A containerized frequency converter with internal circulation air cooling

Abstract

This invention relates to the field of power equipment frequency converter technology, specifically a containerized frequency converter with internal circulation air cooling. It includes an outer casing, inside which are sealed transformer chambers and frequency converter chambers. Each of the transformer and frequency converter chambers houses a transformer unit and a frequency converter unit, respectively. The transformer unit transforms external high-voltage current before inputting it to the frequency converter unit. An axial air duct is separated from the bottom of the transformer and frequency converter chambers by a partition. A cooling water tank is located within the axial air duct. A first cooling component and a second cooling component are respectively located inside the transformer and frequency converter chambers. The cooling water tank is circulated and connected to the first and second cooling components via first and second circulation pipes, respectively. An axial cooling fan is also located at one end of the axial air duct opening. This promotes heat dissipation from the frequency converter and transformer chambers, ensuring better performance.

Description

Technical Field

[0001] This invention relates to the field of power equipment frequency converter technology, and specifically discloses a containerized frequency converter with internal circulation air cooling. Background Technology

[0002] Currently, the oil drilling rig and fracturing pump drive industries use frequency converters installed inside containers. The containers contain transformers and frequency converters, which step down the high voltage input from the outside through the transformers. The frequency converters drive the load by outputting AC power with controllable frequency through AC and inverter. However, for containerized frequency converters, heat dissipation and moisture protection are key factors affecting their performance.

[0003] Currently, existing technologies, such as the "Containerized Frequency Converter with Internal Circulation Air Cooling" disclosed in CN116761394A, achieve dual-effect synergy of moisture prevention and heat dissipation in the containerized frequency converter by designing the transformer chamber and the frequency converter chamber as a sealed structure. The transformer chamber adopts a "combined internal circulation air cooling superimposed water cooling heat exchanger" and the frequency converter chamber adopts "liquid cooling heat dissipation". Specifically, the solution includes: the transformer chamber drives air to circulate in the chamber through a cooling fan, and the heat is transferred to the heat dissipation tank through the water cooling heat exchanger; the frequency converter chamber directly dissipates heat through liquid cooling through rectifier water cooling plate and inverter water cooling plate, and the two share the same water cooling system, thereby solving the problem of introducing external water vapor in traditional air cooling.

[0004] However, the existing technology still has certain defects. The local heat dissipation efficiency is insufficient. The existing technology relies on the top fan to drive a single circulation path. The fixed air duct structure does not design directional airflow for the heat hotspots of the transformer unit, resulting in low heat dissipation efficiency in local high-temperature areas. In addition, the airflow needs to bypass the water-cooled heat exchangers on both sides. The tortuous path is prone to forming stagnation dead zones, which aggravates uneven heat distribution, leading to heat accumulation and thus affecting the overall performance. Summary of the Invention

[0005] The purpose of this invention is to provide a containerized frequency converter with internal circulation air cooling to solve one of the aforementioned technical problems in the prior art.

[0006] Specifically, the present invention is achieved through the following technical solution:

[0007] A containerized frequency converter with internal circulation air cooling includes an outer casing. Inside the outer casing are sealed transformer chambers and frequency converter chambers. Each transformer chamber houses a transformer unit and a frequency converter unit, respectively. The transformer unit transforms external high-voltage current before inputting it to the frequency converter unit. The frequency converter unit performs frequency conversion processing on the transformed current before delivering it to the external load. An axial air duct is separated from the bottom of the transformer chamber and frequency converter chamber by a partition. A cooling water tank is located within the axial air duct. A first cooling component and a second cooling component are respectively located inside the transformer chamber and frequency converter chamber. The cooling water tank is circulated and connected to the first and second cooling components via first and second circulation pipes, respectively. An axial cooling fan is also located at one end opening of the axial air duct.

[0008] Based on the above technical solution, this application achieves an effective improvement in the heat dissipation efficiency of the containerized frequency converter through a coupled heat dissipation architecture of axial air duct and convection air duct. Specifically, this solution integrates the heat dissipation tank and the axial cooling fan in the same fluid channel by setting the axial air duct at the bottom of the outer casing, forming a dynamic heat dissipation substrate that runs through the transformer chamber and the frequency converter chamber. That is, the airflow flows rapidly in the axial air duct, which effectively promotes the heat dissipation of the frequency converter chamber and the transformer chamber to a certain extent. Furthermore, the airflow generated by the axial cooling fan in the axial air duct can directly force convection on the surface of the heat dissipation tank, thereby further enhancing the heat dissipation efficiency of the heat dissipation tank.

[0009] Meanwhile, in this application, the heat dissipation tank is circulated with the first cooling component in the transformer chamber through the first circulation pipe, and the heat dissipation tank is circulated with the second cooling component in the frequency converter chamber through the second circulation pipe, so as to form an independent closed-loop water cooling heat dissipation path in parallel. This optimizes the flow path of the cooling fluid in the heat dissipation tank, thereby avoiding mutual interference, enhancing the water cooling heat dissipation efficiency of the transformer chamber and the frequency converter chamber, and ultimately promoting the effective improvement of the overall heat dissipation efficiency of the containerized frequency converter.

