CN106762709A - A kind of micro- lift vertical axial-flow pump lift measurement apparatus and measuring method - Google Patents

Abstract

The invention relates to a lift measuring device and a measuring method of a micro lift vertical axial flow pump. The measuring device includes an axial flow pump and a water tank, and the pipeline between the pump outlet of the axial flow pump and the water tank is provided with a first pressure sensor, a first valve, an auxiliary pump, and a second valve; the pump of the axial flow pump A flow meter is also arranged on the pipeline between the outlet and the water tank; a second pressure sensor and a third pressure sensor are respectively arranged at the inlet and the outlet of the auxiliary pump. This device effectively overcomes the resistance of the pipeline system during the test by adding an auxiliary pump to the pipeline system of the axial flow pump, thus providing a solid test device platform for accurately measuring the lift of the micro-lift pump and the pipeline characteristic curve . Using the measuring device of the invention to measure the micro-lift of the vertical axial flow pump can effectively reduce the measurement error and improve the accuracy of the measurement result.

Description

A head measuring device and method for a micro-lift vertical axial flow pump

technical field

The invention belongs to the technical field of lift measurement of axial flow pumps, and in particular relates to a lift measurement device and a measurement method of a micro-lift vertical axial flow pump.

Background technique

After the liquid obtains energy through the pump device, it is discharged along the outlet pipeline. Due to the resistance characteristics of the pipeline itself, when the pump device discharges liquid with different flow rates, it needs to overcome different resistance along the way. Specifically, for a pipeline with a certain structure, the greater the flow rate, the greater the resistance loss along the pipeline, and vice versa. The existing head test device is aimed at the pump device with a head of more than several meters. It directly measures the inlet and outlet pressure of the pump device to calculate the corresponding head under a certain flow rate. The impact is very small, and the loss along the pipeline is negligible relative to the head of the pump, and there is no need to consider the problem of overcoming pipe resistance during the operation of the pump device. However, during the operation of the micro-lift pump, due to the low head of the pump itself, it is difficult to overcome the resistance along the pipeline, especially when the pipeline resistance increases significantly under the condition of large flow, the measurement error of the head will be greater, and even may occur The case where the micro-lift pump fails to work. Therefore, when measuring the head of the micro-lift pump, the influence of pipe resistance on the head measurement cannot be ignored. However, how to accurately measure the lift of the micro-lift pump and the pipeline characteristic curve has become a technical problem to be solved urgently by those skilled in the art.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides a lift measurement device for a micro-lift vertical axial flow pump. This device effectively overcomes the resistance of the pipeline system during the test by adding an auxiliary pump to the pipeline system of the axial flow pump. , thus providing a solid test device platform for accurately measuring the head of the micro-lift pump and the pipeline characteristic curve.

In order to realize the purpose of the present invention, the present invention has adopted following technical scheme:

A head measuring device for a micro-lift vertical axial flow pump, comprising an axial flow pump and a water tank, the pipeline between the pump outlet of the axial flow pump and the water tank is provided with a first pressure sensor, a first valve, an auxiliary pump, a second Two valves; a flow meter is arranged on the pipeline between the pump outlet of the axial flow pump and the water tank; a second pressure sensor and a third pressure sensor are respectively arranged at the inlet and outlet of the auxiliary pump.

Preferably, the flow range of the auxiliary pump matches the flow range of the axial flow pump, and the lift of the auxiliary pump is higher than that of the axial flow pump.

Preferably, the device further includes a motor, a coupling is provided between the motor and the axial flow pump, and a torque meter is provided on the coupling.

Further, the coupling includes a motor shaft sleeve sleeved on the output shaft of the motor, and a pump shaft sleeve disposed on the pump shaft, and the two ends of the torque meter are respectively connected to the motor shaft sleeve and the pump shaft. The shaft sleeve, the torque meter is fixedly connected with the support frame of the fixed motor through the fixing frame.

Preferably, the first pressure sensor is arranged on the straight pipe section of the pump outlet of the axial flow pump through a pressure measuring device.

