Enclosed x-ray generating device

Abstract

This invention provides a closed X-ray generator, comprising a metal casing, an anode assembly, an insulating oil chamber, and insulating oil and a colloid filling it. The anode assembly includes an anode rod, which is vertically arranged axially, with its upper part located in a vacuum chamber and its lower part immersed in the insulating oil. The vacuum chamber and the insulating oil chamber are isolated by a sealing cylinder, which is fitted around the anode rod. The top surface of the colloid supports the metal casing and seals the bottom of the insulating oil chamber. An oil pump is installed inside the colloid, and inlet and outlet ports communicating with the insulating oil chamber are provided on the colloid. The oil pump drives the insulating oil to circulate. A first baffle is provided between the inlet and outlet ports to prevent short-circuit flow of the insulating oil. This invention significantly improves the convective heat transfer efficiency of the X-ray generator and extends the service life of the core components by optimizing the insulating oil chamber structure and combining it with the oil pump to force the insulating oil to circulate through the inlet and outlet ports within the insulating oil chamber.

Description

Technical Field

[0001] This invention belongs to the field of X-ray technology, and in particular relates to a closed X-ray generating device. Background Technology

[0002] X-ray tubes, as vacuum electronic devices capable of generating X-rays, are widely used in medical imaging, security inspection, and industrial non-destructive testing. A typical X-ray tube structure includes a cathode assembly, an anode assembly, and a casing. The cathode emits electrons, while the anode houses the target material. A high-voltage electric field is applied between the cathode and anode. The electron beam is accelerated by the high-voltage electric field at both ends of the cathode and anode and ultimately strikes the anode target surface. When the high-energy electron beam strikes the anode target surface, it generates X-rays through bremsstrahlung. The external high voltage, supplied by a high-voltage power supply, provides a stable high-voltage electric field between the cathode and anode. The vacuum-sealed outer casing provides a high-vacuum environment, enabling the electron collision event to operate continuously and stably, ultimately resulting in a continuous and stable output of X-rays.

[0003] In microfocus X-ray sources, to improve imaging resolution, the electron beam is typically focused into tiny spots to bombard the target material, which creates extremely high heat flux density locally on the target surface. The anode of existing microfocus X-ray sources usually consists of a target material embedded at the top of an oxygen-free copper anode rod. One end of the anode rod is located within a vacuum chamber to receive electron bombardment, while the other end extends into insulating oil for heat dissipation. The outer casing is grounded and filled with insulating oil to prevent electrical breakdown between the anode rod and the casing.

[0004] During the operation of an X-ray source, the vast majority of electron kinetic energy is converted into heat energy, with only a very small portion being converted into X-rays. Therefore, the anode target and anode rod experience a dramatic temperature rise. In existing technologies, the heat absorbed by the anode rod is dissipated primarily through two pathways: part of it is transferred to the outer casing via vacuum radiation, and the other part is conducted through the anode rod to the insulating oil, and then dissipated through convection heat transfer.

[0005] However, the heat dissipation design of existing microfocus X-ray sources still has significant shortcomings: on the one hand, the vacuum radiation heat transfer efficiency is low, making it difficult to meet the heat dissipation requirements under high heat flux density; on the other hand, the convective heat transfer capacity between the anode rod and the insulating oil is limited, and the material selection and structural form of the anode rod itself have not been optimized for efficient heat conduction. This leads to a rapid increase in the temperature of the target material and the anode rod, which cannot be reduced in time, easily causing failure problems such as target melting, cracking, or even separation from the base, seriously affecting the working stability and service life of the X-ray source.

[0006] Furthermore, in high-voltage applications, an extremely strong electric field exists between the anode rod and the grounded casing, placing higher demands on the compatibility of the insulation and heat dissipation structures. How to significantly improve the anode's heat dissipation capacity while ensuring insulation reliability has become a key technical bottleneck restricting the performance improvement of high-end microfocus X-ray sources. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a closed X-ray generating device to solve the problems of target surface overheating, easy damage and poor working stability caused by insufficient heat dissipation capacity in the prior art, thereby improving the lifespan and reliability of the X-ray source.

