Rotary joint

Abstract

The utility model discloses a rotary joint which comprises a rotary pipe, an outer gland and a fixed head are sleeved outside the rotary pipe, one end of the fixed head is sunken to form an open inner cavity, the outer gland is arranged at the open end of the open inner cavity and seals the inner cavity, and a front baffle ring located in the open inner cavity is arranged on the outer wall of the rotary pipe. A bearing is arranged between the front baffle ring and the outer gland, sealing filler is arranged in a circumferential gap between the fixed head and the rotating pipe, and the sealing filler comprises a plurality of layers of filling materials distributed in the axial direction of the rotating pipe; an inner pressing ring arranged on the rotating pipe in a sleeving mode is arranged in the opening inner cavity, and one end of the inner pressing ring extends to the position between the fixing head and the rotating pipe in the length direction of the rotating pipe and abuts against the sealing filler. The inner pressing ring is connected with the fixing head through a fastener. The bearing pressure of the high-temperature-resistant high-pressure water pump is 4.0 MPa, and the operating temperature exceeds 500 DEG C.

Description

Technical Field

[0001] The utility model relates to a rotary joint and belongs to the technical field of connection of photothermal power generation pipeline rotation. Background Art

[0002] The collector field of a line-focusing CSP power station includes reflectors, collector tubes, support structures, drive systems, and control systems. The reflectors and collectors stand on the ground with the support structure, and the sun tracking is a circumferential rotation. Since the rotation angle generated by tracking the sun is ±90°, rotating parts are set at both ends of the collector.

[0003] Chinese invention patent CN107355616B discloses a high-temperature rotary joint, a rotary joint product for molten salt pipelines in solar thermal power generation systems, characterized in that the joint adopts a hard sealing structure and uses flexible graphite as a filler, so that the rotary joint has a certain high-temperature dynamic sealing ability; Chinese invention patent CN104806831B discloses a solar thermal power generation high-temperature rotary joint, characterized in that a double right-angle structure is arranged at the head and tail of the joint, and a metal sliding friction sealing method is adopted.

[0004] The heat collection medium involved in the above existing patents is thermal oil (or molten salt). Due to the material problem of its sealing surface, the temperature it can withstand is 400°C or the pressure is 1.5MPa. With the development of solar thermal power generation technology, higher requirements are put forward for heat collection temperature and operating pressure. Generally, the pressure resistance of rotating parts is 4.0MPa, and the operating temperature exceeds 500°C. The above patents are difficult to meet the requirements of molten salt system for sealing and high temperature resistance at the same time.

[0005] Chinese utility model patent CN 210318955 U discloses a high temperature resistant rotary joint, comprising a shell, an end cover and a rotating shaft, wherein one end of the shell is recessed to form an open inner cavity, the end cover is arranged at the open end of the shell to close the inner cavity, the other end of the shell is convex and has a central hole connected to the inner cavity to form a first interface, the rotating shaft is hollow and one end thereof is assembled with the inner cavity wall of the shell through a first rolling bearing so as to be rotatable relative to the shell, and the other end extends out of the end cover to form a second interface, a limiting portion is convex on the inner side wall of the rotating shaft near the end cover, a second rolling bearing is arranged between the limiting portion and the end cover for axially limiting the rotating shaft , carbon-containing sealing rings are arranged in the circumferential gap between the end cover and the rotating shaft, and in the circumferential gap between the shell and the rotating shaft; however, the filler disclosed in this utility model patent is a carbon-containing sealing ring, and one end of the rotating shaft is assembled with the inner cavity wall of the shell through a first rolling bearing and can rotate relative to the shell. The filler is set to the same material, which may cause excessive overall thermal expansion, thereby increasing the gap between the rotating tube and the fixed head during high-temperature operation, causing medium leakage. At the same time, the ordinary carbon-containing sealing ring of the rotary joint will expand too much at high temperature, causing the joint structure to change, thereby affecting the stable operation of the system. Utility Model Content

[0006] The utility model aims to solve the above technical problems and provide a stable solar thermal power generation high-temperature rotary joint under high temperature and high pressure conditions.

