Control method of pneumatic diaphragm pump

Abstract

The invention discloses a control method of a pneumatic diaphragm pump, relates to the technical field of pneumatic diaphragm pumps, and solves the technical problem that monitoring and adjustment of control parameters of the pneumatic diaphragm pump are lack of systematic, comprehensive and accurate control. In the case of overhigh pressure, the opening degree of the valve is uniformly divided, the pressure values corresponding to different opening degrees and the mean value of the change values are calculated to serve as a first adjusting standard, meanwhile, similar analysis is conducted on the pressure reducing valve to obtain a second adjusting standard, and the opening degree of the valve and the opening degree of the pressure reducing valve are accurately calculated according to the standards and the pressure difference value. Scientific and quantitative pressure regulation is realized, regulation blindness is avoided, and accurate and efficient regulation of the flow can be realized according to the motor frequency corresponding to the normal flow in the regulation reference table when the flow is too high or too low by calculating the flow parameter difference and judging the abnormal flow condition.

Description

Technical Field

[0001] The invention relates to the technical field of pneumatic diaphragm pumps, and in particular to a control method for a pneumatic diaphragm pump. Background Art

[0002] In industrial production, pneumatic diaphragm pumps are widely used in liquid transportation and other fields. The stability of its operating state and the precise control of its parameters are crucial to the production process.

[0003] According to the patent application with publication number CN105756907A, a pneumatic diaphragm pump with a controller is disclosed, including a pneumatic diaphragm pump, a controller, a touch screen control panel, a solenoid valve, an air compressor, a pressure sensor, and a flow meter; the controller is connected to the pneumatic diaphragm pump, the touch screen control panel, the solenoid valve, the pressure sensor, and the flow meter through a signal line; the air compressor is connected to the pneumatic diaphragm pump through the solenoid valve, the pressure sensor is installed at the outlet of the pneumatic diaphragm pump, and is used to detect the outlet pressure of the pneumatic diaphragm pump, and transmit the detection result to the controller; the flow meter is installed at the outlet of the pneumatic diaphragm pump, and is used to detect the flow rate of the liquid at the outlet of the pneumatic diaphragm pump, and is transmitted to the controller; the touch screen control panel is used to display the pressure and flow, and to set the pressure threshold and flow value.

[0004] However, in the actual operation of some existing pneumatic diaphragm pumps, the flow parameters and pressure parameters of the pneumatic diaphragm pumps are easily affected by various factors and fluctuate, such as changes in medium characteristics, changes in pipeline resistance, unstable air source, etc. In the past, there was often a lack of systematic, comprehensive and accurate methods for monitoring and adjusting the control parameters of pneumatic diaphragm pumps, making it difficult to quickly and effectively respond to abnormal parameters, resulting in reduced production efficiency, affected product quality, and even equipment failure, increased maintenance costs and the risk of production interruption. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a control method for a pneumatic diaphragm pump, which solves the problem of lack of systematic, comprehensive and precise control over the monitoring and adjustment of the control parameters of the pneumatic diaphragm pump.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a control method for a pneumatic diaphragm pump, the method specifically comprising the following steps:

[0007] Obtaining the flow parameters and pressure parameters of the pneumatic diaphragm pump, comparing them with the corresponding working parameters, and generating abnormal state signals and normal state signals;

[0008] Analyze the generated abnormal state signal, judge the size of the pressure parameter in the abnormal control parameter to generate a high pressure signal or a low pressure signal, and adjust the valve opening of the pneumatic diaphragm pump and the pressure reducing valve opening according to different pressure values ​​to generate pressure control adjustment information;

[0009] Then, the flow parameters in the abnormal control parameters are adjusted, and the motor frequency of the pneumatic diaphragm pump is adjusted in combination with the actual flow parameter difference, and flow control adjustment information is generated;

[0010] The specific abnormal control parameters are obtained, and the pneumatic diaphragm pump is adjusted according to the adjustment information corresponding to the specific abnormal control parameters.

