Spacecraft fluid loop pressure regulation device and method

Abstract

The application discloses a kind of fluid circuit pressure stabilizing device and method for spacecraft, pressure control front end, with spacecraft fluid circuit detachable seal connection, for releasing circuit pressure when loop pressure or pressure increasing rate exceeds set threshold value;Monitoring and energy dissipation component, downstream of pressure control front end is arranged, including cyclone multistage energy dissipation structure and state monitoring module;Cyclone multistage energy dissipation structure and state monitoring module are connected by transparent hose;Flow guide member is arranged in cyclone multistage energy dissipation structure to reduce fluid impact intensity, state monitoring module, for monitoring the state of discharge working medium;Transmission and processing unit, in communication with monitoring and energy dissipation component;Anti-reflux control component, for including sensor and control valve linkage structure, for cutting off backflow channel under abnormal working condition;Working medium absorption container is set as collection structure or absorption reaction structure according to working medium type, for realizing the closed collection or chemical treatment of discharge working medium.

Description

Technical Field

[0001] This invention relates to a fluid loop pressure stabilization device and method for spacecraft, belonging to the field of aerospace application technology. Background Technology

[0002] With the continuous improvement of spacecraft payload power levels, active thermal control technology based on fluid loops has been widely applied to spacecraft systems such as communication satellites, manned spacecraft, and deep space probes. After the spacecraft completes propellant loading, it typically undergoes a long period of ground storage and long-distance transportation. During this period, the propellant in the loop (such as ammonia, perfluorotriethylamine, etc.) undergoes thermal expansion due to ambient temperature fluctuations, leading to an increase in system pressure. Without effective pressure regulation measures, the expanded volume will cause loop overpressure, resulting in damage and leakage risks, affecting the safety and reliability of the spacecraft system.

[0003] In existing technologies, the following methods are typically used to address the pressure stabilization requirements of spacecraft fluid loops during storage and transportation: When the spacecraft is stored in a test hall, the hall temperature must be strictly controlled; when the spacecraft needs to be transported long distances to a base, the working fluid in the fluid loop system must be emptied before transportation and refilled at the base. This method of storage is highly dependent on infrastructure; when transfer is required, the operation process is complex and time-consuming, and the multiple refilling processes can easily introduce contaminants, making it difficult to guarantee the cleanliness requirements of the spacecraft fluid loop.

[0004] In summary, current technology lacks a dedicated pressure stabilizing device that can be directly connected to the spacecraft's fluid loop during the ground phase and achieve safe, controllable pressure release and working fluid containment.

[0005] In addition, if general industrial pressure relief devices are directly applied to the fluid loop of spacecraft, there are the following shortcomings: (1) Lack of status monitoring capability: Existing general pressure relief devices mainly realize the pressure release function, but cannot effectively monitor the working fluid status during the discharge process, and it is difficult to obtain the loop operation status information in a timely manner; (2) Insufficient pressure stabilization capacity: General-purpose pressure relief devices usually rely on mechanical mechanisms such as springs to control the opening and closing of valves. The pressure difference between the opening and closing of mechanical valves may lead to excessive pressure relief. The opening degree of mechanical valves cannot be actively controlled, and the pressure release process is not smooth enough, resulting in large pressure fluctuations in the fluid circuit during pressure relief. (3) Insufficient backflow prevention capability: The fluid circuit of spacecraft is extremely sensitive to external contamination, while general pressure relief devices usually only have a single-stage seal or a simple check structure. Under vibration or pressure fluctuation conditions, there is a risk that external media will backflow into the circuit, which is difficult to meet the requirements of aerospace applications for sealing reliability. (4) Lack of safe handling capability for discharged working fluids: For toxic or harmful working fluids, the common depressurization method is to directly discharge them into the environment, which does not meet the safety and environmental protection requirements of spacecraft ground operation.

[0006] Therefore, it is necessary to provide a fluid loop pressure stabilization device and method suitable for the ground storage and transportation phase of spacecraft, so as to achieve stable control of loop pressure, and take into account functions such as safe handling of working fluid, system status monitoring and backflow prevention, thereby improving the operational safety and reliability of spacecraft fluid loop under complex working conditions. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a pressure stabilizing device and method for a spacecraft fluid circuit, which plays a stabilizing role in the spacecraft fluid circuit during ground storage and transportation.

[0008] The technical solution of this invention is: This invention discloses a fluid loop pressure stabilizing device for spacecraft, comprising: a pressure regulation front end, a monitoring and energy dissipation component, and a transmission and processing unit; wherein, The pressure regulation front end is detachably and sealed to the spacecraft fluid circuit, and is used to release the circuit pressure when the circuit pressure or pressurization rate exceeds a set threshold. The monitoring and energy dissipation component is located downstream of the pressure regulation front end and includes a swirling multi-stage energy dissipation structure and a status monitoring module. The swirling multi-stage energy dissipation structure and the status monitoring module are connected by a transparent flexible tube. The swirling multi-stage energy dissipation structure is equipped with a flow guiding component to reduce the fluid impact intensity. The status monitoring module includes a filter structure and a transparent window for monitoring the status of the discharged working fluid. The transmission and processing unit is connected to the monitoring and energy dissipation component and includes an anti-backflow control component and a working fluid absorption container. The anti-backflow control component is a linkage structure including a sensor and a control valve, used to cut off the backflow channel under abnormal operating conditions. The working fluid absorption container is configured as a collection structure or an absorption reaction structure according to the working fluid type, used to achieve closed collection or chemical treatment of the emitted working fluid.

[0009] Furthermore, in the aforementioned device, the pressure regulation front end includes a quick-break device, a manual shut-off valve, an unloading valve, a proportional solenoid valve, and a control unit; wherein, the quick-break device is connected to the spacecraft fluid circuit via a double O-ring plunger sealing structure to achieve a detachable sealed connection between the device and the circuit; the unloading valve and the proportional solenoid valve are connected in parallel, and the downstream is connected to the status monitoring module; the control unit is used to control the opening of the proportional solenoid valve to release the pressure in the fluid circuit when the circuit pressure or pressurization rate exceeds a set threshold.

[0010] Furthermore, in the above-mentioned device, when the ambient temperature rises, causing the working fluid in the circuit to expand and the system pressure to exceed the set pressure of the unloading valve, the unloading valve automatically opens; after the pressure is released, the unloading valve automatically closes by relying on the reset mechanism.

[0011] Furthermore, in the aforementioned device, the discharged working fluid flows through a status monitoring module, and the filter structure is observed through a transparent window to determine whether the excess matter in the fluid circuit exceeds the standard.

[0012] Furthermore, the above-mentioned device also includes a hand valve F1; the hand valve F1 is located at the front end of the unloading valve, and when the unloading valve fails to close, the circuit is cut off by closing the hand valve F1.

[0013] Furthermore, in the above-mentioned device, all components in contact with the working fluid, including hand valves F1~F5, solenoid valve DF, liquid sensor, cleaning port, sight glass, drain port, pressure sensor, working fluid absorption tank, microporous filter module, ultrasonic transducer module, temperature sensor, and proportional solenoid valve, are made of materials compatible with perfluorotriethylamine.

