A control system, method, and medium for automatic and safe feeding of lithium sand

Abstract

The present invention relates to a control system, method and medium for automatic and safe feeding of lithium sand. The system includes: a main device including a storage bin, a discharging valve and a reaction kettle; a feeding assembly including a weighing detection unit, a temperature detection unit and a feeding control valve; a protective gas assembly including a protective gas pressure detection unit and a protective gas regulating valve; a tail gas assembly including a tail gas pressure detection unit and a tail gas regulating valve; and a controller that realizes one or more operations among controlling the feeding amount of lithium sand, controlling the protective gas during the feeding process, and controlling the tail gas of the reaction kettle during the feeding process according to the acquired different detection information, and implements safety interlock logic control by maintaining a certain pressure difference between the tail gas and the protective gas. The present invention performs automatic optimization and precise control on the discharging of the storage bin during the feeding process, and at the same time considers the precise control of the safety protective gas assembly and the tail gas assembly, realizing safe and efficient unmanned operation and intelligent management while meeting safety, product quality and production output.

Description

Technical Field

[0001] The invention relates to the technical field of lithium battery production, and in particular to a control method for automatic and safe addition of lithium sand. Background Art

[0002] Lithium (Li) is the lightest active metal in nature. It is very soft and can spontaneously combust in oxygen and air. It can easily react with water to generate hydrogen. Due to its excellent properties, lithium is widely used in high-energy lithium batteries and controlled thermonuclear reactions. However, lithium is flammable, explosive and corrosive in production, storage, movement and use. Therefore, lithium is stored in paraffin oil to make lithium sand, which is easy to store, move and use.

[0003] Lithium sand feeding is one of the key processes in the production of lithium batteries. According to the process requirements, the lithium sand in the silo must be added to the reactor at a uniform speed and safely within the specified time in a safe environment by adjusting the feeding control valve.

[0004] For safety reasons, lithium sand is currently mainly added by manual intermittent feeding, but manual operation will inevitably bring the following disadvantages:

[0005] (1) The production process is extensive and poorly controllable. The confirmation of the safety critical point of the lithium sand reaction and the control of the amount of feed are completely dependent on the subjectivity and experience of the operator. Insufficient operating experience is particularly likely to cause production safety accidents.

[0006] (2) The production environment is harsh, with flammable, explosive, corrosive and other harsh environments, which are not conducive to the health of on-site feeding operators.

[0007] (3) Manual operation makes it difficult to control the amount and time of feeding, kettle temperature and pressure, which causes the process indicators to fluctuate, seriously affecting production safety and product quality and output.

[0008] (4) At present, due to the inherent accuracy requirements of automatic control equipment, such as conventional weighing instruments, regulating valves, etc. and complete sets of feeding equipment can only meet the occasions with low feeding accuracy requirements, and cannot meet the applications with high safety and product quality requirements of automatic lithium sand feeding.

[0009] (5) Although a small number of chemical companies have adopted automatic feeding of specific process equipment and added automation links in some processes, they still cannot meet the requirements of automatic safe and accurate feeding of lithium sand and lack batch management and safety management.

[0010] In view of this, improving the production automation of lithium sand and solving the problem of safe feeding control of lithium sand are fully in line with the current development needs of the lithium battery industry. Summary of the invention

[0011] 1. Technical issues to be resolved

[0012] In view of the above-mentioned disadvantages and deficiencies of the prior art, the present invention provides a control system, method and medium for automatic and safe feeding of lithium sand, which solves the technical problem that the existing lithium sand feeding process relies on manual participation.

[0013] (II) Technical solutions

[0014] In order to achieve the above object, the main technical solutions adopted by the present invention include:

[0015] In a first aspect, an embodiment of the present invention provides a control system for automatic and safe feeding of lithium sand, the control system comprising:

[0016] A main device, the main device comprising a storage bin, a discharging valve and a reaction kettle connected in sequence;

[0017] A feeding assembly, the feeding assembly comprising a weighing detection unit arranged on the storage bin, a temperature detection unit arranged on the reaction kettle, and a feeding control valve arranged between the discharging valve and the reaction kettle;

[0018] A protective gas assembly, the protective gas assembly comprising a protective gas pressure detection unit arranged on the storage bin and a protective gas regulating valve arranged at an inlet / outlet of the storage bin;

[0019] An exhaust gas assembly, the exhaust gas assembly comprising an exhaust gas pressure detection unit arranged on the reaction kettle, an exhaust gas regulating valve arranged at an inlet / outlet of the reaction kettle; and,

[0020] A control assembly, the control assembly being respectively connected to the weighing detection unit, the temperature detection unit, the protective gas pressure detection unit, the exhaust gas pressure detection unit, the feeding control valve, the protective gas regulating valve and the exhaust gas regulating valve, so as to perform one or more operations among lithium sand feeding control, storage bin protective gas control and reaction kettle exhaust gas control within corresponding time periods according to the acquired different detection information, and implement safety interlock logic control by maintaining a certain pressure difference between the exhaust gas and the protective gas.

[0021] Optionally, the weighing detection unit comprises: a weighing detection sensor with an accuracy of not less than one ten-thousandth; and the feeding control valve comprises a V-type on-off valve and a pneumatic valve positioner.

