High-pressure gas flow measurement and control device capable of rapid replacement and replacement method

Abstract

This invention discloses a high-pressure gas flow measurement and control device capable of rapid replacement, comprising an upstream sealing short pipe, a first outer nut, a second outer nut, a sonic nozzle, an O-ring seal, and a downstream sealing short pipe. The upstream sealing short pipe and the sonic nozzle are connected by the first outer nut, and the sonic nozzle and the downstream sealing short pipe are connected by the second outer nut, with O-ring seals at the end faces. This invention also discloses a replacement method: when replacing the sonic nozzle, simply loosening the first and second outer nuts allows the sonic nozzle to be directly and easily removed, making replacement and installation very convenient. Furthermore, the sonic nozzle throat features a design with a contraction section, a transition section, a straight section, and an expansion section profile, resulting in a high flow coefficient.

Description

Technical Field

[0001] The present invention relates to a high-pressure gas flow measurement and control device and a replacement method that can be quickly replaced, which is used to measure and control the flow of test airflow in a pneumatic thermal ground simulation test air supply system, and can also be applied to other fields that require high-pressure gas flow control and measurement. Background Art

[0002] In the aerodynamic thermal ground simulation test, arc heaters occupy an important position due to their advantages such as realistic airflow composition and wide range of operating parameters. The wide range of operating parameters of arc heaters is due to the large adjustable range of air intake flow and current.

[0003] In the operation of the arc heater, the air flow rate is an important parameter, which is directly related to whether the heater can operate normally: under the given current parameter conditions, if the air flow rate is too small, the heater will burn out more; if the air flow rate is too large, the arc will be blown out and the heater will not operate stably. During the operation of the arc heater, the air flow rate must be stable to ensure the stable operation of the heater and thus ensure the stability of the test state. Accurate control and measurement of the air flow rate can ensure that the arc heater has good state repeatability, which is crucial for the acceptance test of key models.

[0004] In the ground simulation test of aerodynamic heat, the total enthalpy of the airflow varies over a large range, from about 500 kJ / kg to more than 20,000 kJ / kg. This requires that the air intake flow rate of the arc heater varies over a large range, from a few grams per second to several kilograms per second. Correspondingly, the diameter of the sonic nozzle should also vary greatly. Therefore, in the ground simulation test of aerodynamic heat, the sonic nozzle needs to be replaced frequently according to the test status.

[0005] The structure of the flow measurement and control device currently used in the aerodynamic thermal ground simulation test is shown in the attached figure. Figure 3 As shown, the sonic nozzle is inserted into the downstream sealing short tube. In this structure, when replacing the sonic nozzle, the downstream sealing short tube needs to be withdrawn backward by 20mm to 100mm to take out the sonic nozzle. Since the high-pressure gas pipeline is all made of high-pressure thick-walled metal pipeline under the condition of 26MPa, it is necessary to dismantle a longer pipeline to withdraw the installation distance, and the replacement and installation of the sonic nozzle is very difficult.

[0006] In addition, the currently commonly used sonic nozzles use an arc plus cone method to design the inner surface. At the bottom of the arc, the air flow cross-sectional area is minimized to form a throat. When the throat diameter is ≥10mm, this inner profile will increase the pressure loss of the air flow due to excessive contraction of the air flow, thereby reducing the flow coefficient. Summary of the invention

[0007] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to provide a high-pressure gas flow measurement and control device and a replacement method that can be quickly replaced, thereby solving the problem that the existing high-pressure gas flow measurement and control device requires a large installation space for replacement. At the same time, the sonic nozzle is composed of a contraction section, a transition section, an equal straight section and an expansion section, which reduces the pressure loss of the airflow and improves the flow coefficient.

