The performance of a capillary driven heat pipe used in solar collectors is investigated in the present work. An axisymmetric numerical simulation is presented for analyzing heat and mass transfer in cylindrical heat pipe using the Lattice Boltzmann method. The analysis includes the wall, the liquid-wick material and the vapor regions. Comparison between the present model results and some numerical results available in the literature shows very good agreement. The effect of working fluid, wick structure, evaporator length and inclination angle on the system behavior is addressed. Among these results, some suggest the superior performance of acetone heat pipe with sintered copper structure of 7.3 mm of thickness in 45 degrees inclination. Numerical results under those working conditions are presented, which provide guidance for the heat pipe design used in solar collectors.