Method and system for precise control of liquid flow in a radioisotope separation device

Abstract

This invention provides a method and system for precise control of liquid flow rate in a radioactive separation device, relating to the field of liquid flow control technology. The method involves collecting instantaneous flow rate data at the column inlet, pressure data from the delivery pipeline, and rotational speed data of the metering pump, and processing this data using a sliding time window to obtain the average flow rate and the slope of the flow rate change. It then calculates the equivalent flow resistance coefficient based on the pressure change relationship and the theoretical delivery capacity of the metering pump, and determines the liquid flow transmission delay time according to the pipeline volume parameters, thereby predicting the column inlet flow rate corresponding to the delay time. The metering pump rotational speed is adjusted based on the deviation between the predicted flow rate and the target flow rate, and the effective buffer volume of the buffer flow stabilization chamber is adjusted to suppress flow pulsation. Simultaneously, the control parameters are continuously corrected through rolling data updates to maintain the column inlet flow rate within the preset target flow rate range.

Description

Technical Field

[0001] This invention relates to the field of liquid flow control technology, and in particular to a method and system for precise control of liquid flow in a radioactive separation device. Background Technology

[0002] In existing technologies, liquid flow control in radioactive separation devices often adopts a closed-loop scheme of "storage tank - metering pump - flow meter - regulating valve": the PLC or PID controller adjusts the speed of the metering pump or the opening of the valve according to the set flow rate, the flow meter provides real-time feedback of the instantaneous flow rate, and, if necessary, a pulsation damper and a back pressure valve are used to maintain the stable delivery of acid, eluent or complexing agent at the inlet of the separation column, thereby completing the extraction, rinsing or exchange separation of radionuclides.

[0003] However, when performing column separation of radioactive strontium, cesium, or actinides in a heated chamber, this method is prone to control lag due to long-distance shielded pipelines, metering pump pulsation, and changes in the viscosity of high-density acid. For example, when the set flow rate is switched from 0.8 mL / min to 1.2 mL / min, the actual flow rate at the column inlet often experiences short-term overshoot or drop, causing fluctuations in the resin bed contact time. This leads to overlap between the elution fronts of the target component and the impurity component, increasing the difficulty of subsequent fractional collection and waste liquid identification. Summary of the Invention

[0004] The purpose of this invention is to provide a method and system for precise control of liquid flow rate in a radioactive separation device, aiming to solve the problems mentioned in the background art.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0006] A first aspect is a method for precise control of liquid flow rate in a radioactive separation device, the method comprising:

[0007] S1. Collect instantaneous flow data at the column inlet, pressure data of long-distance shielded infusion pipeline, and speed data of metering pump synchronously according to the preset sampling period, and form a data sequence arranged in chronological order;

[0008] S2. Perform sliding time window processing on the data sequence of multiple consecutive sampling periods, calculate the average flow rate within the time window, the flow rate difference between adjacent sampling periods, and the slope of flow rate change, and calculate the equivalent flow resistance coefficient based on the relationship between pressure data and average flow rate, the difference between the theoretical liquid delivery capacity corresponding to the metering pump speed and the average flow rate.

[0009] S3. Calculate the flow transmission delay time of the liquid in the liquid delivery path based on the equivalent flow resistance coefficient and the preset pipeline volume parameters of the long-distance shielded infusion pipeline, and predict the column inlet flow corresponding to the future delay time by combining the current flow rate change slope, and obtain the predicted flow rate value.

[0010] S4. Compare the predicted flow rate with the preset target flow rate to obtain the predicted flow rate deviation, and determine the pre-compensation speed correction amount of the metering pump based on the predicted flow rate deviation.

[0011] S5. Based on the pre-compensated speed correction amount, perform speed correction on the metering pump, calculate the flow pulsation amplitude value within the continuous time window, compare the flow pulsation amplitude value with the preset pulsation threshold, determine the volume adjustment amount of the buffer flow stabilizing cavity set between the metering pump and the separation column, and adjust the effective buffer volume of the buffer flow stabilizing cavity according to the volume adjustment amount.

[0012] S6. After the current adjustment cycle ends, the data sequence is updated on a rolling basis according to the instantaneous flow rate data, pressure data and metering pump speed data collected in the current adjustment cycle, and the equivalent flow resistance coefficient, flow transmission delay time and predicted flow deviation are recalculated to coordinate the metering pump speed and buffer flow stabilization chamber volume, so that the column inlet flow rate is stably maintained within the preset target flow range.

[0013] Preferably, step S2 includes:

[0014] S21. Perform statistical processing on the instantaneous flow data according to the sampling order within the sliding time window to determine the average flow value, the flow difference between adjacent sampling periods, and the slope of flow change within the sliding time window.

[0015] S22. Match the pressure data with the instantaneous flow rate data according to the sampling time sequence, and determine the pressure-flow rate change characteristics in the liquid delivery path based on the correspondence between pressure changes and average flow rate values.

[0016] S23. Determine the flow deviation state of the liquid during the transportation process based on the difference between the theoretical liquid conveying capacity corresponding to the metering pump speed and the average flow value.

[0017] S24. Determine the flow resistance change state of the liquid transport path based on the pressure-flow change characteristics and the flow deviation state, and convert the flow resistance change state into an equivalent flow resistance coefficient that characterizes the current flow characteristics of the liquid transport path.

[0018] Preferably, step S3 includes:

[0019] S31. Obtain the preset pipeline volume parameters of the long-distance shielded infusion pipeline, and determine the basic transmission time of the liquid in the liquid delivery path by combining the average flow rate value within the sliding time window.

[0020] S32. Correct the basic transmission time for flow resistance based on the equivalent flow resistance coefficient to determine the actual flow transmission delay time of the liquid in the liquid transport path.

[0021] S33. Multiply the slope of the flow rate change with the actual flow rate transmission delay time to obtain the flow rate change value within the delay time.

[0022] S34. Sum the flow change value with the average flow value within the sliding time window to obtain the predicted flow value at the column inlet at the corresponding time of the delay time.

[0023] Preferably, step S5 includes:

[0024] S51. Perform statistical processing on the continuously collected instantaneous flow data within the sliding time window to determine the maximum and minimum flow values ​​within the sliding time window.

