Fluid pipeline switching device, switching method and coating system

Abstract

The present invention discloses a fluid pipeline switching device, a switching method and a coating system. The fluid pipeline switching device includes a first three-way proportional valve, a second three-way proportional valve, a first fluid processing member, a second fluid processing member, a first drain valve and a second drain valve; the first three-way proportional valve is adapted to input the fluid to be processed; the first fluid processing member is communicated with the first three-way proportional valve; the second fluid processing member is communicated with the first three-way proportional valve; the second three-way proportional valve is adapted to output the processed fluid; the first fluid processing member is communicated with the second three-way proportional valve, and the first drain valve is arranged on the pipeline between the first fluid processing member and the second three-way proportional valve; the second fluid processing member is communicated with the second three-way proportional valve, and the second drain valve is arranged on the pipeline between the second fluid processing member and the second three-way proportional valve. The present invention improves the switching device, enhances the air drainage effect, greatly reduces the fluid pulsation generated during switching, and realizes non-stop and maintenance-free switching.

Description

Technical Field

[0001] The present invention relates to the technical field of pipeline switching devices, and in particular to a fluid pipeline switching device, a switching method and a coating system. Background Art

[0002] In the field of fluid pipeline transportation, especially in the fields of food, medicine, and lithium battery coating, high requirements are placed on the quality of pipeline fluids, which often need to undergo multiple filtrations and impurity removals before being made into finished products to ensure that the transported fluids have high quality and high value. Therefore, how to improve the overall pipeline transportation efficiency has become an extremely critical link.

[0003] In traditional technology, after working for a period of time, the filter and impurity removal devices will absorb certain impurities on their surface, which will increase the resistance of the fluid in the pipeline, so they need to be cleaned or replaced regularly. If the filter and impurity removal devices are connected in series in the fluid delivery pipeline, the machine must be shut down for cleaning and replacement, and can only continue to operate after the replacement is completed, which leads to low fluid delivery efficiency.

[0004] At present, in order to improve production efficiency, the method of connecting the working components in the pipeline in parallel is widely used in practical applications. When cleaning and replacing, the manual ball valve or pneumatic ball valve is switched to the bypass to continue transportation. This solution improves the transportation efficiency to a certain extent.

[0005] However, during the coating process, the feed pressure is required to be stable, but this switching device will cause large pulsation when switching pipelines, affecting the coating quality. Summary of the invention

[0006] The main purpose of the present invention is to provide a fluid pipeline switching device, a switching method and a coating system, aiming to reduce the fluid pulsation generated at the switching moment to improve the coating quality.

[0007] To achieve the above object, the present invention provides a fluid pipeline switching device, comprising:

[0008] A first three-way proportional valve, wherein a first pressure sensor is disposed at a first end of the first three-way proportional valve, and the first pressure sensor is used to connect to the fluid to be processed and detect the fluid pressure;

[0009] a first fluid processing member, wherein a feed end of the first fluid processing member is in communication with a second end of the first three-way proportional valve;

[0010] a second fluid processing member, wherein a feed end of the second fluid processing member is connected to a third end of the first three-way proportional valve and is arranged in parallel with the first fluid processing member;

[0011] a second three-way proportional valve, wherein a first end of the second three-way proportional valve is adapted to output the processed fluid;

[0012] A first drain valve, wherein the discharge end of the first fluid processing component is connected to the second end of the second three-way proportional valve, and the first drain valve is arranged on the pipeline between the first fluid processing component and the second three-way proportional valve; and

[0013] The second drain valve, the discharge end of the second fluid processing component is connected to the third end of the second three-way proportional valve, and the second drain valve is arranged on the pipeline between the second fluid processing component and the second three-way proportional valve.

[0014] Optionally, the fluid pipeline switching device further includes a second pressure sensor, which is disposed at the first end of the second three-way proportional valve, and is used to detect the pressure of the processed fluid.

[0015] Optionally, the first fluid processing component is a filter or an iron remover; the second fluid processing component is a filter or an iron remover.

