Heat medium circulation device

Abstract

To provide a heat pump type heat medium circulation device using a combustible refrigerant with low GWP, which is safe and has a long life, and can ensure safety when the refrigerant leaks and lower a temperature of a control device.SOLUTION: A refrigerant is made to be a combustible refrigerant having specific gravity larger than that of air. A control board 16 is stored in a power supply box 21, and the power supply box 21 is disposed above a ventilation device 11. The inside of the power supply box 21 is prevented from communicating with an internal machine chamber 18.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a heat pump type heat medium circulator that uses a refrigerant. [Background technology]

[0002] 2. Description of the Related Art In a heat pump type heat medium circulating device or a heat pump water heater, an inverter that controls a compressor and a heat sink that dissipates heat from the inverter are known to be arranged above the air blower. For example, in Patent Document 1, a heat sink is arranged in the air blower circuit. Furthermore, in Patent Document 2, the control device is disposed above the air blowing circuit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-083692 [Patent Document 2] Patent No. 4899510 Summary of the Invention [Problem to be solved by the invention]

[0004] Currently, with growing environmental awareness, there is a demand for the use of low-GWP refrigerants, especially in Europe. Low-GWP refrigerants include carbon dioxide (R744) and flammable propane (R290). However, carbon dioxide is inefficient when the inlet water temperature of a heat pump water heater is high. Carbon dioxide also requires high pressure resistance due to its high pressure, which increases the cost of components. Furthermore, the cooling efficiency of carbon dioxide is about 60% of that of R32 refrigerant. Therefore, propane is more suitable than carbon dioxide for heat transfer medium circulation systems that heat or cool a room by heating or cooling a heat transfer medium. However, propane is a flammable refrigerant, and ensuring safety in the event of a leak is important. In particular, the control boards and control components that control the compressor are subject to electrical potential, so ensuring safety in the event of a leak is particularly important.

[0005] SUMMARY OF THE INVENTION Accordingly, the present invention has been made to solve the above-mentioned problems in the prior art, and has an object to provide a heat medium circulating device that uses a flammable refrigerant, is safe, durable, and low cost. [Means for solving the problem]

[0006] The outdoor unit is provided with a refrigerant circuit that connects a compressor, a user-side heat exchanger, a pressure reducing means, and a heat source-side heat exchanger to circulate a refrigerant, a heat medium circuit that is connected to the user-side heat exchanger, a blower that generates air for heat exchange with the heat source-side heat exchanger, and a control board that controls the operation of the compressor, the pressure reducing means, and the blower, and the inside of the outdoor unit is divided by a partition plate, one side of the partition plate is an outside air communication chamber, and the other side of the partition plate is an internal machine chamber, and the outside air communication chamber is connected to the heat source-side heat exchanger. a heat medium circulating device in which the compressor, the use-side heat exchanger, and the air blower are arranged in the internal machine room, and the refrigerant is a flammable refrigerant having a specific gravity greater than that of air, the control board is housed in a power supply box, and the power supply box is arranged above the air blower, the power supply box has a lead wire passing hole for passing a lead wire connected to the control board, the inside of the power supply box does not communicate with the internal machine room, and the lead wire passing hole is sealed. The control board has a heat dissipation section, and the power supply box is provided with a ventilation duct that takes in the air from outside the outdoor unit into the power supply box, and an outlet section that discharges the air in the power supply box to the outside of the power supply box. It is characterized by the following. [Effects of the Invention]

[0007] According to the present invention, the refrigerant is a flammable refrigerant having a specific gravity greater than that of air, the control board is housed in a power supply box, the power supply box is disposed above the air blower, and the inside of the power supply box is not in communication with the internal machine room, thereby preventing the flammable refrigerant from entering the power supply box where the control board is located, and thus a heat medium circulation device using a heat pump with excellent safety can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] A piping circuit diagram of a heat medium circulator according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing the configuration of an outdoor unit of the heat medium circulator. [Figure 3] FIG. 10 is a diagram showing the configuration of an outdoor unit of a heat medium circulator according to a second embodiment of the present invention. [Figure 4] Air flow diagram of the power supply box in the outdoor unit DETAILED DESCRIPTION OF THE INVENTION

[0009] The heat medium circulating device according to the first embodiment of the present invention uses a flammable refrigerant having a specific gravity greater than that of air, and has a control board housed in a power supply box that is located above the blower, with the inside of the power supply box not communicating with the internal machine room. According to this embodiment, it is possible to prevent a flammable refrigerant from entering the power supply box containing the control board, thereby providing a heat medium circulation device using a heat pump that is excellent in safety.

