阅读说明：本技术 一种在线监测密封环间隙的方法 (Method for monitoring clearance of sealing ring on line ) 是由 朱荣生 安策 付强 王秀礼 陈一鸣 龙云 于 2020-06-12 设计创作，主要内容包括：本发明提供了一种在线监测密封环间隙的方法,包括如下步骤：对未磨损的泵数据采集：在额定流量Q<Sub>0</Sub>的工况下,采集i组泵的进口压力P<Sub>in,i</Sub>和出口压力P<Sub>out,i</Sub>；根据进口压力P<Sub>in,i</Sub>和出口压力P<Sub>out,i</Sub>计算在额定流量Q<Sub>0</Sub>工况下泵的实际扬程H<Sub>0</Sub>；根据实际扬程H<Sub>0</Sub>计算出扬程系数K<Sub>h</Sub>；对磨损的泵数据采集：在随机流量Q<Sub>1</Sub>的工况下,第j采样时刻的进口压力P<Sub>in,j</Sub>和出口压力P<Sub>out,j</Sub>；根据进口压力P<Sub>in,j</Sub>和出口压力P<Sub>out,j</Sub>计算在随机流量Q<Sub>1</Sub>工况下泵的扬程H<Sub>1</Sub>；根据随机流量Q<Sub>1</Sub>和扬程H<Sub>1</Sub>预测叶轮与密封环之间的磨损间隙值δ。本发明可以快速地在线检测叶轮与密封环之间的间隙值。(The invention provides a method for monitoring a sealing ring gap on line, which comprises the following steps: data acquisition for unworn pumps: at rated flow rate Q 0 Under the working condition of (1), collecting the inlet pressure P of the i groups of pumps in，i And an outlet pressure P out，i (ii) a According to inlet pressure P in，i And an outlet pressure P out，i Calculated at rated flow rate Q 0 Actual pump head H of pump under working condition 0 (ii) a According to the actual lift H 0 Calculating the lift coefficient K h (ii) a Data acquisition for worn pumps: at random flow rate Q 1 Under the condition of (1), the inlet pressure P at the j-th sampling moment in，j And an outlet pressure P out，j (ii) a According to inlet pressure P in，j And an outlet pressure P out，j Calculated at random flow rate Q 1 Pump head H under working condition 1 (ii) a According to random flow Q 1 Lift H 1 And predicting the abrasion clearance value between the impeller and the sealing ring. The invention can quickly detect the clearance value between the impeller and the sealing ring on line.)

1. A method for monitoring the clearance of a sealing ring on line is characterized by comprising the following steps:

data acquisition for unworn pumps: at rated flow rate Q₀Under the working condition of (1), collecting the inlet pressure P of the i groups of pumps_in，iAnd an outlet pressure P_out，i；

According to inlet pressure P_in，iAnd an outlet pressure P_out，iCalculated at rated flow rate Q₀Actual pump head H of pump under working condition₀；

According to the actual lift H₀Calculating the lift coefficient K_h；

Data acquisition for worn pumps: at the measured flow rate Q₁Sampling the inlet pressure P at the j-th time_in，jAnd an outlet pressure P_out，j；

According to inlet pressure P_in，jAnd an outlet pressure P_out，jCalculating the measured flow Q₁Pump head H under working condition₁；

According to the measured flow Q₁Lift H₁Lift coefficient K_hAnd rated flow rate Q₀Predictive impeller(1) The abrasion clearance value between the sealing ring (3) and the sealing ring is as follows:

K_h＝H′₀+K_q

in the formula:

the abrasion clearance value between the impeller (1) and the sealing ring (3) is mm;

₀the clearance value between the impeller (1) and the sealing ring (3) is mm when the impeller is not worn;

Kthe value of the clearance coefficient is 0.3-1;

is unit gap, mm;

Q₁for measured flow, m³/h；

Q₀For rated flow, m³/h；

K_hIs the lift coefficient;

K_qthe flow coefficient is in a value range of 7-9;

h is unit lift, m;

H₀m is the actual lift;

H′₀a dimensionless rated lift;

H′₁for measured flow Q₁The dimensionless lift of the pump under the working condition;

Q₁₁for measured flow Q₁To rated flow Q₀The ratio of (a) to (b).

2. The method of on-line monitoring of seal ring clearance of claim 1, wherein inlet pressure P is based_in，iAnd inlet pressure P_out，iCalculated at rated flow rate Q₀Actual pump head H of pump under working condition₀The method specifically comprises the following steps:

in the formula:

H_0，iat rated flow rate Q for the i-th group of pumps₀Actual lift under operating conditions, m;

P_in，iat rated flow rate Q for the i-th group of pumps₀Inlet pressure, Pa, under operating conditions;

P_out，iat rated flow rate Q for the i-th group of pumps₀Outlet pressure, Pa, under operating conditions;

v_1，iat rated flow rate Q₀Inlet speed under working conditions, m/s;

v_2，iat rated flow rate Q₀Outlet speed under working conditions, m/s;

H₀m is the actual lift;

and n is the total number of collected data.

