Constant flow bubble water level measurement system and method

Abstract

This application discloses a constant flow bubble level measurement system and method, including a constant flow bubble level component, an ultrasonic comparison and correction component, and a control component independently connected to the constant flow bubble level component and the ultrasonic comparison and correction component. The control component acquires data provided by the ultrasonic comparison and correction component and the constant flow bubble level component, and processes the acquired data to obtain the water level value. Based on the above disclosure, ultrasonic ranging can be used to perform data correction on a temperature-compensated constant flow bubble level gauge, improving detection accuracy. In practical applications, it can withstand the influence of various factors such as temperature environment, flow inrush, and changes in its own constant pressure output.

Description

Technical Field

[0001] This disclosure relates to the field of liquid level measurement, specifically a high-precision constant flow bubble water level system method. This water level system adopts a novel structure and uses an ultrasonic liquid level component for comprehensive compensation, and utilizes a measurement method to identify surges and achieve accurate measurement. Background Technology

[0002] Water level measurement is of great importance in many fields, such as reservoir management, river monitoring, and urban drainage systems. To ensure accurate water level measurement, several different types of water level gauges exist, among which two common methods are constant flow bubble level gauges and ultrasonic level gauges.

[0003] Constant flow bubble level gauge: This method generates bubbles by injecting a constant flow rate of gas into the liquid, and calculates the liquid depth using the difference between the pressure at the moment of bubble generation and atmospheric pressure. This method offers high accuracy and stability, but it requires precise pressure control within the gas chamber. Furthermore, constant flow bubble level gauges are susceptible to interference from factors such as blockage, temperature variations, and surges.

[0004] Ultrasonic water level gauge: This method calculates the liquid depth by emitting ultrasonic waves and receiving the signals reflected back from the liquid surface based on the time difference. It is easy to install and unaffected by liquid properties, but may be affected by environmental noise, temperature changes, and other factors.

[0005] In summary, the anti-interference capability of existing water level measurements needs improvement. Addressing the limitations and problems of both constant-flow bubble level gauges and ultrasonic level gauges in existing technologies, this application proposes a water level measurement technology that combines the advantages of both. This solution improves the accuracy of the constant-flow bubble level gauge through the following improvements: Introducing a PID controller to adjust the constant pressure output system, achieving precise control of the pressure within the bubble chamber; Incorporating the pressure error within the bubble chamber into the constant-flow bubble level calculation method to eliminate water depth deviations caused by pressure fluctuations; Using ultrasonic level measurement data for correction to further improve the accuracy of the constant-flow bubble level calculation method; When there is a significant deviation between the ultrasonic measurement data and the constant-flow bubble calculation results, the constant pressure output system can be optimized by adjusting the PID controller parameters.

[0006] Through the improved technical solution described above, this disclosure can fully utilize ultrasonic water level measurement data for calibration and optimization while maintaining the high accuracy and stability of the constant flow bubble level gauge. This will help achieve more accurate and reliable water level measurement under different operating conditions and provide more effective technical support for fields involving water resource management and environmental monitoring. Summary of the Invention

[0007] The main objective of this disclosure is to provide a constant flow bubble level measurement system and method with higher accuracy and stronger resistance to environmental interference. The constant flow bubble level measurement system has a self-cleaning function and also uses ultrasound to achieve higher accuracy and more reliable data output.

[0008] In a first aspect, to achieve one of the above objectives, this application discloses a constant flow bubble water level measurement system, including a constant flow bubble water level component, an ultrasonic contrast correction component, and a control component connected to the constant flow bubble water level component and the ultrasonic contrast correction component respectively. The control component is used to acquire data provided by the ultrasonic contrast correction component and the constant flow bubble water level component, and process the acquired data to obtain a water level value.

[0009] The constant flow bubble level assembly, to achieve its level measurement function, includes an air pump that generates high-pressure air, a high-pressure air tank that is unidirectionally connected to the air pump, an air chamber connected to the high-pressure air tank, an electrically controlled valve for adjusting the air supply from the high-pressure air tank to the air chamber, a probe connected to the air chamber via an air pipe and extending into the liquid level being measured, and a pressure sensor connected to a branch air pipe extending from the air pipe; the air chamber has an output end, on which a constant flow valve is installed, and the air pipe is connected to the constant flow valve, thereby indirectly connecting the air pipe to the air chamber;

[0010] Each of the high-pressure gas tank and the gas chamber is equipped with a gas pressure sensor connected to the control component. The control component calculates and judges based on the gas pressure sensor values ​​to control the operation of the electric valve and the gas pump, thereby better ensuring the stability of the gas pressure in the gas chamber.

