Dual cooling technology combining phase change refrigeration and spraying liquid cooling

Abstract

The invention relates to the technical field of motor cooling, in particular to a dual cooling technology combining phase change refrigeration and spraying liquid cooling. And efficient cooling of the motor is realized through a dual heat dissipation mechanism of phase-change cooling of the refrigerant and spraying of the heat-conducting oil. After being compressed by an external compressor unit, a refrigerant cools a stator core and a coil through double capillary tube bundles which are arranged in a reverse S shape; meanwhile, the heat conduction oil is driven by the oil pump to be sprayed to the surface of the stator, is recycled through the oil collecting box and then exchanges heat with residual cooling capacity in the cooling pipeline, and circulation is formed. The high efficiency of refrigerant phase change cooling and the uniform heat dissipation characteristic of heat conduction oil liquid cooling are integrated, the heat management problem of the high-power-density motor under the high-temperature working condition is solved, the operation reliability of the motor is remarkably improved, and the service life of the motor is remarkably prolonged.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor cooling, and in particular relates to a dual cooling technology combining phase change refrigeration and spray liquid cooling. Background Art

[0002] In the context of the rapid development of modern industry and technology, motors, as core power components, play an indispensable role in many fields. From machine tool drives and ventilation systems in traditional manufacturing to electric vehicles and rail transportation in the transportation field, and high-end equipment such as aerospace, ships and warships, motors are used everywhere. As the requirements for equipment performance and energy efficiency in various industries continue to rise, motors are continuing to evolve towards high power density, high speed and high load.

[0003] Traditional motor cooling technologies, such as single liquid cooling or air cooling, have many difficult-to-overcome problems when dealing with the large amount of heat generated by current high-power density motors. Although air cooling technology has a simple structure and low cost, its heat dissipation efficiency is relatively low. Under high-speed and high-load conditions, the heat dissipation capacity of air is far from meeting the needs of rapid heat dissipation of the motor, causing the motor temperature to rise rapidly, which in turn affects the motor performance. Although the cooling effect of single liquid cooling technology is better than that of air cooling, it also has obvious defects. It is difficult to achieve uniform flow distribution of the cooling medium inside the motor, which can easily cause uneven heat dissipation in various parts of the motor and prominent local overheating problems. For example, in key parts such as the stator core and windings of the motor, heat is easily accumulated due to poor flow or insufficient flow of the cooling medium, which accelerates the aging of the insulation material and reduces the service life and reliability of the motor.

[0004] Under extreme conditions of high speed and high load, the stator core and winding will generate a lot of heat. If this heat cannot be dissipated in a timely and effective manner, it will continue to accumulate inside the motor, causing a series of serious consequences. Excessive temperature will accelerate the aging of the motor's insulation materials, causing its insulation performance to gradually decline, and increase the risk of motor short circuit failure. At the same time, thermal expansion will cause the deformation of motor parts, destroy the mechanical structure accuracy of the motor, affect the normal operation of the motor, and may even cause equipment damage, resulting in huge economic losses.

[0005] In the prior art, the refrigerant phase change cooling technology has received some attention in the field of motor cooling due to its high cooling efficiency. The refrigerant can absorb a large amount of heat during the phase change process, thereby quickly reducing the temperature of the motor. However, the internal structure of the motor is complex, and there are many difficult-to-reach areas, making it difficult for the refrigerant to fully cover the entire motor and evenly cool the entire motor, and the heat dissipation effect in some areas is poor. For example, in some motors with complex winding structures, it is difficult for the refrigerant to fully contact every heating part, resulting in the problem of local overheating.

[0006] The spray liquid cooling technology realizes the heat dissipation of the motor by spraying the cooling medium onto the motor surface. It can cover the motor surface relatively evenly, take away heat, and solve the problem of heat dissipation uniformity to a certain extent. However, the spray liquid cooling technology relies on a single cooling medium. As the heat of the motor continuously generates, the cooling medium is prone to reach the thermal saturation state, and the heat dissipation capacity will gradually decline, unable to continuously and effectively dissipate heat for the motor. For example, in a motor running at high load for a long time, the cooling medium of the spray liquid cooling system will increase in temperature due to absorbing too much heat, and the heat dissipation effect will gradually become worse. In summary, the traditional single cooling technology can no longer meet the heat dissipation requirements of high-power density motors under complex working conditions. In summary, the traditional single cooling technology can no longer meet the heat dissipation requirements of high-power density motors under complex working conditions. Summary of the Invention

[0007] Aiming at the deficiencies of the above-mentioned existing technologies, the present invention proposes a dual cooling technology combining phase change refrigeration and spray liquid cooling. Through the dual heat dissipation mechanisms of the phase change cooling of the refrigerant and the spray of the heat-conducting oil, the efficient cooling of the motor is realized.

