An accurate total pressure measurement device for the settling chamber of an arc-heated wind tunnel

Abstract

The present invention belongs to the technical research field of wind tunnel tests, and discloses a device for accurately measuring the total pressure of the settling chamber of an arc-heated wind tunnel. The measuring device comprises a cooling pipe, a high-voltage insulating hose and a solid-liquid separator which are sequentially connected through a loose flange nut and a gasket. The front end of the cooling pipe is installed on the total pressure measurement port of the settling chamber of the arc-heated wind tunnel. The cooling pipe is used for reducing the temperature of the measured gas, the high-voltage insulating hose is used for isolating the high voltage of the arc-heated wind tunnel, and the solid-liquid separator is used for separating the impurities in the measured gas flow. The measuring device reduces the gas temperature through the cooling pipe, isolates the high voltage through the insulating pipe, and separates the impurities through the solid-liquid separator, solving the technical problem of difficult accurate measurement of the total pressure caused by the high voltage, high total temperature and multi-phase flow of the incoming flow in the arc-heated wind tunnel. The measuring device has a simple structure, low cost and high efficiency, realizes the accurate measurement of the total pressure of the settling chamber of the arc-heated wind tunnel, provides a technical basis for model development and scientific research, and has engineering practical value.

Description

Technical Field

[0001] The invention belongs to the research field of wind tunnel test technology, and in particular relates to a device for accurately measuring the total pressure of a stable section of an arc-heated wind tunnel. Background Art

[0002] The high-temperature wind tunnel operated by arc heater is an arc-heated wind tunnel. The total operating temperature of the arc heater can reach more than 6000K, and the arc chamber temperature can reach more than 10000K. To obtain the total pressure of the stable section of the high-temperature wind tunnel, there are the following technical difficulties: a. The arc heater has a high voltage, and its voltage value can reach thousands of volts or even tens of thousands of volts, which has a great interference to the sensor and the data acquisition system. If it is not handled properly, it will damage the sensitive components of the sensor and even burn the data acquisition system; b. The high temperature of the airflow will damage the sensor and the pressure measuring pipeline. Once the high-temperature gas leaks, it will damage the test equipment and cause harm to the test personnel; c. Due to the high temperature, the arc chamber material is partially liquefied to form liquid particles; at the same time, the arc chamber material will also oxidize at high temperature to form detached solid oxides, resulting in the presence of solid and liquid impurities in the airflow, resulting in blockage of the pressure measuring pipeline and the sensor's sensing port, and there is a risk of damaging the sensor and causing inaccurate test results.

[0003] Currently, there is an urgent need to develop an accurate measurement device for the total pressure in the stable section of an arc-heated wind tunnel. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a device for accurately measuring the total pressure of a stable section of an arc-heated wind tunnel.

[0005] The arc heating wind tunnel stable section total pressure accurate measuring device of the present invention comprises a cooling pipe, a high-voltage insulating hose and a solid-liquid separator which are sequentially connected through a slip-on nut and a sealing gasket; the front end of the cooling pipe is installed on the arc heating wind tunnel stable section total pressure measuring port, the sealing gasket at the front end of the cooling pipe is a copper sealing gasket; the sealing gasket at the rear end of the cooling pipe and the sealing gaskets between the various components of the measuring device are fluororubber sealing gaskets;

[0006] The cooling tube is used to reduce the temperature of the gas being measured, the high-voltage insulating hose is used to isolate the voltage of hundreds to tens of thousands of volts in the arc-heated wind tunnel, and the solid-liquid separator is used to separate impurities in the measured airflow.

[0007] Furthermore, the tube body of the cooling tube comprises an inner tube and an outer tube nested inside and outside, the inner tube and the outer tube have the same central axis, an isolation gap is arranged between the inner tube and the outer tube, and the isolation gap forms a cooling water channel; slip-on nuts are respectively fixed at the upper and lower ends of the tube body, the slip-on nut at the upper end is installed on the total pressure measuring port of the stable section of the arc heating wind tunnel to realize the connection between the central cavity of the inner tube and the stable section of the arc heating wind tunnel, and the slip-on nut at the lower end is connected to the high-voltage insulating hose to realize insulation; a cooling water pipe is respectively arranged on the outer tube of the upper and lower sections of the tube body close to the slip-on nut, and the central cavity of the cooling water pipe is connected to the cooling water channel; cooling water interfaces are respectively arranged at the ends of the cooling water pipes, the cooling water interface of the lower section is externally connected to a cooling water source, and the cooling water interface of the upper section is externally connected to a cooling water recovery pool.

