CN-121994876-A - Continuous conductivity measurement method and system for temperature reduction of hydrophobic recovery sampling branch

CN121994876ACN 121994876 ACN121994876 ACN 121994876ACN-121994876-A

Abstract

The invention discloses a continuous conductivity measurement method and a continuous conductivity measurement system for temperature reduction of a hydrophobic recovery sampling branch, which relate to the field of conductivity measurement and are used for collecting sample water temperature, internal temperature of a conductivity electrode and flow data in the temperature reduction process of the hydrophobic recovery sampling branch, establishing a dynamic time sequence reflecting thermal response hysteresis, adjusting electrode temperature response rhythm according to time sequence characteristics, determining a slow change area, extracting time nodes to construct a synchronous compensation reference, adjusting flow rhythm by combining the slow change area time nodes, realizing temperature dynamic alignment through flow delay, reallocating temperature compensation curve weight in an aligned state, translating the hysteresis temperature nodes to instantaneous nodes, smoothing a conductivity signal according to compensation results, and dissipating instantaneous errors. According to the invention, the time synchronization of temperature compensation and the real temperature of the sample water is realized through time sequence and flow regulation, so that the conductivity result truly reflects the water quality change, and the instantaneous fluctuation is dissipated through continuous smooth control, so that the reliability and judgment accuracy of online monitoring are improved.

Inventors

SHI YAN
Tan Pingyu
SHAO NING
YAN ZHIXIN
DONG XIAOMING

Assignees

国能常州第二发电有限公司
国能常州发电有限公司

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (10)