[0011] The constant flow bubble level assembly includes an ambient air pressure sensor for measuring ambient air pressure.

[0012] The constant flow bubble level assembly includes at least one gas temperature sensor located in the gas chamber and at least one liquid temperature sensor located below the liquid surface. Both the gas temperature sensor and the liquid temperature sensor are connected to the control assembly and provide the control assembly with the liquid temperature and gas temperature, respectively.

[0013] The ultrasonic contrast correction component includes an ultrasonic generator and an echo receiver. Both the ultrasonic generator and the echo receiver are substantially connected to the control component. The control component obtains the time difference between the sound wave generation time of the ultrasonic generator and the echo reception time to calculate the liquid level based on the reference position of the ultrasonic contrast correction component. The ultrasonic contrast correction component includes an ambient temperature sensor, which is substantially connected to the control component and sends the ambient temperature to the control component.

[0014] The control component includes a microcontroller for processing various data, a solenoid valve drive module, a motor drive module, a data storage module, and a wireless communication module for remote data transmission. The solenoid valve drive module drives the electrically controlled valve, the motor drive module drives the air pump, the data storage module stores data, and the wireless communication module sends data to a remote server. The microcontroller integrates a PID controller in program form.

[0015] The ultrasonic contrast correction component is fixedly installed above the liquid surface and above the probe, with a horizontal position difference of 1-3 meters. The constant flow bubble level component is detected and corrected by timed detection data.

[0016] The air pump inlet can be alternatively equipped with a gas pretreatment module, which filters and dries the incoming air.

[0017] In some embodiments, to achieve self-cleaning of the probe, the probe includes a base connected to the trachea, a perforated outer cover fixedly connected to the base, and an air outlet core located inside the perforated outer cover and flexibly connected to the base. The hollow air outlet core is substantially connected to the trachea through a channel pre-set in the base. The distance between the air outlet core and the perforated outer cover is 1-3 mm, and the air outlet core has at least one exhaust port for venting gas from the trachea. The interior of the air outlet core is provided with a sealed installation chamber, in which a high-frequency vibration magnetic levitation motor is installed. The magnetic levitation motor drives the air outlet core to complete high-frequency vibration of 16,000-18,000 times / minute, forming a high-frequency shock wave between the perforated outer cover and the air outlet core, thereby generating ultrasonic cleaning. By controlling the intermittent operation of the magnetic levitation motor, automatic cleaning is achieved to prevent blockage.

[0018] In some embodiments, the liquid temperature sensor is fixed to a perforated housing.

[0019] Secondly, to achieve one of the objectives of this application, this application discloses a constant pressure output control method for a constant flow bubble water level measurement system, comprising the following steps:

[0020] S1: Measurement, measuring the actual tank pressure P_tank inside the tank and the chamber pressure P_chamber inside the tank;

[0021] S2: Control the operation of the air pump. If P_tank is lower than the preset minimum threshold, start the air pump to replenish gas. If P_tank is higher than the preset maximum threshold, turn off the air pump.

[0022] S3: Calculate the current error value e_current between P_chamber and the target pressure P_target, e_current = P_target - P_chamber;

[0023] S4: Use the PID controller to calculate the valve opening adjustment value Δvalve, Δvalve=K_p×(e_current-e_last)+K_i×e_sum+K_d×(e_current-2×e_last+e_before_last). In the initial state of the first execution, the previous error value e_last=0 and the cumulative error value e_sum=0.

[0024] S5: Update valve opening degree valve_opening, valve_opening = valve + Δvalve, where valve is the existing opening degree value. When valve_opening is less than 0, set valve_opening directly to 0. When valve_opening is greater than 100, set valve_opening directly to 100.

[0025] S6: Controls the solenoid valve drive module to adjust the electrically controlled adjustable valve according to the new valve opening;

[0026] S7: Update the error value and the cumulative error value. Assign the current error value e_last to the previous error value e_before_last to form a new e_before_last; assign the current error value e_current to the previous error value e_last to form a new e_last, e_last = e_current; add the current error value e_current to the existing cumulative error value e_sum and update it to a new e_sum to prepare for the loop execution;

[0027] S8: Execute S1-S7 in a loop.

[0028] The interval between steps S7 and S8 is set appropriately.

