Discharge unit and power device

Abstract

The discharge unit of this embodiment includes a drain pan, an insulated discharge section, a grounded drain pipe, and an insulated liquid shearing section. The drain pan collects liquid. The discharge section is connected to the drain pan and discharges the liquid retained in the drain pan. The liquid shearing section prevents continuous transfer of liquid between the discharge section and the drain pipe.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to a discharge unit and a power device. BACKGROUND

[0002] For example, in a power conversion device or the like, a water-cooled cooling unit is sometimes provided in order to cool a circuit (for example, a power conversion unit) housed in a case. In this case, the voltage of the device is high, and the circuit that is the cooling target is charged at the main circuit potential. In this case, the cooling unit in the device is also at the main circuit potential, and therefore, pure water that is insulating is often used as the cooling water. The pure water is adjusted in conductivity by ion exchange resin, and flows in a closed circulation flow path.

[0003] Here, as a countermeasure in the case where leakage of water occurs in the device, various technologies are disclosed. For example, there is a technology in which a drain pan that receives leakage of water and a drain pipe that drains water that remains in the drain pan are provided in the device (for example, refer to Patent Documents 1 and 2).

[0004] However, for example, in the case where the device and the drain pan are integrated, the drain pan itself is at the main circuit potential. In addition, the conductivity of the water that leaks deteriorates and is no longer pure water, and therefore, the water that remains in the drain pan can be at the main circuit potential. If such water is drained via the drain pipe that is at the ground potential, a ground fault can occur in the circuit via the leakage of water.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT DOCUMENTS

[0007] Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 9-84349

[0008] Patent Document 2: Japanese Patent Application Laid-Open (JP-A) No. 10-144838 SUMMARY

[0009] PROBLEMS TO BE SOLVED BY THE INVENTION

[0010] The present application is to provide a discharge unit and a power device that can prevent a drain pan and a drain pipe that is grounded from being electrically connected via a liquid such as water.

[0011] MEANS FOR SOLVING THE PROBLEMS

[0012] The discharge unit of the embodiment includes a drain pan, a discharge portion having insulating properties, a drain pipe that is grounded, and a liquid cutting portion having insulating properties. The drain pan receives a liquid. The discharge portion is connected to the drain pan, and discharges the liquid that remains in the drain pan. The liquid cutting portion prevents the liquid from continuously passing between the discharge portion and the drain pipe. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a perspective view of a power device representing an embodiment.

[0014] Figure 2 is an enlarged view of A portion of Figure 1

[0015] Figure 3 is a schematic configuration view of a drainage unit representing an embodiment. DETAILED DESCRIPTION

[0016] Hereinafter, a drainage unit and a power device of an embodiment will be described with reference to the drawings.

[0017] Figure 1 is a perspective view of a power device 1. Figure 2 is an enlarged view of A portion of Figure 1

[0018] As shown in Figure 1 , Figure 2 , the power device 1 is provided with: a power device case (one example of a device case in the claims) 2; electrical equipment 3 and a cooling unit 4 for cooling the electrical equipment 3, which are housed in the power device case 2; and a drainage unit (one example of a drainage unit in the claims) 5 provided to the power device case 2. In the following description, the upward and downward directions and the horizontal direction in a state where the power device 1 is disposed on a ground F will be simply referred to as upward and downward directions, and a horizontal direction, respectively.

[0019] The power device case 2 is formed in a rectangular parallelepiped shape that is long in the upward and downward directions. That is, the power device case 2 is provided with a frame 6 that extends along the upward and downward directions and a cover 7 that covers an opening of the frame 6 from the outside. In Figure 1 , in order to make the description easy to understand, a state in which a part of the cover 7 is removed is shown.

[0020] In the power device case 2, an intermediate frame 6a that constitutes a part of the frame 6 and extends along the horizontal direction, and a shelf plate 9 that is loaded on the intermediate frame 6a via an insulating member 8 are provided.

