Pressure control device and method for non-closed constant-flow output

Abstract

The invention discloses a non-closed constant-flow output pressure control device and method, and the device comprises a gas source assembly which is used for providing needed gas; one end of the pressure pipeline is connected with the air source assembly, and the other end is communicated to atmosphere; the first flow adjusting assembly is arranged on the pressure pipeline; the second flow adjusting assembly is arranged on the pressure pipeline and located on the downstream of the first flow adjusting assembly. The first pressure adjusting part and the first flow adjusting assembly are connected into the pressure pipeline in parallel; one end of the second pressure adjusting part is connected to the pressure pipeline and located between the first flow adjusting assembly and the second flow adjusting assembly, and the other end of the second pressure adjusting part communicates with the atmosphere; the first pressure adjusting piece and the second pressure adjusting piece conduct pressure increasing and pressure reducing adjustment on gas in the pressure pipeline correspondingly so that the pressure of the gas can be adjusted to be within the target pressure range. The problem that in the prior art, the pressure of a non-closed constant-flow output system is difficult to accurately and stably control is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of pressure control, and in particular relates to a pressure control device and method for non-sealed constant flow output. Background Art

[0002] Gas pressure control has obvious nonlinearity and uncertainty, especially small flow pressure is difficult to control accurately. Common pressure control methods include variable volume control, proportional valve control and flow combined solenoid valve control. In recent years, intelligent control theory has been successfully applied to gas pressure control. The precise control method of gas pressure is mostly to use PID control, pulse width modulation (PWM) control method combined with high-speed switching valve, which can achieve precise control of small flow pressure in closed system and solve nonlinearity and uncertainty problems.

[0003] However, for a non-sealed open system with a gas source input at one end and an air output directly open to the atmosphere at the other end, there is a lack of accurate and stable pressure control method for continuous output of constant flow rate. In other words, it is difficult to achieve both ensuring that the system continuously outputs a constant flow rate to the outside and ensuring that the internal pressure of the system is accurate and highly stable.

[0004] As can be seen from the above, in the prior art, there is a problem that the pressure of a non-sealed constant flow output system is difficult to control accurately and stably. Summary of the invention

[0005] The main purpose of the present invention is to provide a pressure control device and method for non-sealed constant flow output, which can accurately and stably control the pressure of the non-sealed constant flow output system.

[0006] In order to achieve the above object, one aspect of the present invention provides a non-sealed constant flow output pressure control device, comprising:

[0007] A gas source component, used to provide the required gas;

[0008] A pressure pipeline, one end of which is connected to the gas source assembly and the other end of which is connected to the atmosphere;

[0009] a first flow regulating component, the first flow regulating component being arranged on the pressure pipeline and being used for regulating the flow of the gas entering the pressure pipeline;

[0010] a second flow regulating component, which is disposed on the pressure pipeline and is located downstream of the first flow regulating component, and is used to regulate the flow of the gas flowing out of the pressure pipeline;

[0011] a first pressure regulating member, the first pressure regulating member and the first flow regulating assembly being connected in parallel to the pressure pipeline;

[0012] a second pressure regulating member, one end of which is connected to the pressure pipeline and is located between the first flow regulating assembly and the second flow regulating assembly, and the other end of which is connected to the atmosphere;

[0013] The first pressure regulating member and the second pressure regulating member respectively increase and decrease the pressure of the gas in the pressure pipeline to adjust the pressure of the gas to a target pressure range.

[0014] Preferably, the first flow regulating assembly includes a first regulating valve, a first actuator and a first flow sensor, the first actuator is used to control the opening of the first regulating valve, and the first flow sensor is located downstream of the first regulating valve.

[0015] Preferably, the second flow regulating component includes a second regulating valve, a second actuator and a second flow sensor, the second actuator is used to control the opening of the second regulating valve, and the second flow sensor is located downstream of the second regulating valve.