[0022] Optionally, the control assembly comprises:

[0023] A feeding control unit respectively connected to the feeding control valve and the weighing detection unit;

[0024] A temperature control unit respectively connected to the feeding control unit and the temperature detection unit;

[0025] A protective gas pressure control unit respectively connected to the protective gas pressure detection unit and the protective gas regulating valve;

[0026] An exhaust gas pressure control unit respectively connected to an exhaust gas pressure detection unit and an exhaust gas regulating valve;

[0027] A differential pressure control unit respectively connected to a protective gas pressure detection unit and an exhaust gas pressure detection unit;

[0028] A logic control unit respectively connected to a discharging valve, a feeding control unit, and a differential pressure control unit, the logic control unit is used to issue sequential logic control instructions and safety interlock logic control instructions including lithium sand feeding, exhaust gas, and protective gas; and,

[0029] An algorithm control unit respectively connected to a feeding control unit, a temperature control unit, a protective gas pressure control unit, and a logic control unit, the algorithm control unit is used to obtain the instructions issued by the logic control unit and call a pre-deployed algorithm model to control the corresponding control units.

[0030] Optionally, the sequential logic control instructions issued by the logic control unit are used to indicate the following operations:

[0031] During the initial feeding process, the sequential logic control instructions instruct the feeding control unit to control the feeding amount through a feeding control valve based on the weight of lithium sand detected by a weighing detection unit;

[0032] When the lithium sand reaction process reaches a safety critical point during feeding, the sequential logic control instructions instruct the feeding control unit to control the feeding amount through a feeding control valve based on the weight of lithium sand detected by a weighing detection unit and the reaction kettle temperature detected by a temperature detection unit;

[0033] When the pressure difference between the protective gas and the exhaust gas does not meet the set value, the sequential logic control instructions instruct the differential pressure control unit to control the protective gas pressure control unit and the exhaust gas pressure control unit respectively to maintain a certain pressure difference between the exhaust gas and the protective gas. If the pressure difference exceeds the normal requirement, an alarm is issued and the discharging valve is interlocked and closed;

[0034] When the weighing of the lithium sand bin reaches the feeding end value, the sequential logic control instructions instruct the discharging valve to close and the feeding control unit to close the regulating valve.

[0035] Optionally, the pre-deployed algorithm models include: a feeding control algorithm model and a safe and smooth feeding control algorithm model;

[0036] The feeding control model is:

[0037] CS_WT101 - WSV101 = END_WT101

[0038] (CS_WT101 - SCP_WT101) / t1 = K1

[0039] (SCP_WT101-END_WT101) / (t2-t1)=K2

[0040] Wherein, CS_WT101 is the total weight of the silo and lithium sand at the beginning of the feeding; WSV101 is the total weight of the lithium sand in a single batch of feeding required by the process, that is, the setting value of the total amount of lithium sand added by the operator on the control system; END_WT101 is the weight of the silo and the remaining lithium sand at the end of the feeding; SCP_WT101 is the safety critical value of lithium sand feeding, t1 and t2 are the feeding times at different stages of the feeding process; K1 is the slope of the feeding control curve of lithium sand that only considers the current feeding amount during the reaction process, and K2 is the second slope of the feeding control curve of lithium sand that simultaneously considers the current feeding amount and the reactor temperature during the reaction process;

[0041] The safe and smooth material unloading control model includes:

[0042] PT101-PT102=DP101

[0043] In the formula, PT101 is the pressure detection of the protective gas component, PT102 is the pressure detection of the exhaust gas component, and DP101 is the system pressure difference.

[0044] In a second aspect, an embodiment of the present invention provides a control method for automatic and safe addition of lithium sand, which is applied to the system as described above, comprising:

[0045] The controller performs one or more operations of lithium sand feeding control, silo protection gas control, reactor tail gas control in the corresponding time period according to the different detection information obtained, and implements safety interlock logic control by maintaining a certain pressure difference between tail gas and protection gas;

[0046] Among them, the lithium sand feeding control controls the feeding amount based on the reactor temperature and the lithium sand reaction progress; the protective gas control controls the silo protective gas pressure by judging the deviation between the silo protective gas pressure and the first safety setting value; the reactor exhaust gas control controls the reactor exhaust gas pressure by judging the deviation between the reactor exhaust gas and the second safety setting value; the safety interlock logic control controls the switch state of the discharge valve based on the pressure difference change between the exhaust gas and the protective gas.

[0047] Optionally, the controller performs one or more operations of lithium sand feeding control, silo protection gas control, and reactor tail gas control within a corresponding time period according to different detection information obtained, and implements safety interlock logic control by maintaining a certain pressure difference between the tail gas and the protection gas, including:

[0048] After initializing and troubleshooting the control system, the logic control unit in the controller controls the discharge valve to open;

[0049] The logic control unit activates the feeding control unit so that the feeding control unit controls the feeding amount based on the feeding control algorithm model, combining the self-weight of the silo and the total weight of the lithium sand, through the feeding control valve; until the feeding amount reaches the safety critical value, the feeding control unit controls the feeding amount based on the feeding control algorithm model, combining the self-weight of the silo and the total weight of the lithium sand and the reaction kettle temperature, through the feeding control valve.

[0050] The logic control unit activates the differential pressure control unit so that the differential pressure control unit controls the pressure difference between the protective gas and the tail gas to meet the set value based on the safe and smooth feeding control model.

[0051] When the self-weight of the silo and the weight of the remaining lithium sand reach the feeding end value, the logic control unit controls the discharge valve to close and controls the feeding control unit to close the feeding control valve.

