Radio frequency coaxial transmission line

Abstract

The invention discloses a radio frequency coaxial transmission line which comprises a straight feeder line section located in the middle, a male head end / female head end arranged at one end of the straight feeder line section and a male head end / female head end arranged at the other end of the straight feeder line section. Wherein the male head end and the female head end are both connected with water injection sections, and the male head end and / or the female head end, the straight feeder section and the water injection sections are communicated to form a cooling flow channel through which a cooling medium can pass; a cooling medium is injected into the male head end / female head end through the water injection section located at one end of the straight feeder line section, and the cooling medium flows into the straight feeder line section and flows out from the male head end / female head end at the other end of the straight feeder line section and the water injection section on the male head end / female head end, so that the transmission line is cooled. Therefore, the transmission line has an excellent heat dissipation function, can transmit high-power radio frequency waves, and can be applied to continuous transmission of high-power radio frequency waves with different sizes.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency transmission, and in particular to a radio frequency coaxial transmission line. Background Art

[0002] RF coaxial transmission lines transmit RF signals from the RF source to the terminal and are widely used in signal transmission occasions such as broadcasting, television, radar, and various occasions using RF applications. They are particularly widely used in the field of megawatt-level high-power RF wave heating, usually as the front and end stages of the RF power source or between the output and the heating antenna.

[0003] Radio frequency waves, as a major auxiliary heating method, have been widely used in fusion devices. The total power level is generally between hundreds of kilowatts and tens of megawatts, and the operating frequency is 10 to 200 MHz. Depending on the total power of the system, power transmission generally requires several or more than a dozen coaxial transmission lines. The radio frequency power to be transmitted by each transmission line is about 1.5 megawatts, and its power level is as high as the megawatt level.

[0004] In the ion cyclotron wave power transmission system of the EAST (Experimental and Advanced Superconducting Tokamak) device, since the RF heating system is far away from EAST, the transmission line length usually needs to be about tens of meters to more than one hundred meters, and is generally connected by a coaxial line with a length of about two meters, so the overall length is relatively long. Due to the existence of the surface resistance of the conductor, the coaxial transmission line will produce RF loss in the process of power transmission. For example, when transmitting 1.5 megawatts of RF power, the transmission line will produce about 200 watts of ohmic loss per meter, and the heat generation is relatively large, especially when the RF system is running in continuous wave, the heat generated is extremely large. Therefore, when transmitting megawatt-level RF high power, the heat dissipation problem of the transmission line must be considered, but the coaxial transmission line in the prior art has insufficient heat dissipation capacity. Summary of the invention

[0005] The embodiment of the present application provides a radio frequency coaxial transmission line, which solves the technical problem in the prior art that the coaxial transmission line has insufficient heat dissipation capacity and is unable to transmit high-power radio frequency.

[0006] In order to solve the above technical problems, an embodiment of the present application provides a radio frequency coaxial transmission line, wherein the transmission line includes a direct feed line segment located in the middle, a male end / female end arranged at one end of the direct feed line segment, and a male end / female end arranged at the other end of the direct feed line segment;

[0007] Wherein, the male end and the female end are both connected to a water injection section, and the male end and / or the female end, the direct feeder line section, and the water injection section are connected to form a cooling flow channel through which the cooling medium can pass;

[0008] A cooling medium is injected into the male / female end through the water injection section at one end of the direct feeder line segment. The cooling medium flows into the direct feeder line segment and flows out from the male / female end at the other end of the direct feeder line segment and the water injection section thereon, thereby cooling the transmission line.

[0009] Furthermore, the direct feeder segment includes a direct feeder segment inner conductor tube, a direct feeder segment middle conductor tube and a direct feeder segment outer conductor tube, which are coaxially arranged and are nested inside and outside, and the gap between the direct feeder segment inner conductor tube and the direct feeder segment middle conductor tube forms a cooling channel for the cooling medium to pass through, wherein:

[0010] Connectors for connecting male ends / female ends are respectively provided on the left and right ends of the outer conductor tube of the direct feeder line segment;

[0011] The left and right ends of the conductor tube in the direct feeder line segment are symmetrically provided with conductor tube plugs in the direct feeder line segment;

[0012] The left and right ends of the direct feeder line segment inner conductor tube are symmetrically provided with direct feeder line segment inner conductor tube plugs, and a concave cavity recessed into the direct feeder line segment inner conductor tube is formed on the outer end surface of the direct feeder line segment inner conductor tube plug;

[0013] The axial gap between the conductor tube plug in the direct feeder line segment and the conductor tube plug inside the direct feeder line segment communicates with the cooling channel and the male end / female end.

[0014] Furthermore, the female end and the male end each include a body segment for being inserted and fixed in a conductor tube plug in the direct feeder line segment, and the inner end of the body segment is in communication with the axial gap;

[0015] The female end also includes a female end inner conductor electrical contact spring claw disposed on the outer end of the body section, so as to connect the male end / the water injection section and conduct the inner cavity of the body section of the female end and the male end / the water injection section;

[0016] The male end also includes a male end inner conductor arranged on the outer end of the body section for connecting the female end / the water injection section and conducting the inner cavity of the body section of the male end and the inner cavity / water injection section of the body section of the female end.

[0017] Furthermore, the female end also includes a female end outer conductor coaxially arranged outside the female end inner conductor electrical contact spring claw, so as to protect the female end inner conductor electrical contact spring claw located therein.

[0018] Furthermore, an insulating support member is provided between the main body segment and the connecting member, two ends of the insulating support member respectively support the outer circumference of the main body segment and the inner circumference of the connecting member, and the insulating support member is made of ceramic material.

[0019] Furthermore, the water injection section comprises a water injection section outer conductor and a water injection section inner conductor coaxially arranged in the water injection section outer conductor;

[0020] The left end of the inner conductor of the water injection section is connected to a water injection section inner conductor electrical contact spring claw for connecting and communicating with the male end inner conductor of the male end, and the right end of the inner conductor of the water injection section is connected to a water injection section male end inner conductor electrical contact spring claw for connecting and communicating with the female end inner conductor of the female end.

