Nowadays the following. main aspects of heat and mass transfer m narrow channels can be defined:
1 The aspects of critical heal fluxes and maximum total power when intensive forced motion of subcooled liquid or binary mixtures lakes place inside capillary or split channels -for liquid cooling systems of super - high frequency electronic devices or lazers.
2. The aspects of critical heal fluxes have no such importance for microelectronic plates cooling, when: heat from microelectronic elements is removed to liquid moving m narrow channels inside plates. The hydrodynamic and heat transfer aspects for single and two-phase flows m these conditions are considerably important.
3 The heat transfer and critical heat fluxes aspects when boiling on heating surfaces submerged in liquid has to become more important The other cases are possibly.
Last years the authors again returned to this field experimentation and discovered some peculiarities in single phase heat transfer in microcannels Besides it the authors made an attempt to generalize their and other investigators experimental results in two-phase flow critical heal fluxes field and to suggest an approach and some principles of the generalization.