Electronic expansion valve and thermal management system

By adjusting the valve port channel size ratio of the electronic expansion valve, especially the inner diameter ratio of the throttling section and the fluid outlet section, the problem of fluid noise in the air conditioning system was solved, resulting in lower acoustic resonance and whistling noise, and improving the quietness of the air conditioning system.

CN121953545APending Publication Date: 2026-05-01HANGZHOU SANHUA RES INST CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
HANGZHOU SANHUA RES INST CO LTD
Filing Date
2024-10-18
Publication Date
2026-05-01

AI Technical Summary

Technical Problem

Existing electronic expansion valves have many noise problems in air conditioning systems, especially fluid noise, and particularly the whistling sound is difficult to reduce effectively.

Method used

By adjusting the size ratio of the valve port passage, especially the inner diameter ratio of the throttling section and the fluid outlet section k=L/D≤0.2, the vibration frequency of the fluid flowing in the valve port passage can be adjusted to reduce acoustic resonance and whistling sound.

Benefits of technology

It effectively reduces the acoustic resonance and whistling noise of the electronic expansion valve, improving the quietness of the air conditioning system.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention provides an electronic expansion valve which comprises a valve port channel, the valve port channel comprises a throttling section and a fluid leading-out section, the electronic expansion valve is provided with a valve cavity, the wall forming the valve cavity comprises a bottom wall face, the distance between the junction point of the wall forming the throttling section and the wall forming the fluid leading-out section and the bottom wall face is L, the minimum inner diameter of the throttling section is D, k is defined to be equal to L / D, and k is larger than 0 and smaller than or equal to 0.2. According to the electronic expansion valve, by adjusting the size of the valve port channel, the vibration frequency generated when the fluid flows in the valve port channel can be adjusted, and therefore the resonance phenomenon generated when the fluid flows through the valve port channel can be reduced, and noise of acoustic resonance of the electronic expansion valve is reduced.
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Description

Electronic expansion valve and thermal management system Technical Field

[0001] This application relates to the field of thermal management technology, and in particular to an electronic expansion valve and a thermal management system for household air conditioners. Background Technology

[0002] As people's demands for quality of life increase, their requirements for air conditioning noise are also rising, especially indoor noise. This noise is directly received by indoor users and seriously affects their normal rest and comfort. Electronic expansion valves, due to their compact structure and high control precision, are widely used in air conditioning thermal management systems, particularly in indoor units.

[0003] Reducing the noise caused by the electronic expansion valve can reduce air conditioning noise. However, in actual use, there are many factors that affect the noise of the electronic expansion valve. Currently, the noise problem of the electronic expansion valve includes fluid noise, and most of the noise reduction research on fluid noise is attributed to the sound of bubbles bursting in the fluid. Summary of the Invention

[0004] After extensive research, the applicant was surprised to discover that the noise of the electronic expansion valve includes acoustic resonance generated when fluid flows through the valve port channel.

[0005] This application provides a low-noise electronic expansion valve.

[0006] To solve the above-mentioned technical problems, this application provides an electronic expansion valve, including a valve seat and a valve core, wherein the valve seat includes a valve port passage, and the electronic expansion valve has a valve cavity, wherein at least a portion of the valve core is located in the valve cavity;

[0007] The valve port passage includes a throttling section and a fluid outlet section. The throttling section is located between the valve cavity and the fluid outlet section. The minimum inner diameter of the throttling section is smaller than the minimum inner diameter of the valve cavity, and the minimum inner diameter of the throttling section is smaller than the maximum inner diameter of the fluid outlet section.

[0008] The wall forming the valve cavity includes a bottom wall surface. The distance from the junction of the wall forming the throttling section and the wall forming the fluid outlet section to the bottom wall surface is L. The minimum inner diameter of the throttling section is D. Define k = L / D, then 0 < k ≤ 0.2.

[0009] The electronic expansion valve provided in this application includes a valve port channel, which includes a throttling section and a fluid outlet section. The electronic expansion valve has a valve cavity, and the wall forming the valve cavity includes a bottom wall surface. The distance from the junction of the wall forming the throttling section and the wall forming the fluid outlet section to the bottom wall surface is L. The minimum inner diameter of the throttling section is D. Define k = L / D, then 0 < k ≤ 0.2. By adjusting the size of the valve port channel, the vibration frequency generated when the fluid flows through the valve port channel can be adjusted, thereby reducing the resonance phenomenon that occurs when the fluid flows through the valve port channel, and reducing the acoustic resonance noise of the electronic expansion valve.

[0010] This application also provides a thermal management system, including a compressor, an electronic expansion valve, a first heat exchanger, and a second heat exchanger, wherein the electronic expansion valve includes a valve body and a valve core, and the valve body includes a valve port passage;

[0011] The thermal management system has a heating mode. In the heating mode, the outlet of the compressor is connected to the inlet of the first heat exchanger, the inlet of the electronic expansion valve is connected to the outlet of the first heat exchanger, the valve core of the electronic expansion valve moves closer to the valve port channel to throttle the fluid flowing through the electronic expansion valve, the outlet of the electronic expansion valve is connected to the inlet of the second heat exchanger, and the outlet of the second heat exchanger is connected to the inlet of the compressor.

[0012] The electronic expansion valve has a valve cavity, the wall forming the valve cavity includes a bottom wall surface, and the valve port passage includes a throttling section and a fluid outlet section, the throttling section being located between the valve cavity and the fluid outlet section;

[0013] The distance from the junction of the wall forming the throttling section and the wall forming the fluid outlet section to the bottom wall surface is L. The minimum inner diameter of the throttling section is D. Define k = L / D, then 0 < k ≤ 0.2.

[0014] The thermal management system provided in this application includes an electronic expansion valve, which includes a valve port channel, a throttling section, and a fluid outlet section. The electronic expansion valve has a valve cavity, and the wall forming the valve cavity includes a bottom wall surface. The distance from the junction of the wall forming the throttling section and the wall forming the fluid outlet section to the bottom wall surface is L. The minimum inner diameter of the throttling section is D, and k = L / D. When the thermal management system is in cooling mode, 0 < k ≤ 0.2. By adjusting the size of the valve port channel, the vibration frequency generated when the fluid flows through the valve port channel can be adjusted, thereby reducing the resonance phenomenon that occurs when the fluid flows through the valve port channel, and reducing the acoustic resonance noise of the thermal management system in cooling mode. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 is a schematic diagram of the structure of an electronic expansion valve provided in an embodiment of this application;

[0017] Figure 2 is a top view of Figure 1;

[0018] Figure 3 is a cross-sectional view of section A in Figure 2;

[0019] Figure 4 is a schematic diagram of the valve body in Figure 1;

[0020] Figure 5 is a cross-sectional schematic diagram of Figure 4;

[0021] Figure 6 is an enlarged schematic diagram of B in Figure 3;

[0022] Figure 7 is a partially enlarged schematic diagram of the valve port channel in Figure 5;

[0023] Figure 8 is a schematic diagram of the connection relationship of a thermal management system provided in an embodiment of this application;

[0024] Figure 9 is a partially enlarged schematic diagram of the valve port channel in an electronic expansion valve according to another embodiment of this application;

[0025] Figure 10 is a partially enlarged schematic diagram of the valve port channel in an electronic expansion valve provided in another embodiment of this application.