[0016] Preferably, the first regulating valve and the second regulating valve are needle valves, and the first pressure regulating member and the second pressure regulating member are solenoid valves.

[0017] Preferably, the pressure control device further comprises a pressure sensor, which is connected to the pressure pipeline and is located between the first flow regulating component and the second flow regulating component.

[0018] Preferably, the pressure control device further comprises an air container, which is connected to the pressure pipeline and is located between the first flow regulating component and the second flow regulating component.

[0019] Preferably, the pressure control device further comprises a controller, and the controller is electrically connected to the first flow regulating component, the second flow regulating component, the first pressure regulating member and the second pressure regulating member respectively.

[0020] Another aspect of the present invention provides a pressure control method for non-sealed constant flow output, which uses the above-mentioned pressure control device to implement pressure control. The pressure control method includes:

[0021] Step S1: first close the first flow regulating component, the second flow regulating component, the first pressure regulating member and the second pressure regulating member to keep the pressure pipeline airtight;

[0022] Step S2: opening the first flow regulating component to allow the gas to enter the pressure pipeline, or opening the second flow regulating component to allow the gas in the pressure pipeline to flow out;

[0023] Step S3: when the pressure of the gas in the pressure pipeline rises or drops to the target pressure range and remains stable, closing the first flow regulating component or the second flow regulating component;

[0024] Step S4: adjusting the openings of the first regulating valve of the first flow regulating assembly and the second regulating valve of the second flow regulating assembly so that the gas in the pressure pipeline is output to the outside at a preset output flow rate.

[0025] Preferably, the pressure control method further comprises:

[0026] Step S5: when the pressure of the gas in the pressure pipeline changes while being output to the outside, adjusting the opening of the first regulating valve so that the pressure of the gas in the pressure pipeline is restored to the target pressure range and remains stable;

[0027] Step S6: If the pressure of the gas in the pressure pipeline cannot be restored to the target pressure range by adjusting the opening of the first regulating valve, open the first pressure regulating component and / or the second pressure regulating component to increase and / or reduce the pressure so that the pressure of the gas in the pressure pipeline is restored to the target pressure range.

[0028] Preferably, the step S3 further includes:

[0029] When the pressure of the gas in the pressure pipeline rises or falls and gradually approaches the target pressure range, adjusting the opening of the first regulating valve so that the pressure of the gas in the pressure pipeline is adjusted to the target pressure range;

[0030] If the pressure of the gas in the pressure pipeline cannot be adjusted to the target pressure range by adjusting the opening of the first regulating valve, open the first pressure regulating member and / or the second pressure regulating member to increase and / or reduce the pressure so that the pressure of the gas in the pressure pipeline is adjusted to the target pressure range.

[0031] The pressure control device and method for non-sealed constant flow output according to the above aspects of the present invention can accurately and stably control the pressure of the non-sealed constant flow output system. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings used in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work:

[0033] Figure 1 A schematic diagram showing the structure of a pressure control device with a non-sealed constant flow output according to an embodiment of the present invention; and

[0034] Figure 2 A flow chart showing a pressure control method for a non-sealed constant flow output according to an embodiment of the present invention is shown.

[0035] Description of reference numerals:

[0036] 1. Gas source; 2. Pressure reducing valve; 3. First pressure regulating member; 4. First regulating valve; 5. First flow sensor; 6. First actuator; 7. Pressure sensor; 8. Gas container; 9. Second regulating valve; 10. Second flow sensor; 11. Second actuator; 12. Second pressure regulating member; 13. Pressure pipeline. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In order to solve the problem that the pressure of a non-sealed constant flow output system in the prior art is difficult to control accurately and stably, an embodiment of the present invention provides a pressure control device for a non-sealed constant flow output. Figure 1 As shown, the pressure control device with non-sealed constant flow output according to the embodiment of the present invention includes an air source component, a pressure pipeline 13, a first flow regulating component, a second flow regulating component, a first pressure regulating component 3 and a second pressure regulating component 12.

