Supercritical CO 2 is a promising working fluid for next-generation power conversion systems. The key component of sCO 2 power generation systems is the turbomachinery, which includes a turbine. sCO 2 can attain low compression work because of its high density and low compressibility near the critical point compared to conventional air Brayton cycles. In addition, small size of sCO 2 turbine can be fabricated owing to their low volume flow rate and relatively high viscosity in the turbine operation range. However, there are technical challenges in the design and operation of such turbomachinery systems. Therefore, in this study, a 350-kW-class sCO 2 radial inflow turbine for a sCO 2 power generation system was designed and developed. The design points of the turbine, expansion ratio, and rotational speed were 1.2899 and 40,000 RPM. The turbine operation was experimentally investigated. The purpose of this test was to verify the normal operation of an sCO 2 pilot plant and the operability of an sCO 2 radial inflow turbine. Two tests were conducted: the turbine cold-run test and the commissioning test for turbine power generation. The turbine cold-run test was performed by controlling the rotational speed of the compressor impeller and the opening rate of the control valve without heat input from the waste heat recovery heat exchanger. A commissioning test of the turbine power generation was performed using the heat input from a waste heat recovery heat exchanger. The stable operation of the turbine was verified by evaluating sCO 2 radial inflow turbine, which succeeded in generating electric power.
Park et al. (Fri,) studied this question.