Nitrogen supply system for multiple production lines and control method thereof

Abstract

This invention discloses a nitrogen supply system and its control method for multiple production lines. The device includes: nitrogen supply systems for two production lines connected to the nitrogen supply pipelines of their respective production lines; a nitrogen outlet pipeline installed on the nitrogen supply pipeline of each production line's nitrogen supply system, with a switch device installed on the nitrogen outlet pipeline; the nitrogen outlet pipeline of each internal nitrogen supply pipeline connected to the nitrogen supply pipelines of the other three or more production lines (excluding the two existing production lines); external nitrogen inlet pipelines connected to the nitrogen supply pipelines of each production line; and a pressure detection device and a regulating device installed in each of the nitrogen outlet pipelines and nitrogen supply pipelines. This solution, through the rearrangement and debugging of the pipelines of the nitrogen supply systems for two production lines, enables the supply of nitrogen to three production lines using two sets of liquid nitrogen tanks and vaporizers, thereby improving production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of automatic control technology, specifically relating to a nitrogen supply system and its control method for multiple production lines. Background Technology

[0002] Generally, a complete set of control equipment is needed for the nitrogen supply chain of a production line. However, for three production lines, due to limitations in site area and investment costs, the nitrogen supply for each line cannot rely solely on liquid nitrogen tanks and vaporizers; they must share existing nitrogen supply facilities with the other two lines. However, the proposed solutions do not include technology for supplying all three production lines with two sets of liquid nitrogen tanks and vaporizers, which complicates the implementation of this shared nitrogen supply system and impacts production efficiency.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The purpose of this invention is to provide a nitrogen supply system and its control method for multiple production lines, in order to solve the problem that the use of two sets of liquid nitrogen tanks and vaporizers in related solutions cannot supply three production lines, thus affecting production efficiency. By rearranging and debugging the pipelines of the nitrogen supply system for two production lines and adding some detection and actuators, it is possible to use two sets of liquid nitrogen tanks and vaporizers to supply three production lines, which is beneficial to improving production efficiency.

[0005] This invention provides a nitrogen supply system for multiple production lines, wherein the multiple production lines are three or more production lines. The nitrogen supply system for multiple production lines includes: nitrogen supply systems for two production lines, a pressure detection device, a switching device, a regulating device, and an external nitrogen supply inlet pipeline. The external nitrogen supply inlet pipeline is a nitrogen inlet pipeline for connecting to an external nitrogen source. The nitrogen supply systems for the two production lines are respectively connected to the nitrogen supply pipelines of corresponding production lines within the two production lines. A nitrogen outlet pipeline is provided on the nitrogen supply pipeline of each production line's nitrogen supply system within the two production lines. The switching device is provided on the nitrogen outlet pipeline of each nitrogen supply pipeline within the two production lines for controlling the opening or closing of the corresponding nitrogen outlet pipeline. The nitrogen outlet pipelines of each nitrogen supply pipeline within the two production lines are respectively connected to three or more production lines. The nitrogen supply pipelines of all production lines except the two production lines are connected to the nitrogen supply pipelines of each of the three or more production lines. The external nitrogen supply inlet pipelines are connected to the nitrogen supply pipelines of each of the three or more production lines to introduce an external nitrogen source into each of the three or more production lines. Pressure detection devices are installed in the nitrogen outlet pipelines of each of the two internal nitrogen supply pipelines and in the nitrogen supply pipelines of each of the three or more production lines to detect the nitrogen pressure in the corresponding pipelines. Adjustment devices are also installed in each of the nitrogen outlet pipelines of each of the two internal nitrogen supply pipelines, the nitrogen supply pipelines of each of the three or more production lines, and the external nitrogen supply inlet pipelines. These devices adjust the opening of the adjustment device in the corresponding pipeline according to the nitrogen pressure in the corresponding pipeline to ensure a normal nitrogen supply to the production line where the corresponding pipeline is located.

[0006] In some embodiments, the two production lines include: a first production line and a second production line; other production lines besides the two production lines among three or more production lines are referred to as a third production line; the nitrogen supply system for the two production lines includes: a first liquid nitrogen tank and a second liquid nitrogen tank, as well as a first vaporizer and a second vaporizer; wherein, the outlet pipeline of the first liquid nitrogen tank and the outlet pipeline of the second liquid nitrogen tank merge and connect to form an internal nitrogen supply pipeline; the internal nitrogen supply pipeline is divided into two paths, referred to as the first internal nitrogen supply pipeline and the second internal nitrogen supply pipeline; the first internal nitrogen supply pipeline, after passing through the first vaporizer, is divided into two paths: one path is the nitrogen supply pipeline for the first production line, and the other path is the nitrogen outlet pipeline of the first internal nitrogen supply pipeline; the nitrogen supply pipeline of the first production line is connected to the nitrogen inlet of the first production line; the second internal nitrogen supply pipeline, after passing through the second vaporizer, is divided into two paths: one path is the nitrogen supply pipeline for the second production line, and the other path is the nitrogen outlet pipeline of the second internal nitrogen supply pipeline. The nitrogen supply pipeline of the first production line is connected to the nitrogen inlet of the second production line; the nitrogen outlet pipeline of the first nitrogen supply pipeline merges and connects with the nitrogen outlet pipeline of the second nitrogen supply pipeline to form a combined nitrogen outlet pipeline for the first and second production lines; the combined nitrogen outlet pipeline of the first and second production lines connects to the nitrogen supply pipeline of the third production line; the nitrogen supply pipeline of the third production line... The external nitrogen supply pipeline is connected to the nitrogen inlet of the third production line; the external nitrogen supply pipeline has three branches, referred to as the first external nitrogen branch pipeline, the second external nitrogen branch pipeline, and the third external nitrogen branch pipeline; the first external nitrogen branch pipeline is connected to the nitrogen supply pipeline of the first production line; the second external nitrogen branch pipeline is connected to the nitrogen supply pipeline of the second production line; and the third external nitrogen branch pipeline is connected to the nitrogen supply pipeline of the third production line.

[0007] In some embodiments, the nitrogen supply system for multiple production lines further includes: a first buffer tank, a second buffer tank, and a third buffer tank; wherein, the first buffer tank is located at the nitrogen inlet of the first production line; the nitrogen supply pipeline of the first production line passes through the first buffer tank and is then connected to the nitrogen inlet of the first production line; the second buffer tank is located at the nitrogen inlet of the second production line; the nitrogen supply pipeline of the second production line passes through the second buffer tank and is then connected to the nitrogen inlet of the second production line; the third buffer tank is located at the nitrogen inlet of the third production line; the nitrogen supply pipeline of the third production line passes through the third buffer tank and is then connected to the nitrogen inlet of the third production line.

[0008] In some embodiments, the regulating device includes: a first regulating valve, a second regulating valve, a third regulating valve, a fourth regulating valve, a fifth regulating valve, a sixth regulating valve, a seventh regulating valve, and an eighth regulating valve; the switching device includes: a first switching valve and a second switching valve; wherein, the first regulating valve is disposed in the pipeline where the inlet of the first vaporizer is located in the first internal nitrogen supply pipeline; the second regulating valve is disposed in the pipeline where the inlet of the second vaporizer is located in the second internal nitrogen supply pipeline; the third regulating valve is disposed in the first external nitrogen branch pipeline; the fourth regulating valve is disposed in the second external nitrogen branch pipeline; and the seventh regulating valve is disposed in the third external nitrogen branch pipeline and located at the external nitrogen gas... The source inlet is located between the nitrogen outlet and the nitrogen outlet collection pipeline of the first and second production lines; the eighth regulating valve is located in the nitrogen outlet collection pipeline of the first and second production lines; the first switching valve is located in the nitrogen outlet pipeline of the first nitrogen internal supply pipeline; the second switching valve is located in the nitrogen outlet pipeline of the second nitrogen internal supply pipeline; the fifth regulating valve is located in the nitrogen supply pipeline of the first production line and between the pipeline where the outlet of the first vaporizer is located and the first external nitrogen branch pipeline; the sixth regulating valve is located in the nitrogen supply pipeline of the second production line and between the pipeline where the outlet of the second vaporizer is located and the second external nitrogen branch pipeline.

[0009] In some embodiments, the pressure detection device includes: a first pressure detection instrument, a second pressure detection instrument, a third pressure detection instrument, a fourth pressure detection instrument, and a fifth pressure detection instrument; wherein, the first pressure detection instrument is disposed on the nitrogen supply pipeline of the first production line, and located between the first external nitrogen branch pipeline and the nitrogen inlet of the first production line, for detecting a first pressure, so that the third regulating valve and the fifth regulating valve adjust the opening of the regulating device in the corresponding pipeline according to the first pressure; the second pressure detection instrument is disposed on the nitrogen supply pipeline of the second production line, and located between the second internal nitrogen supply pipeline and the second external nitrogen branch pipeline, for detecting a second pressure, so that the fourth regulating valve and the sixth regulating valve adjust the opening of the regulating device in the corresponding pipeline according to the second pressure; the third pressure detection instrument... A third pressure detector is installed on the nitrogen supply pipeline of the first production line and located at the outlet of the first vaporizer. This detector is used to detect a third pressure, so that the first regulating valve adjusts the opening of the regulating device in the corresponding pipeline based on this third pressure. A fourth pressure detector is installed on the nitrogen supply pipeline of the second production line and located at the outlet of the second vaporizer. This detector is used to detect a fourth pressure, so that the second regulating valve adjusts the opening of the regulating device in the corresponding pipeline based on this fourth pressure. A fifth pressure detector is installed on the nitrogen supply pipeline of the third production line and located between the nitrogen outlet and collection pipelines of the first and second production lines and the nitrogen inlet of the third production line. This detector is used to detect a fifth pressure, so that the seventh and eighth regulating valves adjust the opening of the regulating device in the corresponding pipeline based on this fifth pressure.

