Method for operating a micro-cow-level gem-based dual-gas capacity variable thrust closed-loop cold gas thruster

Abstract

The application provides a running method of a micro-cow-level gem-based double-gas capacity variable thrust closed-loop cold gas thruster, a working medium gas inlet, a first-stage gas capacity, a connecting channel, a second-stage gas capacity and a working medium gas outlet are sequentially arranged in a soft magnetic material shell, and a Laval nozzle body is arranged at the working medium gas outlet; a valve assembly is arranged at a narrow throat working medium inlet of the Laval nozzle body, the valve assembly comprises a valve and a restoring elastic element, a restoring force of the restoring elastic element controls the working medium gas inlet to be communicated or sealed, and the restoring force of the restoring elastic element synchronously controls the valve assembly to be communicated or sealed with the connecting channel and the Laval nozzle body; a driving electromagnetic coil is arranged on an outer wall of the soft magnetic material shell to drive the valve assembly to move in different directions, and the elastic force of the restoring elastic element is used to control the sealing force of the valve. The running method of the micro-cow-level gem-based double-gas capacity variable thrust closed-loop cold gas thruster realizes continuous precision control and continuous stable output of thrust.

Description

[0001] This application is a divisional application of the invention patent application with application number 2022103826198;

[0002] The original application was filed on April 13, 2022.

[0003] The original application number was 2022103826198;

[0004] Original application title: A micro-Newton level gemstone-based dual-gas capacitive variable thrust closed-loop cold gas thruster and its operation method. Technical Field

[0005] This invention relates to the field of thrusters in precision machinery and aerospace propulsion technology, specifically to a method for operating a micro-Newton level gemstone-based dual-gas-capacity variable thrust closed-loop cold gas thruster. Background Technology

[0006] Thrusters are crucial power units in aerospace technology. During operation, they eject working materials at high speeds from a nozzle, using the recoil of the ejected material to provide thrust to the thruster and its carrier. Based on their working principles, propulsion systems used in space are categorized into cold gas propulsion, chemical propulsion, and electric propulsion. For short-term use, when the total impulse required for satellite control is relatively small, the effective specific impulse of a cold gas propulsion system is greater than that of an electric propulsion system. For microsatellites, the propulsion system is primarily used for orbit maintenance and attitude control, requiring small thrust and short operational time. Therefore, given sufficient payload space and total mass requirements, a cold gas propulsion system is the preferred choice for the space propulsion system of microsatellites.

[0007] A cold gas propulsion system includes a working fluid tank, a pressure reducer, electrically controlled valves, a nozzle, and a drive circuit; some systems also include pressure or flow sensors. The working fluid flows from a gas source, is reduced in pressure by the pressure reducer, and is then ejected through the electrically controlled valves and nozzle to generate thrust. The electrically controlled valves are shut-off valves, and the thruster operates in a continuously open / closed or pulsed state; the on-time of the electrically controlled shut-off valve determines the duration and impulse of each propulsion process. The cold gas micro-thruster is the core component of the cold gas micro-propulsion system.

[0008] In existing cold air micro-thrusters, the nozzle seats are mostly made of metal or alloy materials; the one-way valves mostly use traditional proportional control valves or electromagnetic proportional valves, and the valve heads are mostly made of organic or metal materials; there is no buffer gas capacity or only one buffer gas capacity, and the sealing method is simple, often using diversion or thermal microfluidic chips to monitor flow; most are open-loop control or closed-loop control for a single parameter.

[0009] Existing cold gas thrusters have the following problems:

[0010] 1. Nozzle seats made of metal and alloy materials have a relatively large coefficient of thermal expansion. In a space environment with a temperature difference of up to hundreds of K, the nozzle will expand / contract and deform, especially the throat diameter will change significantly. This is detrimental to high-precision micro-Newton cold gas thrusters and will directly affect their thrust accuracy.

[0011] 2. Common valve heads and valve seats (nozzle seats) are generally soft seals made of organic materials and metals. After long-term operation, organic valve heads will experience fatigue deformation, which will cause changes in valve stroke, resulting in flow deviation, and may even cause the valve to fail to seal completely, resulting in air leakage.

[0012] 3. Another type of metal-to-metal hard seal can solve the fatigue deformation of soft seal to some extent, but the collision loss of metal is relatively large, especially for pulse solenoid valves, the wear on the metal valve head and valve seat / nozzle seat will be greater, shortening the working life of the cold gas thruster, affecting the long-term working stability of the cold gas thruster, and increasing its thrust noise.

[0013] 4. Conventional micro-Newton level cold air thrusters do not have a pre-stage buffer gas capacity or only a single-stage gas capacity. The airflow cannot form a uniform and stable distribution, resulting in uneven pressure distribution, poor thrust stability, and large thrust noise.

[0014] 5. In a single-capacity cold gas thruster, the gas container is typically placed before the self-locking valve. The working gas is first homogenized by the gas container before flowing into the nozzle through a one-way valve to generate thrust. If the one-way valve fails due to fatigue deformation or wear and tear, resulting in leakage, the gas container completely loses its buffering function.

[0015] 6. Thermal flow meters require localized heating of the gas, which can cause some disturbance to the stable flow of the gas.

[0016] 7. Diverter flow meters consume a small amount of gas, which also disturbs the stable flow of the gas.

[0017] 8. Open-loop control of parameters such as temperature and flow rate cannot achieve precise control of the thruster, affecting thrust accuracy and thrust noise.