[0026] In the diagram: 1-Valve body; 10-Valve port passage; 101-Throttling section; 1011-Straight cylinder section; 102-Fluid inlet section; 102a-First port; 102b-Second port; 103-Fluid outlet section; 103c-Third port; 103d-Fourth port; 11-Inflow channel; 12-Outflow channel; 13-Valve cavity; 14-Protrusion; 15-First limiting step; 16-First tube limiting part; 2-Valve core; 21-Columnar part; 22-Needle tip; 31-First tube; 32-Second pipe; 4-Cover body; 40-Cover cavity; 5-Shell; 6-Guide part; 61-Second limiting step; 62-First guide part; 7-Sleeve part; 71-End plate part; 72-Limiting boss; 73-Spring; 8-Gasket; 91-Lead screw; 92-Magnetic rotor component; 93-Connecting plate; 94-Nut; 95-Connecting piece; 96-Fixing plate; D-Electronic expansion valve; C-First heat exchanger; E-Second heat exchanger; F-Compressor; S-Centerline direction of valve port passage. Detailed Implementation

[0027] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. In the following description relating to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements.

[0028] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0029] It should be understood that the terms "first," "second," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, "a" or "one," and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one; "multiple" indicates two or more. Unless otherwise stated, terms such as "front," "rear," "lower," and / or "upper" are for illustrative purposes only and are not limited to a location or spatial orientation. Terms such as "comprising" or "including" indicate that the elements or objects preceding "comprising" encompass the elements or objects listed following "comprising" or "including" and their equivalents, but do not exclude other elements or objects.

[0030] The exemplary embodiments of this application will now be described in detail with reference to the accompanying drawings. Unless otherwise specified, the features of the following embodiments and implementation methods can complement or combine with each other.

[0031] This application provides an electronic expansion valve, including a valve body 1 and a valve core 2. The valve body 1 includes a valve port passage 10, and the valve core 2 can be close to or away from the valve port passage 10 to adjust the cross-sectional area of ​​fluid flow.

[0032] The valve passage 10 includes a throttling section 101 and a fluid outlet section 103. The throttling section 101 is located between the valve cavity 13 and the fluid outlet section 103. The minimum inner diameter of the throttling section 101 is smaller than the minimum inner diameter of the valve cavity 13, and the minimum inner diameter of the throttling section 101 is smaller than the maximum inner diameter of the fluid outlet section 103.

[0033] The electronic expansion valve has a valve cavity 13, at least a portion of the valve core 2 is located in the valve cavity 13, the wall forming the valve cavity 13 includes a bottom wall 131, the valve core 2 can be close to or away from the bottom wall 131, the distance from the junction of the wall forming the throttling section 101 and the wall forming the fluid outlet section 103 to the bottom wall surface 131 is L, the minimum inner diameter of the throttling section 101 is defined as D, and k = L / D is defined, then 0 < k ≤ 0.2.

[0034] The electronic expansion valve provided in this application includes a valve port channel 10, which includes a throttling section 101 and a fluid outlet section 103. The electronic expansion valve has a valve cavity 10, and the wall forming the valve cavity 10 includes a bottom wall surface 131. The distance from the junction of the wall forming the throttling section 101 and the wall forming the fluid outlet section 103 to the bottom wall surface 131 is L. The minimum inner diameter of the throttling section 101 is D, and k = L / D. Therefore, 0 < k ≤ 0.2. By adjusting the size of the valve port channel 10, the vibration frequency generated when the fluid flows through the valve port channel 10 can be adjusted, thereby reducing the resonance phenomenon that occurs when the fluid flows through the valve port channel 10, and reducing the acoustic resonance noise of the electronic expansion valve.

[0035] According to a specific embodiment of this application, as shown in Figures 1 to 3, an electronic expansion valve includes a valve body 1 and a valve core 2. The valve body 1 has a valve cavity 13, and the valve core 2 is at least partially located in the valve cavity 13.

[0036] The valve body 1 includes a valve port passage 10. The valve core 2 can move closer to or further away from the valve port passage 10 along its length direction / center line direction S of the valve port passage 10 to adjust the cross-sectional area of ​​fluid flow. During the process of the valve core 2 adjusting the fluid flow rate, the valve port passage 10 can communicate with the valve cavity 13.

[0037] The electronic expansion valve of this embodiment includes an inflow channel 11 and an outflow channel 12. The inflow channel 11 is connected to the valve chamber 13, and the inflow channel 11 and the valve chamber 13 are always in a connected state, allowing fluid to enter the valve chamber 13 through the inflow channel 11. The outflow channel 12 is connected to the valve chamber 13, and the outflow channel 12 and the valve chamber 13 are always in a connected state. Of course, in some other embodiments, the outflow channel 12 can be kept in a non-connected state with the valve chamber 13, that is, the electronic expansion valve has a closed state. When the electronic expansion valve is in a closed state, the fluid entering the inflow channel 11 cannot flow out of the electronic expansion valve through the outflow channel 12.

[0038] As shown in Figure 5, the outflow channel 12 and the valve port channel 10 are arranged along the center line direction S of the valve port channel 10. The valve port channel 10 connects the outflow channel 12 and the valve chamber 13. Fluid can enter the outflow channel 12 from the inflow channel 11 through the valve port channel 10. Specifically, fluid can enter the valve chamber 13 from the inflow channel 11, and fluid located in the valve chamber 13 can enter the outflow channel 12 through the valve port channel 10.

[0039] In this embodiment, as shown in FIG5, the length direction of the valve port channel 10 is consistent with the length direction of the outflow channel 12, and the length direction of the inflow channel 11 is perpendicular to the length direction of the valve port channel 10, that is, the inflow channel 11 extends along the perpendicular direction of the center line direction S of the valve port channel 10.

[0040] The wall forming the valve cavity 13 includes a bottom wall 131, the valve core 2 can be close to or away from the bottom wall 131, and the bottom wall 131 is connected to the wall forming the valve port passage 10.