[0010] In conjunction with the above system, the present invention further provides a control method for a nitrogen supply system for multiple production lines, comprising: using the nitrogen supply systems of two production lines as internal gas sources, using an external nitrogen source connected to the external nitrogen inlet pipeline as an external gas source, and using the gas source obtained by combining the internal gas source and the external gas source as the gas source for the nitrogen supply system of multiple production lines, denoted as the combined gas source; when using the combined gas source to supply nitrogen to each of the three or more production lines, controlling the switching devices in the pipeline between the outlet of the first vaporizer in the nitrogen supply system of the two production lines and the switching devices in the pipeline between the outlet of the second vaporizer in the nitrogen supply system of the two production lines and the third production line. At least one of the devices is turned on, and it is determined whether the gas supply pressure of the combined gas source is equal to the set gas supply pressure. If it is determined that the gas supply pressure of the combined gas source is equal to the set gas supply pressure, the opening degree of all regulating devices in the regulating devices in the pipeline between the external gas supply source and the corresponding production line, and in the regulating devices in the pipeline between the internal gas supply source and the corresponding production line, is maintained at the current opening degree. If it is determined that the gas supply pressure of the combined gas source is not equal to the set gas supply pressure, the opening degree of at least some of the regulating devices in the regulating devices in the pipeline between the external gas supply source and the corresponding production line, and in the regulating devices in the pipeline between the internal gas supply source and the corresponding production line, is changed to make the gas supply pressure of the combined gas source reach the set gas supply pressure.

[0011] In some embodiments, controlling the opening of the regulating device in the pipeline between the external gas source and the corresponding production line, and the opening of at least some of the regulating devices in the pipeline between the internal gas source and the corresponding production line, to change so that the gas supply pressure of the merging gas source reaches the set gas supply pressure, includes: when the gas supply pressure of the merging gas source is less than the set gas supply pressure, controlling the opening of the regulating device in the pipeline between the external gas source and the corresponding production line to change according to the pressure detected by the detection device in the pipeline of the merging gas source; if the opening of the regulating device in the pipeline between the external gas source and the corresponding production line has reached the set opening of the corresponding regulating device, but the gas supply pressure of the merging gas source still cannot reach the set pressure, then controlling the opening of the regulating device in the pipeline between the internal gas source and the corresponding production line to gradually change according to the pressure detected by the detection device in the pipeline of the merging gas source, so that the gas supply pressure of the merging gas source reaches the set gas supply pressure.

[0012] In some embodiments, when nitrogen is supplied to each of the three or more production lines using the combined gas source, controlling at least one of the switching devices in the pipeline between the outlet of the first vaporizer and the third production line in the nitrogen supply system of the two production lines and the switching devices in the pipeline between the outlet of the second vaporizer and the third production line in the nitrogen supply system of the two production lines to be turned on includes: when the nitrogen supply system of the two production lines includes a first vaporizer and a second vaporizer, and the two production lines include the first production line and the second production line, for the third production line (excluding the two production lines), determining whether the pressure detected by the pressure detection device at the outlet of the first vaporizer and the pressure detected by the pressure detection device at the outlet of the second vaporizer are equal to a set pressure; if it is determined that the pressure detected by the pressure detection device at the outlet of the first vaporizer is equal to the set pressure, then the switching device in the nitrogen supply pipeline from the outlet of the first vaporizer to the third production line can be turned on to select the first vaporizer to supply nitrogen to the third production line from the internal gas source; if it is determined that the pressure detected by the pressure detection device at the outlet of the first vaporizer is not equal to the set pressure, then the first vaporizer... When the pressure detected by the pressure detection device at the outlet of the first vaporizer is less than the set pressure, the opening of the regulating device at the inlet of the first vaporizer is increased; when the pressure detected by the pressure detection device at the outlet of the first vaporizer is greater than the set pressure, the opening of the regulating device at the inlet of the first vaporizer is decreased, so that the pressure detected by the pressure detection device at the outlet of the first vaporizer equals the set pressure. If it is determined that the pressure detected by the pressure detection device at the outlet of the second vaporizer equals the set pressure, the switch device in the nitrogen supply pipeline from the outlet of the second vaporizer to the third production line can be opened to select the second vaporizer to supply nitrogen to the third production line from the internal gas supply source. If it is determined that the pressure detected by the pressure detection device at the outlet of the second vaporizer is also not equal to the set pressure, when the pressure detected by the pressure detection device at the outlet of the second vaporizer is less than the set pressure, the opening of the regulating device at the inlet of the second vaporizer is increased; when the pressure detected by the pressure detection device at the outlet of the second vaporizer is greater than the set pressure, the opening of the regulating device at the inlet of the second vaporizer is decreased, so that the pressure detected by the pressure detection device at the outlet of the second vaporizer equals the set pressure.Specifically, if it is determined that the pressure detected by the pressure detection device at the outlet of the first vaporizer is equal to the set pressure, and it is also determined that the pressure detected by the pressure detection device at the outlet of the second vaporizer is equal to the set pressure, then the switch device in the nitrogen supply pipeline from the outlet of the first vaporizer to the third production line can be turned on, and the switch device in the nitrogen supply pipeline from the outlet of the second vaporizer to the third production line can also be turned on, so that the first vaporizer and the second vaporizer can be selected together to supply nitrogen to the third production line from the internal gas supply source.

[0013] In some implementations, the method further includes: for three or more production lines, each production line has a controller and an OPC server, and the controller and OPC server of each production line are connected via a network switch; selecting one production line as the master control production line; having the controller of any one of the three or more production lines control the opening degree of the regulating device in the nitrogen supply pipeline of that production line based on the pressure detected by the pressure detection device in the nitrogen supply pipeline of that production line; and uploading the pressure detected by the pressure detection device in the nitrogen supply pipeline of that production line and the opening degree of the regulating device in the nitrogen supply pipeline of that production line as the field nitrogen supply data of that production line, and uploading the field nitrogen supply data of that production line to the OPC server of that production line via the network switch; and having the master control production line retrieve the field nitrogen supply data from the OPC server of any one of the three or more production lines via the network switch, so as to initiate an alert message indicating an abnormal field nitrogen supply data for that production line if the retrieved field nitrogen supply data of any one of the three or more production lines is not within the set data range.

[0014] Therefore, the solution of this invention utilizes two sets of liquid nitrogen tanks and vaporizers for two production lines, combined with an external nitrogen supply source, to rearrange and adjust the pipelines of the nitrogen supply system for the two production lines. Furthermore, pressure detection devices and switching devices are added to the two production lines. By using the pressure detection devices to monitor the nitrogen pressure in the three production lines, and controlling the opening of the corresponding regulating devices based on the detection results, nitrogen can be supplied to the three production lines using the two sets of liquid nitrogen tanks and vaporizers for the two production lines and an external nitrogen supply source. Thus, by rearranging and adjusting the pipelines of the nitrogen supply system for the two production lines and adding some detection and execution mechanisms, the use of two sets of liquid nitrogen tanks and vaporizers to supply nitrogen to the three production lines can improve production efficiency.

[0015] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an embodiment of the nitrogen supply system for multiple production lines according to the present invention;

[0018] Figure 2 Configuration diagram for nitrogen system supply for three production lines;

[0019] Figure 3 Select a control logic diagram for the vaporizer;

[0020] Figure 4 Diagram of the OPC server and instrumentation in the on-site nitrogen area;

[0021] Figure 5 This is a schematic flowchart of an embodiment of the control method for a nitrogen supply system for multiple production lines according to the present invention;

[0022] Figure 6 This is a schematic flowchart of an embodiment of the method of the present invention, which selects at least one of the first and second gasifiers for nitrogen supply to a third production line.

[0023] Figure 7 This is a schematic flowchart of an embodiment of the method of the present invention, which uses one production line to monitor the on-site nitrogen supply data of other production lines. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0025] Considering that the existing nitrogen supply facilities are shared by three production lines and two production lines, if nitrogen is directly supplied from the first or second production line to the third production line, the nitrogen supply to the first or second production line will not meet the production capacity. Therefore, it is necessary to rearrange and debug the pipelines of the nitrogen supply systems of the two production lines, add some detection and actuators, and then use some control methods to ensure the normal nitrogen supply to each production line.

[0026] Therefore, through research on nitrogen supply control technology in multiple production lines, and considering factors such as nitrogen pressure and flow direction during the nitrogen supply process, this invention proposes a nitrogen supply system for multiple production lines. By rearranging and debugging the pipelines of the nitrogen supply systems for two production lines, and adding some detection and actuators, the normal supply of nitrogen to each production line is achieved through some control methods. This solves the problem that using two sets of liquid nitrogen tanks and vaporizers in related solutions cannot supply nitrogen to three production lines, thus affecting production efficiency. It also solves the problem of unstable nitrogen pressure control during the production process of multiple production lines in the factory.

