工程科学与技术 (Nov 2024)
Study on Efficiency Expression and Conversion Method of Wankel Pump
Abstract
The Wankel pump, a novel rotor pump based on the Reuleaux triangle, can simultaneously deliver high flow and pressure with superior conveying performance. However, the current efficiency expressions and conversion theory for the Wankel pump are insufficient and do not offer guidance for designing and producing prototype pumps through hydraulic testing of model pumps in laboratories. Therefore, this study proposes a method for expressing and converting the efficiency of the Wankel pump based on the sub-parameter conversion method. Initially, the basic composition and operating principles of the Wankel pump are analyzed, and equations for the motion trajectory, velocity, and acceleration of the rotor vertex are established based on the cylinder profile. Then, the equation for calculating the head of the Wankel pump is derived from the energy conservation, and the similar relationship between the flow rate and head of the prototype pump and the model pump under equivalent working conditions is analyzed. Then, expressions for mechanical, hydraulic, and volumetric efficiency are constructed based on the structural characteristics of the pump, and the loss coefficients of each are derived by analyzing the composition of these expressions. A similar conversion method for each loss coefficient is then analyzed based on the analogous relationship between flow and head. An expression for the total efficiency and a similar conversion formula for the Wankel pump is established based on the relationship between loss and efficiency. Lastly, a hydraulic test system for the Wankel pump is constructed, and hydraulic performance tests of different models and speeds on Wankel pumps are conducted. The MATLAB genetic algorithm fits and analyzes the total efficiency expression, and a similar conversion formula is validated based on similar operating conditions. The results indicated that the goodness of fit of the Wankel pump's total efficiency expression for various speeds is > 0.80, while the average error of the similar conversion formula is <5% under comparable operating conditions, thus confirming their accuracy. This study is intended to predict the efficiency performance of the Wankel pump at various speeds and heads, providing a fundamental basis for the design and development of the Wankel pump.