[0041] Referring to Figures 5 and 7, the valve port passage 10 includes a throttling section 101 and a fluid outlet section 103. The throttling section 101 is located between the valve cavity 13 and the fluid outlet section 103. The minimum inner diameter of the throttling section 101 is smaller than the minimum inner diameter of the valve cavity 13, and the minimum inner diameter of the throttling section 101 is smaller than the maximum inner diameter of the fluid outlet section 103.

[0042] As shown in Figure 5, the distance from the junction of the wall forming the throttling section 101 and the wall forming the fluid outlet section 103 to the bottom wall surface 131 is L, and the minimum inner diameter of the throttling section 101 is D. Define k = L / D, then 0 < k ≤ 0.2.

[0043] Through extensive research, the applicant surprisingly discovered that the acoustic resonance generated by fluid flowing through the valve port channel 10 of the electronic expansion valve is one of the sources of noise in the electronic expansion valve. This embodiment, by adjusting the dimensions of the valve port channel 10, can regulate the vibration frequency generated by the fluid flowing through it, thereby reducing the resonance phenomenon that occurs when the fluid flows through the valve port channel 10, and thus reducing the acoustic resonance noise of the electronic expansion valve.

[0044] The acoustic resonance generated when fluid flows through the valve port channel 10 of the electronic expansion valve is generally defined as the piercing whistling sound in the electronic expansion valve. Therefore, the electronic expansion valve in this embodiment can reduce the noise of the whistling sound of the electronic expansion valve.

[0045] Unlike conventional noise reduction methods for electronic expansion valves, the applicant has discovered through extensive research that whistling is the key challenge in addressing the noise issue of electronic expansion valves. Further research by the applicant revealed that the resonant frequency is crucial for generating the piercing whistling sound. This embodiment reduces acoustic resonance by adjusting the difference between the vibration frequency of the fluid flowing through the valve port channel 10 and the modal frequency of the acoustic cavity in the valve port channel 10, thereby controlling the piercing whistling sound. By reducing the whistling sound, the noise of the electronic expansion valve can be significantly reduced.

[0046] This embodiment can adjust the resonance frequency generated when the fluid flows through the valve port channel 10 by adjusting the size of the valve port channel 10, thereby reducing the resonance phenomenon that occurs when the fluid flows through the valve port channel 10 and reducing the noise of the whistling sound of the electronic expansion valve.

[0047] In this embodiment, the throttling section 101 includes a straight section 1011. The height of the straight section 1011 extending along the centerline direction S of the valve port channel 10 is defined as L1, and the inner diameter of the straight section 1011 is defined as D1. k1 = L1 / D1, then 0 < k1 ≤ 0.15, as shown in Figure 7. By adjusting the ratio of the height of the straight section 1011 in the valve port channel 10 to the inner diameter of the straight section 1011 in the valve port channel 10, the resonance frequency generated when the fluid flows through the valve port channel 10 can be adjusted. This reduces the resonance phenomenon when the fluid flows through the valve port channel 10, thereby reducing the noise of the electronic expansion valve's whistling sound. The size ratio of the valve port channel 10 in this embodiment, as verified by experiments, shows that the noise of the electronic expansion valve's whistling sound is well controlled.

[0048] In this embodiment, the valve port passage 10 includes a fluid inlet section 102, which is located on the side of the straight section (1011) near the valve cavity 13. The fluid inlet section 102 has a first port 102a and a second port 102b. The second port 102b is located on the side of the fluid inlet section 102 near the straight section 1011. The diameter of the first port 102a is larger than the diameter of the second port 102b. The diameter of the second port 102b is the same as the inner diameter of the straight section 1011, as shown in Figure 7. In other words, along the centerline direction S of the valve port passage 10, the end of the fluid inlet section 102 away from the straight section 1011 is defined as the upper end, and the end of the fluid inlet section 102 near the straight section 1011 is defined as the lower end. The fluid inlet section 102 has a trumpet-shaped or roughly trumpet-shaped profile with a larger upper end and a smaller lower end.

[0049] The fluid inlet section 102 can change the vortex structure within the valve port channel 10, causing the fluid flow through the valve port channel 10 to redistribute. The fluid inlet section 102 can prevent the airflow from separating prematurely at the boundary layer, thereby suppressing the development of separation bubbles. Overall, the design of the fluid inlet section 102 of the valve port channel 10 helps to improve the flow field characteristics of the valve port channel 10 and suppress secondary flow in the channel, thus reducing flow noise.

[0050] In this embodiment, the valve port channel 10 includes a straight section 1011 and a fluid inlet section 102. The fluid inlet section 102 is located on the side of the straight section 1011 away from the outlet channel 12. Along the center line direction S of the valve port channel 10, the total height of the straight section 1011 and the fluid inlet section 102 is defined as L, the inner diameter of the straight section 1011 is defined as D, and k = L / D is defined. Then 0 < k ≤ 0.2.

[0051] Therefore, by adjusting the ratio of the height of the fluid inlet section 102 and the straight section 1011 in the valve port channel 10 to the inner diameter of the straight section 1011, this embodiment can not only reduce the noise of the whistling sound of the electronic expansion valve, but also reduce the noise of the separation bubble rupture of the electronic expansion valve. The electronic expansion valve provided in this embodiment has lower noise.

[0052] In this embodiment, the cylindrical walls forming the straight section 1011 are located on the side circumferential walls of the same cylinder. In other words, the inner diameter of the straight section 1011 remains consistent along the centerline direction S of the valve port channel 10.

[0053] In this embodiment, the valve port passage 10 includes a fluid outlet section 103, which is located on the side of the straight section 1011 away from the fluid inlet section 102. Along the centerline direction S of the valve port passage 10, the height of the fluid inlet section 102 is less than the height of the straight section 1011. That is, the proportion of the height of the fluid inlet section 102 to the total height of the valve port passage 10 is less than the proportion of the straight section 1011 to the total height of the valve port passage 10. By adjusting the height of the fluid inlet section 102 to be less than the height of the straight section 1011, the fluid can flow through the fluid inlet section 102 and flow to the fluid outlet section 103 as quickly as possible, thereby reducing the probability of the separation bubble in the fluid rupturing at the valve port of the valve port passage 10. Therefore, the electronic expansion valve of this embodiment has lower noise from the rupture of the separation bubble.

[0054] As shown in Figure 7, the height of the straight section 1011 is less than the height of the fluid outlet section 103, which allows the fluid to flow through the straight section 1011 and to the fluid outlet section 103 as quickly as possible. This reduces the probability of the separation bubble in the fluid rupturing at the valve port of the valve port channel 10. Therefore, the electronic expansion valve of this embodiment has lower noise from the rupture of the separation bubble.

