CN114526900A - Cavitation identification method, experiment method and experiment device for flow characteristic experiment of regulating valve - Google Patents
Cavitation identification method, experiment method and experiment device for flow characteristic experiment of regulating valve Download PDFInfo
- Publication number
- CN114526900A CN114526900A CN202210158837.3A CN202210158837A CN114526900A CN 114526900 A CN114526900 A CN 114526900A CN 202210158837 A CN202210158837 A CN 202210158837A CN 114526900 A CN114526900 A CN 114526900A
- Authority
- CN
- China
- Prior art keywords
- regulating valve
- cavitation
- boundary condition
- flow characteristic
- pressure boundary
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000001105 regulatory effect Effects 0.000 title claims abstract description 162
- 238000002474 experimental method Methods 0.000 title claims abstract description 83
- 238000000034 method Methods 0.000 title claims abstract description 53
- 238000012360 testing method Methods 0.000 claims abstract description 104
- 230000001133 acceleration Effects 0.000 claims abstract description 66
- 238000001514 detection method Methods 0.000 claims abstract description 20
- 238000012545 processing Methods 0.000 claims abstract description 10
- 238000004088 simulation Methods 0.000 claims description 19
- 230000007246 mechanism Effects 0.000 description 9
- 230000000694 effects Effects 0.000 description 7
- 239000002184 metal Substances 0.000 description 7
- 238000004458 analytical method Methods 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 238000011160 research Methods 0.000 description 5
- 238000004364 calculation method Methods 0.000 description 4
- 238000005070 sampling Methods 0.000 description 4
- 230000008054 signal transmission Effects 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000004973 liquid crystal related substance Substances 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 238000012544 monitoring process Methods 0.000 description 3
- 238000009434 installation Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 230000001052 transient effect Effects 0.000 description 2
- 238000012935 Averaging Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000007620 mathematical function Methods 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 230000007306 turnover Effects 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M13/00—Testing of machine parts
- G01M13/003—Machine valves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
- G01F1/05—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects
- G01F1/34—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using mechanical effects by measuring pressure or differential pressure
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Details Of Valves (AREA)
- Testing Of Devices, Machine Parts, Or Other Structures Thereof (AREA)
Abstract
The invention provides a regulating valve flow characteristic experiment cavitation identification method, an experiment method and an experiment device, and belongs to the technical field of regulating valve flow characteristic experiments. The cavitation identification method comprises the following steps: establishing a reference data set, acquiring detection data, judging cavitation, comparing the detection data with the reference data set, and judging whether the regulating valve is cavitated. An experimental method comprising the steps of: and presetting a judgment threshold, adjusting a preset pressure boundary condition, and determining a critical pressure boundary condition according to the judgment threshold to perform flow characteristic test on the regulating valve. The experiment method comprises the steps of testing the flow characteristic of the regulating valve and identifying whether the regulating valve is cavitated or not by adopting the cavitation identification method. The experimental device comprises a valve flow characteristic test platform, a sound level meter, an acceleration sensor and a signal acquisition and processing module. The invention can identify whether the regulating valve is cavitated, avoid experiment failure after being influenced by cavitation, improve experiment efficiency and reduce experiment cost.
Description
Technical Field
The invention relates to the technical field of regulating valve flow characteristic experiments, in particular to a regulating valve flow characteristic experiment cavitation identification method, an experiment method and an experiment device.
Background
The flow capacity and the flow characteristic of the regulating valve are used as important indexes when the industrial process valve is selected, and are mainly obtained by measuring through a flow characteristic testing device. The flow characteristic test should be carried out on 3 pressure difference points with larger interval and not less than 0.1bar in a turbulent flow and cavitation-free area. If the difference between the 3 sets of flow coefficients obtained by the flow characteristic test is more than or equal to 4 percent and is caused by cavitation, the test should be carried out again under higher inlet pressure.
Therefore, cavitation should be avoided as much as possible during the flow characteristic test of the regulating valve. Cavitation in regulating valves is a common phenomenon of liquid flow. When the liquid pressure difference increases enough to cause vaporization, a first stage of cavitation where two phases of vapor and liquid coexist, i.e., flash phenomenon, is formed. After a plurality of bubbles are concentrated in the throttling hole, the increase of the flow is influenced, and the blocking condition is generated, so that the correctness of a flow coefficient calculation formula is influenced, and the calculation is complicated; subsequently, in the cavitation second stage of collapse of the bubble, all the energy is concentrated at the point of collapse, producing a very high impact force, causing vibration, noise and damage to the material, directly affecting the service life of the regulator valve.
In the prior art, cavitation mainly comprises research methods such as an optical method, a coating covering method, a resistance method, a vibroacoustic method, an acoustic emission technology and the like, but at present, much attention is paid to the research on cavitation mechanism and the research on structural damage, material selection, vibration reduction and noise reduction by cavitation. The researches provide some guidance suggestions for conditions generated by cavitation in the flow characteristic test process, but a method for diagnosing the cavitation in the flow characteristic test process on line is lacked, so that the influence of the cavitation on the flow coefficient of the regulating valve is eliminated, and the flow characteristic curve cannot be efficiently and accurately obtained.
Disclosure of Invention
In view of the above disadvantages of the prior art, an object of the present invention is to provide a cavitation identification method, an experiment method and an experiment apparatus for regulating valve flow characteristic experiments, which are used to solve the problems of the prior art that the flow characteristic experiments are interfered by cavitation and the experiment efficiency is low.
In order to achieve the above objects and other related objects, the present invention provides a cavitation identification method for a flow characteristic experiment of a regulating valve, comprising the steps of:
establishing a reference data set, wherein the reference data set comprises a vibration noise signal of a regulating valve in a cavitation state and a vibration noise signal of a regulating valve in a non-cavitation state;
acquiring detection data, acquiring a vibration noise signal of the regulating valve during flow characteristic test as the detection data,
and judging cavitation, namely comparing the detection data with the reference data set, and judging whether the regulating valve is cavitated according to the comparison result.