[0008] Furthermore, the cooling water source is softened water.

[0009] Furthermore, the materials of the various components of the cooling pipe are all stainless steel; the cooling water interface, the cooling water pipe, the inner pipe and the outer pipe are connected by welding.

[0010] Furthermore, the inner diameter d of the inner tube is in the range of 3 mm to 5 mm, the width of the isolation gap is in the range of 2 mm to 3 mm, and the length L of the tube body is in the range of 150 d to 200 d.

[0011] Furthermore, the main body of the high-voltage insulating hose is an insulating hose body, and connectors are respectively provided at both ends of the insulating hose body, the connector at the upper end is connected to the cooling pipe, and the connector at the lower end is connected to the solid-liquid separator;

[0012] The technical indicators of high voltage insulating hose are as follows:

[0013] Burst pressure: ≥3 times the design pressure;

[0014] Insulation level: ≥30 kV / m;

[0015] Length: ≥1m;

[0016] Leakage current: ≤50uA;

[0017] Temperature resistance: not less than 500K.

[0018] Furthermore, the material of the connector is stainless steel; the diameter of the insulating hose body matches the inner diameter d of the inner tube of the cooling tube.

[0019] Furthermore, the solid-liquid separator comprises an air inlet pipe, a separation cylinder, a pressure measuring tube and a sealing head; an air inlet pipe and a pressure measuring tube of equal length are sealed and inserted into the upper end of the separation cylinder, the height of the air inlet pipe is lower than the pressure measuring tube, and the upper end of the air inlet pipe is connected to a high-voltage insulating hose; a sealing head is provided at the lower end of the separation cylinder;

[0020] The lower section of the inner cavity of the separation cylinder is the separation area; a number of dust-proof nets are arranged from bottom to top between the upper section of the inner cavity of the separation cylinder, the lower end of the air inlet pipe and the lower end of the pressure measuring tube; the space between the upper surface of the uppermost dust-proof net and the lower end of the pressure measuring tube is the clean area; the sensor is installed at the top of the pressure measuring tube, and the pressure sensing port of the sensor senses the airflow pressure downward.

[0021] Furthermore, the separation cylinder is installed vertically, and the diameter of the separation cylinder is 3 to 5 times the diameter of the air intake pipe.

[0022] Furthermore, the sealing head is a sealed and detachable sealing head.

[0023] The arc-heated wind tunnel stable section total pressure accurate measurement device of the present invention has the following characteristics:

[0024] 1. The measuring device consists of three parts: cooling tube, high-voltage insulating hose and solid-liquid separator, which respectively solve the problems of high voltage, high temperature and many impurities in the airflow of the arc heating wind tunnel. The technical difficulty is reduced through functional decomposition. The measuring device has a compact structure and good effect.

[0025] 2. The cooling pipe adopts a large pipe sleeve small pipe structure, which has a simple structure, low cost and good effect;

[0026] 3. The solid-liquid separator separates impurities in the gas through the principle of mass conservation in fluid mechanics. A dustproof net is set between the air inlet pipe and the pressure measuring tube to ensure that the gas contacted by the sensor is clean, the diaphragm of the sensor remains clean during long-term use, and the test accuracy is high.

[0027] The accurate measuring device for total pressure of the stable section of an arc-heated wind tunnel of the present invention reduces the gas temperature by a cooling tube, isolates the high voltage by an insulating tube, and separates impurities by a solid-liquid separator, thereby effectively solving the technical problem that the total pressure of an arc-heated wind tunnel is difficult to accurately measure due to high voltage, high total temperature, and multi-phase flow. The measuring device has a simple structure, low cost, and high efficiency, and realizes accurate measurement of the total pressure of the stable section of an arc-heated wind tunnel, providing a technical basis for model development and scientific research, and having practical engineering value.

[0028] The arc heating wind tunnel stable section total pressure accurate measuring device of the present invention can be widely used to measure the arc heater arc chamber pressure or multiphase flow gas pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the device for accurately measuring the total pressure of the stable section of an arc-heated wind tunnel according to the present invention;

[0030] Figure 2a It is a schematic diagram (stereoscopic diagram) of the cooling pipe structure in the device for accurately measuring the total pressure of the stable section of an arc-heated wind tunnel of the present invention;

[0031] Figure 2b It is a schematic diagram (cross-sectional view) of the cooling pipe structure in the arc-heated wind tunnel stable section total pressure accurate measurement device of the present invention;

[0032] Figure 3 It is a schematic diagram (stereoscopic diagram) of the structure of a high-voltage insulating hose in the device for accurately measuring the total pressure of the stable section of an arc-heated wind tunnel of the present invention;

[0033] Figure 4a It is a structural schematic diagram (stereoscopic diagram) of a solid-liquid separator in the device for accurately measuring the total pressure of the stable section of an arc-heated wind tunnel of the present invention;

[0034] Figure 4b It is a structural schematic diagram (cross-sectional view) of a solid-liquid separator in the device for accurately measuring the total pressure in the stable section of an arc-heated wind tunnel according to the present invention.