Further, the pressure measurement device includes two positioning baffles fixed on the straight pipe section of the pump outlet sequentially in the axial direction, and a measuring sleeve sleeved on the straight pipe section of the pump outlet is arranged between the two positioning baffles. The measuring sleeve and the two positioning baffles jointly form a measuring area; the measuring sleeve is provided with a support for placing the first pressure sensor; the straight pipe section of the pump outlet is located in the measuring area A pressure measuring hole is arranged on the pipe body; an exhaust hole is arranged on the upper positioning baffle or the top of the measuring sleeve, and a plug is arranged at the exhaust hole.

Furthermore, the four pressure measuring holes are evenly distributed along the circumference of the pump outlet straight pipe section, and the hole center of the pressure measuring hole is on the same level as the hole center of the support; The axial cross-sectional area within the measurement region is greater than four times the total cross-sectional area of the four pressure measuring holes.

In order to avoid adverse effects of liquid pressure fluctuations in the annular measurement area on pressure measurement, it is necessary to ensure that the axial cross-sectional area of the annular measurement area is greater than four times the total cross-sectional area of the four pressure measurement holes 83 .

Preferably, the inner diameter of the pump outlet straight pipe section is D, the pipe length of the pump outlet straight pipe section is greater than 4D, and the distance between the installation position of the first pressure sensor and the pump outlet of the axial flow pump is greater than 2D.

Preferably, the auxiliary pump is a pipeline pump.

The present invention also provides a method for measuring the head of a micro-lift vertical axial flow pump as described above, the technical solution of which is as follows:

S1, the axial flow pump is not turned on, adjust the opening of the first valve and the second valve, turn on the auxiliary pump, verify the cavitation characteristics of the auxiliary pump, and obtain the non-cavitation flow range of the auxiliary pump;

S2, in the non-cavitation flow range of the auxiliary pump, keep the axial flow pump closed and the auxiliary pump continue to open, measure the pressure values of the first pressure sensor corresponding to different flow rates, and obtain the pipe resistance characteristic curve of the outlet pipe section of the axial flow pump;

S3, fully open the first valve and the second valve, the auxiliary pump continues to run, and turn on the axial flow pump; in the non-cavitation flow range of the auxiliary pump, measure the flow head curve and the corresponding efficiency curve of the axial flow pump , Shaft power curve;

S4, using the pipe resistance characteristic curve measured in step S2 to check the flow head curve, efficiency curve, and shaft power curve of the axial flow pump, and obtain the checked flow head curve, efficiency curve, and shaft power curve of the axial flow pump. shaft power curve;

S5, remove the auxiliary pump, conduct tests under different working conditions within the flow range of the axial flow pump, and measure the working condition characteristic curve of the axial flow pump when it works alone;

S6, compare the characteristic curves of step S4 and step S5, if the corresponding parts of the corresponding curves measured by the two steps are consistent with each other, then the measurement ends; otherwise, steps S1 to S5 need to be repeated until the corresponding curves obtained by step S4 and step S5 are measured. Corresponding parts of the curves fit each other.

The beneficial effects of the present invention are:

1) In the present invention, an auxiliary pump is added to the piping system of the axial flow pump, and the auxiliary pump is used to overcome the resistance of the piping system during testing. During the test, by adjusting the valves at the front and rear ends of the auxiliary pump, the pipe resistance characteristic curve of the pipeline system when the vertical axial flow pump is not running can be accurately measured. After the vertical axial flow pump and the auxiliary pump work together, the head curve when the axial flow pump and the auxiliary pump work together can be measured, and the head curve measured again is compared with the measured pipe resistance characteristic curve of the pipeline system Combined, the true head of the vertical axial flow pump can be accurately obtained. Therefore, using the measuring device of the present invention to measure the micro-lift of the vertical axial flow pump can effectively reduce the measurement error and improve the accuracy of the measurement result.

2) The present invention uses a torque meter to measure the torque of the axial flow pump during operation, and can accurately calculate the axial power of the pump device; the present invention installs the first pressure sensor on the straight pipe section of the pump outlet of the axial flow pump, and can measure the axial flow pump outlet pressure. In the present invention, a metal hose is also connected to the outlet end of the auxiliary pump, and the metal hose is used to adjust the distance between the outlet of the auxiliary pump and the third valve. By setting the torque meter and the first pressure sensor, the present invention can also measure the efficiency curve and shaft power curve of the axial flow pump.

