High-flow and large-pipe-diameter hydrogen fuel conveying piping for vehicle-mounted system with pressure of 70 MPa and above

Abstract

The utility model relates to a high-flow and large-pipe-diameter hydrogen fuel conveying piping for a vehicle-mounted system with the pressure of 70 MPa and above, which is characterized by comprising a connecting head part, and the connecting head part is fastened on an adapter conical surface matched with the connecting head part through a nut formed by machining and cold heading; the connecting head part comprises a front ball head S1 and a rear ball head S2 which are connected through a vertical line H and an auxiliary straight line C. The vertical line H connecting the front ball head and the rear ball head is tangent to the front ball head S2. According to the large-pipe-diameter head with the special structural size, the requirement for cold heading forming of the head can be well met, meanwhile, hydrogen under the high-pressure environment of 70 MPa or above can be extremely sealed, and the problem that high-pressure gas is difficult to seal through the large-pipe-diameter head can be effectively solved.

Description

[Technical field]

[0001] The utility model relates to a large-flow and large-diameter fuel piping for a hydrogen storage system, in particular to a large-flow and large-diameter hydrogen fuel piping for a vehicle-mounted 70MPa and above system. [Background technology]

[0002] With the transformation of the global energy structure and the development of the fuel cell vehicle industry, hydrogen fuel cell vehicles are rapidly developing towards longer range, greater power, greater safety and efficiency. Longer range means more high-pressure hydrogen storage bottles and more powerful hydrogen fuel cell stacks are needed. Improving hydrogenation efficiency and increasing hydrogen flow have become the core issues that need to be solved in the industry. One of the most direct ways to improve hydrogenation efficiency is to increase the flow diameter of the hydrogenation pipeline. The specifications of the hydrogenation pipelines used in the current FCV-70MPa system are basically The 3.05mm diameter has severely restricted the improvement of hydrogenation efficiency. Increasing the diameter of the pipeline can not only increase the flow rate of hydrogen transmission, but also significantly reduce the pressure loss of the hydrogen transmission pipeline, avoiding the shortage of hydrogen transmission flow due to throttling of the pipeline. Therefore, seeking a larger diameter hydrogen transmission pipeline is an urgent need for FCV-70MPa and above hydrogen storage systems.

[0003] Increasing the pipeline diameter to withstand hydrogen storage pressures of 70MPa and above requires a thicker wall. As the wall thickness increases, the outer diameter will also increase. Hydrogen pipelines with larger diameters face more stringent sealing performance challenges. Although cold-forged metal sealing heads with an outer diameter greater than 6.35mm / an inner diameter greater than 3.05mm have been maturely used in FCV hydrogen storage systems, they are only used in FCV-35MPa low-pressure systems. For metal cone seals, the higher the pressure and the larger the pipe diameter, the higher the risk of gas leakage, and the more difficult it is to design the end head for sealing. How to design a large-diameter head with a special structure and a diameter of 5 mm or more that can not only meet the demand for a larger hydrogen flow rate, but also ensure that hydrogen does not leak under system pressures of 70MPa and above is a difficult problem that the market urgently needs to solve. [Contents of the utility model]

[0004] The utility model aims to overcome the deficiencies of the prior art and to provide a large-diameter fuel piping connection form for a vehicle-mounted hydrogen storage system and a large-diameter head with a special structure having a diameter of 5 mm or more.

[0005] This application seeks a large diameter pipeline with a larger flow rate to seal the 70MPa and above high pressure hydrogen storage system. This application designs a special end structure. The outer diameter specification of the fuel pipe is Millimeters and other specifications of fuel piping that are close to the outer diameter, the piping wall thickness is between 1 and 2 mm, and the end of this piping is completed by a cold heading process. Pipes of this diameter and the end head of the special structure can not only meet the demand for large-flow hydrogen transmission, but also meet the requirements of no leakage under system pressure of 70MPa and above, and achieve high-quality sealing under ultra-high pressure, large flow and large diameter conditions. Since the end structure is cold-headed, the production process is simple and can be mass-produced. The present application relates to a hard-seal connection method and structure for large-flow and large-diameter fuel piping and connectors for on-board 70MPa and above systems. The connecting head of the fuel piping is fastened to the matching connecting cone surface by a nut machined and cold-headed, and the nut matching the end can be made of carbon steel or conventional stainless steel.

