 11 detects the bus voltage Vdc and outputs the detected value of the bus voltage Vdc to the control units 14 and 15. The current detection unit 10 detects the converter current I1, which is a first current flowing between the converter 3 and the terminal N of the capacitor 4. In the configuration of FIG. 1 , the converter current I1 flows through the shunt resistor 7, so the current detection unit 10 detects this. The current detection unit 10 converts a voltage value generated when the converter current I1 flows through the shunt resistor 7 into a current value and outputs the current value to the control unit 14.

[0019] The converter 3 includes six semiconductor elements Q1 to Q6 connected in a three-phase bridge configuration. The semiconductor elements Q1 and Q2 are connected in series in this order, with a connection point 3a between the semiconductor elements Q1 and Q2 electrically connected to the R phase of the three-phase power supply 110. The semiconductor elements Q3 and Q4 are connected in series in this order, with a connection point 3b between the semiconductor elements Q3 and Q4 electrically connected to the S phase of the three-phase power supply 110. The semiconductor elements Q5 and Q6 are connected in series in this order, with a connection point 3c between the semiconductor elements Q5 and Q6 electrically connected to the T phase of the three-phase power supply 110. In this document, the side of the three-phase power supply 110 on which the connection points 3a to 3c are located, as viewed from the converter 3, will be referred to as the "AC side" where appropriate, and the side on which the load 130 is located will be referred to as the "DC side" where appropriate.

[0020] The semiconductor elements Q1 to Q6 each include a diode D1 to D6 connected in parallel. The diodes D1 to D6 are connected so that their anodes are located on the AC side and their cathodes are located on the DC side. While FIG. 1 illustrates a case where the semiconductor elements Q1 to Q6 are IGBTs (insulated gate bipolar transistors), MOSFETs (metal oxide semiconductor field effect transistors) may be used instead of IGBTs. Note that, because MOSFETs have a built-in parasitic diode due to their structure, a configuration in which the diodes D1 to D6 are not connected in parallel may also be employed.

[0021] The inverter 9 converts direct current into alternating current. More specifically, the inverter 9 converts the output voltage of the power conversion device 150 into an alternating current voltage and applies it to the motor 120 provided in the load 130. An example of an appliance in which the motor 120 is installed is a compressor or a blower in an air conditioner.

[0022] The current detection unit 12 detects the inverter current I2, which is a second current flowing between the inverter 9 and the terminal N of the capacitor 4. In the configuration of FIG. 1 , the inverter current I2 flows through the shunt resistor 8, and the current detection unit 12 detects this. The current detection unit 12 converts a voltage value generated when the inverter current I2 flows through the shunt resistor 8 into a current value and outputs the current value to the control unit 15.

[0023] The inverter 9 includes six semiconductor elements Q21 to Q26 that are connected in a three-phase bridge configuration. The semiconductor elements Q21 and Q22 are connected in series in this order, with a connection point 9a between the semiconductor elements Q21 and Q22 electrically connected to the U-phase of the motor 120. The semiconductor elements Q23 and Q24 are connected in series in this order, with a connection point 9b between the semiconductor elements Q23 and Q24 electrically connected to the V-phase of the motor 120. The semiconductor elements Q25 and Q26 are connected in series in this order, with a connection point 9c between the semiconductor elements Q25 and Q26 electrically connected to the W-phase of the motor 120. Note that, from the perspective of the inverter 9, the side of the converter 3 is the DC side, and the side of the motor 120 where the connection points 9a to 9c are located is the AC side. In this paper, in order to distinguish between the semiconductor elements Q1 to Q6 provided in the converter 3 and the semiconductor elements Q21 to Q26 provided in the inverter 9 without using symbols, the former may be referred to as the "first semiconductor elements" and the latter as the "second semiconductor elements."

[0024] The semiconductor elements Q21 to Q26 each include a diode D21 to D26 connected in parallel. The diodes D21 to D26 are connected so that their cathodes are on the DC side and their anodes are on the AC side. While FIG. 1 shows a case where the semiconductor elements Q21 to Q26 are IGBTs, MOSFETs may be used instead of the IGBTs. Note that, in the case of MOSFETs, a parasitic diode is built into the structure, so a configuration in which the diodes D21 to D26 are not connected in parallel may also be employed. Furthermore, an IGCT (Integrated Gate Commutated Thyristor) may be used instead of the IGBTs.