3) The present invention effectively solves the problem that the gas in the measurement area cannot be exhausted by providing a vent hole on the measuring sleeve of the pressure measuring device; by separately opening and closing the vent hole at the top of the measuring sleeve, Thus, the self-exhausting function of the gas in the measurement area is realized, and finally the interference of the air bubbles in the measurement area on the pressure measurement process is avoided, and the measurement data obtained are naturally more accurate. Specifically, during the test, the liquid in the straight pipe section of the pump outlet enters the annular measurement area through the pressure measuring hole. At this time, under the action of the hydraulic pressure, the gas in the annular measurement area escapes through the exhaust hole; After the air in the annular measurement area is sealed, the exhaust hole can be accurately measured by the first pressure sensor.

4) The support made of round steel pipe is used here as the installation carrier of the first pressure sensor and as the connecting fixture between the first pressure sensor and the measuring sleeve. On the one hand, the support realizes the fixing function of the two through the welding between the measuring sleeve; on the other hand, it realizes the tightening operation of the first pressure sensor through the large-diameter section at its own stepped hole-shaped lumen. When in use, the central axis of the support is on the same level as the axis of the pressure measuring hole, and the accurate transmission of hydraulic pressure is guaranteed through the small diameter section of the support.

5) The present invention is equipped with four pressure measuring holes uniformly arranged around the straight pipe section of the pump outlet, which can at least ensure the balance of pressure distribution in the area around the water outlet of the pressure measuring hole, and then cooperate with the round steel pipe at the same level as the axis of the pressure measuring hole The manufactured support can effectively improve the measurement accuracy of the first pressure sensor.

Description of drawings

Figure 1 is a schematic diagram of the connection structure between the motor and the axial flow pump.

Fig. 2 is a structural schematic diagram of the pressure measuring device on the straight pipe section at the outlet of the pump.

FIG. 3 is a schematic cross-sectional view along line A-A of FIG. 2 .

Fig. 4 is a structural schematic diagram of the present invention.

Fig. 5 is a front view of Fig. 4 .

FIG. 6 is a top view of FIG. 4 .

Figure 7 is the cavitation curve of the auxiliary pump.

Fig. 8 is the pipe resistance characteristic curve of the outlet pipeline of the vertical axial flow pump.

Fig. 9 is a pump characteristic curve of a vertical axial flow pump.

Figure 10 is the characteristic curve of the vertical axial flow pump after calibration.

Fig. 11 is the characteristic curve of the small flow condition when the vertical axial flow pump works independently.

Fig. 12 is a partial comparison diagram of the characteristic curve of the vertical axial flow pump with and without the auxiliary pump.

The meanings of the marks in the figure are as follows:

1-motor 2-support frame 3-motor shaft sleeve 4-fixed frame 5-torque meter

6-Pump shaft casing 7-Axial flow pump 8-Pump outlet straight pipe section 81-Connecting flange

82-90° elbow 83-pressure measuring hole 9-first pressure sensor 91-support

92-measurement sleeve 921-vent hole 922-plug 923-installation hole

93-positioning baffle 10/12-long straight pipe 11-flow meter 13/15-straight pipe

14-first valve 16-second pressure sensor 17-auxiliary pump

18-Third pressure sensor 19-Metal hose 20-Second valve 21-Water tank

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figures 4-6, a micro-lift vertical axial flow pump lift measurement device includes an axial flow pump 7 and a water tank 21, and the pipeline between the pump outlet of the axial flow pump 7 and the water tank 21 is provided with a first A pressure sensor 9, a first valve 14, an auxiliary pump 17, and a second valve 19; a flow meter 11 is also arranged on the pipeline between the pump outlet of the axial flow pump 7 and the water tank 21; the inlet of the auxiliary pump 17 A second pressure sensor 16 and a third pressure sensor 18 are respectively arranged at the outlet and the outlet. The flow range of the auxiliary pump 17 is adapted to the flow range of the axial flow pump 7 , and the lift of the auxiliary pump 17 is higher than that of the axial flow pump 7 . The auxiliary pump 17 in this embodiment is a pipeline pump.

