Intelligent multi-point temperature-pressure-flow monitoring system integrated with automatic zero calibration and blowing anti-blocking function

Abstract

This invention discloses an intelligent multi-point temperature, pressure, and flow monitoring system integrating automatic zeroing and purging anti-blocking functions, consisting of a control cabinet, a gas circuit cabinet, and at least two probes. The control cabinet integrates a PLC and power control circuit. The gas circuit cabinet integrates multiple differential pressure transmitters, multiple 2-position 3-way solenoid valves, multiple 2-position 2-way solenoid valves, multiple flue gas pressure sensors, and one purging pressure sensor. Each differential pressure transmitter corresponds to one 2-position 3-way solenoid valve and one 2-position 2-way solenoid valve. The 2-position 3-way solenoid valve acts as a pressure tapping valve when not energized and as a purging valve when energized, while the 2-position 2-way solenoid valve acts as a balancing valve. For the size of the power plant's main exhaust flue, each probe integrates one PT100, one flue gas pressure tapping tube, and at least five pairs of S-type Pitot tubes. Each pair of S-type Pitot tubes corresponds to one differential pressure transmitter.

Description

Technical Field

[0001] This invention relates to an intelligent multi-point temperature, pressure and flow monitoring system that integrates automatic zeroing and purging anti-blocking functions. Background Technology

[0002] In environmental monitoring (such as Continuous Emission Monitoring Systems (CEMS) for flue gas in thermal power plants, waste incineration plants, and cement plants) and industrial process control (such as boiler, metallurgical, and chemical process pipelines), accurate and continuous monitoring of flue gas velocity, temperature, and pressure is crucial. Flow velocity measurement is directly related to the calculation of total pollutant emissions, the assessment of desulfurization and denitrification efficiency, and the optimization of process combustion control.

[0003] Currently, the most commonly used method for measuring flue gas velocity, both domestically and internationally, is the differential pressure method, which is based on the principle of Pitot tubes (especially S-type Pitot tubes).

[0004] Its basic formula is:

[0005] Flue gas density (ρ) needs to be corrected by simultaneously measuring the temperature and pressure of the flue gas. Therefore, a complete flue gas velocity measurement system typically requires three basic measurement parameters: differential pressure, temperature, and pressure.

[0006] The following problems may occur when obtaining these three parameters in practice: (1) Zero drift of differential pressure transmitters: After long-term operation, the characteristics of the internal sensing element of a differential pressure transmitter will change with temperature and time. Even if the input differential pressure is zero, its output value will shift, i.e., zero drift. This will cause systematic deviations in flow rate measurement, and these deviations will change over time, seriously affecting the long-term accuracy of the data. According to environmental protection standards, differential pressure transmitters must be zero-calibrated regularly.

[0007] Zero-point calibration has the following disadvantages: ① Lack of stability judgment: The zero point value is read directly during zeroing without the logic of "waiting for the reading to stabilize", which may introduce errors due to pressure disturbance at the moment of zeroing.

[0008] ② The bias application is simple: after calibration, the zero point value can be easily corrected, but there is a lack of an intelligent, recordable "bias" management system, and there may be no alarm function when the deviation is too large.

[0009] ③ Inefficient: The zeroing process is usually performed simultaneously at all measurement points or has a simple logic, which makes it impossible to achieve efficient and uninterrupted automatic zeroing in turn.

[0010] (2) Blockage of pressure tapping lines: Flue gas contains high concentrations of viscous substances such as dust, water droplets, and acid mist, which are very easy to adhere to and accumulate on the pressure tapping port and inner wall of the pressure tapping line of the Pitot tube, eventually causing blockage of the line. Once blocked, the pressure signal cannot be accurately transmitted to the differential pressure transmitter, resulting in serious distortion of the measured value or even complete failure.

[0011] In existing technologies, purging is "time-driven" rather than "state-driven" or "demand-driven." It cannot assess the purging effect, nor can it determine if the pipeline is blocked, the degree of blockage, or whether the purging is truly effective. The pipeline may be severely blocked, and simple timed purging may not clear the blockage, preventing the system from triggering alarms. Furthermore, relying on manual, periodic on-site zeroing and purging is labor-intensive, costly, and requires system shutdown during maintenance, leading to data interruptions. Simple timed purging and zeroing cannot detect the effectiveness of the operation, diagnose the system status, and may even initiate purging when unnecessary, wasting compressed air and increasing operating energy consumption.

[0012] (3) Representativeness of measurement points: The velocity field distribution in large flues or pipes is often uneven. Using a single probe to measure cannot represent the average velocity of the entire cross section, which will lead to a large measurement error. Temperature and pressure data from multiple probes may simply display their individual values ​​or be averaged by the host computer software in the later stage. Real-time and automatic average value calculation and output cannot be achieved at the control layer of this device, resulting in low system integration and intelligence. Summary of the Invention

[0013] The purpose of this invention is to provide an intelligent multi-point temperature, pressure and flow monitoring system that integrates automatic zeroing and purging anti-blocking functions.