[0008] To achieve the above and other related objectives, the present invention provides a closed X-ray generating device, comprising a metal shell, an anode assembly disposed within the metal shell, an insulating oil chamber, and insulating oil filling the insulating oil chamber. The device further comprises a colloid located at the bottom, the top surface of which supports the metal shell and seals the bottom of the insulating oil chamber.

[0009] The anode assembly includes an anode rod, which is vertically arranged along the axial direction. The upper part of the anode rod is located in the vacuum chamber, and the lower part is immersed in the insulating oil.

[0010] The vacuum chamber and the insulating oil chamber are isolated by a sealing cylinder, which is sleeved around the outer periphery of the anode rod, dividing the anode rod into a vacuum section and an oil-immersed section.

[0011] An oil pump is installed inside the colloid, and an oil inlet and an oil outlet are provided on the colloid to communicate with the insulating oil chamber. The oil pump drives the insulating oil to circulate in the insulating oil chamber through the oil inlet and the oil outlet.

[0012] A first baffle is provided between the oil inlet and the oil outlet, which is used to prevent insulating oil from flowing directly between the oil inlet and the oil outlet.

[0013] Preferably, the outer peripheral surface of the portion of the anode rod immersed in the insulating oil is provided with a plurality of continuous corrugated grooves, the corrugated grooves being formed by a continuous transition of a circular arc surface, and the surface having no sharp edges.

[0014] Preferably, the outer surface of the portion of the anode rod located inside the vacuum chamber is coated with a radiation-dissipating coating, the surface emissivity of which is not less than 0.96.

[0015] Preferably, the thickness of the radiative heat dissipation coating is 30~80μm, and the thermal conductivity of the radiative heat dissipation coating is not less than 100W / (m·K).

[0016] Preferably, the sealing cylinder is made of alumina ceramic or aluminum nitride ceramic.

[0017] Preferably, the top of the colloid is integrally formed with an upwardly extending annular baffle, which is sleeved around the oil-immersed section of the anode rod to increase the creepage distance between the anode rod and the metal shell; the side wall of the annular baffle is provided with a through hole, through which insulating oil flows through the interior of the annular baffle.

[0018] Preferably, the annular baffle has two through holes on its sidewall, and a second partition is provided between the two through holes. The second partition extends radially inside the annular baffle to the anode rod. The second partition is used to guide the insulating oil to flow into the annular baffle from one of the through holes and then out from the other through hole.

[0019] Preferably, the device further includes a cooling fan, which is installed on the side of the colloid, and the airflow direction generated by the cooling fan is adapted to the heat dissipation fin structure formed on the outer surface of the colloid.

[0020] Preferably, the heat dissipation fin structure is a horizontally straight fin, which extends outward along the outer surface of the colloid, and the airflow direction generated by the cooling fan is parallel to the extension direction of the horizontally straight fin.

[0021] Preferably, the heat dissipation fin structure is columnar fins, which are arranged perpendicular to the outer surface of the colloid and in an array.

[0022] As described above, the enclosed X-ray generating device of the present invention has the following beneficial effects:

[0023] This invention significantly improves the convective heat transfer efficiency of the X-ray generator by optimizing the insulating oil chamber structure and combining it with a pump-driven circulation system that forces the insulating oil to flow through the inlet and outlet within the chamber. Addressing the issue of limited radiative heat transfer in the vacuum section of the anode rod, a high-emissivity radiative heat dissipation coating is applied to the surface of oxygen-free copper, greatly enhancing the surface radiative heat dissipation capacity of the anode rod. The use of a sealing cylinder made of high-thermal-conductivity alumina ceramic or aluminum nitride ceramic effectively reduces the thermal resistance of heat transfer from the vacuum side to the insulating oil side, breaking through the bottleneck of the critical heat conduction path. The continuous corrugated groove design of the anode rod immersion section and the integrated oil pump forced circulation system within the colloid further enhance the convective heat transfer effect. Numerical simulation results show that the closed X-ray generator of this invention can reduce the maximum surface temperature of the target material by 70°C and the average temperature of the anode rod by 90°C after 10 minutes of operation, effectively solving failure problems such as target melting, cracking, and detachment, and significantly extending the service life of the core components.

