Abstract
The shaft front-positioned tubular pump device has been widely used in practical engineering, but the shaft rear-positioned pump device is rarely used due to its low efficiency. To investigate the effect of the shaft position on the performance of a tubular pump device, the optimized shaft front-positioned and shaft rear-positioned pump devices were compared and studied. Both tubular pump devices adopt a TJ04-ZL-06 pump model. Three dimensional steady and unsteady numerical simulations combined with model tests were used to compare the difference of two pump devices. Meanwhile, three groups of pressure monitoring points were set at different positions of the pump device to collect pressure information and pressure pulsation was analyzed. The results show that, the highest efficiency of the shaft front and rear positioned pump device are 81.78% and 80.26%, respectively. The hydraulic performance of the two inlet passages is excellent, and the hydraulic loss is close to each other. Therefore, the hydraulic performance of the pump device depends mainly on the hydraulic performance of the outlet passage. The shaft is set in the outlet passage, which will increase the hydraulic loss and reduce efficiency. Under design conditions, the pressure pulsation amplitude at the impeller inlet is the largest, and the pressure pulsation amplitude increases from the hub to the shroud. The pressure pulsation amplitude of the shaft rear-positioned pump device is larger than that of the shaft front-positioned pump device. The pressure pulsation at the impeller inlet and outlet is greatly affected by the number of blades, and the main frequency is three times the RF. This study can provide practical and effective guidance for the design and optimization of the shaft front-positioned and rear-positioned tubular pump devices, which has theoretical value and application value.
Highlights
Axial flow pump devices play a significant role in water diversion projects, environmental management and improvement projects, flood control applications and irrigation and drainage projects due to their large flow and low head characteristics [1]
Xu et al [6,7] performed a comprehensive study of commonly used tubular pump devices; the results showed that pre-shaft tubular pump devices have excellent hydraulic performance
The hydraulic performance of both pump devices is excellent, which exceeds the standard Chinese requirements (GB50265-2010) that the efficiency of axial flow pump stations and mixed flow pump stations should not be less than 70~75%
Summary
Axial flow pump devices play a significant role in water diversion projects, environmental management and improvement projects, flood control applications and irrigation and drainage projects due to their large flow and low head characteristics [1]. Lu et al [8] conducted a model experiment of a preshaft pump device of a low head pumping station and studied the hydraulic performance by adjusting the blade angle. The flow in the outlet passage of the rear shaft pump device is disordered and the head loss is relatively large, resulting in the efficiency of the device being lower than that of shaft front-positioned tubular pump devices. Many scholars have conducted studies on the optimization of shaft pump devices [12,13,14] They found that when the shaft is set in the outlet passage, the flow in the outlet passage will be disordered, and the hydraulic loss is large. The results show that the vibration of these pumps is closely related to unsteady pressure pulsations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