[0014] To achieve the above objectives, the present invention adopts the following technical solution: The intelligent multi-point temperature, pressure and flow monitoring system integrating automatic zeroing and purging anti-blocking functions consists of a control cabinet, a gas circuit cabinet, and at least two probes. The gas circuit cabinet integrates multiple differential pressure transmitters, multiple 2-position 3-way solenoid valves (I), multiple 2-position 3-way solenoid valves (II), multiple 2-position 2-way solenoid valves, multiple flue gas pressure sensors, and one purging pressure sensor. Each differential pressure transmitter corresponds to one 2-position 3-way solenoid valve (I), one 2-position 3-way solenoid valve (II), and one 2-position 2-way solenoid valve. When not energized, 2-position 3-way solenoid valves (I and II) function as pressure tapping valves. 2-position 3-way solenoid valve (I) is a total pressure tapping valve, and 2-position 3-way solenoid valve (II) is a static pressure tapping valve. When energized, they function as purging valves, and the 2-position 2-way solenoid valve functions as a balancing valve.

[0015] Furthermore, it also includes a gas distribution module, which is connected to each of the 2-position 3-way solenoid valves and multiple 2-position 3-way solenoid valves.

[0016] Preferably, each probe integrates one temperature sensor, one flue gas pressure tapping tube, and at least five pairs of S-shaped pitot tubes.

[0017] Preferably, the front end of the S-type pitot tube 11 is a pitot tube head, and each pair of S-type pitot tubes corresponds to one differential pressure transmitter.

[0018] Preferably, the differential pressure transmitter includes an automatic zeroing function, which includes periodically zeroing each differential pressure transmitter; multiple differential pressure transmitters are zeroed in turn, and the zero drift of the differential pressure transmitter exceeds a required preset value, which can be 10 Pa.

[0019] Preferably, the automatic zeroing includes an early warning function and an intelligent diagnostic function, which are implemented through the following methods: Zeroing begins with the opening of the corresponding balance valve and the closing of the corresponding total pressure and static pressure tapping valves. The pressure change value begins to decrease. If the change in pressure change value within a certain time is less than a set value, it is determined that the pressure change is in a stable state. Several consecutive values ​​at this point are read, and the average value is calculated. This average value is used as the pressure change value A before zeroing. A is assigned to the automatic differential pressure bias value at this point. After the automatic differential pressure bias value is set, the average value of the instantaneous flow velocity at this point over a continuous time period is recorded as the zero-point flow velocity value after zeroing the pressure change. When the absolute value of the bias value is greater than the required preset value, an alarm is triggered. The zeroing timer at this point ends, the corresponding balance valve is closed, and then the corresponding total pressure and static pressure tapping valves are opened. Zeroing is then performed at the next measuring point.

[0020] In one embodiment, the automatic zeroing process includes the following steps: S1: Start with zeroing in rotation, then proceed to S2; S2: Initialize the current measurement point index N=1, then go to S3; S3: Determine if there are still measurement points N. If the result is yes, go to S4; if the result is no, go to S17. S4: For measuring point N: Open the balance valve and turn to S5; S5: Close the total pressure and static pressure tapping valves, then turn to S6; S6: The pressure transformer value begins to decrease; monitor and switch to S7. S7: Determine if the change in 5 seconds is less than 1 Pa. If the result is yes, proceed to S8; if the result is no, proceed to S6. S8: Read 10 consecutive values ​​of this point, then go to S9; S9: Calculate the average value to obtain the compressive transformer value A, then proceed to S10; S10: Assign A to the differential pressure automatic bias, then go to S11; S11: Record the 30-second average instantaneous flow velocity as the zero-point value of the flow velocity, then proceed to S12; S12: Determine if the absolute value of the bias is >10Pa. If the result is no, proceed to S13. If the result is yes, proceed to S14. S13: The zero-time for this calibration point ends; proceed to S15. S14: Issue an alarm, proceed to S13; S15: For measuring point N: Open the total pressure and static pressure tapping valves, close the balance valve, and turn to S16; S16: Set N=N+1; S17: All calibrations are complete.

[0021] Preferably, the differential pressure transmitter includes an automatic purging operation. The automatic purging operation automatically purges each pressure tap in turn at regular intervals, recording the compressed air pressure value P1 before purging and the minimum compressed air pressure value P2 during the purging process for each pressure tap. The ratio of the pressure drop value (P1-P2) to the set pressure drop value P0 is calculated to determine the degree of blockage. If the blockage is severe, the purging time and frequency are increased. If the blockage is still severe after the last purging, an alarm is triggered, and the purging of the next pressure tap is performed according to the normal purging sequence until all pressure taps have completed one round of purging.

