Numerical investigation on the performance of gas-lift pump with large density ratio of liquid to gas

Heavy liquid metals such as sodium and liquid lead-bismuth eutectic (LBE) have excellent heat transfer capa-bility and receive increasing attention as the primary coolant in fast reactors and accelerator driven systems (ADS). In ADS system, coolant system is designed as natural circulation, to simplify the primary system, improve the compactness of reactors and most important of all is to increase the inherent safety of reactor. Because the electromagnetic pump that drives the flow of liquid metal is eliminated in the coolant natural circulation system. In such situation, gas-lift technique named gas-lift pump could be adopted to enhance the coolant natural cir-culation capacity. The open research on the performance of gas-lift liquid metal pump is much less than that of air-lift water pump. The physical properties of large density ratio of liquid to gas, small kinematic viscosity and high surface tension of liquid metal is believed to have effects on the performance of gas-lift liquid metal pump. The present paper carries out some preliminary numerical simulation work on the two-phase flow characteristics of argon-liquid LBE in the up-riser tube and the performance of gas-lift liquid metal pump. Eulerian-Eulerian two-fluid model is used to describe the two-phase flow. Some interphase momentum transfer models from literature are used to account for the interfacial momentum transfer between liquid and gas phases. SST k-omega model with mixture treatment is used to compute the turbulence parameters of the homogeneous mixing phase in the present study. The influence of such parameters as argon injection superficial velocity, submergence ratio and diameter of up-riser tube on the discharged LBE mass flow rate and pressure drop of gas-lift pump are checked. The results could be helpful for the design of the gas-lift liquid metal pump.