PIPE BEND STRUCTURE FOR REDUCING LOAD ON NOZZLE OF ROTATING DEVICE

Abstract

Provided is a pipe bend structure for reducing the load on the nozzle of a rotating device, including a pipe bend, a reinforcing rib and a reinforcing plate. The reinforcing plate is arranged on an outer surface of the pipe bend, and the reinforcing rib is arranged on an inner arc side of the outer surface of the pipe bend. In the structure, the arrangement of the reinforcing rib and the reinforcing plate on the pipe bend increases the strength of the pipe bend, so that the stress in the pipe bend resulting from a pipe connected thereto can be relieved, ensuring the stable and reliable operation of the rotating device.

Claims

1.-11. (canceled)

12. A pipe bend structure for reducing the load on a nozzle of a rotating apparatus, the pipe bend structure comprising a pipe bend, a reinforcing rib and a reinforcing plate, wherein both ends of the pipe bend are respectively connected to the nozzle of the rotating apparatus and an external pipeline via flanges, the reinforcing plate is disposed on an outer surface of the pipe bend, and the reinforcing rib is disposed on an inner arc side of the outer surface of the pipe bend.

13. The pipe bend structure as claimed in claim 12, further comprising two reinforcing plates comprising arc surfaces, respectively fitted to both sides of the outer surface of the pipe bend and are left-right symmetric with respect to an axial longitudinal section of the pipe bend.

14. The pipe bend structure as claimed in claim 12, wherein the thickness of the reinforcing plate is not less than the wall thickness of the pipe bend.

15. The pipe bend structure as claimed in claim 12, wherein the reinforcing rib has an arc shape and is fitted to the inner arc side of the pipe bend.

16. The pipe bend structure as claimed in claim 15, wherein the thickness of the reinforcing rib is not less than the wall thickness of the pipe bend.

17. The pipe bend structure as claimed in claim 12, wherein the material of each of the reinforcing plate and the reinforcing rib is selected from stainless steel or carbon steel.

18. The pipe bend structure as claimed in claim 17, wherein the reinforcing plate and the reinforcing rib are fixed to the pipe bend by means of welding.

19. The pipe bend structure as claimed in claim 12, wherein the pipe bend is a circular section pipe bend of 90 degrees.

20. The pipe bend structure as claimed in claim 12, wherein the pipe bend structure further comprises a support device, which comprises: a support pipe and a pipe holder, wherein the support pipe is perpendicularly disposed, and is freely movable in a perpendicular direction along a sleeve outside same; the pipe holder has an arc surface and is disposed at a top end of the support pipe for holding the pipe bend, and an inner arc side of the arc surface pipe holder and an outer arc side of the pipe bend are fitted to each other.

21. The pipe bend structure as claimed in claim 20, wherein the pipe holder and the pipe bend are connected by means of welding.

22. The pipe bend structure as claimed in claim 12, wherein the rotating apparatus comprises a turbine, a steam turbine, a turbomachine, a centrifugal compressor, and/or a cryogenic liquid pump.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. 1 is a schematic view of a pipe bend bracket connecting a cryogenic liquid pump in an existing air separation apparatus.

[0023] FIG. 2 is a schematic structural view of an embodiment of the present invention.

[0024] FIG. 3a is a side view of a pipe bend structure in an X direction in an embodiment of the present invention.

[0025] FIG. 3b is a side view of the pipe bend structure in a Z direction in an embodiment of the present invention.

[0026] 1Cryogenic liquid pump, 2Outlet nozzle of pump, 3Flexible pipe bend, 3Pipe bend, 4Flange, 5Flexible pipe, 6Rigid pipe, 7Support frame, 8Support pipe, 9Pipe holder, 10Reinforcing rib, 11Reinforcing plate, 12Sleeve.

DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the drawings and embodiments.

[0028] As shown in FIG. 1, in an existing air separation apparatus, a pipe bend connecting an outlet nozzle 2 of a cryogenic liquid pump 1 is a flexible pipe bend 3, the other end thereof is connected to a flexible pipe 5 through a flange 4, the other end of the flexible pipe 5 is connected to a rigid pipe 6, and a support frame 7 is provided on the rigid pipe 6. The operating temperature of the cryogenic liquid pump 1 is about 190 C, and the pump has a displacement in an axial direction (dy) of the nozzle, and has no displacement in other directions (dy0, dx=0, dz=0). A support pipe 8 is perpendicularly disposed, and a pipe holder 9 is of an arc surface and is disposed at a top end of the support pipe to ensure that the outlet nozzle 2 of the pump can only move along the axial direction (dy) of the nozzle. However, the stress from the pipe 6 can still be transferred to the outlet nozzle 2 of the pump through the pipe bend. It can be seen that the outlet nozzle 2 of the pump is connected to external piping through the pipe bend 3, and a flexible elbow can unload some of the stress from the external piping. However, leakage of the cryogenic liquid pump is also easily caused due to the deformation of the flexible elbow itself and due to material-related reasons.