[0022] Specifically, a pressure drop value P0 is set, and the degree of blockage is reflected by d, where d = (1 - (P1 - P2) / P0). When d is greater than the set value, the blockage purging function for that tube is triggered. Compared with normal purging, the purging frequency and purging time are increased, and the blockage purging is increased to m rounds, with each purging lasting n seconds to ensure the purging effect is maximized. The last blockage degree value is recorded. If it is still greater than the set value, an alarm is triggered, and the purging of that pressure tapping tube is completely finished. The purging of the next pressure tapping tube is performed in the normal purging sequence until all pressure tapping tubes have completed one round of purging.

[0023] In one embodiment, the automatic purging operation includes the following steps: S21: Begin, proceed to S22; S22: Re-enter the next timed wait, proceed to S23; S23: Check the compressed air pressure and determine if it is >= the set value. If the result is yes, proceed to S24; if the result is no, proceed to S25. S24: Initialize the pressure tap sequence: Determine the alternating purging order, then proceed to S26; S25: Trigger purge gas low pressure alarm, proceed to S22; S26: Select the next pressure tapping tube to be purged, then proceed to S27; S27: Record the compressed air pressure value P1 before purging the pressure tap, then go to S28; S28: Perform normal purging, then proceed to S29; S29: Record the minimum compressed air pressure P2 during the purging process, then proceed to S210; S210: Calculate the pressure drop ΔP=P1-P2, the ratio k=ΔP / P0, calculate the degree of blockage d=1-k, then proceed to S211; S211: Determine if the degree of blockage d > 50%. If the result is yes, proceed to S212; if the result is no, proceed to S219. S212: Perform blockage purging, proceed to S213; S213: Record the minimum pressure P3 during the last purging process, then proceed to S214; S214: Recalculate the degree of blockage, recalculate the pressure drop ΔP=P1-P3, the new degree of blockage d=1-(ΔP / P0), go to S215; S215: Determine if the degree of blockage d > 50%. If the result is yes, proceed to S216; if the result is no, proceed to S217. S216: Trigger the blockage alarm for the pressure tapping tube, then proceed to S217; S217: Record the complete data of this pressure tap: P1, P3, ΔP, k, d, then transfer to S218; S218: Determine whether all pressure taps have completed one round of purging. If the result is yes, proceed to S22; if the result is no, proceed to S26. S219: Record the complete data of the pressure tapping tube: P1, P2, ΔP, k, d, then transfer to S218.

[0024] Preferably, each flue gas pressure tapping tube's thermal resistance sensor probe measures one temperature, and the temperatures measured by multiple probes are logically averaged in the control cabinet. A normal temperature range is set, and the average temperature within the normal temperature range is taken. If all values ​​within the range are greater than the maximum temperature of the range, the minimum temperature is taken as the flue gas temperature; if all values ​​are less than the minimum temperature of the range, the maximum temperature is taken as the flue gas temperature. Similarly, each flue gas pressure tapping tube's thermal resistance sensor probe measures one flue gas pressure, and the flue gas pressure measured by multiple probes is logically averaged in the control cabinet. A normal flue gas pressure range is set, and the average pressure within the normal pressure range is taken. If all values ​​within the normal pressure range are greater than the maximum pressure of the range, the minimum pressure is taken as the flue gas pressure; if all values ​​are less than the minimum pressure of the range, the maximum pressure is taken as the flue gas pressure.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention fundamentally eliminates the zero-point drift problem of differential pressure transmitters caused by factors such as temperature changes and component aging through fully automatic and periodic alternating zero calibration, ensuring the long-term accuracy and stability of flow velocity measurement data.

[0026] 2. This invention achieves intelligent diagnosis and early warning through intelligent timed purging and blockage degree diagnosis. By focusing on purging maintenance and uninterrupted measurement, it can effectively prevent blockage of pressure tapping pipelines, ensuring that the pressure signal can be transmitted to the transmitter truthfully and without attenuation, avoiding measurement distortion or complete failure caused by pipeline blockage, and reducing manual maintenance. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the structure of the present invention.

[0029] Figure 2 This is a schematic diagram of the differential pressure transmitter structure and connection relationship of the present invention.

[0030] Figure 3 This is a flowchart of the automatic zeroing process for the differential pressure transmitter of the present invention.

[0031] Figure 4 This is a flowchart of the timed automatic purging process for the differential pressure transmitter of the present invention. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0033] Reference Figures 1-2 The intelligent multi-point temperature, pressure, and flow monitoring system, integrating automatic zeroing and purging anti-blocking functions, consists of a control cabinet 1, a gas circuit cabinet 2, and at least two probes 3. The control cabinet integrates a PLC and power control circuit. The gas circuit cabinet 2 integrates multiple differential pressure transmitters 4, multiple 2-position 3-way solenoid valves 5, multiple 2-position 3-way solenoid valves 8, multiple 2-position 2-way solenoid valves 6, multiple flue gas pressure sensors 7, and one purging pressure sensor 9. Each differential pressure transmitter 4 corresponds to one 2-position 3-way solenoid valve and one 2-position 2-way solenoid valve.