[0021] The power device case 2 is divided into three unit housing rooms S1 arranged in the upward and downward directions and a drainage room S2 located at the lowermost portion by the three intermediate frames 6a and the shelf plates 9. In each of the unit housing rooms S1, the electrical equipment 3 and the cooling unit 4 are housed. In the drainage room S2, a drainage case 15 described later is housed.

[0022] The electrical equipment 3 is disposed on each of the shelf plates 9. The electrical equipment 3 is, for example, a circuit unit that constitutes a power conversion device, a power supply device, and a motor drive device, and is constituted by various electrical equipment such as a transformer, an on-off device, a circuit breaker, a measuring device, and a control device.​​

[0023] Cooling unit 4 is a water-cooled system that uses water as a refrigerant. Cooling unit 4 has a unit body 10 mounted on the shelf 9 and located on the side of electrical equipment 3. Unit body 10 has a cooling housing 11 and refrigerant piping 12 introduced into the cooling housing 11.

[0024] The cooling housing 11 is rectangular in shape. Water, acting as refrigerant, flows through the refrigerant piping 12. The refrigerant piping 12 is introduced into the cooling housing 11 in a single stroke. The refrigerant piping 12 protrudes from the cooling housing 11 with an inlet pipe and an outlet pipe. The inlet and outlet of the refrigerant piping 12 protruding from the cooling housing 11 are connected to a refrigerant circulation pump (not shown). The refrigerant circulation pump circulates water within the refrigerant piping 12. As a result, the electrical equipment 3 is cooled.

[0025] In addition, the cooling unit 4 is equipped with a water volume detection device (not shown) that monitors the amount of water circulating in the refrigerant piping 12. For example, if the amount of water circulating in the refrigerant piping 12 falls below a certain threshold due to leakage from the cooling unit 4, the electrical device 1 will stop or an alarm will be displayed based on the detection result of the water volume detection device. Furthermore, the detection result of the water volume detection device is used, for example, in the operation of the valve 17 described later (details will be described later).

[0026] Figure 3 This is a schematic diagram of the drainage unit 5.

[0027] The drainage unit 5 is used, for example, to drain water (refrigerant) leaking from the cooling unit 4 to the outside of the electrical unit housing 2.

[0028] like Figure 2 , Figure 3 As shown, the drainage unit 5 includes: a drain tray 13, corresponding to each shelf 9, disposed between the electrical equipment 3 and the unit body 10 of the cooling unit 4, which are arranged on the shelf 9; a drain hose (an example of the discharge section in the claim) 14, one end 14a of which is connected to each drain tray 13; a drainage tank (an example of the discharge tank in the claim) 15, which is connected to the other end 14b of the drain hose (an example of the hose in the claim) 14; and a drain pipe 16, which is connected to the drainage tank 15.

[0029] The drain pan 13 is a receiving pan for water leaking from the cooling unit 4. The drain pan 13 is formed into a box shape with an open top and shallow depth. One end 14a of the drain hose 14 is connected to the side wall 13a of the drain pan 13, specifically at a corner. The bottom of the drain pan 13 has a water gradient so that water flows towards the part connected to the end 14a of the drain hose 14.

[0030] The drain hose 14 has insulation. For example, the drain hose 14 is formed of resin. The other end 14b of each drain hose 14 extends to the lowermost portion of the power device case 2, and is connected to a drain case 15 housed in a drain chamber S2 of the power device case 2.

[0031] The drain case 15 has insulation, and is formed in a square box shape. For example, the drain case 15 is formed of resin.

[0032] Here, as described in detail in Figure 3 the position of the connection portion (one example of the drain connection portion in the claim) 14c of the other end 14b of the drain hose 14, which is connected to the drain case 15, is located at the upper portion of the side wall 15a of the drain case 15. The other end 14b of the drain hose 14 protrudes from the inner surface of the side wall 15a into the drain case 15. The protruding direction of the other end 14b of the drain hose 14 from the inner surface of the side wall 15a is either the horizontal direction or a direction in which the other end 14b is inclined slightly downward from the horizontal direction.

