Liquid supply system and liquid supply method

Abstract

The invention discloses a liquid supply system and a liquid supply method. The liquid supply system comprises a liquid supply pipeline and a pressure regulating pipeline, the liquid supply pipeline comprises a solution storage device used for storing coating liquid; the first end of the buffer unit is connected with the solution storage device, and the second end of the buffer unit is used for being connected with an external coating device; the pump set is arranged on a pipeline between the solution storage device and the buffer unit and is used for pumping the coating liquid in the solution storage device into the buffer unit; the pressure regulating pipeline comprises a gas storage device which is used for storing inert gas and is connected with the buffer unit; and the pressure regulating device is arranged on a pipeline between the gas storage device and the buffer unit and is used for regulating the pressure intensity in the buffer unit, so that the buffer unit supplies liquid to the coating device. The flow velocity of the coating liquid at the liquid outlet end of the liquid supply system and the liquid inlet end of the coating device can be quickly adjusted.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid supply, and in particular to a liquid supply system and a liquid supply method. Background Art

[0002] In the field of solar cell manufacturing, slit coating technology is widely used in the preparation of various types of solar cells, such as crystalline silicon perovskite stacked cells and single-junction perovskite cells, because it can achieve high-precision and high-uniformity thin-film coating. Slit coating technology can form a uniform and dense thin film layer on the substrate material by precisely controlling the supply amount and flow rate of the coating liquid, which is crucial to improving the conversion efficiency and stability of solar cells.

[0003] However, in the existing solar cell batch manufacturing scheme, the performance of the liquid supply system often becomes one of the key factors that restrict the potential of slit coating technology. Although traditional syringe pumps or diaphragm pumps can meet the demand for coating liquid supply to a certain extent, their working principle determines that they must reciprocate to suck and discharge liquid and can only work in an intermittent manner. This method not only limits the coating speed, but may also cause fluctuations in the coating liquid during the supply process, affecting the uniformity and accuracy of the coating layer.

[0004] In order to overcome this defect, attempts have been made to use continuous liquid supply equipment such as screw pumps or gear pumps. These devices can achieve continuous discharge of coating liquid through the continuous movement of rotating parts, thereby improving coating efficiency. However, in practical applications, these continuous liquid supply devices face new challenges. Especially in the perovskite slit coating process, due to the need to achieve low flow and high-precision liquid supply, the existing screw pumps or gear pumps are often difficult to meet the requirements in terms of flow control and accuracy. This may not only lead to uneven coating layer thickness, but may also affect the performance and stability of solar cells.

[0005] Therefore, the present application proposes a liquid supply system and a liquid supply method. Summary of the invention

[0006] The object of the present invention is to provide a liquid supply system and a liquid supply method for realizing rapid adjustment of the flow rate of the coating liquid at the liquid outlet end of the liquid supply system and the liquid inlet end of the coating device.

[0007] The purpose of the present invention is achieved by the following technical solutions:

[0008] In one aspect, the present invention provides a liquid supply system, comprising: a liquid supply pipeline and a pressure regulating pipeline;

[0009] The liquid supply pipeline comprises:

[0010] A solution storage device, used for storing the coating solution;

[0011] A buffer unit, wherein a first end of the buffer unit is connected to the solution storage device, and a second end of the buffer unit is used to connect to an external coating device;

[0012] A pump group, the pump group is arranged on the pipeline between the solution storage device and the buffer unit, and is used to pump the coating liquid in the solution storage device into the buffer unit;

[0013] The pressure regulating pipeline comprises:

[0014] A gas storage device, used for storing inert gas and connected to the buffer unit;

[0015] A pressure regulating device is arranged on the pipeline between the gas storage device and the buffer unit, and is used to adjust the pressure in the buffer unit so that the buffer unit supplies liquid to the coating device.

[0016] Furthermore, the voltage regulating device comprises:

[0017] A syringe, an opening of which is connected to the upper portion of the buffer unit;

[0018] A driving unit, the driving unit is connected to the piston of the syringe and drives the piston to move back and forth in the empty cylinder of the syringe;

[0019] A pressure regulating valve, wherein a first end of the pressure regulating valve is connected to the gas storage device, and a second end of the pressure regulating valve is connected to an opening of the syringe and an upper portion of the buffer unit.

[0020] Furthermore, the pressure regulating pipeline also includes:

[0021] Three-way connector, used to connect pipelines;

[0022] A first pipeline, wherein a first end of the first pipeline is connected to a first end of the three-way connector, and a second end of the first pipeline is connected to an upper portion of the buffer unit;

[0023] a second pipeline, wherein a first end of the second pipeline is connected to a second end of the three-way connector, and a second end of the second pipeline is connected to an opening of the syringe;

[0024] A third pipeline, wherein a first end of the third pipeline is connected to the third end of the three-way connector, and a second end of the third pipeline is connected to the pressure regulating valve.

[0025] Furthermore, the liquid supply system also includes:

[0026] A waste liquid recovery device for recovering the coating liquid;

[0027] a first pressure relief pipeline, wherein a first end of the first pressure relief pipeline is connected to the waste liquid recovery device, and a second end of the first pressure relief pipeline is connected to a lower part of the buffer unit;

[0028] a second pressure relief pipeline, wherein a first end of the second pressure relief pipeline is connected to the waste liquid recovery device, and a second end of the second pressure relief pipeline is connected to an upper portion of the buffer unit;

[0029] An emptying pipeline, wherein a first end of the emptying pipeline is connected to the waste liquid recovery device, and a second end of the emptying pipeline is connected to the bottom of the buffer unit.