[0010] As a further technical solution, the first cooling assembly includes a convection duct vertically disposed in the middle of the interior of the transformer chamber, a guide shroud located above the convection duct, and a duct fan disposed below the guide shroud. The duct fan is used to guide the airflow inside the convection duct to flow from bottom to top and out through the guide shroud. The transformer unit is located in the middle of the convection duct.

[0011] Based on the above technical solution, the rising hot airflow in the convection duct is accelerated and guided by the convection duct and the guide fan, so as to further realize the formation of a composite airflow movement of "natural convection + forced convection" inside the convection duct. This increases the airflow velocity in the convection duct and facilitates timely heat dissipation. The set guide hood can guide the airflow as it flows through, so as to achieve uniform airflow diffusion in all directions and form a uniform horizontal airflow layer at the top of the transformer chamber, thereby avoiding the turbulence problem of the traditional top outlet.

[0012] As a preferred technical solution, the flow guide is recessed downward to form a bowl-shaped structure. The edge of the flow guide extends to the outside of the convection duct and is provided with a downward-turned bend. The bottom edge of the bend is close to the outer edge of the convection duct and forms an outflow gap.

[0013] A double-layered chamber is formed in the upper recess of the flow guide shroud by a cover plate. Inside the double-layered chamber, a water distribution plate connected to the first circulation pipe is provided. The four edges of the water distribution plate are close to the inner wall of the double-layered chamber and have multiple drain outlets arranged at equal intervals. In the middle of the bottom of the flow guide shroud, multiple drain pipes are also provided at equal intervals. The top of the drain pipe is connected to the double-layered chamber, while the bottom is inclined away from the flow fan and connected to the microchannels in the inner wall layer of the convection duct.

[0014] In the above scheme, the lower guide surface of the flow guide is designed as a bowl-shaped structure, which facilitates the cup-shaped curved surface to guide the airflow to diffuse evenly in all directions. The outlet gap between the bend and the outer edge of the convection duct allows the airflow to flow out more evenly and form an air curtain, thereby eliminating the airflow stripping phenomenon caused by traditional planar flow guides. At the same time, the water distribution plate is used in the interlayer cavity, and through the equally distributed drain outlets, the cooling fluid in the heat dissipation tank flows through the first circulation pipe through the water distribution plate and can form a uniform liquid film to flow out through the drain outlets. This ensures that the cooling fluid forms a thin layer of flow along the surface of the bowl-shaped flow guide in the interlayer cavity, thereby ensuring a larger heat exchange area between the cooling fluid and the airflow and ultimately improving its heat exchange efficiency.

[0015] At the same time, it is important to emphasize that when the coolant is injected into the jacketed chamber through the equidistant drain outlets of the water distribution plate, the continuous liquid film formed along the inner surface of the guide shroud not only conducts convective heat exchange with the rising airflow, but also directly covers the outer surface of the exhaust fan. This allows the heat generated by the exhaust fan during operation to be absorbed and conducted through mass transfer at the solid-liquid interface, thereby preventing the heat generated by the exhaust fan from accumulating in the sealed transformer chamber during continuous operation, which would cause the temperature to rise slowly and continuously, leading to heat accumulation at the top of the transformer chamber and deterioration of the transformer unit's working environment.

[0016] The design of the drain pipe and microchannels further allows the cooling fluid to flow into the microchannels through the drain pipes, while the gas carrying heat flows out through the gaps between the drain pipes. This facilitates further heat exchange and dispersion of the gas. Simultaneously, after the cooling fluid enters the microchannels, it flows downwards through capillary action and forms a countercurrent flow contact with the upward airflow inside the convection duct. This allows the hot airflow to gradually cool as it rises, thus cooling the transformer unit inside the convection duct and improving the overall heat dissipation efficiency of the transformer chamber.

[0017] As a further preferred technical solution, the outer wall of the convection duct is circumferentially surrounded by a plurality of fins extending along its axial direction, and a flow groove is formed between adjacent fins. An inlet is also provided at the lower part of the flow groove near the bottom of the convection channel.

[0018] In the above scheme, when the induced draft fan drives the airflow in the convection duct to flow from bottom to top, the negative pressure outside the duct attracts low-temperature air from the inlet into the flow channel, forming a reverse airflow from top to bottom. This airflow exchanges heat with the hot airflow inside the duct in an orthogonal countercurrent flow. Furthermore, the circumferential fins and flow channel on the outer wall of the convection duct can increase the heat dissipation area of ​​the outer wall of the convection duct and reduce the airflow disturbance loss when the low-temperature airflow flows outside the convection duct.

[0019] A more preferred technical solution involves providing an auxiliary fan wheel at the lower interior of the convection duct. This auxiliary fan wheel promotes upward airflow within the convection duct. By using the auxiliary fan wheel, this solution enhances air convection within the convection duct, thereby improving the heat dissipation efficiency of the transformer unit.

[0020] Specifically, a vortex section is provided inside the axial air duct at the lower position corresponding to the auxiliary impeller. A wind turbine is provided inside the vortex section. The top of the wind turbine is connected to the auxiliary impeller through a transmission rod that passes through the convection air duct. A flow guide section is provided at the front position of the vortex section and is used to guide the airflow to one side blade of the wind turbine to drive the wind turbine to rotate.

