An ultra-low temperature pipeline visualization device for liquid rocket engine testing

Abstract

The application provides a liquid rocket engine test super-low temperature pipeline visualizing device, which comprises an inlet flange, an outer sealing gasket, a vacuum sealing ring, an inner sealing gasket, an outer observation tube, an inner observation tube, an outlet flange and a vacuum quick-release connector; the inlet flange and the outlet flange have the same inner sealing structure, both of which comprise an annular sealing groove, the annular sealing groove is provided with an outer sealing gasket, and the outer sealing gasket is used for sealing the outer observation tube and maintaining the vacuum degree between the outer observation tube and the inner observation tube; a protruding sealing ring is arranged at the center of the inner side, the protruding sealing ring comprises a sealing ring groove and a wedge-shaped end surface sealing groove, the vacuum sealing ring is arranged in the sealing ring groove, and the vacuum degree between the outer observation tube and the inner observation tube is maintained; and the inner sealing gasket is arranged in the wedge-shaped end surface sealing groove, and is used for preventing the medium in the inner observation tube from leaking out.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of low-temperature technology, and particularly relates to a medium observation and pre-cooling state confirmation means for a low-temperature test system. BACKGROUND

[0002] With the rapid development of aerospace, petrochemical industry and other fields, the demand for reliability verification of components applied to low-temperature operating environment is increasing, and the amount of low-temperature tests is increasing year by year. However, the pre-cooling or action flexibility test of the workpiece in the existing low-temperature test relies on experience or time accumulation for judgment, and cannot directly and visually confirm the pre-cooling condition of the test product and the test system or the low-temperature action condition of the test product, which is insufficient for the low-temperature real working condition test, especially for the key low-temperature components in the aerospace, LNG and other systems. The test accuracy and test efficiency of the existing test system cannot meet the current large number of test requirements. SUMMARY

[0003] The technical problem solved by the application is to overcome the problems in the related test technology, and a device for directly and visually observing the flow state of low-temperature medium is provided, and an assembly method and a use method for the device are given.

[0004] The technical solution of the application is: a liquid rocket engine test super-low-temperature pipeline visualization device, comprising: an inlet flange, an outer sealing gasket, a vacuum sealing ring, an inner sealing gasket, an outer observation tube, an inner observation tube, an outlet flange and a vacuum quick-release connector.

[0005] The inlet flange and the outlet flange have the same inner sealing structure, both comprising an annular sealing groove, and the annular sealing groove is provided with an outer sealing gasket to seal the outer observation tube and maintain the vacuum degree between the outer observation tube and the inner observation tube; a protruding sealing ring is arranged at the center of the inner side, the protruding sealing ring comprises a sealing ring groove and a wedge-shaped end face sealing groove, the vacuum sealing ring is arranged in the sealing ring groove to maintain the vacuum degree between the outer observation tube and the inner observation tube, and the inner sealing gasket is arranged in the wedge-shaped end face sealing groove to prevent the medium in the inner observation tube from leaking out;

[0006] The inlet flange is provided with a radial hole on the side surface and an axial hole on the inner side, and the radial hole is communicated with the axial hole; the vacuum quick-release connector is welded to the radial hole, and the axial hole is located between the annular sealing groove and the protruding sealing ring to provide a vacuum degree between the outer observation tube and the inner observation tube;

[0007] The inlet flange and the outlet flange are fastened through a structural member to clamp the inner and outer sealing gaskets and the inner and outer observation tubes.

[0008] Preferably, the inlet flange is externally threaded with a pipeline joint, and the outlet flange is externally threaded with a system evacuation pipeline or directly evacuated.

[0009] Preferably, the outer observation tube is designed with a port limiting step to prevent uneven stress on the inner and outer observation tubes caused by excessive compression of the sealing gasket during tightening, thereby reducing material stiffness.

[0010] Preferably, the inner observation tube is designed with a sealing chamfer and a limiting step from the outside to the inside at both ends, the sealing chamfer is used to prevent the inner observation tube from cutting the vacuum sealing ring during assembly, and the limiting step is used for wedge-shaped end face sealing with the inner sealing gasket.