[0027] According to an embodiment of the present invention, a nitrogen supply system for multiple production lines is provided. See also... Figure 1 The diagram shows a structural schematic of an embodiment of the device of the present invention. The multiple production lines refer to three or more production lines. The nitrogen supply system for the multiple production lines includes: nitrogen supply systems for two production lines, a pressure detection device, a switching device, a regulating device, and an external nitrogen supply pipeline. The external nitrogen supply pipeline is a nitrogen inlet pipeline used to connect to an external nitrogen source. The nitrogen supplied by the external source is produced by a nitrogen generator. In actual operation, two problems exist: first, the supply pressure fluctuates; second, equipment malfunctions can occur, failing to meet the supply requirements of continuous production lines. The liquid nitrogen system involved in the solution of the present invention has the functions of supplementary supply and emergency supply, ensuring the continuous and normal operation of the production line.

[0028] The nitrogen supply systems of the two production lines are each connected to the nitrogen supply pipeline of the corresponding production line within the two production lines. Each production line's nitrogen supply pipeline has a nitrogen outlet pipeline; each nitrogen outlet pipeline of the internal nitrogen supply line in the two production lines is equipped with the aforementioned switching device to control the opening or closing of the corresponding nitrogen outlet pipeline. Each nitrogen outlet pipeline of the internal nitrogen supply line in the two production lines is connected to the nitrogen supply pipelines of the other three or more production lines (excluding the two production lines). Specifically, the nitrogen outlet pipeline of each internal nitrogen supply line in the two production lines, after passing through the aforementioned switching device, is connected to the nitrogen supply pipelines of the other production lines besides the two production lines.

[0029] The external nitrogen supply pipeline is connected to the nitrogen supply pipeline of each of the three or more production lines, and is used to introduce an external nitrogen source into the nitrogen supply pipeline of each of the three or more production lines. The pressure detection device is installed in the nitrogen outlet pipeline of each of the two internal nitrogen supply pipelines and in the nitrogen supply pipeline of each of the three or more production lines to detect the nitrogen pressure in the corresponding pipeline. The regulating device is also installed in each of the nitrogen outlet pipelines of the two internal nitrogen supply pipelines, the nitrogen supply pipeline of each of the three or more production lines, and the external nitrogen supply pipeline, to adjust the opening of the regulating device in the corresponding pipeline according to the nitrogen pressure in the corresponding pipeline, so as to ensure the normal nitrogen supply to the production line where the corresponding pipeline is located.

[0030] This invention proposes a nitrogen supply system for multiple production lines, involving nitrogen in two states (liquid and gas). The implementation of this invention involves not only the configuration of nitrogen pipeline hardware but also the implementation of control software. Specifically, by rearranging and debugging the pipelines of the nitrogen supply systems for two production lines, adding detection and actuators, and then using control methods to ensure normal nitrogen supply to each production line, the invention effectively controls the nitrogen supply to the factory production lines, reduces equipment footprint, lowers equipment investment costs, and improves production efficiency. This solves the problem in related solutions where using two sets of liquid nitrogen tanks and vaporizers cannot supply three production lines, thus affecting production efficiency. It also solves the problem of unstable nitrogen pressure control during multi-production line operation. Generally, under conditions where space and funding permit, the nitrogen supply device is designed to be integrated with the production lines. This invention is applicable to situations where space or funding does not allow for integrated design, but normal nitrogen supply is still required. If there are still two vaporizers, and two systems supply nitrogen to three production lines, then the control method has undergone a fundamental change. The most important thing is to ensure the stability of the nitrogen supply system by controlling the nitrogen pressure. If the solution in this application is used for four or more production lines, the work required is the same as the method of connecting the nitrogen pipeline for the third production line, and it is not difficult to implement.

[0031] In some embodiments, the two production lines include: a first production line and a second production line. Other production lines besides the two mentioned above are referred to as the third production line. The nitrogen supply system for the two production lines includes: a first liquid nitrogen tank and a second liquid nitrogen tank, as well as a first vaporizer and a second vaporizer, wherein the first liquid nitrogen tank is, for example, liquid nitrogen tank A, the second liquid nitrogen tank is, for example, liquid nitrogen tank B, the first vaporizer is, for example, vaporizer A, and the second vaporizer is, for example, vaporizer B.

[0032] In this invention, the outlet pipelines of the first and second liquid nitrogen tanks are combined and connected to form an internal nitrogen supply pipeline, such as a shared nitrogen supply pipeline for liquid nitrogen tanks A and B. In this invention, the two liquid nitrogen tanks (i.e., liquid nitrogen tank A and liquid nitrogen tank B) are used for storing liquid nitrogen. The purpose of the combined pipelines is that each tank can supply liquid nitrogen to several production lines; simultaneously, if one tank has a potential hazard requiring maintenance, it will not affect the operation of the production line (short-term maintenance).

[0033] The nitrogen internal supply pipeline is divided into two lines, referred to as the first nitrogen internal supply pipeline and the second nitrogen internal supply pipeline. The first nitrogen internal supply pipeline, after passing through the first vaporizer, splits into two lines: one is the nitrogen supply pipeline for the first production line, and the other is the nitrogen outlet pipeline for the first nitrogen internal supply pipeline. The nitrogen supply pipeline for the first production line is connected to the nitrogen inlet of the first production line. The second nitrogen internal supply pipeline, after passing through the second vaporizer, splits into two lines: one is the nitrogen supply pipeline for the second production line, and the other is the nitrogen outlet pipeline for the second nitrogen internal supply pipeline. The nitrogen supply pipeline for the second production line is connected to the nitrogen inlet of the second production line. The nitrogen outlet pipeline of the first nitrogen internal supply pipeline merges and connects with the nitrogen outlet pipeline of the second nitrogen internal supply pipeline to form a combined nitrogen outlet pipeline for both the first and second production lines. The nitrogen outlet and collection pipelines of the first and second production lines are connected to the nitrogen supply pipeline of the third production line. The nitrogen supply pipeline of the third production line is connected to its nitrogen inlet. The external nitrogen supply pipeline has three branches, designated as the first external nitrogen branch pipeline, the second external nitrogen branch pipeline, and the third external nitrogen branch pipeline. The first external nitrogen branch pipeline is connected to the nitrogen supply pipeline of the first production line. The second external nitrogen branch pipeline is connected to the nitrogen supply pipeline of the second production line. The third external nitrogen branch pipeline is connected to the nitrogen supply pipeline of the third production line.

[0034] In the nitrogen supply system for multiple production lines proposed in this invention, based on two sets of liquid nitrogen tanks and vaporizers for two production lines (i.e., two liquid nitrogen tanks and two vaporizers), gas is supplied to three or more production lines. To ensure that the gas consumption of the two vaporizer users is comparable, or at least that there is no situation where the gas consumption is too high and cannot meet the user's needs, the control system and field valve configuration need to have a gas path selection function. Related solutions only use two sets of vaporizers to supply two production lines, thus eliminating the gas path selection issue. The gas path selection function proposed in this invention is precisely designed to enable two sets of vaporizers to supply three production lines.

[0035] In some embodiments, the nitrogen supply system for multiple production lines further includes: a first buffer tank, a second buffer tank, and a third buffer tank, wherein the first buffer tank is such as buffer tank A, the second buffer tank is such as buffer tank B, and the third buffer tank is such as buffer tank C.

[0036] The first buffer tank is located at the nitrogen inlet of the first production line. The nitrogen supply pipeline of the first production line passes through the first buffer tank and then connects to the nitrogen inlet of the first production line. The second buffer tank is located at the nitrogen inlet of the second production line. The nitrogen supply pipeline of the second production line passes through the second buffer tank and then connects to the nitrogen inlet of the second production line. The third buffer tank is located at the nitrogen inlet of the third production line. The nitrogen supply pipeline of the third production line passes through the third buffer tank and then connects to the nitrogen inlet of the third production line.

[0037] Since a single production line configuration requires two liquid nitrogen storage tanks and two vaporizers, when adding a new production line, pipelines are simultaneously drawn from the outlets of both vaporizers. These pipelines merge and connect to an external nitrogen supply, then to a new nitrogen buffer tank. This allows for the supply of nitrogen from both the vaporizer outlet and the external supply to the nitrogen buffer tank. In terms of pipeline details, each vaporizer outlet pipeline can be connected to the pipelines of each production line. This interconnection of pipelines is designed to enable a manual solution for supplying nitrogen from a single vaporizer in case of sudden vaporizer malfunctions. By appropriately adding detection and execution units to the nitrogen pipelines and developing control programs, a stable nitrogen supply to each production line can be achieved, effectively controlling the nitrogen supply to the factory production lines, reducing equipment footprint, lowering equipment investment costs, and improving production efficiency.

[0038] In some embodiments, the regulating device includes: a first regulating valve (e.g., valve PV-0001), a second regulating valve (e.g., valve PV-0002), a third regulating valve (e.g., valve PV-0003), a fourth regulating valve (e.g., a switch valve installed in the pipeline between an external nitrogen source and the nitrogen supply pipeline of a second production line), a fifth regulating valve (e.g., valve PV-0005), a sixth regulating valve (e.g., valve PV-0006), a seventh regulating valve (e.g., valve PV-0007), and an eighth regulating valve (e.g., valve PV-0008). The switching device includes: a first switching valve (e.g., valve XV-0001) and a second switching valve (e.g., valve XV-0002). The opening degree of the regulating valve is adjustable, used to regulate the nitrogen pressure in the nitrogen pipeline to which it is located. The opening degree of the switch valve is not adjustable, used to control the opening or closing of the nitrogen pipeline to which it is located.