[0008] The technical solution of the present invention:

[0009] A high-pressure gas flow measurement and control device capable of rapid replacement, comprising an upstream sealing short tube, a first outer shell nut, a second outer shell nut, a sonic nozzle, an O-type sealing ring and a downstream sealing short tube;

[0010] The front end of the upstream sealing short tube is welded to the air supply pipeline, and the rear end is designed as a boss structure. The first outer sleeve nut is fixed on the upstream sealing short tube through the boss structure, and the inner wall of the part of the first outer sleeve nut extending out of the upstream sealing short tube is designed with threads;

[0011] The rear end of the downstream sealing short tube is welded to the air supply pipeline, and the front end is designed as a boss structure. The second outer sleeve nut is fixed on the downstream sealing short tube through the boss structure, and the inner wall of the part of the second outer sleeve nut extending out of the downstream sealing short tube is designed with threads;

[0012] The sonic nozzle is a columnar structure with an airflow channel processed inside. The airflow channel is composed of a contraction section, a transition section, an equal straight section and an expansion section in sequence. The sonic nozzle is formed by a high-pressure integrated design. The front end of the outer wall of the sonic nozzle is connected to the first outer sleeve nut through a thread, and the rear end of the outer wall is connected to the second outer sleeve nut through a thread. A regular hexagonal structure is set in the middle part of the outer wall for fixing the installation tool;

[0013] A sealing groove is processed on the rear end surface of the upstream sealing short tube, and a sealing groove is processed on the rear end surface of the sonic nozzle, and O-type sealing rings are installed in the sealing grooves.

[0014] The contraction angle of the sonic nozzle contraction section is 60°, the expansion angle of the expansion section is 12°, the transition section between the contraction section and the straight section is an arc, and the length of the straight section is not more than 3 mm.

[0015] The arc radius of the transition section is half the diameter of the straight section.

[0016] The surface roughness of the inner surface of the sonic nozzle air flow channel is controlled within 1.6.

[0017] The first outer shell nut and the second outer shell nut are made of the same material, both are 304 stainless steel, and the sonic nozzle material is 3Cr13.

[0018] The design pressure of the first outer sleeve nut, the second outer sleeve nut and the sonic nozzle is 26MPa.

[0019] The pipe wall thickness of the upstream sealing short pipe and the downstream sealing short pipe can meet the pressure bearing capacity of 26Mpa.

[0020] A method for replacing a high-pressure gas flow measurement and control device comprises the following steps:

[0021] (1) respectively rotating the first outer sleeve nut and the second outer sleeve nut in opposite directions to release the connection between the first outer sleeve nut, the second outer sleeve nut and the sonic nozzle;

[0022] (2) Remove the sonic nozzle and replace it with a new sonic nozzle that meets the size requirements. Connect the front end of the outer wall of the new sonic nozzle to the first outer sleeve nut through a thread, and connect the rear end of the outer wall to the second outer sleeve nut through a thread to complete the quick replacement.

[0023] The advantages of the present invention compared with the prior art are as follows:

[0024] (1) The sonic nozzle of the present invention adopts a high-pressure integrated design structure. At the same time, the upstream sealing short tube, the sonic nozzle and the downstream sealing short tube in the device of the present invention are connected by two outer sleeve nuts. When replacing the sonic nozzle, it is only necessary to loosen the two outer sleeve nuts, and the sonic nozzle can be directly taken out horizontally. Replacement and installation are very convenient, which solves the problem that the existing high-pressure gas flow measurement and control device requires a large installation space for replacement.

[0025] (2) The air flow channel of the sonic nozzle of the present invention adopts a contraction section, a transition section, an equal straight section and an expansion section profile design, which reduces the pressure loss of the air flow and improves the flow coefficient compared with the existing design. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the structure of the device of the present invention;

[0027] Figure 2 It is a schematic diagram of the pneumatic profile design of the present invention;

[0028] Figure 3 It is a structural schematic diagram of an existing high-pressure gas flow measurement and control device. DETAILED DESCRIPTION

[0029] like Figure 1 and Figure 2 As shown, the present invention proposes a high-pressure gas flow measurement and control device that can be quickly replaced, including an upstream sealing short tube 1, a first outer sleeve nut 2, a second outer sleeve nut 6, a sonic nozzle 3, an O-ring 4 and a downstream sealing short tube 5.

