Ultra-large flow unloading valve loading pressure control system and method

Abstract

The invention provides an ultra-large flow unloading valve loading pressure control system and method, and the system comprises a first pipeline which is provided with a first adjustment assembly; a second adjusting assembly is arranged on the second pipeline; the connecting pipeline is connected with an energy accumulator group; the tested unloading valve at least has a pressurization state and an unloading state; a working port of the tested unloading valve is communicated with the first end of the connecting pipeline, the first pipeline is connected with the second pipeline in parallel, and the second end of the connecting pipeline is communicated with the first end of the first pipeline and the first end of the second pipeline. The load simulation effect is closer to the real working condition; regulation and control of pressurization duration and loading pressure gradient in a pressurization state are achieved, regulation and control of unloading duration and unloading pressure gradient in an unloading state are achieved, the whole device is flexible and adjustable, and the problems that pressure impact is too large and a system pipeline vibrates due to the fact that liquid charging and discharging of an energy accumulator are too fast are solved; the energy accumulator does not need to adopt a larger volume.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic valve testing, and in particular to a super-large flow unloading valve loading pressure control system and method. Background Art

[0002] The unloading valve is a key control component in coal mine emulsion pumping stations. By regulating the pumping station's pressure, it ensures the stability and flexibility of the emulsion supply process. When the pressure in the support working face pipeline exceeds the preset maximum operating pressure, the unloading valve begins unloading, reducing the emulsion pump's supply pressure. When the pressure in the support working face pipeline falls below the preset minimum operating pressure, the unloading valve stops unloading, restoring the emulsion pump's supply pressure. This process eliminates overflow losses and achieves energy-saving benefits.

[0003] Coal industry standards require that the pressure regulation performance test of unloading valves be conducted under full flow conditions. Currently, unloading valves are developing towards ultra-large flow rates (for example, 2000L / min), which places stricter demands on the loading pressure control capability of the test system. If the loading time is too short, it is easy to cause problems such as large hydraulic shock and pipeline vibration. If the accumulator is required to have a good energy storage and buffering effect, then the accumulator needs to have a larger total volume, that is, more accumulators are required to form an accumulator group, which increases the complexity of the test system. Summary of the Invention

[0004] The main purpose of the present invention is to provide a hydraulic valve-controlled actuator displacement control system and method to solve at least one of the technical problems in the prior art of installing linear or angular displacement sensors on valve-controlled actuators, which are limited by environmental requirements and installation space requirements.

[0005] In order to achieve the above object, the present invention provides an ultra-large flow unloading valve loading pressure control system, comprising:

[0006] a first pipeline, wherein a first regulating assembly is provided on the first pipeline;

[0007] a second pipeline, wherein a second regulating assembly is provided on the second pipeline;

[0008] a connecting pipeline, wherein the connecting pipeline is connected to the accumulator group;

[0009] The unloading valve under test shall have at least a pressurized state and an unloading state;

[0010] The working port of the tested unloading valve is communicated with the first end of the connecting pipeline, the first pipeline and the second pipeline are connected in parallel, and the second end of the connecting pipeline is communicated with the first end of the first pipeline and the first end of the second pipeline.

[0011] Furthermore, when the tested unloading valve is in a pressurized state, the liquid outlet of the tested unloading valve is cut off, the liquid inlet and the working port of the tested unloading valve are connected to each other, the second regulating component is closed, and the loading pressure gradient of the accumulator group is adjusted by the first regulating component.

[0012] Furthermore, when the tested unloading valve is in the unloading state, the working port of the tested unloading valve is cut off, the liquid inlet and liquid outlet of the tested unloading valve are connected to each other, the first regulating component is closed, and the unloading pressure gradient of the accumulator group is adjusted by the second regulating component.

[0013] Furthermore, the first regulating assembly includes a first regulating valve, and the loading pressure gradient of the accumulator group is adjusted by the first regulating valve.

