Flexible connection spherical joint for high-temperature heat conduction oil groove type heat collector

Abstract

The invention belongs to the technical field of connecting parts and solar thermal power generation, and discloses a flexible connecting spherical joint for a high-temperature heat conduction oil groove type heat collector, which comprises a shell (01), a first ball seat (02), two groups of sealing rings (03), a sealing ring support (04), a hollow ball core (05), a second ball seat (06), two rotation stopping pins (07), a threaded flange (08), injectable filler (09) and a plurality of injection port bolts (10), a plurality of threaded injection holes are formed in the circumferential surface of the shell and are used for adding injectable filler into the shell by connecting a one-way valve and a high-pressure injection gun during assembly and online maintenance; two ends of the hollow ball core are respectively provided with a group of sealing rings; a sealing ring support is arranged between the two groups of sealing rings; the first ball seat is installed at the bottom of an inner cavity of the shell, and then one of the two sealing rings, the sealing ring support, the hollow ball core, the other of the two sealing rings, the second ball seat, the two rotation stopping pins and the threaded flange are sequentially arranged from the outer side to the inner side.

Description

Technical Field

[0001] This invention belongs to the field of flexible connection technology of solar thermal power generation collectors and pipelines, specifically involving a flexible connection spherical joint for high-temperature heat transfer oil trough collectors. It is suitable for flexible connection systems of trough collectors with non-strong oxidizing media such as heat transfer oil or water / steam, operating at a working pressure of 4MPa, a high temperature of 430℃, and a large swing angle of ±15°. Background Technology

[0002] Parabolic trough solar thermal power generation systems have become one of the important development directions of new energy sources internationally due to their outstanding advantages such as excellent power generation quality, energy storage, environmental friendliness, and mature technology. When a solar collector tracks the rotation of the sun and heats the heat transfer medium inside the collector tubes, the inner metal tubes not only rotate with the collector but also expand and contract due to thermal expansion and contraction. During the day when the collector is heating, the inner tubes expand and elongate, while at night when the collector is not operating, the temperature drops and the tubes shorten. Therefore, a flexible connection system is needed between the collector tubes and the stationary pipes. There are three main types of flexible connections: pure corrugated hoses, flat rotating heads + oscillating corrugated hoses, and ball joints. Pure corrugated hose flexible connections are not only costly but also prone to damage due to torsion during rotation, thus limiting their use. Flat rotating heads with oscillating corrugated hoses are mainly used in molten salt tanks. On the one hand, molten salt is a strong oxidizing medium and operates at higher temperatures, so flexible graphite / worm-shaped expanded graphite with good sealing performance cannot be used as a sealing material. On the other hand, flat rotating heads have fewer size limitations and can use more sealing materials, so using flat rotating heads with oscillating corrugated hoses is more reliable. However, for heat transfer oil or water / steam trough collectors, since they are non-oxidizing or have low oxidizing properties and operate at lower temperatures, spherical joints using flexible graphite / worm-shaped expanded graphite as sealing materials are the main technical direction. Summary of the Invention

[0004] In view of this, the present invention provides a flexible ball joint for high-temperature thermal oil trough collectors, which not only solves the problem of flexible ball joints for high-temperature thermal oil trough collectors with working pressure of 4MPa, high temperature (430℃), and swing angle of ±15°, but is also suitable for flexible connection of trough collectors with non-strong oxidizing thermal media such as water / steam below 430℃, achieving reliable sealing and enabling complete and true online maintenance without disassembling or replacing any parts. It can completely replace imported flexible ball joints for thermal oil below 430℃.

[0005] The purpose of this invention is to provide a flexible spherical joint for high-temperature thermal oil trough collectors, comprising:

[0006] The structure comprises a housing (01), a first ball seat (02), two sets of sealing rings (03), a sealing ring support (04), a hollow ball core (05), a second ball seat (06), two anti-rotation pins (07), a threaded flange (08), injectable filler (09), and multiple injection port bolts (10), wherein...