[0052] Optionally, the logic control unit activates the feeding control unit so that the feeding control unit controls the feeding amount based on the feeding control algorithm model, combining the self-weight of the silo and the total weight of the lithium sand, through the feeding control valve; until the feeding amount is close to the safety critical value, the feeding control unit controls the feeding amount based on the feeding control algorithm model, combining the self-weight of the silo and the total weight of the lithium sand and the reaction kettle temperature, through the feeding control valve, including:

[0053] The logic control unit activates the feeding control unit so that the feeding control unit controls the feeding amount based on the feeding control algorithm model, combining the weight of the lithium sand detected by the weighing detection unit, through the feeding control valve.

[0054] The logic control unit determines whether the feeding amount is not less than the safety critical value of lithium sand feeding.

[0055] If the feeding amount is not less than the safety critical value of lithium sand feeding, the logic control unit controls the feeding amount through the feeding control unit according to the weight of the lithium sand detected by the weighing detection unit and the reaction kettle temperature detected by the temperature detection unit, through the feeding control valve.

[0056] Optionally, the logic control unit activates the differential pressure control unit so that the differential pressure control unit controls the pressure difference between the protective gas and the tail gas to meet the set value based on the safe and smooth feeding control model, including:

[0057] The logic control unit activates the differential pressure control unit and determines whether the difference between the tail gas and the protective gas is not less than the third safety set value.

[0058] If the difference is not less than the third safety set value, the logic control unit closes the discharge valve so that the differential pressure control unit controls the pressure difference between the protective gas and the tail gas based on the safe and smooth feeding control model.

[0059] When the difference between the protective gas and the tail gas is not less than the fourth safety set value, the logic control unit controls the discharge valve to open.

[0060] In a third aspect, an embodiment of the present invention provides a computer-readable medium, on which computer-executable instructions are stored. When the executable instructions are executed by a processor, a control method for automatic and safe feeding of lithium sand as described in any one of the above is implemented.

[0061] (III) Advantageous Effects

[0062] The advantageous effects of the present invention are as follows: Based on the properties of metallic lithium, safety requirements, precise feeding, and management requirements, the traditional manual feeding operation is transformed into mainly automatic and safe feeding with precise control. Automatic optimization and precise control are carried out for the feeding of the bin during the feeding process. At the same time, precise control of the safety protection gas and tail gas is considered. While meeting safety, product quality, and output, automatic control is achieved, and safe and efficient unmanned operation and intelligent management are realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a flowchart of the lithium sand feeding process of a control system for automatic and safe feeding of lithium sand proposed in an embodiment of the present invention;

[0064] Figure 2 It is a structural diagram of a control system for automatic and safe feeding of lithium sand proposed in an embodiment of the present invention;

[0065] Figure 3 It is a lithium sand feeding control algorithm model diagram of a control system for automatic and safe feeding of lithium sand proposed in an embodiment of the present invention;

[0066] Figure 4 It is a specific flowchart of step S1 of a control method for automatic and safe feeding of lithium sand proposed in an embodiment of the present invention;

[0067] Figure 5 It is a specific flowchart of step S12 of a control method for automatic and safe feeding of lithium sand proposed in an embodiment of the present invention;

[0068] Figure 6 It is a specific flowchart of step S13 of a control method for automatic and safe feeding of lithium sand proposed in an embodiment of the present invention;

[0069] Figure 7 It is a control flowchart of the automatic and safe feeding logic sequence of a control method for automatic and safe feeding of lithium sand proposed in an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0070] To better explain the present invention for easy understanding, the present invention will be described in detail below with reference to the accompanying drawings through specific embodiments.

[0071] As Figure 1As shown in the figure, a control system for automatic and safe feeding of lithium sand proposed in an embodiment of the present invention includes: a main device, which includes a feed bin, a discharge valve, and a reaction kettle connected in sequence; a feeding assembly, which includes a weighing and detection unit provided on the feed bin, a temperature detection unit provided on the reaction kettle, and a feeding control valve provided between the discharge valve and the reaction kettle; a protective gas assembly, which includes a protective gas pressure detection unit provided on the feed bin and a protective gas regulating valve provided at an inlet and outlet of the feed bin; a tail gas assembly, which includes a tail gas pressure detection unit provided on the reaction kettle and a tail gas regulating valve provided at an inlet and outlet of the reaction kettle; and a control assembly, which is respectively connected to the weighing and detection unit, the temperature detection unit, the protective gas pressure detection unit, the tail gas pressure detection unit, the feeding control valve, the protective gas regulating valve, and the tail gas regulating valve to perform one or more operations among lithium sand feeding control, feed bin protective gas control, and reaction kettle tail gas control according to the obtained different detection information within corresponding time periods, and implement safety interlock logic control by maintaining a certain pressure difference between the tail gas and the protective gas.

[0072] Among them, the safety logic interlock control is to control the pressure of the tail gas assembly and the protective gas assembly within the safe process value range and achieve safe feeding of lithium sand according to the specified logical sequence. If the pressure in the reaction kettle rises, causing the pressure of the tail gas assembly to rise and resulting in the pressure of the tail gas assembly exceeding the safe process value specified for the protective gas assembly, the lithium sand to be fed cannot enter the reaction kettle, then the discharge valve is closed and the pressure of the tail gas assembly is adjusted to the normal process value; secondly, if the system pressure of the protective gas assembly and the tail gas assembly itself exceeds the specified process value, the corresponding gas assembly is interlock controlled.

