Control device and air conditioner

Abstract

To provide a control device and a heat exchange system capable of easily maintaining a temperature of an electric component at a constant level or more.SOLUTION: A control device is a device for controlling a heat exchange system including air blowing means for taking in and discharging air that exchanges heat with a refrigerant. The control device includes: one or more electric components that control the heat exchange system; an electric product box in which the one or more electric components are accommodated and air flows inside and outside by air blowing means; and planar heating means disposed to cover at least part of the one or more electric components and heating inside of the electric product box. The control device controls heating by the heating means on the basis of presence / absence of an operation of the heat exchange system and a temperature inside of the electric product box or an ambient temperature of the heat exchange system.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a control device for controlling a heat exchange system and a heat exchange system. [Background technology]

[0002] A heat exchange system such as an air conditioner includes a compressor, an expansion valve, a fan, etc., and is equipped with a control device that controls these devices. The control device houses electrical components such as a control board in an electrical equipment box, and is located inside the casing of the outdoor unit of the heat exchange system.

[0003] As the outdoor temperature drops, the temperature inside the electrical equipment box of the outdoor unit also drops, and the temperature may fall below the lower limit of the allowable temperature for the electrical components. This makes it impossible to guarantee the operation of the electrical components, resulting in a problem of reduced reliability.

[0004] To address this issue, air conditioners equipped with a heater in an electrical equipment box are known (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-270732 [Patent Document 2] International Publication No. 2017 / 077649 Summary of the Invention [Problem to be solved by the invention]

[0006] However, with the above-mentioned conventional technology, when the outside temperature is low, even if the electrical components generate heat during operation, the temperature inside the electrical equipment box during operation is lower than during standby, and the degree of temperature rise varies greatly depending on whether the unit is in operation or not, making it difficult to maintain the temperature of the electrical components at a constant level or higher. [Means for solving the problem]

[0007] In view of the above-mentioned problems, the present invention provides a control device for controlling a heat exchange system including a blower that takes in and discharges air that exchanges heat with a refrigerant, the control device comprising: one or more electrical components for controlling the heat exchange system; an electrical equipment box that houses one or more electrical components therein and in which air is circulated between the inside and / or the outside by a blower; a planar heating means arranged to cover at least a part of one or more electric components and heat the inside of the electric component box; Including, A control device is provided that controls heating by the heating means based on whether the heat exchange system is operating and the temperature inside the electrical equipment box or the ambient temperature around the heat exchange system. [Effects of the Invention]

[0008] According to the present invention, it becomes easy to maintain the temperature of the electrical components at a constant level or higher. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing an example of the configuration of an air conditioning apparatus as an example of a heat exchange system. [Figure 2] FIG. 2 is a diagram showing an example of the arrangement of components in an outdoor unit of an air conditioning apparatus. [Figure 3] FIG. 3 is a diagram illustrating the flow of air inside the outdoor unit of the air conditioner during operation. [Figure 4] FIG. 2 is a diagram showing an example of the arrangement of electrical components in an electrical equipment box arranged in the outdoor unit. [Figure 5] FIG. 4 is a diagram illustrating the flow of air inside the electrical equipment box while the air conditioner is operating. [Figure 6] 3A and 3B are diagrams illustrating a first shape and a first mounting position of the planar heater. [Figure 7] FIG. 2 is a diagram showing an example of the configuration of a planar heater. [Figure 8] 10A and 10B are diagrams illustrating a second shape and a second mounting position of the planar heater. [Figure 9] 10 is a flowchart showing an example of heating control of a planar heater. DETAILED DESCRIPTION OF THE INVENTION

[0010] FIG. 1 is a diagram showing an example of the configuration of an air conditioner as an example of a heat exchange system. In a heat exchange system, a refrigerant serving as a heat medium is compressed and expanded while circulating within a sealed system, and a fluid, such as air or water, that is the subject of heat exchange is indirectly brought into contact with the refrigerant, thereby exchanging heat between the refrigerant and the fluid. The heat exchange system also exchanges heat between the refrigerant and air, such as outside air, before or after exchanging heat between the fluid and the refrigerant. Therefore, the heat exchange system is not limited to an air conditioner as long as it has such a configuration, but may also be a refrigerator, chiller, heat pump, or the like. Hereinafter, the heat exchange system will be described as an air conditioner.

[0011] The air conditioning device 10 includes an indoor unit 11 installed in the space (indoors) to be air-conditioned, and an outdoor unit 20 installed outdoors, and performs air conditioning by circulating a refrigerant between the indoor unit 11 and the outdoor unit 20 and exchanging heat with the air in the room.

[0012] The indoor unit 11 and the outdoor unit 20 may each be configured with two or more units, and two or more indoor units 11 may be connected to one outdoor unit 20. Hydrofluorocarbons (HFCs) and hydrofluoroolefins (HFOs) can be used as refrigerants. Examples of HFCs include R410A and R32. Examples of HFOs include R1234yf.