[0010] In the second embodiment of the present invention, in the heat medium circulator according to the first embodiment, the control board has a heat dissipation section, and the power supply box is provided with an air duct that takes air into the power supply box from outside the outdoor unit, and an outlet section that discharges the air inside the power supply box to the outside of the power supply box. According to this embodiment, the air outside the outdoor unit can be circulated through the ventilation duct into the power supply box, thereby cooling the control board. By lowering the temperature of the control board, deterioration of components can be prevented, and the unit can be used with stable performance for a long period of time.

[0011] In a third embodiment of the present invention, in the heat medium circulator according to the first or second embodiment, the control board is disposed in the outside air communication chamber. According to this embodiment, since there is no control board above the internal machine room, even if a flammable refrigerant leaks from the refrigerant circuit, the flammable refrigerant will not flow toward the control board, resulting in a heat medium circulating device with excellent safety. [Example]

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments.

[0013] Example 1 FIG. 1 is a piping circuit diagram of a heat medium circulating device according to a first embodiment of the present invention. The heat medium circulating device according to this embodiment comprises an outdoor unit 1, an intermediate relay device 2, and an external radiator 4, and heats or cools a circulating heat medium such as water or antifreeze liquid. The outdoor unit 1 and the intermediate relay device 2 are connected by a heat medium pipe 3. The intermediate relay device 2 and the external radiator 4 are also connected by the heat medium pipe 3. Although the external radiator 4 shown in FIG. 1 is a panel-shaped external radiator 4 such as a floor heating system, it may also be a radiator used for home use such as a panel heater or a fan convector equipped with a blower 11, or an industrial hot air heater or hot water radiator. The hot water or cold water heated or cooled in the outdoor unit 1 passes through the heat transfer pipe 3 and is sent to the external radiator 4, where it heats or cools the room in which the external radiator 4 is installed. In this way, the external radiator 4 heats or cools components and spaces. The outdoor unit 1 generates hot water or cold water for heating or cooling the components and spaces.

[0014] The outdoor unit 1 contains a compressor 5 that compresses and circulates the refrigerant, a water-refrigerant heat exchanger 6 that exchanges heat between a heat medium such as water or antifreeze and the refrigerant circulated by the compressor 5, an expansion valve 7 that serves as a pressure reduction means, an air-refrigerant heat exchanger 8, and a four-way valve 9 that switches between heating and cooling operation of the heat medium. The refrigerant circuit 10 is a closed circuit formed by connecting a compressor 5, a four-way valve 9, a water-refrigerant heat exchanger 6, a pressure reducing means 7, and an air-refrigerant heat exchanger 8 in a circular arrangement, and circulates the refrigerant. The water-refrigerant heat exchanger 6 is composed of a refrigerant pipe 6a through which a refrigerant flows and a heat medium pipe 6b through which a heat medium flows. The water-refrigerant heat exchanger 6 is made of copper or stainless steel pipes with high thermal conductivity and is a heat exchanger that exchanges heat between the refrigerant and the heat medium, heating or cooling the heat medium, such as water or antifreeze, with the refrigerant. In this embodiment, the water-refrigerant heat exchanger 6 corresponds to a utilization-side heat exchanger, and the air-refrigerant heat exchanger 8 corresponds to a heat-source-side heat exchanger.

