Device for online collection of primary fuel gas of solid rocket ramjet

Abstract

The invention discloses a device for online collection of primary fuel gas of a solid rocket ramjet, and belongs to the field of rocket ramjet. The device comprises a gas storage tank, a flange connecting section, a sealing structure, a piston, an electric push rod and a remote control part. The piston is used as a movable part in the cylinder body, and the piston is of a two-sealing-ring structure. The working condition that negative pressure appears on the expansion section of the spray pipe in the low-pressure environment is adopted, real-time collection of primary fuel gas of the solid ramjet engine is achieved, and the accuracy of primary fuel gas component collection and analysis is improved; the shell, the pipeline and various pipeline joints adopt high-temperature-resistant and high-pressure-resistant design, meanwhile, the piston is additionally arranged in the storage tank, and gas in the storage tank can be completely exhausted by pushing the piston after a single test is finished. The electromagnetic valve and other devices are additionally arranged on the pipeline, opening of the electromagnetic valve or the electric ball valve is controlled through the remote controller or the pressure control starting unit, so that the remote control effect is achieved, and the safety of operators is guaranteed.

Description

Technical Field

[0001] The present invention relates to a device for on-line collection of primary gas in a solid rocket ramjet engine, specifically to an on-line collection device for primary gas that is high-temperature resistant, can be experimented multiple times, and can be remotely controlled, belonging to the field of rocket ramjet engines. Background Technique

[0002] Solid rocket ramjet engines are expected to become the preferred power for future hypersonic missiles due to their unique advantages and have important application value. The combustion of boron-rich fuel-rich propellants in solid rocket ramjet engines is divided into primary combustion and secondary combustion. Due to the oxygen-poor environment, low pressure, and short residence time of the propellant in the gas generator, the combustion degree of the primary combustion of boron-based propellants is very low. According to the working principle of solid rocket ramjet engines, external air is inhaled through the inlet duct and enters the afterburning chamber to mix with the combustion products of the primary combustion of boron-based propellants for secondary combustion. The combustion products of the primary combustion of boron-based propellants are an important bridge connecting the primary combustion and the secondary combustion. The combustion degree and energy release of the primary combustion directly affect the secondary combustion in the afterburning chamber, and thus affect the overall performance of the engine. Therefore, analyzing the composition and morphological structure of the primary combustion products of boron-based propellants and studying the ignition and combustion characteristics of the components are effective ways to improve the secondary combustion characteristics in the afterburning chamber and the energy release efficiency of the propellants.

[0003] Currently, the analysis of primary combustion products mostly focuses on the offline collection and analysis of primary combustion products, and it is very difficult to collect the products online. The present invention can realize the on-line collection of primary gas and improve the accuracy of the composition of primary gas. Summary of the Invention

[0004] The purpose of the present invention is to provide a device for on-line collection of primary gas in a solid rocket ramjet engine. According to the high-temperature and high-pressure environment in which the gas generator test is located, based on the design standard of "GB150.1-202011 Pressure Vessels", the optimization of the primary gas collection device of the gas generator is carried out, and the on-line collection of primary gas can be realized to improve the accuracy of the collection and analysis of the composition of primary gas.

[0005] The purpose of the present invention is achieved through the following technical solutions.

[0006] An on-line collection device for primary gas in a solid rocket ramjet engine disclosed by the present invention includes a gas storage tank, a flange connection section, a sealing structure, a piston, an electric push rod, and a remote control part.

[0007] The pressure-bearing and heat-resistant capacity of the gas storage tank meets the preset requirements. Considering the harsh conditions for multiple tests and test sites, 304 stainless steel is used as the shell material of the gas storage tank. The gas storage tank is designed with a cylindrical structure, and the cylinder and the front and rear end covers are connected by flanges. Referring to GB-150-2011 "Pressure Vessels", the calculated thickness is obtained according to the corresponding formula of this standard, and the allowance for the thickness required by other factors is reserved if necessary. The calculated thickness of the pressure-bearing cylinder is calculated by the following formula:

[0008]

[0009] Where: p max is the calculated pressure, D i is the inner diameter of the storage tank. The design temperature is taken as 20°C. Then, according to GB150.2, [σ] is the allowable stress, ξ is the welded joint coefficient, is the pressure fluctuation coefficient.

