Comparison of the 1D and 2D calculation models used for determination of the heat transfer coefficient during flow boiling heat transfer in a minichannel

Abstract

The paper discusses the results of the flow boiling heat transfer in a vertical minichannel with rectangular cross-section. The heating element for FC-72 flowing in the minichannel is a thin plate. Infrared thermography is used to determine changes in the temperature on its outer side. The aim of the calculation is to determine the heat transfer coefficient using 1D and 2D calculation models. Local values of heat transfer coefficient on the surface between the heated plate and boiling fluid are calculated from the Newton`s and Fourier`s laws. In 2D model the plate temperature distribution is obtained by solving the inverse heat conduction problem. The governing equation is solved by means of two methods: the non-continuous Trefftz method and the Beck method. The results are presented as plate temperature and heat transfer coefficient calculated using 1D and 2D models as a function of the distance from the minichannel inlet. The analysis of the results revealed that the values and distributions of the heat transfer coefficient calculated by means of both models were similar. This suggests that all mentioned methods are interchangeable.

Experimental and Numerical Investigation of Micro/Mini Channel Flow-Boiling Heat Transfer with Non-Uniform Circumferential Heat Fluxes at Different Rotational Orientations

“…However, due to thermal conduction in the microchannel substrate, this inevitably results in some degree of circumferential non-uniform heat flux on the internal wetted surface. Studies have been conducted on the influence of parameters such as the number of channels [6,7], the cross-sectional profile [8][9][10], hydraulic diameters [11][12][13][14][15], systems with uniform heating [16][17][18][19][20][21][22], the orientation of the channel [1,23,24], hydrodynamic effects like confinement [25][26][27] and the effect of varying working fluids [28,29].…”