Crimping type phase change cooling heat dissipation structure and method for power unit

Abstract

The invention relates to a crimping type phase change cooling heat radiation structure and method for a power unit, every three phase change cooling heat radiators form a group, a power device I and a power device II are sequentially arranged among the phase change cooling heat radiators, a shell of the phase change cooling heat radiator II is connected with an alternating current output row of the power unit, and the shell of the phase change cooling heat radiator II is connected with the alternating current output row of the power unit. An electrode is arranged in a phase-change working medium of the second phase-change cooling radiator, one end of the electrode is arranged in the phase-change working medium of the second phase-change cooling radiator, the other end of the electrode is arranged outside the second phase-change cooling radiator, the potential of the electrode is a direct-current positive electrode of the power unit, and a shell of the third phase-change cooling radiator is connected with a direct-current negative electrode of the power unit; the phase-change cooling radiator has the advantages that the direct-current positive potential of the power unit is introduced to the electrode in the radiator with the alternating-current potential, the equipotential state of the metal radiator is broken, the alternating electric field is established in the flow channel / phase-change working medium in the radiator, the flowability of the phase-change working medium can be improved through the alternating electric field, and the heat dissipation capacity of the phase-change cooling radiator is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible high-voltage direct current power transmission, and in particular to a press-fit phase-change cooling and heat dissipation structure and method for a power unit. Background Art

[0002] As the transmission capacity of high-voltage converter valves increases, the power density of components increases significantly, which brings great challenges to the cooling of power electronic devices such as IGBTs, diodes and thyristors. At the same time, with the rapid development of power electronic technology, the high density, high integration, high frequency, high performance and miniaturization of components have become an irreversible trend, so the cooling technology of power electronic equipment is extremely important.

[0003] At present, the commonly used cooling technologies for power electronic equipment include air cooling and liquid cooling. Flexible DC converter valves generally use traditional water cooling, which has the following disadvantages:

[0004] (1) The system is highly complex and requires solving complex insulation design and equipotential pin layout issues;

[0005] (2) Low heat dissipation efficiency. As the heat generation power of power electronic devices increases, the traditional water cooling system may not be able to meet the heat dissipation requirements, resulting in overheating of the converter valve.

[0006] (3) Difficult to maintain: the traditional water cooling system has a complex structure and requires a lot of maintenance and repair work;

[0007] (4) Low system reliability. Traditional water cooling systems require complex pump circulation equipment with a high probability of failure.

[0008] (5) Large space occupation: Traditional water cooling systems are usually large in size and take up valuable space resources.

[0009] Although the traditional water cooling system plays an important role in converter valve cooling, its shortcomings are gradually emerging with the advancement of technology and the increase in heat dissipation requirements. New heat dissipation technologies such as phase change cooling technology will become a better choice for converter valve cooling in the future. Summary of the invention

[0010] The object of the present invention is to provide a pressure-connected phase-change cooling and heat dissipation structure and method for a power unit, which adopts phase-change cooling and heat dissipation to improve the heat dissipation efficiency of the power unit.

[0011] To achieve the above object, the present invention is implemented through the following technical solutions:

[0012] A crimped phase change cooling and heat dissipation structure for a power unit comprises a plurality of phase change cooling radiators, wherein three phase change cooling radiators form a group, namely phase change cooling radiator 1, phase change cooling radiator 2 and phase change cooling radiator 3, power device 1 and power device 2 are arranged between the phase change cooling radiators in sequence, the shell of phase change cooling radiator 2 is connected to the AC output row of the power unit, an electrode is arranged in the phase change working fluid of phase change cooling radiator 2, one end of the electrode is in the phase change working fluid of phase change cooling radiator 2, the other end of the electrode is outside the phase change cooling radiator 2 and is connected to the shell of phase change cooling radiator 1 through a cable, the electrode potential is the DC positive pole of the power unit, and the shell of phase change cooling radiator 3 is connected to the DC negative pole of the power unit.

[0013] Phase change cooling radiator 1, phase change cooling radiator 2 and phase change cooling radiator 3 are provided with heat dissipation channels, which are formed by a cavity surrounded by a radiator body, a cover plate, reinforcing ribs and a support column. Phase change working fluid flows in the cavity, and the support column connects the phase change cooling radiator body and the cover plate.

[0014] Electrodes are arranged between the reinforcing ribs of the second phase-change cooling radiator or in the cavity between the reinforcing ribs and the cover plate.