[0025] Current detectors 18a and 18b detect three-phase motor currents flowing between inverter 9 and motor 120 and output the detected motor current values ​​to control unit 15. An example of current detectors 18a and 18b is an ACCT. Note that while FIG. 1 shows an example in which current detector 18a detects U-phase motor current Iu and current detector 18b detects W-phase motor current Iw, this example is not limiting. Current detectors 18a and 18b only need to detect currents in any two of the three phases, and the currents in the remaining phases can be calculated by utilizing the fact that motor currents are three-phase balanced.

[0026] The control unit 14 controls the operation of the converter 3. Specifically, the control unit 14 generates control signals S1 to S6 for controlling the bus voltage Vdc to a desired voltage while controlling the power supply current to have a sinusoidal waveform based on the detection values ​​of the current detectors 5a and 5b, the detection value of the phase voltage detection unit 6, the detection value of the current detection unit 10, and the detection value of the voltage detection unit 11. The control signals S1 to S6 are PWM signals that control the semiconductor elements Q1 to Q6 of the converter 3, respectively. The control signals S1 to S6 generated by the control unit 14 are input to the drive circuit 16.

[0027] Furthermore, the control unit 15 controls the operation of the inverter 9. Specifically, the control unit 15 generates control signals S21 to S26 for rotating the motor 120 at a desired rotation speed based on the detection values ​​of the voltage detection unit 11, the current detection unit 12, and the current detectors 18a and 18b. The control signals S21 to S26 are control signals for controlling the semiconductor elements Q21 to Q26 of the inverter 9, respectively. The control signals S21 to S26 generated by the control unit 15 are input to the drive circuit 17.

[0028] Drive circuit 16 generates drive pulses G1 to G6 based on control signals S1 to S6. Semiconductor elements Q1 to Q6 of converter 3 perform switching operations in response to the drive pulses G1 to G6. Drive circuit 17 generates drive pulses G21 to G26 based on control signals S21 to S26. Semiconductor elements Q21 to Q26 of inverter 9 perform switching operations in response to the drive pulses G21 to G26.

[0029] 1, the control units 14 and 15 are provided inside the motor drive device 100, but this configuration is not limiting. The control unit 14 may be provided inside the power conversion device 150, and the control unit 15 may be provided inside the load 130. Also, in FIG. 1, the control units 14 and 15 are configured as separate control units, but this configuration is not limiting. The control units 14 and 15 may be integrated into a common control unit that controls both the converter 3 and the inverter 9.

[0030] Fig. 2 is a diagram showing waveforms of voltages and currents at key points when the power conversion device 150 shown in Fig. 1 is operating. From top to bottom, Fig. 2 shows waveforms of the phase voltages of each of the three phases, the phase currents of each of the three phases, and the bus voltage Vdc. The horizontal axis in Fig. 2 represents time.

[0031] The upper part of FIG. 2 shows the waveforms of the R-phase voltage Vr, the S-phase voltage Vs, and the T-phase voltage Vt, which are sinusoidal voltage waveforms. The middle part of FIG. 2 shows the waveforms of the R-phase current Ir, the S-phase current Is, and the T-phase current It, which are sinusoidal current waveforms. These sinusoidal current waveforms are obtained by PWM control of the semiconductor elements Q1 to Q6 of the converter 3. By making the R-phase current Ir, the S-phase current Is, and the T-phase current It sinusoidal, power supply harmonics are suppressed. The lower part of FIG. 2 shows the waveform of the bus voltage Vdc, which is controlled to be approximately constant. By controlling the bus voltage Vdc to be constant, the load 130 can be driven stably. Note that in the first embodiment, the bus voltage Vdc does not necessarily have to be controlled to be constant.

[0032] FIG. 3 is a block diagram showing an example of a hardware configuration for realizing the functions of the control units 14 and 15 shown in FIG.

[0033] To realize some or all of the functions of the control units 14 and 15, a configuration including a processor 201 that performs calculations and a memory 202 that stores programs read by the processor 201 can be used, as shown in FIG.

[0034] The processor 201 is an example of a computing unit. The processor 201 may be a computing unit called a microprocessor, a microcomputer, a central processing unit (CPU), or a digital signal processor (DSP). Examples of the memory 202 include non-volatile or volatile semiconductor memory such as random access memory (RAM), read-only memory (ROM), flash memory, erasable programmable read-only memory (EPROM), and electrically programmable programmable read-only memory (EEPROM), a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, and a digital versatile disk (DVD).

[0035] The memory 202 holds programs that execute the functions of the control units 14 and 15. The processor 201 exchanges necessary information and stores it in the memory 202, and the processor 201 executes the programs held in the memory 202 and refers to the data and tables stored in the memory 202, thereby executing the above-mentioned processing. The calculation results by the processor 201 can be stored in the memory 202.