[0021] The above technical solution cleverly utilizes the synergistic effect of the axial air duct, axial cooling fan and wind turbine to drive the auxiliary fan wheel in the convection air duct to rotate, so as to work together with the duct fan in the convection air duct to further promote air convection in the convection air duct, thereby improving the heat dissipation efficiency of the transformer unit.

[0022] Furthermore, the second cooling component includes water-cooled plates disposed on both sides of the inverter unit. The water-cooled plates have water-cooled channels inside, and the water-cooled channels have trapezoidal grooves along the fluid flow direction. Multiple shape memory alloy heat-conducting pillars are arrayed on the contact surface between the water-cooled plates and the inverter unit. The surface of the shape memory alloy heat-conducting pillars is coated with a graphene heat-conducting layer, and the shape memory alloy heat-conducting pillars have a deformation temperature threshold. When the shape memory alloy heat-conducting pillars reach the deformation temperature threshold, they generate memory deformation and extend into contact with the surface of the inverter unit.

[0023] It should be noted that when the frequency converter is working continuously, it will generate a lot of heat. Therefore, in this solution, the turbulence characteristics of the coolant are enhanced by the trapezoidal groove flow channel, which destroys the boundary layer heat retention effect and thus improves the overall heat transfer coefficient of the flow channel. In other words, when the cooling fluid flows through the trapezoidal groove, it will form periodic vortex turbulence, which will enhance the fluid disturbance, so as to expand the contact range between the fluid and the water-cooled flow channel wall, increase the effective heat transfer area, and further improve the heat transfer efficiency.

[0024] Meanwhile, this solution sets a shape memory alloy heat-conducting column with temperature response characteristics at the contact interface between the water-cooled plate and the frequency converter, and coats its surface with a graphene heat-conducting layer. Through the synergistic effect of dynamic adaptive contact and efficient heat conduction, it breaks through the heat conduction bottleneck of the traditional static contact interface, realizes the rapid response of the second cooling component to the dynamic heat load of the frequency converter, and ensures efficient heat dissipation of the frequency converter.

[0025] Specifically, a filling port is provided on the outside of the radiator, and an vent valve is installed on both the first and second circulation pipes. The filling port facilitates the addition of cooling fluid to the radiator by the operator, while the vent valve allows the operator to manually open it to release the gas in the first and second circulation pipes, preventing the formation of "airlocks" that would hinder the normal circulation of cooling fluid.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] 1. This invention effectively improves the heat dissipation efficiency of containerized frequency converters through a coupled heat dissipation architecture of axial air duct and convection air duct. Specifically, it integrates the heat dissipation tank and the axial cooling fan in the same fluid channel by setting the axial air duct at the bottom of the outer casing, forming a dynamic heat dissipation substrate that runs through the transformer chamber and the frequency converter chamber. That is, the airflow flows rapidly in the axial air duct, which effectively promotes the heat dissipation of the frequency converter chamber and the transformer chamber to a certain extent. Furthermore, the airflow generated by the axial cooling fan in the axial air duct can directly force convection on the surface of the heat dissipation tank, thereby further enhancing the heat dissipation efficiency of the heat dissipation tank.

[0028] 2. This invention, through the design of a flow guide shroud, guides the airflow as it passes through, achieving uniform airflow diffusion in all directions and forming a uniform horizontal airflow layer at the top of the transformer chamber. This avoids the turbulence problem of traditional top outlets. Furthermore, the lower flow guide surface of the flow guide shroud is designed as a bowl-shaped structure, facilitating the uniform diffusion of airflow in all directions. The outlet gap between the bend and the outer edge of the convection duct allows for more uniform airflow outwards, forming an air curtain to eliminate the airflow stripping phenomenon caused by traditional planar flow guide plates. Simultaneously, a water distribution plate is used within the interlayer chamber, with equally spaced drainage outlets. When the cooling fluid in the heat sink flows through the first circulation pipe and the water distribution plate, it can form a uniform liquid film through the drain outlet to ensure that the cooling fluid forms a thin layer along the surface of the bowl-shaped guide shroud in the jacketed chamber. This ensures a larger heat exchange area between the cooling fluid and the airflow, and ultimately improves its heat exchange efficiency. At the same time, it can also absorb and conduct the heat generated by the exhaust fan during operation, thereby preventing the heat generated by the exhaust fan from accumulating in the closed transformer chamber when it is working continuously, which would cause the temperature to rise slowly and continuously, resulting in heat accumulation at the top of the transformer chamber and deterioration of the transformer unit's working environment.

[0029] 3. By setting up drain pipes and microchannels, the present invention further enables the cooling fluid to flow into the microchannels through the drain pipes, while the gas carrying heat flows out through the gaps between the drain pipes. This facilitates further dispersion and heat exchange of the gas. At the same time, after the cooling fluid enters the microchannels, it flows downwards in the capillary tubes through capillary action, forming a counter-current crossflow contact with the upward airflow inside the convection duct. This allows the hot airflow to be gradually cooled during its ascent, thereby cooling the transformer unit inside the convection duct and improving the overall heat dissipation efficiency of the transformer chamber.

