A GENERAL CORRELATION FOR FRICTIONAL PRESSURE DROP OF FLOW BOILING IN PLATE HEAT EXCHANGERS

Plate heat exchangers are widely used in various industries for many years. The corrugated channels on the plates effectively enhance the turbulence of flow boiling and complicate the prediction of pressure drop. This paper presents a brief review about the influence factors of frictional pressure drop during flow boiling in plate heat exchangers. Experimental data points of frictional pressure drop were collected from previous literatures to develop a general correlation. The database contained 454 data points, covering eight refrigerants, mass flux range 5.5-137 kg m-2 s-1, heat flux 0-30 kW m-2, vapor quality 0.07-0.95, saturation pressure 0.11-2.7114Pa, chevron angle 30 degrees-70 degrees and hydraulic diameter 1.7-5.4 mm. In this work, several existing correlations were compared with the database, and all of them seem fail to give an acceptable prediction. A new correlation was proposed with multiple regression analysis in terms of two-phase Fanning friction factor. The new method showed good agreement and predicted 63.2% and 92.9% of data points within +/- 30% and +/- 50% errors, respectively.