As shown in FIG. 1 , the device further includes a motor 1 , a coupling is provided between the motor 1 and the axial flow pump 7 , and a torque meter 5 is provided on the coupling. The shaft coupling includes a motor shaft sleeve 3 sleeved on the motor output shaft, and a pump shaft sleeve 6 arranged on the pump shaft. The two ends of the torque meter 5 are respectively connected to the motor shaft sleeve 3 and The pump shaft sleeve 6, the torque meter 5 is fixedly connected with the support frame 2 of the fixed motor 1 through the fixed frame 4.

As shown in Fig. 4, the entire inlet structure composed of the motor 1 and the vertical axial flow pump 7 is installed in the open water tank 21, and there is a rectangular space under the partition in the middle of the water tank 21, and this rectangular space is convenient for the water to flow back stably. At the inlet of the vertical axial flow pump 7. The axial flow pump 7 is installed at the bottom of the water tank 21, and the support frame 2 is installed above the axial flow pump 7, as shown in Figure 1, the motor 1 is installed on the support frame 2, and the motor shaft sleeve 3 is connected with the output shaft of the motor , the torque meter 5 is connected with the motor shaft sleeve 3, the bottom plates of the two fixed frames 4 are fixed on the support frame 2, the side plates of the fixed frame 4 clamp the torque meter 5 in the middle, and the side plates of the fixed frame 4 are screwed Fasten together with torque meter 5. A U-shaped groove is arranged on the base plate of the fixed mount 4, so that the position of the side plate can be adjusted conveniently. When installing, the side plate is set against the torque meter 5; Tighten the screws. Below the torque meter 5 is the pump shaft sleeve 6 , which is connected to the pump shaft of the axial flow pump 7 . The length of the pump shaft casing 6 can be set longer to ensure that the torque meter 5 is located in a safe position above the water surface.

As shown in FIG. 4 , the first pressure sensor 9 is arranged on the pump outlet straight pipe section 8 of the axial flow pump 7 through a pressure measuring device.

As shown in Figures 2 and 3, the pressure measurement device includes two positioning baffles 93 fixed on the straight pipe section 8 of the pump outlet in sequence in the axial direction, and a sleeve is set between the two positioning baffles 93. The measuring sleeve 92 on the straight pipe section 8 of the pump outlet, the measuring sleeve 92 and the two positioning baffles 93 together form a measurement area; Support 91; the pump outlet straight pipe section 8 is provided with a pressure measuring hole 83 on the pipe body located in the measurement area; the top of the measuring sleeve 92 is provided with a vent hole 921, and a plug is provided at the vent hole 921 922.

As shown in Figures 2 and 3, the four pressure measuring holes 83 are evenly distributed along the circumference of the pump outlet straight pipe section 8, and the hole centers of the pressure measuring holes 83 and the hole centers of the support 91 are in the same position. On the same horizontal plane; the axial cross-sectional area of the ring-shaped measurement area is greater than four times the total cross-sectional area of the four pressure measuring holes 83 .

As shown in Figure 4, below the outlet of the axial flow pump 7 is a pump outlet straight pipe section 8 with a length greater than 4D (D is the inner diameter of the pipe). The first pressure sensor 9 is installed on the pump outlet straight pipe section 8, and the first pressure sensor 9 The distance between the position and the pump outlet is 2D; the long straight pipe 10 is connected to the pump outlet straight pipe section 8 through a 90° elbow 82, the length of the long straight pipe 10 is greater than 4D, and the flow meter 11 is installed at the end of the long straight pipe 10. The length of the long straight pipe 12 at the rear end of the meter 11 is also greater than 4D; the first valve 14 is installed at the outlet rear end of the flow meter 11, the length of the straight pipe 13 at the front section of the first valve 14 inlet is 2.5D, and the flow rate of the auxiliary pump 17 is the same as that of the vertical flow meter. The flow rate of the axial flow pump 7 is equivalent, the auxiliary pump 17 is installed at the rear end of the first valve 14, and the inlet and outlet of the auxiliary pump 17 are each equipped with a pressure sensor, which are respectively the second pressure sensor 16 and the third pressure sensor 18, the described The length of the straight pipe 15 at the entrance section of the auxiliary pump 17 is 4D, and the outlet section is connected with the second valve 20 controlling the flow of the pump through a metal hose 19, and the outlet end of the second valve 20 extends into the water tank 21.

