Back pressure type anti-corrosion device for closed pressure container and control method of back pressure type anti-corrosion device

Abstract

The invention discloses a closed pressure vessel back pressure type anti-corrosion device and a control method, the closed pressure vessel back pressure type anti-corrosion device comprises a pressure vessel main body, an anti-corrosion and anti-corrosion film structure and a pressure control system, the pressure vessel main body is divided into a working cavity and a balance cavity by the anti-corrosion and anti-corrosion film structure; the pressure control system controls the pressure difference value between the working cavity and the balance cavity to be not larger than 10 KPa. The control method of the device comprises the steps that when the closed pressure container works, the pressure difference sensor feeds back the detected pressure difference value between the working cavity and the balance cavity to the electric control device, and the electric control device judges whether the pressure difference value is not larger than 10 KPa or not; when the pressure difference value is not greater than 10KPa, the working cavity of the closed pressure container works normally; when the pressure difference value is larger than 10 KPa, the electric control device controls the air pressure source to inflate the pressurizing openings of the working cavity and the balance cavity, and the electric control device enables the pressure difference value between the working cavity and the balance cavity to be not larger than 10 KPa through the pressure difference sensor and the flow control valve.

Description

Technical Field

[0001] The invention relates to the technical field of pressure vessel anti-corrosion, and in particular to a back-pressure anti-corrosion device for a closed pressure vessel and a control method thereof. Background Art

[0002] In the use of pressure vessels, when positive and negative pressures are alternately involved and corrosive gases are filled into the inner cavity, stainless steel is generally used to make the container; however, this method has high manufacturing costs and complex processing technology.

[0003] Therefore, there is still room for improvement in the prior art. Summary of the invention

[0004] The purpose of the present invention is to provide a back-pressure anti-corrosion device for a closed pressure vessel and a control method thereof, aiming to solve the technical problems of high manufacturing cost and complex processing technology of the closed pressure vessel.

[0005] To achieve the above-mentioned purpose, the technical solution of the present invention is: a back-pressure anti-corrosion device for a closed pressure vessel, which includes: a pressure vessel body, an anti-corrosion and corrosion-resistant membrane structure and a pressure control system, wherein the anti-corrosion and corrosion-resistant membrane structure divides the pressure vessel body into a working chamber and a balancing chamber; the pressure control system controls the pressure difference between the working chamber and the balancing chamber to be no more than 10KPa.

[0006] The closed pressure vessel back-pressure anti-corrosion device, wherein the anti-corrosion and corrosion-resistant membrane structure is a stainless steel plate membrane structure or a Teflon rubber membrane structure.

[0007] The closed pressure vessel back pressure anti-corrosion device, wherein the pressure control system includes an air pressure source for filling pressure into the working chamber and the balancing chamber, a first flow control valve, a second flow control valve, and a third flow control valve for controlling the gas flow, a differential pressure sensor for measuring the pressure difference between the working chamber and the balancing chamber, and an electronic control device; the differential pressure sensor is connected to the working chamber and the balancing chamber, respectively; the air pressure source is connected to the working chamber through the first flow control valve, and the air pressure source is connected to the balancing chamber through the second flow control valve; the electronic control device is used to receive signals from the differential pressure sensor, and control the air pressure source, the first flow control valve, the second flow control valve, and the third flow control valve.

[0008] The closed pressure vessel back pressure anti-corrosion device, wherein the working chamber is provided with a working chamber pressurization port and a working chamber pressure measuring port, and the balancing chamber is provided with a balancing chamber pressurization port and a balancing chamber pressure measuring port; the working chamber pressurization port is connected to the first flow control valve through an air pipe, and the working chamber pressure measuring port is connected to a differential pressure sensor; the balancing chamber pressurization port is connected to the second flow control valve through an air pipe, and the balancing chamber pressure measuring port is connected to the differential pressure sensor; the balancing chamber is also provided with a pressure relief port, and the pressure relief port is connected to a third flow control valve, and the first flow control valve, the second flow control valve, and the third flow control valve are connected to an electronic control device.

[0009] The closed pressure vessel back-pressure anti-corrosion device, wherein the differential pressure sensor is a differential pressure gauge.