[0029] Thirdly, to achieve one of the objectives of this application, this application discloses a measurement method based on a constant flow bubble water level measurement system, comprising the following steps:

[0030] Step 1: Obtain atmospheric pressure P0, gas pressure P measured by the gas pressure sensor connected to the branch gas pipe, and gas temperature T_gas1 measured in the gas chamber.

[0031] Ambient gas temperature T_gas2, liquid temperature T_liquid, reference temperature T_ref, reference liquid density ρ_liquid_ref measured at the reference temperature, ultrasonic speed v_ref in the gas at the reference temperature, distance D_ultrasound between the ultrasonic contrast correction component and the water level, height H_sensor of the ultrasonic contrast correction component from the bottom of the liquid being measured, and height H of the probe from the bottom of the liquid;

[0032] Step 2: Calculate the actual liquid density ρ_liquid and the actual gas density ρ_gas, ρ_liquid=ρ_liquid_ref×(1-α×(T_liquid-T_ref)), where α is the coefficient of thermal expansion; ρ_gas=P / (R×T_gas1), where R is the specific gas constant of the gas;

[0033] Step 3: Calculate the liquid level height H_bubble, H_bubble=(P-P0) / (ρ_liquid×g+ρ_gas×g)+H, where g is the acceleration due to gravity;

[0034] Step 4: Measure the liquid level height H_ultrasound using ultrasound. First, calculate the actual propagation speed of ultrasound in the gas: v = v_ref × sqrt(T_gas2 / T_ref). Use the actual propagation speed to determine the actual liquid level height: H_ultrasound = H_sensor - D_ultrasound × (v / v_ref).

[0035] Step 5: Calculate the corrected water level H_final, compare H_bubble with H_ultrasound, and calculate the error between them, error_h, error_h = H_ultrasound - H_bubble. If error_h exceeds the allowable threshold, discard the data set and determine that it is a surge. If the error is within the allowable threshold, H_final = 0.79 × H_bubble + 0.21 × H_ultrasound.

[0036] The units for air pressure and water pressure mentioned above are Pa, the unit for temperature is K, the unit for velocity is m / s, and the unit for distance is m.

[0037] Based on the above information, ultrasonic ranging can be used to correct the data of a temperature-compensated constant-flow bubble level gauge, improving detection accuracy. In practical applications, it can withstand the influence of various factors such as temperature environment, flow inrush, and its own constant pressure output changes.

[0038] Additional aspects and other advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0039] A better understanding of various aspects of this disclosure will be achieved by reading the following detailed description in conjunction with the accompanying drawings. The positions, dimensions, and extents of the structures shown in the drawings, etc., do not always represent actual positions, dimensions, and extents. In the drawings:

[0040] Figure 1 This is an example diagram of an embodiment of this application in an application state, where the liquid surface in the example diagram is a tiny water ripple.

[0041] Figure 2 This is a schematic diagram of the structure of one embodiment of this application when applying a surge.

[0042] Figure 3 This is a hardware block diagram of one embodiment of this application.

[0043] Figure 4 This is a schematic diagram of the probe structure in one embodiment of this application.

[0044] Figure 5 This is a schematic diagram of the probe in a vibration state according to one embodiment of this application. In this state, self-cleaning can be achieved to prevent clogging.

[0045] Figure 6 This is a flowchart of a measurement method based on a constant flow bubble water level measurement system according to this application. Detailed Implementation

[0046] The present disclosure will now be described with reference to the accompanying drawings, which illustrate several embodiments of the present disclosure. However, it should be understood that the present disclosure can be presented in many different ways and is not limited to the embodiments described below; in fact, the embodiments described below are intended to make the disclosure more complete and to fully illustrate the scope of protection of the present disclosure to those skilled in the art. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide more additional embodiments.

[0047] It should be understood that the same reference numerals denote the same elements in all the accompanying drawings. For clarity, the dimensions of certain features may be modified in the drawings.

[0048] It should be understood that the terminology used in this specification is for describing specific embodiments only and is not intended to limit this disclosure. All terms used in this specification (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. For the sake of brevity and / or clarity, techniques, methods, and devices known to those skilled in the art may not be discussed in detail; however, where appropriate, such techniques, methods, and devices should be considered part of this specification.

[0049] Unless otherwise specified, the singular forms “a,” “the,” and “the” used in this specification include the plural forms. The terms “comprising,” “including,” and “containing” used in this specification indicate the presence of the claimed feature but do not exclude the presence of one or more other features. The term “and / or” used in this specification includes any and all combinations of one or more of the related listed items. The terms “between X and Y” and “between approximately X and Y” used in this specification should be interpreted as including both X and Y. The term “between approximately X and Y” used in this specification means “between approximately X and approximately Y,” and the term “from approximately X to Y” used in this specification means “from approximately X to approximately Y.”