[0073] Based on the properties of metallic lithium, safety requirements, precise feeding, and management requirements, the present invention transforms the traditional manual feeding operation into mainly automatic and safe feeding precise control, performs automatic optimization and precise control on the discharge of the feed bin during the feeding process, and at the same time considers the precise control of the protective gas and the tail gas. While meeting safety, product quality, and output, it realizes automatic control, achieving safe and efficient unmanned operation and intelligent management.

[0074] In order to better understand the above technical solution, the exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a more clear and thorough understanding of the present invention and to convey the full scope of the present invention to those skilled in the art.

[0075] Secondly, the weighing detection unit includes a weighing detection sensor with an accuracy of not less than one in ten thousand. In order to meet the minute changes in the lithium sand feeding amount during the lithium sand feeding process, the weighing detection sensor should have at least an accuracy of one in ten thousand and good real-time data transmission. The weighing detection signal is transmitted in real time to the control system via ProfiBus communication, and one of the paths is transmitted to the corresponding control platform as an alarm prompt using a 4-20mA analog signal.

[0076] Next, the feeding control valve uses a V-type on-off valve + pneumatic valve position regulator to solve the problems of easy blockage of the pipeline by solid raw material lithium sand, non-inner leakage switch control, and adjustment of the feeding amount during the feeding process.

[0077] Furthermore, the control components include: a feeding control unit respectively connected to the feeding control valve and the weighing detection unit; a temperature control unit respectively connected to the feeding control unit and the temperature detection unit; a protective gas pressure control unit respectively connected to the protective gas pressure detection unit and the protective gas regulating valve; an exhaust gas pressure control unit respectively connected to the exhaust gas pressure detection unit and the exhaust gas regulating valve; a differential pressure control unit respectively connected to the protective gas pressure detection unit and the exhaust gas pressure detection unit; a logic control unit respectively connected to the discharge valve, the feeding control unit, and the differential pressure control unit. The logic control unit is used to issue sequential logic control instructions and safety interlock logic control instructions for lithium sand feeding, exhaust gas, and protective gas; and an algorithm control unit respectively connected to the feeding control unit, the temperature control unit, the protective gas pressure control unit, and the logic control unit. The algorithm control unit is used to obtain the instructions issued by the logic control unit and call the pre-deployed algorithm model to control the corresponding control units.

[0078] Each of the above control units includes a corresponding controller. As Figure 2 shown, the feeding control unit includes a feeding controller, the protective gas pressure control unit includes a protective gas controller, the exhaust gas pressure control unit includes an exhaust gas controller, the differential pressure control unit includes a differential pressure controller, the algorithm control unit includes an algorithm controller, and the logic control unit includes a logic controller.

[0079] Based on the components of the above controllers, referring to Figure 2 , the automatic and safe lithium sand feeding control system consists of four control loops:

[0080] The lithium sand feeding control loop consists of the weighing detection WT101, the feeding controller WIC101, the feeding control valve WV101, the temperature detection TT101, and the temperature controller TIC101.

[0081] The logic control loop consists of the algorithm controller AIC101, the logic controller LC101, the differential pressure controller DPC101, the discharge valve KV101, etc.

[0082] The protective gas control loop for lithium sand feeding consists of a pressure detector PT101, a pressure controller PIC101, a pressure regulating valve PV101, etc.

[0083] The tail gas control loop for lithium sand feeding consists of a pressure detector PT102, a pressure controller PIC102, a pressure regulating valve PV102, etc.

[0084] The feeding control loop mainly automatically adjusts the amount of lithium sand feeding according to the process parameter requirements. The logic control loop mainly completes control algorithms, discharging control, safety interlocking and sequential logic control. The protective gas control loop mainly automatically adjusts to maintain the pressure of the protective gas component during the lithium sand feeding process according to the process parameter requirements. The tail gas control loop mainly automatically adjusts to maintain the pressure of the tail gas component during the lithium sand feeding process according to the process parameter requirements.

[0085] Furthermore, the logical sequence control instructions issued by the logic control unit are used to indicate the following operations:

[0086] During the initial feeding process, the logical sequence control instructions indicate that the feeding control unit controls the feeding amount through the feeding control valve based on the weight of the lithium sand detected by the weight detection unit.

[0087] When the reaction process of the lithium sand reaches the safety critical point during feeding, the logical sequence control instructions indicate that the feeding control unit controls the feeding amount through the feeding control valve based on the weight of the lithium sand detected by the weight detection unit and the temperature of the reaction kettle detected by the temperature detection unit.

[0088] When the pressure difference between the protective gas and the tail gas does not meet the set value, the logical sequence control instructions indicate that the pressure difference control unit controls the protective gas pressure control unit and the tail gas pressure control unit respectively to maintain a certain pressure difference between the tail gas and the protective gas. If the pressure difference exceeds the normal requirement, an alarm is given and the discharging valve is closed interlockingly.

[0089] When the weighing of the lithium sand bin reaches the feeding end value, the logical sequence control instructions indicate that the discharging valve is closed and the feeding control unit is instructed to close the regulating valve.

[0090] In Figure 1 KV101 is the discharging valve of the lithium sand bin, controlling the opening and closing of lithium sand discharging. WT101 is the weighing detection unit of the lithium sand bin, realizing the weight detection and data transmission of the lithium sand. WV101 is the feeding control and regulating unit, realizing the control and regulation of the feeding amount. WIC101 is the feeding control unit, realizing the automatic control of the feeding amount. AIC101 is the algorithm control unit, realizing the control algorithms of the tail gas, protective gas, and lithium sand feeding, mainly completing the feeding control algorithm, control model selection, feeding time, and feeding amount selection and confirmation.

