Storage tank oil gas full-component real-time monitoring system and method combining PID and NDIR sensors

Abstract

The invention discloses a storage tank oil gas full-component real-time monitoring system and method combining PID and NDIR sensors, and belongs to the technical field of environment monitoring. The method is used for detecting the concentration of leaked oil gas above a floating disc in an oil storage tank in an oil tank area, and particularly relates to gas collection, gas circulation detection and multi-principle gas concentration calculation. On the premise that the oil gas concentration in the tank is not damaged, real-time monitoring of the oil gas concentration in the oil storage tank is achieved, and the detection technology of the oil gas concentration in the oil storage tank can be further improved. All-component concentration measurement can be achieved for complex and multivariate oil gas concentration, detected signals are transmitted to a computer in real time, the detection precision of the oil gas concentration in the oil storage tank is improved, and the oil tank area safety evaluation technology can be further promoted.

Description

Technical Field

[0001] The present invention relates to the technical field of safety monitoring of oil and gas storage tanks, and specifically to a real-time monitoring system and method for all components of oil and gas in storage tanks that combines a PID (Photoionization Detector) and an NDIR (Non-Dispersive Infrared) sensor, aiming to achieve high-precision and real-time monitoring of the oil and gas components in the storage tank and improve the safety and reliability of the storage tank operation. Background Art

[0002] In an oil tank area, oil and gas leakage is a common risk factor, and real-time monitoring of the concentration of oil and gas (such as methane, propane, isooctane, etc.) is particularly important.

[0003] Currently, the common tank types for storing oil products can be divided into three forms according to the structural characteristics of the tank top: fixed roof tanks, external floating roofs, and internal floating roofs. Among them, the internal floating roof tank can greatly reduce the evaporation loss during oil storage because the floating roof is close to the oil surface. It is one of the most commonly used tank types in national reserve warehouses. There is a 10 - 30 cm gap, that is, a sealing ring, between the floating roof and the tank wall of the internal floating roof tank. After long-term use, the sealing ring will be corroded and perforated by oil and gas, resulting in oil and gas leakage in the tank. The oil and gas accumulate in the area above the floating roof, forming a high-concentration risk area, and even causing fire and explosion. Traditional methods for monitoring oil and gas in storage tanks often rely on a single sensor technology, such as a PID sensor or an NDIR sensor. These methods have limitations in measurement accuracy and component identification. The PID sensor does not respond to specific hydrocarbon gases such as methane and propane, resulting in incomplete monitoring results. Although the NDIR sensor is sensitive to specific components (such as methane, propane), it may be interfered in a complex oil and gas environment. Therefore, it is of great significance to develop a monitoring system that can simultaneously measure all components of oil and gas with high precision.

[0004] The PID (Photoionization Detector) sensor has a good response to most volatile organic compounds in oil and gas, and the non-dispersive infrared (NDIR) gas sensor has strong selectivity and good responses to both methane and propane. However, the PID (Photoionization Detector) sensor detects the gas concentration based on the ionization energy of the gas to be measured, and the ionization energies of methane and propane are higher than the ionization range that a commercial PID (Photoionization Detector) sensor can ionize, so it is impossible to achieve full-component detection of oil and gas components. The non-dispersive infrared (NDIR) gas sensor also cannot achieve full-component detection of oil and gas concentration due to its strong selectivity. In addition, gas concentration sensors cannot be installed in the internal space of the storage tank above the floating roof of the internal floating roof storage tank, so it is impossible to directly detect the concentration inside the tank.

[0005] The patent "Product Oil Leak Detection Device and Detection Method (CN 105445443B)" provides a product oil leak detection device integrating a PID gas sensor and an NDIR gas sensor and its corresponding detection method. This device can monitor the gas volatilized from product oil in the environment in real time, analyze data through a built-in processing unit, eliminate the interference of water vapor on the NDIR sensor, and trigger an alarm when a leak is detected. However, during the on-line monitoring of the oil and gas inside the storage tank, it is impossible to monitor from the inside, so it is not applicable to the monitoring of the oil and gas concentration inside the storage tank; there is no water vapor inside the oil storage tank, so there is no need to consider the interference of water vapor and set up a special detection device for this purpose; in addition, existing oil and gas monitoring methods often rely on a single sensor technology, such as a PID sensor or an NDIR sensor, and these methods have limitations in measurement accuracy and component identification, and may be interfered in a complex oil and gas environment. Summary of the Invention