[0010] The closed pressure vessel back-pressure anti-corrosion device comprises one air pressure source, which is also connected to a filter for filtering.

[0011] The closed pressure vessel back-pressure anti-corrosion device, wherein the number of the air pressure sources is two, the two air pressure sources are a working air source and a back-pressure air source, the working air source is connected to the working chamber through a first flow control valve, and the back-pressure air source is connected to the balance chamber through a second flow control valve.

[0012] A control method for a back pressure anti-corrosion device of a closed pressure vessel, comprising the following steps: S1: When the closed pressure vessel starts working, the air pressure source simultaneously pressurizes the working chamber and the balance chamber of the closed pressure vessel to the set working pressure value of the working chamber; S11: firstly, the working chamber of the sealed pressure vessel is filled with positive pressure gas or vacuumed to form negative pressure, and at the same time, the balancing chamber is also filled with gas or vacuumed to form negative pressure; S12: The pressure difference sensor feeds back the detected pressure difference between the working chamber and the balance chamber to the electronic control device, and the electronic control device determines and controls the pressure difference to be no greater than 10KPa; S13: When the pressure in the working chamber of the sealed pressure vessel reaches the set pressure value, stop charging the working chamber and the balance chamber; S2: When the closed pressure vessel is working, the working chamber and the balance chamber of the closed vessel are pressurized; S21: When the pressure in the working chamber of the sealed pressure vessel is at the set pressure value, the electronic control device controls the air pressure source to remain static; S22: The pressure difference sensor feeds back the detected pressure difference between the working chamber and the balance chamber to the electronic control device, which determines and controls the pressure difference to be no greater than 10KPa.

[0013] The control method of the back pressure anti-corrosion device for a closed pressure vessel, wherein how to ensure the pressure difference between the working chamber and the balance chamber during the working chamber pressurization process in step S12: S121: When the pressure difference of the differential pressure sensor is not greater than 10 KPa, the electronic control device controls the air pressure source to pressurize and inflate the working chamber and the balancing chamber at the same time, so that the pressure difference between the working chamber and the balancing chamber is maintained at no more than 10 KPa; S122: When the pressure difference of the differential pressure sensor is greater than 10KPa; taking the pressure of the working chamber of the closed pressure vessel as a reference, when the pressure of the balancing chamber is less than the pressure of the working chamber, the electronic control device controls the air pressure source to inflate the working chamber and the balancing chamber, and increases the inflation volume of the balancing chamber, so that the pressure difference is not greater than 10KPa; taking the pressure of the working chamber of the closed pressure vessel as a reference, when the pressure of the balancing chamber is greater than the pressure of the working chamber, the electronic control device controls the air pressure source to inflate the working chamber and the balancing chamber, and reduces the inflation volume of the balancing chamber, so that the pressure difference is not greater than 10KPa.

[0014] The control method of the back pressure anti-corrosion device for a closed pressure vessel, wherein how to ensure the pressure difference between the working chamber and the balance chamber during the working chamber pressure maintenance process in step S22: S211: When the pressure difference of the pressure difference sensor is not greater than 10KPa, the air pressure source is controlled by the electronic control device to remain static and not inflated; S212: When the pressure difference of the differential pressure sensor is greater than 10KPa; taking the pressure of the working chamber of the closed pressure vessel as a reference, when the pressure of the balancing chamber is less than the pressure of the working chamber, the electronic control device controls the inflation volume of the balancing chamber of the air pressure source to make the pressure difference no greater than 10KPa; taking the pressure of the working chamber of the closed pressure vessel as a reference, when the pressure of the balancing chamber is greater than the pressure of the working chamber, the electronic control device controls the pressure relief port of the third flow control valve to relieve the pressure in the balancing chamber to make the pressure difference no greater than 10KPa.

[0015] The control method of the closed pressure vessel back pressure anti-corrosion device, wherein the pressure range of the working chamber is -0.1MPa-1.6MPa.

[0016] The control method of the back pressure anti-corrosion device of the closed pressure vessel is as follows: when the pressure of the closed pressure vessel is working, the pressure of the working chamber is in the normal pressure range, and the pressure difference between the working chamber and the balancing chamber is greater than 10KPa, and at the same time, the pressure in the balancing chamber is greater than the pressure in the working chamber, then the electronic control device needs to control the pressure relief of the pressure relief port of the balancing chamber through the flow control valve.