[0008] To achieve the above technical objectives, the technical solution of the present invention is as follows:

[0009] A dual cooling technology combining phase change refrigeration and spray liquid cooling, characterized in that: it combines the phase change cooling of the refrigerant and the spray liquid cooling of the heat-conducting oil to achieve dual collaborative heat dissipation; in the refrigerant cooling system, the refrigerant is compressed by the compressor and then flows through the expansion valve for throttling and pressure reduction to become a low-temperature misty refrigerant, and enters the internal cooling pipeline of the stator. The cooling pipeline is divided into two paths, one of which is distributed in a counterclockwise S shape along the circumference, and the other is distributed clockwise. The two paths surround the stator and then converge and flow out. After absorbing the heat of the stator core and the coil, it vaporizes and returns to the compressor to form a closed-loop cycle; at the same time, the heat-conducting oil cooling system sprays the heat-conducting oil onto the stator surface through the drive of the oil pump, covers the core and the coil and absorbs heat, and then flows through the gap between the stator and the cooling pipeline to the oil sump at the lower part of the motor, and exchanges heat with the refrigerant pipeline surrounding the inner wall of the oil sump, that is, the residual cold quantity section, for cooling. The cooled heat-conducting oil is sprayed onto the stator again by the drive of the oil pump to form a cycle; in the collaborative cooling structure, the heat-conducting oil fills the gap between the cooling pipeline and the stator, which not only serves as a heat-conducting medium to improve the heat exchange efficiency, but also has a lubricating function.

[0010] Further, the cooling pipeline adopts a capillary bundle, and the capillary bundle is combined by multiple capillary tubes.

[0011] Further, the capillary bundle of the refrigerant cooling system adopts a double-bundle reverse S-shaped arrangement, including one of the following arrangement methods:

[0012] The first one: The cooling pipeline is closely attached to the circumferential surface of the outer side of the stator core and spirally arranged along the circumference from one axial side of the stator core to the opposite axial side;

[0013] The second type: The cooling pipeline is arranged in the axial dedicated cooling channels opened on the outer circumferential surface of the stator core, and is arranged in a double-beam reverse S shape.

[0014] The third type: The cooling pipeline is arranged along the axial cooling channels specially opened between the stator slots and the circumferential surface, and is arranged in a double-beam reverse S shape.

[0015] The fourth type: The cooling pipeline and the copper wire are arranged together in the stator slot in a double-beam reverse S shape.

[0016] Furthermore, the way the refrigerant flows out of the stator is related to the above arrangement. For the first type, the refrigerant spirally surrounds the stator side and then flows out of the stator. For the second and third types, the refrigerant flows out of the stator after surrounding the stator once in the axial dedicated cooling channels. For the fourth type, the refrigerant flows out of the stator after circulating once in the stator slot.

[0017] Furthermore, for the fourth type of cooling pipeline winding method, the copper wire and the cooling circuit are bundled into a single pipeline. The copper wire surrounds the outside of the cooling circuit, and the copper wire cooling wire bundle is arranged along the stator slot together, tightly wrapping the outside of the cooling pipeline, forming a mechanical support structure that can enhance the anti-vibration strength of the lines in the stator slot, and at the same time increasing the heat conduction contact area between the copper wire and the cooling pipeline.

[0018] Furthermore, the oil collecting box is arranged at the lower part of the motor, and the cooling pipeline is integrated inside, which is used to cool the heat-conducting oil by using the residual cold of the refrigerant, and drive the heat-conducting oil to circulate and spray through an oil pump.

[0019] Furthermore, the heat-conducting oil has three functions:

[0020] Function 1: As the heat-conducting medium between the refrigerant pipeline and the stator;

[0021] Function 2: Directly cool the stator surface by spraying;

[0022] Function 3: Provide lubrication inside the motor.

