Experimental And Numerical Simulation Research On Energy Recovery Process Of Rotary Pressure Booster

Rotary Pressure Booster (RPB) is a typical technique which recovers pressure energy through direct contact between high and low pressure fluids. Due to its simple structure, easy operation, stability and high recovery efficiency, RPB has been widely used for energy recovery in process industries such as Seawater Reverse Osmosis (SWRO).In recent over20years, there is ever no public and sophisticated report on theoretical analysis and experimental research of Rotary Pressure Booster (RPB) possibly due to the technological secret and complexity of its own. Therefore, in this paper the Rotary Pressure Booster (RPB) was designed, and so was experimental system with RPB equipment. As RPB devices use direct contact of fluids to realize pressure energy recovery, this brings it about two core problems-effective control of fluid mixing and achieve face seal. Based on those two points, this paper will use numerical simulation and experimental research to study and analyze fluid mixing inside of rotor duct and face seal between rotor and stator.The main research and results were as following:(1) The experimental system with RPB equipment as energy recovery unit was set up and the Rotary Pressure Booster (RPB) was designed, manufactured and assembled respectively. In this paper, the experiments of characteristics of face seal and fluid energy recovery were carried out on the experimental system. In addition, Contrast analysis on the experimental results and the numerical calculation results of leakage, is one of the simple and effective methods to judger the rotation of rotor.(2) The mechanism of face seal between rotor and stator played the very important role in the RPB’s energy recovery process. In order to get the mechanism of seal and the way to make it reached,3D numerical simulation on seal zone were used. The model is proven to be rational and valid, comparing the experiment results with theoretical analysis. The relationship of leakage with differential pressure, gap, rotary speed and wall thickness was deeply studied. The simulation results indicate that the leakage grows with the rise of the gap. The research of rotary speed shows that the rotary speed influences heavily on the tangential velocity, while it has little effect on leakage, and even can be ignored. This paper also studies the influence of rotor channel wall thickness on leakage, it is found that with the increase of the wall thickness, leakage decreases, but the gradient of decrease reduces. (3)3D model is set up in order to simulate the mixing process in RPB’s duct. This model successfully describes the fluid mass transportation at transient contact inside the duct. During the above process, a stable plume piston is formed. Effects of rotary speed and inlet flow rate on RPB’s volumetric mixing, maximum entrance length and effective volume rate is studied. What’s more, volumetric mixing, maximum entrance length and effective volume rate is In direct proportion relationship with inlet flow rate. Rotary speed is just the opposite. There is the optimization composition of these parameters, which was the basis of RPB optimum design principle.