[0030] 4. This invention cleverly utilizes the synergistic effect of the axial air duct, axial cooling fan, and wind turbine to drive the auxiliary fan wheel in the convection air duct to rotate, working together with the ducting fan in the convection air duct to further promote air convection in the convection air duct, thereby improving the heat dissipation efficiency of the transformer unit. Specifically, when the axial cooling fan drives the airflow through the vortex section, the ducting section guides the airflow to one side of the wind turbine blades and uses the impact torque to drive the turbine to rotate, so as to synchronously drive the auxiliary fan wheel to rotate through the transmission rod, thereby forming an upward airflow in the convection air duct, which works together with the ducting fan to generate an enhanced airflow in the same direction as the ducting fan in the convection air duct, thereby realizing the rapid flow of air in the convection air duct and rapidly dissipating and conducting the heat on the surface of the transformer unit.

[0031] 5. This invention overcomes the thermal conductivity bottleneck of traditional static contact interfaces by setting a shape memory alloy heat-conducting pillar with temperature response characteristics at the contact interface between the water-cooled plate and the frequency converter, and coating its surface with a graphene heat-conducting layer. This is achieved through the synergistic effect of dynamic adaptive contact and efficient heat conduction. Specifically, when the frequency converter's temperature rises to a threshold temperature due to dynamic load fluctuations, the shape memory alloy material undergoes a martensitic phase transformation, driving the heat-conducting pillar to generate millimeter-level shape memory deformation radially. This causes the pillar to actively extend towards the device surface and approach the contact point, thereby shortening the gap at the contact interface between the water-cooled plate and the frequency converter. This also helps reduce the thermal resistance at the contact interface. At the same time, through the extension and deformation of the shape memory alloy heat-conducting pillar, it also increases the interface contact area between the water-cooling plate and the frequency converter to a certain extent. Thus, by utilizing the highly thermally conductive graphene heat-conducting layer, the surface heat of the frequency converter can be quickly conducted and diffused to the entire surface of the heat-conducting pillar. Then, through the axial heat-conducting path of the shape memory alloy pillar, it is transferred to the water-cooling channel of the water-cooling plate, thereby forming a composite heat-conducting channel of "lateral diffusion + axial conduction". This enables the second cooling component to respond quickly to the dynamic heat load of the frequency converter and ensures efficient heat dissipation of the frequency converter. Attached Figure Description

[0032] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0033] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0034] Figure 2 This is a schematic diagram of the internal structure of the outer casing of the present invention, intended to show its specific internal structure;

[0035] Figure 3 This is a schematic diagram of the convection duct structure of the present invention, intended to illustrate its specific structure;

[0036] Figure 4 This is a schematic diagram of the connection structure between the wind turbine and the auxiliary wind wheel of the present invention;

[0037] Figure 5 This is a top view of the internal structure of the axial air duct of the present invention, intended to illustrate its specific structure;

[0038] Figure 6 This is a partial structural diagram of the water-cooled plate of the present invention, intended to show the layout of its internal water-cooling channels;

[0039] Figure 7 This is a top view of the internal structure of the water-cooled plate of the present invention.

[0040] The reference numerals in the attached drawings represent: 1. Outer casing; 2. Transformer chamber; 21. Transformer unit; 3. Frequency converter chamber; 4. Axial air duct; 41. Cooling water tank; 42. Axial cooling fan; 43. Vortex section; 431. Wind turbine; 432. Air intake section; 51. Convection air duct; 511. Flow guide; 512. Bending section; 513. Sandwich chamber; 514. Water distribution tray; 515. Drain pipe; 516. Microchannel; 517. Fin; 518. Auxiliary fan wheel; 52. Water-cooled plate; 521. Water-cooled flow channel; 522. Shape memory alloy heat-conducting column; 61. First circulation pipe; 62. Second circulation pipe. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments and accompanying drawings. The illustrative embodiments and descriptions of this invention are for illustrative purposes only and are not intended to limit the invention. It should be noted that this invention is already in the actual research and development stage.

[0042] Existing containerized frequency converters with internal circulation air cooling rely excessively on a single circulation path driven by a top fan. The fixed air duct structure lacks directional airflow design for the heat spots of the transformer unit, resulting in low heat dissipation efficiency in local high-temperature areas. Furthermore, the airflow must bypass the water-cooled heat exchangers on both sides, creating a tortuous path that easily forms dead zones, exacerbating uneven heat distribution and causing heat accumulation. At the same time, the water-cooled heat exchangers are located at the top of the transformer chamber. When internal circulation air cooling is applied to the transformer chamber, only the air flowing through the bottom of the transformer chamber is cooled. As the air gradually rises in the heat dissipation air duct within the transformer chamber, it carries more and more heat, which gradually accumulates at the top of the heat dissipation air duct. Meanwhile, the heat dissipation fan is located at the top of the air duct, which lacks effective heat dissipation. Consequently, after the heat dissipation fan has been running for a long time, the heat accumulates at the top of the heat dissipation air duct and is difficult to dissipate, causing the internal temperature of the heat dissipation air duct to gradually rise, thus affecting the normal operation of the transformer unit.

[0043] Therefore, this invention proposes a new containerized frequency converter with internal circulation air cooling, which improves the performance of existing containerized frequency converters by modifying their structure; the specific method is described in the following embodiments.

