Calibration method and system for water turbine volute flow measurement through differential pressure method

Abstract

The invention relates to a calibration method and system for measuring flow through a water turbine volute differential pressure method. The method comprises the steps of 1, arranging measuring assemblies; firstly, based on a volute of the water turbine, a straight section flow channel is arranged on the upstream of the volute, and a plurality of sound channels and ultrasonic transducers are arranged in the straight section flow channel in parallel according to the height of the sound channels.

Description

Technical Field

[0001] The invention relates to a calibration method and a system for measuring flow using a turbine volute pressure difference method, and relates to the technical field of measuring water flow through a turbine volute. Background Art

[0002] Turbine efficiency testing is an important part of the operation and management of hydropower stations. It is of great significance to ensure the safe, stable and efficient operation of turbines. Its main purpose is to evaluate the performance and efficiency of turbines to determine whether they meet the design requirements and actual operation needs. The process of turbine efficiency testing is inseparable from the measurement of water flow. The more accurate the flow measurement, the more accurate the calculation of turbine efficiency will be.

[0003] At present, the main method for measuring turbine flow is: volute pressure difference flow measurement method (Winter-Kennedy method): although its installation and implementation are relatively simple, it can obtain higher measurement accuracy after calibration according to absolute flow, has a long working life, and is simple to maintain online. Disadvantages: It is necessary to calibrate the coefficient according to the flow. Since the absolute flow calibration is actually obtained under ideal conditions before leaving the factory, it cannot truly and accurately represent the actual coefficient, which leads to measurement errors that cannot be avoided. The existing ideas of technical personnel in this field do not correct the coefficient based on the actual working state. When wear, deformation and inclusions occur, the prior coefficient is still used for calculation, resulting in errors in flow calculation and inability to achieve real-time adjustment. Although the ultrasonic flow measurement method has high flow measurement accuracy and can be measured online in real time, its installation is relatively complicated, the equipment life is relatively short, and it is difficult to repair underwater equipment after damage. Summary of the invention

[0004] The technical problem to be solved by the present invention is generally to provide a calibration method and system for turbine volute pressure differential flow measurement, with the purpose of providing a way of integrating two flow measurement methods, and automatically calibrating the pressure differential flow measurement in real time according to the accuracy of the ultrasonic flow measurement method, so as to improve the flow measurement accuracy and extend the service life of the flow measurement device. At the same time, early warning of pressure differential flow measurement failures is achieved. Even if the underwater equipment of the ultrasonic flow measurement device is damaged, the volute pressure differential flow measurement device after coefficient correction and calibration can still ensure the accuracy of flow measurement. When an error occurs in the volute pressure differential method, timely correction can be achieved through the ultrasonic method.

[0005] To solve the above problems, the technical solution adopted by the present invention is: In order to achieve accurate calibration, a method for calibrating flow measurement using a turbine volute pressure difference method includes the following steps: Step 1, arranging a measurement component; First, based on the volute of the turbine, there is a straight section flow channel upstream of the volute, and in the straight section flow channel, a plurality of sound channels are arranged in parallel according to the sound channel height, and an ultrasonic transducer is arranged; Then, based on the volute pressure difference flow measurement method, the flow rate Q is obtained , formula (1); in, , is to use the pressure sensor installed on the inner and outer circular tube walls of the volute to measure the pressure difference between the high and low pressure sides of the pressure measuring tube. k and n are Winter-Kennedy coefficients; Secondly, based on the ultrasonic flow measurement method, the flow rate Q is obtained; , formula (2); In the formula, is the flow channel cross-sectional radius, is the number of channels, is the integral weight coefficient, is the flow velocity of the vocal tract; Again, obtain the flow rate obtained by the ultrasonic flow measurement method for group i , and obtain the volute pressure difference , calibrate the k and n coefficients in formula (1); Step 2: First, take the logarithm of both sides of formula (1): , formula (3); make , , transform formula (3) into a linear function , formula (4); Afterwards, the flow rates obtained by the multiple sets of ultrasonic flow measurement methods were , take the natural logarithm ; and flow Corresponding multiple sets of pressure difference values , take the natural logarithm , formula (5); where is the measurement order number of the measured value; In formula (4), , is a constant to be determined, get the point ; Later, through the point Assume a straight line; set a straight line ,deviation , Formula (6), Formula (6) expresses The value on the corresponding straight line With actual value The smaller the deviation, the smaller the point The closer it is to the assumed straight line, the to measure the total deviation; Then, the constructor: , formula (7); When formula (7) takes the minimum value, the obtained and That is the solution sought; Then, according to the extreme value principle: ,Right now , Formula (8); Performing the equations together we get: Formula (9); Obtain Formula (10); The obtained values ​​of k and n are the exact values ​​of the Winter-Kennedy coefficients in formula (1); Among them, at point Assuming that in the straight line step, based on the linear regression process, with the help of coefficients Formula (11); The correlation coefficient is calculated based on the product difference method. The closer to 1 the better.