[0017] Beneficial effect: The present invention sets a layer of anti-corrosion and corrosion-resistant film structure in the main body of the pressure vessel, so that the anti-corrosion and corrosion-resistant effect can be achieved in the closed pressure vessel cavity when working. However, since the anti-corrosion and corrosion-resistant film structure is easy to deform when the positive and negative pressures of the closed pressure vessel are alternately working, the pressure control system is used to control the pressure between the working chamber and the balance chamber when the closed pressure vessel is working, so that the anti-corrosion and corrosion-resistant film structure produces a small deformation, ensuring that the anti-corrosion layer of the anti-corrosion and corrosion-resistant film structure will not fall off. The closed pressure vessel with this design structure has low manufacturing cost and simple processing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of an embodiment of the present invention.

[0019] Figure 2 It is a schematic diagram of a second embodiment of the present invention.

[0020] Figure 3 It is a flow chart of the method of the present invention.

[0021] Figure 4 It is a specific step block diagram of step S1 in the method of the present invention.

[0022] Figure 5 It is a specific step block diagram of step S2 in the method of the present invention.

[0023] Figure 6 It is a specific step block diagram of step S12 in the method of the present invention.

[0024] Figure 7 It is a specific step block diagram of step S21 in the method of the present invention.

[0025] In the figure: 1. Pressure vessel body; 2. Anti-corrosion and corrosion resistant membrane structure; 3. Working chamber; 4. Balancing chamber; 5. Air pressure source; 6a. First flow control valve; 6b. Second flow control valve; 6c. Third flow control valve; 7. Pressure difference sensor; 8. Electronic control device; 9a. Working chamber pressurization port; 9b. Balancing chamber pressurization port; 10a. Working chamber pressure measuring port; 10b. Balancing chamber pressure measuring port; 11. Pressure relief port; 12. Filter; 13. Working air source; 14. Back pressure air source. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clear and explicit, the present invention is further described in detail below with reference to the accompanying drawings and examples.

[0027] like Figure 1-2As shown, the present invention discloses a back-pressure anti-corrosion device for a closed pressure vessel, which comprises: a pressure vessel body 1, an anti-corrosion and corrosion-resistant membrane structure 2 and a pressure control system, wherein the anti-corrosion and corrosion-resistant membrane structure 2 divides the pressure vessel body 1 into a working chamber 3 and a balancing chamber 4; the pressure control system controls the pressure difference between the working chamber 3 and the balancing chamber 4 to be no greater than 10KPa; the pressure control system comprises an air pressure source 5 for filling pressure into the working chamber 3 and the balancing chamber 4, a first flow control valve 6a, a second flow control valve 6b, and a third flow control valve 6c for controlling the gas flow, A pressure difference sensor 7 and an electronic control device 8 for measuring the pressure difference between the working chamber 3 and the balancing chamber 4; the pressure difference sensor 7 is connected to the working chamber 3 and the balancing chamber 4 respectively; the air pressure source 5 is connected to the working chamber 3 through the first flow control valve 6a, and the air pressure source 5 is connected to the balancing chamber 4 through the second flow control valve 6b; the electronic control device 8 is used to receive the signal of the pressure difference sensor 7, and control the air pressure source 5, the first flow control valve 6a, the second flow control valve 6b, and the third flow control valve 6c, so that the pressure difference between the working chamber 3 and the balancing chamber 4 is not greater than 10KPa.

[0028] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 9 KPa.

[0029] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 8 KPa.

[0030] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 7 KPa.

[0031] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 6 KPa.

[0032] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 5 KPa.

[0033] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 4 KPa.

[0034] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 3 KPa.

[0035] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 2 KPa.

[0036] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 1 KPa.

[0037] In actual work, the pressure difference between the working chamber 3 and the balancing chamber 4 is 0 KPa.

