Heat transfer effectiveness of heat pipes

Heat transfer effectiveness (recovery factor) - HTE - of one heat pipe (HP) is defined as the function of two dimensionless groups of NTU type (Number of Transfer Units) from the evaporator and the condenser. In the case of the HP heat exchanger it is demonstrated that the HTE is a function made up of only three elements, viz: the HTE of the single component HP; the number of rows parallel to the flow of the two fluids; and the ratio of the heat capacities of the two fluids. The optimization consists in the selection of the values of the NTU groups in order to obtain an optimum HTE for the HP. This optimum is defined in a subjective way using a percentage method. The modeling equations are deduced for the optimum values of NTU in all cases that have been analyzed.