[0018] Therefore, how to solve the thrust accuracy control and continuous stable thrust output in micro-Newton level variable thrust cold gas micro-thrusters has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0019] The purpose of this invention is to provide a method for operating a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster, addressing the problems of insufficient thrust precision control and difficulty in maintaining stable thrust output in existing technologies.

[0020] Therefore, the above-mentioned objectives of the present invention are achieved through the following technical solutions:

[0021] A method for operating a micro-Newton level gemstone-based dual-capacity variable thrust closed-loop cold gas thruster, characterized in that: in the thruster, a working gas inlet, a primary gas container, a connecting channel, a secondary gas container, and a working gas outlet are sequentially arranged inside a soft magnetic material shell, and a Laval nozzle body is provided at the working gas outlet;

[0022] The Laval nozzle body is equipped with a valve assembly at the working fluid inlet in the narrow throat. The valve assembly includes a valve and a restoring elastic element. The restoring force of the restoring elastic element synchronously controls the valve assembly to communicate with or seal the connection channel and the Laval nozzle body.

[0023] The outer wall of the soft magnetic material shell is equipped with a driving electromagnetic coil to drive the valve assembly to generate upward movement, while the elastic force of the restoring elastic element is used to control the sealing force of the valve.

[0024] The Laval nozzle body is a nozzle seat made of jewel material. A jewel valve head is installed at the front end of the valve to seal against the working gas inlet of the Laval nozzle body. At the rear end of the valve, a restoring elastic element elastically presses against the working gas inlet at one end and against the valve assembly at the other end to secure the connecting channel.

[0025] The operation steps of the thruster are as follows:

[0026] S1, the thruster is connected to a stable air source and receives the flow rate setpoint Qset and the temperature setpoint Tset;

[0027] S2, set the electromagnetic coil working parameters and temperature control module according to Qset and Tset, the thruster works, the valve is magnetized, and under the action of electromagnetic force, it overcomes the elastic force and pressure difference force to lift upward, the seal is released, and the electromagnetic coil working parameters are related to the electromagnetic coil working parameters and the actual flow value by formula (1): Qreal=k1*D, where Qreal is the actual flow value, D is the electromagnetic coil working parameter, and k1 is the calibration coefficient;

[0028] S3, the working gas first enters the first-stage gas container for buffering, and the inlet pressure of the gas in the first-stage gas container is obtained by the pressure sensor of the first-stage gas container;

[0029] S4, the working gas enters the secondary gas container through the inlet, is buffered, and the inlet and outlet pressures are obtained by the secondary gas container pressure sensor to calculate the pressure difference Δp; the working gas temperature Treal is obtained by the secondary gas container temperature sensor.

[0030] S5, when the actual working gas temperature Treal is less than Tset, the heating coil of the temperature control module operates to heat the working gas to Tset, and switches on and off in real time according to the temperature reading Treal of the secondary gas capacity temperature sensor to maintain a stable working temperature of the working gas and achieve closed-loop temperature control; when the actual working gas temperature Treal is greater than Tset, the temperature control module shuts down and only records the temperature reading Treal of the secondary gas capacity temperature sensor, and corrects the relationship between flow rate and thrust based on the actual working gas temperature Treal.

[0031] S6, by measuring the relationship between the pressure difference Δp and the actual flow rate (2): Qreal=k2*Δp, where Qreal is the actual flow rate, Δp is the measured pressure difference, and k2 is the calibration coefficient 2, which is to correct the flow conductance of the outlet, the actual flow rate Qreal is obtained. If Qreal and Qset are inconsistent, the electromagnetic coil adjusts its working parameters to make Qreal approach Qset, maintain the stability and accuracy of the working gas flow rate, and realize the closed-loop control of the flow rate;

[0032] S7: The working gas enters the sapphire nozzle after being controlled by flow rate and temperature, and is then accelerated and ejected to obtain the required thrust.

[0033] While adopting the above technical solutions, the present invention may also adopt or combine the following technical solutions:

[0034] As a preferred technical solution of the present invention: the valve is T-shaped, and the valve's crossbar is locked in the connecting channel on the side facing the primary gas container. When the piston moves in the connecting channel seat, the valve crossbar presses against the connecting channel, and at the same time the jewel valve head presses against the Laval nozzle body to seal the primary and secondary gas containers. When the valve crossbar leaves the connecting channel, the jewel valve head connects the primary and secondary gas containers.

[0035] As a preferred technical solution of the present invention: the valve includes a jewel valve head, a valve core and a valve core housing, the valve core housing is sleeved on the outside of the valve core and the jewel valve head, and the jewel valve head is adhered to the valve core;

[0036] Alternatively, the jewel valve head may be a ruby ​​valve head.

[0037] As a preferred technical solution of the present invention: a groove is provided at the connection end between the Laval nozzle body and the soft magnetic material shell to install the valve seat sealing ring; a shell is fitted over the Laval nozzle body and the soft magnetic material shell; the shell is fixedly connected to the soft magnetic material shell on the side near the working gas inlet to clamp the Laval nozzle body and the soft magnetic material shell; and the sealing is achieved by the valve seat sealing ring.

[0038] As a preferred technical solution of the present invention: a temperature control module is provided, which is disposed between the soft magnetic material outer shell and the housing, and is located on the circumferential outer side of the secondary gas container.