Optionally, the method of establishing the reference data set includes:
presetting the boundary condition of non-cavitation pressure and the boundary condition of cavitation pressure,
testing the flow characteristic of the regulating valve according to the non-cavitation pressure boundary condition to obtain a vibration noise signal of the regulating valve in a non-cavitation state,
and carrying out flow characteristic test on the regulating valve according to the cavitation pressure boundary condition to obtain a vibration noise signal of the regulating valve in a cavitation state.
Optionally, the method of establishing the non-cavitation pressure boundary condition and the cavitation pressure boundary condition comprises:
establishing a simulation model according to the relation between the pressure boundary condition of the regulating valve and whether the regulating valve is cavitated, presetting the pressure boundary condition, and judging whether the regulating valve is cavitated under the preset pressure boundary condition through the simulation model;
if cavitation occurs, recording the preset pressure boundary condition as a cavitation pressure boundary condition, otherwise, recording the preset pressure boundary condition as a non-cavitation pressure boundary condition;
and adjusting the pressure boundary condition until obtaining the cavitation pressure boundary condition and the non-cavitation pressure boundary condition of the regulating valve.
Optionally, the vibration noise signal includes sound pressure and acceleration.
The invention also provides an experimental method for the flow characteristic experiment of the regulating valve, which comprises the following steps:
presetting a reference data set, wherein the reference data set comprises a vibration noise signal of a regulating valve in a cavitation state and a vibration noise signal of a regulating valve in a non-cavitation state;
presetting a pressure boundary condition, carrying out flow characteristic test on the regulating valve according to the pressure boundary condition, and acquiring a vibration noise signal as detection data when the flow characteristic of the regulating valve is tested;
comparing the detection data with the reference data set, and judging whether the regulating valve is cavitated according to the comparison result; if cavitation, recording the pressure boundary condition as a cavitation pressure boundary condition, otherwise, recording the pressure boundary condition when the regulating valve is not cavitated as a non-cavitation pressure boundary condition;
presetting a judgment threshold, and adjusting a preset pressure boundary condition until a cavitation pressure boundary condition and a non-cavitation pressure boundary condition are obtained, wherein the difference value between the cavitation pressure boundary condition and the non-cavitation pressure boundary condition is smaller than the judgment threshold;
and the non-cavitation pressure boundary condition is a critical pressure boundary condition, and the flow characteristic test is carried out on the regulating valve according to the critical pressure boundary condition.
Optionally, an experimental device is used for performing a flow characteristic test on the regulating valve, the critical pressure boundary condition is compared with the maximum pressure difference provided by the experimental device, if the critical pressure boundary condition is greater than or equal to the maximum pressure difference, the maximum pressure difference provided by the experimental device is used as the test pressure difference, otherwise, the critical pressure boundary condition is used as the test pressure difference.
Optionally, the flow characteristic of the regulating valve is tested by taking the test differential pressure, the 50% test differential pressure and the 10% test differential pressure as pressure boundary conditions respectively.
The invention also provides an experimental method for the flow characteristic experiment of the regulating valve, the regulating valve is used for carrying out flow characteristic test, and whether the regulating valve is cavitated is identified by adopting the cavitation identification method for the flow characteristic experiment of the regulating valve.
The invention also provides an experimental device for the flow characteristic experiment of the regulating valve, which is used for implementing the cavitation identification method for the flow characteristic experiment of the regulating valve, and the method comprises the following steps: the valve flow characteristic testing platform is used for testing the flow characteristic of the regulating valve, and comprises a sound level meter, an acceleration sensor and a signal acquisition and processing module, wherein the sound level meter and the acceleration sensor are used for acquiring vibration noise signals, and the signal acquisition and processing module is respectively connected with the sound level meter and the acceleration sensor.
Optionally, the acceleration sensor includes a single axis sensor and a three axis sensor.
As described above, the cavitation identification method, the experiment method and the experiment apparatus for the experiment of the flow characteristic of the regulating valve of the present invention have the following beneficial effects: whether the adjusting valve is cavitated or not can be identified in the process of adjusting valve flow characteristic experiment, if cavitation occurs, the adjusting valve can be avoided or adjusted in time, so that experiment failure after the flow characteristic experiment result is influenced by cavitation is avoided, experiment efficiency is improved, and experiment cost is reduced.
Drawings
Fig. 1 is a schematic structural diagram of an experimental apparatus for an experiment of flow characteristics of a regulating valve according to an embodiment of the present invention.
Fig. 2 shows a cloud of cavitation effects in an embodiment of the present invention.
FIG. 3 is a cloud showing the non-cavitation effect in an embodiment of the present invention.
FIG. 4 shows graphs of cavitation and non-cavitation sound pressure levels in examples of the present invention.
FIG. 5 is a graph showing cavitation and no cavitation acceleration levels in an example of the present invention.
FIG. 6 is a graph comparing a numerical simulation curve and a test curve of a valve flow characteristic according to an embodiment of the present invention.
Description of reference numerals:
1. a circulating water power module; 2. a liquid crystal display; 3. a control unit; 4. a stop valve; 5. a computer; 6. an inlet duct; 7. a regulating valve to be measured; 8. a signal collector; 9. a sound level meter support; 10. a sound level meter; 11. an outlet conduit; 12. a flow regulating valve; 13. a second uniaxial acceleration sensor; 14. taking a flow hole behind the valve; 15. a third uniaxial acceleration sensor; 16. a pressure port is taken after the valve; 17. a fourth uniaxial acceleration sensor; 18. a three-axis acceleration sensor; 19. a pressure reducing valve; 20. an actuator; 21. a dial indicator; 22. a metal sheet; 23. a pressure port is arranged in front of the valve; 24. a first uniaxial acceleration sensor; 25. a flow port is arranged in front of the valve.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
Please refer to fig. 1 to 6. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated. The structures, proportions, sizes, and other dimensions shown in the drawings and described in the specification are for understanding and reading the present disclosure, and are not intended to limit the scope of the present disclosure, which is defined in the claims, and are not essential to the art, and any structural modifications, changes in proportions, or adjustments in size, which do not affect the efficacy and attainment of the same are intended to fall within the scope of the present disclosure. In addition, the terms "upper", "lower", "left", "right", "middle" and "one" used in the present specification are for clarity of description, and are not intended to limit the scope of the present invention, and the relative relationship between the terms and the terms is not to be construed as a scope of the present invention.