[0024] Furthermore, this invention achieves synergistic optimization of electrical insulation and heat dissipation performance in the colloidal structure; by opening through holes and setting baffles on the annular baffle, the insulating oil is guided to fully contact the anode rod for heat exchange, taking into account both creepage distance requirements and heat exchange efficiency; at the same time, the heat dissipation fin structure on the outer surface of the colloidal body, in conjunction with the cooling fan, effectively solves the heat accumulation problem of the internal transformer and oil pump, and the heat dissipation fins can be columnar fins that are not sensitive to wind direction, or straight fins to increase the heat exchange area, further improving the heat dissipation adaptability and reliability of the device in different installation environments. Attached Figure Description

[0025] Figure 1 The diagram shown is a cross-sectional view of a closed X-ray generating device in a specific embodiment of the present invention.

[0026] Figure 2 The diagram shown is a three-dimensional structural schematic of the colloid in a specific embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the colloid structure from another perspective in a specific embodiment of the present invention.

[0028] Figure 4 The diagram shown is a three-dimensional structural schematic of a closed X-ray generating device in a specific embodiment of the present invention.

[0029] Figure 5 The curves showing the change of the average temperature of the anode rod over time, as numerically simulated in Example 1 and the comparative example, are displayed.

[0030] Component designation explanation

[0031] 10 Metal casing 20 vacuum chamber 21 anode rod 30 Insulating oil chamber 40 Sealing cylinder 50 colloid 51 oil outlet 52 Oil inlet 53 First partition 54 Annular baffle 541 Through hole 542 Second partition 55 Heat sink fin structure 61 oil pump 62 transformer 70 Cooling fan 81 upper partition 82 lower partition Detailed Implementation

[0032] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0033] Before further describing specific embodiments of the present invention, it should be understood that the scope of protection of the present invention is not limited to the specific embodiments described below; it should also be understood that the terminology used in the embodiments of the present invention is for describing specific embodiments and not for limiting the scope of protection of the present invention. Test methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers.

[0034] When numerical ranges are given in the embodiments, it should be understood that, unless otherwise stated in the present invention, both endpoints of each numerical range and any value between the two endpoints may be selected. Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art. In addition to the specific methods, apparatus, and materials used in the embodiments, based on the knowledge of the prior art possessed by one of ordinary skill in the art and the description of this invention, any prior art methods, apparatus, and materials similar to or equivalent to those described, apparatus, and materials in the embodiments of this invention may be used to implement the present invention.

[0035] Please see Figures 1-4 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0036] The present invention provides a closed X-ray generating device, including a metal shell 10, an anode assembly disposed within the metal shell 10, an insulating oil chamber 30, and insulating oil filled in the insulating oil chamber 30. The device also includes a colloid 50 located at the bottom, the top surface of which supports the metal shell 10 and seals the bottom of the insulating oil chamber 30.

[0037] The anode assembly includes an anode rod 21, which is vertically arranged along the axial direction. The upper part of the anode rod 21 is located in the vacuum chamber 20, and the lower part is immersed in the insulating oil.

[0038] The vacuum chamber 20 and the insulating oil chamber 30 are separated by a sealing cylinder 40, which is sleeved on the outer periphery of the anode rod 21, dividing the anode rod 21 into a vacuum section and an oil-immersed section.

[0039] The colloid 50 is equipped with an oil pump 61. The colloid 50 has an oil inlet 52 and an oil outlet 51 that communicate with the insulating oil chamber 30. The oil pump 61 drives the insulating oil to circulate in the insulating oil chamber 30 through the oil inlet 52 and the oil outlet 51.