[0039] As a preferred technical solution of the present invention: the temperature control module is provided with a secondary gas capacity temperature sensor on the periphery of the connection channel. The real-time temperature is monitored by the secondary gas capacity temperature sensor and the power of the temperature control module is adjusted at the same time to control the temperature of the working gas in the secondary gas capacity in a closed loop.

[0040] As a preferred technical solution of the present invention: the primary gas container is equipped with a primary gas container pressure sensor, and the secondary gas container is equipped with a secondary gas container pressure sensor to measure the pressure p1 at the front end of the primary gas container and the pressure p2 at the front end of the secondary gas container respectively, and obtain the pressure difference Δp. After determining that Δp is approximately the pressure difference on both sides of the air inlet, the theoretical approximate flow rate value is obtained by calculation, and the working parameters of the electromagnetic pulse valve are adjusted in real time to realize closed-loop control of the flow rate.

[0041] As a preferred technical solution of the present invention: the electromagnetic coil is wound in the coil frame outside the rear end of the soft magnetic material shell, and the outer side is restricted from dislocation by the shell, driving the electromagnetic coil to drive the valve assembly to move in the direction of the working gas inlet.

[0042] As a preferred technical solution of the present invention: the restoring elastic element is a tension spring, one end of which is fixed on the valve core and the other end is installed on the rear end of the soft magnetic material shell. The electromagnetic coil drives the valve and overcomes the elastic force of the restoring elastic element to lift it, opening the working gas outlet and the connecting channel, opening the gas channels of the primary gas container and the secondary gas container, closing the electromagnetic coil, and sealing the valve by the tensioning force of the tension spring.

[0043] This invention discloses a method for operating a micro-Newton level gemstone-based dual-gas-capacity variable-thrust closed-loop cold gas thruster. By adjusting the operating parameters of the pulse electrical signal of the adjusting electromagnetic coil, the valve and the restoring elastic element are driven to move upwards. This allows for real-time control of the working gas output at the inlet and outlet of the primary gas container, achieving continuous and variable adjustment of the working gas flow rate. This provides the hardware conditions for achieving a continuous and stable thrust output from the cold gas thruster. The invention utilizes a T-shaped valve design and a waist-tightening design in the middle of the soft magnetic material shell, along with the restoring elastic element, to divide the gas container into a primary and a secondary gas container. This provides the foundation for closed-loop control of the working gas flow rate. Combined with pressure sensors in the primary and secondary gas containers, a theoretical approximate flow rate value can be achieved. Constant flow rate control of the working gas outlet is achieved through negative feedback control of the front-end gas supply and adjustment of the electromagnetic coil, enabling real-time high-precision thrust control of the cold gas thruster of this invention. The separate design of the primary and secondary gas capacities in this invention provides double protection against gas leakage, ensuring the high sealing performance of the thruster. In the dual-stage gas capacities, the combination of air pressure monitoring and flow control improves the continuous uniformity and stability of airflow, realizing the continuous and stable thrust of the cold gas thruster and reducing thrust noise. The hard-seal combination of the sapphire nozzle seat and the sapphire valve head effectively overcomes the effects of thermal expansion and contraction on the nozzle seat and valve head caused by the extreme high and low temperatures in space, and effectively solves the wear problem of traditional valve heads and seats during long-term operation, realizing the continuous thrust output accuracy and stability.

[0044] This invention discloses a micro-Newton level sapphire-based dual-gas-capacity variable thrust closed-loop cold gas thruster and its operation method. It utilizes a dual-sapphire hard seal formed by a sapphire nozzle seat and a ruby ​​valve head, effectively improving the continuous and stable sealing effect and service life. In particular, the lower coefficient of thermal expansion of sapphire materials compared to metals and alloys makes it more suitable for operation in the high-temperature environment of space, ensuring the stability of the nozzle structure and guaranteeing the stability and accuracy of the thruster. The use of a dual-stage gas capacity effectively buffers the working gas, ensuring its uniformity and guaranteeing the stability and accuracy of the thrust. Pressure sensors placed in the dual-stage gas capacities are also utilized. It can monitor the pressure difference between the two gas tanks in real time, that is, the pressure difference at both ends of the inlet, and thus obtain the thruster's working flow rate. Using the two-stage gas tank, the working parameters of the electromagnetic pulse signal can be adjusted in real time according to this flow rate to complete the closed-loop control of the flow rate and ensure the stability and accuracy of the flow rate. The temperature control module realizes the precise control of the temperature of the secondary gas tank, that is, the outlet working gas temperature, and completes the closed-loop control of the gas in the secondary gas tank through the real-time feedback signal of the temperature sensor to ensure the stability of the working gas temperature. Even when the working gas temperature is higher than the working temperature, the thrust value can be corrected by theoretical formulas based on the actual temperature to obtain the actual thrust value. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the thruster structure used in the operation method of a micro-Newton level gemstone-based dual-gas capacity variable thrust closed-loop cold gas thruster of the present invention.