[0015] The number of electrodes is ≥ 1, the electrodes are metal electrodes, and the outer side of the electrodes has an insulating coating layer to isolate the electrodes from the phase change medium.

[0016] A gas collecting port is arranged on the upper end surface of the body of the second phase-change cooling radiator, and the gas collecting port is used to collect the gas working medium and is connected to the converging pipeline.

[0017] The power device 1 and the power device 2 are IGBT devices.

[0018] The power unit consists of power devices, heat sinks, copper busbars, etc.

[0019] A press-fit phase change cooling method for a power unit, the contents are as follows:

[0020] When the power device 2 is turned on and the power device 1 is turned off, the shell of the phase change cooling radiator 2 is at a DC negative potential;

[0021] When the power device 2 is turned off and the power device 1 is turned on, the shell of the phase change cooling radiator 2 is at a DC positive potential;

[0022] As the power device 1 and the power device 2 are turned off / on, the potential of the outer shell of the phase change cooling radiator 2 changes, and the internal electrode potential of the phase change cooling radiator 2 is always the DC positive pole. The phase change working fluid inside the phase change cooling radiator is in a changing electric field, causing the charged phase change working fluid to produce a tiny flow in a direction perpendicular to the electric field equipotential surface.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The support column in the heat dissipation channel connects the radiator body and the cover plate. The support column and the reinforcing ribs together ensure that the radiator can withstand the higher pressing force required by the press-fit type device. The radiator is equipped with an electrode, one end of the electrode is outside the radiator, and the other end is inside the radiator. The electrode is connected to the adjacent radiator to ensure that the electrode potential is different from the phase change cooling radiator potential;

[0025] 2. The radiator has an electrode insulated from the radiator body. The electrode is insulated from the radiator reinforcement ribs, support columns, and radiator shell. The electrode lead-in end is outside the radiator for easy wiring. The potential of the adjacent radiator is introduced to the electrode inside the radiator through the electrode lead-in end. The electrode lead-in end is electrically insulated from the radiator and well sealed.

[0026] 3. The surface of the electrode inside the radiator that is connected to the potential of the external power unit has an insulating coating to ensure that the metal part of the electrode is isolated from the phase change medium, thereby improving the insulation reliability;

[0027] 4. The electrode structure is divided into sheet electrodes and columnar electrodes. The electrode in contact with the phase change medium is an integrated structure or a multi-segment structure connected by welding, which can prevent the phase change medium from penetrating into the lap joint and affecting the reliability of the electrical connection;

[0028] 5. Introducing the DC positive potential of the power unit to the electrode inside the radiator of AC potential can break the state of the metal radiator equipotential body and establish an alternating electric field in the flow channel / phase change medium inside the radiator. The alternating electric field can improve the fluidity of the phase change medium and improve the heat dissipation capacity of the phase change cooling radiator;

[0029] 6. The heat sink on the emitter side (AC) of the power device T2 is used as a phase change cooling heat sink for enhanced heat dissipation, and the electrode provided in the phase change working fluid of the heat sink is connected to the emitter (DC+) of the power device T1. During the shutdown / on process of the power devices T1 and T2, a changing electric field is formed inside the heat sink, which can enhance the heat dissipation capacity of the power device T2 with the largest loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of a press-fit phase change cooling heat dissipation structure for a power unit;

[0031] Figure 2 The structure diagram of the phase change cooling radiator for the introduced electrode;

[0032] Figure 3 A cross-sectional view of a phase change cooling radiator for introducing an electrode;

[0033] Figure 4This is a diagram of the structure of the built-in sheet electrode of the radiator;

[0034] Figure 5 The structure diagram of the built-in columnar electrode of the radiator

[0035] In the figure: 101 - phase change cooling radiator body 102 - electrode 103 - reinforcing rib 104 - support column 201 - introduction electrode 202 - sealing ring 203 - sealing connection terminal 204 - electrode binding wire 205 - sheet electrode 206 - insulating partition one 207 - insulating partition two 208 - threaded hole 209 - electrode column 301 - columnar electrode 302 - gas collecting port. DETAILED DESCRIPTION