[0015] The blower 11 delivers air to the air-refrigerant heat exchanger 8 to promote the heat exchange capacity of the air-refrigerant heat exchanger 8 . On the other hand, the heat medium circulates in the heat medium circuit 12, and the circulating heat medium exchanges heat with the refrigerant in the water-refrigerant heat exchanger 6. The circulation pump 13 forcibly circulates the heat medium in the heat medium circuit 12, and is disposed upstream of the water-refrigerant heat exchanger 6. The intermediate relay device 2 has a flow rate sensor 14 provided in series with the heat medium pipe 3, and an expansion absorption tank 15 arranged in parallel with the heat medium pipe 3. The expansion absorption tank 15 is of a sealed type. The pair of connection ports 3 a connects the heat medium pipes 3 and the heat medium circuit 12 . The control board 16 has control components arranged thereon that control various actuators and various sensors (for example, a temperature sensor) of the outdoor unit 1. A remote control 17 allows the user to operate the outdoor unit 1 and the intermediate relay device 2 and to operate various settings.

[0016] FIG. 2 shows the configuration of the outdoor unit of the heat medium circulator, with FIG. 2(a) being a front view of the interior, FIG. 2(b) being a side view of the interior, and FIG. 2(c) being a top view of the interior. The outdoor unit 1 has a housing formed by a bottom plate 1a and a cover 1b, and an internal machine chamber 18 and an external air communication chamber 19 are formed inside the outdoor unit 1. The interior of the outdoor unit 1 is divided by a partition plate 20, with one side of the partition plate 20 being an outside air communication chamber 19 and the other side of the partition plate 20 being an internal machine chamber 18. The air-refrigerant heat exchanger 8 and the blower 11 are disposed in the outside air communication chamber 19. The internal machine chamber 18 contains the compressor 5, the water-refrigerant heat exchanger 6, the pressure reducing means 7, the circulation pump 13, and the four-way valve 9.

[0017] A bottom plate 1a is provided at the bottom of the outdoor unit 1, and the compressor 5 is placed in an internal machine chamber 18 on the right side of this bottom plate 1a. The water-refrigerant heat exchanger 6 is a plate-type heat exchanger mounted on the right rear position of the bottom plate 1a. A pair of connection ports 3a connected to the water-refrigerant heat exchanger 6 extend from the rear of the housing to the outside. Heat transfer medium pipes 3 are connected to the connection ports 3a. Although a plate-type heat exchanger is shown in FIG. 2, a heat exchanger with a double-pipe structure may also be used as long as it is capable of exchanging heat between the refrigerant and the heat medium. An expansion valve 7 as a pressure reducing means and a four-way valve 9 for switching the heat medium between heating operation and cooling operation are arranged near the compressor 5 and together with the compressor 5 constitute a refrigerant circuit 10 .

[0018] The air-refrigerant heat exchanger 8 is disposed to the left and rear of the bottom plate 1a. The air-refrigerant heat exchanger 8 is connected to the expansion valve 7 and the four-way valve 9 by piping extending from the rightmost part of the air-refrigerant heat exchanger 8. A blower 11 for transporting air is disposed opposite the air-refrigerant heat exchanger 8, and the blower 11 promotes the heat exchange capacity of the air-refrigerant heat exchanger 8. The circulation pump 13 is disposed below the water-refrigerant heat exchanger 6, and forcibly circulates the heat medium in the heat medium circuit 12. The circulation pump 13 is connected to the water-refrigerant heat exchanger 6 and the connection port 3a. The circulation pump 13 circulates the heat medium in the heat medium circuit 12 and may be provided in the intermediate relay device 2 . The internal machine chamber 18 and the outside air communication chamber 19 are separated by a partition plate 20. The partition plate 20 is provided between the front of the housing and the air-refrigerant heat exchanger 8 located at the rear of the housing. The control board 16 is placed above the partition plate 20 and is provided in a power supply box 21 arranged above the outside air communication chamber 19.

[0019] The control board 16 has an IPM (intelligent power module) 16a for driving the compressor 5 with an inverter, heat dissipation fins 16b for cooling the IPM 16a, and an electrolytic capacitor 16c for driving the inverter with high efficiency. The IPM 16a and electrolytic capacitor 16c are part of the heat dissipation section. The heat dissipation fins 16b protrude downward from the power supply box 21 and are cooled by the fan device 11. The power supply box 21 is composed of a roughly hexahedral box body consisting of a power supply box bottom 21a and a power supply box lid 21b. After the control board 16 is set in the power supply box bottom 21a, the power supply box 21 covers the control board 16 with the power supply box lid 21b. The control board 16 is covered by the power supply box 21. Lead wires of various actuators and sensors are connected to the control board 16. The lead wire passage holes of the power supply box 21 are sealed so that these lead wires prevent or almost prevent outside air from flowing into the power supply box 21. Although a small portion of the power supply box 21 is located above the internal machine room 18, the power supply box 21 is completely separated from the internal machine room 18. The control board 16 is disposed above the outside air communication chamber 19. The refrigerant used in the refrigerant circuit 10 is a flammable refrigerant with a specific gravity greater than that of air, such as propane (R290).