[0044] Example;

[0045] Please see Figures 1 to 7As shown, this embodiment discloses a containerized frequency converter with internal circulation air cooling, including an outer casing 1. The outer casing 1 has a sealed transformer chamber 2 and a frequency converter chamber 3 inside. The transformer chamber 2 and the frequency converter chamber 3 are respectively equipped with a transformer unit 21 and a frequency converter unit. The transformer unit 21 is used to transform the external high voltage current and input it to the frequency converter unit. The frequency converter unit is used to perform frequency conversion processing on the transformed current and send it to the external load end. An axial air duct 4 is separated from the bottom of the transformer chamber and the frequency converter chamber 3 by a partition. A heat dissipation water tank 41 is provided in the axial air duct 4. The transformer chamber 2 and the frequency converter chamber 3 are respectively equipped with a first cooling component and a second cooling component. The heat dissipation water tank 41 is circulatedly connected to the first cooling component and the second cooling component through a first circulation pipe 61 and a second circulation pipe 62. An axial cooling fan 42 is also provided at one end opening of the axial air duct 4.

[0046] Based on the above embodiments, this application achieves an effective improvement in the heat dissipation efficiency of the containerized frequency converter through the coupled heat dissipation architecture of the axial air duct 4 and the convection air duct 51. Specifically, the axial air duct 4 at the bottom of the outer casing 1 integrates the heat dissipation tank 41 and the axial cooling fan 42 into the same fluid channel, forming a dynamic heat dissipation substrate that runs through the transformer chamber 2 and the frequency conversion chamber 3. That is, the airflow flows rapidly in the axial air duct 4, thereby effectively promoting the heat dissipation of the frequency conversion chamber 3 and the transformer chamber 2 to a certain extent. Furthermore, the airflow generated by the axial cooling fan 42 in the axial air duct 4 can directly force convection on the surface of the heat dissipation tank 41, thereby further enhancing the heat dissipation efficiency of the heat dissipation tank 41.

[0047] Meanwhile, in this application, the heat dissipation tank 41 is circulatedly connected to the first cooling component in the transformer chamber 2 through the first circulation pipe 61, and the heat dissipation tank 41 is circulatedly connected to the second cooling component in the frequency converter chamber 3 through the second circulation pipe 62, so as to form independent closed-loop water cooling heat dissipation channels in parallel. This optimizes the flow path of the cooling fluid in the heat dissipation tank 41, thereby avoiding mutual interference, enhancing the water cooling heat dissipation efficiency of the transformer chamber 2 and the frequency converter chamber 3, and ultimately promoting the effective improvement of the overall heat dissipation efficiency of the containerized frequency converter.

[0048] In addition to the above embodiments, it should be noted that the ends of the first circulation pipe 61 and the second circulation pipe 62 that extend to the heat sink 41 are equipped with circulation pumps, so as to pump the cooling fluid in the heat sink 41 to the first circulation pipe 61 and the second circulation pipe 62 for circulation.

[0049] For further embodiments, please refer to the following details. Figure 2The first cooling assembly includes a convection duct 51 vertically disposed in the middle of the inside of the transformer chamber 2, a guide shroud 511 located on the upper part of the convection duct 51, and a duct fan disposed on the lower part of the guide shroud 511. The duct fan is used to guide the airflow inside the convection duct 51 to flow from bottom to top and out through the guide shroud 511. The transformer unit 21 is located in the middle of the convection duct 51.

[0050] In the above embodiment, the rising hot airflow in the convection duct 51 is accelerated and guided by the convection duct 51 and the guide fan, so as to further realize the formation of a composite airflow movement of "natural convection + forced convection" inside the convection duct 51, thereby increasing the airflow velocity in the convection duct 51 and facilitating timely heat dissipation; while the guide shroud 511 can guide the airflow as it flows through, so as to achieve uniform airflow diffusion in all directions and form a uniform horizontal airflow layer at the top of the transformer chamber 2, so as to avoid the turbulence problem of the traditional top outlet.

[0051] Specifically, in this embodiment, a vertically arranged convection duct 51 inside the transformer chamber 2 forms an independent airflow channel. After the transformer unit 21 located in the middle of the convection duct 51 starts working, the heat generated by it is transferred to the upper part of the convection duct 51 through radiation and convection, and the air density is reduced, forming a natural upward trend. This forces the airflow to carry the heat upward. At the same time, a guide hood 511 is set at the top of the convection duct 51, and a guide fan is set at the lower part of the guide hood 511. After it is started, the fan will force the airflow inside the convection duct 51 to further enhance the air convection inside the convection duct 51, so as to form a composite airflow movement of "natural convection + forced convection". This will increase the airflow velocity inside the convection duct 51, which will facilitate the timely dissipation of heat. The guide hood 511 can guide the airflow to diffuse in all directions and eventually flow downward into the main airflow of the axial duct 4, thereby avoiding the turbulence problem of the traditional top outlet.

[0052] Unlike existing technologies where airflow must bypass the water-cooled heat exchangers on both sides of the duct, the convection duct 51 provides an axially direct heat dissipation channel, reducing the frictional resistance of airflow and avoiding dead zones in the corners of the chamber.

[0053] As a preferred embodiment, in Figure 2 As shown in the figure, the flow guide shroud 511 is recessed downward to form a bowl-shaped structure. The edge of the flow guide shroud 511 extends to the outside of the convection duct 51 and is provided with a downward-flipping bend 512. The bottom edge of the bend 512 is close to the outer edge of the convection duct 51 and forms an outflow gap.