[0014] Furthermore, the second regulating assembly includes a second regulating valve, and the unloading pressure gradient of the accumulator group is adjusted by the second regulating valve.

[0015] Furthermore, the first regulating component further includes a first switch valve, which is arranged in series with the first regulating valve on the first pipeline, and the first pipeline is opened or closed by the first switch valve.

[0016] Furthermore, the second regulating component further includes a second switch valve, which is arranged in series with the second regulating valve on the second pipeline, and the second pipeline is opened or closed by the second switch valve.

[0017] Furthermore, the operating opening of the second regulating valve is smaller than the operating opening of the first regulating valve.

[0018] Furthermore, the accumulator group includes at least one accumulator, and the liquid cavity interfaces of the accumulator are respectively communicated with the connecting pipelines.

[0019] The present invention also provides a method for controlling the loading pressure of an ultra-large flow unloading valve, which adopts the control system and includes:

[0020] When the unloading valve under test is in a pressurized state, the second pipeline is closed by the second regulating component, and the first flow of the first pipeline is adjusted by the first regulating component to control the change of the loading pressure gradient;

[0021] When the tested unloading valve is in the unloading state, the first pipeline is closed by the first regulating component, and the second flow of the second pipeline is adjusted by the second regulating component to control the change of the unloading pressure gradient.

[0022] The ultra-large flow unloading valve loading pressure control system in the present invention adopts capacitive loading means and uses an accumulator to simulate the liquid chamber of the comprehensive mining working face liquid supply system. The load simulation effect is closer to the actual working conditions; the first regulating component is used to realize the pressurization duration and loading pressure gradient regulation in the pressurization (loading) state, and the second regulating component is used to realize the unloading duration and unloading pressure gradient regulation in the unloading state. The overall flexibility is adjustable, which can avoid the problem of excessive pressure shock and vibration of the system pipeline caused by too fast charging and discharging of the accumulator; different specifications of the first regulating component and the second regulating component can be used for large flow and small flow respectively (usually the liquid inlet is a large flow, and the total discharge flow of the accumulator group is a small flow), so that the accumulator does not need to adopt a larger volume.

[0023] The ultra-large flow unloading valve loading pressure control method in the present invention adopts a control method based on the accumulator gas pressure derivative principle. Capacitive loading means is adopted in the corresponding control system, and the accumulator is used to simulate the liquid chamber of the comprehensive mining working face liquid supply system. The load simulation effect is closer to the actual working condition. The control method realizes the boosting duration and loading pressure gradient regulation in the boosting (loading) state through the first regulating component, and realizes the unloading duration and unloading pressure gradient regulation in the unloading state through the second regulating component. The overall method is flexible and adjustable, which can avoid the problem of excessive pressure shock and vibration of the system pipeline caused by too fast charging and discharging of the accumulator. Different specifications of first regulating components and second regulating components can be used for large flow and small flow respectively (usually the liquid inlet is large flow, and the total discharge flow of the accumulator group is small flow), so that the accumulator does not need to adopt a larger volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 A structural diagram of a large flow unloading valve loading pressure control system provided by an embodiment of the present invention;

[0026] Figure 2 A structural diagram of a super-large flow unloading valve loading pressure control system in a pressurized state provided by an embodiment of the present invention;

[0027] Figure 3 This is a structural diagram of the ultra-large flow unloading valve loading pressure control system provided by an embodiment of the present invention in the unloading state.