[0021] Furthermore, at least one water injection rod is arranged between the outer conductor of the water injection section and the inner conductor of the water injection section along the circumferential direction, and both ends of the water injection rod are connected;

[0022] The outer end of the water injection rod passes through the outer circumference of the outer conductor of the water injection section and is fixed on the outer circumference of the outer conductor of the water injection section; the inner end of the water injection rod penetrates the inner conductor of the water injection section and communicates with the inner cavity of the inner conductor of the water injection section, and the inner cavity of the inner conductor of the water injection section is used to communicate with the male end or the female end;

[0023] The cooling medium can be injected into the inner cavity of the conductor in the water injection section through any of the water injection rods, and the injected cooling medium can flow from the inner cavity of the conductor in the water injection section into the male end or the female end, and flow from the axial gap into the cooling channel;

[0024] Alternatively, the water in the cooling channel may flow out from the axial gap into the male end or the female end, and be discharged from the inner cavity of the conductor in the water injection section through any one of the water injection rods.

[0025] Furthermore, the transmission line is also provided with a self-locking water-proof leakage-proof structure to prevent the cooling medium from leaking out of the cooling channel when the male end and / or the female end is repaired and disassembled on the direct feeder line segment;

[0026] The self-locking water-proofing structure includes a movable inner conductor of a self-locking water-blocking core rod, and the inner conductor of the self-locking water-blocking core rod has a first position and a second position during the movement;

[0027] When the inner conductor of the self-locking water core rod is located at the first position, the axial gap is connected; when the inner conductor of the self-locking water core rod is located at the second position, the axial gap is sealed and the two ends of the cooling channel are cut off.

[0028] Furthermore, the inner conductor of the self-locking water core rod includes a self-locking core rod that is axially movable and arranged in the inner cavity of the body segment, and one end of the self-locking core rod facing the inner conductor tube plug of the direct feeder segment is connected to a stop surface;

[0029] A spring is sandwiched between the stop surface and the bottom of the concave cavity, and the outer diameter of the stop surface is equal to the outer diameter of the body section and the inner diameter of the concave cavity;

[0030] The water injection section is provided with a pushing piece which can push the self-locking core rod when the male end or the female end is installed in place on the straight feeder line section, so as to push the stop surface to move into the concave cavity to the first position, and the axial gap is connected;

[0031] When the male end and / or the female end becomes loose on the straight feeder line segment, the stop surface loses the pushing effect of the pushing member, and the stop surface moves to the second position in contact with the inner end surface of the main body segment under the action of the restoring elastic force of the spring, and the outer peripheral surface of the stop surface seals the axial gap, and the two ends of the cooling channel are cut off.

[0032] Furthermore, the interior of the conductor inside the self-locking water-blocking core rod is hollow.

[0033] Furthermore, a plurality of limiting columns are arranged on the stop surface at intervals around the spring to limit the radial position of the spring on the stop surface.

[0034] Furthermore, the outer end of the water injection rod passes through the outer circumference of the outer conductor of the water injection section and is fixed on the outer circumference of the outer conductor of the water injection section through a sealing cover;

[0035] The sealing cover is provided with a water injection port, through which the cooling medium can be injected into the water injection rod or discharged.

[0036] The RF coaxial transmission line described in the embodiment of the present application is provided with a male end / female end at both ends of a direct feed line segment, and a water injection segment is connected to the male end and the female end. Water is injected into the male end / female end through the water injection segment on the male end / female end at one end of the direct feed line segment. The water will flow into the direct feed line segment and flow out from the male end / female end at the other end of the direct feed line segment and the water injection segment thereon, thereby forming water cooling, so that the transmission line has excellent heat dissipation function, can transmit high-power RF waves, and can be used for continuous transmission of high-power RF waves of different sizes.

[0037] In addition, in order to prevent the male end or the female end from loosening or separating on the direct feed line segment during disassembly and maintenance, thereby preventing water from leaking out between the conductor tube inside the direct feed line segment and the conductor tube in the direct feed line segment, the RF coaxial transmission line is also provided with a self-locking water-proof structure, which further improves the practicability of the transmission line.

[0038] In addition, the RF coaxial transmission line uses ceramic insulation support inside, which can reduce the power loss of the insulating medium during high-power transmission, improve the stability of the transmission line during high-power transmission and the convenience of maintenance and cleaning when the insulation support is ignited, and reduce maintenance costs.

[0039] Finally, it should be noted that the RF coaxial transmission line described in the embodiment of the present application has a simple structure and is easy to install and implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 This is a schematic diagram of the overall structure of a radio frequency coaxial transmission line in one embodiment of the present invention;

[0042] Figure 2 It is a partial structural schematic diagram (female end and male end) of another radio frequency coaxial transmission line in one embodiment of the present invention;

[0043] Figure 3 It is a partial structural schematic diagram (two male ends) of another radio frequency coaxial transmission line in one embodiment of the present invention;

[0044] Figure 4 It is a partial structural schematic diagram (two female ends) of another radio frequency coaxial transmission line in one embodiment of the present invention;

[0045] Figure 5 This is a schematic structural diagram of a water injection section in one embodiment of the present invention;

[0046] Figure 6 It is a schematic diagram of the structure of the male end and the female end matching in one embodiment of the present invention;

[0047] Figure 7 It is an end view of a water injection section in one embodiment of the present invention;

[0048] in, Figure 1 The arrows in the figure are schematic diagrams of the flow direction of the cooling medium in the cooling channel. DETAILED DESCRIPTION

[0049] The embodiment of the present application provides a radio frequency coaxial transmission line, which solves the technical problem in the prior art that the coaxial transmission line has insufficient heat dissipation capacity and is unable to transmit high-power radio frequency.