[0025] S52. Determine the flow pulsation amplitude based on the difference between the maximum and minimum flow values;

[0026] S53. Based on the comparison between the flow pulsation amplitude and the preset pulsation threshold, determine the volume adjustment requirements of the buffer flow stabilization cavity.

[0027] S54. Determine the volume adjustment amount of the buffer flow stabilizing cavity according to the volume adjustment requirements, and adjust the effective buffer volume of the buffer flow stabilizing cavity according to the volume adjustment amount to change the flow pulsation state in the liquid delivery path.

[0028] Preferably, step S23 includes:

[0029] S231. Determine the theoretical flow rate of the metering pump under the current speed condition based on the metering pump speed and the rated delivery characteristics of the metering pump.

[0030] S232. Compare the theoretical flow rate with the average flow rate within the sliding time window to obtain the flow rate difference between the theoretical flow rate and the average flow rate.

[0031] S233. Calculate the ratio between the flow difference and the average flow value to obtain the flow deviation coefficient, which characterizes the degree of flow deviation in the liquid transport path.

[0032] S234. The flow deviation coefficient is used as a quantitative characterization of the flow deviation state generated by the liquid during the transportation process.

[0033] Preferably, step S24 includes:

[0034] S241. Determine the maximum and minimum pressure values ​​within the sliding time window based on the pressure data, and calculate the pressure difference between the maximum and minimum pressure values.

[0035] S242. The pressure difference value is calculated by comparing the pressure difference value with the average flow rate value, which is the unit flow pressure variation coefficient that characterizes the flow resistance characteristics of the liquid transport path.

[0036] S243. Multiply the pressure variation coefficient per unit flow rate with the flow deviation coefficient to obtain the resistance variation coefficient, which characterizes the degree of change in flow resistance in the liquid transport path.

[0037] S244. Use the resistance variation coefficient as the equivalent flow resistance coefficient of the liquid transport path.

[0038] Preferably, step S32 includes:

[0039] S321. Determine the degree of change in the flow resistance of liquid in the liquid transport path based on the equivalent flow resistance coefficient;

[0040] S322. Determine the delay correction ratio corresponding to the basic transmission time based on the degree of change in flow resistance, and convert the basic transmission time according to the delay correction ratio to obtain the resistance correction time used to characterize the influence of flow resistance.

[0041] S323. The resistance correction time is superimposed with the basic transmission time to obtain the actual flow transmission delay time of the liquid in the liquid transport path.

[0042] Secondly, a precise liquid flow control system in a radioactive separation device, the system comprising:

[0043] The data acquisition module is used to synchronously collect instantaneous flow data at the column inlet, pressure data of long-distance shielded infusion pipeline, and speed data of metering pump according to a preset sampling period, and form a data sequence arranged in chronological order.

[0044] The flow resistance identification module is used to process the data sequence of multiple consecutive sampling periods through a sliding time window, calculate the average flow rate within the time window, the flow rate difference between adjacent sampling periods, and the slope of the flow rate change, and calculate the equivalent flow resistance coefficient based on the relationship between the pressure data and the average flow rate, the difference between the theoretical liquid delivery capacity corresponding to the metering pump speed and the average flow rate.

[0045] The delay prediction module is used to calculate the flow transmission delay time of liquid in the liquid delivery path based on the equivalent flow resistance coefficient and the preset pipeline volume parameters of the long-distance shielded infusion pipeline, and to predict the column inlet flow corresponding to the future delay time by combining the current flow rate change slope, so as to obtain the predicted flow rate value.

[0046] The pre-compensation control module is used to compare the predicted flow rate value with the preset target flow rate value to obtain the predicted flow rate deviation, and to determine the pre-compensation speed correction amount of the metering pump based on the predicted flow rate deviation.

[0047] The flow stabilization module is used to perform speed correction on the metering pump according to the pre-compensated speed correction amount, and at the same time calculate the flow pulsation amplitude value within the continuous time window, compare the flow pulsation amplitude value with the preset pulsation threshold, determine the volume adjustment amount of the buffer flow stabilization cavity set between the metering pump and the separation column, and adjust the effective buffer volume of the buffer flow stabilization cavity according to the volume adjustment amount.

[0048] The rolling update module is used to update the data sequence based on the instantaneous flow rate data, pressure data and metering pump speed data collected during the current adjustment cycle after the current adjustment cycle ends. It also recalculates the equivalent flow resistance coefficient, flow transmission delay time and predicted flow deviation to coordinately correct the metering pump speed and buffer flow stabilization chamber volume, so that the column inlet flow rate is stably maintained within the preset target flow range.

[0049] The above-described solution of the present invention has at least the following beneficial effects:

[0050] By synchronously collecting instantaneous flow data at the column inlet, pressure data of long-distance shielded infusion pipeline, and speed data of metering pump according to a preset sampling period, and processing the continuous sampling data with a sliding time window, parameters reflecting the trend of flow change, such as average flow rate and flow change slope, can be obtained. At the same time, by combining the pressure change and the difference between the theoretical delivery capacity of the metering pump and the actual flow rate, the equivalent flow resistance coefficient can be calculated, so that the flow resistance change in the liquid delivery path can be identified, thereby providing a parameter basis reflecting the actual delivery status for subsequent flow prediction.

[0051] Based on this, the flow transmission delay time of the liquid in the delivery path is calculated according to the equivalent flow resistance coefficient and the preset pipeline volume parameters of the long-distance shielded infusion pipeline. Combined with the flow change slope, the column inlet flow rate at the corresponding moment of the delay time is predicted, so that the liquid flow rate can be predicted before it actually reaches the separation column inlet. This allows for advance adjustment before the flow change is fully transmitted to the separation column inlet, reducing the phenomenon of column inlet flow overshoot or drop caused by delivery lag under long-distance shielded pipeline conditions.

[0052] Furthermore, the pre-compensation speed correction amount of the metering pump is determined based on the deviation between the predicted flow rate and the preset target flow rate, and the flow pulsation is buffered by adjusting the effective buffer volume of the buffer flow stabilizing chamber. This allows the output flow rate of the metering pump and the flow fluctuation in the delivery path to be adjusted simultaneously, thereby maintaining the stability of the column inlet flow rate under the combined effect of flow prediction compensation and flow pulsation suppression.

