A method for automatic air supply control of pressure tank based on Boyle function fitting

Abstract

The present invention discloses a method for controlling automatic air replenishment of a pressure tank, comprising: obtaining real-time oil pressure data and liquid level data in the oil tank; determining whether the real-time oil pressure data is within a set basic oil pressure range and whether the liquid level data is greater than a set minimum liquid level; if both conditions are met, calculating theoretical liquid level data based on the real-time oil pressure data using a relationship model between the oil pressure and liquid level of the pressure tank; determining whether the difference between the theoretical liquid level data and the real-time liquid level data is within a set threshold range; if not, outputting a control signal for controlling the opening of an air replenishment valve; during the opening of the air replenishment valve, calculating current theoretical oil pressure data based on the relationship model between the oil pressure and liquid level of the pressure tank; determining whether the real-time oil pressure is greater than or equal to the current theoretical oil pressure data; if so, outputting a control signal for controlling the closing of the air replenishment valve. The present invention can achieve precise air replenishment of the pressure tank, ensure a balanced oil-gas ratio, and thus ensure safe and stable operation of the unit controlled by the hydraulic system in which the pressure tank is located.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic system oil pressure control, in particular to an automatic air-filling control method for a pressure tank based on Boyle function fitting. Background Art

[0002] Many control units in hydropower plants are powered by hydraulic systems, typically powered by hydraulic devices such as turbine speed governors and ball or butterfly valve hydraulic devices. A key energy storage device for hydraulic devices is the pressure tank. Industry standards clearly stipulate the oil-to-air ratio within the tank: 1 / 3 of the volume must be hydraulic oil and 2 / 3 compressed air. These devices are generally operated within the rated pressure range.

[0003] In actual operation, the compressed air in the pressure tank leaks at valves, flanges, etc., and as the pressure oil circulates, the gas dissolved in the oil will also be carried out. Therefore, the pressure tank is generally equipped with an automatic air supply device. The air supply function of this device is divided into two categories, one is manual air supply, and the other is automatic air supply. The automatic air supply is completed by an electrical control device. The electrical control device is connected to the air supply device. The electrical control device detects the relationship between the oil level and oil pressure of the pressure tank, and controls the opening and closing of the air supply device based on this relationship. In order to realize the collection of liquid level and pressure information of the pressure tank, some automatic components are generally installed on the pressure tank, such as setting a pressure transmitter to measure the internal pressure oil pressure and setting a liquid level transmitter to measure the internal pressure oil level.

[0004] If leaks aren't promptly replenished, the oil pump's ability to maintain the rated oil pressure in the hydraulic system will cause the oil level in the pressure tank to gradually rise. Similarly, if the air replenishment logic in the air replenishment system is illogical, the control program is flawed, and excessive air is added, the pump's ability to maintain the rated oil pressure will cause the oil level in the pressure tank to gradually drop. In both cases, the oil-to-air ratio will ultimately fail to meet the 1:2 requirement. If the oil-to-air ratio becomes unbalanced, critical operating mechanisms will lose power, posing a significant risk to the safe and stable operation of the unit.

[0005] However, because hydraulic systems are typically in operation, oil is consumed and replenished in a cycle, a dynamic process. Therefore, the currently used automatic air replenishment method still has certain drawbacks. It cannot achieve precise, one-time air replenishment, making it difficult to achieve the required 1:2 oil-to-air ratio. Furthermore, due to constant fluctuations in oil pressure and fluid level, automatic air replenishment frequently opens and closes, shortening the life of the air replenishment device. Summary of the Invention

[0006] The present invention aims to provide a method for automatically controlling the air supply to a pressure tank based on Boyle function fitting. This method enables precise air supply to the pressure tank, ensuring a balanced oil-to-gas ratio, and thus ensuring safe and stable operation of the unit controlled by the hydraulic system in which the pressure tank is located. The technical solution employed by the present invention is as follows.