1. The continuous conductivity measurement method for the temperature reduction of the hydrophobic recovery sampling branch is characterized by comprising the following steps of: Collecting real-time sample water temperature, internal temperature of a conductivity electrode and sample water flow change data in the temperature reduction process of a hydrophobic recovery sampling branch, and establishing a dynamic time sequence reflecting thermal response hysteresis characteristics between the sample water temperature and the electrode temperature; according to the temperature difference hysteresis characteristic represented in the dynamic time sequence, time-division adjustment is carried out on the collected internal temperature response rhythm of the conductivity electrode, the temperature hysteresis interval is confirmed to be a slow-change zone, and a time node of the slow-change zone is extracted to construct a transition reference for synchronously compensating the sample water temperature and the electrode temperature; The time node of the slow-change area is combined, transient flow adjustment is carried out on the inflow rhythm of the sample water, the temperature gradient in the slow-change area is taken as a regulating basis, and the temperature change curve of the sample water and the thermal response rhythm of the conductivity electrode are dynamically aligned in time through a flow delay process; Under the state of temperature dynamic alignment, the time weight distribution of a temperature compensation curve adopted by conductivity measurement is redistributed, the synchronous rhythm formed in the flow delay process is used as a time sequence reference, the compensation proportion of the original corresponding lagged temperature node is adjusted and translated to the instantaneous temperature node of the sample water, and a temperature compensation result consistent with the temperature change time of the sample water is formed; And according to the temperature compensation result, performing continuous smooth control on the output signal of the conductivity, and dissipating the instantaneous error in the measurement process by using the time weight after the redistribution.
2. The continuous conductivity measurement method of the hydrophobic recovery sampling leg desuperheating of claim 1, wherein the step of establishing a dynamic time series reflecting thermal response hysteresis characteristics between the sample water temperature and the temperature inside the conductivity electrode comprises: Selecting a measurement position of a temperature reduction section of the hydrophobic recovery sampling branch, and collecting real-time parameters of the running state of the hydrophobic sample water, wherein a first temperature measurement unit is used for continuously measuring the instant temperature of the hydrophobic sample water, a second temperature measurement unit is used for detecting the internal temperature of the conductivity electrode, and a flow measurement unit is used for recording the flow change of the sample water; the collected sample water temperature, the temperature inside the conductivity electrode and the flow change data are correspondingly arranged according to time sequence, a dynamic time sequence with continuous time is established, the time difference between the sample water temperature change rate and the temperature response rate inside the conductivity electrode is recorded, and the influence rule of the running state of the hydrophobic sample water on the thermal response hysteresis characteristic is obtained; And according to the corresponding relation between the sample water temperature and the internal temperature of the conductivity electrode through dynamic time sequence analysis, identifying a temperature stabilizing region, a temperature rapid change region and a temperature difference recovery region by setting a temperature change rate and a temperature difference comparison threshold value.
3. The continuous conductivity measurement method for temperature reduction of a hydrophobic recovery sampling branch according to claim 2, wherein the step of extracting a time node of the graded region to construct a transition reference for synchronous compensation of sample water temperature and electrode temperature comprises: Performing time correlation analysis on the hydrophobic sample water temperature, the internal temperature of the conductivity electrode and hydrophobic flow rate change data in a dynamic time sequence, determining a time interval between a sample water temperature change starting point and an electrode temperature response starting point, and defining the time interval as a temperature hysteresis interval; According to the time characteristics of the temperature hysteresis interval, the time segment adjustment is carried out on the temperature response rhythm inside the conductivity electrode, the time period when the temperature change of the sample water does not cause the temperature response of the electrode is divided into an initial response period, the time period when the temperature difference continuously exists is divided into a slowly-changing area core period, the time period when the temperature is gradually stabilized is divided into a stabilizing period, and the duration time and the flow state of each time period are synchronously recorded; Starting from the starting point of a core section of the slow-change area, extracting continuous time nodes according to sampling time intervals, and recording sample water temperature, electrode temperature and hydrophobic flow data of each time node to form a node sequence arranged in time sequence; And connecting time nodes in the buffer zone in time sequence, establishing a temperature corresponding relation table, converting the corresponding relation between the sample water temperature and the electrode temperature into a compensation transition reference corresponding to time, and synchronously recording the hydrophobic flow state in the compensation reference.
4. The continuous conductivity measurement method for the temperature reduction of the hydrophobic recovery sampling branch according to claim 3, wherein the time node of the core section of the graded region is determined according to the difference between the sample water temperature and the internal temperature change rate of the conductivity electrode, when the temperature change rate difference is continuously reduced, the corresponding time node is marked as a key node, and the temperature difference change trend between adjacent key nodes is used as the adjustment basis of the temperature synchronous compensation.
5. A continuous conductivity measurement method according to claim 3, wherein the step of dynamically aligning the sample water temperature profile with the thermal response cadence of the conductivity electrode over time by a flow delay process comprises: Analyzing the corresponding relation among the sample water temperature, the internal temperature of the conductivity electrode and the hydrophobic flow on the time node of the time delay zone, and recording the sample water temperature value, the electrode temperature value and the temperature difference between adjacent nodes to form a temperature gradient distribution table; According to the change characteristics of the temperature gradient of the slow-change area, transient flow adjustment is implemented on the inflow rhythm of the sample water by taking a time node as a control reference, the flow is reduced when the temperature change rate of the sample water is increased, and the flow is increased when the temperature change rate of the sample water is slowed down; in the flow delay process, taking the time distribution of the temperature gradient of the slow-change area as a control reference, continuously recording the temperature change of each time node, confirming that the time difference between the sample water temperature change curve and the electrode temperature response curve is reduced, and finally realizing the dynamic alignment of the sample water temperature change curve and the electrode temperature response curve in the time dimension; And continuously monitoring the flow of the sample water by taking the time node at the end of the flow delay process as a temperature synchronization starting point and taking the time node at the time of the slow change as a reference, and immediately adjusting the flow when the temperature of the sample water has a change trend.