[0006] In order to realize long-term automatic self-monitoring, a method for measuring flow of a volute of a water turbine is provided, wherein an ultrasonic transducer and a pressure sensor are installed on the water turbine, and the ultrasonic transducer and the pressure sensor are electrically connected to a host computer; The measurement method includes the following steps: Step A, starting the pressure sensor to measure flow based on the volute pressure difference, and starting the ultrasonic transducer to measure flow based on the ultrasonic flow measurement method; Step B, executing the above calibration method to correct the coefficient of the volute pressure difference flow measurement; Step C, using a volute pressure difference flow measurement method after correction coefficient to perform real-time flow measurement; Step D, regularly turning on the ultrasonic transducer to detect whether the flow rate of the volute pressure difference flow measurement method is correct, so as to determine whether there is equipment failure or wear; Step E, after the faulty or worn equipment is replaced, repeat steps B and C.

[0007] As a further improvement of the above technical solution: Since turbine replacement or repair involves a large amount of work, in order to further verify whether there is a fault and avoid false alarms, when it is determined that there is equipment failure or wear, especially when there are several turbines, one of the following strategies is initiated; Strategy 1: When the expected standard amount of water flow is introduced into the turbine, the ultrasonic flow measurement method is started to calibrate whether there is equipment failure or wear of the ultrasonic transducer and / or the volute pressure difference flow measurement method is started for secondary calibration; Strategy 2: Start the ultrasonic transducers of adjacent turbines for comparison and verification.

[0008] Probe failure is generally caused by water flow impact, especially high-speed impact of debris mixed in the water flow, which causes probe damage. Therefore, in order to further ensure the accuracy and long-term calibration from the hardware, the ultrasonic transducer is equipped with a protective head cover; When the ultrasonic transducer is started, open the protective head cover of the ultrasonic transducer; When the ultrasonic transducer is turned off, close the protective head cover of the ultrasonic transducer.

[0009] The protective head cover comprises a push rod base arranged on the guide housing and a sliding sleeve connected with the push rod base through a polished rod sleeve and sleeved on the guide housing; A plurality of swing arms are hinged at the end of the guide housing; a petal guard is provided on one side of the swing arm; A hinged sliding seat slides in a radial groove on the other side arm of the swing bending arm; There are petal gaps between adjacent petal guard plates; The sliding sleeve is hingedly connected to an articulated sliding seat through a traction rod; When the protective hood needs to be moved, the push rod base drives the sliding sleeve to move through the light rod sleeve, so that the traction rod drives the hinged sliding seat, causing the swing arm to swing, thereby driving the petal guard plate to open and close.

[0010] In order to match the above method, a turbine volute flow measurement system includes an ultrasonic transducer and a pressure sensor installed on the turbine, and the ultrasonic transducer and the pressure sensor are electrically connected to a host computer; used to match the above calibration method; As a basic installation requirement, the ultrasonic transducer includes a transducer probe; the transducer probe is installed and inserted into the inner cavity of the straight section flow channel; the protective head cover is installed on the guide housing and is used to cover the transducer probe to avoid the influence of pipe wall vibration; As a further improvement of the above technical solution: in order to achieve better protection, an elastic net is connected between the petal guards.

[0011] In order to better overcome the shortcomings of the volute pressure difference method and the ultrasonic method, the patent of the present invention adopts a combined integrated flow measurement solution of the two, and uses the ultrasonic flow measurement method to calibrate the coefficients in the formula of the volute pressure difference method, which solves the problem of volute flow measurement coefficient calibration and improves the accuracy of the volute pressure difference method flow measurement equipment. Through the clever combination of the two, the real-time online measurement of the volute pressure difference method flow measurement is realized, and the ultrasonic method flow measurement is regularly calibrated. When an error occurs in the measurement, a detection method that does not require disassembly and does not stop the machine is further provided. Furthermore, in order to ensure the normal operation of the turbine and the reliability of regular calibration, a protective hood is added, thereby ensuring the verification of the coefficient of the volute pressure difference method flow measurement to the greatest extent and ensuring non-stop monitoring of turbine failures.