[0023] Furthermore, it includes an external refrigeration cycle and an external heat-conducting oil cycle. Among them, the external refrigeration cycle includes a compressor, a condenser, a liquid storage and dryer, an expansion valve, and the internal cooling pipeline of the stator; the external heat-conducting oil cycle includes an oil pump, a spraying device, and an oil collecting box.

[0024] Furthermore, the refrigerant phase change cooling system includes a compressor, a condenser, a liquid storage dryer, an expansion valve, a refrigerant flow pipeline and a cooling pipeline arranged inside the motor, and the thermal oil spray cooling system includes an oil collecting box, a lubricating oil pump and a lubricating oil flow pipeline.; wherein the cooling capacity distribution ratio of the refrigerant phase change cooling system and the thermal oil spray cooling system is 8:2, that is, the refrigerant in the cooling pipeline inside the motor bears 80% of the total heat dissipation of the motor, and the thermal oil utilizes the residual cooling capacity of the refrigerant to bear 20%, and the residual cooling capacity is secondary utilized by the refrigerant pipeline surrounding the inner wall of the oil collecting box.

[0025] Compared with the prior art, the present invention adopts the above technical solution and has the following beneficial effects:

[0026] (1) The present invention combines refrigerant phase change cooling with thermal oil spray liquid cooling, and significantly improves the motor cooling effect through a dual synergistic heat dissipation mechanism. The refrigerant efficiently absorbs the heat of the stator core through phase change, solving the heat dissipation bottleneck under high power density; the thermal oil spray covers the stator surface and fills the gap, which not only dissipates heat evenly but also serves as a lubricating medium, eliminates local heat accumulation and reduces mechanical loss, breaking through the limitations of a single cooling method.

[0027] (2) In terms of structural design, the double-bundle reverse S-shaped capillary tube bundle is axially spirally distributed to ensure uniform flow of refrigerant and expand the heat exchange area to avoid local overheating; the oil collecting box uses the residual cold of the refrigerant to passively cool the thermal oil and improve energy utilization. The copper wire and tube bundle in the stator slot are arranged in the same slot, which optimizes the thermal contact while enhancing the mechanical strength, realizing the integration of structure and heat dissipation function.

[0028] (3) This technology is suitable for high-load and high-temperature working conditions, effectively solving the problem of stator heat accumulation, reducing the risk of insulation aging and thermal deformation, and improving the reliability and life of the motor. The system has high system integration and compact structure, providing an efficient and practical thermal management solution for high-power density motors. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 It is a specific flow chart of a dual cooling technology combining phase change refrigeration and spray liquid cooling proposed by the present invention;

[0031] Figure 2 It is a flowchart of the present invention;

[0032] Figure 3 This is the front view of the oil collecting box;

[0033] Figure 4 It is the top view of the oil collecting box;

[0034] Figure 5 It is the positive three - axis isometric view of the oil collecting box;

[0035] Figure 6 It is the layout diagram of the spiral cooling pipeline;

[0036] Figure 7 It is the layout diagram of the cooling pipeline for the external slots of the stator;

[0037] Figure 8 It is the layout diagram of the cooling pipeline for the internal slots of the stator;

[0038] Figure 9 It is the co - layout of the cooling pipeline in the stator slot and the copper wire;

[0039] Figure 10 It is the schematic diagram of the layout of the copper wire and the cooling pipeline;

[0040] In the figure: 1. Outlet of the refrigerant oil collecting box; 2. Outlet of the heat - conducting oil collecting box; 3. Oil collecting box; 4. Refrigerant loop; 5. Generator stator; 6. Stator slot; 7. External slots of the stator; 8. Forward inlet of the cooling capillary bundle; 9. Forward outlet of the cooling capillary bundle of the pipeline; 10. Reverse inlet of the cooling capillary bundle; 11. Reverse outlet of the cooling capillary bundle; 12. Inlet of the capillary cooling bundle of the stator winding; 13. Outlet of the capillary cooling bundle of the stator winding; 14. Stator winding; 15. Copper wire of the stator winding; 16. Capillary cooling pipeline. Specific implementation manner

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this application without creative efforts shall fall within the scope of protection of this application.

