Research On Multi-functional Fusion Reverse Osmosis Desalination Variable Speed Piston Motor Pump Motor

China is one of the countries in the world with extremely scarce water resources.As an effective way to alleviate the shortage of water resources,reverse osmosis seawater desalination technology has received more and more attention in recent years and has been rapidly developed and applied.However,the traditional reverse osmosis seawater desalination system has many components and each component is installed independently,thus limiting the improvement of the working efficiency of the entire desalination system and the promotion and application in scenarios and working conditions such as small space or power shortage.In view of the problems of the above reverse osmosis seawater desalination system,such as low integration,low work efficiency and large installation space,this dissertation organically integrates multiple components in the desalination system,and innovatively proposes a multi-functional fusion reverse osmosis seawater desalination variable speed piston motor pump motor that integrates pressurization function,booster function,energy recovery function and driving function.The main dynamic characteristics and multi-parameter multi-objective optimization of the motor pump motor are studied,and the influence of the key parameters of the motor pump motor on its dynamic characteristics is revealed,which strongly supports the research and development and the research on key technologies of the motor pump motor.The high-pressure plunger pump,booster pump,energy recovery device and drive motor in the desalination system are organically integrated,and amultifunctional fusion reverse osmosis desalination variable speed piston motor pump motor is innovatively proposed.The principle and structure of the multifunctional fusion reverse osmosis desalination variable speed piston motor pump motor are analyzed.The integrated design of the reverse osmosis seawater desalination system greatly reduces the space required for installation,and further improves the working efficiency of the whole system.Taking the piston pump in the variable speed piston motor pump motor for reverse osmosis seawater desalination as the research object,the research on the pressure and flow characteristics of different concentrations of seawater in the piston pump at different key parameters is carried out.The influence of operating parameters and structural parameters on its pressure and flow characteristics.The complex leakage characteristics and mutual mixing characteristics of different concentrations of seawater at different friction pairs in the piston pump are theoretically analyzed,and a mathematical model of seawater leakage and mutual mixing of different concentrations is constructed.A detailed numerical analysis is carried out on the influence of the key parameters of the piston pump on the leakage and mutual mixing characteristics of seawater with different concentrations at the distribution pair.Based on the theories of computational fluid dynamics,electromagnetism and heat transfer,and comprehensively using the electromagnetic field analysis model,fluid flow model and fluid-solid coupling heat conduction model,a multi-field coupling model such as electric field,magnetic field,flow field,and temperature field is constructed.The main heat-generating components in the working process of the motor pump motor are analyzed,and the mathematical model of the loss of each heat-generating component is constructed.At the same time,based on the multi-field coupling model,the research and analysis of the self-cooling characteristics of the motor pump motor are carried out.The influence of different key structural parameters of the self-cooling flow channel on the self-cooling characteristics of the motor pump motor is revealed,which provides an effective optimization method for improving the self-cooling characteristics of the motor pump motor.Based on orthogonal test,BP neural network and genetic algorithm,the multiparameter and multi-objective optimization of the motor pump motor is carried out.In the multi-parameter and multi-objective optimization of the motor pump motor,the cylinder speed,the raw seawater inlet pressure,the thickness of the liquid film,the width of the damping groove,the wrap angle of the damping groove and the depth of the damping groove are selected as 6 key parameters and the raw seawater cavity pressure pulsation rate,the raw seawater outlet flow pulsation rate and the seawater average concentration in the raw seawater distribution windows are selected as 3 characteristic indicators.Finally,the influence weight of each parameter on the comprehensive characteristic index of the motor pump motor is determined,and the optimal parameter combination in the global scope is obtained under the premise of the multi-objective comprehensive optimization of the motor pump motor.The prototype of variable speed piston motor pump motor for reverse osmosis seawater desalination was processed and manufactured,and the dynamic characteristics of the motor pump motor at different rotation speeds were tested and analyzed,so as to obtain the dynamic characteristics of the motor pump motor at different speeds,and verify the feasibility and rationality of the structure of the motor pump motor.It lays a solid foundation for the research and development and the research on key technologies of this new type of reverse osmosis seawater desalination variable speed piston motor pump motor,and provides the main dynamic characteristic data of the motor pump motor.The results of this dissertation have important theoretical guiding significance for further expanding the integrated design theory of reverse osmosis desalination systems and enriching the research on dynamic characteristics of integrated reverse osmosis desalination power components.It is of great practical significance to further reduce the installation space of the reverse osmosis seawater desalination system,improve the integration degree and work efficiency of the reverse osmosis seawater desalination system,and at the same time improve the independent innovation capability and equipment upgrade of the key equipment of the reverse osmosis seawater desalination system of China.