6. The continuous conductivity measurement method for temperature reduction of a hydrophobic recovery sampling branch according to claim 5, wherein in the transient flow adjustment process, the adjustment amplitude of the sample water flow is determined according to the continuous change rate of the temperature gradient of the buffer zone, the flow is maintained stable when the temperature difference between adjacent time nodes is continuously reduced, and the flow is gradually reduced when the temperature difference is continuously increased.
7. The continuous conductivity measurement method of a hydrophobic recovery sampling leg de-temperature of claim 5, wherein the step of adjusting and translating the compensation gravity of the otherwise corresponding hysteresis temperature node to the instantaneous temperature node of the sample water comprises: Analyzing the relation of the temperature of the sample water, the internal temperature of the conductivity electrode and the flow rate change on a time node in the time delay zone, determining a node of which the temperature of the sample water is consistent with the internal temperature of the conductivity electrode in the time dimension according to the synchronous rhythm formed in the flow rate delay process, marking the node as an instantaneous temperature node, and establishing a one-to-one correspondence relation between a hysteresis temperature node and the instantaneous temperature node; Reorganizing the time weight distribution of a temperature compensation curve adopted by conductivity measurement according to the corresponding relation between the instantaneous temperature nodes and the hysteresis temperature nodes, taking the time rhythm formed in the flow delay process as a time reference, advancing the compensation weight of the hysteresis temperature nodes to the corresponding instantaneous temperature nodes along a time axis, and recording the weight change value to form synchronous distribution; Based on the translated time sequence, continuously optimizing the time weight distribution of the temperature compensation curve, and adjusting the weight transition of adjacent nodes according to the temperature change trend of the sample water; and taking the optimized temperature compensation curve as a time reference, reading the corresponding instantaneous temperature node compensation weight value in real time in the conductivity measurement process, and executing conductivity correction calculation to form a conductivity correction time sequence.
8. The continuous conductivity measurement method for temperature reduction of a hydrophobic recovery sampling branch according to claim 7, wherein when the time weight distribution of the temperature compensation curve used for conductivity measurement is continuously optimized, the weight change rate is defined according to the actual trend of the temperature change of the sample water, and when the weight change span of the adjacent time nodes exceeds a set change span threshold, gradual transition adjustment is performed according to the change direction of the temperature of the sample water.
9. The continuous conductivity measurement method for temperature reduction of a hydrophobic recovery sampling branch according to claim 7, wherein the step of obtaining a conductivity dynamic curve synchronized with a real temperature change process of a sample water by using an instantaneous error in a time weight dissipation measurement process after redistribution comprises: Performing time correspondence and synchronous matching on the output signal of the conductivity and the temperature compensation result, and rearranging the sample water temperature, the internal temperature of the conductivity electrode and the flow change data according to a time sequence according to a temperature compensation time sequence; Continuously smoothing control is carried out on the output signal of the conductivity according to the time weight after redistribution, the conductivity measured value is sequentially read from the first node of the time sequence, smoothing processing is carried out by combining the time weight of the adjacent time node, and the instantaneous error is dispersed to the adjacent time node through the time weight when the signal fluctuates; after the smoothing control is completed, carrying out time sequence reconstruction on the output signal of the conductivity, and connecting the conductivity values subjected to the smoothing treatment according to the time sequence to form a dynamic change curve covering the whole process of sampling and temperature reduction of the hydrophobic sample water.
10. The continuous conductivity measurement system for reducing the temperature of the hydrophobic recovery sampling branch, which is used for realizing the continuous conductivity measurement method for reducing the temperature of the hydrophobic recovery sampling branch according to any one of the claims 1-9, is characterized by comprising a dynamic time sequence building module, a temperature difference lag segmentation module, a flow rhythm regulation module, a time weight redistribution module and a conductivity smoothing control module; The dynamic time sequence establishing module is used for acquiring real-time sample water temperature, the internal temperature of the conductivity electrode and sample water flow change data in the temperature reduction process of the hydrophobic recovery sampling branch, and establishing a dynamic time sequence reflecting thermal response hysteresis characteristics between the sample water temperature and the electrode temperature; The temperature difference hysteresis segmentation module is used for carrying out time segmentation adjustment on the collected internal temperature response rhythm of the conductivity electrode according to the temperature difference hysteresis characteristics represented in the dynamic time sequence, confirming a temperature hysteresis interval as a slow-change region, extracting time nodes of the slow-change region and constructing a transition reference for synchronously compensating the sample water temperature and the electrode temperature; the flow rhythm regulation and control module combines the time node of the slow-change area to implement transient flow regulation on the inflow rhythm of the sample water, takes the temperature gradient in the slow-change area as a regulation basis, and dynamically aligns the temperature change curve of the sample water with the thermal response rhythm of the conductivity electrode in time through the flow delay process; The time weight redistribution module is used for performing redistribution on the time weight distribution of the temperature compensation curve adopted by the conductivity measurement in a temperature dynamic alignment state, taking the synchronous rhythm formed in the flow delay process as a time sequence reference, and adjusting and translating the compensation proportion of the original corresponding lagged temperature node to the instantaneous temperature node of the sample water to form a temperature compensation result consistent with the temperature change time of the sample water; And the conductivity smoothing control module is used for executing continuous smoothing control on the output signal of the conductivity according to the temperature compensation result, and dissipating the instantaneous error in the measuring process by using the time weight after reassignment.