[0036] Next, structural features of the outdoor unit 50 according to the first embodiment will be described with reference to several drawings. FIG. 4 is an external perspective view of the outdoor unit 50 according to the first embodiment. FIG. 5 is an interior perspective view of the outdoor unit 50 shown in FIG. 4, as seen from the front. FIGS. 6 and 7 are first and second perspective views showing selected components of the outdoor unit 50 shown in FIG. 4. FIG. 8 is an interior top view of the interior of the outdoor unit 50 shown in FIG. 4, as seen from above. FIG. 9 is a left side view and a cross-sectional view taken along the arrows, used to explain the configuration of a cooler 80 according to the first embodiment. The left side of FIG. 9 is a left side view of the cooler 80 shown in FIGS. 5 to 8, as seen from the left side, and the right side of FIG. 9 is a cross-sectional view taken along the arrows IX-IX in the left side view. In addition, in FIG. 9, the x, y, and z axes represent right-handed Cartesian coordinate axes, with the x axis being positive in the direction from the back side to the front side, the y axis being positive in the direction from the left side to the right side, and the z axis being positive in the direction from the bottom side to the top side.

[0037] The outdoor unit 50 includes mechanical components including a compressor 75 for compressing the refrigerant, a fan 64 that rotates when the compressor 75 is driven, electrical components including a power board 82 on which semiconductor element modules 83 a, 83 b are mounted, a cooler 80 that cools the semiconductor element modules 83 a, 83 b, and a housing 51 that houses the fan 64, the mechanical components, the electrical components, and the cooler 80. The housing 51 forms the outer shell of the outdoor unit 50.

[0038] The housing 51 is composed of a front panel 56 that forms the front of the housing 51, a back panel 57 that faces the front panel 56 and forms the back of the housing 51, a bottom panel 58 that forms the bottom of the housing 51, a top panel 59 that faces the bottom panel 58, a left side panel 60 that forms the left side when the housing 51 is viewed from the front, and a right side panel 61 that faces the left side panel 60.

[0039] As shown in FIGS. 7 and 8, the power board 82 is mounted with semiconductor element modules 83a and 83b, which are heat-generating components that generate heat when the compressor 75 is driven.

[0040] The semiconductor element module 83a houses six semiconductor elements Q1 to Q6 and six diodes D1 to D6 that are included in the converter 3 shown in FIG. 1. That is, the semiconductor element module 83a is a circuit component of the converter 3 that converts AC to DC. The semiconductor element module 83b houses six semiconductor elements Q21 to Q26 and six diodes D21 to D26 that are included in the inverter 9 shown in FIG. 1. That is, the semiconductor element module 83b is a circuit component of the inverter 9 that converts DC to AC. In this document, to distinguish between the semiconductor element modules 83a and 83b without using reference numerals, the semiconductor element module 83a may be referred to as the "first semiconductor element module" and the semiconductor element module 83b may be referred to as the "second semiconductor element module."

[0041] In the power conversion device 150 assumed in the first embodiment, AC chopping is performed to suppress power supply harmonics. When AC chopping is performed, the switching frequency for controlling the switching of the semiconductor elements Q1 to Q6 of the converter 3 is characterized by being higher than the switching frequency for controlling the switching of the semiconductor elements Q21 to Q26 of the inverter 9. As a result, the amount of heat generated by the semiconductor element module 83a is greater than the amount of heat generated by the semiconductor element module 83b.

[0042] In the outdoor unit 50, the interior of the housing 51 is divided into a first compartment 71 and a second compartment 72. The first compartment 71 and the second compartment 72 are separated by a power board 82 and a partition plate 69. The partition plate 69 is provided inside the housing 51 and is generally parallel to the left side panel 60 and the right side panel 61.

[0043] 8, the semiconductor element modules 83a and 83b are mounted on a first main surface 82a of the power board 82 on the side of the first section 71. That is, the semiconductor element modules 83a and 83b are present in the first section 71, not in the second section 72. Also, as shown in FIG. 7, the capacitor 84 is mounted on a second main surface 82b of the power board 82 on the side of the second section 72.

[0044] The fan 64 and the cooler 80 are housed in the first compartment 71. Furthermore, the main mechanical components and the main electrical components excluding the semiconductor element modules 83a and 83b are housed in the second compartment 72. In FIG. 4 , the machine chamber 53 housing the main mechanical components is indicated by a dashed line, and the electrical component chamber 52 housing the main electrical components excluding the semiconductor element modules 83a and 83b is indicated by a broken line. The main mechanical components here include the compressor 75, the expansion valve 74, the refrigerant piping 76, and the like. The main electrical components excluding the semiconductor element modules 83a and 83b here include the power board 82 on which the semiconductor element modules 83a and 83b are mounted, the capacitor 84, the reactor 86, the NF (Noise Filter) board 85, the control board 87, and the like.

