CN110425153B - Centrifugal pump lift prediction method - Google Patents

Centrifugal pump lift prediction method Download PDF

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CN110425153B
CN110425153B CN201910623409.1A CN201910623409A CN110425153B CN 110425153 B CN110425153 B CN 110425153B CN 201910623409 A CN201910623409 A CN 201910623409A CN 110425153 B CN110425153 B CN 110425153B
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centrifugal pump
value
head
sealing ring
clearance
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CN110425153A (en
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朱荣生
安策
王秀礼
陈一鸣
林彬
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Jiangsu University
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    • 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

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  • General Engineering & Computer Science (AREA)
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Abstract

The invention provides a centrifugal pump lifterThe program prediction method comprises the following steps: determining the initial clearance value between the impeller and the sealing ring of a centrifugal pump without wear0(ii) a Determining the gap value between the impeller and the sealing ring of the worn centrifugal pump; according to the clearance difference delta and the actual measurement flow Q of the worn centrifugal pump1The head of the centrifugal pump, which is worn, is corrected. The invention can predict the lift of the centrifugal pump after abrasion by measuring the abrasion clearance value between the impeller and the sealing ring.

Description

Centrifugal pump lift prediction method
Technical Field
The invention relates to the field of performance prediction of pumps, in particular to a method for predicting the lift of a centrifugal pump.
Background
As a rotary machine widely applied to various fields of national economy such as power industry, petrochemical industry, field irrigation, hydraulic engineering, ship industry and the like, research on a sealing device of the centrifugal pump is a hot spot and a difficult point of domestic and foreign research. The matching of the impeller mouth ring and the sealing surface is a common sealing device, and the main function of the sealing device is to limit the leakage of high-pressure liquid in the impeller working chamber to a low-pressure area at the inlet of the impeller or the center of the impeller. The presence of the orifice ring not only changes the flow conditions of the fluid inside the centrifugal pump, but also causes a loss of volume inside the pump. In addition, a disturbance effect exists between the leakage flow at the impeller opening ring and the main flow at the impeller inlet, so that the flow state at the impeller inlet is more disordered, and the whole performance of the centrifugal pump is influenced. 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, and the performance of the conventional centrifugal pump can not be predicted by the performance curve of the conventional device.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a centrifugal pump lift prediction method, which can predict the centrifugal pump lift after abrasion by measuring the abrasion clearance value between an impeller and a sealing ring.
The present invention achieves the above-described object by the following technical means.
A method for predicting the lift of a centrifugal pump comprises the following steps:
determining the initial clearance value between the impeller and the sealing ring of a centrifugal pump without wear0；
Determining the gap value between the impeller and the sealing ring of the worn centrifugal pump;
according to the clearance difference delta and the actual measurement flow Q of the worn centrifugal pump1The head of the centrifugal pump, which is worn, is corrected.
Further, the initial clearance value between the impeller and the seal ring of the centrifugal pump without wear is measured by direct measurement or sensor measurement0(ii) a The gap value between the impeller and the sealing ring of the centrifugal pump with wear is measured by direct measurement or by a sensor.
Further, according to the gap difference value delta and the actually measured flow Q of the worn centrifugal pump1Correcting the head of the centrifugal pump with wear, and specifically determining the head of the centrifugal pump with wear by the following relational expression:
Figure BDA0002126266000000011
in the formula:
h is measured flow Q of the centrifugal pump after abrasion1Corrected lift, m, under operating conditions;
k is a lift coefficient, and the value range of K is 1.2-2;
Kathe value of the clearance coefficient is 0.02-0.05;
and delta' is a dimensionless gap difference value, and specifically comprises the following steps:
Figure BDA0002126266000000021
in the formula:
the gap value of the sealing ring of the centrifugal pump after abrasion is mm;
0the initial clearance value of the sealing ring of the centrifugal pump without abrasion is mm;
1is a unit gap, and has a value of 1 mm;
Q11for measured flow Q1Normalized value ofThe method specifically comprises the following steps:
Figure BDA0002126266000000022
in the formula:
Q1m is measured flow of the centrifugal pump after abrasion3/h；
Q0For rated flow, m3/h；
KbThe flow index coefficient is in a value range of 1-4;
H0for centrifugal pumps with no wear at rated flow Q0Lift under operating conditions, m.
Further, when the specific speed of the centrifugal pump is within the range of 120-350, the recommended value of the head coefficient K is 1.53.
Further, when the specific rotating speed of the centrifugal pump is within the range of 120-350, the clearance coefficient K isaIs 0.035.
Further, when the specific rotating speed of the centrifugal pump is in the range of 120-350, the flow index coefficient KbIs 2.64.
The invention has the beneficial effects that:
1. the method for predicting the lift of the centrifugal pump can predict the lift of the centrifugal pump with the sealing abrasion through a correction formula.
2. The method for predicting the lift of the centrifugal pump needs few parameters and can be realized by only measuring the worn sealing clearance of the centrifugal pump.
3. According to the method for predicting the lift of the centrifugal pump, when the specific rotating speed of the centrifugal pump is within the range of 120-350, the accuracy of predicting and fitting the lift curve of the centrifugal pump is over 95%.
Drawings
FIG. 1 is a flow chart of a method of pump seal clearance wear amount in accordance with 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
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 and 2, the method for predicting the head of a centrifugal pump according to the present invention includes the following steps:
determination of the initial gap value between the impeller 1 and the sealing ring 3 of a centrifugal pump without wear0(ii) a The initial clearance value between the impeller 1 and the sealing ring 3 of a centrifugal pump without wear is measured by direct measurement or by a sensor0；
Determining the gap value between the impeller 1 and the sealing ring 3 of the worn centrifugal pump; the gap value between the impeller 1 and the sealing ring 3 of the centrifugal pump with abrasion is measured by direct measurement or a sensor;
according to the clearance difference delta and the actual measurement flow Q of the worn centrifugal pump1Correcting the head of the centrifugal pump with wear, and specifically determining the head of the centrifugal pump with wear by the following relational expression:
Figure BDA0002126266000000031
in the formula:
h is measured flow Q of the centrifugal pump after abrasion1Corrected lift, m, under operating conditions;
k is a lift coefficient, and the value range of K is 1.2-2;
Kathe value of the clearance coefficient is 0.02-0.05;
and delta' is a dimensionless gap difference value, and specifically comprises the following steps:
Figure BDA0002126266000000032
in the formula:
the gap value of the sealing ring of the centrifugal pump after abrasion is mm;
0for the sealing ring of centrifugal pump without abrasionInitial gap value, mm;
1is a unit gap, and has a value of 1 mm;
Q11for measured flow Q1Specifically, the normalized values of (a):
Figure BDA0002126266000000033
in the formula:
Q1m is measured flow of the centrifugal pump after abrasion3/h；
Q0For rated flow, m3/h；
KbThe flow index coefficient is in a value range of 1-4;
H0for centrifugal pumps with no wear at rated flow Q0Lift under operating conditions, m.
When the specific rotating speed of the centrifugal pump is within the range of 120-350, the recommended value of the head coefficient K is 1.53, and the clearance coefficient K isaIs 0.035, the flow index coefficient KbThe recommended value of (2.64) and the head curve prediction fitting accuracy of the centrifugal pump is more than 95%.
The following is verified by the specific examples:
