NMP system and control method and control device thereof

Abstract

The invention discloses an NMP system and a control method and device thereof.The control method comprises the steps that a liquid supply set value is obtained, and the current available liquid supply amount of a buffer tank is determined according to a buffer liquid level signal output by a buffer liquid level meter; judging whether the liquid supply set value is smaller than or equal to the current available liquid supply amount; if the liquid supply set value is smaller than or equal to the current available liquid supply amount, a conveying pump is started, and the NMP liquid in the liquid storage tank is conveyed to a buffer tank; according to a conveying flow signal output by the conveying flow meter, whether single NMP liquid conveying is completed or not is judged, if it is judged that single NMP liquid conveying is completed, the conveying pump is closed, and the liquid supply set value is set to be zero; if the liquid supply set value is larger than the current available liquid supply amount, the liquid supply set value is set to be zero. By the adoption of the technical scheme, the protection measure of redundant safety leakage prevention can be achieved, and the risk of NMP leakage caused by accidents in the NMP liquid transmission process is reduced.

Description

Technical Field

[0001] This invention relates to the field of NMP liquid transport technology, and in particular to an NMP system and its control method and control device. Background Technology

[0002] NMP (N-methyl-2-pyrrolidone), scientifically known as N-methylpyrrolidone, possesses advantages such as high boiling point, low viscosity, and excellent solubility. It is a crucial auxiliary material in the production of lithium-ion battery electrodes, used as a solvent in electrode formulations to mix active materials, conductive agents, and binders. In recent years, in line with national new energy industry policies, NMP has been increasingly applied in lithium-ion battery production. However, due to its certain degree of biotoxicity, its use and protective measures must be carefully considered in industrial applications.

[0003] Currently, NMP liquid transfer systems on the market are either manually monitored or semi-automatically controlled. Even semi-automatic or the rare fully automatic liquid transfer systems lack various redundant safety and leak-proof protection measures. Summary of the Invention

[0004] This invention provides an NMP system and its control method and device to reduce the risk of NMP leakage due to accidents during NMP liquid transportation.

[0005] According to one aspect of the present invention, a control method for an NMP system is provided. The NMP system includes a storage tank, a delivery pump, a buffer tank, and a controller. The outlet of the storage tank is connected to the inlet of the delivery pump via a first delivery pipe, and the outlet of the delivery pump is connected to the inlet of the buffer tank via a second delivery pipe. A delivery flow meter is provided on the second delivery pipe. A buffer level gauge is provided on the buffer tank. The controller is communicatively connected to the delivery pump, the delivery flow meter, and the buffer level gauge.

[0006] The control method includes:

[0007] Obtain the liquid supply setting value, and determine the current liquid supply volume of the buffer tank based on the buffer level signal output by the buffer level gauge;

[0008] Determine whether the liquid supply setting value is less than or equal to the current liquid supply volume;

[0009] If the liquid supply setting value is less than or equal to the current available liquid volume, then the delivery pump is turned on to deliver the NMP liquid in the storage tank to the buffer tank;

[0010] Based on the delivery flow signal output by the delivery flow meter, it is determined whether a single NMP liquid delivery is completed. If it is determined that a single NMP liquid delivery is completed, the delivery pump is turned off and the liquid supply setting value is set to zero.

[0011] If the liquid supply setting value is greater than the current available liquid supply, then the liquid supply setting value is set to zero.

[0012] Optionally, if it is determined that a single NMP liquid delivery is not completed, then it is determined whether the delivery pump has stopped pumping NMP liquid. If the delivery pump stops pumping NMP liquid, then the liquid supply setting value is set to zero; if the delivery pump does not stop pumping NMP liquid, then the process returns to the step of determining whether a single NMP liquid delivery is completed based on the delivery flow rate signal output by the delivery flow meter.

[0013] Optionally, if the liquid supply setting value is less than or equal to the current available liquid volume, the transfer pump is activated to transfer the NMP liquid in the storage tank to the buffer tank, including:

[0014] If the liquid supply setting value is less than or equal to the current available liquid volume, then determine whether the liquid supply setting value is less than or equal to the single liquid supply threshold.

[0015] If the liquid supply setting value is less than or equal to the single liquid supply threshold, the delivery pump is turned on to deliver the NMP liquid in the storage tank to the buffer tank.

[0016] If the liquid supply setting value is greater than the single liquid supply threshold, then the liquid supply setting value is set to zero.

[0017] Optionally, the NMP system further includes an outlet valve disposed at the outlet of the storage tank and a buffer valve disposed at the second delivery pipeline; a first position sensor is disposed at the outlet valve and a second position sensor is disposed at the buffer valve, and both the first position sensor and the second position sensor are communicatively connected to the controller.

[0018] Starting the delivery pump to deliver NMP liquid from the storage tank to the buffer tank includes:

[0019] Before starting the delivery pump and during the period when the delivery pump is started, the first position signal of the first position sensor and the second position signal of the second position sensor are acquired, and based on the first position signal and the second position signal, it is confirmed whether the liquid outlet valve and the buffer valve are opened to the preset position.

[0020] If both the outlet valve and the buffer valve are opened to the preset position, the delivery pump is turned on to deliver the NMP liquid in the storage tank to the buffer tank.

[0021] If the outlet valve and / or the buffer valve are not opened to the preset position, the delivery pump shall be shut down.

[0022] Optionally, the control method further includes:

[0023] During the period when the delivery pump is turned on, the buffer level signal output by the buffer level gauge is acquired, and the liquid level in the buffer tank is determined based on the buffer level signal.

[0024] When the liquid level in the buffer tank is at or above the first buffer level, the outlet valve, the delivery pump, and the buffer valve are closed. The system detects whether the liquid level in the buffer tank is at or above the second buffer level, and issues an alarm when the liquid level in the buffer tank is at or above the second buffer level; wherein the second buffer level is higher than the first buffer level.

[0025] Optionally, the second delivery pipeline includes a first sub-pipeline and a second sub-pipeline. The first sub-pipeline is connected to the inlet of the buffer tank via the second sub-pipeline, and the second sub-pipeline is connected to the outlet of the delivery pump via the first sub-pipeline. The NMP system also includes a pressure relief pipeline. One end of the pressure relief pipeline is connected to the outlet of the delivery pump via the first sub-pipeline, and the other end of the pressure relief pipeline is connected to the pressure relief inlet of the storage tank. The first sub-pipeline is equipped with a first pressure detection device, and / or the second sub-pipeline is equipped with a second pressure detection device. The pressure relief pipeline is equipped with a pressure relief valve. The first pressure detection device, the second pressure detection device, and the pressure relief valve are all communicatively connected to the controller.

[0026] The control method further includes:

[0027] During the period when the delivery pump is turned on, the pressure in the first sub-pipe and / or the second sub-pipe is detected by the first pressure detection device and / or the second pressure detection device;

[0028] When the pressure in the first sub-pipe and / or the second sub-pipe exceeds the pressure threshold, the pressure relief valve is opened to relieve pressure in the first sub-pipe and / or the second sub-pipe.

[0029] When the pressure in the first sub-pipe and / or the second sub-pipe is less than or equal to the pressure threshold, the pressure relief valve is closed.

[0030] Optionally, the controller includes a main controller and sub-controllers; the main controller is communicatively connected to the delivery pump, the delivery flow meter, and the sub-controllers; the sub-controllers are communicatively connected to the buffer level gauge.

[0031] The control method further includes: detecting whether the communication connection between the main controller and the sub-controller is interrupted before the delivery pump is turned on and during the period when the delivery pump is turned on; and when the communication connection between the main controller and the sub-controller is interrupted, turning off the delivery pump and stopping the delivery of NMP liquid from the storage tank to the buffer tank.

[0032] Optionally, the NMP system further includes an unloading pump and an unloading electrostatic grounding device. The unloading electrostatic grounding device includes an unloading electrostatic clamp and an unloading electrostatic control circuit. The inlet of the unloading pump is connected to the new liquid tank of the new liquid truck through a first unloading pipe. The outlet of the unloading pump is connected to the storage port of the storage tank through a second unloading pipe. The storage port is equipped with a storage valve, and the storage valve is equipped with a third position sensor. The unloading pump, the unloading electrostatic control circuit, and the third position sensor are all communicatively connected to the controller.

[0033] The control method further includes: before starting the unloading pump and during the period when the unloading pump is started, acquiring the unloading electrostatic clamp signal of the unloading electrostatic control circuit and the third position signal of the third position sensor to confirm whether the unloading electrostatic clamp has been clamped and whether the liquid storage valve has been opened to the preset position.

[0034] When the electrostatic clamp for unloading is engaged and the storage valve is opened to the preset position, the unloading pump is controlled to start, unloading the NMP liquid from the new liquid tank of the new liquid truck into the storage tank.

[0035] The unloading pump is shut down when the electrostatic clamp for unloading is not properly engaged and / or the storage valve is not opened to the preset position.

[0036] Optionally, the NMP system further includes a waste liquid tank, a drain pump, and a drain electrostatic grounding device. The drain electrostatic grounding device includes a drain electrostatic clamp and a drain electrostatic control circuit. The inlet of the drain pump is connected to the outlet of the waste liquid tank through a first drain pipe. The outlet of the waste liquid tank is equipped with a drain valve, and the drain valve is equipped with a fourth position sensor. The outlet of the drain pump is connected to the waste liquid tank of the waste liquid truck through a second drain pipe. The drain pump, the drain electrostatic control circuit, and the fourth position sensor are all communicatively connected to the controller.

