Multipoint Design Optimization of a Radial-Outflow Turbine for Kalina Cycle System Considering Flexible Operating Conditions and Variable Ammonia-Water Mass Fraction

Abstract

The radial-outflow turbine has advantages due to its liquid-rich gas adaptability when applied in the Kalina ammonia-water cycle system. However, the operational conditions of the turbine often deviate from its design values due to changes of the heat source or the cooling conditions, and such deviates may deteriorate the flow behavior and degrade the turbine performance. To enhance the turbine efficiency at complex conditions for flexible running of the Kalina cycle system, a multipoint design optimization method is developed: the flexible operating has been defined by three critical, dimensionless parameters, which cover a wide range in a 3D operating space; the representative off-design points are identified to define the objective function; and adaptive optimization methods are integrated to permit optimization searching using limited CFD callings. The developed multipoint design method is adopted to improve the turbine performance under complex operating conditions. The obtained results demonstrate that the application of the developed multipoint optimization method effectively eliminates the flow separation at various operating conditions; thus, the turbine off-design performance has been comprehensively improved.

Dynamic Modelling and Experimental Validation of a Pneumatic Radial Piston Motor

“…A significant shift towards renewable energy has been the primary focus of many areas and countries in the last decade. New applications for pneumatic motors such as small-scale expanders have been fit in effective exhaust or cooling systems such as the organic Rankine cycle and Kalina cycle [8,9] because heat-driven power generation process is exceptionally effective at low-temperature heat conversion. Waste-heat recovery has been a recent implementation and yields more efficient energy conversion that, in turn, decreases harmful pollution emissions on a large scale.…”