[0091] WIC101 is the feeding control unit, which realizes the automatic control of the feeding amount; TT101 is the temperature detection unit of the reaction kettle, which realizes the temperature detection of the reaction kettle; TIC101 is the temperature control unit of the reaction kettle, which realizes the automatic control of the reaction kettle temperature; LC101 is the logic control unit, which realizes the logic relationship and safety interlock logic control of the tail gas, protective gas, and lithium sand feeding; PT101 is the protective gas pressure detection unit of the lithium sand bin, which realizes the pressure detection of the lithium sand bin; PIC101 is the protective gas pressure control unit of the lithium sand bin, which realizes the automatic control of the protective gas pressure of the lithium sand bin; PT102 is the tail gas pressure detection unit of the reaction kettle, which realizes the pressure detection of the reaction kettle tail gas; PIC102 is the tail gas pressure control unit of the reaction kettle, which realizes the automatic control of the reaction kettle tail gas pressure; DPC101 is the tail gas differential pressure control unit of the reaction kettle, which realizes the automatic control and safety interlock of the reaction kettle tail gas differential pressure.

[0092] Reference Figure 1 , after the operator checks that the protective gas pressure is normal, sets the total amount of lithium sand to be fed WSV101 and the time t on the control system according to the process parameter requirements, the discharge valve KV101 opens and the regulating valve WV101 automatically adjusts the feeding amount, and starts feeding to the reaction kettle. During the feeding process, as the reaction process continuously changes and the reaction reaches the safety critical point, the lithium sand feeding control switches from the weighing single-loop control to the reaction kettle temperature + weighing combined control to maintain the reaction kettle temperature. At the same time, the pressure of the tail gas assembly rises to the safety set value PSV101, and the protective gas assembly pressure control switches to the differential pressure controller DPC101 control, and maintains a certain differential pressure between the tail gas assembly and the protective gas assembly. If the differential pressure exceeds the normal requirement, an alarm is given and the lithium sand discharge valve KV101 is interlocked and closed. When the weighing of the lithium sand bin reaches the feeding end value END_WT101, the discharge valve KV101 and the regulating valve WV101 are closed, that is, the lithium sand feeding for this batch is completed.

[0093] Furthermore, referring to Figure 3 , the control algorithm of the present invention has two control models: the safe and smooth feeding control algorithm and the feeding control algorithm.

[0094] Because lithium sand is light and participates in the reaction by floating on the upper layer of the liquid, lithium sand cannot complete the feeding in a short time. The feeding amount must be controlled according to the kettle temperature change curve and the reaction process. At the same time, during the lithium sand reaction feeding process, in the initial stage of the reaction, the reaction needs to be initiated within a short time, and the heat release is rapid, which belongs to a hazardous chemical reaction. At this time, the safety critical value is the best reaction initiation point under safe conditions. Subsequently, within the specified time, as long as the lithium sand feeding amount is controlled to maintain the kettle temperature within the process set range, if the manual operation control is improper, it is easy to cause safety accidents, that is, the feeding control curve.

[0095] (1) Feeding control model

[0096] In Figure 3 wherein, CS_WT101 is the total weight of the silo self-weight and lithium sand at the initial stage of feeding; END_WT101 is the weight of the silo self-weight and the remaining lithium sand at the end of feeding; WSV101 is the total weight of lithium sand required for single-batch feeding according to process requirements, that is, the set value of the total feeding amount of lithium sand by the operator on the control system; SCP_WT101 is the safety critical value of lithium sand feeding; t1 and t2 are the feeding times at different stages during the feeding process; T0 is the initial temperature of the reaction kettle; TSV101 is the set value of the reaction kettle temperature; the feeding control curve is a curve representing the control of lithium sand feeding during the reaction process.

[0097] In order to avoid weighing data errors caused by the drift of the weighing sensor after the weighing detection form has been used for a long time during actual use, the feeding control has developed a proprietary control rule algorithm.

[0098] Feeding control algorithm: total weight of the silo - total feeding amount = weight at the end of feeding, that is

[0099] CS_WT101 - WSV101 = END_WT101;

[0100] The feeding amount control is the total feeding amount of each stage in a single batch divided by the total time of each feeding stage = feeding amount, that is

[0101] (CS_WT101 - SCP_WT101) / t1 = K1, (SCP_WT101 - END_WT101) / (t2 - t1) = K2, that is, the slopes K1 and K2 of the feeding control curve.

[0102] (2) Safe and smooth feeding control algorithm

[0103] Since the gas continuously generated during the reaction process of lithium sand cannot be discharged into the tail gas assembly in time and enters the feeding system, resulting in the inability of lithium sand to be fed smoothly, it is necessary to ensure a certain pressure difference during the feeding process of lithium sand.

[0104] Referring to Figure 3 , PT101 is the pressure detection of the protective gas assembly; PT102 is the pressure detection of the tail gas assembly; DP101 is the system pressure difference; safe and smooth feeding control algorithm: protective gas pressure - tail gas pressure = feeding system pressure difference, that is, PT101 - PT102 = DP101.

[0105] In addition, the embodiment of the present invention provides a control method for automatic safe feeding of lithium sand, which is applied to the system as described above, including:

[0106] S1. The controller performs one or more operations among lithium sand feeding control, silo protective gas control, and reactor tail gas control according to the acquired different detection information within corresponding time periods, and implements safety interlock logic control by maintaining a certain pressure difference between the tail gas and the protective gas.