[0020] The operation of the heat medium circulating device will be described below with reference to the drawings. In FIG. 1, the four-way valve 9 is in a state where hot water is being produced, so the hot water production operation will be described first. When the compressor 5 is operated, the refrigerant compressed to a high pressure by the compressor 5 and discharged passes through the four-way valve 9 and is sent to the water-refrigerant heat exchanger 6, where it exchanges heat with low-temperature water that has passed through the heat medium circuit 12 with the power of the circulation pump 13, thereby releasing heat. As a result, the low-temperature water is heated and becomes high-temperature water, which passes through the heat medium piping 3 and is sent to the intermediate relay device 2, and from the intermediate relay device 2 is sent to the external radiator 4, where it heats the room. The refrigerant flowing out from the water-refrigerant heat exchanger 6 is decompressed and expanded by the expansion valve 7, and sent to the air-refrigerant heat exchanger 8, which is an evaporator, where it exchanges heat with air sent by the air blower 11, and evaporates and gasifies while passing through the air-refrigerant heat exchanger 8. This gasified refrigerant passes through four-way valve 9 and is sucked into compressor 5, where it is compressed again.

[0021] The refrigerant used in this case is propane (R290), a natural refrigerant with a very low GWP (global warming potential) of 3, and will not be subject to fluorocarbon gas regulations in the future. Propane is used in air conditioners and is an environmentally friendly refrigerant, significantly different from R32 (GWP: 675), which will be subject to future fluorocarbon regulations. In terms of refrigeration performance, carbon dioxide (GWP: 1) has a low GWP, but unlike carbon dioxide, which has significantly lower cooling performance, its heating and cooling performance is comparable to that of fluorocarbon refrigerants, and it is highly likely that carbon dioxide will become the mainstream in the future.

[0022] However, propane refrigerant is a flammable refrigerant. Propane refrigerant may leak within the refrigerant circuit 10, and leakage may occur due to cracks in components within the refrigerant circuit 10, for example. The control board 16 has many components to which a potential is applied, and ensuring safety is important. In contrast, the control board 16 is placed inside a power supply box 21 that is covered on six sides, and this power supply box 21 is placed above an outside air communication chamber 19 through which outside air passes, rather than above an internal machine room 18 in which a refrigerant circuit 10 such as a compressor 5 is placed, thereby making it possible to prevent refrigerant from flowing into the power supply box 21. In particular, since propane has a specific gravity of 1.56, which is heavier than air, if it leaks it will tend to accumulate below the outdoor unit 1, making it more advantageous to place it above the outdoor unit 1.

[0023] However, if a crack occurs in the refrigerant circuit 10 during operation, the propane refrigerant may spray out with such force that it may reach above the outdoor unit 1. To cope with this, the control board 16 is placed inside the power supply box 21, which is covered on six sides, thereby preventing flammable refrigerant from flowing into the power supply box 21. This makes it possible to provide a heat medium circulation device using a heat pump that can be used safely even when a flammable refrigerant is used.

[0024] Furthermore, by placing the control board 16 above the outdoor unit 1 and covering the control board 16 with the power supply box 21, a relatively simple configuration can be achieved, and safety can be improved at low cost. Although the heat medium heating operation for generating hot water has been explained, heat medium cooling operation is also possible by switching the four-way valve 9 to change the flow of refrigerant. In this case, the behavior in the event of a refrigerant leak is the same, ensuring safety.

