Session: 08-05: Computational Fluid Dynamics (CFD) and Applications - V

Paper Number: 135197

135197 - Hydrodynamic Characteristics of Single Phase Flowing Through Orifice Plate 

Abstract: 

Gas and liquid concurrent flow through the sieve hole and sieve plate packing is an effective gas–liquid contact mode, and the industrial equipment involving this flow mode has been widely used in radioactive wastewater treatment due to its advantages of simple structure, high operating flexibility, no liquid flooding, and so on. For example, in the degassing section of the TEP system in nuclear power wastewater treatment, the fission gas accounts for more than 90% of the radioactive components of the coolant. In order to significantly reduce the ratio of purification, and to ensure the heat transfer of the evaporative sequence condenser in subsequent sections, it is required that the degassing rate of the TEP system must be greater than 99%. In the TEP system, the degassing device is a sieve plate pacing tower involving the gas–liquid contact mode aforementioned. However, the hydrodynamics of this contact mode are still blank so far, and thus the design of the packing tower involving this flow mode is mainly based on experience and simulation. As the core unit of the sieve plate packing, the orifice plate plays an important role between gas and liquid. In addition to this, the orifice plate also as key components, such as throttle component, flow measurement component and pipe entry component, is very important to match system resistance, flow measurement, cavitation elimination, eddy current control and fluid distribution in large heat and mass transfer equipment. The hydrodynamic characteristics of a single fluid flowing through an orifice plate were experimentally studied. Also, it’s flow behaviors were simulated by using computational fluid dynamics. It was found that the pressure drop of single phase flowing through the orifice is mainly caused by the contraction and expansion of the fluid. With increasing flowrate, the contraction effect of the fluid more obvious is and the larger the pressure drop is. Moreover, the pressure drop increases exponentially with increasing flowrate. The smaller the orifice diameter, the larger the velocity of the fluid is and the more obvious the contraction effect of the fluid after passing through the orifice is, and thus the larger the pressure drop is. The smaller the orifice relative thickness, the greater the velocity of the fluid along the axis after passing through the orifice is and the stronger the contraction effect of the fluid after passing through the orifice is, thus the greater the pressure drop is. The research on this characteristic of single fluid passing through orifice is expected to provide support for the optimal design of sieve plate packed tower and other large heat and mass transfer equipment.

Presenting Author: Xiao Deng Key Laboratory on Reactor System Design Technology, Nuclear Power Institute of China

Presenting Author Biography: Associate research fellow of Key Laboratory on Reactor System Design Technology, Nuclear Power Institute of China

Authors:

Min Qiao CNNC Key Laboratory on Nuclear Reactor Thermal Hydraulics Technology
Xiao Deng Key Laboratory on Reactor System Design Technology, Nuclear Power Institute of China
Dawei Pan School of Chemical Engineering, Sichuan University
Weixing Huang School of Chemical Engineering, Sichuan University, Sichuan Chengdu