[0011] Preferably, the inlet flange and the outlet flange have multiple axial through holes for inserting a screw rod, and bolts are used to symmetrically tighten the inlet and outlet flanges on both sides, respectively, so that the inlet flange and the outlet flange clamp the inner and outer sealing gaskets and the inner and outer observation tubes, ensuring the vacuum degree between the outer observation tube and the inner observation tube and preventing the medium flowing through the inner observation tube from leaking out.

[0012] Preferably, the volume of the vacuum cavity formed between the inner observation tube and the outer observation tube is not greater than 0.5L, and the effective wall thickness of the outer observation tube and the inner observation tube is 5-8mm.

[0013] Preferably, the vacuum sealing ring uses an O-shaped rubber ring that can withstand low temperature environments, and the materials of the inner and outer sealing gaskets are compressible low-temperature-resistant sealing gasket materials, including F4, copper, or soft aluminum.

[0014] Preferably, the outer observation tube and the inner observation tube are made of PMMA or quartz.

[0015] An assembly method of a liquid rocket engine test super-low-temperature pipeline visualization device, comprising:

[0016] The outer sealing gasket is installed in the annular sealing groove of the inlet flange, the vacuum sealing ring is installed in the sealing ring groove, the inner sealing gasket is installed in the wedge-shaped end face sealing groove of the protruding sealing ring, and the vacuum sealing mud that can withstand low temperature environments is applied around the vacuum sealing ring;

[0017] The inner observation tube is assembled with the inlet flange, the vacuum sealing ring passes through the inner observation tube sealing chamfer into the straight tube section, and the inner observation tube limiting step contacts the inner sealing gasket, the outer observation tube is placed in the outer sealing gasket, the inner sealing gasket is placed in the free end of the inner observation tube, and the outer sealing gasket is placed in the free end of the outer observation tube;

[0018] Put the vacuum sealing ring into the sealing ring groove of the convex sealing ring of the outlet flange, and evenly apply low-temperature-resistant vacuum mud; install the outlet flange in place, confirm that the inner observation tube and the outer observation tube are perpendicular to the inlet flange and the outlet flange, and then symmetrically fasten the inlet flange and the outlet flange using bolts and nuts, so that the two ends of the inner observation tube are in contact with the inner sealing gasket, and the two ends of the outer observation tube are in contact with the outer sealing gasket, and the vacuum sealing ring is completely located in the sealing ring groove of the convex sealing ring;

[0019] Perform shaking observation, and assemble after no error.

[0020] A use method of a liquid rocket engine test super-low-temperature pipeline visualization device, comprising:

[0021] Connect the equipped super-low-temperature pipeline visualization device inlet flange with a product downstream system, and threadedly connect or directly evacuate the outlet flange with a system evacuation pipeline;

[0022] Connect the vacuum pump to the inlet flange side welded vacuum quick-disconnect connector, open the vacuum pump, and when the vacuum degree is better than 4.0*10 -3 pa, pass the super-low-temperature medium into the inner observation tube, and observe that the medium flows in the inner observation tube.

[0023] Compared with the prior art, the application has the beneficial effects that:

[0024] The super-low-temperature pipeline visualization device has been installed at the outlet end of a super-low-temperature test system for verification test for many times, and the super-low-temperature medium flow can be successfully observed.

[0025] (1) The radial low-temperature-resistant O-ring seal and the axial wedge-shaped end face seal are combined, the O-ring is used for ensuring the vacuum degree, and the wedge-shaped end face seal is used for medium sealing.

[0026] (2) The bolts, nuts (the bolts and nuts of the application can uniformly bear the force during compression), inlet flanges and outlet flanges are used to compress the observation tubes, the symmetric installation has good sealing effect, the device has the advantages of simple structure, convenient disassembly and inspection, and low installation and maintenance cost.