[0034] The purge pressure sensor 9 is used to monitor the pressure of the compressed air used for purging.

[0035] It also includes a gas distribution module 13, which is connected to each of the 2-position 3-way solenoid valves 5 and multiple 2-position 3-way solenoid valves 8.

[0036] When the 2-position 3-way solenoid valve 1 and the 2-position 3-way solenoid valve 2 are not energized, they function as pressure tapping valves. The 2-position 3-way solenoid valve 1 is a full pressure tapping valve, and the 2-position 3-way solenoid valve 2 is a static pressure tapping valve. When energized, it functions as a purge valve.

[0037] The 2-position 2-way solenoid valve 6 is used as a balancing valve.

[0038] For the size of the main exhaust flue of the power plant, each probe 3 integrates 1 temperature sensor, 1 flue gas pressure tapping tube 10 and at least 5 pairs of S-type Pitot tubes 11; the front end of the S-type Pitot tube 11 is the Pitot tube head, and each pair of S-type Pitot tubes corresponds to 1 differential pressure transmitter 4.

[0039] The flue gas pressure tapping tube 10 is connected to the flue gas pressure sensor 7 and the temperature transmitter 12. The flue gas pressure tapping tube 10 integrates a thermal resistance sensor for measuring temperature. The thermal resistance sensor is connected to the temperature transmitter 12, and the temperature transmitter 12 is connected to the PLC in the control cabinet. Example 1:

[0040] The differential pressure transmitter of the present invention includes an automatic zeroing function, and this embodiment is a specific description of the automatic zeroing function.

[0041] According to standard requirements, each differential pressure transmitter is periodically zeroed; multiple differential pressure transmitters are zeroed in turn. Zeroing begins with opening the corresponding balance valve, then closing the corresponding total pressure and static pressure tapping valves. The pressure transducer value begins to decrease. If the change in pressure transducer value is less than 1 Pa within 5 seconds, it is considered to be in a stable state. Ten consecutive values ​​are read from this point, and the average value is calculated as the pressure transducer value A before zeroing. A is assigned to the automatic differential pressure bias value for this point. After setting the automatic differential pressure bias value, the average value of the instantaneous flow velocity at this point is recorded for 30 consecutive seconds, serving as the zero-point flow velocity value after zeroing. An alarm is triggered if the absolute value of the bias value exceeds 10 Pa. After the zeroing timer for this point ends, the corresponding balance valve is closed, then the corresponding total pressure and static pressure tapping valves are opened. Zeroing begins at the next measuring point.

[0042] The specific algorithm for recording the average value of the instantaneous flow velocity at a point over 30 consecutive seconds can be as follows: take a differential pressure value every second, and the flow velocity value will be automatically calculated once. Take 30 differential pressure values, and 30 instantaneous flow velocities will be calculated. The average value over 30 seconds = the cumulative flow velocity value over 30 seconds / the number of cumulative values.

[0043] 1. Initialization and Loop Control: The automatic zeroing process starts with "starting with alternating zeroing"; the current measurement point index N is initialized to 1; the main judgment node "whether there are still measurement points N" controls the entire loop; as long as there are still measurement points that have not been zeroed, the loop continues; the process ends after all points are completed.

[0044] 2. Single transformer zeroing process: Valve operation: This includes opening the balancing valve and closing the pressure tapping valve. Opening the balancing valve and closing the pressure tapping valve are key preparatory steps. The valve operation puts the pressure transformer into a zero-calibration state.

[0045] Monitoring and stability assessment: The system monitors the pressure change value and determines whether its change within 5 seconds is less than 1 Pa. This is a cyclical assessment process. If unstable, the assessment result is negative, and monitoring continues; if stable, the assessment result is positive, and the next step of data acquisition is performed.

[0046] Data acquisition and processing: Read 10 values ​​and calculate the average value to obtain the pressure transformer value A.

[0047] Setting the bias and recording the zero point: Set A to automatic differential pressure bias and record the zero point value of the flow rate after zeroing (30-second average).

[0048] Alarm determination: Check if the absolute value of bias value A is greater than 10 Pa. If it is, trigger an alarm. Regardless of whether an alarm is triggered, continue with the zeroing process at that point.

[0049] 3. Single-point termination and switching: After the zero-time calibration is completed, a crucial recovery operation is performed: open the total pressure and static pressure tapping valves and close the balance valve to restore the measuring point to normal measurement status.

[0050] Increment the measurement point index N by 1 to prepare for zeroing the next measurement point.