[0107] Among them, the lithium sand feeding control is to control the feeding amount based on the reactor temperature and the lithium sand reaction process; the protective gas control is to control the silo protective gas pressure by judging the deviation between the silo protective gas pressure and the first safety set value; the reactor tail gas control is to control the reactor tail gas pressure by judging the deviation between the reactor tail gas and the second safety set value; the safety interlock logic control is to interlock and control the opening and closing state of the discharge valve based on the pressure difference change between the tail gas and the protective gas.

[0108] As Figure 4 shown, step S1 includes:

[0109] S11. After initializing the control system and troubleshooting (including troubleshooting whether KV101 is closed, whether the pressure of PT101 is normal, whether the set parameters are correct, etc.), the logic control unit in the controller controls the discharge valve to open.

[0110] S12. The logic control unit starts the feeding control unit so that the feeding control unit controls the feeding amount based on the feeding control algorithm model in combination with the self-weight of the silo and the total weight of the lithium sand through the feeding control valve; until the feeding amount reaches the safety critical value, the feeding control unit controls the feeding amount based on the feeding control algorithm model in combination with the self-weight of the silo, the total weight of the lithium sand, and the reactor temperature through the feeding control valve.

[0111] Furthermore, as Figure 5 shown, step S12 includes:

[0112] S121. The logic control unit starts the feeding control unit so that the feeding control unit controls the feeding amount based on the feeding control algorithm model in combination with the weight of the lithium sand detected by the weight detection unit through the feeding control valve.

[0113] S122. The logic control unit judges whether the feeding amount is not less than the safety critical value of lithium sand feeding.

[0114] S123. If the feeding amount is not less than the safety critical value of lithium sand feeding, the logic control unit controls the feeding amount through the feeding control unit according to the weight of the lithium sand detected by the weight detection unit and the reactor temperature detected by the temperature detection unit through the feeding control valve.

[0115] S13. The logic control unit starts the pressure difference control unit so that the pressure difference control unit controls the pressure difference between the protective gas and the tail gas to meet the set value based on the safe and smooth feeding control model.

[0116] Furthermore, asFigure 6 As shown, step S13 includes:

[0117] S131. The logic control unit starts the differential pressure control unit and determines whether the difference between the tail gas and the protective gas is not less than the third safety set value.

[0118] S132. If the difference is not less than the third safety set value, the logic control unit closes the discharge valve so that the differential pressure control unit controls the differential pressure between the protective gas and the tail gas based on the safe and smooth feeding control model.

[0119] S133. When the difference between the protective gas and the tail gas is not less than the fourth safety set value, the logic control unit controls the discharge valve to open.

[0120] S14. When the weight of the silo itself and the remaining lithium sand reaches the feeding end value, the logic control unit controls the discharge valve to close and controls the feeding control unit to close the feeding control valve.

[0121] Referring to Figure 7 , the feeding logic control loop mainly completes algorithm control, discharge control, differential pressure control, and safety interlock and sequential logic control. It mainly includes an algorithm controller, a logic controller, and a discharge control unit. The algorithm controller consists of a control algorithm model, a feeding control model selection, a feeding time control, etc., and mainly completes the feeding control algorithm, control model selection, feeding time, and feeding amount selection and confirmation. The discharge control unit is composed of a discharge valve KV101, a weighing unit, a metering tank, etc., and mainly completes the discharge amount control. The logic control unit cooperates with the feeding control unit to complete the initial safety inspection, safe and smooth feeding judgment, discharge and other logical sequences and safety interlocks, so as to complete the feeding sequence logic, discharge amount control, etc.

[0122] It is worth mentioning that Figure 7 in, PIC102.A / M = M means that the automatic / manual of the tail gas control loop is switched to the manual state; PIC102.MV = 100% means that the output value of the tail gas control loop is 100%, that is, the fully open state; PIC102.A / M = A means that the automatic / manual of the tail gas control loop is switched to the automatic state; WIC101 A / M = M means that the automatic / manual of the weighing control loop is switched to the manual state; WIC101.MV = 100% means that the output value of the weighing control loop is 0, that is, the fully closed state.

[0123] In addition, the present invention also provides a computer-readable medium, on which computer-executable instructions are stored. When the executable instructions are executed by a processor, a control method for automatic and safe feeding of lithium sand as described above is implemented.

[0124] In summary, the present invention provides a control system, method, and medium for automatic and safe feeding of lithium sand. The present invention establishes the adjustment control of the feeding amount during the feeding process. On the premise of ensuring safe and smooth operation, automatic feeding control is performed through a high-precision weighing detection unit WT101, a feeding controller WC101, and a feeding control valve WV101 to accurately control the feeding amount. At the same time, the logical sequence control relationship during the feeding process is established. On the premise of ensuring feeding safety, logical sequence control and safety interlock logical control are performed through a logical controller, feeding method selection, feeding timer, and discharging valve KV101. Furthermore, a control algorithm model for the feeding process (as shown in Figure 3 ) is established to achieve automatic, safe, and accurate control of the lithium sand feeding process while ensuring the safety of the reaction kettle and the stability of product quality.

