| High pressure syringe pump is a core component widely used in various analytical instruments.With the advancement of science and technology,miniaturization and intelligence have become important development trends of modern scientific research instruments,Micro-flow high-pressure syringe pump has become the focus and difficulty in the development of analytical instruments.The main problems of high-pressure syringe pumps are that the flow span is not large enough and the switching magnitude is small;it cannot guarantee long-term stable operation under high-pressure conditions;it cannot achieve specific occasions(high temperature、high pressure、strong acid and alkali)and accurate metering of ultra-fine flow and free delivery.At present,domestic research on high-pressure syringe pumps is still inadequate,and related foreign products are expensive.Therefore,it is particularly important to carry out targeted research and development.This article is based on the problem that high-pressure syringe pumps are difficult to achieve ultra-fine flow and accurate metering and stable delivery of fluids across multiple scales under specific conditions.The new high-pressure syringe pumps are designed from the overall structure and core components,and the selection of materials and seals.In terms of theoretical analysis,structural innovation and numerical simulation.The main research work includes:(1)Aiming at the problems of the existing high-pressure syringe pumps,designed a four-stage syringe pump unit with a flow range of(10n L / s ～ 4m L / s).Each stage of the syringe pump unit has a different flow range and pressure setting,and uses a more stable lead screw transmission method,and the relevant innovative design of the overall structure of the pump body is made,which lays the foundation for the stable operation of the pump under high pressure conditions.(2)Aiming at the problems in the design process of the most prone to check valve components of high-pressure syringe pumps,corresponding optimization and improvement were made from the aspects of mechanical analysis and ball valve movement laws,It provides a theoretical guarantee for improving the working accuracy of check valve components.(3)Based on the laminar flow model and Realizable k-epsilon turbulence model,this paper uses ANSYS CFD technology to numerically simulate the two-dimensional incompressible flow field inside the check valve and the pump cavity,from the speed residual curve and outlet flow changes,and related post-processing images,It is proved that the designed four-stage syringe pump unit can achieve constant flow under high pressure conditions and the check valve of each level of syringe pump can stably complete the set range.(4)In order to make the high-pressure syringe pump meet the work under specific working conditions,this article has carried out relevant selection and design from the aspects of material selection and sealing.The four-stage syringe pump unit pump body uses 316 L stainless steel,which is widely used in chemical,medical and other fields,and has excellent corrosion resistance and good comprehensive mechanical properties as the manufacturing material.At the same time,in order to cope with high-pressure working conditions,a high-pressure sealing ring made of a special material and a corresponding high-pressure sealing method are designed.This article uses a four-stage syringe pump unit,which can meet the conditions of working under high pressure in terms of structure、materials,、design and sealing.The corresponding numerical simulation by ANSYS CFD has confirmed that the syringe pump unit can achieve constant flow under high pressure conditions,based on the hierarchical joint control technology,various valves can be automatically switched,and a combination of syringe pump units can be selectively constructed,and the stepper motor can be used to achieve ultra-fine flow rate and fluid transmission and metering across multiple scales.Has higher application value. |
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