[0039] The gas source assembly is used to provide the required gas. One end of the pressure pipeline 13 is connected to the gas source assembly, and the other end is connected to the atmosphere. The first flow regulating assembly is arranged on the pressure pipeline 13, and is used to regulate the flow of gas entering the pressure pipeline 13. The second flow regulating assembly is arranged on the pressure pipeline 13 and is located downstream of the first flow regulating assembly, and is used to regulate the flow of gas flowing out of the pressure pipeline 13. The first pressure regulating member 3 is connected to the pressure pipeline 13 in parallel with the first flow regulating assembly. One end of the second pressure regulating member 12 is connected to the pressure pipeline 13 and is located between the first flow regulating assembly and the second flow regulating assembly, and the other end is connected to the atmosphere. The first pressure regulating member 3 and the second pressure regulating member 12 respectively increase and decrease the pressure of the gas in the pressure pipeline 13 to adjust the pressure of the gas to the target pressure range.

[0040] By setting the first flow regulating component and the second flow regulating component, the gas flow is accurately controlled and the inlet and outlet flows are accurately matched. At the same time, the gas in the pressure pipeline 13 can be accurately controlled. Furthermore, by setting the first pressure regulating component 3 and the second pressure regulating component 12, the pressure control accuracy of the flow regulating component is compensated to achieve more precise pressure control, thereby accurately and stably controlling the pressure of the non-closed constant flow output system.

[0041] In this embodiment, if Figure 1 As shown, the gas source assembly includes a gas source 1 and a pressure reducing valve 2. The gas source 1 provides a gas medium as a pressure input. Specifically, the gas source 1 is usually an industrial gas cylinder or a screw compressor or other gas supply equipment. The pressure reducing valve 2 reduces the pressure of the gas output by the gas source 1 to provide a suitable input gas source pressure to the pressure pipeline 13.

[0042] In this embodiment, the first pressure regulating member 3 is a pressure-increasing regulating member, which is used to precisely regulate and compensate for the pressure increase of the gas pressure in the pressure pipeline 13, so that the pressure control device can ensure that the pressure control stability is within the required range when the fixed flow output is opened. Correspondingly, the second pressure regulating member 12 is a pressure-reducing regulating member, which is used to precisely regulate and compensate for the pressure decrease of the gas pressure in the pressure pipeline 13, so that the pressure control device can ensure that the pressure control stability is within the required range when the fixed flow output is opened.

[0043] like Figure 1 As shown, the first flow regulating assembly includes a first regulating valve 4 and a first actuator 6, and the first actuator 6 is used to control the opening of the first regulating valve 4. Further, the first flow regulating assembly also includes a first flow sensor 5, and the first flow sensor 5 is located downstream of the first regulating valve 4. The first flow sensor 5 can measure and feedback the flow of the first regulating valve 4 at a fixed opening, so that the first actuator 6 can accurately control the opening of the first regulating valve 4, so that the input flow of the pressure pipeline 13 can be accurately controlled.

[0044] like Figure 1 As shown, the second flow regulating component includes a second regulating valve 9 and a second actuator 11, and the second actuator 11 is used to control the opening of the second regulating valve 9. Furthermore, the second flow regulating component also includes a second flow sensor 10, and the second flow sensor 10 is located downstream of the second regulating valve 9. The second flow sensor 10 can measure and feedback the flow of the second regulating valve 9 at a fixed opening, so that the second actuator 11 can accurately control the opening of the second regulating valve 9, so that the gas in the pressure pipeline 13 can be output at a fixed flow rate. In this embodiment, two actuators are used to respectively adjust and control the linkage of the two regulating valves, so that the inlet and outlet flows are accurately matched, and precise control of the pressure is achieved.

