Flow through a solar chimney power plant collector-to-chimney transition section

[摘要] ENGLISH ABSTRACT: One of the areas of the fluid dynamic design of solar chimney power plants that hasnot been investigated sufficiently is the collector-to-chimney transition section of asingle turbine layout. The transition section contains the turbine inlet guide vanes(IGVs) that support the whole chimney and guide the flow entering the turbine. Theprimary objective of the study was to determine the dependence of the loss coefficientof the section on inlet guide vane stagger angle and collector roof height. Experimentswere done on a nominal 900 mm chimney diameter rig, with four combinations oftwo collector roof heights and two IGV stagger angles. Velocity components andpressures in the transition section were measured in three conical planes, respectivelyat the IGV exit and midway to, and just below the turbine position, using a five-holepneumatic pressure probe. Very good agreement was found between experimentalvalues and commercial CFD code predictions of flow angles, velocity componentsand internal and wall static pressures. The agreement between measured and predictedtotal pressure loss coefficient was reasonable when considering that most of the lossoccurred in the weak wakes of the IGVs and in the very thin transition section wallboundary layers. The CFD code served to extend the predictions to a proposed fullscale geometry. The losses are less than previously assumed. The study led tocorrelations between respectively loss and turning angle as dependent variables, andcollector roof height and IGV stagger angle as independent variables.

[发布机构] Stellenbosch University