[0030] Furthermore, the liquid supply system also includes a valve assembly, a filtering device and a detection device;

[0031] The valve assembly comprises:

[0032] a first liquid medicine valve, the first liquid medicine valve being arranged on the first pressure relief pipeline;

[0033] a second liquid medicine valve, the second liquid medicine valve being arranged on the second pressure relief pipeline;

[0034] a fourth liquid medicine valve, the fourth liquid medicine valve being arranged on the third pipeline;

[0035] a third liquid medicine valve, the third liquid medicine valve being arranged on the drain pipeline;

[0036] a fifth liquid medicine valve, the fifth liquid medicine valve being arranged on a pipeline between the buffer unit and the coating device;

[0037] a sixth liquid medicine valve, the sixth liquid medicine valve being arranged on a pipeline between the waste liquid recovery device and the coating device;

[0038] The filtering device comprises:

[0039] a first filter, wherein the first filter is disposed on the third pipeline;

[0040] A degassing filter, wherein the degassing filter is arranged on a pipeline between the buffer unit and the coating device;

[0041] A solution filter, wherein the solution filter is arranged on a pipeline between the solution storage device and the buffer unit;

[0042] The detection device comprises:

[0043] a first pressure sensor, the first pressure sensor being used to detect the pressure on the first pressure relief pipeline;

[0044] a second pressure sensor, the second pressure sensor being used to detect the pressure of the buffer unit;

[0045] A third pressure sensor is used to detect the negative pressure value of the vacuum end of the degassing filter,

[0046] A flow sensor is used to detect the flow rate of the coating liquid at the liquid inlet end of the coating device.

[0047] In a second aspect, the present invention provides a liquid supply method, wherein the liquid supply method is implemented using the above-mentioned liquid supply system;

[0048] The liquid supply method comprises:

[0049] Obtaining target flow rate and current parameters of the liquid supply system;

[0050] The rotation speed of the pump group and the position of the piston of the syringe are adjusted according to the target flow rate and the current parameters so that the flow rate of the coating liquid at the liquid inlet end of the coating device is the target flow rate.

[0051] Further, the current parameters include: the current flow rate of the coating liquid at the liquid inlet end of the coating device;

[0052] The step of adjusting the rotation speed of the pump group and the position of the piston of the syringe according to the target flow rate and the current parameters includes:

[0053] Calculating the flow rate difference between the current flow rate of the coating liquid at the liquid inlet end of the coating device and the target flow rate;

[0054] When the absolute value of the flow rate difference is less than or equal to the first threshold value: in response to the flow rate difference being a negative number, the piston of the syringe is moved toward the open end so that the flow rate of the coating liquid at the liquid inlet end of the coating device is the target flow rate; in response to the flow rate difference being a positive number, the piston of the syringe is moved toward the end so that the flow rate of the coating liquid at the liquid inlet end of the coating device is the target flow rate;

[0055] When the absolute value of the flow rate difference is greater than a first threshold value: in response to the flow rate difference being a negative number, the piston of the syringe is moved to the open end, and the rotation speed of the pump group is increased so that the flow rate of the coating liquid at the liquid inlet end of the coating device is the target flow rate; in response to the flow rate difference being a positive number, the piston of the syringe is moved to the end, and the rotation speed of the pump group is reduced so that the flow rate of the coating liquid at the liquid inlet end of the coating device is the target flow rate.

[0056] Further, the current parameters include: the current pressure value in the buffer;

[0057] When the absolute value of the flow rate difference is less than or equal to a first threshold, the method for determining the moving distance of the piston includes:

[0058] Based on a pre-constructed pressure-flow rate curve, determining a first target pressure value according to the flow rate difference and the current pressure value;

[0059] Calculating a first pressure difference between the current pressure value and the first target pressure value;

[0060] Based on the pre-configured displacement pressure curve, determining the moving distance of the piston according to the first pressure difference;

[0061] The moving distance is less than or equal to half the length of the empty barrel of the syringe.

[0062] Further, the current parameters include: the current position of the piston of the syringe;

[0063] The step of determining the moving distance of the piston according to the first pressure difference based on the pre-configured displacement pressure curve comprises:

[0064] Let the target end be the open end or the end;

[0065] Based on a pre-configured displacement-pressure curve, a proposed distance for the piston to move is determined according to the first pressure difference, wherein the proposed distance is less than or equal to half the length of the empty barrel of the syringe;

[0066] When the distance between the current position of the piston and the target end is less than the planned distance, the distance between the current position and the target end is set as the moving distance, and the speed of the pump group is adjusted;

[0067] When the distance between the current position of the piston and the target end is less than the planned distance, the planned distance is set as the moving distance.

[0068] Further, the current parameters include: the current rotation speed of the pump group and the current pressure value in the buffer;

[0069] The method for determining the speed change value of the pump group includes:

[0070] Let the target end be the open end or the end;

[0071] Based on the pre-constructed displacement pressure curve, according to the distance between the piston and the target end and the current pressure value in the buffer, determine the intermediate pressure value in the buffer after the piston moves;

[0072] Based on a pre-constructed pressure-flow rate curve, determining a second target pressure value according to the flow rate difference and the intermediate pressure value;

[0073] calculating a second pressure difference between the intermediate pressure value and the second target pressure value;

[0074] Based on a pre-configured speed-pressure curve, a speed change value of the pump group is determined according to the second pressure difference and the current speed.

