Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Evaluation of flow boiling pressure drop at high mass velocities in microchannels using R123
Submission Author:
Thalles Coimbra Borba Roldão , SP , Brazil
Co-Authors:
Thalles Coimbra Borba Roldão , Juliana Silva Brasil, Cristiano Tibiriçá
Presenter: Thalles Coimbra Borba Roldão
doi://10.26678/ABCM.COBEM2023.COB2023-0253
Abstract
This paper presents new experimental data on pressure drop during convective boiling in microchannels. The tests were conducted in a single stainles steel microchannel with an internal diameter of 1.1mm, a heated length of 100mm and a total length of 210mm. High mass velocities of 2000 and 2500 kg/m²s were used. The working fluid approached was R123, which has a potential of use in applications such as Organic Rankine Cycles. The data may be used, as well, to compare the pressure drop of R123 with other new fluids that shall replace it in the next years. The objective of this paper is to evaluate the predicted values of pressure drop with the experimental data. During calculations it is necessary to use a friccional pressure drop correlation and a void fraction correlation, so the error associated to each correlation has an influence in the final result. The correlation of void fraction is used in the prediction of the acceleration component. Three correlations for void fraction and as many others frictional pressure drop correlations for two phase flow available in the literature were selected. In order to evaluate the influence of both kinds of correlations in the predicted values, they were combined, resulting in nine different combinations. The experimental values were compared to the results of each combination. The results shows that all combinations have had similar and good results in the prediction of the pressure drop. Although the acceleration parcel of the pressure drop is often neglected, the void fraction correlation have had an important influence in the results.
Keywords
Flow boiling, pressure drop, microchannels, High mass velocities, R123