[0014] Furthermore, the aforementioned device also includes manual valves F2-F5, solenoid valve DF, liquid sensor, cleaning port, sight glass, drain port, pressure sensor, ultrasonic transducer module, and temperature sensor; among which, Pressure sensors, temperature sensors, and liquid sensors are located at the top of the working fluid absorption tank; The working fluid absorption tank is equipped with a cleaning port at the top and a drain port at the bottom; The hand valve F2 is connected in series with the solenoid valve DF and is positioned downstream of the swirling multi-stage energy dissipation structure and upstream of the liquid sensor; The manual valve F3 is located between the pressure sensor and the working fluid absorption tank; Hand valve F4 is located between the cleaning port and the working fluid absorption tank; The manual valve F5 is located at the end of the drain port; The sight glass is made of transparent material and is a hollow tube. It is installed on the outside of the working fluid absorption tank, with its two ends connected to the bottom and top of the working fluid absorption tank, respectively. The ultrasonic transducer module is located at the bottom of the working fluid absorption tank, and it breaks up and accelerates the dissolution of ammonia salt precipitate through high-frequency oscillation. If the liquid sensor detects backflow of liquid in the working fluid absorption tank, it will immediately activate the solenoid valve DF to cut off the channel within milliseconds. If the solenoid valve DF fails and backflow occurs, after observing through the transparent hose, manually close the hand valve F2 to ensure circuit safety.

[0015] Furthermore, in the above-mentioned device, the temperature sensor is an insertion type and is located in the upper cavity of the working fluid absorption tank to measure the temperature of the working fluid discharged from the fluid loop into the working fluid absorption tank.

[0016] Furthermore, in the above-mentioned device, the working fluid enters the working fluid absorption tank through a transparent flexible tube via an air inlet hard pipe; the height h2 of the inlet of the air inlet hard pipe from the bottom of the tank is 5 to 10 mm, and the inlet adopts a 45° beveled form.

[0017] Furthermore, in the above-described device, the opening degree of the proportional solenoid valve is:

[0018]

[0019]

[0020] in, The weighting coefficient for the rate of change of pressure. This is the weighting coefficient for pressure deviation; Let t be the rate of pressure change inside the working fluid absorption tank at time t; The rate of pressure change inside the working fluid absorption tank; The target for controlling the rate of pressure change; (t) represents the difference between the actual pressure inside the working fluid absorption tank and the target safe pressure; The pressure inside the working fluid absorption tank at time t To regulate the target pressure, max() is used to retrieve the maximum value.

[0021] Furthermore, in the aforementioned device, when and At this time, the solenoid valve is in the closed state; when or Open the solenoid valve; when At the same time, increase the regulating frequency of the solenoid valve. ; When P(t) At that time, the solenoid valve is fully open; when and At this time, the solenoid valve changes from the open state to the closed state; At this time, increase the opening degree of the solenoid valve; in, It is the absolute value of the rate of pressure change inside the working fluid absorption tank; The rate of pressure change inside the working fluid absorption tank; The target for controlling the rate of pressure change; This is the difference between the actual pressure inside the working fluid absorption tank and the target safe pressure. The acceleration due to pressure change; For indicators that are in a rapidly changing state, the proportional solenoid valve switches to pulse mode at this time; This refers to the opening degree of the solenoid valve in pulse mode; Let t be the opening degree of the proportional solenoid valve at time t; This refers to the opening pulsation frequency of the solenoid valve. This refers to the amplitude of the solenoid valve opening pulsation. This refers to the opening pressure of the mechanical valve.

[0022] Furthermore, in the above-mentioned device, the swirling multi-stage energy dissipation structure includes a rotating guide unit, a two-stage sleeve expansion unit, a sintered copper mesh rectification unit, and a bottom outlet; wherein, The rotating guide unit is located downstream of the fluid inlet and has a set of fixed spiral guide blades inside. The spiral guide blades are arranged at equal intervals along the axial direction and the spiral angle is 30° to 50°. The two-stage sleeve expansion unit is located downstream of the rotating guide unit, and is used to cause the fluid to contract and expand multiple times during the passage process; The sintered copper mesh rectifier unit, which is a stainless steel sintered wire mesh, is located at the bottom outlet and is used to eliminate residual pulsation and optimize the outlet flow field.

[0023] Furthermore, in the above-mentioned device, the two-stage sleeve expansion unit includes two layers of throttling sleeves nested in a radial direction, with an annular flow channel formed between each sleeve; each sleeve has throttling holes evenly distributed in the circumferential direction on its cylinder wall, the throttling holes being used to cause the fluid to undergo multiple contractions and expansions during the passage process; the diameter of the throttling holes in each sleeve increases gradually along the flow direction, thereby increasing the flow area step by step.

[0024] This invention discloses a fluid loop voltage stabilization method for spacecraft, employing a fluid loop voltage stabilization device for spacecraft, comprising: Mix citric acid and water evenly in the specified ratio. Open the top cover of the absorption tank and pour in the neutralizing working medium, citric acid aqueous solution. Observe through the sight glass to ensure that there is 10-20% space left above the working medium absorption tank. Close the top cover and ensure it is sealed. The fast-break device is connected to the spacecraft's fluid circuit using a fast-break switch. The fast-break switch base is located on the spacecraft's fluid circuit side, and the fast-break switch head is located on the voltage stabilizing device side. Open hand valves F1, F2 and F3, and close hand valves F4 and F5; Start the pressure sensor, temperature sensor, liquid sensor, and ultrasonic controller; During storage or transportation, the control unit of the pressure stabilizing device automatically monitors the pressure and temperature data of the fluid circuit. When the ambient temperature rises, the working fluid in the fluid circuit expands, resulting in an increase in the working fluid pressure of the system. When the fluid circuit pressure or the rate of pressure change exceeds the threshold, the proportional solenoid valve opens, and the working fluid flows through the liquid circuit connector and along the hose into the working fluid absorption tank, where it is neutralized with the solution. When the proportional solenoid valve or unloading valve is opened, the ultrasonic module is activated to accelerate the neutralization of the ammonia working fluid and prevent precipitation. During depressurization, the liquid sensor monitors the hose status in real time; if backflow occurs, the solenoid valve DF automatically cuts off the channel within milliseconds; the manual valve F2 is manually closed as a safety redundancy to monitor the transparent hose status. By observing the observation window of the microporous filtration monitoring module, the status of foreign matter in the fluid circuit can be monitored.

[0025] Furthermore, in the above method, the quick-break head is disconnected after use; The ultrasonic transducer module is activated to break up the ammonia salt crystals generated by the reaction. Open the manual valve F5 to drain the citric acid solution through the drain port; Open the hand valve F4, connect the cleaning port to clean water, and flush the working fluid absorption tank. After reacting with any remaining ammonia, the ammonia will be discharged from the drain port. After cleaning is complete, close the manual valve F4 at the cleaning port.