[0039] The system comprises the following components: The first regulating valve is located in the inlet pipeline of the first vaporizer within the first nitrogen internal supply pipeline. The second regulating valve is located in the inlet pipeline of the second vaporizer within the second nitrogen internal supply pipeline. The third regulating valve is located in the first external nitrogen branch pipeline. The fourth regulating valve is located in the second external nitrogen branch pipeline. The seventh regulating valve is located in the third external nitrogen branch pipeline, between the inlet of the external nitrogen source and the nitrogen outlet confluence pipeline of the first and second production lines. The eighth regulating valve is located in the nitrogen outlet confluence pipeline of the first and second production lines. The first switching valve is located in the nitrogen outlet pipeline of the first nitrogen internal supply pipeline. The second switching valve is located in the nitrogen outlet pipeline of the second nitrogen internal supply pipeline. The fifth regulating valve is located in the nitrogen supply pipeline of the first production line, between the outlet pipeline of the first vaporizer and the first external nitrogen branch pipeline. The sixth regulating valve is installed in the nitrogen supply pipeline of the second production line, and is located between the outlet pipeline of the second vaporizer and the second external nitrogen branch pipeline.

[0040] In the present invention, the redesign and commissioning of the nitrogen supply system pipelines for the two production lines can be achieved by: setting up an internal nitrogen supply pipeline and an external nitrogen supply pipeline for the nitrogen supply pipeline of the third production line. The internal nitrogen supply pipeline for the third production line connects to the existing vaporizer outlets of the two liquid nitrogen tanks and vaporizers in the two production lines. Simultaneously, the internal nitrogen supply pipeline of the third production line merges with the new external nitrogen supply pipeline to form the nitrogen supply pipeline for the third production line. Furthermore, the main parts requiring commissioning for the nitrogen supply pipeline of the third production line include: controlling the vaporizer outlet pressure, and controlling and commissioning the nitrogen supply pressures of the first, second, and third production lines. Thus, it is possible to use liquid nitrogen and externally supplied nitrogen in multiple production lines without increasing the floor space, effectively saving the floor space occupied by liquid nitrogen tanks and vaporizer equipment. It effectively reduces the purchase cost of liquid nitrogen tanks, vaporizers and their auxiliary equipment, and effectively saves on the installation and maintenance costs of liquid nitrogen tanks, vaporizers and their auxiliary equipment.

[0041] In some embodiments, the pressure detection device includes: a first pressure detection instrument (such as pressure detection instrument PICA0001), a second pressure detection instrument (such as pressure detection instrument PICA0002), a third pressure detection instrument (such as pressure detection instrument PICA0003), a fourth pressure detection instrument (such as pressure detection instrument PICA0004), and a fifth pressure detection instrument (such as pressure detection instrument PICA0005).

[0042] The first pressure detection instrument is installed on the nitrogen supply pipeline of the first production line, between the first external nitrogen branch pipeline and the nitrogen inlet of the first production line, to detect a first pressure, so that the third and fifth regulating valves adjust the opening of the regulating devices in the corresponding pipelines according to the first pressure. The second pressure detection instrument is installed on the nitrogen supply pipeline of the second production line, between the second internal nitrogen supply pipeline and the second external nitrogen branch pipeline, to detect a second pressure, so that the fourth and sixth regulating valves adjust the opening of the regulating devices in the corresponding pipelines according to the second pressure. The third pressure detection instrument is installed on the nitrogen supply pipeline of the first production line, at the outlet of the first vaporizer, to detect a third pressure, so that the first regulating valve adjusts the opening of the regulating device in the corresponding pipeline according to the third pressure. The fourth pressure detection instrument is installed on the nitrogen supply pipeline of the second production line, at the outlet of the second vaporizer, to detect a fourth pressure, so that the second regulating valve adjusts the opening of the regulating device in the corresponding pipeline according to the fourth pressure. The fifth pressure detection instrument is installed on the nitrogen supply pipeline of the third production line, and is located between the nitrogen outlet and collection pipeline of the first and second production lines and the nitrogen inlet of the third production line. It is used to detect the fifth pressure so that the seventh regulating valve and the eighth regulating valve can adjust the opening of the regulating device in the corresponding pipeline according to the fifth pressure.

[0043] Specifically, Figure 2 This diagram shows the nitrogen supply system configuration for three production lines. Figure 2 As shown, the three production lines include Production Line 1 (i.e., Production Line 1#), Production Line 2 (i.e., Production Line 2#), and Production Line 3 (i.e., Production Line 3#), the two liquid nitrogen tanks include Liquid Nitrogen Tank A and Liquid Nitrogen Tank B, and the two vaporizers include Vaporizer A and Vaporizer B. Figure 2 In the example shown, for the three production lines, three buffer tanks, such as buffer tank A, buffer tank B, and buffer tank C, are also provided, along with an external nitrogen supply device (such as an external N2 supply). Figure 2In the example shown, for the three production lines, switching devices and pressure detection devices are also installed. The switching devices include control valves PV-0001, PV-0002, PV-0003, PV-0005, PV-0006, PV-0007, PV-0008, switch valves XV-0001 and XV-0002, and the pressure detection devices include pressure detection instruments PICA0001, PICA0002, PICA0003, PICA0004, and PICA0005.

[0044] The outlet pipelines of liquid nitrogen tank A and liquid nitrogen tank B are connected to the same pipeline, referred to as the shared nitrogen supply pipeline. This shared nitrogen supply pipeline is divided into two branches, referred to as nitrogen supply pipeline A and nitrogen supply pipeline B. Nitrogen supply pipeline A, after passing through valve PV-0001 and vaporizer A, further divides into two branches, referred to as the first branch pipeline and the second branch pipeline of nitrogen supply pipeline A: The first branch pipeline of nitrogen supply pipeline A, after passing through regulating valve PV-0005, merges with the first external nitrogen supply pipeline, which passes through regulating valve PV-0003, and then supplies nitrogen to production line 1 after passing through buffer tank A; the nitrogen supply pipeline of this first external nitrogen supply device is connected to the inlet pipeline of buffer tank B in production line 2 after passing through a regulating valve. The second branch pipeline of nitrogen supply pipeline A, after passing through switch valve XV-0001 and regulating valve PV-0008, is connected to the inlet pipeline of buffer tank C in production line 3. Nitrogen supply line B, after passing through regulating valve PV-0002 and vaporizer B, splits into two branches, designated as the first branch and the second branch. The first branch merges with the external nitrogen supply line via regulating valve PV-0006, and connects to production line #2 after passing through buffer tank B. The second branch connects to the pipeline between switching valve XV-0001 and regulating valve PV-0008 after passing through switch valve XV-0002. The second external nitrogen supply device connects to production line #3 after passing through buffer tank C, via the outlet pipelines of regulating valves PV-0007 and PV-0008. The first and second external nitrogen supply devices can use the same or different external nitrogen sources.

[0045] A pressure sensor PICA0003 is installed on the outlet pipeline of vaporizer A to control the opening of regulating valve PV-0001. A pressure sensor PICA0001 is installed on the inlet pipeline of buffer tank A to control the opening of valves PV-0003 and PV-0005. A pressure sensor PICA0004 is installed on the outlet pipeline of vaporizer B to control the opening of valve PV-0002. A pressure sensor PICA0002 is installed on the inlet pipeline of buffer tank B to control the opening of valve PV-0006 and the on / off valve of the first external nitrogen supply device. A pressure sensor PICA0005 is installed on the inlet pipeline of buffer tank C to control the opening of valves PV-0007 and PV-0008.

[0046] In the nitrogen supply system for multiple production lines proposed in this invention, when two sets of vaporizers supply nitrogen to three production lines, the outlet pressure of the vaporizer cannot be effectively guaranteed in cases where two or more production lines simultaneously use nitrogen from the outlet of a single vaporizer. Therefore, a pressure detection device needs to be added to the vaporizer outlet, and a single-loop pressure control function needs to be added to the control system to ensure the vaporizer outlet pressure. This provides the necessary condition for the two sets of vaporizers to supply nitrogen to three production lines. In this way, a stable nitrogen supply to multiple production lines can be achieved without adding liquid nitrogen storage tanks and vaporizers or other supporting facilities.

[0047] By employing the technical solution of this invention, the pipelines of the nitrogen supply system for the two production lines are rearranged and adjusted using two sets of liquid nitrogen tanks and vaporizers for the two production lines, combined with an external nitrogen supply source. Pressure detection devices and switching devices are added to the two production lines. The pressure detection devices monitor the nitrogen pressure in the three production lines, and the opening of the corresponding regulating devices is controlled based on the detection results. This allows for the supply of nitrogen to the three production lines using two sets of liquid nitrogen tanks and vaporizers from the two production lines, along with an external nitrogen supply source. Therefore, by rearranging and adjusting the pipelines of the nitrogen supply system for the two production lines and adding some detection and execution mechanisms, the use of two sets of liquid nitrogen tanks and vaporizers to supply nitrogen to the three production lines can be achieved, which helps to improve production efficiency.

[0048] According to embodiments of the present invention, a control method for a nitrogen supply system for multiple production lines is also provided, corresponding to a nitrogen supply system for multiple production lines, such as... Figure 5 The diagram shows a flowchart of an embodiment of the method of the present invention. The control method for a nitrogen supply system for multiple production lines may include: a process of selecting whether to prioritize external or internal supply for internal and external gas sources, including steps S110 to S130.