[0006] The purpose of this utility model is achieved through the following technical solutions:

[0007] A large flow and large diameter hydrogen fuel pipe for a vehicle-mounted system of 70MPa or above, characterized in that it comprises a connecting head;

[0008] The connecting head includes a front ball head S1 and a rear ball head S2, which are connected by a vertical line H and an auxiliary straight line C. The vertical line H connecting the front and rear balls is tangent to the front ball S2.

[0009] The nut is machined and cold headed;

[0010] The length of the vertical line H ranges from 1 to 2.5 mm.

[0011] The angle formed by the auxiliary straight line C ranges from 90° to 180°.

[0012] The auxiliary straight line C transitions smoothly with the rear ball head.

[0013] The diameter of the front ball head S1 ranges from 8 to 10.5 mm.

[0014] The diameter of the rear ball head S2 ranges from 12 to 14 mm.

[0015] The center of the front ball head S1 is O and the center of the rear ball head S2 is O ， Located on the same axis, and the distance between the centers of the circles is 0 to 1.5 mm.

[0016] The outer diameter D of the fuel pipe is between 9 and 10 mm.

[0017] The wall thickness of the fuel pipe is 1 to 2 mm.

[0018] The connection head is cold headed.

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

[0020] All dimensions of this special structure of large-diameter head are strictly calculated, taking into account the rigidity of the head monomer structure and the feasibility of the cold heading process, and fully considering the ultra-high pressure sealing of the head after forming and assembling with the nut and the connector. At the same time, the head of the present invention comprehensively considers the relevant correlations. The size of the ball head at the end of the head determines the angle size of the nut force surface, and the size of the ball head at the front of the head and the angle of the connecting cone are the prerequisites for sealing. The quality of the sealing is determined by the joint action of the nut, the head and the cone. The special structure of the large-diameter head with a diameter of 5 mm or more invented by the utility model can not only meet the demand for a larger hydrogen flow rate, but also meet the requirement of no leakage under a system pressure of 70 MPa or more. It is a difficult problem that the current market urgently needs to solve. At the same time, the structure can be easily and low-cost mass-produced.

Brief Description of the Drawings

[0021] Figure 1 It is a cross-sectional view of the assembly structure of the head and the connecting parts;

[0022] Figure 2 Head structure diagram;

[0023] Figure 3 It is the assembly nut;

[0024] Figure 4 It is an assembly connector;

[0025] The markings in the accompanying drawings are:

[0026] 1- Connect the head;

[0027] 2- nut;

[0028] 3- Assemble the connectors;

[0029] K1-contact point between connector and head;

[0030] K2-contact point between nut and head;

[0031] H-vertical line

[0032] S1-front ball head;

[0033] S2- rear ball head; [Specific implementation method]

[0034] The following provides a specific implementation of a large-diameter fuel pipe connection form of a vehicle-mounted hydrogen transmission system and a special structure large-diameter head with a diameter of 5 mm or more of the utility model.

[0035] Example 1

[0036] Embodiment Referring to the accompanying drawings, the present application relates to a connection structure of a large flow and large diameter fuel pipe and an end cold forging forming system for a vehicle-mounted high pressure hydrogen transmission system, see Figure 1As shown. The connection head 1 at the end of the pipe is fastened to the conical surface of the matching assembly connector 3 by a nut 2. The shape of the connection head 1 at the end is completed by a cold heading process, and is mainly composed of a front ball head S1 and a rear ball head S2, as well as H, C straight lines and other auxiliary lines between the two. The surface where the joint assembly connector 3 contacts the front end of the head is a conical surface. The cone angle (ψ) of the joint is generally 60°, and the inner diameter d1 is not less than 5 mm. The joint form is shown in Figure 4 The external thread of the joint and the nut are of the same size, and the external size (L) of the nut of the present invention is not limited. Figure 3 As shown, the nuts need to be put on the pipes before the heads at both ends of the pipes are formed. The fuel pipe is formed at the end or prefabricated and bent into a specific shape before being assembled with the assembly connector 3, and finally forms the function of large-flow hydrogen transmission and high-pressure gas sealing. The specific implementation process of achieving high-pressure sealing is as follows: pre-tighten the nut 2 on the corresponding assembly connector 3. After pre-tightening, the joint cone surface contacts the front ball head S1 of the head, and the contact point is K1. The nut contacts the rear ball head of the head, and the contact point is K2. After pre-tightening, a certain installation torque is applied to the nut (this installation torque value needs to be strictly controlled). Under the action of the specific torque, the nut converts the torque into an axial force and transmits it to the head through point K2. The head has sufficient rigidity to accept this axial force. After being subjected to the axial force, the head will move toward the joint cone surface. Under the action of the axial force of the contact point K1 between the front ball head of the head and the joint cone surface, the area near point K1 will undergo elastic-plastic deformation to form an annular sealing surface. This special large-diameter head, due to the front and rear ball structure, can not only obtain an ideal sealing ring surface, but also ensure good sealing uniformity even when the head is installed skewed.