[0028] The above drawings include the following reference numerals:

[0029] 1. First pipeline; 11. First regulating valve; 12. First on-off valve; 2. Second pipeline; 21. Second regulating valve; 22. Second on-off valve; 3. Connecting pipeline; 31. Accumulator group; 4. Test unloading valve. DETAILED DESCRIPTION

[0030] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0032] Unless otherwise specifically stated, the relative arrangement of the parts and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0033] The present invention provides a large flow unloading valve loading pressure control system, combined with Figure 1 Shown, including:

[0034] A first pipeline 1, wherein the first pipeline 1 is provided with a first regulating component;

[0035] A second pipeline 2, wherein the second pipeline 2 is provided with a second regulating assembly;

[0036] A connecting pipeline 3, to which an accumulator group 31 is connected;

[0037] The unloading valve 4 under test has at least a pressurizing state and an unloading state;

[0038] The working port of the tested unloading valve 4 is connected to the first end of the connecting pipeline 3, the first pipeline 1 and the second pipeline 2 are connected in parallel, and the second end of the connecting pipeline 3 is connected to the first end of the first pipeline 1 and the first end of the second pipeline 2.

[0039] Specifically, combined Figure 1 As shown, the first regulating component on the first pipeline 1 can adopt various devices or components that can directly or indirectly regulate the pipeline flow, and the second regulating component on the second pipeline 2 can adopt various devices or components that can directly or indirectly regulate the pipeline flow. The first regulating component and the second regulating component can, for example, adopt regulating valves or valve groups, which are not specifically limited here.

[0040] The connecting line 3 is connected to an accumulator group 31. For example, the accumulator group 31 includes at least one accumulator, and the liquid cavity interfaces of the accumulator are respectively connected to the connecting line 3. Figure 1 Three accumulators are shown in the figure. In actual application, a corresponding number of accumulators can be selected according to needs, and no specific limitation is made here.

[0041] Exemplarily, the tested unloading valve 4 has a liquid inlet P, a liquid outlet T, and a working port A. The tested unloading valve 4 has at least a pressurized state and an unloading state. When the tested unloading valve 4 is in the pressurized state, the liquid outlet T is cut off, and the liquid inlet P is connected to the working port A; when the tested unloading valve 4 is in the unloading state, the working port A is reversely cut off, and the liquid inlet P is connected to the liquid outlet T.

[0042] The following is a detailed description of the working principle of the ultra-large flow unloading valve loading pressure control system in the embodiment of the present invention: When the accumulator group 31 is filled or discharged, the gas is compressed and the pressure changes. When the liquid pressure is lower than the gas pressure, the gas expands and discharges the liquid outward, and the pressure drops; when the liquid pressure is higher than the gas pressure, the accumulator is filled with liquid, the gas is compressed, and the pressure rises. The volume change of the gas is the same as the volume change of the liquid in the accumulator, but the elastic modulus of the liquid is much greater than that of the gas. During the pressure change process, the compression of the liquid is negligible compared to the compression of the gas. Therefore, the hydraulic derivative and the gas pressure derivative are approximately the same, and the following relationship exists:

[0043]

[0044] Where:

[0045] V1——The volume of compressed gas when the accumulator output pressure is P1;

[0046] P1 - accumulator output pressure. When the accumulator is in the charging and discharging stage, the output pressure is approximately equal to the pressure of the accumulator gas after compression;

[0047] n is the ratio of the heat capacity of a gas at constant pressure to the heat capacity of a gas at constant volume, in adiabatic state, which is about 1.4;

[0048] Q1——Liquid flow rate of the accumulator when the accumulator output pressure is P1.

[0049] The above formula shows that the change in P1's pressure gradient (dP1 / dt) is positively correlated with Q1; the greater the flow rate, the greater the pressure gradient. It is negatively correlated with V1. If P1 is in the loading phase, V1 is negative, meaning V1 is a positive gain factor. If P1 is in the unloading phase, V1 is positive, meaning V1 is a negative gain factor. Therefore, the speed of pressure change can be changed by controlling the accumulator's charging and discharging rate.

[0050] Furthermore, when the tested unloading valve 4 is in the pressurized state, the liquid outlet of the tested unloading valve 4 is cut off, the liquid inlet and the working port of the tested unloading valve 4 are connected to each other, the second regulating component is closed, and the loading pressure gradient of the accumulator group 31 is adjusted by the first regulating component.

