The paper presents the methods of determination of the actual operation of solid fuel heating boilers in Poland. The analysis was based on an average annual distribution of the actual power outputs of the solid fuel heating boilers operated in four selected locations in Poland. Based on said data, three characteristic percent shares have been estimated of the nominal power outputs, at which the heating boilers in Poland operate throughout the year (divided into four characteristic portions—the seasons of the year). Additionally, for the analysis, the authors took into account the average annual temperature amplitude and the annual air quality information for the discussed locations and analyzed 30 solid fuel heating boilers in terms of their performance in the laboratory certification tests. In the final stage of the investigations, the authors initiated laboratory tests on the application of the combustion quality analyzers and their potential benefits.

The paper concerns the analysis of the heat transfer process that occurred during solid fuel burning in fixed bed conditions. The subject of the analysis is a cylindrical combustion chamber with an output of 12 kW heating power equipped with a retort burner for hard coal and biomass combustion. During the research, a numerical and experimental study is performed. The analysis is prepared for various heat load of the combustion chamber, which allowed for the reconstruction of real working conditions for heating devices working with solid fuels combustion. The temperature distribution obtained by the experimental way is compared with results of the numerical modeling. Local distribution of principal heat transfer magnitudes like a heat flux density and a heat transfer coefficient that occurred on the sidewall of the combustion chamber is analyzed. The analysis showed, that the participation of convection and radiation in the overall heat transfer process has resulted from the heat load of the heating device. Research results may be used for improving an analytical approach of design process taking place for domestic and industrial combustion chambers.

The aim of the experimental research was to determine the impact of changes in the air-fuel equivalence ratio during the combustion of wood pellet in the boiler on CO and NOX emissions. To realize the tests was used the 10 kW wood pellet boiler equipped with a dedicated wood pellet burner. Based...

Low-power boilers fueled with solid fuels comprised a group of most rapidly technologically advancing traditional equipment in Poland. New energy/emissions related criteria are the most influencing factors in this respect. They clearly put a lot of emphasis on the reduction of emission from the 'distributed energy sector'. The authors have attempted to investigate the possibilities of application of modern numerical methods in improving the efficiency of low-power heating equipment. In order to validate the obtained results of numerical calculations, a series of experimental investigations has been performed that directly referred to the simulation and confirmed the applicability in this sector.

The article presents the construction of modular a shell and tube heat exchanger, which is proposed for food industry. Authors analyzed possibilities of applying this type of heat exchanger to recover waste heat from a heating boiler used in food production companies. Recovered waste heat can be utilized for palm oil heating, which is a common ingredient used in food companies. This construction of heat exchanger allows controlling a heating power of realized process by simple adjusting area of heat transfer by a system of valves, by disconnecting subsequent sections of the heat exchanger from the plant, when heat requirement is decreasing. The research was divided into two parts. First analytical calculations, related to the design of the heat exchanger were realized. Subsequently, the power of heat exchanger obtained during analytical calculations was compared to numerical calculations. The numerical analysis allowed to demonstrate, that the flow of exhaust gases through the shell side of the heat exchanger is not homogenous Prepared numerical calculations showed the non-uniform character of flow through the subsequent modules of the heat exchanger.