[0038] After adopting the above structure, the present invention divides the pressure vessel body 1 into a working chamber 3 and a balancing chamber 4 by setting an anti-corrosion and corrosion-resistant membrane structure 2 in the pressure vessel body 1. When working, it is necessary to put a battery into the working chamber 3 and seal it, and then inflate the working chamber to make the working chamber 3 reach a certain pressure; and in the process of inflation, the anti-corrosion and corrosion-resistant membrane structure 2 will deform, and when the deformation is too large, it will fall off; so the pressure control system is required to control the pressure difference between the working chamber 3 and the balancing chamber 4 within 10KPa; so as to prevent the anti-corrosion and corrosion-resistant membrane structure 2 from deforming excessively; and because the anti-corrosion and corrosion-resistant membrane structure 2 is adopted, the anti-corrosion and corrosion-resistant effect of the pressure vessel body can be achieved; at the same time, the anti-corrosion and corrosion-resistant membrane structure 2 will not cause damage to the working battery cell when a fault occurs, and a pressure difference sensor 7 is added, which is equivalent to adding a layer of safety protection mechanism. The manufacturing cost of the present invention is lower than that of the existing closed pressure vessel, and the processing technology is simple and the safety is better.

[0039] The pressure vessel body 1 is made of carbon steel, which can reduce manufacturing costs.

[0040] Preferably, the anti-corrosion and corrosion-resistant membrane structure 2 is a stainless steel plate membrane structure or a Teflon rubber membrane structure, so it can achieve the anti-corrosion and corrosion-resistant effect on the pressure vessel body and has low manufacturing cost.

[0041] Specifically, the working chamber 3 is provided with a working chamber pressurization port 9a and a working chamber pressure measuring port 10a, and the balancing chamber 4 is provided with a balancing chamber pressurization port 9b and a balancing chamber pressure measuring port 10b; the working chamber pressurization port 9a is connected to the first flow control valve 6a through an air pipe, and the working chamber pressure measuring port 10a is connected to the differential pressure sensor 7; the balancing chamber pressurization port 9b is connected to the second flow control valve 6b through an air pipe, and the balancing chamber pressure measuring port 10b is connected to the differential pressure sensor 7; the balancing chamber 4 is also provided with a pressure relief port 11, and the pressure relief port 11 is connected to the third flow control valve 6c, and the first flow control valve 6a, the second flow control valve 6b, and the third flow control valve 6c are connected to the electronic control device 8. .

[0042] After adopting the above structure, the present invention is provided with a working chamber pressurization port 9a and a working chamber pressure measuring port 10a through the working chamber 3, and a balancing chamber pressurization port 9b and a balancing chamber pressure measuring port 10b through the balancing chamber 4; therefore, the air pressure source 5 can inflate and pressurize the working chamber 3 and the balancing chamber 4, and control the air volume of the working chamber 3 and the balancing chamber 4 by the air pressure source 5 through the first flow control valve 6a, the second flow control valve 6b, and the third flow control valve 6c, thereby realizing the pressure control between the working chamber 3 and the balancing chamber 4. The working chamber pressure measuring port 10a is connected to the pressure difference sensor 7; the balancing chamber pressure measuring port 10b is connected to the pressure difference sensor 7; thereby realizing the pressure difference between the working chamber 3 and the balancing chamber 4, and feeding it back to the electronic control device 8, so that the electronic control device 8 can monitor the pressure difference between the working chamber 3 and the balancing chamber 4 in real time.

[0043] Preferably, the differential pressure sensor 7 is a differential pressure gauge.

[0044] In one of the embodiments, the number of the air pressure source 5 is one, and the air pressure source 5 is also connected to a filter 12 for filtering. Since the air pressure source 5 is one, the working chamber 3 and the balancing chamber 4 need to be inflated at the same time, so the gas in the balancing chamber 4 will pollute the working chamber 3. Therefore, the gas can be filtered through the filter 12, so that the gas filled into the working chamber 3 is clean and will not pollute the working chamber 3.

[0045] In another embodiment, the number of the air pressure sources 5 is two, and the two air pressure sources 5 are respectively a working air source 13 and a back pressure air source 14. The working air source 13 is connected to the working chamber 3 through the first flow control valve 6a, and the back pressure air source 14 is connected to the balancing chamber 4 through the second flow control valve 6b. The working chamber 3 is inflated by the working air source 13, and the balancing chamber 4 is inflated by the back pressure air source 14, forming an independent control loop, which can ensure the cleanliness of the working chamber 3.