[0053] By continuously updating the instantaneous flow rate data, pressure data, and metering pump speed data after each adjustment cycle, and recalculating the equivalent flow resistance coefficient, flow transmission delay time, and predicted flow deviation, the flow control process can continuously correct the control parameters as the delivery conditions change. This ensures that the column inlet flow rate remains within the preset range even in long-distance liquid delivery environments in hot chambers, reducing changes in resin bed contact time caused by flow fluctuations and minimizing the overlap of the elution fronts of target and impurity components. Attached Figure Description

[0054] Figure 1 This is a flowchart of a method for precise control of liquid flow rate in a radioactive separation device provided in an embodiment of the present invention. Detailed Implementation

[0055] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0056] like Figure 1 As shown, embodiments of the present invention propose a method for precise control of liquid flow rate in a radioactive separation device, the method comprising:

[0057] S0. Construct a liquid delivery path, including a storage tank, a metering pump, a long-distance shielded delivery pipeline, a buffer flow stabilizing chamber, and a separation column. The buffer flow stabilizing chamber is located between the metering pump and the separation column. The buffer flow stabilizing chamber is equipped with a volume adjustment structure for changing the effective internal buffer volume. A flow detection unit is installed at the inlet of the separation column, and a pressure detection unit is installed on the long-distance shielded delivery pipeline.

[0058] S1. Collect instantaneous flow data at the column inlet, pressure data of long-distance shielded infusion pipeline, and speed data of metering pump synchronously according to the preset sampling period, and form a data sequence arranged in chronological order;

[0059] S2. Perform sliding time window processing on the data sequence of multiple consecutive sampling periods, calculate the average flow rate within the time window, the flow rate difference between adjacent sampling periods, and the slope of flow rate change, and calculate the equivalent flow resistance coefficient based on the relationship between pressure data and average flow rate, the difference between the theoretical liquid delivery capacity corresponding to the metering pump speed and the average flow rate.

[0060] S3. Calculate the flow transmission delay time of the liquid in the liquid delivery path based on the equivalent flow resistance coefficient and the preset pipeline volume parameters of the long-distance shielded infusion pipeline, and predict the column inlet flow corresponding to the future delay time by combining the current flow rate change slope, and obtain the predicted flow rate value.

[0061] S4. Compare the predicted flow rate with the preset target flow rate to obtain the predicted flow rate deviation, and determine the pre-compensation speed correction amount of the metering pump based on the predicted flow rate deviation.

[0062] S5. Based on the pre-compensated speed correction amount, perform speed correction on the metering pump, calculate the flow pulsation amplitude value within the continuous time window, compare the flow pulsation amplitude value with the preset pulsation threshold, determine the buffer flow stabilization chamber volume adjustment amount, and adjust the effective buffer volume of the buffer flow stabilization chamber according to the volume adjustment amount.

[0063] S6. After the current adjustment cycle ends, the data sequence is updated on a rolling basis according to the instantaneous flow rate data, pressure data and metering pump speed data collected in the current adjustment cycle, and the equivalent flow resistance coefficient, flow transmission delay time and predicted flow deviation are recalculated to coordinate the metering pump speed and buffer flow stabilization chamber volume, so that the column inlet flow rate is stably maintained within the preset target flow range.

[0064] In this embodiment of the invention, by synchronously collecting instantaneous flow rate data at the column inlet, pressure data of the long-distance shielded infusion pipeline, and rotational speed data of the metering pump according to a preset sampling period, and processing the data from multiple consecutive sampling periods using a sliding time window, key parameters reflecting the flow rate change trend, such as average flow rate, flow rate difference, and flow rate change slope, can be obtained. Based on this, combining the relationship between pressure data and average flow rate, and the difference between the theoretical liquid delivery capacity corresponding to the metering pump rotational speed and the average flow rate, the equivalent flow resistance coefficient of the liquid delivery path is calculated. This reflects the actual flow state of the liquid in the long-distance infusion pipeline, allowing subsequent flow prediction and control processes to be adjusted based on real-time flow characteristics.

[0065] Furthermore, by combining the equivalent flow resistance coefficient with the preset pipeline volume parameters of the long-distance shielded infusion pipeline to calculate the flow transmission delay time of the liquid in the liquid delivery path, and combining this with the flow change slope to predict the column inlet flow rate corresponding to the future delay time, the flow change trend can be predicted before the liquid actually reaches the separation column inlet. Based on the deviation between this predicted flow rate and the preset target flow rate, the pre-compensation speed correction amount of the metering pump is determined, enabling the metering pump to complete the corresponding adjustment before the actual flow deviation occurs, thereby reducing the impact of liquid delivery lag in long-distance pipelines on the stability of the column inlet flow rate.

[0066] During the flow compensation control process, the instantaneous flow data within the continuous time window is statistically analyzed to obtain the flow pulsation amplitude, which is then compared with the preset pulsation threshold. Based on the comparison result, the volume adjustment amount of the buffer flow stabilization chamber is determined. By adjusting the effective buffer volume of the buffer flow stabilization chamber, the flow pulsation is regulated, thereby buffering the flow fluctuations in the liquid delivery path, making the flow change at the column inlet more stable and maintaining the liquid delivery state during the separation process.

[0067] In addition, after each adjustment cycle, the data sequence is updated on a rolling basis according to the instantaneous flow rate data, pressure data and metering pump speed data collected in the current cycle, and the equivalent flow resistance coefficient, flow transmission delay time and predicted flow deviation are recalculated. This allows the flow control process to continuously correct the control parameters based on the real-time data collected, so that the column inlet flow rate is kept within the preset target flow range during continuous operation.

[0068] The following explanation uses a specific scenario: In a radioactive separation device, an acidic solution is transported to the inlet of the separation column via a long-distance shielded pipeline using a metering pump. During operation, the inlet flow rate, pipeline pressure, and metering pump speed are continuously collected. The average flow rate and flow rate change slope are calculated using a sliding time window. Simultaneously, the equivalent flow resistance coefficient of the current liquid delivery path is determined based on pressure changes. Subsequently, the flow transmission delay time from the metering pump outlet to the separation column inlet is calculated based on pipeline volume parameters. The inlet flow rate at the corresponding moment of the delay time is then predicted. When a deviation occurs between the predicted flow rate and the target flow rate, compensation is made by adjusting the metering pump speed in advance. At the same time, the effective buffer volume of the buffer stabilizing cavity is adjusted according to the flow pulsation amplitude to keep the liquid flow rate entering the separation column within a preset range, thereby achieving stable control of the liquid delivery process in the radioactive separation device.

