Heat sink device for a microwave magnetron

Abstract

Heat sink device for a microwave magnetron (17), comprising a heat conduction space (10) comprising a first block (101) and a second block (102), wherein the first block (101) has a first crescent-shaped cavity and the second block (102) has a second crescent-shaped cavity; wherein, since the first block (101) and the second block (102) are connected to form the heat conduction space (10), the first crescent-shaped cavity and the second crescent-shaped cavity are integrated to form a central hole (100) for an antenna (170) to pass through, a first set of heat sinks (12); and at least one first flat and curved heat tube (11), one end of which projects into the space for conducting heat (10) and the other end of which extends into the first heat fin set (12) and wherein the first heat fin set (12) is located above the space for conducting heat (10); a second set of heat sinks (15); and at least one second flat and curved heat tube (14), wherein one end of the second heat tube (14) penetrates the heat conduction space (10) and another end of the second heat tube (14) extends into the second heat fin set, and wherein the second heat fin set (15) is located above the heat conduction space (10) in such a way that it is symmetrical to the first heat fin set (12) with respect to the heat conduction space (10); the space for conducting heat (10) allows an antenna (170) of the microwave magnetron (17) to pass through it.

Description

TECHNICAL FIELD

[0001] The invention relates to a heat sink device for a microwave magnetron, and more particularly to a heat sink device that provides better heat dissipation performance for microwave magnetrons. STATE OF THE ART

[0002] The diverse applications of microwave technology are primarily attributed to two inventions in the 1930s: the magnetron and the waveguide. Indeed, microwave technology was successfully used during World War II to develop radar and communications components.

[0003] After World War II, in addition to broader applications in military technology, the output power and energy of microwaves and magnetrons also improved. Furthermore, their applications expanded to everyday and industrial areas. For example, the household microwave oven is one of many innovative developments in these applications. Other examples of these innovative developments include medium- and high-power microwave heating systems, microwave chemical digestion and polymerization reactors, microwave plasma generators and sources, high-power microwave light sources, and so on.

[0004] EP 1 355 340 A2 discloses a magnetron which has an improved self-cooling effect.

[0005] US 4 296 355 A describes a magnetron comprising an elongated cooling structure.

[0006] CN 1 04 329 867 A discloses a cold transfer and heat dissipation arrangement for a semiconductor refrigerator, a modular assembly, an assembly method and a semiconductor refrigerator.

[0007] TW 2016 40992 A describes a combined heat dissipation module for removing heat from a heat source.

[0008] A heat dissipation device for heat dissipation for electronic components is known from TW 2009 30275 A.

[0009] The TW M350974 U is a thin heat dissipation device.

[0010] DE 27 06 165 A1 discloses a cooling arrangement for electrical components.

[0011] As described above, the magnetron is one of the milestones that has played a key role in these microwave applications. The magnetron's features include clear structure, simple designs, small size, high power density, high power output, higher stability, and simple power supply and power control design, making it one of the most common components for microwave generators.

[0012] However, the magnetron may have some weaknesses, such as narrower operating bandwidths, less frequency adjustability, and enormous heat dissipation requirements in a tiny volume.

[0013] For small- and medium-power magnetrons with power ratings between 200W and 3000W, the heat dissipation mechanism required for stable operation is at least a reinforced air cooling system or a water cooling system. On the other hand, for high-power magnetrons or microwave ovens, the heat dissipation mechanism is usually a water cooling system.

[0014] Although a small- to medium-power magnetron can be cooled by forced air cooling, it can still result in excessive operating temperatures or an output power approaching the limits of the heat dissipation fan. Therefore, for devices operating under harsh environmental conditions, a water-cooled heat dissipation mechanism is generally the better choice.

[0015] Furthermore, a magnetron using a water cooling system may experience poor heat dissipation efficiency while a blockage occurs in the heat dissipation tube or associated piping. In this situation, the magnetron could potentially be damaged or fail, or the associated manufacturing process could be compromised, for example, due to water loss. Therefore, it is quite possible that a major production downtime or equipment damage could occur. TECHNICAL SOLUTION

[0016] Accordingly, an object of the present invention is to provide a heat sink device for a microwave magnetron that uses heat pipes to dissipate heat. Thus, compared to a conventional air- or water-cooled heat dissipation kit, better heat dissipation performance can be achieved by using the heat sink device of the present invention.

[0017] In the present invention, the heat sink device for a microwave magnetron includes a heat conduction space, a first heat conduction set, and at least one first heat pipe. One end of the first heat pipe protrudes into the heat conduction space, while the other end protrudes into the first heat fin set. The heat conduction space allows an antenna of the microwave magnetron to pass through it.