[0013] The indoor unit 11 communicates wirelessly with the remote control using infrared or other means to receive various signals such as operation commands, stop commands, commands to change the set temperature, and commands to change the operation mode. The indoor unit 11 and the remote control may be connected by a communication line and configured to perform wired communication. The indoor unit 11 is connected to the outdoor unit 20 via a communication line and works in cooperation with the outdoor unit 20 to condition the air in the room.

[0014] The indoor unit 11 starts up upon receiving an operation command from the remote control, and instructs the outdoor unit 20 to start up. After starting up, the outdoor unit 20 adjusts the compressor rotation speed and the opening of the expansion valve, etc., and controls the amount of refrigerant circulating, etc., so that the indoor temperature becomes the set temperature.

[0015] The indoor unit 11 includes an indoor heat exchanger 12, an indoor fan 13, and an indoor fan motor 14. The indoor fan 13 is driven by the indoor fan motor 14 to take in indoor air and send it to the indoor heat exchanger 12. The indoor heat exchanger 12 has heat transfer tubes through which a refrigerant flows, and is configured so that the sent air comes into contact with the surface of the heat transfer tubes to exchange heat. The air that has undergone heat exchange by the indoor heat exchanger 12 is discharged into the room.

[0016] The indoor unit 11 may also be equipped with various sensors for detecting the indoor temperature, etc., an indoor expansion valve, etc. The indoor unit 11 is equipped with an indoor control device, which controls the rotation speed of the indoor fan motor 14, the opening degree of the indoor expansion valve, etc.

[0017] The outdoor unit 20 includes a compressor 21, an accumulator 22, a four-way valve 23, an expansion valve (outdoor expansion valve) 24, an outdoor heat exchanger 25, an outdoor fan 26 as a blower, and an outdoor fan motor 27. The compressor 21 is, for example, a rotary compressor or a scroll compressor, and is driven by a compressor motor to compress low-pressure gas refrigerant and discharge it as high-pressure gas refrigerant. The accumulator 22 is a container for storing liquid return during transient periods and adjusts the refrigerant to an appropriate quality. The quality fraction is the proportion of steam in wet steam, which indicates the mixed state of steam and micro-droplets.

[0018] The four-way valve 23 is a valve that switches the refrigerant flow path depending on the operating state (operating mode) of the air conditioner 10. The operating modes include cooling mode, heating mode, and fan mode. The expansion valve 24 is a valve that reduces the pressure of the high-pressure refrigerant and expands it. The outdoor fan 26 is driven by an outdoor fan motor 27, takes in outdoor air, and sends it to the outdoor heat exchanger 25. Like the indoor heat exchanger 12, the outdoor heat exchanger 25 has heat transfer tubes through which the refrigerant flows, and is configured so that the sent-in air comes into contact with the surface of the heat transfer tubes to exchange heat. The air that has undergone heat exchange by the outdoor heat exchanger 25 is discharged outdoors.

[0019] The outdoor unit 20 further includes a control device (outdoor control device) 28. The control device 28 is connected to the compressor 21, the four-way valve 23, the expansion valve 24, and the outdoor fan motor 27, and controls these. Specifically, it controls the rotation speed of the compressor motor, the opening of the expansion valve 24, the rotation speed of the outdoor fan motor 27, etc. In order to control these, various sensors, such as a sensor that detects the outdoor air temperature, are also attached to the outdoor unit 20. The control device 28 controls these based on information detected by the various sensors.

[0020] During heating operation, the indoor heat exchanger 12 is used as a condenser, and the outdoor heat exchanger 25 is used as an evaporator. Therefore, the control device 28 circulates the refrigerant sealed in the system in the following order, as shown by the arrows: compressor 21, four-way valve 23, indoor heat exchanger 12, expansion valve 24, outdoor heat exchanger 25, four-way valve 23, accumulator 22, and compressor 21.

[0021] The compressor 21 compresses a low-temperature, low-pressure gaseous refrigerant (refrigerant gas) and discharges it as a high-temperature, high-pressure refrigerant gas. The indoor heat exchanger 12 exchanges heat with indoor air to cool and condense the refrigerant gas. The expansion valve 24 reduces the pressure of the liquid refrigerant. The opening of the expansion valve 24 is adjusted by a control device 28 so that the amount of liquid is appropriate. The outdoor heat exchanger 25 exchanges heat with outdoor air to evaporate the refrigerant. The refrigerant is then sent to the accumulator 22 through a four-way valve 23 and returned to the compressor 21.