The embodiment provides a cavitation identification method for a flow characteristic experiment of a regulating valve, which comprises the following steps:
and S1, establishing a reference data set, wherein the reference data set comprises a vibration noise signal of the regulating valve in a cavitation state and a vibration noise signal of the regulating valve in a non-cavitation state.
And S2, acquiring the detection data, and acquiring a vibration noise signal of the regulating valve during the flow characteristic test as the detection data.
And S3, cavitation judgment, namely comparing the detection data with the reference data set, and judging whether the regulating valve is cavitated according to the comparison result.
According to the comparison result, whether the regulating valve cavitates or not during flow characteristic test can be judged by an operator, and after cavitation occurs, the operator can timely perform corresponding avoidance or adjustment, so that the experiment failure after the flow characteristic experiment result is influenced by cavitation is avoided, and the experiment is repeated. The experimental efficiency of the flow characteristic experiment is improved, and the experimental cost is reduced.
Specifically, in step S1, the method for creating the reference data set includes the following steps:
firstly, the boundary condition of non-cavitation pressure and the boundary condition of cavitation pressure are preset. And then carrying out flow characteristic test on the regulating valve according to the non-cavitation pressure boundary condition to obtain a vibration noise signal of the regulating valve in a non-cavitation state, and carrying out flow characteristic test on the regulating valve according to the cavitation pressure boundary condition to obtain a vibration noise signal of the regulating valve in a cavitation state.
Specifically, the method for establishing the non-cavitation pressure boundary condition and the cavitation pressure boundary condition comprises the following steps:
firstly, establishing a simulation model according to the relation between the pressure boundary condition of the regulating valve and whether the regulating valve is cavitated, presetting the pressure boundary condition, and then judging whether the regulating valve is cavitated under the preset pressure boundary condition through the simulation model. And if cavitation occurs, recording the preset pressure boundary condition as a cavitation pressure boundary condition, otherwise, recording the preset pressure boundary condition as a non-cavitation pressure boundary condition.
And adjusting the pressure boundary condition until obtaining the cavitation pressure boundary condition and the non-cavitation pressure boundary condition of the regulating valve.
Specifically, the vibration noise signal includes sound pressure and acceleration.
The embodiment provides an experimental method for a regulating valve flow characteristic experiment, and when a regulating valve is used for flow characteristic test, whether the regulating valve is cavitated is identified by adopting the cavitation identification method for the regulating valve flow characteristic experiment. When cavitation occurs, an operator can correspondingly avoid or adjust the cavitation in time, so that the experiment failure and the re-experiment after the flow characteristic experiment result is influenced by the cavitation are avoided. The experimental efficiency of the flow characteristic experiment is improved, and the experimental cost is reduced.
The embodiment also provides an experimental method for the flow characteristic experiment of the regulating valve, which comprises the following steps:
s01, presetting a reference data set, wherein the reference data set comprises vibration noise signals of the cavitation state of the regulating valve;
s02, presetting a pressure boundary condition, carrying out flow characteristic test on the regulating valve according to the pressure boundary condition, acquiring a vibration noise signal as detection data when the flow characteristic of the regulating valve is tested,
s03, comparing the detection data with the reference data set, and judging whether the regulating valve is cavitated or not according to the comparison result; if cavitation, recording the pressure boundary condition as cavitation pressure boundary condition, otherwise, recording the pressure boundary condition when the regulating valve is not cavitated as non-cavitation pressure boundary condition,
and presetting a judgment threshold, and adjusting the preset pressure boundary condition until a cavitation pressure boundary condition and a non-cavitation pressure boundary condition are obtained, wherein the difference value between the cavitation pressure boundary condition and the non-cavitation pressure boundary condition is smaller than the judgment threshold.
And when the difference value between the boundary condition of the cavitation pressure and the boundary condition of the non-cavitation pressure is smaller than the judgment threshold value, the boundary condition of the non-cavitation pressure is the critical pressure boundary condition. And then carrying out a flow characteristic test on the regulating valve according to the critical pressure boundary condition.
After the critical pressure boundary condition is obtained, the flow characteristic test can be carried out on the regulating valve within the critical pressure boundary condition so as to prevent cavitation during the flow characteristic test of the regulating valve.
When the experimental device is actually used for carrying out flow characteristic test on the regulating valve, firstly, the critical pressure boundary condition is compared with the maximum pressure difference provided by the experimental device, if the critical pressure boundary condition is larger than or equal to the maximum pressure difference, the maximum pressure difference provided by the experimental device is used as the test pressure difference, and if the critical pressure boundary condition is smaller than the maximum pressure difference, the critical pressure boundary condition is used as the test pressure difference.
Specifically, when the flow characteristic of the regulating valve is tested, the flow characteristic of the regulating valve is tested by taking the test differential pressure, the 50% test differential pressure and the 10% test differential pressure as pressure boundary conditions.
The embodiment also provides an experimental device for the flow characteristic experiment of the regulating valve, which is used for implementing the cavitation identification method for the flow characteristic experiment of the regulating valve. And the signal acquisition and processing module is respectively connected with the sound level meter and the acceleration sensor. Specifically, the acceleration sensor includes a single-axis acceleration sensor and a three-axis acceleration sensor. The signal acquisition processing module comprises a control unit, a signal acquisition device and a computer.