[0050] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0051] like Figures 1 to 3 As shown, one or more embodiments of the present application provide a radio frequency coaxial transmission line, including a direct feed line segment b located in the middle, a male end c / female end a arranged at the left end of the direct feed line segment b, and a male end c / female end a arranged at the right end of the direct feed line segment b, wherein the male end c and the female end a are both connected to a water injection segment d, and water is injected into the male end c / female end a through the water injection segment d on the male end c / female end a at one end of the direct feed line segment b, and the water will flow into the direct feed line segment b, and flow out from the male end c / female end a at the other end of the direct feed line segment b and the water injection segment d thereon, thereby forming water cooling, so that it has better heat dissipation capacity, so that high-power radio frequency waves can be transmitted. Of course, other cooling media, such as cooling oil, etc., can also be used, which is not limited here.

[0052] It should be noted that for ease of description, reference Figure 1 In the embodiment of the present application, the central axis direction of the direct feeder segment b or the direction parallel to the central axis of the direct feeder segment b is the axial direction, the radial direction refers to the diameter of the cross section of the direct feeder segment b or the direction parallel to the diameter of the cross section of the direct feeder segment b, the circumferential direction is the direction around the central axis of the direct feeder segment b, and one end along the axial direction is the left end, the other opposite end is the right end, the inner direction is toward the center of the direct feeder segment b, and the outer direction is toward the outside of the direct feeder segment b; symmetry refers to the symmetry of the cross section of the direct feeder segment b. The following description is based on the above-mentioned reference orientation, which will not be repeated here, but it should be noted that the above-mentioned limitation of the orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiment of the present application.

[0053] Specifically, Figure 2 As shown, the left end of the direct feeder line segment b is provided with a female end a, and the right end is provided with a male end c. Figure 3 As shown, a pair of male ends c are symmetrically provided at the left and right ends of the direct feeder line segment b. Figure 4 As shown, a pair of female end a are symmetrically arranged at the left and right ends of the direct feed line segment b.

[0054] like Figures 1 to 4As shown, the direct feeder line segment b includes a direct feeder line segment inner conductor tube 16, a direct feeder line segment middle conductor tube 17 and a direct feeder line segment outer conductor tube 4 which are sequentially arranged from the inside to the outside and spaced apart from each other, and the direct feeder line segment inner conductor tube 16, the direct feeder line segment middle conductor tube 17 and the direct feeder line segment outer conductor tube 4 are coaxially arranged. The gap between the direct feeder line segment inner conductor tube 16 and the direct feeder line segment middle conductor tube 17 forms a cooling channel 41 for cooling water to pass through.

[0055] Still Figures 1 to 4 As shown, a first flange 5 and a second flange 22 are welded on the left and right ends of the outer conductor tube 4 of the direct feed line segment, respectively, and a live flange 19 is also sleeved on the second flange 22. The live flange 19 is fixed to the second flange 22 by a live flange fixing ring 20. The live flange 19 is provided to facilitate adjustment of the angle and direction.

[0056] like Figure 2 As shown, the left and right ends of the conductor tube 17 in the direct feed line segment are symmetrically provided with conductor tube plugs 12 and 18 in the direct feed line segment, respectively. The conductor tube plugs 12 and 18 in the direct feed line segment include two sections with different diameters arranged in sequence along the axial direction, wherein the section with a larger diameter is welded to the inner circumferential walls at the left and right ends of the conductor tube 17 in the direct feed line segment, and the section with a smaller diameter extends axially outward of the conductor tube 17 in the direct feed line segment, and due to the variable diameter setting of the conductor tube plugs 12 and 18 in the direct feed line segment, a first step surface is formed on the outer circumferential surface of the conductor tube plugs 12 and 18 in the direct feed line segment.

[0057] Still Figure 2 As shown, the left and right ends of the direct feed line segment inner conductor tube 16 are symmetrically provided with direct feed line segment inner conductor tube plugs 15, the outer circumferential surface of the direct feed line segment inner conductor tube plug 15 is welded to the inner circumferential surface of the two ends of the direct feed line segment inner conductor tube 16, and the end surface of the direct feed line segment inner conductor tube plug 15 is recessed into the direct feed line segment inner conductor tube 16, forming a concave cavity 151 coaxially arranged with the direct feed line segment inner conductor tube 16.

[0058] The lengths of the two ends of the conductor tube 16 in the direct feed line segment are shorter than the lengths of the two ends of the conductor tube 17 in the direct feed line segment. Thus, there is an axial gap 40 between the conductor tube plug 15 in the direct feed line segment and the conductor tube plugs 12 and 18 in the direct feed line segment. The axial gap 40 can connect the cooling channel 41 and the male end c / female end a.

[0059] like Figures 2 to 4As shown, the female end a and the male end c both include a body section 8 for being inserted and fixed in the conductor tube plug 12, 18 in the direct feeder line segment, and the body section 8 includes a first shaft section 81 with a smaller diameter and a second shaft section 82 with a larger diameter, wherein the first shaft section 81 is used to be inserted into the conductor tube plug 12, 18 in the direct feeder line segment, and the second shaft section 82 is used to abut against the outer end surface of the conductor tube plug 12, 18 in the direct feeder line segment when the first shaft section 81 is inserted into the conductor tube plug 12, 18 in the direct feeder line segment and has a function of limiting the axial position of the body section 8. The outer diameter of the second shaft section 82 is the same as the outer diameter of the smaller diameter section of the conductor tube plug 12, 18 in the direct feeder line segment, so that the outer circumferential surface of the second shaft section 82 is flush with the outer circumferential surface of the smaller diameter section of the conductor tube plug 12, 18 in the direct feeder line segment. A ceramic insulating support 6 is provided between the first flange 5 and the second flange 22 on the left and right ends of the outer conductor tube 4 of the direct feed line segment and the main body segment 8. The outer end of the ceramic insulating support 6 is clamped on the inner circumferential surface of the first flange 5 or the second flange 22, and the inner end of the ceramic insulating support 6 is in contact with the outer circumferential surface of the second shaft segment 82 and the first step surface.