[0055] The fluid can enter the fluid outlet section 103 from the fluid inlet section 102 through the straight section 1011. In other words, during the operation of the electronic expansion valve in this embodiment, the fluid has a flow path from the fluid inlet section 102 through the straight section 1011 to the fluid outlet section 103. The fluid outlet section 103 has a fluid buffering effect and forms a buffer space larger than the straight section 1011, which can reduce the noise of the flow-induced sound of the electronic expansion valve.

[0056] The volume of the fluid outlet section 103 is larger than that of the straight section 1011. The fluid outlet section 103 can provide a larger buffer space for the fluid flowing through the straight section 1011, which is beneficial to reducing the noise of the flow-induced sound of the electronic expansion valve.

[0057] As shown in Figures 5 and 7, the straight section 1011 connects the fluid inlet section 102 and the fluid outlet section 103. The center line of the fluid outlet section 103, the center line of the straight section 1011, and the center line of the fluid outlet section 103 coincide / are located on the same straight line. The fluid can flow smoothly under the action of gravity, thereby reducing the noise caused by the flow of the electronic expansion valve due to the fluid hitting the wall during the flow process.

[0058] As shown in Figure 7, the fluid outlet section 103 has a third port 103c and a fourth port 103d. The third port 103c is located on the side of the fluid outlet section 103 near the straight section 1011, and the fourth port 103d is located on the other side of the fluid outlet section 103. The third port 103c and the fourth port 103d are two ports located in the fluid outlet section 103 along the center line direction S of the valve port channel 10, respectively. Similarly, the first port 102a and the second port 102b are two ports located in the fluid inlet section 102 along the center line direction S of the valve port channel 10, respectively.

[0059] The fluid outlet section 103 is designed with one end of a third port 103c connected to the straight section 1011, and the fluid inlet section 102 is designed with one end of a second port 102b connected to the straight section 1011.

[0060] The diameter of the third port 103c is smaller than the diameter of the fourth port 103d. That is, along the center line direction S of the valve port channel 10, the end of the fluid outlet section 103 away from the straight cylinder section 1011 is defined as the lower end, and the end of the fluid outlet section 103 close to the straight cylinder section 1011 is defined as the upper end. The fluid outlet section 103 has a trumpet-shaped or roughly trumpet-shaped profile with a smaller upper end and a larger lower end.

[0061] In this embodiment, the fluid outlet section 103 is configured as a conical structure as shown in FIG7. Of course, in some other embodiments, the fluid outlet section 103 is configured as an arc-shaped profile as shown in FIG9. Of course, in some other embodiments, the throttling section 101 can be configured as a conical structure as shown in FIG10, that is, the fluid radius of the throttling section 101 gradually changes and there is no abrupt change.

[0062] The diameter of the third port 103c is the same as the inner diameter of the straight section 1011. In other words, there is no protruding structure protruding from the wall of the straight section 1011 and / or the fluid outlet section 103 between the straight section 1011 and the fluid outlet section 103. During the process of the fluid flowing from the straight section 1011 to the fluid outlet section 103, the noise of the flow-induced sound of the electronic expansion valve generated during fluid collision can be reduced.

[0063] Similarly, the diameter of the second port 102b is the same as the inner diameter of the straight section 1011. In other words, there is no protruding structure protruding from the wall of the straight section 1011 and / or the fluid inlet section 102 between the straight section 1011 and the fluid inlet section 102. During the process of the fluid flowing from the fluid inlet section 102 to the straight section 1011, the noise of the flow-induced sound of the electronic expansion valve generated during fluid collision can be reduced.

[0064] In this embodiment, during operation, fluid enters the valve chamber 13 from the inlet channel 11. The fluid in the valve chamber 13 follows a flow path from the fluid inlet section 102 through the straight section 1011 to the fluid outlet section 103. This is the flow path of the fluid when the electronic expansion valve is in cooling mode. This embodiment of the electronic expansion valve is applied to air conditioning systems, particularly residential air conditioning systems. When the air conditioning system is in cooling mode, the fluid flowing through the electronic expansion valve enters the valve chamber 13 from the inlet channel 11, and the fluid in the valve chamber 13 follows a flow path from the fluid inlet section 102 through the straight section 1011 to the fluid outlet section 103. Of course, in other embodiments, the above-described electronic expansion valve can also be applied to other systems, such as commercial air conditioning systems.

[0065] The fluid in this embodiment is a refrigerant used in air conditioning systems.

[0066] In this embodiment, the valve core 2 includes a cylindrical part 21 and a needle end 22. The cylindrical part 21 and the needle end 22 are arranged along the center line direction S of the valve port channel 10. The outer diameter of the cylindrical part 21 remains consistent along the center line direction S of the valve port channel 10. The needle end 22 is designed as a conical or approximately conical structure. At least a portion of the needle end 22 can be located in the valve port channel 10, and at least a portion of the cylindrical part 21 is located in the valve cavity 13. In this embodiment, the cylindrical part 21 and the needle end 22 are integrally formed structures, and the center line of the cylindrical part 21 coincides with the center line of the needle end 22, resulting in a simple structure.

[0067] The electronic expansion valve in this embodiment can adjust the gap between the needle tip 22 and the wall forming the valve port channel 10 by adjusting how much the needle tip 22 extends into the valve port channel 10, thereby achieving the effect of adjusting the fluid flow rate at the gap.

[0068] In this embodiment, the column portion 21 and the needle end portion 22 form a valve needle structure. In other words, the valve core 2 in this embodiment is designed as a valve needle structure.

[0069] Along the center line direction S of the valve port channel 10, the needle tip 22 extends away from the column part 21, and the outer diameter of the needle tip 22 gradually decreases.

[0070] The maximum value of the outer diameter of the needle tip 22 is defined as R, then R≤D; in other words, during the operation of the electronic expansion valve in this embodiment, the needle tip 22 and the wall forming the valve port channel 10 always maintain a gap, that is, the valve cavity 13 / inflow channel 11 and the valve port channel 10 in this embodiment always remain in communication. Moving the valve core 2 can adjust the fluid flow rate. The valve core 2 cannot block the valve port channel 10, and the valve core 2 cannot prevent the fluid from flowing out of the outflow channel 12. Through the above design, the needle tip 22 has a guiding effect on the flow of fluid.

[0071] Along the center line direction S of the valve port channel 10, the outer diameter of the column part 21 remains consistent; in other words, the side walls of the column part 21 are located on the side circumferential wall of the same cylinder.

[0072] The valve core 2 includes a transition portion 23, which is located between the column portion 21 and the needle end portion 22. The transition portion 23 connects the column portion 21 and the needle end portion 22. The outer diameter of the transition portion 23 gradually decreases from the column portion 21 to the needle end portion 22, as shown in Figure 6.