[0007] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0008] A rotary joint comprises a rotary tube, an outer pressure cover and a fixed head are arranged on the outer sleeve of the rotary tube, one end of the fixed head is recessed to form an open inner cavity, the outer pressure cover is arranged at the open end of the open inner cavity and closes the open inner cavity, a front baffle ring located inside the open inner cavity is arranged on the outer wall of the rotary tube, a bearing is arranged between the front baffle ring and the outer pressure cover, a sealing filler is arranged in the circumferential gap between the fixed head and the rotary tube, the sealing filler comprises several layers of filling material distributed along the axial direction of the rotary tube, the material hardness of each layer of filling material of the sealing filler gradually increases from the right side to the left side along the length direction of the rotary tube; an inner pressure ring sleeved on the rotary tube is arranged in the open inner cavity, one end of the inner pressure ring extends between the fixed head and the rotary tube along the length direction of the rotary tube, and presses against the sealing filler; the inner pressure ring is connected to the fixed head by a fastener.

[0009] Therefore, through the effective matching connection of the inner pressure ring, the outer pressure cover and the fixed head, the center of the rotating tube and the axis of the fixed head can be effectively aligned, and a high-temperature and high-pressure resistant sealing filler is set to fill the gap between the rotating tube and the fixed head. The material of each layer of the multi-layer sealing filler is different, and the material hardness of each layer of filling material gradually increases from the right side to the left side along the length direction of the rotating tube, which can make the overall expansion of the filler smaller under high-temperature operation; when the high-temperature and high-pressure medium flows in the rotating tube, it will flow from the rotating tube to the side of the outer pressure cover, and the part of the inner pressure ring extending between the fixed head and the rotating tube will withstand the axial expansion of the sealing filler, thereby enhancing the sealing of the rotary joint.

[0010] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization:

[0011] Specifically, a rear baffle ring is fixedly arranged on the outer wall of the rotating tube, and the rear baffle ring is located between the front baffle ring and the inner pressure ring.

[0012] The relative position of the rotating tube and the fixed head is limited by setting the outer pressure cover / front baffle ring and the inner pressure ring / rear baffle ring. The former prevents the reverse flow of high-temperature and high-pressure media from increasing the connection gap between the rotating tube and the fixed head and causing leakage. The latter reduces the wear of the sealing ring due to the axial thrust generated by the flow of high-temperature and high-pressure media during operation. When the expansion of the packing layer is too large, the rear baffle ring and the inner pressure ring bolt will play a dual protective role in preventing the inner pressure ring from moving backward, so as to avoid leakage and enhance the sealing performance during high-temperature and high-pressure processes.

[0013] Specifically, the inner pressure ring includes a circular adjusting portion and a cylindrical connecting portion, and a first bolt is movably provided on the adjusting portion; the first bolt passes through the fixed head, and the threaded portion of the first bolt is threadedly connected to the fixed head, and a nut is provided on the portion of the first bolt passing through the fixed head.

[0014] By providing an adjusting nut connecting the inner pressure ring and the fixed head, when the packing leaks at the connection between the rotating tube and the fixed head due to high temperature, high pressure and wear after long-term operation, the adjusting nut can be adjusted to tighten the packing and quickly deal with the leakage.

[0015] Specifically, the outer pressure cover is provided with a second bolt, the second bolt passes through the inner pressure ring and is threadedly connected to the fixing head, and the inner pressure ring is provided with a through hole for the second bolt to pass through.

[0016] The use of multiple sets of anti-loosening bolts can effectively maintain the relative positions of various components after long-term high-temperature and high-pressure operation and avoid eccentricity between the inlet inner cavity of the rotating tube and the outlet inner cavity of the fixed head.

[0017] Specifically, the interior of the rotating tube is a medium inlet inner cavity, and the right side of the interior of the fixed head is an outlet inner cavity coaxially arranged with the inlet inner cavity.

[0018] Specifically, the inner diameter of the middle part of the fixed head is larger than the outer diameter of the rotating tube, and the rotating tube is inserted into the fixed head; a sealing ring is provided in the connection gap between the inlet inner cavity and the outlet inner cavity.

[0019] Compared with the prior art, the beneficial effects of the utility model are:

[0020] 1) A rotary joint of the utility model can effectively align the center of the rotating tube and the center of the fixed head through the effective matching connection of the inner pressure ring, the outer pressure cover and the fixed head. The use of multiple sets of anti-loosening bolts can effectively maintain the relative positions of various components after long-term high temperature and high pressure operation and avoid eccentricity between the inlet inner cavity of the rotating tube and the outlet inner cavity of the fixed head.

