| Transportation of liquid is widely present in all kinds of production and life.According to previous statistics,the power consumed by the pump set and its supporting systems accounted for about 20%of the global industrial production.The performance of the pump is a key factor affecting its energy consumption.In actual engineering,the viscosity of the liquid to be transported is generally higher than that of water.Using an inappropriate pump to transport the high-viscosity liquid will seriously affect its performance and cause energy waste.Efficiency is an important technical indicator to measure the performance of the pump.As the core equipment of the liquid delivery system,improving the efficiency of the pump can greatly reduce the power consumption of the liquid delivery system,which is of great significance to the sustainable development of the national economy.Existing pumps have restricted their development due to their own defects.In view of the above problems,this paper takes Wankel pump as the research object,and uses theoretical analysis,laboratory tests and numerical simulation to discuss the effect mechanism of liquid viscosity on its performance.The working performance change law of Wankel pump when transporting viscous liquid under different working conditions is studied.Taking the total efficiency as the evaluation index,the liquid viscosity and working conditions suitable for Wankel pump transportation are proposed,and the pump is proposed to improve the measures.The specific research results are as follows:(1)According to the geometric structure and motion law of Wankel pump,the mechanical loss model is established,and the dynamic analysis of the pump sealing system is carried out.The relationship between the parameters of the liquid medium in the pump working chamber and the mechanical loss is established,and the effect of liquid viscosity on pump mechanical efficiency was studied.(2)The form of the flow resistance of the liquid in the Wankel pump was studied,and the hydraulic loss model inside the Wankel pump was established.By analyzing the causes and influencing factors of the two types of flow resistance(the route loss and local loss),the main factors affecting the hydraulic loss were proposed.(3)The leakage path inside the Wankel pump was analyzed,the flow law at the radial gap of the pump was studied based on the parallel plate flow model,the flow loss model caused by liquid leakage was established,and the effect of liquid viscosity on the volumetric efficiency of the pump was studied.(4)The laboratory test of the performance of Wankel pumps when transporting liquids with different viscosities was carried out.The influence of the three factors of liquid viscosity,spindle speed and working pressure on the working characteristics of Wankel pumps was studied.Based on the total efficiency,the viscosity range and working conditions of the liquid suitable for Wankel pump delivery were determined,and the working method for the delivery of viscous liquid is proposed,and the pump is proposed to improve the measures.(5)According to the geometric structure and motion law of Wankel pump,its three-dimensional flow channel model was established based on XFlow numerical simulation software.The lattice Boltzmann method was used to simulate the liquid flow state inside the pump when the liquid of different viscosity was transported,and the change law of its internal flow field characteristics was analyzed.Improvement measures are also proposed for important parts of the pump. |
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