[0026] Furthermore, in the above method, after closing the cleaning port manual valve F4, open the top cover of the working fluid absorption tank, continue to clean the working fluid absorption tank with clean water, and then close the drain port manual valve F5. Open the top cover of the working fluid absorption tank and clean and dry the inside; Connect the quick-break head to the vacuum pump and evacuate the voltage regulator. When the vacuum level is below 100Pa, maintain the pressure for at least 30 minutes and the vacuum level should not rise by more than 50Pa. High-purity nitrogen is used to repressurize the pressure stabilizing device. The pressure stabilizing device is at a slightly positive pressure of 0.15~0.2MPa. After disconnecting the quick-break switch, the system self-seales for future use.

[0027] The advantages of this invention over the prior art are as follows: (1) This invention achieves stable pressure control of the fluid circuit under varying ambient temperature conditions by setting up a proportional solenoid valve, a control unit, an unloading valve, and a swirling multi-stage energy dissipation structure. When parameters such as circuit pressure and pressure change rate reach the set values, the proportional solenoid valve opens, allowing the expansion of the working fluid caused by temperature changes to be released, thereby keeping the system pressure within the allowable range. The opening degree of the proportional solenoid valve can be calculated according to the actual working conditions and adjusted in real time to achieve smooth control of the fluid circuit pressure release process; the valve is accurately reset by judging the pressure change trend, significantly reducing the pressure difference between opening and closing of traditional mechanical valves; the proportional solenoid valve and the mechanical unloading valve are used in parallel and in synergy to improve the overall reliability of the system. A manual shut-off valve is set at the front end of the unloading valve. When the unloading valve malfunctions and cannot be closed, the circuit can be cut off by manual operation, improving system safety. At the same time, a swirling multi-stage energy dissipation structure is set downstream of the unloading valve. The flow diversion structure is used to divert the fluid and dissipate energy during the pressure relief process, reducing transient flow impact.

[0028] (2) This invention achieves visualization of the depressurization process and determination of the working fluid status by setting up a transparent delivery channel and monitoring structure. In the Type I configuration, the hose and working fluid collection bag are made of transparent material, allowing direct observation of the flow state during the depressurization process, thus facilitating the judgment of the system's operating status. Simultaneously, a microporous filtration monitoring module is set in the fluid path. This module consists of a filter and a transparent observation window, with the window facing the filter screen. The cleanliness level of the filter screen can be observed in real time to determine whether the discharged working fluid contains particles or impurities, thereby indirectly characterizing the cleanliness of the spacecraft's fluid circuit. Furthermore, the quick-connect device enables rapid connection and separation under liquid conditions, improving the flexibility of the device under different operating conditions; the hose and working fluid collection bag are lightweight and easy to transport with the entire satellite.

[0029] (3) This invention, targeting the Type II configuration, achieves treatment of the discharged working fluid and control of backflow risk by setting up an absorption reaction structure and multi-stage anti-backflow measures. The hose length can be adjusted according to the usage environment to adapt to different layout conditions. In terms of anti-backflow, a liquid level sensor and solenoid valve are linked. When liquid is detected passing the sensor position, the solenoid valve is controlled to close, thereby blocking the liquid from flowing towards the spacecraft fluid loop. In the case of solenoid valve failure, the flow status can be observed through the transparent hose, and the valve can be closed manually, thus forming a protection measure that combines electronic control and manual operation. In terms of working fluid neutralization reaction and anti-clogging, an ultrasonic transducer is set at the bottom of the absorption tank to enhance the contact process between the gas and the citric acid aqueous solution through cavitation, thereby increasing the reaction rate. At the same time, the vibration slows down the deposition of reaction products at the bottom of the tank and promotes the redissolution of possible precipitates. Combined with the bottom drain structure, the possibility of the discharge channel being blocked is reduced, thereby ensuring the smooth operation of the device during long-term use. Regarding structural parameters, the total height of the ammonia absorption tank is H, and the height of the upper cavity is h1, satisfying an h1 / H ratio of 10%–20% to provide gas buffer space. The height of the inlet pipe from the bottom of the tank is h2, preferably 5–10 mm, or a 45° angled opening, to enhance the dispersion of gas in the citric acid aqueous solution and improve gas-liquid mixing. The absorption tank is equipped with a pressure sensor, an insertion-type temperature sensor, and a sight glass. The temperature sensor is located in the upper gas phase space; by observing the correlation between pressure and temperature, the working state of the absorption liquid can be determined, and the reaction process and deposition can be observed using the sight glass. In terms of device layout, the pressure stabilizing device is mounted on a mobile trolley and connected to the spacecraft's fluid loop via a standard interface. It does not need to be fixed to the spacecraft body, thus avoiding space occupation and reducing risks during installation and disassembly.

[0030] (4) By adopting a double O-ring sealing structure and a standardized connection method, the present invention achieves reliable sealing and convenient operation of the device during the connection process. The double O-ring plunger sealing structure between the metal hose and the quick-break and related connecting parts meets the pressure resistance requirements while reducing the risk of leakage at the connection; at the same time, this structure facilitates the disassembly and assembly of the device and is conducive to repeated use during ground support.

[0031] (5) In view of the problem that the existing technology of spacecraft fluid loop lacks effective pressure stabilization means during ground storage and transportation, the present invention can release and treat the volume expansion of working fluid caused by changes in ambient temperature in a fully enclosed manner. While achieving stable control of system pressure, it also takes into account the stability of the pressure relief process, online monitoring of the loop status and anti-blocking treatment of reaction products, thereby improving the safety and reliability of system operation. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the high-temperature component of the present invention; Figure 2 This is a schematic diagram of the high-temperature component structure of the present invention; Figure 3 This is a cross-sectional schematic diagram of the swirling multi-stage energy dissipation structure in this invention. Detailed Implementation

[0033] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0034] This embodiment provides a fluid loop voltage regulator for spacecraft, comprising: (1) Pressure regulation front end, including quick-break device, manual shut-off valve, unloading valve, proportional solenoid valve and control unit. The quick-break device is connected to the spacecraft fluid circuit through a double O-ring plunger sealing structure to realize a detachable sealed connection between the device and the circuit. The unloading valve and the proportional solenoid valve are connected in parallel to open the pressure release channel when the circuit pressure or pressure rise rate exceeds a set threshold. The control unit is used to open the proportional solenoid valve to realize the stable release of fluid circuit pressure.

[0035] (2) Monitoring and energy dissipation components are located downstream of the unloading valve, including a swirling multi-stage energy dissipation structure and a status monitoring module. The swirling multi-stage energy dissipation structure is equipped with a flow guide component to reduce the fluid impact intensity. The status monitoring module includes a filter structure and a transparent observation window for monitoring the status of the discharged working fluid. (3) Transmission and processing unit, connected to the monitoring and energy dissipation component, including pressure-resistant conveying pipeline, anti-backflow control component and working fluid absorption container (Type I is a transparent collection bag, Type II is a neutralization absorption tank with integrated ultrasonic transducer module); wherein the anti-backflow control component includes a linkage structure of sensor and control valve, used to cut off the backflow channel under abnormal working conditions; the working fluid processing container is set as a collection structure or absorption reaction structure according to the working fluid type, used to realize closed collection or chemical treatment of the emitted working fluid.