[0050] In the specification, when an element is described as being "on," "attached," "connected," "coupled," or "in contact" with another element, the element can be directly located on, attached to, connected to, coupled to, or in contact with the other element, or there may be intermediate elements present. Conversely, when an element is described as being "directly" located on, directly attached to, directly connected to, directly coupled to, or directly in contact with another element, no intermediate elements are present. In the specification, the description of a feature being arranged "adjacent" to another feature can mean that a feature has a portion overlapping with the adjacent feature or a portion located above or below the adjacent feature.

[0051] In the specification, spatial relationship terms such as "up," "down," "left," "right," "front," "back," "high," and "low" describe the relationship between one feature and another in the accompanying drawings. It should be understood that spatial relationship terms include not only the orientation shown in the drawings but also different orientations of the device during use or operation. For example, when the device in the drawings is inverted, a feature previously described as "below" other features can now be described as "above" other features. The device can also be oriented in other ways (rotated 90 degrees or in other orientations), in which case the relative spatial relationships will be interpreted accordingly.

[0052] Example:

[0053] Reference Figure 1-3 This embodiment discloses an exemplary structure of a constant flow bubble level measurement system, comprising a waterproof cabinet 1 with a door, which is fixed to a pole 102 on the shore 101. The waterproof cabinet 1 houses a constant flow bubble level component 2 and a control component 3. An ultrasonic contrast correction component 4 is mounted above the liquid surface 104 via a connecting rod 103 extending laterally from the pole 102. A probe 201 inside the constant flow bubble level component 2 extends into the liquid surface 104 via an air tube 202. The ultrasonic contrast correction component 4 is located above the probe 201, with a horizontal position difference of 1 meter. This position difference is to prevent surges. When a surge exceeds 1 meter, the ultrasonic measurement data will still be on the surge, easily causing misjudgment. Under normal circumstances, liquid surface fluctuations are as follows: Figure 2 As shown, the slight fluctuations mentioned above will be naturally corrected by the positions of the ultrasonic comparison correction component 4 and the constant flow bubble water level component 2, that is, what is measured by each is the peak and trough of the fluctuation or the position between the two.

[0054] Specifically in this embodiment, refer to Figure 3 The control component 3 includes a microcontroller 301, a solenoid valve drive module 302, a motor drive module 303, a data storage module 304, and a wireless communication module 305. 302-305 are connected to the microcontroller 301 and are controlled by the microcontroller 301. The microcontroller 301 integrates a PID controller loaded in the form of a program (the purpose and function of which are described in the description of the invention). The wireless communication module 305 can interact with a remote server 306.

[0055] Optionally, the microcontroller 301 is an STM32F103C8T6 microprocessor, a 32-bit microcontroller based on the ARM Cortex-M3 core, with 64KB flash memory and 20KB RAM, which can meet the computing needs.

[0056] Compile the PID program project using development tools such as STM32CubeIDE or Keil MDK, burn the generated binary file onto the STM32 microcontroller and run it. This will result in a microcontroller 301 with a built-in PID controller.

[0057] Specifically, regarding the structural composition, in this embodiment, refer to... Figure 3In addition to the probe 201 and pipe 202, the constant flow bubble level assembly 2 also includes an air pump 203. This air pump 203 is connected to and driven by the motor drive module 303 in the control assembly 3. The air inlet of the air pump 203 is aligned with a replaceable gas pretreatment module 204, which filters and dries the air entering the air pump 203. For example, the gas pretreatment module 204 has a metal filter screen for filtration and a drying chamber filled with desiccant for drying. The incoming air is first filtered by the metal filter screen before entering the drying chamber for dehumidification and drying. One purpose of drying the gas is to prevent excessive moisture content from causing internal water accumulation and corrosion, which would affect its service life and accuracy. (Continue to refer to...) Figure 3 The air pump 203 supplies high-pressure air unidirectionally to the high-pressure air tank 206 via a pipe with a one-way valve 205. The high-pressure air tank 206 is connected to the air chamber 208 via a pipe with an electrically controlled valve 207 controlled by a solenoid valve control module 302. A gas temperature sensor 210 connected to the control component 3 is installed in the air chamber 208. This gas temperature sensor 210 provides the gas temperature inside the air chamber. The purpose of this measurement is that after the gas is dried and pressurized, its temperature value differs from the ambient temperature. This temperature difference affects the gas density, thus affecting the measurement result of the water level gauge. Similarly, the constant flow bubble water level assembly 2 includes an ambient air pressure sensor 212 for measuring ambient air pressure. This ambient air pressure sensor 212 also provides necessary parameters for data correction. As the core of the constant flow bubble water level assembly 2, a branch air pipe extends from the air pipe 202, which is connected to a pressure sensor 209.

