ТЕПЛООБМЕННЫЙ БЛОК ДЛЯ РЕГЕНЕРАТИВНОЙ ГОРЕЛКИ

Abstract

Modern regenerative burners for heating and thermal furnaces have rather larger sizes and small heat exchange period time that is connected with a low thermal capacity of the refractory materials applied to production of a nozzle. Considerable decrease in the sizes of nozzle and increase in heat exchange period time can be reached by using the hidden warmth of metals melting, which can be placed in the closed thin-walled reservoirs. In addition, the paper propose section design and a heat exchange unit enable to solve the problem of reducing the size of regenerative unit and increase the time of the swap, compared to existing regenerators that are used for air heating in regenerative burners. The proposed design can be used to create regenerative burners, a new class of highly effective, high temperature air preheating, and considerable time of swap. Such reservoirs, in which temperature of metal melting is equal, are packed in the sections. The next sections’ melting temperature differs approximately by 100 °C. It allows to maintain the fixed section temperature, which is equal the temperature of metal melting in this section, and removing from its surface or giving it, by products of combustion, warmth, which sets out in case of crystallization or is absorbed when metal kernel melts. Calculation of the swap time and the metal mass in one section, based on the joint solution of equations of heat balance and heat transfer between the heated air and the surface of tanks, allows to determine the overall dimensions of each section, filled with melting or crystallizing metal and its heat exchange surface. Fusible kernel mass, sizes of section and heat exchange period time calculations for regenerative block consisting of ten sections with a fusible kernel is given in this work. Calculation proves a possibility of decrease in dimensions of a regenerative nozzle for a 200 kW burner, and increase in heat exchange period time, while air heating temperature remains constant. The technical solution can be used in a thin-walled container in which are placed the metals with different heat of fusion. Large size regenerative burners hamper their use in heating and thermal furnaces, and fast parecidos leads to a decrease in period of operation of the changeover valve. © 2017, National University of Science and Technology MISIS. All rights reserved.