[0007] In one aspect, the present invention provides a method for controlling automatic air replenishment of a pressure tank, comprising:

[0008] Obtain a predetermined relationship model between the oil pressure and the liquid level of the pressure tank;

[0009] Obtain real-time oil pressure and liquid level data in the pressure tank;

[0010] determining whether the real-time oil pressure data is within a set basic oil pressure range and whether the liquid level data is greater than a set minimum liquid level; if both conditions are met, calculating theoretical liquid level data based on the real-time oil pressure data and using a relationship model between the oil pressure and liquid level of the pressure tank;

[0011] Determine whether the difference between the theoretical liquid level data and the real-time liquid level data is within a set threshold range, and if not, output a control signal for controlling the opening of the air supply valve;

[0012] During the opening of the air supply valve, the current theoretical oil pressure data is calculated based on the real-time liquid level data and the relationship model between the oil pressure and the liquid level of the pressure tank;

[0013] Determine whether the real-time oil pressure is greater than or equal to the calculated current theoretical oil pressure data. If so, output a control signal for controlling the closing of the air supply valve.

[0014] Optionally, the pressure tank automatic air supply control method further includes:

[0015] After outputting a control signal for controlling the opening of the air supply valve, the air supply valve receives an opening position signal of the air supply valve returned by the air supply device. If an opening position signal corresponding to the full opening of the air supply valve is received within a set period of time, the air supply valve opening control signal is reset; if no such signal is received, it is determined that an opening failure exists, and a control signal for controlling the closing of the air supply valve is output, and / or an air supply valve opening failure alarm signal is output;

[0016] After outputting the control signal for controlling the closing of the air supply valve, the air supply valve closing position signal returned by the air supply device is received. If the closing position signal corresponding to the full closure of the air supply valve is received within the set time period, the air supply valve closing control signal is controlled to be restored; if not received, it is determined that there is a closing fault, and an air supply valve closing failure alarm message is output.

[0017] The above technical solution can realize the detection of whether the opening and closing of the air supply valve is faulty. The set time period can be set to 120 seconds, or adjusted according to the characteristics of the air supply valve and actual needs.

[0018] Optionally, the method for determining the predetermined relationship model between the oil pressure and the liquid level of the pressure tank includes:

[0019] Ignoring the influence of temperature, under standard operating conditions where the oil-gas ratio in the pressure tank is the standard ratio and the oil pressure is the rated pressure, obtain and record the oil pressure and liquid level data in the pressure tank;

[0020] Starting from the standard working condition, the pressure oil in the pressure tank is discharged multiple times, and the oil pressure and liquid level data in the pressure tank after each pressure oil discharge are obtained and recorded to obtain multiple sets of fitting data;

[0021] Based on the multiple sets of fitting data, a linear relationship between the oil pressure data and the liquid level data is obtained by fitting;

[0022] The linear relationship obtained by fitting is used as the relationship model between the oil pressure and the liquid level of the pressure tank.

[0023] Furthermore, the method for determining the predetermined relationship model between the oil pressure and the liquid level of the pressure tank includes:

[0024] According to Boyle's law, the gas temperature and volume in the pressure tank are regarded as constants, and a linear relationship is found between the inverse of the oil pressure in the pressure tank and the liquid level.

[0025] Under standard working conditions where the oil-gas ratio in the pressure tank is the standard ratio and the oil pressure is the rated pressure, obtain and record the oil pressure and liquid level data in the pressure tank;

[0026] Starting from the standard working condition, the pressure oil in the pressure tank is discharged multiple times, and the oil pressure and liquid level data in the pressure tank after each discharge of the pressure oil are obtained and recorded;

[0027] Converting the oil pressure data in each set of recorded oil pressure and liquid level data to obtain a fitting data combination of multiple liquid level data and corresponding oil pressure reciprocal data;

[0028] Based on the plurality of fitting data combinations, a linear relationship between the oil pressure reciprocal data and the liquid level data is obtained by fitting: y=kx+b, where y and x represent the oil pressure reciprocal and the liquid level, respectively;

[0029] The linear relationship obtained by fitting is used as the relationship model between the oil pressure and the liquid level of the pressure tank.

[0030] The core concept behind the above fitting data collection and relationship fitting method is that, theoretically, under a 1:2 oil-to-gas ratio and no air leakage, both oil pressure and oil level should satisfy a linear equation. Any deviation from this equation indicates the need to activate and replenish air in the pressure tank until the equation is satisfied. However, since systems generally experience air leakage rather than excess air, this invention does not consider exhaustion.

[0031] The two fitting methods mentioned above have the same basic idea, but the relationship constructed and fitted based on Boyle's law can better fit the actual relationship between the oil pressure and the liquid level in the pressure tank, making the judgment in the control process more accurate and more conducive to achieving precise air replenishment.

[0032] In addition, the standard oil-gas ratio in the above-mentioned pressure tank is generally 1:2, and other standard ratios are not excluded.