[0006] To solve the above problems, the present invention provides a real-time monitoring system and method for all components of oil and gas in a storage tank combining a PID and an NDIR sensor. Through steps such as system integration, determination of sensor response coefficients, real-time data acquisition and processing, concentration calculation and correction, and result output and monitoring, the real-time monitoring of all components of oil and gas in the storage tank is realized. The accuracy and reliability of oil and gas monitoring are improved, providing strong technical support for the safety management of storage tanks.

[0007] The technical solution adopted by the present invention is as follows: A real-time monitoring system for all components of oil and gas in a storage tank combining a PID and an NDIR sensor, the system includes a sensor module, a data acquisition module, a data processing unit, a data display and storage module, a gas path circulation module, and an alarm module; The sensor module is used to detect all components of the oil and gas inside the storage tank, and all components of the oil and gas at least include volatile hydrocarbons and olefinic organic compounds; the sensor module includes a PID sensor, an NDIR methane sensor, and an NDIR propane sensor. The PID sensor is used to detect the hydrocarbon concentration, and the NDIR methane sensor and the NDIR propane sensor are respectively used to detect the concentrations of methane and propane; The data acquisition module is used to collect the detection data of the sensor module and transmit it in real time; The data processing unit is used to receive the data transmitted by the data acquisition module, calculate using the pre-stored response coefficients of methane and propane to obtain the accurate concentrations of methane and propane, and at the same time receive the hydrocarbon concentration data of the PID sensor, and correct the total concentration of methane and propane with the hydrocarbon concentration measured by the PID sensor to obtain the total oil and gas concentration value; The data display and storage module is used to display and store the oil and gas concentration data inside the storage tank according to the total oil and gas concentration value; The gas circuit circulation module is used to transport the oil and gas inside the storage tank to the sensor module for detection and then send it back to the storage tank; The alarm module is used to automatically trigger an alarm when the oil and gas concentration exceeds the preset safety threshold.

[0008] Furthermore, the full components of the oil and gas at least include methane, propane, and butene.

[0009] Furthermore, the range of the PID sensor is 10000ppm, and the specification of the ionization lamp is 10.6eV; The range of the NDIR methane sensor is 30000ppm, and the resolution is 50ppm; The range of the NDIR propane sensor is 50000ppm, and the resolution is 100ppm.

[0010] Furthermore, the data acquisition module uses the time library to set up a timing task to regularly collect and process data.

[0011] Furthermore, the data processing unit performs the following steps: receiving the detection data of the PID sensor and two NDIR sensors in real time; calculating the accurate concentrations of methane and propane by using the response coefficients in the algorithm library; correcting the total concentration of methane and propane with the hydrocarbon concentration measured by the PID sensor to obtain the total oil and gas concentration value; and outputting the total oil and gas concentration value to the data display and storage module in real time.

[0012] Furthermore, the data processing unit uses NumPy for numerical calculations, including the application of response coefficients and the calculation of concentrations.

[0013] Furthermore, the data display and storage module uses Matplotli for data visualization to display the oil and gas concentration in real time; and uses Pandas for data storage to save the data to CSV.

[0014] Furthermore, the alarm module includes a threshold setting function for setting the safety threshold of the oil and gas concentration; and an alarm trigger function for automatically triggering an alarm signal when the oil and gas concentration exceeds the preset safety threshold.