[0035] In the figure, 1. cooling pipe; 2. high voltage insulating hose; 3. solid-liquid separator;

[0036] 1-1. Loose nut; 1-2. Cooling water interface; 1-3. Cooling water pipe; 1-4. Inner pipe; 1-5. Outer pipe;

[0037] 2-1. Connector; 2-2. Insulating hose body;

[0038] 3-1. Inlet pipe; 3-2. Separation tube; 3-3. Pressure measuring tube; 3-4. End cap;

[0039] 3-2-1. Separation area; 3-2-2. Dust-proof net; 3-2-3. Clean area. DETAILED DESCRIPTION

[0040] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0041] Example: Figure 1 As shown, the arc heating wind tunnel stable section total pressure accurate measuring device of this embodiment comprises a cooling pipe 1, a high-voltage insulating hose 2 and a solid-liquid separator 3 which are sequentially connected through a slip-on nut 1-1 and a sealing gasket; the front end of the cooling pipe 1 is installed on the arc heating wind tunnel stable section total pressure measuring port, and the sealing gasket at the front end of the cooling pipe 1 is a copper sealing gasket; the sealing gasket at the rear end of the cooling pipe 1 and the sealing gaskets between the various components of the measuring device are fluororubber sealing gaskets;

[0042] The cooling tube 1 is used to reduce the temperature of the gas being measured, the high-voltage insulating hose 2 is used to isolate the voltage of the arc heating wind tunnel from hundreds of volts to tens of thousands of volts, and the solid-liquid separator 3 is used to separate impurities in the gas flow being measured.

[0043] Furthermore, if Figure 2a , Figure 2bAs shown, the tube body of the cooling tube 1 includes an inner tube 1-4 and an outer tube 1-5 nested inside and outside, the inner tube 1-4 and the outer tube 1-5 have the same central axis, an isolation gap is set between the inner tube 1-4 and the outer tube 1-5, and the isolation gap forms a cooling water channel; the upper and lower ends of the tube body are respectively fixed with slip-on nuts 1-1, the slip-on nut 1-1 at the upper end is installed on the total pressure measuring port of the stable section of the arc heating wind tunnel, so that the central cavity of the inner tube 1-4 is connected with the stable section of the arc heating wind tunnel, and the slip-on nut 1-1 at the lower end is connected with the high-voltage insulating hose 2 to achieve insulation; a cooling water pipe 1-3 is respectively arranged on the outer tube 1-5 near the slip-on nut 1-1 at the upper and lower sections of the tube body, and the central cavity of the cooling water pipe 1-3 is connected with the cooling water channel; the ends of the cooling water pipe 1-3 are respectively provided with cooling water interfaces 1-2, the cooling water interface 1-2 of the lower section is externally connected to a cooling water source, and the cooling water interface 1-2 of the upper section is externally connected to a cooling water recovery pool.

[0044] Furthermore, the cooling water source is softened water.

[0045] Furthermore, the materials of the various components of the cooling pipe 1 are all stainless steel; the cooling water interface 1-2, the cooling water pipe 1-3, the inner pipe 1-4 and the outer pipe 1-5 are connected by welding; during the welding process, it is required to ensure that the inner pipe 1-4 and the outer pipe 1-5 are coaxial with the central axis to ensure the radial uniformity of the cooling water channel.

[0046] Furthermore, the inner diameter d of the inner tube 1-4 ranges from 3mm to 5mm, the width of the isolation gap ranges from 2mm to 3mm, and the length L of the tube body ranges from 150d to 200d.

[0047] Furthermore, the high-voltage insulating hose 2 is the weak link of the measuring device. If there is a gas leak, high-temperature gas will flow out, causing damage to surrounding equipment and personnel; if the insulation is not enough, the high voltage will affect the sensor and the data acquisition system, resulting in inaccurate pressure measurement data, and even damage to the sensor and the data acquisition system; Figure 3 As shown, the main body of the high-voltage insulating hose 2 is an insulating hose body 2-2, and connectors 2-1 are respectively provided at both ends of the insulating hose body 2-2, the upper connector 2-1 is connected to the cooling pipe 1, and the lower connector 2-1 is connected to the solid-liquid separator 3;

[0048] The technical indicators of high voltage insulating hose 2 are as follows:

[0049] Burst pressure: ≥3 times the design pressure;

[0050] Insulation level: ≥30 kV / m;

[0051] Length: ≥1m;

[0052] Leakage current: ≤50uA;

[0053] Temperature resistance: not less than 500K.