[0037] The control method further includes: before starting the drain pump and during the period when the drain pump is started, acquiring the drain electrostatic clamp signal of the drain electrostatic control circuit and the fourth position signal of the fourth position sensor to confirm whether the drain electrostatic clamp has been clamped and whether the drain valve has been opened to the preset position.

[0038] When the electrostatic clamp for draining is engaged and the drain valve is opened to the preset position, the drain pump is controlled to start, draining the NMP liquid in the waste tank to the waste tank.

[0039] The drain pump is shut down when the electrostatic clamp is not properly engaged and / or the drain valve is not opened to the preset position.

[0040] According to another aspect of the present invention, a control device for an NMP system is provided. The NMP system includes a storage tank, a delivery pump, a buffer tank, and a controller. The outlet of the storage tank is connected to the inlet of the delivery pump via a first delivery pipe, and the outlet of the delivery pump is connected to the inlet of the buffer tank via a second delivery pipe. A delivery flow meter is provided on the second delivery pipe. A buffer level gauge is provided on the buffer tank. The controller is communicatively connected to the delivery pump, the delivery flow meter, and the buffer level gauge.

[0041] The control device is used to execute the control method of the NMP system described in any embodiment of the present invention.

[0042] According to another aspect of the present invention, an NMP system is provided, the NMP system comprising a storage tank, a delivery pump, a buffer tank, and a controller, the controller comprising the control device of the above-described NMP system; the outlet of the storage tank is connected to the inlet of the delivery pump via a first delivery pipe, and the outlet of the delivery pump is connected to the inlet of the buffer tank via a second delivery pipe; the second delivery pipe is provided with a delivery flow meter; the buffer tank is provided with a buffer level gauge; the controller is communicatively connected to the delivery pump, the delivery flow meter, and the buffer level gauge respectively.

[0043] Optionally, the NMP system further includes a buffer level magnetic switch;

[0044] The liquid level magnetic switch is set at the third buffer level of the buffer tank;

[0045] The buffer level magnetic switch is connected in series with the delivery pump;

[0046] The buffer level magnetic switch can be triggered to turn off when the liquid level in the buffer tank is at the third buffer level, thereby shutting down the delivery pump.

[0047] Optionally, the NMP system further includes multiple emergency stop switches for the conveyor: each of the multiple emergency stop switches for the conveyor is connected in series with the conveyor pump;

[0048] When any of the emergency stop switches is pressed, the conveying pump will be shut down.

[0049] The technical solution of this invention determines the relationship between the liquid supply setting value and the current available liquid volume before controlling the transfer pump to start according to the liquid supply setting value. If the liquid supply setting value is greater than the current available liquid volume, the transfer pump can be stopped and the liquid supply setting value can be set to zero. This helps improve the safety of NMP liquid transfer and avoids the risk of leakage caused by excessive NMP liquid being transferred to the storage tank. In addition, after a single NMP liquid transfer is completed, the transfer pump is turned off and the liquid supply setting value is set to zero, which also helps improve the safety of NMP liquid transfer and avoids incorrect transmission and safety problems when the transfer pump is turned on again. In this way, redundant safety and leakage prevention protection measures can be achieved.

[0050] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is a schematic diagram of the structure of an NMP system provided in Embodiment 1 of the present invention. Figure 1 ;

[0053] Figure 2 This is a communication diagram of an NMP system provided in Embodiment 1 of the present invention;

[0054] Figure 3 This is a schematic diagram of the structure of an NMP system provided in Embodiment 1 of the present invention. Figure 2 ;

[0055] Figure 4 This is a flowchart of a control method for an NMP system provided in Embodiment 2 of the present invention;

[0056] Figure 5 This is a schematic diagram of the structure of a control device for an NMP system provided in Embodiment 3 of the present invention. Detailed Implementation

[0057] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0058] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0059] Example 1

[0060] Figure 1 This is a schematic diagram of the structure of an NMP system provided in Embodiment 1 of the present invention. Figure 1 , Figure 2 This is a communication diagram of an NMP system provided in Embodiment 1 of the present invention, for reference. Figure 1 and Figure 2 The NMP system includes a storage tank 100, a transfer pump 110, a buffer tank 200, and a controller 300. The outlet of the storage tank 100 is connected to the inlet of the transfer pump 110 through a first transfer pipe 410, and the outlet of the transfer pump 110 is connected to the inlet of the buffer tank 200 through a second transfer pipe 420. A transfer flow meter FM1 is installed in the second transfer pipe 420. A buffer level meter LT1 is installed in the buffer tank 200. The controller 300 is communicatively connected to the transfer pump 110, the transfer flow meter FM1, and the buffer level meter LT1.

[0061] The system includes a storage tank 100 for storing pure, unused NMP liquid; a buffer tank 200 for temporarily storing NMP liquid to be used; a transfer pump 110 for pumping NMP liquid from the storage tank 100 to the buffer tank 200; a first transfer pipe 410 and a second transfer pipe 420 for connecting the outlet of the storage tank 100 and the inlet of the buffer tank 200; a flow meter FM1 for detecting the total amount of NMP liquid pumped by the transfer pump 110 per unit time, and the cumulative total amount of NMP liquid pumped by the transfer pump 110; a buffer level gauge LT1 for detecting the NMP liquid level in the buffer tank 200; and a controller 300 for monitoring the liquid delivery status of the NMP system and controlling the opening and closing of the transfer pump 110. The controller 300 includes, but is not limited to, industrial computers, industrial control computers, programmable logic controllers (PLCs), servers, and large computers.

[0062] For example, the controller 300 can monitor the NMP liquid level in the buffer tank 200 via the buffer level gauge LT1 and monitor the total amount of NMP liquid pumped by the transfer pump 110 via the transfer flow meter FM1. The controller 300 can control the opening and closing of the transfer pump 110 based on the NMP liquid level in the buffer tank 200 and the total amount of NMP liquid pumped by the transfer pump 110. This can prevent the NMP liquid level in the buffer tank 200 from being too high and the transfer pump 110 from pumping too much NMP liquid, which could lead to NMP liquid leakage and cause serious production accidents.

[0063] In an optional embodiment, a first flow switch 111 and a first temperature detection device TP1 are provided at the outlet of the delivery pump 110. Both the first flow switch 111 and the first temperature detection device TP1 can be communicatively connected to the controller 300.

[0064] The first flow switch 111 is used to detect the flow rate at the outlet of the transfer pump 110, turning it off when the flow rate is low and turning it on when the flow rate is high. The first temperature detection device TP1 is used to detect the temperature at the outlet of the transfer pump 110. The controller 300 can acquire the flow switch signal of the first flow switch 111 and the temperature at the outlet of the transfer pump 110. When the flow switch signal of the first flow switch 111 is zero or the temperature at the outlet of the transfer pump 110 is abnormally high (wherein, the temperature threshold is adjustable), the controller 300 can control the transfer pump 110 to shut down.

[0065] Based on the above embodiments, the delivery pump 110 is connected to a frequency converter ( Figure 1 and Figure 2(Not shown in the image) is used to detect whether the transfer pump 110 is malfunctioning. The frequency converter can communicate with the controller 300. When the transfer pump 110 malfunctions, the controller 300 can control the transfer pump 110 to shut down according to the signal output by the frequency converter.

[0066] In another optional embodiment, the NMP system includes multiple storage tanks 100, the outlets of which are connected to the same first delivery pipe 410, which helps to increase the storage capacity of the NMP system.

[0067] In another optional embodiment, the NMP system includes multiple transfer pumps 110, with the inlets of the multiple transfer pumps 110 connected to the same first transfer pipe 410 and the outlets of the multiple transfer pumps 110 connected to the same second transfer pipe 420. The transfer pumps 110 can be turned on alternately. For example, when performing multiple NMP liquid transfers, pumping NMP liquid from the storage tank 100 to the buffer tank 200, multiple transfer pumps 110 can be turned on alternately to avoid using the same transfer pump 110 for two consecutive transfers, which could cause the transfer pump 110 to overheat due to prolonged use and pose a safety risk.

[0068] In another alternative embodiment, the NMP system includes a plurality of buffer tanks 200, and a balance pipe 204 may be provided between the buffer tanks 200 to make the liquid level in the plurality of buffer tanks 200 the same.

[0069] In Embodiment 1 of the present invention, by setting up a controller that is communicatively connected to the delivery pump, the delivery flow meter, and the buffer level gauge, the opening and closing of the delivery pump can be controlled according to the current liquid volume in the buffer tank and the total amount of NMP liquid pumped by the delivery pump. This is beneficial to improving the safety of NMP liquid delivery, and can avoid delivering excessive NMP liquid to the buffer tank, which could lead to NMP liquid leakage and cause serious production accidents. It can realize redundant safety and leakage prevention protection measures.