[0010] Preferably, the calculated pressure p of the gas storage tank c is taken as 3 MPa, the inner diameter D of the storage tank i is 150 mm, the material is selected as 304 steel, and the design temperature is taken as 20°C. Then, according to GB150.2, the allowable stress [σ] is 137 MPa, the welded joint coefficient is taken as ξ = 1, and the pressure fluctuation coefficient It can be calculated that the wall thickness of the gas storage tank is 1.8 mm. Considering wear and corrosion, and the piston movement requires ensuring that the gas storage tank has small machining errors and deformations, the wall thickness of the gas storage tank should be as thick as possible, and the final thickness is taken as 4 mm.

[0011] In the connection of the flange connection structure, the axial force received by the bolt group is mainly the action of the combustion chamber pressure, and is calculated by the following formula:

[0012]

[0013] The allowable stress of the bolt for the axially loaded tight bolt connection is expressed as:

[0014]

[0015] Where R eL is the bolt yield strength, and S s is the safety factor.

[0016] Preferably, R eL is the bolt yield strength, S s is the safety factor. The bolt material of grade 4.8 is selected as alloy steel, its tensile strength is 400 MPa, the bolt diameter is selected from M6 to M16, and the safety factor S s= 4, according to the allowable stress calculation formula, the allowable stress [σ] of the bolt is 100 MPa. Calculate the cross-sectional area of the required bolt group based on the required stress of the bolt and the maximum axial force borne by the flange, so as to provide a reference for the selection of bolt specifications.

[0017] The bolt length is estimated based on the flange thickness, gasket and nut dimensions. On this basis, leave 2 - 3 times the pitch, select according to the bolt specification, determine the hexagonal head bolt and the number of hexagonal head bolts evenly distributed on the flange; since the working pressure of the gas storage tank is 0 - 3 MPa, according to the reference value of the bolt spacing for container flange connection, calculate the maximum bolt spacing l < 6d; from the requirement of the maximum bolt spacing l max = 60 mm, calculate the required maximum bolt distribution diameter D 0max = 193 mm. For safety, here take the bolt distribution diameter D0 = 180 mm. The distance from the bolt to the edge: e = d + (3 - 6) mm. Substitute the bolt size into the formula to get e = 13 - 16 mm; thus obtain the outer diameter D of the connecting flange 法兰外 :

[0018] D 法兰外 = D0 + 2e = 210 mm

[0019] Preferably, the bolt length is estimated based on the flange thickness of 20 mm, gasket and nut of 9 mm. The gasket includes a flat gasket of 2×1 mm and a spring washer of 3 mm. On this basis, leave 2 - 3 times the pitch, calculate that the bolt length is about 40 mm, select according to the bolt specification, and finally determine to be a grade 4.8 M10×40 hexagonal head bolt, and evenly distribute 10 on the flange. Since the working pressure of the gas storage tank is 0 - 3 MPa, according to the reference value of the bolt spacing for container flange connection, calculate the maximum bolt spacing l < 6d = 70 mm. From the requirement of the maximum bolt spacing l max = 60 mm, calculate the required maximum bolt distribution diameter D 0max = 193 mm. For safety, here take D0 = 180 mm. The distance from the bolt to the edge: e = d + (3 - 6) mm. Substitute the bolt size d = 10 mm into the formula to get e = 13 - 16 mm, and here take 15 mm. Thus obtain the outer diameter of the connecting flange:

[0020] D 法兰外 = D0 + 2e = 210 mm

[0021] The sealing structure selected is an O-ring sealing structure. The design of the O-ring sealing structure includes: selecting the O-ring material, determining the O-ring size and compression amount, and determining the shape and size of the sealing groove. The inner diameter of the O-ring is determined according to the inner diameter of the gas storage tank shell, and then the cross-sectional diameter d2 of the O-ring is determined. The flange connection part is a fixed part, and the material selected is silicone rubber. The compression amount of the O-ring is ε. For plane fixed sealing, take ε = 15% - 25%. Refer to the axial sealing groove size standard GB / T 3452.3 - 2005 for the O-ring under internal pressure to determine the groove size.

