Theoretical and experimental verification for determining pool boiling heat transfer coefficient using fuzzy logic

Finding pool boiling heat transfer coefficient of refrigerant is considered one of the great challenges which affects the refrigeration system in terms of design and power consumed. Yet most of the calculation is done based on empirical equations. The major defect with those equations is that they rely on certain operating range for the pressure and heat flux. Outside that range the correctness of the equation will be weak. A fuzzy logic model to predict the heat transfer coefficient of the pool boiling process is exposed in this research. The model is utilized to find the heat transfer coefficient for refrigerant R-134a at different operating conditions. The operating pressure, the applied heat flux and the surface roughness of brass heating plate are changed to exam the ability of the model to find the heat transfer coefficient correctly. Mamdani method is used to model the fuzzy system. An experimental confirmation is done to authenticate the proposed fuzzy model. The obtained fuzzy logic results have a deviation of ± 2% at low heat flux and maximum deviation is ± 6% at high heat flux. In addition, the attained results from both fuzzy logic and experimental work are compared with previous work and found to have the same qualitative behave and near quantitative with previous results of other researchers worked in the same range.