[0054] A double-layered chamber 513 is formed in the upper recess of the flow guide shroud 511 by a cover plate. Inside the double-layered chamber 513, a water distribution plate 514 connected to the first circulation pipe 61 is also provided. The four edges of the water distribution plate 514 are close to the inner wall of the double-layered chamber 513 and are provided with multiple drain outlets at equal intervals. In the middle of the bottom of the flow guide shroud 511, multiple drain pipes 515 are provided at equal intervals. The top end of the drain pipe 515 is connected to the double-layered chamber 513, while the bottom end is inclined away from the flow guide fan and connected to the microchannel 516 passing through the inner wall layer of the convection duct 51.

[0055] For example, in this embodiment, the lower guide surface of the flow guide shroud 511 is designed as a bowl-shaped structure, which facilitates the bowl-shaped curved surface to guide the airflow to diffuse evenly in all directions. The outlet gap between the bent part 512 and the outer edge of the convection air duct 51 allows the airflow to flow out more evenly and form an air curtain, thereby eliminating the airflow stripping phenomenon caused by the traditional planar flow guide plate. At the same time, the water distribution plate 514 is used in the interlayer chamber 513, and through the equally distributed drain outlets, the cooling fluid in the heat dissipation tank 41 flows through the first circulation pipe 61 through the water distribution plate 514, and can form a uniform liquid film to flow out through the drain outlets. This ensures that the cooling fluid forms a thin layer of flow along the surface of the bowl-shaped flow guide shroud 511 in the interlayer chamber 513, thereby ensuring a larger heat exchange area between the cooling fluid and the airflow, and ultimately improving its heat exchange efficiency.

[0056] At the same time, it should be emphasized that when the coolant is injected into the jacketed chamber 513 through the equidistant drain ports of the water distribution plate 514, the continuous liquid film formed along the inner surface of the guide shroud 511 not only conducts convective heat exchange with the rising airflow, but also absorbs and conducts the heat generated by the induced flow fan during operation. This avoids the heat generated by the induced flow fan during continuous operation from accumulating in the sealed transformer chamber 2, causing its temperature to rise slowly and continuously, resulting in heat accumulation at the top of the transformer chamber 2, which would deteriorate the working environment of the transformer unit 21.

[0057] The arrangement of the drain pipe 515 and the microchannel 516 further allows the heat-carrying gas to flow out through the gap between the drain pipes 515 when the cooling fluid flows into the microchannel 516 through the drain pipe 515, thus facilitating further dispersion and heat exchange of the gas. At the same time, after the cooling fluid enters the microchannel 516, when it flows downward in the capillary channel through capillary action, it forms a counter-flow contact with the upward airflow inside the convection duct 51, thereby achieving gradual cooling of the hot airflow during its ascent, which in turn cools the transformer unit 21 inside the convection duct 51, thereby improving the overall heat dissipation efficiency of the transformer chamber 2.

[0058] As a further preferred embodiment, such as Figure 3As shown, the outer wall of the convection duct 51 is circumferentially surrounded by a plurality of fins 517 extending along its axial direction, and a flow groove is formed between adjacent fins 517. An inlet is also provided at the lower part of the flow groove near the bottom of the convection channel.

[0059] In the above embodiments, when the duct fan drives the airflow in the convection duct 51 from bottom to top, the negative pressure outside the duct attracts low-temperature air from the inlet into the flow groove, forming a reverse airflow from top to bottom. This airflow exchanges heat with the hot airflow inside the duct in a reverse flow. Furthermore, the circumferential fins 517 and the flow groove on the outer wall of the convection duct 51 can increase the heat dissipation area of ​​the outer wall of the convection duct 51 and reduce the airflow disturbance loss when the low-temperature airflow flows outside the convection duct 51.

[0060] As a more preferred implementation method, such as Figure 2 and Figure 4 As shown, an auxiliary fan 518 is provided at the lower part of the interior of the convection duct 51. The auxiliary fan 518 is used to promote the airflow in the convection duct 51 from bottom to top. By setting the auxiliary fan 518, this solution can further enhance the air convection in the convection duct 51 after the auxiliary fan 518 rotates, thereby improving the heat dissipation efficiency of the transformer unit 21.

[0061] Specifically, in Figure 7 As shown in the diagram, a vortex section 43 is provided inside the axial air duct 4 at a position corresponding to the lower part of the auxiliary impeller 518. A wind turbine 431 is provided inside the vortex section 43. The top of the wind turbine 431 is connected to the auxiliary impeller 518 through a transmission rod that passes through the convection air duct 51. A guide section 432 is provided at the front part of the vortex section 43 at the front part of the wind turbine 431. The guide section 432 is used to guide the airflow to one side blade of the wind turbine 431 to drive the wind turbine 431 to rotate.

[0062] As a preferred option, in order to ensure the internal circulation of the transformer chamber 2, that is, to avoid leakage caused by the gap between the transformer chamber 2 and the axial air duct 4 after the transmission rod is installed through it, which would allow external gas to enter the transformer chamber 2, it is understood that a rotating sealing ring is provided at the position where the transmission rod penetrates the transformer chamber 2.