[0046] In the attached diagram: 1. Gem nozzle seat; 2. Outlet temperature sensor; 3. Housing; 4. Gem valve head; 5. Valve seat sealing O-ring; 6. Valve core housing; 7. Valve core; 8. Temperature control module; 9. Secondary gas capacitor; 10. Secondary gas capacitor pressure sensor; 11. Secondary gas capacitor temperature sensor; 12. Connecting channel; 13. Primary gas capacitor pressure sensor; 14. Electromagnetic coil; 15. Primary gas capacitor; 16. Resilient elastic element; 17. Soft magnetic material housing; 18. Lead wire; 19. Working gas inlet; 20. Working gas outlet. Detailed Implementation

[0047] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0048] The present invention discloses an operating method for a micro-Newton level gemstone-based dual-capacity variable thrust closed-loop cold gas thruster. In the thruster used, a working gas inlet 19, a primary gas container 15, a connecting channel 12, a secondary gas container 9, and a working gas outlet 20 are sequentially arranged inside a soft magnetic material shell 17. The working gas outlet 20 is provided with a Laval nozzle body 1. A valve assembly is provided at the narrow throat working gas inlet of the Laval nozzle body 1. The valve assembly includes a valve and a restoring elastic element 16. The restoring force of the restoring elastic element 16 synchronously controls the valve assembly to communicate with or seal the connecting channel 12 and the Laval nozzle body.

[0049] The outer wall of the soft magnetic material shell 17 is provided with an electromagnetic coil 14 to drive the valve assembly to move in different directions. At the same time, the elastic force of the restoring elastic element 16 is used to control the sealing force of the valve. The Laval nozzle body 1 is a nozzle seat made of gemstone material. A gemstone valve head is provided at the front end of the valve to press against the working gas inlet of the Laval nozzle body 1 to achieve a seal. At the rear end of the valve, one end of the restoring elastic element 16 elastically presses against the working gas inlet 19, and the other end presses against the valve assembly to press against the connecting channel 12.

[0050] The valve is T-shaped, and the valve's crossbar is engaged in the connecting channel 12 on the side facing the primary gas container 15. When the piston moves in the connecting channel 12, the valve crossbar presses against the connecting channel 12, and at the same time, the jewel valve head 4 presses against the Laval nozzle body 1 to seal the primary and secondary gas containers. When the valve crossbar leaves the connecting channel 12, the jewel valve head 4 connects the primary and secondary gas containers.

[0051] The valve includes a jewel valve head 4, a valve core 7, and a valve core housing 6. The valve core housing 6 is fitted over the valve core 7 and the jewel valve head 4, and the jewel valve head 4 is attached to the valve core 7. The jewel valve head 4 is made of ruby.

[0052] A groove is provided at the connection end between the Laval nozzle body 1 and the soft magnetic material shell 17 to install the valve seat sealing ring 5. The Laval nozzle body 1 and the soft magnetic material shell 17 are covered with a shell 3. The shell 3 is fixedly connected to the soft magnetic material shell 17 on the side near the working gas inlet to clamp the Laval nozzle body 1 and the soft magnetic material shell 17, and the seal is achieved by the valve seat sealing ring.

[0053] A temperature control module 8 is provided, which is disposed between the soft magnetic material outer shell 17 and the shell 3, and is located on the circumferential outer side of the secondary gas container.

[0054] The temperature control module 8 is equipped with a secondary gas capacity temperature sensor 11 on the periphery of the connection channel 12. The secondary gas capacity temperature sensor 11 monitors the real-time temperature and simultaneously adjusts the power of the temperature control module 8 to achieve closed-loop control of the temperature of the working gas in the secondary gas container 9.

[0055] The primary gas container 15 is equipped with a primary gas container pressure sensor 13, and the secondary gas container 9 is equipped with a secondary gas container pressure sensor 10. The pressure p1 at the front end of the primary gas container 13 and the pressure p2 at the front end of the secondary gas container 10 are measured respectively, and the pressure difference Δp is obtained. After determining that Δp is approximately the pressure difference on both sides of the connecting channel 12, the theoretical approximate flow rate value is calculated by Q = K2 * Δp. The working parameters of the electromagnetic pulse valve are adjusted in real time to achieve closed-loop control of the flow rate.

[0056] The driving electromagnetic coil 14 is wound in the coil frame outside the rear end of the soft magnetic material shell 17, and is restricted from dislocation by the shell 3 on the outside. The driving electromagnetic coil 14 drives the valve assembly to move in the direction of the working gas inlet.

[0057] The restoring elastic element 16 is a tension spring that drives the electromagnetic coil 14 to drive the valve and overcome the elastic force of the restoring elastic element 16 to lift it, opening the working gas outlet 20 and the connecting channel, and opening the gas channels of the primary gas container 15 and the secondary gas container 9.

[0058] When the working gas temperature is lower than the required operating temperature, this invention achieves closed-loop temperature control through a temperature sensor 11 located in the secondary gas container 9, enabling rapid and precise adjustment of the working gas temperature. When the working gas temperature is higher than the required operating temperature, the relationship between flow rate and thrust is corrected based on the temperature reading from the secondary gas container temperature sensor 11.

[0059] Flow calibration and closed-loop control are achieved through pressure sensors 10 and 13 in the first-stage gas container 9 and the second-stage gas container 15, thus achieving high accuracy of the working gas flow rate.

[0060] By adjusting the operating parameters of the electromagnetic coil, the flow rate can be continuously and variably adjusted, thereby achieving continuous and variable adjustment of the thrust.

[0061] The thruster achieves closed-loop control of temperature and flow, effectively ensuring the stability of the working gas temperature and the flow output, thereby realizing the stability of thrust output and rapid closed-loop adjustment, effectively reducing its thrust noise and ensuring its long-term working stability.

[0062] The dual-stage gas capacity ensures the uniformity and stability of airflow, provides measurement and calibration space for closed-loop flow control, enhances sealing performance, and effectively reduces thrust noise.