3. The method of on-line monitoring of seal ring clearance of claim 1, wherein inlet pressure P is based_in，jAnd an outlet pressure P_out，jCalculating the measured flow Q₁Pump head H under working condition₁The method specifically comprises the following steps:

in the formula:

H_1，jto measure the flow rate Q₁The lift at the jth sampling moment m under the working condition of (1);

P_in，jto measure the flow rate Q₁The inlet pressure at the jth sampling moment, Pa;

P_out，jto measure the flow rate Q₁The outlet pressure at the jth sampling moment, Pa;

v_1，jto measure the flow rate Q₁Inlet speed under working conditions, m/s;

v_2，jto measure the flow rate Q₁Outlet speed under working conditions, m/s;

H₁to measure the flow rate Q₁M under the working condition of (1);

m is the total sampling instant.

4. The method for on-line monitoring of the clearance of the sealing ring as claimed in claim 1, wherein the flow coefficient K is determined when the specific rotation speed of the pump is 120-350_qIs 7.9.

5. The method for on-line monitoring of the clearance of the sealing ring according to claim 1, wherein the clearance coefficient K is determined when the specific rotating speed of the pump is 120-350Is 0.58.

6. The method for on-line monitoring of the clearance of the sealing ring according to claim 1, wherein the measured flow rate Q is measured when the specific rotating speed of the pump is in the range of 120-350₁To rated flow Q₀Ratio Q of₁₁And when the predicted gap value is more than or equal to 1.4, the error of the predicted gap value is less than 3 percent.

Technical Field

The invention relates to the field of pump detection, in particular to a method for monitoring a sealing ring gap on line.

Background

With the continuous development of the modern pump industry, the research of the basic theory of the water pump, the improvement of the performance of the water pump and the design of the water pump scheme are continuously perfected, and the corresponding intelligent monitoring technical level of the water pump also needs to be continuously improved to meet the requirements of the modern pump industry. The characteristics of the water pump are mainly described through technical indexes such as flow, lift and the like. As a plurality of pump station monitoring systems applied in China adopt the traditional semi-automatic mode, the system has the defects of low measurement precision, poor real-time performance and poor reliability. On the other hand, when the pump is operated for a long time, a failure such as abrasion of a seal ring occurs inside the pump, which changes a flow state of fluid inside the centrifugal pump and 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. These changes will ultimately have a large impact on the external characteristic curve of the centrifugal pump, so that the performance curve of the original device can no longer predict the performance of the existing centrifugal pump. Therefore, in order to monitor and predict the operation of the pump in real time, the clearance of the sealing ring inside the pump needs to be monitored online so as to correct the device curve of the pump in time.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for monitoring the clearance of a sealing ring on line, which can quickly detect the abrasion clearance value between an impeller and the sealing ring.

The present invention achieves the above-described object by the following technical means.

A method for monitoring the clearance of a sealing ring on line comprises the following steps:

data acquisition for unworn pumps: at rated flow rate Q₀Under the working condition of (1), collecting the inlet pressure P of the i groups of pumps_in，iAnd an outlet pressure P_out，i；

According to inlet pressure P_in，iAnd an outlet pressure P_out，iCalculated at rated flow rate Q₀Actual pump head H of pump under working condition₀；

According to the actual lift H₀Calculating the lift coefficient K_h；

Data acquisition for worn pumps: at the measured flow rate Q₁Sampling the inlet pressure P at the j-th time_in，jAnd an outlet pressure P_out，j；

According to inlet pressure P_in，jAnd an outlet pressure P_out，jCalculating the measured flow Q₁Pump head H under working condition₁；

According to the measured flow Q₁Lift H₁Lift coefficient K_hAnd rated flow rate Q₀Predicting a wear clearance value between the impeller (1) and the sealing ring (3), specifically:

K_h＝H'₀+K_q

in the formula:

the abrasion clearance value between the impeller (1) and the sealing ring (3) is mm;

₀in order that the impeller (1) is not wornThe gap value between the sealing rings (3) is mm;

Kthe value of the clearance coefficient is 0.3-1;

is unit gap, mm, with the value of 1 mm;

Q₁for measured flow, m³/h；

Q₀For rated flow, m³/h；

K_hIs the lift coefficient;

K_qthe flow coefficient is in a value range of 7-9;

h is unit lift, m;

H₀m is the actual lift;

H'₀a dimensionless rated lift;

H₁is measured flow rate Q₁The dimensionless lift of the pump under the working condition;

Q₁₁for measured flow Q₁To rated flow Q₀The ratio of (a) to (b).