[0036] The present invention also provides a fluid circuit pressure stabilization method based on the above-mentioned device. The control unit collects the fluid circuit pressure and temperature and calculates characteristic parameters. When the characteristic parameters exceed a set threshold, the pressure release path is opened and the discharged working fluid is introduced into a closed treatment unit for collection or absorption, thereby realizing the stable regulation of fluid circuit pressure and safe treatment of working fluid.

[0037] This invention provides a fluid loop pressure stabilizing device for spacecraft, which has two typical configuration schemes (Type I configuration and Type II configuration) according to different working fluid properties and system pressure levels, so as to achieve precise adaptation to different load loops.

[0038] (I) Type I configuration for the first type of working fluid The first type of working fluid is represented by non-toxic, harmless, and low-saturated vapor pressure working fluids such as perfluorotriethylamine. For example... Figure 1 As shown, the Type I configuration mainly includes: a quick-break head, a hand valve F1, an unloading valve, a microporous filter monitoring module, a transparent hose, and a transparent working fluid collection bag as a working fluid absorption container.

[0039] Its working principle and key technical points are as follows: 1. Connection: The pressure stabilizing device is connected to the spacecraft fluid circuit via a quick-break switch. The product is connected to the pipeline and quick-break switch via a double O-ring plunger joint, making replacement convenient.

[0040] 2. Automatic Pressure Control: When the ambient temperature rises, causing the working fluid in the loop to expand and the system pressure exceeds the set pressure of the unloading valve (preferably 90%–95% of the maximum allowable system pressure), the unloading valve automatically opens. After depressurization, the unloading valve automatically closes using a reset mechanism, ensuring no leakage in the loop system. The unloading valve has high adjustability, allowing for pressure adjustment as needed, and can be adjusted online in real time, providing a wide range of adaptability to different pressure ranges.

[0041] 3. Excess material monitoring: The discharged working fluid flows through the microporous filter monitoring module. The operator can observe the status of the filter through a transparent window to determine whether the excess material in the fluid circuit exceeds the standard.

[0042] 4. Collection: The discharged working fluid flows into the working fluid collection bag through a transparent hose. Both the hose and the collection bag are transparent to facilitate assessment of the pressure relief.

[0043] 5. Safety Redundancy: A manual valve F1 is installed at the front end of the unloading valve. If the unloading valve fails to close, F1 can be manually closed to cut off the circuit and ensure the safety of the spacecraft.

[0044] 6. System compatibility: The entire device meets the requirements for positive pressure and vacuum, and all components in contact with the working fluid are made of materials compatible with perfluorotriethylamine, ensuring the reliability of long-term storage.

[0045] (II) Type II configuration for the second type of working fluid The second type of working fluid is represented by toxic and harmful substances such as ammonia, which have a high saturated vapor pressure at room temperature. Liquid ammonia has a saturated vapor pressure of 0.86 MPa at room temperature (20°C), therefore, once leaked, it will quickly turn into ammonia gas, posing a danger. Figure 2As shown, the Type II configuration enhances the active pressure regulation, chemical neutralization, multi-stage backflow prevention, and anti-clogging functions based on the Type I configuration. It includes the following core components: quick-break head, manual valve F1, proportional solenoid valve, control unit, unloading valve, microporous filter monitoring module, transparent hose, vortex multi-stage energy dissipation structure, manual valve F2, solenoid valve DF, liquid sensor, manual valve F3, manual valve F4, manual valve F5, cleaning port, ammonia absorption tank, sight glass, drain port, pressure sensor, ultrasonic transducer module, and insertion temperature sensor.

[0046] Its structure and working principle are as follows: Preparation: Open the top cover of the ammonia absorption tank and pour in the neutralizing working fluid (such as citric acid aqueous solution). Control the liquid level to maintain the ratio of the upper gas phase cavity height h1 to the total tank height H at 10%–20%.

[0047] Active pressure control: After the system is connected, when parameters such as loop pressure and pressure change rate reach the set values, the proportional solenoid valve opens, releasing the expansion of the working fluid caused by temperature changes, thereby maintaining the system pressure within the allowable range. The opening degree of the proportional solenoid valve can be calculated according to actual operating conditions and adjusted in real time to achieve smooth control of the fluid loop pressure release process; precise valve reset is achieved by judging the pressure change trend, significantly reducing the pressure difference between opening and closing traditional mechanical valves; the proportional solenoid valve and the mechanical unloading valve are used in parallel and in synergy to improve the overall reliability of the system. The active pressure control strategy is described below.

[0048] Excess material monitoring: The discharged working fluid flows through the microporous filter monitoring module. The operator can observe the status of the filter through a transparent window to determine whether the excess material in the fluid circuit exceeds the standard.

[0049] Energy dissipation: After the working fluid exits the microporous filter monitoring module, it enters the vortex multi-stage energy dissipation structure through a flexible tube. The internal spiral flow guide structure reduces the fluid velocity, improving the stability of the device's operation. Detailed structural design of the vortex multi-stage energy dissipation structure is described below.

[0050] High-efficiency neutralization: The working fluid enters the absorption tank through a transparent flexible tube and an inlet hard pipe. The height h2 of the inlet pipe from the bottom of the tank is 5-10 mm, and the pipe opening is in a 45° bevel shape. Combined with the cavitation effect generated by the bottom-mounted ultrasonic transducer module, this significantly enhances the contact area and reaction rate between ammonia and citric acid solution.

[0051] Multi-level backflow protection: Active protection: The liquid sensor monitors the fluid in real time. Once liquid backflow is detected, it immediately activates the solenoid valve (DF) to cut off the channel within milliseconds.

[0052] Passive monitoring: If the solenoid valve fails and backflow occurs, the operator can observe it through the transparent hose and ensure circuit safety by manually closing the hand valve F2.

[0053] Replenishment of citric acid aqueous solution: The working fluid recovery tank has a pressure sensor and a temperature sensor. The temperature sensor is an insertion type and is located inside h1, that is, in the upper cavity of the working fluid absorption tank. It can measure the temperature of the working fluid discharged from the fluid loop into the working fluid absorption tank, rather than the surface temperature of the working fluid absorption tank. The advantage of this is that when the citric acid aqueous solution is saturated with ammonia, if more ammonia enters the working fluid absorption tank, it will be unable to absorb the working fluid. At this time, the pressure inside the absorption tank will increase. By judging the relationship between temperature and pressure (the temperature and pressure of ammonia gas correspond one-to-one), it can be comprehensively determined whether citric acid aqueous solution needs to be replenished.

[0054] Multiple anti-clogging features: Ammonia reacts with citric acid solution to form ammonium salts, which may precipitate. The drain outlet is located at the bottom of the tank, designed to prevent clogging. Simultaneously, an ultrasonic module at the bottom of the tank uses high-frequency oscillation to break up and accelerate the dissolution of ammonium salt precipitates, preventing channel blockage.

[0055] Mobile deployment: The entire Type II voltage stabilizer is mounted on a mobile trolley and connected to the spacecraft via a standard quick-connect interface, providing excellent ground support mobility.

