A screw pump pressure regulating method and device, computer equipment and storage medium

Abstract

The present application relates to lithium battery coating feed technology field, disclose a kind of screw pump pressure regulating method, device, computer equipment and storage medium, the method is applied to coating system, comprising: obtaining the pressure of screw pump discharge port in first preset period when not adjusting, obtain pressure fluctuation curve;According to the pressure fluctuation curve, obtain pressure reference interval;Obtain the pressure of screw pump discharge port to be adjusted;According to the relationship between pressure and pressure reference interval, the rotational speed of screw pump is adjusted, changes the pressure of screw pump discharge port.The present application solves the problem that fluctuation is generated in the coating process of screw pump conveying slurry, which easily affects the consistency of coating surface density, and further easily affects the final coating effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium battery coating supply technology, and in particular to a screw pump pressure adjusting method and device, computer equipment and a storage medium. BACKGROUND

[0002] Coating is one of the key processes in the production of lithium battery pole pieces. The main purpose of this process is to uniformly coat the slurry with good stability, viscosity and flowability on the positive and negative current collectors. The main component of pumping slurry is screw pump. In the existing supply system, the whole pumping process from the starting end of pumping to the slurry extrusion end of the die head is an open-loop control process. Due to the high stability of the coating process, only high-precision screw pump feeding can be used at present. The main working components of the screw pump are the eccentric screw body (called rotor) and the screw bushing (called stator) with a double helical surface on the inner surface. Due to the non-equal wall thickness design of the stator, when the outlet end is pressed, the stator will be extruded and deformed, causing pressure fluctuation at the outlet end, thereby causing instability in the pumping process, and the pump-out pressure detection also presents a periodic fluctuation curve. Therefore, regardless of the type of screw pump, this fluctuation will occur during the coating process of the screw pump conveying slurry, which will easily affect the uniformity of the coating surface density and further affect the final coating effect.

[0003] Therefore, there is an urgent need for a screw pump pressure adjusting technical solution to solve the problem of pressure fluctuation during the coating process of the screw pump conveying slurry, which will easily affect the uniformity of the coating surface density and further affect the final coating effect. SUMMARY

[0004] Therefore, the embodiments of the present application provide a screw pump pressure adjusting method, device, computer equipment and storage medium to solve the problem of fluctuation during the coating process of the screw pump conveying slurry, which will easily affect the uniformity of the coating surface density and further affect the final coating effect.

[0005] In a first aspect, the embodiments of the present application provide a screw pump pressure adjusting method applied to a coating system, which comprises the following steps:

[0006] Obtaining the pressure of the screw pump outlet at a first preset period when not adjusted to obtain a pressure fluctuation curve;

[0007] Obtaining a pressure reference interval according to the pressure fluctuation curve;

[0008] Obtaining the pressure of the screw pump outlet to be adjusted;

[0009] Adjusting the rotating speed of the screw pump according to the relationship between the pressure and the pressure reference interval to change the pressure of the screw pump outlet.

[0010] The screw pump pressure adjusting method provided by the embodiment of the present application obtains the pressure of the screw pump discharge port in the first preset period before adjustment, obtains a pressure fluctuation curve, obtains a pressure reference interval according to the pressure fluctuation curve, then obtains the pressure of the screw pump discharge port to be adjusted again, adjusts the rotating speed of the screw pump according to the relationship between the pressure and the pressure reference interval, and changes the pressure of the screw pump discharge port, so that the pressure fluctuation generated in the coating process of the coating system during the screw pump conveying of slurry tends to be gentle, the coating surface density consistency is improved, the final coating effect is better, and the problem that the fluctuation is generated in the coating process of the coating system during the screw pump conveying of slurry, the coating surface density consistency is extremely easy to be affected, and the final coating effect is extremely easy to be affected is solved.

[0011] In combination with the first aspect, in an implementation manner, the coating system comprises a buffer tank, before the pressure of the screw pump discharge port in the first preset period before adjustment is obtained, the method comprises the following steps of:

[0012] obtaining the weight of the buffer tank;

[0013] judging whether the change trend of the weight in the second preset period conforms to a preset change trend.

[0014] The screw pump pressure adjusting method provided by the embodiment of the present application judges whether the change trend of the weight of the buffer tank in the second preset period conforms to a preset change trend, when the preset change trend is met, the pressure of the screw pump discharge port in the preset period before adjustment is obtained again, the fluctuation stability period of the screw pump discharge port conveying slurry flow can be monitored and detected in real time, and the abnormality of the screw pump pressure caused by the abnormality of the slurry flow in the buffer tank due to external factors is avoided.

[0015] In an optional implementation manner, before the weight of the buffer tank is obtained, the method further comprises the following steps of:

[0016] clearing the initial weight value of the buffer tank and the initial pressure value of the screw pump when no coating slurry is stored.

[0017] The screw pump pressure adjusting method provided by the embodiment of the present application clears the initial weight value of the buffer tank and the initial pressure value of the screw pump when no coating slurry is stored before the weight of the buffer tank is obtained, so that the weight value of the buffer tank and the pressure value of the screw pump obtained after the coating slurry is stored start from zero, the accuracy of the subsequent weight value of the buffer tank and the pressure value of the screw pump is improved, the acquisition of the screw pump discharge port pressure affected by external factors is prevented, and the adjustment of the rotating speed of the screw pump is further affected.