[0040] A first baffle 53 is provided between the oil inlet 52 and the oil outlet 51. The first baffle 53 is used to prevent the insulating oil from flowing directly between the oil inlet 52 and the oil outlet 51.

[0041] Specifically, X-rays are generated within the vacuum chamber 20, insulating oil provides insulation and heat dissipation, and the colloid 50 encapsulates an oil pump 61 and a transformer 62, primarily for providing power and electrical energy. The sealing cylinder 40 isolates the vacuum chamber 20 from the insulating oil chamber 30, ensuring both a tight seal and heat transfer from the vacuum chamber 20. This invention significantly improves the convective heat transfer efficiency of the X-ray generator by optimizing the structure of the insulating oil chamber 30 and combining it with the oil pump 61 to force the insulating oil to circulate within the insulating oil chamber 30 via the inlet 52 and outlet 51.

[0042] In existing X-ray generating devices, the insulating oil is enclosed in an insulating oil chamber 30. The flow of the insulating oil relies solely on natural convection. The intensity of natural convection depends on the density change of the fluid with temperature. However, the density change of insulating oil is minimal, resulting in weak natural convection. In a specific embodiment of this invention, an oil pump 61 is used to force the insulating oil to circulate within the insulating oil chamber 30, thereby increasing the convection intensity. See [link to relevant documentation]. Figure 2 An oil pump 61 can be encapsulated inside the colloid 50. The power supply for the oil pump 61 can be led out through a sealed wire. Two channels are opened inside the colloid 50 to connect the oil pump 61. Through the oil inlet channel and the oil outlet channel, the oil pump 61 forces the insulating oil to circulate within the insulating oil chamber 30. In addition, since the oil inlets 52 and 53 are close together, the insulating oil can easily enter through the oil inlet 52 and flow directly out through the oil outlet 51. Short-circuit flow cannot circulate sufficiently within the insulating oil chamber 30. Therefore, a first baffle 53 is added between the oil outlet 51 and the oil inlet to prevent short-circuit flow.

[0043] Preferably, the oil pump 61 is a miniature centrifugal oil pump 61 that drives the insulating oil to circulate in a forced manner, replacing natural convection; the colloid 50 is encapsulated with epoxy resin or injection molded.

[0044] In addition, see Figure 1 and Figure 4 The upper partition 81 and the lower partition 82 are fixedly installed at the upper and lower ends of the colloid 50, and the metal shell 10 is fixedly installed on the upper partition 81.

[0045] As an example, the outer peripheral surface of the portion of the anode rod 21 immersed in the insulating oil is provided with a plurality of continuous corrugated grooves, the corrugated grooves being formed by a continuous transition of a circular arc surface and having no sharp edges.

[0046] Specifically, a small portion of the anode rod 21 is immersed in insulating oil, transferring heat through convection. A continuous wave-shaped groove composed of arcs is machined into the oil-immersed section of the anode rod 21 to increase the heat dissipation area, and the absence of sharp edges prevents tip discharge. For practical applications, refer to... Figure 1The outer surface of the anode rod 21, which is completely immersed in insulating oil, is formed with continuous corrugated grooves. In addition, continuous corrugated grooves are also formed in the area adjacent to the actual oil-immersed section.

[0047] As an example, the outer surface of the portion of the anode rod 21 located inside the vacuum chamber 20 is coated with a radiation heat dissipation coating, the surface emissivity of which is not less than 0.96.