[0022] FIG. 2 is a diagram showing an example of the arrangement of components within the outdoor unit 20 of the air conditioner 10. The outdoor unit 20 has an outdoor fan 26 at the top of a substantially rectangular parallelepiped casing 30. Inside the casing 30, there is a machine chamber 31 accommodating the compressor 21 and other components, an accumulator 22, and an electrical equipment box 32. The casing 30 has a bottom plate, a metal plate to which the electrical equipment box 32 is attached, an upper opening communicating with the outdoor fan 26, and a side opening for drawing air. The casing 30 may have, for example, a frame member to which a mesh member is attached, with the opening of the mesh member serving as the side opening, and the outdoor heat exchanger 25 disposed inside the frame member adjacent to the mesh member. Alternatively, the outdoor heat exchanger 25 may be used as part of the casing 30, and be disposed so as to cover part of the side. When the outdoor heat exchanger 25 is used as part of the casing 30, the gaps between the heat transfer tubes of the outdoor heat exchanger 25 formed in a panel shape using heat transfer tubes can be used as the side openings.

[0023] The machine room 31 and the accumulator 22 are heavy objects and are therefore arranged at the bottom inside the casing 30. The electrical equipment box 32 is arranged above the machine room 31 in consideration of manual operation, making it easier to operate.

[0024] 3 is a diagram illustrating the flow of air inside the outdoor unit 20 while the air conditioner 10 is in operation. When the outdoor heat exchanger 25 is disposed inside the casing 30 of the outdoor unit 20, the interior of the casing 30 is divided into two spaces (a first space 33 and a second space 34) by the outdoor heat exchanger 25. Because the outdoor heat exchanger 25 is disposed adjacent to a side opening of the casing 30, the second space 34 is smaller than the first space 33.

[0025] The outdoor unit 20 uses the outdoor fan 26 to take in outside air from a side opening in the casing 30 into the second space 34 inside the casing 30. If one side surface formed by sheet metal of the casing 30 is defined as the front, side openings can be provided on the other three surfaces: the left and right side surfaces and the back surface, and air can be taken in through side openings provided on these three surfaces. Note that the side openings are not limited to being provided on the three surfaces: the left and right side surfaces and the back surface, and they may also be provided on a part of the front surface, and air can also be taken in through side openings provided in a part of the front surface.

[0026] The air taken into the second space 34 inside the casing 30 passes through the gaps between the heat transfer tubes of the outdoor heat exchanger 25 while in contact with the heat transfer tubes, thereby exchanging heat with the refrigerant circulating inside the heat transfer tubes. The air that has exchanged heat in the outdoor heat exchanger 25 enters the first space 33 and is discharged to the outside from the top of the casing 30 (a hole in the ceiling panel). Note that if the outdoor heat exchanger 25 forms part of the side of the casing 30, there is no second space 34, and the air is drawn directly into the first space 33 through the gaps between the heat transfer tubes.

[0027] In the outdoor unit 20, the outdoor heat exchanger 25 functions as a condenser during cooling operation, so the air taken into the second space 34 is heated by the outdoor heat exchanger 25 and discharged from the first space 33 to the outside at a higher temperature than when it was taken in.

[0028] On the other hand, in the outdoor unit 20, the outdoor heat exchanger 25 acts as an evaporator during heating operation, so that the air taken into the second space 34 is cooled by the outdoor heat exchanger 25 and discharged from the first space 33 to the outside at a lower temperature than when it was taken in.

[0029] 4 is a diagram showing an example of the arrangement of electrical components in an electrical equipment box 32 arranged in the outdoor unit 20. A control board 40 serving as control means for controlling the operation of the air conditioner 10 is housed inside the electrical equipment box 32. The control board 40 includes a processor and memory, and controls the starting and stopping of the motor of the compressor 21, the starting and stopping of the outdoor fan motor 27, the valve opening degree of the expansion valve 24, etc.

[0030] An inverter power module assembly 41 is housed in the electrical equipment box 32 as a load adjusting means for adjusting the rotation speed and workload of the motor of the compressor 21 to match a target load. The inverter power module assembly 41 includes multiple semiconductor switching elements, and adjusts the rotation speed and other parameters by changing the timing of switching the semiconductor switching elements on and off. The semiconductor switching elements are, for example, field effect transistors such as MOSFETs (Metal Oxide Semiconductor Field Effect Transistors).

[0031] Since the inverter power module assembly 41 includes multiple semiconductor switching elements, an overcurrent protection means is required to prevent deterioration or destruction of the semiconductor switching elements due to an overcurrent caused by an output short circuit or the like. For this reason, an overcurrent protection device 42 is also housed in the electrical equipment box 32 as overcurrent protection means. The overcurrent protection device 42 stops output when the output current exceeds a threshold value. The overcurrent protection device 42 can be configured, for example, with a transistor and a resistor, but is not limited to this.

[0032] Various manual switches, wiring, lamps, etc. are also contained inside the electrical equipment box 32. The inverter power module assembly 41 is provided with a module for measuring inverter overheating at the location where thermal grease is applied, and a sensor built into the module can detect the temperature inside the electrical equipment box.

[0033] 4, one control board 40, two inverter power module assemblies 41, and two overcurrent protection devices 42 are mounted on one board of a predetermined size made of plastic resin. The plastic resin is, for example, phenol resin, epoxy resin, polyimide resin, or the like.