[0030] The front end of the upstream sealing short tube 1 is welded to the air supply pipeline, and the rear end is designed as a boss structure. The first outer sleeve nut 2 is fixed to the upstream sealing short tube 1 by using the boss structure. The rear end surface of the upstream sealing short tube 1 is provided with a sealing groove for installing the O-ring 4. The wall thickness of the upstream sealing short tube 1 is determined according to the design pressure of 26Mpa, the diameter and thickness of the boss structure are determined according to the structure of the first outer sleeve nut 2, and the material of the upstream sealing short tube 1 is consistent with the material of the air supply system pipeline for easy welding.

[0031] The rear end of the downstream sealing short tube 5 adopts a welding structure, which is welded to the gas supply pipeline, and the front end adopts a boss structure, and the second outer sleeve nut 6 is fixed on the downstream sealing short tube 5 by using the boss structure. The wall thickness of the downstream sealing short tube 5 is determined according to the design pressure of 26Mpa, and the diameter and thickness of the boss structure are determined according to the structure of the second outer sleeve nut 6, and the material is consistent with the material of the gas supply system pipeline for easy welding.

[0032] The first outer sleeve nut 2 and the second outer sleeve nut 6 can be purchased as standard products or designed by themselves. The structural design pressure is 26MPa. The material is 304 stainless steel. The shape is generally designed as a regular hexagon to facilitate the fixing of installation tools. The first outer sleeve nut 2 is designed with a thread on the inner wall of the part extending from the upstream sealing short tube 1 for connection with the sonic nozzle 3. The second outer sleeve nut 6 is designed with a thread on the inner wall of the part extending from the downstream sealing short tube 5 for connection with the sonic nozzle 3.

[0033] The sonic nozzle 3 adopts an integrated design structure, with no sealing groove on the front end face and a sealing groove on the rear end face for installing the O-ring 4, and a design pressure of 26MPa. The sonic nozzle 3 is a columnar structure with an airflow channel processed inside. The throat is composed of a contraction section, a transition section, an equal straight section and an expansion section in sequence. The front end and the rear end cylinder of the outer wall are provided with threads. The front end of the outer wall is connected to the first outer sleeve nut through threads, and the rear end of the outer wall is connected to the second outer sleeve nut through threads. A regular hexagonal structure is provided in the middle part of the outer wall for fixing installation tools such as wrenches; the sonic nozzle 3 is a replaceable component, and different airflow channel sizes need to be changed according to the flow requirements of the test.

[0034] When designing the inner profile of the airflow channel of the sonic nozzle, the contraction angle of the contraction section is 60°, the expansion angle of the expansion section is 12°, the length of the straight section is generally not more than 3mm, and the transition section between the contraction section and the straight section is an arc, and the arc radius can be selected as half of the diameter of the straight section. The material of the sonic nozzle 3 can be selected as 3Cr13 to prevent the thread from biting, and the surface roughness of the inner profile is controlled within 1.6 to reduce the airflow resistance.

[0035] The O-ring 4 is a standard purchased part, selected according to GB / T3452.1-1992, and the material is silicone rubber.

[0036] The material selection of the sonic nozzle 3 should be inconsistent with the outer shell nuts at the front and rear ends. In the present invention, the first outer shell nut and the second outer shell nut are made of the same material, both of which are 304 stainless steel, and the material of the sonic nozzle 3 is 3Cr13.

[0037] A method for replacing a high-pressure gas flow measurement and control device comprises the following steps:

[0038] (1) respectively rotating the first outer sleeve nut and the second outer sleeve nut in opposite directions to release the connection between the first outer sleeve nut, the second outer sleeve nut and the sonic nozzle;

[0039] (2) Remove the sonic nozzle and replace it with a new sonic nozzle that meets the size requirements. Connect the front end of the outer wall of the new sonic nozzle to the first outer sleeve nut through a thread, and connect the rear end of the outer wall to the second outer sleeve nut through a thread to complete the quick replacement.