[0070] Optional, continue to refer to Figure 1 The NMP system also includes a buffer level magnetic switch 202; the buffer level magnetic switch 202 is set at the third buffer level of the buffer tank 200; the buffer level magnetic switch 202 is connected in series with the transfer pump 110 (not shown in the figure); wherein, when the liquid level in the buffer tank 200 is at the third buffer level, the buffer level magnetic switch 202 can be triggered to turn off, thereby turning off the transfer pump 110.

[0071] The third buffer level of the buffer tank 200 is the ultra-high liquid level of the buffer tank 200, for example, it can be 90% of the capacity of the buffer tank 200. When the NMP liquid level in the buffer tank 200 reaches the third buffer level, it means that the NMP liquid in the buffer tank 200 is about to reach 100% of the capacity of the buffer tank 200. If NMP liquid is continued to be supplied to the buffer tank 200, there is a risk of NMP liquid leakage.

[0072] For example, the power supply terminal of the transfer pump 110 is electrically connected to a high-voltage power line, and the buffer level magnetic switch 202 can be connected in series between the power supply terminal of the transfer pump 110 and the high-voltage power line (not shown in the figure). When the NMP liquid level in the buffer tank 200 reaches the third buffer level of the buffer tank 200, the buffer level magnetic switch 202 can be triggered to turn off, interrupting the connection between the power supply terminal of the transfer pump 110 and the high-voltage power line, thereby forcibly powering down the transfer pump 110 and shutting it off to prevent the transfer pump 110 from continuing to pump NMP liquid into the buffer tank 200, which could lead to NMP liquid leakage.

[0073] Optional, continue to refer to Figure 1 The NMP system also includes multiple emergency stop switches 510: each of the multiple emergency stop switches 510 is connected in series with the delivery pump 110; wherein, pressing any one of the emergency stop switches 510 can shut down the delivery pump 110.

[0074] For example, the emergency stop switch 510 can be set near the delivery pump 110, controller 300, buffer tank 200, etc. Multiple emergency stop switches 510 are connected in series between the power supply terminal of the delivery pump 110 and the high-voltage power line (not shown in the figure). When any emergency stop switch 510 is pressed, the connection between the power supply terminal of the delivery pump 110 and the high-voltage power line can be interrupted, so that the delivery pump 110 is forcibly powered down and shut down. In this way, when the controller 300 fails, malfunctions, or disconnects from the network, the delivery pump 110 can be shut down in time to avoid the delivery pump 110 from continuously pumping excessive NMP liquid, which could lead to NMP liquid leakage.

[0075] Optional, continue to refer to Figure 1 and Figure 2 The NMP system also includes an outlet valve 109 located at the outlet of the storage tank 100 and a buffer valve 201 located in the second delivery pipeline 420; a first position sensor VP1 is installed at the outlet valve 109, and a second position sensor VP2 is installed at the buffer valve 201. Figure 1 (Not shown in the image), the first position sensor VP1 and the second position sensor VP2 are both communicatively connected to the controller 300.

[0076] The first position sensor VP1 is used to detect the open position of the outlet valve 109 located at the outlet of the liquid storage tank 100; the second position sensor VP2 is used to detect the open position of the buffer valve 201 located in the second delivery pipeline 420.

[0077] For example, the controller 300 can determine the opening degree of the discharge valve 109 and the buffer valve 201 based on the first position sensor VP1 and the second position sensor VP2, so as to ensure that the delivery pump 110 is turned on when both the discharge valve 109 and the buffer valve 201 are fully open, thereby avoiding the discharge valve 109 and / or the buffer valve 201 not being fully open, which would cause the pressure in the first delivery pipeline 410 and / or the second delivery pipeline 420 to increase the risk of leakage.

[0078] In an optional embodiment, the NMP system includes multiple buffer valves 201 to prevent partial failure of the buffer valves 201, which could lead to failure to shut off and a significant risk of leakage.

[0079] Optional, continue to refer to Figure 1 and Figure 2 The second delivery pipeline 420 includes a first sub-pipeline 421 and a second sub-pipeline 422. The first sub-pipeline 421 is connected to the inlet of the buffer tank 200 through the second sub-pipeline 422, and the second sub-pipeline 422 is connected to the outlet of the delivery pump 110 through the first sub-pipeline 421. The NMP system also includes a pressure relief pipeline 430. One end of the pressure relief pipeline 430 is connected to the outlet of the delivery pump 110 through the first sub-pipeline 411, and the other end of the pressure relief pipeline 430 is connected to the pressure relief inlet of the storage tank 100. The first sub-pipeline 411 is equipped with a first pressure detection device NP1 and / or the second sub-pipeline 422 is equipped with a second pressure detection device NP2. The pressure relief pipeline 430 is equipped with a pressure relief valve 431. The first pressure detection device NP1, the second pressure detection device NP2, and the pressure relief valve 431 are all communicatively connected to the controller 300.

[0080] The first pressure detection device NP1 is used to detect the pressure in the first sub-pipe 411, the second pressure detection device NP2 is used to detect the pressure in the second sub-pipe 422, and the pressure relief valve 431 is used to open or close under the control of the controller 300.

[0081] For example, the first pressure detection device NP1 can be an electrical contact pressure gauge, and the second pressure detection device NP2 can be a pressure sensor.

[0082] In an optional embodiment, a pressure relief flow meter FM2 is installed in the pressure relief pipe 430, and the pressure relief flow meter FM2 is communicatively connected to the controller 300. The pressure relief flow meter FM2 is used to detect the total amount of NMP liquid discharged from the pressure relief pipe 430 per unit time, as well as the cumulative total amount of NMP liquid discharged;

[0083] In another optional embodiment, an auxiliary flow meter FM3 is provided in the second sub-pipe 422, and the auxiliary flow meter FM3 is communicatively connected to the controller 300. The auxiliary flow meter FM3 is used to detect the total amount of NMP liquid transported by the second sub-pipe 422 per unit time, as well as the cumulative total amount of NMP liquid transported, i.e., the actual flow rate buffered in the buffer tank 200.

[0084] For example, the controller 300 can calculate the relationship between the total delivery flow rate counted by the delivery flow meter FM1, the pressure relief flow rate counted by the pressure relief flow meter FM2, and the actual buffer flow rate counted by the auxiliary flow meter FM3, thereby determining whether NMP liquid is leaking. If the total delivery flow rate counted by the delivery flow meter FM1 is equal to the sum of the pressure relief flow rate counted by the pressure relief flow meter FM2 and the actual buffer flow rate counted by the auxiliary flow meter FM3, it indicates that NMP liquid is not leaking. If the total delivery flow rate counted by the delivery flow meter FM1 is greater than the sum of the pressure relief flow rate counted by the pressure relief flow meter FM2 and the actual buffer flow rate counted by the auxiliary flow meter FM3, it indicates that there is a leak.

[0085] Optional, continue to refer to Figure 1 and Figure 2 The controller 300 includes a main controller 310 and a sub-controller 320; the main controller 310 is communicatively connected to the delivery pump 110, the delivery flow meter FM1 and the sub-controller 320; the sub-controller 320 is communicatively connected to the buffer level meter LT1.

[0086] For example, in the NMP system, the storage tank 100, transfer pump 110, first transfer pipeline 410, first sub-pipeline 421, pressure relief pipeline 430, etc. are all located in the pump room, while the buffer valve 201, buffer tank 200, etc. are all located in the solvent room. The distance between the pump room and the solvent room is relatively far, resulting in a relatively far distance between the equipment located in the pump room and the solvent room. A main controller 310 can be set in the pump room, and a sub-controller 320 can be set in the solvent room. The main controller 310 can communicate with the transfer pump 110, transfer flow meter FM1, first position sensor VP1, first pressure detection device NP1, second pressure detection device NP2, pressure relief valve 431, liquid outlet valve 109, first flow switch 111, and first temperature detection device TP1, etc. The sub-controller 320 can communicate with the second position sensor VP2, buffer level gauge LT1, buffer valve 201, etc.

[0087] In an optional embodiment, one or more first NMP concentration detectors 001 are provided in the pump room, and the first NMP concentration detectors 001 are communicatively connected to the main controller 310; one or more second NMP concentration detectors 002 are provided in the solvent room, and the second NMP concentration detectors 002 are communicatively connected to the sub-controller 320. The controller 300 can shut down the pump and valve when the NMP concentration exceeds a concentration threshold.

[0088] Optional, continue to refer to Figure 1 and Figure 2 The NMP system also includes a discharge pump 120 and a discharge electrostatic grounding device 600. The discharge electrostatic grounding device 600 includes a discharge electrostatic clamp 610 and a discharge electrostatic control circuit 620. The inlet of the discharge pump 120 is connected to the new liquid tank of the new liquid truck through a first discharge pipe 440. The outlet of the discharge pump 120 is connected to the storage port of the storage tank 100 through a second discharge pipe 450. The storage port is equipped with a storage valve 101, and the storage valve 101 is equipped with a third position sensor VP3. Figure 1 (Not shown in the image); the unloading pump 120, the unloading electrostatic control circuit 620, and the third position sensor VP3 are all communicatively connected to the controller 300.