[0058] In this embodiment, refer to Figure 4 and 5To achieve self-cleaning of the probe 201, structurally, the probe 201 includes a base 213 connected to the trachea 202, a perforated outer cover 214 fixedly connected to the base 213, and an air outlet core 216 located inside the perforated outer cover 214 and flexibly connected to the base 213 via a rubber component 215. The hollow air outlet core 216 is substantially connected to the trachea 202 via the channeled rubber component 215 and a channel pre-set in the base 213. The distance between the air outlet core 216 and the perforated outer cover 214 is 2mm, and the air outlet core 216... At least one exhaust port 217 is provided for the gas to be discharged from the air pipe 202; the interior of the air outlet core 216 is provided with a sealed installation chamber 218, in which a high-frequency vibration magnetic levitation motor 219 is installed. The magnetic levitation motor 219 drives the air outlet core 216 to complete a high-frequency vibration of 1.6 times / minute, forming a high-frequency shock wave between the perforated outer cover 214 and the air outlet core 216, thereby forming ultrasonic cleaning; by controlling the intermittent operation of the magnetic levitation motor 219, automatic cleaning is achieved and blockage is prevented.

[0059] Continuing in the structure of this embodiment, refer to Figure 3 The constant flow bubble level assembly 2 has a liquid temperature sensor 211 located below the liquid surface and fixed on the perforated outer cover 214. The liquid temperature sensor 211 is also used to correct the measurement error caused by the different liquid densities at different temperatures.

[0060] In this embodiment, to ensure that the internal air pressure of the high-pressure gas tank 206 is maintained at a constant pressure, a pressure sensor 209 is provided in both the air chamber 208 and the high-pressure gas tank 206. More specific steps and processes are as follows:

[0061] For example: the preset minimum threshold is 750 kPa;

[0062] For example: the preset maximum threshold is 850 kPa;

[0063] For example, the control parameters in a PID controller are K_p: 0.5, Ki: 0.1, and K_d: 0.2.

[0064] At a certain moment, the actual pressure inside the gas tank, P_tank, is measured to be 820 kPa, and the pressure in the gas chamber, P_chamber, is 760 kPa. The current valve opening is 50. The actual implementation steps are as follows:

[0065] S1: Measurements show that P_tank = 820 kPa and P_chamber = 760 kPa.

[0066] S2: Controls the operation of the air pump. Since P_tank is between the minimum and maximum thresholds, there is no need to start or stop the air pump.

[0067] S3: Calculate the current error value e_current, e_current P_target-P_chamber=780-760=20kPa.

[0068] S4: Use the PID controller to calculate the valve opening adjustment value Δvalve. Since this is the first execution, e_last = 0, e_sum = 0, so Δvalve = K_p × (20 - 0) + K_i × 0 + K_d × (20 - 2 × 0 + 0) = 0.5 × 20 + 0 + 0.2 × 20 = 14.

[0069] S5: Update valve opening degree valve_opening, valve_opening = valve + Δvalve = 50 + 14 = 64.

[0070] S6: Controls the solenoid valve drive module to adjust the electrically adjustable valve according to the new valve opening degree 64.

[0071] S7: Update the error value and the cumulative error value. Assign the current error value e_last to the previous error value e_before_last to form a new e_before_last; assign the current error value e_current to the previous error value e_last to form a new e_last, e_last = e_current; add the current error value e_current to the existing cumulative error value e_sum and update it to a new e_sum to prepare for the loop execution;

[0072] S8: Repeat steps S1-S7 to continue adjusting the pressure in the air chamber until a stable expected pressure value of 780 kPa is reached.

[0073] For example, during cyclic execution, at the next moment, the actual tank pressure P_tank is measured to be 815 kPa, and the chamber pressure P_chamber is 770 kPa. The current valve opening is 64. The specific repetitive execution is as follows:

[0074] S1: Measurements show that P_tank = 815 kPa and P_chamber = 770 kPa.

[0075] S2: Controls the operation of the air pump. Since P_tank is between the minimum and maximum thresholds, there is no need to start or stop the air pump.