[0016] Optionally, the fluid pipeline switching device further includes:

[0017] A first discharge ball valve is provided on the pipeline between the first fluid treatment component and the first three-way proportional valve; and

[0018] The second discharge ball valve is arranged on the pipeline between the second fluid processing component and the first three-way proportional valve.

[0019] Optionally, the fluid pipeline switching device further includes:

[0020] a third pressure sensor, disposed on the first exhaust valve, for detecting the exhaust pressure of the first fluid processing member; and

[0021] The fourth pressure sensor is disposed on the second exhaust valve to detect the exhaust pressure of the second fluid processing component.

[0022] Optionally, the first three-way proportional valve is an electric proportional three-way ball valve; and the second three-way proportional valve is an electric proportional three-way ball valve.

[0023] Optionally, the first drain valve is a pneumatic two-way clamp ball valve; the second drain valve is a pneumatic two-way clamp ball valve.

[0024] In order to achieve the above object, the present invention further proposes a switching method of a fluid pipeline switching device. Based on the fluid pipeline switching device as described above, the switching method comprises the following steps:

[0025] S10, detecting a feed pressure value of the first fluid processing component;

[0026] S20, when the feed pressure value reaches a preset pressure value, starting the second drain valve to connect to the atmosphere;

[0027] S30, gradually adjusting the valve core opening of the first three-way proportional valve to a first target opening value, and gradually increasing the feeding speed of the feeding pump to a target feeding speed value to compensate for the flow loss of the second fluid processing component;

[0028] S40, detecting the exhaust pressure value of the second exhaust valve;

[0029] S50, when the exhaust pressure value is at a constant value, gradually adjust the valve core opening of the first three-way proportional valve back to the initial opening value, and gradually reduce the feeding speed of the feed pump to the initial feeding speed;

[0030] S60, closing the second drain valve;

[0031] S70, gradually adjusting the valve core opening of the first three-way proportional valve to a second target opening value, and gradually adjusting the valve core opening of the second three-way proportional valve to a third target opening value.

[0032] Optionally, the preset pressure value is 0.5 MPa; the initial opening value is 0%; the first target opening value is 20%; the second target opening value is 100%; and the third target opening value is 100%.

[0033] In order to achieve the above object, the present invention further provides a coating system, comprising the fluid pipeline switching device as described above, wherein the fluid pipeline switching device comprises:

[0034] A first three-way proportional valve, wherein a first pressure sensor is disposed at a first end of the first three-way proportional valve, and the first pressure sensor is used to connect to the fluid to be processed and detect the fluid pressure;

[0035] a first fluid processing member, wherein a feed end of the first fluid processing member is in communication with a second end of the first three-way proportional valve;

[0036] a second fluid processing member, wherein a feed end of the second fluid processing member is connected to a third end of the first three-way proportional valve and is arranged in parallel with the first fluid processing member;

[0037] a second three-way proportional valve, wherein a first end of the second three-way proportional valve is adapted to output the processed fluid;

[0038] A first drain valve, wherein the discharge end of the first fluid processing component is connected to the second end of the second three-way proportional valve, and the first drain valve is arranged on the pipeline between the first fluid processing component and the second three-way proportional valve; and

[0039] The second drain valve, the discharge end of the second fluid processing component is connected to the third end of the second three-way proportional valve, and the second drain valve is arranged on the pipeline between the second fluid processing component and the second three-way proportional valve.