Further, according to the inlet pressure P_in，iAnd inlet pressure P_out，iCalculated at rated flow rate Q₀Actual pump head H of pump under working condition₀The method specifically comprises the following steps:

in the formula:

H_0，iat rated flow rate Q for the i-th group of pumps₀Actual lift under operating conditions, m;

P_in，iat rated flow rate Q for the i-th group of pumps₀Inlet pressure, Pa, under operating conditions;

P_out，iat rated flow rate Q for the i-th group of pumps₀Outlet pressure, Pa, under operating conditions;

v_1，iat rated flow rate Q₀Inlet velocity under operating conditions，m/s；

v_2，iAt rated flow rate Q₀Outlet speed under working conditions, m/s;

H₀m is the actual lift;

and n is the total number of collected data.

Further, according to the inlet pressure P_in，jAnd an outlet pressure P_out，jCalculating the measured flow Q₁Pump head H under working condition₁The method specifically comprises the following steps:

in the formula:

H_1，jto measure the flow rate Q₁The lift at the jth sampling moment m under the working condition of (1);

P_in，jto measure the flow rate Q₁The inlet pressure at the jth sampling moment, Pa;

P_out，jto measure the flow rate Q₁The outlet pressure at the jth sampling moment, Pa;

v_1，jto measure the flow rate Q₁Inlet speed under working conditions, m/s;

v_2，jto measure the flow rate Q₁Outlet speed under working conditions, m/s;

H₁to measure the flow rate Q₁M under the working condition of (1);

m is the total sampling instant.

Further, when the specific rotating speed of the pump is within the range of 120-350, the flow coefficient K is_qIs 7.9.

Further, when the specific rotating speed of the pump is within the range of 120-350, the clearance coefficient K isIs 0.58.

Further, when the specific rotating speed of the pump is within the range of 120-350, the actual measurement is carried outFlow rate Q₁To rated flow Q₀Ratio Q of₁₁And when the predicted gap value is more than or equal to 1.4, the error of the predicted gap value is less than 3 percent.

The invention has the beneficial effects that:

1. the method for monitoring the sealing ring clearance on line can monitor the sealing ring clearance of the pump in the running process of the pump.

2. According to the method for monitoring the clearance of the sealing ring on line, when the specific rotating speed of the centrifugal pump is 120-350, the flow Q is selected₁To rated flow Q₀Ratio Q of₁₁The method predicts the sealing ring clearance of the centrifugal pump more than or equal to 1.4, and the error can be kept within 3 percent.

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.

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, the method for measuring the abrasion loss of the sealing clearance of the pump comprises the following steps:

data acquisition for unworn pumps: at rated flow rate Q₀Under the working condition of (1), collecting the inlet pressure P of the i groups of pumps_in，iAnd an outlet pressure P_out，i；

According to inlet pressure P_in，iAnd an outlet pressure P_out，iCalculated at rated flow rate Q₀Actual pump head H of pump under working condition₀；

According to the actual lift H₀Calculating the lift coefficient K_h；

Data acquisition for worn pumps: at the measured flow rate Q₁Sampling the inlet pressure P at the j-th time_in，jAnd an outlet pressure P_out，j；

According to inlet pressure P_in，jAnd an outlet pressure P_out，jCalculating the measured flow Q₁Pump head H under working condition₁；

According to the measured flow Q₁Lift H₁The value of the wear clearance between the impeller 1 and the seal ring 3 is predicted.

The following are specific examples: in this embodiment, a specific rotation speed of 185.5 and a rated flow rate of 250m are selected³H, as shown in FIG. 2, a centrifugal pump in which the clearance between the impeller 1 and the seal ring 3 is 0.45mm when no wear occurs was tested:

data acquisition for unworn pumps: at rated flow rate Q₀Under the working condition of (1), collecting the inlet pressure P of the i groups of pumps_in，iAnd an outlet pressure P_out，i；

According to inlet pressure P_in，iAnd an outlet pressure P_out，iCalculated at rated flow rate Q₀Actual pump head H of pump under working condition₀The method specifically comprises the following steps:

in the formula:

H_0，iat rated flow rate Q for the i-th group of pumps₀Actual lift under operating conditions, m;

P_in，iat rated flow rate Q for the i-th group of pumps₀Inlet pressure, Pa, under operating conditions;

P_out，iat rated flow rate Q for the i-th group of pumps₀Outlet pressure, Pa, under operating conditions;

v_1，iat rated flow rate Q₀Inlet speed under working conditions, m/s; can pass through the inlet section and the rated flow Q₀Calculating to obtain;

v_2，iat rated flow rate Q₀Outlet speed under working conditions, m/s; can pass through the outlet section and the rated flow Q₀Calculating to obtain;

H₀m is the actual lift;

and n is the total number of collected data.