[0048] Specifically, after electrons bombard the anode target surface, a large amount of heat is released. This heat is transferred to the surface of the anode rod 21 through solid thermal conductivity. The surface of the anode rod 21 is divided into a vacuum section and a section in contact with the insulating oil. The vacuum section (vacuum segment) relies on radiation heat transfer, and the heat released per unit area of ​​surface is q = εσT. 4 T is the surface temperature, σ is the Stefan-Boltzmann constant, and ε is the surface emissivity, where ε is an intrinsic property of the material. In a specific embodiment of the invention, the anode rod 21 is made of oxygen-free copper, and the ε value of oxygen-free copper is between 0.03 and 0.2 (depending on different surface processes and wavelengths). The anode rod 21 is divided into a vacuum section and an oil-immersed section. The outer surface of the portion of the anode rod 21 located inside the vacuum chamber 20 is coated with a high-emissivity radiation heat dissipation coating to improve radiation heat dissipation efficiency and transfer heat to the sealing cylinder 40 via radiation. The surface emissivity of this radiation heat dissipation coating is not less than 0.96, which is much higher than the ε value of oxygen-free copper, increasing the radiation heat transfer by 5 to 10 times at the same surface temperature. Even considering the impact of adding the coating on solid heat transfer, the decrease in surface temperature is negligible compared to the increase in radiation heat transfer.

[0049] As an example, the thickness of the radiative heat dissipation coating is 30~80μm, and the thermal conductivity of the radiative heat dissipation coating is not less than 100W / (m·K).

[0050] Specifically, the thickness of the radiative heat dissipation coating can be any value within the range of 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, etc., and can be adjusted according to actual conditions, and its thermal conductivity is not less than 100W / (m·K); preferably, in the specific embodiment of the present invention, the superconducting infrared radiative heat dissipation coating QD385 produced by Bass Fluorine New Material Technology Co., Ltd. is used. The thermal conductivity of this coating itself is 175.2W / (m·K), which is lower than the thermal conductivity of copper (400W / (m·K)) but is on the same order of magnitude, and the coating thickness is extremely small. The resulting decrease in surface temperature is negligible compared with the increase in radiative heat transfer.

[0051] As an example, the sealing cylinder 40 is made of alumina ceramic or aluminum nitride ceramic.

[0052] Specifically, the heat lost from the surface of the anode rod 21 through radiation will be transferred to the inner surface of the sealing cylinder 40. The sealing cylinder 40 is the component that separates the vacuum chamber 20 and the insulating oil chamber 30. Therefore, the heat on the inner surface will be transferred to the outer surface through solid heat conduction, and then to the insulating oil through convection heat transfer. However, the material of the sealing cylinder 40 will affect the heat transfer between the inner and outer surfaces. Replacing the material of the sealing cylinder 40 with a material with a higher thermal conductivity, while ensuring that the electrical insulation is not lower than that of glass, is necessary. The thermal conductivity of alumina ceramic is 30~35 W / (m²). The aluminum nitride ceramic has a thermal conductivity of 320 W / (m·K) and extremely low electrical conductivity, making it suitable as an insulator. Its hardness is also sufficient to support the negative pressure generated by a vacuum. The aluminum nitride ceramic seal 40, using high thermal conductivity alumina or aluminum nitride ceramic, effectively reduces the thermal resistance of heat conduction from the vacuum side through the seal 40 to the insulating oil side. This allows the heat radiated from the anode rod 21 to quickly pass through the wall of the seal 40 and be transferred to the external insulating oil, instead of accumulating on the inner wall and reflecting back to the anode rod 21, thus breaking through the bottleneck of the critical heat conduction path. As an example, the top of the colloid 50 is integrally formed with an upwardly extending annular baffle 54. The annular baffle 54 is sleeved around the oil-immersed section of the anode rod 21 to increase the creepage distance between the anode rod 21 and the metal casing 10. The side wall of the annular baffle 54 has a through hole 541 through which the insulating oil flows through the interior of the annular baffle 54.

[0053] Specifically, the anode rod 21 carries an extremely high voltage (high potential), while the outer metal casing 10 is grounded (low potential). If the bottom of the anode rod 21 is too close to the bottom of the metal casing 10, surface creepage breakdown is likely to occur. By setting the annular baffle 54, the surface path length from the surface of the anode rod 21 to the surface of the metal casing 10 is forcibly increased, i.e., the creepage distance, thereby improving insulation reliability and preventing high-voltage breakdown. However, the setting of the annular baffle 54 also prevents the insulating oil from contacting the anode rod 21, which has a high temperature, so that the insulating oil can only flow outside the annular baffle 54, affecting convective heat transfer; in a specific embodiment of the present invention, see... Figure 3 An through hole 541 is opened on the side wall of the annular baffle 54. The insulating oil flows through the through hole 541 through the interior of the annular baffle 54 to exchange heat with the anode rod 21 which has a higher temperature, and then flows out, forming an effective cooling cycle.