[0021] 2) A rotary joint of the utility model limits the relative position of the rotary tube and the fixed head by arranging an outer pressure cover / front baffle ring and an inner pressure ring / rear baffle ring. The former prevents the reverse flow of high-temperature and high-pressure media from increasing the connection gap between the rotary tube and the fixed head and causing leakage. The latter reduces the wear of the sealing ring due to the axial thrust generated by the flow of high-temperature and high-pressure media during operation. When the expansion of the packing layer is too large, the rear baffle ring and the inner pressure ring bolt will play a dual protective role in preventing the inner pressure ring from moving backward, so as to avoid leakage and enhance the sealing performance in the high-temperature and high-pressure process.

[0022] 3) A rotary joint of the utility model limits the relative position of the rotary tube and the fixed head by arranging an outer pressure cover and a front baffle ring, thereby reducing the wear of the sealing ring due to the axial thrust generated by the flow of the medium during operation and enhancing the sealing performance during high-temperature operation.

[0023] 4) A rotary joint of the utility model fills the gap between the rotary tube and the fixed head by setting a multi-layer sealing filler and a sealing ring resistant to high temperature and high pressure. Each layer of the multi-layer sealing filler is made of different materials, which can reduce the overall expansion of the filler under high temperature operation. The filler increases in hardness from right to left, and the hard sealing filler on the left has a self-locking function to resist the pressure of the internal pressure ring to avoid deformation, thereby enhancing the sealing of the rotary joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the utility model;

[0025] Figure 2 A schematic longitudinal section view of the present invention.

[0026] In the figure

[0027] 1-rotating tube, 2-first bolt, 3-spring washer, 4-external pressure cover, 5-bearing, 6-inner pressure ring, 7-fixed head, 8-sealing packing, 9-flat washer, 10-nut, 11-rear retaining ring, 12-front retaining ring, 13-A gap, 14-B gap, 15-sealing ring, 16-inlet inner cavity, 17-outlet inner cavity, 18-second bolt. DETAILED DESCRIPTION

[0028] The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict. For the convenience of description, if the words "upper", "lower", "left" and "right" appear in the following text, they only indicate that the upper, lower, left and right directions are consistent with the drawings themselves, and do not limit the structure.

[0029] like Figure 1-Figure 2 As shown, the high-temperature rotary joint of this embodiment includes a rotary tube 1, an outer cover 4 and a fixed head 7 are sleeved on the outer side of the rotary tube 1, one end of the fixed head 7 is recessed to form an open inner cavity, the outer cover 4 is arranged at the open end of the open inner cavity and seals the open inner cavity, a front retaining ring 12 located inside the open inner cavity is arranged on the outer wall of the rotary tube 1, a B gap 14 is present between the outer cover 4 and the left side of the rotary tube 1 and its rear retaining ring 11, a bearing 5 is provided in the B gap 14, and the bearing 5 is a high-temperature rolling bearing; the interior of the rotary tube 1 is a medium inlet inner cavity 16, and the right side of the interior of the fixed head 7 is an outlet inner cavity 17 coaxially arranged with the inlet inner cavity 16.

[0030] A sealing filler 8 is arranged in the circumferential gap between the fixed head 7 and the rotating tube 1. The sealing filler 8 includes several layers of filling materials of different materials distributed along the axial direction of the rotating tube. The material hardness of each layer of the filling material of the sealing filler gradually increases from the right side to the left side along the length direction of the rotating tube 1. The rotating tube 1 is provided with an integrally formed front baffle ring 4 and a rear baffle ring 6 and is passed through the interior of the fixed head 7. The inner pressure ring 6 is connected to the fixed head 7 on the right side of the front baffle ring 4. There is a gap A 13 between the outer wall of the rotating tube 1, the inner wall of the fixed head 7 and the inner pressure ring 6. The multi-layer sealing filler 8 is filled in the gap A 13. The outer pressure cover 4 is connected to the fixed head 7 on the left side of the rear baffle ring 11. A rear baffle ring 11 is fixedly arranged on the outer wall of the rotating tube 1. The rear baffle ring 11 is located between the front baffle ring 12 and the inner pressure ring 6. The outer pressure cover 4 contacts with the front baffle ring 12, and the inner pressure ring 6 contacts with the rear baffle ring 11, so as to limit the relative position of the rotating tube 1 and the fixed head 7. The former prevents the reverse flow of the medium in the case of salt withdrawal, which increases the connection gap between the rotating tube 1 and the fixed head 7 and causes leakage. The latter reduces the wear of the sealing ring 8 caused by the axial thrust generated by the flow of the medium during operation, thereby enhancing the sealing performance during high-temperature operation.