[0012] The invention has reasonable design, low cost, durability, safety and reliability, simple operation, time and labor saving, money saving, compact structure and convenient use. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the structure of the existing volute pressure difference flow measurement method used in the present invention.

[0014] Figure 2 It is a structural schematic diagram of the ultrasonic flow measurement method of the present invention.

[0015] Figure 3 It is a simple schematic diagram of the present invention.

[0016] Figure 4 It is a schematic diagram of the improved transducer of the present invention.

[0017] Figure 5 It is a schematic diagram of the internal structure of the transducer head of the present invention.

[0018] Among them: 1. Water gate; 2. Ultrasonic transducer; 3. Pressure sensor; 4. Volute; 5. Straight section flow channel; 6. Transducer probe; 7. Guide shell; 8. Push rod base; 9. Sliding sleeve; 10. Traction rod; 11. Articulated slide; 12. Swinging arm; 13. Petal guard plate; 14. Petal gap. DETAILED DESCRIPTION

[0019] See also Figure 1 The existing volute pressure differential flow measurement method (Winter-Kennedy method) uses the pressure difference between the high and low pressure sides of the pressure measuring tubes installed on the inner and outer circular tube walls of the volute. When the turbine is running, there is a certain mathematical relationship between the volute pressure difference and flow rate, and the empirical formula for flow rate is: , formula (1); Among them, k and n are Winter-Kennedy coefficients, n is about 0.5, and the values ​​of n and k are generally determined based on the model experiment of the turbine in the laboratory or the computational fluid simulation (CFD) method. The precise value of the coefficient determines the accuracy of the flow rate. Since the values ​​of n and k are different from the actual values ​​of the on-site conditions, the simulated values ​​under non-actual working conditions, so the corresponding flow value is only a reference value under the actual working conditions on site. The reverse thrust coefficient is adjusted by model test, and there is an error with the site. When the volute is repaired or worn or inclusions appear, it cannot be corrected. The specific implementation method is to measure the pressure difference of the pressure measuring tube installed on the inner and outer circular pipe walls of the volute, and obtain the flow rate based on the corresponding relationship between the pressure difference and the flow rate.

[0020] The ultrasonic flow measurement method is to arrange several channels in parallel at different channel heights in the straight section of the flow channel upstream of the volute, such as Figure 2As shown, the axial velocity of each channel represents the average velocity within a certain area above and below it. The axial velocities of multiple channels are used to better estimate the average velocity of the channel surface, and then the flow rate is obtained by integrating the velocity area method. The probe wears, is damaged, and has time drift, where Figure 1 This is a diagram illustrating the existing equipment. Figure 2 These two drawings are layout drawings and are for reference only. Their presence or absence does not affect the protection scope of the present invention.

[0021] , formula (2); In the formula, is the flow channel cross-sectional radius, is the number of channels, is the integral weight coefficient, is the channel flow velocity.

[0022] Obtain flow rates from multiple sets of ultrasonic flow measurement methods , and simultaneously obtain the volute pressure difference ,right The k and n coefficients in are accurately calibrated.

[0023] Among them, the formula Taking the logarithm of both sides is: , formula (3); make , , you can Transformed into a linear function , formula (4); The flow rates obtained by multiple sets of ultrasonic flow measurement methods , take its natural logarithm ; and flow Corresponding multiple sets of pressure difference values , take its natural logarithm , formula (5); in is the measurement order number of the measured value.

[0024] About Functions ,in and is a constant to be determined. Generally speaking, These points are not necessarily completely on the same straight line. Assume there is a straight line ,deviation , formula (6); which expresses The value on the corresponding straight line With actual value The smaller the deviation, the smaller the point The closer it is to the assumed straight line.

[0025] use To measure the total deviation, the constructor: , formula (7); When the function takes its minimum value, the obtained and This is the solution we are looking for.

[0026] According to the extreme value principle, we can get: ,Right now , Formula (8); The equations are combined to get: Formula (9); Further seek Formula (10); The obtained k and n values ​​are the formula The exact value of the Winter-Kennedy coefficient in .