[0075] Compared with the prior art, the beneficial effects of the present invention include at least:

[0076] The present invention forms a stable and controllable coating liquid supply path through the combination of the solution storage device, the buffer unit and the pump group, thereby ensuring the uniformity of the coating thickness. In addition, by setting a pressure regulating pipeline, the system can quickly adjust the pressure in the buffer unit according to the coating requirements, thereby realizing the rapid adjustment of the flow rate of the coating liquid at the liquid outlet of the liquid supply system and the liquid inlet of the coating device.

[0077] The present invention can quickly respond and adjust the system state by acquiring the target flow rate and the current parameters of the liquid supply system (such as the current rotation speed of the pump group, the current position of the piston of the syringe, etc.) in real time. Furthermore, by adjusting the rotation speed of the pump group and the piston position of the syringe, the dual response mechanism is realized to quickly and accurately control the flow rate of the coating liquid, so that the flow rate of the coating liquid at the liquid inlet end of the coating device quickly and accurately reaches the preset target value. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] Figure 1 It is a structural schematic diagram of a liquid supply system according to an embodiment of the present invention.

[0079] Figure 2 It is a flow chart of a liquid supply method according to an embodiment of the present invention.

[0080] In the figure: 1. Pump group; 2. First liquid medicine valve; 3. First pressure sensor; 4. Pressure regulating valve; 5. Fourth liquid medicine valve; 6. First filter; 7. Second pressure sensor; 8. Syringe; 9. Degassing filter; 10. Third pressure sensor; 11. Flow sensor; 12. Fifth liquid medicine valve; 13. Coating device; 14. Sixth liquid medicine valve; 15. Second liquid medicine valve; 16. Buffer unit; 17. Third liquid medicine valve; 18. Solution filter; 21. Solution storage device; 22. Waste liquid recovery device; 31. Gas storage device; 32. Vacuum source. DETAILED DESCRIPTION

[0081] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete and to fully convey the concepts of example embodiments to those skilled in the art. The same reference numerals in the figures represent the same or similar structures, and thus their repeated description will be omitted.

[0082] The words expressing positions and directions described in the present invention are all explained with reference to the accompanying drawings as examples, but they can be changed as needed, and all such changes are included in the protection scope of the present invention.

[0083] The present invention provides a liquid supply system that can simultaneously meet the requirements of continuous liquid supply, small flow rate and high precision, and can quickly adjust the flow rate of the coating liquid at the liquid outlet of the liquid supply system and the liquid inlet of the coating device 13. Generally, the flow rate of the coating liquid at the liquid outlet of the liquid supply system is equal to the flow rate of the coating liquid at the liquid inlet of the coating device 13.

[0084] In order to achieve continuous, stable and high-precision supply of the coating liquid, the liquid supply system of the present invention includes: a liquid supply pipeline and a pressure regulating pipeline. Further, in order to improve the safety and environmental protection of the system, the liquid supply system of the present invention may also include: a waste liquid recovery device 22, a first pressure relief pipeline (not shown), a second pressure relief pipeline (not shown) and an emptying pipeline (not shown). Further, in order to improve the reliability and stability of the system, the liquid supply system of the present invention may also include: a valve assembly, a filtering device and a detection device.

[0085] refer to Figure 1 In order to realize continuous liquid supply, the liquid supply pipeline of the present invention includes: a solution storage device 21, a buffer unit 16 and a pump group 1. Among them, the solution storage device 21 is used to store the coating liquid. Further, the liquid supply pipeline of the present invention can also include a first liquid path (not shown) and a second liquid path (not shown).

[0086] The first end of the buffer unit 16 of the present invention is connected to the solution storage device 21, and the second end of the buffer unit 16 is used to connect to the external coating device 13. The pump group 1 is arranged on the pipeline between the solution storage device 21 and the buffer unit 16, and is used to pump the coating liquid in the solution storage device 21 into the buffer unit 16. When used, the first end of the first liquid circuit is connected to the solution storage device 21, and the second end of the first liquid circuit is connected to the first end of the buffer unit 16. The first end of the second liquid circuit is connected to the second end of the buffer unit 16, and the second end of the second liquid circuit is connected to the external coating device 13. The pump group 1 is arranged on the first liquid circuit. In actual application, the buffer unit 16 is a buffer tank. It can be seen that the solution storage device 21 ensures sufficient supply of the coating liquid; the buffer unit 16 plays a role in smoothing the flow of the coating liquid and reducing pressure fluctuations; the pump group 1 accurately controls the conveying speed of the coating liquid according to demand, thereby ensuring the stability of the coating liquid supply.

[0087] refer to Figure 1 In order to quickly adjust the flow rate of the coating liquid at the liquid outlet of the liquid supply system and the liquid inlet of the coating device 13, the pressure regulating pipeline of the present invention includes: a gas storage device 31 and a pressure regulating device. Among them, the gas storage device 31 is used to store inert gas (such as nitrogen). Further, the pressure regulating pipeline of the present invention can also include: a three-way connector, a first pipeline, a second pipeline and a third pipeline.