[0018] In an optional implementation manner, the pressure reference interval is obtained according to the pressure fluctuation curve, and the method comprises the following steps of:

[0019] obtaining the peak and the trough of the pressure fluctuation curve;

[0020] determining the reference value according to the wave crest and the wave trough;

[0021] determining the pressure reference interval according to the reference value.

[0022] In an alternative embodiment, the adjusting the rotating speed of the screw pump according to the relationship between the pressure and the pressure reference interval comprises:

[0023] when the pressure is greater than the pressure reference interval, reducing the rotating speed of the screw pump;

[0024] when the pressure is less than the pressure reference interval, increasing the rotating speed of the screw pump.

[0025] The screw pump pressure adjusting method provided by the embodiment of the present application determines the reference value according to the wave crest and the wave trough of the pressure fluctuation curve in the first preset period, and determines the pressure reference interval according to the reference value, so that a pressure stable interval can be obtained, which provides data guarantee for subsequent adjustment of the rotating speed of the screw pump to change the pressure at the discharge port of the screw pump. In actual operation, when the pressure is greater than the pressure reference interval, the rotating speed of the screw pump is reduced; when the pressure is less than the pressure reference interval, the rotating speed of the screw pump is increased, so that the pressure wave crest and wave trough at the discharge port of the screw pump tend to be gentle, and the coating surface density consistency is improved.

[0026] In an alternative embodiment, the screw pump pressure adjusting method further comprises: after the coating system runs for a preset time, the pressure fluctuation curve of the screw pump discharge port in a third preset period is obtained again; when the wave crest and the wave trough of the pressure fluctuation curve of the screw pump discharge port in the third preset period exceed the wave crest and the wave trough of the pressure fluctuation curve of the screw pump discharge port in the first preset period, the pressure reference interval is adjusted according to a preset proportionality coefficient.

[0027] The screw pump pressure adjusting method provided by the embodiment of the present application can adjust the pressure reference interval according to the preset proportionality coefficient when the wave crest and the wave trough of the pressure fluctuation curve of the screw pump discharge port exceed the wave crest and the wave trough of the pressure fluctuation curve of the screw pump discharge port in the first preset period after the coating system runs for a preset time, so that the pressure fluctuation curve of the screw pump discharge port can be detected in real time, and the rotating speed of the screw pump can be adjusted according to the adjusted pressure reference interval, so that the adjustment is more accurate.

[0028] In an alternative embodiment, the coating system further comprises a wet film thickness gauge and a dry film thickness gauge, and the screw pump pressure adjusting method further comprises:

[0029] obtaining a first film thickness fluctuation value of the wet film thickness gauge;

[0030] determining whether the first film thickness fluctuation value is within a first preset fluctuation threshold value;

[0031] if yes, obtaining a second film thickness fluctuation value of the dry film thickness gauge;

[0032] If no, continue to acquire the pressure of the discharge port of the screw pump to be adjusted, and adjust the rotating speed of the screw pump according to the relationship between the pressure and the pressure reference interval.

[0033] In an optional embodiment, the acquiring the second film thickness fluctuation value of the dry film thickness gauge comprises:

[0034] determining whether the second film thickness fluctuation value is within the second preset fluctuation threshold value;

[0035] If yes, maintaining the current rotating speed of the screw pump;

[0036] If no, continuing to acquire the pressure of the discharge port of the screw pump to be adjusted, and adjusting the rotating speed of the screw pump according to the relationship between the pressure and the pressure reference interval.

[0037] The screw pump pressure adjusting method provided by the embodiment of the present application can detect the influence of the pressure of the discharge port of the screw pump on the first film thickness fluctuation of the wet film thickness gauge and the second film thickness fluctuation of the dry film thickness gauge in real time, so that the rotating speed of the screw pump can be adjusted in real time, and the consistency of the coating surface density is improved.

[0038] In a second aspect, the embodiment of the present application provides a screw pump pressure adjusting device applied to a coating system, which comprises:

[0039] a first acquiring module, configured to acquire the pressure of the discharge port of the screw pump in a first preset period when the screw pump is not adjusted, to obtain a pressure fluctuation curve;

[0040] a second acquiring module, configured to acquire a pressure reference interval according to the pressure fluctuation curve;

[0041] a third acquiring module, configured to acquire the pressure of the discharge port of the screw pump to be adjusted;

[0042] an adjusting module, configured to adjust the rotating speed of the screw pump according to the relationship between the pressure and the pressure reference interval, to change the pressure of the discharge port of the screw pump.

[0043] In a third aspect, the embodiment of the present application provides a computer device, which comprises a memory and a processor, the memory and the processor are communicatively connected, the memory stores computer instructions, and the processor executes the computer instructions to perform the screw pump pressure adjusting method of the first aspect or any of the corresponding embodiments thereof.

