CN110630530B - Low-specific-speed centrifugal pump flow prediction method based on soft monitoring - Google Patents
Low-specific-speed centrifugal pump flow prediction method based on soft monitoring Download PDFInfo
- Publication number
- CN110630530B CN110630530B CN201910998034.7A CN201910998034A CN110630530B CN 110630530 B CN110630530 B CN 110630530B CN 201910998034 A CN201910998034 A CN 201910998034A CN 110630530 B CN110630530 B CN 110630530B
- Authority
- CN
- China
- Prior art keywords
- value
- centrifugal pump
- flow
- coefficient
- monitoring
- 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.)
- Active
Links
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04D—NON-POSITIVE-DISPLACEMENT PUMPS
- F04D15/00—Control, e.g. regulation, of pumps, pumping installations or systems
- F04D15/0088—Testing machines
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Structures Of Non-Positive Displacement Pumps (AREA)
- Control Of Non-Positive-Displacement Pumps (AREA)
Abstract
The invention provides a soft monitoring-based flow prediction method, namely a soft measurement method for replacing flow with power is adopted, and when the performance of a centrifugal pump with the specific rotating speed of below 120 is monitored, the power value P of a motor can be monitored more accurately onlyPredicted outflow value Q1The gap value of the sealing ring of the centrifugal pump after abrasion and the initial gap value of the sealing ring of the centrifugal pump without abrasion are obtained by measurement or monitoring0And calculating the difference between the two and performing dimensionless transformation to obtain the dimensionless gap difference delta'. In actual operation, the flow value Q is obtained by predicting the power value P of the motor obtained by real-time monitoring1Simultaneously using the dimensionless gap difference delta' to the flow value Q1And (6) correcting.
Description
Technical Field
The invention relates to the field of performance prediction of pumps, in particular to a flow prediction method of a low-specific-speed centrifugal pump.
Background
A centrifugal pump is widely applied to various fields of national economy such as power industry, petrochemical industry, farmland irrigation, hydraulic engineering, ship industry and the like, and can meet installation conditions with limited space, such as an integrated prefabricated pump station with a compact structure and the like, in the practical application process of the centrifugal pump. Compared with the traditional monitoring system which directly measures parameters such as flow, pressure, current, rotating speed and the like, the pump stations with limited space can only select sensors in a limited way, and a soft measurement method which replaces the flow with power is provided. In addition, in the actual operation process of the centrifugal pump, the impeller opening ring and the sealing surface are abraded due to various reasons, so that the gap value between the impeller opening ring and the sealing surface is changed, and further, the external characteristic curve of the centrifugal pump is greatly influenced. Therefore, on the basis of the soft monitoring technology, the method and the device increase the correction of the gap variation of the sealing ring of the centrifugal pump, provide a basis for accurate prediction of flow and provide technical support for a monitoring system of soft monitoring.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a low specific speed centrifugal pump flow prediction method based on soft monitoring, which can predict the centrifugal pump flow in the real-time operation process by monitoring the power value of a motor and the lift value of a centrifugal pump.
The present invention achieves the above-described object by the following technical means.
A low specific speed centrifugal pump flow prediction method based on soft monitoring is characterized in that for a centrifugal pump with the specific speed below 120, when the performance is monitored, the flow value Q can be predicted more accurately only by monitoring the power value P of a motor1By measuring orThe clearance value between the centrifugal pump sealing ring and the impeller after the abrasion and the initial clearance value between the centrifugal pump sealing ring and the impeller without the abrasion are obtained by monitoring0And calculating the difference between the two and performing dimensionless transformation to obtain the dimensionless gap difference delta'. In actual operation, the flow value Q is obtained by predicting the power value P of the motor obtained by real-time monitoring1Simultaneously using the dimensionless gap difference delta' to the flow value Q1The correction is made, mainly determined by the following relation:
in the formula:
Q1is the flow value, m3/h；
Q0Rated flow of centrifugal pump, m3/h；
P' is a dimensionless power number;
K1the flow coefficient is in a value range of 0.5-1;
Δ' is the dimensionless gap difference;
K2the power coefficient is 1-3;
K3the value of the clearance coefficient is 0.01-0.05;
K4the value range of the index coefficient is 0.2-1.
Further, the dimensionless power number P' is obtained according to the measured motor power value P and the rated power P of the centrifugal pump0The calculation result is specifically as follows:
in the formula:
p is the actually monitored motor power value, W;
P0rated power, W.