[0007] The housing (01) is the base of the ball joint and is used to install and fix other components. Multiple threaded injection holes are provided on the circumferential surface. The threaded injection holes and the multiple injection port bolts (10) form a one-to-one matching relationship. During assembly and online maintenance, the injectable filler (09) is added into the housing (01) by connecting a one-way valve and a high-pressure injection gun. After the injectable filler (09) is added, the multiple injection port bolts (10) are used to seal the multiple threaded injection holes.

[0008] One set of the sealing rings is provided at each end of the hollow spherical core (05); a sealing ring support (04) is provided between the two sets of sealing rings (03);

[0009] The first ball seat (02) is installed at the bottom of the inner cavity of the housing (01). Then, from the outside to the inside, one of the two sealing rings (03), a sealing ring support (04), a hollow ball core (05), the other of the two sealing rings (03), a second ball seat (06), two anti-rotation pins (07), and a threaded flange (08) are arranged in sequence. After the second ball seat (06) is pressed into position using an assembly tool, the multiple threaded flanges (08) are tightened to make close contact with the end face of the housing (01). When the second ball seat (06) is pressed into position using an assembly tool, the assembly pressure is transmitted through the sealing ring support (04), thereby making the two sealing rings at both ends... All sealing rings (03) are compressed to achieve static and dynamic sealing of the working medium, as well as sealing of the injectable packing (09); the two anti-rotation pins (07) are used to prevent the second ball seat (06) from rotating under the action of rotational and oscillating friction; the two sealing rings (03) at both ends of the hollow ball core (05) form an injectable packing sealing cavity for injecting the injectable packing (09) between the two sealing rings (03) at both ends and the housing (01) and the hollow ball core (05), and the injectable packing (09) and the two sealing rings (03) at both ends together form a static seal on the housing (01) and a dynamic seal on the hollow ball core (05).

[0010] Preferably, there are three threaded injection holes and three injection port bolts (10).

[0011] Preferably, the plurality of threaded injection holes are evenly distributed on the housing (01).

[0012] Preferably, the sealing ring support (04) is provided with a plurality of holes evenly arranged in the radial direction to ensure that the entire packing sealing cavity is filled with the injectable soft packing (09) when the injectable soft packing (09) is added.

[0013] Preferably, the plurality of holes are circular holes.

[0014] Preferably, the sealing ring (03) is a metal-edged, wire-reinforced flexible graphite sealing ring. The metal-edged, wire-reinforced flexible graphite sealing ring (03) is composed of metal edging and wire-reinforced flexible graphite, and is formed by molding. The outer cylindrical surface of the metal-edged, wire-reinforced flexible graphite sealing ring (03) is tightly fitted with the shell (01) to achieve static sealing, and the inner spherical surface of the metal-edged, wire-reinforced flexible graphite sealing ring (03) is tightly fitted with the outer spherical surface of the hollow spherical core (05) to achieve dynamic sealing.

[0015] Preferably, the main components of the injectable filler (09) are worm-like expanded graphite particles, scaly graphite, and graphite fibers or carbon fibers.

[0016] Preferably, the inner hole of the first ball seat (02) is a spherical surface with the same diameter as the hollow ball core (05), and the material is QTANi30Cr3 high-nickel austenitic ductile iron; the inner hole of the second ball seat (06) is a spherical surface with the same diameter as the hollow ball core (05), and the material is QTANi30Cr3 high-nickel austenitic ductile iron. The second ball seat (06) and the first ball seat (02) together position the spherical surface of the hollow ball core (05) and bear the rotation and oscillation torque.

[0017] Preferably, the housing (01), sealing ring support (04), hollow ball core (05), and threaded flange (08) are made of the same metal material.

[0018] Preferably, depending on the operating temperature, the metal material is 20# steel, 25# steel, or 20CrMo.

[0019] Preferably, the surface of the hollow sphere (05) is laser-clad with an iron-based alloy; wherein the iron-based alloy is composed of Fe and Co.

[0020] Preferably, the ball seat material at both ends of the hollow spherical core (05) is selected from high-nickel ductile iron with a thermal expansion coefficient close to that of the spherical core.