[0089] The unloading electrostatic grounding device 600 is used to release static electricity from the new liquid truck; the unloading electrostatic control circuit 620 has a loop detection function, which can detect whether the unloading electrostatic clamp 610 is correctly and reliably clamped on the effective grounding point; the unloading pump 120 is used to pump NMP liquid from the new liquid tank of the new liquid truck to the storage tank 100; the first unloading pipe 440 and the second unloading pipe 450 are used to connect the outlet of the new liquid tank and the storage port of the storage tank 100; the third position sensor VP3 is used to monitor the opening position of the storage valve 101 set at the storage port.

[0090] For example, after receiving the start command or unloading command of the unloading pump 120, if the controller 300 does not receive the electrostatic clamp signal from the unloading electrostatic control circuit 620 and / or the storage valve 101 is not fully open, the controller 300 controls the unloading pump 120 to close. If the controller 300 receives the electrostatic clamp signal from the unloading electrostatic control circuit 620 and the storage valve 101 is fully open, the controller controls the unloading pump 120 to open.

[0091] In an optional embodiment, a second flow switch 121 and a second temperature detection device TP2 are provided at the outlet of the unloading pump 120. Both the second flow switch 121 and the second temperature detection device TP2 can be communicatively connected to the controller 300.

[0092] The second flow switch 121 is used to detect the flow rate at the outlet of the unloading pump 120, turning it off when the flow rate is low and turning it on when the flow rate is high. The second temperature detection device TP2 is used to detect the temperature at the outlet of the unloading pump 120. The controller 300 can acquire the flow switch signal of the second flow switch 121 and the temperature at the outlet of the unloading pump 120. When the flow switch signal of the second flow switch 121 is zero or the temperature at the outlet of the unloading pump 120 is abnormally high (wherein, the temperature threshold is adjustable), the controller 300 can control the unloading pump 120 to shut down.

[0093] Based on the above embodiments, the unloading pump 120 is connected to a frequency converter ( Figure 1 and Figure 2 (Not shown in the image) is used to detect whether the unloading pump 120 is malfunctioning. The frequency converter can communicate with the controller 300. When the unloading pump 120 malfunctions, the controller 300 can control the unloading pump 120 to shut down according to the signal output by the frequency converter.

[0094] In another optional embodiment, the NMP system includes a plurality of unloading pumps 120, the inlets of which are connected to the same first unloading pipe 440, and the outlets of which are connected to the same second unloading pipe 450.

[0095] In another alternative embodiment, a discharge flow meter FM4 is provided in the second discharge pipe 450, and the discharge flow meter FM4 can be communicatively connected to the controller 300.

[0096] The unloading flow meter FM4 is used to detect the total amount of NMP liquid pumped by the unloading pump 120 per unit time, as well as the cumulative total amount of NMP liquid pumped by the unloading pump 120. The controller 300 can control the unloading pump 120 to shut down when the flow rate in the second unloading pipe 450 is less than a preset value. For example, if the flow rate in the second unloading pipe 450 is less than the preset value within a preset time, it means that the NMP liquid in the new liquid tank has been basically unloaded. The unloading pump 120 is prone to damage if it runs dry for a long time. At this time, the unloading pump 120 can be shut down.

[0097] In another alternative embodiment, a third pressure detection device NP3 is provided in the second unloading pipe 450, and the third pressure detection device NP3 is communicatively connected to the control 300.

[0098] Among them, the third pressure detection device NP3 is used to detect the pressure in the second unloading pipeline 450.

[0099] For example, the third pressure detection device NP3 can be an electrical contact pressure gauge. When the pressure in the second unloading pipeline 450 exceeds the pressure threshold, the controller 300 can control the unloading pump 120 to shut down to prevent NMP liquid leakage.

[0100] Optional, continue to refer to Figure 1 and Figure 2 The storage tank 100 is equipped with a storage level gauge LT2: the storage level gauge LT2 is communicatively connected to the controller 300.

[0101] The liquid level gauge LT2 is used to measure the NMP liquid level in the storage tank 100. The controller 300 can monitor the NMP liquid level in the storage tank 100 through the liquid level gauge LT2. Based on the NMP liquid level in the storage tank 100, the controller controls the storage valve 101 and the unloading pump 120. For example, when the NMP liquid level in the storage tank 100 reaches 70% of the total capacity, the storage valve 101 at the inlet of the storage tank 100 can be closed, but the unloading pump 120 can remain open. Other storage tanks 100 whose liquid levels have not reached 70% can continue to receive liquid. When the NMP liquid level in all storage tanks 100 reaches 70% of the total capacity or all storage valves 101 are closed, the unloading pump 120 is closed.

[0102] Optional, continue to refer to Figure 1 The NMP system also includes a liquid level magnetic switch 102; the liquid level magnetic switch 102 is set at the third buffer level of the liquid storage tank 100; the liquid level magnetic switch 102 is connected in series with the unloading pump 120 (not shown in the figure); wherein, when the liquid level in the liquid storage tank 100 is at the third buffer level, the liquid level magnetic switch 102 is triggered to turn off, thereby shutting down the unloading pump 120.

[0103] The third buffer level of the storage tank 100 is the highest liquid level of the storage tank 100, such as 90% of the capacity of the storage tank 100. When the NMP liquid level in the storage tank 100 reaches the third buffer level, it means that the NMP liquid in the storage tank 100 is about to reach 100% of the capacity of the storage tank 100. If NMP liquid is continued to be supplied to the storage tank 100, there is a risk of NMP liquid leakage.

[0104] For example, the power supply terminal of the unloading pump 120 is electrically connected to a high-voltage power line, and the liquid level magnetic switch 102 can be connected in series between the power supply terminal of the unloading pump 120 and the high-voltage power line (not shown in the figure). When the NMP liquid level in the storage tank 100 reaches the third buffer level of the storage tank 100, the liquid level magnetic switch 102 can be triggered to turn off, interrupting the connection between the power supply terminal of the unloading pump 120 and the high-voltage power line, thereby forcibly de-energizing the unloading pump 120 and shutting it down. This prevents the storage valve 101 from failing and the unloading pump 120 from continuing to pump NMP liquid into the storage tank 100, which could lead to NMP liquid leakage.

[0105] Optional, continue to refer to Figure 1The NMP system also includes multiple emergency stop switches 520: each of these switches is connected in series with the discharge pump 120 (not shown in the figure); pressing any one of these switches will shut down the discharge pump 120. Thus, in the event of a controller 300 malfunction, failure, or network outage, the discharge pump 120 can be shut down promptly, preventing it from continuously pumping excessive amounts of NMP liquid and causing leakage.

[0106] Optional, Figure 3 This is a schematic diagram of the structure of an NMP system provided in Embodiment 1 of the present invention. Figure 2 ,refer to Figure 2 and Figure 3 The NMP system also includes a waste liquid tank 700, a drain pump 130, and a drain electrostatic grounding device 800. The drain electrostatic grounding device 800 includes a drain electrostatic clamp 810 and a drain electrostatic control circuit 820. The inlet of the drain pump 130 is connected to the outlet of the waste liquid tank 700 through a first drain pipe 460. The outlet of the waste liquid tank 700 is equipped with a drain valve 709, and the drain valve 709 is equipped with a fourth position sensor VP4. Figure 3 (Not shown in the image); the outlet of the drain pump 130 is connected to the waste liquid tank of the waste liquid vehicle through the second drain pipe 470; the drain pump 130, the drain electrostatic control circuit 820 and the fourth position sensor VP4 are all communicatively connected to the controller 300.

[0107] The waste liquid tank 700 is used to store used NMP liquid that cannot be reused; the drain electrostatic grounding device 800 is used to release static electricity from the waste liquid vehicle; the drain electrostatic control circuit 820 has a loop detection function, which can detect whether the drain electrostatic clamp 810 is correctly and reliably clamped on the effective grounding point; the drain pump 130 is used to pump the NMP liquid in the waste liquid tank 700 to the waste liquid tank of the waste liquid vehicle; the first drain pipe 460 and the second drain pipe 470 are used to connect the outlet of the waste liquid tank 700 and the inlet of the waste liquid tank; the fourth position sensor VP4 is used to monitor the open position of the drain valve 709.

[0108] For example, after receiving the start command or drain command of the drain pump 130, if the controller 300 does not receive the electrostatic clamp signal from the drain electrostatic control circuit 820 and / or the drain valve 709 is not fully open, the controller 300 controls the drain pump 130 to close. If the controller 300 receives the electrostatic clamp signal from the drain electrostatic control circuit 820 and the drain valve 709 is fully open, the controller controls the drain pump 130 to open.

[0109] In an optional embodiment, a third flow switch 131 and a third temperature detection device TP3 are provided at the outlet of the discharge pump 130. Both the third flow switch 131 and the third temperature detection device TP3 can be communicatively connected to the controller 300.

[0110] The third flow switch 131 is used to detect the flow rate at the outlet of the drain pump 130, turning it off when the flow rate is low and turning it on when the flow rate is high. The third temperature detection device TP3 is used to detect the temperature at the outlet of the drain pump 130. The controller 300 can acquire the flow switch signal of the third flow switch 131 and the temperature at the outlet of the drain pump 130. When the flow switch signal of the third flow switch 131 is zero or the temperature at the outlet of the drain pump 130 is abnormally high (wherein, the temperature threshold is adjustable), the controller 300 can control the drain pump 130 to shut down.

