Abstract

Presented in this paper is an experimental investigation of the steady-state air-side pressure drop through a delugable bare tube bundle. The tube bundle forms a part of a systematic investigation of the subcomponents of a hybrid dry/wet dephlegmator (HDWD), also known as a secondary steam condenser, used in direct dry-cooling. A modular bare tube bundle is designed and built to experimentally investigate the pressure drop in a counter-flow test facility with 19 mm and 25 mm tubes at various tube depths. The tests are conducted under both dry and wet (deluged) operating modes. The test results are used to develop empirical correlations for both dry and wet operating modes. The absolute average error is found to be 3.2% between the measured and predicted values for the dry correlation and for the wet correlation the absolute average error is found to be 4.5%. The newly developed correlation is used in a thermal case study to illustrate the effect of the under- and overprediction that the air-side pressure drop will have on a relatively small evaporative cooler where two cases corresponding to fan power consumptions of 1.1 kW and 5.5 kW were considered.

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