With the rapid development of micro-electro-mechanical system (MEMS) technology

heat dissipation with high heat flux in limited space has become a key problem restricting the efficient and stable operation of the equipment. Heat dissipation technology of liquid-liquid two-phase flow in microchannels has emerged as an effective solution to this problem. In this paper

the classification of liquid-liquid two-phase flow patterns in microchannels was first reviewed. Compared with other flow patterns

slug flow is a critical flow pattern in it

which has significantly enhanced heat and mass transfer performance. Then

this paper summarizes and analyzes the current research progress on heat transfer of liquid-liquid two-phase slug flow in microchannels. At present

most studies in this field rely heavily on numerical simulations

with relatively few experimental investigations. Existing numerical models often simplify the complexities of physical phenomena

and many have not been validated against experimental data. Furthermore

these models frequently employ macroscopic numerical methods

such as Volume of Fluid (VOF) and Finite Volume Method (FVM)

to capture the two-phase interface. However

the accuracy of these models in calculating the flow field

temperature field

and the rates of heat and mass transfer in two-phase interface still requires further verification. Experimental studies tend to focus on mini-channels

primarily measuring macro-scale global data

such as total pressure drop

overall heat transfer coefficient

and average fluid temperature. There is a notable lack of research involving micro-scale local and instantaneous data

such as local heat transfer coefficient and detailed flow and temperature fields. Finally

the future research direction of heat transfer for liquid-liquid two-phase slug flow in microchannels is prospected.