STUDY OF LOCAL EXERGETIC LOSSES OF DIFFERENT TYPES IN THE HEAT RECOVERY SYSTEMS OF BOILER PLANTS
Abstract
The paper presents studies of local exergy losses of various types in heat recovery systems of boiler houses. The purpose of the work is a comparative analysis of local exergy losses of various types, aimed at increasing the exergy efficiency of heat recovery systems.
The main tasks of the work:
- determination of the location and type of exergy losses in heat recovery systems for various purposes and their classification;
- obtaining exergy equations for calculation and calculation of local exergy losses of various types;
- conducting a comparative analysis of exergy losses and identifying ways to increase the exergy efficiency of heat recovery systems.
Research methodology: The authors used a comprehensive methodology for studying the exergy efficiency of heat recovery systems based on the exergy approach, developed by the authors. The technique includes structural-variant and balance methods of exergy analysis, as well as methods of heat transfer theory and hydrodynamics as applied to heat recovery systems.
Research results:
A classification of local exergy losses of various types has been carried out. Exergetic losses, which can be calculated from the input and output thermodynamic parameters of coolants, are referred to the losses of the first level. Exergy losses arising within individual elements of heat recovery systems as a result of irreversible processes during heat exchange between heat carriers are classified as losses of the second level. A system of equations has been developed for calculating local exergy losses of the first and second levels, and the corresponding exergy equations have been obtained. The calculation of local exergy losses of the second level for an air-heating heat exchanger was carried out for various values of the relative power of the boiler and the heat recovery efficiency of the heat exchanger. The conditions for the most effective reduction of total exergy losses in heat recovery systems by reducing local exergy losses of the first and second levels are substantiated. The results of the work can be used to design optimal heat recovery systems for boiler houses.
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