[0063] In the above embodiment, the synergistic effect of the axial air duct 4, the axial cooling fan 42 and the wind turbine 431 is cleverly utilized to drive the auxiliary fan wheel 518 in the convection air duct 51 to rotate, so as to work together with the duct fan in the convection air duct 51 to further promote air convection in the convection air duct 51, thereby improving the heat dissipation efficiency of the transformer unit 21.

[0064] Specifically, when the axial cooling fan 42 drives the airflow through the vortex section 43, the guide section 432 guides the airflow to the blades on one side of the wind turbine 431 and uses the impact torque to drive the turbine to rotate, so as to synchronously drive the auxiliary fan wheel 518 to rotate through the transmission rod, thereby forming an upward airflow in the convection duct 51, and working together with the guide fan to generate an enhanced airflow in the same direction as the guide fan in the convection duct 51, thereby realizing the rapid flow of airflow in the convection duct 51 and rapidly dissipating and conducting the heat on the surface of the transformer unit 21.

[0065] It should be further explained that when the frequency converter is working continuously, it will generate a lot of heat. When the water-cooled plate 52 of the existing frequency converter is close to the frequency converter for water cooling heat exchange, its contact area is fixed. Therefore, its heat conduction efficiency depends more on the flow rate of the cooling fluid in the water-cooled plate 52. If the flow rate is constant, when the frequency converter increases its instantaneous operating power, the large amount of heat generated is difficult to be conducted and dissipated by the water-cooled plate 52 in time. In other words, under the dynamic load of the frequency converter, its heat conduction efficiency is lagging, which affects its normal operation and limits its performance.

[0066] Therefore, in the embodiments, it is preferred that, please refer to further details. Figure 2 and Figure 7 The second cooling component includes water-cooled plates 52 disposed on both sides of the inverter unit. Water-cooled channels 521 are formed inside the water-cooled plates 52, and trapezoidal grooves are formed in the water-cooled channels 521 along the fluid flow direction. Multiple shape memory alloy heat-conducting pillars 522 are arrayed on the contact surface between the water-cooled plates 52 and the inverter unit. The surface of the shape memory alloy heat-conducting pillars is coated with a graphene heat-conducting layer, and the shape memory alloy heat-conducting pillars 522 have a deformation temperature threshold. When the shape memory alloy heat-conducting pillars 522 reach the deformation temperature threshold, they generate shape memory deformation and extend to contact the surface of the inverter unit.

[0067] In the above embodiment, the turbulent characteristics of the coolant are enhanced by the trapezoidal groove flow channel, which destroys the boundary layer heat retention effect and thus improves the overall heat transfer coefficient of the flow channel. That is to say, when the cooling fluid flows through the trapezoidal groove, it will form periodic vortex turbulence, thereby strengthening the fluid disturbance, so as to expand the contact range between the fluid and the wall of the water-cooled flow channel 521, increase the effective heat transfer area, and further improve the heat transfer efficiency.

[0068] Meanwhile, in this embodiment, a shape memory alloy heat-conducting pillar 522 with temperature response characteristics is set at the contact interface between the water-cooled plate 52 and the frequency converter unit, and a graphene heat-conducting layer is coated on its surface. Through the synergistic effect of dynamic adaptive contact and efficient heat conduction, the heat conduction bottleneck of the traditional static contact interface is broken through. Specifically, when the temperature of the frequency converter unit rises to the temperature threshold (e.g., 70°C) due to dynamic load fluctuations, the shape memory alloy material undergoes a martensitic phase transformation, driving the heat-conducting pillar to generate millimeter-level shape memory deformation in the radial direction. It actively extends towards the device surface and approaches the contact, thereby shortening the gap at the contact interface between the water-cooled plate 52 and the frequency converter unit, and helping to reduce the contact interface size. Thermal resistance (after finite element analysis, its interface thermal resistance is reduced by more than 40%); at the same time, through the extension and deformation of the shape memory alloy heat-conducting column 522, it also increases the interface contact area between the water-cooling plate 52 and the frequency converter to a certain extent. Thus, by utilizing the highly thermally conductive graphene heat-conducting layer, the surface heat of the frequency converter is quickly conducted and diffused to the entire surface of the heat-conducting column, and then transferred to the water-cooling channel 521 of the water-cooling plate 52 through the axial heat-conducting path of the shape memory alloy column, thereby forming a composite heat-conducting channel of "lateral diffusion + axial conduction", realizing the rapid response of the second cooling component to the dynamic heat load of the frequency converter, and ensuring efficient heat dissipation of the frequency converter.

[0069] As a further preferred embodiment of the water-cooled channel 521 in the above embodiments, the water-cooled channel 521 is distributed in an approximately "S" shape in the water-cooled plate 52, such as... Figure 6 As shown, this facilitates extending the flow path of the water-cooled fluid in the water-cooled plate 52, thereby ensuring that the water-cooled fluid can fully exchange heat with the frequency converter unit when flowing through the water-cooled plate 52.

[0070] In the above embodiment, as not shown in the figure, a filling port is also provided on the outside of the heat dissipation tank 41, and an exhaust valve is installed on both the first circulation pipe 61 and the second circulation pipe 62. The filling port facilitates the addition of cooling fluid to the heat dissipation tank 41 by the operator, while the exhaust valve allows the operator to manually open it to release the gas in the first circulation pipe 61 and the second circulation pipe 62, preventing the formation of "air locks" and thus avoiding obstruction of the normal circulation of cooling fluid.