[0063] T-type valves have a dual-stage seal. Even if one stage of the gas reservoir leaks and fails, the other stage still provides a sealing and buffering function to prevent leakage.

[0064] The hard seal combination of the jewel nozzle seat 1 and the jewel valve head 4 effectively overcomes the thermal expansion and contraction effects of extreme high and low temperatures in space on the nozzle seat and valve head, and can effectively reduce the impact loss of the pulse valve, improve the thrust output accuracy and stability, and extend the service life.

[0065] This invention discloses a micro-Newton level gemstone-based dual-gas-capacity variable-thrust closed-loop cold gas thruster. By adjusting the operating parameters of the pulse electrical signal of the adjusting electromagnetic coil, the valve and the restoring elastic element are driven to move upwards. This allows for real-time control of the working gas flow rate at the inlet of the primary gas container and the outlet 20 of the working gas, achieving continuous and variable adjustment of the working gas flow rate. This provides the hardware conditions for achieving a continuous and stable thrust output from the cold gas thruster. The invention utilizes a T-shaped valve design and a waist-tightening design in the middle of the soft magnetic material shell 17, along with the restoring elastic element, to divide the gas container into a primary and a secondary gas container. This provides the foundation for closed-loop control of the working gas flow rate. Combined with the pressure sensors 13 and 10 of the primary and secondary gas containers, a theoretical approximate flow rate value can be achieved. Constant flow rate control of the working gas outlet is achieved through negative feedback control of the front-end gas supply and adjustment of the electromagnetic coil, enabling real-time high-precision thrust control of the cold gas thruster of this invention. The separate design of the primary and secondary gas capacities in this invention provides double protection against gas leakage, ensuring the high sealing performance of the thruster. In the dual-stage gas capacities, the combination of air pressure monitoring and flow control improves the continuous uniformity and stability of airflow, achieving continuous and stable thrust of the cold gas thruster and reducing thrust noise. The hard-seal combination of the sapphire nozzle seat and the sapphire valve head effectively overcomes the effects of thermal expansion and contraction on the nozzle seat and valve head caused by the extreme high and low temperatures in space, providing the hardware conditions for continuous thrust output accuracy and stability.

[0066] Example 1

[0067] like Figure 1As shown, the present invention discloses an operation method for a micro-Newton level sapphire-based dual-capacity variable thrust closed-loop cold gas thruster. A shallow groove exists on the contact surface between the housing 3 and the Laval nozzle body 1. An outlet temperature sensor 2 is placed in the groove to monitor the front-end outlet temperature and is fixed to the housing 3 by adhesive bonding. The Laval nozzle body 1 is hollow internally, with a double-arc contraction at the rear end and a conical expansion at the front end, forming a Laval nozzle structure. A valve seat sealing ring 5 is located in a groove at the front end of the soft magnetic material housing 17, at the rear end of the sapphire nozzle seat, ensuring a seal between the Laval nozzle body 1 and the soft magnetic material housing 17. A temperature control module 8 is wound in a coil frame outside the front end of the soft magnetic material housing 17, with the other side confined within the housing 3 to prevent detachment, and is used to control the temperature of the working gas in the secondary gas capacity. The secondary gas capacity pressure sensor 10 and the secondary gas capacity temperature sensor 11 are positioned at the rear end of the secondary gas container 9 and the front end of the connecting channel 12 via pipe joints welded to the slots in the soft magnetic material housing 17. Sealant is used to ensure the pipe joints are sealed. These sensors are used to monitor the temperature of the working gas in the secondary gas container 9 and the outlet pressure of the connecting channel 12, respectively. The primary gas capacity pressure sensor is positioned at the front end of the primary gas container 15 and the rear end of the connecting channel 12 via pipe joints welded to the slots in the soft magnetic material housing 17. Sealant is used to ensure the pipe joints are sealed. This sensor is used to monitor the inlet pressure of the connecting channel 12. The drive electromagnetic coil 14 is wound around a coil frame outside the rear end of the soft magnetic material housing 17, with the other side confined within the housing 3 to prevent it from falling off. This coil is used to generate the force that drives the valve assembly upwards. The valve assembly consists of a ruby ​​valve head 4, a valve core 7, a valve core housing 6, and a restoring elastic element 16. The ruby ​​valve head 4 is connected to the valve core 7 by adhesion. The valve core housing 6 is fitted over the ruby ​​valve head 4 and valve core 7 for protection. The valve's front end abuts against the rear end of the Laval nozzle body 1 via the ruby ​​valve head 4, and its rear end abuts against the front end of the primary gas container 15 in the soft magnetic material housing 17 via the valve core housing 6, forming a double-stage seal. The front end of the restoring elastic element 16 is mounted on the valve core 7, and its rear end is mounted on the rear end of the soft magnetic material housing 17, used to generate the valve's sealing force and restoring force. In the structure of the soft magnetic material housing 17, four connecting channels 12 are evenly arranged between the primary gas container 15 and the secondary gas container 9. The housing 3 and the soft magnetic material shell 17 are connected by sealant and rear screws. The lead wires 18 of the outlet temperature sensor 2, temperature control module 8, secondary gas capacity pressure sensor 10, secondary gas capacity temperature sensor 11, primary gas capacity pressure sensor 13 and drive electromagnetic coil 14 extend to the rear exterior of the soft magnetic material shell 17 through shallow grooves on the housing 3 and through holes in the soft magnetic material shell 17.