Further, the dimensionless clearance difference Δ' is based on the measured wear of the seal ring and the vane of the centrifugal pumpThe gap value between the wheels and the initial gap value between the centrifugal pump sealing ring and the impeller without abrasion0The calculation result is specifically as follows:
in the formula:
Δ' is the dimensionless gap difference;
the value of the gap between the centrifugal pump sealing ring and the impeller after abrasion is mm;
0the initial clearance value between the centrifugal pump sealing ring and the impeller without abrasion is mm;
1the value is 1mm per unit gap.
Further, the flow coefficient K1Is 0.85.
Further, the power coefficient K2Recommended value of (2.8).
Further, the clearance coefficient K3Is 0.0257.
Further, the index coefficient K4Is 0.65.
Further, the flow coefficient K1Power coefficient K2Coefficient of clearance K3And the coefficient K4The goodness of fit of the centrifugal pump flow curve prediction with the specific speed below 120 reaches more than 95%.
Drawings
FIG. 1 is a flow chart of a method for predicting the flow rate of a low specific speed centrifugal pump based on soft monitoring according to the present invention.
FIG. 2 is a schematic view of a seal gap according to an embodiment of the present invention.
FIG. 3 is a graph comparing experimental values with calculated values for examples of the present invention.
In the figure:
1-an impeller; 2-anterior chamber; 3-sealing ring.
Detailed description of the invention
The invention will be further described with reference to the following figures and specific examples, but the scope of the invention is not limited thereto.
As shown in FIG. 1, the method for predicting the flow rate of a low specific speed centrifugal pump based on soft monitoring is characterized in that when the performance of the centrifugal pump with the specific speed below 120 is monitored, the flow rate value Q can be predicted more accurately only by monitoring the power value P of a motor1And obtaining the gap value between the centrifugal pump sealing ring and the impeller after the abrasion and the initial gap value between the centrifugal pump sealing ring and the impeller without the abrasion through measurement or monitoring0And calculating the difference between the two and performing dimensionless transformation to obtain the dimensionless gap difference delta'. In actual operation, the flow value Q is obtained by predicting the power value P of the motor obtained by real-time monitoring1Simultaneously using the dimensionless gap difference delta' to the flow value Q1The correction is made, mainly determined by the following relation:
in the formula:
Q1is the flow value, m3/h；
Q0Rated flow of centrifugal pump, m3/h；
P' is a dimensionless power number;
K1is a flow coefficient, and the value range of the flow coefficient is 0.5-1
Δ' is the dimensionless gap difference;
K2the power coefficient is 1-3;
K3the value of the clearance coefficient is 0.01-0.05;
K4the value range of the index coefficient is 0.2-1.
The dimensionless power number P' is obtained according to the measured motor power value P and the rated power P of the centrifugal pump0The calculation result is specifically as follows:
in the formula:
p is the actually monitored motor power value, W;
P0rated power, W.
The dimensionless clearance difference value delta' is determined according to the measured clearance value between the centrifugal pump sealing ring and the impeller after the wear occurs and the initial clearance value between the centrifugal pump sealing ring and the impeller without the wear0The calculation result is specifically as follows:
in the formula:
Δ' is the dimensionless gap difference;
the value of the gap between the centrifugal pump sealing ring and the impeller after abrasion is mm;
0the initial clearance value between the centrifugal pump sealing ring and the impeller without abrasion is mm;
1the value is 1mm per unit gap.
Selecting a centrifugal pump with the specific speed of 96.2 as a test object, and when the centrifugal pump is not worn, performing test at the rated flow Q0＝260m3Head H under/H working condition037.28m, and the rated power of the motor is 45 kW.
The external characteristic parameters of the centrifugal pump at a certain working condition point are obtained through detection as follows:
| flow rate (m)3/h) | Power (kW) |
| 312 | 33.442 |
Calculating to obtain a power number:
P’＝0.743
the seal clearance of the original pump was measured and then machined to 1.05mm by turning the impeller eye. The dimensionless clearance difference value delta' is determined according to the measured clearance value between the centrifugal pump sealing ring and the impeller after the wear occurs and the initial clearance value between the centrifugal pump sealing ring and the impeller without the wear0The calculation result is specifically as follows:
in the formula:
Δ' is the dimensionless gap difference;
in the embodiment, 1.05mm is tested for the value of the clearance between the sealing ring of the centrifugal pump and the impeller after abrasion;
0the initial clearance value between the sealing ring of the centrifugal pump and the impeller without abrasion is 0.45mm in the embodiment;
1is a unit gap, and has a value of 1 mm;
the dimensionless gap difference calculation process in the example is as follows:
the flow coefficient K1Taking the recommended value as 0.85, and the power coefficient K2Taking the recommended value as 2.8, and the clearance coefficient K3Taking the recommended value as 0.0257, and the index coefficient K4The recommended value was taken to be 0.65.