[0021] The beneficial effects of this invention are:

[0022] 1. This invention uses soft packing seals, which not only reduces costs but also provides reliable sealing, low rotational torque, stable operation, and an oscillation angle of ±15°. Moreover, it enables online maintenance without replacing any seals. During product assembly and on-site maintenance, injection packing can be added through the packing holes on the shell, thereby enabling online maintenance of the product, ensuring product reliability and long service life, and guaranteeing the 25 to 30-year lifespan requirement of solar thermal power plants.

[0023] 2. Worm-like expanded graphite is used as a high-temperature sealing material, which has good resilience, sealing performance and low coefficient of friction; scaly graphite provides excellent lubricity and interlayer slippage ability, effectively reducing friction and wear; graphite / carbon fiber gives the material higher structural strength, creep resistance and thermal stability, significantly enhancing the durability of the seal.

[0024] 3. The spherical joint of the present invention can be used in the flexible connection system of high-temperature thermal oil trough collectors with a working pressure of 4MPa, a working temperature of 430℃, and a maximum swing angle of ±15°. It can also realize true online maintenance, filling a domestic gap and solving the technical bottleneck for the development and commercial application of solar thermal power generation.

[0025] 4. Given that a parabolic trough solar thermal power plant requires a large number of flexible connections (for example, a 100MW parabolic trough solar thermal power plant with 360 circuits requires more than 8,000 ball joints), the implementation of this invention will bring huge social and economic benefits. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the overall structure of the ball joint provided in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the housing 01 provided in an embodiment of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the first ball seat 02 provided in an embodiment of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the metal-edged, wire-reinforced flexible graphite sealing ring provided in an embodiment of the present invention;

[0030] Figure 5 This is a schematic diagram of the sealing ring support 04 provided in an embodiment of the present invention;

[0031] Figure 6 This is a schematic diagram of the structure of the hollow sphere core 05 provided in an embodiment of the present invention;

[0032] Figure 7 This is a schematic diagram of the structure of the second ball seat 06 provided in an embodiment of the present invention;

[0033] Figure 8 This is a schematic diagram of the structure of the threaded flange 08 provided in an embodiment of the present invention. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] This embodiment provides a flexible ball joint for a high-temperature thermal oil trough type solar collector, including:

[0036] The structure comprises a housing (01), a first ball seat (02), two sets of sealing rings (03), a sealing ring support (04), a hollow ball core (05), a second ball seat (06), two anti-rotation pins (07), a threaded flange (08), injectable filler (09), and multiple injection port bolts (10), wherein...

[0037] The housing (01) is the base of the ball joint and is used to install and fix other components. Multiple threaded injection holes are provided on the circumferential surface. The threaded injection holes and the multiple injection port bolts (10) form a one-to-one matching relationship. During assembly and online maintenance, the injectable filler (09) is added into the housing (01) through a one-way valve and a high-pressure injection gun. After the injectable filler (09) is added, the multiple injection port bolts (10) are used to seal the multiple threaded injection holes. In this embodiment, the multiple threaded injection holes are preferably three, and correspondingly, there are three injection port bolts (10).

[0038] One set of the sealing rings is provided at each end of the hollow spherical core (05); a sealing ring support (04) is provided between the two sets of sealing rings (03);

[0039] The first ball seat (02) is installed at the bottom of the inner cavity of the housing (01). Then, from the outside to the inside, one of the two sealing rings (03), a sealing ring support (04), a hollow ball core (05), the other of the two sealing rings (03), a second ball seat (06), two anti-rotation pins (07), and a threaded flange (08) are arranged in sequence. After the second ball seat (06) is pressed into position using an assembly tool, the multiple threaded flanges (08) are tightened to make close contact with the end face of the housing (01). When the second ball seat (06) is pressed into position using an assembly tool, the assembly pressure is transmitted through the sealing ring support (04), so that both sets of sealing rings (03) at both ends are pressed. The compression achieves static and dynamic sealing of the working medium, as well as sealing of the injectable packing (09); the two anti-rotation pins (07) are used to prevent the second ball seat (06) from rotating under the action of rotational and oscillating friction; the two sealing rings (03) at both ends of the hollow ball core (05) form an injectable packing sealing cavity for injecting the injectable packing (09) between the two sealing rings (03) at both ends and the housing (01) and the hollow ball core (05), and the injectable packing (09) and the two sealing rings (03) at both ends together form a static seal on the housing (01) and a dynamic seal on the hollow ball core (05), which is the key to ensuring the sealing reliability of the ball joint and online maintenance.