[0034] The electrical equipment box 32 is attached to the sheet metal constituting the casing 30 of the outdoor unit 20. As shown in FIG. 5 , the interior of the electrical equipment box 32 is closed by a lid 43. To prevent heat generated by the electrical components from accumulating inside the electrical equipment box 32, the electrical equipment box 32 has vents on the bottom and upper side when attached to the casing 30. Air flows in through the vent 44 on the bottom side, passes through the interior, and is exhausted through the vent 45 on the upper side. The vent 44 is not limited to being located on the bottom, but may also be located on the lower side, and the vent 45 is not limited to being located on the upper side, but may also be located on the upper (top) side. The number of vents 44 and 45 is not limited to one each, but two or more may be provided. In this case, air flows both inside and outside the electrical equipment box 32. However, a configuration in which air flows only inside the electrical equipment box 32 through the vents 44 and 45 may also be used.

[0035] The electrical equipment box 32 is not limited to a structure that allows air to circulate as described above, and may be a completely sealed structure that uses a refrigerant from a heat exchange system for cooling. In this case, air circulates only outside the electrical equipment box 32.

[0036] Electrical components such as the control board 40, inverter power module assembly 41, and overcurrent protection device 42 include semiconductor elements, wiring, etc., which have electrical resistance, and therefore generate heat when power is supplied and they operate, causing their temperature to rise. However, air flows through the electrical equipment box 32 from the bottom vent 44 to the upper side vent 45, cooling these electrical components and preventing their temperature from rising.

[0037] The inverter power module assembly 41 is a power semiconductor that controls and converts electric power, and generates a large amount of heat due to the large current flowing through it. Therefore, ventilation through the vents 44 and 45 alone is not sufficient to suppress temperature rise. Therefore, a heat sink 46 having multiple fins is provided on the outer surface of the electrical equipment box 32 as a heat dissipation means for dissipating heat generated by the inverter power module assembly 41. The heat sink 46 comes into contact with the air flowing from the bottom to the top of the outer surface of the electrical equipment box 32, and dissipates the heat generated by the inverter power module assembly 41. The heat sink 46 can be provided not only for the inverter power module assembly 41 but also for the overcurrent protection device 42, through which a large current flows. The heat sink 46 may also be provided for electrical components other than the inverter power module assembly 41 and the overcurrent protection device 42.

[0038] When the air conditioner 10 stops operating, it goes into standby mode and the outdoor fan 26 stops, which stops the intake of air into the casing 30 and stops the air flow inside the electrical equipment box 32. The electrical components inside the electrical equipment box 32 no longer receive power and stop operating, so they no longer generate heat, but because there is no air flow, they are indirectly cooled by the outside air and their temperature drops.

[0039] A minimum operating temperature is set for each electrical component inside the electrical equipment box 32, but depending on the region where the air conditioner 10 is provided, the outside air temperature may fall below this minimum operating temperature, causing the temperature inside the electrical equipment box 32 to fall below this minimum operating temperature during standby. This makes it impossible to guarantee the operation of each electrical component, reducing reliability.

[0040] Therefore, a heater is provided as a heating means within the electrical equipment box 32, and the temperature inside the electrical equipment box 32 can be heated and adjusted so that it does not fall below the lower limit temperature for use.

[0041] During heating operation of the air conditioner 10, the electrical components in the electrical equipment box 32 are supplied with power and are in operation, so they generate heat, but air that has been cooled by the outdoor heat exchanger 25 and is cooler than the outside air circulates inside and / or outside the electrical equipment box 32, so that the electrical equipment box 32 is constantly cooled. For this reason, during heating operation, the temperature inside the electrical equipment box 32 is lower than during standby.

[0042] When heating a fixed amount of heat, the temperature inside the electrical equipment box 32 is lower during heating operation, so not much heat is needed for heating during standby, but a fixed amount of heat is needed, so the amount of heat may be excessive, and when heating operation is performed, heat is needed for heating, but only a fixed amount is heated, so the amount of heat may be insufficient. This results in a large difference in temperature rise depending on whether the unit is operating, and the degree of temperature rise varies greatly.

[0043] If the temperature difference inside the electrical equipment box 32 during heating operation and standby can be reduced, it is thought that the excess heat during standby and the lack of heat during heating operation can be eliminated, and the variation in the degree of temperature rise depending on whether the unit is operating or not can be reduced.

[0044] The temperature difference inside the electrical equipment box 32 during heating operation and standby is mainly caused by the fact that during heating operation, the outdoor fan 26 circulates low-temperature air inside and / or outside the electrical equipment box 32, constantly cooling the electrical components. Therefore, if the cooling of the electrical components due to air circulation can be reduced, it is thought that the temperature difference inside the electrical equipment box 32 during heating operation and standby can be reduced.