[0068] The temperature control module 8 controls the temperature of the working gas in the secondary gas container 9 through the soft magnetic material shell 17. The real-time temperature is monitored by the secondary gas container temperature sensor 11, and the power of the temperature control module 8 is adjusted at the same time to achieve closed-loop control of the temperature of the working gas in the secondary gas container 9.

[0069] In the non-operating state, due to the action of the restoring elastic element, the valve core housing 6 abuts against the front end of the primary gas container 15 in the soft magnetic material housing 17, the connecting channel 12 cannot work, and the ruby ​​valve core 4 abuts against the rear end of the Laval nozzle body 1, preventing the gas working fluid from being ejected to generate thrust, thus entering a double-cut-off state. In the operating state, the electromagnetic coil 14 is energized, and the ruby ​​valve head 4, valve core 7, and valve core housing 6 rise against the elastic force of the restoring elastic element 16, opening the gas channels of both the primary gas container 15 and the secondary gas container 9. The gas working fluid in the secondary gas container is ejected from the Laval nozzle body 1 to generate thrust, and then the working fluid gas in the primary gas container is replenished to the secondary gas container 9 through the connecting channel 12.

[0070] Under stable operating conditions, due to the pressure difference between the secondary gas container 9 and the working environment, the working gas will be ejected through the Laval nozzle body 1, and the gas pressure in the secondary gas container 9 will decrease accordingly. As the gas pressure in the secondary gas container 9 decreases, a pressure difference is formed between the primary gas container 15 and the secondary gas container 9. The working gas in the primary gas container 15 is replenished to the secondary gas container 9 through the connecting channel 12. This replenishment flow rate is in series with the flow rate ejected through the Laval nozzle body 1, and their values ​​are equal. The pressure p1 at the front end of the primary gas container 13 (i.e., the rear end of the connecting channel 12) and the pressure p2 at the front end of the secondary gas container 10 (i.e., the front end of the connecting channel 12) can be measured using the primary gas container pressure sensor 13 and the secondary gas container pressure sensor 10, respectively, and the pressure difference Δp can be obtained. Assuming Δp is approximately the pressure difference across the connecting channel 12, the theoretical approximate flow rate can be calculated using Q = K2 * Δp. Since the entire air-supported propulsion system is connected in series, the flow rates entering the primary air tank 15 and the secondary air tank 10 are completely consistent with those in the working environment. A high-precision flow calibrator can be used at the front end to supply air, and this flow rate can be used as a standard flow rate to calibrate the relationship between the pressure difference Δp across the connecting channel 12 and the flow rate, resulting in a calibrated flow rate formula. The flow rate value corresponding to the pressure difference is measured by the primary air tank pressure sensor 13 and the secondary air tank pressure sensor 10, which is used to adjust the duty cycle of the electromagnetic pulse valve in real time, thereby achieving closed-loop flow control.

[0071] The Laval nozzle body 1 is made of sapphire, the ruby ​​valve head 4 is made of ruby, the housing 3 and the soft magnetic material outer shell 17 are both made of stainless steel, and the valve core housing 6 and valve core 7 are made of soft magnetic alloy. The Laval nozzle body 1 is laser-machined to create a hollow internal structure, ensuring the machining accuracy of the orifice and the linear and nonlinear structures before and after it. The ruby ​​valve head 4 is machined using dry etching-assisted laser processing. The housing 3, the soft magnetic material outer shell 17, and the valve core housing 6 are all precision-machined to ensure that the thruster's mounting axis and thrust axis are aligned, improving thrust accuracy.

[0072] The operation method of the thruster of the present invention is described below.

[0073] When the drive solenoid coil 14 is not in operation, the valve is pressed against the Laval nozzle body 1 and the soft magnetic material shell 17 by the elastic force of the restoring elastic element 16, forming a double-stage seal. When the thruster is working, a certain electrical signal is applied to the drive solenoid coil 14, magnetizing the valve core 7 and generating an axial suction force on it. When this suction force is greater than the elastic force of the restoring elastic element 16, the valve rises, the double-stage seal is released, and the working gas is first throttled and then expanded and ejected from the secondary gas container 9 through the Laval nozzle body 1, forming thrust. At the same time, the working gas in the primary gas container 15 is replenished to the secondary gas container 9 through the connecting channel 12. In this thruster, the drive signal is a pulse signal, so the thruster operates in pulse jet mode. The valve controls the ejection of the working gas through continuous opening and closing actions. The flow rate of the working gas can be controlled by adjusting the duty cycle of the working pulse signal of the drive solenoid coil 14, thereby achieving continuous adjustment of the flow rate and the thrust. During thruster operation, the temperature control module 8 adjusts the temperature of the working gas in the secondary gas container 9 in real time based on the feedback temperature from the secondary gas container temperature sensor 10, forming a closed-loop control of the working gas temperature to ensure the stability of the ejected working gas temperature and thus the stability of the thrust. The secondary gas container pressure sensor 11 and the primary gas container pressure sensor measure the pressure difference between the two ends of the connection channel 12 during thruster operation in real time and convert it into real-time flow rate. This real-time flow rate value is fed back to the front-end control system, which adjusts the duty cycle of the pulse drive signal based on this feedback to regulate the flow rate and achieve closed-loop flow control.

[0074] The flow calibration control process and the operation method of the cold gas thruster of the present invention will be further described below.