[0049] In step S110, the nitrogen supply systems of the two production lines are used as internal gas sources (specifically, the gas source at the vaporizer outlet of the nitrogen supply systems of the two production lines is used as the internal gas source), and the external nitrogen source connected to the external nitrogen inlet pipeline is used as the external gas source. The gas source after the internal gas source and the external gas source are combined is used as the gas source of the nitrogen supply system of multiple production lines, and is denoted as the combined gas source. When the combined gas source is used to supply nitrogen to each of the three or more production lines, at least one of the switching devices in the pipeline between the first vaporizer outlet and the third production line in the nitrogen supply system of the two production lines and the switching devices in the pipeline between the second vaporizer outlet and the third production line in the nitrogen supply system of the two production lines is turned on, and it is determined whether the gas supply pressure of the combined gas source is equal to the set gas supply pressure.

[0050] In step S120, if it is determined that the gas supply pressure of the combined gas source is equal to the set gas supply pressure, then the opening degree of all regulating devices in the regulating devices in the pipeline between the external gas supply source and the corresponding production line, and in the regulating devices in the pipeline between the internal gas supply source and the corresponding production line, is maintained at the current opening degree.

[0051] In step S130, if it is determined that the gas supply pressure of the combined gas source is not equal to the set gas supply pressure, the opening of the regulating device in the pipeline between the external gas source and the corresponding production line, and the opening of at least some of the regulating devices in the pipeline between the internal gas source and the corresponding production line are controlled to change, so that the gas supply pressure of the combined gas source reaches the set gas supply pressure.

[0052] In some implementations, during the process of selecting whether to prioritize external or internal gas supply for both internal and external gas sources, step S130 involves controlling the opening of the regulating device in the pipeline between the external gas source and the corresponding production line, as well as the opening of at least some of the regulating devices in the pipeline between the internal gas source and the corresponding production line, to change the gas supply pressure of the combined gas source to reach the set gas supply pressure. This includes: when the gas supply pressure of the combined gas source is less than the set gas supply pressure, controlling the opening of the regulating device in the pipeline between the external gas source and the corresponding production line to change based on the pressure detected by the detection device in the pipeline of the combined gas source; if the opening of the regulating device in the pipeline between the external gas source and the corresponding production line has reached the set opening of the corresponding regulating device, but the gas supply pressure of the combined gas source still cannot reach the set pressure, then controlling the opening of the regulating device in the pipeline between the internal gas source and the corresponding production line to gradually change based on the pressure detected by the detection device in the pipeline of the combined gas source, so that the gas supply pressure of the combined gas source reaches the set gas supply pressure.

[0053] In this invention, by selecting either "external supply as the primary mode" or "internal supply as the primary mode" control, and using a split-range control method to simultaneously control the opening of the internal / external supply valves, stable nitrogen pressure control of the production line is achieved. Specifically, when the external nitrogen supply pressure is normal, external supply is selected as the primary mode; when there is a fault or interruption in the external nitrogen supply, internal supply is selected as the primary mode. To ensure a normal nitrogen supply to each production line, a split-range control method is used to ensure stable nitrogen pressure control when external supply is the primary mode. Under this control method, if the external nitrogen supply regulating valve operates within a certain opening range and can maintain the pipeline pressure, the internal supply regulating valve remains closed. If the operation of the external nitrogen supply regulating valve within a certain opening range is still insufficient, the internal supply valve needs to be opened to supplement the internal nitrogen supply and maintain the pipeline pressure. In the external supply-primary mode, it is necessary to control the opening of both the external and internal supply valves, and the split-range control method can effectively achieve simultaneous control of both valves.

[0054] For example, when the control mode primarily uses external nitrogen supply, the split-range control works as follows: When the pressure detected by the pressure sensor PICA0001 is not equal to the set pressure value, the opening of valve PV-0003 increases from zero. If the opening of valve PV-0003 reaches the set value (e.g., set opening A%), but the pressure detected by the pressure sensor PICA0001 is still not equal to the set pressure value, then the opening of valve PV-0005 also increases from zero until the set pressure value is reached. If the opening of valve PV-0003 is less than the set value, and the pressure detected by the pressure sensor PICA0001 reaches the set pressure value, then valve PV-0005 remains at zero opening. In other words, this control is equivalent to a single-loop control: when the actual pressure is less than the set pressure, the valve opening increases; when the actual pressure is greater than the set pressure, the valve opening decreases.

[0055] In some embodiments, the control method for a nitrogen supply system for multiple production lines described in the present invention further includes: a process of selecting at least one vaporizer, either a first vaporizer or a second vaporizer, for nitrogen supply to a third production line.

[0056] The following is combined with Figure 6The schematic diagram shown is a flowchart of an embodiment of the method of the present invention in which at least one of the first vaporizer and the second vaporizer is selected for nitrogen supply to the third production line. The specific process of selecting at least one of the first vaporizer and the second vaporizer for nitrogen supply to the third production line is further explained. Specifically, in step S110, when nitrogen is supplied to each of the three or more production lines using the combined gas source, at least one of the switching devices in the pipeline between the outlet of the first vaporizer of the two production lines and the switching device in the pipeline between the outlet of the second vaporizer of the two production lines and the third production line is turned on, including steps S210 to S250.

[0057] Step S210: In the case where the nitrogen supply system of the two production lines includes a first vaporizer and a second vaporizer, and the two production lines include a first production line and a second production line, for the other production line (i.e., the third production line) among the three or more production lines, it is determined whether the pressure detected by the pressure detection device at the outlet of the first vaporizer and the pressure detected by the pressure detection device at the outlet of the second vaporizer are equal to the set pressure.

[0058] Step S220: If it is determined that the pressure detected by the pressure detection device at the outlet of the first vaporizer is equal to the set pressure, then the switch device in the nitrogen supply pipeline from the outlet of the first vaporizer to the third production line can be turned on, so that the first vaporizer can be selected from the internal gas supply source to supply nitrogen to the third production line.

[0059] Step S230: If it is determined that the pressure detected by the pressure detection device at the outlet of the first vaporizer is not equal to the set pressure, then when the pressure detected by the pressure detection device at the outlet of the first vaporizer is less than the set pressure, the opening of the regulating device at the inlet of the first vaporizer is increased; when the pressure detected by the pressure detection device at the outlet of the first vaporizer is greater than the set pressure, the opening of the regulating device at the inlet of the first vaporizer is decreased, so that the pressure detected by the pressure detection device at the outlet of the first vaporizer is equal to the set pressure.

[0060] In step S240, if it is determined that the pressure detected by the pressure detection device at the outlet of the second vaporizer is equal to the set pressure, then the switch device in the nitrogen supply pipeline from the outlet of the second vaporizer to the third production line can be turned on, so as to select the second vaporizer to supply nitrogen to the third production line from the internal gas supply source.

[0061] Step S250: If it is determined that the pressure detected by the pressure detection device at the outlet of the second vaporizer is not equal to the set pressure, then when the pressure detected by the pressure detection device at the outlet of the second vaporizer is less than the set pressure, the opening of the regulating device at the inlet of the second vaporizer is increased; when the pressure detected by the pressure detection device at the outlet of the second vaporizer is greater than the set pressure, the opening of the regulating device at the inlet of the second vaporizer is decreased, so that the pressure detected by the pressure detection device at the outlet of the second vaporizer is equal to the set pressure.

[0062] In cases where it is determined that the pressure detected by the pressure detection device at the outlet of the first vaporizer is equal to the set pressure, and it is also determined that the pressure detected by the pressure detection device at the outlet of the second vaporizer is equal to the set pressure, the switch device in the nitrogen supply pipeline from the outlet of the first vaporizer to the third production line can be turned on, and the switch device in the nitrogen supply pipeline from the outlet of the second vaporizer to the third production line can also be turned on, so that the first vaporizer and the second vaporizer can be selected together to supply nitrogen to the third production line from the internal gas supply source.

[0063] The ability to choose means that one can choose to open the switch device in the nitrogen supply pipeline from the outlet of the corresponding vaporizer to the third production line that meets the corresponding conditions, or one can choose not to open the switch device in the nitrogen supply pipeline from the outlet of the corresponding vaporizer to the third production line that meets the corresponding conditions, and instead choose to open the switch device in the nitrogen supply pipeline from the outlet of another vaporizer to the third production line.

[0064] like Figure 2 As shown, pressure detection devices are installed on the outlet pipelines of vaporizer A and vaporizer B to control the opening of regulating valves PV-0001 and PV-0002, ensuring the stability of the vaporizer outlet pressure. Taking the pipeline of production line 1 as an example, pressure detection instrument PICA0001 is used to control the opening of regulating valves PV-0003 and PV-0005, ensuring that the inlet pressure of nitrogen buffer tank A is stable and controlled. The control of the opening of regulating valves PV-0003 and PV-0005 here is equivalent to the control of the regulator, i.e., the single-loop control system mentioned above.

