Abstract
The application of splitter blades can improve passage obstructions and reduce flow loss of small-scale organic Rankine cycle (ORC) radial inflow turbines. In this study, taking R245fa as the working fluid, splitter blades are applied to design an impeller layout for a 10 kW ORC radial inflow turbine, and numerical simulation is conducted on different impeller schemes through Fluent 15.0. The influence of the meridian length and circumferential position of the splitter blade on the performance of the turbine impeller is studied. The results show that the meridian length and circumferential position of the splitter blade exert greater effects on the flow field distribution inside the impeller and the impeller performance. When the circumferential offset of the splitter blade is around 0.6 and the blade length is around 80% of the length of main blade, the ORC radial inflow turbine designed in this study reaches optimum performance, and its performance is better than the traditional impeller.
Highlights
The organic Rankine cycle (ORC) system is one of the most effective ways to use low-temperature waste heat for power generation, and it is widely used in geothermal, biomass, and other low-grade energy power generation fields [1,2,3]
When the residualofofthe each parameter was lower than 10−5, it was regarded as the calcula3.1
The numerical prediction was validated by the experimental data from reference [35], wherein the radial turbine operating with R12 refrigerant as a working fluid was experimentally investigated
Summary
The organic Rankine cycle (ORC) system is one of the most effective ways to use low-temperature waste heat for power generation, and it is widely used in geothermal, biomass, and other low-grade energy power generation fields [1,2,3]. Compared with the Rankine cycle using water as a working fluid, the ORC system can recover low-grade energy below 370 ◦ C, which has the characteristics of high efficiency, a relatively simple and compact system, low operation and maintenance costs, and remarkable economic benefits [4,5]. The expander is a key part of the ORC system, and the main types include the radial turbine, axial turbine, and the scroll [6,7]. For the characteristics of compact structure, small size, large stage enthalpy drops, high expansion ratio, and superior efficiency, the radial inflow turbine is the main type used in commercial ORC plants [8,9,10]. Glassman et al [11] researched loss models, and compiled the program for the 1D aerodynamic design method of radial inflow turbines
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