[0022] Preferably, the O-rings commonly used for fixed parts are mostly made of silicone rubber, and the O-rings used for moving parts are commonly made of fluororubber and polytetrafluoroethylene. Since the inner diameter of the gas storage tank shell is 150 mm, the inner diameter of the O-ring is selected as d1 = 155 mm. Therefore, the cross-sectional diameter of the O-ring is selected as d2 = 3.55 mm. The flange connection part is a fixed part, and the material selected is silicone rubber. The compression amount of the O-ring is ε. For plane fixed sealing, take ε = 15% - 25%. Refer to the axial sealing groove size standard for the O-ring under internal pressure (GB / T 3452.3 - 2005), and the groove sizes obtained are: d7 = 158 mm, b = 4.2 mm, h = 5 mm, r1 = 1 mm, r2 = 0.2 mm.

[0023] The piston, as a movable part inside the cylinder, adopts a two-sealing-ring structure to ensure its sealing performance.

[0024] Preferably, the selection of the piston's sealing ring is as follows: the piston outer diameter is 149 mm, d1 = 145 mm, d7 = 150 mm, d2 = 2.65 mm, b = 3.6 mm, h = 2.25 mm, r1 = 0.6 mm, r2 = 0.2 mm.

[0025] The selection of the electric push rod is determined according to two parameters: the push rod stroke and the thrust. The electric push rod with a stroke of 200 mm is selected for the piston of the primary gas collection device, which can meet the use requirements.

[0026] The air pressure difference ΔP before and after the piston is taken as 0.1 MPa, then the force F on the piston p is:

[0027] F p = ΔP·S

[0028] where: S is the force-bearing area of the piston, and F p = 1767 N. The rated thrust of the selected push rod is 3000 N, which can meet the use requirements. The electric push rod and the piston are connected through a connector with external threads at both ends, and the thread design is carried out according to the size structure of the connecting rod.

[0029] The remote control part controls the opening and closing of the solenoid valve or the electric ball valve by controlling the on / off of the power supply according to the working characteristics of the solenoid valve or the electric ball valve to control the opening and closing of the power supply.

[0030] Preferably, the opening and closing of the solenoid valve or the electric ball valve are controlled by wirelessly controlling a relay. This solution can control the opening and closing of the solenoid valve or the electric ball valve more than 100 m away.

[0031] The working method of a device for on-line collection of primary gas of a solid rocket ramjet engine disclosed by the present invention is as follows: Before the test, a vacuum pump, an engine, and a gas sample bag or a gas analyzer are connected to the gas collection device. The gas in the gas storage chamber and the pipeline is pumped out by the vacuum pump to reach a vacuum state. After the engine is ignited, the electric ball valve on the intake pipeline is opened, and the primary gas is sucked into the gas storage chamber through the pressure difference. Subsequently, the electric ball valve is closed, and the collection of the primary gas ends. After a single test, the manual ball valve on the outlet pipeline is opened, and the electric push rod is activated to move the piston to discharge the gas in the gas storage chamber into the gas collection bag for sample collection or directly into the gas analyzer for gas analysis. After this process ends, the piston is pulled back to its original position to prepare for the next test.

[0032] Beneficial effects:

[0033] 1. A device for on-line collection of primary gas of a solid rocket ramjet engine disclosed by the present invention adopts the working condition that a negative pressure appears in the divergent section of the nozzle under a low-pressure environment to realize the real-time collection of the primary gas of the solid ramjet engine. Compared with the off-line collection of the primary gas, the on-line collection can ensure that the collected product is the primary gas under the real working state of the engine and will not be interfered by air or other gases, ensuring the purity of the sample.