[0033] Optionally, the upper limit of the basic oil pressure range is the maximum allowable oil pressure within the pressure tank, and the lower limit is the minimum allowable oil pressure within the pressure tank; the set minimum liquid level is the minimum allowable liquid level within the pressure tank. If both conditions are not met, it can be assumed that the pressure tank is not currently in a normal state that can be restored to normal by controlling air replenishment, and other maintenance methods may be considered.

[0034] In a second aspect, the present invention provides a pressure tank automatic air replenishment control device, comprising:

[0035] a data acquisition module configured to acquire a predetermined relationship model between the oil pressure and the liquid level of the pressure tank, and to acquire real-time oil pressure data and liquid level data in the pressure tank;

[0036] a state determination module configured to determine whether the real-time oil pressure data is within a set basic oil pressure range and whether the liquid level data is greater than a set minimum liquid level; if both conditions are met, calculating theoretical liquid level data based on the real-time oil pressure data using a relationship model between the pressure tank oil pressure and liquid level;

[0037] a gas leakage judgment module configured to judge whether the difference between the theoretical liquid level data and the real-time liquid level data is within a set threshold range, and if not, output a control signal for controlling the opening of the gas supply valve;

[0038] The feedback calculation module is configured to calculate the current theoretical oil pressure data according to the real-time liquid level data and the relationship model between the oil pressure and the liquid level of the pressure tank during the opening process of the air supply valve;

[0039] And, the stop control module is configured to determine whether the real-time oil pressure is greater than or equal to the calculated current theoretical oil pressure data, and if so, output a control signal for controlling the air supply valve to close.

[0040] Optionally, the pressure tank automatic air replenishment control device further includes a feedback control module configured to:

[0041] After outputting a control signal for controlling the opening of the air supply valve, the air supply valve receives an opening position signal of the air supply valve returned by the air supply device. If an opening position signal corresponding to the full opening of the air supply valve is received within a set period of time, the air supply valve opening control signal is reset; if no such signal is received, it is determined that an opening failure exists, and a control signal for controlling the closing of the air supply valve is output, and / or an air supply valve opening failure alarm signal is output;

[0042] After outputting the control signal for controlling the closing of the air supply valve, the air supply valve closing position signal returned by the air supply device is received. If the closing position signal corresponding to the full closure of the air supply valve is received within the set time period, the air supply valve closing control signal is controlled to be restored; if not received, it is determined that there is a closing fault, and an air supply valve closing failure alarm message is output.

[0043] In a third aspect, the present invention further discloses a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the pressure tank automatic gas replenishment control method as described in the first aspect is implemented.

[0044] Beneficial effects

[0045] Compared with the existing technology, the present invention collects big data of oil pressure at different liquid levels in the pressure tank under normal working conditions, and mines the intrinsic relationship between the oil level and oil pressure data in the pressure tank through data fitting, which is used as a basis for judging whether air replenishment is needed in the pressure tank, and then controls the opening and closing of the automatic air replenishment device. It can realize the precise replenishment of compressed air in the pressure tank, meet the standard oil-gas ratio of 1:2 in the pressure tank, ensure the balance of the oil-gas ratio, and enable the hydraulic system where the pressure tank is located to operate normally, safely and stably, and thus the unit it controls can operate safely and stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 Shown is a schematic diagram of the hydraulic system;

[0047] Figure 2 The figure shows the schematic diagram of the pressure tank structure;

[0048] Figure 3 The figure shows the electrical connection relationship between the pressure tank electrical control device and the air supply device;

[0049] Figure 4 FIG2 is a flow chart of an embodiment of a method for controlling automatic air supply to a pressure tank according to the present invention;

[0050] Figure 5 It is a schematic diagram of the pins of the functional modules for executing the automatic air replenishment control method for a pressure tank of the present invention;

[0051] Figure 6 The figure shows a schematic diagram of the relationship between the liquid level and the inverse of the oil pressure in an application example;

[0052] Figures 1 to 6 In the figure, 1-pressure tank, 2-oil pump, 3-return oil tank, 4-pressure transmitter, 5-liquid level transmitter, 01-liquid level. DETAILED DESCRIPTION

[0053] The following is a further description with reference to the accompanying drawings and specific embodiments.