[0027] (3) The wedge-shaped sealing gasket is used to have the guiding effect while having the sealing property, so that the perpendicularity between the inlet flange, the outlet and the inner observation tube is ensured during assembly, and the assembly difficulty of the device is reduced.

[0028] (4) The limit steps of the outer observation tube and the inner observation tube have the self-limiting design, so that the observation tube is prevented from being damaged during the fastening process, and the assembly success rate is reduced by over-positioning.

[0029] (5) The application has a 360° observation window, and can freely define the installation position according to the system pipeline direction, and can observe the flow of medium in all directions, and can observe the flow state of different density ultra-low temperature fluid, and is suitable for observing various ultra-low temperature media such as liquid nitrogen.

[0030] (6) The application adopts a vacuum jacket structure, and after confirming that the vacuum degree of the outer observation tube and the inner observation tube is better than 4.0*10 -3 pa, the total heat leakage can be maintained at a low level, so that the deformation and rupture of the observation tube caused by the alternating stress of the device due to heat exchange are prevented. The device is installed downstream of the test system, and the flow of low-temperature medium can be observed. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The application provides a visualization device for an ultra-low temperature pipeline of a liquid rocket engine test system.

[0032] Figure 2 The application provides an import flange schematic diagram.

[0033] Figure 3 The application provides an outer observation tube schematic diagram.

[0034] Figure 4 The application provides an inner observation tube schematic diagram.

[0035] Figure 5 The application provides an export flange schematic diagram.

[0036] BRIEF DESCRIPTION OF DRAWINGS:

[0037] 1, import flange; 11, axial hole; 12, radial hole; 13, convex sealing ring; 14, annular sealing groove; 15, sealing ring groove; 16, wedge-shaped end face sealing groove

[0038] 2, nut; 3, vacuum quick-release connector; 4, stud

[0039] 5, outer observation tube; 51, outer observation tube limiting step

[0040] 6, inner observation tube; 61, inner observation tube limiting step; 62, inner observation tube sealing bevel

[0041] 7, inner sealing pad; 8, vacuum sealing ring; 9, outer sealing pad

[0042] 10, export flange; 101, convex sealing ring; 102, annular sealing groove; 103, sealing ring groove; 104, wedge-shaped end face sealing groove DETAILED DESCRIPTION

[0043] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly explain the spirit of the present application with the attached drawings and detailed description. Any person skilled in the art can make changes and modifications to the technology taught by the present application without departing from the spirit and scope of the present application.

[0044] The illustrative embodiments of the present application and their description serve the purpose of explaining the present application. They are provided to further enable those in the art to make and use the present application, and are not intended to limit the scope of the present application, which is defined solely by the claims.

[0045] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" or the like are open-ended and do not exclude additional, unrecited elements or method steps.

[0046] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0047] As used herein, the terms "align", "vertical", "surrounding", "uniform", "in place", "normal" and the like are used to modify any quantity or error that can be subject to slight variation, but that do not change the nature of the quantity or error. Generally, the slight variation or error that is modified by such terms can be within 5% or other value in the embodiments. Those skilled in the art will appreciate that the aforementioned values can be adjusted as desired and are not limited thereto.

[0048] Certain words used in the description of the present application are discussed below or elsewhere in this specification to provide additional guidance to the practitioner in the art for making and using the present application.