[0111] Based on the above embodiments, the drain pump 130 is connected to a frequency converter ( Figure 2 and Figure 3 (Not shown in the image) is used to detect whether the drain pump 130 is malfunctioning. The frequency converter can communicate with the controller 300. When the drain pump 130 malfunctions, the controller 300 can control the drain pump 130 to shut down according to the signal output by the frequency converter.

[0112] In another optional embodiment, the NMP system includes a plurality of drain pumps 130, the inlets of which are connected to the same first drain pipe 460, and the outlets of which are connected to the same second drain pipe 470.

[0113] In another alternative embodiment, a drain flow meter FM5 is provided in the first drain pipe 460, and the drain flow meter FM5 can be communicatively connected to the controller 300.

[0114] The FM5 flow meter is used to measure the total amount of NMP liquid discharged from the first drain pipe 460 per unit time, as well as the cumulative total amount of NMP liquid discharged from the first drain pipe 460. The controller 300 can control the drain pump 130 to shut down when the flow rate in the first drain pipe 460 is less than a preset value. For example, if the flow rate in the first drain pipe 460 is less than the preset value within a preset time, it means that the NMP liquid in the waste tank 700 has been basically drained. The drain pump 130 is prone to damage if it runs dry for a long time, so the drain pump 130 can be shut down at this time.

[0115] In another alternative embodiment, a fourth pressure detection device NP4 is provided in the second drain pipe 470, and the fourth pressure detection device NP4 is communicatively connected to the controller 300.

[0116] Among them, the fourth pressure detection device NP4 is used to detect the pressure in the second drain pipe 470.

[0117] For example, the fourth pressure detection device NP4 can be an electrical contact pressure gauge. When the pressure in the second drain pipe 470 is greater than the pressure threshold, the controller 300 can control the drain pump 130 to shut down to prevent NMP liquid leakage.

[0118] Optional, continue to refer to Figure 2 and Figure 3 The waste liquid tank 700 is equipped with a recovery valve 701 at the inlet; the waste liquid tank 700 is equipped with a waste liquid level gauge LT3; both the recovery valve 701 and the waste liquid level gauge LT3 are communicatively connected to the controller 300.

[0119] The waste liquid level gauge LT3 is used to monitor the NMP liquid level in the waste liquid tank 700. The controller 300 can monitor the NMP liquid level in the waste liquid tank 700 through the waste liquid level gauge LT3 and control the recovery valve 701 according to the NMP liquid level in the waste liquid tank 700. For example, the recovery valve 701 at the inlet of the waste liquid tank 700 can be closed when the NMP liquid level in the waste liquid tank 700 reaches 70% of the total capacity.

[0120] Optional, continue to refer to Figure 3 The NMP system also includes multiple emergency stop switches 530, each connected in series with the drain pump 130 (not shown in the figure). Pressing any one of these switches will shut down the drain pump 130. This ensures that the drain pump 130 can be shut down promptly in case of controller 300 failure, malfunction, or network outage, preventing the drain pump 130 from continuously pumping excessive amounts of NMP liquid and causing leakage.

[0121] In addition, the controller 300 can communicate with a human-machine interface device (not shown in the figure), which can be a touch screen or a combination of a display screen, mouse, and keyboard. The controller 300 can be placed in a field monitoring room or a field power distribution room. The human-machine interface device can perform functions such as parameter query and command control.

[0122] Example 2

[0123] Figure 4 This is a flowchart of a control method for an NMP system provided in Embodiment 2 of the present invention. This embodiment is applicable to NMP liquid transfer in an NMP system. The method can be executed by a control device of the NMP system, which can be implemented in hardware and / or software and can be configured in the controller of the NMP system. Figure 4 As shown, the method includes:

[0124] S110. Obtain the liquid supply setting value and determine the current liquid supply volume of the buffer tank based on the buffer level signal output by the buffer level gauge.

[0125] The liquid supply setting value is the total amount of NMP liquid delivered by the transfer pump 110 in a single operation. This value can be input by the user, and the controller 300 can obtain it through user-input commands. The buffer level signal output by the buffer level gauge LT1 reflects the current liquid level of the NMP liquid in the buffer tank 200. Based on the current liquid level of the NMP liquid in the buffer tank 200, the controller 300 can determine the total amount of liquid that can still be added to the buffer tank 200, which is the current available liquid volume of the buffer tank 200. The current available liquid volume is equal to the full load liquid volume of the buffer tank 200 (less than 100%, adjustable) minus the current liquid volume.

[0126] S120. Determine whether the liquid supply setting value is less than or equal to the current available liquid volume. If yes, proceed to S130; otherwise, proceed to S160.

[0127] For example, if the liquid supply setting value is less than or equal to the current available liquid volume, it means that after the delivery pump 110 is controlled to pump NMP liquid to the buffer tank 200 with the liquid supply setting value, the liquid volume in the buffer tank 200 is less than or equal to the full load liquid volume, and there is no risk of leakage or the risk of leakage is low.

[0128] If the liquid supply setting value is greater than the current available liquid volume, it means that after the transfer pump 110 is controlled to pump NMP liquid to the buffer tank 200 with the liquid supply setting value, the liquid volume in the buffer tank 200 is greater than the full load liquid volume, and there is a risk of leakage.

[0129] S130. Start the transfer pump to transfer the NMP liquid in the storage tank to the buffer tank.

[0130] Specifically, when the liquid supply setting value is less than or equal to the current available liquid volume, the control transfer pump 110 pumps NMP liquid to the buffer tank 200.

[0131] In one embodiment, before turning on the transfer pump 110, a pop-up window on the human-machine interface device can be used to confirm with the user that the transfer pump 110 is to be turned on to transfer the NMP liquid in the storage tank 100 to the buffer tank 200. After obtaining the user's confirmation instruction, the transfer pump 110 is turned on.

[0132] S140. Based on the delivery flow rate signal output by the delivery flow meter, determine whether a single NMP liquid delivery is complete. If yes, proceed to S150.

[0133] For example, the controller 300 can obtain the total amount of NMP liquid pumped by the current transfer pump 110 through the transfer flow meter FM1. When the total amount of NMP liquid pumped by the transfer pump 110 in a single operation reaches the supply set value, the controller 300 can control the transfer pump 110 to shut down, and the single NMP liquid transfer ends. Alternatively, the remaining supply volume can be obtained through the transfer flow meter FM1, which is the supply set value minus the total amount of NMP liquid pumped by the transfer pump 110 in a single operation. When the remaining supply volume is zero, the controller 300 can control the transfer pump 110 to shut down, and the single NMP liquid transfer ends.

[0134] In one embodiment, parameters such as the liquid supply setting value, the current available liquid supply volume, and the remaining liquid supply volume can be displayed on the human-machine interface. When the delivery pump 110 is turned on, the parameters such as the liquid supply setting value, the current available liquid supply volume, and the remaining liquid supply volume displayed on the human-machine interface can be updated in real time over time.

[0135] S150. Turn off the transfer pump and set the liquid supply setting to zero.

[0136] Specifically, after a single NMP liquid transfer is completed, the transfer pump is turned off and the liquid supply setting value is set to zero to avoid the risk that the transfer pump 110 will pump NMP liquid at the previous liquid supply setting value when it is turned on again, which could exceed the full load capacity of the buffer tank 200.

[0137] In an optional embodiment, the control method further includes: if a single NMP liquid delivery is not completed, determining whether the delivery pump has stopped pumping NMP liquid; if the delivery pump has stopped pumping NMP liquid, setting the liquid supply setting value to zero; if the delivery pump has not stopped pumping NMP liquid, returning to execute S140.

[0138] For example, if the total amount of NMP liquid pumped by the transfer pump 110 does not reach the supply setting value, but the transfer pump 110 is shut down due to special circumstances such as power failure, malfunction, or leakage risk, the supply setting value will be set to zero regardless of whether the remaining supply volume is zero, and the remaining supply volume will also be zero. Thus, when the transfer pump 110 is restarted, it will not continue the previous pumping task, preventing the transfer pump 110 from automatically pumping NMP liquid according to the previous supply setting value or the remaining supply volume after starting or powering on, which could pose a leakage risk.

[0139] S150, Set the liquid supply setting value to zero.

[0140] Specifically, when the liquid supply setting value is greater than the current available liquid volume, the liquid supply setting value is set to zero, and the transfer pump 110 is not turned on. This is to avoid pumping NMP liquid into the buffer tank 200 with such a large liquid supply setting value, which would exceed the full capacity of the buffer tank 200 and cause NMP liquid to overflow, posing a risk of leakage.

[0141] In an optional implementation, when the liquid supply setting value is greater than the current available liquid volume, the liquid supply setting value is set to zero, and a prompt signal can also be displayed in a pop-up window on the human-machine interface to remind the user that the current liquid supply setting value is greater than the current available liquid volume and that there is a safety risk in the liquid supply.

[0142] In Embodiment 1 of this invention, before controlling the transfer pump to start according to the liquid supply setting value, the relationship between the liquid supply setting value and the current available liquid volume is determined. If the liquid supply setting value is greater than the current available liquid volume, the transfer pump can be stopped and the liquid supply setting value can be set to zero. This helps improve the safety of NMP liquid transfer and avoids the risk of leakage caused by excessive NMP liquid being transferred to the storage tank. In addition, after a single NMP liquid transfer is completed, the transfer pump is turned off and the liquid supply setting value is set to zero, which also helps improve the safety of NMP liquid transfer and can avoid incorrect transmission and safety problems when the transfer pump is turned on again. In this way, redundant safety and leakage prevention protection measures can be achieved.

