Centrifugal Pump Performance Test

离心泵的性能测试是通过泵制造商的组装完成后进行,以证明在泵所需的规格如在泵数据表和其他购买文件表示。

The performance test is conducted after completion ofcasing inspection,casing hydrostatic test,叶轮, and rotor dynamic balancing. TheNPSH test,mechanical running test, and final inspection are done after performance test. Thevibration testing性能试验和机械运行测试期间被执行。您还可以查看一般betway GD真人centrifugal pump inspection and test procedure.

让通过一个例子来解释的性能测试。你参加到泵制造商店见证了离心泵的性能测试,是保持点上泵ITP. You review the pump approved datasheet and find following information:

Rate flow = 238.5 m³/h (1050.08 Gal/Min)

Rated Differential Head = 2690.28 m (8826.37 feet)

额定功率= 2985千瓦(4003马力)

Rated Efficiency = 68 %

Upon completion of the centrifugal pump performance test, the pump manufacturer provides you following performance curve. You need to match this curve with datasheet specification to make sure the pump passed the performance test.

让我们开始与压头 - 能力曲线,我们得出在238.5一个verticle线(水平轴),并且它将越过压头 - 能力曲线,然后我们得出从交叉点的水平线,并且它在2640越过垂直轴所以在238.5立方米/小时测量的头部是2640米。

什么预期在数据表中的值?这是2690.28米但测试结果却2640米。

What is the test result ( the head almost is 50.28 meters less than required value)? The pump outperforming or underperforming?

The API 610 at table 18 says the head can be +/- 3% of the rated value. The 3 % of the rated value (2690.28 x 3%) would be 80.7 which is greater than 50.28, the pump underperforming but the test result is acceptable.

Let's assess the power consumption; we repeat the same process but this time with the power curve. The curve indicates the consumed power at 238.5 m³/h is 2600KW (power consumption was provided at the left side of the vertical axis). Compare 2600 KW with datasheet value which is 2985 KW.

Obviously, the pump outperforming since consumes less power. However, API 610 acceptance range is 4% it means the pump test result would be satisfactory even if consumes more than 4 % from what indicated in the datasheet.

我们还需要检查效率。最低efficiency in the approved datasheet is 68 %. Check the efficiency curve, the efficiency amount at the 238.5 m³/h is 70%. So the pump is outperforming and gives higher efficiency than what required in the datasheet.

So the result of the centrifugal pump performance test for the differential head, power consumption, and efficiency is satisfactory.

The head value also shall be checked in shut off point but since this pump is high energy pump, the centrifugal pump performance test at the shut-off point (no flow at discharge valve) is not a requirement based on API 610.

The above example was a simplified example. The pump manufacturers usually provide a tabulated format to make it easy for review.

制造商还可以模拟测试结果,以实际现场情况。该泵可能设计用于原油,但在店铺将被水进行测试。在这种情况下,所达到的值将通过工程计算被转换成场条件。

Subsequently, you need to check轴承箱和轴振动FFT频谱(曲线)at each data point from minimum to maximum flow to ensure the vibration values are within acceptance range.

The泵汽蚀余量测试(净正吸入热试验)report also shall be verified against approved datasheet values.

The泵的机械运转试验is performed after successful completion of performance and NPSH test.

现在,让我们加深由流量,扬程,功率和效率的理解离心泵性能测试。

What is the Flowrate and Head in Centrifugal Pump Performance Test?

Volume flow rate (Q), also referred to as capacity, is the volume of liquid that travels through the pump in a given time (measured in gallons per minute or GPM).

It defines the rate at which a pump can push fluid through the system. Flowrate is the first parameter specified by the process designer, who determines the pump requirement on the flowrate that the process needs to function.

这种“额定”流速在体积方面正常表达,并且它是由符号Q表示,其中的立方米/秒或GPM单元。

The static head of a pump is the maximum height (pressure) it can deliver. The capability of the pump at a certain RPM can be obtained from its Q-H curve.