[0031] The sealing filler 8 is a multi-layer combination type. The filler is resistant to high temperature and high pressure corrosion and has good lubricity. Each layer is made of different materials and the material hardness increases from the right to the left. It is filled in the A gap 13 formed by the outer wall of the rotating tube 1, the inner wall of the fixed head 7 and the inner pressure ring 6. The combined filler has good sealing and self-locking function.

[0032] When the rotary joint is in operation, the internal pressure ring 6 will not deform the multi-layer sealing filler 8 and the overall deformation of the combined filler in a high temperature environment is small. The materials used for the multi-layer sealing filler 8 and the sealing ring 15 are not limited to graphite, vermiculite and other materials with good lubricity, corrosion resistance, high temperature resistance above 500°C, and high pressure resistance above 4.0MPa, so as to avoid damage to the rotary joint and leakage of the heat transfer medium.

[0033] The inner diameter of the middle part of the fixed head 7 is larger than the outer diameter of the rotating tube 1, and the rotating tube 1 is inserted into the fixed head 7; a sealing ring 15 is provided in the connection gap between the inlet inner cavity 16 and the outlet inner cavity 17 to reduce the friction at the edge of the interface between the two inner cavities during rotation and avoid leakage of high-temperature medium.

[0034] The inner cavity of the opening is provided with an inner pressure ring 6 sleeved on the rotating tube 1, one end of the inner pressure ring 6 extends along the length direction of the rotating tube 1 to between the fixed head 7 and the rotating tube 1, and presses against the sealing packing 8; the inner diameter of the outer pressure cover 4 is slightly larger than the outer diameter of the rotating tube 1 so as to pass through the rotating tube 1, and the outer pressure cover 4 is connected to the fixed head 7 by bolts, and the bolts are anti-loosening bolts with spring washers 3. The inner diameter of the inner pressure ring 6 is slightly larger than the outer diameter of the rotating tube 1 so as to allow the rotating tube 1 to pass through, the left side of the inner pressure ring 6 is close to the front baffle ring 12 on the rotating tube 1, and the inner pressure ring 6 is connected to the fixed head 7 by bolts, and the bolts are anti-loosening bolts composed of flat washers 9 and spring washers 3. The nut connecting the inner pressure ring and the fixed head is an adjusting nut, and the space size of the packing gap can be adjusted by rotating the nut. After long-term operation, when the packing leaks at the connection between the rotating tube and the fixed head due to high temperature, high pressure and wear, the adjusting nut can be adjusted to compress the packing and quickly deal with the leakage phenomenon.

[0035] The inner pressure ring 6 includes a circular adjusting portion and a cylindrical connecting portion, and a first bolt 2 is movably inserted into the adjusting portion; the first bolt 2 passes through the fixing head 7, and the threaded portion of the first bolt 2 is threadedly connected to the fixing head 7, and a nut 10 is provided at the portion of the first bolt 2 passing through the fixing head 7, and a fixing portion is provided on the left side of the inner pressure ring 6.

[0036] The outer pressure cover 4 is provided with a second bolt 18, which passes through the inner pressure ring 6 and is threadedly connected to the fixed head 7. The inner pressure ring 6 is provided with a through hole for the second bolt 18 to pass through. The number of bolt holes connecting the inner pressure ring and the fixed head is an even number greater than or equal to 4 and is symmetrically arranged, and the number of bolt holes connecting the outer pressure cover 4 and the fixed head 7 is an even number greater than or equal to 4 and is symmetrically arranged.