[0045] Here, as shown in FIG. 7, the reactor 86 is configured to be housed in multiple housings, and some of the housings are arranged in an electrical component storage section 79 provided on the upper part of the partition plate 69 so as to protrude toward the first compartment 71, as shown in FIGS. 5 and 6.

[0046] As described above, in the power conversion device 150 assumed in the first embodiment, in order to suppress power supply harmonics, the switching frequency for controlling the switching of the semiconductor elements Q1 to Q6 of the converter 3 is set to be higher than the switching frequency for controlling the switching of the semiconductor elements Q21 to Q26 of the inverter 9. The higher the switching frequency for controlling the switching of the semiconductor elements Q1 to Q6, the more compact the reactor 86 can be. Therefore, if the reactor 86 can be made smaller by increasing the switching frequency of the semiconductor elements Q1 to Q6, it becomes possible to house the reactor 86 in the electric component chamber 52 without providing the electric component housing portion 79.

[0047] An air outlet 67 is formed in the center of the portion of the front panel 56 that is located in the first compartment 71. The air outlet 67 is an opening for discharging air that has been taken into the housing 51 to the outside of the housing 51. A bell mouth 63 is provided on the annular wall surface 62 that defines the air outlet 67. The bell mouth 63 is an annular member that protrudes from the wall surface 62 into the inside of the housing 51.

[0048] An air inlet 68 is formed in the lower part of the right side panel 61 in a portion located in the second compartment 72. The air inlet 68 may be formed in the rear panel 57, or may be formed in both the rear panel 57 and the right side panel 61. The air inlet 68 is provided to take air from the outside of the housing 51 into the inside of the housing 51. Note that in FIG. 5 , when viewing the outdoor unit 50 from the front side, the first compartment 71 is provided on the left side and the second compartment 72 is provided on the right side, but this relationship may be reversed. That is, the first compartment 71 may be provided on the right side and the second compartment 72 may be provided on the left side. In this structure, the air inlet 68 is formed in at least one of the rear panel 57 and the left side panel 60.

[0049] As shown in Figure 4, the suction port 68 can be configured by, for example, opening a portion of the right side panel 61 to form an opening, and connecting a rectangular plate to the upper edge of the opening with the lower, left, and right edges open. A plurality of such configurations can then be arranged vertically. In this configuration, the lower, left, and right edges of the rectangle can be cut off, leaving the upper edge, and the rectangular plate can be lifted upward to open the lower, left, and right edges of the rectangle.

[0050] As another configuration of the intake port 68, for example, at least one gap that occurs between the bottom panel 58 of the housing 51 in which the machine room 53 is located and the bottom side of the front panel 56, right side panel 61, and back panel 57 facing the machine room 53 may be configured as the intake port 68.

[0051] In the first compartment 71, the fan 64 is located on the rear side of the air outlet 67. The fan 64 is driven by a fan motor 65. The fan 64 rotates as the fan motor 65 is driven, generating an airflow. Air that forms the source of the airflow is taken in through the rear panel 57, the air inlet 68, and the bottom panel 58.

[0052] The airflow generated by the air taken in through the rear panel 57 is sent to the cooler 80 in the first compartment 71 and is used as cooling air for cooling the semiconductor element modules 83 a, 83 b. The airflow generated by the air taken in through the air inlet 68 is sent to the second compartment 72 and is used as cooling air for cooling the mechanical and electrical components.

[0053] An example of the cooler 80 is a heat sink as shown in FIG. 6 . The cooler 80, which is a heat sink, includes a base 80a and a heat dissipation section 80b. The base 80a is a plate-shaped member whose first surface 80a1 abuts against the semiconductor element modules 83a and 83b. The heat dissipation section 80b is a plate-shaped member having multiple fins. The heat dissipation section 80b is also composed of a first fin section 80b1 and a second fin section 80b2 disposed below the first fin section 80b1. The first fin section 80b1 and the second fin section 80b2 have multiple fins arranged in a vertical direction perpendicular to the direction of the cooling airflow, i.e., along the z-axis direction in FIG. 9 . Each fin rises from the second surface 80a2, which is the surface opposite the first surface 80a1, and extends leftward perpendicular to the direction of the cooling airflow, i.e., in the negative y-axis direction in FIG. 9 .