[0069] In a preferred embodiment of the present invention, the method for determining the preset sampling period includes:

[0070] First, based on the shortest response time required for the liquid in the long-distance shielded infusion pipeline to be transferred from the output end of the metering pump to the inlet of the separation column, determine the upper limit of the sampling period so that at least multiple continuous sampling points are included within a flow transmission delay time.

[0071] Then, based on the actual response time of the column inlet flow detection unit and the pressure detection unit, the lower limit of the sampling period is determined so that effective change data can be obtained between each sampling.

[0072] Subsequently, a test sampling period was selected between the upper and lower limits. Instantaneous flow and pressure data were collected in multiple adjustment periods. The continuity of flow and pressure differences between adjacent sampling periods was compared. When the collected results could fully reflect the flow fluctuation trend and there were no continuous repeated values, the corresponding test sampling period was determined as the preset sampling period.

[0073] When data jumps and omissions occur in the collection results, the experimental sampling period is shortened and the data is collected again. When the changes in adjacent sampling data are insufficient to distinguish the flow fluctuation trend, the experimental sampling period is extended and the data is collected again until a sampling period that meets the requirements for flow trend identification is determined.

[0074] In a preferred embodiment of the present invention, the method for determining the preset pipeline volume parameters includes:

[0075] Measure the length and inner diameter of each section of the long-distance shielded infusion pipeline involved in liquid transport, and determine the internal volume of each section separately.

[0076] The internal cross-sectional area of ​​each pipe section is converted to its corresponding length to obtain the internal space volume of each pipe section.

[0077] For locations containing elbows, joints, valve bodies, buffer flow stabilizing chamber connection sections, and detection interfaces, further measure the internal volume of the liquid-containing space.

[0078] The total internal volume of the long-distance shielded infusion pipeline is obtained by summing the volumes of all straight pipe sections, connecting sections, and internal volumes of auxiliary components.

[0079] Subsequently, a known volume of calibration liquid is introduced into the pipeline, and the volume of the liquid before it reaches the inlet of the separation column from the output end of the metering pump is recorded. When the volume of the calibration liquid is consistent with the aforementioned total internal volume, the total internal volume is determined as the preset pipeline volume parameter. When the two are inconsistent, the preset pipeline volume parameter is re-determined after correcting the volume calculation results of each section based on the measured full volume.

[0080] In a preferred embodiment of the present invention, the method for determining the preset target flow rate value includes:

[0081] First, determine the target delivery speed range of the liquid after it enters the separation column based on the structural dimensions of the separation column, the packing state, and the allowable residence time range of the liquid to be separated in the separation column;

[0082] In addition, considering the properties of the liquid to be separated, the allowable pressure range at the inlet of the separation column, and the requirements of the separation process for the stability of the elution front, a target delivery speed that can maintain the stability of the flow state inside the separation column is selected.

[0083] Subsequently, the target conveying speed was converted into the target flow rate at the column inlet based on the cross-sectional area of ​​the inlet flow of the separation column, and a continuous conveying test was conducted under trial operation conditions with multiple candidate flow rates.

[0084] Record the stability of the column inlet flow rate, the change of the separation column inlet pressure, and the range of flow fluctuation during the separation process for each candidate flow rate value. When the column inlet flow rate fluctuation corresponding to a certain candidate flow rate value is within the allowable range and the separation column inlet pressure does not exceed the set limit, the candidate flow rate value is determined as the preset target flow rate value.

[0085] When multiple candidate flow values ​​meet the criteria, the flow value that balances flow stability and separation process continuity is selected as the preset target flow value.

[0086] In a preferred embodiment of the present invention, the method for determining the preset pulsation threshold includes:

[0087] With the buffer flow stabilizing chamber in a reference volume state, the metering pump continuously delivers liquid to the long-distance shielded infusion pipeline under multiple different speed conditions, and instantaneous flow data are collected within multiple consecutive sliding time windows under each speed condition.

[0088] The maximum and minimum flow rates within each sliding time window are determined, and the difference between the two is taken as the flow pulsation amplitude within the corresponding time window.

[0089] The flow pulsation amplitude obtained under multiple rotational speed conditions is compared with the corresponding average flow value to screen out the maximum allowable pulsation amplitude that can still keep the column inlet flow stable and will not cause abnormal fluctuations in the separation column inlet pressure.

[0090] In addition, considering the control requirements for the stability of the column inlet flow during the separation process, a safety margin correction is made for the maximum allowable pulsation amplitude, and the corrected flow pulsation amplitude is determined as the preset pulsation threshold.

[0091] In subsequent operation, when the liquid properties, separation column filling status, or infusion line length change, the above determination process is repeated to update the preset pulsation threshold applicable to the current operating conditions.

[0092] In a preferred embodiment of the present invention, step S2 includes:

[0093] S21. Perform statistical processing on the instantaneous flow data according to the sampling order within the sliding time window to determine the average flow value, the flow difference between adjacent sampling periods, and the slope of flow change within the sliding time window.

[0094] S22. Match the pressure data with the instantaneous flow rate data according to the sampling time sequence, and determine the pressure-flow rate change characteristics in the liquid delivery path based on the correspondence between pressure changes and average flow rate values.

[0095] S23. Determine the flow deviation state of the liquid during the transportation process based on the difference between the theoretical liquid conveying capacity corresponding to the metering pump speed and the average flow value.

[0096] S24. Determine the flow resistance change state of the liquid transport path based on the pressure-flow change characteristics and the flow deviation state, and convert the flow resistance change state into an equivalent flow resistance coefficient that characterizes the current flow characteristics of the liquid transport path.