[0045] Therefore, the heater is configured to be arranged in a shape and position that covers part or all of the target electrical component so that the heat generated by the heater is diffused over the entire surface and the heat can be transferred in a uniform distribution to the target electrical component on the opposite side.

[0046] Here, the electrical components that need to be heated are those required for controlling the operation of the air conditioner 10, and include the control board 40, the inverter power module assembly 41, and the overcurrent protection device .

[0047] Furthermore, by detecting the temperature inside the electrical equipment box 32, the outside air temperature, etc. and adjusting the amount of heat to match the target temperature, it is possible to reduce the amount of heat required for heating during standby, thereby eliminating excess heat, and to increase the amount of heat required for heating during heating operation, thereby eliminating insufficient heat. The amount of heat can be adjusted using control logic or a PTC (Positive Temperature Coefficient) heater with a self-temperature control function. The control logic can be implemented in the control board 40 or other control circuits.

[0048] 6 is a diagram illustrating a first shape and a first mounting position of the sheet heater. The electrical equipment box 32 is a substantially rectangular parallelepiped, and is large enough to accommodate a board 47 on which are mounted a control board 40, an inverter power module assembly 41, and an overcurrent protection device 42 as target electrical components. The box is equipped with a lid 43 having a surface (back surface) 48 facing the mounting surface of the board 47.

[0049] The heater 49 is a thin, planar heater with a certain area, and is shaped and sized so that when it is placed on the substrate 47, as shown by the dashed line in FIG. 6( a), it can cover part or all of the target electrical component. As shown in FIG. 6( b), the heater 49 is attached to the surface 48 of the lid 43 so as to face the target electrical component. Note that the heater 49 is not limited to being attached to the surface 48 of the lid 43, as long as it is positioned so as to cover part or all of the target electrical component. For example, the substrate 47 can be provided with multiple legs, and the heater 49 can be attached to the legs and positioned so as to cover part or all of the electrical component. Note that this is merely an example and is not limiting.

[0050] The heater 49 can provide a constant amount of heat by ON / OFF control, and a variable heat sheet heater that can adjust the amount of heat generated can be used.

[0051] FIG. 7 shows an example of a heater 49. The heater 49 is a planar heater having a heating wire 51 sandwiched between two sheets 50 made of silicone rubber, polyimide resin, or the like. The heater 49 is several millimeters thick. The heating wire 51 is a linear member made of a nickel-chromium alloy, an iron-chromium-aluminum alloy, or the like, which has high electrical resistance and generates heat. As shown in FIG. 7, the heating wire 51 is shaped like a wave, moving back and forth between both ends of the two sheets 50, enabling uniform heating at any position on the surface of the sheets 50. In the example shown in FIG. 7, the heating wires 51 are spaced widely apart, but narrower spacing is preferable for uniform heating. This is merely an example, and the structure is not limited to this as long as a consistent amount of heat can be applied to any position on the surface of the heater 49. The amount of heat generated by the heater 49 can be adjusted by changing the amount of current supplied to the heating wire 51.

[0052] 6 again, heater 49 has a shape and size sufficient to cover portions of two inverter power module assemblies 41 and two overcurrent protection devices 42, which are the target electrical components, and is attached to surface 48 of lid 43 using an adhesive or the like. The two inverter power module assemblies 41 have a lower limit temperature for board use that is higher than that of control board 40, and therefore require heating by heater 49, including two overcurrent protection devices 42 that prevent overcurrent from flowing to the two inverter power module assemblies 41. For this reason, heater 49 is formed with a shape and size sufficient to cover portions of two inverter power module assemblies 41 and two overcurrent protection devices 42, excluding control board 40.

[0053] Note that this is just one example, and heater 49 may be formed in a shape and size that covers a total of five components, including control board 40, two inverter power module assemblies 41, and two overcurrent protection devices 42, and attached to surface 48 of lid 43. As long as all five components, including control board 40, two inverter power module assemblies 41, and two overcurrent protection devices 42, can be maintained at or above their lower limit operating temperatures, the shape and size are not limited to covering the entire two inverter power module assemblies 41 and a portion of each of two overcurrent protection devices 42, and other shapes and sizes may also be used.

[0054] Here, since the two inverter power module assemblies 41 have a higher minimum usable temperature than the other electrical components, the heater 49 is formed to cover the two inverter power module assemblies 41 and attached to the lid 43, but this is not limiting. Therefore, if there is an electrical component whose minimum usable temperature is higher than that of the two inverter power module assemblies 41, the heater 49 can be formed to cover that electrical component and attached to the lid 43 so as to face that electrical component.

[0055] In this way, it is possible to prevent a lack of heat during heating operation and an excess of heat during standby, so the degree of temperature rise does not vary greatly depending on whether the heater is operating or not. Also, because the heater 49 is arranged to cover the target electrical component, heat from the heater 49 is easily transferred to the target electrical component, reducing the cooling of the target electrical component. This makes it easier to maintain the temperature of the target electrical component at a constant level or higher.