[0011] As a further solution of the present invention, the specific method of generating the abnormal state signal and the normal state signal is:

[0012] Compare the control parameters of the pneumatic diaphragm pump with the corresponding working parameters under the working state, wherein the control parameters specifically include flow parameters and pressure parameters, and the working parameters include the flow parameters and pressure parameters corresponding to the normal working condition;

[0013] If the control parameter does not exist in the numerical range of the working parameter, it means that the control parameter is abnormal and an abnormal state signal is generated. Otherwise, it means that the control parameter is normal and a normal state signal is generated.

[0014] As a further solution of the present invention, the specific method of analyzing the abnormal state signal is:

[0015] The abnormal state signal is obtained, and the pressure parameter in the abnormal control parameter is obtained at the same time, and the difference between the pressure parameter and the working parameter is calculated and recorded as the pressure difference. If the pressure difference is greater than zero, it means that the pressure parameter is lower than the normal value, and a low pressure signal is generated. Conversely, if the pressure difference is greater than zero, it means that the pressure parameter is higher than the normal value, and a high pressure signal is generated, and the two are analyzed and processed.

[0016] As a further solution of the present invention, the specific method of analyzing and processing the underpressure signal and the overpressure signal is:

[0017] The generated high pressure signal is analyzed, the valve opening is divided and labeled as i, and i=1, 2, ..., j, where j represents the valve opening size, and the pressure values ​​corresponding to different valve openings i are recorded as Yi, and the average value of the change value corresponding to the relationship between the valve opening and the pressure is calculated and recorded as the first adjustment standard Q;

[0018] The pressure reducing valve is adjusted to reduce the air source pressure, and the relationship between the pressure reducing valve opening and the output pressure of the pneumatic diaphragm pump is analyzed. Similarly, the valve opening analysis method is used to calculate the second adjustment standard R corresponding to the pressure reducing valve opening and the output pressure of the pneumatic diaphragm pump. Then, the calculated pressure difference is obtained, and the pressure difference is adjusted according to the first adjustment standard and the second adjustment standard to generate pressure control adjustment information.

[0019] As a further solution of the present invention, the specific method of generating the pressure control adjustment information is:

[0020] Get the valve opening and pressure reducing valve opening corresponding to the same adjustment pressure value, and calculate the ratio of the valve opening and pressure reducing valve opening to the adjustment pressure value, record them as valve ratio F1 and pressure reducing valve ratio F2, then substitute the first adjustment standard Q and the second adjustment standard R into the formula The valve opening k1 and the pressure reducing valve opening k2 are obtained by solving, where Yc is the pressure difference, and the pressure control adjustment information is generated at the same time;

[0021] For the case where the pressure is too low, or too high, the valve opening and the pressure reducing valve opening are adjusted to generate pressure control adjustment information.

[0022] As a further solution of the present invention, the specific method of adjusting the flow parameters is:

[0023] The flow parameters in the abnormal control parameters are recorded as the parameters to be analyzed, and the normal flow parameters in the working parameters are obtained. The flow parameter difference is calculated at the same time, and the motor frequency corresponding to the parameter to be analyzed is recorded as the real-time frequency. The relationship between different motor frequencies and flow sizes is analyzed according to historical data, and an adjustment reference table is generated. Adjustment is performed based on the comprehensive adjustment reference table.

[0024] As a further solution of the present invention, the specific manner of adjusting the comprehensive adjustment reference table is:

[0025] If the flow parameter difference is greater than zero, it means that the parameter to be analyzed is higher than the normal flow parameter, and a high flow signal is generated. Conversely, if the flow parameter difference is less than zero, it means that the parameter to be analyzed is lower than the normal flow parameter, and a low flow signal is generated. Then the two are analyzed separately.

[0026] The generated high flow signal is analyzed to obtain the real-time frequency. At the same time, the corresponding motor frequency in the adjustment reference table is obtained based on the normal flow parameters, and the motor frequency is adjusted based on the obtained motor frequency to generate flow control adjustment information.

