Experimental investigation of flow boiling in narrow channel

• We have studying the smaller evaporator in the macro scale.
• Prediction of flow pattern based on the temperature fluctuations.
• Influences of velocity and the heat flux on heat transfer coefficient are studied.
• A new correlation has been developed to predict the heat transfer coefficient.

The flow boiling in narrow channel is investigated experimentally. The aim of the present work is to study the heat transfer phenomena. The working fluid is n-pentane which is chosen for its low boiling point (36 °C at atmospheric pressure). The independent variables are velocity in the range from 0.015 m/s to 0.06 m/s and boiling heat flux with values between 9 and 137 kW/m². The wall superheat and exit vapor quality are presented as dependent variables. The flow pattern was predicted based on temperature fluctuations. The experimental results are compared to those available in the literature (Shah, Gungor-Winterton and Jens correlations). A new correlation has been developed for the average heat transfer coefficient during flow boiling in a rectangular channel with validity in boiling heat flux from 9 to 137 kW/m² and Reynolds number between 380 and 1522.

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