[0033] In the side wall 15a of the drain case 15, the drain pipe 16 is connected at the lower portion. In the side wall 15a of the drain case 15, the height H between the position of the connection portion (one example of the pipe connection portion in the claim) 16a of the drain pipe 16 and the position of the connection portion 14c of the drain hose 14 is ensured to be a sufficient height (distance).

[0034] Such a drain pipe 16 communicates with an external drain tank, not shown. A valve 17 that opens and closes the inside of the drain pipe 16 is provided midway in the drain pipe 16.

[0035] Next, the function of the drain unit 5 will be described.

[0036] For example, in the case where water leaks from the cooling unit 4, the water falls to the drain pan 13 disposed below the cooling unit 4. The water flows into the drain case 15 via the drain hose 14. By opening the valve 17 of the drain pipe 16, the water accumulated in the drain case 15 is drained to the outside of the power device 1.

[0037] Here, in the side wall 15a of the drain case 15, the height H between the position of the connection portion 16a of the drain pipe 16 and the position of the connection portion 14c of the drain hose 14 is ensured to be a sufficient height (distance). Therefore, the water drained from the other end 14b of the drain hose 14 falls as droplets W and accumulates at the bottom of the drain case 15. Thus, in the drain case 15, the flow of water between the drain hose 14 and the drain pipe 16 is completely cut off. Furthermore, the drain case 15 is formed of, for example, resin, which has insulation. Therefore, the drain hose 14 and the drain pipe 16 are not electrically connected via the water.

[0038] However, the drain pipe 16 is connected to an external drain trough (not shown) and is grounded. On the other hand, insulation is not ensured between the drain pan 13 and the electrical equipment 3 and cooling unit 4, thus the drain pan 13 becomes the main circuit potential. Consequently, the water flowing from the drain pan 13 also becomes the main circuit potential. However, the drain pan 13 and the drain pipe 16 are not electrically connected via water; the connection is severed, thus preventing grounding faults in the electrical equipment 3.

[0039] The valve 17 can be opened or closed manually or electrically. In the case of electric operation, the valve 17 can be opened, for example, based on the detection result of a water level detection device (not shown) installed in the cooling unit 4. That is, for example, if the water level detection device detects that the amount of water circulating in the refrigerant piping 12 is below a certain threshold, it is conceivable that a corresponding amount of water has accumulated in the drain tank 15. Therefore, the valve 17 is opened to drain the water accumulated in the drain tank 15.

[0040] By preventing valve 17 from always being open, the water in the drain tank 15 can be prevented from always being grounded. As a result, grounding faults in electrical equipment 3 can be prevented more reliably.

[0041] As a method for detecting the amount of water accumulated in the drainage tank 15, a sensor for detecting the amount of water accumulated in the drainage tank 15 may be provided instead of a water volume detection device (not shown). The valve 17 may also be opened based on the detection result of this sensor. Furthermore, the valve 17 may be opened at regular time intervals.

[0042] Thus, the drainage unit 5 includes: a drain pan 13 for receiving water leaking from the cooling unit 4; a drain hose 14 for draining water retained in the drain pan 13; a grounded drain pipe 16; and a drain tank 15 to prevent continuous water transfer between the drain hose 14 and the drain pipe 16. Therefore, it is possible to prevent the drain pan 13 and the drain pipe 16 from becoming electrically connected via water leaking from the cooling unit 4. Therefore, even if the drain pan 13 is energized to the main circuit potential, grounding faults in the electrical equipment 3 caused by water leaking from the cooling unit 4 can be prevented.

[0043] Inside the drain tank 15, to prevent continuous water transfer between the drain hose 14 and the drain pipe 16, a sufficient height (distance) H is ensured between the connection portion 16a of the drain pipe 16 and the connection portion 14c of the drain hose 14. Thus, by utilizing the height difference between the connection portion 16a of the drain pipe 16 and the connection portion 14c of the drain hose 14, continuous water transfer can be reliably prevented with a simple construction.