[0060] Specifically, during installation, the left and right direct feed line segment inner conductor tube plugs 15 need to be respectively welded on the direct feed line segment inner conductor tube 16 and inserted together into the direct feed line segment middle conductor tube 17, and then the direct feed line segment middle conductor tube plugs 12 and 18 need to be respectively welded on the two ends of the direct feed line segment middle conductor tube 17 and inserted together into the direct feed line segment outer conductor tube 4.

[0061] like Figure 2 , 4 As shown, in the female end a, the outer end of the second shaft section 82 of the body section 8 is also coaxially connected to the female end inner conductor electrical contact spring claw 7, the female end inner conductor electrical contact spring claw 7 can be made of aluminum bronze, and a first female insertion cavity is formed on its outer end surface, which can be inserted into the male end c or the water injection section d, as shown in FIG. Figure 1 , 7 As shown. Figure 2 , 3 As shown, in the male end c, the outer end of the second shaft section 82 of the body section 8 is also coaxially connected to the male end inner conductor 21, which can be made of brass, and a first male plug is formed on its outer end surface, which can be inserted into the first female plug cavity or the water injection section d of the female end a, as shown in FIG. Figure 1 , 7 And the inner conductor 21 of the male end and the body section 8 of the male end c can be integrally formed, as shown in FIG. Figure 3 shown.

[0062] like Figure 2 , 4As shown, inside the female end a, the female end inner conductor electrical contact spring claw 7 is coaxially provided with a female end outer conductor 1, and the female end outer conductor 1 can be connected and fixed to the first flange 5 on the outer conductor tube 4 of the direct feeder segment by bolts 39, and the main body section 8 superimposed on the female end a is inserted and fixed in the conductor tube plug 12 of the direct feeder segment, so that the female end a is fixed on one end of the direct feeder segment b. In addition, the female end inner conductor electrical contact spring claw 7 is completely located in the female end outer conductor 1, so that the female end outer conductor 1 can protect the female end inner conductor electrical contact spring claw 7 located therein to prevent the female end inner conductor electrical contact spring claw 7 from being deformed during storage and transportation.

[0063] The main body section 8 of the female end a is axially penetrated, and one end is connected to the inner cavity of the conductor electrical contact spring claw 7 in the female end, and the other end is connected to the concave cavity 151 of the conductor tube 16 in the direct feed line segment, the conductor tube 16 in the direct feed line segment, and the cooling channel 41 between the conductor tube 17 in the direct feed line segment.

[0064] like Figure 1 , 5 As shown, the water injection section d includes a water injection section outer conductor 24 and a water injection section inner conductor 26 coaxially arranged in the water injection section outer conductor 24. The left end of the water injection section outer conductor 24 can be connected to the female end outer conductor 1, and the right end of the water injection section outer conductor 24 is provided with a water injection section outer conductor flange 25 for connecting to the male end live flange 19. The left end of the water injection section inner conductor 26 is connected with a water injection section inner conductor electrical contact spring claw 28 for plugging with the male end c. The water injection section inner conductor electrical contact spring claw 28 is mushroom-shaped and can be made of aluminum bronze. It has a second female cavity that is plugged with the first male plug of the male end inner conductor 21, and can be used for the male end inner conductor 21 to be inserted; the right end of the water injection section inner conductor 26 is connected with a water injection section male inner conductor 31 for connecting with the female end a. The water injection section male inner conductor 31 can be made of brass, and has a second male plug that is plugged with the first female cavity of the female end inner conductor electrical contact spring claw 7. The water injection section male inner conductor 31 can be fixed to the right end of the water injection section inner conductor 26 by axially arranged pins, screws, etc.

[0065] like Figure 5 , 6As shown, three ceramic water injection rods 37 are arranged between the water injection section outer conductor 24 and the water injection section inner conductor 26 at intervals of 120° in the circumferential direction. Both ends of the ceramic water injection rods 37 are through-connected. The radial outer end of the ceramic water injection rod 37 passes through the outer circumferential surface of the water injection section outer conductor 24 and is fixed on the outer circumferential surface of the water injection section outer conductor 24 through the sealing cover 34. A water injection port connected to the ceramic water injection rod 37 is formed on the sealing cover 34. The radial inner end of the ceramic water injection rod 37 penetrates the water injection section inner conductor 26 and is connected to the inner cavity of the water injection section inner conductor 26. The ceramic water injection rod 37 provides star-point support, which can not only inject water, but also support the water injection section inner conductor 26 and the water injection section outer conductor 24 to each other to maintain the overall stability. Of course, the ceramic water injection rods 37 can also be provided with 4, more or less, which is not limited here.

[0066] like Figure 1 As shown, when the water injection section d is used to connect the female end a, an axially extending through inner cavity is formed in the brass male inner conductor 31 of the water injection section, and the inner cavity of the brass male inner conductor 31 of the water injection section is communicated with the inner cavity of the water injection section inner conductor 26. When the water injection section d is used to connect the male end c, an axially extending through inner cavity is formed in the electrical contact spring claw 28 of the inner conductor of the water injection section, and the inner cavity of the electrical contact spring claw 28 of the inner conductor of the water injection section is communicated with the inner cavity of the inner conductor 26 of the water injection section.

[0067] like Figure 1 , 5 As shown, the right end of the water injection section d is used to connect the female end a. When the water injection section d is connected to the female end a, the second male plug of the water injection section d is inserted into the first female plug cavity of the female end inner conductor electrical contact spring claw 7, and the female end inner conductor electrical contact spring claw 7 is connected and fixed to the water injection section inner conductor 26 of the water injection section d by screws. The water injection port at the left end, the ceramic water injection rod 37, the inner cavity of the water injection section inner conductor 26, the inner cavity of the water injection section brass male inner conductor 31, the inner cavity of the body section 8 of the female end a, the gap between the direct feeder line segment conductor tube 17 plug and the direct feeder line segment conductor tube plug 15, and the gap between the direct feeder line segment conductor tube 16 and the direct feeder line segment conductor tube 17 are connected in sequence to form a first flow channel, so that water can be fed into or drained from the direct feeder line segment b.