[0046] like Figure 3-7 As shown, the present invention discloses a control method for a back pressure anti-corrosion device of a closed pressure vessel, which comprises the following steps: S1: When the closed pressure vessel is started, the air pressure source 5 simultaneously pressurizes the working chamber 3 and the balance chamber 4 of the closed pressure vessel to the set working pressure value of the working chamber; S11: firstly, the working chamber 3 of the sealed pressure vessel is filled with positive pressure gas or vacuumed to form a negative pressure, and at the same time, the balancing chamber 4 is also filled with gas or vacuumed to form a negative pressure; S12: The pressure difference sensor 7 feeds back the detected pressure difference between the working chamber 3 and the balancing chamber 4 to the electronic control device 8, and the electronic control device 8 determines and controls the pressure difference to be no greater than 10 KPa; S13: When the pressure in the working chamber 3 of the sealed pressure container reaches the set pressure value, stop charging the working chamber 3 and the balance chamber 4; S2: When the closed pressure vessel is working, the working chamber 3 and the balance chamber 4 of the closed vessel are pressurized; S21: When the pressure in the working chamber of the sealed pressure container is at the set pressure value, the electronic control device 8 controls the air pressure source 5 to remain static; S22: The pressure difference sensor 7 feeds back the detected pressure difference between the working chamber 3 and the balancing chamber 4 to the electronic control device 8, and the electronic control device 8 determines and controls the pressure difference to be no greater than 10 KPa.

[0047] The control method of the closed pressure vessel back pressure anti-corrosion device, wherein how to ensure the pressure difference between the working chamber 3 and the balance chamber 4 during the pressure charging process of the working chamber 3 in step S12: S121: When the pressure difference of the pressure difference sensor 7 is not greater than 10 KPa, the electronic control device 8 controls the air pressure source 5 to pressurize and inflate the working chamber 3 and the balancing chamber 4 at the same time, so that the pressure difference between the working chamber 3 and the balancing chamber 4 is maintained at no more than 10 KPa; S122: When the pressure difference of the pressure difference sensor 7 is greater than 10 KPa; taking the pressure of the working chamber 3 of the sealed pressure container as a reference, when the pressure of the balancing chamber 4 is less than the pressure of the working chamber 3, the electronic control device 8 controls the air pressure source (5) to inflate the working chamber 3 and the balancing chamber 4, and increases the amount of air in the balancing chamber 4, so that the pressure difference is not greater than 10 KPa; taking the pressure of the working chamber 3 of the sealed pressure container as a reference, when the pressure of the balancing chamber 4 is greater than the pressure of the working chamber 3, the electronic control device 8 controls the air pressure source 5 to inflate the working chamber 3 and the balancing chamber 4, and reduces the amount of air in the balancing chamber 4, so that the pressure difference is not greater than 10 KPa; The control method of the back pressure anti-corrosion device of the closed pressure vessel, wherein, in the pressure maintaining process of the working chamber 3 in step S22, how to ensure the pressure difference between the working chamber 3 and the balance chamber 4: S211: When the pressure difference value of the pressure difference sensor 7 is not greater than 10KPa, the electronic control device 8 controls the air pressure source 5 to remain static and not inflated; S212: When the pressure difference of the pressure difference sensor 7 is greater than 10KPa; taking the pressure of the working chamber 3 of the sealed pressure container as a reference, when the pressure of the balancing chamber 4 is less than the pressure of the working chamber 3, the electronic control device 8 controls the air pressure source 5 to pressurize the balancing chamber 4 so that the pressure difference is not greater than 10KPa; taking the pressure of the working chamber 3 of the sealed pressure container as a reference, when the pressure of the balancing chamber 4 is greater than the pressure of the working chamber 3, the electronic control device 8 controls the pressure relief port 11 of the third flow control valve 6c to relieve the pressure of the balancing chamber 4 so that the pressure difference is not greater than 10KPa.

[0048] Preferably, the pressure range of the working chamber 3 is -0.1 MPa-1.6 MPa.

[0049] The present invention is mainly applied to the lithium battery injection process environment.