[0044] By making the drain hose 14 and the drain tank 15 from insulating resin, grounding faults in the electrical equipment 3 caused by water leakage from the cooling unit 4 can be reliably prevented simply by cutting off the continuous flow of water within the drain tank 15.

[0045] Inside the drain tank 15, the other end 14b of the drain hose 14 protrudes into the drain tank 15 from the inner surface of the side wall 15a. Therefore, water discharged from the other end 14b of the drain hose 14 into the drain tank 15 does not travel along the side wall 15a. As a result, water can be reliably discharged from the other end 14b of the drain hose 14 as droplets W (see reference). Figure 3 Therefore, within the drain tank 15, continuous water transfer between the drain hose 14 and the drain pipe 16 can be more reliably prevented.

[0046] The drain pan 13 is electrically connected to the electrical equipment 3 and is energized to the main circuit potential. Here, for example, in order to make the drain pan 13 a ground potential, the electrical connection between the drain pan 13 and the electrical equipment 3 may be disconnected, for example, by mounting the electrical equipment 3 on the drain pan 13 via an insulating member. When this configuration is adopted, the overall size of the electrical device 1 increases accordingly. In this embodiment, by intentionally making the drain pan 13 a main circuit potential, the overall size of the electrical device 1 can be reduced. Furthermore, even if the drain pan 13 is a main circuit potential, grounding faults in the electrical equipment 3 can be reliably prevented.

[0047] Furthermore, in the above embodiment, the case where the drain tank 15 is provided as a liquid shearing section to prevent continuous water transfer between the drain hose 14 and the drain pipe 16 is described. Then, the case where the height H between the position of the connection 16a of the drain pipe 16 and the position of the connection 14c of the drain hose 14 within the drain tank 15 is confirmed to be sufficient is explained. However, this is not a limitation; as long as the liquid shearing section is configured to prevent discontinuous water transfer between the drain hose 14 and the drain pipe 16, it is acceptable. For example, continuous water transfer between the drain hose 14 and the drain pipe 16 can also be prevented by blowing air.

[0048] In the above embodiment, the cooling unit 4 is described as a water-cooling method that uses water as the refrigerant. However, it is not limited to this, and the refrigerant can be any liquid.

[0049] In the above embodiment, the location of the connection portion 16a of the drain pipe 16 and the connection portion 14c of the drain hose 14 are described on the side wall 15a of the drain tank 15. However, it is not limited to this, as long as there is a height difference between the location of the connection portion 16a of the drain pipe 16 and the connection portion 14c of the drain hose 14. For example, the connection portion 16a of the drain pipe 16 may also be provided on the top plate of the drain tank 15 or on the bottom wall of the drain tank 15.

[0050] In the above embodiment, the case where valve 17 is provided in the drain pipe 16 is described. However, it is not limited to this, and valve 17 may not be provided in the drain pipe 16.

[0051] In the above embodiment, the case where the drain hose 14 is provided as a drain section for draining water from the drain pan 13 is described. However, it is not limited to this; the drain section can be any insulated component capable of draining water from the drain pan 13. For example, it can be configured as a rain gut or a suction tube. It may also not extend continuously to the drain housing 15.

[0052] In the above embodiments, the drain hose 14 and drain tank 15 are described as being formed of an insulating resin. However, this is not a limitation; the drain hose 14 and drain tank 15 may be insulating as long as they are not. For example, the drain hose 14 and drain tank 15 themselves may not be insulating, but may be covered by an insulating film or the like.

[0053] According to at least one embodiment described above, it is possible to prevent the drain pan 13 from being electrically connected to the drain pipe 16 via water leaking from the cooling unit 4. Therefore, even if the drain pan 13 is energized at the main circuit potential, it is possible to prevent grounding faults in the electrical equipment 3 caused by water leaking from the cooling unit 4.