[0097] In this embodiment of the invention, by statistically processing instantaneous flow rate data within a sliding time window, the average flow rate, flow rate difference, and flow rate change slope are obtained. This allows for the extraction of trend information on liquid flow rate changes over time from continuously sampled data, enabling quantitative characterization of flow rate variations. Based on this, pressure data and instantaneous flow rate data are matched sequentially according to sampling time. The pressure-flow rate variation characteristics in the liquid transport path are determined based on the correspondence between pressure changes and the average flow rate, reflecting the impact of pressure changes on fluid transport. Simultaneously, the flow rate deviation is determined by comparing the difference between the theoretical transport capacity of the metering pump and the average flow rate, identifying the difference between the metering pump's output capacity and the actual transport flow rate. Furthermore, the flow resistance variation is determined by combining the pressure-flow rate variation characteristics and the flow rate deviation, and converted into an equivalent flow resistance coefficient. This allows the flow resistance characteristics of the liquid transport path to be characterized using a unified parameter, providing a basis for subsequent delay time calculations and flow rate prediction.

[0098] In a preferred embodiment of the present invention, step S21 includes:

[0099] First, set the length of the sliding time window corresponding to the preset sampling period in the control unit, and then read the instantaneous flow data corresponding to multiple consecutive sampling points in the sampling time order within each sliding time window to form a flow data group within the current time window;

[0100] Then sum all the instantaneous flow data in the flow data group in sequence, and divide the sum by the number of sampling points in the flow data group to obtain the average flow value within the sliding time window;

[0101] Then, the instantaneous flow data of the previous sampling period is compared with the instantaneous flow data of the next sampling period one by one according to the sampling order. The flow difference between adjacent sampling periods is obtained by subtracting the instantaneous flow data of the previous sampling period from the instantaneous flow data of the next sampling period.

[0102] The flow rate difference is then converted to the time interval between two adjacent sampling periods to obtain the degree of flow rate change per unit time, and this degree of flow rate change per unit time is determined as the flow rate change slope.

[0103] After completing the data processing for the current sliding time window, the earliest sampling point is removed and a new sampling point is introduced to update the flow data set within the sliding time window. The above process is repeated to continuously output the average flow value, flow difference, and flow change slope corresponding to each sliding time window.

[0104] In a preferred embodiment of the present invention, step S22 includes:

[0105] The pressure data and instantaneous flow data of the long-distance shielded infusion pipeline are recorded synchronously in each sampling period, and a one-to-one correspondence table between the pressure data and the instantaneous flow data is established according to the sampling time sequence.

[0106] After arranging all the pressure data within a sliding time window in sequence, the pressure change process corresponding to each sampling point within the sliding time window is determined, and the pressure data and average flow rate of each sampling point are analyzed in conjunction with the average flow rate value within the aforementioned sliding time window.

[0107] When the pressure data increases continuously with the increase of the average flow rate, it is determined that the liquid delivery path is under the pressure-flow rate change characteristics of an increased resistance state.

[0108] When the pressure data decreases continuously as the average flow rate decreases, the pressure-flow rate change characteristics of the liquid delivery path are determined to be under a state of reduced resistance. When the pressure data fluctuates while the average flow rate remains basically unchanged, the pressure-flow rate change characteristics of the liquid delivery path are determined to be under a state of pressure disturbance. The above determination results are written into the current time window status data of the control unit as the basis for subsequent determination of the flow resistance change status.

[0109] In a preferred embodiment of the present invention, step S3 includes:

[0110] S31. Obtain the preset pipeline volume parameters of the long-distance shielded infusion pipeline, and determine the basic transmission time of the liquid in the liquid delivery path by combining the average flow rate value within the sliding time window.

[0111] S32. Correct the basic transmission time for flow resistance based on the equivalent flow resistance coefficient to determine the actual flow transmission delay time of the liquid in the liquid transport path.

[0112] S33. Multiply the slope of the flow rate change with the actual flow rate transmission delay time to obtain the flow rate change value within the delay time.

[0113] S34. Sum the flow change value with the average flow value within the sliding time window to obtain the predicted flow value at the column inlet at the corresponding time of the delay time.

[0114] In this embodiment of the invention, the basic transmission time of the liquid in the delivery path can be estimated by obtaining the preset pipeline volume parameters of the long-distance shielded infusion pipeline and combining them with the average flow rate value within a sliding time window. Based on this, the basic transmission time is corrected according to the equivalent flow resistance coefficient, so that the calculated actual flow transmission delay time can reflect the influence of flow resistance experienced by the liquid during delivery. Furthermore, the flow rate change slope is multiplied by the actual flow transmission delay time to obtain the flow rate change value within the delay time, and this flow rate change value is summed with the average flow rate value to obtain the predicted inlet flow rate value at the corresponding moment of the delay time. This allows the inlet flow rate to be predicted based on the current flow rate change trend, thereby providing a basis for subsequent flow compensation control.

[0115] In a preferred embodiment of the present invention, step S5 includes:

[0116] S51. Perform statistical processing on the continuously collected instantaneous flow data within the sliding time window to determine the maximum and minimum flow values ​​within the sliding time window.

[0117] S52. Determine the flow pulsation amplitude based on the difference between the maximum and minimum flow values;

[0118] S53. Based on the comparison between the flow pulsation amplitude and the preset pulsation threshold, determine the volume adjustment requirements of the buffer flow stabilization cavity.

[0119] S54. Determine the volume adjustment amount of the buffer flow stabilizing cavity according to the volume adjustment requirements, and adjust the effective buffer volume of the buffer flow stabilizing cavity according to the volume adjustment amount to change the flow pulsation state in the liquid delivery path.

[0120] In this embodiment of the invention, by statistically processing continuously collected instantaneous flow data within a sliding time window to determine the maximum and minimum flow values, and determining the flow pulsation amplitude based on the difference between the two, the flow fluctuation during liquid delivery can be quantitatively described. Based on this, the flow pulsation amplitude is compared with a preset pulsation threshold, and the volume adjustment requirement of the buffer flow stabilization chamber is determined according to the comparison result. Furthermore, the corresponding volume adjustment amount is determined, enabling the buffer flow stabilization chamber to adjust its effective buffer volume according to flow fluctuations. By adjusting the effective buffer volume of the buffer flow stabilization chamber, the flow pulsation state in the liquid delivery path can be changed, thereby making the flow change at the column inlet more stable and maintaining the flow control state during liquid delivery.