[0037] like Figure 2 As shown, the present application relates to a hard-seal connection method and structure for large-flow and large-diameter fuel piping and connectors in a vehicle-mounted hydrogen transmission system. The fuel piping head is fastened to a matching connecting cone surface by a nut, and the nut matching the end can be made of carbon steel or conventional stainless steel. The shape of the end head is completed by a cold heading process, and the head is mainly composed of a front ball head S1 and a rear ball head S2, as well as a vertical line H and an auxiliary straight line C between the two. The vertical line H connecting the front and rear balls is tangent to the front ball head S2, and the length range is 1 to 2.5 mm. The angle range of the auxiliary straight line C is 90° to 135°. The auxiliary straight line C smoothly transitions to the rear ball head, where the diameter size range of the front ball head S1 is 8 to 10.5 mm, and the diameter size range of the rear ball head S2 is 12 to 14 mm. The center O of the front ball S1 and the center O of the rear ball S2 ，, located on the same axis, and the distance between the centers is 0 to 1.5 mm. This large-diameter head with special structural dimensions can not only meet the requirements of head cold heading, but also form an extreme seal for hydrogen under high pressure environments of 70MPa and above, and can also effectively solve the problem of large-diameter heads having difficulty sealing high-pressure gases.

[0038] The preferred embodiments of the present invention are described above, but the present invention is not limited to the above embodiments. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the concept of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A large flow and large diameter hydrogen fuel pipe for vehicle-mounted 70MPa and above systems, characterized in that: It includes a connection header; The connecting head includes a front ball head S1 and a rear ball head S2, which are connected by a vertical line H and an auxiliary straight line C. The vertical line H connecting the front and rear balls is tangent to the front ball head S1.

2. A large flow and large diameter hydrogen fuel pipe for a vehicle-mounted 70MPa and above system as claimed in claim 1, characterized in that: The length of the vertical line H ranges from 1 to 2.5 mm.

3. A large flow and large diameter hydrogen fuel pipe for a vehicle-mounted 70MPa and above system as claimed in claim 1, characterized in that: The angle formed by the auxiliary straight line C ranges from 90° to 180°.

4. A large flow and large diameter hydrogen fuel pipe for a vehicle-mounted 70MPa and above system as claimed in claim 1, characterized in that: The auxiliary straight line C transitions smoothly with the rear ball head.

5. A large flow and large diameter hydrogen fuel pipe for a vehicle-mounted 70MPa and above system as claimed in claim 1, characterized in that: The diameter of the front ball head S1 ranges from 8 to 10.5 mm.

6. A large flow and large diameter hydrogen fuel pipe for a vehicle-mounted 70MPa and above system as claimed in claim 1, characterized in that: The diameter of the rear ball head S2 ranges from 12 to 14 mm.

7. The large flow and large diameter hydrogen fuel pipe for vehicle-mounted 70MPa and above systems as claimed in claim 1, characterized in that: The center of the front ball head S1 is O and the center of the rear ball head S2 is O ， Located on the same axis, and the distance between the centers of the circles is 0 to 1.5 mm.

8. A large flow and large diameter hydrogen fuel pipe for a vehicle-mounted system with a pressure of 70 MPa or above as claimed in claim 1, characterized in that: The outer diameter D of the fuel pipe is between 9 and 10 mm.

9. A large flow and large diameter hydrogen fuel pipe for a vehicle-mounted system with a pressure of 70 MPa or above as claimed in claim 1, characterized in that: The wall thickness of the fuel pipe is 1 to 2 mm.

10. A large flow and large diameter hydrogen fuel pipe for a vehicle-mounted system with a pressure of 70 MPa or above as claimed in claim 1, characterized in that: The connection head is cold headed.

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