| Fresh water shortage has become a global problem in recent years.It has gradually become an important way to solve the water crisis in the world by using seawater desalination technology,which increase the total supply of fresh water.Reverse osmosis seawater desalination is the most recommended technology among the seawater desalination technologies,in order to cut down the costs of reverse osmosis seawater desalination and reduce the energy consumption of the system,it is necessary to recover energy that contained in the high pressure brine by the energy recovery device.Therefore,under the situation of water resources shortage in our country,it is particularly urgent and important to develop technology of reverse osmosis desalination,thus prepare reverse osmosis desalination integrated energy recovery device of high efficiency and low ripple.The article was focused on the Piston booster pump-pressure exchanger integrated energy recovery device for reverse osmosis seawater desalination(PPX),then developed the sample of PPX,in addition,the article analyzed mixing characteristics,flow characteristics and pressure exchange process of Pressure exchanger and integrated energy recovery device respectively,and set up a mathematical model of pressure field which takes port plate of PPX of tilt effect into consideration.Besides,the pressure distribution and leakage equation of the plate under different conditions were analyzed,and completed the optimal design of port plate of PPX.This major research work are as follows:(1)Summarized the development of desalination technology in the domestic and foreign research,compared performance characteristics and development status of several energy recovery device and rotary pressure exchanger of reverse osmosis desalination,thus put forward the research of PPX,and the article solve the key technical problems of PPX device which was difficulties in the past theory research.(2)Designed a simple reverse osmosis seawater system which set the water production as destination function,the article studied the dynamic process of the pressure distribution in PPX with the certain working parameters of component and carried out the structure design of the pressure exchanger and the plunger pump.(3)Established the numerical simulation of the turbulent flow model of CFD and the pressure control model of the pressure exchanger under the premise of considering the lubrication characteristics of the leakage of port plate and the compressibility of the water,then simulated the internal flow field and pressure exchange process of the pressure exchanger and the integrated energy recovery device with different clearances by PumpLinx.Thus determined the optimum matching relations of different parameters of pressure exchanger.Besides,the transient flow field,flow rateand pressure overshoot of the pressure exchanger were studied in this paper.Furthermore,the pressure and flow pulsation characteristics of booster pump were studied under the condition of high backpressure suction(4)With the consideration of the clearance between the plate and the cylinder,obtained the analytical solution and the leakage equation of pressure field of the inner and outer sealing zone in the high pressure area under the influence of the unloading,and studied the distribution of pressure field and leakage in different clearance.(5)In order to reduce the pv value,leakage and viscous friction power loss,based on genetic algorithm,the multi-objective optimization problem of the port plate was calculated,the results show that the optimized results reduce the power loss and improve the volumetric efficiency of PPX.At last,the main research conclusion was summarized and the following work was forecasted. |