[0015] A working method of a real-time monitoring system for the full components of oil and gas in a storage tank combining PID and NDIR sensors includes the following steps: S1: Before the system runs formally, use known concentration methane and propane gas samples to measure their response values through the NDIR methane sensor and the NDIR propane sensor respectively, calculate and store the response coefficients; S2: Methane gas cross-response test. Introduce a single methane gas into the above-calibrated NDIR methane sensor and NDIR propane sensor simultaneously, record the output readings of the two sensors synchronously, record the response values to the methane gas, calculate and store the response coefficient of the NDIR propane sensor to methane, denoted as ; S3: Propane gas cross-response test. Input a single propane gas into the NDIR methane sensor and the calibrated NDIR propane sensor simultaneously, record the output readings of the two sensors synchronously again, and record the response values to the propane gas; calculate and store the response coefficient of the NDIR methane sensor to propane gas, denoted as ; S4: Start the gas circuit circulation module, continuously extract oil and gas samples from the storage tank, and transport them to the PID sensor and two NDIR sensors; S5: The sensors collect data in real time and transmit the data to the data processing unit; the data processing unit receives the transmitted data, uses the pre-stored response coefficients of methane and propane, and performs calculations using NumPy to obtain the accurate concentrations of methane and propane and : , wherein, 、 are the readings of the NDIR methane sensor and the NDIR propane sensor, and are the concentrations of methane and propane gases respectively, is the response coefficient of the NDIR methane sensor to propane gas, is the response coefficient of the NDIR propane sensor to methane gas; The data processing unit also receives the hydrocarbon concentration data of the PID sensor, and obtains the total oil and gas concentration value after correction; S6: Output the total oil and gas concentration value to the data display and storage module in real time; S7: Set the safety threshold of the oil and gas concentration. When the oil and gas concentration exceeds the preset safety threshold, an alarm is automatically triggered.

[0016] Furthermore, the alarm module uses an if statement in Python to check whether the oil and gas concentration exceeds the preset threshold, and uses the playsound library to play an alarm sound.

[0017] Specifically, the detection method includes the following steps: S1. Before the system runs officially, it is necessary to measure the response coefficients of methane and propane respectively. Use methane and propane gas samples with known concentrations, measure their response values through the NDIR sensor, and calculate the corresponding response coefficients. Store the measured response coefficients in the algorithm library of the system for use in subsequent data processing.

[0018] S2. The gas circulation system continuously extracts oil and gas samples from the storage tank and transports them to the PID and two NDIR sensors.

[0019] S3. Collect sensor data in real time and transmit the data to the data processing unit. Use the time library to set up a timed task to collect and process data regularly.

[0020] S4. Utilize the response coefficients pre-stored in the algorithm library, combine the readings of the two NDIR sensors, and obtain accurate methane and propane concentrations through numerical calculations using NumPy. At the same time, the hydrocarbon concentration directly measured by the PID sensor is also collected. Add the methane and propane concentrations calculated by the NDIR sensors to obtain the total concentration of methane and propane. Calibrate this total concentration of methane and propane with the hydrocarbon concentration measured by the PID sensor to obtain an accurate value of the total oil and gas concentration.

[0021] S5. Output the calculated total oil and gas concentration value to the display screen or monitoring system in real time so that the operator can understand the oil and gas concentration in the storage tank in real time. The data display and storage module uses Matplotli for data visualization and displays the oil and gas concentration in real time. Use Pandas for data storage and save the data to CSV for subsequent analysis.

[0022] S6. Set up a threshold alarm function. When the oil and gas concentration exceeds the preset safety value, the system can automatically trigger an alarm and play an alarm sound using the playsound library. Remind the operator to take corresponding measures.

[0023] The range of the PID sensor should be 10000 ppm, and the specification of the ionization lamp in the sensor is 10.6 eV.

[0024] The range of the NDIR methane sensor is 30000 ppm, and the resolution is 50 ppm.

[0025] The range of the NDIR propane sensor is 50000 ppm, and the resolution is 100 ppm.

[0026] The beneficial effects of the present invention are as follows: The present invention combines a PID sensor with two NDIR sensors (for methane and propane respectively), achieving comprehensive monitoring of the oil and gas components in the storage tank. This multi-sensor fusion method improves the accuracy and reliability of monitoring and can more accurately reflect the oil and gas conditions in the storage tank.

[0027] Through preliminary experiments, the present invention determines the response coefficients of methane and propane to the NDIR sensors and designs an algorithm to use these coefficients to correct the measurement results of the sensors. This innovation ensures that the system can accurately measure the concentrations of methane and propane even in a complex and variable oil and gas environment.

[0028] This technology of the present invention not only provides real-time output of oil and gas concentration data but also sets up intelligent monitoring and alarm functions. When the oil and gas concentration exceeds the preset safety threshold, the system can automatically trigger an alarm, timely reminding the operator to take corresponding measures, thus effectively ensuring the safe operation of the storage tank.