The calculation process is as follows:
the predicted flow corresponding to the dimensionless power number P' can be calculated by the same method, and by comparison with the test values, the following table shows:
| P’ | 0.5253 | 0.5991 | 0.628 | 0.6713 |
| predicted flow (m)3/h) | 156.6311 | 210.3464 | 231.3681 | 262.9413 |
| Test flow (m)3/h) | 156 | 208 | 234 | 260 |
| Error of the measurement | 0.405％ | 1.128％ | -1.125％ | 1.131％ |
| P’ | 0.7017 | 0.7432 | 0.7738 | 0.8102 |
| Prediction flow (m3/h) | 285.0736 | 315.222 | 337.4993 | 364.0412 |
| Test flow (m3/h) | 286 | 312 | 338 | 364 |
| Error of the measurement | -0.324％ | 1.033％ | -0.148％ | 0.011％ |
By comparison, the maximum error between the two is 1.131%, which proves that the invention is reliable.
The embodiment is a preferred implementation method of the invention, but the invention is not limited to the implementation method, and any obvious improvement, replacement or modification can be made by those skilled in the art without departing from the essence of the invention, and the invention belongs to the protection scope of the invention.
Claims (8)
1. A low specific speed centrifugal pump flow prediction method based on soft monitoring is characterized in that for a centrifugal pump with the specific speed below 120, when the performance is monitored, the flow value Q can be predicted more accurately only by monitoring the power value P of a motor1The clearance value between the centrifugal pump sealing ring and the impeller after the abrasion and the distance between the centrifugal pump sealing ring and the impeller without the abrasion are obtained through measurement or monitoringInitial clearance value between core pump sealing ring and impeller0And calculating to obtain the difference between the two, performing dimensionless transformation to obtain a dimensionless gap difference delta', and predicting to obtain a flow value Q by monitoring the obtained power value P of the motor in real time in actual operation1Simultaneously using the dimensionless gap difference delta' to the flow value Q1The correction is made, mainly determined by the following relation:
in the formula:
Q1is the flow value, m3/h；
Q0Rated flow of centrifugal pump, m3/h；
P' is a dimensionless power number;
K1the flow coefficient is in a value range of 0.5-1;
Δ' is the dimensionless gap difference;
K2the power coefficient is 1-3;
K3the value of the clearance coefficient is 0.01-0.05;
K4the value range of the index coefficient is 0.2-1.
2. The method for predicting the flow of a low specific speed centrifugal pump based on soft monitoring as claimed in claim 1, wherein the dimensionless power number P' is determined according to the measured motor power value P and the rated power P of the centrifugal pump0The calculation result is specifically as follows:
in the formula:
p is the actually monitored motor power value, W;
P0rated power, W.
3. According to claimThe method for predicting the flow rate of a centrifugal pump with low specific speed based on soft monitoring as claimed in claim 1, wherein the dimensionless clearance difference Δ' is determined according to the measured clearance value between the centrifugal pump seal ring and the impeller after the occurrence of wear and the initial clearance value between the centrifugal pump seal ring and the impeller without the occurrence of wear0The calculation result is specifically as follows:
in the formula:
Δ' is the dimensionless gap difference;
the value of the gap between the centrifugal pump sealing ring and the impeller after abrasion is mm;
0the initial clearance value between the centrifugal pump sealing ring and the impeller without abrasion is mm;
1the value is 1mm per unit gap.
4. The method for predicting the flow rate of a low specific speed centrifugal pump based on soft monitoring as claimed in claim 1, wherein the flow coefficient K is1Is 0.85.
5. The method for predicting low specific speed centrifugal pump flow based on soft monitoring as claimed in claim 1, wherein the power coefficient K is2Recommended value of (2.8).
6. The soft-monitoring-based low specific speed centrifugal pump flow prediction method according to claim 1, wherein the clearance coefficient K is3Is 0.0257.