[0068] like Figure 1 , 5As shown, the left end of the water injection section d is used to connect to the male end c. When the water injection section d is connected to the male end c, the first male plug of the conductor 21 in the male end is inserted into the second female plug cavity of the water injection section d. The water injection port at the right end, the ceramic water injection rod 37, the inner cavity of the conductor 26 in the water injection section, the inner cavity of the conductor electrical contact spring claw 28 in the water injection section, the inner cavity of the body section 8 of the male end c, the gap between the conductor tube 17 plug in the direct feed line segment and the conductor tube plug 15 in the direct feed line segment, and the gap between the conductor tube 16 in the direct feed line segment and the conductor tube 17 in the direct feed line segment are connected in sequence to form a second flow channel, so that water can be supplied or discharged to the direct feed line segment b. The above-mentioned first flow channel and the second flow channel are connected to each other, and the coolant enters and exits the first flow channel and the second flow channel, thereby forming a cooling flow channel, as shown in FIG. Figure 1 shown.

[0069] It should be noted that the conductor tube 16 in the direct feed line segment and the conductor tube plug 15 in the direct feed line segment are made of stainless steel to meet the cooling channel requirements. In addition, the entire cooling channel is designed as a sandwich cooling channel, which not only reduces the demand for the total amount of cooling water, but also reduces the weight of the entire transmission line, and can increase the flow rate of cooling water and improve heat exchange efficiency. In this way, the RF coaxial transmission line described in the embodiment of the present application can withstand MW-level continuous wave power.

[0070] Further, such as Figures 1 to 5 As shown, the inner conductor electrical contact spring claw 7 of the female end and the inner conductor electrical contact spring claw 28 of the water injection section both adopt a mushroom-shaped head notch design, and multiple electrical contact spring claws are arranged along the circumference therein, for example, 100 electrical contact spring claws. The 100 electrical contact spring claws can fully disperse the current requirement of 1500A, and can achieve good electrical contact when assembled with the inner conductor 21 of the male end.

[0071] Further, such as Figure 2 As shown, a first sealing ring 10 is provided between the main body section 8 and the conductor tube plugs 12, 18 in the direct feeder line section, and an end face sealing ring 9 is provided between the main body section 8 and the inner conductor electrical contact spring claw 7 at the female end, and the first sealing ring 10 is an O-ring embedded on the outer circumferential surface of the main body section 8 to seal the assembly gap between the main body section 8 and the conductor tube plugs 12, 18 in the direct feeder line section, and the end face sealing ring 9 is an O-ring embedded on the outer end surface of the main body section 8 to seal the assembly gap between the main body section 8 and the inner conductor electrical contact spring claw 7 at the female end to prevent water leakage in the cooling channel.

[0072] Further, such as Figure 2 As shown, two second sealing rings 23 are axially spaced apart on the first male plug of the inner conductor 21 of the male end to enhance the sealing performance when inserted into the female end a or the water injection section d to prevent water leakage in the cooling channel.

[0073] Further, such as Figure 2 As shown, the left and right ends of the female end outer conductor 1 are respectively provided with a female end outer conductor sealing special-shaped ring 3 and a female end outer conductor contact spring 2 to ensure good contact of the flange section, which can provide effective RF leakage shielding function and meet the design requirements of avoiding electromagnetic radiation leakage.

[0074] In order to prevent the male end c or the female end a from loosening or separating on the direct feeder line segment b during disassembly and maintenance, thereby preventing water from leaking out between the conductor tube 16 in the direct feeder line segment and the conductor tube 17 in the direct feeder line segment, the transmission line is also provided with a self-locking water-proof structure.

[0075] like Figures 1 to 4 As shown in , 7, the self-locking water-proof structure includes a self-locking water-blocking core rod inner conductor 11, and the self-locking water-blocking core rod inner conductor 11 includes a self-locking core rod 111 which can be axially moved left and right and is arranged in the inner cavity of the main body section 8. The self-locking core rod 111 is provided with a stop surface 112 at one end facing the inner conductor tube plug 15 of the direct feed line segment, and the self-locking core rod 111 is vertically connected to the stop surface 112, and the whole is approximately umbrella-shaped. The outer diameter of the stop surface 112 is equal to the outer diameter of the body section 8 and the inner diameter of the concave cavity 151, so that the stop surface 112 also has the function of supporting the conductor tube plug 15 in the direct feeder segment. A spring 14 is sandwiched between the stop surface 112 and the bottom of the concave cavity 151. One end of the spring 14 abuts against the stop surface 112, and a plurality of limit posts 113 are arranged around the spring 14 on the stop surface 112 to limit the radial position of the spring 14 on the stop surface 112, and the gaps between the limit posts 113 allow water to flow through. The outer end of the self-locking core rod 111 extends into the inner cavity of the inner conductor electrical contact spring claw 7 at the female end or the inner conductor 21 at the male end. In addition, a shoulder 114 is provided on the outer circumference of the self-locking core rod 111 to play a limiting role.

[0076] like Figure 1 As shown, the water injection section d is provided with a pushing member 42 which can push the self-locking core rod 111 when the male end c or the female end a is installed in place on the straight feeder line section b, so as to compress the spring 14 and push the stop surface 112 to move into the concave cavity 151 to the first position, and the axial gap 40 is connected, as shown in FIG. Figure 1 As shown, in this way, the first flow channel and the second flow channel are connected;

[0077] When disassembly and maintenance are required, the male end c and / or the female end a are loosened on the straight feeder line segment b, the distance between the self-locking core rod 111 and the pushing member 42 increases, the stop surface 112 loses the pushing effect of the pushing member 42, and the stop surface 112 moves to the second position in contact with the inner end surface of the body segment 8 under the restoring elastic force of the spring 14, and the outer peripheral surface of the stop surface 112 seals the axial gap 40, as shown in FIG. Figure 2 , 3 As shown in FIG. 4 , the two ends of the cooling channel 41 are cut off to prevent water leakage. The self-locking water-proof structure can realize the self-locking water-proof function during disassembly and maintenance by blocking the axial free movement of the inner conductor 11 of the self-locking water core rod.