[0125] Therefore, the present invention solves the difficulties in the danger and feeding control during the lithium sand feeding process, improves automation, intelligence, and safety, and has the following characteristics:

[0126] 1. According to the requirements of batch management and traceability in the lithium battery industry, process characteristics, and safety management needs, the present invention solves the accurate control of automatic lithium sand feeding and unmanned operation during the feeding process, improving the automation level of feeding control;

[0127] 2. Automatic and safe feeding can solve the problem that operation in a harsh environment is not conducive to the health and safety of personnel;

[0128] 3. Accurate control of the feeding amount during automatic feeding can solve the problem that the product quality and output are uncontrollable due to manual operation, reducing the batch difference of products;

[0129] 4. According to the feeding and reaction characteristics of lithium sand, unique control algorithms are designed: a safe and smooth feeding control algorithm and a feeding control algorithm;

[0130] 5. According to the properties and reaction characteristics of lithium sand, a special valve structure and a special valve driving method are adopted to adapt to the lithium sand feeding process.

[0131] 6. According to the properties and reaction requirements of lithium sand, a silo with a relatively small self-weight, a high-precision weighing sensor, a special feeding control valve, a special control algorithm, a feeding safety management logic, and a safety protection gas control system and a tail gas control system are adopted.

[0132] 7. The automatic feeding logic control improves the safety of the feeding process and reduces the operation risk.

[0133] Since the system / apparatus described in the above embodiments of the present invention is the system / apparatus adopted for implementing the method of the above embodiments of the present invention, those skilled in the art can understand the specific structure and variations of the system / apparatus based on the method described in the above embodiments of the present invention, and thus will not be elaborated herein. Any system / apparatus adopted for the method of the above embodiments of the present invention falls within the scope of protection of the present invention.

[0134] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can be implemented in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can be implemented in the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0135] The present invention is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be realized by computer program instructions.

[0136] It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In a claim listing several devices, several of these devices can be embodied by the same hardware. The use of the words first, second, third, etc. is only for convenience of expression and does not indicate any order. These words can be understood as part of the element name.

[0137] In addition, it should be noted that in the description of this specification, the description of terms such as "one embodiment", "some embodiments", "embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0138] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications after learning the basic creative concepts. Therefore, the claims should be construed to cover the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0139] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and its equivalent technologies, the present invention should also cover these modifications and variations.

Claims

1. A control system for automatic and safe feeding of lithium sand, characterized in that, The control system includes: A main device, which includes a bin, a discharging valve, and a reaction kettle connected in sequence; A feeding assembly, which includes a weighing detection unit arranged on the bin, a temperature detection unit arranged on the reaction kettle, and a feeding control valve arranged between the discharging valve and the reaction kettle; A protective gas assembly, which includes a protective gas pressure detection unit arranged on the bin and a protective gas regulating valve arranged at an inlet / outlet of the bin; An exhaust gas assembly, which includes an exhaust gas pressure detection unit arranged on the reaction kettle and an exhaust gas regulating valve arranged at an inlet / outlet of the reaction kettle; and A control assembly, which is respectively connected to the weighing detection unit, the temperature detection unit, the protective gas pressure detection unit, the exhaust gas pressure detection unit, the feeding control valve, the protective gas regulating valve, and the exhaust gas regulating valve, so as to perform one or more operations among lithium sand feeding control, bin protective gas control, and reaction kettle exhaust gas control according to the acquired different detection information within corresponding time periods, and implement safety interlock logic control by maintaining a certain pressure difference between the exhaust gas and the protective gas; Among them, the control assembly includes: a feeding control unit respectively connected to the feeding control valve and the weighing detection unit; a temperature control unit respectively connected to the feeding control unit and the temperature detection unit; a protective gas pressure control unit respectively connected to the protective gas pressure detection unit and the protective gas regulating valve; an exhaust gas pressure control unit respectively connected to the exhaust gas pressure detection unit and the exhaust gas regulating valve; a pressure difference control unit respectively connected to the protective gas pressure detection unit and the exhaust gas pressure detection unit; a logic control unit respectively connected to the discharging valve, the feeding control unit, and the pressure difference control unit, and the logic control unit is used to issue sequential logic control instructions and safety interlock logic control instructions including lithium sand feeding, exhaust gas, and protective gas; and an algorithm control unit respectively connected to the feeding control unit, the temperature control unit, the protective gas pressure control unit, and the logic control unit, and the algorithm control unit is used to obtain the instructions issued by the logic control unit and call a pre-deployed algorithm model to control the corresponding control units; The logic sequence control instructions issued by the logic control unit are used to indicate the following operations: during the initial feeding process, the logic sequence control instructions indicate that the feeding control unit controls the feeding amount through the feeding control valve according to the weight of the lithium sand detected by the weighing detection unit; when the lithium sand reaction process reaches the safety critical point during feeding, the logic sequence control instructions indicate that the feeding control unit controls the feeding amount through the feeding control valve according to the weight of the lithium sand detected by the weighing detection unit and the temperature of the reaction kettle detected by the temperature detection unit; when the pressure difference between the protective gas and the exhaust gas pressure does not meet the set value, the logic sequence control instructions indicate that the pressure difference control unit respectively controls the protective gas pressure control unit and the exhaust gas pressure control unit to maintain a certain pressure difference between the exhaust gas and the protective gas, and if the pressure difference exceeds the normal requirement, an alarm is given and the discharging valve is interlocked and closed; when the weighing of the lithium sand bin reaches the feeding end value, the logic sequence control instructions indicate that the discharging valve is closed and the feeding control unit is instructed to close the regulating valve.