[0025] Example 2 3 shows the configuration of an outdoor unit of a heat medium circulator according to a second embodiment of the present invention, with Fig. 3(a) being a front view of the interior, Fig. 3(b) being a side view of the interior, and Fig. 3(c) being a top view of the interior. The same functional members as those in the first embodiment are designated by the same reference numerals and their explanations are omitted, and the following description will focus on the configurations that differ from those in the first embodiment.

[0026] The control board 16 is placed above the partition plate 20 and is provided in a power supply box 21 arranged above the outside air communication chamber 19. The control board 16 has an IPM (intelligent power module) 16a for driving the compressor 5 with an inverter, heat dissipation fins 16b for cooling the IPM 16a, and an electrolytic capacitor 16c for driving the inverter with high efficiency. The IPM 16a is one of the heat dissipation parts. The heat dissipation fins 16b protrude downward from the power supply box 21 and are cooled by the air blower 11. The power supply box 21 is composed of a roughly hexahedral box body consisting of a power supply box bottom 21a and a power supply box lid 21b. After the control board 16 is set in the power supply box bottom 21a, the power supply box 21 covers the control board 16 with the power supply box lid 21b. The control board 16 is covered by the power supply box 21. Lead wires of various actuators and sensors are connected to the control board 16. The lead wire passage holes of the power supply box 21 are sealed so that these lead wires prevent or almost prevent outside air from flowing into the power supply box 21.

[0027] A ventilation duct 22 is provided on the side of the power supply box 21 facing the internal machine room 18. The ventilation duct 22 is fixed to the power supply box 21, and the power supply box 21 facing the ventilation duct 22 is provided with a power supply box opening inlet 21c. The ventilation duct 22 is connected to a right side plate 23 of the outdoor unit 1, and the power supply box 21 facing the ventilation duct 22 on the right side plate 23 is provided with a right side plate opening inlet 23a. Furthermore, on the front surface of the power supply box 21, facing the outside air communication chamber 19, a power supply box opening outlet 21d is provided.

[0028] Here again, the operation for generating hot water will be described. When the heat medium circulator is operated by operating the remote control 17, the compressor 5 is driven, and the refrigerant compressed to high pressure by the compressor 5 and discharged passes through the four-way valve 9 and is sent to the water-refrigerant heat exchanger 6, where it exchanges heat with low-temperature water that has passed through the heat medium circuit 12 with the power of the circulation pump 13, thereby releasing heat. As a result, the low-temperature water is heated to become high-temperature water, which passes through the heat medium piping 3 and is sent to the intermediate relay device 2, and from the intermediate relay device 2 is sent to the external radiator 4, where it heats the room. The refrigerant flowing out from the water-refrigerant heat exchanger 6 is decompressed and expanded by the expansion valve 7, and sent to the air-refrigerant heat exchanger 8, which is an evaporator, where it exchanges heat with air sent by the air blower 11, and evaporates and gasifies while passing through the air-refrigerant heat exchanger 8. This gasified refrigerant passes through four-way valve 9 and is sucked into compressor 5, where it is compressed again.

[0029] At this time, the temperatures of the IPM 16a, electrolytic capacitor 16c, etc. rise. The heat dissipation fins 16b protrude downward from the power supply box 21 and are cooled by the blower 11, but this may not be sufficient. In particular, during the hot and cold water generation operation, the outside air temperature is high and the water-refrigerant heat exchanger 6 functions as a condenser, so the air-refrigerant heat exchanger 8 reaches a high temperature, and cooling by the blower 11 may not be sufficient to cool the heat dissipation fins 16b. In particular, since the control board 16 is configured to be covered by the power supply box 21, the heat generated in the control board 16 does not escape, and the power supply box 21 tends to become very hot.

