The influence of gas-liquid two-phase flow on turbines
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Ladies and gentlemen, our facility plans to install a hydraulic turbine for residual pressure recovery on the rich amine liquid pipeline of the decarbonization system. Since the rich liquid absorbs CO2, a large portion of this gas is released upon depressurization, resulting in a two-phase mixture. I would like to know whether this will have a significant impact on the stable operation of our turbine as well as its recovery efficiency Is there no solution either?
If possible, install a larger vapor-liquid equilibrium tank
There will definitely be an impact； Including impeller seals and the like
Regarding the phase change of the medium alone, whether stable operation is affected depends, on the one hand, on whether gas entrapment and cavitation occur, and on the other hand, on the changes in the radial and axial forces acting on the turbine rotor. In the chemical industry, hydraulic turbines are essentially centrifugal pumps that have been modified by reversing their operation. Medium with high potential energy (high inlet pressure) enters the hydraulic turbine’s inlet; no external air can enter, so there is no risk of vapor lock. Due to the high inlet pressure, cavitation does not occur in the high-pressure area at the turbine inlet. Cavitation may occur in the low-pressure area at the turbine outlet, where gas can escape, but its primary function remains to generate power, similar to that of an expander. Cavitation is not a significant issue here, as proven by practical experience – there are hardly any records of cavitation occurring in turbine pumps. Therefore, the effect of vapor lock due to cavitation does not exist. Radial and axial forces have a certain impact, which should be taken into account when designing turbine pumps, especially regarding sealing. Regarding recovery efficiency, the amine-rich liquid should be sent to the stripping tower after passing through a turbine pump, which should be beneficial for stripping.