The valve flow characteristic test platform is used for carrying out flow characteristic test to the regulating valve, and sound level meter and acceleration sensor are used for gathering vibration noise signal, and signal acquisition processing module is used for cooperating with sound level meter and acceleration sensor, gathers vibration noise signal and handles, and the operating personnel of being convenient for reads.
When the flow characteristic experiment of the regulating valve is actually carried out, the method comprises the following steps:
firstly, set up test system
Adopt valve flow characteristic test platform, the governing valve that will await measuring passes through flange and pipe connection, and the installation direction is low business turn over side play, and the entry of governing valve passes through the inlet pipe and links to each other with the stop valve, and the export of governing valve passes through the export pipeline and links to each other with flow control valve 12. The liquid power source of the regulating valve is provided by a circulating water power module packaged in the isolation chamber, and the stop valve is communicated with the circulating water power module.
The inlet pipeline is provided with a front valve pressure taking port 23 and a front valve flow taking port 25, the outlet pipeline is provided with a rear valve pressure taking port 16 and a rear valve flow taking port 14, the front valve pressure taking port 23, the front valve flow taking port 25, the rear valve pressure taking port 16 and the rear valve flow taking port 14 are respectively connected into the control unit 3 through signal transmission lines, and operators can control all parameters conveniently.
A sound level meter support 9 is arranged at a position 11 far away from the valve outlet and the outlet pipeline, and a sound level meter 10 is arranged on the sound level meter support 9. The acceleration sensors include a single-axis acceleration sensor and a three-axis acceleration sensor 18. The single-axis acceleration sensors are arranged on the inlet pipe 6 and the outlet pipe 11, respectively, and need to be at a certain distance from the regulating valve when the single-axis acceleration sensors are arranged. A three-axis acceleration sensor 18 is disposed on the cast step floor of the regulator valve body.
The signal acquisition processing module comprises a signal collector 8 and a computer 5 connected with the signal collector. The sound level meter and the acceleration sensor are respectively connected into the signal collector through signal transmission lines, one end of the signal collector is connected with a power supply, the other end of the signal collector is connected with a computer, and signal collection and signal processing software is installed on the computer 5 and used for being matched with the signal collector 8 to collect signals and process the collected signals.
Secondly, debugging the regulating valve to be tested
The valve flow characteristic testing platform comprises an actuating mechanism used for adjusting the opening of the regulating valve, the actuating mechanism is connected with an air source line through a pressure reducing valve, and the air source line is connected with an air source and used for driving the actuating mechanism. A dial indicator is fixedly arranged corresponding to the upper membrane cover of the actuating mechanism, an opening metal sheet is fixedly arranged on the valve rod of the regulating valve, and a measuring head of the dial indicator is in light contact with the metal sheet. And (3) introducing an air source, wherein the air source enters the actuating mechanism through the pressure reducing valve, and the actuating mechanism drives the valve rod of the regulating valve to be tested to move up and down so as to regulate the opening degree of the valve. The holding metal sheet moves up and down along with the valve rod of the regulating valve to be measured, so that the numerical value of the dial plate of the dial gauge changes. When the valve rod moves downwards to the limit position, the valve is completely closed, the opening degree is zero at the moment, the dial data of the dial gauge is corrected to the zero position, and when the valve rod moves upwards to the rated stroke S of the valve, the dial data of the dial gauge is S.
Third, debug the test system
And recording the test channels corresponding to the serial numbers of the acceleration sensors, and numbering. Opening signal processing software of the computer 5, setting information of the regulating valve to be measured and working condition information, respectively inputting a serial number and sensitivity information of a corresponding sensor in channel setting, setting sampling frequency, carrying out Fourier transform during time-frequency conversion, weighting A, windowing, and setting frequency resolution and signal overlapping rate. And the monitoring interface displays a sound pressure level curve and an acceleration level curve, and a total sound pressure level value and a total acceleration level value. And knocking the valve and the pipeline structure in sequence near each channel, observing whether the curve of the signal recorder corresponding to each channel changes, and if the amplitude of the curve changes obviously, indicating that the wiring of each sensor is firm.
Fourthly, testing cavitation and non-cavitation vibration noise signals
Closing the stop valve, and presetting the pressure difference value between the inlet pipeline and the outlet pipeline of the two valves to be tested as delta p respectively1And Δ p2. Adjusting the valve to be measured to the opening SnOpening the flow control valve 12 until the flow values of the inlet and outlet pipes are consistent, and reading the flow value Q of the inlet pipe1And the flow rate value Q of the outlet pipe2。
Establishing the opening S of the regulating valve to be measured and the auxiliary pipeline thereofnAnd the simulation model comprises a three-dimensional model and a grid model. Based on the independence analysis and the solution convergence analysis of the grid model, the cavitation model and the pressure boundary condition are adopted to carry out the numerical simulation of the transient flow field on the regulating valve to be measured, so as to obtain a cloud picture with cavitation effect and a cloud picture without cavitation effect, and determine the pressure difference value delta p of the inlet pipeline1Differential pressure value of outlet pipeline△p2Under the condition of (1), whether the working condition is cavitation or not is tested. Adjusting inlet duct differential pressure value Deltap1And outlet pipe differential pressure value delta p2Recording the inlet pipeline differential pressure value delta p until the regulating valve to be measured is cavitated1And outlet pipe differential pressure value delta p2Is a boundary condition of cavitation pressure.
Starting a channel of the vibration noise tester, and recording the pressure difference value delta p of the inlet pipeline1And outlet pipe differential pressure value delta p2And carrying out flow characteristic test on the regulating valve to be tested. And sound pressure and acceleration signals are collected and used as a reference data set, so that comparison in a subsequent flow characteristic test is facilitated.
Acquiring a cavitation sound pressure level curve, an acceleration level curve, a total sound pressure level value and a total acceleration level value within sampling time, and calculating a flow coefficient, wherein if the error of the flow coefficient is more than or equal to 4%, the regulating valve to be measured is cavitated under the boundary condition of cavitation pressure, otherwise, the regulating valve is not cavitated, and the simulation is required to be carried out again to acquire a new boundary condition of cavitation pressure.
