Lukisha A. Pinch of energy efficiency of porous heat exchangers on the basis of a choice of rational constructive and regime parameters

The dissertation for competition on a scientific degree of the candidate of technical science on a speciality 05.14.06 - Technical thermal physics and industrial heat power engineering. - National metallurgical academy of Ukraine, Dnepropetrovsk, 2010. In dissertation the area of parameters of round porous channels are searched , at a motion of a liquid coolant, where there is an energy scoring in comparison with channels with smooth wall. Research is carried out on the basis of a procedure of Guhman А.А. According to this procedure three parameters - quantities of heat, transferred by channels Q, quantities of power that are expended on moving of a coolant along channels N and a lateral area of channels F are compared. The calculations are carried out for laminar, turbulent and transition bands of a motion of the heat transfer medium in compared channels with smooth wall at boundary conditions of 1-st kind, and for a laminar band the calculations are carried out at boundary conditions of 3-rd kind too . The greatest energy effect is observed on boundary of laminar and transition band, in case of increase of a porosity of channels (up to 0,8 ? 0,9), in case of diminution of a diameter of channels (up to 3 ? 5 mm) and in case of deterioration of heat exchange on an exterior surface. Numerical values of coefficients of efficiency in this case can reach of quantities of the order: 50 % for a laminar band, 30 % for a transition band and 20 % for a turbulent band. At deterioration of heat exchange on an exterior canal surface (boundary conditions of 3-rd kind, Bi= 1) the values of of coefficients of efficiency can increase in tens time.