[0121] In a preferred embodiment of the present invention, step S54 includes:

[0122] First, the adjustment direction of the buffer flow stabilization cavity is determined based on the comparison between the flow pulsation amplitude and the preset pulsation threshold. When the flow pulsation amplitude is higher than the preset pulsation threshold, the adjustment direction is determined to increase the effective buffer volume. When the flow pulsation amplitude is lower than the preset pulsation threshold, the adjustment direction is determined to decrease the effective buffer volume.

[0123] The volume adjustment levels are then divided according to the difference between the flow pulsation amplitude and the preset pulsation threshold, and corresponding volume adjustment amounts are set for each volume adjustment level.

[0124] Subsequently, the volume adjustment structure connected to the buffer flow stabilizing cavity is controlled to move, causing the variable volume component inside the buffer flow stabilizing cavity to move according to the determined volume adjustment amount, thereby changing the effective buffer space inside the buffer flow stabilizing cavity used to absorb flow fluctuations.

[0125] After completing one volume adjustment, the instantaneous flow data within the subsequent sliding time window is collected, and the flow pulsation amplitude is recalculated. When the recalculated flow pulsation amplitude still does not enter the range corresponding to the preset pulsation threshold, the volume adjustment process is executed again until the effective buffer volume of the buffer flow stabilization cavity matches the current flow pulsation state.

[0126] In a preferred embodiment of the present invention, step S23 includes:

[0127] S231. Determine the theoretical flow rate of the metering pump under the current speed condition based on the metering pump speed and the rated delivery characteristics of the metering pump.

[0128] S232. Compare the theoretical flow rate with the average flow rate within the sliding time window to obtain the flow rate difference between the theoretical flow rate and the average flow rate.

[0129] S233. Calculate the ratio between the flow difference and the average flow value to obtain the flow deviation coefficient, which characterizes the degree of flow deviation in the liquid transport path.

[0130] S234. The flow deviation coefficient is used as a quantitative characterization of the flow deviation state generated by the liquid during the transportation process.

[0131] In this embodiment of the invention, the theoretical flow rate under the current speed condition is determined based on the metering pump's rotational speed and rated delivery characteristics, thus obtaining the liquid flow rate that the metering pump should output under ideal operating conditions. Subsequently, the theoretical flow rate is compared with the average flow rate within a sliding time window to obtain the flow difference between the theoretical and actual flow rates. By ratioing this flow difference to the average flow rate, a flow deviation coefficient is obtained, thereby quantifying the degree of flow deviation during liquid delivery. By using the flow deviation coefficient as a quantitative representation of the flow deviation state, the deviation between the metering pump's theoretical delivery capacity and the actual flow rate can be reflected. This allows for the identification of flow deviations caused by factors such as changes in pipeline resistance, liquid properties, or delivery conditions during liquid delivery, providing a basis for subsequently determining the flow resistance changes in the liquid delivery path.

[0132] In a preferred embodiment of the present invention, step S231 includes:

[0133] The rated delivery characteristic parameters of the metering pump under standard operating conditions are obtained in advance, and a table of correspondence between the metering pump speed and the output flow rate per unit time is established.

[0134] Read the real-time speed data of the metering pump within the current adjustment cycle, and look up the rated output flow value corresponding to the real-time speed data in the corresponding relationship table;

[0135] When the real-time speed data is located between two known speed nodes, the output flow under the current speed condition is converted according to the rated output flow change relationship between the two adjacent speed nodes to obtain the theoretical delivery flow corresponding to the current real-time speed.

[0136] When the metering pump is in the start-stop switching stage or speed adjustment stage, the theoretical delivery flow rate is corrected in stages based on the direction and magnitude of the current speed change, so that the determined theoretical delivery flow rate corresponds to the actual output capacity of the metering pump under the current speed conditions.

[0137] The finalized theoretical transport flow rate is written into the data sequence of the current adjustment cycle as the basis for subsequent comparisons of the difference between the theoretical transport flow rate and the average flow rate.

[0138] In a preferred embodiment of the present invention, step S24 includes:

[0139] S241. Determine the maximum and minimum pressure values ​​within the sliding time window based on the pressure data, and calculate the pressure difference between the maximum and minimum pressure values.

[0140] S242. The pressure difference value is calculated by comparing the pressure difference value with the average flow rate value, which is the unit flow pressure variation coefficient that characterizes the flow resistance characteristics of the liquid transport path.

[0141] S243. Multiply the pressure variation coefficient per unit flow rate with the flow deviation coefficient to obtain the resistance variation coefficient, which characterizes the degree of change in flow resistance in the liquid transport path.

[0142] S244. Use the resistance variation coefficient as the equivalent flow resistance coefficient of the liquid transport path.

[0143] In this embodiment of the invention, by determining the maximum and minimum pressure values ​​within a sliding time window based on pressure data and calculating the pressure difference between them, the pressure fluctuations of the liquid in the transport path can be reflected. Furthermore, the pressure difference is compared with the average flow rate to obtain a pressure variation coefficient per unit flow rate, allowing the impact of pressure changes on the fluid transport state to be characterized by the degree of pressure change per unit flow rate. Based on this, the pressure variation coefficient per unit flow rate is multiplied by the flow deviation coefficient to obtain a resistance variation coefficient, which comprehensively reflects the impact of pressure change characteristics and flow deviation on the fluid transport process, thereby quantifying the degree of flow resistance variation in the liquid transport path. By using the resistance variation coefficient as an equivalent flow resistance coefficient, complex flow resistance variations can be uniformly converted into parameters that can be used for calculation and control, enabling real-time characterization of the flow state in the liquid transport path and providing a basis for subsequent calculation of flow transmission delay time.

[0144] In a preferred embodiment of the present invention, step S32 includes:

[0145] S321. Determine the degree of change in the flow resistance of liquid in the liquid transport path based on the equivalent flow resistance coefficient;

[0146] S322. Determine the delay correction ratio corresponding to the basic transmission time based on the degree of change in flow resistance, and convert the basic transmission time according to the delay correction ratio to obtain the resistance correction time used to characterize the influence of flow resistance.