[0036] The present invention is described in detail below in conjunction with the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0037] A press-fit phase-change cooling heat dissipation structure for a power unit, comprising a plurality of phase-change cooling heat sinks, wherein three phase-change cooling heat sinks form a group, namely phase-change cooling heat sink HS1, phase-change cooling heat sink HS2, and phase-change cooling heat sink HS3, wherein complex heat dissipation channels are arranged in the phase-change cooling heat sink HS1, phase-change cooling heat sink HS2, and phase-change cooling heat sink HS3, wherein the heat dissipation channels are formed by a cavity surrounded by a heat sink body, a cover plate, reinforcing ribs, and a support column, wherein a phase-change working medium flows in the above-mentioned cavity, and the support column connects the phase-change cooling heat sink body and the cover plate; a power device 1 and a power device 2 are arranged in sequence between the phase-change cooling heat sinks, and the power device 1 and the power device 2 are both IGBT devices The shell of the phase change cooling radiator HS2 is connected to the AC output row (AC) of the power unit; a gas collecting port is provided on the end face above the phase change cooling radiator HS2 body, and the gas collecting port is used to collect the gas working medium and is connected to the gas collecting and converging pipeline; electrodes are provided between the reinforcing ribs of the phase change cooling radiator HS2, or between the reinforcing ribs and the cover plate, and the number of electrodes is ≥1, one end of the electrode is in the phase change working medium of the phase change cooling radiator HS2, and the other end of the electrode is outside the phase change cooling radiator HS2, and is connected to the shell of the phase change cooling radiator HS1 through a cable, and the electrode potential is the DC positive pole DC+ of the power unit, and the shell of the phase change cooling radiator HS3 is connected to the DC negative pole DC- of the power unit.

[0038] A press-fit phase change cooling method for a power unit, the contents are as follows:

[0039] When the power device T2 is turned on and the power device T1 is turned off, the shell of the phase change cooling radiator is at the DC negative pole DC- potential; when the power device T2 is turned off and the power device T1 is turned on, the shell of the phase change cooling radiator is at the DC positive pole DC+ potential; as the power devices T1 and T2 are turned off / on, the potential of the shell of the phase change cooling radiator changes, and the potential of the internal electrode of the phase change cooling radiator is always the DC positive pole DC+; the phase change working fluid inside the phase change cooling radiator is in a changing electric field, so that the phase change working fluid flows in a direction perpendicular to the electric field equipotential surface.

[0040] Working principle:

[0041] The shell of the phase change cooling radiator HS2 is connected to AC alternating current, the electrodes are inserted into the phase change working fluid of the phase change cooling radiator HS2, the electrodes are connected to DC+ and are insulated from the phase change cooling radiator HS2, and an alternating electric field is generated in the flow channel where the phase change working fluid is located. The alternating electric field environment can cause the charged phase change working fluid to move in a direction perpendicular to the electric field equipotential surface, thereby improving the fluidity of the phase change working fluid perpendicular to the contact surface between the radiator and the phase change working fluid, strengthening the surface heat exchange capacity inside the radiator, and enhancing the heat dissipation effect.

[0042] The following examples are implemented on the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operation processes, but the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are conventional methods unless otherwise specified.

[0043] [Example 1]

[0044] Phase change cooling is a new, efficient and clean cooling method with higher heat exchange efficiency and can form a cooling circuit without external power. Phase change cooling uses a low-boiling point phase change working fluid, which has stable physical and chemical properties and excellent insulation properties. The high phase change latent heat of the phase change working fluid improves the heat transfer efficiency and replaces the water cooling part of the cooling system in the flexible DC converter valve. In order to further explore the heat dissipation potential of phase change cooling, studies have shown that the heat dissipation efficiency of phase change cooling can be enhanced when the phase change cooling working fluid is in a changing electric field.

[0045] See Figure 1The phase change cooling radiator HS2 is installed between the power device T1 and the power device T2, and the shell of the phase change cooling radiator HS2 is connected to the AC output row AC of the power unit; electrodes are installed inside the phase change cooling radiator HS2, and the electrodes are connected to the phase change cooling radiator HS1 through cables, and the electrode potential is the DC positive pole DC+; by changing the shutdown / conduction action of the power device T1 and the power device T2, the phase change cooling radiator HS2 can be intermittently connected to the phase change cooling radiator HS1 and the phase change cooling radiator HS3, and the shell potential of the phase change cooling radiator HS2 continuously changes between DC+ and DC-; thereby generating an alternating electric field in the heat dissipation channel between the electrode in the phase change cooling radiator HS2 and the shell of the phase change cooling radiator HS2.