[0045] In this embodiment, the first regulating valve 4 and the second regulating valve 9 are needle valves. Specifically, the first regulating valve 4 maintains a certain opening under the control of the first actuator 6, so that the gas from the gas source 1 is input into the pressure pipeline 13 at a fixed flow rate. The second regulating valve 9 maintains a certain opening under the control of the second actuator 11, so that the gas in the pressure pipeline 13 is output to the outside at a fixed flow rate.

[0046] like Figure 1 As shown, the pressure control device further includes a pressure sensor 7, which is connected to the pressure line 13 and is located between the first flow regulating assembly and the second flow regulating assembly. In this embodiment, the pressure sensor 7 is a standard pressure sensor, which is used to provide high-accuracy pressure measurement, monitor and feedback the gas pressure in the pressure line 13, so as to ensure that the pressure in the pressure line 13 is maintained within the required stability range.

[0047] like Figure 1 As shown, the pressure control device further includes an air container 8, which is connected to the pressure pipeline 13 and is located between the first flow regulating component and the second flow regulating component. By providing the air container 8, an energy storage volume can be provided, so that the pressure in the pressure pipeline 13 can be stably controlled in the air container 8; in addition, the air container 8 can also provide sufficient energy storage and buffering to ensure that the large flow output has little impact on the stable control of the pressure.

[0048] In this embodiment, the first pressure regulating member 3 and the second pressure regulating member 12 are both solenoid valves.

[0049] In this embodiment, the pressure control device further includes a controller, which is electrically connected to the first flow regulating component, the second flow regulating component, the first pressure regulating member 3 and the second pressure regulating member 12. The controller controls and regulates the first pressure regulating member 3 and the second pressure regulating member 12 in a PWM manner.

[0050] like Figure 2As shown, the present application also provides a pressure control method for non-closed constant flow output, which implements pressure control using the above-mentioned pressure control device, and the pressure control method includes: step S1: first close the first flow regulating component, the second flow regulating component, the first pressure regulating member 3 and the second pressure regulating member 12 to keep the pressure pipeline 13 closed; step S2: open the first flow regulating component to allow gas to enter the pressure pipeline 13, or open the second flow regulating component to allow the gas in the pressure pipeline 13 to flow out; step S3: when the pressure of the gas in the pressure pipeline 13 rises or falls to the target pressure range and remains stable, close the first flow regulating component or the second flow regulating component; step S4: simultaneously adjust the opening of the first regulating valve 4 of the first flow regulating component and the second regulating valve 9 of the second flow regulating component (the openings of the two components are accurately calibrated values) to allow the gas in the pressure pipeline 13 to be output outward at a preset output flow rate.

[0051] In this embodiment, the pressure control method also includes: Step S5: When the pressure of the gas in the pressure pipeline 13 changes when it is output to the outside, the opening of the first regulating valve 4 is reduced so that the pressure of the gas in the pressure pipeline 13 is accurately and highly resolved. It is restored to the target pressure range and remains stable.

[0052] In this embodiment, the pressure control method also includes: Step S6: If the pressure of the gas in the pressure pipeline 13 cannot be restored to the target pressure range by adjusting the opening of the first regulating valve 4, open the first pressure regulating component 3 and / or the second pressure regulating component 12 to increase and / or reduce the pressure so that the pressure of the gas in the pressure pipeline 13 is restored to the target pressure range.

[0053] In this embodiment, step S3 also includes: when the pressure of the gas in the pressure pipeline 13 rises or falls and gradually approaches the target pressure range, adjusting the opening of the first regulating valve 4 to adjust the pressure of the gas in the pressure pipeline 13 to the target pressure range.

[0054] In this embodiment, step S3 also includes: if the pressure of the gas in the pressure pipeline 13 cannot be adjusted to the target pressure range by adjusting the opening of the first regulating valve 4, opening the first pressure regulating component 3 and / or the second pressure regulating component 12 to increase and / or reduce the pressure so that the pressure of the gas in the pressure pipeline 13 is adjusted to the target pressure range.