[0147] S323. The resistance correction time is superimposed with the basic transmission time to obtain the actual flow transmission delay time of the liquid in the liquid transport path.

[0148] In this embodiment of the invention, by obtaining the basic transmission time and combining it with the equivalent flow resistance coefficient, the degree of change in flow resistance of the liquid in the liquid delivery path is identified. This allows the basic transmission time to reflect the influence of flow resistance on the liquid during actual delivery, thus providing a basis for subsequent delay time correction. Based on this, the delay correction ratio corresponding to the basic transmission time is determined according to the degree of change in flow resistance, and the basic transmission time is converted according to the delay correction ratio to obtain the resistance correction time used to characterize the influence of flow resistance. This allows the additional transmission time caused by changes in liquid viscosity, pipeline resistance, or delivery conditions to be quantitatively described. Furthermore, by superimposing the resistance correction time with the basic transmission time, the actual flow transmission delay time of the liquid in the liquid delivery path is obtained. This makes the transmission time of the liquid from the metering pump to the inlet of the separation column more consistent with the actual delivery state, providing a more accurate time parameter basis for the subsequent column inlet flow prediction process.

[0149] Embodiments of the present invention also provide a precise control system for liquid flow rate in a radioactive separation apparatus, the system comprising:

[0150] The data acquisition module is used to synchronously collect instantaneous flow data at the column inlet, pressure data of long-distance shielded infusion pipeline, and speed data of metering pump according to a preset sampling period, and form a data sequence arranged in chronological order.

[0151] The flow resistance identification module is used to process the data sequence of multiple consecutive sampling periods through a sliding time window, calculate the average flow rate within the time window, the flow rate difference between adjacent sampling periods, and the slope of the flow rate change, and calculate the equivalent flow resistance coefficient based on the relationship between the pressure data and the average flow rate, the difference between the theoretical liquid delivery capacity corresponding to the metering pump speed and the average flow rate.

[0152] The delay prediction module is used to calculate the flow transmission delay time of liquid in the liquid delivery path based on the equivalent flow resistance coefficient and the preset pipeline volume parameters of the long-distance shielded infusion pipeline, and to predict the column inlet flow corresponding to the future delay time by combining the current flow rate change slope, so as to obtain the predicted flow rate value.

[0153] The pre-compensation control module is used to compare the predicted flow rate value with the preset target flow rate value to obtain the predicted flow rate deviation, and to determine the pre-compensation speed correction amount of the metering pump based on the predicted flow rate deviation.

[0154] The flow stabilization module is used to perform speed correction on the metering pump according to the pre-compensated speed correction amount, and at the same time calculate the flow pulsation amplitude value within the continuous time window, compare the flow pulsation amplitude value with the preset pulsation threshold, determine the volume adjustment amount of the buffer flow stabilization cavity set between the metering pump and the separation column, and adjust the effective buffer volume of the buffer flow stabilization cavity according to the volume adjustment amount.

[0155] The rolling update module is used to update the data sequence based on the instantaneous flow rate data, pressure data and metering pump speed data collected during the current adjustment cycle after the current adjustment cycle ends. It also recalculates the equivalent flow resistance coefficient, flow transmission delay time and predicted flow deviation to coordinately correct the metering pump speed and buffer flow stabilization chamber volume, so that the column inlet flow rate is stably maintained within the preset target flow range.

[0156] It should be noted that this system is a system corresponding to the above method. All implementation methods in the above method embodiments are applicable to this embodiment and can achieve the same technical effect.

[0157] Embodiments of the present invention also provide a computing device, including: a processor and a memory storing a computer program, wherein the computer program, when executed by the processor, performs the method described above. All implementations in the above method embodiments are applicable to this embodiment and can achieve the same technical effects.

[0158] Embodiments of the present invention also provide a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the method described above. All implementations in the above method embodiments are applicable to this embodiment and can achieve the same technical effects.

[0159] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for precise control of liquid flow rate in a radioactive separation device, characterized in that, The method includes: S1. Collect instantaneous flow data at the column inlet, pressure data of long-distance shielded infusion pipeline, and speed data of metering pump synchronously according to the preset sampling period, and form a data sequence arranged in chronological order; S2. Perform sliding time window processing on the data sequence of multiple consecutive sampling periods, calculate the average flow rate, the flow rate difference between adjacent sampling periods and the slope of flow rate change within the sliding time window, and calculate the equivalent flow resistance coefficient based on the relationship between pressure data and average flow rate, the difference between the theoretical liquid delivery capacity corresponding to the metering pump speed and the average flow rate. S3. Calculate the flow transmission delay time of the liquid in the liquid delivery path based on the equivalent flow resistance coefficient and the preset pipeline volume parameters of the long-distance shielded infusion pipeline, and predict the column inlet flow corresponding to the future delay time by combining the current flow rate change slope, and obtain the predicted flow rate value. S4. Compare the predicted flow rate with the preset target flow rate to obtain the predicted flow rate deviation, and determine the pre-compensation speed correction amount of the metering pump based on the predicted flow rate deviation. S5. Based on the pre-compensated speed correction amount, perform speed correction on the metering pump, calculate the flow pulsation amplitude value within the continuous sliding time window, compare the flow pulsation amplitude value with the preset pulsation threshold, determine the volume adjustment amount of the buffer flow stabilizing cavity set between the metering pump and the separation column, and adjust the effective buffer volume of the buffer flow stabilizing cavity according to the volume adjustment amount. S6. After the current adjustment cycle ends, the data sequence is updated on a rolling basis according to the instantaneous flow rate data, pressure data and metering pump speed data collected in the current adjustment cycle, and the equivalent flow resistance coefficient, flow transmission delay time and predicted flow deviation are recalculated in order to coordinate the metering pump speed and buffer flow stabilization chamber volume to keep the column inlet flow rate stably within the preset target flow range. Step S2 includes: S21. Perform statistical processing on the instantaneous flow data according to the sampling order within the sliding time window to determine the average flow value, the flow difference between adjacent sampling periods, and the slope of flow change within the sliding time window. S22. Match the pressure data with the instantaneous flow rate data according to the sampling time sequence, and determine the pressure-flow rate change characteristics in the liquid delivery path based on the correspondence between pressure changes and average flow rate values. S23. Determine the flow deviation state of the liquid during the transportation process based on the difference between the theoretical liquid conveying capacity corresponding to the metering pump speed and the average flow value. S24. Determine the flow resistance change state of the liquid transport path based on the pressure-flow change characteristics and the flow deviation state, and convert the flow resistance change state into an equivalent flow resistance coefficient that characterizes the current flow characteristics of the liquid transport path.