[0051] Combine Figure 2 As shown, the unloading valve 4 under test is in the pressurized state, the second regulating assembly is closed, preventing liquid from passing through the second pipeline 2, and the first regulating assembly is open, allowing liquid to pass through the first pipeline 1. At this time, the flow rate at the liquid inlet P is Q, the flow rate out of the working port A is Q2, the total filling flow rate of the accumulator group 31 is Q3, the flow rate at the second end of the connecting pipeline 3 is Q4, and the flow rate of the first pipeline 1 is Q5. The first regulating assembly can adjust the flow rate of the first pipeline 1 to Q5. In the above process, the various flow rates are in the following relationship: Q = Q2 = Q3 + Q4, and Q4 = Q5.

[0052] Therefore, the flow rate Q5 of the first pipeline 1 is adjusted by the first adjustment component. If Q5 increases, Q3 decreases, the loading pressure gradient decreases, and the boost duration becomes longer; if Q5 decreases, Q3 increases, the loading pressure gradient increases, and the boost duration becomes shorter.

[0053] Furthermore, when the tested unloading valve 4 is in the unloading state, the working port of the tested unloading valve 4 is cut off, the liquid inlet and the liquid outlet of the tested unloading valve 4 are connected to each other, the first regulating component is closed, and the unloading pressure gradient of the accumulator group 31 is adjusted by the second regulating component.

[0054] Combine Figure 3As shown, the unloading valve 4 under test is in the unloading state. The first regulating assembly is closed, preventing liquid from passing through the first pipeline 2. The second regulating assembly is open, allowing liquid to pass through the second pipeline 2. At this time, the working port A is reversely blocked. The total discharge flow rate of the accumulator group 31 is Q3, the flow rate at the second end of the connecting pipeline 3 is Q4, and the flow rate of the second pipeline 2 is Q6. The second regulating assembly can adjust the flow rate of the second pipeline 2 to Q6. In this process, the relationships between the flow rates are: Q3 = Q4, and Q4 = Q6.

[0055] Therefore, the flow rate Q6 of the second pipeline 2 is adjusted by the second regulating component. If Q6 increases, the pressure drop rate becomes faster, the unloading pressure gradient increases, and the accumulator discharge and unloading duration becomes shorter; if Q6 decreases, the pressure drop rate becomes slower, the unloading pressure gradient decreases, and the unloading duration becomes longer.

[0056] The ultra-large flow unloading valve loading pressure control system in the present invention adopts capacitive loading means and uses an accumulator to simulate the liquid chamber of the comprehensive mining working face liquid supply system. The load simulation effect is closer to the actual working conditions; the first regulating component is used to realize the pressurization duration and loading pressure gradient control in the pressurization (loading) state, and the second regulating component is used to realize the unloading duration and unloading pressure gradient control in the unloading state. The overall flexibility is adjustable, which can avoid the problem of excessive pressure shock and vibration of the system pipeline caused by too fast charging and discharging of the accumulator; different specifications of the first regulating component and the second regulating component can be used for large flow and small flow respectively (usually the liquid inlet P is a large flow, and the total discharge flow of the accumulator group 31 is a small flow), so that the accumulator does not need to adopt a larger volume.

[0057] Preferably, the first regulating assembly includes a first regulating valve 11 , and the loading pressure gradient of the accumulator group 31 is adjusted by the first regulating valve 11 .

[0058] Furthermore, the second regulating assembly includes a second regulating valve 21 , and the unloading pressure gradient of the accumulator group 31 is adjusted by the second regulating valve 21 .

[0059] The first regulating valve 11 and the second regulating valve 21 here can be any valve with flow regulation capability. The first regulating valve 11 and the second regulating valve 21 can be used to regulate the flow of the first pipeline 1 and the second pipeline 2 respectively, thereby realizing the function of regulating the boost duration and the unloading duration.