[0029] One embodiment of the present invention provides a pipe bend structure for reducing load on a nozzle of a rotating apparatus, in which embodiment the cryogenic liquid pump 1 has a displacement in the axial direction (dy) of the nozzle. As shown in FIG. 2, the device comprises a rigid pipe bend 3 having a size of DN80 (diameter)*7.62 (wall thickness) mm, and both ends of the pipe bend 3 are respectively connected to the nozzle 2 of the pump and the external rigid pipe 6 via flanges. As shown in FIG. 3a and FIG. 3b, two reinforcing plates 11 are provided, and they have arc surfaces, a thickness (T) of 10 mm, a central arc length (L) of 150 mm in a lengthwise direction, and an arc length (W) of 50 mm in a widthwise direction, are disposed on both sides of an outer surface of the pipe bend by means of welding (see FIG. 3a and FIG. 3b for details), and are closely fitted to the pipe bend symmetrically with respect to an axial longitudinal section of the pipe bend. A reinforcing rib 10 has an arc shape, has a thickness (T) of 10 mm, an arc length (L) of 50 mm along the axial direction of the pipe bend, and an arc length (W) of 20 mm in the widthwise direction; the bending radius of the center line of the reinforcing rib in the axial direction of the pipe bend on the side where the reinforcing rib is connected to the pipe bend is consistent with the bending radius of an inner arc of the pipe bend; and the reinforcing rib is closely fitted to the inner arc of the outer surface of the pipe bend 3 by means of welding. A support device is provided at a lower part of the pipe bend structure, and comprises: a support pipe 8 and a pipe holder 9, wherein the support pipe 8 is perpendicularly disposed, and is freely movable in a vertical direction (dy) along a sleeve 12 outside same; the pipe holder 9 has an arc surface and is disposed at the top end of the support pipe, and an inner arc side of the arc surface pipe holder 9 and an outer arc side of the pipe bend 3 are closely fitted, both of which are connected by means of welding to support the pipe bend 3. According to the stiffness of an elbow, that is, the ability of the elbow to resist deformation when subjected to force, CAESARII pipeline stress analysis software (CAESARII 2014 from American company Intergraph) is used to calculate the load on the nozzle of the pump connecting the elbow (an unreinforced elbow and a reinforced elbow). Under installation working conditions, that is, under normal temperature working conditions, the pump does not operate, the stress in the dy direction is mainly the gravity of the device; and under operating working conditions, the pump operates at a low temperature, and the stress in the dy direction is mainly the stress caused by low temperature shrinkage of metal. For the pipe bend which is not reinforced by the reinforcing rib and the reinforcing plate, even if there is a support device to unload the stress in a horizontal direction, compared with the present invention, the stress in the dx direction is still large under the operating working conditions. In the present invention, the lateral line force Fx applied to the nozzle of the pump is significantly reduced, and the load of the nozzle in the horizontal direction is significantly lowered. The specific line forces {Fx, Fy, Fz} and torques {Mx, My, Mz} change as follows:

TABLE-US-00001 TABLE 1 Analysis data of respective axial forces and torques before and after the addition of the reinforcing plates and the reinforcing rib in the embodiment of the present invention (FIG. 2) Working Fx Fy Fz Mx My Mz condition (N) (N) (N) (N .Math. m) (N .Math. m) (N .Math. m) Comparative Installation 35 769 0 0 0 24 example working (without the conditions reinforcing (normal plates and the temperature reinforcing rib) working conditions) Operating 2031 1672 8 0 1 478 working conditions (cold working conditions) Embodiment Installation 71 810 0 0 0 35 of the present working invention conditions (with the (normal reinforcing temperature plates and the working reinforcing conditions) rib as in FIG. 2) Operating 730 1682 8 1 1 395 working conditions (cold working conditions)

[0030] The above embodiments are merely preferred embodiments of the present invention, but are not intended to limit the present invention, and any simple modifications, alterations, and equivalent structural changes made to the above embodiments in accordance with the technical substance of the present invention still fall within the scope of protection of the technical solutions of the present invention. Meanwhile, the terms that are cited in this specification such as upper, lower, left, right and a/an are merely intended for convenience of description rather than to limit the implementable scope of the present invention, and the changes or adjustments of the relative relationship thereof should be seen as the implementable scope of the present invention without substantial changes in the technical content.