[0075] 1. Flow rate calibration:

[0076] 1. Given the operating parameters of electromagnetic coil 14 and open temperature control module 8, release the seal of T-valve;

[0077] 2. Supply gas to this thruster through the air inlet, and install a standard mass flow meter on the pipeline before the working gas enters the thruster, and use the reading of this standard mass flow meter as the standard flow value;

[0078] 3. Under this working condition, record the pressure readings of the secondary gas capacity pressure sensor 10 and the primary gas capacity pressure sensor 13 and obtain the pressure difference Δp; under this working condition, record the temperature reading of the secondary gas capacity temperature sensor 11;

[0079] 4. If the temperature reading of the secondary gas capacity temperature sensor 11 is lower than the required operating temperature, the heating electromagnetic coil will operate to maintain the working gas temperature at the required operating temperature throughout the calibration process. If the temperature reading of the secondary gas capacity temperature sensor 11 is higher than the required operating temperature, the temperature control module 7 will stop operating and use the working gas temperature data collected by the secondary gas capacity temperature sensor 11 to correct the relationship between flow rate and thrust, thereby obtaining the corrected thrust value.

[0080] 5. Repeat the above process to obtain the standard flow rate, pressure difference Δp, and working gas temperature corresponding to multiple sets of electromagnetic coil 14 operating parameters;

[0081] 6. Fit the working parameters of the electromagnetic coil 14 with the standard flow data to obtain the relationship between the working parameters and the standard flow value (1): Q = k1 * D, where Q is the standard flow value, D is the working parameter of the electromagnetic coil, and k1 is the calibration coefficient 1. Then fit the pressure difference Δp with the standard flow value data to obtain the relationship between the pressure difference Δp and the standard flow value (2): Q = k2 * Δp, where Q is the standard flow value, Δp is the measured pressure difference, and k2 is the calibration coefficient 2. Through the relationship (1) and (2), establish the relationship between the pressure difference Δp, the standard flow value, and the working parameters of the electromagnetic coil 14 to obtain the flow calibration formula: D = k2 * Δp / k1, which serves as the transfer function for flow closed-loop control.

[0082] 7. After calibration, turn off the power. The T-valve will return to its elastic element and achieve a seal.

[0083] The operating method of the cold gas thruster of the present invention includes the following operating steps:

[0084] S1, the thruster is connected to a stable air source and receives the flow rate setpoint Qset and the temperature setpoint Tset;

[0085] S2, according to Qset and Tset, set the working parameters of the electromagnetic coil and the temperature control module, the thruster works, the valve is magnetized, and under the action of electromagnetic force, it overcomes the elastic force and pressure difference force to lift upward, the seal is released, and the working parameters of the electromagnetic coil are related to the working parameters of the electromagnetic coil and the standard flow value (1): Q=k1*D (where Q is the standard flow value, D is the working parameter of the electromagnetic coil, and k1 is the calibration coefficient 1;

[0086] S3, the working gas first enters the first-stage gas container for buffering, and the inlet pressure of the gas in the first-stage gas container is obtained by the pressure sensor of the first-stage gas container;

[0087] S4, the working gas enters the secondary gas container through the inlet, is buffered, and the inlet and outlet pressures are obtained by the secondary gas container pressure sensor to calculate the pressure difference Δp; the working gas temperature Treal is obtained by the secondary gas container temperature sensor.

[0088] S5, when the working gas temperature Treal is less than Tset, the heating coil of the temperature control module operates to heat the working gas to Tset, and switches on and off in real time according to the working gas temperature Treal of the secondary gas capacity temperature sensor to maintain a stable operating temperature of the working gas, thus achieving closed-loop temperature control. When the working gas temperature Treal is greater than Tset, the temperature control module shuts down, only recording the working gas temperature Treal of the secondary gas capacity temperature sensor, and using the working gas temperature Treal to correct the relationship between flow rate and thrust.

[0089] S6, by measuring the pressure difference Δp and the standard flow value relationship (2): Q=k2*Δp, where Q is the standard flow value, Δp is the measured pressure difference, and k2 is the calibration coefficient 2. By substituting Δp, the measured pressure difference, into the relationship (2), the actual flow value Qreal is obtained. If Qreal and Qset are inconsistent, the electromagnetic coil adjusts its working parameters to make Qreal tend to Qset, maintain the stability and accuracy of the working gas flow, and realize the closed-loop control of the flow.

[0090] S7, the working gas enters the sapphire nozzle after flow and temperature control, is accelerated, and then ejected to obtain the required thrust. The above specific embodiments are used to explain and illustrate the present invention, and are merely preferred embodiments of the present invention, not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made to the present invention within the spirit and scope of the claims fall within the protection scope of the present invention.