[0054] Furthermore, the material of the connector 2-1 is stainless steel; when the gas in the stable section reaches the connector 2-1, the temperature has dropped, but it may still reach about 500K, and the sealing gasket at the connector 2-1 still needs to be made of fluororubber that can withstand high temperatures; the diameter of the insulating hose body 2-2 matches the inner diameter d of the inner tube 1-4 of the cooling tube 1.

[0055] Furthermore, if Figure 4a , Figure 4b As shown, the solid-liquid separator 3 comprises an air inlet pipe 3-1, a separation cylinder 3-2, a pressure measuring tube 3-3 and a sealing head 3-4; at the upper end of the separation cylinder 3-2, the air inlet pipe 3-1 and the pressure measuring tube 3-3 of equal length are sealed and inserted, the height of the air inlet pipe 3-1 is lower than the pressure measuring tube 3-3, and the upper end of the air inlet pipe 3-1 is connected to the high-voltage insulating hose 2; the lower end of the separation cylinder 3-2 is provided with a sealing head 3-4;

[0056] The lower section of the inner cavity of the separation cylinder 3-2 is the separation area 3-2-1; a number of dust-proof nets 3-2-2 are arranged in sequence from bottom to top between the upper section of the inner cavity of the separation cylinder 3-2, the lower end of the air inlet pipe 3-1 and the lower end of the pressure measuring tube 3-3; the space between the upper surface of the uppermost dust-proof net 3-2-2 and the lower end of the pressure measuring tube 3-3 is the clean area 3-2-3; the sensor is installed at the top of the pressure measuring tube 3-3, and the pressure sensing port of the sensor senses the airflow pressure downward.

[0057] Furthermore, the separation cylinder 3-2 is installed vertically, and the diameter of the separation cylinder 3-2 is 3 to 5 times the diameter of the air inlet pipe 3-1. The separation cylinder 3-2 is used to separate the liquid droplets and solid particles in the air flow, ensuring that the gas at the sensor inlet at the top of the pressure measuring tube 3-3 is pure and free of impurities; the air flow with impurities passes through the air inlet pipe 3-1 and enters the separation area 3-2-1. According to the principle of conservation of mass, the mass of the air flow in the flow remains unchanged, and the flow rate , due to the increase in air volume and density Basically unchanged, the channel area of ​​the separation cylinder 3-2 Compared with the case where the passage area of ​​the intake pipe 3-1 is increased, the flow rate The pushing effect of the airflow on the impurities is reduced, and the impurities are precipitated under the action of their own gravity and fall into the separation area 3-2-1; the airflow is filtered through the dustproof net 3-2-2 and enters the clean area 3-2-3. The sensor senses the total pressure through the pressure measuring tube 3-3. Since the pressure measuring tube 3-3 is in the clean area 3-2-3, it will not be blocked or contaminated, thereby improving the test accuracy of the total pressure in the stable section of the arc heating wind tunnel.

[0058] Furthermore, the head 3-4 is a sealed and detachable head 3-4.

[0059] When a lot of impurities accumulate in the separation cylinder 3-2, the head 3-4 can be removed for cleaning. When installing it again, pay attention to sealing the head 3-4 to avoid air leakage.