[0054] Preferably, the annular baffle 54 is located at the bottom center of the insulating oil chamber 30, surrounding the oil-immersed section of the anode rod 21.

[0055] As an example, the sidewall of the annular baffle 54 has two through holes 541, and a second partition 542 is provided between the two through holes 541. The second partition 542 extends radially inside the annular baffle 54 to the anode rod 21. The second partition 542 is used to guide the insulating oil to flow into the annular baffle 54 from one of the through holes 541 and then out from the other through hole 541.

[0056] Specifically, the second partition 542 prevents short-circuit flow of insulating oil inside the annular baffle 54. See [link / reference]. Figure 3 The arrow points to the flow path of the insulating oil inside the annular baffle 54. The insulating oil enters the annular baffle 54 and directly contacts the root of the anode rod 21 for heat exchange before flowing out.

[0057] As an example, the device further includes a cooling fan 70, which is mounted on the side of the colloid 50, and the airflow direction generated by the cooling fan 70 is adapted to the heat dissipation fin structure 55 formed on the outer surface of the colloid 50.

[0058] As an example, the heat dissipation fin structure 55 is a horizontally straight fin that extends outward along the outer surface of the colloid 50, and the airflow direction generated by the cooling fan 70 is parallel to the extension direction of the horizontally straight fin.

[0059] As an example, the heat dissipation fin structure 55 is a columnar fin, which is arranged perpendicular to the outer surface of the colloid 50 and in an array.

[0060] Specifically, some of the heat absorbed by the insulating oil is carried away by the circulating flow, some is dissipated into the outside air through the metal casing 10, and a small portion is transferred to the colloid 50. Furthermore, the colloid 50 also encapsulates the transformer 62 that maintains the normal operation of the X-ray source, and the oil pump 61 is also encapsulated within the colloid 50. The normal operation of the oil pump 61 and the transformer 62 also generates heat. See [link to relevant documentation]. Figure 4 A cooling fan 70 is installed on the side bottom of the colloid 50 to increase the convective heat transfer coefficient of the colloid 50 surface.

[0061] In a specific embodiment of the present invention, see Figure 4 The outer surface of the colloid 50 is made into a horizontally straight fin shape to increase the heat dissipation area, and its shape is also adapted to the airflow direction generated by the fan.

[0062] In other examples, the outer surface of the colloid 50 may also be a columnar fin structure, arranged in an array perpendicular to the outer surface of the colloid 50, and is not affected by the airflow direction of the cooling fan 70.

[0063] To better understand the enclosed X-ray generating device of the present invention, the enclosed X-ray generating device of the present invention will be described below with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the present invention in any way.

[0064] Example 1

[0065] See Figures 1-4 This embodiment provides a closed X-ray generating device, including a metal shell 10, an anode assembly disposed within the metal shell 10, an insulating oil chamber 30, and insulating oil filled in the insulating oil chamber 30. The device also includes a colloid 50 located at the bottom, the top surface of which supports the metal shell 10 and seals the bottom of the insulating oil chamber 30.

[0066] The anode assembly includes an anode rod 21, which is vertically arranged along the axial direction. The upper part of the anode rod 21 is located inside the vacuum chamber 20, and the lower part is immersed in the insulating oil. The outer peripheral surface of the portion of the anode rod 21 immersed in the insulating oil is provided with several continuous corrugated grooves. The corrugated grooves are formed by a continuous transition of a circular arc surface and have no sharp edges. The anode rod 21 is made of oxygen-free copper. The outer surface of the portion of the anode rod 21 located inside the vacuum chamber 20 is coated with QD385 superconducting infrared radiation heat dissipation coating (thermal conductivity of 175.2 W / (m·K) and coating thickness of 30~80 μm) produced by Bass Fluorine New Material Technology Co., Ltd.