2. The control system for automatic and safe feeding of lithium sand according to claim 1, wherein The weighing detection unit includes: a weighing detection sensor with an accuracy of not less than one ten-thousandth; and the feeding control valve includes a V-type switch valve and a pneumatic valve position regulator.

3. The control system for automatic and safe feeding of lithium sand according to claim 1, wherein, The pre-deployed algorithm models include: a feeding control algorithm model and a safe and smooth feeding control algorithm model; The feeding control model is: CS_WT101 - WSV101 = END_WT101 (CS_WT101 - SCP_WT101) / t1 = K1 (SCP_WT101 - END_WT101) / (t2 - t1) = K2 In the formula, CS_WT101 is the total weight of the hopper self-weight and lithium sand at the beginning of feeding; WSV101 is the total weight of lithium sand required for a single batch of feeding in the process, that is, the set value of the total feeding amount of lithium sand by the operator on the control system; END_WT101 is the weight of the hopper self-weight and the remaining lithium sand at the end of feeding; SCP_WT101 is the safety critical value of lithium sand feeding, t1 and t2 are the feeding times at different stages during the feeding process; K1 is the slope of the feeding control curve considering only the current feeding amount during the reaction of lithium sand, and K2 is the second slope of the feeding control curve considering both the current feeding amount and the reaction kettle temperature during the reaction of lithium sand; The safe and smooth feeding control model includes: PT101 - PT102 = DP101 In the formula, PT101 is the protection gas component pressure detection, PT102 is the tail gas component pressure detection, and DP101 is the system pressure difference.

4. A control method for automatic and safe feeding of lithium sand, which is applied to the system as described in claim 3, and is characterized in that, It includes: The controller performs one or more operations among lithium sand feeding control, hopper protection gas control, and reaction kettle tail gas control according to the obtained different detection information within the corresponding time period, and implements safety interlock logic control by maintaining a certain pressure difference between the tail gas and the protection gas; Among them, the lithium sand feeding control is to control the feeding amount based on the reaction kettle temperature and the lithium sand reaction process; The protection gas control is to control the hopper protection gas pressure by judging the deviation between the hopper protection gas pressure and the first safety set value; the reaction kettle tail gas control is to control the reaction kettle tail gas pressure by judging the deviation between the reaction kettle tail gas and the second safety set value; the safety interlock logic control is to interlock and control the opening and closing state of the discharge valve based on the pressure difference change between the tail gas and the protection gas.

5. The control method for automatic and safe feeding of lithium sand according to claim 4, characterized in that, The controller performs one or more operations among lithium sand feeding control, hopper protection gas control, and reaction kettle tail gas control according to the obtained different detection information within the corresponding time period, and implements safety interlock logic control by maintaining a certain pressure difference between the tail gas and the protection gas, including: After initializing the control system and troubleshooting, the logic control unit in the controller controls the discharge valve to open; The logic control unit starts the feeding control unit so that the feeding control unit controls the feeding amount based on the feeding control algorithm model combined with the total weight of the hopper self-weight and lithium sand through the feeding control valve; until the feeding amount reaches the safety critical value, the feeding control unit controls the feeding amount based on the feeding control algorithm model combined with the total weight of the hopper self-weight and lithium sand and the reaction kettle temperature through the feeding control valve; The logic control unit starts the differential pressure control unit so that the differential pressure control unit controls the pressure difference between the protective gas and the tail gas to meet the set value based on the safe and smooth feeding control model; When the self-weight of the silo and the weight of the remaining lithium sand reach the feeding end value, the logic control unit controls the discharge valve to close and controls the feeding control unit to close the feeding control valve.

6. The control method for automatic and safe feeding of lithium sand according to claim 5, characterized in that The logic control unit starts the feeding control unit so that the feeding control unit controls the feeding amount based on the feeding control algorithm model in combination with the self-weight of the silo and the total weight of the lithium sand through the feeding control valve; until the feeding amount is close to the safety critical value, the feeding amount is controlled through the feeding control unit based on the feeding control algorithm model in combination with the self-weight of the silo and the total weight of the lithium sand and the temperature of the reaction kettle through the feeding control valve, including: The logic control unit starts the feeding control unit so that the feeding control unit controls the feeding amount based on the feeding control algorithm model in combination with the weight of the lithium sand detected by the weighing detection unit through the feeding control valve; The logic control unit determines whether the feeding amount is not less than the safety critical value of lithium sand feeding; If the feeding amount is not less than the safety critical value of lithium sand feeding, the logic control unit controls the feeding amount through the feeding control unit according to the weight of the lithium sand detected by the weighing detection unit and the temperature of the reaction kettle detected by the temperature detection unit through the feeding control valve.

7. The control method for automatic and safe feeding of lithium sand according to claim 5, characterized in that, The logic control unit starts the differential pressure control unit so that the differential pressure control unit controls the pressure difference between the protective gas and the tail gas to meet the set value based on the safe and smooth feeding control model, including: The logic control unit starts the differential pressure control unit and determines whether the difference between the tail gas and the protective gas is not less than the third safety set value; If the difference is not less than the third safety set value, the logic control unit closes the discharge valve so that the differential pressure control unit controls the pressure difference between the protective gas and the tail gas based on the safe and smooth feeding control model; When the difference between the protective gas and the tail gas is not less than the fourth safety set value, the logic control unit controls the discharge valve to open.

8. A computer-readable medium having computer-executable instructions stored thereon, characterized in that, When the executable instruction is executed by the processor, it implements a control method for automatic safe feeding of lithium sand as described in any one of claims 4-7.

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