Analysis of heat exchange in the compensation chamber of a loop heat pipe

•Loop heat pipes (LHP) are highly efficient heat–transfer devices that use capillary pressure for pumping the working fluid.•A 3D model of heat and mass transfer in a flat evaporator of an LHP was developed.•Heat-exchange in the compensation chamber was analyzed at different heat loads.•A method for investigation of the wick drying phenomenon in the active zone of the evaporator is presented.•Crisis modes in the evaporator active zone connected with the wick drying were simulated.

A three-dimensional heat–and–mass transfer model of a flat evaporator of a loop heat pipe has been developed for investigating heat–and–mass in a compensation chamber filled with a liquid. Numerical simulation was implemented using EFDLab® software package in order to predict the temperature distribution of the flat evaporator of a copper-water LHP (loop heat pipe) as well as the flow streamline and velocity field in the compensation chamber as a function of heat load. A computer simulation makes it possible to evaluate the heat exchange at the inner surface of the compensation chamber. Heat exchange data were used as a boundary condition in researching the problem of the drying effect of a wick and a transformation of the evaporating front in the active zone of the flat evaporator.