[0029] The design of the gas circulation system of the present invention ensures that the oil and gas samples can be stably and continuously transported to each sensor for analysis. This optimization improves the stability and reliability of the system and provides a strong guarantee for accurate measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the system of the present invention.

[0031] Figure 2 It is a flowchart of on-line monitoring of oil and gas concentration of this design. DETAILED DESCRIPTION OF THE INVENTION

[0032] To clearly illustrate the technical features of this solution, the following elaborates on this solution through specific implementation cases. These implementation cases are implemented on the premise of the technical solution of the present invention, but the protection scope of the present invention should not be limited to the following implementation cases.

[0033] Figure 1 There is shown a real-time monitoring system for all components of oil and gas in a storage tank that combines a PID (Photoionization Detector) with NDIR (Non-Dispersive Infrared) sensors, including: Sensor module: Detect all components of the oil and gas inside the storage tank. The all components of the oil and gas include volatile organic compounds such as methane, propane, isobutane, and butene. Among them, the sensor module includes a PID (Photoionization Detector) sensor and two NDIR (Non-Dispersive Infrared) sensors. The PID sensor is used to detect the hydrocarbon concentration, and the two NDIR sensors are respectively used to detect the concentrations of methane and propane; Data acquisition module: Collect the detection data of the sensor module and transmit it in real time; Data processing unit: Receives the data transmitted by the data acquisition module, calculates using the pre-stored response coefficients of methane and propane to obtain the accurate concentrations of methane and propane, and at the same time receives the hydrocarbon concentration data of the PID sensor, corrects the total concentration of methane and propane with the hydrocarbon concentration measured by the PID sensor to obtain the total oil and gas concentration value; Data display and storage module: Displays and stores the internal oil and gas concentration data of the storage tank according to the total oil and gas concentration value; Gas circuit circulation module: Transports the internal oil and gas of the storage tank to the sensor module for detection and then sends it back to the storage tank; Alarm module: Automatically triggers an alarm when the oil and gas concentration exceeds the preset safety threshold.

[0034] The present invention also provides a real-time monitoring method for all components of the oil and gas in the storage tank combining a PID (Photoionization Detector) and an NDIR (Non-Dispersive Infrared) sensor, including the following steps: Step 1, Before the system runs formally, it is necessary to measure the response coefficients of methane and propane respectively.

[0035] Step 2, The gas circulation system continuously extracts oil and gas samples from the storage tank and transports them to the PID and two NDIR sensors.

[0036] Step 3, The sensors collect data in real time and transmit the data to the data processing unit.

[0037] Step 4, Add the concentrations of methane and propane calculated by the NDIR sensors to obtain the total concentration of methane and propane.

[0038] Step 5, Output the calculated total oil and gas concentration value to the display screen or the monitoring system in real time so that the operator can understand the oil and gas concentration situation in the storage tank in real time.

[0039] Step 6, Set the threshold monitoring function.

[0040] The range of the PID sensor is 10000 ppm, and the ionization lamp specification is 10.6 eV; the range of the NDIR methane sensor is 30000 ppm, and the resolution is 50 ppm; the range of the NDIR propane sensor is 50000 ppm, and the resolution is 100 ppm.

[0041] Use known concentration methane and propane gas samples, measure their response values through the NDIR sensors, and calculate the corresponding response coefficients. Store the measured response coefficients in the algorithm library of the system for use in subsequent data processing.

[0042] Using the response coefficients pre-stored in the algorithm library, combining the readings of two NDIR sensors, and through algorithm analysis, accurate methane and propane concentrations are obtained. At the same time, the hydrocarbon concentration directly measured by the PID sensor is also collected. The total concentration of methane and propane is corrected with the hydrocarbon concentration measured by the PID sensor to obtain an accurate value of the total oil and gas concentration.

[0043] Set a safety threshold for the oil and gas concentration. When the oil and gas concentration exceeds the preset safety threshold, the system can automatically trigger an alarm to remind the operator to take corresponding measures.

[0044] The specific inspection method includes the following steps: Step 1: Gas ratio and sensor calibration. Using the gas partial pressure law, accurately prepare methane gas with a preset concentration, and input the gas into the NDIR methane sensor to perform the concentration calibration operation to ensure that the response value of the sensor to methane gas is accurate and reliable. Record the calibration result as the reference data.

