EXERGY PINCH ANALYSIS OF ALL ELEMENTS OF THE BOILER UNIT AND THE BOILER UNIT AS A WHOLE

Abstract

The relevance of the research is caused by the need to improve the energy efficiency of heating systems, since all types of fuel are becoming more expensive. In this regard, there is a need to create a method of thermodynamic improvement of heat engineering systems. The main aim of the research is the creation of a method for improving heating systems, the application of this method on the example of a boiler unit PP-2650-255 GM. Objects: a direct-flow boiler PP-2650-255 GM, for which a thermodynamic analysis of the processes occurring in individual elements of the boiler – an air heater, economizer, firebox, and superheater – is performed. The article analyzes all heat fluxes on each element of the boiler. Methods. An exergy method of thermodynamic analysis is used as a research tool. It allows taking into account the energy potential of thermal processes. To date, the most effective method of parametric optimization of heat and power processes is the method of integration of heat flows (pinch method). However, the pinch method is based on a change in flow enthalpy, which does not take into account the qualitative characteristics of energy. In the article, the development of the pinch method continues; flow exergy is used instead of flow enthalpy. Optimization of heat engineering parameters is carried out using an exergy pinch method. Results. Exergy pinch analysis allows you to identify unused exergy and determine in which part the loss occurs. According to the calculations and the graph, it can be seen that hot flows lost 1503,57 MW of exergy, cold flows took 1295,57 MW of exergy, taking into account cooling of the working fluid by bypass. Thus, 47,9 MW of unused exergy was detected in this boiler unit. The results of the exergy pinch analysis allow us to formulate and justify specific design measures to improve the energy efficiency of the boiler unit. This analysis allows you to effectively use the energy and resources of heating equipment.

Keywords

• energy efficiency
• exergy
• exergy analysis
• heat balance
• exergy balance
• pinch analysis