[0073] During the flow of fluid from the valve chamber 13 to the valve port passage 10, some fluid can flow along the transition section 23. The transition section 23 guides the flow of fluid and allows more fluid to flow into the valve port passage 10, thereby reducing the noise caused by the flow of the electronic expansion valve.

[0074] In this embodiment, the straight section 1011 has a first port 101a and a second port 101b. The first port 101a is connected to the fluid inlet section 102, and the second port 101b is connected to the fluid outlet section 103. As shown in FIG7, the first port 101a coincides with the second port 102b, and the second port 101b coincides with the third port 103c.

[0075] The electronic expansion valve of this embodiment includes a first pipe 31 and a second pipe 32. The first pipe 31 is at least partially located in the inflow channel 11. The pipe of the first pipe 31 extends at least partially perpendicular to the center line direction S of the valve port channel 10. In other words, the length direction of at least a portion of the pipe of the first pipe 31 is perpendicular to the center line direction S of the valve port channel 10. The portion of the first pipe 31 used for connecting to the valve body 1 extends perpendicular to the length direction S. Fluid in the first pipe 31 can flow in the direction perpendicular to the center line S of the valve port channel 10 and enter the valve chamber 13 of the electronic expansion valve, as shown in Figures 1 and 3. The second pipe 32 is at least partially located in the outflow channel 12. The pipe of the second pipe 32 extends at least partially along the center line direction S of the valve port channel 10. In this embodiment, the entire pipe of the second pipe 32 extends along the center line direction S of the valve port channel 10, as shown in Figures 1 and 3. This facilitates the smooth outflow of fluid and reduces flow noise during fluid flow. In summary, the electronic expansion valve of this embodiment has stronger noise reduction.

[0076] In addition, the electronic expansion valve in this embodiment achieves better noise reduction by adjusting the size ratio of the valve port channel 10, without changing other structures of the electronic expansion valve itself, and without adding other noise reduction and filtration structures at the valve port channel 10. This effectively controls production costs without hindering the normal flow of fluid.

[0077] In this embodiment, the electronic expansion valve also includes a cover 4, which is fixedly connected to the valve body 1;

[0078] Specifically, as shown in Figures 1, 2, and 3, the cover 4 is generally cup-shaped with an opening at the bottom, and is connected and fixed to the valve body 1. Specifically, a protrusion 14 can be provided at the upper end of the valve body 1, as shown in Figure 3. The bottom opening of the cover 4 is then fitted with the protrusion 14 and welded for fixation. This is one method of fixing the cover 4 to the valve body 1; other methods can also be used to achieve the connection and fixation.

[0079] The control valve includes a housing 5, which is fixedly connected to a cover 4. The valve body 1, cover 4 and housing 5 are arranged along the center line direction S of the valve port passage 10.

[0080] The housing 5 and the cover 4 can be fixed by welding, thus forming a relatively sealed space between the housing 5, the cover 4, and the valve body 1.

[0081] The electronic expansion valve includes a guide portion 6, which is fixedly connected to the valve body 1. The guide portion 6 has a valve core guide hole, and the column portion 21 of the valve core 2 is placed in the valve core guide hole.

[0082] The valve body 1 includes a first limiting step 15, and the guide part 6 includes a second limiting step 61. The first limiting step 15 and the second limiting step 61 abut against each other, as shown in Figure 3.

[0083] The cover 4 has a cover cavity 40, the valve body 1 has a valve cavity 13, and one end of the guide part 6 is placed in the cover cavity 40 and its opposite end is placed in the valve cavity 13, as shown in Figure 3.

[0084] The electronic expansion valve includes a sleeve portion 7 with an opening, through which a valve core 2 passes and is connected to the sleeve portion 7, and a gasket 8 is provided between the valve core 2 and the sleeve portion 7, as shown in Figure 3.

[0085] The guide part 6 has a guide cavity, and the sleeve part 7 is located in the guide cavity.

[0086] The electronic expansion valve includes a magnetic rotor assembly and a lead screw assembly, with the valve core 2 connected to the magnetic rotor assembly via the lead screw assembly.

[0087] Specifically, the lead screw assembly includes a lead screw 91, which is floatingly connected to the valve core 2 via a sleeve portion 7. The sleeve portion 7 is generally cup-shaped with an opening at its bottom. The valve core 2 passes through this opening, enters the valve chamber 13, and can extend into the valve port passage 10. That is, during the operation of the electronic expansion valve, the valve core 2 can move up and down relative to the sleeve portion 7 within a certain stroke, but cannot break free from the restriction of the sleeve portion 7.

[0088] An end plate 71 is provided at the top of the sleeve portion 7, as shown in Figure 3. A limiting boss 72 is fixedly connected to the lower end of the lead screw 91. During assembly, the limiting boss 72 can be fixedly connected to the lead screw 91 first and then placed into the internal space of the sleeve portion 7. Then, the end plate 71 is fixed to the sleeve portion 7 by means such as welding, and the sleeve portion 7 is suspended on the lead screw 91. The sleeve portion 7 and the lead screw 91 cannot be separated, but relative movement is possible. In this article, separation refers to the sleeve portion 7 and the lead screw 91 being separated into two separate parts without any restriction between them, and not merely to the absence of physical contact between them.

[0089] The magnetic rotor assembly includes a magnetic rotor component 92 and a connecting plate 93, as shown in Figure 3. The magnetic rotor component 92 serves as the rotor of the stepper motor and can rotate in response to signals from the coil components, which act as the stator. The lead screw 91 is fixedly connected to the magnetic rotor component 92 as a whole via the connecting plate 93. Specifically, the lead screw 91 and the connecting plate 93 can be fixed by welding, while the magnetic rotor component 92 can be directly injection molded onto the connecting plate 93.

[0090] Below the limiting boss 72 shown in Figure 3, the electronic expansion valve is also provided with a spring 73 and supported by a support member 22. A gasket 8 is also provided between the valve core 2 and the sleeve part 7, so that the valve core 2 is suspended on the sleeve part 7.

[0091] It should be noted that the internal structure of the sleeve 7 can be modified in various ways, and this application does not limit it.

[0092] The electronic expansion valve includes a nut 94 and a connecting piece 95, as shown in Figure 3. The nut 94 is fixed within the space enclosed by the housing 5 and the cover 4 by the metal connecting piece 95. Specifically, the nut 94 can be integrally injection molded with the connecting piece 95 using a non-metallic material, and the connecting piece 95 can be fixedly connected to the cover 4 by welding. That is, the metal connecting piece can be used as an insert, placed in a mold, and the nut 94 can be formed on the connecting piece by injection molding or other means. The nut 94 and the connecting piece 95 constitute the nut assembly.