[0027] As a further solution of the present invention, the specific method of analyzing the low flow rate signal is:

[0028] The motor frequency corresponding to the normal flow parameters is obtained, and the difference between the motor frequency and the real-time frequency is calculated. The real-time frequency is adjusted based on the calculated difference, and flow control adjustment information is generated.

[0029] The present invention provides a control method for a pneumatic diaphragm pump. Compared with the prior art, the present invention has the following beneficial effects:

[0030] The present invention calculates the pressure difference when the pressure parameter is abnormal to clarify the direction of the pressure abnormality. For the case of excessive pressure, the valve opening is evenly divided, and the pressure values ​​corresponding to different openings and the average of the change values ​​are calculated as the first adjustment standard. At the same time, a similar analysis is performed on the pressure reducing valve to obtain the second adjustment standard. The valve opening and the pressure reducing valve opening are accurately calculated according to these standards and the pressure difference, so as to realize scientific and quantitative pressure regulation and avoid blind regulation.

[0031] By calculating the difference in flow parameters, the abnormal flow situation can be judged. If the flow is too high, the current motor frequency can be accurately adjusted to reduce the flow according to the motor frequency corresponding to the normal flow in the adjustment reference table; if the flow is too low, the motor frequency difference corresponding to the normal flow and the abnormal flow is calculated, and the motor frequency is adjusted based on the difference to increase the flow, thus achieving accurate and efficient flow regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a step method diagram of the present invention;

[0033] Figure 2 This is the principle control diagram of the pneumatic diaphragm pump system of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1 and Figure 2 The present application provides a control method for a pneumatic diaphragm pump. Specifically, the pneumatic diaphragm pump includes components such as a pump body, a joint, a control valve, and a connecting pipeline. Each pump chamber is equipped with an independent inlet and outlet, and the pump chambers are connected through connecting pipelines. The control valve is used to control the working mode of the pneumatic diaphragm pump, including a single pumping mode and a multi-pumping mode. The method specifically includes the following steps:

[0036] Step 1: Obtain the control parameters of the pneumatic diaphragm pump, compare the control parameters with the working parameters, and generate a state recognition result.

[0037] The control parameters of the pneumatic diaphragm pump are obtained, and the control parameters include the flow parameters and pressure parameters of the pneumatic diaphragm pump. Then, the obtained control parameters are compared with the corresponding working parameters under the working state. The working parameters here are represented by the flow data and pressure data of the pneumatic diaphragm pump under the current working state, wherein the flow data and the pressure data are range values. If the control parameters do not match the working parameters, it indicates that the control parameters are abnormal, and an abnormal state signal is generated. Otherwise, if the control parameters match the working parameters, it indicates that the control parameters are normal, and a normal state signal is generated.

[0038] Step 2: Analyze the generated abnormal state signal, adjust the pressure parameters in the abnormal control parameters, and adjust the valve opening of the pneumatic diaphragm pump and the pressure reducing valve opening according to different pressure values ​​to generate pressure control adjustment information.

[0039] Acquire the abnormal state signal, and at the same time acquire the pressure parameter in the abnormal control parameter, and here is the abnormal pressure parameter obtained after comparison, and calculate the difference between the pressure parameter and the working parameter as the pressure difference, and the specific calculation formula here is pressure difference = pressure parameter - working parameter, if the pressure difference is greater than zero, it means that the pressure parameter is lower than the normal value, and a low pressure signal is generated, otherwise if the pressure difference is greater than zero, it means that the pressure parameter is higher than the normal value, and a high pressure signal is generated;

[0040] Suppose there is a pneumatic diaphragm pump for conveying liquid, and the normal working pressure parameter is set to 50 kilopascals (kPa). The control system monitors the pressure of the pump in real time. At a certain moment, the control system obtains an abnormal state signal. If the current pressure parameter obtained is 40kPa, the pressure difference between the current pressure parameter and the normal working pressure parameter is calculated, that is, 40-50=-10kPa. The pressure difference is less than 0, and the actual pressure is lower than the normal working pressure, so a low pressure signal is generated. Conversely, if the current pressure parameter obtained is 60kPa, the difference is calculated to be 60-50=10kPa, and the pressure difference is greater than 0. The actual pressure is higher than the normal working pressure, and a high pressure signal is generated.

