Study on the Transient Characteristics of Pump During the Starting Process With Assisted Valve

Abstract

Among the various transient operations, the startup process of a centrifugal pump brings attention to a number of practical issues. A representative application of the startup process is the underwater launch, which requires transient high pressure and high flowrate during a very short time. Due to the rotational inertia of the pump and motor, the dynamic response of the pump is slow, so the rotational speed cannot reach the design point rapidly. To get a high response of the starting process, a throttle valve is installed in the downstream of the pump. The valve keeps closed before the rotational speed of the pump reaches a certain point. It is important to investigate the transient behavior of pump during such transient operations. In this paper, experiment and numerical simulation are implemented to study the external transient hydrodynamic performance and the internal flow of the pump during the transient process. Different operating schemes of the pump and valve are designed to find the best coordinated modes. The contents and conclusions of the current work can provide references for the performance prediction, design optimization and fluid control of the pump and valve during the transient process.

Influence of the Trailing Edge Shape of Impeller Blades on Centrifugal Pumps with Unsteady Characteristics

“…, m p p p = − (36) where the mean pressure, p , is the average value at a certain measurement point over one complete revolution of the impeller. m p is selected as a reference value, which is the pressure value of a single monitoring point minus p .…”

“…The DMD method was first proposed by Schmid [24,25], and with the development of experimental technology and numerical calculations, it has been widely employed in the analysis of various flow phenomena [26][27][28][29][30]. For example, the DMD method has been used to analyze the internal flow structures of rotating machinery [31][32][33][34][35][36]. DMD primarily focuses on analyzing the changes in a variable field at specific frequencies, with a significant impact on the flow field resulting from changes in the trailing edge.…”

Analysis of internal flow characteristics of a multistage pump during start-up

“…During the start-up of a centrifugal pump, the rotor components experience stress responses over time, which impacts fatigue damage to impeller hub and pump shaft [7]. Li W [8] studied the stress and deformation of the impeller under steady state, transient conditions for an axial flow pump based on a two-way altering fluid-structure interaction method. It was found that under the combined effect of the changing internal flow field and centrifugal force during start-up, the deformation had increased by 68.7% compared to the steady state condition, making it more prone to fatigue damage.…”

Hydraulic loss characteristics of closed-loop piping system during start-up process of mixed-flow pump

“…The velocity, streamline, pressure distribution, and vortex core development laws of different cross-sectional positions were investigated. Qiao et al. (2017) installed a throttle valve downstream the pump to get a high response in the starting process.…”