[0056] Easy to clean: After use, drain the citric acid solution through the drain port, then close the drain port. Next, rinse with clean water through the cleaning port to react with any remaining ammonia and then drain it through the drain port. Then open the top cover of the absorption tank to clean and dry the inside for the next use.

[0057] System compatibility: The entire device meets the requirements for positive pressure and vacuum, and all components in contact with the working fluid are made of materials compatible with perfluorotriethylamine, ensuring the reliability of long-term storage.

[0058] Active stress control strategy I. System Architecture The pressure relief function of the fluid circuit is accomplished by two parallel branches: Electrically controlled pressure regulating branch: This branch consists of a control unit and a proportional solenoid valve. As the main control unit, it is responsible for high-precision daily pressure regulation. The control unit collects pressure sensor readings (P(t)) and temperature sensor readings (T(t)) from the fluid circuit; the control unit executes the control algorithm; and the proportional solenoid valve regulates the discharge flow rate.

[0059] Mechanical protection branch: Consists of a spring-loaded safety unloading valve. This branch serves as physical redundancy, with an opening threshold P. mech Slightly higher than the electronic control start-up threshold P elec .

[0060] Logical relationship: Under normal operating conditions, the pressure relief function of the fluid circuit system is achieved by the electrical control branch; when the system loses power or the electrical control branch fails, causing the pressure to continue to rise to P... mech At that time, the mechanical branch circuit is forcibly opened.

[0061] II. Control Methods (I) Feature Parameter Construction The control unit performs discrete sampling of the system with a sampling period (Δt) and calculates the following characteristic quantities: 1. Pressure change rate (first-order characteristic quantity)

[0062] Used to characterize trends in pressure changes.

[0063] 2. Acceleration of pressure change (second-order characteristic quantity)

[0064] Used to identify whether pressure changes are accelerated.

[0065] 3. Pressure margin

[0066] in, This is the difference between the actual pressure inside the working fluid absorption tank and the target safe pressure. To absorb the pressure inside the working fluid tank, To regulate the target pressure.

[0067] (II) Definition of Control Objectives This invention achieves proactive regulation of the system's energy release process by constraining the pressure change process, rather than simply controlling the pressure value.

[0068] Control objective:

[0069] The target for pressure change rate control is to limit the rate of pressure rise.

[0070]

[0071] The actual pressure inside the working fluid absorption tank is kept below the target safe pressure.

[0072] (III) Determining the Operating Status Based on the above characteristics, the system is divided into the following states: 1. Steady state Criterion: and

[0073] Control strategy: Proportional solenoid valve closed. 2. Pressure Rising State Criterion:

[0074] Control strategy: Open the proportional solenoid valve in advance; Controlling the opening makes the rate of pressure change tend to be

[0075] 3. Pressure exceeding the limit Criterion:

[0076] Control strategy: Open the proportional solenoid valve.

[0077] 4. Rapidly changing state Criterion:

[0078] Control strategy: The proportional solenoid valve enters pulsating mode; small-amplitude dynamic adjustment is introduced to avoid the flow coupling amplification effect caused by continuous release.

[0079] ; in This refers to the opening degree of a proportional solenoid valve when it enters pulsating mode under rapidly changing conditions. This refers to the opening pulsation frequency of the solenoid valve. This refers to the amplitude of the solenoid valve opening pulsation. This refers to the opening degree of the proportional solenoid valve in other conventional modes.

[0080] This control strategy is based on the conventional feedback opening calculated from the pressure deviation. Above, superimposed high-frequency pulses By utilizing the pulsation of the solenoid valve opening to physically discretize and cut the continuous fluid, the energy feedback closed loop is disrupted, reducing the flow coupling amplification effect caused by continuous discharge. 5. Overpressure protection status Criterion: P(t)

[0081] Control strategy: Solenoid valve fully open; mechanical valve intervention for protection.

[0082] (iv) Valve opening calculation Electromagnetic regulating valve opening Determined by the following function:

[0083] in: The weighting coefficient for the rate of change of pressure. This is the weighting coefficient for pressure deviation; The rate of pressure change inside the working fluid absorption tank; The target for controlling the rate of pressure change; This is the difference between the actual pressure inside the working fluid absorption tank and the target safe pressure.

[0084] Physical meaning: The faster the pressure rises in the fluid circuit, the higher the pressure, and the greater the opening degree of the proportional solenoid valve.

[0085] (v) Solenoid valve closing conditions and

[0086] Control logic: If the fluid loop pressure is already below the target pressure but is still rising ( If the pressure is >0, the solenoid valve will not close; if the pressure drops below the target pressure and the trend stabilizes, the valve will close. This control logic avoids repeated opening and closing caused by pressure inertia, and also solves the problem of a large difference between the opening pressure and the reset pressure of a mechanical pressure relief valve, which is beneficial for stable control of the fluid circuit pressure.

[0087] (vi) Anomaly Identification and Protection If both conditions are met:

[0088] If the valve is open but the pressure continues to rise rapidly, it is considered an abnormal condition.

[0089] Corrective action: Further increase the valve opening.

[0090] Swirl multi-stage energy dissipation structure Figure 3 This is a cross-sectional schematic diagram of the swirling multi-stage energy dissipation structure in this invention. Fluid flows in from the top inlet and sequentially passes through the rotating guide unit, the two-stage sleeve expansion unit, the sintered copper mesh rectification unit, and the bottom outlet. The installation direction of the swirling multi-stage energy dissipation structure does not affect its performance.

[0091] 1. Rotary flow guide unit (first-stage energy dissipation) The rotating guide unit is located downstream of the fluid inlet and contains a set of fixed helical guide vanes. The helical guide vanes are arranged at equal intervals along the axial direction, and their helix angle is 30° to 60°.

[0092] After the high-pressure fluid enters the unit, it is transformed from axial flow to a helical flow with a rotational component by the action of the guide vanes. This design significantly lengthens the flow path of the fluid within a unit space, increases the contact and friction between the fluid and the guide vanes and the inner wall of the casing, and achieves the initial dissipation of the fluid's kinetic energy.

[0093] 2. Two-stage sleeve expansion unit (two-stage energy dissipation) Downstream of the rotating guide unit, a two-stage sleeve expansion unit is provided, which is the core energy dissipation structure of this invention. This unit includes two layers of radially nested throttling sleeves, forming an annular flow channel between each sleeve. Each sleeve has throttling orifices uniformly distributed circumferentially on its wall, which cause the fluid to undergo multiple contractions and expansions during its passage. Furthermore, the throttling orifice parameters of each sleeve layer vary gradually along the flow direction, resulting in a progressively larger flow area to accommodate the volume expansion of the working fluid during decompression. Through this structure, the fluid repeatedly undergoes throttling, expansion, and redistribution processes between the two sleeves, thereby achieving a progressive reduction in pressure and the dispersion and dissipation of energy.

[0094] 3. Sintered copper mesh rectifier unit (three-stage energy dissipation) A sintered copper mesh rectifying unit is installed at the final outlet of the energy dissipation assembly to eliminate residual pulsations and optimize the outlet flow field. The main structure of this unit is a sintered stainless steel wire mesh. The sintered stainless steel wire mesh has a large porosity and good structural strength. When the working fluid passes through the sintered wire mesh, it is refined into countless tiny flow streams. Due to the intense viscous friction within the micropores, the fluid is ultimately integrated into a stable laminar flow state before being discharged. This structure can eliminate pressure pulsations caused by uneven flow patterns and reduce the risk of vibration fatigue in downstream pipelines.

