Evaluation and performance prediction of cooling tower rain zones

[摘要] Cooling tower rain zone performance characteristics such as the loss coefficientand the Merkel number are evaluated and simulated. To this end the influence ofdrop diameter and drop deformation on the velocity, path length and cooling ofsingle water drops are investigated. Experimental drop size and pressure drop dataover a counterflow rain zone are presented and the effect of drop deformation onthe pressure drop is investigated using the experimental data and CFD. Using theexperimental drop size data and CFD, the performance uncertainty produced byusing the Rosin-Rammler drop distribution function as opposed to the discretedrop distribution data is investigated. CFD models are developed to investigatethe feasibility of modelling rain zones by assuming a constant drop diameter andto establish which diameter definition is the most representative of a particularpolydisperse drop distribution. These models were used to validate thecorrelations for the rain zone performance characteristics proposed in literature.

[发布机构] Stellenbosch University