[0054] The cooler 80 of the first embodiment is characterized in that the length of the fins of the second fin portion 80b2 is shorter than the length of the fins of the first fin portion 80b1. By arranging the second fin portion 80b2, which has a shorter fin length, below the first fin portion 80b1, which has a longer fin length, it is possible to easily obtain a structure that avoids interference between the heat dissipation portion 80b and the fan 64 while suppressing an increase in the size of the housing 51.

[0055] The semiconductor element modules 83a, 83b are in contact with the first surface 80a1 of the base portion 80a, and are thereby thermally connected to the first fin portion 80b1 and the second fin portion 80b2. With this structure, heat from the semiconductor element modules 83a, 83b is transferred to the first fin portion 80b1 and the second fin portion 80b2 via the base portion 80a, and is dissipated in these first fin portion 80b1 and second fin portion 80b2.

[0056] 7 to 9, the semiconductor element modules 83a and 83b are mounted on a first main surface 82a of the power board 82 that is located on the first section 71 side, and are arranged in this order from the upwind side in the direction of the cooling air flow: semiconductor element module 83a, semiconductor element module 83b. The reason for this arrangement will be further explained with reference to FIGS. 10 and 11. FIGS. 10 and 11 are first and second diagrams used to explain the results of a simulation performed on the cooler 80 according to the first embodiment.

[0057] The left side of Fig. 10 shows a simulation model that imitates the actual outdoor unit 50. The center of Fig. 10 shows wind speed contours that represent the wind speed distribution when the simulation model is viewed from above, and the right side of Fig. 10 shows wind speed vectors when the simulation model is viewed from above.

[0058] As shown by the wind speed contours and wind speed vectors in Figure 10, it can be seen that the wind speed decreases the further downwind you go inside the cooler 80. Figure 11 shows approximate wind speed values ​​in the cooler 80 at the portion where the semiconductor element modules 83a and 83b are arranged. As shown in Figure 11, the wind speed is 2.2 m / s on the upwind side of the portion where the semiconductor element module 83a is arranged, but decreases to 1.5 m / s on the upwind side of the portion where the semiconductor element module 83b is arranged, and further decreases to 0.7 m / s on the downwind side of the portion where the semiconductor element module 83b is arranged.

[0059] 10 and 11 , the wind speed decreases on the downwind side of the cooler 80. For this reason, the semiconductor element module 83 a, which generates a relatively large amount of heat, is arranged on the upwind side, and the semiconductor element module 83 b, which generates a relatively small amount of heat, is arranged on the downwind side. By arranging them in this manner, the semiconductor element modules 83 a and 83 b mounted on the common power board 82 can be efficiently cooled.

[0060] Note that the number of fins shown in Figure 9 is an example and is not limited to this example. Furthermore, the simulation results shown in Figures 10 and 11 are the results of a specific actual model, and the numerical examples are also examples. The number of fins in the first fin portion 80b1 and the second fin portion 80b2 is a design factor that depends on the amount of heat generated by the semiconductor element modules 83a and 83b, and can be determined based on the amount of heat generated by the semiconductor element modules 83a and 83b. The same applies to the length of each fin in the first fin portion 80b1 and the second fin portion 80b2.

[0061] As described above, the outdoor unit according to the first embodiment includes mechanical components including a compressor for compressing a refrigerant, a fan that rotates when the compressor is operating, electrical components including a circuit board mounted with a semiconductor device module housing a semiconductor device that generates heat when the compressor is operating, a cooler that cools the semiconductor device module, and a housing that houses the fan, mechanical components, electrical components, and cooler. The fan and cooler are housed in a first compartment within the housing, and the mechanical components and electrical components are housed in a second compartment within the housing. The first and second compartments are separated by a partition plate parallel to the circuit board and the side panels of the housing, and an air outlet is formed in the center of the first compartment on the front panel of the housing. The semiconductor device modules include a first semiconductor device module that is a circuit component of a converter that converts AC to DC, and a second semiconductor device module that is a circuit component of a converter that converts DC to AC. Cooling air that cools the first and second semiconductor device modules flows in from the rear panel of the housing, passes through the cooler, and flows out from the outlet. The first and second semiconductor element modules are mounted on a first main surface of the substrate that is located on the side of the first section, and are arranged in the order of the first and second semiconductor element modules from the upwind side in the direction of the flow of cooling air.