[0040] It can be understood that the fluid pipeline switching device of the present invention is provided with a first exhaust valve and a second exhaust valve to exhaust the air in the pipeline, and the first three-way proportional valve and the second three-way proportional valve gradually change the valve core opening to smoothly adjust the fluid flow and pressure, and cooperate with the first pressure sensor to adjust the pressure of the fluid during the switching process so that the fluid smoothly transitions to the bypass, greatly reducing the fluid pulsation generated at the moment of switching and improving the coating quality. In addition, the fluid pipeline switching device is provided with a first exhaust valve and a second exhaust valve to exhaust the air in the pipeline. Before the switching action starts, the air in the bypass working device can be exhausted to avoid the generation of bubbles in the fluid delivery pipeline, thereby improving the quality of the delivered fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0042] Figure 1 It is a structural schematic diagram of an embodiment of a fluid pipeline switching device of the present invention;

[0043] Figure 2 It is a principle diagram of an embodiment of a fluid pipeline switching device of the present invention;

[0044] Figure 3 It is a flow chart of an embodiment of a switching method of a fluid pipeline switching device of the present invention.

[0045] Description of Figure Numbers:

[0046] 10. First three-way proportional valve; 20. First fluid processing component; 30. Second fluid processing component; 40. Second three-way proportional valve; 50. First drain valve; 60. Second drain valve; 11. First pressure sensor; 41. Second pressure sensor; 70. First discharge ball valve; 80. Second discharge ball valve; 51. Third pressure sensor; 61. Fourth pressure sensor.

[0047] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0048] The following will be combined with the 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 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.

[0049] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0050] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0051] The present invention provides a fluid pipeline switching device, which can be applicable to a coating system, but is not limited here.

[0052] Reference Figure 1 and Figure 2In one embodiment of the present invention, the fluid pipeline switching device includes a first three-way proportional valve 10, a second three-way proportional valve 40, a first fluid processing component 20, a second fluid processing component 30, a first drain valve 50 and a second drain valve 60; the first end of the first three-way proportional valve 10 is suitable for inputting a fluid to be processed and is provided with a first pressure sensor 11, and the first pressure sensor 11 is used to detect the fluid pressure; the feed end of the first fluid processing component 20 is connected to the second end of the first three-way proportional valve 10; the feed end of the second fluid processing component 30 is connected to the first three-way proportional valve 10 The third end of the second fluid processing component 30 is connected, and the second fluid processing component 30 is arranged in parallel with the first fluid processing component 20; the first end of the second three-way proportional valve 40 is suitable for outputting the processed fluid; the discharge end of the first fluid processing component 20 is connected to the second end of the second three-way proportional valve 40, and the first drain valve 50 is arranged on the pipeline between the first fluid processing component 20 and the second three-way proportional valve 40; the discharge end of the second fluid processing component 30 is connected to the third end of the second three-way proportional valve 40, and the second drain valve 60 is arranged on the pipeline between the second fluid processing component 30 and the second three-way proportional valve 40.

[0053] In this embodiment, the first three-way proportional valve 10 may be an electric proportional three-way ball valve, and the second three-way proportional valve 40 may be an electric proportional three-way ball valve, etc., which is not specifically limited here.

[0054] In this embodiment, the first fluid treatment component 20 may be a filter or an iron remover, and the second fluid treatment component 30 may also be a filter or an iron remover, which is not specifically limited here.

[0055] In this embodiment, the first drain valve 50 may be a pneumatic two-way clamp ball valve, etc., and the second drain valve 60 may also be a pneumatic two-way clamp ball valve, etc., which is not specifically limited here.

[0056] It should be noted that the components of the fluid pipeline switching device can be connected through pipelines, and the connection parts can use quick-release chucks, two-way joints, three-way joints and other connectors. The pipeline can be preferably a sanitary stainless steel pipe fitting, and the connector can be preferably a sanitary quick-release three-way joint. The specific pipeline structure is not limited here.