[0067] The vacuum chamber 20 and the insulating oil chamber 30 are separated by a sealing cylinder 40. The sealing cylinder 40 is sleeved on the outer periphery of the anode rod 21, dividing the anode rod 21 into a vacuum section and an oil-immersed section. The sealing cylinder 40 is made of alumina ceramic.

[0068] An oil pump 61 is installed inside the colloid 50. The colloid 50 has an oil inlet 52 and an oil outlet 51 communicating with the insulating oil chamber 30. The oil pump 61 drives the insulating oil to circulate within the insulating oil chamber 30 through the oil inlet 52 and the oil outlet 51. A first baffle 53 is provided between the oil inlet 52 and the oil outlet 51 to prevent the insulating oil from flowing directly between them. An upwardly extending annular baffle is integrally formed at the top of the colloid 50. 54. The annular baffle 54 is sleeved around the oil-immersed section of the anode rod 21 to increase the creepage distance between the anode rod 21 and the metal casing 10. The side wall of the annular baffle 54 has two through holes 541, and a second partition 542 is provided between the two through holes 541. The second partition 542 extends radially inside the annular baffle 54 to the anode rod 21. The second partition 542 is used to guide the insulating oil to flow into the annular baffle 54 from one of the through holes 541 and then out from the other through hole 541.

[0069] It also includes a cooling fan 70, which is installed on the side of the colloid 50, and the airflow generated by the cooling fan 70 is parallel to the extension direction of the transverse straight fins formed on the outer surface of the colloid 50.

[0070] Comparative Example 1

[0071] This comparative example provides a closed X-ray generating device, which differs from that in Example 1 in that: the vacuum section of the anode rod 21 is made of oxygen-free copper, and the outer surface of the oil-immersed section is a smooth surface; the sealing cylinder 40 is made of quartz glass; the top of the colloid 50 does not have an annular baffle 54, and it does not have an oil pump 61 and a cooling fan 70 installed; other structures are similar to those in Example 1, and will not be described in detail here.

[0072] See Figure 5 The curves showing the change of the average temperature of the anode rod 21 over time, as simulated numerically in Example 1 and Comparative Example 1, are shown. The X-ray generating devices in Example 1 and Comparative Example 1 operated for 10 minutes. Compared with Comparative Example 1, the average temperature of the anode rod 21 in Example 1 decreased by 90°C, showing a significant heat dissipation effect. At this time, the highest temperature on the surface of the anode target material in Example 1 decreased by 70°C.

[0073] In summary, this invention significantly improves the convective heat transfer efficiency of the X-ray generator by optimizing the insulating oil chamber structure and combining it with a pump-driven circulation system that forces the insulating oil to flow through the inlet and outlet within the chamber. Addressing the issue of limited radiative heat transfer in the vacuum section of the anode rod, a high-emissivity radiative heat dissipation coating is applied to the oxygen-free copper surface, greatly enhancing the surface radiative heat dissipation capacity of the anode rod. The use of a high-thermal-conductivity alumina ceramic or aluminum nitride ceramic sealing cylinder effectively reduces the thermal resistance of heat transfer from the vacuum side to the insulating oil side, breaking through the bottleneck of the key heat conduction path. The continuous corrugated groove design of the anode rod immersion section and the integrated oil pump forced circulation system within the colloid further enhance the convective heat transfer effect. Numerical simulation results show that the closed X-ray generator of this invention, under 10 minutes of operation, can reduce the maximum surface temperature of the target material by 70°C and the average temperature of the anode rod by 90°C, effectively solving failure problems such as target melting, cracking, and detachment, and significantly extending the service life of the core components. Furthermore, this invention achieves synergistic optimization of electrical insulation and heat dissipation performance in its colloidal structure. By creating through holes and installing partitions on the annular baffle, the insulating oil is guided to fully contact the anode rod for heat exchange, balancing creepage distance requirements and heat exchange efficiency. Simultaneously, the heat dissipation fin structure on the outer surface of the colloidal body, in conjunction with a cooling fan, effectively solves the heat accumulation problem of the internal transformer and oil pump. Moreover, the heat dissipation fins can be columnar fins insensitive to wind direction, or straight fins to increase the heat exchange area, further improving the device's heat dissipation adaptability and reliability in different installation environments. Therefore, this invention effectively overcomes the various shortcomings of existing technologies and has high industrial application value.