[0076] S3: Calculate the current error value e_current, e_current = P_target - P_chamber = 780 - 770 = 10 kPa.

[0077] S4: Calculate the valve opening adjustment value Δvalve using a PID controller. Since this is not the first execution, we use the error value e_last = 20 kPa and the cumulative error value e_sum = 20 kPa obtained in the previous step. Therefore, Δvalve = K_p × (10 - 20) + K_i × 20 + K_d × (10 - 2 × 20 + 0) = 0.5 × (-10) + 0.1 × 20 + 0.2 × (-30) = -5 + 2 - 6 = -9.

[0078] S5: Update valve opening degree valve_opening, valve_opening = valve + Δvalve = 64 - 9 = 55.

[0079] S6: Controls the solenoid valve drive module to adjust the electrically adjustable valve according to the new valve opening degree of 55.

[0080] S7: Update the error value and the cumulative error value. Assign the current error value e_last = 20kPa to the previous error value e_before_last to form a new e_before_last = 20kPa; assign the current error value e_current = 10kPa to the previous error value e_last to form a new e_last = 10kPa; add the current error value e_current = 10kPa to the existing cumulative error value e_sum = 20kPa and update it to a new e_sum = 30kPa, in preparation for the loop execution.

[0081] During the next cycle, for example, the actual tank pressure P_tank is measured to be 810 kPa, and the chamber pressure P_chamber is measured to be 775 kPa. The current valve opening is 55. The following implementation steps are:

[0082] S1: Measurements show that P_tank = 810 kPa and P_chamber = 775 kPa.

[0083] S2: Controls the operation of the air pump. Since P_tank is between the minimum and maximum thresholds, there is no need to start or stop the air pump.

[0084] S3: Calculate the current error value e_current, e_current = P_target - P_chamber = 780 - 775 = 5 kPa.

[0085] S4: Calculate the valve opening adjustment value Δvalve using a PID controller. Since this is not the first execution, we use the error value e_last = 10 kPa and the cumulative error value e_sum = 30 kPa obtained in the previous step. Therefore, Δvalve = K_p × (5-10) + Ki × 30 + K_d × (5-2 × 10 + 20) = 0.5 × (-5) + 0.1 × 30 + 0.2 × 5 = -2.5 + 3 + 1 = 1.5.

[0086] S5: Update valve opening degree valve_opening, valve_open=valve+Δvalve=55+1.5=56.5.

[0087] S6: Controls the solenoid valve drive module to adjust the electrically adjustable valve according to the new valve opening of 56.5.

[0088] S7: Update the error value and error accumulation value. Assign the current error value e_last = 10kPa to the previous error value e_before_last to form a new e_before_last = 10kPa; assign the current error value e_current = 5kPa to the previous error value e_last to form a new e_last = 5kPa; add the current error value e_current = 5kPa to the existing error accumulation value e_sum = 30kPa and update it to a new e_sum = 35kPa, in preparation for the loop execution.

[0089] After several cycles, we found that the chamber pressure P_chamber had reached the expected pressure value of 780 kPa. At this stage, the PID controller will continue to adjust the valve opening to keep the chamber pressure stable at the expected pressure value of 780 kPa.

[0090] It should be understood that the above steps are performed by the microcontroller 301 within the controller.

[0091] Based on the aforementioned hardware, see [link / reference] Figure 6 The microcontroller 301 acquires the following data and processes it as follows:

[0092] Step 1: Obtain atmospheric pressure P0 from ambient air pressure sensor 212, gas pressure P from air pressure sensor 209 connected to the branch gas pipe, gas temperature T_gas1 from gas temperature sensor 210 in gas chamber 208, liquid temperature T_liquid from liquid temperature sensor 211, and parameter temperature T_ref and reference liquid density ρ_liquid_ref preset in data storage module 304.

[0093] Step 2: Calculate the actual liquid density and the actual gas density.

[0094] Step 3: Calculate the liquid level height using the measured pressure difference, actual liquid density, and actual gas density.

[0095] Continuing with regard to structural composition, refer to Figure 3 In this embodiment, the ultrasonic contrast correction component 4 includes an ultrasonic generator 401 and an echo receiver 402. Both the ultrasonic generator 401 and the echo receiver 402 are substantially connected to the microcontroller 301 in the control group 3. The microcontroller 301 obtains the time difference between the sound wave generation time and the echo reception time of the ultrasonic generator 401 to calculate the liquid level based on the reference position of the ultrasonic contrast correction component 4. The ultrasonic contrast correction component 4 includes an ambient temperature sensor 403, which is also substantially connected to the microcontroller 301 and sends the ambient temperature to the microcontroller 301.