[0060] Preferably, the first regulating assembly further includes a first switch valve 12 , which is arranged in series with the first regulating valve 11 on the first pipeline 1 , and the first pipeline 1 is opened or closed by the first switch valve 12 .

[0061] Furthermore, the second regulating component further includes a second switch valve 22 , which is arranged in series with the second regulating valve 21 on the second pipeline 2 , and the second pipeline 2 is opened or closed by the second switch valve 22 .

[0062] The first switch valve 12 and the second switch valve 22 here can be any valve with a liquid circuit on-off function. The first switch valve 12 and the second switch valve 22 can respectively control the liquid circuit on-off of the first pipeline 1 and the second pipeline 2, and then can correspondingly control the on-off of the corresponding pipeline when switching between the boost state and the unloading state.

[0063] Preferably, the operating opening of the second regulating valve 21 is smaller than the operating opening of the first regulating valve 11 .

[0064] Combine Figure 2 As shown, the first pipeline 1 is opened by the first switch valve 12, and the loading pressure gradient is adjusted by the first regulating valve 11. In this process, the opening amplitude of the first regulating valve 11 is the working opening of the first regulating valve 11; combined with Figure 3 As shown, the second pipeline 2 is opened by the second switch valve 22 , and the unloading pressure gradient is adjusted by the second regulating valve 21 . In this process, the opening amplitude of the second regulating valve 21 is the working opening degree of the second regulating valve 21 .

[0065] The operating opening of the second regulating valve 21 is smaller than that of the first regulating valve 11 , which is more suitable for ultra-large flow conditions.

[0066] In the boost state, the liquid flow rate of the liquid source is very large (the maximum flow rate is about 2000 L / min). It enters the connecting pipeline 3 through the liquid inlet P and the working port A, and is respectively directed to the accumulator group 31 and the first pipeline 1. The flow rate Q3 entering the accumulator group 31 is very small (Q3 is smaller than the maximum flow rate of 2000 L / min), and the flow rate Q5 entering the first pipeline 1 is very large. Therefore, the first regulating valve 11 needs to adopt a larger working opening to slow down the filling speed of the accumulator group 31 as much as possible to prevent the accumulator from filling too quickly.

[0067] In the unloading state, the working port A is reversely blocked, and the total discharge flow rate Q6 of the accumulator group 31 is very small (Q3 is smaller than the ultra-large flow rate of 2000L / min). The liquid coming out of the accumulator group 31 enters the second pipeline 2 through the connecting pipeline 3. The flow rate Q6 into the second pipeline 2 is Q3, and its flow value is also very small. The second regulating valve 21 needs to adopt a smaller working opening, which can achieve better unloading pressure gradient control and slow down the discharge speed of the accumulator group 31 as much as possible to avoid excessive discharge of the accumulator.

[0068] The present invention also provides a method for controlling the loading pressure of an ultra-large flow unloading valve, which adopts the control system described above, and the control system includes:

[0069] A first pipeline 1, wherein the first pipeline 1 is provided with a first regulating component;

[0070] A second pipeline 2, wherein the second pipeline 2 is provided with a second regulating assembly;

[0071] A connecting pipeline 3, to which an accumulator group 31 is connected;

[0072] The unloading valve 4 under test has at least a pressurizing state and an unloading state;

[0073] The working port of the tested unloading valve 4 is connected to the first end of the connecting pipeline 3, the first pipeline 1 and the second pipeline 2 are connected in parallel, and the second end of the connecting pipeline 3 is connected to the first end of the first pipeline 1 and the first end of the second pipeline 2.

[0074] The control method includes:

[0075] When the unloading valve 4 under test is in a pressurized state, the second pipeline 2 is closed by the second regulating component, and the first flow of the first pipeline 1 is adjusted by the first regulating component to control the change of the loading pressure gradient;

[0076] When the tested unloading valve 4 is in the unloading state, the first pipeline 1 is closed by the first regulating component, and the second flow of the second pipeline 2 is adjusted by the second regulating component to control the change of the unloading pressure gradient.