[0044] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, having stored thereon computer instructions for causing a computer to execute the screw pump pressure regulating method of the first aspect or any of the corresponding embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the specific embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0046] Figure 1 is a flowchart of a screw pump pressure regulating method according to some embodiments of the present application;

[0047] Figure 2 is a structural block diagram of a coating system according to some embodiments of the present application;

[0048] Figure 3 is a pump-out pressure fluctuation curve diagram of a screw pump discharge port according to some embodiments of the present application;

[0049] Figure 4 is a pump-out pressure fluctuation curve diagram of a screw pump discharge port after adjustment according to some embodiments of the present application;

[0050] Figure 5 is a flowchart of another screw pump pressure regulating method according to some embodiments of the present application;

[0051] Figure 6 is a structural block diagram of another coating system according to some embodiments of the present application;

[0052] Figure 7 is a flowchart of still another screw pump pressure regulating method according to some embodiments of the present application;

[0053] Figure 8 is a flowchart of yet another screw pump pressure regulating method according to some embodiments of the present application;

[0054] Figure 9 is a control principle diagram of a coating system pump closed loop according to some embodiments of the present application;

[0055] Figure 10 is a flowchart of still another screw pump pressure regulating method according to some embodiments of the present application;

[0056] Figure 11is a structural block diagram of a screw pump pressure regulating device according to an embodiment of the present application;

[0057] Figure 12 is a hardware structure schematic diagram of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0058] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0059] In the present embodiment, a screw pump pressure regulating method is provided, which can be used for a PLC controller, Figure 1 is a flow chart of a screw pump pressure regulating method according to an embodiment of the present application, which is applied to a coating system, such as Figure 1 as shown, the flow chart comprises the following steps:

[0060] In step S101, the pressure of the screw pump discharge port in a first preset period before regulation is obtained, and a pressure fluctuation curve is obtained.

[0061] Exemplarily, in combination with Figure 2 , Figure 2 is a structural block diagram of a coating system according to some embodiments of the present application, which comprises a servo motor 12, a screw pump 13 and a pressure sensor 14. The discharge port is connected to the screw pump 13 through a pipeline, the pressure sensor 14 is arranged at the discharge port of the screw pump 13 to detect the pressure of the discharge port of the screw pump 13. The servo motor 12 is connected to the screw pump 13 to drive the screw pump 13 to rotate. The coating system is also connected to an external terminal control module (for example, a PLC controller), which is used to obtain the value of the pressure sensor and control the movement of the servo motor.

[0062] When the coating system works, the pressure value of the pressure sensor of the screw pump discharge port is obtained through the external terminal control module in a first preset period, such as time T. The first preset period T can be the time for one or two rotations of the screw pump. The pressure fluctuation of the screw pump in the time for one or two rotations is generally periodic fluctuation, as shown in Figure 3 a pump discharge pressure fluctuation curve of the screw pump discharge port can be obtained. The specific time of the first preset period is not specially limited, as long as the periodic pressure fluctuation curve can be obtained.

[0063] In step S102, the pressure reference interval is obtained according to the pressure fluctuation curve.

[0064] Exemplarily, a pressure fluctuation curve obtained is as shown in Figure 3 Figure 3 In the figure, the horizontal axis represents the number of revolutions of the screw pump (unit: revolutions / minute), and the vertical axis represents the pressure at the discharge port of the screw pump (unit: Mpa). A section with relatively stable pressure can be selected from the curve as a pressure reference section. In the pressure reference section, the coating surface with consistent density can be obtained through the operation of the screw pump.

[0065] In step S103, the pressure at the discharge port of the screw pump to be adjusted is obtained.

[0066] Specifically, after the pressure reference section is obtained, the screw pump continues to operate, and the pressure of the pressure sensor at the discharge port of the screw pump at this time is obtained again through the external terminal control module.

[0067] In step S104, the speed of the screw pump is adjusted according to the relationship between the pressure and the pressure reference section, so as to change the pressure at the discharge port of the screw pump.

[0068] Specifically, when the pressure at the discharge port of the screw pump is obtained again, it is analyzed where the pressure is located in the pressure reference section. If the pressure value at this time has a trend of exceeding the pressure reference section, the PLC controller controls the servo motor to reduce the speed of the screw pump, so as to reduce the pressure at the discharge port of the screw pump at this time. If the pressure value at this time has a trend of being lower than the pressure reference section, the PLC controller controls the servo motor to increase the speed of the screw pump, so as to increase the pressure at the discharge port of the screw pump at this time. The pump-out pressure fluctuation curve of the discharge port of the screw pump after adjustment is as shown in Figure 4 Figure 4 In the figure, the horizontal axis represents the number of revolutions of the screw pump (unit: revolutions / minute), and the vertical axis represents the pressure at the discharge port of the screw pump (unit: Mpa). It can be seen from Figure 4 that the peaks and troughs of the pump-out pressure fluctuation curve of the discharge port of the screw pump after adjustment tend to be stable.