The pump manufacturers are interested in providing pump performance curve in a way that does not depend on to the pumped fluid physical properties.

That is why they are using head instead of pressure. The following formula converts pressure to the head; H(meter) = 10.2 P/SG or H(feet)= 2.3P/SG

Once the rated flowrate has been determined, the designer subsequently specifies the total head (H) needed at this flowrate.

This is expressed in meter or feet and represents the usable mechanical work transmitted to the fluid by the pump. Together q and H define the duty point.

The q/H Curve Test;

The test is carried out at a nominally constant shaft speed, and the head (H) decreases as flowrate (q) increases, giving a negative slope to the curve. (See above H-Q curve)

Look at the following sketch; this illustrates a simple H-Q curve loop. The test engineer changes the flowrate through discharge control valve and takes measurement of different variables and calculates the corresponding head.

The first set of measurements is taken at duty point (100 percent q). The valve is opened to give a flowrate greater than the duty flow (normally 120 or 130 percent q), and further readings are taken.

The valve is then closed in a series of steps, progressively decreasing the flow (note that we are moving from right to left on the Q-H curve). With some pumps, the final reading can be taken with the valve closed, i.e. the q = 0 or shut-off condition.

Once the test points are obtained, you can now check against the acceptance criteria requirements

离心泵性能测试功耗

的功率消耗是在不同流率同样地,测定,并且电源流速曲线作图。甲瓦特计被连接到马达的电源输入,通过以不同的流率被计算在电动机效率的电机输出功率乘以瓦特计量。通过这些相应的读数,电源流量曲线绘制。

The Efficiency-Flowrate Curve at Centrifugal Pump Performance Test

The efficiency-flowrate (ƞ-Q) curve can be plotted based on measured values from combination of H-q curve and P-q curve and this formula ƞ=(P out of Pump)/(P input of Pump)=ρgHQ/(P input of pump) (ρ is density, g is gravitational acceleration, H is Head and Q is Flowrate)

Pump efficiency (ƞ percent): the efficiency is the ratio of transferred mechanical work of the fluid to consumed power (P) in watts by the pump.

The efficiency test; the efficiency is checked using the same set of test measurements as the q/H test. Pump efficiency is plotted against q in above figure.

You may also reviewthird party inspection for centrifugal pumpand泵的检查和测试计划文章作为补充信息。

此内容为您提供了在制造车间样本离心泵性能测试程序。这个过程非常简单,笼统。betway GD真人

Centrifugal Pump Performance Test Procedure

1.Scope

This description of procedure defines the conditions for the hydraulic testing of centrifugal pumps according to API Standard 610.

Scope of test, type of test, test class and guarantee values are defined by standardized test plans agreed between pump manufacturer and pump purchaser.

2.Objective

Objective of the tests is the continuous control of performance data as process control, keeping the guarantees given according to the supply agreement, testing of relevant pump functions.

Preparation of test reports and test curves according to the supply agreement as integral part of the test documentation.

3.标准和其他法规适用

  • API 610
  • Manufacture Standard

4. Centrifugal Pump PerformanceTest procedure

4.1Testing Personnel

For the handling of the test beds, only trained personnel is employed. The setting of test data is done semi-automatically and requires appropriate test experience and accuracy.

4.2 Place and Time Of Testing

该测试是在制造商的测试间完成。用ρ= 1千克/立方分米的密度只有纯净冷水被用作测试培养基。

Pump block units are normally tested with installed motor. In case of acceptance by the customer, the readiness for the acceptance inspection is notified in time to the sales departments.

4.3 Pump Test Beds

无论下面的测试床是可用的,将被用作每个订单规格

  • Closed System
  • Open System, Alternatively With Booster Pump

4.4 Measurement And Testing Methods

The measurement and evaluation of hydraulic characteristic values is made by means of an electronic data logger.

