The Design And Performance Analysis For Elliptic Conjugate Rotor Pump

Currently, forest fires occur frequently in our country. This would not only cause great harm to the ecological environment, will be a threat to the lives’safety of wildlife and forest dwellers. Compared with the advanced forest fighting system in foreign, China’s forest fire control technology is still in its infancy. Because of China’s forest coverage mostly in remote areas, the portable fire pump become the most practical forest fire-fighting equipment.In order to improve the performance of the fire pump, this article presents an idea that apply the conjugate rotor pump to fire pump. And a new design theory and method for the profile design of conjugate pump rotor is proposed. This method combines the generating method and the theory of envelope curves to get the conjugate analytic expression, and it is suitable for any parameter expressed curves. Take arc-type rotor profile for example, the profile generated by the new method is same to the profile generated by the conventional method, thus proving the accuracy of the method.On the basis of the traditional cycloidal and arc-type rotor pump, the paper proposes the design of elliptic conjugate rotor pump. The volumetric efficiency of the pump is used as comparison object, and the performance comparison foe the three types of rotor pump was done. The comparison results indicate that Elliptic rotor pump has the highest volumetric efficiency and the largest adjustment range. The shaft of rotor pump is designed at the goal design state in 2MPa, and the physical performance was tested. The test results show that the largest outlet pressure can be achieved 1.726MPa under the condition that the outlet diameter is 10mm, slightly lower than the design goal.Based on the experimental test data, this article uses the Fluent software to simulate the fluid motion of elliptic conjugate rotor pump whose rotational speed is 600r/min. The simulation results show that the import and export of the pump has vortex, the clearance has reflux, and outlet flow has pulsation. These are the reasons for reducing the energy, reducing the volumetric efficiency as well as noise. Then, the analysis for the impact of speed on the flow fluctuation coefficient was done. The results show that when the pump has higher speed, it will have a greater flow fluctuation coefficient. Therefore, at the desired lift is not very high, as much as possible make the pump speed maintained at 600r/min or less.