Cross-flow-state air pressure controllable environment simulation system and regulation and control method

Abstract

The invention discloses a cross-flow-state air pressure controllable environment simulation system and a regulation and control method, and the environment simulation system integrates an environment simulation cabin, a multi-pipeline air inlet system, a cross-flow-state hierarchical control system, a pressure measurement unit and various vacuum pump units. According to the air exhaust characteristics of various vacuum pump units, a multi-pipeline air inlet system provides an accurate regulation and control scheme of air inlet flow required by coarse vacuum, low vacuum and high vacuum pressure set points, a PID self-diagnosis system built by a cross-flow-state hierarchical control system and a high-precision pressure sensor of a pressure measurement unit realize continuous adjustment of full-flow-state pressure. According to the regulation and control method, continuous and controllable wide-range pressure from coarse vacuum to high vacuum is achieved through single equipment, environment gas components are accurately configured, a multi-flow-state pressure stabilization scheme is constructed based on a hierarchical regulation and control scheme and a PID self-diagnosis technology, and limitation of a single flow state is broken through; and a precise regulation and control scheme is provided for the research and development of a wide-range and high-precision environment simulation system in the engineering field.

Description

Technical Field

[0001] The present invention belongs to the technical field of planetary and space environment simulation. Specifically, the present invention relates to a cross-flow state air pressure controllable environment simulation system and a control method, which are used to simulate the gas environment on the surface of a planet and are suitable for tasks such as simulating detector component testing, vacuum testing of spacecraft and related instruments and equipment, and performance verification of equipment on the Earth's plateau. Background Art

[0002] Due to the rapid development of aerospace, military industry, and geological plateau equipment, the demand for environmental simulation systems in my country is increasing. However, in order to meet these conditions, traditional solutions usually require the preparation of specialized test equipment for each environment. These devices are expensive, have a narrow controllable range of air pressure, occupy a large area, and are equipped with complex control equipment, thereby increasing the total cost of environmental simulation.

[0003] Patent document CN107290296A discloses a "Mars Environment Simulation Experimental Apparatus and Method." The patent design includes a vacuum chamber, vacuum control unit, humidity control unit, temperature control unit, pressure control unit, ultraviolet radiation source, and electric field control unit, capable of simulating various parameters of the Martian surface environment. However, the device is designed only for the Martian environment (600Pa-1000Pa), with a narrow controllable pressure range. It cannot simulate pressure simulation experiments in the transition phase from low vacuum to high vacuum, or from rough vacuum to low vacuum, and therefore cannot meet the pressure control requirements of high and rough vacuum environments.

[0004] Patent document CN101008651A discloses a "Large-Scale Comprehensive Environmental Simulation Test Device." This patent incorporates a high-temperature chamber, a thermobaric chamber, an air refrigeration system, a vacuum system, a rapid-transfer railcar, and a remote measurement and control system. It simulates various environments, including atmospheric and low-temperature, atmospheric and high-temperature, intermediate pressure, temperature-altitude, and temperature shock. The pressure regulation range is from atmospheric to intermediate pressure, but it doesn't address low- and high-vacuum environment simulation requirements. This means it can't meet the pressure and high-vacuum requirements of Mars and lunar exploration equipment. Furthermore, the device occupies a large area and has high maintenance costs.

[0005] It can be seen from this that the current air pressure control range of environmental simulation test equipment needs to be expanded from rough vacuum to high vacuum flow state, reducing the number of equipment, avoiding the purchase of multiple devices to increase experimental costs and reduce the overall efficiency of the test. Therefore, environmental simulation equipment needs to transition from single-environment dedicated equipment to multi-flow state air pressure continuously controllable environmental simulation system, so that professionals can efficiently complete the environmental testing requirements of precise configuration of multiple gases and continuous control of air pressure from one system, improve test efficiency and reduce test costs. Summary of the Invention

[0006] In response to the problems in the existing technology that multiple professional equipment is required to simulate different environmental conditions, resulting in high cost, large space, complex operation, and a narrow controllable range of air pressure that cannot meet the needs of cross-flow pressure testing, the main purpose of the present invention is to provide a cross-flow air pressure controllable environment simulation system to achieve accurate and continuous control of cross-flow air pressure and precise supply of high-purity gas or mixed gas, thereby reducing equipment cost and space cost, improving equipment utilization, and expanding the scope of use of the environmental simulation system.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A cross-flow regime pressure-controlled environment simulation system is provided. Its features include an environmental simulation chamber, a multi-pipeline air intake system, a cross-flow regime graded control system, a pressure measurement unit, and various vacuum pump units. The multi-pipeline air intake system includes a first gas cylinder, a second gas cylinder, a third gas cylinder, a first solenoid valve, a second solenoid valve, a third solenoid valve, a first pressure regulator, a second pressure regulator, a third pressure regulator, a fourth pressure regulator, a fifth pressure regulator, an electric needle valve, a first electric regulating valve, a first mass flow controller, a second mass flow controller, and a third mass flow controller. This system provides precise control of the air intake flow required for the rough, low, and high vacuum pressure set points in the test space. The cross-flow regime graded control system includes a first control loop, a second control loop, and a third control loop. The pressure measurement unit includes a high-precision cold cathode ionization vacuum gauge, a thermal conductivity vacuum gauge, and a diaphragm vacuum gauge. The various vacuum pump units include a negative pressure evacuation vacuum pump unit and a pressure maintenance vacuum pump unit.