Claims

1. A method for operating a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster, characterized in that: In the thruster, the working gas inlet, primary gas container, connecting channel, secondary gas container and working gas outlet are arranged sequentially inside the soft magnetic material shell. The working gas outlet is equipped with the Laval nozzle body. The Laval nozzle body is equipped with a valve assembly at the working fluid inlet in the narrow throat. The valve assembly includes a valve and a restoring elastic element. The restoring force of the restoring elastic element synchronously controls the valve assembly to communicate with or seal the connection channel and the Laval nozzle body. The outer wall of the soft magnetic material shell is equipped with a driving electromagnetic coil to drive the valve assembly to generate upward movement, while the elastic force of the restoring elastic element is used to control the sealing force of the valve. The Laval nozzle body is a nozzle seat made of jewel material. A jewel valve head is installed at the front end of the valve to seal against the working gas inlet of the Laval nozzle body. At the rear end of the valve, a restoring elastic element elastically presses against the working gas inlet at one end and against the valve assembly at the other end to secure the connecting channel. The operation steps of the thruster are as follows: S1, the thruster is connected to a stable air source and receives the flow rate setpoint Qset and the temperature setpoint Tset; S2, according to Qset and Tset, set the working parameters of the electromagnetic coil and the temperature control module, the thruster works, the valve is magnetized, and under the action of electromagnetic force, it overcomes the elastic force and pressure difference force to lift upward, the seal is released, and the working parameters of the electromagnetic coil are related to the working parameters of the electromagnetic coil and the actual flow value by formula (1): Qreal=k1*D, where Qreal is the actual flow value, D is the working parameter of the electromagnetic coil, and k1 is the calibration coefficient; S3, the working gas first enters the first-stage gas container for buffering, and the inlet pressure of the gas in the first-stage gas container is obtained by the pressure sensor of the first-stage gas container; S4, the working gas enters the secondary gas container through the inlet for buffering, and the inlet and outlet pressures are obtained by the secondary gas container pressure sensor to calculate the pressure difference Δp; The working gas temperature Treal is obtained from a secondary gas capacity temperature sensor; S5, when the actual working gas temperature Treal is less than Tset, the heating coil of the temperature control module operates to heat the working gas to Tset, and switches on and off in real time according to the temperature reading Treal of the secondary gas capacity temperature sensor to maintain a stable working temperature of the working gas and achieve closed-loop temperature control; when the actual working gas temperature Treal is greater than Tset, the temperature control module shuts down and only records the temperature reading Treal of the secondary gas capacity temperature sensor, and corrects the relationship between flow rate and thrust based on the actual working gas temperature Treal. S6, by measuring the relationship between the pressure difference Δp and the actual flow rate (2): Qreal=k2*Δp, where Qreal is the actual flow rate, Δp is the measured pressure difference, and k2 is the calibration coefficient 2, which is to correct the flow conductance of the outlet, the actual flow rate Qreal is obtained. If Qreal and Qset are inconsistent, the electromagnetic coil adjusts its working parameters to make Qreal approach Qset, maintain the stability and accuracy of the working gas flow rate, and realize the closed-loop control of the flow rate. S7: The working gas enters the sapphire nozzle after being controlled by flow rate and temperature, and is then accelerated and ejected to obtain the required thrust.

2. The operating method of a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster as described in claim 1, characterized in that: The valve is T-shaped, with the valve stem locked in the connecting channel on the side facing the primary gas container. It moves like a piston in the connecting channel. While the valve stem presses against the connecting channel, the jewel valve head presses against the Laval nozzle body to seal the primary and secondary gas containers. When the valve stem leaves the connecting channel, the jewel valve head connects the primary and secondary gas containers.

3. The operating method of a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster as described in claim 1, characterized in that: The valve includes a jewel valve head, a valve core, and a valve core housing. The valve core housing is fitted over the valve core and the jewel valve head, and the jewel valve head is adhered to the valve core. The jewel valve head is selected from rubies.

4. The operating method of a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster as described in claim 1, characterized in that: A groove is provided at the connection end between the Laval nozzle body and the soft magnetic material shell to install the valve seat sealing ring. The Laval nozzle body and the soft magnetic material shell are covered with a housing. The housing is fixedly connected to the soft magnetic material shell on the side near the working gas inlet to clamp the Laval nozzle body and the soft magnetic material shell. The sealing is achieved by the valve seat sealing ring.

5. The operating method of a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster as described in claim 4, characterized in that: A temperature control module is provided, which is disposed between the soft magnetic material outer shell and the housing, and is located on the circumferential outer side of the secondary gas container.

6. The operating method of a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster as described in claim 5, characterized in that: The temperature control module is equipped with a secondary gas container temperature sensor on the periphery of the connection channel. The real-time temperature is monitored by the secondary gas container temperature sensor, and the power of the temperature control module is adjusted at the same time to control the temperature of the working gas in the secondary gas container in a closed loop.

7. The operating method of a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster as described in claim 1, characterized in that: The primary gas container is equipped with a primary gas container pressure sensor, and the secondary gas container is equipped with a secondary gas container pressure sensor to measure the pressure p1 at the front end of the primary gas container and the pressure p2 at the front end of the secondary gas container, respectively, and obtain the pressure difference Δp. After determining that Δp is approximately the pressure difference on both sides of the air inlet, the theoretical approximate flow rate value is obtained by calculation, and the working parameters of the electromagnetic pulse valve are adjusted in real time to achieve closed-loop control of the flow rate.

8. The operating method of a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster as described in claim 4, characterized in that: The electromagnetic coil is wound in a coil frame outside the rear end of the soft magnetic material shell, and the outer side is restricted from dislocation by the shell. The electromagnetic coil drives the valve assembly to move towards the working gas inlet.

9. The operating method of a micro-Newton level sapphire-based dual-gas capacitive variable thrust closed-loop cold gas thruster as described in claim 8, characterized in that: The restoring elastic element is a tension spring, with one end fixed to the valve core and the other end installed at the rear end of the soft magnetic material shell. It drives the electromagnetic coil to drive the valve and overcome the elastic force of the restoring elastic element to lift it, opening the working gas outlet and connection channel, opening the gas channels of the primary gas container and the secondary gas container, closing the electromagnetic coil, and achieving a seal by tightening the valve through the tension force of the tension spring.

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