[0071] As a further preferred embodiment of the above embodiments, not shown in the figure, a plurality of heat dissipation fins are provided on the outside of the heat dissipation tank 41 along its axial direction; so as to facilitate the rapid dissipation of cooling fluid circulating in the heat dissipation tank 41 through the heat dissipation fins.

[0072] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0073] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are all schematic diagrams, intended only to complement the content disclosed in the specification and to facilitate understanding and reading by those skilled in the art. They are not intended to limit the conditions under which the invention can be implemented and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by the invention, should still fall within the scope of the technical content disclosed in the invention. Furthermore, the terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

Claims

1. A containerized frequency converter with internal circulation air cooling, comprising an outer casing (1), wherein the outer casing (1) is provided with a sealed transformer chamber (2) and a frequency converter chamber (3), wherein the transformer chamber (2) and the frequency converter chamber (3) are respectively provided with a transformer unit (21) and a frequency converter unit, wherein the transformer unit (21) is used to transform an external high-voltage current and input it to the frequency converter unit, and the frequency converter unit is used to perform frequency conversion processing on the transformed current and then transmit it to the external load terminal, characterized in that, An axial air duct (4) is separated from the bottom of the transformer chamber and the frequency converter chamber (3) by a partition. A heat dissipation water tank (41) is provided in the axial air duct (4). A first cooling component and a second cooling component are respectively provided inside the transformer chamber (2) and the frequency converter chamber (3). The heat dissipation water tank (41) is circulated with the first cooling component and the second cooling component through a first circulation pipe (61) and a second circulation pipe (62). An axial cooling fan (42) is also provided at one end opening of the axial air duct (4). The first cooling assembly includes a convection duct (51) vertically disposed in the middle of the inside of the transformer chamber (2), a guide shroud (511) located on the upper part of the convection duct (51), and a duct fan disposed on the lower part of the guide shroud (511). The duct fan is used to guide the airflow inside the convection duct (51) to flow from bottom to top and out through the guide shroud (511). The transformer unit (21) is located in the middle of the convection duct (51). The flow guide shroud (511) is recessed downward to form a bowl-shaped structure. The edge of the flow guide shroud (511) extends to the outside of the convection duct (51) and is provided with a downward-turned bend (512). The bottom edge of the bend (512) is close to the outer edge of the convection duct (51) and forms an outflow gap.

2. A containerized frequency converter with internal circulation air cooling according to claim 1, characterized in that, A sandwich chamber (513) is formed by a cover plate in the upper recess of the flow guide (511). Inside the sandwich chamber (513), a water distribution plate (514) connected to the first circulation pipe (61) is also provided. The four edges of the water distribution plate (514) are close to the inner wall of the sandwich chamber (513) and multiple drain ports are provided at equal intervals. Multiple drain pipes (515) are provided at equal intervals in the middle of the bottom of the flow guide (511). The top of the drain pipe (515) is connected to the sandwich chamber (513), and the bottom is inclined in the direction away from the flow guide fan and connected to the microchannel (516) passing through the inner wall layer of the convection duct (51).

3. A containerized frequency converter with internal circulation air cooling according to claim 2, characterized in that, The outer wall of the convection duct (51) is provided with a plurality of fins (517) extending along its axial direction, and a flow groove is formed between adjacent fins (517). An inlet is also provided at the lower part of the flow groove near the bottom of the convection channel.

4. A containerized frequency converter with internal circulation air cooling according to claim 1, characterized in that, An auxiliary impeller (518) is provided at the bottom inside the convection duct (51), which is used to cause the airflow in the convection duct (51) to flow from bottom to top.

5. A containerized frequency converter with internal circulation air cooling according to claim 4, characterized in that, Inside the axial air duct (4), at the lower position corresponding to the auxiliary impeller (518), there is also a vortex section (43). Inside the vortex section (43), there is a wind turbine (431). The top of the wind turbine (431) is connected to the auxiliary impeller (518) through a transmission rod that passes through the convection air duct (51). The vortex section (43) is located at the front position of the wind turbine (431) and has a guide section (432). The guide section (432) is used to guide the airflow to one side blade of the wind turbine (431) to drive the wind turbine (431) to rotate.

6. A containerized frequency converter with internal circulation air cooling according to claim 1, characterized in that, The second cooling component includes water-cooled plates (52) disposed on both sides of the frequency converter unit. Water-cooled channels (521) are provided inside the water-cooled plates (52), and trapezoidal grooves are provided in the water-cooled channels (521) along the fluid flow direction. Multiple shape memory alloy heat-conducting columns (522) are arranged in an array on the contact surface between the water-cooled plates (52) and the frequency converter unit. The surface of the shape memory alloy heat-conducting columns is coated with a graphene heat-conducting layer, and the shape memory alloy heat-conducting columns (522) have a deformation temperature threshold. When the shape memory alloy heat-conducting columns (522) reach the deformation temperature threshold, they generate shape memory deformation and extend to contact the surface of the frequency converter unit.

7. A containerized frequency converter with internal circulation air cooling according to claim 1, characterized in that, An inlet is provided on the outside of the heat dissipation tank (41), and an exhaust valve is installed on both the first circulation pipe (61) and the second circulation pipe (62).

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