[0057] In the technical solution of the present invention, the fluid pipeline switching device includes a first three-way proportional valve 10, a second three-way proportional valve 40, a first fluid processing component 20, a second fluid processing component 30, a first drain valve 50 and a second drain valve 60; the first end of the first three-way proportional valve 10 is suitable for inputting a fluid to be processed and is provided with a first pressure sensor 11, and the first pressure sensor 11 detects the fluid pressure; the feed end of the first fluid processing component 20 is connected to the second end of the first three-way proportional valve 10; the feed end of the second fluid processing component 30 is connected to the first three-way proportional valve 10 The third end is connected, the second fluid treatment part 30 is arranged in parallel with the first fluid treatment part 20; the first end of the second three-way proportional valve 40 is suitable for outputting the processed fluid; the discharge end of the first fluid treatment part 20 is connected with the second end of the second three-way proportional valve 40, and the first emptying valve 50 is arranged on the pipeline between the first fluid treatment part 20 and the second three-way proportional valve 40; the discharge end of the second fluid treatment part 30 is connected with the third end of the second three-way proportional valve 40, and the second emptying valve 60 is arranged on the pipeline between the second fluid treatment part 30 and the second three-way proportional valve 40. It can be understood that the fluid pipeline switching device of the present invention is provided with the first emptying valve 50 and the second emptying valve 60 to empty the air in the pipeline, the first three-way proportional valve 10 and the second three-way proportional valve 40 gradually change the valve core opening to smoothly adjust the fluid flow and pressure, and cooperate with the first pressure sensor 11 to work, so as to adjust the pressure of the fluid during the switching process, so that the fluid smoothly transitions to the bypass, greatly reducing the fluid pulsation generated at the switching moment, and improving the coating quality. In addition, the fluid pipeline switching device exhausts the air in the pipeline by setting a first exhaust valve 50 and a second exhaust valve 60. Before the switching action starts, the air in the bypass working device can be exhausted to avoid the generation of bubbles in the fluid delivery pipeline, thereby improving the quality of the delivered fluid.

[0058] In order to further reduce the fluid pulsation generated at the switching moment and further improve the quality of the conveyed fluid, refer to Figure 1 and Figure 2 In one embodiment, the fluid pipeline switching device may further include a second pressure sensor 41, which is disposed at the first end of the second three-way proportional valve 40, and is used to detect the pressure of the processed fluid.

[0059] In this embodiment, by providing the second pressure sensor 41, the pressure of the delivered fluid can be detected, thereby determining whether the fluid pipeline is in a stable state, to ensure that the fluid is completely transferred to the bypass.

[0060] In order to facilitate the cleaning of the slurry in the blocked pipeline after switching the pipeline, in one embodiment, the fluid pipeline switching device may also include a first discharge ball valve 70 and a second discharge ball valve 80; the first discharge ball valve 70 is arranged on the pipeline between the first fluid processing component 20 and the first three-way proportional valve 10; the second discharge ball valve 80 is arranged on the pipeline between the second fluid processing component 30 and the first three-way proportional valve 10.

[0061] In order to adjust the fluid pressure during the switching process so that the fluid can smoothly transition to the bypass and further reduce the fluid pulsation generated at the moment of switching, refer to Figure 1 and Figure 2 In one embodiment, the fluid pipeline switching device may also include a third pressure sensor 51 and a fourth pressure sensor 61. The third pressure sensor 51 is arranged on the first drain valve 50 to detect the drain pressure of the first fluid processing component 20; the fourth pressure sensor 61 is arranged on the second drain valve 60 to detect the drain pressure of the second fluid processing component 30.

[0062] In this embodiment, the fluid pipeline switching device is provided with a first drain valve 50 and a second drain valve 60 to drain the air in the pipeline. The first pressure sensor 11 detects the pressure of the fluid to be processed, the second pressure sensor 41 detects the pressure of the processed fluid, the third pressure sensor 51 detects the drain pressure of the first fluid processing component 20, and the fourth pressure sensor 61 detects the drain pressure of the second fluid processing component 30. The valve core opening is adjusted by the first three-way proportional valve 10 and the second proportional valve, and the pressure of the fluid in the switching process can be further adjusted so that the fluid can smoothly transition to the bypass, further reducing the fluid pulsation generated at the switching moment.