[0088] The pressure regulating device of the present invention is arranged on the pipeline between the gas storage device 31 and the buffer unit 16, and is used to adjust the pressure in the buffer unit 16 so that the buffer unit 16 supplies liquid to the coating device 13. When in use, the coating liquid in the buffer unit 16 divides the buffer unit 16 into an upper part and a lower part, the upper part of the buffer unit 16 corresponds to the part without the coating liquid, and the lower part of the buffer unit 16 corresponds to the part with the coating liquid. In actual application, when the system is working, the actual liquid level of the coating liquid in the buffer unit 16 is greater than the first liquid level and less than the second liquid level. The upper part of the buffer unit 16 corresponds to the part above the second liquid level of the buffer unit 16, and the lower part of the buffer unit 16 corresponds to the part below the first liquid level of the buffer unit 16.

[0089] refer to Figure 1 In order to achieve rapid and accurate regulation of the pressure in the buffer unit 16 , the pressure regulating device of the present invention includes: a syringe 8 , a driving unit (not shown) and a pressure regulating valve 4 .

[0090] The first end of the pressure regulating valve 4 of the present invention is connected to the gas storage device 31, and the second end of the pressure regulating valve 4 is connected to the opening of the syringe 8 (not shown) and the upper part of the buffer unit 16; the opening of the syringe 8 is connected to the upper part of the buffer unit 16; the driving part is connected to the piston of the syringe 8 (not shown), and drives the piston to move back and forth in the empty cylinder (not shown) of the syringe 8. The driving part can be a motor. Further, the first end of the first pipeline of the present invention is connected to the first end of the three-way connector, and the second end of the first pipeline is connected to the upper part of the buffer unit 16; the first end of the second pipeline is connected to the second end of the three-way connector, and the second end of the second pipeline is connected to the opening of the syringe 8; the first end of the third pipeline is connected to the third end of the three-way connector, and the second end of the third pipeline is connected to the second end of the pressure regulating valve 4. When used, the pressure regulating valve 4 is used to connect the gas storage device 31 to provide the necessary inert gas for the pressure regulation process of the system, thereby enhancing the reliability and stability of the system. In actual application, the syringe 8 serves as a medium for pressure regulation. The piston is driven back and forth by the driving part to change the pressure in the buffer unit 16, thereby quickly changing the flow rate of the coating liquid at the outlet of the buffer unit 16, and then quickly adjusting the flow rate of the coating liquid at the liquid outlet end of the liquid supply system and the liquid inlet end of the coating device 13.

[0091] refer to Figure 1 In order to achieve effective treatment of waste liquid and safe pressure relief of the system, the first end of the first pressure relief pipeline of the present invention is connected to the waste liquid recovery device 22, and the second end of the first pressure relief pipeline is connected to the lower part of the buffer unit 16. Further, the first end of the second pressure relief pipeline of the present invention is connected to the waste liquid recovery device 22, and the second end of the second pressure relief pipeline is connected to the upper part of the buffer unit 16. Further, the first end of the emptying pipeline of the present invention is connected to the waste liquid recovery device 22, and the second end of the emptying pipeline is connected to the bottom of the buffer unit 16.

[0092] refer to Figure 1 In order to make the control of the system more flexible and accurate, the valve assembly of the present invention includes: a first liquid medicine valve 2, a second liquid medicine valve 15, a third liquid medicine valve 17, a fourth liquid medicine valve 5, a fifth liquid medicine valve 12 and a sixth liquid medicine valve 14. Further, the valve assembly of the present invention includes a seventh liquid medicine valve (not shown).

[0093] The first liquid medicine valve 2 of the present invention is arranged on the first pressure relief pipeline; the second liquid medicine valve 15 is arranged on the second pressure relief pipeline; the third liquid medicine valve 17 is arranged on the emptying pipeline; the fourth liquid medicine valve 5 is arranged on the third pipeline; the fifth liquid medicine valve 12 is arranged on the pipeline between the buffer unit 16 and the coating device 13; the sixth liquid medicine valve 14 is arranged on the pipeline between the waste liquid recovery device 22 and the coating device 13; the seventh liquid medicine valve is arranged on the first pipeline.

[0094] refer to Figure 1 In order to ensure the purity and quality of the coating liquid, the filtering device of the present invention includes: a first filter 6, a degassing filter 9 and a solution filter 18.

[0095] The first filter 6 of the present invention is arranged on the third pipeline; the degassing filter 9 is arranged on the pipeline between the buffer unit 16 and the coating device 13; and the solution filter 18 is arranged on the pipeline between the solution storage device 21 and the buffer unit 16.

[0096] refer to Figure 1 In order to monitor the key parameters of the system in real time, the detection device of the present invention includes: a first pressure sensor 3, a second pressure sensor 7, a third pressure sensor 10, and a flow sensor 11.

[0097] The flow sensor 11 of the present invention is used to detect the flow rate of the coating liquid at the liquid inlet end of the coating device 13; the first pressure sensor 3 is used to detect the pressure on the first pressure relief pipeline; the second pressure sensor 7 is used to detect the pressure of the buffer unit 16; the third pressure sensor 10 is used to detect the negative pressure value of the vacuum end of the degassing filter 9. When in use, the vacuum end of the degassing filter 9 is connected to an external vacuum source 32.

[0098] In summary, the present invention forms a stable and controllable coating liquid supply path through the combination of the solution storage device 21, the buffer unit 16 and the pump group 1, thereby ensuring the uniformity of the coating thickness. In addition, by setting a pressure regulating pipeline, the system can quickly adjust the pressure in the buffer unit 16 according to the coating requirements, thereby realizing the rapid adjustment of the flow rate of the coating liquid at the liquid outlet of the liquid supply system and the liquid inlet of the coating device 13.