[0041] Then, the generated high pressure signal is analyzed, and the valve opening is analyzed. The valve opening is divided and labeled as i, and i=1, 2, ..., j, where j represents the size of the valve opening, and the size here is represented by the cross-sectional area. At the same time, the divided valve opening is equally divided, and the pressure values ​​corresponding to different valve openings i are recorded and recorded as Yi. Then, the relationship between the valve opening and the pressure is analyzed and the corresponding change value is calculated. The change value is calculated by calculating the pressure difference corresponding to two adjacent groups of valve openings and the ratio of the valve opening difference, and calculating the average of all the change values. The obtained average value is used as the first adjustment standard and recorded as Q;

[0042] For example, there is a valve for regulating pressure with a maximum cross-sectional area of ​​100 cm 2 , minimum cross-sectional area is 10cm 2 , divide the valve opening evenly into 5 intervals, that is, i=5, and then calculate the cross-sectional area difference of each interval to be 18cm 2 , when i=1, the valve cross-sectional area A1=18cm 2 , when i=2, the valve cross-sectional area A1=28cm 2 , when i=3, the valve cross-sectional area A1=46cm 2 , when i=4, the valve cross-sectional area A1=64cm 2 , when i=5, the valve cross-sectional area A1=82cm 2 ;

[0043] Then calculate the corresponding change value. The specific formula is: That is, the ratio of the pressure difference between two adjacent groups to the cross-sectional area difference of the valve. When i=1 changes to i=2, the change value is -0.56 kPa / cm 2 , and so on to calculate all the change values, and then calculate the average of the calculated change values ​​to get the final adjustment standard of -0.49kPa / cm 2 .

[0044] At the same time, the pressure reducing valve is adjusted to reduce the gas source pressure, and the relationship between the pressure reducing valve opening and the output pressure of the pneumatic diaphragm pump is analyzed. Similarly, the valve opening analysis method is used to calculate the second adjustment standard corresponding to the pressure reducing valve opening and the output pressure of the pneumatic diaphragm pump, which is recorded as R. Then, the calculated pressure difference is obtained, and the pressure difference here is the value calculated above, and the pressure difference is adjusted according to the first adjustment standard and the second adjustment standard, and the specific adjustment method is as follows:

[0045] The valve opening and the pressure reducing valve opening corresponding to the same adjustment pressure value are obtained, and the ratios of the valve opening and the pressure reducing valve opening to the adjustment pressure value are calculated respectively, which are recorded as valve ratio F1 and pressure reducing valve ratio F2. The specific calculation expressions are valve ratio F1 = valve opening ÷ adjustment pressure value, pressure reducing valve ratio F2 = pressure reducing valve opening ÷ adjustment pressure value. Then, the first adjustment standard Q and the second adjustment standard R obtained are substituted into the formula The valve opening k1 and the pressure reducing valve opening k2 are obtained by solving, where Yc is the pressure difference, and the pressure control adjustment information is generated at the same time;

[0046] For the case where the pressure is too low, or too high, the valve opening and the pressure reducing valve opening are adjusted to generate pressure control adjustment information.

[0047] Step 3: Adjust the flow parameters in the abnormal control parameters, combine the actual flow parameter difference, adjust the motor frequency of the pneumatic diaphragm pump, and generate flow control adjustment information.

[0048] The flow parameter in the abnormal control parameter is obtained and recorded as the parameter to be analyzed, and then the normal flow parameter in the working parameter is obtained, and the flow parameter difference is calculated, and the specific calculation formula is: flow parameter difference = parameter to be analyzed - normal flow parameter, and at the same time, the motor frequency corresponding to the parameter to be analyzed is obtained and recorded as the real-time frequency, and the motor frequency here is represented as the motor frequency corresponding to the current abnormal control parameter. Then, historical data is obtained, and the relationship between different motor frequencies and flow sizes is analyzed to generate an adjustment reference table, and the adjustment reference table here indicates that different motor frequencies will correspond to a flow size parameter, and the obtained relationship is further sorted to obtain an adjustment reference table, and then the obtained flow parameter difference is judged;

[0049] If the flow parameter difference is greater than zero, it means that the parameter to be analyzed is higher than the normal flow parameter, and a high flow signal is generated. Conversely, if the flow parameter difference is less than zero, it means that the parameter to be analyzed is lower than the normal flow parameter, and a low flow signal is generated. Then the two are analyzed separately.

