Hydraulic shock damper with and without diaphragm

Abstract

The article provides an analysis of scientific papers devoted to the study of hydraulic shock absorbers used in pumping stations with long pressure pipelines. The efficiency of pumping stations depends on ensuring trouble-free operation - the reliability of pressure-hydraulic systems. The reliability of pumping units and long pressure pipelines is ensured using the proposed designs of hydraulic shock absorbers. In the experimental study of hydraulic shock absorbers, modern scientific instruments were used. The authors of this work have developed a special pressure sensor to record changes in hydrodynamic pressure during hydraulic shock. The paper presents the results of experimental studies of hydraulic shock absorbers with and without a diaphragm. At the same time, a reliable agreement was obtained between the results of calculations of hydraulic shock absorbers with and without a diaphragm using the proposed method with experimental data. The performed research experiments prove that the damper with a diaphragm is a very effective and economical water hammer damper for long pressure pipelines of pumping stations with the values of the polytropic coefficient n=1.2. Calculations and experiments confirm that the proposed method for calculating an absorber with a diaphragm can be applied to calculate an absorber without a diaphragm.

Anti-shock pneumohydraulic damper

“…When solving the problem of determining the main parameters and dimensions of hydraulic shock dampers in a pipeline in a general form, in the presence of dampers in the place of perturbation of the flow, the following three equations are used [3,7,10,11]. The differential equation of acting forces obtained as a result of transformations of the known Navier-Stokes dependences and having the form [3,7,10]…”

“…The equation expressing the law of change in the volume of air in the damper has the following form [3,7,10]…”

“…The above equations have the following notation: ϑ and H are flow velocity and the absolute pressure in the pipeline at the damper installation site at time t; Q is flow rate of the fluid during steady motion; β is coefficient of momentum; x is coordinate along the length of the pipeline; ρ is liquid density; R is hydraulic radius of the pipe; τ nu is shear stress at the pipe wall in unsteady flow; g is acceleration of gravity; V is volume of air in the damper at the moment t; V 1 is increase in the volume of air in the damper; V г is volume of air in the damper at the absolute geodetic head H o-a (Fig. 1); n is polytropic index [3,4].…”

“…Currently, to dampen the force of hydraulic shock that occurs in a long pressure pipeline, pneumohydraulic dampers are widely used [1][2][3][4][5][6][7]. Similar anti-shock devices (dampers) can protect water supply pipelines from water hammers.…”

“…Similar anti-shock devices (dampers) can protect water supply pipelines from water hammers. When installing a damper at the beginning of pressure pipelines of pumping stations, their dimensions are determined by the conditions for starting and stopping pumps [3,4,7,8,9]. Dampers are calculated in different ways according to the conditions for stopping the pumps.…”