[0009] Furthermore, the multi-pipeline air intake system, integrated with the multi-channel flow control module, can be used to provide a precise control scheme for the air intake flow required for the rough vacuum, low vacuum, and high vacuum pressure set points for the environmental simulation chamber.

[0010] Furthermore, the cross-flow state hierarchical control system is equipped with a PID self-diagnosis system to achieve continuous control of the pressure of the environmental simulation chamber under various flow states.

[0011] Furthermore, the pressure measuring unit includes: a high-precision cold cathode ionization vacuum gauge, a thermal conductivity vacuum gauge and a thin film vacuum gauge, which are used to measure the vacuum degree of the environmental simulation chamber and convert electrical signals into corresponding PID controllers to regulate the intake or exhaust flow.

[0012] Furthermore, the various types of vacuum pump units include: low vacuum pressure maintaining pumping units, high vacuum pressure maintaining pumping units and rough vacuum pressure maintaining pumping units, which are respectively used to provide stable and controllable pumping flow within the corresponding vacuum pressure range and to create a clean, oil-free high vacuum environment and a negative pressure pumping vacuum pump unit for timely removing impurity gases.

[0013] Furthermore, the environmental simulation chamber retains a quick-release flange connector to which a high-precision thermometer and hygrometer can be externally connected for measuring the temperature and humidity in the environmental simulation chamber.

[0014] In order to achieve the above object, the present invention also provides a method for simulating and controlling a high vacuum pressure maintenance environment. Using the above environmental simulation system, the specific steps of the high vacuum pressure maintenance control method are as follows:

[0015] Check the environmental simulation system and debug it to normal working condition;

[0016] Start the negative pressure vacuum pump unit to pump the pressure of the environmental simulation chamber to a high vacuum environment;

[0017] Configure the required simulated gas cylinders according to the required gas environment;

[0018] Connect the simulated gas to the multi-line air inlet system, start the fourth and fifth pressure regulators, and quickly inject the configured gas through the second and third mass flow controllers to make the gas pressure in the environmental simulation chamber reach the stable pressure setting target pressure value from the high vacuum condition;

[0019] Start the cryopump, the second Roots vacuum pump, and the first oil-free rotary vane pump, start the second control loop, control the electric needle valve according to the target air pressure set by the first PID controller, and adjust the air intake flow rate so that the gas pressure in the environmental simulation chamber reaches the set working pressure;

[0020] Environmental simulation of atmosphere components and pressure simulation is completed.

[0021] In order to achieve the above object, the present invention also provides a method for simulating and controlling a low vacuum pressure maintenance environment. Using the above environmental simulation system, the specific steps of the low vacuum pressure maintenance control method are as follows:

[0022] Check the environmental simulation system and debug it to normal working condition;

[0023] Start the negative pressure vacuum pump unit to pump the pressure of the environmental simulation chamber to a high vacuum environment;

[0024] Configure the required simulated gas cylinders according to the required gas environment;

[0025] Connect the simulated gas to the multi-line air inlet system, start the fourth and fifth pressure regulators, and quickly inject the configured gas through the second and third mass flow controllers to make the pressure of the environmental simulation chamber reach the target pressure value set by the stable pressure from the high vacuum condition;

[0026] Start the first Roots vacuum pump, start the third control loop, control the first electric regulating valve according to the target air pressure set by the third PID controller, and adjust the air extraction flow rate so that the air pressure in the environmental simulation chamber reaches the set working pressure;

[0027] Environmental simulation of atmosphere components and pressure simulation is completed.

[0028] In order to achieve the above object, the present invention also provides a method for simulating and controlling the environment for maintaining rough vacuum pressure. Using the above environmental simulation experimental system, the specific steps of the method for maintaining rough vacuum pressure are as follows:

[0029] Check the environmental simulation system and debug it to normal working condition;

[0030] Start the negative pressure vacuum pump unit to pump the pressure of the environmental simulation chamber to a high vacuum environment;

[0031] Prepare the required simulated gas cylinder according to the required gas environment, connect the simulated gas to the multi-pipeline gas inlet system, start the fourth pressure regulator and the fifth pressure regulator, and quickly inject the configured gas through the second mass flow controller and the third mass flow controller to make the gas pressure in the environmental simulation chamber reach the target pressure value set from the high vacuum condition to the stable pressure;

[0032] Start the variable frequency screw vacuum pump, start the first control loop, control the first electric regulating valve according to the target air pressure set by the second PID controller, and adjust the air extraction flow rate so that the gas pressure in the environmental simulation chamber reaches the set working pressure;

[0033] Environmental simulation of atmosphere components and pressure simulation is completed.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] (1) The environmental simulation system provided by the present invention is equipped with a negative pressure vacuum pump unit, which can quickly make the environmental simulation chamber reach a vacuum degree of 10 -5 The high vacuum environment of Pa can quickly and timely remove the impurity gases originally remaining in the environmental simulation cabin.

