Energy loss mechanism of a full tubular pump under reverse power generation conditions using entropy production theory

Abstract

This paper investigates the energy dissipation mechanism of the internal flow field of the full tubular pump during reverse power generation and pump conditions, utilizing CFD and model test methods to research the device’s hydraulic characteristics, internal flow field and entropy production. The results indicate that the reverse power generation and pump conditions’ performance curves have opposite trends. Under PRPG conditions, the flow uniformity and weighted average angle of the impeller inlet flow field are smaller and the inlet flow field is poor. The stator-rotor gap flow under PRPG conditions increases with the increase in total flow, the gap flow under the design flow is 2.88 L/s, and the torque is 7.35 N·m. Under the PRPG condition, the turbulent and wall entropy production ratio increases gradually with the flow increase. Under the design flow rate, the entropy production rate of the impeller is 55.07%, and the entropy production rate of the impeller is the largest among the components under different flow rates. The entropy production of the outlet channel rises significantly with the flow rate. The research results of this paper provide a theoretical basis for the distribution of energy loss in reverse power generation of the full tubular pump.