[0078] Further, such as Figure 1 As shown, the pushing member 42 is coaxially fixed in the inner cavity of the male inner conductor 31 of the water injection section, the outer ring of the pushing member 42 is fixed on the inner wall surface of the inner cavity of the male inner conductor 31 of the water injection section, and the center of the pushing member 42 is provided with a pushing surface 421 for pushing the outer end of the self-locking core rod 111, and the pushing surface 421 is connected to the outer ring through spaced connecting columns, and the gap between adjacent connecting columns is for cooling medium to pass through.

[0079] Furthermore, a pushing screw 422 may be provided on the pushing surface 421 , so that when the pushing surface 421 fails to contact the self-locking core rod 111 , the pushing screw 422 is used to push the outer end surface of the self-locking core rod 111 .

[0080] Furthermore, the inner conductor 11 of the self-locking water-blocking rod is hollow, which reduces its own weight and enables it to move back and forth under the bearing force of the spring.

[0081] Furthermore, a third sealing ring 13 is embedded on the side of the stop surface 112 facing the main body section 8. The third sealing ring 13 is an O-ring to further seal the gap between the stop surface 112 and the main body section 8, thereby preventing water leakage in the cooling channel.

[0082] Furthermore, a fourth sealing ring 30 is arranged between the inner conductor 31 of the water injection section male head and the inner conductor 26 of the water injection section, and the fourth sealing ring 30 is embedded in the inner conductor 31 of the water injection section male head to seal the installation gap between the inner conductor 31 of the water injection section male head and the inner conductor 26 of the water injection section to prevent water leakage in the cooling channel.

[0083] Furthermore, a fifth sealing ring 32 is coaxially sleeved on the second male plug of the inner conductor 31 of the male plug of the water injection section.

[0084] Furthermore, a sixth sealing ring 29 is provided between the inner conductor 26 of the water injection section and the inner conductor electrical contact spring claw 28 of the water injection section, and the sixth sealing ring 29 is used to seal the installation gap between the inner conductor 26 of the water injection section and the inner conductor electrical contact spring claw 28 of the water injection section to prevent water leakage in the cooling channel.

[0085] Furthermore, a first radial through hole for inserting a ceramic water injection rod 37 is provided on the outer conductor 24 of the water injection section, and the ceramic water injection rod 37 passes through the first radial through hole. The top surface of the sealing cover 34 buckles the ceramic water injection rod 37, and the bottom surface of the sealing cover 34 is tightened on the outer circumferential surface of the outer conductor 24 of the water injection section by screws, and the water injection port is provided on the top surface of the sealing cover 34. In addition, a seventh sealing ring 33 is provided between the inner wall surface of the sealing cover 34 and the outer circumferential surface of the ceramic water injection rod 37, and an eighth sealing ring 38 is provided between the sealing cover 34 and the outer conductor 24 of the water injection section. The seventh sealing ring 33 and the eighth sealing ring 38 are both fixed on the sealing cover 34 to seal the assembly gap between the sealing cover 34 and the ceramic water injection rod 37 and the outer conductor 24 of the water injection section to avoid water leakage in the cooling channel.

[0086] Furthermore, a second radial through hole for inserting a ceramic water injection rod 37 is provided on the inner conductor 26 of the water injection section, and a ninth sealing ring 27 is provided on the inner wall of the second radial through hole to seal the installation gap between the outer conductor 24 of the water injection section, the inner conductor 26 of the water injection section and the ceramic water injection rod 37 to prevent water leakage in the cooling channel.

[0087] Furthermore, the left and right end faces of the water injection section outer conductor 24 are respectively provided with water injection section outer conductor contact springs 36 and water injection section outer conductor sealing special-shaped rings 35 to ensure good contact of the flange section, which can provide effective RF leakage shielding function and meet the design requirements of electromagnetic radiation leakage.

[0088] like Figures 1 to 7 As shown, when the female end a is installed, first put the spring 14 into the concave cavity 151 at the left end of the conductor tube plug 15 in the direct feed line segment, then assemble the first sealing ring 13 on the inner conductor 11 of the self-locking water core rod, and assemble them into the conductor tube plug 15 in the direct feed line segment at the left end, install the first sealing ring 10 on the main body section 8 at the left end and insert it into the conductor tube plug 12 in the direct feed line segment, then put the outer periphery of the ceramic insulating support 6 into the first flange 5, insert the whole into the central axis hole of the ceramic insulating support 6, and fix it with screws, then clamp the inner conductor electrical contact spring claw 7 of the female end a onto the main body section 8 and fix it with screws.

[0089] When installing the male end c, first put the spring 14 into the concave cavity 151 at the right end of the direct feed line segment inner conductor tube plug 15, then assemble the third sealing ring 13 on the inner conductor 11 of the self-locking water core rod, and assemble them together into the direct feed line segment inner conductor tube plug 15 at the right end, put the ceramic insulating support 6 into the second flange 22, put the first sealing ring 10 on the main body section 8 of the male end, put the second sealing ring 23 on the inner conductor 21 of the male end, and then insert it into the central axis hole of the ceramic insulating support 6 and fix it with screws.

[0090] Next, the female end outer conductor sealing shaped ring 3 and the female end outer conductor contact spring piece 2 are respectively installed on the left and right ends of the female end outer conductor 1, and then fixed on the second outer conductor flange 5 with screws. In this way, a coaxial straight feeder transmission line is assembled.