[0069] The screw pump pressure adjustment method provided by the embodiment of the present application obtains the pressure at the discharge port of the screw pump in a first preset period before adjustment, obtains a pressure fluctuation curve, and then obtains the pressure at the discharge port of the screw pump to be adjusted according to the relationship between the pressure and the pressure reference section, so as to adjust the speed of the screw pump and change the pressure at the discharge port of the screw pump. In this way, the pressure fluctuation in the coating process of the coating system in which the screw pump is used to transport slurry tends to be stable, the density consistency of the coating surface is improved, the final coating effect is better, and the problem that the fluctuation in the coating process of the coating system in which the screw pump is used to transport slurry easily affects the density consistency of the coating surface and further easily affects the final coating effect is solved.

[0070] In an embodiment, before the pressure at the discharge port of the screw pump in a first preset period before adjustment is obtained, the following steps are included:​​

[0071] In step S201, the weight of the buffer tank is obtained; specifically, before obtaining the weight of the buffer tank, the initial weight value of the buffer tank not storing coating slurry and the initial pressure value of the screw pump are cleared, so that the weight value of the buffer tank and the pressure value of the screw pump obtained after the coating slurry is stored start from zero, the accuracy of the subsequent weight value of the buffer tank and the pressure value of the screw pump is improved, and the influence of external factors on the acquisition of the discharge port pressure of the screw pump and the adjustment of the rotation speed of the screw pump is prevented. Figure 2 As shown in FIG. 1, the coating system further comprises a buffer tank 11 and a weighing sensor 15, the buffer tank 11 is arranged on a support, the weighing sensor 15 is arranged on the support of the buffer tank 11 and is used to weigh the weight of the buffer tank, the weighing sensor 15 is connected to an external terminal control module and transmits the weight data of the buffer tank 11 to the external terminal control module for analysis. When the coating system starts to work, the external terminal control module obtains the weight of the weighing sensor 15, and the weight is the weight of the buffer tank 11.

[0072] In step S202, it is judged whether the change trend of the weight in the second preset period conforms to a preset change trend; specifically, the change trend of the weight in the second preset period can indirectly judge whether the coating system works normally, the second preset period can also be set as the time for one rotation or two rotations of the screw pump, and the preset change trend is specifically that the change of the weighing sensor is a linearly decreasing change trend. When the change trend of the weight in the second preset period conforms to the linearly decreasing change trend, it is indicated that the coating system works normally, and when the change trend of the weight in the second preset period does not conform to the linearly decreasing change trend, it is indicated that the coating system is disturbed by external factors. Then, the external terminal control module discards the weight value of the nonlinear change, and continues to obtain the weight of the buffer tank after the external factors are eliminated, so that the change trend of the weight in the second preset period conforms to the preset change trend.

[0073] In the embodiment, a screw pump pressure adjusting method is provided, Figure 5 The flow chart of the screw pump pressure adjusting method according to the embodiment of the present application is shown in FIG. 2, which comprises the following steps: Figure 5

[0074] In step S301, the pressure of the discharge port of the screw pump in the first preset period before adjustment is obtained, and a pressure fluctuation curve is obtained. For details, refer to step S101 of the embodiment shown in FIG. 1, which will not be repeated here. Figure 1

[0075] In step S302, the pressure reference interval is obtained according to the pressure fluctuation curve.

[0076] Specifically, the above step S302 comprises:

[0077] ​​Step S3021: Obtain the peaks and troughs of the pressure fluctuation curve.

[0078] Step S3022: Determine the reference value based on the peaks and troughs.

[0079] Specifically, the reference value should be selected between the peak and the trough so that the pressure fluctuation at the screw pump outlet tends to the reference value. This will make the fluctuation range of the peak and the trough more gradual. The midpoint between the peak and the trough can be set as the pressure reference value.

[0080] Step S3023: Determine the pressure reference range based on the reference value.

[0081] Specifically, such as Figure 3 As shown, when the midpoint of the pressure fluctuation curve, i.e. the reference value, is 0.2060 MPa, the pressure reference range can be set to a fluctuation range of ±0.0001 MPa of the reference value of 0.2060 MPa, or other fluctuation ranges can be selected according to actual needs to obtain the pressure reference range.

[0082] Step S303: Obtain the pressure at the discharge port of the screw pump to be adjusted. For details, please refer to [link to relevant documentation]. Figure 1 Step S103 of the illustrated embodiment will not be described again here.

[0083] Step S304: Adjust the screw pump speed according to the relationship between the pressure and the pressure reference range to change the screw pump outlet pressure. For details, please refer to [link to relevant documentation]. Figure 1 Step S104 of the illustrated embodiment will not be described again here.

[0084] The screw pump pressure regulation method provided in this embodiment ensures that the pressure fluctuations of the screw pump outlet and the flow rate of the buffer tank can be monitored and stabilized in real time from the time the slurry pumped from the screw pump outlet enters the buffer tank to the final extrusion process of the coating system die. Furthermore, when the screw pump outlet pressure is not within the pressure reference range, the external terminal control module controls the servo motor to adjust the screw pump's own speed, thereby effectively reducing the pumping pressure generated by the stator and rotor extrusion. This makes the peaks and troughs of the screw pump outlet pressure fluctuations tend to be smoother, improving the uniformity of the coating surface density.