[0143] Optionally, if the liquid supply setting value is less than or equal to the current available liquid volume, the transfer pump 110 is turned on to transfer the NMP liquid in the storage tank 100 to the buffer tank 200, including: if the liquid supply setting value is less than or equal to the current available liquid volume, determining whether the liquid supply setting value is less than or equal to the single liquid supply threshold; if the liquid supply setting value is less than or equal to the single liquid supply threshold, turning on the transfer pump 110 to transfer the NMP liquid in the storage tank 100 to the buffer tank 200; if the liquid supply setting value is greater than the single liquid supply threshold, setting the liquid supply setting value to zero.

[0144] The single-supply threshold refers to the upper limit of the total amount of NMP liquid delivered by the transfer pump 110 in a single operation. This upper limit can be flexibly set according to actual needs.

[0145] For example, if the liquid supply setting value is greater than the single liquid supply threshold, it indicates that the current liquid supply setting value is too large, and the total amount of NMP liquid delivered by the transfer pump 110 in a single operation is too large, which may easily lead to leakage risk. Therefore, when the liquid supply setting value is greater than the single liquid supply threshold, setting the liquid supply setting value to zero and stopping the transfer pump 110 can help improve the safety of NMP liquid delivery and avoid the risk of leakage caused by delivering excessive NMP liquid to the storage tank.

[0146] In an optional implementation, before starting the transfer pump 110, a pop-up window on the human-machine interface device can be used to confirm with the user that the transfer pump is to be started, so that the NMP liquid in the storage tank 100 can be transferred to the buffer tank 200. After obtaining the user's confirmation command, the transfer pump 110 is started.

[0147] In another optional implementation, when the liquid supply setting value is greater than the single liquid supply threshold, the liquid supply setting value is set to zero, and a prompt signal can also be displayed in a pop-up window on the human-machine interface to prompt the user that the current liquid supply setting value is greater than the single liquid supply threshold and cannot be set.

[0148] Optionally, starting the transfer pump 110 to transfer NMP liquid from the storage tank 100 to the buffer tank 200 includes: before starting the transfer pump 110 and during the period when the transfer pump 110 is started, acquiring the first position signal of the first position sensor VP1 and the second position signal of the second position sensor VP2, and confirming whether the outlet valve 109 and the buffer valve 201 are open to the preset position based on the first position signal and the second position signal; if both the outlet valve 109 and the buffer valve 201 are open to the preset position, then starting the transfer pump 110 to transfer NMP liquid from the storage tank 100 to the buffer tank 200; if the outlet valve 109 and / or the buffer valve 201 are not open to the preset position, then turning off the transfer pump 110.

[0149] For example, before and during the period when the delivery pump 110 is turned on, the controller 300 can determine whether the outlet valve 109 and the buffer valve 201 are fully open based on the first position sensor VP1 at the outlet valve 109 and the second position sensor VP2 at the buffer valve 201. If either the outlet valve 109 or the buffer valve 201 is not fully open, the delivery pump 110 is turned off to prevent the outlet valve 109 and / or the buffer valve 201 from not being fully open, which could lead to an increase in pressure in the first delivery pipeline 410 and / or the second delivery pipeline 420 and a risk of leakage.

[0150] Optionally, the control method further includes: acquiring the buffer level signal output by the buffer level gauge LT1 during the period when the transfer pump 110 is on, determining the liquid level in the buffer tank 200 based on the buffer level signal; closing the outlet valve 109, the transfer pump 110, and the buffer valve 201 when the liquid level in the buffer tank 200 is at or above the first buffer level; detecting whether the liquid level in the buffer tank 200 is at or above the second buffer level; and issuing an alarm when the liquid level in the buffer tank 200 is at or above the second buffer level. The second buffer level is higher than the first buffer level.

[0151] The first buffer level is the high level of the buffer tank 200, for example, it can be 70% of the capacity of the buffer tank 200; the second buffer level is the very high level of the buffer tank 200, for example, it can be 80% of the capacity of the buffer tank 200.

[0152] For example, when the liquid level in buffer tank 200 reaches the first buffer level, buffer tank 200 reaches full capacity. Controller 300 can then close the outlet valve 109, the transfer pump 110, and the buffer valve 201 to stop supplying NMP liquid to buffer tank 200. After the liquid level in buffer tank 200 reaches the first buffer level, the controller continuously monitors whether the liquid level in buffer tank 200 is at or above the second buffer level. If the liquid level in buffer tank 200 has not reached the second buffer level, it indicates that controller 300 has successfully controlled the system to stop supplying NMP liquid to buffer tank 200. If the liquid level in buffer tank 200 reaches the second buffer level, it indicates that controller 300 has failed to successfully control the system to stop supplying NMP liquid to buffer tank 200, and a fault exists in the system. Controller 300 can issue an alarm warning through the human-machine interface.

[0153] Optionally, the control method further includes: during the period when the delivery pump 110 is turned on, detecting the pressure in the first sub-pipe 421 and / or the second sub-pipe 422 using the first pressure detection device NP1 and / or the second pressure detection device NP2; when the pressure in the first sub-pipe 421 and / or the second sub-pipe 422 is greater than a pressure threshold, opening the pressure relief valve 431 to relieve pressure in the first sub-pipe 421 and / or the second sub-pipe 422; and closing the pressure relief valve 431 when the pressure in the first sub-pipe 421 and / or the second sub-pipe 422 is less than or equal to the pressure threshold. This avoids excessive pressure in the first sub-pipe 421 and / or the second sub-pipe 422, which could lead to NMP liquid leakage.

[0154] Optionally, the control method further includes: detecting whether the communication connection between the main controller 310 and the sub-controller 320 is interrupted before the transfer pump 110 is turned on and during the period when the transfer pump 110 is turned on, and turning off the transfer pump 110 and stopping the transfer of NMP liquid in the storage tank 100 to the buffer tank 200 when the communication connection between the main controller 310 and the sub-controller 320 is interrupted.

[0155] For example, the main controller 310 can periodically send communication detection signals to the sub-controller 320. The sub-controller 320 can send a response signal to the main controller 310 based on the communication detection signal. The main controller 310 can detect whether the communication connection between the main controller 310 and the sub-controller 320 is interrupted based on the response signal. When the communication connection between the main controller 310 and the sub-controller 320 is interrupted due to human error, machine failure, or other reasons, the main controller 310 cannot monitor the liquid level in the buffer tank 200 in real time, nor can it control the buffer valve 201 to promptly shut down the transfer pump 110. This can prevent the transfer pump 110 from pumping excessive NMP liquid into the storage tank 200, which could lead to NMP liquid leakage.

[0156] Optionally, the control method further includes: during the period when the delivery pump 110 is turned on, acquiring the flow switch signal of the first flow switch 111; and controlling the delivery pump 110 to turn off when no flow switch signal is received from the first flow switch 111 or when the flow switch signal of the first flow switch 111 is zero. This avoids the delivery pump 110 from running dry and being damaged.

[0157] Optionally, the control method further includes: during the period when the transfer pump 110 is turned on, obtaining the pumping flow rate of the transfer pump 110 per unit time according to the transfer flow meter FM1, and turning off the transfer pump 110 when the pumping flow rate of the transfer pump 110 per unit time is less than the flow threshold. In this way, the transfer pump 110 can also be prevented from running dry.

[0158] Optionally, the control method further includes: during the period when the transfer pump 110 is turned on, obtaining the temperature of the outlet of the transfer pump 110 according to the first temperature detection device TP1; when the temperature of the outlet of the transfer pump 110 is abnormally high (wherein the temperature threshold is adjustable), the controller 300 can control the transfer pump 110 to shut down to avoid safety risks.

[0159] Optionally, the control method further includes: acquiring the frequency conversion signal of the frequency converter connected to the delivery pump 110 before starting the delivery pump 110 and during the period when the delivery pump 110 is started, detecting whether the delivery pump 110 is faulty based on the frequency conversion signal, and shutting down the delivery pump 110 when the delivery pump 110 is faulty.

[0160] Optionally, the control method further includes: before starting the transfer pump 110 and during the period when the transfer pump 110 is started, acquiring the first concentration signal of the first NMP concentration detector 001 in the pump room where the storage tank 100 is located, and determining whether the NMP concentration in the pump room where the storage tank 100 is located exceeds the first concentration threshold based on the first concentration signal, and closing the outlet valve 109, the transfer pump 110, and the buffer valve 201 when the NMP concentration in the pump room where the storage tank 100 is located exceeds the first concentration threshold.

[0161] Optionally, the control method further includes: acquiring a second concentration signal from the second NMP concentration detector 002 in the solvent chamber where the buffer tank 200 is located before starting the transfer pump 110 and during the period when the transfer pump 110 is started; determining whether the NMP concentration in the solvent chamber where the buffer tank 200 is located exceeds a second concentration threshold based on the second concentration signal; and closing the outlet valve 109, the transfer pump 110, and the buffer valve 201 when the NMP concentration in the solvent chamber where the buffer tank 200 is located exceeds the second concentration threshold. The first concentration threshold and the second concentration threshold can be the same or different, and this embodiment of the invention does not limit this.