[0054] like Figure 1 and Figure 2 As shown, in the hydraulic system, the pressure tank 1 is connected back to the oil tank 3 through an oil inlet pipeline and an oil outlet pipeline. The pressure tank 1 is provided with a pressure transmitter 4 for detecting the oil pressure and a liquid level transmitter 5 for detecting the liquid level 01. The liquid level transmitter uses the principle of a communicating vessel to display the current liquid level outside the pressure tank, such as: liquid level too low, liquid level low, liquid level high, liquid level too high.

[0055] The automatic air supply logic of the existing air supply device is generally as follows: when it is detected that: pressure P < rated oil pressure, and the liquid level Y is relatively high, an "air supply valve opening command" is issued, and the air supply device starts to supply air. When the electrical device detects that pressure P>=rated oil pressure, or the liquid level Y is relatively low, an "air supply valve closing command" is issued, and the air supply device stops supplying air. However, when the system has a large oil consumption, the oil may be consumed rapidly at one time, and the pressure and oil level will drop rapidly. Under the action of the oil pump 2, the automatic air supply closing logic judgment condition is met, and the air supply is stopped. But in reality, the oil pump needs to be loaded to replenish oil at this time, and it must be loaded to the rated oil pressure. Therefore, it is necessary to wait for the next time the air supply conditions are met before starting to supply air. Therefore, it is difficult for the existing air supply device to achieve precise air supply.

[0056] The technical concept of the present invention is: by exploring the correlation between the oil pressure and the oil level of the pressure tank under the standard oil pressure ratio, it is possible to determine in real time whether air replenishment is needed, and to replenish air accurately to maintain the oil and gas balance in the pressure tank.

[0057] Example 1

[0058] This embodiment introduces a pressure tank automatic air replenishment control method, including:

[0059] Obtain a predetermined relationship model between the oil pressure and the liquid level of the pressure tank;

[0060] Obtain real-time oil pressure and liquid level data in the pressure tank;

[0061] determining whether the real-time oil pressure data is within a set basic oil pressure range and whether the liquid level data is greater than a set minimum liquid level; if both conditions are met, calculating theoretical liquid level data based on the real-time oil pressure data and using a relationship model between the oil pressure and liquid level of the pressure tank;

[0062] Determine whether the difference between the theoretical liquid level data and the real-time liquid level data is within a set threshold range, and if not, output a control signal for controlling the opening of the air supply valve;

[0063] During the opening of the air supply valve, the current theoretical oil pressure data is calculated based on the real-time liquid level data and the relationship model between the oil pressure and the liquid level of the pressure tank;

[0064] Determine whether the real-time oil pressure is greater than or equal to the calculated current theoretical oil pressure data. If so, output a control signal for controlling the closing of the air supply valve.

[0065] like Figure 1 As shown, the specific implementation process of the method in this embodiment is introduced as follows.

[0066] 1. Linear relationship fitting between oil pressure and oil level

[0067] The basic theoretical basis for linear relationship fitting in this embodiment is Boyle's law formula: PV = nRT

[0068] Where P is pressure (Pa), V is gas volume (m 3 ), T is the compressed air temperature (K), n and R are constants.

[0069] According to the volume formula: V = S * H q , where S is the inner cross-sectional area of the pressure tank, which is a constant; H q is the gas height, H q Equal to the total height of the pressure tank H0 minus the liquid level height H y , H0 is a constant.

[0070] From this, we can deduce that:

[0071] P×S×(H0-H y )=nRT, if we ignore the temperature change, classify it as a constant, and equalize the constant to C, we can get P×(C0-H y )=C1;

[0072] From the above, we can deduce Simplified again to:

[0073] This shows that pressure and liquid level are related by the simplified formula above. In actual operation, oil level, oil pressure, and temperature also interact with each other. To simplify calculations and control, this embodiment only establishes the relationship between pressure and liquid level, ignoring the influence of temperature T. If the influence of temperature is not ignored, it is necessary to simultaneously monitor temperature data during data acquisition.