[0074] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A closed X-ray generating device, comprising a metal casing, an anode assembly disposed within the metal casing, an insulating oil chamber, and insulating oil filling the insulating oil chamber, characterized in that, The device also includes a colloid located at the bottom, the top surface of which supports the metal housing and seals the bottom of the insulating oil chamber; The anode assembly includes an anode rod, which is vertically arranged along the axial direction. The upper part of the anode rod is located in the vacuum chamber, and the lower part is immersed in the insulating oil. The vacuum chamber and the insulating oil chamber are isolated by a sealing cylinder, which is sleeved around the outer periphery of the anode rod, dividing the anode rod into a vacuum section and an oil-immersed section. An oil pump is installed inside the colloid, and an oil inlet and an oil outlet are provided on the colloid to communicate with the insulating oil chamber. The oil pump drives the insulating oil to circulate in the insulating oil chamber through the oil inlet and the oil outlet. A first baffle is provided between the oil inlet and the oil outlet, which is used to prevent insulating oil from flowing directly between the oil inlet and the oil outlet.

2. The enclosed X-ray generating device according to claim 1, characterized in that: The outer peripheral surface of the portion of the anode rod submerged in the insulating oil is provided with several continuous corrugated grooves, which are formed by a continuous transition of a circular arc surface and have no sharp edges.

3. The enclosed X-ray generating device according to claim 1, characterized in that: The outer surface of the portion of the anode rod located inside the vacuum chamber is coated with a radiation heat dissipation coating, the surface emissivity of which is not less than 0.

96.

4. The enclosed X-ray generating device according to claim 3, characterized in that: The thickness of the radiative heat dissipation coating is 30~80μm, and the thermal conductivity of the radiative heat dissipation coating is not less than 100W / (m·K).

5. The enclosed X-ray generating device according to claim 1, characterized in that: The sealing cylinder is made of alumina ceramic or aluminum nitride ceramic.

6. The enclosed X-ray generating device according to claim 1, characterized in that: The top of the colloid is integrally formed with an upwardly extending annular baffle, which is sleeved around the oil-immersed section of the anode rod to increase the creepage distance between the anode rod and the metal shell; the side wall of the annular baffle has a through hole, through which insulating oil flows through the interior of the annular baffle.

7. The enclosed X-ray generating device according to claim 6, characterized in that: The annular baffle has two through holes on its side wall, and a second partition is provided between the two through holes. The second partition extends radially inside the annular baffle to the anode rod. The second partition is used to guide the insulating oil to flow into the annular baffle from one of the through holes and then out from the other through hole.

8. The enclosed X-ray generating device according to claim 1, characterized in that: The device also includes a cooling fan, which is installed on the side of the colloid, and the airflow direction generated by the cooling fan is adapted to the heat dissipation fin structure formed on the outer surface of the colloid.

9. The enclosed X-ray generating device according to claim 8, characterized in that: The heat dissipation fin structure is a horizontally straight fin, which extends outward along the outer surface of the colloid, and the airflow direction generated by the cooling fan is parallel to the extension direction of the horizontally straight fin.

10. The enclosed X-ray generating device according to claim 8, characterized in that: The heat dissipation fin structure is columnar fins, which are arranged perpendicular to the outer surface of the colloid and in an array.

Images