[0095] Protection point The voltage stabilizing device is divided into Class I and Class II configurations according to different working fluids, which can cover the current operating conditions of the fluid circuit of spacecraft; The unloading valve is highly adjustable, allowing for pressure adjustment as needed, and can be adjusted online in real time. It has a wide range of adaptability to pressure ranges. The product is connected to pipelines and quick-break devices via double O-ring plunger joints, making replacement convenient. There is a manual valve before the unloading valve. If the unloading valve malfunctions and cannot close automatically, it can be closed manually. After the unloading valve, there is a microporous filter monitoring module. The operator can observe the status of the filter through a transparent window to determine whether the excess material in the fluid circuit exceeds the standard. All hoses are transparent, which facilitates the assessment of pressure relief. In addition, in case of backflow, it can be observed and the manual valve can be closed immediately. The unloading pressure of the unloading valve is 90% to 95% of the maximum allowable pressure of the system, that is, a margin of 5% to 10%. For the Type II pressure stabilizing device, the height of the working fluid absorption tank is H, the cavity height is h1, and the height of the rigid pipe from the bottom is h2, where (h1 / H1) is 10%~20%, meaning a 10~20% space should be reserved; while h2 = 5~10mm, or the bottom pipe opening is at a 45° bevel. This facilitates the mixing of ammonia and citric acid aqueous solution, and also the mixing of precipitates. (This is used to remove citric acid aqueous solution.) For the Type II pressure stabilizing device, the backflow prevention design includes: ① Solenoid valve: After the liquid level sensor detects the liquid level, it sends a signal to the solenoid valve, which then shuts off to prevent the citric acid solution from flowing into the backflow prevention tank. It should be noted that when the liquid level sensor detects the liquid passing by, the solenoid valve closes within milliseconds, ensuring that the liquid closes before reaching the solenoid valve, thus preventing the citric acid solution from flowing into the backflow prevention tank along the transparent hose. ② If the solenoid valve fails, backflow will occur, and the transparent hose will be visible. Manual closure will ensure circuit safety.

[0096] For the Type II pressure stabilizing device, a proportional solenoid valve and an unloading valve are connected in parallel to control the fluid circuit pressure. The control unit acquires the pressure and temperature information of the fluid circuit, then calculates the pressure change rate and pressure change acceleration, and simultaneously calculates the corresponding saturation pressure based on the temperature and constructs a relative pressure margin. The control unit determines the system operating status based on the pressure change rate and the relative pressure margin. When the pressure change rate exceeds a set threshold, it controls the opening of the solenoid regulating valve to limit the pressure change rate, achieving smooth control of the fluid circuit pressure release process; precise valve reset is achieved by judging the pressure change trend, significantly reducing the pressure difference between opening and closing traditional mechanical valves. The parallel mechanical unloading valve acts as a backup to improve the stability of the fluid circuit.

[0097] For the Type II pressure stabilizing device, the circuit is equipped with a multi-stage swirling energy dissipation structure, which converts the fluid pressure potential energy into rotational kinetic energy through a rotating guide unit and performs primary energy dissipation. A two-stage sleeve expansion unit is used to achieve a secondary gradient release of fluid pressure. A sintered copper mesh rectifier unit is used to eliminate residual pressure pulsations, increase fluid viscous friction, and integrate the fluid into a stable laminar flow state for discharge.

[0098] For the Type II pressure stabilizing device, the bottom of the storage tank is equipped with an ultrasonic transducer module, which enhances the contact process between the gas and the citric acid aqueous solution through cavitation, thereby increasing the reaction rate. At the same time, the vibration slows down the deposition of reaction products at the bottom of the tank and promotes the redissolution of possible precipitates. Combined with the bottom drain structure, it reduces the possibility of the discharge channel being blocked, thus ensuring the smooth operation of the device during long-term use.

[0099] For the Type II pressure stabilizing device, the working fluid recovery tank has a pressure sensor and a temperature sensor. The temperature sensor is an insertion type and is located inside h1, that is, in the upper cavity of the working fluid absorption tank. It can measure the temperature of the working fluid discharged from the fluid loop into the working fluid absorption tank, rather than the surface temperature of the working fluid absorption tank. The advantage of this is that when the citric acid aqueous solution is saturated with ammonia, if more ammonia enters the working fluid absorption tank, the ammonia gas will diffuse in the h1 cavity, and the working fluid can no longer be absorbed. At this time, the pressure in the absorption tank will increase. By judging the relationship between temperature and pressure (the temperature and pressure of ammonia gas correspond one-to-one), it can be comprehensively determined whether citric acid aqueous solution needs to be added.

[0100] For the Type II pressure stabilizing device, the working fluid absorption tank is equipped with a sight glass, which can be used to observe the liquid level, the reaction between ammonia and citric acid aqueous solution, and whether any reaction deposits are produced, so as to take relevant measures. For the Type II pressure stabilizing device, the working fluid absorption tank has a cleaning port at the top, an openable cover, and a drain port at the bottom: the cleaning port is used to remove any residual ammonia gas in the absorption tank, the drain port is at the bottom of the tank, and the open cover allows for further cleaning of the absorption tank and facilitates the filling of the reaction neutralization liquid. The pressure stabilizing device uses a metal hose and is equipped with a quick-break device. The length of the metal hose can be adjusted according to the environment where the spacecraft is located, and the quick-break device can enable the rapid insertion and removal of the pipeline in the presence of liquid. Therefore, it has strong adaptability and high efficiency. The metal hose of the pressure stabilizing device is double-sealed with the quick-break and the expansion valve by double O-rings, which not only meets the pressure resistance requirements, but also facilitates disassembly and assembly. The voltage regulator does not need to be fixed to the spacecraft mounting plate. It can be connected to the inlet and outlet of the onboard fluid loop through a standard connector. Therefore, it does not occupy valuable space on the spacecraft and will not increase the risk of damaging the spacecraft due to the disassembly process.

[0101] Working principle The pressure stabilizing device is connected to the spacecraft's fluid loop via a quick-break device. When the ambient temperature rises, causing the working fluid in the loop to expand, or the system pressure or rate of pressure change to exceed a set threshold, the unloading valve or proportional solenoid valve automatically opens. The working fluid first passes through a monitoring and energy dissipation component, where the microporous filter monitoring module can monitor the content of excess substances in the fluid loop in real time. It then enters a swirling multi-stage energy dissipation structure to smooth out flow impacts. Subsequently, the working fluid flows along a transparent hose into the working fluid absorption tank (taking the Type II configuration as an example), and then penetrates below the liquid surface of the ammonia absorption tank via a 45-degree angled inlet pipe. With the assistance of an ultrasonic transducer module at the bottom of the tank, ammonia and citric acid aqueous solution undergo a highly efficient neutralization reaction. This reduces the system pressure to the normal range, and the unloading valve automatically closes, ensuring pressure relief without leakage and maintaining system pressure stability.