[0045] Step 2: Propane gas ratio and sensor calibration. Similarly, based on the gas partial pressure law, prepare propane gas with a preset concentration, and input the gas into the NDIR propane sensor to carry out the concentration calibration process, verify the detection accuracy of the sensor to propane gas, and record the calibration result as the reference benchmark.

[0046] Step 3: Methane gas cross-response test. Introduce a single methane gas into the above-calibrated NDIR methane sensor and NDIR propane sensor simultaneously, synchronously record the output readings of the two sensors, record the response value to methane gas, calculate and store the response coefficient of the NDIR propane sensor to methane, denoted as ; Step 4: Propane gas cross-response test. Input a single propane gas into the NDIR methane sensor and the calibrated NDIR propane sensor simultaneously, and again synchronously record the output readings of the two sensors, record the response value to propane gas; calculate and store the response coefficient of the NDIR methane sensor to propane gas, denoted as ; Step 5: Start the gas circuit circulation system and continuously extract oil and gas samples from the storage tank. Transport the extracted oil and gas samples to the PID sensor and two NDIR sensors for detection.

[0047] Step 6: The sensors collect oil and gas data in real time.

[0048] Step 7: The data acquisition module uses the time library to set a timed task, regularly collect data and transmit the collected data to the data processing unit.

[0049] Step Eight: The data processing unit calculates the accurate concentrations of methane and propane using the stored response coefficients, and at the same time receives the hydrocarbon concentration data from the PID sensor, and obtains the total oil and gas concentration value after correction; Step Nine: The data processing unit receives the transmitted data, uses the pre-stored response coefficients of methane and propane, and uses NumPy to calculate the accurate concentrations of methane and propane and : , wherein, 、 are the readings of the NDIR methane sensor and the NDIR propane sensor, and are the concentrations of methane and propane gases respectively, is the response coefficient of the NDIR methane sensor to propane gas, is the response coefficient of the NDIR propane sensor to methane gas; Step Ten: Correct the total concentration of methane and propane with the hydrocarbon concentration measured by the PID sensor to obtain the total oil and gas concentration value.

[0050] Step Eleven: The data display and storage module displays the internal oil and gas concentration data of the storage tank in real time according to the total oil and gas concentration value.

[0051] Step Twelve: Use Matplotlib for data visualization.

[0052] Step Thirteen: Use Pandas to store the data in a CSV for subsequent analysis.

[0053] Step Fourteen: Set the safety threshold of the oil and gas concentration in the alarm module. Use the if statement in Python to check whether the oil and gas concentration exceeds the preset threshold. When the oil and gas concentration exceeds the preset safety threshold, the alarm module automatically triggers an alarm and uses the playsound library to play an alarm sound to remind the operator to take corresponding measures.

Claims

1. A real-time monitoring system for all components of oil and gas in a storage tank combining PID and NDIR sensors, characterized in that: The system includes a sensor module, a data acquisition module, a data processing unit, a data display and storage module, a gas circuit circulation module and an alarm module; The sensor module is used to detect the oil and gas components inside the storage tank; the sensor module includes a PID sensor, an NDIR methane sensor and an NDIR propane sensor, the PID sensor is used to detect the concentration of hydrocarbons, and the NDIR methane sensor and the NDIR propane sensor are used to detect the concentrations of methane and propane, respectively; The data acquisition module is used to collect the detection data of the sensor module and transmit it in real time; The data processing unit is used to receive the data transmitted by the data acquisition module, and calculate using the pre-stored response coefficients of methane and propane to obtain the accurate concentrations of methane and propane, and at the same time receive the hydrocarbon concentration data of the PID sensor, and calibrate the total concentration of methane and propane with the hydrocarbon concentration measured by the PID sensor to obtain the total oil and gas concentration value; The data display and storage module is used to display and store the oil and gas concentration data inside the storage tank according to the total oil and gas concentration value; The gas circulation module is used to transport the oil and gas inside the storage tank to the sensor module for detection and then send it back to the storage tank; The alarm module is used to automatically trigger an alarm when the oil and gas concentration exceeds a preset safety threshold.