[0040] In a preferred embodiment, the plurality of threaded injection holes are evenly distributed on the housing (01). Of course, those skilled in the art will know that, depending on the installation environment, non-uniformly distributed threaded injection holes can also be customized. However, uniform distribution and equiangular distribution are the best implementation in the mechanical field, whether based on processing costs or installation convenience requirements.

[0041] In a preferred embodiment, the sealing ring support (04) is provided with a plurality of holes evenly arranged radially to ensure that the entire packing sealing cavity is filled with the injectable soft packing (09) when the injectable soft packing (09) is added. In a preferred embodiment, the plurality of holes are a plurality of circular holes. Of course, those skilled in the art should know that other suitable shapes of holes can also be used, all of which are within the protection scope of the present invention.

[0042] In a preferred embodiment, the sealing ring (03) is a metal-edged, wire-reinforced flexible graphite sealing ring, which increases the rigidity, erosion resistance and sealing performance of the sealing ring (03). The metal-edged, wire-reinforced flexible graphite sealing ring (03) is composed of metal edging and wire-reinforced flexible graphite, and is formed by molding. The outer cylindrical surface of the metal-edged, wire-reinforced flexible graphite sealing ring (03) is tightly fitted with the shell (01) to achieve static sealing, and the inner spherical surface of the metal-edged, wire-reinforced flexible graphite sealing ring (03) is tightly fitted with the outer spherical surface of the hollow spherical core (05) to achieve dynamic sealing.

[0043] In a preferred embodiment, the main components of the injectable filler (09) are worm-like expanded graphite particles, scaly graphite, and graphite fibers or carbon fibers.

[0044] In a preferred embodiment, the inner hole of the first ball seat (02) is a spherical surface with the same diameter as the hollow ball core (05), and the material is QTANi30Cr3 high-nickel austenitic ductile iron.

[0045] In a preferred embodiment, the inner hole of the second ball seat (06) is a spherical surface with the same diameter as the hollow ball core (05), and the material is QTANi30Cr3 high-nickel austenitic ductile iron. The second ball seat (06) and the first ball seat (02) together position the spherical surface of the hollow ball core (05) and bear the rotation and swing torque.

[0046] In a preferred embodiment, the housing (01), sealing ring support (04), hollow ball core (05), and threaded flange (08) are made of the same metal material to ensure that the coefficient of thermal expansion is the same and to reduce the impact on sealing performance at high temperatures.

[0047] As a preferred embodiment, the metal material is a weldable metal material, depending on the operating temperature; preferably, for example, it is 20# steel, 25# steel, and 20CrMo. Of course, those skilled in the art can select other metal materials as needed, as long as the weldability meets the requirements according to the processing conditions, especially the operating temperature, and all such materials are within the protection scope of this invention.

[0048] In a preferred embodiment, the surface of the hollow sphere (05) is laser-clad with an iron-based alloy to ensure high hardness, wear resistance and low coefficient of friction at high temperatures; wherein the iron-based alloy is composed of Fe and Co.

[0049] As a preferred embodiment, the ball seat material at both ends of the hollow ball core (05) is selected as high-nickel ductile iron with a thermal expansion coefficient close to that of the ball core (05), thereby ensuring that the friction pair formed by the hollow ball core (05) guarantees high-temperature performance stability, a certain degree of self-lubrication and low friction coefficient.

[0050] like Figure 1 As shown, a flexible spherical joint for a high-temperature thermal oil trough collector includes: a shell 01, a first ball seat 02, two sets of metal-edged wire-reinforced flexible graphite sealing rings 03, a sealing ring support 04, a hollow ball core 05, a second ball seat 06, two anti-rotation pins 07, a threaded flange 08, injectable filler 09, and three injection port bolts 10.

[0051] like Figure 2 As shown, housing 01 is the base of the ball joint, made of 20CrMo, used to install and fix other components. Three evenly distributed threaded holes are provided on the circumference surface for connecting the check valve and the high-pressure injection gun to add injectable filler during assembly and online maintenance. After adding injectable filler, the injection threaded ports are plugged with three injection port bolts 10.