[0050] Analyze the generated high flow rate signal to obtain the real-time frequency, and at the same time obtain the corresponding motor frequency in the adjustment reference table based on the normal flow parameters, and adjust it based on the obtained motor frequency to generate flow control adjustment information;

[0051] For example, the normal flow parameter of a certain device is set to 50 cubic meters / hour. At a certain moment, the flow parameter (parameter to be analyzed) in the abnormal control parameter is 60 cubic meters / hour. At this time, the calculated flow parameter difference = 60-50 = 10 cubic meters / hour. The difference is greater than 0, and the system generates a high flow signal. The real-time frequency corresponding to the parameter to be analyzed is 55Hz. From the adjustment reference table generated from historical data, it can be seen that the motor frequency corresponding to the normal flow of 50 cubic meters / hour is 50Hz. Then, based on 50Hz as the standard, the generated flow control adjustment information may be to reduce the motor frequency from 55Hz to 50Hz, thereby reducing the flow.

[0052] The generated low flow signal is analyzed to obtain the motor frequency corresponding to the normal flow parameters, and the difference between the motor frequency and the real-time frequency is calculated. The real-time frequency is adjusted based on the calculated difference, and the flow control adjustment information is generated.

[0053] For another example, if the parameter to be analyzed is 40 cubic meters per hour, the flow parameter difference = 40-50 = -10 cubic meters per hour, and the difference is less than 0, the system generates a low flow signal, and the real-time frequency is 45Hz. The motor frequency corresponding to the normal flow of 50 cubic meters per hour is 50Hz, and the difference between the two is 50-45 = 5Hz. Then, the real-time frequency is adjusted based on this 5Hz difference, and the generated flow control adjustment information may be to increase the motor frequency from 45Hz to 50Hz, thereby increasing the flow rate.

[0054] Step 4: Obtain specific abnormal control parameters, and adjust the pneumatic diaphragm pump according to adjustment information corresponding to the specific abnormal control parameters.

[0055] Some of the data in the above formulas are calculated by taking their numerical values, and are not substituted into parameter units for calculation. At the same time, the contents not described in detail in this specification belong to the existing technologies known to those skilled in the art.

[0056] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A control method for a pneumatic diaphragm pump, characterized in that: The method specifically comprises the following steps: Obtaining the flow parameters and pressure parameters of the pneumatic diaphragm pump, comparing them with the corresponding working parameters, and generating abnormal state signals and normal state signals; Analyze the generated abnormal state signal, judge the size of the pressure parameter in the abnormal control parameter to generate a high pressure signal or a low pressure signal, and adjust the valve opening of the pneumatic diaphragm pump and the pressure reducing valve opening according to different pressure values ​​to generate pressure control adjustment information; Then, the flow parameters in the abnormal control parameters are adjusted, and the motor frequency of the pneumatic diaphragm pump is adjusted in combination with the actual flow parameter difference, and flow control adjustment information is generated; The specific abnormal control parameters are obtained, and the pneumatic diaphragm pump is adjusted according to the adjustment information corresponding to the specific abnormal control parameters.

2. The control method of a pneumatic diaphragm pump according to claim 1, characterized in that: The specific method of generating the abnormal state signal and the normal state signal is: Compare the control parameters of the pneumatic diaphragm pump with the corresponding working parameters under the working state, wherein the control parameters specifically include flow parameters and pressure parameters, and the working parameters include the flow parameters and pressure parameters corresponding to the normal working condition; If the control parameter does not exist in the numerical range of the working parameter, it means that the control parameter is abnormal and an abnormal state signal is generated. Otherwise, it means that the control parameter is normal and a normal state signal is generated.

