CN-122018574-A - Method and system for accurately controlling liquid flow in radioactive separation device

CN122018574ACN 122018574 ACN122018574 ACN 122018574ACN-122018574-A

Abstract

The invention provides a method and a system for accurately controlling liquid flow in a radioactive separation device, and relates to the technical field of liquid flow control, wherein the method acquires instantaneous flow data of a column inlet, pressure data of a transfusion pipeline and rotating speed data of a metering pump, and carries out sliding time window processing to obtain average flow value and flow change slope; the method comprises the steps of calculating equivalent flow resistance coefficient by combining pressure change relation and theoretical conveying capacity of a metering pump, determining liquid flow transmission delay time according to pipeline volume parameters, predicting column inlet flow corresponding to the delay time, adjusting the rotating speed of the metering pump according to deviation between the predicted flow and target flow, adjusting effective buffer volume of a buffer steady flow cavity to inhibit flow pulsation, and continuously correcting control parameters through rolling update data to enable the column inlet flow to be maintained within a preset target flow range.

Inventors

GU LONG
Su Xingkang
WANG GUAN

Assignees

福建睿斯科医疗技术有限公司

Dates

Publication Date: 20260512
Application Date: 20260410

Claims (10)

1. A method for precisely controlling the flow of a liquid in a radioactive separation device, said method comprising: S1, synchronously acquiring instantaneous flow data of a column inlet, pressure data of a long-distance shielding infusion pipeline and rotating speed data of a metering pump according to a preset sampling period, and forming a data sequence arranged in time sequence; S2, carrying out sliding time window processing on the data sequences of a plurality of continuous sampling periods, calculating average flow value, flow difference value and flow change slope of adjacent sampling periods in a time window, and calculating an equivalent flow resistance coefficient according to the change relation between pressure data and the average flow value and the difference relation between liquid theoretical conveying capacity corresponding to the rotation speed of a metering pump and the average flow value; S3, calculating flow transmission delay time of the liquid in the liquid conveying passage according to the equivalent flow resistance coefficient and preset pipeline volume parameters of the long-distance shielding transfusion pipeline, and predicting column inlet flow corresponding to the delay time in the future by combining the current flow change slope to obtain a predicted flow value; S4, comparing the predicted flow value with a preset target flow value to obtain a predicted flow deviation, and determining a pre-compensation rotational speed correction amount of the metering pump according to the predicted flow deviation; S5, according to the precompensation rotational speed correction amount, performing rotational speed correction on the metering pump, simultaneously calculating a flow pulsation amplitude value in a continuous time window, comparing the flow pulsation amplitude value with a preset pulsation threshold value, determining a buffer steady flow cavity volume adjustment amount arranged between the metering pump and the separation column, and adjusting the effective buffer volume of the buffer steady flow cavity according to the volume adjustment amount; And S6, after the current regulation period is finished, rolling and updating a data sequence according to the instantaneous flow data, the pressure data and the rotational speed data of the metering pump acquired in the current regulation period, and recalculating the equivalent flow resistance coefficient, the flow transmission delay time and the predicted flow deviation so as to carry out cooperative correction on the rotational speed of the metering pump and the volume of the buffering steady flow cavity, so that the flow of the inlet of the column is stably maintained within a preset target flow range.
2. The method for precisely controlling the flow rate of a liquid in a radioactive separation apparatus according to claim 1, wherein step S2 comprises: S21, carrying out statistical processing on instantaneous flow data in a sliding time window according to a sampling sequence, and determining average flow value in the sliding time window, flow difference values between adjacent sampling periods and flow change slope; S22, correspondingly matching the pressure data with the instantaneous flow data according to the sampling time sequence, and determining the pressure-flow change characteristics in the liquid conveying passage according to the corresponding relation between the pressure change condition and the average flow value; S23, determining a flow deviation state of the liquid in the conveying process according to the difference condition between the theoretical conveying capacity of the liquid corresponding to the rotating speed of the metering pump and the average flow value; s24, determining the flow resistance change state of the liquid conveying passage according to the pressure-flow change characteristic and the flow deviation state, and converting the flow resistance change state into an equivalent flow resistance coefficient representing the flow characteristic of the current liquid conveying passage.
3. The method for precisely controlling the flow rate of a liquid in a radioactive separation apparatus according to claim 1, wherein step S3 comprises: S31, acquiring preset pipeline volume parameters of a long-distance shielding infusion pipeline, and determining basic transmission time of liquid in a liquid conveying passage by combining an average flow value in a sliding time window; S32, carrying out flow resistance correction on the basic transmission time according to the equivalent flow resistance coefficient so as to determine the actual flow transmission delay time of the liquid in the liquid conveying passage; S33, performing product operation on the flow change slope and the actual flow transmission delay time to obtain a flow change value in the delay time; and S34, carrying out summation operation on the flow variation value and the average flow value in the sliding time window to obtain a column inlet predicted flow value at the moment corresponding to the delay time.
