SU1399503A1 - Method of testing impeller pump - Google Patents

Abstract

The invention relates to the field of hydraulic engineering and allows you to extend the functionality of the pump by determining the location of the zone of development of cavitation. Initially, the discharge-flow characteristic of the pump 4 in the non-cavitating mode and the same characteristic in the developed cavitation mode are removed. At the same time, the working agent's t-ru is measured at the inlet to pump 4 and. in addition to the t-ru working agent at the outlet of the pump, determine the difference measured by t-p. The location of the cavitation development zone is judged by the sign of the difference in the difference tp determined at a fixed flow rate in the non-cavitation mode and the advanced cavitation mode. The method allows to determine the place of cavitation development regardless of the coefficient of rapidity under conditions of a small change in temperature and a wide range of change in operating costs. 3 il. about s (l

Description

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The invention relates to hydraulic engineering and can be used in tests of vane pumps, carried out to fine-tune the flow part.

The purpose of the invention is to expand the functionality by determining the location of the zone of development of cavitation,

FIG. 1 shows a schematic of a test bench where the proposed method for testing a vane pump is carried out; in fig. 2 - characteristics

at the outlet of pump 4. Determine the measured temperature difference .At.

  OUT

-t

in

(one)

The location of the cavitation development zone is judged by the sign of the difference in temperature differences 11 „, determined at a fixed flow rate in the non-cavitation mode and the developed cavitation mode (curves 19 and 20, respectively).

Set the required pressure in the supply tank 1 with i

the test pump for cavitation-free 15 means 21 and 22 to the specified mode ra

the nominal mode and the advanced cavitation mode in the pump outlet channel; in fig. : 3 - characteristics of the test pump in the cavitation free mode and the advanced cavitation mode in the flow channels of the pump impeller. The test bench of the vane pump contains the supply tank 1, to which the booster pump 2 is connected in series, the pipeline

3 and the test pump 4. The delivery line 5 is equipped with flow controllers 6 and communicated with the supply tank 1..

The pressure is measured by gauge sensors 7-10, temperature by sensors 11-14, flow by meter 15.

FIG. Figures 2 and 3 show the consumption characteristics 16 and 17, respectively, of the cavitationless mode and the advanced cavitation mode, the dependence 18 of the temperature difference of the working agent at the outlet and inlet of the pump 4 (or pump 2) in the cavitational mode, and dependences 19 and 20 of the specified temperature difference in the mode of developed cavitation at the location of cavitation development zones, respectively, in the bypass channel and in the flow channels of the impeller. The diverter tank 1 is equipped with a means 21 for pressurization and a means 22 for evacuating.

The method for testing a vane pump is as follows.

Originally removed pressure-flow characteristic of the pump 16

4 on the no-accreditation mode and a similar characteristic 17 on. advanced cavitation mode. At the same time, the temperature t of the working agent is entered at the inlet to the pump 4 and, additionally, the temperature t, of the working agent

five

0

five

bots of the pump under test in terms of frequency of rotation and supply of G of the working agent.

The pressure at the inlet of the test pump 4 is set to the maximum, 0 ensuring the cavitation-free mode of its operation. Reduce the resistance at the outlet of the pump 4 by means of the controller 6, increasing the flow rate of the working agent. The pressure at the inlet and outlet is measured. Pump 4, determine the pressure drop kp head pressure H created by pump 4 and build pressure-flow characteristic 16. At the same time fix the dependence of ut on the flow rate G of the working agent (curve 18 in Figs. 2 and 3) .

Then the pressure in the supply tank 1 is reduced to the value at which the cavitation operation of the pump 4 occurs. The change in the flow rate of pressure and temperature is repeated as indicated and the pressure-flow characteristic 17 is removed and the temperature difference t depends on this mode.

The difference between the pairs is determined.

house temperature it, measured on the cavitation free mode, and a similar differential measured on the mode of advanced cavitation.

It was established experimentally that when the cavitation development zone is located in the bypass channel of pump 4, the dependence Δt –f (G) shown in FIG. 2 (curve 19), which corresponds to the minus difference of the values measured on Curves 18 and 19 at a fixed flow rate in the cavitation discharge mode. Accordingly, curve 20 and the plus sign of the indicated difference in temperature (Fig. 3) are evidence of the location of the cavitation development zone in the flow channels of the pump 4 impeller. Using the proposed method, it is possible to determine the location of the cavitation development, regardless of the speed ratio, temperatures (tg, l-const) and wide, more G „„ „1 0 times, the range of operating costs.

Claims (1)

Formula Shaded Shade Testing Method for Vane Pump, including discharge pressure-flow-15 lenk at a fixed flow rate characteristics on the cavitation free mode. and advanced cavitation mode, H.tH Pu9.2 while measuring the temperature of the working agent at the pump inlet, which is characterized by the fact that, in order to expand the functional possibilities by determining the location of the cavitation zone, in the process of characterization, the temperature of the working agent at the pump outlet is also measured The difference in measured temperatures is determined, and the location of the cavitation development zone is judged by the sign of the difference in temperature difference between a certain de-cavitation mode and a developed cavitation mode. const G6 P ft const b