[0056] As long as the heater 49 can be placed so as to cover the target electric component, the sheet 50 of the heater 49 may or may not be in contact with the target electric component. Even if it is not in contact, the heater 49 is placed in a position facing the target electric component and adjacent to it. An adjacent position is, for example, a position about 0.1 to 10 cm away.

[0057] FIG. 8 is a diagram illustrating a second shape and a second mounting position of the sheet heater. In the example shown in FIG. 8, the heater 49 has a shape and size that covers only the two inverter power module assemblies 41. The two inverter power module assemblies 41 are essential for operation in order to adjust the load of the air conditioning apparatus 10. On the other hand, the overcurrent protection device 42 is not essential for operation because it does not need to protect the inverter power module assemblies 41 unless an overcurrent occurs. For this reason, the heater 49 is formed with a shape and size that covers only the two inverter power module assemblies 41.

[0058] In the example shown in Fig. 8, the heater has a shape and size that completely covers the two inverter power module assemblies 41, but as long as the two inverter power module assemblies 41 can be maintained at or above the lower limit temperature of use, it is not necessary to completely cover the two inverter power module assemblies 41, and the heater may have a shape and size that only covers a portion of them. Therefore, as long as the temperature of the two inverter power module assemblies 41 can be maintained at or above the lower limit temperature of use by covering half of each of them, the rectangular heater 49 in the example shown in Fig. 8 can be made into a rectangular heater with half the area. This is just one example, and the present invention is not limited to this.

[0059] By giving the heater 49 the above-described shape and size, when the lid 43 is attached, at least a portion of the target electrical component can be covered by the heater 49. This allows the heat generated by the heater 49 to be diffused over the entire surface, and the heat is transferred evenly to the target electrical component on the opposite side of the heater 49. Therefore, the target electrical component can be heated efficiently without the need for a separate AC (Alternating Current) fan.

[0060] Furthermore, the heater 49 can control heating so as to maintain the temperature of the target electrical component at a certain level or higher by controlling ON / OFF or adjusting the amount of heat generated, but when controlling ON / OFF or adjusting the amount of heat generated, it is possible to use values from a sensor that detects the operating state of the outdoor unit 20 and the outdoor air temperature (outdoor air temperature). The outdoor unit 20 already has a sensor that detects the outdoor air temperature, so there is no need to provide an additional sensor.

[0061] The operating state of the outdoor unit 20 indicates whether the outdoor unit 20 is operating, whether the outdoor fan 26 is running, and whether air is circulating inside the casing 30. During heating operation, the outdoor heat exchanger 25 of the outdoor unit 20 functions as an evaporator, so that air taken in from outside exchanges heat with the refrigerant and is cooled. As a result, the cooled air circulates outside and inside the electrical equipment box 32, and even if the electrical components inside the electrical equipment box 32 are operating and generating heat, it may be cooled even more, causing the temperature to fall below the minimum operating temperature.

[0062] When the outdoor unit 20 is not operating, the outside air temperature cools the air inside the casing 30 through the casing 30, cools the air inside the electrical equipment box 32, and also cools the electrical components inside the electrical equipment box 32. As a result, there is a risk that the electrical components inside the electrical equipment box 32 may fall below their minimum operating temperature.

[0063] For these reasons, the heater 49 is controlled to turn on and off by using values from sensors that detect the operating state of the outdoor unit 20 and the outdoor air temperature, and the amount of heat generated is adjusted. Specific control will be described in detail with reference to FIG. 9.

[0064] 9 is a flowchart showing an example of heating control by the heater 49. Regardless of whether the outdoor unit 20 is operating or stopped, the outdoor unit 20 is connected to a power source and power is supplied to the control board 40, whereby control begins from step 100. Here, the heating control is described as being performed by the control board 40, but heating control may also be performed by another control circuit or the like.

[0065] In step 101, it is determined whether the outdoor unit 20 is operating and the outdoor fan 26 is ON. If the outdoor unit 20 is operating, the outdoor fan 26 is ON, and the process proceeds to step 102, where it is determined whether the component temperature of the target electrical component satisfies the heater ON condition. The component temperature of the target electrical component is set to the temperature inside the electrical component box 32. If it is determined that the heater ON condition is not satisfied, the process returns to step 101.

[0066] If the outdoor unit 20 is not operating in step 101, it is stopped, and the process proceeds to step 103, where it is determined whether or not the value detected by the sensor that detects the outdoor air temperature satisfies the heater ON condition. If it is determined that the heater ON condition is not met, the process returns to step 101.

[0067] If it is determined in steps 102 and 103 that the heater ON conditions are met, the process proceeds to step 104, where the heater 49 is turned ON. That is, heating by the heater 49 begins.