4. The method for precisely controlling the flow rate of a liquid in a radioactive separation apparatus according to claim 1, wherein step S5 comprises: s51, carrying out statistical processing on continuously acquired instantaneous flow data in a sliding time window to determine a maximum flow value and a minimum flow value in the sliding time window; S52, determining the flow pulsation amplitude according to the difference value between the maximum flow value and the minimum flow value; S53, determining the volume adjustment requirement of the buffering steady flow cavity according to a comparison result between the flow pulsation amplitude and a preset pulsation threshold value; S54, determining the volume adjustment quantity of the buffering steady flow cavity according to the volume adjustment requirement, and adjusting the effective buffering volume of the buffering steady flow cavity according to the volume adjustment quantity so as to change the flow pulsation state in the liquid conveying passage.
5. The method for precisely controlling the flow rate of a liquid in a radioactive separation apparatus according to claim 2, wherein step S23 comprises: s231, determining theoretical conveying flow of the metering pump under the current rotating speed condition according to the rotating speed of the metering pump and the rated conveying characteristic of the metering pump; S232, comparing the theoretical conveying flow with an average flow value in a sliding time window to obtain a flow difference value between the theoretical conveying flow and the average flow value; s233, carrying out ratio operation on the flow difference value and the average flow value to obtain a flow deviation coefficient representing the flow deviation degree in the liquid conveying passage; S234, taking the flow deviation coefficient as a quantitative representation of the flow deviation state generated in the liquid conveying process.
6. The method for precisely controlling the flow rate of a liquid in a radioactive separation apparatus according to claim 2, wherein step S24 includes: S241, determining a pressure maximum value and a pressure minimum value in the sliding time window according to the pressure data, and calculating a pressure difference value between the pressure maximum value and the pressure minimum value; S242, carrying out ratio operation on the pressure difference value and the average flow value, and representing a unit flow pressure change coefficient of the flow resistance characteristic of the liquid conveying passage; s243, carrying out product operation on the pressure change coefficient of the unit flow and the flow deviation coefficient to obtain a resistance change coefficient representing the change degree of the flow resistance of the liquid conveying passage; s244, the resistance change coefficient is taken as the equivalent flow resistance coefficient of the liquid conveying passage.
7. The method for precisely controlling the flow rate of a liquid in a radioactive separation apparatus according to claim 3, wherein step S32 comprises: s321, determining the change degree of the flow resistance of the liquid in the liquid conveying passage according to the equivalent flow resistance coefficient; S322, determining a delay correction proportion corresponding to the basic transmission time according to the change degree of the flow resistance, and converting the basic transmission time according to the delay correction proportion to obtain resistance correction time for representing the influence of the flow resistance; and S323, performing superposition operation on the resistance correction time and the basic transmission time to obtain the actual flow transmission delay time of the liquid in the liquid conveying passage.
8. A system for precisely controlling the flow of a liquid in a radioactive separation apparatus, for use in a method according to any one of claims 1 to 7, said system comprising: The data acquisition module is used for synchronously acquiring instantaneous flow data of the inlet of the column, pressure data of the long-distance shielding transfusion pipeline and rotating speed data of the metering pump according to a preset sampling period, and forming a data sequence arranged in time sequence; The flow resistance identification module is used for carrying out sliding time window processing on the data sequences of a plurality of continuous sampling periods, calculating average flow value, flow difference value and flow change slope of adjacent sampling periods in the time window, and calculating an equivalent flow resistance coefficient according to the change relation between pressure data and the average flow value and the difference relation between the theoretical liquid conveying capacity corresponding to the rotating speed of the metering pump and the average flow value; the delay prediction module is used for calculating the flow transmission delay time of the liquid in the liquid conveying passage according to the equivalent flow resistance coefficient and the preset pipeline volume parameter of the long-distance shielding transfusion pipeline, and predicting the column inlet flow corresponding to the future delay time by combining the current flow change slope to obtain a predicted flow value; the pre-compensation control module is used for comparing the predicted flow value with a preset target flow value to obtain a predicted flow deviation, and determining a pre-compensation rotating speed correction amount of the metering pump according to the predicted flow deviation; The steady flow adjusting module is used for carrying out rotational speed correction on the metering pump according to the precompensated rotational speed correction amount, simultaneously calculating a flow pulsation amplitude value in the continuous time window, comparing the flow pulsation amplitude value with a preset pulsation threshold value, determining the volume adjusting amount of the buffering steady flow cavity arranged between the metering pump and the separation column, and adjusting the effective buffering volume of the buffering steady flow cavity according to the volume adjusting amount; And the rolling updating module is used for rolling updating the data sequence according to the instantaneous flow data, the pressure data and the metering pump rotating speed data acquired in the current adjusting period after the current adjusting period is finished, and recalculating the equivalent flow resistance coefficient, the flow transmission delay time and the predicted flow deviation so as to carry out cooperative correction on the metering pump rotating speed and the buffer steady flow cavity volume, so that the column inlet flow is stably maintained within the preset target flow range.
9. A computing device, comprising: one or more processors; Storage means for storing one or more programs which when executed by the one or more processors cause the one or more processors to implement the method of any of claims 1 to 7.
10. A computer readable storage medium, characterized in that the computer readable storage medium has stored therein a program which, when executed by a processor, implements the method according to any of claims 1 to 7.