[0034] 2. A device for on-line collection of primary gas of a solid rocket ramjet engine disclosed by the present invention. Since the gas generator needs to conduct tests under various working conditions, and the generated gas is high-temperature and high-pressure gas, the primary gas collection device also needs to be reused multiple times. At the same time, the test preparation time should be short to facilitate the next test. The housing, pipeline, and various pipeline joints of the present invention can withstand high temperature and high pressure. At the same time, a piston is added to the storage tank. After a single test, the piston is pushed to completely discharge the gas in the storage tank.

[0035] 3. A device for on-line collection of primary gas of a solid rocket ramjet engine disclosed by the present invention. Since the experiment of the gas generator requires personnel to leave the site, and the operation of instruments and equipment needs to be remotely controlled, the present invention adds devices such as electric ball valves to the pipeline, and controls the opening of the electric ball valve through a remote controller or a pressure control starting unit to achieve the effect of remote control and ensure the safety of the operator. Description of the Drawings

[0036] Figure 1 This is a schematic diagram of the device for on-line collection of primary combustion gas in the solid rocket ramjet engine of the present invention.

[0037] Wherein: 1 - electric push rod motor, 2 - piston, 3 - gas storage chamber, 4 - electric push rod, 5 - high-pressure pipeline, 6 - manual ball valve, 7 - manual ball valve, 8 - manual ball valve, 9 - vacuum pump, 10 - electric ball valve.

[0038] Figure 2 This is a three-dimensional view of the primary combustion gas collection device. Specific implementation mode

[0039] In order to better illustrate the purpose and advantages of the present invention, the following further describes the content of the invention in conjunction with the accompanying drawings and examples.

[0040] As Figure 1 shown, a device for on-line collection of primary combustion gas in a solid rocket ramjet engine disclosed in this embodiment mainly consists of an electric push rod motor 1, a piston 2, a gas storage chamber 3, an electric push rod 4, a high-pressure pipeline 5, a manual ball valve 6, a manual ball valve 7, a manual ball valve 8, a vacuum pump 9, and an electric ball valve 10.

[0041] The pressure-bearing and heat-resistant capacity of the gas storage chamber 3 meets the preset requirements. Considering multiple tests and the harsh conditions of the test site, 304 stainless steel is used as the shell material of the gas storage chamber 3. The gas storage chamber 3 is designed in a cylindrical structure, and the cylinder and the front and rear end covers are connected by flanges. Referring to GB-150-2011 "Pressure Vessels", the calculated thickness is the thickness calculated according to the corresponding formula of this standard, and the allowance for the thickness required by other factors is reserved if necessary. The calculated thickness of the pressure-bearing cylinder is calculated according to the following formula:

[0042]

[0043] Where: p max is the calculated pressure, D i is the inner diameter of the gas storage chamber 3, the design temperature is taken as 20 °C, then according to GB150.2, [σ] is the allowable stress, ξ is the welded joint coefficient, is the pressure fluctuation coefficient.

[0044] The calculated pressure p of the gas storage chamber 3 max is taken as 3 MPa, the inner diameter D of the gas storage chamber 3 i is 150 mm, the material is selected as 304 steel, the design temperature is taken as 20 °C, then according to GB150.2, the allowable stress [σ] is 137 MPa, the welded joint coefficient is taken as ξ = 1, and the pressure fluctuation coefficient It can be calculated that the wall thickness of the gas storage chamber 3 is 1.8 mm. Considering wear and corrosion, and ensuring that the gas storage chamber 3 has a small machining error and deformation during the movement of the piston 2, the wall thickness of the gas storage chamber 3 should be as thick as possible, and the final thickness is taken as 4 mm.

[0045] The flange connection structure includes: The axial force on the bolt group in the flange connection is mainly due to the combustion chamber pressure, and is calculated by the following formula:

[0046]

[0047] The allowable stress of the bolt under axial load for a tight bolt connection is expressed as:

[0048]

[0049] Where R eL is the bolt yield strength, and S s is the safety factor.