[0018] In one embodiment of the present invention, a first heat dissipation fan is further included and mounted on the first heat fin set, and the first heat fin set further includes a side shield. The first heat pipe is one of a flat heat pipe and a plurality of heat pipes.

[0019] In one embodiment of the present invention, at least one second heat pipe and a second heat conduction set are further included. One end of the second heat pipe penetrates the heat conduction space, and another end of the second heat pipe extends into the second heat fin set.

[0020] In one embodiment of the present invention, a second heat dissipation fan is further included, which is mounted on the second heat fin set. Furthermore, the second heat fin set further includes a side shield, and the second heat pipe is one of a flat heat pipe and a plurality of heat pipes.

[0021] In one embodiment of the present invention, the heat conduction space comprises a first block and a second block. The first block has a first crescent-shaped cavity, and the second block has a second crescent-shaped cavity. Since the first block and the second block are coupled together to form the heat conduction space, the first crescent-shaped cavity and the second crescent-shaped cavity are integrated into a central hole for the antenna to pass through.

[0022] In one embodiment of the present invention, one end of the first heat pipe penetrates through the first block and another end of the first heat pipe penetrates through the first heat fin set and projects into the second block.

[0023] In one embodiment of the present invention, one end of the first heat pipe extends into the first heat fin set and another end of the first heat pipe extends into the first block; one end of the second heat pipe extends into the second heat fin set and another end of the second heat pipe extends into the second block.

[0024] As mentioned above, by providing the heat sink device for a microwave magnetron of the present invention, better heat dissipation performance can be achieved by applying the heat sink device of the present invention compared to the conventional air-cooled or water-cooled heat dissipation kit.

[0025] All these goals are achieved by the heat sink device for a microwave magnetron described below. SHORT DESCRIPTION OF THE CHARACTERS

[0026] The present invention will now be specified with reference to its preferred embodiment illustrated in the drawings in which: Fig. 1 is a schematic perspective view of a first embodiment of the heat sink device for a microwave magnetron according to the present invention; Fig. 2 shows part of Fig. 1; Fig. Figure 3 schematically shows the changes of heat dissipation temperature gradients for 8 heat pipes under 600W, 800W, 1000W and 1300W respectively; Fig. Figure 4 schematically shows the changes in the heat dissipation temperature gradients for 8, 10, 12 and 14 heat pipes, respectively; Fig. 5 is a schematic perspective view of a second embodiment of the heat sink device for a microwave magnetron according to the present invention; Fig. 6 is a schematic cross-sectional view of Fig. 5; Fig. Figure 7 is a schematic diagram of the output powers and temperatures at the detection points of the microwave magnetron according to the present invention. DESCRIPTION OF A PREFERRED EMBODIMENT

[0027] The disclosed invention relates to a heat sink device for a microwave magnetron. In the following description, numerous details are set forth to provide a thorough understanding of the present invention. It will be appreciated by one skilled in the art that variations of these specific details are possible while still achieving the effects of the present invention. In other instances, well-known components are not described in detail so as not to unnecessarily obscure the present invention.

[0028] With reference to Fig. 1 and Fig.Figure 2 shows a first embodiment of the heat sink device for a microwave magnetron. The heat sink device includes a heat conduction space 10, at least one first heat pipe 11, a first heat fin set 12, a first heat dissipation fan 13, at least one second heat pipe 14, a second heat fin set 15, and a second heat dissipation fan 16.

[0029] The heat conduction seat 10, made of a conductive metal (e.g., copper), has a central hole 100 through which an antenna 170 of a microwave magnetron 17 can pass. Furthermore, the heat conduction seat 10 includes a first block 101 and a second block 102. A first crescent-shaped cavity is formed on one side of the first block 101, and a second crescent-shaped cavity is formed on another side of the second block 102. Since the first block 101 and the second block 102 are coupled to form the heat conduction seat 10, the first crescent-shaped cavity and the second crescent-shaped cavity are integrated with each other to form the central hole 100 of the heat conduction seat 10.

[0030] The microwave magnetron 17 has a first magnet, a cathode, an anode, a second magnet, and a set of fins. The antenna 170 penetrates the first magnet, the cathode, the anode, and the second magnet. The set of fins is mounted outside the first magnet, the cathode, the anode, and the second magnet.

[0031] In addition, the microwave magnetron 17 has a cathode and anode forming a diode core structure, magnetic poles, and an antenna. The microwave magnetron 17, as a vacuum tube with a diode structure, mainly includes a cathode for generating an electron beam, an anode for receiving the electron beam, a microwave resonance chamber for converting the electron beam into a corresponding microwave, and an antenna for guiding the microwave from the resonance chamber.