[0051] The process returns to the main judgment node to determine if there are still measurement points N, and then starts the next loop.

[0052] Reference Figure 3 Specifically, the automatic zeroing process includes the following steps: S1: Start with zeroing in rotation, then proceed to S2; S2: Initialize the current measurement point index N=1, then go to S3; S3: Determine if there are still measurement points N. If the result is yes, go to S4; if the result is no, go to S17. S4: For measuring point N: Open the balance valve and turn to S5; S5: Close the total pressure and static pressure tapping valves, then turn to S6; S6: The pressure transformer value begins to decrease; monitor and switch to S7. S7: Determine if the change in 5 seconds is less than 1 Pa. If the result is yes, proceed to S8; if the result is no, proceed to S6. S8: Read 10 consecutive values ​​of this point, then go to S9; S9: Calculate the average value to obtain the compressive transformer value A, then proceed to S10; S10: Assign A to the differential pressure automatic bias, then go to S11; S11: Record the 30-second average instantaneous flow velocity as the zero-point value of the flow velocity, then proceed to S12; S12: Determine if the absolute value of the bias is >10Pa. If the result is no, proceed to S13. If the result is yes, proceed to S14. S13: The zero-time for this calibration point ends; proceed to S15. S14: Issue an alarm, proceed to S13; S15: For measuring point N: Open the total pressure and static pressure tapping valves, close the balance valve, and turn to S16; S16: Set N=N+1.

[0053] S17: All calibrations are complete. Example 2:

[0054] This embodiment describes the automatic purging operation of a differential pressure transmitter.

[0055] Automatic timed purging, for example, a time setting of 4 hours, normal purging, for example, 2 rounds, 3 seconds per round; each pressure tap is purged in turn, and the pressure value of compressed air before purging of each pressure tap is recorded as P1, and the minimum pressure value of compressed air during the purging process is recorded as P2.

[0056] The ratio of the calculated pressure drop value (P1-P2) to the set pressure drop value P0 is (P1-P2) / P0, where d = (1-(P1-P2) / P0). This ratio reflects the degree of blockage. When d is greater than 50%, the blockage purging function for that pipe is triggered. Compared to normal purging, the purging frequency and duration are increased, with 5 rounds of purging performed, each lasting 5 seconds, to ensure maximum purging effectiveness. The final blockage degree value is recorded. If it is still greater than 50%, an alarm is triggered, and the purging of that pressure tap is completely finished. The purging of the next pressure tap is performed in the normal purging sequence until all pressure taps have completed one round of purging. If the compressed air pressure is less than the set value, such as 0.2 MPa, a low-pressure purging alarm is triggered.

[0057] The timed automatic purging process includes the following steps: 1. Triggering and Preconditions (Starting Point of the Process) Timed trigger: The system starts a "full pressure tap purge cycle" every 4 hours by default, and enters standby mode before the time expires; Compressed air pressure check: Before starting the purging process, the air source pressure must be verified (≥0.2MPa). If the pressure is low, an alarm will be triggered and the current purging process will be terminated. The pressure will be checked again after the next timed trigger to avoid the purging process being ineffective due to insufficient pressure.

[0058] 2. Single pressure tap purging process (core execution step) Each pressure tapping tube is purged independently according to the logic of "normal purging first, then determining whether blockage purging is needed", to avoid gas source pressure fluctuations caused by purging multiple tubes at the same time.

[0059] During normal purging, record the gas source pressure P1 before the current tube is purged to ensure that the data is the initial pressure before purging interference.

[0060] During normal purging, only two cycles are purged of the current pipe, each lasting 3 seconds. Short intervals can be set between cycles to avoid a sudden drop in pressure inside the pipe.

[0061] The degree of blockage is calculated and indirectly reflected by the "pressure drop ratio". Here, ΔP = P1 - P2, the larger the pressure drop, the more severe the blockage may be; d = 1 - (ΔP / P0), the smaller d is, the lower the degree of blockage and the less likely purging is needed. P0 is the set pressure drop.

[0062] The purging trigger condition is: when d>50%, it indicates that the resistance inside the pipe has exceeded the normal range and purging needs to be intensified.

[0063] The blockage purging process involves purging the current pipe 5 times, each time for 5 seconds, increasing both the frequency and duration to maximize the purging effect, and recording the last purging.

[0064] After purging the blockage, a second assessment is performed, and d'=1-[(P1-P2) / P0] is recalculated. If d' is still greater than 50%, it means that the blockage cannot be resolved by purging, and an alarm is triggered.

[0065] 3. Loop and Termination Rules (Process Closed Loop) Single-round full-pipe coverage: All pressure taps are purged one by one in a preset order, such as numbered 1-n, without skipping any.

[0066] Process closed loop: When the last pressure tapping tube is purged, regardless of whether an alarm is triggered, the system automatically returns to the "timed standby" state and waits for the trigger signal in the next 4 hours to achieve unattended periodic purging.