Opening S of regulating valvenIn the case of (2), the flow coefficient is obtained by the following formula:
where Cv is the flow coefficient, unit m3H; q is the volume flow in m3H; n1 is a unit coefficient with a value of 8.65X 10-2; rho1/ρ0Rho at 15.5 ℃ for water, relative density1/ρ 01 is ═ 1; delta p is the pressure difference value of the inlet pipeline and the outlet pipeline of the valve to be measured, and delta p1＝∣△p1-△p2| in kPa.
Fifthly, testing the flow characteristic curve of the regulating valve
Obtaining a preset opening degree SnAnd (5) carrying out critical pressure boundary conditions of the lower cavitation, and then carrying out flow characteristic test on the regulating valve according to the critical pressure boundary conditions.
Specifically, a pressure boundary condition data set and a judgment threshold are preset, then a flow characteristic test is performed according to the preset pressure boundary condition, a sound pressure signal and an acceleration signal in the test are collected as detection data, and the detection data are compared with the sound pressure signal and the acceleration signal obtained in the fourth step. And judging whether the regulating valve is cavitated or not according to the comparison result. And if cavitation occurs, recording the preset pressure boundary condition as a cavitation pressure boundary condition, and otherwise, recording the preset pressure boundary condition as a non-cavitation pressure boundary condition.
And continuously adjusting the pressure boundary condition until a cavitation pressure boundary condition and a non-cavitation pressure boundary condition are obtained, wherein the difference value between the cavitation pressure boundary condition and the non-cavitation pressure boundary condition is smaller than a judgment threshold value. And when the difference value between the boundary condition of the cavitation pressure and the boundary condition of the non-cavitation pressure is smaller than the judgment threshold value, the boundary condition of the non-cavitation pressure is considered as the critical pressure boundary condition.
When the experimental device is actually used for carrying out flow characteristic test on the regulating valve, firstly, the critical pressure boundary condition is compared with the maximum pressure difference provided by the experimental device, if the critical pressure boundary condition is larger than or equal to the maximum pressure difference, the maximum pressure difference provided by the experimental device is used as the test pressure difference, and if the critical pressure boundary condition is smaller than the maximum pressure difference, the critical pressure boundary condition is used as the test pressure difference.
Then, flow characteristic tests are respectively carried out on the test pressure difference, 50% of the test pressure difference and 10% of the test pressure difference, the flow regulating valve 12 is adjusted until the flow values of the inlet pipeline and the outlet pipeline are consistent, the flow values are read, flow coefficients under three test working conditions of the test pressure difference, the 50% of the test pressure difference and the 10% of the test pressure difference are obtained, and then the flow coefficients are averaged to obtain a preset opening SnTest flow coefficient of (2).
Adjusting the preset opening degree SnAnd obtaining the test flow coefficient of the regulating valve under each opening degree.
Respectively establishing a three-dimensional model and a grid model of the valve to be tested and the auxiliary pipeline under each opening degree, analyzing independence and solving convergence based on the grid model, and adopting an SST (shear stress transmission) k-omega turbulence model. The standard k-omega turbulence model has higher calculation accuracy on free shear turbulence, adhesion boundary layer turbulence and moderate separation turbulence, and compared with the standard k-omega turbulence model, the SST (shear stress transmission) k-omega turbulence model can better predict separation and reattachment and is suitable for the simulation of a flow field in the regulating valve.
And adjusting the pressure boundary conditions of the test, performing numerical simulation of a steady-state flow field, extracting the front-back pressure difference and the flow of the regulating valve, and calculating to obtain the numerical simulation flow coefficient under each opening. And drawing a numerical simulation method curve and a test curve according to the corresponding relation between the flow coefficient and the opening, and comparing the fitting degree between the numerical simulation method curve and the test curve, thereby verifying the reliability of the flow characteristic test result.
Taking a flow characteristic experiment of a porous sleeve regulating valve with the caliber of DN80 and the rated flow coefficient of 68 as an example, the practical experiment process is as follows:
1. building a test system
The test system is built based on a professional valve flow characteristic test platform, as shown in fig. 1. The regulating valve 7 to be measured is connected with the inlet pipeline 6 and the outlet pipeline 11 through flanges, and the installation direction is low-inlet side-outlet. The inlet of the regulating valve is connected to the shut-off valve 4 via an inlet line 6, and the outlet of the regulating valve is connected to a flow regulating valve 12 via an outlet line 11. The liquid power source is provided by circulating water power module 1, and circulating water power module 1 is packaged in the isolated chamber to guarantee safety.
The pressure taking port 23 in front of the valve, the flow taking port 25 in front of the valve, the pressure taking port 16 behind the valve and the flow taking port 14 behind the valve are connected to the control unit 3 through signal transmission lines respectively, the control unit 3 is used for controlling the pressure and the flow of the regulating valve, the control unit 3 is connected with the liquid crystal display 2, and the test results of the pressure and the flow can be displayed in real time through the liquid crystal display 2.
The sound level meter support 9 is provided with a sound level meter 10 which is arranged at a position 1 meter away from the valve outlet and the outlet pipeline. In this embodiment, the number of the uniaxial acceleration sensors is 4, and the uniaxial acceleration sensors are respectively the first uniaxial acceleration sensor to the fourth uniaxial acceleration sensor.
The first single-axis acceleration sensor 24 is arranged on the outer wall of the inlet pipe at a distance of 0.5 m from the valve inlet. Second unipolar acceleration sensor 13, third unipolar acceleration sensor 15 and fourth unipolar acceleration sensor 17 are respectively on the outer wall of export pipeline, and the distance between second unipolar acceleration sensor 13, third unipolar acceleration sensor 15 and fourth unipolar acceleration sensor 17 and the valve export is 1.5 meters, 1 meter, 0.5 meter respectively. The three-axis acceleration sensor 18 is one and is arranged on a casting step of the valve body of the regulating valve.