[0032] The cathode is structured as a tubular, high-temperature-resistant fiber made of a high-temperature-resistant material, such as W, Th, W-Th alloy, or a rare-earth alloy. The purpose of using the rare-earth material is to generate more thermal electrons to increase the output power.

[0033] The anode is made of high-purity, oxygen-free copper with low electrical conductivity and high thermal conductivity.

[0034] The core structure consists of a central fiber, a cathode, and an anode surrounding the cathode. The anode has an internal hole or cavity that serves as a resonance cavity for microwave oscillations. A space between the cathode and the anode serves as an electron passage.

[0035] The fiber, acting as the cathode, is connected to a low voltage, i.e., to a negative end of the power source for the microwave generator. On the other hand, the anode is connected to a positive end (usually ground) of the power source. Generally, the power source for the microwave magnetron 17 is a high-voltage electrical source.

[0036] The core structure is clamped between two lateral magnets arranged parallel to the opposite sides of the anode so that the corresponding magnetic lines can run parallel to the line connecting the anode and the cathode.

[0037] The first heat pipe 11 may be a single flat heat pipe or a plurality of heat pipes. One end of the first heat pipe 11 extends into the first heat fin set 12, while another end of the first heat pipe 11 extends into the first block 101 of the heat conduction space 10.

[0038] The first heat dissipation fan 13 is mounted on the first heat fin set 12, which has a side shield 120. The side shield 120, located below the first heat dissipation fan 13, covers the first heat fin set 12.

[0039] The second heat pipe 14 can be a single flat heat pipe or a plurality of heat pipes. One end of the second heat pipe 14 extends into the second block 102 of the heat conduction space 10, while another end of the second heat pipe 14 extends into the second heat fin set 15.

[0040] The second heat dissipation fan 16 is arranged on the second heat fin set 15, which further includes a side shield 150. The side shield 150, located below the second heat dissipation fan 16, covers the second heat fin set 15.

[0041] Both the first heat pipe 11 and the second heat pipe 14 have the following advantages: high thermal conductivity for better heat conduction in terms of capacity and distance, uniform temperature distribution for temperature compensation because it is a passive element with low power consumption, no specific heat conduction direction, which facilitates changing the heat conduction path and thus exchanging the evaporation and condensation sides, simple design and processing, light weight and simple structuring, long service life, reliability and easy storage.

[0042] Regarding heat dissipation capacity and heat source, the heat source (for generating heat) on the microwave magnetron is located in the core area surrounded by the anode, including the heat generated by the high-temperature fiber and during the conversion from electricity to microwave. For a typical microwave magnetron with a power of less than 10 kW, the anode can have a diameter of about 4.5 cm, a height of about 5.0 cm, and a calculated volume of about 79.5 cm. 3 (ml) and a surface area of ​​about 70.7cm 2 Based on a heat dissipation requirement of 1285 W, the heat dissipation rate per square centimeter for calculating the heat dissipation capacity is approximately 18.2 W / cm 2 .

[0043] Related to Fig.3, in this embodiment, each of the first heat pipe 11 and the second heat pipe 14 has 8 heat pipes, and the heat dissipation power for the test is set to 600 W, 800 W, 1000 W, and 1300 W, respectively. Table 1 600W 800W 1000W 1300W Core heat source 90.23°C 105.28°C 120.32°C 142.83°C Environment heat source 87.77°C 102.00°C 116.21°C 137.48°C Heat dissipation fins 87.07°C 101.07°C 115.05°C 135.98°C Outside heat dissipation fins 56.44°C 60.25°C 64.04°C 69.73°C

[0044] As in Fig. 3, curve A represents the changes in the heat dissipation gradients for the heat dissipation power of 600 W in Table 1. Curve B represents the changes in the heat dissipation gradients for the heat dissipation power of 800 W in Table 1. Curve C represents the changes in the heat dissipation gradients for the heat dissipation power of 1000 W in Table 1 and curve D represents the changes in the heat dissipation gradients for the heat dissipation power of 1300 W in Table 1. In Table 1 and Fig.3 shows an 8-tube example that when the heat dissipation power is increased from 600 W to 1300 W, the temperature in the core of the heat source is increased by approximately 53°C, while the temperature outside the heat dissipation fins is increased by approximately 14°C.