[0102] How to use 1) Mix citric acid and water in a certain proportion, open the top cover of the absorption tank, pour in the neutralizing working medium citric acid aqueous solution, and observe through the sight glass to ensure that (h1 / H1) is 10%~20%, that is, leave 10~20% space above the absorption tank. Then close the top cover and ensure good sealing. 2) Push the pressure stabilizing device trolley to the designated position, and use the quick-connect switch to connect the device to the spacecraft fluid circuit according to the attached... Figure 2 The components are connected in a manner such that the spacecraft fluid circuit side has a fast-break seat and the voltage regulator side has a fast-break head. 3) Open F1, F2, and F3 to ensure that the pressure relief and absorption passages are unobstructed; close the cleaning port valve F4 and the drain port valve F5 to ensure that the system is closed.

[0103] 4) Start the pressure sensor, temperature sensor, liquid sensor, and ultrasonic controller. Check that all readings are normal. Note: The sensors can be powered by built-in batteries to improve portability.

[0104] 5) During storage or transportation, the control unit automatically monitors the pressure and temperature data of the fluid circuit. When the ambient temperature rises, the working fluid in the fluid circuit expands, causing the working fluid pressure in the system to increase. When the fluid circuit pressure or the rate of pressure change exceeds the threshold, the proportional solenoid valve opens, and the working fluid flows through the liquid circuit connector and along the hose into the working fluid absorption tank, where it is neutralized with the solution. 6) After the proportional solenoid valve or unloading valve is opened, the ultrasonic module will automatically start briefly to accelerate the neutralization of ammonia working fluid and prevent precipitation. 7) During depressurization, the liquid sensor monitors the hose status in real time. If backflow occurs, the system will automatically shut off the flow within milliseconds using the solenoid valve DF; operators can also manually close F2 as a safety redundancy based on the transparent hose status. 8) Operators can observe the observation window of the microporous filter monitoring module at any time to monitor the amount of foreign matter in the fluid circuit; 9) After use, disconnect the quick-break head. Due to the quick-break self-sealing structure, it can be ensured that there is no leakage of working fluid during the disassembly process.

[0105] 10) Activate the ultrasonic transducer module to break up the ammonia salt crystals generated by the reaction. Turn on F5 to drain the citric acid solution through the drain port; 11) Open the hand valve F4, connect the cleaning port to clean water, and rinse the working fluid absorption tank. After reacting with any remaining ammonia, the ammonia will be discharged from the drain port. This will ensure that there is no ammonia in the working fluid absorption tank when you open the top cover in the next step. 12) After cleaning, close the manual valve F4 at the cleaning port; 13) After that, open the top cover and continue to rinse the working fluid absorption tank with clean water. Then, open the drain valve F5. 14) Dry thoroughly before next use; 15) Then open the top cover of the absorption tank and clean and dry the inside; 16) Connect the quick-break head to the vacuum pump and evacuate the system. When the vacuum degree is below 100Pa, hold the pressure for 30 minutes. If the vacuum degree rises by no more than 50Pa, the seal is considered qualified. It should be noted that the vacuum gauge can be installed on the voltage stabilizing device or the reading can be obtained through the vacuum gauge on the vacuum pump. 17) Pressurize the system with high-purity nitrogen to a slightly positive pressure of 0.15~0.2MPa, disconnect the quick-break switch, and the system will self-seal for future use.

[0106] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

[0107] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A fluid loop voltage regulator for spacecraft, characterized in that, include: Pressure regulation front end, monitoring and energy dissipation components, transmission and processing unit; among which, The pressure regulation front end is detachably and sealed to the spacecraft fluid circuit, and is used to release the circuit pressure when the circuit pressure or pressurization rate exceeds a set threshold. The monitoring and energy dissipation component is located downstream of the pressure regulation front end and includes a swirling multi-stage energy dissipation structure and a status monitoring module. The swirling multi-stage energy dissipation structure and the status monitoring module are connected by a transparent flexible tube. The swirling multi-stage energy dissipation structure is equipped with a flow guiding component to reduce the fluid impact intensity. The status monitoring module includes a filter structure and a transparent window for monitoring the status of the discharged working fluid. The transmission and processing unit is connected to the monitoring and energy dissipation component and includes an anti-backflow control component and a working fluid absorption container. The anti-backflow control component is a linkage structure including a sensor and a control valve, used to cut off the backflow channel under abnormal operating conditions. The working fluid absorption container is configured as a collection structure or an absorption reaction structure according to the working fluid type, used to achieve closed collection or chemical treatment of the emitted working fluid.

2. The spacecraft fluid loop voltage regulator according to claim 1, characterized in that: The pressure regulation front end includes a quick-break device, a manual shut-off valve, an unloading valve, a proportional solenoid valve, and a control unit. The quick-break device is connected to the spacecraft fluid circuit via a double O-ring plunger sealing structure to achieve a detachable sealed connection between the device and the circuit. The unloading valve and the proportional solenoid valve are connected in parallel and downstream to the status monitoring module. The control unit is used to control the opening of the proportional solenoid valve to release the pressure in the fluid circuit when the circuit pressure or pressurization rate exceeds a set threshold.

3. The spacecraft fluid loop voltage regulator according to claim 2, characterized in that: When the ambient temperature rises, causing the working fluid in the circuit to expand and the system pressure to exceed the set pressure of the unloading valve, the unloading valve will automatically open; after the pressure is released, the unloading valve will automatically close by relying on the reset mechanism.

4. The spacecraft fluid loop voltage regulator according to claim 1, characterized in that: The discharged working fluid flows through the status monitoring module, and the filter structure is observed through a transparent window to determine whether the excess matter in the fluid circuit exceeds the standard.

5. A fluid loop voltage regulator for spacecraft according to claim 1, characterized in that: It also includes a hand valve F1; the hand valve F1 is located at the front end of the unloading valve, and the circuit is cut off by closing the hand valve F1 when the unloading valve fails to close.

6. The spacecraft fluid loop voltage regulator according to claim 1, characterized in that: All components that come into contact with the working fluid, including hand valves F1~F5, solenoid valve DF, liquid sensor, cleaning port, sight glass, drain port, pressure sensor, working fluid absorption tank, microporous filter module, ultrasonic transducer module, temperature sensor, and proportional solenoid valve, are made of materials compatible with perfluorotriethylamine.

7. A fluid loop voltage regulator for spacecraft according to claim 1, characterized in that, It also includes manual valves F2~F5, solenoid valve DF, liquid sensor, cleaning port, sight glass, drain port, pressure sensor, ultrasonic transducer module, and temperature sensor; among which, Pressure sensors, temperature sensors, and liquid sensors are located at the top of the working fluid absorption tank; The working fluid absorption tank is equipped with a cleaning port at the top and a drain port at the bottom; The hand valve F2 is connected in series with the solenoid valve DF and is positioned downstream of the swirling multi-stage energy dissipation structure and upstream of the liquid sensor; The manual valve F3 is located between the pressure sensor and the working fluid absorption tank; Hand valve F4 is located between the cleaning port and the working fluid absorption tank; The manual valve F5 is located at the end of the drain port; The sight glass is made of transparent material and is a hollow tube. It is installed on the outside of the working fluid absorption tank, with its two ends connected to the bottom and top of the working fluid absorption tank, respectively. The ultrasonic transducer module is located at the bottom of the working fluid absorption tank, and it breaks up and accelerates the dissolution of ammonia salt precipitate through high-frequency oscillation. If the liquid sensor detects backflow of liquid in the working fluid absorption tank, it will immediately activate the solenoid valve DF to cut off the channel within milliseconds. If the solenoid valve DF fails and backflow occurs, after observing through the transparent hose, manually close the hand valve F2 to ensure circuit safety.