[0049] The inlet flange 1 should be first installed in the annular sealing groove 14 of the outer sealing gasket 9, the vacuum sealing ring 8 in the sealing ring groove 15, the inner sealing gasket 7 in the wedge-shaped end face sealing groove 16 of the protruding sealing ring 13, and the inner observation tube 6 is assembled with the inlet flange 1, and the vacuum sealing ring 8 is confirmed to pass through the inner observation tube sealing slope 62 into the straight tube section (the straight tube section is the part between 61 and 62), and the inner observation tube limiting step 61 is in contact with the inner sealing gasket 7, and then the outer observation tube 5 is placed in the outer sealing gasket 9, the inner sealing gasket 7 is placed in the free end of the inner observation tube 6, the outer sealing gasket 9 is placed in the free end of the outer observation tube 5 (from right to left, the installation process is 1, 5, 6, 7, 8, 9, 10), the vacuum sealing ring 8 is placed in the sealing ring groove 103 of the protruding sealing ring 101, and the low-temperature resistant vacuum mud is uniformly applied around the vacuum sealing ring (every time the assembly is reassembled, the vacuum mud is uniformly applied around the vacuum sealing ring); the outlet flange 10 is installed in place, and after confirming that the inner observation tube 6 and the outer observation tube 5 are perpendicular to the inlet flange 1 and the outlet flange 10, the visual device of the ultra-low temperature pipeline is symmetrically fastened by using bolts and nuts, and finally the two ends of the inner observation tube 6 are in contact with the inner sealing gasket 7, and the two ends of the outer observation tube 5 are in contact with the outer sealing gasket 9, and the vacuum sealing ring 8 is completely stopped in the sealing ring groove 15, 103 of the protruding sealing ring 13, 101. When the device is shaken, there is no abnormal sound, the outer observation tube 5 does not move relative to the inlet flange 1 and the outlet flange 10, and the inlet flange 1 and the outlet flange 10 are visually horizontal, that is, the assembly is considered to be completed, and the assembly state after completion is shown in Figure 1

[0050] The inlet flange of the visual device of the ultra-low temperature pipeline is connected with the product downstream system, and the outlet flange is threadedly connected with the system evacuation pipeline or directly evacuated. In this example, the thickness of the inlet flange is 20 mm, the thickness of the outlet flange is 16 mm, the effective wall thickness of the outer observation tube and the inner observation tube is 5 mm, and the volume of the vacuum cavity formed between the inner observation tube and the outer observation tube is not greater than 0.5L. The vacuum pump is connected to the vacuum quick release connector 3 on the side surface of the inlet flange, the vacuum pump is opened, and it is observed that the vacuum degree can normally decrease, and after the vacuum degree is better than 4.0x10 -3 pa, the ultra-low temperature medium (liquid oxygen, liquid nitrogen environment temperature range) is allowed to enter, and after the device is cooled, the medium flowing in the inner observation tube can be observed (naked eye or collection system) smoothly.

[0051] ​The visualization device of the ultra-low temperature pipeline described in the application has been successfully applied in the ultra-low temperature test system for many times. Through the device, the flow of the liquid coolant can be observed, which can be considered as that the system has reached heat transfer balance with the coolant. The above description is only a specific embodiment of the application. The device described in the application can also be used for verifying the heat transfer efficiency of the vaporizer and other example applications. Any equivalent changes and modifications made by any person skilled in the art without departing from the concept and principles of the application shall fall within the scope of protection of the application.

[0052] The part of the application not described in detail belongs to the common knowledge of those skilled in the art.

Claims

1. An ultra-cold liquid rocket engine test line visualization device, characterized in that It comprises: the inlet flange, the outer sealing gasket, the vacuum sealing ring, the inner sealing gasket, the outer observation tube, the inner observation tube, the outlet flange, and the vacuum quick-release connector; the inlet flange and the outlet flange have the same inner sealing structure, both comprising an annular sealing groove, and the annular sealing groove is provided with an outer sealing gasket for sealing with the outer observation tube to maintain the vacuum degree between the outer observation tube and the inner observation tube; a protruding sealing ring is arranged at the center of the inner side, and the protruding sealing ring comprises a sealing ring groove and a wedge-shaped end face sealing groove, wherein the sealing ring groove is provided with a vacuum sealing ring for maintaining the vacuum degree between the outer observation tube and the inner observation tube; and the wedge-shaped end face sealing groove is provided with an inner sealing gasket for preventing the medium in the inner observation tube from leaking out; the inlet flange is provided with a radial hole on the side surface and an axial hole on the inner side, and the radial hole is communicated with the axial hole; the radial hole is welded with the vacuum quick-release connector, and the axial hole is located between the annular sealing groove and the protruding sealing ring to provide a vacuum degree between the outer observation tube and the inner observation tube; the inlet flange and the outlet flange are fastened by a structural member to clamp the inner and outer sealing gaskets and the inner and outer observation tubes.