[0067] 4. Alarm Mechanism Description (Abnormal Handling) The underpressure alarm for purging gas means that when the gas source pressure is <0.2MPa, the current purging will be terminated and only an alarm will be triggered.

[0068] The pressure tap blockage alarm occurs when the blockage rate (d) is still greater than 50% after purging. The alarm is associated with the specific pipe number.

[0069] Alarm data retention means that all alarm events must be bound and stored with the corresponding pipe number, time, and pressure data for easy traceability.

[0070] This invention uses data-driven judgment: by replacing subjective judgment with quantitative calculation of "P1-P2→d", the objectivity of the congestion assessment is ensured.

[0071] This invention employs a tiered purging strategy: switching between normal purging (energy saving) and blockage purging (high efficiency) as needed, balancing purging effectiveness and gas consumption.

[0072] The entire process of this invention is traceable: the pressure data, calculation results, and alarm records of each pipe are stored in real time, which facilitates subsequent fault analysis.

[0073] This invention features an anomaly pre-interception: placing air source pressure checks at the very beginning of the process to avoid "ineffective purging" due to insufficient pressure, thereby reducing equipment waste.

[0074] Reference Figure 4 The steps for timed automatic purging are as follows: S21: Begin, proceed to S22; S22: Re-enter the next timed wait, proceed to S23; S23: Check the compressed air pressure and determine if it is >= the set value. If the result is yes, proceed to S24; if the result is no, proceed to S25. S24: Initialize the pressure tap sequence: Determine the alternating purging order, then proceed to S26; S25: Trigger purge gas low pressure alarm, proceed to S22; S26: Select the next pressure tapping tube to be purged, then proceed to S27; S27: Record the compressed air pressure value P1 before purging the pressure tap, then go to S28; S28: Perform normal purging, then proceed to S29; S29: Record the minimum compressed air pressure P2 during the purging process, then proceed to S210; S210: Calculate the pressure drop ΔP=P1-P2, the ratio k=ΔP / P0, calculate the degree of blockage d=1-k, then proceed to S211; S211: Determine if the degree of blockage d > 50%. If the result is yes, proceed to S212; if the result is no, proceed to S219. S212: Perform blockage purging, proceed to S213; S213: Record the minimum pressure P3 during the last purging process, then proceed to S214; S214: Recalculate the degree of blockage, recalculate the pressure drop ΔP=P1-P3, the new degree of blockage d=1-(ΔP / P0), go to S215; S215: Determine if the degree of blockage d > 50%. If the result is yes, proceed to S216; if the result is no, proceed to S217. S216: Trigger the blockage alarm for the pressure tapping tube, then proceed to S217; S217: Record the complete data of this pressure tap: P1, P3, ΔP, k, d, then transfer to S218; S218: Determine whether all pressure taps have completed one round of purging. If the result is yes, proceed to S22; if the result is no, proceed to S26. S219: Record the complete data of the pressure tapping tube: P1, P2, ΔP, k, d, then transfer to S218. Example 3:

[0075] Each flue gas pressure tap 10 thermal resistance sensor probe measures one temperature. The temperatures measured by multiple probes are logically averaged in the control cabinet. A normal temperature range is set, and the average temperature within the normal temperature range is taken. If all temperatures are greater than the maximum temperature in the range, the minimum temperature is taken as the flue gas temperature; if all temperatures are less than the minimum temperature in the range, the maximum temperature is taken as the flue gas temperature. The purpose is to avoid interference from bad temperature points on the measurement results, which could cause a serious deviation in the average temperature.

[0076] Each flue gas pressure tap 10 thermal resistance sensor probe measures one flue gas pressure. The flue gas pressures measured by multiple probes are logically averaged in the control cabinet. A normal flue gas pressure range is set, and the average pressure within the normal pressure range is taken. If all pressures are greater than the maximum pressure in the range, the minimum pressure is taken as the flue gas pressure; if all pressures are less than the minimum pressure in the range, the maximum pressure is taken as the flue gas pressure. The purpose is to avoid interference from faulty pressures on the measurement results, which could cause a serious deviation in the average temperature.

[0077] This invention employs an intelligent automatic zeroing logic and structure. During the zeroing process, the valve is first closed, and the differential pressure value is checked for stability before the zero-point value is read. This solves the problem of errors caused by instantaneous pressure disturbances in traditional zeroing, ensuring high accuracy and reliability. The read zero-point value A is assigned to the measuring point as an "automatic differential pressure bias" value, and the absolute value of this bias is continuously monitored. This upgrades the simple zeroing operation into a diagnostic tool for the health status of the differential pressure transmitter, enabling predictive maintenance.