The measurement method of the present invention will be further described in detail in conjunction with specific working processes below.

(1) Preliminary preparation.

After the axial flow pump 7 and the pipeline system are installed, water is poured into the water tank 21. At this time, the first valve 14 and the second valve 20 are fully opened, so as to discharge the air in the pipeline system. Open the first valve 14 to the maximum, close the second valve 20 at the outlet section of the auxiliary pump 17, and start the auxiliary pump 17.

(2) Verification of the cavitation characteristics of the auxiliary pump.

Slowly open the second valve 20 to adjust the outlet flow from small to large. When the flow is adjusted to a fixed value Q1, the inlet pressure value Po _ut of the auxiliary pump 17 (measured by the second pressure sensor 16) is P1, and the outlet pressure value is P1. P _in (measured by the third pressure sensor 18) is P1', according to Calculate the head H1 _of the auxiliary pump at this time, then slowly adjust the opening of the first valve 14, and fine-tune the opening of the second valve 20 under the condition that the outlet flow Q1 _of the pipeline is kept constant; 14 and the second valve 20, if the head H1 drops within ₃ %, cavitation does not occur, and if the head drops more than 3%, cavitation occurs in the auxiliary pump 17. Restore the opening of the second valve 20 and adjust the second valve 20 to the flow rate Q2. At this time, the inlet and outlet pressure values of the auxiliary pump 17 are respectively P2 and P2'. Calculate the head H2 of the auxiliary pump at this time, and then slowly reduce the first The opening of the first valve 14 is still fine-tuned to the opening of the second valve 20 to keep the flow rate Q2 constant until the lift of the auxiliary pump 17 drops by 3%, and cavitation occurs in the auxiliary pump 17. Adjust the opening of the second valve 20 to the flow rates Q3, Q4, Q5, Q6, etc. according to the same steps above, and then adjust the first valve 14 at the inlet section of the auxiliary pump 17 to verify the cavitation characteristics of the auxiliary pump 17.

(3) In Fig. 7, the auxiliary pump 17 does not have cavitation between the flows of points A and B. At this time, the data collected by the flow meter 11 and the first pressure sensor 9 are available. When the flow is between A and B Outside the point, all collected data is unusable due to cavitation of the auxiliary pump 17. Therefore, adjust the auxiliary pump 17 from small to large between points A and B to obtain several flow points Qa, Qb, Qc, Qd, Qe, Qf, Qg, Qh, Qi, Qj, Qk, Ql, vertical shaft The first pressure sensor 9 at the outlet of the flow pump 7 will also display the corresponding pressure values pa, pb, pc, pd, pe, pf, pg, ph, pi, pj, pk, pl; according to the same steps, cycle adjustment The flow rate of the auxiliary pump 17 is 7 times, and 7 sets of data of the above-mentioned flow rate and pressure are obtained, and then the 7 sets of data are added and averaged to obtain the pressure value p displayed by Q between the flow points A and B and the first pressure sensor 9 respective mean values, according to Convert the pressure values into H to obtain a QH curve I, which shows the pipe resistance characteristic curve between the inlet and outlet sections of the vertical axial flow pump 7, as shown in FIG. 7 .

(4) Measurement of the external characteristic parameters of the vertical axial flow pump.