[0085] In an embodiment, the screw pump pressure regulating method further comprises: obtaining the pressure fluctuation curve of the screw pump discharge port again in a third preset period after the coating system runs for a preset time; and adjusting the pressure reference interval according to a preset proportion coefficient when the peaks and troughs of the pressure fluctuation curve of the screw pump discharge port in the third preset period exceed the peaks and troughs of the pressure fluctuation curve of the screw pump discharge port in the first preset period. Specifically, the specific time of the preset time is not specially limited and can be set to a coating time or a coating length. The specific time of the third preset period is not specially limited as long as a periodic pressure fluctuation curve can be obtained. The preset proportion coefficient can be the ratio between two points P1 and P2 at the same position in two consecutive coating periods of lithium batteries. When the range of the peaks and troughs of the pressure fluctuation curve of the screw pump discharge port increases and exceeds the peaks and troughs of the pressure fluctuation curve in the first preset period after the coating system runs for the preset time, the programmable controller PLC should also adjust the pressure reference interval, for example, taking two points P1 and P2 at the same position in two consecutive coating periods of lithium batteries, P2 / P1 = a as the proportion coefficient of the pressure reference interval in the next period, that is, P(n+1) / Pn = an, and then the pressure reference interval in the next period is an0.2055MPa≦P≦an0.2065MPa, where n represents the serial number of the time period.

[0086] As shown in Figure 7 In an embodiment, the screw pump pressure regulating method further comprises the following steps:

[0087] Step S401: obtaining a first film thickness fluctuation value of a wet film thickness gauge; specifically, as shown in Figure 6 The coating system further comprises a wet film thickness gauge, which is installed between the coating die and the oven and connected with the external terminal control module. The wet film thickness gauge is used to test the initial coating effect after the ingredients pass through the feeding vehicle and the coating die of the coating system, and the first film thickness fluctuation value is obtained. The external terminal control module obtains the first film thickness fluctuation value of the wet film thickness gauge, and the first film thickness fluctuation value can reflect the initial coating effect.

[0088] Step S402: determining whether the first film thickness fluctuation value is within a first preset fluctuation threshold. Specifically, the first preset fluctuation threshold is specifically a normal fluctuation range, for example, the wet film thickness gauge measures 120 microns, and the normal fluctuation range is 10 microns in positive and negative directions, that is, the first preset fluctuation threshold of the wet film thickness gauge is between 110 microns and 130 microns.

[0089] Step S403: if yes, obtaining a second film thickness fluctuation value of a dry film thickness gauge. Specifically, as shown in Figure 6As shown, the coating system further comprises a dry film thickness gauge, which is installed behind the oven and connected with the external terminal control module. When the first film thickness fluctuation value is within the first preset fluctuation threshold, i.e. the first film thickness fluctuation value is between 110 microns and 130 microns, it indicates that the initial coating effect reaches the preset coating effect, and the second film thickness fluctuation value of the dry film thickness gauge is continuously detected to determine whether it meets the preset coating effect. At this time, the second film thickness fluctuation value of the dry film thickness gauge is obtained by the external terminal control module, and the second film thickness fluctuation value can reflect the final coating effect. After the coated foil is dried (the foil after drying refers to the foil after the slurry is coated on the foil and dried by the oven, because the dry film thickness gauge detects the foil after drying), the final coating effect is detected by the dry film thickness gauge.

[0090] In step S404, if no, the pressure at the discharge port of the screw pump to be adjusted is continuously obtained, and the speed of the screw pump is adjusted according to the relationship between the pressure and the pressure reference interval. Specifically, for example, the wet film thickness gauge measures 120 microns, and the normal fluctuation range is 10 microns. When the first film thickness fluctuation value is not within the first preset fluctuation threshold, it indicates that the first film thickness fluctuation value of the wet film thickness gauge exceeds the range between 110 microns and 130 microns, and therefore the preset coating effect is not reached. The pressure at the discharge port of the screw pump to be adjusted is continuously obtained, and the speed of the screw pump is increased or decreased according to the relationship between the pressure and the pressure reference interval, so as to change the pressure fluctuation at the discharge port of the screw pump, so that the first film thickness fluctuation value of the wet film thickness gauge reaches the preset coating effect.

[0091] In an optional embodiment, as shown in Figure 8 Step S403 includes:

[0092] In step S4031, it is determined whether the second film thickness fluctuation value is within the second preset fluctuation threshold. The second preset fluctuation threshold is specifically set as the normal fluctuation range of the thickness of the dried foil, for example, the second preset fluctuation threshold of the dry film thickness gauge can be set to fluctuate between 90 microns and 110 microns.

[0093] In step S4032, if yes, the current speed of the screw pump is maintained. Specifically, when the second film thickness fluctuation value is within the second preset fluctuation threshold, i.e. the second film thickness fluctuation value is between 90 microns and 110 microns, it indicates that the final coating effect reaches the preset coating effect, and then the current speed of the screw pump is maintained.