[0074] Based on the above derivation, in this embodiment, the method for determining the relationship model between the oil pressure and the liquid level of the pressure tank includes:

[0075] Under standard working conditions where the oil-gas ratio in the pressure tank is a standard ratio of 1:2 and the oil pressure is a rated pressure of 6.3 MPa, obtain and record the oil pressure and liquid level data in the pressure tank;

[0076] Starting from the standard working condition, slowly discharge the pressure oil in the pressure tank multiple times, obtain and record the oil pressure and liquid level data in the pressure tank after each pressure oil discharge. If the pressure oil discharge is performed 19 times, a total of 20 sets of oil pressure and liquid level data will be recorded. The last data should include the pressure of the oil pump main pump and the corresponding liquid level. Refer to the first set of data in the table below:

[0077] Table 1

[0078]

[0079]

[0080] The oil pressure data in each set of recorded oil pressure and liquid level data is converted to obtain a fitting data combination of multiple liquid level data and corresponding oil pressure inverse data, such as the second set of data in Table 1;

[0081] Based on the plurality of fitting data combinations, a linear relationship between the oil pressure reciprocal data and the liquid level data is obtained by fitting: y=kx+b, where y and x represent the oil pressure reciprocal and the liquid level, respectively;

[0082] The linear relationship obtained by fitting is used as the relationship model between the oil pressure and the liquid level of the pressure tank.

[0083] In this embodiment, when fitting the second set of data, in order to reduce unnecessary calculation difficulty, the oil pressure reciprocal 1 / P is expanded by 100 times. Figure 6 As shown, this will not change the linearity. When fitting the data, more than one function equation may be obtained. A set of equations with the best linearity is selected as the final relationship model between the oil pressure and the liquid level of the pressure tank, such as Figure 6 The final linear relationship equation is: Y = -271.12x + 6781.5, where Y represents the liquid level in the pressure tank, and x represents 100 times the inverse of the oil pressure in the pressure tank, that is, 100 / p.

[0084] 2. Real-time gas replenishment control method

[0085] refer to Figure 4 The basic principle of real-time and accurate Qi replenishment in this embodiment is:

[0086] Real-time detection of oil pressure and liquid level. When the oil pressure and liquid level meet the basic range, the actual detected oil pressure is substituted into the linear relationship equation to calculate the theoretical liquid level Y corresponding to the current pressure. LL , then the actual liquid level and the theoretical liquid level Y LL Compare them. If the deviation between the two is greater than a certain set threshold value θ, such as 80mm, it means that the liquid level has increased, which means there is a leak. Because the system requires the oil pump to keep the pressure tank near the rated pressure, a leak in the pressure tank will definitely show up as a higher liquid level. At this time, the electronic control system needs to issue an instruction to open the air supply device. When the opening position reaches the full open position, the opening command is reset. During the air supply process, the electronic control system can periodically detect the relationship between the real-time pressure and the liquid level, that is, substitute the actual liquid level detected in real time into the equation to calculate the theoretical oil pressure P LL and compare the actual oil pressure with the theoretical oil pressure P LL By comparison, when the former is greater than or equal to the latter, the air supply valve closing command is issued. When the air supply valve fully closed position signal is reached, the closing command is reset and air supply is stopped.

[0087] To detect opening and closing failures of the air supply valve, this embodiment also provides for a valve that fails to fully open within 120 seconds (or other timeframes depending on the actual equipment operating characteristics) after issuing an opening control command. This is considered an opening failure, and for safety reasons, a valve closing command is immediately issued. Similarly, if the valve fails to fully close within 120 seconds after issuing a valve closing command, this is considered a closing failure, and a valve closing failure alarm signal is output.

[0088] By periodically executing the pressure tank air replenishment control method of this embodiment, the pressure tank can be automatically and accurately replenished to maintain oil pressure balance.

[0089] Example 1-2

[0090] Different from Example 1, this embodiment directly uses a plurality of combinations of oil pressure and oil level data that meet the rated oil pressure obtained from the experiment to perform linear relationship fitting, that is:

[0091] Ignoring the influence of temperature, under standard operating conditions where the oil-gas ratio in the pressure tank is 1:2 and the oil pressure is at the rated pressure, obtain and record the oil pressure and liquid level data in the pressure tank.

[0092] Starting from the standard working condition, the pressure oil in the pressure tank is discharged multiple times, and the oil pressure and liquid level data in the pressure tank after each pressure oil discharge are obtained and recorded to obtain multiple sets of fitting data;

[0093] Based on the multiple sets of fitting data, a linear relationship between the oil pressure data and the liquid level data is obtained by fitting;

[0094] The linear relationship obtained by fitting is used as the relationship model between the oil pressure and the liquid level of the pressure tank.