[0050] R eL is the bolt yield strength, and S s is the safety factor. The bolt material of grade 4.8 is selected as alloy steel, its tensile strength is 400 MPa, the bolt diameter is selected from M6 - M16, and the safety factor S s = 4. According to the allowable stress calculation formula, the allowable stress [σ] of the bolt is 100 MPa. According to the required stress of the bolt and the maximum axial force on the flange, the cross-sectional area of the required bolt group is calculated, so as to provide a reference for the bolt specification selection.

[0051] The bolt length is estimated according to the flange thickness, gasket and nut dimensions. On this basis, 2 - 3 times the pitch is left, and it is selected according to the bolt specification to determine the hexagon head bolt and the number of hexagon head bolts evenly distributed on the flange. Since the working pressure of the gas storage tank is 0 - 3 MPa, according to the reference value of the bolt spacing for the container flange connection, the maximum bolt spacing l < 6d is calculated. From the requirement of the maximum bolt spacing l max , the maximum bolt distribution diameter D 0max is calculated, and a safety margin is reserved. The distance from the bolt to the edge: e = d + (3 - 6) mm. Substituting the bolt size into the formula, e = 13 - 16 mm is obtained. Thus, the outer diameter of the connecting flange is obtained:

[0052] D 法兰外 = D0 + 2e = 210 mm

[0053] The bolt length is estimated based on the flange thickness of 20 mm, the dimensions of the gasket and nut of 9 mm. The gasket includes a flat gasket of 2×1 mm and a spring washer of 3 mm. On this basis, a pitch of 2 to 3 times is left, and the calculated bolt length is about 40 mm. Select according to the bolt specification, and finally determine the hexagonal head bolt of M10×40 of grade 4.8, with 10 evenly distributed on the flange. Since the working pressure of the gas storage tank is 0 to 3 MPa, according to the reference value of the bolt spacing for the connection of the vessel flange, calculate the maximum bolt spacing l < 6d = 70 mm. From the requirement of the maximum bolt spacing l max = 60 mm, calculate the required maximum bolt distribution diameter D 0max = 193 mm. For safety, here D0 = 180 mm is taken. Bolt distance from the edge: e = d + (3 to 6) mm. Substitute the bolt size into the formula to get e = 13 to 16 mm, and here 15 mm is taken. Thus, the outer diameter of the connecting flange is obtained:

[0054] D 法兰外 = D0 + 2e = 210 mm

[0055] The O-ring seal structure is selected for the sealing structure. To prevent the leakage of gas during the operation of the gas storage tank, good sealing performance of all connecting parts must be required. Therefore, the seal design is very important. The commonly used seal structures are O-ring and flat gasket seals, especially the former is the most widely used. The O-ring seal does not require too much pre-tightening force. It is placed in the seal groove and realizes the seal by the compression deformation after installation and loading. The characteristic of this seal structure is that the higher the gas pressure, the greater the pressing force, and the better the sealing effect. Usually, the O-rings used in fixed parts are made of silicone rubber, and the O-rings used in moving parts are commonly made of fluororubber and polytetrafluoroethylene. Since the inner diameter of the gas storage tank shell is 150 mm, the inner diameter of the O-ring is selected as d1 = 155 mm. Therefore, the cross-sectional diameter of the O-ring is selected as d2 = 3.55 mm. The flange connection is a fixed part, and the material is selected as silicone rubber. The compression amount of the O-ring is ε. For plane fixed seals, ε = 15% to 25% is taken. Referring to the standard of the axial seal groove dimensions of the O-ring under internal pressure (GB / T 3452.3 - 2005), the groove dimensions can be obtained as: d7 = 158 mm, b = 4.2 mm, h = 5 mm, r1 = 1 mm, r2 = 0.2 mm.

[0056] The piston 2, as a movable part inside the cylinder body, is the most important structure in the entire tail gas collection device and the only moving part in the entire device. Its sealing performance is crucial. To ensure its sealing performance, the piston 2 adopts a two-seal-ring structure.