2. The method for precise control of liquid flow rate in a radioactive separation device according to claim 1, characterized in that, Step S3 includes: S31. Obtain the preset pipeline volume parameters of the long-distance shielded infusion pipeline, and determine the basic transmission time of the liquid in the liquid delivery path by combining the average flow rate value within the sliding time window. S32. Correct the basic transmission time for flow resistance based on the equivalent flow resistance coefficient to determine the actual flow transmission delay time of the liquid in the liquid transport path. S33. Multiply the slope of the flow rate change with the actual flow rate transmission delay time to obtain the flow rate change value within the delay time. S34. Sum the flow change value with the average flow value within the sliding time window to obtain the predicted flow value at the column inlet at the corresponding time of the delay time.

3. The method for precise control of liquid flow rate in the radioactive separation device according to claim 1, characterized in that, Step S5 includes: S51. Perform statistical processing on the continuously collected instantaneous flow data within the sliding time window to determine the maximum and minimum flow values ​​within the sliding time window. S52. Determine the flow pulsation amplitude based on the difference between the maximum and minimum flow values; S53. Based on the comparison between the flow pulsation amplitude and the preset pulsation threshold, determine the volume adjustment requirements of the buffer flow stabilization cavity. S54. Determine the volume adjustment amount of the buffer flow stabilizing cavity according to the volume adjustment requirements, and adjust the effective buffer volume of the buffer flow stabilizing cavity according to the volume adjustment amount to change the flow pulsation state in the liquid delivery path.

4. The method for precise control of liquid flow rate in a radioactive separation device according to claim 1, characterized in that, Step S23 includes: S231. Determine the theoretical flow rate of the metering pump under the current speed condition based on the metering pump speed and the rated delivery characteristics of the metering pump. S232. Compare the theoretical flow rate with the average flow rate within the sliding time window to obtain the flow rate difference between the theoretical flow rate and the average flow rate. S233. Calculate the ratio between the flow difference and the average flow value to obtain the flow deviation coefficient, which characterizes the degree of flow deviation in the liquid transport path. S234. The flow deviation coefficient is used as a quantitative characterization of the flow deviation state generated by the liquid during the transportation process.

5. The method for precise control of liquid flow rate in a radioactive separation device according to claim 1, characterized in that, Step S24 includes: S241. Determine the maximum and minimum pressure values ​​within the sliding time window based on the pressure data, and calculate the pressure difference between the maximum and minimum pressure values. S242. The pressure difference value is calculated by comparing the pressure difference value with the average flow rate value, which is the unit flow pressure variation coefficient that characterizes the flow resistance characteristics of the liquid transport path. S243. Multiply the pressure variation coefficient per unit flow rate with the flow deviation coefficient to obtain the resistance variation coefficient, which characterizes the degree of change in flow resistance in the liquid transport path. S244. Use the resistance variation coefficient as the equivalent flow resistance coefficient of the liquid transport path.

6. The method for precise control of liquid flow rate in a radioactive separation device according to claim 2, characterized in that, Step S32 includes: S321. Determine the degree of change in the flow resistance of liquid in the liquid transport path based on the equivalent flow resistance coefficient; S322. Determine the delay correction ratio corresponding to the basic transmission time based on the degree of change in flow resistance, and convert the basic transmission time according to the delay correction ratio to obtain the resistance correction time used to characterize the influence of flow resistance. S323. The resistance correction time is superimposed with the basic transmission time to obtain the actual flow transmission delay time of the liquid in the liquid transport path.

7. A precise control system for liquid flow rate in a radioactive separation device, characterized in that, The system, used in the method of any one of claims 2 to 6, comprises: The data acquisition module is used to synchronously collect instantaneous flow data at the column inlet, pressure data of long-distance shielded infusion pipeline, and speed data of metering pump according to a preset sampling period, and form a data sequence arranged in chronological order. The flow resistance identification module is used to process the data sequence of multiple consecutive sampling periods through a sliding time window, calculate the average flow rate within the sliding time window, the flow rate difference between adjacent sampling periods, and the slope of the flow rate change, and calculate the equivalent flow resistance coefficient based on the relationship between the pressure data and the average flow rate, and the difference between the theoretical liquid delivery capacity corresponding to the metering pump speed and the average flow rate. The delay prediction module is used to calculate the flow transmission delay time of liquid in the liquid delivery path based on the equivalent flow resistance coefficient and the preset pipeline volume parameters of the long-distance shielded infusion pipeline, and to predict the column inlet flow corresponding to the future delay time by combining the current flow rate change slope, so as to obtain the predicted flow rate value. The pre-compensation control module is used to compare the predicted flow rate value with the preset target flow rate value to obtain the predicted flow rate deviation, and to determine the pre-compensation speed correction amount of the metering pump based on the predicted flow rate deviation. The flow stabilization module is used to perform speed correction on the metering pump according to the pre-compensated speed correction amount, and at the same time calculate the flow pulsation amplitude value within the continuous sliding time window, compare the flow pulsation amplitude value with the preset pulsation threshold, determine the volume adjustment amount of the buffer flow stabilization cavity set between the metering pump and the separation column, and adjust the effective buffer volume of the buffer flow stabilization cavity according to the volume adjustment amount. The rolling update module is used to update the data sequence based on the instantaneous flow rate data, pressure data and metering pump speed data collected during the current adjustment cycle after the current adjustment cycle ends. It also recalculates the equivalent flow resistance coefficient, flow transmission delay time and predicted flow deviation to coordinately correct the metering pump speed and buffer flow stabilization chamber volume, so that the column inlet flow rate is stably maintained within the preset target flow range.

8. A computing device, characterized in that, include: One or more processors; A storage device for storing one or more programs that, when executed by one or more processors, cause the one or more processors to implement the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a program that, when executed by a processor, implements the method as described in any one of claims 1 to 6.

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