All the sound level meters and the acceleration sensors are connected into a signal collector 8 through signal transmission lines, one end of the signal collector is connected with a power supply, the other end of the signal collector is connected with a computer 5, and signal collection and signal processing software is installed on the computer 5 and used for collecting signals in cooperation with the sound pressure meters and the acceleration sensors and analyzing the collected signals.
2. Debugging valve to be tested
The actuator 20 is connected with the air supply line through the connecting pressure reducing valve 19, and the actuator 20 can drive the valve rod of the regulating valve 7 to be tested to move up and down so as to adjust the valve opening of the regulating valve. The dial indicator 21 is fixed on an upper diaphragm cover of the actuator, the opening metal sheet 22 is fixed on the valve rod, and a measuring head of the dial indicator 21 is in contact with the metal sheet 22. And (3) introducing an air source, wherein the air source enters the actuating mechanism 20 through the pressure reducing valve 19, the actuating mechanism 20 drives the valve rod to move up and down, and the metal sheet 22 moves up and down along with the valve rod, so that the numerical value of the dial gauge is correspondingly changed. When the valve rod moves downwards to the limit position, the valve is completely closed, the opening degree is zero at the moment, and the data of the dial plate 21 of the dial indicator is corrected to the zero position. In this embodiment, the rated stroke S of the regulating valve is 38mm, and when the valve rod moves up to the rated stroke of the regulating valve, the dial data of the dial gauge is 38 mm.
3. Debugging test system
The test channels corresponding to the serial numbers of the acceleration sensors are recorded and numbered, the sound level meter is numbered as Y1, the single-shaft acceleration sensors on the outlet pipeline are numbered as A2, A3 and A4 in sequence from far to near from the regulating valve to be tested, the single-shaft acceleration sensors on the inlet pipeline are numbered as A8, and the three-shaft acceleration sensor 18 comprises three mutually perpendicular detection directions which are respectively numbered as A5X, A6Y and A7Z. Where A5X corresponds to the liquid flow direction, A6Y corresponds to the up-down mounting direction of the regulator valve, and A7Z corresponds to the front-rear direction of the regulator valve. Opening signal processing software of a computer, setting information of a valve to be tested as a porous sleeve regulating valve and working condition information as flow characteristic test opening, inputting serial numbers and sensitivity information of corresponding sensors according to sensor numbers into channels 1-8 respectively, setting sampling frequency as 51.2kHz, performing primary integration processing on acceleration signals by adopting a mathematical function to obtain speed signals, performing Fourier transform on all time domain signals, weighting by adopting A, adding Hanning window, setting frequency resolution as 5Hz and signal overlapping rate as 75%. And the monitoring interface displays a sound pressure level curve and an acceleration level curve, and a total sound pressure level value and a total acceleration level value. And knocking the valve and the pipeline structure in sequence near each channel, observing whether the curve of the signal recorder corresponding to each channel changes, and if the amplitude of the curve changes obviously, indicating that the wiring of each sensor is firm.
4. Testing cavitation and non-cavitation vibration noise signals
And (3) closing the stop valve 4, presetting the pressure difference value between the inlet pipeline and the outlet pipeline of the two valves to be tested by the control unit 3, wherein the pressure difference value is 2Mp and 0.2MPa respectively, and adjusting the opening of the valves to be tested to be 19 mm. The flow rate regulating valve 12 was opened until the flow rate values of the inlet pipe and the outlet pipe were kept consistent, and the corresponding flow rate values of 46.44m3/h and 13.86m3/h were read. And establishing a three-dimensional model of the valve to be tested and the auxiliary pipeline under the opening degree, extracting a fluid domain, dividing by adopting a polyhedral grid method, and performing independence analysis and convergence analysis. And (3) performing numerical simulation of the transient flow field by adopting a Zwart-Gerbera-Belamri cavitation model and taking inlet and outlet pressures as boundary conditions. The Zwart-Gerbera-Belamri cavitation model has good numerical stability and calculation convergence, and is widely applied to cavitation flow research. And (3) taking the center of the valve body as an origin of coordinates and taking X-0 as a monitoring surface to obtain a cavitation effect cloud picture as shown in figure 2 and an uncovitation effect cloud picture as shown in figure 3, and determining that the regulating valves are respectively cavitation and non-cavitation under two differential pressure values of 2Mp and 0.2 MPa.
Starting a channel of the vibration noise tester, collecting a sound pressure signal and an acceleration signal, sampling for 10s, and obtaining a graph4, and cavitation and non-cavitation acceleration level curves, as shown in figure 5. From fig. 4 and 5, the difference value between the cavitation and non-cavitation total sound pressure level value and the total acceleration level value is 9dBA, and the flow coefficients Cv of cavitation and non-cavitation are respectively 11.33m3/h、12m3The difference between the two is 6 percent and is more than 4 percent, the flow coefficient error is large due to the generation of cavitation, and the fact that the regulating valve generates cavitation under the pressure boundary condition of 2Mpa is proved. In the subsequent flow characteristic test, the obtained cavitation sound pressure and acceleration signal results are used as reference, and the amplitude change of a sound pressure level curve and an acceleration level curve within the frequency range of 2 kHz-5 kHz and the change of the total sound pressure level and the total acceleration level are focused.
5. Testing flow characteristic curve of regulating valve
Based on the cavitation vibration noise signal analysis method in the step 4, the test pressure difference of the regulating valve at the opening degree of 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100% is preset, in this embodiment, the maximum pressure difference of the flow characteristic equipment is 3MPa, and if no cavitation exists below 3MPa, 3MPa is taken as the test pressure difference of the test. And then, respectively presetting differential pressure by 50% and 10% of the maximum differential pressure, adjusting the flow regulating valve 12 until the flow values of the inlet pipeline and the outlet pipeline are consistent, reading flow values Q1-Q11, calculating flow coefficients under three test working conditions, and then averaging to obtain the test flow coefficient of each opening.