[0057] The selection of the sealing ring for the piston 2 is as follows: the outer diameter of the piston 2 is 149 mm, d1 = 145 mm, d7 = 150 mm, d2 = 2.65 mm, b = 3.6 mm, h = 2.25 mm. r1 = 0.6 mm, r2 = 0.2 mm.

[0058] The selection of the electric push rod 4 is determined according to two parameters: the push rod stroke and the thrust. For the piston 2 of the primary gas collection device, an electric push rod 4 with a stroke of 200 mm is selected, which can meet the usage requirements.

[0059] If the air pressure difference △P before and after the piston 2 is taken as 0.1 MPa, then the force F on the piston 2 p is:

[0060] F p = △P·S

[0061] where: S is the force-bearing area of the piston 2, and F is obtained as p = 1767 N. The rated thrust of the selected electric push rod 4 is 3000 N, which can meet the usage requirements. The electric push rod 4 and the piston 2 are connected through a connector with external threads at both ends, and the thread design is carried out according to the size structure of the connecting rod.

[0062] For the remote control part, according to the working characteristics of controlling the opening and closing of the electric ball valve 10 by the on-off of the power supply, the opening and closing of the electric ball valve 10 are controlled by controlling the power switch.

[0063] The opening and closing of the electric ball valve 10 are controlled by wirelessly controlling the relay. This scheme can control the opening and closing of the electric ball valve 10 at a distance of more than 100 m.

[0064] The working method of a device for online collection of primary gas of a solid rocket ramjet engine disclosed by the present invention is as follows: Before the test, the vacuum pump 9, the engine, and the gas sample bag or the gas analyzer are connected to the gas collection device. The gas in the gas storage chamber 3 and the pipeline 5 is pumped out by the vacuum pump 9 to reach a vacuum state. After the engine is ignited, the solenoid valve 6 on the intake path is opened, and the primary gas is sucked into the gas storage chamber by the pressure difference. Subsequently, the electric ball valve 10 is closed, and the collection of the primary gas ends. After a single test, the manual ball valve 8 on the outlet pipeline is opened, and the electric push rod 1 is started to move the piston 2 to discharge the gas in the gas storage chamber 3 into the gas collection bag for sample collection or directly into the gas analyzer for gas analysis. After this process ends, the piston 2 is pulled back to its original position to prepare for the next test.

[0065] The working method of a device for on-line collection of primary gas in a solid rocket ramjet engine disclosed in this embodiment is as follows: Before the test, connect the vacuum pump 9, the engine and the gas sample bag to the collection device, close the manual ball valve 8, open the manual ball valves 6 and 7, close the electric ball valve 10, and use the vacuum pump 9 to extract the gas in the gas storage chamber 3 and the high-pressure pipeline 5 to reach a vacuum state. Then close the manual ball valve 7 and conduct the experiment. After the engine is ignited, open the electric ball valve 10, and suck the primary gas into the gas storage chamber 3 through the pressure difference. Then close the electric ball valve 10, and the collection of the primary gas is completed. After a single test is completed, open the manual ball valve 8, start the electric push rod motor 1 to operate the electric push rod 4 to move the piston 2 to discharge the gas in the gas storage chamber 3 into the gas collection bag for sample collection or directly into the gas analyzer for gas analysis. After the gas is discharged, start the electric push rod motor 1 to operate the electric push rod 4 to move the piston 2 back to its original position to prepare for the next test.