Fully open the first valve 14 and the second valve 20, the auxiliary pump 17 continues to run, and the vertical axial flow pump 7 is turned on; the opening degree of the second valve 20 is adjusted from large to small in turn, and the vertical axial flow pump is recorded respectively. The data Qa, Qb, Qc, Qd, Qe, Qf, Qg, Qh, Qi, Qj, Qk, Ql of the flow meter 11 of 7 and the value pa', pb', pc', pd' of the first pressure sensor 9, pe', pf', pg', ph', pi', pj', pk', pl'; adjust the flow point of the pump 7 times according to the above steps, and obtain 7 sets of data of the above flow and pressure, and then The average value of the 7 groups of data was taken respectively, according to The data of the first pressure sensor 9 is converted into Ha', Hb', Hc', Hd', He', Hf', Hg', Hh', Hi', Hj', Hk', Hl', at this time, according to pump power Calculate the pump power corresponding to each flow point, and the torque measured by the torque meter 5 on the vertical axial flow pump 7 is Ta', Tb', Tc', Td', Te', Tf', Tg', Th', Ti', Tj', Tk', Tl'. According to shaft power Calculate the shaft power as Pa', Pb', Pc', Pd', Pe', Pf', Pg', Ph', Pi', Pj', Pk', Pl', according to the efficiency of the pump Calculate pump efficiency points ηa', ηb', ηc', ηd', ηe', ηf', ηg', ηh', ηi', ηj', ηk', ηl'. Finally, head curve II, efficiency curve III, and shaft power curve IV are obtained, as shown in Figure 9.

(5) Verification of the characteristic curve of the vertical axial flow pump.

Check the characteristic curve of the vertical axial flow pump 7 in conjunction with Fig. 8 and Fig. 9, and add the lifts of the two curves under the same flow rate, that is, H _total = H + H', to obtain a new QH curve Ⅴ, this curve is the actual head curve of the vertical axial flow pump. For example, when the flow rate is Qa, the actual head of the vertical axial flow pump 17 is HA=Ha+Ha', and its actual pump power is According to the torque T' measured by the torque meter 5 on the vertical axial flow pump 7, the shaft power of the vertical axial flow pump at this time Calculate new pump efficiency As shown in Figure 10.

(6) Verify the accuracy of the test plan.

Close the second valve 20, and then close the vertical axial flow pump 7 and the auxiliary pump 17. Remove the auxiliary pump 17, open the valve and restart the vertical axial flow pump 7. Since the head of the vertical axial flow pump 7 is very small, it cannot operate normally under high flow conditions after removing the auxiliary pump 17, so only the vertical axial flow pump 7 is measured. For the pump characteristic parameters of the axial flow pump 7 under the condition of small flow rate, 7 sets of tests were repeated, and after taking the average value of the collected data, the characteristic curve of the vertical axial flow pump in the small flow section was obtained as shown in Figure 11. The obtained The curve is compared with the small flow section of the curve of the vertical axial flow pump after calibration in step (5), as shown in Figure 12. If the corresponding curves basically overlap or coincide with each other, the measurement ends; otherwise, steps (1) to (5) need to be repeated until the corresponding parts of the corresponding curves measured in steps (4) and (5) coincide with each other.

Claims (10)

1. a kind of micro- lift vertical axial-flow pump lift measurement apparatus, including axial-flow pump (7) and water tank (21), it is characterised in that：Institute State and first pressure sensor (9), the first valve are provided with the pipeline between the pump discharge of axial-flow pump (7) and water tank (21) (14), auxiliary pump (17), the second valve (19)；Also set on pipeline between the pump discharge and water tank (21) of the axial-flow pump (7) It is equipped with flowmeter (11)；The inlet and outlet of the auxiliary pump (17) is respectively arranged with second pressure sensor (16) and the 3rd Pressure sensor (18).

2. a kind of micro- lift vertical axial-flow pump lift measurement apparatus as claimed in claim 1, it is characterised in that：The auxiliary pump (17) range of flow is adapted with the range of flow of axial-flow pump (7), and the lift of the auxiliary pump (17) is higher than axial-flow pump (7) Lift.

3. a kind of micro- lift vertical axial-flow pump lift measurement apparatus as claimed in claim 2, it is characterised in that：The present apparatus is also wrapped Motor (1) is included, shaft coupling is provided between the motor (1) and the axial-flow pump (7), torquemeter is provided with the shaft coupling (5)。

4. a kind of micro- lift vertical axial-flow pump lift measurement apparatus as claimed in claim 3, it is characterised in that：The shaft coupling Including the motor shaft sleeve pipe (3) being set on motor output shaft, also including the pump shaft sleeve pipe (6) being arranged on pump shaft, the torsion The two ends of square instrument (5) connect motor shaft sleeve pipe (3) and pump shaft sleeve pipe (6) respectively, the torquemeter (5) by fixed mount (4) with The support frame (2) of fixed motor (1) is fixed together.

