Performance and Sizes of sCO2 Multistage Axial Compressors at Various Power Capacities

The supercritical carbon dioxide (sCO(2)) cycle can be powered by traditional as well as clean energy. To help users obtain more accurate results than the literatures with pre-set compressor efficiency, we proposed a complete model to establish a link between the performance, sizes of compressors and parameters such as power W-C, inlet temperature T-in, inlet pressure P-in and pressure ratio epsilon. Characteristic sizes of compressors l(c), profile loss Y-p and clearance loss Y-cl are all proportional to powers of W-C with powers of 0.5,-0.075 and -0.5 to 0 respectively; the scaling laws are constant in the range of capacities from 20 MW to 200 MW. The compressor isentropic efficiency eta(tt) grows as the W-C increases, and the curves become gentle. Compressor efficiency improves over the full power range when the speed is changed from standard speed to the optimal speed; the eta(tt) curves turn soft as the n increase. As the P-in and T-in approach the critical point, the eta(tt) increase. Compressor efficiency follows a parabolic curve as the epsilon increases, this parabolic distribution results from the tradeoff between the change in losses and the pressure distribution of blades. The eta(tt) versus P-in, T-in and epsilon relations are similar at various capacities because of insignificant changes in the distribution of losses. Compressor efficiency maps facilitate the estimation of system performance, while scaling law for irreversible losses and characteristic lengths, along with constant criterion analyses, aid in comprehending the characteristics of compressors across various capacities.