[0065] Adding switch valves XV-0001 and XV-0002 to the outlet pipelines of vaporizers A and B allows for selection of the vaporizer used on production line three. For example, a control panel can be set up with corresponding selection buttons. When "Vaguler A" is selected, the program sends a command to open switch valve XV-0001; when "Vaguler B" is selected, the program sends a command to open switch valve XV-0002; and when both "Vaguler A" and "Vaguler B" are selected, the program sends commands to open both switch valves XV-0001 and XV-0002. Related solutions do not use vaporizer outlet pressure detection to control the vaporizer outlet pressure. If a single vaporizer outputs nitrogen from two lines, the pipeline pressure cannot be reliably controlled, and the stability of the nitrogen pressure in the system pipeline cannot be guaranteed. However, in the solution of this invention, adding detection and actuator mechanisms can solve the problem of unstable nitrogen pressure control during production on multiple production lines in a factory. For example, for the two sets of liquid nitrogen tanks and vaporizers (Vagulant A and Vagulant B) on the two production lines, pressure detection devices are installed on the outlet pipelines of Vagulant A and Vagulant B respectively. These devices control the opening of regulating valve PV-0001 on the pipeline of Vagulant A and regulating valve PV-0002 on the pipeline of Vagulant B, ensuring the stability of the outlet pressure of Vagulant A and Vagulant B. Adding on / off valves XV-0001 and XV-0002 to the outlet pipelines of Vagulant A and Vagulant B allows for the selection of the vaporizer used in production line number three.

[0066] Figure 3 Select a control logic diagram for the vaporizer. Based on Figure 2 The nitrogen system supply configurations for the three production lines shown are as follows: Figure 2 The specific equipment to be deployed involves installing corresponding facilities on-site. First, equipment selection, procurement, and installation are conducted based on the production site's pipeline and gas pressure. The key focus is on the development and debugging of control programs. Afterwards, [further steps can be taken]. Figure 3 The example shown illustrates the selection and control of the vaporizer.

[0067] In this invention, the vaporizer outlet pressure control function is applied to the internal and external nitrogen supply system. The control process for the vaporizer A outlet pressure includes: introducing the pressure signal detected by the pressure detection instrument PICA0003 at the vaporizer A outlet into the control system; using the pressure signal to control the opening of the regulating valve PV-0001; when the pressure signal detected by the pressure detection instrument PICA0003 is less than the target value, the opening of the regulating valve PV-0001 increases; when the pressure signal detected by the pressure detection instrument PICA0003 is greater than the target value, the opening of the regulating valve PV-0001 decreases. In specific implementation, this single-loop pressure control system can be implemented through programming. The control process for the vaporizer B outlet pressure is consistent with the control process for the vaporizer A outlet pressure.

[0068] For details on the completion of the gasifier selection function on production line 3, please refer to [link / reference]. Figure 3 The example shown. For example... Figure 3 As shown, the vaporizer selection control logic includes:

[0069] Step 1: After the program starts, the operator determines which vaporizer needs to be selected based on the on-site process. When vaporizer A needs to be selected, the program automatically opens the switch valve XV-0001.

[0070] Step 2: When it is necessary to select the use of vaporizer B, the program will automatically open the switch valve XV-0002.

[0071] Step 3: When it is necessary to select to use vaporizer A and vaporizer B, the program will automatically open the switch valves XV-0001 and XV-0002 simultaneously. This function allows operators to perform the operation quickly and conveniently. The operator needs to manually confirm the operation based on the nitrogen pipeline pressure.

[0072] In the nitrogen supply system for multiple production lines proposed in this invention, the mixing of nitrogen supplied internally and externally in a particular production line requires ensuring the inlet pressure of the nitrogen buffer tank. Therefore, an application program for controlling the mixing of internal and external nitrogen supply needs to be developed to re-debug and optimize the controller parameters. The program development for the internal and external nitrogen supply function involves providing a nitrogen supply selection function for each production line. When the external nitrogen supply is normal, "external supply as the primary method" is selected; when the external nitrogen supply is abnormal, "internal supply as the primary method" is selected, meaning liquid nitrogen from the nitrogen tank is used, which is then vaporized before being supplied to each production line.

[0073] The following procedures are the basic steps to realize the internal and external supply functions (taking production line #1 as an example):

[0074] When using REM internal power supply, first set the PICA0001 PID mode to MAN (manual), and the PID output to the manually set value:

[0075] ' / / PICA0001 / PID1 / MODE.TARGET':=MAN;

[0076] ' / / PICA0001 / PID1 / OUT.CV':='^ / MAN_SET.CV';

[0077] When REM internal supply is activated, close the external supply main regulating valve PV-0003:

[0078] IF' / / PV-0003 / BAD ACTIVE.CV'=0THEN

[0079] ' / / PV-0003 / REQ_SP.CV':=0;

[0080] ' / / PV-0003 / AO1 / MODE.TARGET':=AUTO;

[0081] ' / / PV-0003 / AO1 / SP.CV':=0;

[0082] end_if;

[0083] REM selects external supply, reads the split-range parameters set during external supply, and simultaneously sets the PV-0003 and PV-0005 control valves to cascade mode:

[0084] IF'^ / SELECT1.CV'=1AND' / / PV-0003 / BAD_ACTIVE.CV'=0THEN

[0085] ' / / PV-0003 / AO1 / MODE.TARGET':=CAS;

[0086] ' / / PV-0005 / AO1 / MODE.TARGET':=CAS;

[0087] ' / / PICA0001 / SPLTR1 / IN_ARRAY[1][1].CV':='^ / IN_ARRAY-1-1.CV';

[0088] ' / / PICA0001 / SPLTR1 / IN_ARRAY[2][1].CV':='^ / IN_ARRAY-2-1.CV';

[0089] ' / / PICA0001 / SPLTR1 / IN_ARRAY[3][1].CV':='^ / IN_ARRAY-3-1.CV';

[0090] ' / / PICA0001 / SPLTR1 / IN_ARRAY[4][1].CV':='^ / IN_ARRAY-4-1.CV';

[0091] END_IF;

[0092] REM selects internal supply, reads the split-range parameters set during internal supply, and simultaneously sets the PV-0003 control valve to automatic mode and the PV-0005 control valve to cascade mode.

[0093] ' / / PV-0003 / AO1 / MODE.TARGET':=AUTO;

[0094] ' / / PV-0005 / AO1 / MODE.TARGET':=CAS;

[0095] ' / / PICA0001 / SPLTR1 / IN_ARRAY[1][1].CV':=0;

[0096] ' / / PICA0001 / SPLTR1 / IN_ARRAY[2][1].CV':=100;

[0097] ' / / PICA0001 / SPLTR1 / IN_ARRAY[3][1].CV':=0;

[0098] ' / / PICA0001 / SPLTR1 / IN_ARRAY[4][1].CV':=100;

[0099] This selection function scientifically ensures the stability of nitrogen pipeline pressure control under different gas supply conditions.

[0100] In some embodiments, the control method for a nitrogen supply system for multiple production lines described in the present invention further includes: a process of monitoring the on-site nitrogen supply data of other production lines using one production line.

[0101] The following is combined with Figure 7 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for monitoring the on-site nitrogen supply data of other production lines using one production line. It further illustrates the specific process of monitoring the on-site nitrogen supply data of other production lines using one production line, including steps S310 to S330.

[0102] Step S310: For three or more production lines, each production line has a controller and an OPC server, and the controller and OPC server of each production line are connected through a network switch; select one production line as the master control production line from the three or more production lines.

[0103] In step S320, the controller in any one of the three or more production lines controls the opening degree of the regulating device in the nitrogen supply pipeline of that production line based on the pressure detected by the pressure detection device in the nitrogen supply pipeline of that production line; and the pressure detected by the pressure detection device in the nitrogen supply pipeline of that production line and the opening degree of the regulating device in the nitrogen supply pipeline of that production line are used as the field nitrogen supply data of that production line, and the field nitrogen supply data of that production line is uploaded to the OPC server of that production line through the network switch.

[0104] Step S330: The main control production line retrieves the field nitrogen supply data from the OPC server of any one of the three or more production lines through the network switch. If the retrieved field nitrogen supply data of any one of the three or more production lines is not within the set data range, an alert message indicating an abnormal field nitrogen supply data for that production line is initiated.

[0105] In the nitrogen supply system for multiple production lines proposed in this invention, when multiple production lines share nitrogen, each production line control room needs to monitor not only the equipment on its own production line but also the equipment status of other production lines for more scientific operation. Therefore, this invention requires the implementation of screen monitoring and operation functions for each production line control room. For each production line, the primary concern is the nitrogen pressure and the status of each valve. However, the pressure at each pressure detection point and the status of each valve in the entire nitrogen supply area are also important production data. Therefore, implementing this function through the development of an OPC (a data security exchange and interoperability standard used in automation and other industries) communication program is significant. Generally, the hardware signals of a production line are already connected to its controller, so it can be operated directly using that controller. However, the equipment on other production lines is not connected to the same controller; therefore, the data status of other production line equipment needs to be communicated. After receiving the data communication content, the screen program is developed to display the data from other production lines on the screen.

[0106] Figure 4 This is a structural diagram of the OPC server and the instruments in the field nitrogen area. (Example:) Figure 4As shown, the field nitrogen area instrument 1 of production line 1 (such as pressure sensors PICA0001 and PICA0003) is connected to the production line 1 control cabinet (i.e., the cabinet containing the controller). Both the production line 1 control cabinet (i.e., the cabinet containing the controller) and the production line 1 OPC server are connected to a network switch. The field nitrogen area instrument 2 of production line 2 (such as pressure sensors PICA0002 and PICA0004) is connected to the production line 2 control cabinet (i.e., the cabinet containing the controller). Both the production line 2 control cabinet (i.e., the cabinet containing the controller) and the production line 2 OPC server are connected to a network switch. The field nitrogen area instrument 3 of production line 3 (such as pressure sensor PICA0005) is connected to the production line 3 control cabinet (i.e., the cabinet containing the controller). Both the production line 3 control cabinet (i.e., the cabinet containing the controller) and the production line 3 OPC server are connected to a network switch.