Respectively establishing a three-dimensional model and a grid model of the valve to be tested and the auxiliary pipeline under each opening degree, analyzing independence and solving convergence analysis based on the grid model, carrying out numerical simulation of a steady-state flow field by adopting an SST (shear stress transmission) k-omega turbulence model according to the boundary condition of test pressure, extracting the front-back pressure difference and the flow of the regulating valve, and calculating to obtain the numerical simulation flow coefficient under each opening degree as shown in figure 6. In fig. 6, the fitting between the numerical simulation method curve and the test curve is good, and the flow characteristic test result is reliable.
In summary, the cavitation identification method, the experiment method and the experiment device for the experiment of the flow characteristic of the regulating valve in the embodiment can identify whether the regulating valve is cavitated or not in the process of the experiment of the flow characteristic of the regulating valve, and if cavitation occurs, the regulating valve can be avoided or adjusted in time, so that the experiment failure caused by the cavitation influence on the flow characteristic experiment result is avoided, the experiment efficiency is improved, and the experiment cost is reduced.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (10)
1. A cavitation identification method for a flow characteristic experiment of a regulating valve is characterized by comprising the following steps:
establishing a reference data set, wherein the reference data set comprises a vibration noise signal of a regulating valve cavitation state;
acquiring detection data, and acquiring a vibration noise signal of the regulating valve during flow characteristic test as the detection data;
and judging cavitation, namely comparing the detection data with the reference data set, and judging whether the regulating valve is cavitated according to the comparison result.
2. The cavitation identification method for the regulation valve flow characteristic experiment as claimed in claim 1, wherein the method for establishing the reference data set comprises:
presetting a cavitation pressure boundary condition, and carrying out flow characteristic test on the regulating valve according to the cavitation pressure boundary condition to obtain a vibration noise signal of the regulating valve in a cavitation state.
3. The cavitation identification method for the regulating valve flow characteristic experiment as claimed in claim 2, wherein the method for establishing the boundary condition of the cavitation pressure comprises the following steps:
establishing a simulation model according to the relation between the pressure boundary condition of the regulating valve and whether the regulating valve is cavitated, presetting the pressure boundary condition, and judging whether the regulating valve is cavitated under the preset pressure boundary condition through the simulation model;
and if cavitation occurs, recording the preset pressure boundary condition as a cavitation pressure boundary condition, otherwise, adjusting the pressure boundary condition until the cavitation pressure boundary condition of the regulating valve is obtained.
4. The cavitation identification method for the regulating valve flow characteristic experiment as recited in claim 1, wherein the vibration noise signal includes sound pressure and acceleration.
5. An experimental method for regulating valve flow characteristic experiments comprises the following steps:
presetting a reference data set, wherein the reference data set comprises a vibration noise signal of a regulating valve in a cavitation state and a vibration noise signal of a regulating valve in a non-cavitation state;
presetting a pressure boundary condition, carrying out flow characteristic test on the regulating valve according to the pressure boundary condition, acquiring a vibration noise signal as detection data when the flow characteristic of the regulating valve is tested,
comparing the detection data with the reference data set, and judging whether the regulating valve is cavitated according to the comparison result; if cavitation, recording the pressure boundary condition as a cavitation pressure boundary condition, otherwise, recording the pressure boundary condition when the regulating valve is not cavitated as a non-cavitation pressure boundary condition,
presetting a judgment threshold, and adjusting a preset pressure boundary condition until a cavitation pressure boundary condition and a non-cavitation pressure boundary condition are obtained, wherein the difference value between the cavitation pressure boundary condition and the non-cavitation pressure boundary condition is smaller than the judgment threshold;
and the non-cavitation pressure boundary condition is a critical pressure boundary condition, and the flow characteristic test is carried out on the regulating valve according to the critical pressure boundary condition.
6. The experimental method for the flow characteristic experiment of the regulating valve according to claim 5, characterized in that: and adopting an experimental device to carry out flow characteristic test on the regulating valve, comparing the critical pressure boundary condition with the maximum pressure difference provided by the experimental device, if the critical pressure boundary condition is greater than or equal to the maximum pressure difference, taking the maximum pressure difference provided by the experimental device as the test pressure difference, otherwise, taking the critical pressure boundary condition as the test pressure difference.
7. The experimental method for the flow characteristic experiment of the regulating valve according to claim 6, characterized in that: and respectively taking the test pressure difference, the 50% test pressure difference and the 10% test pressure difference as pressure boundary conditions to carry out flow characteristic test on the regulating valve.
8. An experimental method for regulating valve flow characteristic experiments is characterized in that: the regulating valve is subjected to flow characteristic test, and whether the regulating valve is cavitated is identified by adopting the cavitation identification method of the regulating valve flow characteristic test as claimed in any one of claims 1 to 4.
9. The utility model provides an experimental apparatus of governing valve flow characteristic experiment which characterized in that: the cavitation identification method for implementing the regulating valve flow characteristic experiment as claimed in any one of claims 1 to 4, comprises the following steps: the valve flow characteristic testing platform is used for testing the flow characteristic of the regulating valve, and comprises a sound level meter, an acceleration sensor and a signal acquisition and processing module, wherein the sound level meter and the acceleration sensor are used for acquiring vibration noise signals, and the signal acquisition and processing module is respectively connected with the sound level meter and the acceleration sensor.