[0093] The nut 94 has a through hole extending along its axial direction, and an internal thread is provided inside the through hole. Correspondingly, the lead screw 91 has an external thread on its outer circumferential surface. When the magnetic rotor component 92 rotates, the lead screw 91, which is linked to it, rotates and moves up and down relative to the nut under the action of the threaded pair. This drives the valve core 2 to move up and down, so that the valve core 2 moves closer to or away from the valve port passage 10, thereby achieving the purpose of regulating the refrigerant flow rate through the throttling valve port passage 10.

[0094] A second guide portion is provided at the lower part of the nut 94. Specifically, the inner wall of the central through hole of the nut 94 constitutes the second guide portion, and the sleeve portion 7 can slide up and down on the second guide portion. That is, the inner diameter of the second guide portion is adapted to the outer diameter of the sleeve portion 7, and can be set to be approximately the same, or the inner diameter of the second guide portion is slightly larger than the outer diameter of the sleeve portion 7, so that the sleeve portion 7 can move up and down along its central axis under the guidance of the second guide portion without deflection. The second guide portion does not obstruct the movement of the sleeve portion 7.

[0095] Meanwhile, the cylindrical outer wall at the lower part of the guide portion 6 forms the first guide portion 62. In this embodiment, the upper end of the valve body 1 is also provided with an inner hole, which communicates with the valve cavity 13. The inner hole can be formed by machining. The first guide portion 62 fits with the inner peripheral wall of the inner hole. That is, the inner diameter of the inner hole can be set to be basically the same as or slightly smaller than the outer diameter of the first guide portion 62 of the nut 94. In this way, during assembly, the guide portion 6 can be tightly fitted and fixed to the valve body 1 by press fitting. During the press fitting process, due to the presence of the first guide portion 62, the coaxiality between the guide portion 6 and the valve seat after assembly can be easily ensured, that is, the two are guaranteed to have the same central axis.

[0096] The electronic expansion valve also includes a fixing plate 96, which is fixedly connected to the housing 5 and the cover 4, as shown in Figure 3. The fixing plate 96 partially covers the joint between the housing 5 and the cover 4. The above-mentioned design structure of the fixing plate 96 can improve the overall strength of the electronic expansion valve.

[0097] In this embodiment, as shown in Figures 3 and 5, the valve body 1 includes a first pipe limiting part 16, which protrudes from the wall of the valve body 1 and has a certain height. The first pipe 31 abuts against the first connecting part 16. The first pipe limiting part 16 can limit the length of the first pipe 31 extending into the valve body 1. Furthermore, the first pipe 31 is sealed to the valve body 1. The wall thickness of the first pipe 31 is greater than or equal to the height of the first pipe limiting part 16 protruding from the wall of the valve body 1. This is used to reduce the noise of the electronic expansion valve caused by the fluid in the first pipe 31 impacting the first pipe limiting part 16 during its flow into the valve body 1.

[0098] Of course, other products with the above-mentioned valve function, such as injectors, are also applicable to the technical solution of this application. That is, the technical solution of this application is also applicable to the noise reduction treatment of products with the above-mentioned valve function, such as injectors.

[0099] This application also provides a thermal management system, including a compressor F, an electronic expansion valve D, a first heat exchanger C and a second heat exchanger E. The electronic expansion valve D includes a valve body 1 and a valve core 2. The valve body 1 includes a valve port passage 10.

[0100] The thermal management system has a cooling mode. In the cooling mode, the outlet of compressor F is connected to the inlet of the first heat exchanger C, the inlet of electronic expansion valve D is connected to the outlet of the first heat exchanger C, the valve core 2 of electronic expansion valve D moves closer to the valve port channel 10 to throttle the fluid flowing through electronic expansion valve D, the outlet of electronic expansion valve D is connected to the inlet of the second heat exchanger E, and the outlet of the second heat exchanger E is connected to the inlet of compressor F.

[0101] The electronic expansion valve D has a valve chamber 13, the wall forming the valve chamber 13 includes a bottom wall surface 131, and the valve port passage 10 includes a throttling section 101 and a fluid outlet section 103, with the throttling section 101 located between the valve chamber 13 and the fluid outlet section 103;

[0102] The distance from the junction of the wall forming the throttling section 101 and the wall forming the fluid outlet section 103 to the bottom wall surface 131 is L. The minimum inner diameter of the throttling section 101 is D. K is defined as L / D. When the thermal management system is in cooling mode, 0 < k ≤ 0.2.

[0103] The thermal management system provided in this application includes an electronic expansion valve D, which includes a valve port channel 10. The valve port channel 10 includes a throttling section 101 and a fluid outlet section 103. The electronic expansion valve has a valve cavity 13, and the wall forming the valve cavity 13 includes a bottom wall surface 131. The distance from the junction of the wall forming the throttling section 101 and the wall forming the fluid outlet section 103 to the bottom wall surface 131 is L. The minimum inner diameter of the throttling section 101 is D. K is defined as L / D. When the thermal management system is in cooling mode, 0 < K ≤ 0.2. By adjusting the size of the valve port channel 10, the vibration frequency generated when the fluid flows through the valve port channel 10 can be adjusted, thereby reducing the resonance phenomenon that occurs when the fluid flows through the valve port channel 10, and reducing the noise of acoustic resonance of the thermal management system in cooling mode.

[0104] According to a specific embodiment of this application, as shown in FIG8, a thermal management system includes a compressor F, an electronic expansion valve D, a first heat exchanger C and a second heat exchanger E, wherein fluid flowing out of the first heat exchanger C can enter the second heat exchanger E after passing through the electronic expansion valve D.

[0105] The electronic expansion valve D includes a valve body 1 and a valve core 2. The valve body 1 includes a valve port passage 10, and the valve core 2 can move closer to or further away from the valve port passage 10 to adjust the cross-sectional area of ​​the fluid / refrigerant flow.

[0106] The thermal management system has a cooling mode. In the cooling mode, the compressor F, electronic expansion valve D, first heat exchanger C, and second heat exchanger E are connected. The electronic expansion valve D is in a throttling state, and the outlet of the electronic expansion valve D is connected to the second heat exchanger E.

[0107] In cooling mode, the outlet of compressor F is connected to the inlet of the first heat exchanger C, the inlet of electronic expansion valve D is connected to the outlet of the first heat exchanger C, the valve core 2 of electronic expansion valve D moves closer to the valve port channel 10 to throttle the fluid flowing through electronic expansion valve D, the outlet of electronic expansion valve D is connected to the inlet of the second heat exchanger E, and the outlet of the second heat exchanger E is connected to the inlet of compressor F.