[0096] Based on the above structural composition, the water level measurement is specifically as follows: the microprocessor 301 first obtains the ultrasonic propagation speed v_ref stored in the data storage module 304 and the distance D_ultrasound that is measured and preset in the data storage module 304, and then calculates H_sensor from the round-trip time difference of the ultrasonic wave.

[0097] Next, calculate the actual propagation speed of ultrasound in gas: v = v_ref × sqrt(T_gas2 / T_ref)

[0098] Determine the actual liquid level using the actual propagation speed:

[0099] H_ultrasound=H_sensor-D_ultrasound×(v / v_ref);

[0100] Specifically, in this embodiment, after obtaining the liquid level height H_bubble and the liquid level height H_ultrasound,

[0101] Compare H_bubble with H_ultrasound and calculate the error between them: error_h = H_ultrasound - H_bubble

[0102] If error_h exceeds the allowed error range, such as Figure 2 As shown, this set of data is discarded, indicating a surge.

[0103] When the error is within the acceptable range, the liquid level height H_final obtained by combining the two measurement methods using the weighted average method is 0.79×H_bubble+0.21×H_ultrasound. The resulting liquid column height H_final is the corrected water level.

[0104] More specifically, for example:

[0105] Step 1: Atmospheric pressure P0 was measured to be 101325 Pa, gas pressure P was measured to be 110000 Pa, gas temperature T_gas1 measured in the gas chamber was measured to be 303 K, ambient gas temperature T_gas2 was measured to be 303 K, liquid temperature T_liquid was measured to be 303 K, reference temperature T_ref was measured to be 273.15 K, the liquid was water, and the reference liquid density ρ_liquid_ref was 1000 kg / m³. 3 The speed of ultrasonic wave propagation in gas, v_ref, is 331 m / s. The distance between the ultrasonic contrast correction component and the water level, D_ultrasound, is 30 m. The height of the ultrasonic contrast correction component from the bottom of the liquid, H_sensor, is 40 m. The height of the probe from the bottom of the liquid, H, is 10 m.

[0106] Step 2:

[0107] Based on the data from step 1, the coefficient of thermal expansion α is found to be 0.000214 1 / ℃; the actual liquid density ρ_liquid=1000×(1-0.000214×(303-273.15))≈993.5kg / m³ 3 The specific gas constant R of air is found to be 287 J / (kg·K); the actual gas density ρ_gas=110000 / (287×303)≈1.32kg / m³ 3 .

[0108] Step 3:

[0109] Given that the acceleration due to gravity g is 9.81 m / s². 2 ;

[0110] The liquid level height H_bubble=(110000-101325) / (993.5×9.81+1.32×9.81)+10≈10.87m.

[0111] Step 4:

[0112] The actual propagation speed of ultrasound in gas is v = 331 × sqrt(303 / 273.15) ≈ 346.3 m / s;

[0113] The actual liquid level height H_ultrasound = 40 - 30 × (346.3 / 331) ≈ 10.56 m.

[0114] Step 5:

[0115] The calculated error is error_h = 10.56 - 10.87 = -0.31m (the error threshold is 1m, which meets the condition).

[0116] The corrected water level H_final = 0.79 × 10.87 + 0.21 × 10.56 ≈ 10.78 m. Therefore, in this specific embodiment, the corrected water level H_final is approximately 10.78 meters.

[0117] While exemplary embodiments of this disclosure have been described, those skilled in the art will understand that various changes and modifications can be made to the exemplary embodiments of this disclosure without departing from the spirit and scope thereof. Therefore, all changes and modifications are included within the scope of protection of this disclosure as defined by the claims. This disclosure is defined by the appended claims, and equivalents of those claims are also included.