[0095] Example 2

[0096] Based on the same inventive concept as Example 1, this embodiment introduces an automatic air replenishment control device for a pressure tank, comprising:

[0097] a data acquisition module configured to acquire a predetermined relationship model between the oil pressure and the liquid level of the pressure tank, and to acquire real-time oil pressure data and liquid level data in the pressure tank;

[0098] a state determination module configured to determine whether the real-time oil pressure data is within a set basic oil pressure range and whether the liquid level data is greater than a set minimum liquid level; if both conditions are met, calculating theoretical liquid level data based on the real-time oil pressure data using a relationship model between the pressure tank oil pressure and liquid level;

[0099] a gas leakage judgment module configured to judge whether the difference between the theoretical liquid level data and the real-time liquid level data is within a set threshold range, and if not, output a control signal for controlling the opening of the gas supply valve;

[0100] The feedback calculation module is configured to calculate the current theoretical oil pressure data according to the real-time liquid level data and the relationship model between the oil pressure and the liquid level of the pressure tank during the opening process of the air supply valve;

[0101] And, the stop control module is configured to determine whether the real-time oil pressure is greater than or equal to the calculated current theoretical oil pressure data, and if so, output a control signal for controlling the air supply valve to close.

[0102] In addition, the pressure tank automatic air replenishment control device also includes a feedback control module, which is configured to:

[0103] After outputting a control signal for controlling the opening of the air supply valve, the air supply valve receives an opening position signal of the air supply valve returned by the air supply device. If an opening position signal corresponding to the full opening of the air supply valve is received within a set period of time, the air supply valve opening control signal is reset; if no such signal is received, it is determined that an opening failure exists, and a control signal for controlling the closing of the air supply valve is output, and / or an air supply valve opening failure alarm signal is output;

[0104] After outputting the control signal for controlling the closing of the air supply valve, the air supply valve closing position signal returned by the air supply device is received. If the closing position signal corresponding to the full closure of the air supply valve is received within the set time period, the air supply valve closing control signal is controlled to be restored; if not received, it is determined that there is a closing fault, and an air supply valve closing failure alarm message is output.

[0105] For the specific functional implementation of the above functional modules, please refer to the relevant introduction in Example 1.

[0106] The device of this embodiment can be implemented as Figure 5 The automatic air replenishment module shown is designed according to the data source and data output requirements: basic oil pressure range setting port YGP_BQ_UP and YGP_BQ_DOWN, minimum oil level setting port YGW_BQ_DOWN, automatic replenishment function enable port AUTO_BQ2 that can be externally controlled, oil pressure data input port YGP, oil level data input port YGW, air replenishment valve open position input port BQ_OPEN_Flag, air replenishment valve closed position input port BQ_CLOSE_Flag, fault reset port, air replenishment valve open control port BQ_OPEN, air replenishment valve close control port BQ_CLOSE, and air replenishment valve switch fault alarm ports BQ_OPEN_ERR and BQ_CLOSE_ERR, etc.

[0107] Example 3

[0108] Based on the same inventive concept as Examples 1 and 2, this example introduces a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the automatic air replenishment control method for the pressure tank as described in Example 1 is implemented.

[0109] In summary, the present invention can achieve: when the air replenishment starting conditions are met, air can be replenished accurately at one time, avoiding the shortcomings of conventional air replenishment logic such as frequent start and stop, inability to replenish in place at one time, and inaccuracy, which can extend the service life of the air replenishment device and ensure the safe and stable operation of the unit under the control of the hydraulic system.

[0110] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0111] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0112] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0113] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0114] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the purpose of the present invention and the claims, which are all protected by the present invention.

