FLOW BOILING IN HORIZONTAL TUBES - PART 1 - DEVELOPMENT OF A DIABATIC2-PHASE FLOW PATTERN MAP

An improved two-phase flow pattern map is proposed for evaporation in horizontal tubes. The new map was developed based on flow pattern data for five different refrigerants covering a wide range of mass velocit ies and vapor qualities. The new map is valid for both adiabatic and d iabatic (evaporating) flows and accurately identifies about 96 percent of the 702 data points. In addition, the new flow pattern map include s the prediction of the onset of dryout at the top of the tube during evaporation inside horizontal tubes as a function of heat flux and flo w parameters.