selecting a centrifugal pump with the specific speed of 185.5 as a test object, and when the centrifugal pump is not worn, performing the test at the rated flow Q0Is 250m3Head H under/H working condition0Is 15 m. The initial clearance value between the impeller 1 and the sealing ring 3 of a centrifugal pump without wear is measured by direct measurement or by a sensor00.45 mm; the clearance between the impeller 1 and the seal ring 3 is machined to 0.65mm by turning the impeller 1. The dimensionless clearance difference delta' is obtained according to the measured clearance value of the centrifugal pump sealing ring after abrasion and the initial clearance value of the centrifugal pump sealing ring without abrasion0The calculation result is specifically as follows:
Figure BDA0002126266000000041
in the formula:
the gap value of the sealing ring of the centrifugal pump after abrasion is mm;
0the initial clearance value of the sealing ring of the centrifugal pump without abrasion is mm;
1is a unit gap, and has a value of 1 mm;
according to the clearance difference delta and the actual measurement flow Q of the worn centrifugal pump1Correcting the head of the centrifugal pump with wear, and specifically determining the head of the centrifugal pump with wear by the following relational expression:
Figure BDA0002126266000000042
in the formula:
h is measured flow Q of the centrifugal pump after abrasion1Is 275m3The corrected lift m under the working condition of/h;
k is a lift coefficient, and the value range of K is 1.53;
Kathe value range of the clearance coefficient is 0.035;
Δ' is 0.2;
Q11for measured flow Q1Is 275m3Normalized values for/h, in particular:
Figure BDA0002126266000000043
in the formula:
Q1m is measured flow of the centrifugal pump after abrasion3/h；
Q0For rated flow, m3/h；
KbThe flow index coefficient is in the value range of 2.64;
H0is 15 m.
Figure BDA0002126266000000051
Q can be calculated by the same method11The corrected head H corresponding to 0.6 to 1.2 was compared with the test values, as shown in table 1 and fig. 3:
TABLE 1 comparison of calculated head values with test head values
Q11 0.6 0.8 0.9 1 1.1 1.2
Calculating the lift value 18.15 16.53 15.72 14.90 14.07 13.24
Test head value 17.69 16.45 15.66 14.92 13.81 12.93
Error of the measurement -2.55％ -0.49％ -0.35％ 0.17％ -1.85％ -2.34％
The error between the calculated lift value and the test lift value is 2.55% at most by comparison, which proves that the invention is reliable.
By selecting a lift coefficient K and a clearance coefficient KaSum flow index KbTo verify that the clearance coefficient K is given when the recommended value of the head coefficient K is 1.53aIs 0.035, the flow index coefficient KbThe recommended value is 2.64, the head curve prediction fitting accuracy of the centrifugal pump reaches more than 95 percent:
for example 1, the lift coefficient K is 1.2 and the clearance coefficient K is selecteda0.02 and a flow index KbAs shown in table 2, the following were obtained:
table 2 comparison of calculated head values with test head values for example 1
Q11 0.6 0.8 0.9 1 1.1 1.2
Calculating the lift value 16.16 15.55 15.25 14.94 14.63 14.33
Test head value 17.69 16.45 15.66 14.92 13.81 12.93
Error of the measurement -8.63％ -5.46％ -2.64％ 0.13％ 5.97％ 10.81％
For example 2, the head coefficient K is 2 and the clearance coefficient K is selecteda0.05 and a flow index KbAs shown in table 3, the following were obtained:
table 3 comparison of calculated head values with test head values for example 2
Figure BDA0002126266000000052
Figure BDA0002126266000000061
As can be seen from tables 2 and 3, the lift coefficient K is between 1.2 and 2, and the clearance coefficient K isaThe flow index coefficient K is between 0.02 and 0.05bThe maximum error between the calculated lift value and the test lift value is 18.60% between 1 and 4; as shown in table 1, when the recommended value of the head coefficient K is 1.53, the clearance coefficient K isaIs 0.035, the flow index coefficient KbThe recommended value of (2.64) and the maximum error between the calculated head value and the test head value is 2.55%. Namely, the gap coefficient K is verified when the recommended value of the lift coefficient K is 1.53aIs 0.035, the flow index coefficient KbThe recommended value of (2.64) and the head curve prediction fitting accuracy of the centrifugal pump is more than 95%.
The present invention is not limited to the above-described embodiments, and any obvious improvements, substitutions or modifications can be made by those skilled in the art without departing from the spirit of the present invention.

