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.