[0027] In the linear regression process, it is impossible for the fitted straight line to pass through all the regression data points. In order to judge the quality of the correlation, we can use the correlation coefficient Formula (11); It is a common form of calculating the correlation coefficient based on the product difference method. The closer it is to 1, the better. In the present invention, the coefficient of determination is used To determine the availability of the Winter-Kennedy coefficient, we need .

[0028] The above coefficient correction method ensures the accuracy of flow measurement under field conditions using the volute pressure difference method.

[0029] Application implementation case: like Figure 1-3 The formula for calculating flow rate using the volute pressure difference method is: , taking the logarithm of both sides of the formula is: ,make , , you can Transformed into a linear function , the flow measurement scheme is enabled to obtain the flow rate obtained by multiple sets of ultrasonic flow measurement methods , and take the natural logarithm ; Record the volute pressure difference method and flow rate Corresponding multiple sets of pressure difference values , taking its natural logarithm ,in is the measurement order number of the measured value. To ensure sufficient accuracy, the value should be greater than 1000.

[0030] About Functions ,in and is a constant to be determined. Generally speaking, These points are not necessarily completely on the same straight line. Assume there is a straight line ,deviation , which expresses The value on the corresponding straight line With actual value The smaller the deviation, the smaller the point The closer it is to the assumed straight line.

[0031] use To measure the total deviation, the constructor: , when the function takes its minimum value, the obtained and This is the solution we are looking for.

[0032] According to the extreme value principle, we can get: , Right now , ; The equations are combined to get: ; Further seek ; , This is the modified Winter-Kennedy coefficient.

[0033] For explanation , The calculation process is shown in Table 1. To simplify the problem, Take 5; see Table 1 below.

[0034] Table 1: Winter-Kennedy coefficient correction data

[0035] According to the above formula, the correction factor is: , .

[0036] As an extended protection, as a current measurement method protection based on calibration methods, such as Figure 1-5As shown, in the turbine volute flow measurement method of this embodiment, an ultrasonic transducer 2 and a pressure sensor 3 are installed on the turbine, and the ultrasonic transducer 2 and the pressure sensor 3 are electrically connected to conventional components such as a host computer.

[0037] like Figure 1-5 ,In order to achieve better monitoring of the turbine, the ,measurement method includes the following steps; Step A, starting the pressure sensor 3 to measure the flow based on the volute pressure difference, starting the ultrasonic transducer 2 to measure the flow based on the ultrasonic flow measurement method, thereby realizing the collection of two data.

[0038] Step B, execute the above calibration method to correct the coefficient of the volute pressure difference flow measurement; since the volute pressure difference method is convenient and practical, turn off the ultrasound and do not use it as the main measurement, use it as a backup, and make corrections through the ultrasonic probe.

[0039] Step C, using the volute pressure difference flow measurement method after the correction coefficient to perform real-time flow measurement, achieving uninterrupted testing and saving costs; However, during use, the equipment is inevitably subject to wear and damage, so step D is performed to regularly turn on the ultrasonic transducer 2 to detect whether the flow rate of the volute pressure differential flow measurement method is correct to determine whether there is equipment failure or wear; thereby achieving detection without disassembly and shutdown, greatly reducing costs.

[0040] Step E, after the faulty or worn equipment is replaced, repeat steps B and C.

[0041] However, theoretically, it cannot be guaranteed that there will be no faults or errors when the ultrasound is turned on, because the ultrasonic probe is generally either intact or faulty, resulting in large measurement errors, and the pipeline may have angle or position changes. The applicant can achieve approximate detection through parallel turbines. Of course, the pipeline can be equipped with a level meter for detection and correction of the inclination, thereby reducing the difficulty of ultrasonic inspection. When there are several turbines, when it is determined that there is equipment failure or wear, start one of the following strategies for verification; Strategy one is to pass an expected standard amount of water flow into the turbine, start the ultrasonic flow measurement method to calibrate whether the ultrasonic transducer 2 has equipment failure or wear and / or start the volute pressure difference flow measurement method for secondary verification; this is theoretical protection and difficult to use in practice because the expected standard water volume is difficult to control in practice, but if it is achieved, the verification accuracy can be improved.

[0042] Strategy 2 is to start the ultrasonic transducer 2 of the adjacent turbine for comparison and verification. This is more convenient in practice, but there are errors and it is only suitable for large rivers and streams.