[0062] According to the outdoor unit of embodiment 1 configured as described above, even if the outdoor unit is equipped with a converter, the first semiconductor element module, which is a circuit component of the converter, is mounted on a common substrate together with the second semiconductor element module, which is a circuit component of the inverter, and the first and second semiconductor element modules are cooled by a common cooler, so that it is possible to efficiently cool the first and second semiconductor element modules while avoiding the outdoor unit from becoming larger.

[0063] Furthermore, according to the outdoor unit of embodiment 1, the interior of the outdoor unit is divided into a first compartment and a second compartment, the first and second semiconductor element modules are arranged in the first compartment, which can obtain a larger air volume and air speed, and cooling air for cooling other electrical and mechanical components that require cooling is taken in from a location different from the cooling air for cooling the first and second semiconductor element modules. The cooling air for cooling the first and second semiconductor element modules can be taken in from the rear panel. Furthermore, cooling air for cooling electrical and mechanical components other than the first and second semiconductor element modules can be taken in from an intake port provided in at least one of the lower part of the right side panel of the housing, the lower part of a portion of the rear panel located in the second compartment, and the lower part of a portion of the front panel located in the second compartment, and from the bottom panel of the housing. According to the outdoor unit of embodiment 1, it is possible to more efficiently take in cooling air for cooling the first and second semiconductor element modules, and since the first compartment and the second compartment are separated, it is possible to cool the cooling objects in each compartment with individual cooling air while reducing thermal interference between the two.

[0064] Furthermore, in the outdoor unit according to the first embodiment, when the cooler is a heat sink, the heat sink is configured to include a base portion having a first surface thermally connected to the first and second semiconductor element modules, and a heat dissipation portion having a plurality of fins extending upright from a second surface opposite the first surface. The heat dissipation portion includes a first fin portion having a plurality of fins arranged in a vertical direction perpendicular to the flow direction of the cooling air, and a second fin portion having a plurality of fins arranged in a vertical direction perpendicular to the flow direction of the cooling air and disposed below the first fin portion. The fins of the second fin portion are configured to be shorter than the fins of the first fin portion. This configuration of the cooler allows the first fin portion, which has longer fins, to be disposed above the second fin portion, which has shorter fins, making it possible to easily achieve a structure that avoids interference between the heat dissipation portion and the fan while minimizing an increase in the size of the outdoor unit housing.

[0065] Embodiment 2 In embodiment 2, a description will be given of a variation in the configuration of the cooler 80 and the arrangement of the semiconductor element modules 83 a, 83 b that differs from embodiment 1. Note that a description of content that overlaps with embodiment 1 will be omitted.

[0066] Fig. 12 is a perspective view illustrating the configuration of the outdoor unit 50 according to the second embodiment. Fig. 13 is a left side view and a cross-sectional view taken along the arrows, illustrating the configuration of a cooler 80 according to the second embodiment. The left side of Fig. 13 is a left side view of the cooler 80 shown in Fig. 12 as seen from the left side, and the right side of Fig. 13 is a cross-sectional view taken along the line XIII-XIII in the left side view. In Figs. 12 and 13, the same reference numerals as in Figs. 7 and 9 are used, respectively.

[0067] In the cooler 80 of the first embodiment, the length of the fins of the second fin portion 80b2 is shorter than the length of the fins of the first fin portion 80b1, but in the cooler 80 of the second embodiment, the length of the fins of the second fin portion 80b2 is the same as the length of the fins of the first fin portion 80b1. On the other hand, in the cooler 80 of the second embodiment, fins are not provided in the portions that interfere with the fan 64, which are indicated by ellipses in Fig. 13. That is, in the cooler 80 of the second embodiment, the length of the second fin portion 80b2 along the direction of flow of the cooling air is shorter than the length of the first fin portion 80b1 along the direction of flow of the cooling air.

[0068] The cooler 80 of the second embodiment has the same effect as that of the first embodiment, that is, even when the first semiconductor element module, which is a circuit component of the converter, is mounted on a common substrate together with the second semiconductor element module, which is a circuit component of the inverter, the effect of being able to efficiently cool the semiconductor element modules 83a, 83b while avoiding an increase in size of the outdoor unit 50. Furthermore, in the cooler 80 of the second embodiment, the length of the fins of the second fin portion 80b2 may be the same as the length of the fins of the first fin portion 80b1, so that a structure that avoids interference between the heat dissipation portion 80b and the fan 64 can be easily obtained.

[0069] In the case of the cooler 80 shown in Fig. 13, the volume of the fin portion that contributes to cooling the semiconductor element module 83b is smaller than in the cooler 80 shown in Fig. 9, so it is expected that the cooling performance for the semiconductor element module 83b will be reduced. As a countermeasure to this, the cooler 80 may be configured as shown in Fig. 14.