[0060] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and the embodiments, and can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional improvements and modifications can be easily realized without departing from the principles of the present invention. Therefore, without departing from the general concept defined by the claims and equivalent scope, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. An accurate measurement device for total pressure in the stable section of an arc-heated wind tunnel, characterized in that: The measuring device comprises a cooling pipe (1), a high-voltage insulating hose (2) and a solid-liquid separator (3) which are connected in sequence via a slip-on nut (1-1) and a sealing gasket; the front end of the cooling pipe (1) is mounted on a total pressure measuring port of a stable section of an arc heating wind tunnel, and the sealing gasket at the front end of the cooling pipe (1) is a copper sealing gasket; the sealing gasket at the rear end of the cooling pipe (1) and the sealing gaskets between the various components of the measuring device are fluororubber sealing gaskets; The cooling tube (1) is used to reduce the temperature of the gas being measured, the high-voltage insulating hose (2) is used to isolate the voltage of the arc heating wind tunnel from hundreds of volts to tens of thousands of volts, and the solid-liquid separator (3) is used to separate impurities from the gas flow being measured; The cooling tube (1) comprises an inner tube (1-4) and an outer tube (1-5) which are nested inside and outside, the inner tube (1-4) and the outer tube (1-5) are coaxial, an isolation gap is provided between the inner tube (1-4) and the outer tube (1-5), and the isolation gap forms a cooling water channel; the upper and lower ends of the tube body are respectively fixed with slip-on nuts (1-1), and the slip-on nut (1-1) at the upper end is installed on the total pressure measuring port of the arc heating wind tunnel stabilization section, so as to realize the central cavity of the inner tube (1-4) and the arc heating wind tunnel stabilization section. The sections are connected, and the slip-on nut (1-1) at the lower end is connected to the high-voltage insulating hose (2) to achieve insulation; a cooling water pipe (1-3) is respectively arranged on the upper and lower sections of the pipe body and on the outer pipe (1-5) close to the slip-on nut (1-1), and the central cavity of the cooling water pipe (1-3) is connected to the cooling water channel; cooling water interfaces (1-2) are respectively arranged at the ends of the cooling water pipe (1-3), the cooling water interface (1-2) of the lower section is connected to an external cooling water source, and the cooling water interface (1-2) of the upper section is connected to an external cooling water recovery pool; The main body of the high-voltage insulating hose (2) is an insulating hose body (2-2), and connectors (2-1) are respectively provided at both ends of the insulating hose body (2-2), the connector (2-1) at the upper end is connected to the cooling pipe (1), and the connector (2-1) at the lower end is connected to the solid-liquid separator (3); The technical specifications of the high voltage insulating hose (2) are as follows: Burst pressure: ≥3 times the design pressure; Insulation level: ≥30 kV / m; Length: ≥1m; Leakage current: ≤50uA; Temperature resistance: not less than 500K; The solid-liquid separator (3) comprises an air inlet pipe (3-1), a separation cylinder (3-2), a pressure measuring tube (3-3) and a sealing head (3-4); an air inlet pipe (3-1) and a pressure measuring tube (3-3) of equal length are sealed and inserted into the upper end of the separation cylinder (3-2); the height of the air inlet pipe (3-1) is lower than the pressure measuring tube (3-3); the upper end of the air inlet pipe (3-1) is connected to a high-voltage insulating hose (2); and a sealing head (3-4) is provided at the lower end of the separation cylinder (3-2); The lower section of the inner cavity of the separation cylinder (3-2) is a separation zone (3-2-1); a plurality of dust screens (3-2-2) are arranged in sequence from bottom to top between the upper section of the inner cavity of the separation cylinder (3-2), the lower end of the air inlet pipe (3-1) and the lower end of the pressure measuring tube (3-3); the space between the upper surface of the uppermost dust screen (3-2-2) and the lower end of the pressure measuring tube (3-3) is a clean zone (3-2-3); a sensor is installed at the top of the pressure measuring tube (3-3), and the pressure sensing port of the sensor senses the airflow pressure downward.

2. The arc-heated wind tunnel stable section total pressure accurate measurement device according to claim 1 is characterized in that: The cooling water source is softened water.

3. The arc-heated wind tunnel stable section total pressure accurate measurement device according to claim 1 is characterized in that: The materials of the various components of the cooling pipe (1) are all stainless steel; the cooling water interface (1-2), the cooling water pipe (1-3), the inner pipe (1-4) and the outer pipe (1-5) are connected by welding.

4. The arc-heated wind tunnel stable section total pressure accurate measurement device according to claim 1 is characterized in that: The inner diameter d of the inner tube (1-4) is in the range of 3 mm to 5 mm, the width of the isolation gap is in the range of 2 mm to 3 mm, and the length L of the tube body is in the range of 150 d to 200 d.

5. The arc-heated wind tunnel stable section total pressure accurate measurement device according to claim 1 is characterized in that: The material of the connector (2-1) is stainless steel; the diameter of the insulating hose body (2-2) matches the inner diameter d of the inner tube (1-4) of the cooling tube (1).

6. The arc-heated wind tunnel stable section total pressure accurate measurement device according to claim 1 is characterized in that: The separation cylinder (3-2) is installed vertically, and the diameter of the separation cylinder (3-2) is 3 to 5 times the diameter of the air inlet pipe (3-1).

7. The arc-heated wind tunnel stable section total pressure accurate measurement device according to claim 1 is characterized in that: The sealing head (3-4) is a sealed and detachable sealing head (3-4).

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