ANALYSIS OF EXERGY LOSSES IN HEAT RECOVERY SYSTEMS OF BOILER PLANTS WHEN IMPLEMENTING THE BYPASS METHOD TO PROTECT CHIMNEYS

Abstract

The results of the analysis of exergy losses in the heat recovery systems of boiler plants during the implementation of one of the thermal methods of anticorrosion protection of gas exhaust ducts - the bypass method - are presented. Gas-consuming boiler plants with a heat recovery system for heating heat supply water are considered. The choice of a complex technique for the analysis of exergy losses in a heat recovery system with gas bypass is substantiated. The technique includes structural-variant and integral balance methods of exergy analysis and is effective due to the small number of parameters required for the calculation, the simplicity of the calculation and analytical methods for obtaining exergy characteristics, and the high accuracy of the results obtained. The principal and structural diagram of the heat recovery system in the implementation of the bypass method is given. In the block diagram, the input and output exergy flows between the individual elements of the heat recovery system are identified. According to the block diagram, an exergy balance equation was compiled, on the basis of which the exergy losses and the heat exergy efficiency criterion were determined. The exergy characteristics of the heat recovery system are given with an increase in the amount of bypassed gases and different values of the heat load of the heat recovery system. It is shown that the nature and extent of the impact of these parameters depend on the specified load. It has been established that an increase in the amount of bypassed gases at all values of the heat load of the heat recovery system leads to a decrease in exergy losses and the heat power criterion. The value of the heat load of the heat recovery system is determined, at which its exergy efficiency in the implementation of the bypass method is the highest.