Thermal and Fluid Dynamics Analysis of Hungarian Folk Heating Appliances

Abstract

Characteristic heating appliances of Hungarian architectural heritage, such as the tiled stove (cserépkályha), a pot-shaped tiled stove (bögrés szemeskályha), and the furnace (kemence), reflect not only architectural history aspects but also their thermal properties in their development and evolution. Since knowledge of these historical heating appliances is largely limited to literary and visual sources, their testing under operational conditions is generally not possible, even with reconstructions. Consequently, the analysis of their thermal and fluid dynamics behaviour is primarily accomplished using CFD simulation (Computational Fluid Dynamics). A previous on-site measurement provides a reliable basis for the simulation, during which the flue gas emissions and temperature data measured at 32 points of a wood- fired tiled stove were recorded. By using the measured firebox temperature curve as a reference, the validation of historical appliances with similar heating and cooling parameters allows for drawing conclusions about the reasons for their design, prevalence, and evolution. Furthermore, the study offers relevant lessons for the design and operation of 21st-century wood-fired appliances. This is particularly significant because in Hungary, biomass, primarily firewood, is the second most common household fuel source. It provides heating for approximately 1 million households, or 4 million people [3], with the majority concentrated in family homes.