8. A fluid loop voltage regulator for spacecraft according to claim 7, characterized in that: The temperature sensor is an insertion type and is located in the upper cavity of the working fluid absorption tank to measure the temperature of the working fluid discharged from the fluid loop into the working fluid absorption tank.

9. A fluid loop voltage regulator for spacecraft according to claim 7, characterized in that: The working fluid enters the working fluid absorption tank through a transparent flexible tube and an air inlet hard pipe; the height h2 of the inlet of the air inlet hard pipe from the bottom of the tank is 5 to 10 mm, and the inlet is in the form of a 45° bevel.

10. A fluid loop voltage regulator for spacecraft according to claim 2, characterized in that: The opening degree of the proportional solenoid valve is: in, The weighting coefficient for the rate of change of pressure. This is the weighting coefficient for pressure deviation; Let t be the rate of pressure change inside the working fluid absorption tank at time t; The rate of pressure change inside the working fluid absorption tank; The target for controlling the rate of pressure change; (t) represents the difference between the actual pressure inside the working fluid absorption tank and the target safe pressure; The pressure inside the working fluid absorption tank at time t To regulate the target pressure, max() is used to retrieve the maximum value.

11. A fluid loop voltage regulator for spacecraft according to claim 7, characterized in that: when and At this time, the solenoid valve is in the closed state; when or Open the solenoid valve; when At the same time, increase the regulating frequency of the solenoid valve. ; When P(t) At that time, the solenoid valve is fully open; when and At this time, the solenoid valve changes from the open state to the closed state; At this time, increase the opening degree of the solenoid valve; in, It is the absolute value of the rate of pressure change inside the working fluid absorption tank; The rate of pressure change inside the working fluid absorption tank; The target for controlling the rate of pressure change; This is the difference between the actual pressure inside the working fluid absorption tank and the target safe pressure. The acceleration due to pressure change; For indicators that are in a rapidly changing state, the proportional solenoid valve switches to pulse mode at this time; This refers to the opening degree of the solenoid valve in pulse mode; Let t be the opening degree of the proportional solenoid valve at time t; This refers to the opening pulsation frequency of the solenoid valve. This refers to the amplitude of the solenoid valve opening pulsation. This refers to the opening pressure of the mechanical valve.

12. A fluid loop voltage regulator for spacecraft according to claim 1, characterized in that: The swirling multi-stage energy dissipation structure includes a rotating guide unit, a two-stage sleeve expansion unit, a sintered copper mesh rectification unit, and a bottom outlet; wherein... The rotating guide unit is located downstream of the fluid inlet and has a set of fixed spiral guide blades inside. The spiral guide blades are arranged at equal intervals along the axial direction and the spiral angle is 30° to 50°. The two-stage sleeve expansion unit is located downstream of the rotating guide unit, and is used to cause the fluid to contract and expand multiple times during the passage process; The sintered copper mesh rectifier unit, which is a stainless steel sintered wire mesh, is located at the bottom outlet and is used to eliminate residual pulsation and optimize the outlet flow field.

13. A fluid loop voltage regulator for spacecraft according to claim 12, characterized in that: The two-stage sleeve expansion unit includes two layers of throttling sleeves nested in a radial direction, with an annular flow channel formed between each sleeve. Each sleeve has throttling holes evenly distributed circumferentially on its wall. These throttling holes are used to cause the fluid to contract and expand multiple times during its passage. The diameter of the throttling holes in each sleeve increases gradually along the flow direction, thereby increasing the flow area step by step.

14. A fluid loop voltage stabilization method for spacecraft, characterized in that: A spacecraft fluid loop voltage regulator as described in any one of claims 1 to 13, comprising: Mix citric acid and water evenly in the specified ratio. Open the top cover of the absorption tank and pour in the neutralizing citric acid solution. Observe through the sight glass to ensure that there is 10-20% space left above the absorption tank. Close the top cover and ensure it is sealed. The fast-break device is connected to the spacecraft's fluid circuit using a fast-break switch. The fast-break switch base is located on the spacecraft's fluid circuit side, and the fast-break switch head is located on the voltage stabilizing device side. Open hand valves F1, F2 and F3, and close hand valves F4 and F5; Start the pressure sensor, temperature sensor, liquid sensor, and ultrasonic controller; During storage or transportation, the control unit of the pressure stabilizing device automatically monitors the pressure and temperature data of the fluid circuit. When the ambient temperature rises, the working fluid in the fluid circuit expands, resulting in an increase in the working fluid pressure of the system. When the fluid circuit pressure or the rate of pressure change exceeds the threshold, the proportional solenoid valve opens, and the working fluid flows through the liquid circuit connector and along the hose into the working fluid absorption tank, where it is neutralized with the solution. When the proportional solenoid valve or unloading valve is opened, the ultrasonic module is activated to accelerate the neutralization of the ammonia working fluid and prevent precipitation. During depressurization, the liquid sensor monitors the hose status in real time; if backflow occurs, the solenoid valve DF automatically cuts off the channel within milliseconds; the manual valve F2 is manually closed as a safety redundancy to monitor the transparent hose status. By observing the observation window of the microporous filtration monitoring module, the status of foreign matter in the fluid circuit can be monitored.

15. A fluid loop voltage stabilization method for spacecraft according to claim 14, characterized in that: After use, disconnect the quick-break head; The ultrasonic transducer module is activated to break up the ammonia salt crystals generated by the reaction. Open the manual valve F5 to drain the citric acid solution through the drain port; Open the hand valve F4, connect the cleaning port to clean water, and flush the working fluid absorption tank. After reacting with any remaining ammonia, the ammonia will be discharged from the drain port. After cleaning is complete, close the manual valve F4 at the cleaning port.

16. A fluid loop voltage stabilization method for spacecraft according to claim 15, characterized in that: After closing the cleaning port manual valve F4, open the top cover of the working fluid absorption tank and continue to clean the working fluid absorption tank with clean water. Then close the drain port manual valve F5. Open the top cover of the working fluid absorption tank and clean and dry the inside; Connect the quick-break head to the vacuum pump and evacuate the voltage regulator. When the vacuum level is below 100Pa, maintain the pressure for at least 30 minutes and the vacuum level should not rise by more than 50Pa. High-purity nitrogen is used to repressurize the pressure stabilizing device. The pressure stabilizing device is at a slightly positive pressure of 0.15~0.2MPa. After disconnecting the quick-break switch, the system self-seales for future use.

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