[0107] To reflect the primary and secondary nature of nitrogen control operations, special permissions are typically granted to production line 1. Its master controller can operate the nitrogen control functions of this line, while operators can also control the nitrogen control functions of all production lines. This function is also accomplished through OPC data communication. This feature facilitates overall coordination of nitrogen control, especially in the event of abnormal gas supply conditions. Since the operation of the nitrogen control system is not frequent but rather for abnormal situations, generally, when the external gas supply stops, it is necessary to switch to "internal supply as the primary mode." In some cases, operators may need to switch the control mode to manual to manually adjust the valve opening and gas supply pressure. For ease of unified coordination, it is more reasonable for these operations to be performed by the operators of one production line. The personnel can then take appropriate actions based on the gas supply status of all three production lines.

[0108] This invention utilizes two liquid nitrogen tanks and two vaporizers across multiple production lines, enabling two vaporizers to supply nitrogen to three production lines. Pressure detection devices are installed at the outlets of the two vaporizers, and a single-loop controller controls the vaporizer inlet valves to ensure consistent outlet pressure. By selecting between "external supply as primary" and "internal supply" control modes and using split-range control to simultaneously control the opening of the internal / external supply valves, stable nitrogen pressure control across the production lines is achieved. Programming allows for selection of vaporizer A, vaporizer B, or a combination of both. OPC communication enables monitoring and operation of the nitrogen supply systems for different production lines. The unique advantage of OPC communication is that operators on each production line can view the operating and control status of the nitrogen supply system, facilitating real-time monitoring and operation. Therefore, this invention provides a control method that effectively reduces investment and maintenance costs for production lines using nitrogen as a protective gas. By adopting single-loop pressure control at the vaporizer outlet and split-range control of internal and external gas supply, it is possible to supply gas to three or more production lines based on two liquid nitrogen tanks and two vaporizers, thereby reducing the equipment footprint and lowering equipment investment costs.

[0109] Since the processing and functions implemented by the method in this embodiment are basically the same as the embodiments, principles and examples of the nitrogen supply system for multiple production lines described above, any details not covered in the description of this embodiment can be found in the relevant descriptions in the foregoing embodiments, and will not be repeated here.

[0110] The technical solution of this embodiment utilizes two sets of liquid nitrogen tanks and vaporizers for two production lines, combined with an external nitrogen supply source, to redesign and adjust the pipelines of the nitrogen supply system for the two production lines. Pressure detection devices and switching devices are added to the two production lines. By using the pressure detection devices to monitor the nitrogen pressure in the three production lines, the opening degree of the corresponding regulating devices is controlled based on the detection results. This allows for the supply of nitrogen to the three production lines using the two sets of liquid nitrogen tanks and vaporizers for the two production lines and an external nitrogen supply source. This effectively controls the nitrogen supply to the factory production lines, reduces equipment footprint, lowers equipment investment costs, and improves production efficiency.

[0111] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0112] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A nitrogen supply system for multiple production lines, characterized in that, The multiple production lines refer to three or more production lines. The nitrogen supply system for these multiple production lines includes: nitrogen supply systems for two production lines, a pressure detection device, a switching device, a regulating device, and an external nitrogen supply inlet pipeline; the external nitrogen supply inlet pipeline is a nitrogen inlet pipeline used to connect to an external nitrogen source; wherein... The nitrogen supply systems for the two production lines are respectively connected to the nitrogen supply pipelines of the corresponding production lines in the two production lines; In each of the two production lines, a nitrogen outlet pipeline is provided on the nitrogen supply pipeline of the nitrogen supply system of each production line; the aforementioned switch device is provided on the nitrogen outlet pipeline of each nitrogen internal supply pipeline of the two production lines to control the opening or closing of the corresponding nitrogen outlet pipeline; the nitrogen outlet pipeline of each nitrogen internal supply pipeline of the two production lines is respectively connected to the nitrogen supply pipeline of the other production lines in the three or more production lines excluding the two production lines. The external nitrogen supply pipeline is connected to the nitrogen supply pipeline of each of the three or more production lines, and is used to introduce the external nitrogen source into the nitrogen supply pipeline of each of the three or more production lines. The pressure detection device is installed in the nitrogen outlet pipeline of each nitrogen supply pipeline in two production lines and in the nitrogen supply pipeline of each production line in three or more production lines to detect the nitrogen pressure in the corresponding pipeline. In each of the nitrogen outlet pipelines of the nitrogen internal supply pipelines in two production lines, the nitrogen supply pipelines of each production line in three or more production lines, and the external nitrogen inlet pipelines, the regulating device is also provided. The device is used to adjust the opening of the regulating device in the corresponding pipeline according to the nitrogen pressure in the corresponding pipeline, so as to realize the normal supply of nitrogen in the production line where the corresponding pipeline is located. By utilizing two sets of liquid nitrogen tanks and vaporizers on two production lines, and combining them with an external nitrogen supply source, the pipelines of the nitrogen supply system for the two production lines were rearranged and debugged. Pressure detection devices and switching devices were added to the two production lines. By using the pressure detection devices to detect the nitrogen pressure in the three production lines, the opening degree of the corresponding regulating devices was controlled according to the detection results, so as to realize the nitrogen supply to the three production lines using the two sets of liquid nitrogen tanks and vaporizers on the two production lines and the external nitrogen supply source. The pipeline layout and commissioning of the nitrogen supply system for the two production lines included: setting up internal and external nitrogen supply pipelines for the nitrogen supply pipeline of the third production line; the internal nitrogen supply pipeline for the third production line was connected to the existing vaporizer outlets of the two liquid nitrogen tanks and vaporizers of the two production lines; at the same time, the internal nitrogen supply pipeline of the third production line merged with the new external nitrogen supply pipeline to form the nitrogen supply pipeline for the third production line; the main parts that needed to be commissioned for the nitrogen supply pipeline of the third production line included: vaporizer outlet pressure control, and control and commissioning of the nitrogen supply pressure of the first, second and third production lines. This was achieved without increasing the floor space when multiple production lines use liquid nitrogen and external nitrogen supply, saving the floor space occupied by liquid nitrogen tanks and vaporizer equipment.

2. The nitrogen supply system for multiple production lines according to claim 1, characterized in that, The two production lines include: a first production line and a second production line; any production lines other than the two mentioned above are referred to as a third production line; the nitrogen supply system for the two production lines includes: a first liquid nitrogen tank and a second liquid nitrogen tank, as well as a first vaporizer and a second vaporizer; wherein, After the outlet pipeline of the first liquid nitrogen tank and the outlet pipeline of the second liquid nitrogen tank are merged and connected, a nitrogen internal supply pipeline is formed; the nitrogen internal supply pipeline is divided into two lines, referred to as the first nitrogen internal supply pipeline and the second nitrogen internal supply pipeline. The first nitrogen internal supply pipeline, after passing through the first vaporizer, is divided into two lines: one line is the nitrogen supply pipeline for the first production line, and the other line is the nitrogen outlet pipeline of the first nitrogen internal supply pipeline; the nitrogen supply pipeline for the first production line is connected to the nitrogen inlet of the first production line. The second nitrogen internal supply pipeline, after passing through the second vaporizer, splits into two lines: one line is the nitrogen supply pipeline for the second production line, and the other line is the nitrogen outlet pipeline of the second nitrogen internal supply pipeline; the nitrogen supply pipeline for the second production line is connected to the nitrogen inlet of the second production line. The nitrogen outlet pipeline of the first nitrogen internal supply pipeline merges and connects with the nitrogen outlet pipeline of the second nitrogen internal supply pipeline to form a nitrogen outlet convergence pipeline for the first production line and the second production line; the nitrogen outlet convergence pipeline of the first production line and the second production line is connected to the nitrogen supply pipeline of the third production line; the nitrogen supply pipeline of the third production line is connected to the nitrogen inlet of the third production line. The external nitrogen supply pipeline has three branches, referred to as the first external nitrogen branch pipeline, the second external nitrogen branch pipeline, and the third external nitrogen branch pipeline. The first external nitrogen branch pipeline is connected to the nitrogen supply pipeline of the first production line; the second external nitrogen branch pipeline is connected to the nitrogen supply pipeline of the second production line; and the third external nitrogen branch pipeline is connected to the nitrogen supply pipeline of the third production line.

3. The nitrogen supply system for multiple production lines according to claim 2, characterized in that, The nitrogen supply system for multiple production lines further includes: a first buffer tank, a second buffer tank, and a third buffer tank; wherein, The first buffer tank is located at the nitrogen inlet of the first production line; the nitrogen supply pipeline of the first production line passes through the first buffer tank and is then connected to the nitrogen inlet of the first production line. The second buffer tank is located at the nitrogen inlet of the second production line; the nitrogen supply pipeline of the second production line passes through the second buffer tank and is then connected to the nitrogen inlet of the second production line. The third buffer tank is located at the nitrogen inlet of the third production line; the nitrogen supply pipeline of the third production line passes through the third buffer tank and is then connected to the nitrogen inlet of the third production line.