[0099] In addition, the present invention also provides a liquid supply method. The liquid supply method of the present invention can be implemented using the above-mentioned liquid supply system. Specifically, by acquiring the target flow rate and the current parameters of the liquid supply system (such as the current rotation speed of the pump group 1, the current position of the piston of the syringe 8, etc.) in real time, the system state is quickly responded and adjusted, so that the flow rate of the coating liquid at the liquid inlet end of the coating device 13 quickly and accurately reaches the preset target value.

[0100] refer to Figure 2 The liquid supply method of the present invention includes: step S1 and step S2.

[0101] Step S1: Obtain the target flow rate and current parameters of the liquid supply system.

[0102] When applied, the current parameters include: the current flow rate of the coating liquid at the liquid inlet end of the coating device 13. Further, the current parameters may also include: the current pressure value in the buffer. Further, the current parameters may also include: the current position of the piston. In addition, the current parameters may also include: the current rotation speed of the pump group 1.

[0103] Step S2: adjusting the rotation speed of the pump group 1 and the position of the piston of the syringe 8 according to the target flow rate and current parameters, so that the flow rate of the coating liquid at the liquid inlet end of the coating device 13 is the target flow rate.

[0104] When used, by adjusting the rotation speed of the pump group 1 and the piston position of the syringe 8, a dual response mechanism is implemented to quickly and accurately control the flow rate of the coating liquid. This not only improves the stability and uniformity of the coating process, but also reduces energy consumption and costs, and improves production efficiency.

[0105] When applied, step S2 of the present invention includes: step S21-step S23. By calculating the flow rate difference and adopting different adjustment strategies according to the absolute value thereof, the flow rate of the coating liquid is adjusted quickly and accurately. This not only improves the response speed of the system, but also ensures the stability and quality of the coating process.

[0106] Step S21: Calculate the flow rate difference between the current flow rate of the coating liquid at the liquid inlet end of the coating device 13 and the target flow rate.

[0107] Step S22: When the absolute value of the flow rate difference is less than or equal to the first threshold value: In response to the flow rate difference being a negative number, the piston of the syringe 8 is moved toward the open end, so that the flow rate of the coating liquid at the liquid inlet end of the coating device 13 is the target flow rate. In response to the flow rate difference being a positive number, the piston of the syringe 8 is moved toward the end, so that the flow rate of the coating liquid at the liquid inlet end of the coating device 13 is the target flow rate.

[0108] When used, the piston has an open end and a tail end that are arranged opposite to each other, the open end corresponds to a region adjacent to the opening, and the tail end corresponds to a region accommodating the piston rod.

[0109] Furthermore, in step S22 of the present invention, the method for determining the moving distance of the piston includes: step S221 to step S224.

[0110] Step S221: Based on the pre-constructed pressure-flow rate curve, determine the first target pressure value according to the flow rate difference and the current pressure value.

[0111] When applied, the pressure-flow rate curve is constructed based on the correlation between the pressure value in the buffer and the flow rate of the coating liquid at the liquid inlet end of the coating device 13. In actual application, when the liquid level of the coating liquid in the buffer is greater than the first liquid level, the greater the pressure value in the buffer, the greater the flow rate of the coating liquid at the liquid inlet end of the coating device 13.

[0112] Step S222: Calculate a first pressure difference between the current pressure value and the first target pressure value.

[0113] Step S223: Based on the pre-configured displacement-pressure curve, determine the moving distance of the piston according to the first pressure difference.

[0114] When applied, the displacement-pressure curve is constructed based on the correlation between the pressure value in the buffer and the displacement of the piston. In actual application, the greater the distance the piston moves toward the open end, the greater the pressure value in the buffer; the greater the distance the piston moves toward the end, the smaller the pressure value in the buffer.

[0115] Furthermore, step S223 of the present invention includes: step S2231-step S2233.

[0116] Step S2231: Set the target end to be an open end or an end.

[0117] In application, when the flow rate difference is greater than 0, the target end is the end; when the flow rate difference is less than 0, the target end is the open end. In actual application, when the flow rate difference is equal to 0, the piston does not move.

[0118] Step S2232: Based on the pre-configured displacement-pressure curve, determine the proposed distance of piston movement according to the first pressure difference.

[0119] When used, the proposed distance is less than or equal to half the length of the empty barrel of the syringe 8. In actual use, when the system is started, the initial position of the piston is located in the middle of the empty barrel.

[0120] Step S2233: When the distance between the current position of the piston and the target end is less than the planned distance, the distance between the current position and the target end is set as the moving distance, and the rotation speed of the pump group 1 is adjusted.

[0121] When applied, when the flow rate difference is greater than 0, the rotation speed of the pump group 1 is reduced, and when the flow rate difference is less than 0, the rotation speed of the pump group 1 is increased. For the method of determining the speed change value of the pump group 1, refer to the subsequent steps S231-S235. In some other embodiments, the piston can be reset first, the piston is moved to the middle of the empty cylinder, and then the proposed distance is set as the moving distance. Specifically, the seventh liquid medicine valve is closed, the fourth liquid medicine valve 5 is opened, and the pressure regulating valve 4 is used to adjust the pressure in the third pipeline and the second pipeline, so that the piston moves to the middle of the empty cylinder, and then the seventh liquid medicine valve is opened, and the fourth liquid medicine valve 5 is closed.