[0162] Optionally, the control method further includes: before starting the unloading pump 120 and during the period when the unloading pump 120 is started, acquiring the unloading electrostatic clamp signal of the unloading electrostatic control circuit 620 and the third position signal of the third position sensor VP3 to confirm whether the unloading electrostatic clamp 610 has been clamped and whether the storage valve 201 has been opened to the preset position; when the unloading electrostatic clamp 610 has been clamped and the storage valve 201 has been opened to the preset position, the unloading pump 120 is started to unload the NMP liquid in the new liquid tank of the new liquid truck into the storage tank 100; when the unloading electrostatic clamp 610 has not been clamped and / or the storage valve 201 has not been opened to the preset position, the unloading pump 120 is turned off.

[0163] For example, before starting the unloading pump 120, it is necessary to confirm that the unloading electrostatic clamp 610 is clamped and the liquid storage valve 201 is fully open; after starting the unloading pump 120, it is also necessary to check in real time whether the unloading electrostatic clamp 610 is clamped and whether the liquid storage valve 201 is fully open, in order to avoid safety accidents or leakage risks.

[0164] In one embodiment, before starting the unloading pump 120, a pop-up window can be used on the human-machine interface device to confirm with the user that the unloading pump 120 needs to be started. After receiving the user's confirmation, the unloading pump 120 is started.

[0165] Optionally, the control method further includes: during the period when the unloading pump 120 is turned on, acquiring the liquid level signal output by the liquid level gauge LT2, determining the liquid level in the storage tank 100 based on the liquid level signal; when the liquid level in the storage tank 100 is at or above the first buffer level, closing the storage valve 101 and the unloading pump 120, detecting whether the liquid level in the storage tank 100 is at or above the second buffer level, and issuing an alarm when the liquid level in the storage tank 100 is at or above the second buffer level. Wherein, the second buffer level is higher than the first buffer level.

[0166] Optionally, the control method further includes: during the period when the unloading pump 120 is turned on, detecting the pressure in the second unloading pipeline 450 through the third pressure detection device NP3; when the pressure in the second unloading pipeline 450 is greater than the pressure threshold, turning off the unloading pump 120.

[0167] Optionally, the control method further includes: during the period when the unloading pump 120 is turned on, acquiring the flow switch signal of the second flow switch 121, and controlling the unloading pump 120 to turn off when no flow switch signal is received from the second flow switch 121 or when the flow switch signal of the second flow switch 121 is zero. This avoids the unloading pump 120 from running dry and being damaged.

[0168] Optionally, the control method also includes: during the period when the unloading pump 120 is turned on, obtaining the pumping flow rate of the unloading pump 120 per unit time according to the unloading flow meter FM4, and turning off the unloading pump 120 when the pumping flow rate of the unloading pump 120 per unit time is less than the flow rate threshold. In this way, the unloading pump 120 can also be prevented from running dry.

[0169] Optionally, the control method also includes: during the period when the unloading pump 120 is turned on, the temperature of the outlet of the unloading pump 120 is obtained according to the second temperature detection device TP2; when the temperature of the outlet of the unloading pump 120 is abnormally high (wherein the temperature threshold is adjustable), the controller 300 can control the unloading pump 120 to shut down to avoid safety risks.

[0170] Optionally, the control method further includes: acquiring the frequency conversion signal of the frequency converter connected to the unloading pump 120 before starting the unloading pump 120 and during the period when the unloading pump 120 is started, detecting whether the unloading pump 120 is faulty based on the frequency conversion signal, and shutting down the unloading pump 120 when the unloading pump 120 is faulty.

[0171] Optionally, the control method further includes: before starting the transfer pump 110 and during the period when the unloading pump 120 is started, acquiring the first concentration signal of the first NMP concentration detector 001 in the pump room where the storage tank 100 is located, and determining whether the NMP concentration in the pump room where the storage tank 100 is located exceeds the first concentration threshold based on the first concentration signal, and turning off the unloading pump 120 when the NMP concentration in the pump room where the storage tank 100 is located exceeds the first concentration threshold.

[0172] Optionally, the control method further includes: before starting the drain pump 130 and during the period when the drain pump 130 is started, acquiring the drain electrostatic clamp signal from the drain electrostatic control circuit 820 and the fourth position signal from the fourth position sensor VP4 to confirm whether the drain electrostatic clamp 810 is clamped and whether the drain valve 709 is opened to the preset position; when the drain electrostatic clamp 810 is clamped and the drain valve 709 is opened to the preset position, controlling the drain pump 130 to start, draining the NMP liquid in the waste tank 700 to the waste tank; when the drain electrostatic clamp 810 is not clamped and / or the drain valve 709 is not opened to the preset position, shutting off the drain pump 130.

[0173] For example, before turning on the drain pump 130, it is necessary to confirm that the drain electrostatic clamp 810 is clamped and the drain valve 709 is in the correct position; after turning on the drain pump 130, it is also necessary to check in real time whether the drain electrostatic clamp 810 is clamped and whether the drain valve 709 is in the correct position to avoid safety accidents or leakage risks.

[0174] In one embodiment, before turning on the drain pump 130, a pop-up window can be used on the human-computer interaction device to confirm with the user that the drain pump 130 needs to be turned on. After obtaining the user's confirmation, the drain pump 130 is turned on.

[0175] Optionally, the control method further includes: during the period when the drain pump 130 is turned on, acquiring the waste liquid level signal output by the waste liquid level gauge LT3, determining the liquid level in the waste liquid tank 700 based on the waste liquid level signal; when the liquid level in the waste liquid tank 700 is at or above the first buffer level, closing the recovery valve 701, detecting whether the liquid level in the waste liquid storage tank 700 is at or above the second buffer level, and issuing an alarm when the liquid level in the waste liquid tank 700 is at or above the second buffer level. The second buffer level is higher than the first buffer level.

[0176] Optionally, the control method further includes: during the period when the drain pump 130 is turned on, detecting the pressure in the second drain pipe 470 through the fourth pressure detection device NP4; when the pressure in the second drain pipe 470 is greater than the pressure threshold, turning off the drain pump 130.

[0177] Optionally, the control method further includes: during the period when the drain pump 130 is turned on, acquiring the flow switch signal of the third flow switch 131, and controlling the drain pump 130 to turn off when no flow switch signal is received from the third flow switch 131 or when the flow switch signal of the third flow switch 131 is zero. This avoids the drain pump 130 from running dry and being damaged.

[0178] Optionally, the control method also includes: during the period when the discharge pump 130 is turned on, obtaining the pumping flow rate of the discharge pump 130 per unit time according to the discharge flow meter FM5, and turning off the discharge pump 130 when the pumping flow rate of the unloading pump 120 per unit time is less than the flow threshold. In this way, the discharge pump 130 can also be prevented from running dry.

[0179] Optionally, the control method also includes: during the period when the drain pump 130 is turned on, the temperature of the outlet of the drain pump 130 is obtained according to the third temperature detection device TP3; when the temperature of the outlet of the drain pump 130 is abnormally high (wherein the temperature threshold is adjustable), the controller 300 can control the drain pump 130 to shut down to avoid safety risks.

[0180] Optionally, the control method further includes: acquiring the frequency conversion signal of the frequency converter connected to the drain pump 130 before the drain pump 130 is turned on and during the period when the drain pump 130 is turned on, detecting whether the drain pump 130 is faulty based on the frequency conversion signal, and turning off the drain pump 130 when the drain pump 130 is faulty.

[0181] Example 3

[0182] Figure 5This is a schematic diagram of the control device of an NMP system provided in Embodiment 3 of the present invention. Figure 5 As shown, the device may include:

[0183] The acquisition module 931 is used to acquire the liquid supply setting value and determine the current liquid supply volume of the buffer tank based on the buffer level signal output by the buffer level gauge.

[0184] The control module 932 is used to determine whether the liquid supply setting value is less than or equal to the current available liquid volume; and when the liquid supply setting value is less than or equal to the current available liquid volume, it starts the transfer pump to transfer NMP liquid from the storage tank to the buffer tank. Based on the transfer flow signal output by the transfer flow meter, it determines whether a single NMP liquid transfer is completed. If it is determined that a single NMP liquid transfer is completed, it stops the transfer pump and sets the liquid supply setting value to zero; when the liquid supply setting value is greater than the current available liquid volume, it sets the liquid supply setting value to zero.

[0185] The control device of the NMP system provided in the embodiments of the present invention can be set in the controller of the NMP system. The control device of the NMP system provided in the embodiments of the present invention can execute the control method of the NMP system provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the execution method.