[0068] After heating by the heater 49 has started, the amount of heat generated by the heater 49 can be adjusted. When the outdoor unit 20 is in operation, the amount of heat generated can be adjusted based on the temperature inside the electrical equipment box 32, and when the outdoor unit 20 is not in operation (standby), the amount of heat generated can be adjusted based on the outside air temperature (ambient temperature of the outdoor unit 20). During heating operation, the temperature inside the electrical equipment box 32 is lower than during standby, so the amount of heat generated can be adjusted to be larger during heating operation and smaller during standby.

[0069] In step 105, it is determined whether the component temperature satisfies the heater-off condition. If it is determined that the heater-off condition is not met, the determination in step 105 is repeated until the heater-off condition is met. The heater 49 remains ON until the heater-off condition is met.

[0070] If it is determined in step 105 that the heater OFF conditions are met, the process proceeds to step 106, where the heater 49 is turned OFF. Then, the process proceeds to step 107, where the control ends. Although the control ends here, it is possible to immediately start the control from step 100. This allows a determination to be made again as to whether the heater ON conditions are met, and if it is determined that the heater ON conditions are met, the heater 49 can be turned ON. This type of control makes it possible to maintain the temperature of the target electrical component at a constant level or higher.

[0071] Here, the heater-ON condition and heater-OFF condition will be explained. The lowest usable temperature of the electrical component with the highest lowest usable temperature can be used as the reference temperature for the condition for turning heater 49 ON (heater-ON condition). However, in actual control, the temperature fluctuates, so there is a high possibility that the temperature will fall below the lowest usable temperature. Therefore, taking into consideration some fluctuation in temperature, a margin of, for example, about 5°C can be set above the lowest usable temperature as the reference temperature (lower limit temperature) for the heater-ON condition. Note that the margin is not limited to 5°C, but may be 10°C, for example.

[0072] The heater 49 can use the upper limit temperature of the electrical component with the lowest upper limit temperature as the reference temperature for the condition for turning off the heater 49 (heater OFF condition). However, because the upper limit temperature is a temperature exceeding 50°C, the heater 49 will not turn off until a considerable amount of time has passed, resulting in unnecessary power consumption. Therefore, a temperature 15 to 20°C higher than the reference temperature (lower limit temperature) for the heater ON condition can be set as the reference temperature (upper limit temperature) for the heater OFF condition. Note that the temperature higher than the reference temperature for the heater ON condition is not limited to 15 to 20°C, and may be 20 to 30°C, etc., as long as it does not exceed the upper limit temperature.

[0073] As described above, the control device and heat exchange system of the present invention make it easy to maintain the temperature of at least specific electrical components above a certain level when the outside air temperature is low. Therefore, it is possible to select electrical components even when it is unavoidable to maintain a temperature range for the electrical components or when the lower limit of their operating temperature is relatively high for overall cost reduction purposes. Furthermore, since heat can be efficiently transferred to specific electrical components and only the temperature of the specific electrical components needs to be maintained above a certain level, the energy required for heating can be reduced.

[0074] The control device and heat exchange system of the present invention have been described in detail using the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments and can be modified within the scope of what a person skilled in the art can conceive, such as other embodiments, additions, modifications, deletions, etc., and any aspect is within the scope of the present invention as long as it achieves the functions and effects of the present invention.

[0075] Therefore, according to the present invention, (1) a control device can be provided that controls a heat exchange system including a blowing means that takes in and exhausts air that exchanges heat with a refrigerant, the control device including one or more electrical components that control the heat exchange system, an electrical equipment box that houses the one or more electrical components and through which air circulates inside, outside, or both by the blowing means, and a planar heating means that is arranged to cover at least a portion of the one or more electrical components and heats the inside of the electrical equipment box, and that controls heating by the heating means based on whether the heat exchange system is operating and the temperature inside the electrical equipment box or the ambient temperature around the heat exchange system.

[0076] According to the present invention, (2) it is possible to provide a control device as described in (1) above, in which the electrical equipment box has a lid having a surface facing the one or more electrical components, and the heating means is attached to that surface.

[0077] According to the present invention, (3) it is possible to provide a control device as described in (1) or (2) above, in which the one or more electrical components include a control means for controlling the operation of the heat exchange system, a load adjustment means for adjusting the operating load of the heat exchange system, and an overcurrent protection means for preventing an overcurrent from flowing to the load adjustment means, and the heating means is formed to a size that covers part or all of the control means, the load adjustment means, and the overcurrent protection means mounted on a single substrate.

[0078] According to the present invention, (4) it is possible to provide the control device as described in (3) above, in which the heating means is formed to a size that covers a part or all of the load adjusting means.

[0079] According to the present invention, (5) it is possible to provide a control device as described in (3) or (4) above, in which the control means starts heating by the heating means when the temperature inside the electrical equipment box or the outside air temperature detected by an outside air temperature detection means provided in the heat exchange system for detecting the outside air temperature falls below a set lower limit temperature.

[0080] According to the present invention, (6) it is possible to provide the control device described in (5) above, in which the control means stops heating by the heating means when the temperature of the electrical component or the outside air temperature becomes equal to or higher than a set upper limit temperature after starting heating by the heating means.