[0091] The outer conductor flange 25 of the water injection section is installed on the outer conductor 24 of the water injection section. The inner conductor electrical contact spring claw 28 of the water injection section and the male inner conductor 31 of the water injection section are respectively fixed to the inner conductor 26 of the water injection section with the sixth sealing ring 29 by screws after the fifth sealing ring 32 and the fourth sealing ring 30 are put on. After the ninth sealing ring 27 is installed in the hole of the inner conductor 26 of the water injection section, the whole is inserted into the outer conductor 24 of the water injection section. Three ceramic water injection rods 37 are respectively inserted from the first radial through hole on the outer conductor 24 of the water injection section into the second radial through hole on the inner conductor 26 of the water injection section. After the seventh sealing ring 33 and the eighth sealing ring 38 are installed on the sealing cover 34, they are fixed to the ceramic water injection rods 37 by screws. The outer conductor contact spring piece 36 of the water injection section and the outer conductor sealing special-shaped ring 35 of the water injection section are installed on the outer conductor flange 25 of the water injection section. Finally, the water injection sections d on both sides are fixed to the direct feeder line segment by screws to form the entire coaxial water-injectable transmission line system.

[0092] The above-mentioned self-locking water-proofing structure, when the male and female ends are matched, the self-locking core rod 111 will open the cold water system to allow water to flow smoothly. When the flanges 5 and 19 are disassembled, the self-locking core rod 111 will be reset to the initial position by the elastic force of the spring to make the cooling flow channel self-locking, so that it can move freely in the main body section 8 to realize the self-locking water-proofing function during disassembly and maintenance.

[0093] It should be noted that in the prior art, the mainstream RF coaxial transmission line uses polytetrafluoroethylene as the inner and outer conductor insulation support material. When running at high power, the transmission line (transmission line insulation support) will spark, causing damage to the insulation support and failure of the transmission line, thus affecting the experiment; because polytetrafluoroethylene will produce a large amount of ablation dust when it ignites, it brings great inconvenience to the maintenance, cleaning, and replacement of the insulation support of the transmission line, which is time-consuming and labor-intensive. Once the insulation is damaged, it can only be replaced with a new support, which increases the maintenance cost.

[0094] The present application adopts the ceramic insulating support 6 and the ceramic water injection rod 37 as support, which adopts 99% high-purity porcelain (alumina ceramic with a purity of 99%, also called 99 porcelain), which can reduce the power loss of the insulating medium during high-power transmission. At the same time, RF compensation, creepage grooves and holes are designed on the ceramic insulating support 6 to extend the creepage distance and improve the withstand voltage of the insulating support. The characteristic impedance of the coaxial transmission line is 50 ohms.

[0095] Applying the RF coaxial transmission line described in the embodiment of the present application to the RF heating system of the large-scale superconducting tokamak nuclear fusion experimental device EAST can achieve good RF wave transmission and heat dissipation effects, improve the stability of the transmission line during high-power transmission and the convenience of maintenance and cleaning when the insulation support is ignited, and reduce maintenance costs; in addition, because it has added a self-locking water leakage prevention function, it can effectively prevent water leakage in the cooling channel during maintenance.

[0096] It should be understood that although the terms "first", "second", etc. may be used herein to describe various units, these units should not be limited by these terms. These terms are used only to distinguish one unit from another. For example, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit without departing from the scope of the exemplary embodiments.

[0097] The directional terms such as outer, middle, inner, etc. mentioned or may be mentioned in this specification are defined relative to the structures shown in the drawings. They are relative concepts and may change accordingly according to different positions and different usage conditions. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0098] The above is only a preferred embodiment of the present application, and is not any formal or substantial limitation to the present application. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the method of the present application, and these improvements and supplements should also be regarded as the protection scope of the present invention. Any technician familiar with this profession, without departing from the spirit and scope of the present application, can make some changes, modifications and evolutions of the technical content disclosed above, which are equivalent embodiments of the present application; at the same time, any changes, modifications and evolutions of any equivalent changes made to the above embodiments based on the substantial technology of the present application are still within the scope of the technical solution of the present application.

Claims

1. A radio frequency coaxial transmission line, characterized in that: The transmission line comprises a direct feed line segment (b) located in the middle, a male end (c) / female end (a) arranged at one end of the direct feed line segment (b), and a male end (c) / female end (a) arranged at the other end of the direct feed line segment (b); Wherein, the male end (c) and the female end (a) are both connected to a water injection section (d), and the male end (c) and / or the female end (a), the direct feeder line section (b), and the water injection section (d) are connected to form a cooling flow channel for the cooling medium to pass through; A cooling medium is injected into the male end (c) / female end (a) through the water injection section (d) located at one end of the direct feed line section (b), and the cooling medium flows into the direct feed line section (b) and flows out from the male end (c) / female end (a) at the other end of the direct feed line section (b) and the water injection section (d) thereon, thereby cooling the transmission line.

2. A radio frequency coaxial transmission line according to claim 1, characterized in that: The direct feeder line segment (b) comprises a direct feeder line segment inner conductor tube (16), a direct feeder line segment middle conductor tube (17) and a direct feeder line segment outer conductor tube (4) which are coaxially arranged and are nested inside and outside, and a gap between the direct feeder line segment inner conductor tube (16) and the direct feeder line segment middle conductor tube (17) forms a cooling channel (41) for the cooling medium to pass through, wherein: Connectors for connecting the male end (c) / female end (a) are respectively provided on the left and right ends of the outer conductor tube (4) of the direct feeder line segment; The left and right ends of the direct feeder line section conductor tube (17) are symmetrically provided with direct feeder line section conductor tube plugs (12, 18); The left and right ends of the direct feeder line segment inner conductor tube (16) are symmetrically provided with direct feeder line segment inner conductor tube plugs (15), and a concave cavity (151) recessed into the direct feeder line segment inner conductor tube (16) is formed on the outer end surface of the direct feeder line segment inner conductor tube plug (15); The axial gap (40) between the conductor tube plug (12, 18) in the direct feeder line segment and the conductor tube plug (15) in the direct feeder line segment communicates with the cooling channel (41) and the male end (c) / female end (a).