Claims

1. A pressure tank automatic air filling control method, characterized in that: include: Obtain a predetermined relationship model between the oil pressure and the liquid level of the pressure tank; Obtain real-time oil pressure and liquid level data in the pressure tank; determining whether the real-time oil pressure data is within a set basic oil pressure range and whether the liquid level data is greater than a set minimum liquid level; if both conditions are met, calculating theoretical liquid level data based on the real-time oil pressure data and using a relationship model between the oil pressure and liquid level of the pressure tank; Determine whether the difference between the theoretical liquid level data and the real-time liquid level data is within a set threshold range, and if not, output a control signal for controlling the opening of the air supply valve; During the opening of the air supply valve, the current theoretical oil pressure data is calculated based on the real-time liquid level data and the relationship model between the oil pressure and the liquid level of the pressure tank; Determine whether the real-time oil pressure is greater than or equal to the calculated current theoretical oil pressure data. If so, output a control signal for controlling the closing of the air supply valve; The method for determining the predetermined relationship model between the oil pressure and the liquid level of the pressure tank includes: According to Boyle's law, the gas temperature and volume in the pressure tank are considered constants, and a linear relationship is found between the inverse of the oil pressure in the pressure tank and the liquid level: ,in, and Respectively represent the inverse of oil pressure and liquid level, is a constant; Under standard working conditions where the oil-gas ratio in the pressure tank is 1:2 and the oil pressure is at the rated pressure, obtain and record the oil pressure and liquid level data in the pressure tank; Starting from the standard working condition, the pressure oil in the pressure tank is discharged multiple times, and the oil pressure and liquid level data in the pressure tank after each discharge of the pressure oil are obtained and recorded; Converting the oil pressure data in each set of recorded oil pressure and liquid level data to obtain a fitting data combination of multiple liquid level data and corresponding oil pressure reciprocal data; Based on the multiple fitting data combinations, a linear relationship between the oil pressure reciprocal data and the liquid level data is obtained by fitting: y = kx + b , where y and x Respectively indicate the inverse of oil pressure and liquid level; The linear relationship obtained by fitting is used as the relationship model between the oil pressure and the liquid level of the pressure tank.

2. The method according to claim 1, wherein include: After outputting a control signal for controlling the opening of the air supply valve, the air supply valve receives an opening position signal of the air supply valve returned by the air supply device. If an opening position signal corresponding to the full opening of the air supply valve is received within a set period of time, the air supply valve opening control signal is reset; if no such signal is received, it is determined that an opening failure exists, and a control signal for controlling the closing of the air supply valve is output, and / or an air supply valve opening failure alarm signal is output; After outputting the control signal for controlling the closing of the air supply valve, the air supply valve closing position signal returned by the air supply device is received. If the closing position signal corresponding to the full closure of the air supply valve is received within the set time period, the air supply valve closing control signal is controlled to be restored; if not received, it is determined that there is a closing fault, and an air supply valve closing failure alarm message is output.

3. The method according to claim 2, wherein: The set time period is 120 seconds.

4. The method according to claim 1, wherein: The upper limit of the basic oil pressure range is the maximum oil pressure allowed in the pressure tank, and the lower limit is the minimum oil pressure allowed in the pressure tank; the set minimum liquid level is the minimum liquid level allowed in the pressure tank.

5. An automatic air filling control device for a pressure tank using the method according to any one of claims 1 to 4, characterized in that: include: a data acquisition module configured to acquire a predetermined relationship model between the oil pressure and the liquid level of the pressure tank, and to acquire real-time oil pressure data and liquid level data in the pressure tank; a state determination module configured to determine whether the real-time oil pressure data is within a set basic oil pressure range and whether the liquid level data is greater than a set minimum liquid level; if both conditions are met, calculating theoretical liquid level data based on the real-time oil pressure data using a relationship model between the pressure tank oil pressure and liquid level; a gas leakage judgment module configured to judge whether the difference between the theoretical liquid level data and the real-time liquid level data is within a set threshold range, and if not, output a control signal for controlling the opening of the gas supply valve; The feedback calculation module is configured to calculate the current theoretical oil pressure data according to the real-time liquid level data and the relationship model between the oil pressure and the liquid level of the pressure tank during the opening process of the air supply valve; And, the stop control module is configured to determine whether the real-time oil pressure is greater than or equal to the calculated current theoretical oil pressure data, and if so, output a control signal for controlling the air supply valve to close.

6. The automatic air supply control device for a pressure tank according to claim 5, characterized in that: Also included is a feedback control module configured to: After outputting a control signal for controlling the opening of the air supply valve, the air supply valve receives an opening position signal of the air supply valve returned by the air supply device. If an opening position signal corresponding to the full opening of the air supply valve is received within a set period of time, the air supply valve opening control signal is reset; if no such signal is received, it is determined that an opening failure exists, and a control signal for controlling the closing of the air supply valve is output, and / or an air supply valve opening failure alarm signal is output; After outputting the control signal for controlling the closing of the air supply valve, the air supply valve closing position signal returned by the air supply device is received. If the closing position signal corresponding to the full closure of the air supply valve is received within the set time period, the air supply valve closing control signal is controlled to be restored; if not received, it is determined that there is a closing fault, and an air supply valve closing failure alarm message is output.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the pressure tank automatic gas replenishment control method according to any one of claims 1 to 4 is implemented.

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