[0050] The present invention sets a layer of anti-corrosion and corrosion-resistant membrane structure 2 in the main body of the pressure vessel, so that the closed pressure vessel can achieve the effect of anti-corrosion and corrosion resistance when working. However, since the anti-corrosion and corrosion-resistant membrane structure 2 is easy to deform when the closed pressure vessel is working, the pressure control system is used to control the pressure between the working chamber 3 and the balance chamber 4 when the closed pressure vessel is working, so that the anti-corrosion and corrosion-resistant membrane structure 2 produces a small deformation, ensuring that the anti-corrosion layer of the anti-corrosion and corrosion-resistant membrane structure 2 will not fall off. The closed pressure vessel adopting this design structure has low manufacturing cost and simple processing technology.

[0051] The above are only preferred implementation modes of the present invention, which certainly cannot be used to limit the scope of rights of the present invention. It should be pointed out that for technicians in this technical field, any modification or equivalent replacement of the technical solution of the present invention without creative work does not depart from the protection scope of the technical solution of the present invention.

Claims

1. A back pressure anti-corrosion device for a closed pressure vessel, characterized in that: The invention comprises a pressure vessel body (1), an anti-corrosion and corrosion resistant membrane structure (2) and a pressure control system, wherein the anti-corrosion and corrosion resistant membrane structure (2) divides the pressure vessel body (1) into a working chamber (3) and a balancing chamber (4); and the pressure control system controls the pressure difference between the working chamber (3) and the balancing chamber (4) to be no greater than 10 kPa.

2. The closed pressure vessel back pressure anti-corrosion device according to claim 1, characterized in that: The anti-corrosion and corrosion-resistant membrane structure (2) is a stainless steel plate membrane structure or a Teflon rubber membrane structure.

3. The closed pressure vessel back pressure anti-corrosion device according to claim 2, characterized in that: The pressure control system comprises an air pressure source (5) for filling the working chamber (3) and the balancing chamber (4) with pressure, a first flow control valve (6a), a second flow control valve (6b), and a third flow control valve (6c) for controlling the gas flow, a differential pressure sensor (7) for measuring the pressure difference between the working chamber (3) and the balancing chamber (4), and an electronic control device (8); the differential pressure sensor (7) is connected to the working chamber (3) and the balancing chamber (4), respectively; the air pressure source (5) is connected to the working chamber (3) through the first flow control valve (6a), and the air pressure source (5) is connected to the balancing chamber (4) through the second flow control valve (6b); the electronic control device (8) is used to receive a signal from the differential pressure sensor (7) and control the air pressure source (5), the first flow control valve (6a), the second flow control valve (6b), and the third flow control valve (6c).

4. The closed pressure vessel back pressure anti-corrosion device according to claim 3, characterized in that: The working chamber (3) is provided with a working chamber pressurization port (9a) and a working chamber pressure measuring port (10a), and the balancing chamber (4) is provided with a balancing chamber pressurization port (9b) and a balancing chamber pressure measuring port (10b); the working chamber pressurization port (9a) is connected to a first flow control valve (6a) via an air pipe, and the working chamber pressure measuring port (10a) is connected to a differential pressure sensor (7); the balancing chamber pressurization port (9b) is connected to a second flow control valve (6b) via an air pipe, and the balancing chamber pressure measuring port (10b) is connected to a differential pressure sensor (7); the balancing chamber (4) is also provided with a pressure relief port (11), and the pressure relief port (11) is connected to a third flow control valve (6c); the first flow control valve (6a), the second flow control valve (6b), and the third flow control valve (6c) are connected to an electronic control device (8).

5. The closed pressure vessel back pressure anti-corrosion device according to claim 4, characterized in that: The differential pressure sensor (7) is a differential pressure gauge.

6. The closed pressure vessel back pressure anti-corrosion device according to claim 5, characterized in that: The number of the air pressure source (5) is one, and the air pressure source (5) is also connected to a filter (11) for filtering.

7. The closed pressure vessel back pressure anti-corrosion device according to claim 5, characterized in that: The number of the air pressure sources (5) is two, and the two air pressure sources (5) are respectively a working air source (13) and a back pressure air source (14); the working air source (13) is connected to the working chamber (3) via a first flow control valve (6a), and the back pressure air source (14) is connected to the balance chamber (4) via a second flow control valve (6b).