3. A radio frequency coaxial transmission line as claimed in claim 2, characterized in that: The female end (a) and the male end (c) both include a body section (8) for being inserted and fixed in a conductor tube plug (12, 18) in the direct feeder line section, and the inner end of the body section (8) is connected to the axial gap (40); The female end (a) further comprises a female end inner conductor electrical contact spring claw (7) arranged on the outer end of the body section (8) for connecting the male end (c) / the water injection section (d) and conducting the inner cavity of the body section (8) of the female end (a) and the male end (c) / the water injection section (d); The male end (c) also includes a male end inner conductor (21) arranged on the outer end of the main body section (8) for connecting the female end (a) / the water injection section (d) and conducting the inner cavity of the main body section (8) of the male end (c) and the inner cavity of the main body section (8) / the water injection section (d) of the female end (a).

4. A radio frequency coaxial transmission line as claimed in claim 3, characterized in that: The female end (a) also includes a female end outer conductor (1) coaxially arranged outside the female end inner conductor electrical contact spring claw (7) to protect the female end inner conductor electrical contact spring claw (7) located therein.

5. The radio frequency coaxial transmission line according to claim 3, characterized in that: An insulating support member (6) is also provided between the main body section (8) and the connecting member, and the two ends of the insulating support member (6) respectively support the outer circumference of the main body section (8) and the inner circumference of the connecting member, and the insulating support member (6) is made of ceramic material.

6. The radio frequency coaxial transmission line according to claim 3, characterized in that: The water injection section (d) comprises a water injection section outer conductor (24) and a water injection section inner conductor (26) coaxially arranged inside the water injection section outer conductor (24); The left end of the water injection section inner conductor (26) is connected to a water injection section inner conductor electrical contact spring claw (28) for connecting and communicating with the male end inner conductor (21) of the male end (c), and the right end of the water injection section inner conductor (26) is connected to a water injection section male end inner conductor (31) for connecting and communicating with the female end inner conductor electrical contact spring claw (7) of the female end (a).

7. A radio frequency coaxial transmission line as claimed in claim 6, characterized in that: At least one water injection rod (37) is arranged between the water injection section outer conductor (24) and the water injection section inner conductor (26) at intervals along the circumferential direction, and both ends of the water injection rod (37) are connected; The outer end of the water injection rod (37) passes through the outer circumference of the water injection section outer conductor (24) and is fixed on the outer circumference of the water injection section outer conductor (24); the inner end of the water injection rod (37) passes through the water injection section inner conductor (26) and is connected to the inner cavity of the water injection section inner conductor (26), and the inner cavity of the water injection section inner conductor (26) is used to communicate with the male end (c) or the female end (a); The cooling medium can be injected into the inner cavity of the conductor (26) in the water injection section through any of the water injection rods (37), and the injected cooling medium can flow from the inner cavity of the conductor (26) in the water injection section into the male end (c) or the female end (a), and flow from the axial gap (40) into the cooling channel (41); Alternatively, the water in the cooling channel (41) can flow out from the axial gap (40) into the male end (c) or the female end (a), and be discharged from the inner cavity of the conductor (26) in the water injection section through any one of the water injection rods (37).

8. The radio frequency coaxial transmission line according to claim 2, characterized in that: The transmission line is also provided with a self-locking water-proof leakage-proof structure to prevent the cooling medium from leaking out of the cooling channel when the male end (c) and / or the female end (a) are repaired and disassembled on the direct feeder line section (b); The self-locking water-proofing structure comprises a movable inner conductor (11) of a self-locking water-blocking core rod, wherein the inner conductor of the self-locking water-blocking core rod has a first position and a second position during the movement; When the inner conductor (11) of the self-locking water core rod is located at a first position, the axial gap (40) is connected; when the inner conductor (11) of the self-locking water core rod is located at a second position, the axial gap (40) is sealed and both ends of the cooling channel (41) are cut off.

9. A radio frequency coaxial transmission line as claimed in claim 8, characterized in that: The self-locking water core rod inner conductor (11) comprises a self-locking core rod (111) which is axially movable and arranged in the inner cavity of the body section (8); one end of the self-locking core rod (111) facing the inner conductor tube plug (15) of the direct feeder section is connected to a stop surface (112); A spring (14) is sandwiched between the stop surface (112) and the bottom of the concave cavity (151); the outer diameter of the stop surface (112) is equal to the outer diameter of the body section (8) and the inner diameter of the concave cavity (151); The water injection section (d) is provided with a pushing member (42) which can push the self-locking core rod (111) when the male end (c) or the female end (a) is installed in place on the straight feeder line section (b), so as to push the stop surface (112) to move into the concave cavity (151) to the first position, and the axial gap (40) is connected; When the male end (c) and / or the female end (a) are loosened on the direct feeder line segment (b), the stop surface (112) loses the pushing effect of the pushing member (42), and the stop surface (112) moves to the second position in contact with the inner end surface of the main body segment (8) under the action of the restoring elastic force of the spring (14), and the outer peripheral surface of the stop surface (112) seals the axial gap (40), and the two ends of the cooling channel (41) are cut off.

10. The radio frequency coaxial transmission line according to claim 9, characterized in that: The inner conductor (11) of the self-locking water-blocking core rod is hollow.

11. The radio frequency coaxial transmission line according to claim 9, characterized in that: A plurality of limiting columns (113) are arranged at intervals on the stop surface (112) around the spring (14) to limit the radial position of the spring (14) on the stop surface (112).

12. The radio frequency coaxial transmission line according to claim 7, characterized in that: The outer end of the water injection rod (37) passes through the outer circumference of the outer conductor (24) of the water injection section and is fixed on the outer circumference of the outer conductor (24) of the water injection section through a sealing cover (34); The sealing cover (34) is provided with a water injection port, through which the cooling medium can be injected into the water injection rod (37) or discharged.

Images