[0078] This invention calculates the pressure drop ratio during the purging process as the ratio of actual pressure drop to set pressure drop, and uses "1 - ratio" to precisely quantify the degree of blockage; representing a leap from "blind purging" to "intelligent diagnosis." It can tell users the severity of the blockage (e.g., 50%), rather than simply "clear" or "blocked," providing accurate data support for maintenance decisions.

[0079] This invention achieves real-time hardware-level fusion of multi-probe measurement data; at the control cabinet (PLC) level, it directly performs real-time arithmetic average calculation on the temperature and pressure values ​​measured by multiple probes and outputs the average value; at the data source, it provides more reliable parameters that are more representative of the overall operating conditions, directly improving the accuracy and representativeness of the final flow rate calculation.

[0080] This invention employs a system-wide rotation scheduling strategy, where all automated operations (zeroing, purging) are scheduled in rotation. This ensures that maintenance operations do not affect the overall continuous operation of the system, achieving "non-stop maintenance" and guaranteeing data continuity.

[0081] This invention integrates the control cabinet, gas circuit cabinet, and probe into a collaborative system through a highly integrated system architecture with specific logic and structure. In particular, the gas circuit cabinet integrates a specific combination of "multiple 2-position 3-way solenoid valves (as pressure tapping valves and purge valves)" and "multiple 2-position 2-way solenoid valves (as balancing valves)," achieving modularity, compactness, and reliability of functions, and providing a physical basis for all the above-mentioned intelligent logic.

[0082] This invention is also a new multi-point flow meter structure; the flow velocity at multiple measuring points is measured simultaneously, with each probe having 5 measuring points.

[0083] Obviously, the embodiments described above are merely some embodiments of the present invention, not all embodiments. The accompanying drawings show preferred embodiments of the present invention, but do not limit the patent scope of the present invention. The present invention can be implemented in many different forms; rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this invention.

Claims

1. An intelligent multi-point temperature, pressure, and flow monitoring system integrating automatic zeroing and purging anti-clogging functions, characterized in that: It consists of a control cabinet, a gas circuit cabinet, and at least two probes. The gas circuit cabinet integrates multiple differential pressure transmitters, multiple 2-position 3-way solenoid valves (I), multiple 2-position 3-way solenoid valves (II), multiple 2-position 2-way solenoid valves, multiple flue gas pressure sensors, and one purge pressure sensor. Each differential pressure transmitter corresponds to one 2-position 3-way solenoid valve (I), one 2-position 3-way solenoid valve (II), and one 2-position 2-way solenoid valve. When not energized, 2-position 3-way solenoid valves (I and II) function as pressure tapping valves. 2-position 3-way solenoid valve (I) is a total pressure tapping valve, and 2-position 3-way solenoid valve (II) is a static pressure tapping valve. When energized, they function as purge valves, and the 2-position 2-way solenoid valve functions as a balancing valve. Each probe integrates at least five pairs of S-type Pitot tubes in an in-situ insertion manner. The differential pressure transmitter includes an automatic zeroing function, which includes periodically zeroing each differential pressure transmitter; multiple differential pressure transmitters are zeroed in turn; and intelligent diagnostic alarm is triggered when the zero drift of the differential pressure transmitter exceeds the required preset value; the required preset value is 10 Pa. The automatic zeroing includes an early warning function and an intelligent diagnostic function, which are implemented through the following methods: Upon starting zeroing, the corresponding balance valve is opened, and the corresponding total pressure and static pressure tapping valves are closed. The pressure transformer value begins to decrease. If the change in pressure transformer value within a certain time is less than the set value, it is determined that the pressure transformer is in a stable state. Several consecutive values ​​at this point are read, and the average value is calculated. This average value is used as the pressure transformer value A before zeroing. A is assigned to the automatic differential pressure bias value at this point. After setting the automatic differential pressure bias value, the average value of the instantaneous flow velocity at this point over a continuous time period is recorded as the zero-point flow velocity value after zeroing the pressure transformer. An alarm is triggered when the absolute value of the bias value exceeds the required preset value. Once the zeroing time for this point has ended, close the corresponding balance valve, and then open the corresponding total pressure and static pressure tapping valves; proceed to the zeroing of the next measuring point. The automatic zeroing process includes the following steps: S1: Start with zeroing in rotation, then proceed to S2; S2: Initialize the current measurement point index N=1, then go to S3; S3: Determine if there are still measurement points N. If the result is yes, go to S4; if the result is no, go to S17. S4: For measuring point N: Open the balance valve and turn to S5; S5: Close the total pressure and static pressure tapping valves, then turn to S6; S6: The pressure transformer value begins to decrease; monitor and switch to S7. S7: Determine if the change in 5 seconds is less than 1 Pa. If the result is yes, proceed to S8; if the result is no, proceed to S6. S8: Read 10 consecutive values ​​of this point, then go to S9; S9: Calculate the average value to obtain the compressive transformer value A, then proceed to S10; S10: Assign A to the differential pressure automatic bias, then go to S11; S11: Record the instantaneous flow velocity average over 30 seconds as the zero-point value of the flow velocity, then proceed to S12; S12: Determine if the absolute value of the bias is >10Pa. If the result is no, proceed to S13. If the result is yes, proceed to S14. S13: The zero-time for this calibration point ends; proceed to S15. S14: Issue an alarm, proceed to S13; S15: For measuring point N: Open the total pressure and static pressure tapping valves, close the balance valve, and turn to S16; S16: Set N=N+1; S17: All calibrations completed; The differential pressure transmitter includes an automatic purging operation. The automatic purging operation automatically purges each pressure tap in turn at regular intervals, recording the compressed air pressure value P1 before purging and the minimum compressed air pressure value P2 during the purging process for each pressure tap. The ratio of the pressure drop value (P1-P2) to the set pressure drop value P0 is calculated to determine the degree of blockage. If the blockage is severe, the purging time and frequency are increased. If the blockage is still severe after the last purging, an alarm is triggered, and the purging of the next pressure tap is performed according to the normal purging sequence until all pressure taps have completed one round of purging.