7. The method for predicting low specific speed centrifugal pump flow based on soft monitoring as claimed in claim 1, wherein the index K is a coefficient4Is 0.65.
8. Low specific conversion based on soft monitoring according to claim 1The flow prediction method of the rapid centrifugal pump is characterized in that the flow coefficient K is1Power coefficient K2Coefficient of clearance K3And the coefficient K4The goodness of fit of the centrifugal pump flow curve prediction with the specific speed below 120 reaches more than 95%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910998034.7A CN110630530B (en) | 2019-10-21 | 2019-10-21 | Low-specific-speed centrifugal pump flow prediction method based on soft monitoring |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910998034.7A CN110630530B (en) | 2019-10-21 | 2019-10-21 | Low-specific-speed centrifugal pump flow prediction method based on soft monitoring |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110630530A CN110630530A (en) | 2019-12-31 |
| CN110630530B true CN110630530B (en) | 2020-10-02 |
Family
ID=68977024
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910998034.7A Active CN110630530B (en) | 2019-10-21 | 2019-10-21 | Low-specific-speed centrifugal pump flow prediction method based on soft monitoring |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110630530B (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6757665B1 (en) * | 1999-09-28 | 2004-06-29 | Rockwell Automation Technologies, Inc. | Detection of pump cavitation/blockage and seal failure via current signature analysis |
| US9678511B2 (en) * | 2012-04-12 | 2017-06-13 | Itt Manufacturing Enterprises Llc. | Method of determining pump flow in rotary positive displacement pumps |
| EP3464901B1 (en) * | 2016-06-07 | 2023-11-01 | Fluid Handling LLC. | Direct numeric 3d sensorless converter for pump flow and pressure |
| KR20180026054A (en) * | 2016-09-02 | 2018-03-12 | 주식회사 대영파워펌프 | Flow rate calculation method using different temperature at pump |
-
2019
- 2019-10-21 CN CN201910998034.7A patent/CN110630530B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110630530A (en) | 2019-12-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10670496B2 (en) | Methods and apparatus for estimating useful life of a seal | |
| Strub et al. | Influence of the Reynolds number on the performance of centrifugal compressors | |
| CN111537257B (en) | Method for online detection of abnormality of air cooler of hydraulic generator | |
| CN112031748B (en) | Oil pumping well abnormal condition diagnosis method based on indicator diagram characteristics | |
| CN114692309B (en) | Real-time calculation method for axial force of low-pressure turbine rotor of aviation turbofan engine | |
| US20130218484A1 (en) | System and method for monitoring rotating and reciprocating machinery | |
| CN110617228B (en) | Flow prediction method based on soft monitoring | |
| CN110630530B (en) | Low-specific-speed centrifugal pump flow prediction method based on soft monitoring | |
| CN117236069B (en) | Method for calculating stress intensity factor at crack free surface under arbitrary stress distribution | |
| CN109441563B (en) | Accurate monitoring system for flutter of last-stage blade of low-pressure cylinder cutting heat supply steam turbine | |
| CN110657106B (en) | Centrifugal pump lift prediction method | |
| CN112414911A (en) | Method for monitoring running state of gas turbine inlet air filtering system in real time | |
| CN110728067B (en) | Centrifugal pump power prediction method | |
| CN103309327A (en) | Monitoring device for detecting leak hydrogen in internal cooling water and evaluating influence on quality of internal cooling water | |
| CN110425153B (en) | Centrifugal pump lift prediction method | |
| CN112699503B (en) | Method for designing inverse problem of S2 of axial flow compressor based on dimensionless load control parameters | |
| CN110455460B (en) | Method for quickly checking leakage of cooler of air cooling system of gas turbine | |
| CN110750845B (en) | Method for improving sealing efficiency of disc cavity based on end wall rough area | |
| CN115906430A (en) | Axial flow compressor labyrinth leakage loss prediction method | |
| CN113868837A (en) | On-line monitoring method for concrete volute pump wall surface abrasion | |
| CN110441011B (en) | Quick leakage checking method for TCA cooler of gas turbine air cooling system | |
| CN208532914U (en) | A kind of the air compressor machine intermediate conduit cooler and linking pipeline coating of anticorrosion cavitation-preventive | |
| Zakharin et al. | Relative wearing resistance of vapor friction rotation vacuum pumps | |
| CN117435990B (en) | Ultrasonic rolling processing temperature detection and analysis method | |
| CN212005137U (en) | High-low pressure thin oil station |
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 |