RU26825U1 - DEVICE FOR INCREASING THE PRESSURE PRESSURE OF THE SUCTION TREATMENT OF A SUBMERSIBLE MULTISTAGE CENTRIFUGAL PUMP - Google Patents

Description

DEVICE FOR INCREASING THE PRESSURE PRESSURE OF THE SUCTION-INLET TUBE OF A SUBMERSIBLE MULTI-STAGE

CENTRIFUGAL PUMP

The utility model relates to multi-stage centrifugal pump devices used in the field of power engineering, in particular to multi-stage submersible centrifugal pump devices used in control and lubrication systems of powerful steam turbines operating using a working fluid with supercritical parameters, in particular, to devices for increasing pressure head suction tract of the second and more stages, submersible multistage centrifugal pumps of the turbine unit lubrication system.

In turbomachines, especially powerful steam turbines operating using a working fluid with supercritical parameters, submersible multistage centrifugal pumps are widely used, serving control systems and lubrication of units and assemblies, and operating on both mineral and synthetic lubricating oils. Such pumps are installed on the oil tanks of a control system or lubrication system of a turbine unit having an integrated oil system for lubricating bearings and components of a control system. As you know, the pressure of the pressure developed by a submersible multistage centrifugal pump is very sensitive to the content of bubbles, emulsified air in the oil of the suction tract, which do not have time to stand out while the working fluid is in the 1 ml tank. Important factors for ensuring the normal operation of a submersible centrifugal pump are also the optimal depth of immersion of the pump intake path into the oil volume, the amplitude of the level fluctuation in the oil tank. The latter is especially relevant for the magnitude of the developed head of a single-stage centrifugal pump, as well as the second and more stages of a submersible multistage centrifugal pump.

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It is proposed to install water locks of a special design, upstream pumps, injectors, water locks, air separators in the oil tank, air traps (LMZ steam turbines of supercritical parameters, edited by A. Ogurtsov et al., Moscow, Energomashizdat, 1991).

However, the known devices do not allow to solve the problem of removing air from the incoming; it is into the oil pump and thereby increase the pressure of the pressure developed by it. So, upstream pumps require drive and control devices, others require additional overpressure, and water traps and traps are ineffective when working with fire-resistant synthetic oils that have a higher viscosity compared to mineral ones.

A device for increasing the pressure of the pressure of the suction tract, submersible, oil, single-stage, centrifugal, starting, electric pump of a turbine unit lubrication system, selected as a prototype and including a suction chamber, pressure chamber, nozzle with a hole of 10 mm., To which oil is supplied using a pressure pipe from the discharge chamber. This design technique allows you to significantly stabilize the pressure head developed by the pump even with a high degree of air entering the suction chamber of the oil. (Shabanov S.Z., Regulation of gas turbine units. L .; Nedra, 1971, p. 105, Fig. 43).

For reasons that impede the achievement of the technical result indicated below when using the known device adopted as a prototype, in relation to submersible multistage centrifugal pumps with two or more stages, it is technically unlikely that the supply of additional pressure to the second and further stages using the device according to the prototype whether feasible, due to the different arrangement of the suction windows, made uniformly around the circumference in the radial, and not axial, as in the prototype, direction.

The task to which the proposed technical solution is directed is to develop such a device for increasing the pressure of the suction head of the second or more stages, a submersible multistage centrifugal pump of the turbine unit lubrication system, which will significantly stabilize the pressure that the pump develops in the second or more stages, even with a large the degree of delivery of strangulation entering the oil suction chamber; eliminate pressure pressure breakdowns when the pump is turned on

in work, which ultimately will improve the reliability of the control system and lubrication of the turbine unit, as well as increase the reliability of the turbine unit as a whole.

To achieve the desired technical result, the proposed device for increasing the pressure of the suction tract of the second and more stages, a submersible multistage centrifugal pump, including a suction and discharge chambers, is additionally equipped with metering holes with a diameter of not more than 4 mm., The angle of inclination is not more than 45 degrees, and amount from 4 to 8 pcs., which are performed in a jumper separating the pressure chamber of the first stage and the suction chamber of the second stage.

In the study of the distinguishing features of the proposed design did not reveal any known or similar technical solutions to solve the specific technical problem.

The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information, and the identification of sources containing information about analogues of the claimed device, allowed to establish that the applicant did not find other technical solutions characterized by signs identical or equivalent to the above signs of the claimed utility model . This, in turn, made it possible to identify a set of significant, in relation to the technical result perceived by the applicant, distinctive features in the proposed device and set forth below in the utility model formula.

Therefore, the claimed technical solution meets the criterion of the novelty of the utility model.

The proposed design of a multistage centrifugal pump control system is illustrated in the figure.

The figure shows a longitudinal section of a two-stage, submersible centrifugal pump of a turbine unit lubrication system, in the region of the first second stage. The proposed device includes a suction chamber of the first stage 1, the impeller 2 and the injection chamber of the first stage 3, the suction window of the second stage 4, the impeller 5 and the injection chamber of the second stage 6, dispensing holes 7, for organizing the bypass pressure in the second stage, the angle metering holes 8 into the suction chamber of the second step 9

the second or more stages, a submersible multistage centrifugal pump, operates as follows.

As when the main pump is turned on for the first time, and when the standby submersible multi-stage centrifugal pump is turned on, the working fluid with the pressure head of the first stage 2 developed by the discharge chamber 3, through the metering holes 7 and the suction windows of the second stage 4, enters the suction chamber of the second stage 9. Dosing holes 7, located uniformly around the circumference of the jumper separating the injection chamber of the first stage 3 and the suction chamber of the second stage 9, bypassing part of the pressure head, pumped by the injection chamber 3 of the first stage, increases the suction pressure of the second stage 9. This ensures the stability of the pressure of the second stage, reduces the dependence of the pump on the amplitude of fluctuations in the oil level in the tank, the degree of airing and the quality of the oil circulating in the lubrication and regulation system turbine unit.

The above information indicates that when using the utility model, the following set of conditions:

- means embodying the proposed device in its implementation,

intended for use in industry, namely

power engineering;

-for the claimed device in the form as described in the independent claim of the utility model formula, the possibility of its implementation using the means and methods described in the application description is confirmed;

the tool embodying the claimed utility model in its implementation is capable of achieving the technical result desired by the applicant, namely, substantially stabilizing the pressure head developed by the pump even with a high degree of airing and lowering the viscosity entering the suction chamber of the second oil stage, eliminating pressure head stuttering when when the pump is turned on and the dependence of its operation on the amplitude of fluctuations in the oil level in the tank circulating in the lubrication and regulation system t rboagregata.

Therefore, the proposed utility model meets the criterion of industrial applicability.

Claims (2)

1. A device for increasing the pressure of the suction path, a submersible multistage centrifugal pump, including a suction and discharge chamber of the first stage, an impeller, suction windows of the second stage, an impeller and a discharge chamber of the second stage, characterized in that the device is additionally provided with metering holes, in an amount from 4 to 8 pcs. and located evenly around the circumference of the jumper separating the injection chamber of the first stage and the suction chamber of the second stage, at an angle of not more than 45 ^o . 2. The device for increasing pressure head according to claim 1, characterized in that the diameter of the metering holes is not more than 4 mm