[0094] Step S4033: If not, continue to acquire the pressure at the outlet of the screw pump to be adjusted, and adjust the speed of the screw pump according to the relationship between the pressure and the pressure reference range. For example, the dry film thickness gauge measures 100 micrometers, with ±10 micrometers being the normal fluctuation range. When the second film thickness fluctuation value is not within the second preset fluctuation threshold, it indicates that the second film thickness fluctuation value of the dry film thickness gauge exceeds the range of 90-110 micrometers, and therefore the preset coating effect has not been achieved. Continue to acquire the pressure at the outlet of the screw pump to be adjusted, and increase or decrease the speed of the screw pump according to the relationship between the pressure and the pressure reference range to change the pressure fluctuation at the outlet of the screw pump, so that the second film thickness fluctuation value of the dry film thickness gauge reaches the preset coating effect.

[0095] The screw pump pressure regulation method provided in this embodiment detects whether the film thickness fluctuation values ​​of the wet film thickness gauge and the dry film thickness gauge are within a preset fluctuation threshold. This reflects the initial coating effect and the final coating effect, allowing for real-time adjustment of the screw pump speed based on these results to achieve the desired coating effect. As one or more specific application embodiments of this invention, this example uses a complete coating line. Figure 9 The diagram shows the control principle of the closed-loop pumping system for the coating system. The coating slurry flows from the buffer tank to the screw pump, and after being pumped out from the screw pump outlet, it flows to the coating die head for the coating process. One end of the screw pump is connected to a servo motor, which controls the speed of the screw pump. A pressure sensor is installed at the outlet of the screw pump to detect the pressure of the pumped slurry. A weighing sensor is installed on the support of the buffer tank to weigh the tank. It is connected to an external terminal control module to transmit data for analysis. When the coating slurry is powered by the screw pump, it is pumped out from the outlet. The pressure sensor detects the pressure fluctuation at the outlet of the screw pump and transmits the pressure fluctuation to the external terminal control module (Programmable Logic Controller, PLC) to analyze the periodic change pattern of the pressure fluctuation and derive its pressure fluctuation curve. Based on this, the programmable logic controller (PLC) controls the servo motor to proportionally adjust the instantaneous speed of the screw pump, with a maximum adjustment frequency of 1ms / time. This changes the pressure at the screw pump outlet, making the peaks and troughs of the pressure fluctuation curve at the outlet smoother, thereby increasing the coating surface density.

[0096] Combination Figure 10 The screw pump pressure regulation method provided in this embodiment is as follows:

[0097] Step S501: After the coating system starts working, the data of the weighing sensor and pressure sensor detected by the programmable controller PLC are cleared.

[0098] Step S502, the programmable controller PLC reads the weight value of the weighing sensor in the second preset period T'; specifically, the second preset period T' can be set to the time for one or two rotations of the screw pump.

[0099] Step S503, it is judged whether the change trend of the weight value is normal. When the coating is normally performed, the change of the weighing sensor is linearly reduced, which is normal, and the next procedure is performed; otherwise, the data is cleared, and the weight value of the weighing sensor is continuously read until the change trend is linearly reduced. Because the weighing sensor measures the weight of the buffer tank, through the detection of the change trend of the weight, the problem of abnormal pressure of the screw pump caused by abnormal slurry flow due to external factors can be avoided.

[0100] Step S504, the value of the pressure sensor in the first preset period T is read to obtain a pressure fluctuation curve; the first preset period T is generally the time for one or two rotations of the screw pump.

[0101] Step S505, the pressure fluctuation curve is transmitted to the programmable controller PLC, and the pressure fluctuation curve is analyzed to obtain a peak and a valley, taking the screw pump 50 r / min (r / min represents revolutions per minute) as an example. The reference value of the pressure fluctuation is obtained according to the peak and the valley, the pressure reference interval is determined according to the reference value, for example, if the pressure reference value is 0.2060 MPa, 0.2055 MPa-0.2065 MPa is selected as the pressure reference interval.

[0102] Step S506, the pressure value of the pressure sensor is read again;

[0103] Step S507, it is analyzed where the pressure value is located in the pressure reference interval, and the speed of the screw pump is adjusted according to the relationship between the pressure reference interval and the pressure value. If the pressure value at this time has a trend of exceeding the pressure reference interval, the PLC controller controls the servo motor to reduce the speed of the screw pump, so as to reduce the pressure at the discharge port of the screw pump at this time; if the pressure value at this time has a trend of being lower than the pressure reference interval, the PLC controller controls the servo motor to increase the speed of the screw pump, so as to increase the pressure at the discharge port of the screw pump at this time.

[0104] Step S508, the film thickness fluctuation value of the wet film thickness gauge is read, and it is set that the film thickness fluctuation value of the wet film thickness gauge within 120 microns plus or minus 10 microns is within the normal range;

[0105] Step S509, judge whether the film thickness fluctuation value of the wet film thickness gauge is in the normal range, if the film thickness fluctuation value of the wet film thickness gauge is in the normal range, read the film thickness fluctuation value of the dry film thickness gauge; if the film thickness fluctuation value of the wet film thickness gauge is not in the normal range, continue to obtain the pressure of the screw pump discharge port to be adjusted, and adjust the speed of the screw pump according to the relationship between the pressure and the pressure reference interval;

[0106] Step S510, read the film thickness fluctuation value of the dry film thickness gauge, and set the film thickness fluctuation value of the dry film thickness gauge in the normal range as 100 microns plus or minus 10 microns;

[0107] Step S511, judge whether the film thickness fluctuation value of the dry film thickness gauge is in the normal range, if the film thickness fluctuation value of the dry film thickness gauge is in the normal range, keep the current speed of the screw pump; if the film thickness fluctuation value of the dry film thickness gauge is not in the normal range, obtain the pressure of the screw pump discharge port to be adjusted, and adjust the speed of the screw pump according to the relationship between the pressure and the pressure reference interval.