[0108] As shown in Figure 8, the thermal management system includes solenoid valve Y1, check valve X1, check valve X2, and check valve X3. The refrigerant flowing from compressor F passes through solenoid valve Y1, first heat exchanger C, check valve X1, check valve X2, electronic expansion valve D, second heat exchanger E, and check valve X3 before finally returning to compressor F. The first heat exchanger C is the outdoor heat exchanger, and the second heat exchanger E is the indoor heat exchanger. The thick solid lines with arrows in Figure 8 represent the flow paths of the fluid / refrigerant. The fluid / refrigerant with the above flow paths constitutes the cooling mode of the thermal management system.

[0109] In cooling mode, refrigerant enters the outlet channel 12 of valve body 1 from the inlet channel 11 of valve body 1 through the valve port channel 10. The outlet channel 12 and the valve port channel 10 are arranged along the center line direction S of the valve port channel 10.

[0110] The wall forming the valve cavity 13 includes a bottom wall surface 131, and the valve port passage 10 includes a throttling section 101 and a fluid outlet section 103, with the throttling section 101 located between the valve cavity 13 and the fluid outlet section 103;

[0111] The distance from the junction of the wall forming the throttling section 101 and the wall forming the fluid outlet section 103 to the bottom wall surface 131 is L. The minimum inner diameter of the throttling section 101 is defined as D. k = L / D is defined. In refrigeration mode, 0 < k ≤ 0.2.

[0112] Through extensive research, the applicant discovered that whistling is a key challenge in addressing the noise issue of electronic expansion valves. Further research revealed that the resonant frequency is crucial for generating the piercing whistling sound. This embodiment adjusts the dimensions of the valve port channel 10 to regulate the difference between the vibration frequency of the fluid flowing through the valve port channel 10 and the modal frequency of the acoustic cavity of the valve port channel 10, thereby reducing acoustic resonance and controlling the piercing whistling sound. By reducing the whistling sound, the noise of the thermal management system in cooling mode can be significantly reduced.

[0113] The throttling section 101 includes a straight section 1011. The straight section 1011 extends along the center line direction S of the valve port passage 10 with a height of L1. The inner diameter of the straight section 1011 is defined as D1. k1 is defined as L1 / D1. When the thermal management system is in cooling mode, 0 < k1 ≤ 0.15.

[0114] The cylindrical wall forming the straight section 1011 is located on the side circumferential wall of the same cylinder;

[0115] Along the centerline direction S of the valve passage 10, the end of the throttling section 101 closest to the outlet passage 12 is defined as the lower end, and the end of the throttling section 101 furthest from the outlet passage 12 is defined as the upper end.

[0116] In cooling mode, the electronic expansion valve D has a first operating state. In the first operating state, when the fluid flows through the throttling section 101 of the electronic expansion valve D, the fluid has a flow path from top to bottom.

[0117] In the cooling mode of the thermal management system, the electronic expansion valve D has a first operating state. By adjusting the ratio of the height of the straight section 1011 in the valve port channel 10 to the inner diameter of the straight section 1011 in the valve port channel 10 during the first operating state, the resonance frequency generated when the fluid flows through the valve port channel 10 can be adjusted. This reduces the resonance phenomenon that occurs when the fluid flows through the valve port channel 10, thereby reducing the noise of the electronic expansion valve's whistling sound. In this embodiment, the size ratio of the valve port channel 10, as verified by experiments, shows that the noise of the electronic expansion valve's whistling sound in the first operating state is well controlled.

[0118] The throttling section 101 includes a fluid inlet section 102. Along the centerline direction S of the valve port passage 10, the fluid inlet section 102 is located on the side of the straight section 1011 close to the inflow passage 11, and the straight section 1011 and the fluid inlet section 102 are connected.

[0119] The extension height of the fluid inlet section 102 along the center line direction S of the valve port passage 10 is less than the extension height of the straight section 1011 along the center line direction S of the valve port passage 10. By adjusting the height dimension of the fluid inlet section 102 in the throttling section 101, it is beneficial to control the flow noise of the fluid.

[0120] The throttling section 101 includes a fluid outlet section 103. Along the centerline direction S of the valve port passage 10, the fluid outlet section 103 is located on the side of the straight section 1011 near the outlet passage 12. The fluid inlet section 102 and the fluid outlet section 103 are located on both sides of the straight section 1011. The fluid outlet section 103 is located on the side of the straight section 1011 near the outlet passage 12, and the straight section 1011, the fluid inlet section 102, and the fluid outlet section 103 are connected.

[0121] The extension height of the fluid outlet section 103 along the center line direction S of the valve port passage 10 is greater than the extension height of the straight section 1011 along the center line direction S of the valve port passage 10. By adjusting the height dimension of the fluid outlet section 103 in the throttling section 101, it is beneficial to control the flow noise of the fluid.

[0122] In the cooling mode of the thermal management system, fluid enters the valve chamber 13 from the inflow channel 11, and the fluid in the valve chamber 13 has a flow path from the fluid inlet section 102 through the straight section 1011 to the fluid outlet section 103. Fluid with this flow path has a better noise reduction effect in the cooling mode of the thermal management system.

[0123] The air conditioning system in this embodiment is an air conditioning system suitable for household air conditioners. When the air conditioning system of a household air conditioner adopts the above technical solution, the noise, especially the resonance sound of the electronic expansion valve D, can be better improved and controlled. Therefore, the air conditioning system of a household air conditioner adopting the above technical solution has better noise reduction.

[0124] Some of the technical features of the implementation method can be combined or replaced.

[0125] The technical principles of this application have been described above in conjunction with specific embodiments. However, it should be noted that these descriptions are merely for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, other technical solutions or equivalent substitutions of this application that can be conceived by those skilled in the art without creative effort will fall within the scope of protection of this application.

Claims

1. An electronic expansion valve, characterized in that: The valve includes a valve body and a valve core. The valve body has a valve port passage, and the electronic expansion valve has a valve cavity, with at least a portion of the valve core located in the valve cavity. The valve port passage includes a throttling section and a fluid outlet section. The throttling section is located between the valve cavity and the fluid outlet section. The minimum inner diameter of the throttling section is smaller than the minimum inner diameter of the valve cavity, and the minimum inner diameter of the throttling section is smaller than the maximum inner diameter of the fluid outlet section. The wall forming the valve cavity includes a bottom wall. The distance from the intersection of the wall forming the throttling section and the wall forming the fluid outlet section to the bottom wall surface is L. The minimum inner diameter of the throttling section is D. Define k = L / D, then 0 < k ≤ 0.

2.