Claims (5)

1. A method for predicting the lift of a centrifugal pump is characterized by comprising the following steps:
determining the initial clearance value between the impeller (1) and the sealing ring (3) of a centrifugal pump without wear0；
Determining the gap value between the impeller (1) and the sealing ring (3) of the worn centrifugal pump;
according to the clearance difference delta and the actual measurement flow Q of the worn centrifugal pump1Correcting the head of the centrifugal pump with wear, and specifically determining the head of the centrifugal pump with wear by the following relational expression:
Figure FDA0002404731770000011
in the formula:
h is measured flow Q of the centrifugal pump after abrasion1Corrected lift, m, under operating conditions;
k is a lift coefficient, and the value range of K is 1.2-2;
Kathe value of the clearance coefficient is 0.02-0.05;
and delta' is a dimensionless gap difference value, and specifically comprises the following steps:
Figure FDA0002404731770000012
in the formula:
the gap value of the sealing ring of the centrifugal pump after abrasion is mm;
0the initial clearance value of the sealing ring of the centrifugal pump without abrasion is mm;
1is a unit gap, and has a value of 1 mm;
Q11for measured flow Q1Specifically, the normalized values of (a):
Figure FDA0002404731770000013
in the formula:
Q1m is measured flow of the centrifugal pump after abrasion3/h；
Q0For rated flow, m3/h；
KbThe flow index coefficient is in a value range of 1-4;
H0for centrifugal pumps with no wear at rated flow Q0Lift under operating conditions, m.
2. Method for predicting the head of a centrifugal pump according to claim 1, characterized in that the initial clearance value between the impeller (1) and the sealing ring (3) of a centrifugal pump without wear is measured by direct measurement or by sensors0(ii) a The clearance value of the centrifugal pump with abrasion between the impeller (1) and the sealing ring (3) is measured through direct measurement or a sensor.
3. The method for predicting the head of a centrifugal pump according to claim 1, wherein the recommended value of the head coefficient K is 1.53 when the specific rotation speed of the centrifugal pump is in the range of 120 to 350.
4. The method for predicting the head of a centrifugal pump according to claim 1, wherein the clearance coefficient K is set when the specific rotation speed of the centrifugal pump is in the range of 120 to 350aIs 0.035.
5. The method for predicting the head of a centrifugal pump according to claim 1, wherein the flow index K is determined when the specific rotation speed of the centrifugal pump is in the range of 120 to 350bIs 2.64.
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CN110439825A (en) * 2019-07-11 2019-11-12 江苏大学 A method of on-line monitoring sealing ring gap

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5924851A (en) * 1995-12-08 1999-07-20 Aisan Kogyo Kabushiki Kaisha Magnetically coupled pump having a back-up radical sliding surface on the shaft
CN101813101A (en) * 2010-03-19 2010-08-25 江苏大学 Anti-abrasion device of sealing opening ring of solid-liquid two-phase flow centrifugal pump
CN105114334A (en) * 2015-07-27 2015-12-02 北京化工大学 Method for monitoring abrasion loss of impeller wear ring of multi-stage centrifugal pump based on computational fluid dynamics theory
CN106050687A (en) * 2016-08-09 2016-10-26 万毅 Abrasion characteristic analysis and optimization method for impeller type water pump
CN207905866U (en) * 2018-02-07 2018-09-25 浙江核芯泵业有限公司 A kind of impeller ring that abrasion resistant effect is good

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5924851A (en) * 1995-12-08 1999-07-20 Aisan Kogyo Kabushiki Kaisha Magnetically coupled pump having a back-up radical sliding surface on the shaft
CN101813101A (en) * 2010-03-19 2010-08-25 江苏大学 Anti-abrasion device of sealing opening ring of solid-liquid two-phase flow centrifugal pump
CN105114334A (en) * 2015-07-27 2015-12-02 北京化工大学 Method for monitoring abrasion loss of impeller wear ring of multi-stage centrifugal pump based on computational fluid dynamics theory
CN106050687A (en) * 2016-08-09 2016-10-26 万毅 Abrasion characteristic analysis and optimization method for impeller type water pump
CN207905866U (en) * 2018-02-07 2018-09-25 浙江核芯泵业有限公司 A kind of impeller ring that abrasion resistant effect is good

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
叶轮口环间隙对井用潜水泵性能的影响;施卫东等;《排灌机械工程学报》;20130831;第31卷(第8期);第651-656页 *

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