[0043] In order to further ensure the convenience and accuracy of calibration, as a hardware improvement, the ultrasonic transducer 2 is equipped with a protective head cover; the inventors found that one of the problems that lead to high ultrasonic flow measurement failures is that due to the presence of high-speed flowing particles in the flow channel, they will collide with the probe and cause damage to the probe. As a specific protection strategy: When the ultrasonic transducer 2 is started, the protective head cover of the ultrasonic transducer 2 is opened; When the ultrasonic transducer 2 is turned off, the protective head cover of the ultrasonic transducer 2 is closed.

[0044] However, the problem arises again. Due to the presence of the protective hood, the measurement near the probe is inaccurate. For this reason, the present invention designs a petal-type structure. When it is opened, its opening angle is large and dispersed, and it does not block the upstream and downstream of the water flow, thereby solving the above problem. This is an ingenious design that has not been proposed in the prior art.

[0045] Specifically, it cleverly utilizes the combination of the umbrella opening structure and the petal structure to form a bent arm effort lever to achieve a large swing with a small angle input. The protective head cover includes a push rod base 8 arranged on a guide housing 7 and a sliding sleeve 9 connected to the push rod base 8 through a bare rod sleeve and sleeved on the guide housing 7; A plurality of swing arms 12 are hinged at the end of the guide housing 7; a petal guard plate 13 is provided on one side arm of the swing arm 12; and by utilizing a hinged arrangement on the guide housing 7 which is not at the same height as the probe, it is possible to avoid obstruction of water flow as much as possible.

[0046] A hinged slide 11 slides in a radial groove on the other side arm of the swing arm 12; There is a petal gap 14 between adjacent petal guard plates 13; The sliding sleeve 9 is hingedly connected to an articulated sliding seat 11 through a traction rod 10; When the protective hood needs to be moved, the push rod base 8 drives the sliding sleeve 9 to move through the light rod sleeve, so that the traction rod 10 drives the articulated sliding seat 11, so that the swing arm 12 swings, thereby driving the petal guard plate 13 to open and close.

[0047] The turbine volute flow measurement system of this embodiment includes an ultrasonic transducer 2 and a pressure sensor 3 installed on the turbine, and the ultrasonic transducer 2 and the pressure sensor 3 are electrically connected to a host computer; Used to support the above calibration method; As a theoretical improvement, an elastic net is connected between the petal guards 13 to further reduce the entry of debris.

[0048] The present invention is fully described for a clearer disclosure, and the prior art is not listed one by one.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some of the technical features therein with equivalents; it is obvious for those skilled in the art to combine multiple technical solutions of the present invention. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention. The technical contents not described in detail in the present invention are all known technologies.

Claims

1. A method for calibrating flow measurement using a turbine volute pressure difference method, characterized in that: The method comprises the following steps: Step 1: Arrange the measurement components; first, based on the volute (4) of the turbine, there is a straight section flow channel (5) upstream of the volute (4), and in the straight section flow channel (5), a plurality of sound channels are arranged in parallel according to the sound channel height, and an ultrasonic transducer (2) is arranged; Then, based on the volute pressure difference flow measurement method, the flow rate Q is obtained , Formula (1); in, , is to use a pressure sensor (3) installed on the inner and outer circular tube walls of the volute (4) to measure the pressure difference between the high and low pressure sides of the pressure measuring tube, k, n are Winter-Kennedy coefficients; Secondly, based on the ultrasonic flow measurement method, the flow rate Q is obtained; , Formula (2); In the formula, is the flow channel cross-sectional radius, is the number of channels, is the integral weight coefficient, is the flow velocity of the vocal tract; Again, obtain the flow rate obtained by the ultrasonic flow measurement method for group i , and obtain the volute pressure difference , calibrate the k and n coefficients in formula (1); Step 2: First, take the logarithm of both sides of formula (1): , Formula (3); make , , transform formula (3) into a linear function , formula (4); Afterwards, the flow rates obtained by the multiple sets of ultrasonic flow measurement methods were , take the natural logarithm ; and flow Corresponding multiple sets of pressure difference values , take the natural logarithm , formula (5); where is the measurement order number of the measured value; In formula (4), , is a constant to be determined, get the point ; Later, through the point Assume a straight line; set a straight line ,deviation , Formula (6), Formula (6) expresses The corresponding value on the straight line With actual value The smaller the deviation, the smaller the point The closer it is to the assumed straight line, the to measure the total deviation; Then, the constructor: , Formula (7); When formula (7) takes the minimum value, the obtained and That is the solution sought; Then, according to the extreme value principle: ,Right now , Formula (8); Solving the equations together we get: Formula (9): Obtain Formula (10); The obtained values ​​of k and n are the exact values ​​of the Winter-Kennedy coefficients in formula (1).