[0066] The above description further details the purpose, method, device solution and advantages of the present invention. It should be understood that the above is only the specific implementation process of the present invention, used to explain the present invention, and is not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for online collection of primary combustion gases of solid rocket ramjet engines, characterized in that: It includes a gas storage tank, a flange connection section, a sealing structure, a piston, an electric push rod and a remote control part; The pressure-bearing and heat-resistant capacity of the gas storage tank meets the preset requirements; the gas storage tank is designed with a cylindrical structure, and the cylinder and the front and rear end covers are connected by flanges; refer to GB-150-2011 "Pressure Vessels", and the thickness is calculated according to the corresponding formula of the standard, and the thickness margin required by other factors is reserved when necessary; the calculated thickness of the pressure cylinder is calculated according to the following formula: Where: p max To calculate the pressure, D i is the inner diameter of the tank, then according to GB150.2, [σ] is the allowable stress, ξ is the welding joint coefficient, is the pressure fluctuation coefficient; The axial force on the bolt group in the flange connection is mainly the effect of the combustion chamber pressure, which is calculated by the following formula: The required stress of the bolts in a bolted connection under axial load is expressed as: Where R eL is the bolt yield strength, S s is the safety factor; The bolt length is estimated based on the flange thickness, gasket and nut size. On this basis, 2 to 3 times the pitch is reserved. The bolts are selected according to the bolt specifications to determine the number of hexagonal bolts and hexagonal bolts evenly distributed on the flange. Since the working pressure of the gas tank is 0 to 3 MPa, the maximum bolt spacing l<6d is calculated based on the reference value of the container flange connection bolt spacing. The maximum bolt spacing requirement l max , calculate the required maximum bolt distribution diameter D 0max , combined with safety factors to determine the bolt distribution diameter D0; bolt distance from the edge: e = d + (3 ~ 6) mm Substitute the bolt size into the formula to get e = 13 ~ 16 mm; thus obtain the outer diameter D of the connecting flange 法兰外 : D 法兰外 =D0+2e The sealing structure adopts an O-ring sealing structure; the design of the O-ring sealing structure includes: selecting the O-ring material, determining the size and compression of the O-ring, and determining the shape and size of the sealing groove; the O-ring used for the fixed part of the O-ring sealing structure is made of silicone rubber, and the O-ring used for the moving part is made of fluororubber and polytetrafluoroethylene; the inner diameter of the O-ring is determined according to the inner diameter of the gas tank shell, and then the cross-sectional diameter d2 of the O-ring is determined, the flange connection is the fixed part, and the material is silicone rubber; the compression of the O-ring is ε, and for the plane fixed seal, ε=15%~25%; the groove size is determined by referring to the axial sealing groove size standard GB / T 3452.3-2005 of the O-ring under internal pressure; The piston is a movable part inside the cylinder, and the piston adopts a two-ring sealing structure; The selection of the electric push rod is determined based on two parameters: the push rod stroke and the thrust; The electric push rod and the piston are connected by a connector with external threads at both ends, and the thread design and size are determined according to the size structure of the connecting rod; The remote control part controls the opening and closing of the solenoid valve or the electric ball valve by controlling the switch of the power supply according to the working characteristics of the solenoid valve or the electric ball valve.

2. The device for online collection of primary combustion gases of solid rocket ramjet engines according to claim 1, characterized in that: The gas tank uses 304 stainless steel as the shell material of the gas tank; the calculated pressure p of the gas tank c Take 3MPa, the inner diameter of the tank is D i The diameter is 150mm, the material is 304 steel, the design temperature is 20℃, then according to GB150.2, the allowable stress [σ] is 137MPa, the welding joint coefficient is ξ=1, and the pressure fluctuation coefficient is The calculated wall thickness of the gas tank is 1.8mm. Considering the wear and corrosion, as well as the piston movement, the material gas tank needs to have a small processing error and deformation. The wall thickness of the gas tank should be as thick as possible, and the final thickness is 4mm.

3. The device for online collection of primary combustion gases of solid rocket ramjet engines according to claim 2, characterized in that: R eL is the bolt yield strength, S s For the safety factor, the bolt material of grade 4.8 is selected as alloy steel, and its tensile strength is 400MPa. The bolt diameter is selected from M6 to M16, and the safety factor S is taken. s =4, according to the allowable stress calculation formula, the allowable stress of the bolt [σ] = 100MPa.