[0055] The specific pressure control process of the pressure control device in this embodiment is as follows:

[0056] The gas in the gas source 1 is decompressed after passing through the pressure reducing valve 2 to provide a suitable gas pressure. In the initial state, the first pressure regulating member 3 and the second pressure regulating member 12 are in a closed state, and the first regulating valve 4 and the second regulating valve 9 are also in a closed state. At this time, the entire device is in a closed state.

[0057] Boost process: The boost control process of the device is divided into two steps:

[0058] In the initial state, the entire device is in a closed state. First, the first actuator 6 is used to open the first regulating valve 4 to a certain degree, and the gas from the gas source 1 flows into the pressure pipeline 13 at a certain flow rate. The pressure sensor 7 monitors and feeds back the pressure value in the pressure pipeline 13 in real time. As the pressure in the pressure pipeline 13 continues to increase and gradually approaches the target pressure range, the first actuator 6 adjusts the opening of the first regulating valve 4 in real time and continuously reduces it, so that the closer the pressure in the pressure pipeline 13 is to the target pressure range, the more accurate the control. When the pressure in the pressure pipeline 13 reaches the target pressure range to be controlled or does not reach the target pressure range but it enters a balanced state and can no longer be fine-tuned by reducing the opening of the first regulating valve 4, the first regulating valve 4 is closed. At this time, if the target pressure range to be controlled has been reached, the pressure increase control process is completed. If the target pressure range is not reached but the pressure enters a balanced state and can no longer be fine-tuned by reducing the opening of the first regulating valve 4, the first regulating valve 4 is closed, and the pressure in the pressure pipeline 13 is precisely adjusted by using the PWM algorithm control of the first pressure regulating component 3 and the second pressure regulating component 12 to reach the required target pressure range.

[0059] In the second step, after the device reaches the target pressure range and reaches a stable state in a closed state, the device is subjected to constant flow output voltage stabilization control. According to the flow requirement of the device that needs constant output (taking 10L / min as an example), the first actuator 6 and the second actuator 11 are used to simultaneously control the opening of the first regulating valve 4 and the second regulating valve 9 (at this time, the output opening of the second regulating valve 9 should be controlled at 10L / min), and ensure that the flow rate under the opening of the first regulating valve 4 and the opening of the second regulating valve 9 is basically equal. After a short shock, the pressure in the pressure line 13 reaches a state of slow rise or slow fall or stability. At this time, according to the change in the indication of the pressure sensor 7, the first actuator 6 is used to slightly adjust the opening of the first regulating valve 4 so that the pressure in the pressure line 13 reaches the required target pressure range and reaches a stable state. If the pressure in the pressure pipeline 13 does not reach the target pressure range after adjustment but it enters a balanced state and can no longer be fine-tuned by reducing the opening of the first regulating valve 4, the opening state of the first regulating valve 4 is maintained at this time, and the PWM algorithm control of the first pressure regulating component 3 and the second pressure regulating component 12 is used to accurately adjust the pressure in the pressure pipeline 13 to reach the required target pressure range.

[0060] Pressure reduction process: The pressure reduction control process of the device is also divided into two steps:

