Research On Solid-liquid Two-phase Three-dimensional Turbulence And Erosion Characteristics Of Slurry Pump

Centrifugal slurry pump is a critical equipment of solid-liquid fluid transmission, widely used in mining, metallurgy, water conservancy, electricity and environmental protection. The presence of rigid solid particle of slurry and strongly erosion wear role of slurry impact on slurry pump lead to outstanding problems about low efficiency in use and short life of pump parts. China is the world's leading consumer of slurry pump but the technical level of China compared with developed countries, there exists a large gap. High-end domestic slurry pump product was only 30% self-sufficiency in China, and compared to similar foreign advanced slurry pump products, the efficiency generally 5% lower to 15%. In the same working conditions, foreign parts of slurry pump life 10% higher than the domestic product to 50%.The breakthrough of research methods and design theory is a essential way to enhance China's slurry pump technology. In view of the present gap of China's slurry pump technology with the international advanced level and limitations of slurry pump design method which based on water pump experience coefficient method. Based on three-dimensional turbulent theory of solid-liquid two-phase flow and combination of numerical methods of computational fluid dynamics, studies of slurry flow field, solid particle erosion characteristics in slurry pump and wear of pump parts are carried on. Several typical flow structure over the slurry pump design and performance prediction methods based on numerical calculation have been proposed.Which order for provide the basis for the development of energy, low wear performance slurry pump, and order for high-end slurry pump out of the situation of long-term dependence on imports.Thesis research content and results are as follows:1. Based on the two-fluid model theory of solid-liquid two-phase, derived the basic equation of centrifugal slurry pump, respectively, flow control equation of solid-liquid two-phase in centrifugal slurry pump is established based on two-fluid model and the discrete phase model. 2. Constructed with more complex geometries of centrifugal slurry pumps full three-dimensional flow model of computing grid. Proposed slurry rotating flow field region and the non-rotating flow field region grid connection method. Base on finite volume method for discretization of slurry flow control equation and SIMPLEC algorithm for flow field calculation, computational fluid dynamics analysis method of solid-liquid two-phase three-dimensional flow in slurry pump is established. Solving strategies, methods and technology of three-dimensional turbulence in centrifugal slurry pump whole flow passage is proposed. Computational fluid dynamics analysis method is the foundation for numerical simulation of slurry pump and other solid-liquid two-phase fluid machinery.3. Based on the application of computational fluid dynamics analysis method, numerical simulation of solid-liquid two-phase flow in centrifugal slurry pump is conducted. The rule about solid-liquid two-phase pressure field and characteristics such as head, efficiency and cavitation of slurry pump are studied. Formed performance prediction method and parts optimization design method based on numerical calculation of slurry pump.4. Based on comprehensive application of mechanics, computational fluid dynamics, tribology and materials science theories, the erosion behavior of solid particles and wear mechanism studies of slurry pump is carried out by means of numerical simulation. Analysis of blade parameters and slurry properties on the influence of the slurry pump is made. Prediction about erosion wear of slurry pump is carried out. The low-wear centrifugal slurry pump optimization design methods and practical data are formed.5. Study about material selection, casting processing, heat treatment processing and mechanical processing technology of slurry pump parts manufacture is carried out. The slurry pump use in experiment is developed. By centrifugal slurry pump experiments, slurry pump head, efficiency, cavitation and wear properties such as test results and numerical simulation results have good agreement.6. Developed a high efficiency, low wear 250/200-ZJB type centrifugal slurry pump, performance indicators are:Rated flow Q= 300m3/h, rotational speed n=960r/min, slurry efficiencyηm=68%, impeller life of 800 hours. Performance reached a similar level of international advanced slurry pump product, and have very good results in engineering applications.