[0037] The high temperature rotary joint of the present embodiment comprises a rotary tube 1, a fixed head 7, an inner pressure ring 6 and an outer pressure cover 4, wherein the rotary tube 1 passes through the outer pressure cover 4, the inner pressure ring 6 and the fixed head 7 in sequence, the rotary tube 1 has a front baffle ring 12 and a rear baffle ring 11, the outer pressure cover 4 is located on the left side of the rear baffle ring 11, the inner pressure ring 6 is located on the right side of the front baffle ring 12, and there is a gap A between the outer wall of the rotary tube 1, the inner wall of the fixed head 7 and the inner pressure ring 6, and there is a gap A between the outer wall of the rotary tube 1, the inner wall of the outer pressure cover 4 and the left side of the rear baffle ring 11. There is a gap B between the two ends of the rotating tube 1. The interior of the rotating tube 1 is the inlet inner cavity 16, and the right side of the interior of the fixed head 7 is the outlet inner cavity 17. The inlet inner cavity 16 and the outlet inner cavity 17 are connected and connected, and a sealing ring 15 is arranged in the middle. The medium is introduced from the inlet inner cavity 16, and the medium flows out from the outlet inner cavity 17. The diameters of the inlet inner cavity 16 and the outlet inner cavity 17 are the same and are on the same center of the circle. The left side of the inlet inner cavity 16 is connected to the pipes related to the outlet of the heat collector, and the rotation of the front connecting pipe will drive the rotating tube 1 to rotate by itself. The left side of the rotating tube 1 is connected to the pipes related to the outlet of the heat collector, and the reserved length of the rotating tube 1 on the left side of the outer gland 4 should be greater than or equal to 0.5 times the diameter of the inlet inner cavity 16 to facilitate the welding and other connection operations of the pipe fittings.

[0038] The metal parts of the high-temperature rotary joint, such as the rotary tube, fixed head, inner pressure ring, and outer pressure cover, are made of high-temperature, high-pressure and corrosion-resistant stainless steel such as SUS321, which has good performance under conditions of 4.0 MPa and 500°C.

[0039] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the present invention by those skilled in the art fall within the scope defined by the claims attached to this application.

Claims

1. A rotary joint, comprising a rotary tube (1), an outer cover (4) and a fixed head (7) are sleeved on the outer side of the rotary tube (1), one end of the fixed head (7) is recessed to form an open inner cavity, the outer cover (4) is arranged at the open end of the open inner cavity and seals the open inner cavity, a front retaining ring (12) is arranged on the outer wall of the rotary tube (1) and is located inside the open inner cavity, a bearing (5) is arranged between the front retaining ring (12) and the outer cover (4), and the characteristics are: A sealing filler (8) is arranged in the circumferential gap between the fixed head (7) and the rotating tube (1), and the sealing filler (8) comprises a plurality of layers of filling materials of different materials distributed along the axial direction of the rotating tube, and the material hardness of each layer of filling material of the sealing filler gradually increases along the flow direction of the medium in the rotating tube (1); an inner pressure ring (6) sleeved on the rotating tube (1) is arranged in the open inner cavity, and one end of the inner pressure ring (6) extends along the length direction of the rotating tube (1) to between the fixed head (7) and the rotating tube (1) and presses against the sealing filler (8); the inner pressure ring (6) and the fixed head (7) are connected by a fastener.

2. The rotary joint according to claim 1, characterized in that: A rear baffle ring (11) is fixedly arranged on the outer wall of the rotating tube (1), and the rear baffle ring (11) is located between the front baffle ring (12) and the inner pressure ring (6).

3. The rotary joint according to claim 1, characterized in that: The inner pressure ring (6) comprises a circular adjusting portion and a cylindrical connecting portion, and a first bolt (2) is movably inserted into the adjusting portion; the first bolt (2) passes through the fixing head (7), and the threaded portion of the first bolt (2) is threadedly connected to the fixing head (7); a nut (10) is provided at the portion of the first bolt (2) passing through the fixing head (7); and a fixing portion is provided on the left side of the inner pressure ring (6).

4. The rotary joint according to claim 1, characterized in that: The outer pressure cover (4) is provided with a second bolt (18), the second bolt (18) passes through the inner pressure ring (6) and is threadedly connected to the fixing head (7), and the inner pressure ring (6) is provided with a through hole for the second bolt (18) to pass through.

5. The rotary joint according to claim 1, characterized in that: The interior of the rotating tube (1) is a medium inlet inner cavity (16), and the right side of the interior of the fixed head (7) is an outlet inner cavity (17) coaxially arranged with the inlet inner cavity (16).

6. The rotary joint according to claim 5, characterized in that: The inner diameter of the middle portion of the fixed head (7) is larger than the outer diameter of the rotating tube (1), and the rotating tube (1) is inserted into the fixed head (7); a sealing ring (15) is provided in the connection gap between the inlet inner cavity (16) and the outlet inner cavity (17).

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