SU989141A1 - Method of determining pressure losses in centrifugal turbomachine impeller - Google Patents

Description

(5) METHOD FOR DETERMINING LOSSES OF PRESSURE IN THE WORKING WHEEL OF CENTRIFUGAL

one

This invention relates to the field of testing of turbomachine elements.

A known method for determining the pressure loss in the impeller of a centrifugal turbomachine by determining the pressure, power and productivity of 1 J.

The disadvantage of this method is its high labor intensity.

The purpose of the invention is to reduce labor input.

The goal is achieved in that according to the method of determining the pressure loss in the impeller of a centrifugal turbomachine by determining pressure, power and performance, these parameters are determined first when the flow is twisted in front of the wheel in the direction of its rotation, and then by the same amount Turbomachines

and the amount of pressure loss is determined from the ratio

).

.. jL / u, Q; l about

LN

; V in

To - about

working density, kg / m;

and.

circumferential speed of the impeller on the diameter of the entrance, m / s;

ten

Q turbomachine performance,

respectively, the diameter and width of the inlet wheel ,, m;

15 loss factor

% power turboiashiny;

n & - respectively, the pressure and power when spinning the flow before

20 against the direction of its rotation;

and

N, the same when twisting

Claims (1)

 than the direction of rotation}. The method is carried out as follows. A spin is created in front of the wheel in the direction of rotation, for example, by rotating the blades of the guide vane, and the pressure, capacity and power parameters are measured. Then create a spin of the same magnitude against the direction of rotation and determine the same parameters. Thereafter, the magnitude of the wheel loss is determined using the above ratio. The power factor is either determined by calculation, or taken to be 0, EB, since its value usually varies within 0.95 0.97. P r and m er. The V1RD-8 fan has a D 0.46 m, 3 m, 6 m / s with a capacity of Q 16 and a capacity of Q 6700 Pa, 6250 Pa, M 120 kW. Accepting 129 kW,% 0.96 and / p 1.2 kg / m, we get S OTJPTM. (1 16. 6700-6250 from 0.96 129000 - 120000 680 Pa. The reduction in labor intensity is achieved by eliminating difficult procedures for measuring pressure before behind the wheel by traversing probes and replacing these procedures with standard definitions of parameters. Formula of the invention A method for determining the pressure loss in the impeller of a centrifugal turbobom is 5 m above the “0 top of the pipe” by determining the pressure and performance, based on the fact that, with a decrease in labor intensity, the used parameters The limit is first the flow is twisted before the rotation control, and the same value is opposed to the rotation rotation, and the amount of suppression is determined from the ratio i (Q HQH Vx lN M.0-Ntd - working medium density, - the diameter of the entrance, m / s; -the productivity of the turbomachine, m / s; respectively, the diameter and width of the wheel at the entrance, m ;, - the coefficient of power losses of the turbomachine; respectively, pressure and crankshaft when spinning the flow in front of the wheel against the direction of its rotation; the same when turning in the direction of rotation. Sources of information taken into account during the examination 1. Centrifugal fans. Under G.S. Solomakhova. M., Machinery, 1975, p. 76, 78.