2. The intelligent multi-point temperature, pressure, and flow monitoring system with integrated automatic zeroing and purging anti-blocking functions according to claim 1, characterized in that, It also includes a gas distribution module, which is connected to each of the 2-position 3-way solenoid valves and multiple 2-position 3-way solenoid valves.

3. The intelligent multi-point temperature, pressure, and flow monitoring system with integrated automatic zeroing and purging anti-blocking functions according to claim 1, characterized in that, Each probe also integrates a temperature sensor and a flue gas pressure tap.

4. The intelligent multi-point temperature, pressure, and flow monitoring system with integrated automatic zeroing and purging anti-blocking functions according to claim 3, characterized in that, The front end of the S-type pitot tube is the pitot tube head, and each pair of S-type pitot tubes corresponds to one differential pressure transmitter.

5. The intelligent multi-point temperature, pressure, and flow monitoring system with integrated automatic zeroing and purging anti-blocking functions according to claim 1, characterized in that, The automatic purging operation includes the following steps: S21: Begin, proceed to S22; S22: Re-enter the next timed wait, proceed to S23; S23: Check the compressed air pressure and determine if it is >= the set value. If the result is yes, proceed to S24; if the result is no, proceed to S25. S24: Initialize the pressure tap sequence: Determine the alternating purging order, then proceed to S26; S25: Trigger purge gas low pressure alarm, proceed to S22; S26: Select the next pressure tapping tube to be purged, then proceed to S27; S27: Record the compressed air pressure value P1 before purging the pressure tap, then go to S28; S28: Perform normal purging, then proceed to S29; S29: Record the minimum compressed air pressure P2 during the purging process, then proceed to S210; S210: Calculate the pressure drop ΔP=P1-P2, the ratio k=ΔP / P0, calculate the degree of blockage d=1-k, then proceed to S211; S211: Determine if the degree of blockage d > 50%. If the result is yes, proceed to S212; if the result is no, proceed to S219. S212: Perform blockage purging, proceed to S213; S213: Record the minimum pressure P3 during the last purging process, then proceed to S214; S214: Recalculate the degree of blockage, recalculate the pressure drop ΔP=P1-P3, the new degree of blockage d=1-(ΔP / P0), go to S215; S215: Determine if the degree of blockage d > 50%. If the result is yes, proceed to S216; if the result is no, proceed to S217. S216: Trigger the blockage alarm for the pressure tapping tube, then proceed to S217; S217: Record the complete data of this pressure tap: P1, P3, ΔP, k, d, then transfer to S218; S218: Determine whether all pressure taps have completed one round of purging. If the result is yes, proceed to S22; if the result is no, proceed to S26. S219: Record the complete data of the pressure tapping tube: P1, P2, ΔP, k, d, then transfer to S218.

6. The intelligent multi-point temperature, pressure, and flow monitoring system with integrated automatic zeroing and purging anti-blocking functions according to claim 1, characterized in that, Each flue gas pressure tap's RTD sensor probe measures one temperature. Multiple probes' temperatures are logically averaged within the control cabinet. A normal temperature range is set, and the average temperature within this range is taken. If all values ​​within the range are greater than the maximum temperature, the minimum value is taken as the flue gas temperature; if all values ​​are less than the minimum temperature, the maximum value is taken as the flue gas temperature. Similarly, each flue gas pressure tap's RTD sensor probe measures one flue gas pressure. Multiple probes' flue gas pressures are logically averaged within the control cabinet. A normal flue gas pressure range is set, and the average pressure within this range is taken. If all values ​​within the range are greater than the maximum pressure, the minimum value is taken as the flue gas pressure; if all values ​​are less than the minimum pressure, the maximum value is taken as the flue gas pressure.

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