[0036] (2) The environmental simulation system provided by the present invention is equipped with a low vacuum pressure maintaining pumping unit, a high vacuum pressure maintaining pumping unit and a rough vacuum pressure maintaining pumping unit, which refine the air pressure range into high vacuum, low vacuum and rough vacuum. The three types of pressure maintaining units are used to match the corresponding flow characteristics respectively. Different from the limitation of the traditional single pressure maintaining unit that is difficult to take into account the full flow state, the dedicated pressure maintaining unit maximizes the operating efficiency under the corresponding flow state and reduces invalid power consumption, thereby effectively improving the accuracy, efficiency and stability of pressure control under the full flow state.

[0037] (3) The environmental simulation system provided by the present invention is equipped with a multi-pipeline air intake system, which can introduce high-purity gas and mixed gas and inject them into the environmental simulation chamber to achieve precise configuration of multiple gases, true simulation of pressure, and precise and continuous regulation of pressure.

[0038] (4) The environmental simulation system provided by the present invention is equipped with a multi-pipeline air intake system. In view of the characteristics of large-flow rapid air supply under rough vacuum, long-term stable pressure air supply under low vacuum, and fine flow minute adjustment under high vacuum, the system integrates rough vacuum, low vacuum, high vacuum flow adjustment pipelines and large-flow supply pipelines. They work together in the form of parallel pipelines, which is different from the traditional solution of single air intake flow adjustment and can meet the large-span flow supply needs from small flow to large flow under different flow states.

[0039] (5) The environmental simulation system provided by the present invention is provided with a cross-flow state graded control system, including a first control loop, a second control loop and a third control loop, which adopts a targeted control strategy to match the characteristics of rapid balance of intake and exhaust flow under rough vacuum, long-term air supply under low vacuum, and fine adjustment of small flow under high vacuum. It can adjust the intake flow or outlet flow in real time during the pressure stabilization process of different flow states, ensure the balance of intake flow and outlet flow under different flow states, and realize real-time pressure control of the environmental simulation chamber.

[0040] (6) The environmental simulation system provided by the present invention integrates an environmental simulation chamber, a multi-pipeline air intake system, a cross-flow state graded control system, a pressure measurement unit, and various vacuum pump units in one system, thereby expanding the air pressure controllable range of the environmental simulation system, effectively reducing the number of equipment required for the test, reducing the floor space, and improving the test efficiency.

[0041] (7) The environmental simulation system provided by the present invention is provided with a pressure measuring sensor and a quick-release flange to which a high-precision temperature and humidity sensor can be externally connected. The pressure measuring sensor includes a high-precision cold cathode ionization vacuum gauge, a thermal conductivity vacuum gauge and a thin film vacuum gauge, which are used for precise measurement of the pressure in the environmental simulation chamber, so that the pressure of the environmental simulation chamber in the environmental simulation system can be better controlled and quantified.

[0042] (8) The control method provided by the present invention provides corresponding control strategies under different flow states for environmental simulation related experiments, which can be used for debugging of continuously adjustable gas pressure and precise configuration of gas components under high vacuum, low vacuum or rough vacuum conditions, and can comprehensively complete cross-flow state simulation experiments, providing technical accumulation and important solutions for the construction and operation of expanded environmental simulation equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Attachment Figure 1 Schematic diagram of the structure of a cross-flow state air pressure controllable environment simulation system according to an example of the present disclosure;

[0044] Attachment Figure 2 This is a flow chart of a method for simulating and controlling an air pressure-controlled environment in a high vacuum flow state according to an example of the present disclosure;

[0045] Attachment Figure 3 This is a flow chart of a method for simulating and controlling an air pressure-controlled environment in a low vacuum flow state according to an example of the present disclosure;

[0046] Attachment Figure 4 This is a flow chart of a method for simulating and controlling an air pressure controllable environment under a rough vacuum flow state according to an example of the present disclosure;

[0047] Numbers in the figure: In the figure: 1, first gas cylinder, 2, second gas cylinder, 3, third gas cylinder, 4, first solenoid valve, 5, second solenoid valve, 6, third solenoid valve, 7, buffer chamber, 8, pressure gauge, 9, fourth solenoid valve, 10, first pressure regulator, 11, second pressure regulator, 12, third pressure regulator, 13, fourth pressure regulator, 14, fifth pressure regulator, 15, electric needle valve, 16, first electric regulating valve, 17, first mass flow controller, 18, second mass flow controller, 19, third mass flow controller, 20, first PID controller, 21, second PID controller, 22, environmental simulation chamber, 23, cold cathode ionization vacuum gauge, 24, thermal conductivity vacuum gauge, 25, thin film vacuum gauge, 26, third PID controller, 27, first electric valve, 28, second electric regulating valve, 29, first Roots vacuum pump, 30 , oil-free scroll vacuum pump, 31. First high vacuum electric plug-in valve, 32. Cryogenic pump, 33. Second electric valve, 34. Second Roots vacuum pump, 35. First oil-free rotary vane pump, 36. Second high vacuum electric plug-in valve, 37. Molecular pump, 38. Third electric valve, 39. Fourth electric valve, 40. Third Roots vacuum pump, 41. Second oil-free rotary vane pump, 42. Third oil-free rotary vane pump, 43. Fourth solenoid valve, 44. First pneumatic butterfly valve, 45. Fifth electric valve, 46. Fifth solenoid valve, 47. Second pneumatic butterfly valve, 48. Frequency conversion vacuum pump, 49. Multi-pipeline air intake system, 50. First control circuit, 51. Second control circuit, 52. Third control circuit, 53. Low vacuum pressure maintaining exhaust unit, 54. High vacuum pressure maintaining exhaust unit, 55. Negative pressure exhaust vacuum pump unit, 56. Rough vacuum pressure maintaining exhaust unit, 57. Quick release flange DETAILED DESCRIPTION

[0048] The following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings. However, these descriptions are merely illustrative and do not limit the scope of the present disclosure. In the following detailed description, many specific details are provided to facilitate explanation and provide a comprehensive understanding of the embodiments of the present disclosure. One or more embodiments may be implemented without these specific details. In addition, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessary confusion of the concepts of the present disclosure.