2. The electronic expansion valve according to claim 1, characterized in that: The throttling section includes a straight cylindrical section, the height of which is L1 along the centerline of the valve port channel. The inner diameter of the straight cylindrical section is defined as D1, and k1 = L1 / D1 is defined, then 0 < k1 ≤ 0.

15. The inner diameter of the straight cylindrical section is consistent along the centerline of the valve port channel.

3. The electronic expansion valve according to claim 2, characterized in that: The valve port passage includes a fluid inlet section located on the side of the straight section near the valve cavity. The fluid inlet section has a first port and a second port, with the second port located on the side of the fluid inlet section near the straight section. The diameter of the first port is larger than the diameter of the second port, and the diameter of the second port is the same as the inner diameter of the straight section.

4. The electronic expansion valve according to claim 3, characterized in that: Along the centerline of the valve port channel, the end of the fluid inlet section furthest from the straight section is defined as the upper end, and the end of the fluid inlet section closest to the straight section is defined as the lower end. The fluid inlet section has a funnel-shaped or roughly funnel-shaped profile, with the upper end larger than the lower end, and the height of the fluid inlet section is less than the height of the straight section. The valve body includes an inflow channel and an outflow channel. The outflow channel and the valve port channel are arranged along the length direction of the valve core. The fluid can enter the valve cavity from the inflow channel and enter the outflow channel through the valve port channel. The electronic expansion valve includes a first pipe and a second pipe. The first pipe is at least partially located in the inflow channel, and the pipe of the first pipe extends at least partially along the vertical line of the length direction. The second pipe is at least partially located in the outflow channel, and the pipe of the second pipe extends at least partially along the length direction.

5. The electronic expansion valve according to claim 2, 3, or 4, characterized in that: The fluid outlet section is located on the side of the straight section away from the fluid inlet section, and along the length of the valve core, the height of the straight section is less than the height of the fluid outlet section.

6. The electronic expansion valve according to claim 5, characterized in that: The fluid outlet section has a third port and a fourth port. The third port is located on the side of the fluid outlet section closer to the straight section. The diameter of the third port is smaller than the diameter of the fourth port. The diameter of the third port is the same as the inner diameter of the straight section. Along the centerline of the valve port channel, the end of the fluid outlet section away from the straight section is defined as the lower end, and the end of the fluid outlet section closer to the straight section is defined as the upper end. The fluid outlet section has a funnel-shaped or roughly funnel-shaped profile that is smaller at the upper end and larger at the lower end.

7. The electronic expansion valve according to claim 1, 2, 3, 4, or 6, characterized in that: The valve core includes a cylindrical part and a needle end, the cylindrical part and the needle end are arranged along the center line of the valve port channel, the needle end is designed as a conical or approximately conical structure, and at least a portion of the needle end can be located in the valve port channel.

8. The electronic expansion valve according to claim 7, characterized in that: Along the centerline of the valve port channel, the needle tip extends away from the column body, and the outer diameter of the needle tip gradually decreases; the maximum value of the outer diameter of the needle tip is defined as R, then R≤D.

9. The electronic expansion valve according to claim 7, characterized in that: Along the centerline of the valve port channel, the outer diameter of the cylindrical portion remains consistent; the valve core includes a transition portion located between the cylindrical portion and the needle end, and the transition portion connects the cylindrical portion and the needle end. From the cylindrical portion toward the needle end, the outer diameter of the transition portion gradually decreases.

10. The electronic expansion valve according to claim 2, 3, or 4, characterized in that: The valve port channel includes a fluid outlet section, the straight section having a first port and a second port, the first port being connected to the fluid inlet section and the second port being connected to the fluid outlet section; the fluid inlet section having a first port located at the end of the fluid inlet section away from the straight section, and the fluid outlet section having a fourth port located at the end of the fluid outlet section away from the straight section, the diameter of the fourth port being larger than the diameter of the first port.

11. A thermal management system, characterized in that, The system includes a compressor, an electronic expansion valve, a first heat exchanger, and a second heat exchanger. The electronic expansion valve includes a valve body and a valve core, and the valve body includes a valve port passage. The thermal management system has a cooling mode. In the cooling mode, the outlet of the compressor is connected to the inlet of the first heat exchanger, the inlet of the electronic expansion valve is connected to the outlet of the first heat exchanger, the valve core of the electronic expansion valve moves towards the valve port passage to throttle the fluid flowing through the electronic expansion valve, the outlet of the electronic expansion valve is connected to the inlet of the second heat exchanger, and the outlet of the second heat exchanger is connected to the inlet of the compressor. The electronic expansion valve has a valve cavity, the wall forming the valve cavity includes a bottom wall surface, and the valve port passage includes a throttling section and a fluid outlet section. The throttling section is located between the valve cavity and the fluid outlet section. The distance from the junction of the wall forming the throttling section and the wall forming the fluid outlet section to the bottom wall surface is L. The minimum inner diameter of the throttling section is D. Define k = L / D, then 0 < k ≤ 0.

2.

12. The thermal management system according to claim 11, characterized in that, The throttling section includes a straight cylindrical section, the height of which is L1 extending along the centerline of the valve port channel, the inner diameter of which is defined as D1, and k1 = L1 / D1. In the cooling mode of the air conditioning system, 0 < k1 ≤ 0.

15. The cylindrical wall forming the straight cylindrical section is located on the side circumferential wall of the same cylinder. In the cooling mode, the fluid enters the valve body's outflow channel from the inflow channel of the valve body through the valve port channel, and the outflow channel and the valve port channel are arranged along the centerline direction of the valve port channel.

13. The thermal management system according to claim 12, characterized in that, Along the centerline of the valve port channel, the end of the throttling section closest to the outlet channel is defined as the lower end, and the end of the throttling section furthest from the outlet channel is defined as the upper end; in the refrigeration mode, the electronic expansion valve has a first operating state, in which the fluid has a top-to-bottom flow path when flowing through the throttling section of the electronic expansion valve.

14. The thermal management system according to claim 12 or 13, characterized in that, The valve port channel includes a fluid inlet section. Along the centerline of the valve port channel, the fluid inlet section is located on the side of the straight section near the inflow channel, and the straight section and the fluid inlet section are connected. The extension height of the fluid inlet section along the centerline of the valve port channel is less than the extension height of the straight section along the centerline of the valve port channel.

15. The thermal management system according to claim 12 or 13, characterized in that, Along the centerline of the valve port channel, the fluid outlet section is located on the side of the straight section near the outlet channel, and the straight section and the fluid outlet section are connected; the extension height of the fluid outlet section along the centerline of the valve port channel is greater than the extension height of the straight section along the centerline of the valve port channel; the thermal management system is an air conditioning system suitable for household air conditioners.