2. The apparatus of claim 1, wherein: the inlet flange and the outlet flange are provided with threaded pipeline joints on the outer side, the inlet flange is connected with the product downstream system, and the outlet flange is connected with the system evacuation pipeline by screwing or directly evacuated.

3. The apparatus of claim 1, wherein: the outer observation tube is designed with a limiting step at the port to prevent the inner and outer observation tubes from being unevenly stressed due to excessive compression of the sealing gasket during fastening, thereby reducing the material rigidity.

4. The apparatus of claim 1, wherein: the inner observation tube is designed with a sealing bevel and a limiting step from the outside to the inside at both ends, the sealing bevel is used to prevent the inner observation tube from cutting the vacuum sealing ring during assembly, and the limiting step is used for wedge-shaped end face sealing with the inner sealing gasket.

5. The apparatus of claim 1, wherein: the inlet flange and the outlet flange are provided with multiple axial through holes for inserting a screw rod, and bolts are used to fasten the inlet flange and the outlet flange on both sides respectively to clamp the inner and outer sealing gaskets and the inner and outer observation tubes, thereby ensuring the vacuum degree between the outer observation tube and the inner observation tube and preventing the medium flowing in the inner observation tube from leaking out.

6. The apparatus of claim 1, wherein: the volume of the vacuum cavity formed between the inner observation tube and the outer observation tube is not greater than 0.5L, and the effective wall thickness of the outer observation tube and the inner observation tube is 5-8mm.

7. The apparatus of claim 1, wherein: the vacuum sealing ring is made of O-shaped rubber ring that can withstand low temperature environment; the materials of the inner and outer sealing gaskets are compressible low-temperature-resistant sealing gasket materials, and the materials include F4, copper, or soft aluminum.

8. The apparatus of claim 1, wherein: the outer observation tube and the inner observation tube are made of PMMA or quartz.

9. A method of assembling a liquid rocket engine test cryogenic line visualization apparatus, comprising It comprises: the outer sealing gasket is installed in the annular sealing groove of the inlet flange, the vacuum sealing ring is installed in the sealing ring groove, the inner sealing gasket is installed in the wedge-shaped end face sealing groove of the protruding sealing ring, and the vacuum sealing mud that can withstand low temperature environment is applied around the vacuum sealing ring; the inner observation tube is assembled with the inlet flange, the vacuum sealing ring passes through the inner observation tube sealing bevel and enters the straight tube section, and the inner observation tube limiting step contacts with the inner sealing gasket, then the outer observation tube is placed in the outer sealing gasket, the inner sealing gasket is placed at the free end of the inner observation tube, and the outer sealing gasket is placed at the free end of the outer observation tube; Put the vacuum sealing ring into the sealing ring groove of the convex sealing ring of the outlet flange, and evenly apply low-temperature-resistant vacuum mud; install the outlet flange in place, confirm that the inner observation tube and the outer observation tube are perpendicular to the inlet flange and the outlet flange, and then symmetrically fasten the inlet flange and the outlet flange using bolts and nuts, so that the two ends of the inner observation tube are in contact with the inner sealing gasket, and the two ends of the outer observation tube are in contact with the outer sealing gasket, and the vacuum sealing ring is completely stopped in the sealing ring groove of the convex sealing ring; Perform shaking observation and inspection, and assemble after no error is found.

10. A method of using the liquid rocket engine test ultralow temperature plumbing visualization apparatus of claim 1, characterized by It comprises: Connect the equipped ultra-low-temperature pipeline visualization device inlet flange with the product downstream system, and threadedly connect or directly evacuate the outlet flange with the system evacuation pipeline; Connect the vacuum pump to the inlet flange side, weld the vacuum quick disconnect connector, turn on the vacuum pump, and when the vacuum is better than 4.0 x 10 -3 The inner observation tube is observed to have the ultra-low temperature medium flowing in the inner observation tube.

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