[0061] First, the first pressure regulating member 3 and the second pressure regulating member 12 are in a closed state, and the first regulating valve 4 and the second regulating valve 9 are also in a closed state. At this time, the entire device is in a closed state. The pressure control process of the entire device is a closed state pressure reduction control process: first, the second actuator 11 is used to open the second regulating valve 9 to a certain degree, and the gas from the gas source 1 flows out of the pressure pipeline 13 at a certain flow rate. The pressure sensor 7 monitors and feedbacks the pressure value in the pressure pipeline 13 in real time. As the pressure in the pressure pipeline 13 continues to decrease and gradually approaches the target pressure range, the second actuator 11 adjusts the opening of the second regulating valve 9 in real time and continuously reduces it. The closer the pressure in the pressure pipeline 13 is to the target pressure, the more accurate the control is. When the pressure in the pressure pipeline 13 reaches the target pressure to be controlled or does not reach the target pressure range but it enters a balanced state and can no longer be fine-tuned by reducing the opening of the second regulating valve 9, the second regulating valve 9 is closed. At this time, if the pressure in the pressure pipeline 13 has reached the target pressure range to be controlled, the pressure reduction and pressure control process is completed. If the target pressure range is not reached but the pressure reaches a balanced state and can no longer be fine-tuned by reducing the opening of the second regulating valve 9, the second regulating valve 9 is closed, and the pressure in the pressure pipeline 13 is precisely adjusted by using the PWM algorithm control of the first pressure regulating component 3 and the second pressure regulating component 12 to reach the required target pressure range.

[0062] In the second step, after the device reaches the required target pressure range and reaches a stable state in a closed state, the device is subjected to constant flow output voltage stabilization control. According to the flow requirement of the device that needs constant output (taking 10L / min as an example), the first actuator 6 and the second actuator 11 are used to simultaneously control the opening of the first regulating valve 4 and the second regulating valve 9 (at this time, the output opening of the second regulating valve 9 should be controlled at 10L / min), and the flow under the opening of the first regulating valve 4 and the opening of the second regulating valve 9 is ensured to be basically equal. After a short shock, the pressure in the pressure line 13 reaches a state of slow rise or slow fall or stability. At this time, according to the change in the indication of the pressure sensor 7, the first actuator 6 is used to slightly adjust the opening of the first regulating valve 4 so that the pressure in the pressure line 13 reaches the required target pressure range and reaches a stable state. If the pressure in the pressure pipeline 13 does not reach the target pressure range after adjustment but it enters a balanced state and can no longer be fine-tuned by reducing the opening of the first regulating valve 4, the opening state of the first regulating valve 4 is maintained at this time, and the PWM algorithm control of the first pressure regulating component 3 and the second pressure regulating component 12 is used to accurately adjust the pressure in the pressure pipeline 13 to reach the required target pressure range.

[0063] From the above description, it can be seen that the pressure control device and method for non-closed constant flow output of the above-mentioned embodiment of the present invention achieve the following technical effects: by setting the first flow regulating component and the second flow regulating component, the gas flow is accurately controlled, and the accurate matching of the inlet and outlet flow is achieved, and the gas in the pressure pipeline 13 can be accurately controlled at the same time. Furthermore, by setting the first pressure regulating component 3 and the second pressure regulating component 12, the pressure control accuracy of the flow regulating component is compensated, and more precise pressure control can be achieved, thereby accurately and stably controlling the pressure of the non-closed constant flow output system. Experiments have shown that the control accuracy of the internal pressure control of the open constant flow output system of the present invention can reach 0.01% FS, and the control stability is 0.005% FS.

[0064] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A non-sealed constant flow output pressure control device, characterized in that: include: A gas source component, used to provide the required gas; A pressure pipeline (13), one end of which is connected to the gas source component and the other end of which is connected to the atmosphere; a first flow regulating component, the first flow regulating component being arranged on the pressure pipeline (13) and being used for regulating the flow of the gas entering the pressure pipeline (13); a second flow regulating component, the second flow regulating component being arranged on the pressure pipeline (13) and located downstream of the first flow regulating component, and being used for regulating the flow of the gas flowing out of the pressure pipeline (13); A first pressure regulating member (3), the first pressure regulating member (3) and the first flow regulating component are connected in parallel to the pressure pipeline (13); a second pressure regulating member (12), one end of the second pressure regulating member (12) being connected to the pressure pipeline (13) and being located between the first flow regulating component and the second flow regulating component, and the other end of the second pressure regulating member (12) being connected to the atmosphere; The first pressure regulating member (3) and the second pressure regulating member (12) respectively increase and decrease the pressure of the gas in the pressure pipeline (13) so as to adjust the pressure of the gas to a target pressure range.

