Design of an Axial Flow Fan for a Unique Cooling Application

Abstract

Abstract A rotor-only axial flow fan is designed for use in a concentrated solar power application. The plant uses a supercritical carbon dioxide Brayton Cycle for power generation and an air-cooled heat exchanger (ACHE) for cooling. Fan specifications are derived by considering the geometry and air flow rate requirements for the ACHE, using simple, circular finned tube bundles. The specifications lead to a fan design with a relatively large hub-to-tip ratio of 0.5102. The fan’s performance is estimated numerically using a periodic three-dimensional model (P3DM) in both an annular computational domain and a computational domain representing a simplified ISO 5801 type A fan test facility. A 1:4.78 scale model of the fan was manufactured and tested in an ISO 5801 Type A fan test facility. Numerical fan performance results for the annular domain show good agreement with those predicted by the design procedure, for both the cases with no tip gap and the design tip gap size present. It also demonstrates the effect of the tip gap on the overall fan performance. Numerical results for the simplified ISO 5801 type A fan test facility indicates that fan performance is significantly worse than in the annular domain, due to the hub size of the fan being considered in this domain. The experimental results for the manufactured fan demonstrates the accuracy of the numerical methods used and provide the fan performance characteristics over a wide range of flowrates.