[0122] Step S2234: When the distance between the current position of the piston and the target end is less than the planned distance, the planned distance is set as the moving distance.

[0123] Step S224 : The moving distance is less than or equal to half the length of the empty barrel of the syringe 8 .

[0124] In application, when the system is started, the initial position of the piston is located in the middle of the empty cylinder. In actual application, the piston can be moved at a preset moving speed so that the pressure value in the buffer changes rapidly and steadily, thereby making the flow rate of the coating liquid at the liquid inlet end of the coating device 13 change rapidly and steadily, which can ensure the coating quality.

[0125] Step S23: When the absolute value of the flow rate difference is greater than the first threshold value: In response to the flow rate difference being a negative number, the piston of the syringe 8 is moved to the open end, and the rotation speed of the pump group 1 is increased, so that the flow rate of the coating liquid at the liquid inlet end of the coating device 13 is the target flow rate. In response to the flow rate difference being a positive number, the piston of the syringe 8 is moved to the end, and the rotation speed of the pump group 1 is reduced, so that the flow rate of the coating liquid at the liquid inlet end of the coating device 13 is the target flow rate.

[0126] The piston is moved to the target end at a preset moving speed to compensate for the defects that the first liquid circuit and the second liquid circuit are too long, and the adjustment of the rotation speed of the pump group 1 cannot be timely reflected in the flow rate of the coating liquid at the liquid outlet of the liquid supply system and the liquid inlet of the coating device 13. In actual application, in order to make full use of the volume of the empty cylinder, when the absolute value of the flow rate difference is greater than the second threshold value, the piston is first end-positioned and moved to the non-target end of the empty cylinder, and then the piston is moved to the target end at a preset moving speed, and then the rotation speed of the pump group 1 is adjusted to adjust the flow rate of the coating liquid at the liquid inlet end of the coating device 13 to the target flow rate as soon as possible. Among them, the second threshold is greater than twice the first threshold. Specifically, the seventh liquid medicine valve is closed, the fourth liquid medicine valve 5 is opened, and the pressure regulating valve 4 is used to adjust the pressure in the third pipeline and the second pipeline, so that the piston moves to the non-target end of the empty cylinder, and then the seventh liquid medicine valve is opened and the fourth liquid medicine valve 5 is closed.

[0127] Furthermore, in step S23 of the present invention, the method for determining the speed change value of the pump group 1 includes: steps S231 to S235.

[0128] Step S231: Set the target end to be an open end or an end.

[0129] In application, when the flow rate difference is greater than 0, the target end is the end; when the flow rate difference is less than 0, the target end is the open end. In actual application, when the flow rate difference is equal to 0, the piston does not move, and the speed of pump group 1 is not adjusted.

[0130] Step S232: Based on the pre-constructed displacement pressure curve, according to the distance between the piston and the target end and the current pressure value in the buffer, determine the intermediate pressure value in the buffer after the piston moves.

[0131] Step S233: Based on the pre-constructed pressure-flow rate curve, determine the second target pressure value according to the flow rate difference and the intermediate pressure value.

[0132] Step S234: Calculate a second pressure difference between the intermediate pressure value and the second target pressure value.

[0133] Step S235: Based on the pre-configured speed-pressure curve, the speed change value of the pump group 1 is determined according to the second pressure difference and the current speed.

[0134] When applied, the speed-pressure curve is constructed based on the correlation between the speed of pump group 1 and the pressure value in the buffer. In actual application, when other conditions remain unchanged, the greater the speed of pump group 1, the greater the pressure value in the buffer.

[0135] In order to further fine-tune the flow rate of the coating liquid at the liquid outlet of the liquid supply system and the liquid inlet of the coating device 13, so that the flow rate of the coating liquid at the liquid inlet of the coating device 13 is the target flow rate, in the process of adjusting the rotation speed of the pump group 1, the seventh liquid valve is closed, the fourth liquid valve 5 is opened, and the pressure in the third pipeline and the second pipeline is adjusted by the pressure regulating valve 4, so that the piston moves to the middle of the empty cylinder, and then the seventh liquid valve is opened and the fourth liquid valve 5 is closed. After adjusting the rotation speed of the pump group 1, the position of the piston is further adjusted so that the flow rate of the coating liquid at the liquid inlet of the coating device 13 is equal to the target flow rate.

[0136] The liquid supply method of the present invention further comprises steps (1) to (9).

[0137] Step (1): Perfusion solution

[0138] The coating liquid in the solution storage device 21 is pumped into the buffer, so that the liquid level in the buffer is a preset height; then, the coating liquid in the buffer enters the coating device 13, and the fifth liquid valve 12 is closed.

[0139] Step (2): Constant pressure

[0140] The fourth liquid medicine valve 5 is opened, and the pressure in the buffer is adjusted to a preset pressure by adjusting the pressure regulating valve 4; then the piston of the syringe 8 is adjusted to the middle position of the empty cylinder, and the fourth liquid medicine valve 54 is closed.

[0141] Step (3): Liquid supply

[0142] Open the fifth liquid valve 12 and start the pump group 1, so that the coating liquid in the solution storage device 21 is pumped into the buffer at a preset speed, the coating liquid in the buffer flows into the coating device 13 at a preset speed, and the coating die head of the coating device 13 discharges liquid at a preset speed.

[0143] Step (4): Exhaust of solution filter 18

[0144] When installing or replacing the solution filter 18, open the first liquid valve 2 to allow the coating liquid in the buffer tank to flow into the waste liquid recovery device 22 through the solution filter 18. After no bubbles are discharged from the solution filter 18 and the first pressure relief pipeline is filled with coating liquid, close the first liquid valve 2.

