Supercritical carbon dioxide Brayton cycle offers numerous advantages,including high efficiency,compact design,low compression power consumption,and excellent heat source adaptability,making it a promising solution fo...Supercritical carbon dioxide Brayton cycle offers numerous advantages,including high efficiency,compact design,low compression power consumption,and excellent heat source adaptability,making it a promising solution for power systems.This is due to the favorable thermal properties of CO_(2)as the circulating working fluid near its critical point.To optimize efficiency,the compressor must operate with CO_(2)near its critical point.However,the physical properties of CO_(2)near the critical point change non-linearly,impacting compressor stability.Condensation can occur at the compressor inlet.Most studies have focused on regulating the inlet condition and anti-condensation design.Fewer studies have explored changes to the inlet structure,flow uniformity,or added inflow cone devices.In this study,the sCO_(2)compressor inlet structure is optimized with two cones of varying aspect ratios and shapes.The impact of these structures on performance and flow uniformity is explored.The results show that ellipsoidal cones improve isentropic efficiency,enhance flow uniformity,reduce energy losses,achieving an efficiency increase of up to 1%at the peak efficiency point and under low-flow conditions,and 0.78%under high-flow conditions.Among the tested geometries,the cone with a 2:1 aspect ratio demonstrates the best performance.While structures of cylindrical cones are less effective;compared with non-cone compressors,they still simplify flow paths and improve flow stability.In addition,cone structures reduce density and viscosity gradients compared with the non-cone case,with the ellipsoidal cone performing the best and highlighting property regulation as a key factor in suppressing condensation.Furthermore,both cone types effectively reduce condensation areas and CO_(2)liquid-phase distribution,with ellipsoidal cones stabilizing flow and minimizing pressure loss.展开更多
基金the supports of National Natural Science Foundation of China (Grant Nos.52076079,52406047)Fundamental Research Funds for the Central Universities (Grant No. 2025MS114)+1 种基金Science Research Project of Hebei Education Department (QN 2025174)Hebei Province Graduate Innovation Funding Project (Grant No. CXZZBS2024165).
文摘Supercritical carbon dioxide Brayton cycle offers numerous advantages,including high efficiency,compact design,low compression power consumption,and excellent heat source adaptability,making it a promising solution for power systems.This is due to the favorable thermal properties of CO_(2)as the circulating working fluid near its critical point.To optimize efficiency,the compressor must operate with CO_(2)near its critical point.However,the physical properties of CO_(2)near the critical point change non-linearly,impacting compressor stability.Condensation can occur at the compressor inlet.Most studies have focused on regulating the inlet condition and anti-condensation design.Fewer studies have explored changes to the inlet structure,flow uniformity,or added inflow cone devices.In this study,the sCO_(2)compressor inlet structure is optimized with two cones of varying aspect ratios and shapes.The impact of these structures on performance and flow uniformity is explored.The results show that ellipsoidal cones improve isentropic efficiency,enhance flow uniformity,reduce energy losses,achieving an efficiency increase of up to 1%at the peak efficiency point and under low-flow conditions,and 0.78%under high-flow conditions.Among the tested geometries,the cone with a 2:1 aspect ratio demonstrates the best performance.While structures of cylindrical cones are less effective;compared with non-cone compressors,they still simplify flow paths and improve flow stability.In addition,cone structures reduce density and viscosity gradients compared with the non-cone case,with the ellipsoidal cone performing the best and highlighting property regulation as a key factor in suppressing condensation.Furthermore,both cone types effectively reduce condensation areas and CO_(2)liquid-phase distribution,with ellipsoidal cones stabilizing flow and minimizing pressure loss.