10. The experimental device for the experiment of the flow characteristic of the regulating valve according to claim 9, is characterized in that: the acceleration sensor comprises a single-axis sensor and a three-axis sensor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210158837.3A CN114526900B (en) | 2022-02-21 | 2022-02-21 | Experimental method for flow characteristic experiment of regulating valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210158837.3A CN114526900B (en) | 2022-02-21 | 2022-02-21 | Experimental method for flow characteristic experiment of regulating valve |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114526900A true CN114526900A (en) | 2022-05-24 |
| CN114526900B CN114526900B (en) | 2024-08-27 |
Family
ID=81625340
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210158837.3A Active CN114526900B (en) | 2022-02-21 | 2022-02-21 | Experimental method for flow characteristic experiment of regulating valve |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114526900B (en) |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012255746A (en) * | 2011-06-10 | 2012-12-27 | Azbil Corp | Cavitation diagnosis apparatus and diagnosis method |
| CN107273570A (en) * | 2017-05-10 | 2017-10-20 | 江苏大学 | A kind of blade pump cavitation Inductive noise Numerical Prediction Method |
| CN108168859A (en) * | 2017-12-05 | 2018-06-15 | 浙江工业大学 | Regulating valve cavitation diagnostic device |
| CN112632877A (en) * | 2021-01-07 | 2021-04-09 | 福州大学 | High-speed switch valve simulation sound field modeling method for coupling high-frequency collision and fluid impact |
| CN113420514A (en) * | 2021-07-13 | 2021-09-21 | 机械工业仪器仪表综合技术经济研究所 | Method for simulating internal flow characteristic numerical value of multistage pressure reduction regulating valve |
| EP3889553A1 (en) * | 2020-04-03 | 2021-10-06 | Focus-on V.O.F. | Method and device for detecting cavitation in the flow of a liquid through a regulating element |
| CN113536631A (en) * | 2021-07-13 | 2021-10-22 | 机械工业仪器仪表综合技术经济研究所 | Method for simulating flow-induced vibration and noise numerical value of multistage pressure reduction regulating valve |
| CN113779709A (en) * | 2021-07-21 | 2021-12-10 | 重庆川仪调节阀有限公司 | Regulating valve noise determination method |
| CN113870240A (en) * | 2021-10-12 | 2021-12-31 | 大连理工大学 | Safety valve cavitation phenomenon discrimination method based on image significance detection |
-
2022
- 2022-02-21 CN CN202210158837.3A patent/CN114526900B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012255746A (en) * | 2011-06-10 | 2012-12-27 | Azbil Corp | Cavitation diagnosis apparatus and diagnosis method |
| CN107273570A (en) * | 2017-05-10 | 2017-10-20 | 江苏大学 | A kind of blade pump cavitation Inductive noise Numerical Prediction Method |
| CN108168859A (en) * | 2017-12-05 | 2018-06-15 | 浙江工业大学 | Regulating valve cavitation diagnostic device |
| EP3889553A1 (en) * | 2020-04-03 | 2021-10-06 | Focus-on V.O.F. | Method and device for detecting cavitation in the flow of a liquid through a regulating element |
| CN112632877A (en) * | 2021-01-07 | 2021-04-09 | 福州大学 | High-speed switch valve simulation sound field modeling method for coupling high-frequency collision and fluid impact |
| CN113420514A (en) * | 2021-07-13 | 2021-09-21 | 机械工业仪器仪表综合技术经济研究所 | Method for simulating internal flow characteristic numerical value of multistage pressure reduction regulating valve |
| CN113536631A (en) * | 2021-07-13 | 2021-10-22 | 机械工业仪器仪表综合技术经济研究所 | Method for simulating flow-induced vibration and noise numerical value of multistage pressure reduction regulating valve |
| CN113779709A (en) * | 2021-07-21 | 2021-12-10 | 重庆川仪调节阀有限公司 | Regulating valve noise determination method |
| CN113870240A (en) * | 2021-10-12 | 2021-12-31 | 大连理工大学 | Safety valve cavitation phenomenon discrimination method based on image significance detection |
Non-Patent Citations (1)
| Title |
|---|
| 夏远志: "离心泵空化现象的模拟试验研究", 30 November 2015, 机电工程, pages: 1433 - 1437 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114526900B (en) | 2024-08-27 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109668723B (en) | Regulating valve cavitation diagnosis system and diagnosis method thereof | |
| CN102734148A (en) | Water pump type test method | |
| CN107014598B (en) | A kind of air valve air inlet performance testing device and test method | |
| KR101920922B1 (en) | Apparatus for diagnosing pneumatic control valve and method thereof | |
| CN112267996B (en) | Flow pulsation testing device of hydraulic pump | |
| CN108195510A (en) | A kind of hot air wind tunnel calibration method of hot diaphragm type shear stress sensor | |
| CN108036200B (en) | Monophone emission sensor leak position method based on gravity frequency attenuation characteristic | |
| CN115876288A (en) | Electronic instrument fault analysis method and system based on big data | |
| CN110530597B (en) | Wind speed calibration system under low pressure | |
| CN114526900A (en) | Cavitation identification method, experiment method and experiment device for flow characteristic experiment of regulating valve | |
| CN104458272A (en) | Exhaust smoke test method and device for engine | |
| CN102879037B (en) | Verifying device for gas drainage comprehensive parameter tester | |
| CN113639987A (en) | Valve state detection system and method based on transient flow | |
| CN107830979B (en) | Visual pilot cobalt target cobalt rod flow induced vibration experimental device | |
| CN109114012A (en) | A kind of vane pump automatic testing equipment and method | |
| CN103048153A (en) | Experiment system for cylindrical structure acoustic performance test | |
| CN113280983A (en) | On-line diagnosis method for internal leakage of pneumatic regulating valve | |
| CN104236844A (en) | High-flow air fluid testing system for nuclear power plant MSR | |
| CN112484796A (en) | Experiment platform and method for calibrating flow of regulating valve by sound wave signal | |
| CN101949772A (en) | Method for measuring pressure reliving rate of pressure reducing valve and detection method of pressure reducing valve | |
| CN103597268A (en) | Method for determining condition of piping and sequence controlled sample pump | |
| CN214222766U (en) | Pipeline leakage point positioning device based on oxygen measurement method | |
| CN107782560A (en) | A kind of bypass type booster fault detection method and device | |
| CN114370915A (en) | Temperature and pressure measurement system of sound velocity nozzle standard device | |
| CN105716682B (en) | Biogas engineering gas production rate test system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |