An experimental study and comparitive validation of macrolayer thickness in nucleate pool boiling for horizontal copper tube heater

摘要

Nucleate Pool boiling is characterised by the progression of several nucleation sites (bubble formation), which surge from distinct points on a surface, whose temperature is slightly above the liquids. To investigate and evaluate this, a pool boiling setup was fabricated with a horizontal copper tube heater of 28mm diameter by imposing cartridge heater. An analytical expression, suggested by literature helps to determine the thickness of macrolayer based on bubble diameter was used. The macrolayer thickness for water was found by measuring the bubble diameter by using Photographic and CAD method. Experiment was carried out in a stainless steel container insulated with Teflon cover to observe the bubble growth and bubble departure characteristics for the heat flux range of 1000-42,000 W/m~2. The bubble diameter were measured and the measured parameters were been used to determine the initial layer thickness, macro layer thickness and critical heat flux and validated through various models. The observed and calculated values are in good agreement as reported in various literature.