Heat Flux: A Design, Diagnostic and Control Parameter for Thermal Equipment

Abstract

Heat flux is a space and time variable reflecting the state of a thermal system. The evaluation of heat flux properties in thermal systems gives the possibility of making an assessment of their efficiency, safety and availability. In this respect, it was proved that heat flux is an important design, diagnostic and control parameter for many thermal systems. This paper describes the evaluation of different aspects of heat flux properties including heat flux as a design parameter, heat flux as a diagnostic parameter and heat flux as a control parameter. The heat flux is proved to reflect the changes in thermal equipment during operation. The malfunction of this equipment is closely related to the change of the heat flux distribution within the system. In this respect, it was demonstrated that the failure of boilers and furnace operation could be diagnosed by the change in the heat flux distribution on the respective heat transfer surfaces. The heat flux, as a diagnostic variable for the assessment of the operation of thermal systems, will open a challenging opportunity for the design of on-line knowledge-based systems. This can be used for the assessment of efficiency and safety of thermal systems. A new method for heat flux measurement is introduced with reference to its use in boiler and glass furnaces. It shows the advantages of the new method when applied in high temperature and hostile environments.