[0049] The terms used herein are intended only to describe specific embodiments and are not intended to limit the present disclosure. Terms such as "comprising" and "including" indicate the presence of the described features, steps, operations, and / or components but do not preclude the presence or addition of one or more other features, steps, operations, or components. The terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

[0050] Due to the rapid development of aerospace, military industry, and geological plateau equipment, the demand for environmental simulation systems in my country is increasing. However, in order to meet these conditions, traditional solutions usually require the preparation of specialized test equipment for each environment. These devices are expensive, require a large footprint, and are equipped with complex control equipment, which increases the total cost of environmental simulation.

[0051] In order to solve the problem of environmental simulation transition from single air pressure dedicated equipment to cross-flow state air pressure controllable environmental simulation system, so that professionals can efficiently complete the precise configuration of multiple gases and air pressure controllable environmental testing requirements from a single professional equipment, the present invention provides a cross-flow state air pressure controllable environmental simulation system, including an environmental simulation cabin, a multi-pipeline air intake system, a cross-flow state graded control system, a pressure measurement unit, and various vacuum pump units, which can realize continuous adjustment of gas pressure parameters under high vacuum, low vacuum and rough vacuum conditions, and precise configuration of multiple gases.

[0052] See also Figure 1 The present invention provides a cross-flow state air pressure controllable environment simulation system, including: an environment simulation cabin 22, a multi-pipeline air intake system 49, a cross-flow state graded control system, a pressure measurement unit, and various vacuum pump units.

[0053] The environmental simulation chamber 22 is used to provide a test space for vacuum environment simulation.

[0054] The multi-pipeline air intake system 49 includes: a first gas cylinder 1, a second gas cylinder 2 and a third gas cylinder 3. The buffer chamber 7 can ensure that the interference of the gas injected into the gas cylinder on the pressure regulator is reduced. The buffer chamber 7 is provided with a pressure gauge 8 to prevent overpressure. The first solenoid valve 4, the second solenoid valve 5 and the third solenoid valve 6 for quickly cutting off the pipeline are provided between the buffer chamber 7 and the first gas cylinder 1, the second gas cylinder 2 and the third gas cylinder 3. A pipeline with adjustable intake air flow and a fourth solenoid valve 9 for quickly cutting off the intake pipeline are provided between the buffer chamber 7 and the environmental simulation cabin 22.

[0055] The pipeline with adjustable intake air flow includes: a first pressure regulator 10, a second pressure regulator 11, a third pressure regulator 12, a fourth pressure regulator 13, a fifth pressure regulator 14, an electric needle valve 15, a first electric regulating valve 16, a first mass flow controller 17, a second mass flow controller 18, and a third mass flow controller 19. The first pressure regulator 10, the second pressure regulator 11, the third pressure regulator 12, the fourth pressure regulator 13 and the fifth pressure regulator 14 are used to ensure in real time the stable front-stage pressure of the pipeline where the electric needle valve 15, the first electric regulating valve 16, the first mass flow controller 17, the second mass flow controller 18, and the third mass flow controller 19 are located.

[0056] The pipeline where the electric needle valve 15 and the first pressure regulator 10 are located is a small-diameter air intake pipeline. The small-diameter air intake pipeline can ensure the regulation of tiny flow rates and ensure that the pressure is continuously adjustable under high vacuum. The first electric regulating valve 16 is equipped with a fast execution motor to ensure the accuracy of air intake flow regulation. The first mass flow controller 17 is a high-precision small-flow mass flow controller, which is used to ensure a stable air intake flow under low vacuum. The second mass flow controller 18 and the third mass flow controller 19 are both large-flow mass flow controllers, which are used to quickly supplement the gas pressure required by the environmental simulation chamber 22, and to help share the air intake flow required by the environmental simulation chamber 22 during the pressure stabilization process under various flow states.

[0057] In order to ensure the flexibility of pressure control, the mass flow controller in the pressure control system is connected by a flange, which is convenient for replacing a mass flow controller with higher precision or higher range.

[0058] The cross-flow state classification control system includes: a high vacuum control system, a low vacuum control system and a rough vacuum control system, wherein:

[0059] The high vacuum control system includes: the first PID control unit 20 of the actuator of the second control loop 51, the electric needle valve 15 of the actuator of the multi-pipeline air intake system 49, the cold cathode ionization vacuum gauge 23 and the high vacuum pressure maintaining vacuum pump unit 54, wherein the high vacuum pressure maintaining exhaust unit 54 includes: a first high vacuum electric gate valve 31, a cryogenic pump 32, a second electric valve 33, a second Roots vacuum pump 34 and a first oil-free rotary vane pump 35, the gate valve 31 is used to cut off the gas path, the cryogenic pump 32 runs at full speed in the gas path, and the second Roots vacuum pump 34 and the first oil-free rotary vane pump 35 are used to solve the regeneration problem that needs to be solved due to the long operation time of the cryogenic pump during the long-term gas pressure stabilization process under high vacuum flow state.