[0145] Step (5): Depressurization of the solution filter 18:

[0146] As the usage time increases, the filter membrane in the solution filter 18 will gradually become clogged, resulting in increased flow resistance and increased pressure at the open end:

[0147] When the pressure value detected by the first pressure sensor 3 is greater than the first pressure limit value, a first troubleshooting alarm signal is issued;

[0148] When the pressure value detected by the first pressure sensor 3 is continuously greater than the first pressure limit value within the second preset time, the first liquid medicine valve 2 is opened to release the pressure in the liquid circuit to prevent damage to components.

[0149] Step (6): Buffer exhaust pressure relief

[0150] In response to the pressure value in the buffer being greater than the first pressure limit value, issuing a second troubleshooting alarm signal;

[0151] In response to the pressure value in the buffer being continuously greater than the first pressure limit value within the second preset time, the second liquid medicine valve 15 is opened to exhaust and depressurize the buffer;

[0152] In response to the pressure value in the buffer being greater than the second pressure limit value, the second liquid medicine valve 15 is opened to exhaust and depressurize the buffer; wherein the second pressure limit value is greater than the first pressure limit value.

[0153] Step (7): Draining the buffer

[0154] The third liquid medicine valve 17 is opened, and the fourth liquid medicine valve 5 is opened to drain the buffer.

[0155] Step (8): Degassing filter 9 alarm

[0156] When the pressure value detected by the third pressure sensor 103 is greater than the third pressure limit value, a third troubleshooting alarm signal is issued, for example, to check the vacuum source 32 .

[0157] Step (9): Piston reset

[0158] The pressure regulating device comprises a syringe 8, the empty barrel of the syringe 8 comprises an opening end and a tail end which are arranged opposite to each other, and the opening end is connected to the opening of the syringe 8 through the opening;

[0159] In response to the piston of the syringe 8 being continuously located at the open end or the end of the empty barrel of the syringe 8 within the first preset time, the seventh medicine liquid valve is closed, the fourth medicine liquid valve 5 is opened, and the pressure in the third pipeline and the second pipeline is adjusted by the pressure regulating valve 4 to move the piston to the middle of the empty barrel, and then the seventh medicine liquid valve is opened and the fourth medicine liquid valve 5 is closed.

[0160] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, substitute and modify the above embodiments within the scope of the invention without departing from the principles and purpose of the present invention. All such changes should fall within the scope of protection of the claims of the present invention.

Claims

1. A liquid supply system, characterized in that: include: Liquid supply pipeline and pressure regulating pipeline; The liquid supply pipeline comprises: A solution storage device (21) for storing a coating solution; A buffer unit (16), wherein a first end of the buffer unit (16) is connected to the solution storage device (21), and a second end of the buffer unit (16) is used to connect to an external coating device (13); A pump group (1), the pump group (1) being arranged on a pipeline between the solution storage device (21) and the buffer unit (16), and being used for pumping the coating liquid in the solution storage device (21) into the buffer unit (16); The pressure regulating pipeline comprises: A gas storage device (31), used for storing inert gas and connected to the buffer unit (16); A pressure regulating device, the pressure regulating device is arranged on the pipeline between the gas storage device (31) and the buffer unit (16), and is used to adjust the pressure in the buffer unit (16) so that the buffer unit (16) supplies liquid to the coating device (13).

2. The liquid supply system according to claim 1, characterized in that: The voltage regulating device comprises: A syringe (8), wherein an opening of the syringe (8) is connected to an upper portion of the buffer unit (16); A driving unit, the driving unit being connected to the piston of the syringe (8) and driving the piston to move back and forth in the empty cylinder of the syringe (8); A pressure regulating valve (4), wherein a first end of the pressure regulating valve (4) is connected to the gas storage device (31), and a second end of the pressure regulating valve (4) is connected to an opening of the syringe (8) and an upper portion of the buffer unit (16).

3. The liquid supply system according to claim 2, characterized in that: The pressure regulating pipeline also includes: Three-way connector, used to connect pipelines; a first pipeline, wherein a first end of the first pipeline is connected to a first end of the three-way connector, and a second end of the first pipeline is connected to an upper portion of the buffer unit (16); a second pipeline, wherein a first end of the second pipeline is connected to a second end of the three-way connector, and a second end of the second pipeline is connected to an opening of the syringe (8); A third pipeline, wherein a first end of the third pipeline is connected to the third end of the three-way connector, and a second end of the third pipeline is connected to the pressure regulating valve (4).

4. The liquid supply system according to claim 1, characterized in that: The liquid supply system also includes: A waste liquid recovery device (22) for recovering the coating liquid; a first pressure relief pipeline, wherein a first end of the first pressure relief pipeline is connected to the waste liquid recovery device (22), and a second end of the first pressure relief pipeline is connected to the lower part of the buffer unit (16); a second pressure relief pipeline, wherein a first end of the second pressure relief pipeline is connected to the waste liquid recovery device (22), and a second end of the second pressure relief pipeline is connected to an upper portion of the buffer unit (16); An emptying pipeline, wherein a first end of the emptying pipeline is connected to the waste liquid recovery device (22), and a second end of the emptying pipeline is connected to the bottom of the buffer unit (16).