[0052] like Figure 3 As shown, the inner hole of the first ball seat 02 is a spherical surface with the same diameter as the hollow ball core 05. The material is QTANi30Cr3 high-nickel austenitic ductile iron (QTANi30Cr3 is a high-alloy ductile iron; QT stands for "QiuTie," meaning ductile iron; A represents "austenite," indicating that the matrix structure of this ductile iron is austenitic at room temperature, possessing excellent corrosion resistance and heat resistance; Ni30 indicates that the nickel (Ni) content is approximately 30%, which is the main alloying element, ensuring the stability and corrosion resistance of the austenitic structure; Cr3 indicates that the chromium (Cr) content is approximately 3%, used to improve the material's high-temperature oxidation resistance and wear resistance), and its coefficient of thermal expansion is 12.60 × 10⁻⁻⁶. 6 / ℃ (within the range of 20-100℃), slightly greater than the thermal expansion coefficient of 20CrMo, which is 11.7-12.3×10⁻ 6 / ℃ (within the range of 20-100℃), which helps prevent the ball seat from rotating and getting stuck with the hollow ball core.

[0053] like Figure 4 As shown, the metal-edged, wire-reinforced flexible graphite sealing ring 03 is composed of metal edging and wire-reinforced flexible graphite. It is formed by mold pressing. The outer cylindrical surface fits tightly with the shell 01 to achieve static sealing, and the inner spherical surface fits tightly with the outer spherical surface of the hollow spherical core 05 to achieve dynamic sealing. The two metal-edged, wire-reinforced flexible graphite sealing rings 03 form an injectable filler sealing cavity between the shell 01 and the hollow spherical core 05.

[0054] like Figure 5 As shown, the sealing ring support 04 is made of 20CrMo material, with 6 circular holes evenly distributed in the circumferential direction to ensure that the injectable filler flows and fills the entire filler sealing cavity.

[0055] like Figure 6 As shown, the hollow sphere core 05 is made of 20CrMo, with an iron-based alloy (mainly Fe and Co) laser-clad on the sphere surface. It still has high hardness, wear resistance and corrosion resistance at 430℃.

[0056] like Figure 7 As shown, the second ball seat 06 is the same as the first ball seat 02. Its inner hole is a spherical surface with the same diameter as the hollow ball core 05. The material is QTANi30Cr3 high-nickel austenitic ductile iron. Together with the first ball seat 02, it positions the spherical surface of the hollow ball core 05 and bears the rotation and oscillation torque.

[0057] like Figure 8 As shown, the threaded flange 08 is made of 20CrMo, and its outer cylindrical surface has 6 flat surfaces to facilitate tightening with tools.

[0058] The main components of injectable filler 09 are worm-like expanded graphite, flake graphite, and graphite fiber / carbon fiber. Worm-like expanded graphite, formed from natural flake graphite through high-temperature expansion, is loose and porous, exhibiting excellent high-temperature resilience, self-lubrication, and compression sealing properties, making it the primary component responsible for the filler's sealing function. Flake graphite, with its layered crystalline structure and weak interlayer bonding, is prone to sliding and primarily acts as a solid lubricant, playing a crucial role in reducing the coefficient of friction and improving lubrication performance within the filler. Graphite fiber / carbon fiber possesses high strength, high modulus, and excellent heat resistance. Dispersed within the filler as a reinforcing skeleton, it effectively improves the overall structural mechanical strength, erosion resistance, and shape stability, preventing plastic deformation or cracking under high temperature and pressure. In injectable high-temperature sealing materials, these three components can also be used synergistically. Their synergistic effects include: worm-like graphite providing basic sealing and resilience, flake graphite ensuring lubrication, and fiber reinforcing the system's integrity, collectively achieving long-lasting and reliable high-temperature dynamic or static sealing.