4. The device for online collection of primary combustion gases of solid rocket ramjet engines according to claim 3, characterized in that: The bolt length is estimated based on the flange thickness of 20mm, the size of the gasket and nut of 9mm, and the gasket includes a flat gasket of 2×1mm and a spring gasket of 3mm; on this basis, 2 to 3 times the pitch is reserved, and the bolt length is calculated to be about 40mm. According to the bolt specifications, it is finally determined to be a 4.8-level M10×40 hexagonal head bolt, with 10 evenly distributed on the flange; since the working pressure of the gas tank is 0 to 3MPa, according to the reference value of the bolt spacing of the container flange connection, the maximum bolt spacing is calculated to be l<6d=70mm; according to the maximum bolt spacing requirement l max =60mm, calculate the required maximum bolt distribution diameter D 0max =193mm, for safety reasons, D0=180mm is taken here; distance between bolt and edge: e=d+(3~6)mm Substituting the bolt size into the formula, we get e=13~16mm, here we take 15mm; thus, we get the outer diameter of the connecting flange: D 法兰外 =D0+2e=210mm。 5. The device for online collection of primary combustion gases of solid rocket ramjet engines as claimed in claim 4, characterized in that: O-rings used in fixed parts are mostly made of silicone rubber, and O-rings used in moving parts are usually made of fluororubber and polytetrafluoroethylene; since the inner diameter of the gas tank shell is 150mm, the inner diameter of the O-ring is selected as d1=155mm, so the cross-sectional diameter of the O-ring is selected as d2=3.55mm, and the flange connection is a fixed part, and the material is selected as silicone rubber; the compression amount of the O-ring is ε, and for flat fixed seals, ε=15%~25% is taken; referring to the axial sealing groove size standard GB / T3452.3-2005 for O-rings subjected to internal pressure, the groove dimensions are: d7=158mm, b=4.2mm, h=5mm, r1=1mm, r2=0.2mm.

6. A device for online collection of primary combustion gases of solid rocket ramjet engines as claimed in claim 1 or 2, characterized in that: The piston is a movable part inside the cylinder, and the piston adopts a two-ring sealing structure; The selection of the piston sealing ring is: piston outer diameter 149mm, d1=145mm, d7=150mm, d2=2.65mm, b=3.6mm, h=2.25mm; r1=0.6mm, r2=0.2mm.

7. The device for online collection of primary combustion gases of solid rocket ramjet engines according to claim 6, characterized in that: The selection of the electric push rod is determined by the two parameters of the push rod stroke and thrust; the piston of the primary gas collection device selects an electric push rod with a stroke of 200mm, which can meet the use requirements; The pressure difference △P before and after the piston is 0.1MPa, then the piston is subjected to force F p for: F p =△P·S Where: S is the piston force area, and F p =1767N, the rated thrust of the selected push rod is 3000N, which can meet the use requirements; the electric push rod and the piston are connected through a connector with external threads at both ends, and the thread design is carried out according to the size structure of the connecting rod.

8. The device for online collection of primary combustion gases of solid rocket ramjet engines as claimed in claim 7, characterized in that: The opening and closing of the solenoid valve or electric ball valve is controlled by a wireless control relay.

9. A device for online collection of primary combustion gases of solid rocket ramjet engines as claimed in claim 1, 2, 3, 4, 5, 6, 7 or 8, characterized in that: Before the test, connect the vacuum pump, engine and gas sample bag or gas analyzer to the gas collection device, and use the vacuum pump to extract the gas in the gas storage chamber and pipeline to reach a vacuum state. After the engine is ignited, open the solenoid valve on the intake path, and draw the primary fuel gas into the gas storage chamber through the pressure difference. Then close the solenoid valve, and the primary fuel gas is collected. After the single test is completed, open the manual ball valve of the gas outlet pipeline, start the electric push rod to move the piston to discharge the gas in the gas storage chamber into the gas collection bag for sample collection or directly perform gas analysis in the gas analyzer. After the process is completed, pull the piston back to its original position to prepare for the next test.

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