[0045] Related to Fig. 4, in this embodiment, the number of heat pipes (including the first heat pipe 11 and the second heat pipe 14) is set to 8, 10, 12, 14 heat pipes, and the heat dissipation power for the test is set to 1300 W. Table 2 8 pipes 10 pipes 12 pipes 14 pipes Core heat source 142.83°C 135.86°C 128.30°C 124.74°C Environment heat source 137.48°C 131.78°C 121.60°C 118.21°C Heat dissipation fins 135.98°C 130.12°C 1121.35°C 118.12°C Outside heat dissipation fins 69.73°C 69.17°C 69.78°C 71.49°C

[0046] As shown in Table 2 and Fig.4, curve E represents changes in heat dissipation gradients when testing 8 pipes. Curve F represents changes in heat dissipation gradients when testing 10 pipes. Curve G represents changes in heat dissipation gradients when testing 12 pipes, and curve H represents changes in heat dissipation gradients when testing 14 pipes. From Table 2 and Fig. 4 shows that at a heat dissipation power of 1300 W, the temperatures in the core of the heat source differ between 8-tube and 14-tube examples by about 18°C ​​and those outside the heat dissipation fins by about 1.8°C.

[0047] With reference to Fig. 5 and Fig.6 shows a second embodiment of the heat sink device for a microwave magnetron, not according to the invention. This embodiment includes a heat conduction space 24, at least one first heat pipe 22, a first heat fin set 21, and a first heat dissipation fan 20.

[0048] The heat conduction space 24 has a central hole 242 through which an antenna of a microwave magnetron 25 can pass. Furthermore, the heat conduction space 24 has a first block 240 and a second block 241. A first crescent-shaped cavity is formed on one side of the first block 240, and a second crescent-shaped cavity is formed on another side of the second block 241. Since the first block 240 and the second block 241 are coupled to form the heat conduction space 24, the first crescent-shaped cavity and the second crescent-shaped cavity are integrated together to form the central hole 242 of the heat conduction space 24.

[0049] The first heat pipe 22 can be a single flat heat pipe or a plurality of heat pipes. One end of the first heat pipe 22 extends into the first block 240 of the heat conduction space 24, while the other end of the first heat pipe 11 extends through the first heat fin set 21 into the second block 241 of the heat conduction space 24.

[0050] The first heat dissipation fan 20 is arranged on the first heat fin set 21. A side shield 23, located below the first heat fin set 21, covers the heat dissipation area 24 and the microwave magnetron 25.

[0051] Since the heat sink device for a microwave magnetron of this invention is operated with an output power of 3000 W and with reference to Fig.7, Curve L implies that the core temperature is maintained at approximately 138°C. Curve K means that the heat conduction space is maintained at approximately 114°C. Curve J means that the end of the heat pipe is maintained at approximately 78°C, and Curve I shows that the heat dissipation fin (either the first set of fins or the second set of fins) is maintained at approximately 46°C. The above temperatures are kept stable throughout the 1-hour test. This proves that the power of 3000W can be applied to the present invention. Some other examples also prove that the present invention can be implemented even with the magnetrons used with an even higher power.

[0052] In summary, comparing with the conventional air-cooled or water-cooled heat dissipation kits, better heat dissipation performance can be achieved by applying the heat sink of the present invention.

[0053] Although the present invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention.

Claims

[1] Heat sink device for a microwave magnetron (17), comprising a heat conduction space (10) comprising a first block (101) and a second block (102), the first block (101) having a first crescent-shaped cavity and the second block (102) having a second crescent-shaped cavity; wherein, since the first block (101) and the second block (102) are connected to each other to form the heat conduction space (10), the first crescent-shaped cavity and the second crescent-shaped cavity are integrated to form a central hole (100) for an antenna (170) to pass through, a first set of heat fins (12); and at least one first flat and curved heat pipe (11), one end of which projects into the heat conducting space (10) and the other end of which extends into the first heat fin set (12), and wherein the first heat fin set (12) is located above the heat conducting space (10); a second set of heat fins (15); and at least one second flat and curved heat pipe (14), one end of the second heat pipe (14) penetrating the heat conducting space (10) and another end of the second heat pipe (14) extending into the second heat fin set, and the second heat fin set (15) being located above the heat conducting space (10) so as to be symmetrically opposite the first heat fin set (12) with respect to the heat conducting space (10); wherein the heat conducting space (10) allows an antenna (170) of the microwave magnetron (17) to pass through it. [2] A heat sink device for a microwave magnetron (17) according to claim 1, comprising a first heat dissipation fan (13) arranged on the first heat fin set (12). [3] A heat sink device for a microwave magnetron (17) according to claim 1, wherein the first heat fin set (12) has a side shield (120). [4] A heat sink device for a microwave magnetron (17) according to claim 1, further comprising a second heat dissipation fan (16) disposed on the second heat fin set (15). [5] A heat sink device for a microwave magnetron (17) according to claim 4, wherein the second heat fin set (15) further has a side shield (150).

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