[0081] According to the present invention, (7) a heat exchange system including the control device according to any one of (1) to (6) above can be provided.

[0082] According to the present invention, (8) a heat exchange system can be provided as described in (7) above, which includes an indoor unit that exchanges heat between indoor air as a fluid and the refrigerant, and an outdoor unit that circulates the refrigerant and exchanges heat between outdoor air and the refrigerant, and the outdoor unit includes the blowing means and the control device. [Explanation of symbols]

[0083] 10...Air conditioning equipment 11...Indoor unit 12…Indoor heat exchanger 13...Indoor fan 14...Indoor fan motor 20...Outdoor unit 21...Compressor 22...Accumulator 23...Four-way valve 24...Expansion valve 25...Outdoor heat exchanger 26...Outdoor fan 27...Outdoor fan motor 28...Control device 30...Casing 31…Machine room 32...Electrical equipment box 33...First Space 34...Second Space 40...Control board 41...Inverter power module assembly 42...Overcurrent protection device 43…Lid 44, 45...Ventilation holes 45…side 46...heat sink 47... Circuit board 48…side 49...Heater 50…sheets 51...Heating wire

Claims

1. A control device for controlling the operation of a heat exchange system including a blower that takes in and discharges air that exchanges heat with a refrigerant, one or more electrical components for controlling the heat exchange system; an electrical equipment box that houses the one or more electrical components therein and in which air flows between the inside and the outside by the air blowing means; a planar heating means arranged to cover at least a part of the one or more electric components and configured to heat the inside of the electric component box; Including, a control device that controls heating by the heating means based on whether the heat exchange system is operating or not, and the temperature inside the electrical equipment box or the ambient temperature around the heat exchange system.

2. The control device according to claim 1 , wherein the electrical equipment box includes a lid having a surface facing the one or more electrical components, and the heating means is attached to the surface.

3. the one or more electrical components include a control means for controlling the operation of the heat exchange system, a load adjustment means for adjusting the operating load of the heat exchange system, and an overcurrent protection means for preventing an overcurrent from flowing to the load adjustment means; 3. The control device according to claim 1, wherein the heating means is formed to a size that covers part or all of the control means, the load adjusting means, and the overcurrent protection means that are mounted on a single substrate.

4. 4. The control device according to claim 3, wherein the heating means is formed to a size that covers a part or all of the load adjusting means.

5. 4. The control device according to claim 3, wherein the control means starts heating by the heating means when the temperature inside the electrical equipment box or the outside air temperature detected by an outside air temperature detection means provided in the heat exchange system for detecting the outside air temperature falls below a set lower limit temperature.

6. 6. The control device according to claim 5, wherein the control means stops the heating by the heating means when the temperature inside the electrical equipment box or the outside air temperature becomes equal to or higher than a set upper limit temperature after the heating by the heating means starts.

7. A heat exchange system for exchanging heat between a fluid and a refrigerant, a control device for controlling the heat exchange system including a blower for taking in and discharging air that exchanges heat with the refrigerant; The control device one or more electrical components for controlling the heat exchange system; an electrical equipment box that houses the one or more electrical components therein and in which air flows between the inside and the outside by the air blowing means; a planar heating means arranged to cover at least a part of the one or more electric components and configured to heat the inside of the electric component box; Including, A heat exchange system that controls heating by the heating means based on whether the heat exchange system is operating or not, and the temperature inside the electrical equipment box or the ambient temperature of the heat exchange system.

8. The heat exchange system according to claim 7 , wherein the electrical equipment box includes a lid having a surface facing the one or more electrical components, and the heating means is attached to the surface.

9. the one or more electrical components include a control means for controlling the operation of the heat exchange system, a load adjustment means for adjusting the operating load of the heat exchange system, and an overcurrent protection means for preventing an overcurrent from flowing to the load adjustment means; 9. The heat exchange system according to claim 7, wherein the heating means is formed to a size that covers part or all of the control means, the load adjusting means, and the overcurrent protection means that are mounted on a single substrate.

10. The heat exchange system according to claim 9, wherein the heating means is formed to a size that covers the entire load adjusting means.

11. The heat exchange system of claim 9, wherein the control means starts heating by the heating means when the temperature inside the electrical equipment box or the outside air temperature detected by an outside air temperature detection means provided in the heat exchange system for detecting the outside air temperature falls below a set lower limit temperature.

12. The heat exchange system according to claim 11, wherein the control means stops heating by the heating means when the temperature inside the electrical equipment box or the outside air temperature becomes equal to or higher than a set upper limit temperature after starting heating by the heating means.

13. The heat exchange system includes an indoor unit that performs heat exchange between indoor air as the fluid and the refrigerant, and an outdoor unit that circulates the refrigerant and performs heat exchange between outdoor air and the refrigerant, The heat exchange system according to claim 11, wherein the outdoor unit includes the blower and the control device.

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