[0077] The loading pressure control method of the ultra-large flow unloading valve in the present invention adopts a control method based on the principle of the derivative of the gas pressure of the accumulator, adopts capacitive loading means, and uses the accumulator to simulate the liquid chamber of the comprehensive mining working face liquid supply system. The load simulation effect is closer to the actual working condition; the boosting duration and loading pressure gradient control in the boosting (loading) state are realized by the first regulating component, and the unloading duration and unloading pressure gradient control in the unloading state are realized by the second regulating component. The overall flexibility and adjustment can avoid the problem of excessive pressure shock and vibration of the system pipeline caused by the accumulator filling and discharging too quickly; different specifications of the first regulating component and the second regulating component can be used for large flow and small flow respectively (usually the liquid inlet P is a large flow, and the total discharge flow of the accumulator group 31 is a small flow), so that the accumulator does not need to adopt a larger volume.

[0078] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "horizontal, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention; the directional words "inside and outside" refer to the inside and outside relative to the outline of each component itself.

[0079] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0080] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A large flow unloading valve loading pressure control system, characterized in that: include: a first pipeline, wherein a first regulating assembly is provided on the first pipeline; a second pipeline, wherein a second regulating assembly is provided on the second pipeline; a connecting pipeline, wherein the connecting pipeline is connected to the accumulator group; The unloading valve under test shall have at least a pressurized state and an unloading state; The working port of the tested unloading valve is communicated with the first end of the connecting pipeline, the first pipeline and the second pipeline are connected in parallel, and the second end of the connecting pipeline is communicated with the first end of the first pipeline and the first end of the second pipeline.

2. The control system according to claim 1, characterized in that: When the tested unloading valve is in a pressurized state, the liquid outlet of the tested unloading valve is cut off, the liquid inlet and the working port of the tested unloading valve are connected to each other, the second regulating component is closed, and the loading pressure gradient of the accumulator group is adjusted by the first regulating component.

3. The control system according to claim 1, characterized in that: When the tested unloading valve is in the unloading state, the working port of the tested unloading valve is cut off, the liquid inlet and the liquid outlet of the tested unloading valve are connected to each other, the first regulating component is closed, and the unloading pressure gradient of the accumulator group is adjusted by the second regulating component.

4. The control system according to claim 1, characterized in that: The first regulating assembly includes a first regulating valve, through which the loading pressure gradient of the accumulator group is adjusted.

5. The control system according to claim 4, characterized in that: The second regulating assembly includes a second regulating valve, and the unloading pressure gradient of the accumulator group is adjusted by the second regulating valve.

6. The control system according to claim 4, characterized in that: The first regulating component further includes a first switch valve, which is arranged in series with the first regulating valve on the first pipeline, and the first pipeline is opened or closed by the first switch valve.

7. The control system according to claim 5, characterized in that: The second regulating assembly further includes a second switch valve, which is arranged in series with the second regulating valve on the second pipeline, and the second pipeline is opened or closed by the second switch valve.

8. The control system according to claim 5, characterized in that: The operating opening of the second regulating valve is smaller than the operating opening of the first regulating valve.

9. The control system according to claim 1, characterized in that: The accumulator group includes at least one accumulator, and the liquid chamber interfaces of the accumulator are respectively communicated with the connecting pipelines.

10. A method for controlling the loading pressure of an ultra-large flow unloading valve, characterized in that: The control system according to any one of claims 1 to 9 comprises: When the unloading valve under test is in a pressurized state, the second pipeline is closed by the second regulating component, and the first flow of the first pipeline is adjusted by the first regulating component to control the change of the loading pressure gradient; When the tested unloading valve is in the unloading state, the first pipeline is closed by the first regulating component, and the second flow of the second pipeline is adjusted by the second regulating component to control the change of the unloading pressure gradient.

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