所有相关的数据都记录在现场通过电子测量设备的手段和在线电子数据在考点处理呈现。测量结束后,数据被传输到测试托架监督中央计算机。除非另有规定,验收性能测试在ACC进行。与API 610,第7.3.3。

4.4.1 Measurements Of Flow Rate Q

The flow rate is measured using magnetic inductive flow measuring devices having the specified stabilization distances in front and after the measuring unit. The setting of the capacity is effected by control valves in the discharge pipe.

头H的4.4.2测量(HD - HS)

Pressure measurements are made using calibrated measuring transmitters for the measuring point Hs (measuring range -10 up to +40 m wc), for measuring point Hd (measuring range -10 up to +180 m, 150 up to 630 m wc). For visual comparison, calibrated spring manometers are connected in parallel for analogous display.

速度水头的4.4.3测定

The velocity head is calculated using the flow rate and the flow cross-section at the pressure measuring point.

LaTeX4Web 1.3 OUTPUT Δ v2/2g=(v2d-V2或多个)/ 2G

Vd = velocity discharge side

VS =速度吸入侧

Δ = velocity difference between suction and discharge side

功率输入的测量4.4.4(P)

The power input of the pump is determined either electrically by means of a calibrated test motor or by directly measuring the speed of rotation using a torque measuring hub.

电测量根据两瓦特计方法,用于确定电机的功率输入作出。电机功率输出使用存储在测试系统中的电动机的效率曲线进行计算。

For comparison of guaranteed data, the test system converts the pump power input required for the customer conditions, i.e to the standardized speed and the density of the acually pumped中。

4.4.5 Measurement Of Speed (n)

The speed measurment occurs by means of a light barrier or photo sensor. For canned motor pumps, not accessible from the outside, the speed is determined by means of a bend coil or by frequency analysis.

泵效率研究的4.4.6测定(η)

The pump efficiency is determined for each measuring point immediately following themeasurement by the testing system.

According to the following formula:

LaTeX4Web 1.3 OUTPUT η=(Q×H×ρ×100)/(367×P)

Flow rate Q [m³/h]

Head H [m]

Density ρ [kg/dm3] of pumped medium

Power P [kW]

4.4.7 Measurement of the NPSH value of the pump (NPSH required)

Normally in the closed circuit, the measurement of the NPSH value is made by reducing the system pressure by means of a vacuum pump. Measurement also is done by throttling using a throttle valve in the suction line, as the case may be.

Reaching the guaranteed value at the required NPSH value can be proven using the following 2 measuring methods.

a)Standard

Proof of reaching the required NPSH value by setting the peripheral conditions which are equal inthe system such as flow rate, head when reducing the suction pressure depending on the water temperature and the barometric level.

Comparison of head, taken from the characteristic curve measurement above, with the head measured at actual suction negative pressure where the guaranteed NPSH value is achieved or is not achieved.

The head decrease may not exceed 3 % of H, but does not have to achieve 3 % (for single-stage pumps).

According to the specifications in the order, 1 or 3 to 5 measuring points are used. For 2 stage pumps, the max head decrease may not be ΔH≤1.5 %

因此,汽蚀余量测试多级泵是不可能的。

B)可选作为顶头击穿曲线

最小的证明。在一个特定的恒定的流量实现的NPSH值。通过降低suctionhead,在NPSH =40米开始,多个测量点(8-12)被记录,直到泵送击穿。在由于在这一点在泵的气蚀条件的测定结果的开头3%下降头的截止点,并且在适用的标准定义为需要NPSH(2级泵1.5%ΔH)

Reference level for calculation of the NPSH

a) Horizontal Pumps

Horizontal level through the shaft axis

b) Vertical Pumps

平面表面垂直于轴的轴线在叶轮入口

汽蚀余量根据测得的或已知参数的计算:

The calculation of the NPSH value occurs simultaneously with the measurement.