[0054] By utilizing the height difference between the position of the connection 16a of the drain pipe 16 and the position of the connection 14c of the drain hose 14, continuous water transmission can be reliably prevented through a simple construction.

[0055] By making the drain hose 14 and the drain tank 15 from insulating resin, grounding faults in the electrical equipment 3 caused by water leaking from the cooling unit 4 can be reliably prevented simply by cutting off the continuous flow of water in the drain tank 15.

[0056] Inside the drain tank 15, the other end 14b of the drain hose 14 protrudes into the drain tank 15 from the inner surface of the side wall 15a. Therefore, water discharged from the other end 14b of the drain hose 14 into the drain tank 15 does not travel along the side wall 15a. As a result, water can be reliably discharged from the other end 14b of the drain hose 14 as droplets W (see reference). Figure 3 ( ) Falling down. Thus, within the drain tank 15, continuous water transfer between the drain hose 14 and the drain pipe 16 can be more reliably prevented.

[0057] The drain pan 13 is electrically connected to the electrical equipment 3 and is energized to the main circuit potential. Here, for example, in order to make the drain pan 13 a ground potential, the electrical connection between the drain pan 13 and the electrical equipment 3 may be disconnected, for example, by mounting the electrical equipment 3 on the drain pan 13 via an insulating member. If this configuration is adopted, the overall size of the power supply unit 1 will increase due to the installation of the insulating member. In this embodiment, by intentionally making the drain pan 13 a main circuit potential, the overall size of the power supply unit 1 can be reduced. Furthermore, even if the drain pan 13 is a main circuit potential, grounding faults in the electrical equipment 3 can be reliably prevented.

[0058] By setting valve 17 but not keeping it always open, the water in the drain tank 15 can be prevented from being constantly grounded. As a result, grounding faults in electrical equipment 3 can be prevented more reliably.

[0059] Several embodiments of the present invention have been described, but these embodiments are merely illustrative and not intended to limit the scope of the invention. These new embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included within the scope and spirit of the invention, and are included within the scope of the invention as described in the claims and its equivalents.

[0060] Explanation of symbols

[0061] 1…electrical equipment, 2…electrical equipment enclosure (equipment enclosure), 3…electrical equipment, 4…cooling unit, 5…drainage unit, 13…drainage pan, 14…drainage hose (hose), 14c…connection (discharge connection), 15…drainage tank (discharge tank), 16…drainage piping, 16a…connection (piping connection), 17…valve.

Claims

1. An electric power device comprising: a discharge unit; a device case provided with the discharge unit; an electric appliance housed in the device case; and a cooling unit provided in the device case and cooling the electric appliance by a liquid refrigerant, wherein the discharge unit comprises: a drain pan that receives a liquid; a discharge portion that has an insulating property, is connected to the drain pan, and discharges the liquid remaining in the drain pan; a drain pipe that is grounded; a liquid cutting portion that has an insulating property and prevents the liquid from continuously passing between the discharge portion and the drain pipe by blowing air; and a valve that is provided in the drain pipe, opens and closes the drain pipe, wherein the electric appliance is directly disposed on the drain pan without ensuring insulation, the drain pan is charged with an electric potential of the electric appliance, the liquid cutting portion comprises a discharge case that has an insulating property and has a discharge connection portion connected to the discharge portion and a pipe connection portion connected to the drain pipe, and the valve opens the drain pipe in at least any one of a case where an amount of the liquid accumulated in the discharge case exceeds a certain threshold, a case where a flow rate of the liquid refrigerant is lower than a certain threshold, and a case where a certain time has elapsed.

2. The electric power device according to claim 1, wherein the discharge connection portion is disposed at a certain interval above the pipe connection portion in a gravity direction.

3. The electric power device according to claim 2, wherein the discharge portion is a hose that has an insulating property, connects the drain pan and the discharge case, and has an inside through which the liquid flows, and an end portion of the hose on the discharge case side protrudes from an inner side wall of the discharge case toward the inside of the discharge case. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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