[0060] The low vacuum control system includes: the third PID control unit 26 of the actuator in the third control loop 52, the second electric regulating valve 28 of the actuator of the multi-pipeline air intake system 49, the thin film vacuum gauge 25 and the low vacuum pressure maintaining pumping unit 53, wherein: the low vacuum pressure maintaining pumping unit 53 includes: a first electric valve 27, a second electric regulating valve 28, a first Roots vacuum pump 29 and an oil-free scroll vacuum pump 30, the first electric regulating valve is used to cut off the air path, the second electric regulating valve 28 is connected to the third PID controller 26, and is used to limit the pumping flow of the first Roots pump 29 in the air path, the first Roots pump 29 runs at full speed in the air path, and the oil-free scroll vacuum pump 30 serves as the front pump of the first Roots pump 29.

[0061] The rough vacuum control system includes: the second PID control unit 20 of the actuator in the first control loop 50, the first electric regulating valve 16 of the actuator of the multi-pipeline air intake system 49, the thermal conductivity vacuum gauge 24 and the rough vacuum pressure maintaining and pumping unit 56, wherein: the rough vacuum pressure maintaining and pumping unit includes: a fourth solenoid valve 43, a first pneumatic butterfly valve 44, a fifth electric valve 45, a fifth solenoid valve 46, a second pneumatic butterfly valve 47 and a variable frequency vacuum pump 48, the fourth solenoid valve 43, the fifth electric valve 45 and the fifth solenoid valve 46 are used to cut off the air path, the first pneumatic butterfly valve 44 and the second pneumatic butterfly valve 47 are used to limit the air pumping flow of the variable frequency vacuum pump 48 in the air path, wherein the second pneumatic butterfly valve 47 is an alternative pipeline, and the variable frequency vacuum pump 48 carries its own PID control system to ensure that the pressure value at its vacuum pump port remains stable, effectively avoiding the problems of pipeline growth and large floor space caused by setting a larger buffer tank unit in the traditional solution.

[0062] The rough vacuum control system adopts the rough vacuum pressure to maintain the flow characteristics of the vacuum pump unit 56 to maintain the pressure at the vacuum pump pump port. The control system adopts the PID self-diagnosis system to adjust the intake flow of the multi-pipeline intake system 49 in real time according to the vacuum degree of the thermal conductivity vacuum gauge 24, and dynamically balances to achieve long-term continuous pressure control.

[0063] The high vacuum control system adopts the high vacuum pressure to maintain the stable exhaust flow characteristics of the vacuum pump in the exhaust unit 54, and the multi-pipeline integrated system 49 can provide a flow characteristic of a small flow. The control system adjusts the intake flow of the multi-pipeline integrated system 49 in real time according to the pressure feedback from the cold cathode ionization vacuum gauge 23, and dynamically balances to achieve long-term continuous pressure control.

[0064] The low vacuum control system adopts the multi-pipeline air intake system 49 to provide a stable large / small flow rate characteristic. The control system adjusts the low vacuum pressure in real time according to the feedback pressure of the thin film vacuum gauge 25 to maintain the exhaust flow of the exhaust unit 53, and dynamically balances to achieve long-term continuous pressure control.

[0065] The pressure measuring unit includes: a cold cathode ionization vacuum gauge 23, a thermal conductivity vacuum gauge 24 and a thin film vacuum gauge 25, which are used to measure the vacuum degree in the environmental simulation chamber 22, and convert the measured value of the vacuum degree into an electrical signal and transmit it to the first PID controller 20, the second PID controller 21, and the third PID controller 26 for regulating the intake flow or exhaust flow in the environmental simulation chamber 22, wherein the cold cathode ionization vacuum gauge 23, the thermal conductivity vacuum gauge 24 and the thin film vacuum gauge 25 are located at the top of the environmental simulation chamber, and are detachably connected to the environmental simulation chamber 22, so as to facilitate the replacement of higher-precision pressure measurement sensors to meet the requirements of continuously adjustable high-precision pressure control.

[0066] The negative pressure vacuum pump unit 55 includes: a second high vacuum gate valve 36, a molecular pump 37, a third electric valve 38, a fourth electric valve 39, a third Roots vacuum pump 40, a second oil-free rotary vane pump 41, and a third oil-free rotary vane pump 42. The negative pressure vacuum pump unit 55 can make the environmental simulation cabin 22 reach a high vacuum environment within half an hour (10 -5 Pa), which can quickly remove the impurity gas in the environmental simulation cabin 22, thereby efficiently completing the gas replacement process of the environmental simulation cabin 22. The vacuum pump and valve unit in the negative pressure vacuum pump unit 55 are both arranged outside the environmental simulation cabin 22, which is convenient for maintenance and replacement.