[0108] Here, it is stipulated that the speed of the screw pump changes by 0.1 revolution, and the pressure fluctuation changes by 0.0005 MPa. When the pressure pumped out of the screw pump discharge port has a trend of exceeding the pressure reference interval, for example, the next stage fluctuation exceeds the pressure reference interval by 0.0003 MPa, the speed of the screw pump can be appropriately reduced, such as 49.9 r / min; further, the next stage fluctuation exceeds the pressure reference interval by 0.00010 MPa, the speed of the screw pump can be appropriately reduced, such as 49.8 r / min, and so on. When the pumped pressure has a trend of being lower than the pressure reference interval, the speed of the screw pump can be increased, such as 50.1 r / min, 50.2 r / min, 50.3 r / min.

[0109] After the coating system runs for a period of time, as the upper and lower limits of the pumped pressure fluctuation curve increase (the interval range exceeds the original periodic change interval), the programmable controller PLC should also adjust the pressure reference interval at this time, but the speed interval of the screw pump adjusted by the programmable controller PLC should not change. Then reduce the pressure fluctuation. The acceptable pressure reference interval after the upper and lower limits increase is set as: take two points P1 and P2 with the same position in the continuous period, P2 / P1=α as the proportional coefficient of the normal interval in the next period, that is, P(n+1) / Pn=αn, then the normal interval of the next period is αn0.2055 MPa≦P≦αn0.2065 MPa.

[0110] A screw pump pressure regulating device is also provided in the present embodiment, which is used to realize the above-mentioned embodiments and preferred embodiments, and will not be described again. As used below, the term "module" can be a combination of software and / or hardware that realizes a predetermined function. Although the device described in the following embodiments is preferably realized in software, realization in hardware, or a combination of software and hardware, is also possible and contemplated.

[0111] The present embodiment provides a screw pump pressure regulating device, which is applied to a coating system, such as Figure 11 as shown, comprising:

[0112] A first obtaining module 601 is configured to obtain the pressure of the outlet of the screw pump in a first preset period when not regulated, to obtain a pressure fluctuation curve.

[0113] A second obtaining module 602 is configured to obtain a pressure reference interval according to the pressure fluctuation curve.

[0114] A third obtaining module 603 is configured to obtain the pressure of the outlet of the screw pump to be regulated.

[0115] A regulating module 604 is configured to regulate the rotating speed of the screw pump according to the relationship between the pressure and the pressure reference interval, to change the pressure of the outlet of the screw pump.

[0116] In some optional embodiments, the second obtaining module 602 comprises:

[0117] A first obtaining unit is configured to obtain the peak and the trough of the pressure fluctuation curve.

[0118] A first determining unit is configured to determine the reference value according to the peak and the trough.

[0119] A second determining unit is configured to determine the pressure reference interval according to the reference value.

[0120] In some optional embodiments, the regulating module 604 comprises:

[0121] A first regulating unit is configured to reduce the rotating speed of the screw pump when the pressure is greater than the pressure reference interval.

[0122] A second regulating unit is configured to increase the rotating speed of the screw pump when the pressure is less than the pressure reference interval.

[0123] The screw pump pressure regulating device in the present embodiment is presented in the form of functional units, where the units refer to ASIC circuits, processors and memories that execute one or more software or fixed programs, and / or other devices that can provide the above-mentioned functions.

[0124] Further function descriptions of the above-mentioned modules are the same as those of the corresponding embodiments, and will not be described again.

[0125] This invention also provides a computer device having the above-described features. Figure 11 The screw pump pressure regulating device shown is shown.

[0126] Please see Figure 12 , Figure 12 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 12 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories and multiple memory modules, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 12 Take a processor 10 as an example.

[0127] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0128] The memory 20 stores instructions executable by at least one processor 10 to cause the at least one processor 10 to perform the method shown in the above embodiments.

[0129] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device as shown by a landing page for an app. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, which can be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0130] The memory 20 can include a volatile memory, such as a random access memory, and / or can include a non-volatile memory, such as a flash memory, a hard disk or a solid state disk. The memory 604 can also include a combination of the above-mentioned types of memory.

[0131] The computer device also includes a communication interface 30 for the computer device to communicate with other devices or communication networks.