[0042] The present invention provides a dual cooling technology combining phase change refrigeration and spray liquid cooling, which realizes dual collaborative heat dissipation by combining refrigerant phase change cooling and heat transfer oil spray liquid cooling. In the refrigerant cooling system, the refrigerant is compressed by a compressor and then throttled and depressurized by an expansion valve into a low-temperature fog-like refrigerant, which enters the internal cooling pipeline of the stator. The cooling pipeline is divided into two paths, one of which is distributed in a counterclockwise S shape along the circumference, and the other is distributed clockwise. The two paths surround the stator and then converge and flow out. After absorbing the heat of the stator core and coil, it vaporizes and returns to the compressor to form a closed-loop cycle. At the same time, the heat transfer oil cooling system sprays the heat transfer oil onto the surface of the stator driven by an oil pump, covering the core and coil and absorbing heat. Then, it flows through the gap between the stator and the cooling pipeline to the oil sump at the lower part of the motor, and exchanges heat with the refrigerant pipeline, that is, the residual cold section, surrounding the inner wall of the oil sump to cool down. The cooled heat transfer oil is sprayed onto the stator again driven by the oil pump to form a cycle. In the collaborative cooling structure, the heat transfer oil fills the gap between the cooling pipeline and the stator, which not only serves as a heat transfer medium to improve the heat exchange efficiency but also has a lubricating function.

[0043] Further, the cooling pipeline adopts a capillary bundle, which is combined by multiple capillaries.

[0044] Further, the capillary bundle of the refrigerant cooling system adopts a double-bundle reverse S-shaped arrangement, including one of the following arrangement methods:

[0045] The first method: The cooling pipeline is closely attached to the circumferential surface of the outer side of the stator core and spirally arranged along the circumference from one axial side of the stator core to the opposite axial side.

[0046] The second method: The cooling pipeline is arranged in the axial special cooling channels opened on the circumferential surface of the outer side of the stator core and arranged in a double-bundle reverse S shape.

[0047] The third method: The cooling pipeline is arranged in the axial cooling channels specially opened between the stator slots and the circumferential surface and arranged in a double-bundle reverse S shape.

[0048] The fourth method: The cooling pipeline and the copper wire are arranged together in the stator slots in a double-bundle reverse S shape.

[0049] Further, the way the refrigerant flows out of the stator is related to the arrangement method. In the second and third methods, the refrigerant flows out of the stator after surrounding the stator for one week, and in the fourth method, the refrigerant flows out of the stator after circulating for one week in the stator slots.

[0050] Further, in the fourth cooling pipeline winding method, the copper wire and the cooling circuit are gathered into a bundle of pipelines, the copper wire surrounds the outside of the cooling circuit, and the copper wire cooling wire bundle is arranged along the stator slots together, tightly wrapping the outside of the cooling pipeline, forming a mechanical support structure that can enhance the anti-vibration strength of the lines in the stator slots, and at the same time increasing the heat conduction contact area between the copper wire and the cooling pipeline.

[0051] Furthermore, the oil collecting box is arranged below the motor and integrates a cooling pipeline inside, which is used to cool the heat-conducting oil by using the residual cold of the refrigerant and drive the heat-conducting oil to circulate and spray through an oil pump.

[0052] Furthermore, the heat-conducting oil has three functions:

[0053] Function 1: As a heat-conducting medium between the refrigerant pipeline and the stator;

[0054] Function 2: Directly cool the stator surface by spraying;

[0055] Function 3: Provide lubrication inside the motor.

[0056] Furthermore, it includes an external refrigeration cycle and an external heat-conducting oil cycle; among them, the external refrigeration cycle includes a compressor, a condenser, a liquid storage dryer, an expansion valve, and an internal cooling pipeline of the stator; the external heat-conducting oil cycle includes an oil pump, a spraying device, and an oil collecting box.

[0057] Furthermore, the refrigerant phase change cooling system includes a compressor, a condenser, a liquid storage dryer, an expansion valve, a refrigerant flow pipeline, and a cooling pipeline arranged inside the motor, and the heat-conducting oil spraying cooling system includes an oil collecting box, a lubricating oil pump, and a lubricating oil flow pipeline.; The cold quantity distribution ratio between the refrigerant phase change cooling system and the heat-conducting oil spraying cooling system is 8:2, that is, the refrigerant in the internal cooling pipeline of the motor bears 80% of the total heat dissipation of the motor, and the heat-conducting oil uses the residual cold of the refrigerant to bear 20%, and the secondary utilization of the residual cold is realized through the refrigerant pipeline surrounding the inner wall of the oil collecting box.