[0063] The present invention also provides a switching method of a fluid pipeline switching device. Based on the above fluid pipeline switching device, refer to Figure 3 In one embodiment of the present invention, the switching method includes the following steps:

[0064] S10, detecting the feed pressure value of the first fluid processing component 20;

[0065] S20, when the feed pressure value reaches a preset pressure value, starting the second drain valve 60 to connect to the atmosphere;

[0066] S30, gradually adjusting the valve core opening of the first three-way proportional valve to a first target opening value, and gradually increasing the feeding speed of the feeding pump to a target feeding speed value to compensate for the flow loss of the second fluid processing component;

[0067] S40, detecting the exhaust pressure value of the second exhaust valve;

[0068] S50, when the exhaust pressure value is at a constant value, gradually adjust the valve core opening of the first three-way proportional valve back to the initial opening value, and gradually reduce the feeding speed of the feed pump to the initial feeding speed;

[0069] S60, closing the second drain valve;

[0070] S70, gradually adjusting the valve core opening of the first three-way proportional valve to a second target opening value, and gradually adjusting the valve core opening of the second three-way proportional valve to a third target opening value.

[0071] In this embodiment, the first fluid treatment component 20 may be a filter or an iron remover, and the second fluid treatment component 30 may also be a filter or an iron remover, which is not specifically limited here.

[0072] In this embodiment, the preset pressure value can be 0.5Mpa, the initial opening value can be 0%, the first target opening value can be 20%, the second target opening value can be 100%, and the third target opening value can be 100%, which are not limited here. Before switching the fluid pipeline, the switching action trigger condition can be set in the system. Here, the feed pressure value of 0.5Mpa is taken as an example and set as the trigger condition. In other words, when the feed pressure is 0.5Mpa or above, the surface of the first fluid treatment component 20 is blocked, and it is necessary to switch to the bypass second fluid treatment component 30 for filtering. The following will take the above parameters as an example to explain the fluid pipeline switching in detail, which does not mean that only the above values ​​can be taken.

[0073] refer to Figures 1 to 3, at the beginning of the switching action, the second drain valve 60 is opened to connect the second fluid treatment part 30 with the atmosphere. After the second drain valve 60 is opened, the valve core opening of the first three-way proportional valve 10 gradually changes to the first target opening value, which is set to 20% as an example. At the same time, the speed of the feed pump needs to be increased to compensate for the flow loss into the second fluid treatment part 30 during the switching period. Next, the air in the fluid pipeline bypass needs to be exhausted. The exhaust can be divided into three stages: air, gas-liquid mixture, and liquid. When the air is exhausted, the slurry in the second fluid treatment part 30 is stably output by the feed pump. At this time, the pressure sensor at the second drain valve 60, that is, the fourth pressure sensor 61 mentioned above, can detect a stable drain pressure. When the drain pressure is in a stable state and reaches a constant value, the valve core opening of the first proportional ball valve is controlled to gradually change back to 0%, and the speed of the feed pump is gradually changed back to the normal fluid delivery pump speed. After this step is completed, the valve core opening of the first three-way proportional valve 10 can be gradually adjusted back to 0%, and then the second drain valve 60 can be closed to avoid the pulsation effect when the second drain valve 60 is instantly closed. Until this time, the second fluid treatment component 30 and its pipeline have been filled with slurry and the air has been exhausted. Finally, the valve core opening of the first three-way proportional valve 10 is adjusted to gradually change to 100%, and the valve core opening of the second three-way proportional valve 40 is gradually changed to 100% to complete the switching action.

[0074] The present invention also proposes a coating system, which includes a fluid pipeline switching device. The specific structure of the fluid pipeline switching device refers to the above-mentioned embodiment. Since the coating system proposed by the present invention includes all schemes of all embodiments of the above-mentioned fluid pipeline switching device, it has at least the same technical effect as the fluid pipeline switching device, which will not be elaborated one by one here.