Description

Method and system for accurately controlling liquid flow in radioactive separation device Technical Field The invention relates to the technical field of liquid flow control, in particular to a method and a system for accurately controlling liquid flow in a radioactive separation device. Background In the prior art, the liquid flow control of the radioactive separation device adopts a closed-loop scheme of 'a liquid storage tank-a metering pump-a flowmeter-a regulating valve', wherein the rotating speed or the valve opening of the metering pump is regulated by a PLC or a PID controller according to the set flow, the flowmeter feeds back the instantaneous flow in real time, and a pulsation damper and a back pressure valve are matched when necessary so as to maintain the stable transportation of acid liquid, eluent or complexing agent at the inlet of a separation column, thereby completing the extraction, leaching or exchange separation of radionuclides. However, when radioactive strontium, cesium or actinide columns are separated in a hot chamber, the scheme is easy to produce control hysteresis due to long-distance shielding pipelines, pulsation of a metering pump and viscosity change of high-density acid liquor. For example, when the set flow is switched from 0.8mL/min to 1.2mL/min, short-time overshoot or fall-back often occurs in the actual flow at the column inlet, so that the contact time of the resin bed layer is fluctuated, and further the elution front of the target component and the elution front of the impurity component are caused to overlap, and the difficulty in subsequent sectional collection and waste liquid discrimination is increased. Disclosure of Invention The invention aims to provide a method and a system for precisely controlling the flow of liquid in a radioactive separation device, and aims to solve the problems in the background art. In order to solve the technical problems, the technical scheme of the invention is as follows: in a first aspect, a method for accurately controlling liquid flow in a radioactive separation apparatus, the method comprising: S1, synchronously acquiring instantaneous flow data of a column inlet, pressure data of a long-distance shielding infusion pipeline and rotating speed data of a metering pump according to a preset sampling period, and forming a data sequence arranged in time sequence; S2, carrying out sliding time window processing on the data sequences of a plurality of continuous sampling periods, calculating average flow value, flow difference value and flow change slope of adjacent sampling periods in a time window, and calculating an equivalent flow resistance coefficient according to the change relation between pressure data and the average flow value and the difference relation between liquid theoretical conveying capacity corresponding to the rotation speed of a metering pump and the average flow value; S3, calculating flow transmission delay time of the liquid in the liquid conveying passage according to the equivalent flow resistance coefficient and preset pipeline volume parameters of the long-distance shielding transfusion pipeline, and predicting column inlet flow corresponding to the delay time in the future by combining the current flow change slope to obtain a predicted flow value; S4, comparing the predicted flow value with a preset target flow value to obtain a predicted flow deviation, and determining a pre-compensation rotational speed correction amount of the metering pump according to the predicted flow deviation; S5, according to the precompensation rotational speed correction amount, performing rotational speed correction on the metering pump, simultaneously calculating a flow pulsation amplitude value in a continuous time window, comparing the flow pulsation amplitude value with a preset pulsation threshold value, determining a buffer steady flow cavity volume adjustment amount arranged between the metering pump and the separation column, and adjusting the effective buffer volume of the buffer steady flow cavity according to the volume adjustment amount; And S6, after the current regulation period is finished, rolling and updating a data sequence according to the instantaneous flow data, the pressure data and the rotational speed data of the metering pump acquired in the current regulation period, and recalculating the equivalent flow resistance coefficient, the flow transmission delay time and the predicted flow deviation so as to carry out cooperative correction on the rotational speed of the metering pump and the volume of the buffering steady flow cavity, so that the flow of the inlet of the column is stably maintained within a preset target flow range. Preferably, step S2 includes: S21, carrying out statistical processing on instantaneous flow data in a sliding time window according to a sampling sequence, and determining average flow value in the sliding time window, flow difference values between adjacent sampling peri