[0067] The environmental simulation chamber 22 retains a quick-release flange 57 to which a high-precision thermometer and hygrometer can be externally connected for measuring the temperature and humidity in the environmental simulation chamber 22 .

[0068] The disclosed embodiments provide a cross-flow state air pressure controllable environment simulation system, which includes, through the operation or shutdown of some or all components of the multi-pipeline air intake system, high-purity gas or mixed gas can be introduced into the environmental simulation chamber, and through the operation or shutdown of some or all components in the pressure control unit and the pressure maintenance exhaust unit, the environmental simulation chamber can complete different mission requirements, such as Mars probe instrument testing, spacecraft vacuum testing, plateau equipment performance verification and other experiments. The provided cross-flow state air pressure controllable environment simulation system can achieve pressure stabilization control of high vacuum, low vacuum and rough vacuum under different gas components, thereby expanding the test range and effectively reducing the test cost and floor space.

[0069] The disclosed example provides a cross-flow state air pressure controllable environment simulation system, which flexibly controls the test conditions of the environmental simulation through a pressure control system and pressure maintenance of part or all components of the vacuum unit. The following provides specific test steps using the above-mentioned cross-flow state air pressure controllable environment simulation system in combination with specific examples.

[0070] See also Figure 2 The present invention provides a high vacuum environment simulation control method, and the specific control method steps are as follows:

[0071] Step 1: Test the environmental simulation system and debug it to normal working state;

[0072] Step 2: Start the negative pressure vacuum pump unit and adjust the environmental simulation chamber to a high vacuum environment;

[0073] Step 3: Obtain the environmental gas composition to be simulated, and configure the required simulated gas cylinders as needed to ensure that the gas composition in the environmental simulation chamber meets the simulated atmosphere conditions;

[0074] Step 4: Connect the simulated gas to the multi-line air inlet system, start the fourth and fifth pressure regulators, and rapidly inject the configured gas through the second and third mass flow controllers to adjust the pressure of the environmental simulation chamber from the high vacuum condition to the set target pressure.

[0075] Step 5: Start the cryopump, the second Roots pump, and the first oil-free rotary vane pump, open the first high vacuum gate valve, estimate the required intake flow rate based on demand, and determine whether a high-flow mass flow controller is needed based on the set target pressure value and the exhaust flow rate of the cryopump at full speed;

[0076] Step 6: Start the first PID controller, the first pressure regulator, and the electric needle valve. The first PID controller controls the electric needle valve according to the target regulated pressure value set by the cold cathode ionization vacuum gauge, so that the intake flow rate and the exhaust flow rate are balanced with each other, so that the gas pressure in the environmental simulation chamber reaches the set working pressure;

[0077] Step 7: Environmental simulation atmosphere components and pressure simulation are completed.

[0078] The above steps 3 and 2 can be interchanged without affecting the realization of environmental simulation.

[0079] In the above step five, the value of the air intake flow controlled by the electric needle valve is small, which belongs to a small flow intake and is suitable for continuous adjustment in a high vacuum environment. If the air intake flow required is large according to demand estimation, the control effect of the electric needle valve will be reduced. At this time, a large flow mass flow controller is required to assist in the operation.

[0080] See also Figure 3 The present invention provides a low vacuum environment simulation control method, and the specific control steps are as follows:

[0081] Step 1: Test the environmental simulation system and debug it to normal working state;

[0082] Step 2: Start the negative pressure vacuum pump unit and adjust the environmental simulation chamber to a high vacuum environment;

[0083] Step 3: Obtain the environmental gas composition to be simulated, and configure the required simulated gas cylinders as needed to ensure that the gas in the environmental simulation chamber meets the simulated atmosphere conditions;

[0084] Step 4: Connect the simulated gas to the multi-line air inlet system, start the fourth and fifth pressure regulators, and rapidly inject the configured gas through the second and third mass flow controllers to adjust the pressure of the environmental simulation chamber from high vacuum to the set target value of the stable pressure required for low vacuum conditions;

[0085] Step 5: Start the Roots vacuum pump to run at full speed, open the second electric regulating valve, estimate the intake flow rate according to the Roots vacuum pump's pumping curve, and determine whether a large-flow intake unit is needed for assistance;

[0086] Step 6: Start the third PID controller, the third pressure regulator, and the first mass flow controller, fix the intake flow rate of the first mass flow controller in the multi-pipeline intake system, and control the second electric regulating valve according to the target pressure value set by the thin film ionization vacuum gauge to balance the exhaust flow rate and the intake flow rate, so that the gas pressure in the environmental simulation cabin reaches the set working pressure;

[0087] Step 7: Environmental simulation atmosphere components and pressure simulation are completed.

[0088] The above steps 3 and 2 can be interchanged without affecting the realization of environmental simulation.

[0089] See also Figure 4 The present invention provides a rough vacuum environment simulation control method, and the specific control steps are as follows:

[0090] Step 1: Test the environmental simulation system and debug it to normal working state;

[0091] Step 2: Start the negative pressure vacuum pump unit and adjust the environmental simulation chamber to a high vacuum environment;

[0092] Step 3: Obtain the environmental gas composition to be simulated, and configure the required simulated gas cylinders as needed to ensure that the gas in the environmental simulation chamber meets the simulated atmosphere conditions;

[0093] Step 4: Connect the simulated gas to the multi-line air inlet system, start the fourth and fifth pressure regulators, and rapidly inject the configured gas through the second and third mass flow controllers to adjust the pressure of the environmental simulation chamber from the high vacuum condition to the set target pressure.