[0040] The present invention relates to a quickly replaceable high-pressure gas flow control and measurement device, which can be applied to the flow measurement and control of high-pressure gas supply pipelines with a pressure of ≤26MPa and a diameter of <50mm. The sonic nozzle adopts a high-pressure integrated design structure, which is very convenient to replace and install. The measured high-temperature flow field parameters are more accurate, and can provide more accurate ground simulation test data for the heat protection design of the model.

[0041] The contents not described in detail in the specification of the present invention belong to the common knowledge of the professionals in this field.

Claims

1. A high-pressure gas flow measurement and control device capable of rapid replacement, characterized in that: It comprises an upstream sealing short tube (1), a first outer sleeve nut (2), a second outer sleeve nut (6), a sonic nozzle (3), an O-type sealing ring (4) and a downstream sealing short tube (5); The front end of the upstream sealing short tube (1) is welded to the air supply pipeline, and the rear end is designed as a boss structure. The first outer sleeve nut (2) is fixed to the upstream sealing short tube (1) through the boss structure, and the inner wall of the portion of the first outer sleeve nut (2) extending out of the upstream sealing short tube (1) is designed with threads; The rear end of the downstream sealing short tube (5) is welded to the air supply pipeline, and the front end is designed as a boss structure. The second outer sleeve nut (6) is fixed to the downstream sealing short tube (5) through the boss structure, and the inner wall of the part of the second outer sleeve nut (6) extending out of the downstream sealing short tube (5) is designed with threads; The sonic nozzle (3) is a columnar structure, and an airflow channel is processed inside. The airflow channel is composed of a contraction section, a transition section, an equal straight section and an expansion section in sequence. The sonic nozzle (3) is formed by a high-pressure integrated design. The front end of the outer wall of the sonic nozzle (3) is connected to the first outer sleeve nut through a thread, and the rear end of the outer wall is connected to the second outer sleeve nut through a thread. The middle part of the outer wall is provided with a regular hexagonal structure for fixing the installation tool. A sealing groove is machined on the rear end surface of the upstream sealing short tube (1), and a sealing groove is machined on the rear end surface of the sonic nozzle (3), and O-type sealing rings (4) are installed in the sealing grooves.

2. A high-pressure gas flow measurement and control device capable of rapid replacement according to claim 1, characterized in that: The sonic nozzle (3) has a contraction angle of 60° in the contraction section, an expansion angle of 12° in the expansion section, a transition section between the contraction section and the straight section is an arc, and the length of the straight section is not greater than 3 mm.

3. A high-pressure gas flow measurement and control device capable of rapid replacement according to claim 2, characterized in that: The arc radius of the transition section is half the diameter of the straight section.

4. A high-pressure gas flow measurement and control device capable of rapid replacement according to claim 3, characterized in that: The surface roughness of the inner surface of the air flow channel of the sonic nozzle (3) is controlled within 1.

6.

5. The high-pressure gas flow measurement and control device capable of rapid replacement according to claim 1, characterized in that: The first outer sleeve nut (2) and the second outer sleeve nut (6) are made of the same material, 304 stainless steel, and the material of the sonic nozzle (3) is 3Cr13.

6. The high-pressure gas flow measurement and control device capable of rapid replacement according to claim 1, characterized in that: The design pressure of the first outer sleeve nut (2), the second outer sleeve nut (6) and the sonic nozzle (3) is 26 MPa.

7. A high-pressure gas flow measurement and control device capable of rapid replacement according to claim 6, characterized in that: The pipe wall thickness of the upstream sealing short pipe (1) and the downstream sealing short pipe (5) can meet the pressure bearing capacity of 26 MPa.

8. The method for replacing the high-pressure gas flow measurement and control device according to any one of claims 1 to 7, characterized in that The steps include: (1) respectively rotating the first outer sleeve nut and the second outer sleeve nut in opposite directions to release the connection between the first outer sleeve nut, the second outer sleeve nut and the sonic nozzle; (2) Remove the sonic nozzle and replace it with a new sonic nozzle that meets the size requirements. Connect the front end of the outer wall of the new sonic nozzle to the first outer sleeve nut through a thread, and connect the rear end of the outer wall to the second outer sleeve nut through a thread to complete the quick replacement.

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