8. A control method for a closed pressure vessel back pressure anti-corrosion device using any one of claims 3 to 7, characterized in that: The following steps are involved: S1: When the closed pressure vessel is started, the air pressure source (5) simultaneously pressurizes the working chamber (3) and the balance chamber (4) of the closed pressure vessel to a set working pressure value of the working chamber; S2: When the closed pressure vessel is in operation, the working chamber (3) and the balance chamber (4) of the closed pressure vessel are pressurized; Wherein step S1 comprises the following steps: S11: first, the working chamber (3) of the sealed pressure vessel is filled with positive pressure gas or vacuumed to form a negative pressure, and at the same time, the balancing chamber (4) is also filled with gas or vacuumed to form a negative pressure; S12: the pressure difference sensor (7) feeds back the detected pressure difference between the working chamber (3) and the balancing chamber (4) to the electronic control device (8), and the electronic control device (8) determines and controls the pressure difference to be no greater than 10 kPa; S13: When the pressure in the working chamber (3) of the sealed pressure container reaches a set pressure value, the inflation of gas into the working chamber (3) and the balance chamber (4) is stopped; Wherein step S2 comprises the following steps: S21: When the pressure in the working chamber of the sealed pressure container is at a set pressure value, the electronic control device (8) controls the air pressure source (5) to remain static; S22: The pressure difference sensor (7) feeds back the detected pressure difference between the working chamber (3) and the balance chamber (4) to the electronic control device (8), and the electronic control device (8) determines and controls the pressure difference to be no greater than 10 kPa.

9. The control method of the back pressure anti-corrosion device for a closed pressure vessel according to claim 8, characterized in that: How to ensure the pressure difference between the working chamber (3) and the balancing chamber (4) during the pressure charging process of the working chamber (3) in step S12: S121: When the pressure difference value of the pressure difference sensor (7) is not greater than 10 KPa, the electronic control device (8) controls the air pressure source (5) to pressurize and inflate the working chamber (3) and the balancing chamber (4) at the same time, so that the pressure difference value between the working chamber (3) and the balancing chamber (4) is maintained at not greater than 10 KPa; S122: When the pressure difference of the pressure difference sensor (7) is greater than 10 KPa; when the pressure of the balance chamber (4) is less than the pressure of the working chamber (3) based on the pressure of the working chamber (3) of the sealed pressure container, the electronic control device (8) controls the air pressure source (5) to inflate the working chamber (3) and the balance chamber (4), and increases the amount of air in the balance chamber (4) so ​​that the pressure difference is not greater than 10 KPa; when the pressure of the balance chamber (4) is greater than the pressure of the working chamber (3) based on the pressure of the working chamber (3) of the sealed pressure container, the electronic control device (8) controls the air pressure source (5) to inflate the working chamber (3) and the balance chamber (4), and reduces the amount of air in the balance chamber (4) so ​​that the pressure difference is not greater than 10 KPa.

10. The control method of the back pressure anti-corrosion device for a closed pressure vessel according to claim 8, characterized in that: How to ensure the pressure difference between the working chamber (3) and the balancing chamber (4) during the pressure-maintaining process of the working chamber (3) in step S22: S211: When the pressure difference value of the pressure difference sensor (7) is not greater than 10 KPa, the air pressure source (5) is controlled by the electronic control device (8) to remain static and not inflated; S212: When the pressure difference of the pressure difference sensor (7) is greater than 10 KPa; when the pressure of the balance chamber (4) is less than the pressure of the working chamber (3) based on the pressure of the working chamber (3) of the sealed pressure container, the electronic control device (8) controls the air pressure source (5) to pressurize the balance chamber (4) so ​​that the pressure difference is not greater than 10 KPa; when the pressure of the balance chamber (4) is greater than the pressure of the working chamber (3) based on the pressure of the working chamber (3) of the sealed pressure container, the electronic control device (8) controls the pressure relief port (11) of the third flow control valve (6C) to relieve the pressure of the balance chamber (4) so ​​that the pressure difference is not greater than 10 KPa.

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