[0186] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0187] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A control method for an NMP system, characterized in that, The NMP system includes a storage tank, a delivery pump, a buffer tank, and a controller. The outlet of the storage tank is connected to the inlet of the delivery pump via a first delivery pipe, and the outlet of the delivery pump is connected to the inlet of the buffer tank via a second delivery pipe. A delivery flow meter is installed in the second delivery pipe. A buffer level gauge is installed in the buffer tank. The controller is communicatively connected to the delivery pump, the delivery flow meter, and the buffer level gauge. The control method includes: Obtain the liquid supply setting value, and determine the current liquid supply volume of the buffer tank based on the buffer level signal output by the buffer level gauge; Determine whether the liquid supply setting value is less than or equal to the current liquid supply volume; If the liquid supply setting value is less than or equal to the current available liquid volume, then the delivery pump is turned on to deliver the NMP liquid in the storage tank to the buffer tank; Based on the delivery flow signal output by the delivery flow meter, it is determined whether a single NMP liquid delivery is completed. If it is determined that a single NMP liquid delivery is completed, the delivery pump is turned off and the liquid supply setting value is set to zero. If the liquid supply setting value is greater than the current available liquid supply, then the liquid supply setting value is set to zero.

2. The control method for the NMP system according to claim 1, characterized in that, If it is determined that a single NMP liquid delivery is not completed, then it is determined whether the delivery pump has stopped pumping NMP liquid. If the delivery pump stops pumping NMP liquid, then the liquid supply setting value is set to zero; if the delivery pump does not stop pumping NMP liquid, then the process returns to the step of determining whether a single NMP liquid delivery is completed based on the delivery flow rate signal output by the delivery flow meter.

3. The control method for the NMP system according to claim 1, characterized in that, If the liquid supply setting value is less than or equal to the current available liquid volume, then the delivery pump is activated to deliver the NMP liquid in the storage tank to the buffer tank, including: If the liquid supply setting value is less than or equal to the current available liquid volume, then determine whether the liquid supply setting value is less than or equal to the single liquid supply threshold. If the liquid supply setting value is less than or equal to the single liquid supply threshold, the delivery pump is turned on to deliver the NMP liquid in the storage tank to the buffer tank. If the liquid supply setting value is greater than the single liquid supply threshold, then the liquid supply setting value is set to zero.

4. The control method for the NMP system according to any one of claims 1-3, characterized in that, The NMP system also includes an outlet valve located at the outlet of the storage tank and a buffer valve located in the second delivery pipeline; a first position sensor is provided at the outlet valve and a second position sensor is provided at the buffer valve, and both the first position sensor and the second position sensor are communicatively connected to the controller. Starting the delivery pump to deliver NMP liquid from the storage tank to the buffer tank includes: Before starting the delivery pump and during the period when the delivery pump is started, the first position signal of the first position sensor and the second position signal of the second position sensor are acquired, and based on the first position signal and the second position signal, it is confirmed whether the liquid outlet valve and the buffer valve are opened to the preset position. If both the outlet valve and the buffer valve are opened to the preset position, the delivery pump is turned on to deliver the NMP liquid in the storage tank to the buffer tank. If the outlet valve and / or the buffer valve are not opened to the preset position, the delivery pump shall be shut down.

5. The control method for the NMP system according to claim 4, characterized in that, The control method further includes: During the period when the delivery pump is turned on, the buffer level signal output by the buffer level gauge is acquired, and the liquid level in the buffer tank is determined based on the buffer level signal. When the liquid level in the buffer tank is at or above the first buffer level, the outlet valve, the delivery pump, and the buffer valve are closed. The system detects whether the liquid level in the buffer tank is at or above the second buffer level, and issues an alarm when the liquid level in the buffer tank is at or above the second buffer level; wherein the second buffer level is higher than the first buffer level.

6. The control method for the NMP system according to claim 1, characterized in that, The second delivery pipeline includes a first sub-pipeline and a second sub-pipeline. The first sub-pipeline is connected to the inlet of the buffer tank via the second sub-pipeline, and the second sub-pipeline is connected to the outlet of the delivery pump via the first sub-pipeline. The NMP system also includes a pressure relief pipeline. One end of the pressure relief pipeline is connected to the outlet of the delivery pump via the first sub-pipeline, and the other end of the pressure relief pipeline is connected to the pressure relief inlet of the storage tank. The first sub-pipeline is equipped with a first pressure detection device, and / or the second sub-pipeline is equipped with a second pressure detection device. The pressure relief pipeline is equipped with a pressure relief valve. The first pressure detection device, the second pressure detection device, and the pressure relief valve are all communicatively connected to the controller. The control method further includes: During the period when the delivery pump is turned on, the pressure in the first sub-pipe and / or the second sub-pipe is detected by the first pressure detection device and / or the second pressure detection device; When the pressure in the first sub-pipe and / or the second sub-pipe exceeds the pressure threshold, the pressure relief valve is opened to relieve pressure in the first sub-pipe and / or the second sub-pipe. When the pressure in the first sub-pipe and / or the second sub-pipe is less than or equal to the pressure threshold, the pressure relief valve is closed.

7. The control method for the NMP system according to claim 1, characterized in that, The controller includes a main controller and sub-controllers; the main controller is communicatively connected to the delivery pump, the delivery flow meter, and the sub-controllers; the sub-controllers are communicatively connected to the buffer level gauge. The control method further includes: detecting whether the communication connection between the main controller and the sub-controller is interrupted before the delivery pump is turned on and during the period when the delivery pump is turned on; and when the communication connection between the main controller and the sub-controller is interrupted, turning off the delivery pump and stopping the delivery of NMP liquid from the storage tank to the buffer tank.

8. The control method for the NMP system according to claim 1, characterized in that, The NMP system also includes an unloading pump and an unloading electrostatic grounding device. The unloading electrostatic grounding device includes an unloading electrostatic clamp and an unloading electrostatic control circuit. The inlet of the unloading pump is connected to the new liquid tank of the new liquid truck through a first unloading pipe. The outlet of the unloading pump is connected to the storage port of the storage tank through a second unloading pipe. The storage port is equipped with a storage valve, and the storage valve is equipped with a third position sensor. The unloading pump, the unloading electrostatic control circuit, and the third position sensor are all communicatively connected to the controller. The control method further includes: before starting the unloading pump and during the period when the unloading pump is started, acquiring the unloading electrostatic clamp signal of the unloading electrostatic control circuit and the third position signal of the third position sensor to confirm whether the unloading electrostatic clamp has been clamped and whether the liquid storage valve has been opened to the preset position. When the electrostatic clamp for unloading is engaged and the storage valve is opened to the preset position, the unloading pump is controlled to start, unloading the NMP liquid from the new liquid tank of the new liquid truck into the storage tank. The unloading pump is shut down when the electrostatic clamp for unloading is not properly engaged and / or the storage valve is not opened to the preset position.

9. The control method for the NMP system according to claim 1, characterized in that, The NMP system also includes a waste liquid tank, a drain pump, and a drain electrostatic grounding device. The drain electrostatic grounding device includes a drain electrostatic clamp and a drain electrostatic control circuit. The inlet of the drain pump is connected to the outlet of the waste liquid tank through a first drain pipe. The outlet of the waste liquid tank is equipped with a drain valve, and the drain valve is equipped with a fourth position sensor. The outlet of the drain pump is connected to the waste liquid tank of the waste liquid vehicle through a second drain pipe. The drain pump, the drain electrostatic control circuit, and the fourth position sensor are all communicatively connected to the controller. The control method further includes: before starting the drain pump and during the period when the drain pump is started, acquiring the drain electrostatic clamp signal of the drain electrostatic control circuit and the fourth position signal of the fourth position sensor to confirm whether the drain electrostatic clamp has been clamped and whether the drain valve has been opened to the preset position. When the electrostatic clamp for draining is engaged and the drain valve is opened to the preset position, the drain pump is controlled to start, draining the NMP liquid in the waste tank to the waste tank. The drain pump is shut down when the electrostatic clamp is not properly engaged and / or the drain valve is not opened to the preset position.

10. A control device for an NMP system, characterized in that, The NMP system includes a storage tank, a delivery pump, a buffer tank, and a controller. The outlet of the storage tank is connected to the inlet of the delivery pump via a first delivery pipe, and the outlet of the delivery pump is connected to the inlet of the buffer tank via a second delivery pipe. A delivery flow meter is installed on the second delivery pipe. A buffer level gauge is installed on the buffer tank. The controller is communicatively connected to the delivery pump, the delivery flow meter, and the buffer level gauge. The control device is used to execute the control method of the NMP system according to any one of claims 1-8.

11. An NMP system, characterized in that, The NMP system includes a storage tank, a delivery pump, a buffer tank, and a controller. The controller includes the control device of the NMP system according to claim 10. The outlet of the storage tank is connected to the inlet of the delivery pump through a first delivery pipe, and the outlet of the delivery pump is connected to the inlet of the buffer tank through a second delivery pipe. The second delivery pipe is equipped with a delivery flow meter. The buffer tank is equipped with a buffer level gauge. The controller is communicatively connected to the delivery pump, the delivery flow meter, and the buffer level gauge.

12. The NMP system according to claim 11, characterized in that, The NMP system also includes a buffer level magnetic switch; The liquid level magnetic switch is set at the third buffer level of the buffer tank; The buffer level magnetic switch is connected in series with the delivery pump; The buffer level magnetic switch can be triggered to turn off when the liquid level in the buffer tank is at the third buffer level, thereby shutting down the delivery pump.

13. The NMP system according to claim 11, characterized in that, The NMP system also includes multiple transport emergency stop switches: each of the multiple transport emergency stop switches is connected in series with the transport pump; When any of the emergency stop switches is pressed, the conveying pump will be shut down.

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