[0046] See Figure 1 , Figure 2 , Figure 3 The phase change cooling radiator body 101 is made of aluminum alloy material, and the gas collecting port 302 is located on the end surface above the phase change cooling radiator body 101. The naturally rising working fluid gas is collected at the gas collecting port and is connected to the gas collecting and converging pipeline above. The phase change cooling radiator HS1, the phase change cooling radiator HS2, and the phase change cooling radiator HS3 are provided with a heat dissipation channel, and the heat dissipation channel is formed by a cavity surrounded by the radiator body, the cover plate, the reinforcing ribs 103 and the support column 104. The phase change working fluid flows in the above-mentioned cavity, and the support column 104 connects the phase change cooling radiator body 101 and the cover plate; a cavity for installing an electrode is reserved between the reinforcing ribs 103 or between the reinforcing ribs 103 and the cover plate, and one to multiple electrodes 102 are installed at the cavity position. The electrode 102 can introduce a potential different from the phase change cooling radiator body 101 into the inside of the radiator.

[0047] [Example 2]

[0048] In this embodiment, a press-fit phase change cooling and heat dissipation structure and method for a power unit are the same as those in Embodiment 1, on the basis of which, the electrode adopts a sheet electrode.

[0049] See Figure 4 The sheet electrode 205 is installed in the cavity position reserved inside the phase change cooling radiator body 101. The sheet electrode 205 is respectively installed with an insulating partition 206 and an insulating partition 207. The insulating partition 206 and the insulating partition 207 are used to fix and limit the sheet electrode 205 inside the phase change cooling radiator, and their surfaces can be coated with insulating materials such as polytetrafluoroethylene coating; the sheet electrode 205, the insulating partition 206, and the insulating partition 207 all have a plurality of round holes and square holes, which are mainly used to avoid the support column 104 on the phase change cooling radiator body 101 for increasing the strength of the chassis, and to ensure the free flow of the phase change working medium.

[0050] The sheet electrode 205 is welded to the lead-in electrode 201 installed on the phase change cooling radiator body 101 through the electrode binding wire 204. The welding connection method can prevent the phase change working fluid from penetrating into the overlap surface and affecting the reliability of the electrical connection. The electrode binding wire 204 and the lead-in electrode 201 are both made of metal materials.

[0051] The electrode 201 is screwed into the sealed adapter terminal 203 through the external thread thereon. A sealing ring groove is reserved on the sealing adapter terminal 203 at the installation side of the electrode 201. The electrode 201 and the sealed adapter terminal 203 are sealed by an end face sealing method using a sealing ring 202. The sealed adapter terminal 203 is connected to the phase change cooling radiator body 101 bracket through threads. A sealing ring groove is reserved on the sealing adapter terminal 203 at the installation side of the phase change cooling radiator body 101. The sealed adapter terminal 203 and the phase change cooling radiator body 101 are sealed by an end face sealing method using a sealing ring 202. The sealed adapter terminal 203 is made of insulating material to ensure the insulation withstand voltage capability between the electrode 201 and the phase change cooling radiator body 101.

[0052] [Example 3]

[0053] In this embodiment, a press-fit phase change cooling and heat dissipation structure and method for a power unit are the same as those in Embodiment 1. On the basis of Embodiment 1, a columnar electrode is used as the electrode.

[0054] See Figure 5 The columnar electrode 301 is made of metal material, such as aluminum alloy 6063, and is screwed into the sealed adapter terminal 203 through the external thread thereon. A sealing ring groove is left on the installation side of the columnar electrode 301 on the sealed adapter terminal 203. The columnar electrode 301 and the sealed adapter terminal 203 are sealed by an end face sealing method using a sealing ring 202; the sealed adapter terminal 203 is connected to the phase change cooling radiator body 101 through a threaded connection, and a sealing ring is left on the installation side of the phase change cooling radiator body 101 on the sealed adapter terminal 203. The sealing adapter terminal 203 and the phase change cooling radiator body 101 are sealed by an end face sealing method using a sealing ring 202; the sealing adapter terminal 203 is made of insulating material, and the columnar electrode 301 is inserted into the electrode column 209 in the phase change cooling radiator 101, and the outer surface is covered with an insulating material such as a polytetrafluoroethylene coating, thereby ensuring the insulation withstand voltage capability between the columnar electrode 301 and the phase change cooling radiator body 101; the columnar electrode 301 has a wiring threaded hole 208 at the lead terminal position on the outside of the radiator.