[0070] Fig. 14 is a left side view and a cross-sectional view taken along an arrow, illustrating the configuration of a cooler 80 according to a modification of the second embodiment. In the cooler 80 shown in Fig. 14, the arrangement of the semiconductor element modules 83a and 83b is different from that in Fig. 13. Specifically, in Fig. 14, on the first main surface 82a of the power board 82, the semiconductor element module 83a is arranged to be shifted downward from the arrangement in Fig. 13, and the semiconductor element module 83b is arranged to be shifted upward from the arrangement in Fig. 13. As a result, in Fig. 14, the semiconductor element module 83b is arranged to be shifted upward from the semiconductor element module 83a on the first main surface 82a of the power board 82.

[0071] 14, the semiconductor element module 83b is arranged offset relative to the semiconductor element module 83a, and therefore the portion of the fin that contributes most to cooling the semiconductor element modules 83a, 83b is also offset relative to the direction of the cooling air. This reduces the degree to which the cooling capacity of the downwind semiconductor element module 83b is affected by the temperature rise of the upwind semiconductor element module 83a, compared to when the semiconductor element modules 83a, 83b are arranged in a straight line along the cooling air, and makes it possible to prevent the temperature of the cooling air that contributes to cooling the semiconductor element module 83b from increasing.

[0072] Furthermore, by displacing the semiconductor element module 83b on the leeward side higher than the semiconductor element module 83a on the upwind side, it is possible to prevent the semiconductor element module 83b on the leeward side from being displaced from the center of the first fin portion 80b1. This makes it possible to further improve the cooling effect of the semiconductor element module 83b compared to when the semiconductor element module 83b is disposed displaced from the center of the first fin portion 80b1.

[0073] As described above, in the outdoor unit according to the second embodiment, the heat sink, which is a cooler, is configured to include a base portion whose first surface is thermally connected to the first and second semiconductor element modules, and a heat dissipation portion having a plurality of fins extending upright from a second surface opposite the first surface. The heat dissipation portion includes a first fin portion having a plurality of fins arranged in a vertical direction perpendicular to the direction of cooling air flow, and a second fin portion having a plurality of fins arranged in a vertical direction perpendicular to the direction of cooling air flow and disposed below the first fin portion. The length of the second fin portion along the direction of cooling air flow is configured to be shorter than the length of the first fin portion along the direction of cooling air flow. This configuration of the cooler eliminates the need to make the fin length of the second fin portion shorter than the fin length of the first fin portion, as in the first embodiment. This makes it possible to easily obtain a structure that avoids interference between the heat dissipation portion and the fan while increasing the cooling capacity of the first semiconductor element module, which is located upwind of the cooler according to the first embodiment.

[0074] In the outdoor unit configuration according to the second embodiment, the second semiconductor element module may be positioned on the first main surface of the substrate, offset upward relative to the first semiconductor element module. This arrangement reduces the degree to which the cooling capacity of the second semiconductor element module on the downwind side is affected by the temperature rise of the first semiconductor element module on the upwind side, compared to when the first and second semiconductor element modules are aligned in a straight line along the cooling air. This arrangement prevents the temperature of the cooling air contributing to cooling the second semiconductor element module on the downwind side from increasing. Furthermore, this arrangement prevents the second semiconductor element module on the downwind side from being offset from the center of the first fin portion, thereby further enhancing the cooling effect of the second semiconductor element module, compared to when the second semiconductor element module on the downwind side is positioned offset from the center of the first fin portion.

[0075] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, and parts of the configurations may be omitted or modified without departing from the spirit of the invention.

[0076] For example, a cooler may be constructed by combining the configuration of FIG. 9 of embodiment 1, in which the length of the fins of the second fin section is shorter than the length of the fins of the first fin section, with the configuration of FIG. 13 of embodiment 2, in which the length of the second fin section along the direction of the cooling air flow is shorter than the length of the first fin section along the direction of the cooling air flow.

[0077] Furthermore, for example, the configuration of FIG. 14 of embodiment 2, in which the second semiconductor element module is positioned on the first main surface of the substrate so as to be shifted upward relative to the first semiconductor element module, may be applied to the configuration of FIG. 9 of embodiment 1, in which the length of the fins of the second fin section is made shorter than the length of the fins of the first fin section.