2. A real-time monitoring system for all components of oil and gas in a storage tank combining PID and NDIR sensors according to claim 1, characterized in that: The oil and gas components include at least methane, propane and butene.

3. According to claim 1, a real-time monitoring system for all components of oil and gas in a storage tank combining PID and NDIR sensors is characterized by: The PID sensor has a range of 10,000 ppm and the ionization lamp specification is 10.6 eV; The NDIR methane sensor has a range of 30,000 ppm and a resolution of 50 ppm; The NDIR propane sensor has a range of 50000ppm and a resolution of 100ppm.

4. The real-time monitoring system for all components of oil and gas in a storage tank combining PID and NDIR sensors according to claim 1 is characterized by: The data collection module uses the time library to set up scheduled tasks, collect data regularly and process it.

5. The real-time monitoring system for all components of oil and gas in a storage tank combined with PID and NDIR sensors according to claim 1 is characterized by: The data processing unit performs the following steps: receiving detection data from the PID sensor and two NDIR sensors in real time; calculating the accurate concentrations of methane and propane using the response coefficients in the algorithm library; correcting the total concentration of methane and propane with the hydrocarbon concentration measured by the PID sensor to obtain a total oil and gas concentration value; and outputting the total oil and gas concentration value to the data display and storage module in real time.

6. A real-time monitoring system for all components of oil and gas in a storage tank combining PID and NDIR sensors according to claim 4, characterized in that: The data processing unit uses NumPy to perform numerical calculations, including calculations of response coefficients and concentrations.

7. The real-time monitoring system for all components of oil and gas in a storage tank combined with PID and NDIR sensors according to claim 1 is characterized by: The data display and storage module uses Matplotli for data visualization and displays oil and gas concentration in real time; and uses Pandas for data storage and saves the data in CSV.

8. The system and method for real-time monitoring of all components of oil and gas in a storage tank combining PID and NDIR sensors according to claim 1, characterized in that: The alarm module includes a threshold setting function for setting a safety threshold of oil and gas concentration; and an alarm triggering function for automatically triggering an alarm signal when the oil and gas concentration exceeds a preset safety threshold.

9. The working method of the real-time monitoring system for all components of oil and gas in a storage tank combined with PID and NDIR sensors according to claim 1 is characterized in that: The following steps are involved: S1: Before the system is officially put into operation, methane and propane gas samples with known concentrations are used to measure their response values ​​through the NDIR methane sensor and NDIR propane sensor respectively, and the response coefficients are calculated and stored; S2: Methane gas cross-response test: introduce single methane gas into the calibrated NDIR methane sensor and NDIR propane sensor at the same time, record the output readings of the two sensors simultaneously, record the response value to methane gas, calculate and store the response coefficient of the NDIR propane sensor to methane, recorded as ; S3: Propane gas cross-response test: input single propane gas into the NDIR methane sensor and the calibrated NDIR propane sensor at the same time, and record the output readings of the two sensors synchronously again, and record the response value to propane gas; calculate and store the response coefficient of the NDIR methane sensor to propane gas, which is recorded as ; S4: Start the gas circulation module to continuously extract oil and gas samples from the storage tank and transport them to the PID sensor and two NDIR sensors; S5: The sensor collects data in real time and transmits the data to the data processing unit; the data processing unit receives the transmitted data, uses the pre-stored response coefficients of methane and propane, and uses NumPy to calculate the accurate concentrations of methane and propane. and : ， in, , The readings of the NDIR methane sensor and the NDIR propane sensor are: and are the methane and propane gas concentrations, is the response coefficient of the NDIR methane sensor to propane gas, is the response coefficient of NDIR propane sensor to methane gas; The data processing unit simultaneously receives the hydrocarbon concentration data from the PID sensor and obtains the total oil and gas concentration value after correction; S6: Output the total oil and gas concentration value to the data display and storage module in real time; S7: Set the safety threshold of oil and gas concentration. When the oil and gas concentration exceeds the preset safety threshold, the alarm is automatically triggered.

10. The working method of the real-time monitoring system for all components of oil and gas in a storage tank combined with PID and NDIR sensors according to claim 9 is characterized in that: The alarm module uses Python's if statement to check whether the oil and gas concentration exceeds the preset threshold and uses the playsound library to play the alarm sound.

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