2. The calibration method for measuring flow using the turbine volute pressure difference method according to claim 1, characterized in that: At the point Assuming that in the straight line step, based on the linear regression process, with the help of coefficients Formula (11): The correlation coefficient is calculated based on the product difference method. The closer to 1 the better.

3. A method for measuring flow of a turbine volute, characterized in that: An ultrasonic transducer (2) and a pressure sensor (3) are installed on the turbine, and the ultrasonic transducer (2) and the pressure sensor (3) are electrically connected to a host computer; The measurement method includes the following steps: Step A, starting the pressure sensor (3) to measure flow based on the volute pressure difference, and starting the ultrasonic transducer (2) to measure flow based on the ultrasonic flow measurement method; Step B, executing the calibration method described in claim 1 to correct the coefficient of the volute pressure difference flow measurement; Step C, using a volute pressure difference flow measurement method after correction coefficient to perform real-time flow measurement; Step D, regularly turning on the ultrasonic transducer (2) to detect whether the flow rate measured by the volute pressure difference flow measurement method is correct, so as to determine whether there is any equipment failure or wear; Step E, after the faulty or worn equipment is replaced, repeat steps B and C.

4. The method for measuring flow of a turbine volute according to claim 3, characterized in that: When there are several turbines, when equipment failure or wear is identified, one of the following strategies is initiated; Strategy 1: introducing an expected standard amount of water flow into the turbine, starting the ultrasonic flow measurement method to calibrate the ultrasonic transducer (2) to check whether there is equipment failure or wear and / or starting the volute pressure difference flow measurement method for secondary calibration; Strategy 2: Start the ultrasonic transducer (2) of the adjacent turbine for comparison and verification.

5. The method for measuring flow of a turbine volute according to claim 3, characterized in that: The ultrasonic transducer (2) is provided with a protective head cover; When the ultrasonic transducer (2) is started, the protective head cover of the ultrasonic transducer (2) is opened; When the ultrasonic transducer (2) is turned off, the protective head cover of the ultrasonic transducer (2) is closed.

6. The method for measuring flow of a turbine volute according to claim 3, characterized in that: The protective head cover comprises a push rod base (8) arranged on the guide housing (7) and a sliding sleeve (9) connected to the push rod base (8) via a smooth rod sleeve and sleeved on the guide housing (7); A plurality of swing arms (12) are hingedly connected to the end of the guide housing (7); a petal guard plate (13) is provided on one side arm of the swing arm (12); A hinged sliding seat (11) slides in a radial groove on the other side arm of the swing arm (12); There is a petal gap (14) between adjacent petal guard plates (13); The sliding sleeve (9) is hingedly connected to a hinged sliding seat (11) via a traction rod (10); When the head cover needs to be protected, the push rod base (8) drives the sliding sleeve (9) to move through the light rod sleeve, so that the traction rod (10) drives the hinged sliding seat (11), so that the swing arm (12) swings, thereby driving the petal guard plate (13) to open and close.

7. A turbine volute flow measurement system, characterized in that: The invention comprises an ultrasonic transducer (2) and a pressure sensor (3) installed on the turbine, wherein the ultrasonic transducer (2) and the pressure sensor (3) are electrically connected to a host computer; Used to support the calibration method described in claim 1; The ultrasonic transducer (2) comprises a transducer probe (6); the transducer probe (6) is installed and inserted into the inner cavity of the straight section flow channel (5); the protective head cover is installed on the guide housing (7) and is used to cover the transducer probe (6); The protective head cover comprises a push rod base (8) arranged on the guide housing (7) and a sliding sleeve (9) connected to the push rod base (8) via a smooth rod sleeve and sleeved on the guide housing (7); A plurality of swing arms (12) are hingedly connected to the end of the guide housing (7); a petal guard plate (13) is provided on one side arm of the swing arm (12); A hinged sliding seat (11) slides in a radial groove on the other side arm of the swing arm (12); There is a petal gap (14) between adjacent petal guard plates (13); The sliding sleeve (9) is hingedly connected to an articulated sliding seat (11) via a traction rod (10).

8. The turbine volute flow measurement system according to claim 7, characterized in that: An elastic net is connected between the petal guard plates (13).

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