2. The pressure control device according to claim 1, characterized in that: The first flow regulating component comprises a first regulating valve (4), a first actuator (6) and a first flow sensor (5), wherein the first actuator (6) is used to control the opening of the first regulating valve (4), and the first flow sensor (5) is located downstream of the first regulating valve (4).

3. The pressure control device according to claim 2, characterized in that: The second flow regulating component comprises a second regulating valve (9), a second actuator (11) and a second flow sensor (10), wherein the second actuator (11) is used to control the opening of the second regulating valve (9), and the second flow sensor (10) is located downstream of the second regulating valve (9).

4. The pressure control device according to claim 3, characterized in that: The first regulating valve (4) and the second regulating valve (9) are needle valves, and the first pressure regulating member (3) and the second pressure regulating member (12) are solenoid valves.

5. The pressure control device according to any one of claims 1 to 4, characterized in that: The pressure control device further comprises a pressure sensor (7), which is connected to the pressure pipeline (13) and is located between the first flow regulating component and the second flow regulating component.

6. The pressure control device according to any one of claims 1 to 4, characterized in that: The pressure control device further comprises an air container (8), which is connected to the pressure pipeline (13) and is located between the first flow regulating component and the second flow regulating component.

7. The pressure control device according to any one of claims 1 to 4, characterized in that: The pressure control device further comprises a controller, which is electrically connected to the first flow regulating component, the second flow regulating component, the first pressure regulating member (3) and the second pressure regulating member (12) respectively.

8. A pressure control method for non-sealed constant flow output, characterized in that: The pressure control method is implemented by using the pressure control device according to any one of claims 1 to 7, and the pressure control method comprises: Step S1: first closing the first flow regulating component, the second flow regulating component, the first pressure regulating member (3) and the second pressure regulating member (12) to keep the pressure pipeline (13) airtight; Step S2: opening the first flow regulating component to allow the gas to enter the pressure pipeline (13), or opening the second flow regulating component to allow the gas in the pressure pipeline (13) to flow out; Step S3: when the pressure of the gas in the pressure pipeline (13) rises or falls to the target pressure range and remains stable, closing the first flow regulating component or the second flow regulating component; Step S4: adjusting the openings of the first regulating valve (4) of the first flow regulating assembly and the second regulating valve (9) of the second flow regulating assembly so that the gas in the pressure pipeline (13) is output to the outside at a preset output flow rate.

9. The pressure control method according to claim 8, characterized in that: The pressure control method further comprises: Step S5: when the pressure of the gas in the pressure pipeline (13) changes while being output to the outside, the opening of the first regulating valve (4) is adjusted so that the pressure of the gas in the pressure pipeline (13) is restored to the target pressure range and remains stable; Step S6: If the pressure of the gas in the pressure pipeline (13) cannot be restored to the target pressure range by adjusting the opening of the first regulating valve (4), open the first pressure regulating component (3) and / or the second pressure regulating component (12) to increase and / or reduce the pressure so that the pressure of the gas in the pressure pipeline (13) is restored to the target pressure range.

10. The pressure control method according to claim 8 or 9, characterized in that: The step S3 further comprises: When the pressure of the gas in the pressure pipeline (13) rises or falls and gradually approaches the target pressure range, adjusting the opening of the first regulating valve (4) so ​​that the pressure of the gas in the pressure pipeline (13) is adjusted to the target pressure range; If the pressure of the gas in the pressure pipeline (13) cannot be adjusted to the target pressure range by adjusting the opening of the first regulating valve (4), the first pressure regulating member (3) and / or the second pressure regulating member (12) are opened to increase and / or decrease the pressure so that the pressure of the gas in the pressure pipeline (13) is adjusted to the target pressure range.

Images