[0058] The above content of the present invention will be further described in detail below in the form of embodiments, but it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments. All technologies implemented based on the above content of the present invention belong to the scope of the present invention.

[0059] Embodiment 1:

[0060] The refrigerant is compressed into a high-pressure gas by the compressor, condensed, depressurized into a low-temperature mist by the expansion valve, and enters the double-beam reverse S-shaped capillary bundle in the stator slot. After the refrigerant absorbs the stator heat, it vaporizes and returns to the compressor for circulation. At the same time, the heat-conducting oil is driven by the oil pump to spray onto the stator surface, absorbs heat and flows into the oil collecting box, exchanges heat with the refrigerant pipeline surrounding the inner wall of the oil collecting box to cool down, and then circulates and sprays again.

[0061] The beneficial effect of Embodiment 1 is that by adopting double cooling of the cooling loop and the heat-conducting oil, compared with the traditional motor cooling method, the cooling efficiency is improved. While the heat-conducting oil cools the motor, it acts as a cooling medium between the cooling loop and the motor stator core, and also improves the heat exchange efficiency.

[0062] Embodiment 2:

[0063] According to the maximum heat generation of the motor under the extreme working state, an external compression cooling device is selected. The refrigerating capacity of the compression cooling device is equal to the extreme heat generation of the motor. The refrigerant pipeline wound around the motor stator first uses a part of the refrigerating capacity to dissipate heat from the motor stator, and then the cooling loop in the oil collecting box uses the remaining cold quantity to cool the heat-conducting oil.

[0064] The beneficial effects of Embodiment 2 are as follows: According to the extreme heat generation of the motor, a refrigeration unit is selected so that the refrigerating capacity of the refrigeration unit covers the heat generation of the motor, thereby ensuring that the generator can dissipate heat sufficiently during operation. When the motor is at the rated speed, the stator iron loss and winding loss are the main heat sources. The stator iron loss accounts for 50% to 60% of the total loss, and the winding loss accounts for 30% to 40% of the total loss. During the motor cooling process, the stator cooling pipeline inside the motor undertakes 80% of the heat dissipation. After the cooling pipeline flows out of the motor, the remaining cold quantity is used to cool the heat-conducting oil in the oil collecting box. The heat-conducting oil is driven by an oil pump to enter the motor again to cool the inside of the motor, and the heat-conducting oil cooling cycle undertakes 20% of the heat generation.

[0065] Embodiment 3:

[0066] After the cooling pipeline compresses and cools the refrigerant, the generated cold quantity has two uses: one is to cool the stator core inside the motor; the other is to use the remaining cold quantity after flowing out of the motor to cool the stator core of the motor, and then cool the heat-conducting oil that has just flowed out of the motor in the oil collecting box again.

[0067] The beneficial effects of Embodiment 3 are as follows: The cold quantity generated by the compression refrigeration cycle is fully utilized, improving the energy utilization efficiency. The cold quantity unused by the cooling pipeline inside the motor is used to cool the heat-conducting oil in the oil collecting box, enabling the cold quantity generated by the compressor to be fully utilized.

[0068] It should be noted that in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0069] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A dual cooling technology combining phase change refrigeration and spray liquid cooling, characterized in that: Combined with refrigerant phase change cooling and heat transfer oil spray liquid cooling, dual collaborative heat dissipation is achieved; in the refrigerant cooling system, the refrigerant is compressed by the compressor and then flows through the expansion valve to throttle down to a low-temperature misty refrigerant, which enters the internal cooling pipeline of the stator. The cooling pipeline is divided into two paths. One path is distributed in a counterclockwise S shape along the circumference, and the other path is distributed clockwise. The two paths surround the stator and then converge and flow out. After absorbing the heat of the stator core and coil, it vaporizes and returns to the compressor to form a closed-loop cycle. At the same time, the heat transfer oil cooling system sprays the heat transfer oil onto the surface of the stator through the drive of the oil pump, covering the core and coil and absorbing heat. Then it flows through the gap between the stator and the cooling pipeline to the oil sump at the lower part of the motor, and exchanges heat with the refrigerant pipeline, that is, the residual cold section, surrounding the inner wall of the oil sump to cool down. The cooled heat transfer oil is sprayed onto the stator again by the drive of the oil pump to form a cycle. In the collaborative cooling structure, the heat transfer oil fills the gap between the cooling pipeline and the stator, serving both as a heat transfer medium to improve the heat transfer efficiency and having a lubricating function.