The following parameters are required for this:

吸头

LaTeX4Web 1.3 OUTPUT H_S [m]

Water temperature

LaTeX4Web 1.3 OUTPUT t_w [℃]

Steam pressure of water(absolute vaporization pressure)

LaTeX4Web 1.3 OUTPUT H_t [m]=P_D/(ρ×g)

Atmospheric pressure (absolute)

Atmospheric height (absolute)

LaTeX4Web 1.3 OUTPUT b_0 [m]=P_O/(ρ×g)

Distance reference level/measurement level

LaTeX4Web 1.3 OUTPUT Y[m]

Speed at suction side

LaTeX4Web 1.3 OUTPUT (V_S2)/2g[m]

Density of test field water

LaTeX4Web 1.3 OUTPUT ρ[kg/(dm3)]

Acceleration due to gravity

LaTeX4Web 1.3 OUTPUT g [m/s²]

The NPSH is calculated according to the following formula:

LaTeX4Web 1.3 OUTPUT NPSH = P_O /(ρ×克)-H_S-P_D /(ρ×G)+(V_S2)/2g∓Y
LaTeX4Web 1.3 OUTPUT NPSH = B_0-H_S-H_t +(V_S2)/2g

从测得的速度与标称速度的NPSH值的转换是根据下式(仅适用于速度范围±3%)制成:

LaTeX4Web 1.3 OUTPUT n*/n>0.97<1.03
LaTeX4Web 1.3 OUTPUT 〖〗汽蚀余量*=NPSH×〖[n*/n]〗2[m]
LaTeX4Web 1.3 OUTPUT Q*= Q×n个*/n [m3/H]

4.4.8 Additional Measurements

Upon request, the electrical current I [A] and the voltage U [V] can also be measured.

4.5 Number of measuring points

The number of measuring points for the pump characteristic curve or NPSH measurements must

be agreed in the supply agreement.

Characteristic curve at 0, Qmin, Qmean, Qnom, Q120%, standard measurement of 5 points (9 max.)

NPSH measurement 0, Qmin, Qmean, Qnom, Q120% 4 points (7 max.)

5离心泵性能测试 - 担保

泵的额定数值保证符合规定,不存在其他任何客户要求API 610。公差的测量是通过测量系统自动完成。

For viscous media, only the specified data for cold water is guaranteed. The results with viscosity will be shown for information as conversion curves according to Hydraulic Institute.

6离心泵性能测试,振动器ration measurement

To assess the mechanical and hydraulic operating behavior of the pump tested, vibrations are recorded at the same time as the hydraulic date (min. 5 points).

Measurement is carried out in three planes - horizontal, vertical and axial - by means of vibration pick-ups fitted on the bearing bracket. The measureng criterion is the root mean square velocity of all vibrations determined (vibration velocity RMS in mm/s).

API 610规定的极限水平pumps 3 mm/s in the preferred operating range of the pump. In the allowable operating range, a vibration velocity of up to 3.9 mm/s (max.) is permissible. For vertical pumps the limit 5 mm/s in the preferred range and 6,5 mm/s in the allowable range is applicable.

Alternatively, it is also possible to measure the max. vibration amplitude (peak-to-peak).

Horizontal

限制在优选的范围:2,0密耳(50微米)

Limit in allowable range: 2,6 mils (65 μm)

垂直

4,0 mils (100 μm)

5,2 mils (130 μm)

The frequency spectrum (FFT analysis) can be measured, if requested.

7 Centrifugal Pump Performance Test - Measurement of Bearing Temperature

If required, the measurement of the bearing temperature will be performed for a specified operating time. The measurement is taken on the bearing bracket on the outside at the level and position of the pump side or motor side bearing in horizontal direction.

8离心泵性能测试报告

The test results are stored in the central computer of the test bay supervision and on other electronic data carriers. Upon request, test reports and test curves are prepared for the customer.

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