5. a kind of micro- lift vertical axial-flow pump lift measurement apparatus as claimed in claim 2, it is characterised in that：First pressure Force snesor (9) is arranged on the pump discharge straight length (8) of axial-flow pump (7) by device for pressure measurement.

6. a kind of micro- lift vertical axial-flow pump lift measurement apparatus as claimed in claim 5, it is characterised in that：The pressure is surveyed Amount device includes two pieces of positioning baffles (93) being installed in successively vertically on the pump discharge straight length (8), two pieces of positioning gears The measurement sleeve pipe (92) being set on pump discharge straight length (8) is provided between plate (93), it is described to measure sleeve pipe (92) and two pieces Positioning baffle encloses measured zone jointly between (93)；It is provided with measurement sleeve pipe (92) and is passed for laying first pressure The bearing (91) of sensor (9)；The pump discharge straight length (8) is being provided with pressure tap on the pipe shaft in measured zone (83)；Steam vent (921), steam vent are provided with the top of positioning baffle (93) or measurement sleeve pipe (92) in top (921) place is provided with plug (922).

7. a kind of micro- lift vertical axial-flow pump lift measurement apparatus as claimed in claim 6, it is characterised in that：The pressure tap (83) be uniformly distributed along the circumference of the pump discharge straight length (8), and the pressure tap (83) hole center and the bearing (91) hole center is in same level；Axial cross section area in measured zone described in ring-type is more than multiple pressure taps (83) four times of total cross sectional area.

8. a kind of micro- lift vertical axial-flow pump lift measurement apparatus as claimed in claim 5, it is characterised in that：The pump discharge The pipe interior diameter of straight length (8) is D, and the pipe range of the pump discharge straight length (8) is more than 4D, the first pressure sensor (9) The distance between the pump discharge of installation site and axial-flow pump (7) be more than 2D.

9. a kind of micro- lift vertical axial-flow pump lift measurement apparatus as claimed in claim 2, it is characterised in that：The auxiliary pump (17) it is pipeline pump.

10. a kind of a kind of measuring method of micro- lift vertical axial-flow pump lift measurement apparatus as claimed in claim 3, its feature It is as follows：

S1, axial-flow pump (7) is not turned on, the aperture of the first valve of regulation (14) and the second valve (19), opens auxiliary pump (17), right The cavitation characteristics of auxiliary pump (17) are verified, obtain the interval without cavitation Flow of auxiliary pump (17)；

S2, in auxiliary pump (17) is interval without cavitation Flow, keeps axial-flow pump (7) to close and is continued on auxiliary pump, measures The pressure value of corresponding first pressure sensor (9) under different flow, the pipe resistance characteristic for obtaining axial-flow pump (7) outlet pipe section is bent Line；

S3, by the first valve (14) and the second valve (19) standard-sized sheet, auxiliary pump (17) is continued to run with, and opens axial-flow pump (7)；Auxiliary Help pump (17) without cavitation Flow it is interval in, measurement obtain the axial-flow pump flow lift curve and corresponding efficiency curve, Shaft power curve；

S4, using being measured in step S2, flow lift curve to the axial-flow pump (7) of the pipe resistance characteristic curve that obtains, efficiency are bent Line, shaft power curve are checked, and obtain the flow lift curve after the check of axial-flow pump (7), efficiency curve, shaft power bent Line；

S5, removes auxiliary pump (17), is tested under the different operating modes in the range of flow of axial-flow pump (7), measures axial-flow pump (7) working characteristicses curve when working independently；

S6, the characteristic curve of step S4 and step S5 is contrasted, if the corresponding portion of the response curve that two step measurements are obtained Divide and coincide each other, then measurement terminates；Repeat step S1 to S5 is otherwise needed, until the corresponding song that step S4 and step S5 measurements are obtained The corresponding part of line coincide each other.