[0059] Furthermore, the first ball seat 02 and the second ball seat 06 form a friction pair with the spherical laser cladding layer of the hollow ball core 05. The austenitic ductile iron has high-temperature performance, low hardness, anti-adhesion friction and certain self-lubricating properties. At the same time, the spherical laser cladding layer of the hollow ball core 05 has good anti-adhesion properties for soft sealing materials and anti-scratch properties, ensuring the reliability of mechanical rotation, low rotational torque and high sealing performance.

[0060] Further, during assembly, the first ball seat 02 is first installed at the bottom of the inner cavity of the housing 01. Then, the first metal-edged wire-reinforced flexible graphite sealing ring 03, the sealing ring support 04, the hollow ball core 05, the second metal-edged wire-reinforced flexible graphite sealing ring 03, the second ball seat 06, the anti-rotation pin 07, and the threaded flange 08 are installed in sequence. Using an assembly tool, the second ball seat 06 is pressed into position, and the threaded flange 08 is tightened to ensure tight contact with the end face of the housing 01. Then, the high-pressure injection gun with a one-way valve is connected through the injection threaded hole on the housing 01, and the injectable filler 09 is added according to the required injection pressure. Then, the one-way valve and the high-pressure injection gun are removed, the injection port bolt 10 is installed, and tightened into the injection threaded hole on the housing 01.

[0061] Furthermore, when the second ball seat 06 is pressed into place during assembly, pressure is transmitted between the two metal-edged wire-reinforced flexible graphite sealing rings 03 through the sealing ring support 05, thereby compressing both sealing rings and making them tightly contact the inner cavity of the housing 01 and the spherical surface of the hollow ball core 05, achieving a static seal for the housing 01 and a dynamic seal for the hollow ball core 05, while simultaneously sealing the injectable filler 09 within its filler chamber.

[0062] Furthermore, the anti-rotation pin 07 serves to prevent the second ball seat 06 from rotating under the action of rotational and oscillating friction.

[0063] Furthermore, if leakage occurs due to wear and consumption of the sealing material after long-term operation, online maintenance can be achieved by adding 09-injectable soft filler.

[0064] In this invention, the metal material used in the planar rotary joint, the material of the sealing ring, the structure of the sealing ring, the number and arrangement of the sealing rings, and the main components of the injectable filler can be changed according to different heat transfer media, operating pressure, and temperature requirements.

[0065] Working principle:

[0066] 1. Assembly of the ball joint: The high-pressure injection gun equipped with the one-way valve is connected to the housing (01) through multiple threaded injection holes on the housing (01). The injectable soft filler (09) is added according to the required injection pressure. Then, the one-way valve and the high-pressure injection gun are removed, and the multiple injection port bolts (10) are tightened to the threaded injection holes on the housing (01) to complete the assembly of the ball joint.

[0067] 2. Online maintenance of ball joints: If leakage occurs due to wear and consumption of sealing material after long-term operation, online maintenance can be achieved by adding injectable soft packing (09). When leakage occurs in the ball joint after long-term use, simply remove the multiple injection port bolts (10), connect the high-pressure injection gun equipped with the one-way valve together through the multiple threaded injection holes, add the injectable soft packing (09) according to the required injection pressure, install the multiple injection port bolts (10) and tighten them to achieve online maintenance.

[0068] The apparatus and methods disclosed in the embodiments are described simply because they correspond to the methods disclosed in the embodiments. For relevant details, please refer to the method section.