Description

Continuous conductivity measurement method and system for temperature reduction of hydrophobic recovery sampling branch Technical Field The invention relates to the technical field of conductivity measurement, in particular to a continuous conductivity measurement method and system for temperature reduction of a hydrophobic recovery sampling branch. Background The hydrophobic recovery sampling branch refers to a separate bypass line leading from the device or line for collecting a hydrophobic (vapor condensate) sample and returning to the hydrophobic recovery system. The branch is generally arranged on a drain recovery line of a urea device, a steam drum or a condensation system and bears the functions of sampling, reducing temperature, detecting and recovering drain without affecting the operation of a main system. The main function of the method is that a small part of hydrophobic sample water is shunted by a branch before high-temperature high-pressure hydrophobic water enters the main recovery tank, and the operation of temperature reduction and on-line analysis is performed so as to continuously monitor hydrophobic water quality indexes (such as conductivity, oxidation-reduction potential and the like). The continuous conductivity measurement of the temperature reduction state of the hydrophobic recovery sampling branch refers to the real-time continuous conductivity detection of the flowing hydrophobic sample water after the temperature reduction treatment of the sampling branch. The method comprises the steps of firstly cooling the hydrophobic sample water through a cooler after the hydrophobic sample water is taken out, so that the temperature of the sample water is reduced from about 100 ℃ to a stable range of 20-30 ℃ to avoid damage to a conductivity electrode caused by high temperature and ensure accurate temperature compensation, and then enabling the sample water to enter a conductivity online detection unit in a continuous flowing state passing through a cooling section, wherein the detection unit continuously reads the conductivity value of the sample water to reflect the ion concentration in the hydrophobic water and possible pollution (such as urea leakage, corrosion products, scaling matters and the like). By the method, real-time quality monitoring and abnormal early warning of the drainage recovery process of the urea station can be realized, so that the stability and accuracy of electrode measurement are ensured, and the safety of a drainage recovery system and the controllability of closed-circuit water quality are ensured. The prior art has the following defects: when the temperature reduction process of the hydrophobic recovery sampling branch circuit fluctuates, the sample water temperature tends to change rapidly. The conductivity electrode has a certain heat capacity and is limited by the heat transfer characteristic of the internal structure, so that the temperature response is obviously delayed, and the real temperature state of the sample water is difficult to reflect in time. At this time, the temperature compensation curve used for the conductivity measurement is corrected according to the hysteresis temperature in the electrode, so that a time deviation is generated between the compensation result and the actual temperature of the sample water, and the measured reading is delayed from the actual change trend as a whole. The phenomenon is particularly obvious in the process of frequent adjustment of the water quality of the water reduction or switching of seasonal operation working conditions, and is easy to cause the excessive smoothness of a conductivity change curve, so that the response sensitivity to sudden changes of the water quality of the water is weakened, and the timely identification and judgment accuracy of an online monitoring system to abnormal working conditions are further affected. The above information disclosed in the background section is only for enhancement of understanding of the background of the disclosure and therefore it may include information that does not form the prior art that is already known to a person of ordinary skill in the art. Disclosure of Invention The invention aims to provide a continuous conductivity measurement method and a continuous conductivity measurement system for reducing temperature of a hydrophobic recovery sampling branch, so as to solve the problems in the background art. In order to achieve the purpose, the invention provides a continuous conductivity measurement method for reducing the temperature of a hydrophobic recovery sampling branch, which comprises the following steps: collecting real-time sample water temperature, the internal temperature of a conductivity electrode and sample water flow change data in the temperature reduction process of a hydrophobic recovery sampling branch, and establishing a dynamic time sequence reflecting thermal response hysteresis characteristics between the sample water temperature