Claims

1. A method for measuring water level using a constant-flow bubble, characterized in that, A constant-flow bubble level measurement system is employed, comprising a constant-flow bubble level component, an ultrasonic contrast calibration component, and a control component connected to both components. The constant-flow bubble level component includes an air chamber, a probe connected to the air chamber via an air tube and extending into the liquid being measured, a pressure sensor connected to a branch air tube extending from the air tube, an ambient pressure sensor for measuring ambient air pressure, at least one gas temperature sensor located within the air chamber, and at least one liquid temperature sensor located below the liquid surface. The gas and liquid temperature sensors provide the liquid and gas temperatures to the control component, respectively. The ultrasonic contrast calibration component includes an ultrasonic generator and an echo receiver. The control component obtains the time difference between the ultrasonic generator's sound wave generation and echo reception to calculate the liquid level using the reference position of the ultrasonic contrast calibration component. The ultrasonic contrast calibration component includes an ambient air temperature sensor that transmits the ambient air temperature to the control component. The ultrasonic contrast calibration component is fixedly installed above the liquid surface, above the probe, with a horizontal position difference of 1-3 meters. Timed data detection is used to calibrate the constant-flow bubble level component. The measurement method further includes the following steps: Step 1: Obtain atmospheric pressure P0, gas pressure P measured by the gas pressure sensor connected to the branch gas pipe, gas temperature T_gas1 measured in the gas chamber, ambient gas temperature T_gas2, liquid temperature T_liquid, reference temperature T_ref, reference liquid density ρ_liquid_ref measured at the reference temperature, ultrasonic speed v_ref in the gas at the reference temperature, distance D_ultrasound between the ultrasonic contrast correction component and the water level, height H_sensor of the ultrasonic contrast correction component from the bottom of the liquid being measured, and height H of the probe from the bottom of the liquid; Step 2: Calculate the actual liquid density ρ_liquid and the actual gas density ρ_gas, ρ_liquid=ρ_liquid_ref×(1-α×(T_liquid-T_ref)), where α is the coefficient of thermal expansion; ρ_gas=P / (R×T_gas1), where R is the specific gas constant of the gas; Step 3: Calculate the liquid level height H_bubble, H_bubble=(P-P0) / (ρ_liquid×g+ρ_gas×g)+H, where g is the acceleration due to gravity; Step 4: Measure the liquid level height H_ultrasound using ultrasound. First, calculate the actual propagation speed of ultrasound in the gas: v = v_ref × sqrt(T_gas2 / T_ref). Use the actual propagation speed to determine the actual liquid level height: H_ultrasound = H_sensor - D_ultrasound × (v / v_ref). Step 5: Calculate the corrected water level H_final, compare H_bubble with H_ultrasound, and calculate the error between them, error_h, error_h = H_ultrasound - H_bubble. If error_h exceeds the allowable threshold, discard the data set and determine that it is a surge. If the error is within the allowable threshold, H_final = 0.79 × H_bubble + 0.21 × H_ultrasound.

2. The constant flow bubble water level measurement method as described in claim 1, characterized in that: The probe includes a base connected to the trachea, a perforated outer cover fixedly connected to the base, and an air outlet core located inside the outer cover and flexibly connected to the base. The hollow air outlet core is substantially connected to the trachea through a channel pre-set in the base. The distance between the air outlet core and the perforated outer cover is 1-3 mm, and the air outlet core has at least one exhaust port for the gas in the trachea to be discharged. The air outlet core has a sealed installation chamber inside, in which a high-frequency vibration magnetic levitation motor is installed. The magnetic levitation motor drives the core to complete high-frequency vibration of 16,000-18,000 times / minute, forming a high-frequency shock wave between the outer cover and the core, thereby generating ultrasonic cleaning. By controlling the intermittent operation of the magnetic levitation motor, automatic cleaning is achieved and blockage is prevented.

3. A constant flow bubble water level measurement system for implementing the constant flow bubble water level measurement method of claim 1, characterized in that: It also includes an air pump that generates high-pressure air, a high-pressure air tank connected unidirectionally to the air pump, an air chamber connected to the high-pressure air tank, and an electrically controlled valve for regulating the air supply from the high-pressure air tank to the air chamber. The air chamber has an output terminal, on which a constant flow valve is installed, and an air pipe is connected to the constant flow valve. Each of the high-pressure air tank and the air chamber is equipped with a pressure sensor connected to the control component. The control component calculates and judges based on the pressure sensor values ​​to control the operation of the electrically controlled valve and the air pump, thereby better ensuring the stability of the air pressure in the air chamber. The control component includes a microcontroller for processing various data, a solenoid valve drive module for driving the electrically controlled valve, a motor drive module for driving the air pump, a data storage module for storing data, and a wireless communication module for remote data transmission. The wireless communication module is used to send data to a remote server. The microcontroller integrates a PID controller in the form of a program.

4. The constant flow bubble water level measurement system as described in claim 3, characterized in that: The air pump inlet can be alternatively equipped with a gas pretreatment module, which filters and dries the incoming air.

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