Simulation And Optimization Of Self-driven Rotary Pressure Exchanger On The Basis Of Salinity Gradient Power Generation System

Salinity gradient energy is new, clean, non-polluting and renewable. Salinitygradient energy comes as the chemical potential difference between seawater andfresh water or two kinds of seawater with different salinity, so it exists in the form ofchemical energy in the ocean. Salinity gradient energy has large reserves and highenergy density per unit area. If salinity gradient energy could be transformed intoelectricity, it would make a significant social and economic benefit.This paper is in reference of the latest salinity gradient energy generationtechnologies and combined with the research project of100W salinity gradient powergeneration in the laboratory. Through the analysis of principle, calculation ofparameters and principle experiment, a text system of salinity gradient powergeneration using the osmotic pressure difference method is established. As one of thecore devices in salinity gradient power generation system using the osmotic pressuredifference method, the performance of pressure exchanger has a great impact on theefficiency of salinity gradient power generation system. However, the currentproducts of pressure exchanger are mainly used in seawater reverse osmosis system.If the existing products are applied in salinity gradient power generation systemdirectly, their energy conversion efficiency would be much lower than the designedvalue. This paper tries to design a self-driven rotary pressure exchanger for theproject of100W salinity gradient power generation system.The main part in the design process of self-driven rotary pressure exchanger isthe rotor and the end cap. The design parameters of rotor include the structure andnumber of channel and other associated sizes. What’s the same, the cover’s maindesign parameters are the size of channel and internal structure of sump. Thestructural and size parameters of the designed pressure exchanger are determined bythe working environment of salinity gradient power generation system and the relateddesign theory. According to the designed parameters, the three-dimensional models of the rotor and cover could be drawn out with the help of SolidWorks. In order to havea further analysis on the core components, the three-dimensional models of the rotorand cover should be saved in the form of STEP and then imported into Gambit. In thissoftware, their grids could be drawn and working conditions of the initial designcould be set. After that, the working status of the core components would besimulated using Fluent. According to the simulation results and the later optimaldesign, a more reasonable design project would come out.