[0132] The embodiments of the present application also provide a computer readable storage medium, the method according to the embodiments of the present application can be implemented in hardware, firmware, or be implemented as computer code recorded in a storage medium, or be implemented through network downloading and originally stored in a remote storage medium or a non-transitory machine readable storage medium and to be stored in a local storage medium, so that the method described herein can be processed by such software on a storage medium using a general purpose computer, a special purpose processor or programmable or special purpose hardware. The storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk or a solid state disk, etc. Further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that the computer, the processor, the microprocessor controller or the programmable hardware includes a storage component that can store or receive software or computer code, when the software or computer code is accessed and executed by the computer, the processor or the hardware, the method shown in the above embodiments is implemented.

[0133] Although the embodiments of the present application are described in conjunction with the accompanying drawings, various modifications and changes can be suggested by those skilled in the art without departing from the spirit and scope of the present application, and such modifications and changes are intended to fall within the scope of the appended claims.

Claims

1. A method for regulating the pressure of a screw pump, characterized in that, Applied to a coating system, the method includes: The pressure at the screw pump outlet during the first preset cycle without adjustment is obtained, and the pressure fluctuation curve is obtained. Obtaining a pressure reference range based on the pressure fluctuation curve; obtaining a pressure reference range based on the pressure fluctuation curve includes: Obtain the peaks and troughs of the pressure fluctuation curve; The baseline value is determined based on the peaks and troughs; Determine the pressure reference range based on the aforementioned reference value; Obtain the pressure at the discharge port of the screw pump to be adjusted; Adjust the screw pump speed according to the relationship between the pressure and the pressure reference range to change the screw pump outlet pressure; The step of adjusting the screw pump speed according to the relationship between the pressure and the pressure reference range includes: When the pressure exceeds the pressure reference range, reduce the speed of the screw pump; When the pressure is less than the pressure reference range, increase the speed of the screw pump; Also includes: After the coating system has been running for a preset time, the pressure fluctuation curve of the screw pump outlet during the third preset cycle without adjustment is obtained again. When the peak and trough of the pressure fluctuation curve at the screw pump outlet in the third preset period exceed the peak and trough of the pressure fluctuation curve at the screw pump outlet in the first preset period, the pressure reference range is adjusted according to the preset proportional coefficient.

2. The method according to claim 1, characterized in that, The coating system includes a buffer tank and, before acquiring the pressure at the screw pump outlet during the first preset cycle when not adjusted, includes: Get the weight of the cache container; Determine whether the trend of weight change within the second preset period conforms to the preset trend.

3. The method according to claim 2, characterized in that, Before obtaining the weight of the buffer jar, the following is also included: The initial weight values ​​of the buffer tank and the initial pressure values ​​of the screw pump are reset to zero when no coating slurry is stored.

4. The method according to claim 1, characterized in that, The coating system further includes a wet film thickness gauge and a dry film thickness gauge, and the method further includes: Obtain the first film thickness fluctuation value from the wet film thickness gauge; Determine whether the first film thickness fluctuation value is within the first preset fluctuation threshold; If so, obtain the second film thickness fluctuation value of the dry film thickness gauge; If not, continue to obtain the pressure at the discharge port of the screw pump to be adjusted, and adjust the speed of the screw pump according to the relationship between the pressure and the pressure reference range.

5. The method according to claim 4, characterized in that, The process of obtaining the second film thickness fluctuation value of the dry film thickness gauge includes: Determine whether the second film thickness fluctuation value is within the second preset fluctuation threshold; If so, maintain the current speed of the screw pump; If not, continue to obtain the pressure at the discharge port of the screw pump to be adjusted, and adjust the speed of the screw pump according to the relationship between the pressure and the pressure reference range.

6. A screw pump pressure regulating device, characterized in that, The device is used in a coating system and includes: The first acquisition module is used to acquire the pressure at the screw pump outlet within the first preset cycle when it is not adjusted, and to obtain the pressure fluctuation curve. The second acquisition module is used to acquire a pressure reference range based on the pressure fluctuation curve; acquiring the pressure reference range based on the pressure fluctuation curve includes: Obtain the peaks and troughs of the pressure fluctuation curve; The baseline value is determined based on the peaks and troughs; Determine the pressure reference range based on the aforementioned reference value; The third acquisition module is used to acquire the pressure at the discharge port of the screw pump to be adjusted. The adjustment module is used to adjust the speed of the screw pump according to the relationship between the pressure and the pressure reference range, thereby changing the discharge port pressure of the screw pump; The step of adjusting the screw pump speed according to the relationship between the pressure and the pressure reference range includes: When the pressure exceeds the pressure reference range, reduce the speed of the screw pump; When the pressure is less than the pressure reference range, increase the speed of the screw pump; Also includes: After the coating system has been running for a preset time, the pressure fluctuation curve of the screw pump outlet during the third preset cycle without adjustment is obtained again. When the peak and trough of the pressure fluctuation curve at the screw pump outlet in the third preset period exceed the peak and trough of the pressure fluctuation curve at the screw pump outlet in the first preset period, the pressure reference range is adjusted according to the preset proportional coefficient.

7. A computer device, characterized in that, include: A memory and a processor are communicatively connected, the memory storing computer instructions, and the processor executing the computer instructions to perform the screw pump pressure regulation method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to perform the screw pump pressure regulation method according to any one of claims 1 to 5.

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