[0094] Step 5: Set the pressure value at the pump port of the variable frequency vacuum pump, fix the opening of the second vacuum butterfly valve, estimate the mass flow rate of the intake flow based on the simulation experiment, and determine whether a large flow intake unit is needed;

[0095] Step 6: Start the second PID controller, the second pressure controller, and the first electric regulating valve. The second PID controller controls the first electric regulating valve according to the target pressure value set by the thermal conductivity vacuum gauge, so that the intake flow rate and the exhaust flow rate are balanced, so that the gas pressure in the environmental simulation cabin reaches the set working pressure.

[0096] Step 7: Environmental simulation atmosphere components and pressure simulation are completed.

[0097] The above steps 3 and 2 can be interchanged without affecting the realization of environmental simulation.

[0098] In the above step five, the value of the intake flow controlled by the first electric control valve is relatively small. When the required intake flow is larger according to demand estimation, the control effect of the electric control valve will be reduced. At this time, it is necessary to increase the target value of the variable frequency vacuum or reduce the valve opening to improve the control effect of the regulating valve under large flow intake conditions.

[0099] The above-mentioned control method can complete the continuously adjustable voltage stabilization control of high vacuum, low vacuum and rough vacuum under different gas components. One device can flexibly control the test conditions of environmental simulation, realize the continuous adjustment of gas pressure parameters under high vacuum, low vacuum and rough vacuum conditions, and control the environmental gas components, effectively reducing costs and floor space.

[0100] The above embodiments are used to explain the present invention rather than to limit the present invention. Any modifications and changes made to the present invention within the scope of protection claimed by the present invention shall fall within the scope of protection of the present invention.

Claims

1. A cross-flow state air pressure controllable environment simulation system, characterized in that: The cross-flow state air pressure controllable environment simulation system comprises: an environment simulation cabin (22), a multi-pipeline air intake system (49), a cross-flow state hierarchical control system, a pressure measurement unit, and various vacuum pump units; An environmental simulation cabin (22) is used to provide a test space for vacuum environment simulation; The multi-pipeline air intake system (49) is integrated with a multi-channel flow control module to provide a precise control scheme for the air intake flow required for the rough vacuum, low vacuum, and high vacuum pressure set points for the test space; The cross-flow state hierarchical control system is equipped with a PID self-diagnosis system to achieve continuous control of the pressure of the environmental simulation chamber (22) under various flow states; The pressure measuring unit includes: a high-precision cold cathode ionization vacuum gauge (23), a thermal conductivity vacuum gauge (24) and a thin film vacuum gauge (25), which are used to measure the vacuum degree of the environmental simulation chamber (22) and convert the electrical signal into a corresponding PID controller to regulate the intake or exhaust flow rate; The various vacuum pump units include: a low vacuum pressure maintaining pumping unit (53), a high vacuum pressure maintaining pumping unit (54) and a rough vacuum pressure maintaining pumping unit (56), which are used to provide stable and controllable pumping flow rates under corresponding vacuum pressure ranges respectively; a negative pressure pumping vacuum pump unit (55) is used to create a clean, oil-free high vacuum environment and to promptly remove impurity gases.

2. A cross-flow state air pressure controllable environment simulation system according to claim 1, characterized in that: The cross-flow state classification system includes: a high vacuum control system, a low vacuum control system and a rough vacuum control system, wherein: The rough vacuum control system adopts the rough vacuum pressure in the various vacuum pump units to maintain the vacuum pump unit (56) to maintain the vacuum pump port pressure pumping characteristics, and adopts the PID self-diagnosis system to adjust the intake flow of the multi-pipeline intake system (49) in real time according to the vacuum degree feedback from the thermal conductivity vacuum gauge (24), so as to achieve dynamic balance and long-term continuous control of the pressure of the environmental simulation cabin (22); The high vacuum control system adopts the high vacuum pressure in the various vacuum pump units to maintain the stable exhaust flow of the vacuum pump in the exhaust unit (54) and the characteristics of the multi-pipeline air intake system (49) providing a small flow rate, and adopts the PID self-diagnosis system to adjust the intake flow of the multi-pipeline integrated system (49) in real time according to the vacuum degree feedback from the cold cathode ionization vacuum gauge (23), so as to achieve dynamic balance and long-term continuous control of the pressure of the environmental simulation cabin (22); The low vacuum control system adopts the characteristics of the multi-pipeline air intake system (49) to provide a stable large flow or small flow, and adopts the PID self-diagnosis system to adjust the low vacuum pressure in the various vacuum pump units in real time according to the vacuum degree feedback from the thin film vacuum gauge (25) to maintain the exhaust flow of the exhaust unit (53), and dynamically balance to achieve long-term continuous control of the pressure of the environmental simulation chamber (22).