4. The nitrogen supply system for multiple production lines according to claim 2 or 3, characterized in that, The regulating device includes: a first regulating valve, a second regulating valve, a third regulating valve, a fourth regulating valve, a fifth regulating valve, a sixth regulating valve, a seventh regulating valve, and an eighth regulating valve; the switching device includes: a first switching valve and a second switching valve; wherein, The first regulating valve is installed in the pipeline where the inlet of the first vaporizer is located in the first nitrogen internal supply pipeline; The second regulating valve is installed in the pipeline where the inlet of the second vaporizer is located in the second nitrogen internal supply pipeline; The third regulating valve is installed in the first external nitrogen branch pipeline; the fourth regulating valve is installed in the second external nitrogen branch pipeline; the seventh regulating valve is installed in the third external nitrogen branch pipeline and is located between the inlet of the external nitrogen source and the nitrogen outlet convergence pipeline of the first and second production lines; the eighth regulating valve is installed in the nitrogen outlet convergence pipeline of the first and second production lines; the first switching valve is installed in the nitrogen outlet pipeline of the first internal nitrogen supply pipeline; the second switching valve is installed in the nitrogen outlet pipeline of the second internal nitrogen supply pipeline. The fifth regulating valve is installed in the nitrogen supply pipeline of the first production line, and is located between the outlet pipeline of the first vaporizer and the first external nitrogen branch pipeline. The sixth regulating valve is installed in the nitrogen supply pipeline of the second production line, and is located between the outlet pipeline of the second vaporizer and the second external nitrogen branch pipeline.

5. The nitrogen supply system for multiple production lines according to claim 4, characterized in that, The pressure detection device includes: a first pressure detection instrument, a second pressure detection instrument, a third pressure detection instrument, a fourth pressure detection instrument, and a fifth pressure detection instrument; wherein, The first pressure detection instrument is installed on the nitrogen supply pipeline of the first production line and is located between the first external nitrogen branch pipeline and the nitrogen inlet of the first production line. It is used to detect the first pressure so that the third regulating valve and the fifth regulating valve can adjust the opening of the regulating device in the corresponding pipeline according to the first pressure. The second pressure detection instrument is installed on the nitrogen supply pipeline of the second production line, and is located between the second internal nitrogen supply pipeline and the second external nitrogen branch pipeline. It is used to detect the second pressure so that the fourth regulating valve and the sixth regulating valve can adjust the opening of the regulating device in the corresponding pipeline according to the second pressure. The third pressure detection instrument is installed on the nitrogen supply pipeline of the first production line and located at the outlet of the first vaporizer. It is used to detect the third pressure so that the first regulating valve can adjust the opening of the regulating device in the corresponding pipeline according to the third pressure. The fourth pressure detection instrument is installed on the nitrogen supply pipeline of the second production line and located at the outlet of the second vaporizer. It is used to detect the fourth pressure so that the second regulating valve can adjust the opening of the regulating device in the corresponding pipeline according to the fourth pressure. The fifth pressure detection instrument is installed on the nitrogen supply pipeline of the third production line, and is located between the nitrogen outlet and collection pipeline of the first and second production lines and the nitrogen inlet of the third production line. It is used to detect the fifth pressure so that the seventh regulating valve and the eighth regulating valve can adjust the opening of the regulating device in the corresponding pipeline according to the fifth pressure.

6. A control method for a nitrogen supply system for multiple production lines as described in any one of claims 1 to 5, characterized in that, include: Using the nitrogen supply systems of two production lines as internal gas sources and the external nitrogen source connected to the external nitrogen inlet pipeline as external gas sources, the gas source after the internal and external gas sources are combined is used as the gas source for the nitrogen supply systems of multiple production lines, and is denoted as the combined gas source. When using the combined gas source to supply nitrogen to each of the three or more production lines, at least one of the switching devices in the pipeline between the first vaporizer outlet and the third production line in the nitrogen supply system of the two production lines and the switching devices in the pipeline between the second vaporizer outlet and the third production line in the nitrogen supply system of the two production lines is turned on, and it is determined whether the gas supply pressure of the combined gas source is equal to the set gas supply pressure. If it is determined that the gas supply pressure of the combined gas source is equal to the set gas supply pressure, then the opening degree of all regulating devices in the regulating device in the pipeline between the external gas supply source and the corresponding production line, and the regulating device in the pipeline between the internal gas supply source and the corresponding production line, shall be maintained at the current opening degree. If it is determined that the gas supply pressure of the combined gas source is not equal to the set gas supply pressure, then the opening of the regulating device in the pipeline between the external gas source and the corresponding production line, and the opening of at least some of the regulating devices in the pipeline between the internal gas source and the corresponding production line are changed, so that the gas supply pressure of the combined gas source reaches the set gas supply pressure.

7. The control method for a nitrogen supply system for multiple production lines according to claim 6, characterized in that, Controlling the opening degree of the regulating device in the pipeline between the external gas supply source and the corresponding production line, and changing the opening degree of at least some of the regulating devices in the pipeline between the internal gas supply source and the corresponding production line, so as to make the gas supply pressure of the combined gas source reach the set gas supply pressure, including: When the gas supply pressure of the combined gas source is less than the set gas supply pressure, the opening of the regulating device in the pipeline between the external gas source and the corresponding production line is controlled to change according to the pressure detected by the detection device in the pipeline of the combined gas source. If the opening of the regulating device in the pipeline between the external gas source and the corresponding production line has reached the set opening of the corresponding regulating device, but the gas supply pressure of the combined gas source still cannot reach the set pressure, the opening of the regulating device in the pipeline between the internal gas source and the corresponding production line is controlled to gradually change according to the pressure detected by the detection device in the pipeline of the combined gas source, so that the gas supply pressure of the combined gas source reaches the set gas supply pressure.

8. The control method for a nitrogen supply system for multiple production lines according to claim 6, characterized in that, When supplying nitrogen to each of the three or more production lines using the combined gas source, controlling at least one of the switching devices in the pipeline between the outlet of the first vaporizer in the nitrogen supply system of the two production lines and the switching devices in the pipeline between the outlet of the second vaporizer in the nitrogen supply system of the two production lines and the third production line to be turned on includes: In the case where the nitrogen supply system of two production lines includes a first vaporizer and a second vaporizer, and the two production lines include the first production line and the second production line, for the other production line besides the two production lines, i.e. the third production line, it is determined whether the pressure detected by the pressure detection device at the outlet of the first vaporizer and the pressure detected by the pressure detection device at the outlet of the second vaporizer are equal to the set pressure. If it is determined that the pressure detected by the pressure detection device at the outlet of the first vaporizer is equal to the set pressure, then the switch device in the nitrogen supply pipeline from the outlet of the first vaporizer to the third production line can be turned on, so that the first vaporizer can be selected in the internal gas supply source to supply nitrogen to the third production line. If it is determined that the pressure detected by the pressure detection device at the outlet of the first vaporizer is not equal to the set pressure, then when the pressure detected by the pressure detection device at the outlet of the first vaporizer is less than the set pressure, the opening of the regulating device at the inlet of the first vaporizer is increased; when the pressure detected by the pressure detection device at the outlet of the first vaporizer is greater than the set pressure, the opening of the regulating device at the inlet of the first vaporizer is decreased, so that the pressure detected by the pressure detection device at the outlet of the first vaporizer is equal to the set pressure. If it is determined that the pressure detected by the pressure detection device at the outlet of the second vaporizer is equal to the set pressure, then the switch device in the nitrogen supply pipeline from the outlet of the second vaporizer to the third production line can be turned on, so that the second vaporizer can be selected in the internal gas supply source to supply nitrogen to the third production line. If it is determined that the pressure detected by the pressure detection device at the outlet of the second vaporizer is not equal to the set pressure, then when the pressure detected by the pressure detection device at the outlet of the second vaporizer is less than the set pressure, the opening of the regulating device at the inlet of the second vaporizer is increased; when the pressure detected by the pressure detection device at the outlet of the second vaporizer is greater than the set pressure, the opening of the regulating device at the inlet of the second vaporizer is decreased, so that the pressure detected by the pressure detection device at the outlet of the second vaporizer is equal to the set pressure. In cases where it is determined that the pressure detected by the pressure detection device at the outlet of the first vaporizer is equal to the set pressure, and it is also determined that the pressure detected by the pressure detection device at the outlet of the second vaporizer is equal to the set pressure, the switch device in the nitrogen supply pipeline from the outlet of the first vaporizer to the third production line can be turned on, and the switch device in the nitrogen supply pipeline from the outlet of the second vaporizer to the third production line can also be turned on, so that the first vaporizer and the second vaporizer can be selected together to supply nitrogen to the third production line from the internal gas supply source.

9. The control method for a nitrogen supply system for multiple production lines according to any one of claims 6 to 8, characterized in that, Also includes: For three or more production lines, each production line should have a controller and an OPC server, and the controller and OPC server of each production line should be connected through a network switch; select one production line as the master production line from the three or more production lines. The controller in any one of the three or more production lines controls the opening degree of the regulating device in the nitrogen supply pipeline of that production line based on the pressure detected by the pressure detection device in the nitrogen supply pipeline of that production line; and the pressure detected by the pressure detection device in the nitrogen supply pipeline of that production line and the opening degree of the regulating device in the nitrogen supply pipeline of that production line are used as the field nitrogen supply data of that production line, and the field nitrogen supply data of that production line is uploaded to the OPC server of that production line through the network switch; The main control production line can retrieve the field nitrogen supply data from the OPC server of any one of the three or more production lines through the network switch. If the field nitrogen supply data of any one of the three or more production lines is not within the set data range, an alert message indicating an abnormal field nitrogen supply data for that production line will be initiated.

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