3. The control method of a pneumatic diaphragm pump according to claim 1, characterized in that: The specific method of analyzing the abnormal state signal is: The abnormal state signal is obtained, and the pressure parameter in the abnormal control parameter is obtained at the same time, and the difference between the pressure parameter and the working parameter is calculated and recorded as the pressure difference. If the pressure difference is greater than zero, it means that the pressure parameter is lower than the normal value, and a low pressure signal is generated. Conversely, if the pressure difference is greater than zero, it means that the pressure parameter is highly normal, and a high pressure signal is generated, and the two are analyzed and processed.

4. The control method of a pneumatic diaphragm pump according to claim 3, characterized in that: The specific method for analyzing and processing the low pressure signal and the high pressure signal is as follows: The generated high pressure signal is analyzed, the valve opening is divided and labeled as i, and i=1, 2, ..., j, where j represents the valve opening size, and the pressure values ​​corresponding to different valve openings i are recorded as Yi, and the average value of the change value corresponding to the relationship between the valve opening and the pressure is calculated and recorded as the first adjustment standard Q; The pressure reducing valve is adjusted to reduce the air source pressure, and the relationship between the pressure reducing valve opening and the output pressure of the pneumatic diaphragm pump is analyzed. Similarly, the valve opening analysis method is used to calculate the second adjustment standard R corresponding to the pressure reducing valve opening and the output pressure of the pneumatic diaphragm pump. Then, the calculated pressure difference is obtained, and the pressure difference is adjusted according to the first adjustment standard and the second adjustment standard to generate pressure control adjustment information.

5. The control method of a pneumatic diaphragm pump according to claim 4, characterized in that: The specific method of generating the pressure control adjustment information is: Get the valve opening and pressure reducing valve opening corresponding to the same adjustment pressure value, and calculate the ratio of the valve opening and pressure reducing valve opening to the adjustment pressure value, record them as valve ratio F1 and pressure reducing valve ratio F2, then substitute the first adjustment standard Q and the second adjustment standard R into the formula The valve opening k1 and the pressure reducing valve opening k2 are obtained by solving, where Yc is the pressure difference, and the pressure control adjustment information is generated at the same time; For the case where the pressure is too low, or too high, the valve opening and the pressure reducing valve opening are adjusted to generate pressure control adjustment information.

6. The control method of a pneumatic diaphragm pump according to claim 1, characterized in that: The specific way to adjust the flow parameters is: The flow parameters in the abnormal control parameters are recorded as the parameters to be analyzed, and the normal flow parameters in the working parameters are obtained. The flow parameter difference is calculated at the same time, and the motor frequency corresponding to the parameter to be analyzed is recorded as the real-time frequency. The relationship between different motor frequencies and flow sizes is analyzed according to historical data, and an adjustment reference table is generated. Adjustment is performed based on the comprehensive adjustment reference table.

7. A control method for a pneumatic diaphragm pump according to claim 6, characterized in that: The specific method of adjusting the comprehensive adjustment reference table is as follows: If the flow parameter difference is greater than zero, it means that the parameter to be analyzed is higher than the normal flow parameter, and a high flow signal is generated. Conversely, if the flow parameter difference is less than zero, it means that the parameter to be analyzed is lower than the normal flow parameter, and a low flow signal is generated. Then the two are analyzed separately. The generated high flow signal is analyzed to obtain the real-time frequency. At the same time, the corresponding motor frequency in the adjustment reference table is obtained based on the normal flow parameters, and the motor frequency is adjusted based on the obtained motor frequency to generate flow control adjustment information.

8. The control method of a pneumatic diaphragm pump according to claim 7, characterized in that: The specific method of analyzing the low flow rate signal is as follows: The motor frequency corresponding to the normal flow parameters is obtained, and the difference between the motor frequency and the real-time frequency is calculated. The real-time frequency is adjusted based on the calculated difference, and flow control adjustment information is generated.

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