3. A cross-flow state air pressure controllable environment simulation system according to claim 2, characterized in that: The multi-pipeline air intake system (49) includes: an air supply structure, a pressure regulator, and a flow regulating unit. The multiple structures are integrated to form an integrated air intake system capable of completing the buffering, diversion and flow regulation of high-purity gas and mixed gas, wherein: The gas supply structure comprises: a first gas cylinder (1), a second gas cylinder (2) and a third gas cylinder (3) which can provide high-purity gas or mixed gas to complete large-flow gas supply and a buffer chamber (7) for slowing down the impact of the intake gas on the pressure regulator; The pressure regulator is used to ensure a stable front-stage pressure in each pipeline branch to avoid pressure fluctuations during the injection of gases with different flow patterns; The flow regulating unit includes: a high vacuum high precision micro flow regulating unit, a low vacuum precise flow stable supply unit, a rough vacuum high precision flow regulating unit and a large flow supply unit. The four units are integrated in the form of parallel pipelines and can work together to meet the requirements of long-term precise flow supply under different flow states. The actuator of the high vacuum micro-flow regulating unit is an electric needle valve (15), which is characterized in that the electric needle valve (15) can complete the regulation of micro-intake air flow with high precision; The actuator of the low vacuum precise flow stable supply unit is a first mass flow controller (17), characterized in that the first mass flow controller (17) can provide a stable intake flow for a long time in the low vacuum range; The actuator of the rough vacuum flow regulating unit is a first electric regulating valve (16), characterized in that the first electric regulating valve (16) can adjust the valve opening with high precision to control the intake air flow; The large flow supply unit actuator is a second mass flow controller (18) and a third mass flow controller (19), which can complete a long-term large flow stable gas supply.

4. According to the cross-flow state air pressure controllable environment simulation system of claim 2, the various vacuum pump units are characterized in that: A first Roots vacuum pump (30) capable of stably and long-term full-speed operation in a low vacuum pressure range, a low-temperature vacuum pump (32) capable of stably and long-term operation in a high vacuum pressure range, and a variable-frequency screw vacuum pump (48) having a self-built PID control system capable of setting the vacuum pump port pressure value are used to maintain the pressure of the environmental simulation chamber (22).

5. A cross-flow state air pressure control environment simulation and control method, using a cross-flow state air pressure control environment simulation system according to claim 1, characterized in that: The specific control steps for maintaining high vacuum pressure are as follows: Check the environmental simulation system and debug it to normal working condition; Starting the negative pressure vacuum pump unit (55) to pump the pressure value of the environmental simulation cabin (22) to a high vacuum environment; Configure the required simulated gas cylinders according to the required gas environment; Connecting the simulated gas to the multi-pipeline air inlet system (49), starting the fourth pressure regulator and the fifth pressure regulator, and rapidly injecting the configured gas through the second mass flow controller and the third mass flow controller, so that the gas pressure of the environmental simulation chamber (22) reaches a stable pressure setting target pressure value from a high vacuum condition; Starting the cryogenic pump (32), the second Roots vacuum pump (34), and the first oil-free rotary vane pump (35), starting the second control loop (51), controlling the electric needle valve (15) according to the target air pressure set by the first PID controller (20), and adjusting the air intake flow rate so that the gas pressure of the environmental simulation chamber (22) reaches the set working pressure; Environmental simulation of atmosphere components and pressure simulation is completed.

6. A cross-flow state air pressure control environment simulation and control method, using a cross-flow state air pressure control environment simulation system according to claim 5, characterized in that: The specific control steps for maintaining low vacuum pressure are as follows: Check the environmental simulation system and debug it to normal working condition; Starting the negative pressure vacuum pump unit (55) to pump the pressure value of the environmental simulation cabin (22) to a high vacuum environment; Configure the required simulated gas cylinders according to the required gas environment; Connecting the simulated gas to the multi-line air inlet system (49), starting the fourth pressure regulator and the fifth pressure regulator, and rapidly injecting the configured gas through the second mass flow controller and the third mass flow controller, so that the pressure of the environmental simulation chamber (22) reaches the target pressure value set by the stable pressure from the high vacuum condition; Starting the first Roots vacuum pump (29), starting the third control loop (52), controlling the second electric regulating valve (28) according to the target air pressure set by the third PID controller (26), and adjusting the air extraction flow rate so that the gas pressure in the environmental simulation chamber (22) reaches the set working pressure; Environmental simulation of atmosphere components and pressure simulation is completed.

7. A cross-flow state air pressure control environment simulation and control method, using a cross-flow state air pressure control environment simulation system according to claim 6, characterized in that: The specific control steps for maintaining the rough vacuum pressure are as follows: Check the environmental simulation control system and debug it to normal working condition; Starting the negative pressure vacuum pump unit (55) to pump the pressure value of the environmental simulation cabin (22) to a high vacuum environment; A gas cylinder of the required simulated gas is configured according to the required gas environment, the simulated gas is connected to the multi-pipeline gas inlet system (49), the fourth pressure regulator and the fifth pressure regulator are started, and the configured gas is quickly injected through the second mass flow controller and the third mass flow controller, so that the gas pressure of the environmental simulation chamber (22) reaches the target pressure value set by the stable pressure from the high vacuum condition; Starting the variable frequency screw vacuum pump (48), starting the first control loop (50), controlling the first electric regulating valve (16) according to the target air pressure set by the second PID controller (21), and adjusting the air extraction flow rate so that the gas pressure in the environmental simulation chamber (22) reaches the set working pressure; Environmental simulation of atmosphere components and pressure simulation is completed.

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