[0078] 1 Noise filter, 2 Reactor, 3 Converter, 3a to 3c, 9a to 9c Connection point, 4 Capacitor, 5a, 5b, 18a, 18b Current detector, 6 Phase voltage detection unit, 7, 8 Shunt resistor, 9 Inverter, 10, 12 Current detection unit, 11 Voltage detection unit, 14, 15 Control unit, 16, 17 Drive circuit, 50 Outdoor unit, 51 Housing, 52 Electrical parts compartment, 53 Machine compartment, 56 Front panel, 57 Rear panel, 58 Bottom panel, 59 Top panel, 60 Left side panel, 61 Right side panel, 62 Wall, 63 Bell mouth, 64 Fan, 65 Fan motor, 67 Air outlet, 68 Intake port, 69 Partition plate, 71 First compartment, 72 Second compartment, 74 Expansion valve, 75 Compressor, 76 Refrigerant piping, 79 Electrical component storage section, 80 cooler, 80a base section, 80a1 first surface, 80a2 second surface, 80b heat dissipation section, 80b1 first fin section, 80b2 second fin section, 82 power board, 82a first main surface, 82b second main surface, 83a, 83b semiconductor element module, 84 capacitor, 85 NF board, 86 reactor, 87 control board, 100 motor drive device, 110 three-phase power supply, 120 motor, 130 load, 150 power conversion device, 170a, 170b, 170c, 172a, 172b, 174a, 174b electrical wiring, 201 processor, 202 memory, D1 to D6, D21 to D26 diodes, N, P terminals, Q1 to Q6, Q21 to Q26 semiconductor elements.

Claims

1. A cooling device comprising: mechanical components including a compressor for compressing a refrigerant; a fan that rotates when the compressor is operating; electrical components including a substrate on which a semiconductor element module is mounted, in which a semiconductor element that generates heat when the compressor is operating is housed; a cooler that cools the semiconductor element module; and a housing that houses the fan, the mechanical components, the electrical components, and the cooler, wherein the fan and the cooler are housed in a first compartment inside the housing, and the mechanical components and the electrical components are housed in a second compartment inside the housing, the first and second compartments are separated by a partition plate that is parallel to the substrate and the side panel of the housing, an air outlet is formed in the center of a portion of the front panel of the housing that is located in the first compartment, and the semiconductor element module comprises a first semiconductor element module that is a circuit component of a converter that converts AC to DC, and a second semiconductor element module that is a circuit component of an inverter that converts DC to AC, cooling air for cooling the first and second semiconductor element modules flows in from the rear panel of the housing, passes through the cooler, and flows out from the air outlet, the first and second semiconductor element modules are mounted on a first main surface of the board that is located on the side of the first compartment, and the first and second semiconductor element modules are arranged in this order from the upwind side in the direction of flow of the cooling air.

2. The outdoor unit according to claim 1, wherein the cooler is a heat sink, the heat sink comprising: a base portion having a first surface thermally connected to the first and second semiconductor element modules; and a heat dissipation portion having a plurality of fins extending up from a second surface opposite the first surface; the heat dissipation portion comprising a first fin portion in which the fins are arranged in a vertical direction perpendicular to the direction of flow of the cooling air; and a second fin portion in which the fins are arranged in a vertical direction perpendicular to the direction of flow of the cooling air and disposed below the first fin portion; and the length of the fins of the second fin portion is shorter than the length of the fins of the first fin portion.

3. The outdoor unit according to claim 1 or 2, wherein the cooler is a heat sink, the heat sink comprising: a base portion having a first surface thermally connected to the first and second semiconductor element modules; and a heat dissipation portion having a plurality of fins extending up from a second surface opposite the first surface; the heat dissipation portion comprising a first fin portion in which the plurality of fins are arranged in a vertical direction perpendicular to the direction of flow of the cooling air; and a second fin portion in which the plurality of fins are arranged in a vertical direction perpendicular to the direction of flow of the cooling air and is disposed below the first fin portion; and the length of the second fin portion along the direction of flow of the cooling air is shorter than the length of the first fin portion along the direction of flow of the cooling air.

4. The outdoor unit according to claim 2 or 3, wherein the second semiconductor element module is arranged on the first main surface of the substrate, shifted upward relative to the first semiconductor element module.

5. An outdoor unit as claimed in any one of claims 1 to 4, wherein an air intake port is formed in at least one of the lower part of the right side panel of the housing, the lower part of the part located in the second compartment of the rear panel, and the lower part of the part located in the second compartment of the front panel, and electrical components other than the first and second semiconductor element modules and the mechanical components are cooled by cooling air flowing in from the intake port and the bottom panel of the housing.

6. An air conditioner equipped with an outdoor unit according to any one of claims 1 to 5.

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