[0055] The support column in the heat dissipation channel of the present invention connects the radiator body and the cover plate. The support column and the reinforcement ribs together ensure that the radiator can withstand the higher pressing force required by the crimping type device. An electrode is installed on the radiator, one end of the electrode is outside the radiator, and the other end is inside the radiator. The electrode is connected to an adjacent radiator to ensure that the electrode potential is different from the phase change cooling radiator potential; the radiator has an electrode insulated from the radiator body, the electrode is insulated and isolated from the radiator reinforcement ribs, the support column, and the radiator shell, the electrode introduction end is outside the radiator, which is convenient for wiring, and the potential of the adjacent radiator is introduced into the electrode inside the radiator through the electrode introduction end. The electrode introduction end is electrically insulated from the radiator and well sealed; the electrode surface connected to the potential of the external power unit inside the radiator has an insulating coating layer to ensure that the metal part of the electrode is isolated from the phase change working medium, thereby improving the insulation reliability; the electrode structure is shaped The electrode in contact with the phase change medium is an integrated structure or a multi-segment structure connected by welding, which can prevent the phase change medium from penetrating into the overlap surface and affecting the reliability of the electrical connection; the DC positive electrode potential of the power unit is introduced into the electrode inside the radiator of the AC potential, which can break the state of the metal radiator equipotential body, and establish an alternating electric field in the flow channel / phase change medium inside the radiator. The alternating electric field can improve the fluidity of the phase change medium and improve the heat dissipation capacity of the phase change cooling radiator; the radiator on the emitter side (AC) of the power device T2 is used as a phase change cooling radiator for enhanced heat dissipation, and the electrode provided in the phase change medium of the radiator is connected to the emitter (DC+) of the power device T1. During the shutdown / conduction process of the power devices T1 and T2, a changing electric field is formed inside the radiator, which can enhance the heat dissipation capacity of the power device T2 with the largest loss.

Claims

1. A press-fit phase change cooling and heat dissipation structure for a power unit, characterized in that: It comprises a plurality of phase change cooling radiators, and each three phase change cooling radiators form a group, namely phase change cooling radiator 1, phase change cooling radiator 2, and phase change cooling radiator 3, and power device 1 and power device 2 are arranged between the phase change cooling radiators in sequence. The shell of phase change cooling radiator 2 is connected to the AC output row of the power unit, and an electrode is arranged in the phase change working fluid of phase change cooling radiator 2, one end of the electrode is in the phase change working fluid of phase change cooling radiator 2, and the other end of the electrode is outside the phase change cooling radiator 2 and is connected to the shell of phase change cooling radiator 1 through a cable, and the electrode potential is the DC positive pole of the power unit, and the shell of phase change cooling radiator 3 is connected to the DC negative pole of the power unit.

2. A press-fit phase change cooling and heat dissipation structure for a power unit according to claim 1, characterized in that: Phase change cooling radiator 1, phase change cooling radiator 2 and phase change cooling radiator 3 are provided with heat dissipation channels, which are formed by a cavity surrounded by a radiator body, a cover plate, reinforcing ribs and a support column. Phase change working fluid flows in the cavity, and the support column connects the phase change cooling radiator body and the cover plate.

3. A press-fit phase change cooling and heat dissipation structure for a power unit according to claim 2, characterized in that: Electrodes are provided between the reinforcing ribs of the second phase-change cooling radiator or in the cavity between the reinforcing ribs and the cover plate.

4. A press-fit phase change cooling and heat dissipation structure for a power unit according to claim 1, characterized in that: The number of the electrodes is ≥1, the electrodes are metal electrodes, and the outer sides of the electrodes are provided with an insulating coating layer so that the electrodes are isolated from the phase change working medium.

5. A press-fit phase change cooling and heat dissipation structure for a power unit according to claim 1, characterized in that: A gas collecting port is arranged on the upper end surface of the body of the second phase change cooling radiator, and the gas collecting port is used to collect the gas working medium and is connected to the converging pipeline.

6. A press-fit phase change cooling and heat dissipation structure for a power unit according to claim 1, characterized in that: The power device 1 and the power device 2 are IGBT devices.

7. A pressure-connected phase change cooling method for a power unit is implemented according to the structure of any one of claims 1 to 6, characterized in that: The content is as follows: When the power device 2 is turned on and the power device 1 is turned off, the shell of the phase change cooling radiator 2 is at a DC negative potential; When the power device 2 is turned off and the power device 1 is turned on, the shell of the phase change cooling radiator 2 is at a DC positive potential; As the power device 1 and the power device 2 are turned off / on, the potential of the outer shell of the phase change cooling radiator 2 changes, and the internal electrode potential of the phase change cooling radiator 2 is always the DC positive pole. The phase change working fluid inside the phase change cooling radiator is in a changing electric field, causing the charged phase change working fluid to produce a tiny flow in a direction perpendicular to the electric field equipotential surface.

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