FEATURES OF THE APPLICATION OF HEAT STORAGE ELEMENTS WITH A PHASE TRANSITION IN THE REGENERATIVE HEAT EXCHANGERS OF GLASS FURNACES

Abstract

Increasing the air temperature in regenerative heat exchangers is one of the most effective means of increasing the efficiency of glass furnaces and reducing their fuel consumption. The value of losses with flue gases in furnaces remains quite high and amounts to 25–40 %. As a result, the question arises in the modernization of flue gas utilizers of glass furnaces, the purpose of which is to increase the amount of heat extracted from flue gases without a significant change in overall dimensions, as well as the aerodynamic characteristics of heat exchangers. One such measure is the use of heat storage elements with a phase change in the packing of regenerators. A feature of such materials is the presence of «residual» heat of the phase transition, i.e., such a packing will receive and transfer more heat by this amount compared to the traditional one. However, when solving this problem, the question arises of choosing a fusible material that satisfies the operating conditions of the packing of regenerative heat exchangers of glass furnaces. The paper analyzes the thermophysical properties of some inorganic substances, the characteristics of which make it possible to use them as a fusible material for packing elements. However, at the moment, inorganic compounds of barium sulfate BaSO4 and sodium sulfate Na2SO4 in combination with magnesite and periclase refractories have acquired practical use for high-temperature installations (regenerative heat exchangers of blast-furnace metallurgical production). Such materials have shown good thermal stability and stability under thermal cycling. The study of the possibility of using materials with a phase transition for heat storage elements of packings is associated with the need for mathematical modeling of complex heat exchange processes in the working space of regenerative heat exchangers under conditions of a quasi-stationary mode of their operation. Therefore, the final conclusions about the effectiveness of the modernization of regenerative heat exchangers by using packing with a phase change can only be made based on the results of additional studies, which will determine the influence of a whole complex of various factors that affect the performance of heat storage elements of this design.