[0069] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible spherical joint for a high-temperature thermal oil trough collector, characterized in that, include: The structure comprises a housing (01), a first ball seat (02), two sets of sealing rings (03), a sealing ring support (04), a hollow ball core (05), a second ball seat (06), two anti-rotation pins (07), a threaded flange (08), injectable filler (09), and multiple injection port bolts (10), wherein... The housing (01) is the base of the ball joint and is used to install and fix other components. Multiple threaded injection holes are provided on the circumferential surface. The threaded injection holes and the multiple injection port bolts (10) form a one-to-one matching relationship. During assembly and online maintenance, the injectable filler (09) is added into the housing (01) by connecting a one-way valve and a high-pressure injection gun. After the injectable filler (09) is added, the multiple injection port bolts (10) are used to seal the multiple threaded injection holes. One set of the sealing rings is provided at each end of the hollow spherical core (05); a sealing ring support (04) is provided between the two sets of sealing rings (03); The first ball seat (02) is installed at the bottom of the inner cavity of the housing (01). Then, from the outside to the inside, one of the two sealing rings (03), a sealing ring support (04), a hollow ball core (05), the other of the two sealing rings (03), a second ball seat (06), two anti-rotation pins (07), and a threaded flange (08) are arranged in sequence. After the second ball seat (06) is pressed into position using an assembly tool, the multiple threaded flanges (08) are tightened to make close contact with the end face of the housing (01). When the second ball seat (06) is pressed into position using an assembly tool, the assembly pressure is transmitted through the sealing ring support (04), thereby making the two sealing rings at both ends... All sealing rings (03) are compressed to achieve static and dynamic sealing of the working medium, as well as sealing of the injectable packing (09); the two anti-rotation pins (07) are used to prevent the second ball seat (06) from rotating under the action of rotational and oscillating friction; the two sealing rings (03) at both ends of the hollow ball core (05) form an injectable packing sealing cavity for injecting the injectable packing (09) between the two sealing rings (03) at both ends and the housing (01) and the hollow ball core (05), and the injectable packing (09) and the two sealing rings (03) at both ends together form a static seal on the housing (01) and a dynamic seal on the hollow ball core (05).

2. The flexible spherical joint for a high-temperature thermal oil trough collector according to claim 1, characterized in that, There are three threaded injection holes and three injection port bolts (10).

3. A flexible spherical joint for a high-temperature thermal oil trough collector according to claim 2, characterized in that, The plurality of threaded injection holes are evenly distributed on the housing (01).

4. A flexible spherical joint for a high-temperature thermal oil trough collector according to claim 3, characterized in that, The sealing ring support (04) has several holes evenly arranged in the radial direction to ensure that the entire packing sealing cavity is filled with the injectable soft packing (09) when the injectable soft packing (09) is added.

5. A flexible spherical joint for a high-temperature thermal oil trough collector according to claim 4, characterized in that, The sealing ring (03) is a metal-edged, wire-reinforced flexible graphite sealing ring. The metal-edged, wire-reinforced flexible graphite sealing ring (03) is composed of metal edging and wire-reinforced flexible graphite, and is formed by molding. The outer cylindrical surface of the metal-edged, wire-reinforced flexible graphite sealing ring (03) is tightly fitted with the shell (01) to achieve static sealing. The inner spherical surface of the metal-edged, wire-reinforced flexible graphite sealing ring (03) is tightly fitted with the outer spherical surface of the hollow spherical core (05) to achieve dynamic sealing.

6. A flexible spherical joint for a high-temperature thermal oil trough collector according to claim 5, characterized in that, The main components of the injectable filler (09) are worm-like expanded graphite particles, scaly graphite, and graphite fibers or carbon fibers.

7. A flexible spherical joint for a high-temperature thermal oil trough collector according to claim 6, characterized in that, The inner hole of the first ball seat (02) is a spherical surface with the same diameter as the hollow ball core (05), and the material is QTANi30Cr3 high-nickel austenitic ductile iron; the inner hole of the second ball seat (06) is a spherical surface with the same diameter as the hollow ball core (05), and the material is QTANi30Cr3 high-nickel austenitic ductile iron. The second ball seat (06) and the first ball seat (02) together position the spherical surface of the hollow ball core (05) and bear the rotation and swing torque.

8. A flexible spherical joint for a high-temperature thermal oil trough collector according to claim 7, characterized in that, The housing (01), sealing ring support (04), hollow spherical core (05) and threaded flange (08) are made of the same metal material; depending on the working temperature, the metal material is 20# steel, 25# steel or 20CrMo.

9. A flexible spherical joint for a high-temperature thermal oil trough collector according to claim 8, characterized in that, The surface of the hollow sphere (05) is clad with an iron-based alloy by laser cladding; wherein the iron-based alloy is composed of Fe and Co.

10. A flexible spherical joint for a high-temperature thermal oil trough collector according to claim 9, characterized in that, The ball seats at both ends of the hollow spherical core (05) are made of high-nickel ductile iron with a thermal expansion coefficient close to that of the spherical core.

Images