5. The liquid supply system according to claim 3, characterized in that: The liquid supply system also includes a valve assembly, a filtering device and a detection device; The valve assembly comprises: A first liquid medicine valve (2), wherein the first liquid medicine valve (2) is arranged on the first pressure relief pipeline; A second liquid medicine valve (15), wherein the second liquid medicine valve (15) is arranged on the second pressure relief pipeline; a fourth liquid medicine valve (5), the fourth liquid medicine valve (5) being arranged on the third pipeline; a third liquid medicine valve (17), the third liquid medicine valve (17) being arranged on the drain pipeline; a fifth liquid medicine valve (12), the fifth liquid medicine valve (12) being arranged on a pipeline between the buffer unit (16) and the coating device (13); a sixth liquid medicine valve (14), the sixth liquid medicine valve (14) being arranged on a pipeline between the waste liquid recovery device (22) and the coating device (13); The filtering device comprises: a first filter (6), the first filter (6) being arranged on the third pipeline; a degassing filter (9), wherein the degassing filter (9) is arranged on a pipeline between the buffer unit (16) and the coating device (13); a solution filter (18), wherein the solution filter (18) is arranged on a pipeline between the solution storage device (21) and the buffer unit (16); The detection device comprises: A first pressure sensor (3), the first pressure sensor (3) being used to detect the pressure on the first pressure relief pipeline; a second pressure sensor (7), the second pressure sensor (7) being used to detect the pressure of the buffer unit (16); a third pressure sensor (10), the third pressure sensor (10) being used to detect the negative pressure value at the vacuum end of the degassing filter (9), A flow sensor (11), wherein the flow sensor (11) is used to detect the flow rate of the coating liquid at the liquid inlet end of the coating device (13).

6. A liquid supply method, characterized in that: The liquid supply method is implemented by using the liquid supply system according to any one of claims 1 to 5; The liquid supply method comprises: Obtaining target flow rate and current parameters of the liquid supply system; The rotation speed of the pump group (1) and the position of the piston of the syringe (8) are adjusted according to the target flow rate and current parameters so that the flow rate of the coating liquid at the liquid inlet end of the coating device (13) reaches the target flow rate.

7. The liquid supply method according to claim 6, characterized in that: The current parameters include: the current flow rate of the coating liquid at the liquid inlet end of the coating device (13); The step of adjusting the rotation speed of the pump group (1) and the position of the piston of the syringe (8) according to the target flow rate and the current parameters comprises: Calculating the flow rate difference between the current flow rate of the coating liquid at the liquid inlet end of the coating device (13) and the target flow rate; When the absolute value of the flow rate difference is less than or equal to a first threshold value: in response to the flow rate difference being a negative number, the piston of the syringe (8) is moved toward the open end so that the flow rate of the coating liquid at the liquid inlet end of the coating device (13) is the target flow rate; in response to the flow rate difference being a positive number, the piston of the syringe (8) is moved toward the end so that the flow rate of the coating liquid at the liquid inlet end of the coating device (13) is the target flow rate; When the absolute value of the flow rate difference is greater than a first threshold value: in response to the flow rate difference being a negative number, the piston of the syringe (8) is moved to the open end, and the rotation speed of the pump group (1) is increased so that the flow rate of the coating liquid at the liquid inlet end of the coating device (13) is the target flow rate; in response to the flow rate difference being a positive number, the piston of the syringe (8) is moved to the end, and the rotation speed of the pump group (1) is reduced so that the flow rate of the coating liquid at the liquid inlet end of the coating device (13) is the target flow rate.

8. The liquid supply method according to claim 7, characterized in that: The current parameters include: the current pressure value in the buffer; When the absolute value of the flow rate difference is less than or equal to a first threshold, the method for determining the moving distance of the piston includes: Based on a pre-constructed pressure-flow rate curve, determining a first target pressure value according to the flow rate difference and the current pressure value; Calculating a first pressure difference between the current pressure value and the first target pressure value; Based on the pre-configured displacement pressure curve, determining the moving distance of the piston according to the first pressure difference; The moving distance is less than or equal to half the length of the empty barrel of the syringe (8).

9. The liquid supply method according to claim 8, characterized in that: The step of determining the moving distance of the piston according to the first pressure difference based on the pre-configured displacement pressure curve comprises: Let the target end be the open end or the end; Based on a pre-configured displacement pressure curve, a proposed distance for the piston to move is determined according to the first pressure difference, wherein the proposed distance is less than or equal to half the length of the empty barrel of the syringe (8); When the distance between the current position of the piston and the target end is smaller than the planned distance, the distance between the current position and the target end is set as the moving distance, and the rotation speed of the pump group (1) is adjusted; When the distance between the current position of the piston and the target end is less than the planned distance, the planned distance is set as the moving distance.

10. The liquid supply method according to claim 7, characterized in that: The current parameters include: the current rotation speed of the pump group (1) and the current pressure value in the buffer; The method for determining the speed change value of the pump group (1) comprises: Let the target end be the open end or the end; Based on the pre-constructed displacement pressure curve, according to the distance between the piston and the target end and the current pressure value in the buffer, determine the intermediate pressure value in the buffer after the piston moves; Based on a pre-constructed pressure-flow rate curve, determining a second target pressure value according to the flow rate difference and the intermediate pressure value; calculating a second pressure difference between the intermediate pressure value and the second target pressure value; Based on a pre-configured speed-pressure curve, a speed change value of the pump group (1) is determined according to the second pressure difference and the current speed.

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