[0075] The above descriptions are only optional embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings, or directly / indirectly applied in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A switching method for a fluid pipeline switching device, It is characterized in that The fluid pipeline switching device comprises: A first three-way proportional valve (10), wherein a first end of the first three-way proportional valve (10) is suitable for inputting a fluid to be treated and is provided with a first pressure sensor (11), wherein the first pressure sensor (11) is used to detect fluid pressure; A first fluid processing component (20), wherein a feed end of the first fluid processing component (20) is connected to a second end of the first three-way proportional valve (10); a second fluid processing component (30), wherein a feed end of the second fluid processing component (30) is connected to a third end of the first three-way proportional valve (10), and the second fluid processing component (30) is arranged in parallel with the first fluid processing component (20); a second three-way proportional valve (40), wherein a first end of the second three-way proportional valve (40) is adapted to output the processed fluid; a first drain valve (50), wherein the discharge end of the first fluid processing component (20) is connected to the second end of the second three-way proportional valve (40), and the first drain valve (50) is arranged on a pipeline between the first fluid processing component (20) and the second three-way proportional valve (40); and a second drain valve (60), wherein the discharge end of the second fluid processing component (30) is connected to the third end of the second three-way proportional valve (40), and the second drain valve (60) is arranged on the pipeline between the second fluid processing component (30) and the second three-way proportional valve (40); The switching method comprises the following steps: S10, detecting a feed pressure value of the first fluid processing component (20); S20, when the feed pressure value reaches a preset pressure value, starting the second drain valve (60) to connect to the atmosphere; S30, gradually adjusting the valve core opening of the first three-way proportional valve (10) to a first target opening value, and gradually increasing the feeding speed of the feeding pump to a target feeding speed value, so as to compensate for the flow loss of the second fluid processing component (30); S40, detecting the exhaust pressure value of the second exhaust valve (60); S50, when the exhaust pressure value is at a constant value, gradually adjust the valve core opening of the first three-way proportional valve (10) back to the initial opening value, and gradually reduce the feeding speed of the feeding pump to the initial feeding speed; S60, closing the second drain valve (60); S70, gradually adjusting the valve core opening of the first three-way proportional valve (10) to a second target opening value, and gradually adjusting the valve core opening of the second three-way proportional valve (40) to a third target opening value.

2. The switching method of the fluid pipeline switching device according to claim 1, It is characterized in that The fluid pipeline switching device further comprises a second pressure sensor (41), wherein the second pressure sensor (41) is arranged at the first end of the second three-way proportional valve (40), and the second pressure sensor (41) is used to detect the pressure of the processed fluid.

3. The switching method of the fluid pipeline switching device according to claim 2, It is characterized in that The first fluid treatment component (20) is a filter or an iron remover; the second fluid treatment component (30) is a filter or an iron remover.

4. The switching method of the fluid pipeline switching device according to claim 1, It is characterized in that The fluid pipeline switching device also includes: A first discharge ball valve (70) is provided on the pipeline between the first fluid treatment component (20) and the first three-way proportional valve (10); and The second discharge ball valve (80) is arranged on the pipeline between the second fluid processing component (30) and the first three-way proportional valve (10).

5. The switching method of the fluid pipeline switching device according to claim 1, It is characterized in that The fluid pipeline switching device also includes: a third pressure sensor (51), arranged on the first exhaust valve (50), for detecting the exhaust pressure of the first fluid processing component (20); and A fourth pressure sensor (61) is provided on the second exhaust valve (60) and is used to detect the exhaust pressure of the second fluid processing component (30).

6. The switching method of the fluid pipeline switching device according to claim 1, It is characterized in that The first three-way proportional valve (10) is an electric proportional three-way ball valve; the second three-way proportional valve (40) is an electric proportional three-way ball valve.

7. The switching method of the fluid pipeline switching device according to claim 1, It is characterized in that The first drain valve (50) is a pneumatic two-way clamp ball valve; the second drain valve (60) is a pneumatic two-way clamp ball valve.

8. The switching method of the fluid pipeline switching device according to claim 1, It is characterized in that The preset pressure value is 0.5 MPa; the initial opening value is 0%; the first target opening value is 20%; the second target opening value is 100%; and the third target opening value is 100%.

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