[0030] The durability of capacitors generally used in inverters is temperature dependent, and temperature has a significant impact on their lifespan. Generally, the relationship between temperature and lifespan is governed by the Arrhenius law, which states that if the temperature rises by 10°C, the evaporation speed of the electrolyte used in the capacitor doubles, and the lifespan is halved, hence the term "10°C double law." Generally, electrolytic capacitors are specified as 105°C for 2000 hours. However, if the capacitor is operated for 10 hours per day for 150 days per year, the lifespan of the capacitor is 1 year and 4 months, which is less than 2 years. In contrast, if the temperature is 20°C lower at 85°C, the lifespan will be doubled to 8,000 hours, and if it can be lowered by another 10°C to 75°C, the lifespan will be 16,000 hours. At 16,000 hours, even if the device is used 10 hours a day, 150 days a year, it will be able to operate without any problems for more than 10 years. This is just one example, but similar trends exist for other control components, and it can be said that lowering the temperature of the control board 16 is extremely important in terms of both reliability and quality. On the other hand, when the air is in operation, it is sucked in by the blower 11, which is always in operation, and passes through the right side panel opening inlet 23a of the right side panel 23, through the ventilation duct 22, through the power box opening inlet 21c of the power box 21, through the control board 16 inside the power box 21, and generates an air flow 24 that passes through the power box opening outlet 21d of the power box 21.

[0031] This air flow 24 is shown in FIG. This air flow 24 makes it possible to cool the control board 16, and by lowering the temperature of the control board 16, it is possible to provide a heat medium circulating device that is highly reliable over a long period of time. Furthermore, even if flammable refrigerant leaks from the refrigerant circuit 10 at this time, the power supply box 21 is covered on six sides, the ventilation duct 22 in the internal machine room 18 does not have an opening facing the internal machine room 18, and the right side panel opening inlet 23a and the power supply box opening outlet 21d, which have openings, are only connected to the outside of the outdoor unit 1, so the flammable refrigerant will not come into contact with it. Therefore, even if a flammable refrigerant is used, safety is not compromised, and a safe heat medium circulating device can be provided. [Industrial Applicability]

[0032] As described above, the present invention is applicable to a heat medium circulating device that heats or cools a heat medium in a refrigerant circuit, and is suitable for, for example, home or commercial heating and cooling equipment. [Explanation of symbols]

[0033] 1 Outdoor unit 1a Bottom plate 1b Cover 2. Intermediate relay device 3 Heat medium piping 3a connection port 4 External heat sink 5. Compressor 6 Water refrigerant heat exchanger (user side heat exchanger) 6a Refrigerant pipe 6b Heat medium pipe 7 Expansion valve (pressure reducing means) 8. Air-refrigerant heat exchanger (heat source side heat exchanger) 9. Four-way valve 10 Refrigerant circuit 11. Blower 12 Heat carrier circuit 13 Circulation pump 14 Flow sensor 15 Expansion absorption tank 16 Control board 16a IPM 16b Heat dissipation fin 16c electrolytic capacitor 17 Remote Control 18 Internal machine room 19 Outdoor air communication room 20 Divider 21 Power Box 21a Under the power box 21b Power box cover 21c Power box opening entrance 21d Power box opening outlet 22 Ventilation duct 23 Right side plate 23a Right side plate opening entrance 24 Air Flow

Claims

1. a refrigerant circuit that connects a compressor, a user-side heat exchanger, a pressure reducing means, and a heat source-side heat exchanger to circulate a refrigerant; a heat medium circuit connected to the utilization side heat exchanger; a blower that generates air for heat exchange with the heat source side heat exchanger; a control board for controlling the operation of the compressor, the pressure reducing means, and the air blower; The outdoor unit is equipped with The interior of the outdoor unit is divided by a partition plate, One side of the partition plate is an outside air communication chamber, The other side of the partition plate is an internal machine room, The heat source-side heat exchanger and the blower are disposed in the outside air communication chamber, The compressor, the utilization side heat exchanger, and the pressure reducing means are arranged in the internal machine room. A heat medium circulating device, The refrigerant is a flammable refrigerant having a specific gravity greater than that of air, The control board is housed in a power supply box, The power supply box is disposed above the air blower; the power supply box includes a lead wire passage hole through which a lead wire connected to the control board passes; The inside of the power supply box is not in communication with the internal machine room, and the lead wire passage hole is sealed. The control board has a heat dissipation section, The power supply box is provided with a ventilation duct that takes in the air from outside the outdoor unit into the power supply box, and an outlet that discharges the air in the power supply box to the outside of the power supply box. A heat medium circulating device characterized by:

2. The control board is disposed in the outside air communication chamber.

2. The heat medium circulating device according to claim 1.

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