2. A dual cooling technology combining phase change refrigeration and spray liquid cooling according to claim 1, characterized in that: The cooling pipeline adopts a capillary bundle, which is combined by multiple capillaries.

3. A dual cooling technology combining phase change refrigeration and spray liquid cooling according to claim 1, characterized in that: The capillary bundle of the refrigerant cooling system adopts a double-bundle reverse S-shaped arrangement, including one of the following arrangement methods: The first one: The cooling pipeline is closely attached to the outer circumferential surface of the stator core and spirally arranged along the circumference from one axial side of the stator core to the opposite axial side. The second one: The cooling pipeline is arranged in the axial dedicated cooling channels opened on the outer circumferential surface of the stator core and arranged in a double-bundle reverse S shape. The third one: The cooling pipeline is arranged along the axial cooling channels specially opened between the stator slots and the circumferential surface and arranged in a double-bundle reverse S shape. The fourth one: The cooling pipeline and the copper wire are arranged together in the stator slot in a double-bundle reverse S shape.

4. A dual cooling technology combining phase change refrigeration and spray liquid cooling according to claim 1, characterized in that: The way the refrigerant flows out of the stator is related to the arrangement method. For the first one, the refrigerant spirally surrounds the stator side and then flows out of the stator. For the second and third ones, the refrigerant flows out of the stator after surrounding the stator once in the axial dedicated cooling channels. For the fourth one, the refrigerant flows out of the stator after circulating once in the stator slot.

5. The arrangement of the capillary tube bundles according to the dual cooling technology combining phase change refrigeration and spray liquid cooling according to claim 3 is characterized in that: In the fourth cooling pipeline winding method, the copper wire and the cooling line are bundled into a single pipeline. The copper wire surrounds the outside of the cooling line. The copper wire cooling wire bundle is arranged along the stator slot together, tightly wrapping the outside of the cooling pipeline, forming a mechanical support structure that can enhance the anti-vibration strength of the lines in the stator slot, and at the same time increasing the heat transfer contact area between the copper wire and the cooling pipeline.

6. A dual cooling technology combining phase change refrigeration and spray liquid cooling according to claim 1, characterized in that: The oil sump is arranged at the lower part of the motor and integrates the cooling pipeline inside, which is used to cool the heat transfer oil by using the residual cold of the refrigerant and drive the heat transfer oil to circulate and spray through the oil pump.

7. A dual cooling technology combining phase change refrigeration and spray liquid cooling according to claim 1, characterized in that: The heat transfer oil has three functions: Function one: As the heat transfer medium between the refrigerant pipeline and the stator. Function two: Directly cool the surface of the stator by spraying. Function three: Provide lubrication inside the motor.

8. A dual cooling technology combining phase change refrigeration and spray liquid cooling according to claim 1, characterized in that: It includes an external refrigeration cycle and an external heat transfer oil cycle. Among them, the external refrigeration cycle includes a compressor, a condenser, a liquid storage dryer, an expansion valve, and the internal cooling pipeline of the stator. The external heat transfer oil cycle includes an oil pump, a spraying device, and an oil sump.

9. A dual cooling technology combining phase change refrigeration and spray liquid cooling according to claim 1, characterized in that: The refrigerant phase change cooling system includes a compressor, a condenser, a liquid receiver dryer, an expansion valve, refrigerant flow pipelines, and cooling pipelines arranged inside the motor. The heat transfer oil spray cooling system includes an oil sump, a lubricating oil pump, and lubricating oil flow pipelines. Among them, the cooling capacity distribution ratio of the refrigerant phase change cooling system to the heat transfer oil spray cooling system is 8:2, that is, the refrigerant in the cooling pipelines inside the motor bears 80% of the total heat dissipation of the motor, and the heat transfer oil uses the residual cooling capacity of the refrigerant to bear 20%. The secondary utilization of the residual cooling capacity is achieved through the refrigerant pipeline surrounding the inner wall of the oil sump.

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